scholarly journals The Behavior of Cement-Bonded Particleboard with Modified Composition under Static Load Stress

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6788
Author(s):  
Tomas Melichar ◽  
Jiri Bydzovsky ◽  
Richard Dvorak ◽  
Libor Topolar ◽  
Sarka Keprdova
Keyword(s):  
Acoustic Emission ◽  
Mechanical Stress ◽  
Static Load ◽  
Raw Materials ◽  
Stress Test ◽  
Mechanical Parameters ◽  
Particle Mixture ◽  
Different Types ◽  
Standard Composition ◽  
Adverse Environments

This article presents research on the behavior of cement-bonded particleboards under mechanical stress caused by the static load. The composition of the boards was modified using alternative raw materials–dust (DU) forming during the processing of cement-fibre boards and particle mixture (PM) generated in the production of cement-bonded particleboards. The particleboards (1-year-old) were subjected to an adverse environment (100 to 250 frost cycles). Mechanical parameters were tested, and the development of defects during static load of the boards by bending was analyzed using acoustic emission. Particleboards with modified compositions are slightly more resistant to adverse environments. The results of the acoustic emission showed the different types of defects occurring under stress by bending. Standard-composition particleboards showed defects located mainly under the cylindrical stress-test head. The modified boards showed larger location distribution of the occurring defects that were also concentrated further away from the cylindrical stress head. The energy during the occurrence of defects was higher in the modified boards in the location of weight application than in the reference boards.

PU composites based on different types of textile fibers

2021 ◽  
pp. 002199832110316
Author(s):  
Nuno Gama ◽  
B Godinho ◽  
Ana Barros-Timmons ◽  
Artur Ferreira
Keyword(s):  
Thermal Conductivity ◽  
Raw Materials ◽  
Natural Fibers ◽  
Tensile Modulus ◽  
High Water ◽  
Textile Fibers ◽  
Synthetic Fibers ◽  
Hydrophilic Nature ◽  
Different Types ◽  
Recycled Composites

In this study polyurethane (PU) residues were mixed with residues of textile fibers (cotton, wool and synthetic fibers up to 70 wt/wt) to produce 100% recycled composites. In addition, the effect of the type of fiber on the performance of the ensuing composites was evaluated. The presence of fibers showed similar effect on the density, reducing the density in the 5.5-9.0% range. In a similar manner, the addition of fillers decreased their thermal conductivity. The 70 wt/wt wool composite presented 38.1% lower thermal conductivity when compared to the neat matrix, a reduction that was similar for the other type of fibers. Moreover, the presence of fillers yields stiffer materials, especially in the case of the Wool based composites, which with 70 wt/wt of filler content increased the tensile modulus of the ensuing material 3.4 times. This was attributed to the aspect ratio and stiffness of this type of fiber. Finally, the high-water absorption and lower thermal stability observed, especially in the case of the natural fibers, was associated with the hydrophilic nature of fibers and porosity of composites. Overall, the results suggest that these textile-based composites are suitable for construction and automotive applications, with the advantage of being produced from 100% recycled raw-materials, without compromised performance.

scholarly journals Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Research Work ◽  
Damping Properties ◽  
Main Research ◽  
Functional Additives ◽  
Different Types ◽  
Elastomeric Materials ◽  
Research Goal ◽  
The Impact

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.

