Development and characterisation of novel structural composites from recycled materials

Carpets are composite materials and, like many composite materials, waste carpet is both difficult and expensive to recycle because of the complicated, multi-stage processes involved. In the UK, approximately 400,000 tonnes of carpet waste are sent to landfill annually. However, the landfill option is becoming uneconomic due to increasing landfill charges, the reduction in landfill sites and changes in environmental legislation. This project, in collaboration with ECO2 Enterprises, aimed to avoid the landfill option and develop novel structural composites from carpet waste, which could be used to replace timber and PVC posts and rails in equestrian fencing. The development of these composites is a recycling approach that makes use of carpet waste which would otherwise be sent to landfill thereby increasing environmental pollution. The study encompasses the investigation of relevant material and mechanical properties and processing characteristics of the prototype novel waste carpet composites both as a structural beam and an assembled fencing system. Details of the manufacturing processes of the novel waste carpet structural composites are described. Extensive experimental testing has been carried out to determine and compare the mechanical properties of the novel waste carpet structural composites to timber and PVC materials. In addition, experimental load tests and Finite Element (FE) analysis on typical equestrian timber and PVC post and rail fencing structures (benchmark data) were carried out to evaluate their stiffness characteristics against corresponding characteristics for a similar fencing structure comprised of the novel waste carpet structural composites. Design optimisation via geometric changes and FE analyses showed that a 69 % increase in the depth (from 71 to 120 mm) of the novel waste carpet composite posts resulted in a transverse stiffness similar to that of the timber fence. The results obtained from this study has demonstrated that the mechanical properties of the novel structural composites could potentially serve as an alternative/replacement for some common materials used in structural applications, such as timber and PVC fencing

Computer Assisted Programmed Instruction and Cognitive Preference Style as Determinant of Achievement of Secondary School Physics Students

The study probes into the effect of Computer Assisted Instruction and Cognitive preference style on achievement of secondary school Physics Students in Ogun State of Nigeria. The population of the study comprises the SS II students in Abeokuta Educational Zone. 186 students sample were drawn from the population for the study. Two main valid and reliable instruments were used for data collection: Physics Achievement Test (KR20 = 0.83) and Physics Cognitive Preference Style Inventory (KR20 = 0.86). The result revealed significant main effect of treatment [F (1,186) =28.651, P < 0.05 ] and cognitive preference style [F (3,186) =23.349,

Experimental investigation and Finite Element (FE) analysis of the load-deformation response of PVC fencing structures

Polyvinyl Chloride (PVC) posts and rails are increasingly being used as components of fencing structures because of their good mechanical properties, which include long service life, good chemical resistance, ability to be processed into complex geometry and good aesthetics. However, there has been no experimental or Finite Element (FE) study on the load-deformation response of PVC fencing structures. In addition, currently, no stiffness or structural load-bearing design standards exist for these types of fencing structures. Therefore, this study describes an investigation of the load-deformation response of a two-bay PVC post and rail fencing structure. The fencing structure was loaded experimentally at the top of the centre post and mid-bay points of the top rail. The load-deflection responses recorded during the tests on the fencing structure are presented and shown to be both linear and repeatable (i.e. three load-unload tests were carried out and showed identical responses). Based on the transverse deflection at the maximum applied load, the transverse stiffness of the two-bay PVC fencing structure was calculated to be 12.7–14 N/mm. A comparison of the transverse stiffness of the PVC fence with a similar timber fence showed the timber fence was approximately 262% stiffer than the PVC fence. Furthermore, FE modelling using a commercial software (ANSYS) was carried out on the PVC fencing structure to supplement the experimental work, and good agreement between the FE analyses and experimental test results was demonstrated. Hence, this paper provides initial knowledge and understanding of the linear elastic load-transverse deflection response of PVC fencing structures, and constitutes useful structural design guidance for what may be regarded as the in-service or practical deformation limit. The results of this study also provide useful benchmarks for future composite materials and components for fencing and other structural applications

Assessing environmental impacts of inland sand mining in parts of Ogun State, Nigeria

