scholarly journals A New Strategy to Produce Hemp Fibers through a Waterglass-Based Ecofriendly Process

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1844
Author(s):  
Aurelio Bifulco ◽  
Brigida Silvestri ◽  
Jessica Passaro ◽  
Luca Boccarusso ◽  
Valentina Roviello ◽  
...  
Keyword(s):  
Natural Fibers ◽  
Silica Coating ◽  
Mechanical Analysis ◽  
Hemp Fibers ◽  
Glass Transformation ◽  
New Process ◽  
New Strategy ◽  
The Subject ◽  
Co2 Release ◽  
Effective Mechanical Properties

Natural fibers such as kenaf, hemp, flax, jute, and sisal have become the subject of much research as potential green or eco-friendly reinforcement composites, since they assure the reduction of weight, cost, and CO2 release with less reliance on oil sources. Herein, an inexpensive and eco-friendly waterglass treatment is proposed, allowing the production of silica-coated fibers that can be easily obtained in micro/nano fibrils through a low power mixer. The silica coating has been exploited to improve the chemical compatibility between fibers and the polymer matrix through the reaction of silanol groups with suitable coupling agents. In particular, silica-coated fibers easily functionalized with (3-Aminopropyl) triethoxysilane (APTS) were used as a filler in the manufacturing of epoxy-based composites. Morphological investigation of the composites through Scanning Electron Microscopy (SEM) demonstrated that the filler has a tendency to produce a web-like structure, formed by continuously interconnected fibrils and microfibrils, from which particularly effective mechanical properties may be obtained. Dynamic Mechanical Analysis (DMA) shows that the functionalized fibers, in a concentration of 5 wt%, strongly affect the glass transformation temperature (10 °C increase) and the storage modulus of the pristine resin. Taking into account the large number of organosilicon compounds (in particular the alkoxide ones) available on the market, the new process appears to pave the way for the cleaner and cheaper production of biocomposites with different polymeric matrices and well-tailored interfaces.

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.

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.

scholarly journals Action Research: a Supplementary Source for the English Langauge Teachers

2019 ◽  
Vol 8 (2S11) ◽  
pp. 2883-2885
Keyword(s):  
Action Research ◽  
Learning Outcomes ◽  
English Language ◽  
Teaching Strategy ◽  
Language Teachers ◽  
New Approach ◽  
New Strategy ◽  
Current Scenario ◽  
English Language Teachers ◽  
The Subject

This paper tries to explore that, Action Research is a supplementary source for English Language Teachers to bring out better teaching outcome of the teachers and better learning outcomes of the students. In the current scenario, apart from the syllabus, English Language teachers expect a supplementary source to follow a new strategy in order to satisfy the expectations of the students inside the classroom. They face many challenges in the classroom and one of the important problems is to draw continuous involvement of the students as well as to create good understanding of the subject in the classroom. In this connection, Action Research helps the teachers to explore effective teaching strategy in the classroom. This Action Research is integrated with a new approach called MUSE (Manageable, Urgent, Significant and Engaging), that helps the teachers to plan effectively. Besides, it is an exploratory or activity based classroom research and so it encourages the students to learn effectively and understand clearly with more involvement in the classroom. This study suggests a need for the supplementary source and it also focuses on Action Research to aid the teachers.

Wales

2019 ◽  
pp. 283-290
Author(s):  
Bob Woods
Keyword(s):  
United Kingdom ◽  
Quality Of Care ◽  
Older People ◽  
Social Movement ◽  
Third Sector ◽  
The United Kingdom ◽  
New Strategy ◽  
The Subject ◽  
Artistic Heritage

This chapter documents the developments in Wales relating to a National Dementia Vision and Strategy. A new Strategy is to appear by December 2016. While activity and progress are evident in many areas, much remains to be done. Wales benefits from having an Older People’s Commissioner, a statutory voice for older people, including those living with dementia, and from its rich cultural, linguistic, and artistic heritage, with active third-sector organizations. Like many countries, Wales has had well-publicized scandals in relation to quality of care in hospitals and care homes, which have provided learning and impetus for development. Compared with other parts of the United Kingdom, dementia diagnosis rates in Wales appear low and are now the subject of government targets. The new Strategy will need to fully engage with people living with dementia in order to address these challenges, while building on the growing social movement of dementia-friendly communities.