Study on Acoustic Emission Signatures during the Process of Edge Chipping for Engineering Ceramics

2011 ◽  
Vol 697-698 ◽  
pp. 93-96 ◽  
Author(s):  
Xiu Jian Tang ◽  
Xin Li Tian ◽  
Jian Quan Wang ◽  
Ya Tao Mao ◽  
F.Q. Li
Keyword(s):  
Acoustic Emission ◽  
Fracture Process ◽  
Static Load ◽  
Average Frequency ◽  
Displacement Curve ◽  
Edge Chipping ◽  
Kaiser Effect ◽  
Engineering Ceramics ◽  
Highly Active ◽  
Fracture Processes

The developments of edge chipping for engineering ceramics are analyzed. An edge chipping experiment under static load is adopted to study the fracture process of edge chipping. The results show that the fracture processes of edge chipping under different edge distances are similar, which can be divided into four stages based on load-displacement curve. There is obviously Kaiser Effect during the fracture processes of edge chipping. Counts, average frequency, RMS, duration, amplitude and inverse calculation can be used to describe the process of edge chipping for engineering ceramics. Amplitude, duration and average frequency become highly active on the eve of fracture, which can be regard as the omens of edge chipping and used to predict the fracture of edge chipping.

Adhesives for the Installation of Cast Basalt Elements on Metal and Comparison of Properties when Using Different Types of Fillers

2021 ◽  
Vol 898 ◽  
pp. 35-41
Author(s):  
Jakub Hodul ◽  
Tomáš Žlebek ◽  
Lenka Mészárosová ◽  
Aleš Jakubík ◽  
Rostislav Drochytka
Keyword(s):  
Construction Industry ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Mineral Admixtures ◽  
Maximum Efficiency ◽  
Organic Additives ◽  
Metal Base ◽  
Secondary Raw Materials ◽  
Ecological Benefit ◽  
Different Types

The polymeric adhesives for the installation of basalt elements on a metal base are designed primarily for environments with increased chemical and mechanical stress. They are composed of polymer resins (epoxy, polyurethane) as binders, as well as organic additives and mineral admixtures that mainly fulfill the function of filler. In all sectors of today's construction industry, maximum efficiency in the production of materials is required for sustainability purposes, which, however, must never be at the expense of the quality or the required performance. Due to these requirements, great emphasis is placed on the maximum use of secondary raw materials. Talc is used as the primary filler for polymer adhesives. Sawdust, tire rubber, and fly ash are used as secondary raw materials. The use of these in building supplies can positively affect some physical and mechanical properties of polymeric adhesives. Also, the use of secondary raw materials has the above-mentioned ecological benefit. Basic properties, such as bulk density and adhesion to both metallic and basalt elements, were monitored. The details of the cohesion of the adhesive with the bonded material, as well as the distribution of secondary raw materials in the polymer matrix, were assessed microscopically.

Research on Feature Extraction Method Based on Rub-Impact Acoustic Emission Signals of Mechanical Seal End Faces

2010 ◽  
Vol 36 ◽  
pp. 68-74
Author(s):  
Chuan Jun Liao ◽  
Shuang Fu Suo ◽  
Wei Feng Huang
Keyword(s):  
Acoustic Emission ◽  
Feature Extraction ◽  
Extraction Methods ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Feature Extraction Method ◽  
Different Types ◽  
Ae Signal ◽  
Feature Information ◽  
Ae Signals

Acoustic emission (AE) techniques are put forward to monitor rub-impacts between rotating rings and stationary rings of mechanical seals by this paper. By analyzing feature extraction methods of the typical rub-impact AE signal, the method combining of wavelet scalogram and power spectrum is found useful, and can used to attribute the feature information implicated in rub-impact AE signals of mechanical seal end faces. Both simulations and experimental research prove that the method is effective, and are used successfully to identify the typical features of different types of rub-impacts of mechanical seal end faces.

scholarly journals Probable evidence of a Middle Palaeolithic site in the northern parts of the Susiana Plain, Khuzestan, Iran

2019 ◽  
Vol 46 ◽  
pp. 424-433
Author(s):  
Saeid Bahramiyan
Keyword(s):  
Raw Materials ◽  
Middle Palaeolithic ◽  
Limited Information ◽  
Zagros Mountains ◽  
Significant Progress ◽  
Khuzestan Province ◽  
Different Types ◽  
Northern Regions ◽  
Considerable Body ◽  
The Karkheh River

