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EN
Purpose The present study aims to evaluate the effect of montmorillonite nanoclay (MMT) and waste glass powder (WGP) on the hardness and thermal conductivity of PMMA polymer composites. Thus, this study concentrates on the potential use of MMT and WGP as reinforcements, in different concentrations, in PMMA polymer matrix, with the expectation of improving the performance of PMMA polymer composites in various applications. Design/methodology/approach There is a growing demand for PMMA with increased mechanical properties and thermal stability for applications where inorganic glass would fail. Montmorillonite (MMT) clay and Waste Glass Powder (WGP) have physical and chemical properties compatible with PMMA. Therefore, they could potentially enhance PMMA’s hardness and thermal conductivity. Silicon dioxide in glass silica and MMT and octahedral aluminium hydroxide sheet in MMT can strengthen both covalent and hydrogen bonding architecture in PMMA composite for better mechanical strength and thermal conductivity. Thus, PMMA composites were designed by combining MMT powder and WGP powder in different ratios before being incorporated into the PMMA polymer matrix and tested for hardness and thermal conductivity. Findings The present study measured Brinell Hardness (HB) and electrical conductivity values of four PMMA composites containing different proportions of MMT and WGP. MMT/WGP filler mix had optimal hardiness (HB number = 74) when glass content was 1% (3MMT1G) or better still (HB number = 63) when an equal mix ratio was used (1MMT1G). PMMA composite with 3MMT1G also had the highest thermal conductivity (0.01899W/m.K-1). However, the higher the glass content, the lower the thermal conductivity of the PMMA composite. Thus, the present study has demonstrated that 3MMT1G filler was the best for enhancing the thermal and mechanical properties of PMMA composite. Research limitations/implications The results of this study demonstrate the potential of this new composite material for a variety of applications. Further research is needed to explore the full potential of this material and to develop new and improved versions. Practical implications Reusing waste glass as filler materials in composites requires minimal processing and therefore has lower environmental impacts than synthetic options. Originality/value Experimental data from the present study has provided new insights into Glass/MMT mix design in PMMA composites. The PMMA composite containing 3MMT1G exhibited the best hardness and thermal conductivity characteristics. Thus, the present study has successfully optimised Glass/MMT mix design for PMMA composite for applications requiring these features.
EN
The moldavites are Miocene tektites foundin Central Europe. Their presence in the Badenian sediments are rare due to fluvial reworking in the area. In the clay sediments of the Poznań Formation, in the Dębina profile, one moldavite was found, which is the fourth tektite from these sediments from Poland. It had dimensions of 14 X 10 X 8 mm and a weight of 1.03 gram. The glass surface was richly ornamented, and indicates a quick deposition, without any long-distance fluvial abrasion. Currently, depending on the age ofthe sediments in which they occur, two substrewn fields of Ries-same-age and redeposited moldavites were characterized in SW Poland.
PL
Temat eksperymentu przeprowadzonego z udziałem studentów Wydziału Architektury w ramach zajęć z przedmiotu rzeźba dotyczy autorskiego ćwiczenia dostosowania zmultiplikowanego naściennego modułu ceramicznego do funkcji użytkowo-wystawienniczej. Projekt opiera się na synergii multiplikowanych ceramicznych kształtek z kartką papieru i kształtowaniu obu elementów przestrzennie. Z założenia projekt ma pełnić określoną funkcję użytkowo-wystawienniczą, dedykowaną instytucjom publicznym, takim jak szkoły i przedszkola. Rozrzeźbione zmultiplikowane moduły tworzą spójny pod względem plastycznym system, a wyeksponowane w modularnej aranżacji kartki stanowią dopełnienie kompozycji. Myślą przewodnią eksperymentu było kreowanie formy plastycznej wraz z kształtowaniem własności użytkowych. Rozwiązanie to miałoby na celu również wizualne uatrakcyjnienie przestrzeni publicznej.
EN
The subject of the experiment, carried out with the participation of Architecture Faculty students in Poznan as part of their sculpting course, concerns an authorial exercise of adjusting a multiplied ceramic wall-module to its utility and exhibitive function. The project is based on the synergy of multiplied ceramic shapes with sheets of paper and shaping both components spatially. By definition, the project is supposed to fulfil a specific exhibitive function intended for public institutions, like schools and kindergartens. The sculpted modules make up a system that is coherent in terms of plasticity, while the pieces of paper displayed in a modular arrangement complete the composition. The main idea of the experiment was to create an artistic form along with shaping its practical properties. This solution is also intended to make public spaces more appealing visually.
