Nano-Structured Alkaline Aluminosilicate Binder by Carbonate Mineral Addition

2018 ◽  
Vol 276 ◽  
pp. 192-197 ◽  
Author(s):  
Lenka Bodnarova ◽  
Sergii Guzii ◽  
Rudolf Hela ◽  
Pavel Krivenko ◽  
Grigorii Vozniuk
Keyword(s):  
Water Resistance ◽  
Structural Formula ◽  
Point Of View ◽  
Cement Stone ◽  
Formation Processes ◽  
Carbonate Mineral ◽  
Mineral Addition ◽  
Plastic Strength ◽  
Time Required ◽  
Alkali Activated

The influence of СаСО3on nano-structured, flowability and plastic strength of alkali activated alumonosilicate binders based on metakaolin for the range of oxide ratios in a structural formula of the Na2O∙Al2O3∙(2.5-4.5)SiO2∙(12-17)H2O + (5-15%)CaCO3system was studied. The results of the study showed that the ratios of SiO2/Al2O3– 3.8, H2O/Al2O3– 13.75, and content of СаСО3of 5% by mass were the most optimal ones from the point of view of meeting requirements for these binders to be used as base in protective coatings.The results of the study showed that process flowability of the binder with optimal ratios of oxides and 5 % by mass of additive 2 hours after preparation was by 5.4% lower, being by 5 times lower than that of the binder without the additive (СаСО3). The binder containing 5% СаСО3by mass during 2 hours after preparation exhibited the same plastic strength (37 Pa), whereas this value of the binder without CaCO3has increased, in average by 5.5 times, affecting negatively shelf life of this binder to be used as base in protective coatings.A conclusion was made that the addition of СаСО3intensified the nano-structured formation processes in the direction of formation of Na-Ca zeolite-like phases; shortening time required the cement stone to gain water resistance in normal conditions.

Structural Formation of the Cement Pastes Based on the Concrete Modified Dispersed Mineral Components

2020 ◽  
Vol 1011 ◽  
pp. 14-22
Author(s):  
A. Khalyushev ◽  
Sergey Stelmakh ◽  
Evgeniy Shcherban ◽  
A. Chernilnik
Keyword(s):  
Surface Modification ◽  
Electric Field ◽  
Structure Formation ◽  
High Voltage ◽  
Angle Of Repose ◽  
Cement Stone ◽  
Formation Processes ◽  
Cement Pastes ◽  
Structural Formation ◽  
Plastic Strength

With the increase in the number of finely dispersed mineral additives in concrete, their water demand increases and the effect of micro-filling weakens. To solve this problem, various methods of dry surface modification are proposed. As a result of the finely dispersed mineral powders’ surface modification, an improvement in their rheological characteristics, a decrease in wettability, a change in granulometry and other properties are achieved. This article discusses the surface modification effect’s laws in a high-voltage electric field on the autogenous properties of mineral dispersed concrete components, structure formation processes, mechanical properties, and cement stone hydration products. According to the results of the study, it was found that the surface modification of bulk materials - concrete components - in a high-voltage electric field changes autohesion properties in comparison with control samples. The data indicate lower values ​​of bulk density and angle of repose. This is due to a change in the balance of forces that arise during the mutual contact of particles after surface modification. With a certain balance of these forces, autohesion will contribute to the dense packing of particles and thereby affect the structure formation processes. The results of changes in the plastic strength of cement pastes confirm that there is an intensification of the structure formation process. Moreover, a more intense increase in plastic strength is observed during bipolar charging of particles in comparison with unipolar charging. This is due to an increase in the number of heterogeneous charges in the system and, as a consequence, an increase in the strength of adhesive contacts, as evidenced by the data of X-ray phase analysis.

Influence of Temperature on Structure Formation Processes Geocements for Rehabilitation of Concrete

2015 ◽  
Vol 1122 ◽  
pp. 111-114 ◽  
Author(s):  
Volodymyr Kyrychok ◽  
Rostislav Drochytka ◽  
Pavlо Krivenko
Keyword(s):  
Structure Formation ◽  
Water Resistance ◽  
Structural Formula ◽  
Treatment Temperature ◽  
Experiment Planning ◽  
Processing Temperature ◽  
Formation Processes ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Level Method

