Kaolin from a Serbian deposit, characterized by high content of impurities, such as mica and quartz, disordered kaolinite and high specific surface area, was subjected to thermal and mechanical ...activation on a large scale. Activations were carried out with a goal to investigate the effects of applied methods on the chemical, structural and morphological changes that occurred in the kaolin, and their influence on the pozzolanic activity. The changes were monitored using XRD, FTIR, TG/DTA, PSD, BET and SEM analyses. Pozzolanic activity was evaluated by determination of the 7-day compressive strength conducted on the lime mortars.
The results showed that mechanical activation by milling the kaolin for 20h in the conventional horizontal ball mill was competitive for obtaining pozzolana as thermal activation. Pozzolanic activity of thermally activated kaolin was mainly influenced by formation of metakaolin. Combined effects (such as significant specific surface area increase, as well as partial kaolinite and complete mica phase amorphization) were dominant in pozzolanic activity of mechanically activated kaolin.
•Mechanical activation of kaolin with impurities was performed on large scale.•Low-energy ball mill was used for mechanical activation of kaolin.•Mechanically activated kaolin showed pozzolanic activity competitive to thermally.•Kaolin modifications induced by thermal and mechanical activation were different.•Mica impurity contributes to pozzolanic activity of mechanically activated kaolin.
Literary critics have paid little attention to the similar artistic goals of Bernard Shaw and Seamus Heaney, who were both critical of the state of humanity. This article examines various aspects of ...their work, focusing specifically on the employment of the classical form in Shaw's Saint Joan and Heaney's The Burial at Thebes. Since the essential action in Greek drama relies on discourse and verbal interaction, its form appealed to both Shaw and Heaney, who are remembered today as masters of the spoken word. This article shows that their use of classical forms and themes sheds light on the power politics of their respective times. While the two plays significantly differ, one being a bona fide history play and the other an adaptation of the famous classic, their authors share a common focal point: they want to cure humanity of a disease whose main symptom is the repetition of History's mistakes.
•The study of incorporation of discourse-pragmatic features from English into Serbian.•The corpus-based study includes: Formal and functional characteristics of pragmatic Anglicisms ...(PAs).•Sociolinguistic, sociopragmatic and sociocultural aspects of PAs.•The motivations for and perceptions of the use of PAs.•Morphological integration of PAs into Serbian and pragmatic function transfer.•Incorporated calqued discourse formulas from English as hidden PAs.•The notion of discourse gap introduced to deal with some calqued formulas and speech acts.
The article focuses on the incorporation of discourse-pragmatic features from English into Serbian, proposing the term ‘pragmatic Anglicisms’ to denote a range of directly or indirectly borrowed forms from English with pragmatic functions. The article offers a descriptive and taxonomic framework for the study of pragmatic Anglicisms in Serbian and analyzes their formal and functional characteristics, as well as sociolinguistic, sociopragmatic and sociocultural aspects of their use, related to the users, registers, stylistic and communicative markedness, motivational factors, perception and evaluation by Serbian native speakers, post hoc effects, and cultural influences.
Apart from the commonly identified classes, such as interjections and discourse markers, the article recognizes the use of (calqued) discourse formulas from English in situations where there are either existing Serbian ones or a discourse ‘gap’ (i.e. when both the previously non-existent communicative act and the formulaic expression are adopted from English). This subclass is particularly interesting since it is not only a novel linguistic element that is thus introduced, but a novel communication and cultural pattern from the Anglo-American globalizing culture that gets adopted through new discourse formulas.
This paper reexamines the way in which traditional fairy tales depict famous heroines (Little Red Riding Hood, Rapunzel, Cinderella, and Snow White) by comparing them to their “liberated” versions ...from James Finn Garner’s
. We argue that the greatest value of the modern adaptations of classic fairy tales lies in their enabling us to see the world as a child might, introducing at the same time the grown-up theme of the liberation of women and breaking the pattern of portraying easily led, ineffectual, and vulnerable female characters in children’s literature.
