143 research outputs found

    The Effect of Using Process Approach on Science Achievement and Scientific Attitudes among Jordanian Basic Stage Students

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    This study aimed to investigate the impact of teaching students using operational-oriented in their achievement in science and the trend towards science. Specifically, the study sought to answer the following questions: Are there differences in achievement at the eighth grade students in Jordan according to the method of teaching (Operational-approach, the usual way)?Does the trend toward science primary grade students in Jordan according to the method of teaching (Operational-approach, the usual way) Sample of the study consisted of (64) students at the eighth grade enrolling at Ajlune City schools at Ajlune Governorate in the second semester of the school year 2012\2013. The sample was selected using purposeful sampling  from Ajlune Basic School For Boys and they were assigned to two sections: the first section ( A) containing ( 32) students and representing the experimental group and was taught using the process approach and the second section represented the control group ( B) containing (32) students and was taught using the traditional instructional method. The experimental group was taught using the Process Approach and the instructional period lasted for one and a half month. As for the control group, it was taught using the traditional instructional method for the same time period. To measure the effectiveness of the Process Approach instructional method compared to the traditional instructional method, a (20) items multiple choice test and (4) alternatives achievement test was developed. The reliability coefficient for the test was calculated using Cronbach alpha formula and was (0.84). Science attitudes scale was also used.To answer the questions of the study, Co- variance analysis ( ANCOVA) was used. The study revealed the following studies: A significant difference at (?=0.05) was found between student means scores on the achievement test due to the instructional method used and in favor of experimental group students   ( Process Approach). A significant difference at (?=0.05) was found between student means scores on the science attitudes scale due to the instructional method used and in favor of experimental group students ( Process Approach). In light of the results reported in the current study, the following recommendations were suggested: To use the Process Approach in teaching school subjects in general and science in particular.Future research is needed examining the effects of using Approach Process in the different subjects and using all school stage

    Eco-friendly composites for brake pads from agro waste: a review

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    Natural fibers possess unique property densities that make them potential alternative reinforcement materials in synthetic brake pad composites. This article presents a comprehensive review for the potential and possibilities of reinforcing brake pads using natural plant-based fibers. The influential keys to designing brake pad composites are found to be thermal stability, interfacial bond of the matrix with the fiber, thermal fade, effectiveness, and recovery. Besides that, the optimization technique for manufacturing process of eco-friendly brake pads is also covered. It can be concluded that natural fibers can be used as potential materials for designing effective eco-friendly brake pad composites in the near future

    Materials selection for natural fibre composites

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    Materials Selection for Natural Fiber Composites covers the use of various tools and techniques that can be applied for natural fiber composite selection to expand the sustainable design possibilities and support cleaner production requirements. These techniques include the analytical hierarchy process, knowledge-based system, Java based materials selection system, artificial neural network, Pugh selection method, and the digital logic technique. Information on related topics, such as materials selection and design, natural fiber composites, and materials selection for composites are discussed to provide background information to the main topic. Current developments in selecting the natural fiber composite material system, including the natural fiber composites and their constituents (fibers and polymers) is the main core of the book, with in detailed sections on various technical, environmental and economic issues to enhance both environmental indices and the industrial sustainability theme. Recent developments on the analytical hierarchy process in natural fiber composite materials selection, materials selection for natural fiber composites, and knowledge based system for natural fiber composite materials selection are also discussed

    Evolving Genetic Programming Tree Models for Predicting the Mechanical Properties of Green Fibers

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    Advanced modern technology and the industrial sustainability theme have contributed to the implementation of composite materials for various industrial applications. Bio-composites are among the desired alternatives for green products. However, to properly control the performance of bio-composites, predicting their constituent properties is of paramount importance. This work introduces an innovative, evolving genetic programming tree model for predicting the mechanical properties of natural fibers for the first time based upon several inherent chemical and physical properties. Cellulose, hemicellulose, lignin, and moisture contents, as well as the Microfibrillar angle of various natural fibers, were considered to establish the prediction models. A one-hold-out methodology was applied for the training/testing phases. Robust models were developed utilizing evolving genetic programming tree models to predict the tensile strength, Young’s modulus, and the elongation at break properties of the natural fibers. It was revealed that the Microfibrillar angle was dominant and capable of determining the ultimate tensile strength of the natural fibers by 44.7%, comparable to other considered properties, while the impact of cellulose content in the model was only 35.6%. This would facilitate utilizing artificial intelligence to predict the overall mechanical properties of natural fibers without exhausting experimental efforts and cost to enhance the development of better green composite materials for various industrial applications. Doi: 10.28991/ESJ-2023-07-06-02 Full Text: PD

    A novel evaluation tool for enhancing the selection of natural fibres for polymeric composites based on fiber moisture content criterion

