637 research outputs found
Module 4 - 4D Printing for Maintenance and Repair of Heritage Structures
No full textThis video workshop, published by Motlow State Community College and led by Dr. Rupinder Singh, is part of an eight-video series from the SMARTT Project. In the video, Singh outlines the National Institute of Technical Teachers Training and Research Chandigarh's modification of and advancements in 4D printing for the maintenance of significant heritage structures. Singh provides an introduction to 3D printing, outlines the basics of 4D printing, goes into further detail on programming and systems, covers the different materials in heritage structures and environmental factors, and discusses real-world applications. The video recording runs 33:30 minutes in length
Development of in-house composite wire based feed stock filaments of fused deposition modelling for wear-resistant materials and structures
No full textIn the recent past many researchers have highlighted the development of in-house filament for fused deposition modelling (FDM) in order to enhance the application domain of the process. But hither to no work has been reported on the manufacturing of wear-resistant materials and structures with hybrid feed stock filament (comprising of Nylon matrix and Al2O3 powder) from process capability point of view. The Al2O3 powder as reinforcement in Nylon-6 matrix has been, e.g., used as rapid tooling in grinding applications for dentistry. The study started with establishing a melt flow index (MFI) of the polymer matrix composite (PMC) to be used as FDM filament. Further an effort has been made to establish the selected proportions of filler, matrix (Nylon-6) and extrusion load on the MFI of reinforced FDM filament as per ASTM-D1238-95 standard. The results of study suggest that FDM process with hybrid filament lies in ±4.5sigma (σ) limit as regard to wear of rapid tooling (grinding wheel selected as a case study) is concerned. This process ensures rapid production of pre-series technological prototypes and proof of concept at less production cost and time
Appendix_Supplementary_material - On 3D-printed ZnO-reinforced PLA matrix composite: Tensile, thermal, morphological and shape memory characteristics
No full textAppendix_Supplementary_material for On 3D-printed ZnO-reinforced PLA matrix composite: Tensile, thermal, morphological and shape memory characteristics by Mohit Singh, Rupinder Singh, Ranvijay Kumar, Pawan Kumar and Pawan Preet in Journal of Thermoplastic Composite Materials</p
On the wear properties of Nylon6-SiC-Al2O3 based fused deposition modelling feed stock filament
No full textFused deposition modelling (FDM) is one of the commonly used additive manufacturing (AM) technologies. In commercial FDM setup a plastic material based filament (usually of ABS) is unwound from a coil to produce functional/non-functional prototypes. The application domain of FDM is limited presently, because of selective material availability in commercial market as regards to the wear of functional prototypes is concerned. In order to enhance the application domain of commercial FDM setup, an effort has been made to develop new polymer composite (with hybrid reinforcement) wire of Nylon6-SiC-Al2O3 with enhanced wear resistant properties. In this research work experimental investigations has been carried out for optimizing wear properties of Nylon6-SiC-Al2O3 based feed stock filament of FDM. Further mathematical model for above mentioned property has been developed and counter verified as a case study
On the additive manufacturing of an energy storage device from recycled material
No full textThe disposal/recycling of plastic materials are one of the biggest challenges of 21st century. Some studies have been reported in recent past on recycling of thermoplastics via three-dimensional (3D) printing as a novel technique under primary and secondary recycling. But hitherto no work has been reported on use of recycled/virgin thermoplastics for use as energy storage devices (ESD). In this paper an effort has been made to develop in house ESD in form of dry cell by printing with low cost fused deposition modeling (FDM) based commercial open source 3D printer. The feed stock filament of FDM has been prepared by twin screw extrusion (TSE) comprising of advanced composite materials (thermoplastic: acrylonitrile butadiene styrene (ABS) matrix, reinforced with different proportions of chemicals/salts namely: MnO2, ZnCl2, NH4Cl and graphite), which has been used to print dry cell for energy storage applications. The commercial dry cell consists of four zones/sections and feed stock filaments for three zones have been prepared separately on TSE (with different proportions of ABS and reinforcement of chemical/salts) and fourth zone (of Zn metal) has been casted with conventional sand casting route. Finally, all four zones have been assembled in series to develop fully functional prototype of ESD. This study highlights that with the proposed methodology, dry cell comprising of minimum 40% by weight recycled thermoplastics can be prepared successfully having voltage potential at par with commercial dry cell. Another major advantage of using this novel route is that the ESD prepared is more thermally stable (confirmed by differential scanning calorimetry (DSC) analysis) and can operate up to 95 °C temperature. Along with this the ESD so prepared has better rheological, mechanical properties (tensile, surface hardness) ensuring it to be useable under severe loading conditions. The results are also supported by photomicrographs