6
Content available Czy zamienimy beton na glinę?
PL
Jednym z mało docenianych współcześnie materiałów proekologicznych mogącym służyć do wyrobu szerokiej gamy wyrobów budowlanych jest glina suszona. Podczas realizacji współczesnych inwestycji wydobywana z gruntu glina na budowie jest traktowana najczęściej jako odpad, który należy usunąć. Pozyskiwany w ten sposób materiał mógłby współcześnie podlegać wstępnej ocenie składu i przydatności dla wykonania różnych wyrobów od materiałów ściennych konstrukcyjnych, przez wyroby spełniające rolę izolacyjną, po wyroby stanowiące warstwę wykończeniową.
EN
One of the currently little appreciated pro-ecological materials that can be used to manufacture a wide range of construction products is dried clay. During the implementation of modern investments, the clay extracted from the ground at the construction site is most often treated as waste that needs to be removed. The material obtained for this material could now be subject to a preliminary assessment of its composition and suitability for the production of various products, from structural wall materials, through products fulfilling an insulating role, to products constituting the finishing layer.
EN
Clay minerals have been modified by polymers for different applications. .e polymer addition affects not only the surface properties but also the rheological properties and the stability of the clay-polymer suspension as a whole. In the current study, the electro-chemical properties of bentonite particles in presence of poly diallyl dimethyl ammonium chloride (PDDACl) were investigated. .ese properties were characterized by as zeta potential, adsorption isotherm, Fourier transform infrared (FTIR) and the apparent viscosity at different solid percent. .e results indicated that the viscosity of the bentonite-PDDACl suspension not only increases by raising the polymer concentration but also by increasing solids %. Adsorption of PDDACl polymer increases the positivity of bentonite surface as a function of polymer concentration, which could be explained mainly by electrostatic interaction of deficient metal ions at the octahedral sheets of bentonite with the cationic head group of the polymer. .e PDDACl adsorption isotherm on bentonite fits more probably Langmuir than Freundlich isotherm.
PL
Minerały ilaste zostały zmodyfikowane przez dodatek polimerów do rożnych zastosowań. Dodatek polimeru wpływa nie tylko na właściwości powierzchni, ale również na właściwości reologiczne i stabilność zawiesiny glina-polimer jako całości. W niniejszej pracy zbadano właściwości elektrochemiczne cząstek bentonitu w obecności chlorku polidiallilodimetyloamoniowego (PDDACl). Właściwości te scharakteryzowano jako potencjał zeta, izotermę adsorpcji, podczerwień z transformacją Fouriera (FTIR) oraz lepkość pozorną przy rożnych zawartościach fazy stałej. Wyniki wskazały, że lepkość zawiesiny bentonit-PDDACl wzrasta nie tylko wraz ze wzrostem stężenia polimeru, ale także ze wzrostem udziału fazy stałej. Adsorpcja polimeru PDDACl zwiększa dodatniość powierzchni bentonitu w funkcji stężenia polimeru, co można tłumaczyć głownie oddziaływaniem elektrostatycznym deficytowych jonów metali na oktaedrycznych arkuszach bentonitu z kationową grupą polimeru. Izoterma adsorpcji PDDACl na bentonicie pasuje bardziej do izotermy Langmuira niż izotermy Freundlicha.
EN
The use of antibiotics for breeding and for humans increased considerably in recent years, as a dietary supplement to enhance animal growth. This frequent use leads to the detection of residues in water and wastewater. Thus, the emergence of new strains of bacteria resistant to these antibiotics and, can lead to incurable diseases of livestock, and can lead to a possible transmission of these strains to humans. The purpose of this work is to develop new materials based on treated Maghnia clay, activated carbon, cement, and PVA polymer, named geomaterials. These materials were intended for the containment of hazardous wastes in landfills. The removal of tetracycline from aqueous solution was tested by adsorption onto synthesised geomaterials and their mineral constituents. Adsorption kinetics revealed that tetracycline was rapidly retained by GM and ATMa. This was confirmed by the relatively short equilibrium time of 30 min. The pseudo-second-order and intraparticle models well fitted the adsorption kinetic of the TC-adsorbent studied systems. It was noticed that the adsorption kinetic passes through several mechanisms, was demonstrated by the multi-linearity on the plot of qt against the square root of t. The adsorption capacity (Qa) of TC onto GM is pH-dependent. Indeed, Qa reaches a maximum value (Qa = 12.58 mg · g–1 at a very acidic pH of 2, then the adsorbed amount decreases to reach a minimum value at pH of 8, and for basic pHsQa increases up to 10 mg · g–1.
