scholarly journals Natural Weathering of Bio-Based Façade Materials

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 642
Author(s):  
Percy Alao ◽  
Kevin Visnapuu ◽  
Heikko Kallakas ◽  
Triinu Poltimäe ◽  
Jaan Kers
Keyword(s):  
Renewable Resources ◽  
Colour Change ◽  
Natural Weathering ◽  
Global Awareness ◽  
Renewable Materials ◽  
Uv Index ◽  
Service Durability ◽  
Natural Wood ◽  
The Impact ◽  
Weathering Resistance

Although there is a global awareness that the exploitation of non-renewable materials is unsustainable, there has been limited interest in fully utilizing natural, renewable resources like wood and its products because of the service durability concerns. One such issue is the aesthetical degradation of wooden facades due to the impact of weathering. This research was carried out as an international cooperation project to ascertain the weathering resistance of bio-based façade materials under the Estonian climate. In total, 120 bio-based façade materials obtained from 31 different companies, universities and research institutions from 17 countries were investigated. The specimens were placed on an exposure rack, inclined at an angle of 45° located at 59°23′50.6″ N 24°39′24.0″ E and then subjected to accelerated natural weathering for 2 years. Parameters such as precipitation, UV index, temperature and relative humidity were measured during the period of the natural weathering. The influence of the weathering on the colour change and cracks on the surface of test specimens was evaluated using Minolta Chroma Meter CR-121 (Konica Minolta INC., Tokyo, Japan) and Avongard Check Width Gauge (Avongard Ltd., Gloucestershire, UK), respectively. The results showed that the untreated natural wood façade materials presented the least resistance to weathering, while 63 of the tested materials developed checks. The outcome of this study is essential to the optimization of software-simulating changes in the appearance of façade materials in outdoor conditions.

scholarly journals SEM-PLS Approach to Green Building

Encyclopedia ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 472-481
Author(s):  
Nasim Aghili ◽  
Mehdi Amirkhani
Keyword(s):  
Structural Equation ◽  
Green Building ◽  
Well Being ◽  
The United States ◽  
Assessment Method ◽  
Assessment System ◽  
Renewable Materials ◽  
Sustainable Building ◽  
Building Operation ◽  
The Impact

Green buildings refer to buildings that decrease adverse environmental effects and maintain natural resources. They can diminish energy consumption, greenhouse gas emissions, the usage of non-renewable materials, water consumption, and waste generation while improving occupants’ health and well-being. As such, several rating tools and benchmarks have been developed worldwide to assess green building performance (GBP), including the Building Research Establishment Environmental Assessment Method (BREEAM) in the United Kingdom, German Sustainable Building Council (DGNB), Leadership in Energy and Environmental Design (LEED) in the United States and Canada, Comprehensive Assessment System for Built Environment Efficiency (CASBEE) in Japan, Green Star in Australia, Green Mark in Singapore, and Green Building Index in Malaysia. Energy management (EM) during building operation could also improve GBP. One of the best approaches to evaluating the impact of EM on GBP is by using structural equation modelling (SEM). SEM is a commanding statistical method to model testing. One of the most used SEM variance-based approaches is partial least squares (PLS), which can be implemented in the SmartPLS application. PLS-SEM uses path coefficients to determine the strength and significance of the hypothesised relationships between the latent constructs.

scholarly journals Biodegradable Flame Retardants for Biodegradable Polymer

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1038
Author(s):  
Muhammad Maqsood ◽  
Gunnar Seide
Keyword(s):  
Renewable Resources ◽  
Flame Retardants ◽  
Fire Risk ◽  
Polymeric Materials ◽  
Good Choice ◽  
Airborne Particle ◽  
Short Term ◽  
Renewable Materials ◽  
Long Time ◽  
Significant Attention

