Influence of Leaning Materials on the Quality of Building Ceramics

2021 ◽  
Vol 903 ◽  
pp. 197-202
Author(s):  
Ruta Švinka ◽  
Visvaldis Švinka ◽  
Maris Rundans ◽  
Inta Timma ◽  
Laila Petersone
Keyword(s):  
Thermal Expansion ◽  
Glass Fibre ◽  
Material Properties ◽  
Quartz Sand ◽  
Main Method ◽  
Different Types ◽  
Ceramic Building ◽  
Formation Of Cracks

Clay of the deposit Liepa is used for the production of ceramic building and finishing bricks in the factory “Lode” in Latvia. In the present work different types of these clays were investigated and “quartz effect” was determined using quartz sand as a leaning material. The substitution of quartz sand with milled E-glass fibre from Valmiera Glass was investigated and the changes in the magnitude of the quartz inversion effect were analysed. Thermal expansion was the main method for the determination of possible formation of cracks during technological process. Powder of milled glass fibre in amount of 5–10 % affects such properties as water uptake, porosity and apparent density and provides the required material properties at a lower firing temperature.

The issue of "oil shrinkage" during the compounding of oils in the processes of production, collection, preparation and transportation of hydrocarbon raw materials

2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Colloidal System ◽  
Main Pipelines ◽  
Different Types ◽  
Preliminary Study ◽  
The Stability ◽  
Mixed Oil

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.

scholarly journals Uncovering Types of Knowledge in Concept Maps

2019 ◽  
Vol 9 (2) ◽  
pp. 131 ◽  
Author(s):  
Ian M. Kinchin ◽  
Aet Möllits ◽  
Priit Reiska
Keyword(s):  
Curriculum Design ◽  
Concept Maps ◽  
Positive Impact ◽  
Educational Levels ◽  
Types Of Knowledge ◽  
Different Types ◽  
Legitimation Code Theory ◽  
Future Learning

Concept maps have been shown to have a positive impact on the quality of student learning in a variety of disciplinary contexts and educational levels from primary school to university by helping students to connect ideas and develop a productive knowledge structure to support future learning. However, the evaluation of concept maps has always been a contentious issue. Some authors focus on the quantitative assessment of maps, while others prefer a more descriptive determination of map quality. To our knowledge, no previous consideration of concept maps has evaluated the different types of knowledge (e.g., procedural and conceptual) embedded within a concept map, or the ways in which they may interact. In this paper we consider maps using the lens provided by the Legitimation Code Theory (LCT) to analyze concept maps in terms of semantic gravity and semantic density. Weaving between these qualitatively, different knowledges are considered necessary to achieve professional knowledge or expert understanding. Exemplar maps are used as illustrations of the way in which students may navigate their learning towards expertise and how this is manifested in their concept maps. Implications for curriculum design and teaching evaluation are included.

scholarly journals METHODOLOGY FOR AUTOMATIC DETERMINATION OF CONTRAST OF LASER MARKING FOR DIFFERENT MATERIALS

2019 ◽  
Vol 3 ◽  
pp. 134
Author(s):  
Lyubomir Lazov ◽  
Edmunds Teirumnieks ◽  
Nikolay Angelov ◽  
Erika Teirumnieka
Keyword(s):  
Laser System ◽  
Digital Camera ◽  
Test Field ◽  
Automatic Determination ◽  
Technological Parameters ◽  
Test Analysis ◽  
Laser Marking ◽  
Different Types

