scholarly journals Environmental Degradation of Plastic Composites with Natural Fillers—A Review

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 166 ◽  
Author(s):  
Mihai Brebu
Keyword(s):  
Recent Literature ◽  
Weight Ratio ◽  
Low Density ◽  
Mechanical Forces ◽  
High Tensile Strength ◽  
Negative Effects ◽  
Inert Matrix ◽  
Plastic Composites ◽  
Biological Attack ◽  
Natural Fillers

Polymer composites are widely used modern-day materials, specially designed to combine good mechanical properties and low density, resulting in a high tensile strength-to-weight ratio. However, materials for outdoor use suffer from the negative effects of environmental factors, loosing properties in various degrees. In particular, natural fillers (particulates or fibers) or components induce biodegradability in the otherwise bio inert matrix of usual commodity plastics. Here we present some aspects found in recent literature related to the effect of aggressive factors such as temperature, mechanical forces, solar radiation, humidity, and biological attack on the properties of plastic composites containing natural fillers.

Open-mindedness as a Corrective Virtue

Philosophy ◽  
2020 ◽  
Vol 96 (1) ◽  
pp. 73-97
Author(s):  
Hassan Alsharif ◽  
John Symons
Keyword(s):  
Recent Literature ◽  
Confirmation Bias ◽  
Negative Effects ◽  
Shed Light

AbstractThis paper argues that open-mindedness is a corrective virtue. It serves as a corrective to the epistemic vice of confirmation bias. Specifically, open-mindedness is the epistemically virtuous disposition to resist the negative effects of confirmation bias on our ability to reason well and to evaluate evidence and arguments. As part of the defense and presentation of our account, we explore four discussions of open-mindedness in the recent literature. All four approaches have strengths and shed light on aspects of the virtue of open-mindedness. Each mentions various symptoms of confirmation bias and some explore aspects of the corrective role of open-mindedness. However, ours is the first to explicitly identify open-mindedness as a corrective virtue to the specific epistemic vice of confirmation bias. We show how the corrective account also permits a response to the concern that open-mindedness might not actually count as a virtue.

scholarly journals Testing and Assessing Method for the Resistance of Wood-Plastic Composites to the Action of Destroying Fungi

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 697
Author(s):  
Anna Wiejak ◽  
Barbara Francke
Keyword(s):  
Bending Strength ◽  
Test Results ◽  
Negative Effects ◽  
Destructive Effect ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Wood Polymer ◽  
Proposed Modification ◽  
Assessing Method ◽  
Biological Corrosion

Durability tests against fungi action for wood-plastic composites are carried out in accordance with European standard ENV 12038, but the authors of the manuscript try to prove that the assessment of the results done according to these methods is imprecise and suffers from a significant error. Fungi exposure is always accompanied by high humidity, so the result of tests made by such method is always burdened with the influence of moisture, which can lead to a wrong assessment of the negative effects of action fungus itself. The manuscript has shown a modification of such a method that separates the destructive effect of fungi from moisture accompanying the test’s destructive effect. The functional properties selected to prove the proposed modification are changes in the mass and bending strength after subsequent environmental exposure. It was found that intensive action of moisture measured in the culture chamber of about (70 ± 5)%, i.e., for 16 weeks, at (22 ± 2) °C, which was the fungi culture, which was accompanying period, led to changes in the mass of the wood-plastic composites, amounting to 50% of the final result of the fungi resistance test, and changes in the bending strength amounting to 30–46% of the final test result. As a result of the research, the correction for assessing the durability of wood-polymer composites to biological corrosion has been proposed. The laboratory tests were compared with the products’ test results following three years of exposure to the natural environment.

scholarly journals The Effect of Phonological Neighborhood Density on Vowel Articulation

2004 ◽  
Vol 47 (5) ◽  
pp. 1048-1058 ◽  
Author(s):  
Benjamin Munson ◽  
Nancy Pearl Solomon
Keyword(s):  
Word Frequency ◽  
Recent Literature ◽  
Low Frequency ◽  
Neighborhood Density ◽  
Low Density ◽  
Vowel Duration ◽  
Vowel Production ◽  
Phonological Neighborhood Density ◽  
Formant Frequencies ◽  
Phonological Neighborhood

Recent literature suggests that phonological neighborhood density and word frequency can affect speech production, in addition to the well-documented effects that they have on speech perception. This article describes 2 experiments that examined how phonological neighborhood density influences the durations and formant frequencies of adults’ productions of vowels in real words. In Experiment 1, 10 normal speakers produced words that covaried in phonological neighborhood density and word frequency. Infrequent words with many phonological neighbors were produced with shorter durations and more expanded vowel spaces than frequent words with few phonological neighbors. Results of this experiment confirmed that this effect was not related to the duration of the vowels constituting the high- and low-density words. In Experiment 2, 15 adults produced words that varied in both word frequency and neighborhood density. Neighborhood density affected vowel articulation in both high- and low-frequency words. Moreover, frequent words were produced with more contracted vowel spaces than infrequent words. There was no interaction between these factors, and the vowel duration did not vary as a function of neighborhood density. Taken together, the results suggest that neighborhood density affects vowel production independent of word frequency and vowel duration.

Towards Mg based light materials of future: Properties, applications, problems and their mitigation.