When using geocements composition (xNa2O+yK2O)·Al2O3·(2÷4)SiO2·10H2O for protective coating of concrete from aggressive environments, the main problem is to determine the optimal treatment temperature, which depends on the ratio of basic oxides structural formula. In this work, using two-factor three level method of experiment planning determined that when the content as a part geocement (0,8÷0,9Na2O+0,2÷0,1K2O) and the ratio of SiO2/Al2O3=2,5÷3,5 achieved the necessary water resistance - Cr>0,8 at 40°C. When the ratio of SiO2/Al2O3>3,5 physico-mechanical properties geocement growing and processing temperature also increases to 50÷60°C. In subsequent researches will explore the possibility of reducing the processing temperature by modifying the geocement in the direction of accelerating processes of structure formation.

scholarly journals Events, Time and the Simple Form

2009 ◽  
Vol 17 (1) ◽  
pp. 85-105 ◽  
Author(s):  
Walter H. Hirtle
Keyword(s):  
Simple Form ◽  
Point Of View ◽  
Event Time ◽  
The Difference ◽  
Time Required ◽  
English Verb

Abstract This is an attempt to discern more clearly the underlying or POTENTIAL meaning of the simple form of the English verb, described in Hirtle 1967 as 'perfective'. Vendler's widely accepted classification of events into ACCOMPLISHMENTS, ACHIEVEMENTS, ACTIVITIES, and STATES is examined from the point of view of the time necessarily contained between the beginning and end of any event, i.e. EVENT TIME as represented by the simple form. This examination justifies the well known dynamic/stative dichotomy by showing that event time is evoked in two different ways, that, in fact, the simple form has two ACTUAL significates. Further reflection on the difference between the two types thus expressed—developmental or action-like events and non-developmental or state-like events—leads to the conclusion that the simple form provides a representation of the time required to situate all the impressions involved in the notional or lexical import of the verb.

scholarly journals Alkali activated cements mix design for concretes application in high corrosive conditions

2018 ◽  
Vol 230 ◽  
pp. 03007 ◽  
Author(s):  
Oleksandr Kovalchuk ◽  
Valentina Grabovchak ◽  
Yaroslav Govdun
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Mix Design ◽  
Cement Stone ◽  
Hydration Products ◽  
Alkali Content ◽  
High Corrosion Resistance ◽  
Corrosion Resistant ◽  
High Corrosion ◽  
Alkali Activated

This paper covers the results of development of corrosion resistant ash alkali-activated cements based on regulation of phase composition of the hydration products through changing the alkali content, content of calciumcontaining cement constituents resulting in the increase strength and density of the cement stone. The results of study suggested to conclude that the cement compositions with predominance in the hydration products of weakly soluble low basic hydrosilicates of calcium, hydrogarnets and minerals similar to natural hydroaluminates exhibited the highest corrosion resistance. The results of comparison suggested to draw a conclusion that the alkali-activated cements Types APC III-400 and ACC V-400, according to National Ukrainian Standard DSTU B V.2.7, had high corrosion resistance compared to that of OPC, thus allowing to recommend the developed cements for the concretes intended for use in aggressive environments, inclusive of sodium and magnesium sulphates and others. Coefficients of corrosion resistance of concretes are higher than 1 after even 42 months.

scholarly journals Valuation And Market Timing In Private M&A Transactions

2011 ◽  
Vol 1 (8) ◽  
Author(s):  
Ted Azarmi ◽  
Florian Eisele ◽  
Christine Haecker
Keyword(s):  
Market Timing ◽  
Point Of View ◽  
Font Size ◽  
Private Companies ◽  
Maximum Price ◽  
Business Conditions ◽  
Privately Held Firms ◽  
Time Required ◽  
The Right ◽  
Privately Held