EN
Concerned about the environmental and economic impact, composite materials are increasingly used in the construction sector. Indeed, the use of plant fibers as reinforcement in construction materials have been the subject of several researches in recent years; the main motivation is the weight gain combined with high mechanical characteristics. The objective of this research concerns the study of the physicomechanical properties of composite materials with cement and clay matrices reinforced with Alfa and Diss fibers with dimensions ranging from 2 to 8 cm. This involves evaluating the performance of these materials according to the formulation, for a volume ratio (Alfa or Diss / Matrix fibers equal to 4), using dry fibers and pre-wetted fibers. The study of the mechanical properties showed a drop of the performance for both compression and bending strength compared to the reference material without adding fibers (cement or clay paste). It should be noted that the best mechanical performance is obtained for the case of composites materials with cementitious matrix with pre-wetted fibers. On the other hand, in the case of composites with clayey matrices, pre-wetting does not improve the mechanical characteristics. It is also noted that the best dimensions of fibers which improve the mechanical characteristics in bending are generally 6 cm for composites with a clay matrix and between 2 and 4 cm for cementitious composites. In all cases, the fibers in composite materials with cement or clay matrix create a bridging effect, making it possible to limit the progression of cracks during loading. This phenomenon gives to the various composite materials a ductile behavior.
EN
A significant number of investigations have been reported on the elaboration and characterization of Polymer/Clays composites, via different methods. In our work, new composites materials were successfully prepared by in-situ polymerization of 4-vinylpyridine (4VP), in presence of two different types of Algerian modified clays (Maghnia and Mostaganem), noted (BC) and (MC), respectively. Different percentage clays (1 wt%, 3 wt% and 5 wt%) have been used. The differential scanning calorimetry analysis reveals the variation of glass transition temperature (Tg) of the copolymer in the composite materials. We show a decrease glass transition temperature (Tg) from 147°C to 131°C for P4VP-BC and from 147°C to 124°C for P4VP-MC according to the increase percentage of clays. Thermogravimetric analysis (TGA) shows good stability of composite materials at high temperature. Fourier Transformed Infrared (FTIR), Scanning Electron Microscopy coupled with Energy dispersive X-Ray Spectroscopy (SEM-EDX) and 1H NMR spectroscopy are used to show the presence of the clays in the materials.
PL
Ceramika budowlana stanowi jeden z najważniejszych materiałów stosowanych w tradycyjnych technikach budowlanych. Dla zobrazowania zagadnienia w niniejszym artykule omówione zostaną wybrane elementy ceramiki budowlanej z oznaczeniami, które zlokalizowano podczas badań terenowych na obszarze województwa lubuskiego. Szczegółowe zestawienie wyników tych badań zawarte zostanie w odrębnym opracowaniu katalogowym.
12
Content available remote Chilijski chill i ceramika
14
Content available remote Ceramiczna Kolumbia. Część 2
PL
Na podstawie analogii struktur budowli podziemnych – warszawskiego Elizeum i wielu obiektów fortecznych z XVIII-XIX w., artykuł podejmuje próbę zestawienia historycznych metod zabezpieczania ich wnętrz przed wilgocią przenikającą z nasypów, kondensacyjną, podciąganą kapilarnie lub dyfundującą z gruntu. Sposoby zabezpieczania przeciwwilgociowego w fortyfikacji nowożytnej zostały wypracowane w ciągu 4 wieków jej rozwoju (XVI-XIX), w wyniku stopniowego gromadzenia doświadczeń i wiedzy inżynierskiej. Ważnymi elementami tych zabezpieczeń były okładziny z gliny/iłu oraz korytarze obiegające pomieszczenia podziemne o funkcji nie tylko komunikacyjnej, ale również otuliny izolacyjno-wentylacyjnej. Budowle podziemne, poprawnie zaprojektowane na skrajnie niekorzystne warunki użytkowania, mogą trwać dzięki delikatnej równowadze, którą bardzo łatwo naruszyć. Pierwszym warunkiem równowagi jest utrzymanie właściwego reżimu wentylacji i ogrzewania wnętrz podatnych na kondensację. Na zakończenie zaproponowano działania pielęgnacyjno-eksploatacyjne mające na celu zahamowanie postępującej degradacji obiektu oraz zakreślono wskazania do programu badań i założeń przedprojektowych do przyszłych, niezbędnych prac remontowych i konserwatorskich.