A new methodology for determining and optimizing the contrast of the technological laser marking process has been developed. It can evaluate the quality of the markings regardless of the type of material and the type of laser system. To perform the test analysis, a specialized test field is programmed, which including the change of two of the main parameters influencing the marking process: the linear energy density (LED) and the linear density of the pulses (LDI). Marking of a test field consisting of squares of a certain size is done by means of a raster marking method with a constant step between the lines. The results are processed with a digital camera and specialized software. The maximum blackening is compared with the background of all fields and is juxtaposed with the effective energy needed to obtain a certain contrast. Several consecutive iterations are made, with each of the following experiments excluding the variants with least contrast. Thus, the study consistently brings the result to a minimum working area of the basic technological parameters, providing the user's desired contrast of the marking. The developed author's method of automatically determining the contrast of the laser marking reduces the time for preliminary experimental research and gives a reliable and subjectively absent way of qualitatively marking different types of industrial products.

scholarly journals Minerālo izejvielu pielietošanas un stikla šķiedras defektu izpēte

2018 ◽  
Vol 35 ◽  
pp. 160-177
Author(s):  
Janīna Sētiņa ◽  
Gundars Mežinskis ◽  
Vasilijs Akišins ◽  
Laila Pētersone ◽  
Inna Juhņeviča ◽  
...  
Keyword(s):  
Glass Fibre ◽  
Quartz Sand ◽  
Raw Materials ◽  
Glass Melts ◽  
Mineral Raw Materials ◽  
X Ray ◽  
Experimental Glass ◽  
Fibre Breakage ◽  
Different Types ◽  
Silicate Materials

Pētītas iespējas izmantot jaunas izejvielas stikla šķiedras ražošanā, īpašu uzmanību pievēršot Latvijas minerālām izejvielām – devona (Bāles atradne) un juras perioda (Skudras atradne un Pīlādžu atradne) kvarca smiltīm. Apstrādājot ūdenī Skudras atradnes kvarca smiltis, krāsojošo oksīdu daudzums samazināts līdz 0,066 %. Iegūto stiklu īpašību pārbaude parādīja attīrīto Skudru atradnes kvarca smilšu izmantošanas perspektīvu E-tipa stikla šķiedras ražošanā. Veikta arī citu šihtas izejvielu izpēte: kolemanīta, kianīta, kaļķakmens.Pielietojot augstas izšķiršanas spējas skenējošo elektronu mikroskopu, diagnosticēti stikla šķiedras defektu rašanās iemesli un izzināta to novēršanas iespēja.Study of Mineral Raw Materials and Defects in Glass FibresLatvian Devonian period sand from deposit Bāle and Jurassic period sand from deposit Skudra were studied, treated and compared with sand from existing Lithuanian supplier. Investigations of Latvian quartz sand showed that sand is characterized by surface impurities, which are easy to separate combining milling and water purification. These investigations and experimental glass melts using different types of sand confirmed that it is possible to use Latvian refined sand in glass industry.Other glass raw materials – colemanite, kyanite, kaolin, limestone – also have been examined.Glass fibre breakage points were studied using SEM, FTIR and X-Ray diffractions methods. Main reasons of glass fibre breakage are non-homogeneous glass and crystalline or gaseous inclusions coming from corrosion of refractory material. This article is result of the cooperation between Institute of Silicate Materials of Riga Technical University and JSC Valmieras stikla šķiedra.Keywords – glass, glass fibre, raw materials for glass, refined sand, glass defects

scholarly journals Methods of Determination of Optimal Points of Radio Monitoring Means Placement

2021 ◽  
Vol 7 (5) ◽  
pp. 2001-2009
Author(s):  
Serhii Dupelych ◽  
◽  
Viktor Bovsunovskyi ◽  
Dmytro Dmytro akymets ◽  
Oleksandr Zhantalai ◽  
...  
Keyword(s):  
Monitoring System ◽  
Optimization Problem ◽  
Radio Sources ◽  
Mathematical Apparatus ◽  
Radio Monitoring ◽  
Monitoring Tools ◽  
Different Types ◽  
The Matrix