Sand is a valuable resource for construction and other purposes, however sand mining often result in serious environmental problems such as land degradation, loss of agricultural lands and biodiversity, as well increased poverty among people. This study assessed the environmental impacts of inland sand mining in six selected local government areas of Ogun state, Nigeria. Twenty-seven (27) inland sand mining sites were identified, fourteen (14) of which are currently active mining sites while thirteen (13) are abandoned. The geographic location and attributes sites were captured for a spatial analysis using Geographic Information System (GIS). The sites were mapped and classified based on the severity of the damage to the ecological system. The study revealed that three of the local governments areas i.e. Abeokuta South, Ifo, Obafemi/Owode and Ado-Odo/Ota have inland sand mining sites with severe degradation, while Sagamu and Ewekoro local governments areas have inland sand mining sites that can be regarded as moderately and less degraded respectively. The intensive urban and industrial developments around these areas contributed enormously to the increased demand of sand for building and construction. Natural resources particularly, land, water quality and quantity, air quality, are the most significant impacts. Other impacts include loss of farmland, depreciation of land value, and destruction of infrastructural facilities. The study concluded that sand mining should be subject to planning and other controls in order to curtail its negative impacts. Keywords: Urbanization, Housing, GIS, Land degradation, Sand mining, Pollutio

Development and testing of material extrusion additive manufactured polymer–textile composites

© 2021, The Author(s). The adoption of Additive Manufacturing (AM) has gradually transformed the fashion industry through innovation and technology over the last decade. Novel AM systems and techniques are continuously being developed, leading to the application of AM polymers with textiles and fabrics in the fashion industry. This work investigates the development and testing of polymer–textile composites using polylactic acid (PLA) filaments on synthetic mesh fabrics using direct material extrusion (ME). An aspect of this paper highlights the appropriate combination of printing material, textile substrate, and printer settings to achieve excellent polymer–textile adhesion. Details of the printing process to create polymer–textile composites are described, as are the interfacial strength results of the T-peel tests, and the observed failure modes post-testing. The peel strengths for different ME bonded polymer–textile composites are examined and used to identify the compatibility of materials. This work visualised the potential of direct ME of polymers onto textile fabrics as a material-joining approach for new textile functionalisation, multi-material composite explorations and innovative aesthetic print techniques. This work also adds to the limited knowledge of AM polymer–textile composites, which can provide helpful information for designers and researchers to develop new applications and facilitate future research development in smart embedded and programmable textiles

Development, characterisation and Finite Element modelling of novel waste carpet composites for structural applications

© 2018 Elsevier Ltd Carpets are composite materials and, like many composite materials, waste carpet is both difficult and expensive to recycle because of the complicated, multi-stage processes involved. Consequently, in the United Kingdom, approximately 400,000 tonnes of carpet waste are sent to landfill annually. However, the landfill option is becoming uneconomic due to increasing landfill charges, the reduction in landfill sites and changes in environmental legislation. This dual economic and environmental burden has led to research interest in the processing of waste carpets into useful feedstocks for use in manufacturing. This study describes the experimental characterisation of a novel structural composite material that has been fabricated from waste carpets, and which is intended for use in low grade structural applications such as agricultural fencing. Details of the manufacturing process for the composites are described, as are the results of tensile and three-point bending tests, and the observed failure modes post-testing. In addition, Finite Element (FE) analysis was used to simulate the structural behaviour of fencing posts and rails manufactured from the carpet-based composite, and these results are compared with commercially available timber and PVC equivalent designs. Finally, structural analysis and design optimisation of the composite fencing was undertaken and this is used to demonstrate that from a mechanical property standpoint, the novel waste carpet structural composite may offer potential as an alternative to the timber and PVC materials typically used in such applications. Therefore, this study has demonstrated a practical approach for recycling carpet waste, which could lead to a substantial reduction in the volume of carpet waste discarded to landfill and subsequently yield both economic and environmental benefits.The authors wish to record their appreciation to the Centre for Global Eco-Innovation and the Engineering Department of Lancaster University for supporting their research. The Centre for Global Eco-Innovation is part-financed by the European Regional Development Fund (Grant No. X02646PR). In addition, they wish to thank Richard Wilbraham and Mohammed Milad for their assistance with the Scanning Electron Microscopy (SEM) analysis and Digital Image Correlation (DIC) operation, respectively

Experimental and Finite Element (FE) modelling of timber fencing for benchmarking novel composite fencing