To improve sustainability of polymers and to reduce carbon footprint, polymers from renewable resources are given significant attention due to the developing concern over environmental protection. The renewable materials are progressively used in many technical applications instead of short-term-use products. However, among other applications, the flame retardancy of such polymers needs to be improved for technical applications due to potential fire risk and their involvement in our daily life. To overcome this potential risk, various flame retardants (FRs) compounds based on conventional and non-conventional approaches such as inorganic FRs, nitrogen-based FRs, halogenated FRs and nanofillers were synthesized. However, most of the conventional FRs are non-biodegradable and if disposed in the landfill, microorganisms in the soil or water cannot degrade them. Hence, they remain in the environment for long time and may find their way not only in the food chain but can also easily attach to any airborne particle and can travel distances and may end up in freshwater, food products, ecosystems, or even can be inhaled if they are present in the air. Furthermore, it is not a good choice to use non-biodegradable FRs in biodegradable polymers such as polylactic acid (PLA). Therefore, the goal of this review paper is to promote the use of biodegradable and bio-based compounds for flame retardants used in polymeric materials.

scholarly journals Influence of Natural and Artificial Weathering on the Colour Change of Different Wood and Wood-Based Materials

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 488 ◽  
Author(s):  
Davor Kržišnik ◽  
Boštjan Lesar ◽  
Nejc Thaler ◽  
Miha Humar
Keyword(s):  
Laboratory Test ◽  
Colour Change ◽  
Natural Weathering ◽  
Blue Staining ◽  
Artificial Weathering ◽  
Blue Stain Fungi ◽  
Colour Changes ◽  
Blue Stain ◽  
Positive Correlations ◽  
The Aesthetic

The importance of the aesthetic performance of wood is increasing and the colour is one of the most important parameters of aesthetics, hence the colour stability of twelve different wood-based materials was evaluated by several in-service and laboratory tests. The wood used for wooden façades and decking belongs to a group of severely exposed surfaces. Discolouration of wood in such applications is a long-known phenomenon, which is a result of different biotic and abiotic causes. The ongoing in-service trial started in October 2013, whilst a laboratory test mimicking seasonal exposure was performed in parallel. Samples were exposed to blue stain fungi (Aureobasidium pullulans and Dothichiza pithyophila) in a laboratory test according to the EN 152 procedure. Afterwards, the same samples were artificially weathered and re-exposed to the same blue stain fungi for the second time. The purpose of this experiment was to investigate the synergistic effect of weathering and staining. The broader aim of the study was to determine the correlation factors between artificial and natural weathering and to compare laboratory and field test data of fungal disfigurement of various bio-based materials. During the four years of exposure, the most prominent colour changes were determined on decking. Respective changes on the façade elements were significantly less prominent, being the lest evident on the south and east façade. The results showed that there are positive correlations between natural weathering and the combination of artificial weathering and blue staining. Hence, the artificial weathering of wood-based materials in the laboratory should consist of two steps, blue staining and artificial weathering, in order to simulate colour changes.

scholarly journals THE POSSIBILITIES OF REDUCING THE FUEL CONSUMPTION BY COVERING THE LOADING CAPACITY OF TIPPING SEMI-TRAILER DESIGNED TO CARRY BULK MATERIALS

2018 ◽  
Vol 6 (1) ◽  
pp. 455-462
Author(s):  
František Synák ◽  
Vladimír Rievaj ◽  
Monika Kiktová ◽  
Tomasz Figlus
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Renewable Resources ◽  
Human Population ◽  
Fossil Fuels ◽  
Loading Capacity ◽  
Direct Impact ◽  
Bulk Materials ◽  
Global Pollution ◽  
The Impact

The amount of fossil fuels consumed has direct impact on global pollution and health status of the human population. An increasing amount of fuel consumed leads to the increase using of non-renewable resources of energy. This article deals with possibilities of reducing the fuel consumption by covering the loading capacity of tipping semi-trailer. The introduction of this paper describes the impact the amount of fuel consumed on production of carbon dioxide. The ratio of driving resistances to fuel consumption is shown in the graph. In the second part of the article there is the methodology of the measurements. The measurements were conducted by driving test. The fuel consumption of tipping semi-trailer was measured during the driving with uncovered and covered loading capacity. The importance of this paper lies in the quantified the possibilities of reducing the fuel consumption by covering the loading capacity of tipping semi-trailer designed to carry bulk materials.