The effectiveness of the radio monitoring system depends on the correctness of determining the coordinates of the location of radio monitoring tools at the stage of planning their application. The decision on the choice of position for radio monitoring should consider the heterogeneity of the terrain in the area of tasks, the presence of natural and electronic interference, which can lead to deterioration of conditions for receiving signals from radio sources. The use of the known methods, techniques, and algorithms for the placement of radio monitoring tools does not fully consider the requirements mentioned above. This leads to a decrease in the effectiveness of radio monitoring in a particular area of performance. Therefore, the purpose of this article is to develop a methodology for spatial placement of radio monitoring to ensure the effectiveness of radio monitoring in a particular area of tasks, taking into account the heterogeneity of the terrain, as well as natural and artificial electronic interference. Determining the coordinates of radio monitoring facilities included in the radio monitoring system involves determining the allowable options for their placement in a particular area of tasks using the mathematical apparatus of the dense placement function and its hodograph and further thinning of the matrix of acceptable solutions based on restrictions. A distinctive feature of the proposed approach is the optimization problem of geometric design for radio monitoring of complex spatial forms. At the same time, the peculiarities of completing the radio monitoring system using different types are also taken into account. It is expedient to use the developed technique for the planning of application of the system of radio monitoring; formation of working decisions on the construction of the radio monitoring system; assessing the quality of decisions and the formation of alternatives; ensuring the adaptation of the structure of the radio monitoring system to changes in the situation under the influence of the enemy and the formation of new zones of electronic interference.

scholarly journals Astringency estimation of wines maturing in different types of containers

2019 ◽  
Vol 15 ◽  
pp. 02014
Author(s):  
M. Basalekou ◽  
C. Pappas ◽  
P. Tarantilis ◽  
M. Kyraleou ◽  
V. Cotea ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Degree Of Polymerization ◽  
Wine Quality ◽  
White Wines ◽  
P Values ◽  
Different Types ◽  
Steel Tanks ◽  
Terminal Units

Astringency is a parameter of great importance for wine quality. During wine maturation in wooden barrels it can be enhanced by tannins extracted by the wood. However, their concentration is not directly correlated with astringency. Mean Degree of Polymerization (mDP) is often employed to characterize the structural characteristics of tannins in wines, providing also information on their proanthocyanidin content. The prodelphinidin content (%P), as well as the percentage of epigallocatechin (EGC) in extension and terminal units, have been negatively linked with astringency. Since the intensity of astringency is a decisive factor for the quality of a barrel-aged wine in this experiment, the structural characteristics of wine proanthocyanidins were determined in four different Greek wines, two white (Vilana and Dafni) and two red (Kotsifali and Mandilari). All wines matured for nine months in different types of containers (stainless steel tanks and barrels made of different woods). The prodelphinidin (terminal or extension) content was determined by means of phloroglucinolysis, followed by HPLC-UV-MS analysis, while astringency was assessed by a panel of trained tasters. Multivariate analysis showed that only white wines that matured in Acacia barrels contained high %P values independently of the variety used and were characterized as less astringent by the panel. Moreover, the determination of %extension and terminal EGC units revealed that the tannins of the wines maturing in Acacia barrels, contain higher amounts of EGC as terminal units. These findings could be used by winemakers in order to select the appropriate type of barrel according to the type of wine. Keywords: Astringency, proanthocyanidin, tannin, barrel

scholarly journals Mathematical Modelling of Process of Shaping of Sand-Pitch Mixes

2019 ◽  
pp. 810-817
Author(s):  
Vitaliy Yu. Kulikov ◽  
Evgeniy N. Eremin ◽  
Tatyana V. Kovalyova ◽  
Elena P. Scherbakova
Keyword(s):  
Mathematical Modelling ◽  
Technological Process ◽  
Static Loading ◽  
Gas Permeability ◽  
State Density ◽  
Technological Parameters ◽  
Different Types ◽  
Deformed State

