Rotational-Moulded Building Blocks for the Circular Economy

2021 ◽  
Vol 1042 ◽  
pp. 17-22
Author(s):  
Sibele Piedade Cestari ◽  
Peter Martin ◽  
Paul Hanna ◽  
Mark Kearns ◽  
Luis Claudio Mendes

Throughout the combination of unique approaches on innovative polymer composites and rotational moulding plastics processing technique, we developed a building block using a mix of recycled and virgin plastic. This block was a technical case study from a multidisciplinary approach - comprising materials science, polymers processing and design - to reinsert recycled plastics in the Circular Economy. The aim was to produce a three-dimensional interlockable block, combining unique design and unconventional materials to create an emblematic building element. We investigated the composition and availability of local plastic waste, as well as other waste-stream materials – concrete waste, red mud, hemp fibre, sugarcane bagasse. We prepared a range of composites and blends to test their prospective aspect and processability. To simulate the end-result of a rotationally-moulded part, we prepared samples of the blends in an oven. The thermal analysis showed that all materials were thermally stable at the processing temperature of the virgin polymer in rotomoulding, around 200 °C. There were an evident LLDPE continuous-phase and a recyclate dispersed-phase. We also explored the aesthetic effect of scattering particles of colour in the mixes. The impact test showed better results for the polyethylene-based recyclates if compared to polypropylene and poly (ethylene terephthalate) ones. We concluded that waste materials could be revalued into something practical and reproducible, produced by rotational moulding plastics processing. And we developed a viable and innovative potential product for the Circular Economy, requiring minimal fixing and no further external finishing.

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Edwin Peraza-Hernandez ◽  
Darren Hartl ◽  
Edgar Galvan ◽  
Richard Malak

Origami engineering—the practice of creating useful three-dimensional structures through folding and fold-like operations on two-dimensional building-blocks—has the potential to impact several areas of design and manufacturing. In this article, we study a new concept for a self-folding system. It consists of an active, self-morphing laminate that includes two meshes of thermally-actuated shape memory alloy (SMA) wire separated by a compliant passive layer. The goal of this article is to analyze the folding behavior and examine key engineering tradeoffs associated with the proposed system. We consider the impact of several design variables including mesh wire thickness, mesh wire spacing, thickness of the insulating elastomer layer, and heating power. Response parameters of interest include effective folding angle, maximum von Mises stress in the SMA, maximum temperature in the SMA, maximum temperature in the elastomer, and radius of curvature at the fold line. We identify an optimized physical realization for maximizing folding capability under mechanical and thermal failure constraints. Furthermore, we conclude that the proposed self-folding system is capable of achieving folds of significant magnitude (as measured by the effective folding angle) as required to create useful 3D structures.


Author(s):  
Mohammed Bakkali ◽  
Yasunobu Ashie

In our growing cities, climate change and energy related uncertainties are of great concern. The impact of the Urban Heat Island on comfort, health and the way we use energy still requires further clarification. The outdoor-indoor energy balance model (3D-City Irradiance) presented in this article was developed so as to address these issues. The effects of view factors between urban surfaces on three-dimensional radiation and the effects of fully integrated outdoor-indoor energy balance schemes on heat islands and building indoor thermal loads could be included within different building blocks at a resolution of several metres. The model operated under the ‘stand alone’ mode. It was tested using the Building Energy Simulation Test (BESTest) which demonstrated good levels of agreement for diurnal and seasonal simulations.


2002 ◽  
Vol 16 (26) ◽  
pp. 3971-3978 ◽  
Author(s):  
A. J. DU ◽  
Z. Y. PAN ◽  
Z. HUANG ◽  
Z. J. LI ◽  
Q. WEI ◽  
...  

In this paper, the initial stage of films assembled by energetic C 36 fullerenes on diamond (001)–(2 × 1) surface at low-temperature was investigated by molecular dynamics simulation using the Brenner potential. The incident energy was first uniformly distributed within an energy interval 20–50 eV, which was known to be the optimum energy range for chemisorption of single C 36 on diamond (001) surface. More than one hundred C 36 cages were impacted one after the other onto the diamond surface by randomly selecting their orientation as well as the impact position relative to the surface. The growth of films was found to be in three-dimensional island mode, where the deposited C 36 acted as building blocks. The study of film morphology shows that it retains the structure of a free C 36 cage, which is consistent with Low Energy Cluster Beam Deposition (LECBD) experiments. The adlayer is composed of many C 36-monomers as well as the covalently bonded C 36 dimers and trimers which is quite different from that of C 20 fullerene-assembled film, where a big polymerlike chain was observed due to the stronger interaction between C 20 cages. In addition, the chemisorption probability of C 36 fullerenes is decreased with increasing coverage because the interaction between these clusters is weaker than that between the cluster and the surface. When the incident energy is increased to 40–65 eV, the chemisorption probability is found to increased and more dimers and trimers as well as polymerlike- C 36 were observed on the deposited films. Furthermore, C 36 film also showed high thermal stability even when the temperature was raised to 1500 K.