Renewable resources-based PTT [poly(trimethylene terephthalate)]/switchgrass fiber composites: The effect of compatibilization

2012 ◽  
Vol 85 (3) ◽  
pp. 521-532 ◽  
Author(s):  
Jeevan Prasad Reddy ◽  
Manjusri Misra ◽  
Amar Mohanty
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Renewable Resources ◽  
Melt Flow Index ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Flow Index ◽  
Methylene Diphenyl Diisocyanate ◽  
Trimethylene Terephthalate ◽  
The Impact

In this research, switchgrass (SG) fiber-reinforced poly(trimethylene terephthalate) (PTT) biocomposites were prepared by extrusion followed by injection molding machine. The methylene-diphenyl-diisocyanate-polybutadiene (MDIPB) prepolymer was used to enhance the impact strength of the biocomposites. In addition, the polymeric methylene-diphenyl-diisocyanate (PMDI) compatibilizer was used to enhance the mechanical properties of the composites. The effect of compatibilizer on mechanical, crystallization melting, thermomechanical, melt flow index (MFI), morphological, and thermal stability properties of the composites was studied. Thermomechanical properties of the biocomposites were studied by dynamic mechanical analysis (DMA). Scanning electron microscopy (SEM) was used to observe the interfacial adhesion between the fiber and matrix. The results showed that MDIPB and PMDI have a significant effect on the mechanical properties of the composites. The impact strength of MDIPB- and PMDI-compatibilized composites was increased by 87 % when compared to the uncompatibilized composite.

Duration Matters: Separating the Impact of Depth and Duration in Study Abroad Programs

2019 ◽  
pp. 102831531988738
Author(s):  
Stephen B. DeLoach ◽  
Mark R. Kurt ◽  
Neal H. Olitsky
Keyword(s):  
Study Abroad ◽  
Academic Program ◽  
Global Awareness ◽  
Short Term ◽  
Study Abroad Programs ◽  
Four Dimensions ◽  
Short Term Study ◽  
English Speaking ◽  
The Impact

Study abroad participation has increased dramatically over the past two decades, primarily through the growth of short-term study abroad experiences. Given this, it is logical to ask whether short-term experiences are capable of delivering student learning outcomes equivalent to those of long-term experiences. The research presented in this article addresses this question by asking if program duration (i.e., temporal length of the academic program) or depth (i.e., focused and reflective interaction with the destination culture) has a greater impact on changes in students’ global awareness. A longitudinal study across 80 study abroad programs from a single institution, measured global awareness pre- and post-abroad experience. This design controlled for preexisting differences (self-selection) and allowed us to rigorously estimate the relative effects of depth and duration across four dimensions of global awareness. Results show that a longer duration was associated with significant changes in three out of the four global awareness dimensions measured. The only depth measure that positively and significantly impacted global awareness was when the study abroad destination was a non-English speaking country. Even in this instance, the impact non-English speaking destination was increased further for longer durations.

scholarly journals Thermal, mechanical and morphological properties of polyurethane–zirconia loading

2020 ◽  
Author(s):  
Ali J Salman ◽  
Ali Assim Al-Obaidi ◽  
Dalya H Al-Mamoori ◽  
Lina M Shaker ◽  
Ahmed A Al-Amiery
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Material Science ◽  
Morphological Properties ◽  
Flexural Stress ◽  
Renewable Materials ◽  
Sem Images ◽  
The Impact ◽  
Scanning Electron