This article considers mathematical dependences of properties of a casting mold on various parameters of her shaping. The competitiveness in production of castings depends on durability, reliability of the made details, ability to meet requirements and expectations of the consumer of production. Technological process of receiving castings most widespread now in the sandyargillaceous forms (SAF) not completely meets the modern requirements as it is characterized by different types of marriage: gas porosity, scorch, shrinkable sinks, blockages, hot and cold cracks, and others. The bigger quality of castings gives casting in the sand-pitch forms (SPF) in which the high gas permeability and durability are combined, they don’t resist shrinkage, don’t absorb moisture the stiffening alloy and aren’t inclined to an fallibility. However, one of shortcomings of this way of casting is rather high cost binding. One of the directions of decrease in an expense binding is use along with heating of mix for shaping of a cover and static loading. Other direction of decrease in a consumption of mix in general, and binding in particular, is determination of dependence of properties of a shell form on technological parameters that will promote management of properties of a form, decrease in marriage, etc. Formulas of the intense deformed state, density, amounts of heat of the sand-pitch form made at the same time in the conditions of heating and static loading are presented

scholarly journals Determination of Nitrogen and Sulphur Mineralization in Batch and Semi-Continuous Anaerobic Digestion Using an Artificial Fiber Bag Technique

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4205
Author(s):  
Jacob Rosholm Mortensen ◽  
Alastair James Ward ◽  
Martin Riis Weisbjerg ◽  
Sasha Daniel Hafner ◽  
Henrik Bjarne Møller
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Nutrient Content ◽  
Sulphur Mineralization ◽  
Different Types ◽  
Before And After ◽  
Thermophilic Conditions ◽  
Semi Solid

In the biogas industry, feedstock plans are used to estimate methane production and nutrient content in the digestate, however, these predictions do not consider the mineralized nitrogen fraction of the feedstock, which is useful when determining the quality of the digestate. In this study, the artificial fiber bag technique, which is commonly used to study feedstock degradation in ruminants, was implemented in anaerobic digestion to quantify mineralization of N and S. The artificial fiber bags were used to enclose substrates but with access to inoculum because of small pores in the bags, thereby enabling digestion. The content of the bags was analyzed before and after digestion to quantify residual mass as well as N and S concentration in the substrate. The method was validated through batch anaerobic digestion of a single substrate with and without bags, where the bags showed little influence on methane production and degradation. Semi-continuous anaerobic digestion experiments showed higher substrate degradation and higher N and S release at thermophilic conditions using four different types of feedstocks and proved useful for solid feedstocks but less so for semi-solid feedstock. For N, most of the mineralization occurred during the first 15 days over a trial of 30 days.

Investigation of complex permittivity spectra of foundry sands

2020 ◽  
Vol 87 (5) ◽  
pp. 372-380
Author(s):  
Luca Bifano ◽  
Alice Fischerauer ◽  
Gerhard Fischerauer
Keyword(s):  
Quartz Sand ◽  
Control Strategies ◽  
Equivalent Circuit Model ◽  
Impedance Spectrum ◽  
Nyquist Plot ◽  
Impedance Spectra ◽  
Foundry Sands ◽  
Different Types ◽  
Regeneration Processes

AbstractThis paper discusses impedance spectroscopy as a method to characterize different types of quartz sand, chromite sand, and mixtures of sand. Based on two types of measurement cells, the impedance spectra for various dry sands were measured. The spectra differ enough to allow the sands to be distinguished. The results were validated by extracting the relative permittivity from the impedance and comparing it to literature data. After that, the method could be applied with confidence to other material systems. The influence of moisture was investigated with two types of quartz sand, and typical mixtures of form sand, chromite sand, and regenerated (quartz) sand were studied. In each case, the sand composition had a distinct influence on the Nyquist plot of the impedance spectrum. Compared to results from a laboratory foundry system, the new method exhibits a much more systematic dependence on the sand composition. If one succeeds in describing the impedance spectra with an equivalent circuit model parameterized by only a few parameters, these parameters could be used to identify and classify sand mixtures in the field. This would allow one, for example, to implement feedback control strategies in foundry regeneration processes, which would stabilize the processes and improve the quality of the casting products.

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