2007 ◽  
Vol 334-335 ◽  
pp. 265-268 ◽  
Author(s):  
Xiao Wen Yuan ◽  
Debes Bhattacharyya ◽  
Allan J. Easteal

The usefulness of rotational moulding (rotomoulding) as a polymer processing technique is often limited by the selection of polymers, which in most cases happens to be polyethylene (PE). In the present study, PE polyethylene was blended with wollastonite microfibres and maleated polyethylene (as a coupling agent) with the purpose of developing an improved material for rotational moulding. The incorporation of wollastonite fibres without any coupling agent improved the tensile strength, but showed a reduction in impact strength. As expected, the most significant enhancement due to wollastonite was in the tensile modulus.. The addition of a coupling agent improved both the impact strength and the processability, especially when wollastonite was coated with aminosilane. Scanning electron microscopy revealed good adhesion between the coated fibre reinforcement and the polyethylene matrix at the fracture surface.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5390
Author(s):  
Lianming Zhang ◽  
Lei Guo ◽  
Gang Wei

Cellulose is one of the important biomass materials in nature and has shown wide applications in various fields from materials science, biomedicine, tissue engineering, wearable devices, energy, and environmental science, as well as many others. Due to their one-dimensional nanostructure, high specific surface area, excellent biodegradability, low cost, and high sustainability, cellulose nanofibrils/nanofibers (CNFs) have been widely used for environmental science applications in the last years. In this review, we summarize the advance in the design, synthesis, and water purification applications of CNF-based functional nanomaterials. To achieve this aim, we firstly introduce the synthesis and functionalization of CNFs, which are further extended for the formation of CNF hybrid materials by combining with other functional nanoscale building blocks, such as polymers, biomolecules, nanoparticles, carbon nanotubes, and two-dimensional (2D) materials. Then, the fabrication methods of CNF-based 2D membranes/films, three-dimensional (3D) hydrogels, and 3D aerogels are presented. Regarding the environmental science applications, CNF-based nanomaterials for the removal of metal ions, anions, organic dyes, oils, and bio-contents are demonstrated and discussed in detail. Finally, the challenges and outlooks in this promising research field are discussed. It is expected that this topical review will guide and inspire the design and fabrication of CNF-based novel nanomaterials with high sustainability for practical applications.


Author(s):  
Brandon Holguin ◽  
James Allison ◽  
Donghyeon Ryu ◽  
Zachary Alvarez ◽  
Francisco Hernandez ◽  
...  

The objective of this study is to develop three dimensional (3D) impact self-sensing composites capable of localizing impact damage in through-the-thickness direction. The 3D impact self-sensing composites (3D-ISSC) are designed by embedding fracto-mechanoluminescent (FML) crystals in cells of honeycomb-cored fiber reinforced polymer (FRP) structural composites. FML crystals were shown to emit light resulting from cleavage of crystalline structures due to external mechanical stimuli. Unlike other conventional sensor networks, without supplying external electrical source, the 3D-ISSC is envisioned to monitor impact occurrences and detect damage. Instead, the emitted light will be utilized for informing severity of impact occurrences and 3D locations of the impact damage. First, FML europium-doped dibenzoylmethide triethylammonium (EuD4TEA) crystals are synthesized. Second, the synthesized EuD4TEA crystals are embedded in the honey-cored FRP structural composites to fabricate 3D-ISSC. Third, to validate its 3D self-sensing capability, Kolsky bar is employed to apply high strain-rate compressive loading to simulate impact occurrences while taking high-speed video footage for quantifying intensity of FML light emission through image processing technique.


2020 ◽  
Author(s):  
María Camarasa-Gómez ◽  
Daniel Hernangómez-Pérez ◽  
Michael S. Inkpen ◽  
Giacomo Lovat ◽  
E-Dean Fung ◽  
...  