Timber is a widely used composite material in structural load-bearing applications because of its good mechanical properties. However, with global forest loss occurring at a high rate, mainly due to the timber trade, and deforestation accounting for about 12% of global CO2 emissions, there is an increasing demand for alternative structural materials with a lower carbon footprint to mitigate climate change. This has led to an increased interest in the use of recycled materials for the development of novel structural composites. This paper describes an investigation of the structural load-deformation behaviour of a typical post and rail type fence fabricated from timber sections – the target application for replacement with alternative novel and lower carbon footprint composite materials/components. The post and rail fence is a two-bay frame comprised of three posts and two rails. Prior to testing the frame, three-point bending tests were carried out on the ungraded timber posts and rails to determine their longitudinal elastic flexural moduli. Tip-loaded cantilever bending tests were also carried out to determine the semi-rigid rotational stiffness of the bolted joint at the base of the posts. Using the geometry, moduli and stiffness results, Finite Element (FE) analyses were carried out using ANSYS software to investigate the structural behaviour of the timber post and rail fence. The FE results were compared with the experimental results and shown to be in good agreement. As there are no structural load-bearing standards for agricultural fencing, the experimental and FE timber fencing results provide useful benchmarks for assessing the structural stiffness of novel recycled composite materials and components presently under development for fencing applications

Nivel de conocimiento y factores influyentes en automedicación de antiulcerosos en usuarios que acuden a la botica Gonzalez distrito de Santa Anita mayo 2022

Este estudio examina dicha estructura como base para un mejor desarrollo del objetivo primordial. Determinar la relación entre el nivel de conocimiento y factores influyentes en la automedicación de antiulcerosos en usuarios que acuden a la botica “González Distrito de Santa Anita mayo 2022”. Y como específicos. Evaluar la relación entre el nivel de conocimiento con los factores socioeconómicos en automedicación de antiulcerosos, identificar la relación entre el nivel de conocimiento con los factores bioculturales en automedicación de antiulcerosos, y, por último. Analizar la relación entre el nivel de conocimiento con las prácticas de automedicación, en términos de su distribución y frecuencia de antiulcerosos en usuarios que acuden a la botica “El González Distrito de Santa Anita mayo”. La metodología utilizada para este estudio fue mediante un estudio de tipo no experimental, transversal de enfoque cuantitativo y de nivel correlacional. Además, se usó como instrumento un cuestionario y la técnica empleada y ejecutada fue la encuesta. Entre los resultados en la encuesta aplicada muestra que. 80,1% de los usuarios tiene un nivel de conocimiento significativamente bajo, el 15,3% tienen nivel de conocimiento medio y el 4,6% tiene un nivel de conocimiento alto. Se concluyó que si existe relación entre el nivel de conocimiento y factores influyentes en la automedicación de antiulcerosos en usuarios que acuden a la botica y también si existe relación de nivel de conocimiento con los factores socioeconómicos en automedicación sin embargo no existe relación entre el nivel de conocimiento con los factores bioculturales mas no existe relación entre el nivel de conocimiento con las prácticas de automedicación, en términos de su distribución y frecuencia de antiulcerosos en usuarios que acuden a la botica “El González Distrito de Santa Anita mayo 2022”http://repositorio.unid.edu.pe/handle/unid/337?show=ful

Experimental characterisation of the moment-rotation behaviour of beam-beam connections using compressed wood connectors

© 2021 The Authors. The widespread use of energy-intensive metallic connectors and synthetic adhesives in modern timber construction has negative implications for the end-of-life disposal or re-use of the structural timber components. Therefore, it is favourable to substitute metallic connectors and synthetic adhesives with bio-based alternatives such as wood-based connectors. Recent studies have shown that densified or compressed wood (CW) with superior mechanical properties could be suitable for the manufacture of wood-based connectors in the form of CW dowels and CW plates. This study experimentally examines the moment-rotation behaviour of semi-rigid type timber-CW beam-beam connections under pure bending. The study also assesses the suitability of current design rules to predict the moment capacity of timber-CW connections. The comparative study has shown that the moment capacity of the timber-CW connection can be conservatively predicted from the characteristic load-carrying capacity of the connections calculated using the EC 5 strength equations.European Regional Development Fund (ERDF) via Interreg North-West Europe grant 348 “Towards Adhesive Free Timber Buildings - AFTB”