scholarly journals Hygrothermal and Mechanical Behaviors of Fiber Mortar: Comparative Study between Palm and Hemp Fibers

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7110
Author(s):  
Younes Zouaoui ◽  
Ferhat Benmahiddine ◽  
Ammar Yahia ◽  
Rafik Belarbi
Keyword(s):  
Natural Fibers ◽  
Fiber Types ◽  
High Porosity ◽  
Environmental Footprint ◽  
Good Efficiency ◽  
Hemp Fibers ◽  
Buffer Value ◽  
Hydrophilic Character ◽  
Moisture Buffering ◽  
Very High

This paper presents an experimental investigation of the hygrothermal and mechanical properties of innovative mortar mixtures reinforced with natural fibers. Fibers extracted from palm stems (PS) and hemp (HF) were evaluated at different percentages. Scanning electron microscope (SEM) observations showed that the PS fibers have rough surfaces and very complex microstructures. Prior to their incorporation into the mortar, the fibers were subjected to different treatments to reduce their hydrophilic character. The employed treatments showed good efficiency in reducing the water absorption of both PS and HF fiber types. Furthermore, the mortar mixtures incorporating these fibers exhibited low thermal conductivity and excellent moisture buffering capacity. Indeed, the moisture buffer value (MBV) of the investigated mixtures ranged between 2.7 [g/(%HR·m2)] and 3.1 [g/(%HR·m2)], hence providing them excellent moisture regulator character. As expected, the fiber mortar mixtures showed very high porosity and low compressive strength ranging between 0.6 and 0.9 MPa after 28 days of age. The low-environmental footprint materials developed in this study are intended for thermal insulation and building filling.

scholarly journals Measurement of the dynamic moisture buffering potential of fabrics

2018 ◽  
Vol 89 (5) ◽  
pp. 739-747 ◽  
Author(s):  
Geoffrey RS Naylor
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Natural Fibers ◽  
Test Sample ◽  
Fiber Types ◽  
Fixed Temperature ◽  
New Approach ◽  
Synthetic Fibers ◽  
Wide Range ◽  
Moisture Buffering

In non-stationary wear conditions, characterized by intermittent pulses of moderate or heavy sweating, a garment with a good moisture buffering action can improve comfort. This is consistent with the common consumer belief that clothing manufactured from hygroscopic natural fibers (e.g., wool or cotton) provides better breathability. The current work describes a new approach for measuring dynamic moisture buffering potential using the sweating guarded hotplate instrument in a novel mode of operation. A fabric test sample is placed on the hotplate following the normal procedure for dry mode testing but with the relative humidity of the surrounding environment set to a low value (45%). After equilibration, the relative humidity is rapidly increased to a high value (85%). In the case of hygroscopic samples, a transient reduction in the heat required to maintain the hotplate at its fixed temperature is observed. It is demonstrated that the area of this transient peak is a measure of the water vapor absorbed during this transition, that is, the moisture buffering potential of the test specimen. A key to this new approach is that the heat of sorption per gram of water vapor absorbed is approximately the same for a wide range of natural and synthetic fibers commonly used in clothing. Using matched knitted fabrics manufactured from wool, cotton or polyester, the technique detected the heat released from light weight fabrics and the performance of the different fiber types is clearly distinguished.

scholarly journals The Structure and Mechanical Properties of Hemp Fibers-Reinforced Poly(ε-Caprolactone) Composites Modified by Electron Beam Irradiation

2021 ◽  
Vol 11 (12) ◽  
pp. 5317
Author(s):  
Rafał Malinowski ◽  
Aneta Raszkowska-Kaczor ◽  
Krzysztof Moraczewski ◽  
Wojciech Głuszewski ◽  
Volodymyr Krasinskyi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Beam ◽  
Impact Strength ◽  
Flexural Modulus ◽  
Natural Fibers ◽  
High Energy ◽  
Electron Radiation ◽  
Elongation At Break ◽  
Hemp Fibers

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.

Buckling analysis of natural fiber reinforced composites

2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Celal Çakıroğlu ◽  
Gebrail Bekdaş
Keyword(s):  
Composite Plate ◽  
Natural Fiber ◽  
Low Cost ◽  
Natural Fibers ◽  
Experimental Studies ◽  
Fiber Reinforced Composites ◽  
Fiber Types ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Element Analysis

In the recent years natural fiber reinforced composites are increasingly receiving attention from the researchers and engineers due to their mechanical properties comparable to the conventional synthetic fibers and due to their ease of preparation, low cost and density, eco-friendliness and bio-degradability. Natural fibers such as kenaf or flux are being considered as a viable replacement for glass, aramid or carbon. Extensive experimental studies have been carried out to determine the mechanical behavior of different natural fiber types such as the elastic modulus, tensile strength, flexural strength and the Poisson’s ratio. This paper presents a review of the various experimental studies in the field of fiber reinforced composites while summarizing the research outcome about the elastic properties of the major types of natural fiber reinforced composites. Furthermore, the performance of a kenaf reinforced composite plate is demonstrated using finite element analysis and results are compared to a glass fiber reinforced laminated composite plate.