Ferrocenes are ubiquitous organometallic building blocks that comprise a Fe atom sandwiched between two cyclopentadienyl (Cp) rings that rotate freely at room temperature. Of widespread interest in fundamental studies and real-world applications, they have also attracted<br>some interest as functional elements of molecular-scale devices. Here we investigate the impact of<br>the configurational degrees of freedom of a ferrocene derivative on its single-molecule junction<br>conductance. Measurements indicate that the conductance of the ferrocene derivative, which is<br>suppressed by two orders of magnitude as compared to a fully conjugated analog, can be modulated<br>by altering the junction configuration. Ab initio transport calculations show that the low conductance is a consequence of destructive quantum interference effects that arise from the hybridization of metal-based d-orbitals and the ligand-based π-system. By rotating the Cp rings, the hybridization, and thus the quantum interference, can be mechanically controlled, resulting in a conductance modulation that is seen experimentally.<br>


2019 ◽  
Vol 3 (2) ◽  
pp. 110
Author(s):  
Suwarno Suwarno

<p><strong>A</strong><strong>bstract</strong><strong>. </strong>This study aims to determine the effectiveness of the Teams Games Tournament (TGT) learning model to improve student learning outcomes. This research is important because the lecture learning model makes learning meaningless so it impacts on low learning outcomes. This research uses quasi experiment using control class and experimental class. Respondents in this study were students of class X SMK 8 Semarang Academic Year 2017/2018. Sample selection using random sampling, class X1 is <em>used</em> as a control class and X2 is an experimental class. The experimental class was given an intervention by learning Teams Games Tournaments (TGT), while the control class used lecture learning. The effectiveness of the model was measured by the student test analysis method. then analyzed by completeness test and average difference test. The findings of this study are the learning outcomes of experimental class students achieving better learning outcomes than classes using the lecture method.</p><p><strong><em>Keywords</em></strong><em>: Learning Model, Teams Games Tournaments (TGT)</em><em>. Students</em></p><p><strong><br /></strong></p><p><strong>Daftar Pustaka</strong></p><p align="center"> </p><p>Bofota, Y. B., &amp; Bofota, Y. B. (2017). <em>The impact of social capital on children educational outcomes : the case of Tanzania The impact of social capital on children educational outcomes : The case of Tanzania</em>.</p><p>Cahuc, P., Shleifer, A., &amp; Algan, Y. (2014). <em>Teaching Practices and Social Capital</em>. (6052).</p><p>Catts, R., &amp; Ozga, J. (2015). <em>What is Social Capital and how might it be used in Scotland ’ s Schools ?</em> (36).</p><p>Flint, N. (2017). <em>Full report Schools , communities and social capital : building blocks in the ’ Big Society ’ Contents</em>.</p><p>Goddard, R. D. (2016). <em>Relational Networks , Social Trust , and Norms : A Social Capital Perspective on Students ’ Chances of Academic Success</em>. <em>25</em>(1), 59–74.</p><p>Eddy Prasongko, 2017. Team Game Tournament. Bandung. Jawa Barat</p><p>Endang Poerwanti, dkk. 2008. <em>Asesmen Pembelajaran SD.</em> Jakarta: Direktorat Jendral Pendidikan Tinggi Departemen Pendidikan Nasional</p><p>Hargreaves, A. (2015). <em>School Social Capital and School Effectiveness</em>. <em>37</em>, 119–136.</p><p>Kurnia, Inggridwati. dkk. 2018. <em>Perkembangan belajar peserta didik</em><em>.</em> Jakarta: Direktorat Jendral Pendidikan Tinggi Departemen Pendidikan Nasional</p><p>Purwanto. M Ngalim. 2015. <em>Psikologi Pendidikan</em>. Bandung: PT Remaja Rosdakarya</p><p>Siddiq, M. Djauhar. 2018. <em>Pengembangan Bahan Pembelajaran SD</em>. Jakarta: Direktorat Jendral Pendidikan Tinggi Departemen Pendidikan Nasional.</p><p>Sugiyono, 2005. Metode Penelitian Kuantitatif, Kualitatif dan Rn D, Bandung Aftabeta</p><p>Lash, D., &amp; Belfiore, G. (2017). <em>5 Essentials in Building Social Capital Report 4 of the MyWays Student Success Series</em>. (October).</p><p>Mikiewicz, P., Jonasson, J. T., Gudmundsson, G., Blondal, K. S., &amp; Korczewska, D. M. (2011). <em>Comparative research between Poland and Iceland</em>.</p><p>Schlesselman, L., Borrego, M., Bloom, T. J., Mehta, B., Drobitch, R. K., &amp; Smith, T. (2015). An Assessment Of Service-Learning In 34 US Schools Of Pharmacy Follow Up On The 2001 Professional Affairs Committee Report. <em>American Journal of Pharmaceutical Education</em>, <em>79</em>(8). https://doi.org/10.5688/ajpe798116</p><p><em><br /></em></p>


Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).


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