EN
Based on the analogy of the structures of underground buildings - the Warsaw Elizeum and many fortress buildings from the eighteenth to the nineteenth century, the article is an attempt to present an overview of historical methods of protecting their interiors against moisture penetrating from embankments, condensation, pulled up by capillaries or diffusing from the ground. The methods of moisture protection in the modern fortifications were developed over 4 centuries of its development (16th – 19th c.), as a result of gradual accumulation of experience and engineering knowledge. Important elements of these protections were clay/loam cladding and corridors running around underground spaces, which had not only transport function, but also served as an insulation and ventilation buffer. Underground buildings, properly designed for extremely unfavorable conditions of use, can last thanks to the delicate balance, which is very easy to disturb. The first condition of this balance is to maintain a proper ventilation and heating regime for condensation-prone interiors. At the end, care and maintenance activities aimed at stopping the progressing degradation of the building are proposed, and indications for the research program and pre-design assumptions for future necessary renovation and conservation works are outlined.
16
Content available remote Investigation of lead removal from drinking water using different sorbents
EN
Lead is a heavy metal with strong toxic properties. This chemical element is found in wastewater and sometimes in drinking water. The article deals with the removal of lead(II) ions from polluted water using a sorption process to determine the most effective sorbent for the removal of lead(II) ions. Three sorbents were used in the research: clay, sapropel, and iron sludge. All three sorbents investigated reduce the concentration of lead(II) ions in water: clay efficiency was of 65.7-90 %, sapropel of 94.3-100 %, and iron sludge of 84.3-97 %, depending on sorbent type and contact duration. The research has shown that the most effective way to remove lead(II) ions from the test water is sapropel. Using different amounts of sapropel (1, 2, 3, 4, 5, 6 g/dm3 and 0.1, 0.2, 0.4, 0.5, 0.6, 0.8 g/dm3) and different duration of contact (30, 60, 90, 120 and 150 minutes), the concentration of lead(II) ions in the test water after purification did not exceed the permissible values for drinking water (10 mg/dm3), so that the lowest sapropel content of 0.1 g/dm3 can be used for sorption. Lead(II) ions are most effectively removed when contact time is 30 min.
17
Content available remote Stabilizacja pęczniejącej ziemi w celu wykonywania budowli z ziemi
PL
Przeprowadzone badania dotyczą metod odlewania budowli z ziemi, jako część programu badawczego poświęconego budowlom ziemnym. Badano wpływ dwóch inhibitorów pęcznienia ziemi zawierającej glinę: poli(tlenku etylenu) [PTE] i karboksymetylocelulozę [KMC], aby była możliwa jej stabilizacja cementem CEM I 42,5N. Ziemię zawierającą 14% gliny, kwarc i kalcyt, stabilizowano 10% dodatkiem cementu. Dodawano równocześnie 3% plastyfikatora polikarboksylanowego w stosunku do masy cementu, aby ziemia uzyskała zdolność do płynięcia. Uzyskane wyniki wykazały, że PTE i KMC – inhibitory pęcznienia gliny, zmniejszyły to pęcznienie o około 30% i 40%, przy czym maksymalne pęcznienie odpowiadało po 90 dniach odpowiednio 24% i 46% wytrzymałości na ściskanie. Omówiono interakcję gliny z cementem i inhibitorami pęcznienia. Znalezione zależności pozwoliły na korzystne zastosowanie tych materiałów do wytwarzania elementów budowlanych, zastosowanych we wznoszeniu budynków na obszarach pustynnych.