A modified resistance to compression (RtC) test for evaluation of natural fiber softness

2022 ◽  
pp. 004051752110694
Author(s):  
Hao Yu ◽  
Christopher Hurren ◽  
Xin Liu ◽  
Stuart Gordon ◽  
Xungai Wang
Keyword(s):  
Compression Test ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Assessment Method ◽  
Fiber Types ◽  
New Approach ◽  
Additional Information ◽  
Significant Difference ◽  
Single Force ◽  
Different Diameters

Comfort is a key feature of any clothing that relates significantly to softness of the fiber, yarn and fabric from which is it constructed. A known softness assessment method for fibers is the resistance to compression test. This traditional test only provides a single force value for the resistance of a loose fiber sample using a fixed mass under compression. In this research, a modified resistance to compression test was introduced to show the effects of repeated compression, providing more information about the softness and resilience of selected fibers. Three different natural fiber types, including wool, cotton and alpaca were compared using this new approach. The results showed compression profiles were quite different for different fiber types as well as for the same fibers with different diameters. While the diameters of the wool and alpaca samples were similar (18.5 μm), the modified resistance to compression values were significantly higher for wool (with a peak value at 9.5 kPa compared to 2.1 kPa for alpaca). Cotton was different from wool and alpaca but showed a similar modified resistance to compression value (10.4 kPa) to wool. During cycles of compression, modified resistance to compression peak values decreased slightly and then tended to be constant. Even though the structures of wool, cotton and alpaca were quite different, there was no significant difference in the magnitude of decline in modified resistance to compression peak values. This means that the modified resistance to compression test is able to provide additional information on the resilience characteristics of different natural fibers, and can reveal the resistance behavior of fiber samples during cyclic compression.

The Damping Study for Dammar Composites Reinforced with Natural Fibers

2015 ◽  
Vol 801 ◽  
pp. 188-193
Author(s):  
Dumitru Bolcu ◽  
Marius Marinel Stănescu ◽  
Cosmin Mihai Miriţoiu ◽  
Cristian Oliviu Burada
Keyword(s):  
External Force ◽  
Natural Fibers ◽  
Free Vibrations ◽  
Vibration Damping ◽  
Initial Deformation ◽  
Rectangular Section ◽  
Hemp Fibers ◽  
Free Length ◽  
Natural Resin

In this paper we have studied the vibration damping for composite bars made by dammar based natural resin, the reinforcement being made by flax, cotton, silk and hemp fibers. There were made rectangular section samples (5x10 mm) with 220 mm length. The bars were clamped, the free length being 100 mm, 120 mm, 140 mm, 160 mm and 180 mm. For each bar, the free vibrations made by an initial deformation, obtained by inserting an external force in the free end, were recorded. In each case, the measured vibration was under-damped.

Phenol Removal from Contaminated Wastewater Using Activated Carbon/Zeolite Composite Coated with Titanium Dioxide

2016 ◽  
Vol 690 ◽  
pp. 103-108
Author(s):  
Khemmakorn Gomonsirisuk ◽  
Thanakorn Wasanapiarnpong ◽  
Charusporn Mongkolkachit
Keyword(s):  
Titanium Dioxide ◽  
Activated Carbon ◽  
High Efficiency ◽  
Adsorption Property ◽  
Phenol Concentration ◽  
Study Phase ◽  
Phenol Removal ◽  
High Porosity ◽  
Good Efficiency ◽  
Composite Substrate

Phenol and phenolic compounds in wastewater from various industries were toxic to water livings and human even in ppm concentration. A number of photocatalysts and adsorbents were applied for the low cost and good efficiency wastewater management to reduce phenol concentration in water. In this work titanium dioxide, one of high efficiency photocatalysts which is widely used in water treatement, was coated on the fabricated adsorbent composite substrate. The composite substrate composed of activated carbon and NaA zeolite presents high phenol adsorption because of high porosity and good ion exchange properties resulting in good adsorption property. Accordingly, the absorption could promote the photocatalytic activity of TiO2 catalyst. As the specimens were easily disposed after water treatment process, therefore, it was a good choice for lower energy consumption. The composite substrate was easily fabricated by simple extrusion and fired under non oxidation atmosphere at 650°C for 3 hours. Then polyurethane foam was inserted into the composite substrate to make it be able to float and be swirled by wind near water surface to get more UV excitation than deeper water. Phenol concentration was investigated by the UV absorbance at 270 nm using UV-Vis spectrophotometer. The XRD and SEM were used to study phase crystal structure and morphology of the composite.