There is a considerable body of studies regarding the activities of the Pleistocene human population in the Zagros and Alborz regions of Iran, as well as significant progress in the Palaeolithic studies in other regions, such as the foothills, plains and deserts’ margins. However, some of these peripheral regions and foothills are still neglected, and the information about the Palaeolithic period in these areas is limited. Khuzestan province, especially its northern regions, is one of these unstudied regions, yet the limited information about this region seems very interesting. Khervali, located on the western foothills of the Zagros Mountains and on the northern heights of Susa, nearby the western bank of the Karkheh River, is one of the few Palaeolithic sites identified in recent years. The site was identified in 2012 and was systemically surveyed. Due to the extension of the site and the distribution of the artefacts, sampling all the site was not feasible, therefore, four sections of the site were chosen for taking the samples and a total of 330 stone artefacts were collected. The results of the techno-typology analyses, as well as the frequency of the flakes, the Levallois samples and different types of scrapers, revealed that the artefacts date to the middle Palaeolithic period, with considerable access to the local raw materials.

scholarly journals ASIAN MARITIME TRANSPORT IN ASIA: A BRIEF STATISTICAL ESSAY

2020 ◽  
pp. 15-27
Author(s):  
Alexander Akimov ◽  
Keyword(s):  
Raw Materials ◽  
East Asian ◽  
Shipbuilding Industry ◽  
Bulk Carriers ◽  
Sea Transportation ◽  
Different Types ◽  
Container Ports ◽  
The Republic ◽  
Flag Of Convenience

The article describes the state of the Asian merchant marine fleet as of 2018. The main trends of international Maritime trade are described, the composition of the fleet by types of vessels is characterized, and the main directions of trade by groups of goods transported by different types of vessels are shown. The transition of leadership in tonnage from tankers to bulk carriers is revealed, due to the reduction of the role of oil in sea transportation and the formation of flows of raw materials and coal for the ferrous metallurgy to China. The largest container ports in the world are shown, among which East Asian ports predominate. Two leading flag of convenience countries in Asia have been identified – Hong Kong and Singapore. In the global shipbuilding industry, three East Asian countries – China, Japan, and the Republic of Korea – account for 90 % of ship production.

scholarly journals Burden or blessing in disguise: interactions in supply chain complexity

2018 ◽  
Vol 38 (2) ◽  
pp. 314-332 ◽  
Author(s):  
Hendryk Dittfeld ◽  
Kirstin Scholten ◽  
Dirk Pieter Van Donk
Keyword(s):  
Supply Chain ◽  
Food Processing ◽  
Raw Materials ◽  
Structured Interviews ◽  
Food Processing Industry ◽  
Dynamic Complexity ◽  
Processing Industry ◽  
Case Study Methodology ◽  
Content Type ◽  
Different Types

Purpose While systems theory explicitly considers interactions as part of a system’s complexity, supply chain complexity (SCC) is mostly conceptualized and measured as a linear summation of several aspects. The purpose of this paper is to challenge the general understanding by explicitly investigating interactions between and across different types (detail and dynamic) and levels (plant, supply chain, environment) of SCC. Design/methodology/approach An exploratory multiple case study methodology is adopted drawing on in-depth semi-structured interviews with respondents from eight manufacturing plants in the food processing industry. Findings On the one hand, it is found that different types add and increase overall SCC. On the other hand, the study also shows the opposite: interactions between detail and dynamic complexity can reduce the overall SCC experienced. Additionally, the findings highlight the specific food processing characteristics such as the variability of quality and quantity of raw materials that underlie interactions between types and levels of SCC. Originality/value This study adds to theory by empirically showing that interactions across and between types and levels do not automatically increase, but might also reduce SCC. As such, the findings contribute new detail to the concept of SCC: aspects of complexity do not necessarily add up linearly. Additionally, this study is one of the first to demonstrate how specific contextual aspects from the food processing industry relate to SCC.

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.

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