Sustainable material for 3d printing in Sri Lanka

3D printing has been prevailing as an efficient and sustainable technology in the fields of advanced manufacturing. The technologies, comparing to traditional manufacturing techniques which can be considered as environmental friendly derivative giving almost unlimited possibilities for geometric complexity realizations. 3D printing also has notable economic and social implications. In terms of work opportunities, it offers the potential for job creation and enhanced entrepreneurship, as well as increased efficiencies in manufacturing. There are number of materials available in 3D printing such as polymers, concrete, mud, metals, composites and etc. This study is aims to investigate about the sustainable material from industrial waste for 3D printing. The paper was discussed about the waste materials that can be used for 3D printing, their characteristics, availability and etc. The industrial waste survey was performed the all-around the Sri Lanka to identify the most suitable solid waste types for the 3D printing. Using that results, identified plastic waste and water treatment plant sludge are the most feasible materials for 3D printing in Sri Lanka. In this research, plastic waste and water treatment sludge are mixed with Portland cement to investigate the possibility to produce printer material. The experiments were done by using the waste plastics and water treatment sludge in the ratio of 4:1 for maximum properties. Within this study the applicability of industrial waste for 3D printing was proven. In addition, their density was decreased, extrudability and buildability was improved, which lead to produced lightweight material

Possibility of recycling plastics from municipal solid waste (MSW) and their potential applications in construction industry

The rate of resource consumption today is more than the rate of generation in natural resources. In developing countries, municipal solid waste (MSW) is a growing problem due to heterogeneous composition, non-biodegradability of plastic waste, lack of recycling facilities, high cost of waste collection, transportation and management and the environmental problems arising from the dumping of waste. Plastics widely used in the food packaging industry. The waste of growing plastics in urban areas presents health and environmental problems. . Construction materials play a key role in construction projects. At the moment, most of the projects focus on the development of construction materials that use waste. The objective of this article is to review the possibility of recycling the plastics that are generated in the MSW and its possible applications in the construction industry. This paper discusses the composition of MSW and plastic waste components in Sri Lanka. Primary, secondary, tertiary and quaternary technologies are considered for the recycling of plastic waste and plastic waste applications in the development of innovative construction materials. The use of municipal waste generated in Sri Lanka for the manufacture of construction materials will help reduce the problems associated with waste in the country. As a sustainable solution to this problem, the development of construction material with waste material is a possible option to address this problem. Recycling can be beneficial, since its energy efficiency reduces the waste generated, reduces the problems related to waste in the country, and studies have investigated the use of waste for construction in the industry

Probing single-unit-cell resolved electronic structure modulations in oxide superlattices with standing-wave photoemission

Control of structural coupling at complex-oxide interfaces is a powerful platform for creating ultrathin layers with electronic and magnetic properties unattainable in the bulk. However, with the capability to design and control the electronic structure of such buried layers and interfaces at a unit-cell level, a new challenge emerges to be able to probe these engineered emergent phenomena with depth-dependent atomic resolution as well as element- and orbital selectivity. Here, we utilize a combination of core-level and valence-band soft x-ray standing-wave photoemission spectroscopy, in conjunction with scanning transmission electron microscopy, to probe the depth-dependent and single-unit-cell resolved electronic structure of an isovalent manganite superlattice [Eu0.7Sr0.3MnO3/La0.7Sr0.3MnO3]×15 wherein the electronic-structural properties are intentionally modulated with depth via engineered oxygen octahedra rotations/tilts and A-site displacements. Our unit-cell resolved measurements reveal significant transformations in the local chemical and electronic valence-band states, which are consistent with the layer-resolved first-principles theoretical calculations, thus opening the door for future depth-resolved studies of a wide variety of heteroengineered material systems

Probing single-unit-cell resolved electronic structure modulations in oxide superlattices with standing-wave photoemission

Control of structural coupling at complex-oxide interfaces is a powerful platform for creating ultrathin layers with electronic and magnetic properties unattainable in the bulk. However, with the capability to design and control the electronic structure of such buried layers and interfaces at a unit-cell level, a new challenge emerges to be able to probe these engineered emergent phenomena with depth-dependent atomic resolution as well as element- and orbital selectivity. Here, we utilize a combination of core-level and valence-band soft x-ray standing-wave photoemission spectroscopy, in conjunction with scanning transmission electron microscopy, to probe the depth-dependent and single-unit-cell resolved electronic structure of an isovalent manganite superlattice [Eu0.7Sr0.3MnO3/La0.7Sr0.3MnO3]×15 wherein the electronic-structural properties are intentionally modulated with depth via engineered oxygen octahedra rotations/tilts and A-site displacements. Our unit-cell resolved measurements reveal significant transformations in the local chemical and electronic valence-band states, which are consistent with the layer-resolved first-principles theoretical calculations, thus opening the door for future depth-resolved studies of a wide variety of heteroengineered material systems

Joint Meeting of the MassDOT Board of Directors and the Fiscal and Management Control Board: Meeting Minutes (2017-05-08)

The nature of the metal-insulator transition in thin films and superlattices of LaNiO3 only a few unit cells in thickness remains elusive despite tremendous effort. Quantum confinement and epitaxial strain have been evoked as the mechanisms, although other factors such as growth-induced disorder, cation non-stoichiometry, oxygen vacancies, and substrate-film interface quality may also affect the observable properties of ultrathin films. Here we report results obtained for near-ideal LaNiO3 films with different thicknesses and terminations grown by atomic layer-by-layer laser molecular beam epitaxy on LaAlO3 substrates. We find that the room-temperature metallic behavior persists until the film thickness is reduced to an unprecedentedly small 1.5 unit cells (NiO2 termination). Electronic structure measurements using X-ray absorption spectroscopy and first-principles calculation suggest that oxygen vacancies existing in the films also contribute to the metal-insulator transition

Depth-resolved charge reconstruction at the LaNi O 3 / CaMn O 3 interface

Rational design of low-dimensional electronic phenomena at oxide interfaces is currently considered to be one of the most promising schemes for realizing new energy-efficient logic and memory devices. An atomically abrupt interface between paramagnetic LaNiO3 and antiferromagnetic CaMnO3 exhibits interfacial ferromagnetism, which can be tuned via a thickness-dependent metal-insulator transition in LaNiO3. Once fully understood, such emergent functionality could turn this archetypal Mott-interface system into a key building block for the above-mentioned future devices. Here, we use depth-resolved standing-wave photoemission spectroscopy in conjunction with scanning transmission electron microscopy and x-ray absorption spectroscopy, to demonstrate a depth-dependent charge reconstruction at the LaNiO3/CaMnO3 interface. Our measurements reveal an increased concentration of Mn3+ and Ni2+ cations at the interface, which create an electronic environment favorable for the emergence of interfacial ferromagnetism mediated via the Mn4+−Mn3+ ferromagnetic double exchange and Ni2+−O−Mn4+ superexchange mechanisms. Our findings suggest a strategy for designing functional Mott oxide heterostructures by tuning the interfacial cation characteristics via controlled manipulation of thickness, strain, and ionic defect states