Effect of Alkali and Silane Treatment on the Thermal Stability of Hemp Fibers as Reinforcement in Composite Structures

2011 ◽  
Vol 415-417 ◽  
pp. 666-670 ◽  
Author(s):  
Na Lu ◽  
Shubhashini Oza ◽  
Ian Ferguson
Keyword(s):  
Thermal Stability ◽  
Composite Structures ◽  
Natural Fiber ◽  
Alkali Treatment ◽  
Thermo Gravimetric Analysis ◽  
Natural Fibers ◽  
Gravimetric Analysis ◽  
Silane Treatment ◽  
Hemp Fibers ◽  
Thermal Stability Of

Natural fiber reinforced composites are being used as reinforcement material in composite system due to their positive environmental benefits. Added to that, natural fibers offer advantages such as low density, low cost, good toughness, high specific strength, relatively non-abrasive and wide availability. However, the low thermal stability of natural fibers is one of the major challenges to increase their use as reinforcing component. In this study, a thorough investigation has been done to compare the effect of two chemical treatment methods on the thermal stability of hemp fibers. 5wt% sodium hydroxide and 5wt% triethoxyvinylsilane was used for the treatment of hemp fibers. Fourier transform infrared spectroscopy, scanning electron microscopy and thermo gravimetric analysis were used for characterization of untreated and treated fiber. The results indicated that 24 hours alkali treatment and 3 hours silane treatment time enhanced the thermal stability of the hemp fiber. However, alkali treatment shows better improvement compared to silane treatment.

Mechanical and morphological characterization of basalt/Cissus quadrangularis hybrid fiber reinforced polylactic acid composites

2020 ◽  
Vol 234 (14) ◽  
pp. 2895-2907 ◽  
Author(s):  
A Arul Jeya Kumar ◽  
M Prakash
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Water Absorption ◽  
Dynamic Mechanical Analysis ◽  
Fourier Transform Infrared Spectroscopy ◽  
Polylactic Acid ◽  
Natural Fibers ◽  
Mechanical Analysis ◽  
Dynamic Mechanical ◽  
Cissus Quadrangularis

In today's scenario, most of the research works are carried out on the replacement of synthetic fibers using eco-friendly materials called natural fibers. Although there are many research findings in connection with natural fibers, in this work, a new combination of natural fiber having high biomedical potential is reinforced in the polymer composite. Three different weight fractions of polylactic acid, basalt, and Cissus quadrangularis fibers were melt mixed using twin-screw extruder named as PBCQ 1, PBCQ 2, and PBCQ 3. The mechanical, physical, and thermomechanical properties were studied by testing tensile, flexural, impact, hardness, water absorption, Fourier-transform infrared spectroscopy, and dynamic mechanical analysis of the injection-molded biomedical composite specimens prepared as per ASTM standards. It was noticed that the PBCQ 2 composite has the maximum elongation strength, bending strength, shear strength, and shore D hardness compared to other composites taken in this study. Water absorption of PBCQ 1 and PBCQ 2 composites are relatively less than PBCQ 3. The scanning electron microscopy micrograph of PBCQ composites shows tight bonding between the matrix and fibers. The adhesion of matrix and fibers was confirmed by Fourier-transform infrared spectroscopy graph, which indicates the stretching of molecular structure for the occurrence of O–H, C=O, and C–H links. The dynamic mechanical analysis curve of the PBCQ 2 composite indicates high storage modulus and less loss modulus compared to PBCQ 1 and PBCQ 3 due to the low weight percentage of basalt fiber in these composites.

scholarly journals Breakfast Box: An Effort to Develop Vocabulary Mastery

2019 ◽  
Vol 7 (1) ◽  
pp. 39
Author(s):  
Dewi Lestari
Keyword(s):  
Learning Process ◽  
Text Comprehension ◽  
Motivation To Learn ◽  
Simple Sentence ◽  
Class D ◽  
New Strategy ◽  
School Learning ◽  
The Subject ◽  
Interest And Motivation ◽  
Write Text