<p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-pagination: none;"><span style="font-size: 10pt; mso-bidi-font-size: 12.0pt;"><span style="font-family: Times New Roman;">The objective of this case is to teach and initiate a classroom discussion about the optimal market timing for the sale of a mid-cap privately held firm.<span style="mso-spacerun: yes;">&nbsp; </span>The discussion is facilitated by a real world case example that focuses on the sale of a Little Rock, AK based plastic injection molding company with approximately $20 million in revenues.</span></span></p><p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-pagination: none;"><span style="font-size: 8pt;"><span style="font-family: Times New Roman;">&nbsp;</span></span></p><p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-pagination: none;"><span style="font-size: 10pt; mso-bidi-font-size: 12.0pt;"><span style="font-family: Times New Roman;">Theoretical and practical issues central to receiving maximum price in relation to selling at the right time are addressed.<span style="mso-spacerun: yes;">&nbsp; </span>Considered are the desired time to close the deal from the owner&rsquo;s point of view, the time required for successful completion of the sale process, business conditions in this industry, firm-specific business conditions, and ability of agents to time this market.<span style="mso-spacerun: yes;">&nbsp; </span></span></span></p><p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-pagination: none;"><span style="font-size: 8pt;"><span style="font-family: Times New Roman;">&nbsp;</span></span></p><p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt; mso-pagination: none;"><span style="font-size: 10pt; mso-bidi-font-size: 12.0pt;"><span style="font-family: Times New Roman;">This case also discusses various reasons for the sale of private companies and the effect of respective sale motives on the placement of these firms.<span style="mso-spacerun: yes;">&nbsp; </span>Principally, the retirement decision by the owners of small privately held firms as the most frequent reason for the sale of these companies is explored.</span></span></p>

Combining Forms and Affixoids in Morphology

2020 ◽  
Author(s):  
Dany Amiot ◽  
Edwige Dugas
Keyword(s):  
Major Part ◽  
Word Formation ◽  
Point Of View ◽  
The Other ◽  
Formation Processes ◽  
Good Criterion ◽  
Part Of Speech ◽  
Starting Point ◽  
Wide Range ◽  
The One

Word-formation encompasses a wide range of processes, among which we find derivation and compounding, two processes yielding productive patterns which enable the speaker to understand and to coin new lexemes. This article draws a distinction between two types of constituents (suffixes, combining forms, splinters, affixoids, etc.) on the one hand and word-formation processes (derivation, compounding, blending, etc.) on the other hand but also shows that a given constituent can appear in different word-formation processes. First, it describes prototypical derivation and compounding in terms of word-formation processes and of their constituents: Prototypical derivation involves a base lexeme, that is, a free lexical elements belonging to a major part-of-speech category (noun, verb, or adjective) and, very often, an affix (e.g., Fr. laverV ‘to wash’ > lavableA ‘washable’), while prototypical compounding involves two lexemes (e.g., Eng. rainN + fallV > rainfallN). The description of these prototypical phenomena provides a starting point for the description of other types of constituents and word-formation processes. There are indeed at least two phenomena which do not meet this description, namely, combining forms (henceforth CFs) and affixoids, and which therefore pose an interesting challenge to linguistic description, be it synchronic or diachronic. The distinction between combining forms and affixoids is not easy to establish and the definitions are often confusing, but productivity is a good criterion to distinguish them from each other, even if it does not answer all the questions raised by bound forms. In the literature, the notions of CF and affixoid are not unanimously agreed upon, especially that of affixoid. Yet this article stresses that they enable us to highlight, and even conceptualize, the gradual nature of linguistic phenomena, whether from a synchronic or a diachronic point of view.

scholarly journals Modeling of structuring processes at hardening of expanding cements and concretes on their basis

2018 ◽  
Vol 196 ◽  
pp. 04035 ◽  
Author(s):  
Igor Kharchenko ◽  
Alexander Panchenko ◽  
Alexey Kharchenko ◽  
Vyacheslav Alekseev
Keyword(s):  
Theoretical Analysis ◽  
Rheological Model ◽  
Experimental Studies ◽  
High Strength ◽  
Cementitious Materials ◽  
Cement Stone ◽  
Formation Processes ◽  
Structure And Properties ◽  
Potential Index ◽  
Kinetics Of

This paper reports the results of experimental research of the effect of strain-restriction conditions on the structure and properties of sulfoaluminate expanding cementitious materials. Theoretical analysis of the development of pattern formation processes is performed by applying the developed rheological model, illustrating features of the kinetics of structure-forming processes according to the ratio of the potential index of extension with linear, flat and volumetric limitation of deformations of the extension. The results show that rheological model adequately correlates with the results of experimental studies and can be described mathematically. Found that with the volume limitation of deformations arising when mixing crystallographic phases with high density and strength, the pore structure of the cement stone contains mainly gel pores. This is the main prerequisite for obtaining a dense, high-strength and durable structure of cement stone and concrete on its basis.