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    A systematic evaluation tool for natural fibers’ capabilities based on moisture content criterion (MCC) was developed and introduced as a new evaluation method. This MCC evaluation tool is designed to predict the behavior of the available natural fibers regarding distinctive desirable characteristics under the effect of the moisture absorption phenomenon. Here, the capabilities of different natural fiber types commonly used in industry, in addition to date palm fibers, were systematically investigated based on MCC. The results demonstrated that MCC is capable of predicting the relative reduction of fiber performance regarding a particular beneficial property because of the effect of moisture absorption. The strong agreements between the predicted values of MCC and results reported in the literature verify its usefulness as an evaluation tool and demonstrate its added value steps in predicting the relative behavior of fibers with a minimal range of errors compared with experimental measurements. Therefore, MCC is capable of better evaluating natural fibers regarding distinctive criteria in a systematic manner, leading to more realistic decisions about their capabilities and therefore enhancing the selection process for both better sustainable design possibilities and industrial product development

    Natural fiber reinforced polymer composites in industrial applications: feasibility of date palm fibers for sustainable automotive industry

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    Proper utilization of the available natural resources and wastes became crucial for developing sustainability in industry. In this work, the feasibility of using the date palm fibers in the natural fiber reinforced polymer composites (NFC) for automotive industry was reported. Moreover, this work identifies a gap in the way of evaluating NFC relative to comprehensive desired criteria. This gap leads to disregard potential natural fiber types in industrial applications and keep it no more than an environmental waste problem. Here, criteria that affect the NFC were categorized and classified into levels. Governing criteria were suggested, collected and tabulated according to each level. To ensure the potential and competitiveness of the date palm fiber (DPF) in developing sustainability of the automotive industry, several comparisons between DPF and other fiber types commonly used in this industry were carried out. In most comparisons, DPF was the best selected fiber among all other types. DPF was the best regarding specific Young's modulus to cost ratio criterion. Technical properties and performance, environmental, economical, and societal aspects strongly contribute toward adopting DPF into the automotive sector to improve its sustainability and productivity. Furthermore, this adoption has a significant environmental influence throughout achieving an efficient sustainable waste management practice

    A review of rice husk bio-based composites

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    Development of new bio- based composites from renewable resources is getting wide attention from researchers due to environmental issue caused by traditional composites. Rice husk is a new potential renewable source of fillers for bio-composites to produce green products. Rice husk is the outer sheath surrounding rice grains during their growth. The aim of this work is to systematically review the parameters that affect the rice husk -polymeric composites in order to enhance their usage in various sustainable designs and applications. It is dedicated that rice husk composites are not used effectively due to the lack of understanding over its potential for such green composites. Moreover, systematic review of the published works demonstrated that the lack of awareness to environmental problems and technology as well as socio-economy problems prevent proper utilization of rice in bio-composites for sustainable products. Moreover, systematic discussions of the parameters that affect the performance of rice husk - composites are illustrated in this work to enhance its implementations for future sustainable products

    Combined multi-criteria evaluation stage technique as an agro waste evaluation indicator for polymeric composites: date palm fibre as a case study

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    The final features of natural fiber composites (NFCs) depend on the integrated characteristics of their constituents. In the industry today, natural agro waste fibers are evaluated using a limited number of criteria. In this work, a combined multi-criteria evaluation stage technique (CMCEST) is introduced as a simple efficient systematic indicator to enhance evaluation of the available natural agro wastes for polymeric composites. In this proposed technique, criteria affecting the proper selection of natural agro waste fibers were combined and divided into sequence stages as follows: single-evaluation-criterion (SEC), combined-double-evaluation-criterion (CDEC), combined-triple-evaluation-criterion (CTEC), etc. These stages are based on combined physical, mechanical, and economic evaluation criteria and can be extended to several further stages to include other beneficial characteristics. The effectiveness of this technique was demonstrated by evaluating coir, date palm, jute, hemp, kenaf, and oil palm fibers simultaneously. This combined evaluation criteria can lead to more informative decisions regarding selection of the most suitable fiber type for polymeric composites. The CMCEST enhancements can reveal new potential fiber types through better evaluation schemes, help achieve clearer indications of the capabilities of available agro wastes to enhance composites, and determine proper ecological waste management practices. Utilizing the proposed technique, the date palm fiber type was found to be quite promising due to beneficial characteristics revealed in CTEC, which provides a reasonable, cheap, and eco-friendly alternative material suitable for different applications

    Mechanical and morphological properties of injection-molded rice husk polypropylene composites

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    In this work, the investigation of the physical, mechanical, and morphological properties of the rice husk flour/polypropylene composites was performed utilizing various filler loadings and coupling agent. Five levels of filler loading (35, 40, 45, 50, and 55 wt%) were designed. In addition, to help the interaction between fiber and polypropylene matrix, struktol coupling agent was added to the composites. All of tensile strength, Young's modulus, flexural strength, flexural modulus, and impact strength properties of the composites were carried out. Moreover, the 50 wt% filler-loaded composites had optimum tensile strength, flexural strength, and flexural modulus, whereas the 35 wt% of filler loading case was the best regarding Young's modulus, flexural strength, flexural modulus, and impact strength. Furthermore, the scanning electron microscope results demonstrate that as filler loading increases, more voids and fiber pullout occur
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