2021 ◽  
pp. 1-43
Author(s):  
Annayath Maqbool ◽  
Noor Zaman Khan ◽  
Arshad Noor Siddiquee
Keyword(s):  
Corrosion Resistance ◽  
Review Paper ◽  
Weight Ratio ◽  
High Strength ◽  
Low Density ◽  
Widespread Application ◽  
Potential Barriers ◽  
Current Review ◽  
Processing Techniques ◽  
Corrosive Resistance

Abstract The use of lighter materials is one of the efficient means to mitigate the increasing demands on fuel resources, reduce CO2 emissions. Mg is one of the lightest material available and possesses exciting range of properties such as low density and high strength to weight ratio. Despite such exciting properties, the applications of Mg and its alloys were very limited in aerospace, automotive and biomedical industries but recently the application is picking-up. The restricted application is attributed to anisotropy, poor corrosive resistance and inflammability of Mg. The current review addresses the barriers limiting the widespread application of Mg based materials. Furthermore, the mitigation of the problems of anisotropy, poor corrosion resistance, ductility and inflammability of Mg are critically reviewed. The findings of this research provide insights of the processing techniques, properties and how to address the potential barriers of limited applications. The review paper will assist and motivate the researchers to ponder and overcome numerous problems related to Mg and its alloys by understanding the importance of each problem discussed in this review. An attempt has also been made to arrange research status on issues and the mitigation thereof with respect to Mg and its alloys as single reference point.

High-Performance Linear Cable Transmission

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Joan Savall ◽  
Javier Martín ◽  
Alejo Avello
Keyword(s):  
High Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Negative Effects ◽  
Low Friction ◽  
Alternative Design ◽  
Cable Length ◽  
High Stiffness ◽  
Length Changes

Cable transmissions offer several advantages such as high stiffness to weight ratio, high strength, low friction, and absence of backlash, which makes them appropriate for demanding mechanical applications. However, while extensively used as rotational transmissions, there are only a few examples of linear cable transmissions in the literature. The reason is that the up-to-date designs are based on a cable layout that leads to cable length changes during movement. This, in turn, produces negative effects such as transmission nonlinearity and cable fatigue. In this paper, an alternative design for linear cable transmissions is presented. The new design overcomes the aforementioned problems through a proper cable layout. Different applications of the new transmission are reported, validating the proposed design.

Rigid Polyurethane Foam: A Versatile Energy Efficient Material

2016 ◽  
Vol 678 ◽  
pp. 88-98 ◽  
Author(s):  
Harpal Singh
Keyword(s):  
Thermal Conductivity ◽  
Polyurethane Foam ◽  
Weight Ratio ◽  
Building Envelope ◽  
Polymerization Reaction ◽  
Low Density ◽  
High Porosity ◽  
Rigid Polyurethane Foam ◽  
Low Thermal Conductivity ◽  
Moisture Permeability

Rigid polyurethane foam (RPUF) is typically prepared by the reaction of an isocyanate, such as methyl diphenyl diisocyanate (MDI) with a polyol blend. During the polymerization reaction, a blowing agent expands the reacting mixture. The finished product is a solid, cellular polymer with a high thermal resistance. RPUF is an outstanding material for different applications. It has many desirable properties such as low thermal conductivity, low density, low water absorption, low moisture permeability, excellent dimensional stability, high strength to weight ratio. So, it is the best insulating material for industrial buildings, cold storages, telecom and defense shelters due to low thermal conductivity, low density, low moisture permeability and high porosity. It works to reduce heating and cooling loss, improving the efficiency of the building envelope. Thus, RPUF insulation in building envelopes brings additional benefits in energy savings, resulting in lower energy bills and protecting the environment by cutting CO2 emissions.

Metallographic Analysis of ECAP Processed Selected Magnesium Alloys

2014 ◽  
Vol 782 ◽  
pp. 404-407 ◽  
Author(s):  
Stanislav Rusz ◽  
Michal Salajka ◽  
Lubomír Čížek ◽  
Stanislav Tylšar ◽  
Jan Kedroň
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloys ◽  
Weight Ratio ◽  
High Strength ◽  
Metallographic Analysis ◽  
Low Density ◽  
Ecap Processing ◽  
Experimental Part ◽  
Composition Study

Magnesium alloys has been used for a wide variety of applications, namely from the reason of their low density and high strength–to–weight ratio. The properties of magnesium alloys are connected with microstructure that is influenced by metallurgical and technological aspects. Scope of utilisation of foundry magnesium alloys is continuously being extended, so if we want to operate as competitive producers, it is necessary to investigate very actively properties of individual alloys, optimise their chemical composition, study issues of their metallurgical preparation, verify experimentally their casting properties and conditions of successful casting of castings by individual methods, including heat treatment. Recently, however, increases also utilisation of formed magnesium alloys namely application of SPD methods. The experimental part deals with hardness and structure determination of selected magnesium alloys after ECAP processing.

Application Technology of Bamboo Reinforced Concrete in Building Structure

2012 ◽  
Vol 195-196 ◽  
pp. 297-302 ◽  
Author(s):  
Wei Feng Zhao ◽  
Jing Zhou ◽  
Guo Bin Bu
Keyword(s):  
Reinforced Concrete ◽  
Weight Ratio ◽  
High Strength ◽  
Concrete Columns ◽  
Building Structures ◽  
Structural Elements ◽  
High Tensile Strength ◽  
Application Technology ◽  
Steel Bar ◽  
Concrete Elements

Bamboo is mainly a tropical and subtropical plant which is found adequate in many countries. The strength of bamboo as concrete reinforcement is much lower than steel bar reinforcement. However, one of the merits is a cheap and replenishable agricultural resource and abundantly available. Due to excellent properties like high strength to weight ratio, high tensile strength and free-cutting and processing, bamboo as a potential reinforcement material in place of steel is widely available in concrete structural elements. The present paper introduces some of the existing studies and application technology of bamboo reinforced concrete elements in building structures, such as bamboo reinforced concrete columns, beams, slabs and walls.

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