Available options for waste disposal

1986 ◽  
Vol 319 (1545) ◽  
pp. 27-38 ◽  
Keyword(s):  
Waste Disposal ◽  
Fuel Cycle ◽  
Point Of View ◽  
Radiological Protection ◽  
Spent Fuel ◽  
Acceptable Solution ◽  
Long Term Storage ◽  
Oceanic Sediments ◽  
Time Required ◽  
Geological Formations

Disposal of vitrified high-activity waste in properly selected deep geological formations is the option that absorbs most of present R&D and appears as an acceptable solution from a technical point of view. As regards safety, disposal projects under development appear to satisfy present radiological protection criteria, even if much uncertainty exists in both models and input data. Other disposal concepts are, however, also being studied, with more limited effort. Their quantification in terms of costs and benefits is therefore rather uncertain at present. Among them the following are treated briefly: disposal in deep oceanic sediments, actinide separation and recycling, and extraterrestrial disposal. Taking into account the cost and development time required to bring these options to industrial operation, they should not be considered as alternatives to present projects of waste disposal, but rather as scientific research that may lead to industrial realization in a more mature nuclear age, in which the balance of costs, risks and benefits will be different. Long-term storage of either spent fuel or vitrified waste, although not an alternative strategy of disposal, is an option that has considerable effects on waste management and the fuel cycle in general. The three scenarios (disposal of vitrified waste in geological formations, extended storage, advanced disposal options) complement each other very well and none of them should be pursued at the sacrifice of the others.

Semantic niches and analogy in word formation

2009 ◽  
Vol 9 (2) ◽  
pp. 183-201 ◽  
Author(s):  
Matthias Hüning
Keyword(s):  
Word Formation ◽  
Point Of View ◽  
Formation Processes ◽  
New Words ◽  
Contrastive Linguistics ◽  
Morphological Differences ◽  
Difficult Terrain

Word formation, like other lexical phenomena, seems to be a difficult terrain for contrastive linguistics since it hardly allows for significant and insightful generalizations about the differences between two languages, as has been stated in the literature more than once. This paper investigates one factor leading to morphological differences and contrasts between historically related languages (Dutch and German). It is argued that word formation processes often show semantic fragmentation: in the course of time they develop ‘semantic niches’, i.e. groups of words (subsets of a morphological category) kept together by formal and semantic criteria and extendable via analogy. When looking at word formation from a contrastive point of view, these niches seem to allow for better generalizations in terms of systematic correspondences and differences between two languages than the category as a whole. As a consequence, productivity should not be seen as an absolute notion, but rather as a local and gradual phenomenon. Morphology should not only account for the possibility of coining new words but also for their probability, because language comparison shows that even allegedly equivalent word formation processes often differ with respect to the probability of their use. The paper therefore argues in favour of an analogy approach that takes the existence of semantic niches seriously.

scholarly journals The Fumigation of Ships with Liston's Cyanide Fumigator

1923 ◽  
Vol 21 (3) ◽  
pp. 199-219
Author(s):  
W. Glen Liston ◽  
S. N. Goré
Keyword(s):  
Artificial Ventilation ◽  
Point Of View ◽  
High Concentrations ◽  
Time Required ◽  
Different Parts ◽  
At Will

(1) These experiments prove that the fumigator is safer to use than the dumping fixture, because high concentrations of the poison gas are avoided, so that dangerous pockets are not developed.(2) The poison gas is more evenly distributed over the different parts of the section of the ship under treatment.(3) High concentrations, however, can be developed^ at will in any part which requires special attention.(4) The maximum concentrations of the poison gas were obtained in every part of the section in a shorter time, when the fumigator was used, than when the dumping fixture was employed.(5) The artificial ventilation caused by the fan, which is capable of blowing into the section 500 to 1000 cubic feet of fresh air per minute, according to the speed of the motor, materially assists the rapid clearing of the poison gas from the ship, after it has accomplished its work. It is thus possible to complete the fumigation and ventilation of a ship in 3 hours using the cyanide fumigator, while more than 4 hours are required for the dumping fixture.(6) Even more important is the fact that smaller quantities of cyanide can be used with greater efficiency in the fumigator, than larger quantities, with less efficiency in the dumping fixture.(7) The general conclusion is arrived at, that, from the point of view of efficiency, safety and economy, the fumigator is superior to the dumping fixture. Creel has shown that, in respect to the time required for completing the fumigation, and in respect to the thoroughness of the process, both in killing rats and insects, the dumping fixture is superior to the Clayton gas machine. It follows, therefore, that the cyanide fumigator is very much superior in these respects to the Clayton gas machine.

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