Abstract The polyurethane (PU) has been showing a dramatic increase in applications related to material science and technology. However, the mechanical, physical and thermal properties could be further improved by loading PU with zirconia (Zr) to create renewable materials known as polyurethane–zirconia (PUZ) composites. In this study, PU matrix was treated with wt.% Zr at 0.5, 1.0, 1.5 and 2.0. In this study, the thermo-mechanical properties and the morphology were investigated of PU and PUZ nano-samples. The images of the scanning electron microscope (SEM) were the prime tool in investigating PU and PUZ surfaces and fractured surfaces showing vanishing the cracks and formation of agglomeration on the sample PUZ-1.5%. In addition, the tensile strength, Young’s modulus and maximum loading were improved by 36.7, 31.8 and 39.1%, respectively, at Zr loading of 1.5 wt.%. The flexural stress and the load were improved by 94.3% and 93.6%, respectively, when Zr loading was 1.5 wt.%. The impact without and with a notch was improved by 110.7% and 62.6%, respectively, at Zr loading of 1.5 wt.%. The the morphologies of the PU surface and Zr surface supported by SEM images. Regarding the storage modulus ability of PU and PUZ composites, Zr loading has negatively influenced E. The E functioning temperature was observed to move from 142 to 183°C. Another effect was determined by adding a small amount of Zr. This small amount was enough to shift the crystallization temperature (${T}_c$) and the melting temperature (${T}_m$) of PU from 125 to 129°C and from 150 to 144°C, respectively.

scholarly journals Assessing the impact of non-thermal and thermal treatment on the shelf-life of onion juice

2019 ◽  
Vol 36 (No. 6) ◽  
pp. 480-486 ◽  
Author(s):  
Hande Demir ◽  
Mustafa Kemal Yıldız ◽  
İsmail Becerikli ◽  
Sevcan Unluturk ◽  
Zehra Kaya
Keyword(s):  
Heat Treatment ◽  
Shelf Life ◽  
Colour Change ◽  
Soluble Solids ◽  
Total Phenolic ◽  
Incident Intensity ◽  
Physicochemical Changes ◽  
Conventional Heat Treatment ◽  
The Impact ◽  
Uv C

Onion (Allium cepa L.) juice is a marinating agent for meat and fish marination and readily usable sauce for any meal that has onion in its formulation. This study aims to assess the microbiological and physicochemical changes in the onion juice processed by UV-C irradiation (0.5 mm sample depth, 30 min exposure time, 7.5 mW/cm<sup>2</sup> UV incident intensity) and conventional heat treatment (74.5°C, 12 min) during its storage. Microbiological results showed processing by UV-C irradiation or heat treatment under optimum conditions extended the microbial shelf-life of untreated onion juice by minimum 6-times. Total colour change of heat-treated samples was lower than that of untreated and UV-C treated samples for 12 weeks. Also, pH, total titratable acidity, total soluble solids content, turbidity, NEBI and total phenolic content were monitored for 12 weeks. The results of this study will form scientific infrastructure for onion juice manufacturers to decide on the processing method with respect to its shelf-life.

Fracture Toughness of PIR Foams Produced from Renewable Resources

2012 ◽  
Vol 525-526 ◽  
pp. 29-32 ◽  
Author(s):  
Janis Andersons ◽  
E. Spārniņš ◽  
Ugis Cabulis ◽  
U. Stirna
Keyword(s):  
Fracture Toughness ◽  
Renewable Resources ◽  
Petrochemical Industry ◽  
Compact Tension ◽  
Environmental Benefits ◽  
Insulation Material ◽  
Renewable Materials ◽  
Tension Tests ◽  
Closed Cell ◽  
Rise Direction

Rigid low-density closed-cell polyisocyanurate (PIR) foams are used primarily as a thermal insulation material. Traditionally, they are manufactured from constituents produced by petrochemical industry. Introducing renewable materials in PIR formulation brings definite economical and environmental benefits. Fracture toughness of PIR foams obtained from renewable resources (with the polyol system comprising up to 80% of rapeseed oil esters) and petrochemical PIR foams has been characterized experimentally, by compact tension tests, for mode I crack propagation along the rise direction of the foams.

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