Vocabulary is difficult skill for students on SMP Muhammadiyah 2 Surakarta. The students usually tend to listen, speak, read, and write text based on their vocabulary mastering. Once they get difficulty in understanding text, they will lose their courage to do more instructions. In order to build or understand a simple sentence, they need to open dictionary per word. As a result, students will easily lose interest and motivation to learn more. This research is carried out in SMP Muhammadiyah 2 Surakarta. It is on Jl. Kerinci No. 15. The research is conducted from July until Agustus 2016. The subject of this research is the IX-D grade students of SMP Muhammadiyah 2 Surakarta. The researcher chooses class D because the students have difficulties in understanding text due to the lack of vocabularies. That is why the researcher decides to improve their mastery in vocabulary through “vocabulary breakfast box”. “Vocabulary Breakfast Box” is adapted from “Kotak Sarapan Pagi” which is mostly applied at elementary school learning. It is about a board which contains of several boxes. Each box has an assignment for each student. The assignment can be the same as or different from others. It depends on the students’ assessment. The assignment exists in a form of a small paper. It consists of questions about words, sentences or text comprehension. Each box has students’ number or name. So students won’t go wrong to take others’ assignment. By using “vocabulary breakfast box”, the learning process in class has become interesting and varieties. Students are excited to try new strategy with teacher and discuss its benefits and lacks after the activity. Their vocabulary mastery becomes improved and they are able to answer most questions in each skill because they have recognized the words on the text or dialogue. Keywords: improving, vocabulary, vocabulary breakfast box

scholarly journals Comparación entre redes de fibras sintéticas y redes de fibras de cáñamo para el refuerzo de muros de albañileria = Comparison between synthetic fiber networks and hemp fiber networks for the reinforcement of masonry walls

2016 ◽  
Vol 2 (3) ◽  
pp. 26
Author(s):  
Alessandra Vilardi
Keyword(s):  
Natural Fibers ◽  
Synthetic Fiber ◽  
Masonry Walls ◽  
Historic Buildings ◽  
Structural Elements ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Fiber Networks ◽  
Synthetic Fibers ◽  
Bidirectional Networks

ResumenLa existencia de una gran cantidad de edificios antiguos ha movilizado la investigación para estudiar nuevos sistemas de refuerzo a aquellas construcciones que sean dañadas por decadencia fisiológica o por terremoto. El presente documento demuestra la eficacia de un sistema de refuerzo innovador para los muros de mampostería, constituyentes los elementos estructurales de los edificios históricos. Se hace una comparación entre unas redes bidireccionales de fibras sintéticas tradicionales y las de fibras naturales, ambas pegadas a las dos fachadas del muro con matriz de mortero. El resultado muestra la aplicación de las fibras de cáñamo como refuerzo sísmico y una mayor compatibilidad de estas con el material que caracterizan los edificios antiguos. AbstractThe existence of a large number of old buildings has mobilized research to study new systems of reinforcement to those buildings that are damaged by physiological decay or earthquake. This document demonstrates the effectiveness of an innovative reinforcement system for masonry walls, which are the structural elements of historic buildings. A comparison is made between bidirectional networks of traditional synthetic fibers and those of natural fibers, both glued to the two facades of the wall with mortar matrix. The result shows the application of hemp fibers as seismic reinforcement and a greater compatibility of these with the material that characterize the old buildings.

scholarly journals OSCE: Time of Reforms

2020 ◽  
pp. 52-58
Author(s):  
Igor Shcherbak ◽  
Keyword(s):  
Foreign Minister ◽  
Strategy Of Development ◽  
Crisis Prevention ◽  
Post Conflict ◽  
New Strategy ◽  
Recent Statement ◽  
The Subject ◽  
Peacekeeping Missions

The article is devoted to the question of reforms in the OSCE in the context of the recent statement of the RF Foreign Minister on this problem. The previous initiatives, as well as proposals on the subject and basic reasons for lack of consensus on the reforms in the OSCE, have been described in the paper. The author pays special attention to the perspective directions of the reforming process in the sphere of crisis prevention and regulation on the basis of the new technological achievements, peacekeeping missions, peacebuilding and post-conflict reconstruction, mediation. The article contains certain recommendations on this topic. The author proposes to elaborate a new strategy of development of the OSCE till 2030 which will define concrete options for the OSCE future reforms.

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