EN
This study is concerned with the method of cast earth as part of an investigation series on earth construction. The effect of two clay swelling inhibitors; polyethylene glycol [PEG] and of carboxymethyl cellulose [CMC] on the swelling of a clay-bearing soil are studied to enable the stabilization of the soil with CEM I 42.5 N. The soil composed of 14% clay, quartz, and calcite, is stabilized with 10% cement. 3% polycarboxylate superplasticizer is added relative to the mass of the cement, to gain the soil pourable properties. The results show that the PEG and CMC clay-swelling inhibitors reduce the expansion of the soil by ~30 and ~40% and lead to a maximum increase of 24 and 46% in the 90-day compressive strength respectively. The interactions between clay, cement, and swelling inhibitors are discussed. The findings allow advantageous applications for producing building units for construction purposes in desert areas.
EN
The question about the harmfulness of electromagnetic radiation is ever more often raised in scientific discussions it is also interesting for the public. Unfortunately, there are no easy answers and no settled opinion. Followers of the catastrophic vision of the future argue, that the electromagnetic smog never grew as fast as today, and our bodies are probably not prepared for such conditions. Opponents, being accused of favoring telecommunication companies, claim that there are (or were) enough sources of electromagnetic radiation in the natural environment for organisms to learn how to self-protect, either by adaptation or development of specific sensory mechanisms. Questions are raised not only about health aspects, but also about security of data transmission and possible military applications, such as protection against radar localization. We want to present our recent investigations about the uses of natural materials for suppressing electromagnetic waves. The materials in question are ordinary clays, which role in Nature is barely now being discovered. Clay minerals, the basic ingredient of clay, are unusual materials, formed by Nature into nanostructures. Just recently we have begun to understand their role, behavior and possible applications. Those minerals, especially kaolinite and halloysite, are widespread, but in pure form occur only in few places in the world. Polish deposits belong to the richest ones.
19
Content available remote Ceramika na pustyni Atacama
PL
W północnym Chile, na pustyni Atacama jak okiem sięgnąć króluje glina. To właśnie z tego materiału budowane są tutaj drogi, domy mieszkalne, ogrodzenia i hotele dla zagubionych turystów. Osoba taka jak ja, która łączy dwie pasje: ceramiczną i podróżniczą, nie może ominąć tego tak wyjątkowego miejsca.
20
Content available Desert loess: a selection of relevant topics
EN
In discussions on loess, two types are often demarcated: glacial loess and desert loess. The origin of the idea of desert loess appears to lie with V.A. Obruchev who observed wind-carried silt on the Potanin expedition to Central Asia in 1895. It might be considered that desert loess would be defined as loess associated with deserts but it came to be thought of as loess produced in deserts. This led to some controversy as no mechanism for producing silt particles in deserts was readily available. Bruce Butler in Australia in particular cast doubt on the existence of desert-made loess. Butler indicated loess-like deposits in Australia which he called Parna; these are very like loess but the silt sized particles are actually clay mineral agglomerates of silt size- formed in dry lake regions. At the heart of the desert loess discussion is the problem of producing loess material in deserts. It has been suggested that there are no realistic mechanisms for forming large amounts of loess dust but there is a possibility that sand grain impact may produce particle shattering and lead to the formation of quartz silt. This would appear to be a reasonable mechanism for the African deposits of desert loess, but possibly inadequate for the huge deposits in China and Central Asia. The desert loess in China and Central Asia is loess associated with a desert. The material is formed in cold, high country and carried by rivers to the vicinity of deserts. It progresses then from deserts to loess deposit. Adobe ground may be defined as desert loess. Adobe occurs on the fringe of deserts, notably in the Sahelian region of Africa, and in SW USA. The use of adobe in construction represents the major utilization of desert loess in a social context. More understanding of adobe is required, in particular with respect to the adobe reaction, the low order chemical reaction which provides modest cementitious properties, and can be likened to the pozzolanic reactions in hydrating cement systems. The location of loess and loess-like ground on the peripheries of deserts is aided by the observation of the nesting sites of bee-eater birds. These birds have a determined preference for loess ground to dig their nesting tunnels; the presence of nest tunnels suggests the occurrence of desert loess, in desert fringe regions. We seek amalgamation and contrast: ten main topics are considered: words and terms, particles, parna, geotechnical, adobe, people, birds, Africa, Central Asia, Mars. The aim is some large generalizations which will benefit all aspects of desert loess investigation.
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