Values Across Cultures and Times is a collection of sixteen articles examining the concept of values understood in its broadest sense as the need of the modern man to examine, redefine, and ...reconstruct previous theories, histories, moralities, social relationships, forms of language and language use. In times of great change, preserving traditional values seems to be particularly difficult, and the authors of these essays respond to the challenge, and approach the notion of changing values from the perspectives of literary studies and linguistics. The book opens with an introductory overview, followed by sixteen articles divided into three sections.The book is aimed at a broad academic audience, while the popular style of the articles also makes the volume appealing to a wider audience interested in different aspects of values. The authors of the articles come from Serbia, Macedonia, Bulgaria, Romania, and the United States.
•Cement composites with two different mechanically activated kaolins are compared.•Strength and microstructure of ordinary cured and autoclaved composites are determined.•Higher strengths exhibited ...AKG composites containing high content of quartz.•AKG composite strengths were higher when autoclaving was applied.•Ordinary curing of composites caused substantial strength decrease.
The effects of two different mechanically activated kaolins, AKV (61% kaolinite, 14% quartz and 16% mica) and AKG (51.6% kaolinite and 40.6% quartz) on the compressive strength of cement composites and microstructure of pastes were investigated. Composite mixtures, in which 10, 20, 30, 40 and 50% of ordinary Portland cement (OPC) was replaced by AKV or AKG, were prepared with w/b of 0.5, and exposed to different curing conditions (ordinary curing for 28 days and autoclaving). Factors affecting microstructure were investigated on pastes by X-ray diffraction (XRD), Differential thermal analysis/thermal gravimetry (DTA/TG) analyses, Mercury intrusion porosimetry (MIP) and Scanning electron microscopy with Energy-dispersive spectroscopy (SEM-EDS).
AKG composites exhibited higher compressive strengths under both curing conditions. Positive autoclaving effects on strengths were predominantly pronounced at the higher cement replacement levels. Comparison of the autoclaved and ordinary cured paste microstructure, revealed more intensive pozzolanic reaction during autoclaving conditions (CH content near zero) and higher total porosity. The negative effect of hydrogarnet on the strength was compensated by the formation of the crystalline tobermorite.
Obtained results revealed that mechanically activated kaolin, with high content of quartz, could be a promising pozzolanic addition, even at high cement replacement levels (30–50%), especially when autoclaving curing conditions were applied.
•Strengths of MK and AK mortars ordinary cured and autoclaved are compared.•The hydration products and microstructure of MK and AK pastes are determined.•Ordinary cured mortar with 20% of MK achieved ...highest strength.•10% AK substitution in both curing conditions led to satisfactory strengths.
The effects of thermally (MK) or mechanically activated kaolin (AK) on the compressive strength of mortars and microstructure of pastes were investigated. Mortar mixtures, in which 10%, 20% and 30% of ordinary Portland cement (OPC) was replaced by either MK or AK, were prepared (w/b of 0.5) and ordinary (age 2, 28 or 90days) and autoclave cured. Hydration products were determined by X-ray diffraction (XRD) and differential thermal analysis/thermal gravimetry (DTA/TG) analysis, while microstructure was investigated by mercury intrusion porosimetry (MIP).
MK substitution increases the compressive strength of ordinary-cured mortars, as a result of the higher content of reactive silica that caused more pronounced pozzolanic reaction, as well as by effective refinement of their pore structure. Positive effects on the compressive strength could be achieved up to 30% substitution of OPC by MK. The OPC substitution by AK resulted in lower strengths of ordinary-cured mortars, compared to both MK mortars and reference. Higher specific surface area and finer particles of AK were insufficient to compensate, through filler effect, lower pozzolanic reaction and additional negative influence of the kaolinite presence. The highest compressive strength was obtained for mortar with 10% of AK (relative strength of 94%).
In comparison to the reference, autoclaved MK and AK mortars, exhibited lower compressive strength, as a consequence of increasing the hydrogarnet formation, instead of tobermorite. The highest strength was achieved for mortar with 10% of AK.
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