Nowe możliwości wykorzystania oleju lnianego tłoczonego na zimno

2019 ◽  
Vol 20 (3) ◽  
Author(s):  
Ryszard Kaniewski ◽  
Janusz Jankowiak ◽  
Karolina Zajączek
Keyword(s):  
Medicinal Plants ◽  
Dairy Products ◽  
Linseed Oil ◽  
Natural Fibers ◽  
Dietary Supplementation ◽  
Flaxseed Oil ◽  
Omega 3 ◽  
Flax Seeds ◽  
Cold Pressed ◽  
Very High

The necessity of launching new dairy products for modern diets has led to the development of a new application of cold pressed linseed oil. The Institute of Natural Fibers and Medicinal Plants in Poznań developed a linseed butter combining the health benefits of butter and cold pressed high-linolenic linseed oil. This combination enables dietary supplementation with omega-3 acids in the form of a component obtained from flax seeds. In relation to other oils available on the market, flaxseed oil is characterized by the highest content of omega-3 acids and a very high content of unsaturated acids.

Comparative between different Natural Sources of Activated Carbon for the Removal Reactive Green Dye from Aqueous Solution

2021 ◽  
Vol 19 (7) ◽  
pp. 156-164
Author(s):  
Ennas Abdul Hussein ◽  
Asraa H. Aljbory ◽  
Sadiq J. Baqir ◽  
Ameera Hassan Hamed ◽  
Azal Shakir Waheeb ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Efficiency ◽  
Nigella Sativa ◽  
Adsorption Kinetic ◽  
High Porosity ◽  
Flower Bud ◽  
Natural Sources ◽  
Freundlich Isotherms ◽  
Kinetic Result ◽  
Very High

Water pollution is one of the biggest problems facing us, so it requires the need to develop a very high-efficiency and inexpensive absorbent material from natural surfaces and compare it with expensive commercial sorbents. Where in this study an absorbent substance was prepared from the natural surfaces of Syzgium Aromaticum Flower Bud (SAFB), Nigella Sativa (NS) Converted to activated carbon to activated carbon Activated (SAFB), and Activated (NS), as these surfaces are characterized by high porosity, cheap price and very high efficiency in removing dye. The composite was illustrated via different analysis apparatus included FTIR, and FE-SEM, The adsorption result were fitted with Freundlich isotherms. The experimental kinetic result at different primary reactive green dye concentrations, were also analyzed through first model, second model and Elovich model. The obtained data appear that the model pseudo-first model fits the adsorption kinetic result through R2 0.96028, R2 0.9486, R2 0.9016 and R2 0.9620 of SAFB and ACTIVE-SAFB and Nigella Sativa (NS) and Activated (NS) in the same order.

scholarly journals Comets and the Origin of Life: Structure of Comets Nuclei and Dust

2004 ◽  
Vol 213 ◽  
pp. 271-274
Author(s):  
A. Chantal Levasseur-Regourd ◽  
Emmanuel Desvoivres
Keyword(s):  
Light Scattering ◽  
Origin Of Life ◽  
High Porosity ◽  
Laboratory Measurements ◽  
Atmospheric Entry ◽  
The Origin Of Life ◽  
Life Structure ◽  
Very High

From observations of fragmentation events, clues to a gravitational aggregates structure of some comets nuclei are given. From in-situ and remote light scattering observations, a very high porosity is estimated for dust in comae. These results suggest a possible survival of cometary organics during atmospheric entry at the epoch of intense bombardment. In the coming years, new missions to comets and laboratory measurements on the ISS, will be used to assess such a scenario.

scholarly journals Moisture Buffering of Multilayer Internal Wall Assemblies at the Micro Scale: Experimental Study and Numerical Modelling

2019 ◽  
Vol 9 (16) ◽  
pp. 3438 ◽  
Author(s):  
Dobrosława Kaczorek
Keyword(s):  
Penetration Depth ◽  
Buffering Capacity ◽  
Internal Wall ◽  
Simplified Method ◽  
Buffer Value ◽  
Series Of Experiments ◽  
Overall Performance ◽  
Wall Assembly ◽  
Moisture Buffering ◽  
Moisture Buffer Value

In this paper, a series of experiments assessing the moisture buffer value (MBV) of four internal wall assembly samples made from hygroscopic materials was performed. A modified Nordtest protocol was used. Moisture buffer values of all the investigated wall assemblies, with varying moisture loads in the range of 50% to 80%, showed a moderate moisture buffer value (MBV: 0.5–1.0 (g·m−2·%RH−1)). The results showed that in a wall assembly where the MBV of the whole assembly is lower than the MBV of the outer layers, the moisture-buffering capacity of the inner layer is untapped. Outer layers affect inner layers by changing their moisture-buffering capacity, which in turn changes the overall performance of the whole assembly. In addition, it was observed that if the penetration depth value of the outer layer is greater than its thickness, vapour reaches into the deeper layer and wall assemblies made of layers with materials characterized by a lower value of penetration depth reach steady state more slowly. The WUFI Pro tool was used to compare the simulated and experimental results. Despite the discrepancies between these results, it offers a simplified method, helping designers make decisions about which materials to choose to improve the moisture-buffering effect.

Sign in / Sign up

Export Citation Format

Share Document