On the applicability of composite PA6-TiO2filaments for the rapid prototyping of innovative materials and structures
No full textIn the present paper a meticulous study for controlling the process parameters of twin screw extruder has been highlighted for in-house preparation of reinforced PA6-TiO2 hybrid feed stock filament (HFSF) of fused deposition modelling (FDM) for applications in several engineering fields. The experimental study has been reported for field engineers, to understand the influence of twin screw extrusion (TSE) process parameters on mechanical and metallurgical properties of Nylon-TiO2 HFSF for printing of functional prototypes by FDM, with special focus on the additive manufacturing of innovative composite materials and structures with arbitrary geometry at different scales. These properties were statistically compared to verify the suitability of the screw extrusion process. The study suggested the long-term performance level of the TSE process after it has been brought under statistical control. The provided data from the experimentation highlights the ability of the TSE process to produce a product that will consistently meet the design requirements and the customer expectation
Azerbaijan: Recent Economic Developments and Policy Issues in Sustainability of Growth
Get PDFThe macro economic stabilisation in Azerbaijan has been successful. Following cessation of conflict with Armenia, and decline of GDP by 60 per cent from 1990 to 1995, the government in effect implemented a big-bang reform process in 1995. The inflation rate has now declined to the lowest rate of any transition country and important reforms in the monetary-fiscal mix have been undertaken. The second plank of first generation reforms, liberalisation, has also been successfully implemented with liberalisation of prices, the trade and foreign exchange regimes and virtual completion of small-scale privatisation, although the onset of the Russian crisis in 1998 has impacted negatively both internal and external balances. The paper presents the current economic picture for Azerbaijan and then assesses economic policy issues facing the country. Azerbaijan is well endowed with natural resources, particularly oil but also gas. The second part of the paper considers the question by focussing on policy issues related to the potential flow of oil-based monies into Azerbaijan. The possibility of the “Dutch Disease” syndrome impacting Azerbaijan through a rising real exchange rate on the non-oil sector is not considered to be a problem at present but is expected to become a policy concern in the medium- to long term. Structural reforms in public finance to deal with expected surpluses are lagging and are necessary in the next phase of the transition of Azerbaijan. Moreover, significant reforms are required in banking – privatisation, improvement in regulation and supervision and in the implementation of supporting legal rights, given the current lack of financial intermediation.Azerbaijan; economic development; oil; Dutch Disease; transition economies
Dimensional accuracy analysis of coupled fused deposition modeling and vapour smoothing operations for biomedical applications
No full textFused Deposition Modeling (FDM) is one of the most extensively used Additive Manufacturing technique which has substantially shortened the product development time and cost. The application has been extended to fabricate biomedical implants through investment casting process. But the FDM replicas exhibit poor surface quality which requires further post finishing. Thus, it is very difficult to achieve adequate dimensional accuracy as surface finishing techniques resulted in material removal and erosion of upper surface. The vapour smoothing is an advanced finishing technique which eliminates tool-workpiece contact and yield ultra smooth finish but dimensional accuracy of FDM replicas is yet to be ascertained. In present research, the efforts are made to explore the influence of FDM and VS process parameters in dimensional features of complex designs. The influence of six parameters on radial (head diameter) and linear dimensions (neck and stem thickness) is studied using Taguchi orthogonal array. The CMM measurements showed shrinkage in head diameter while positive deviation has been observed in linear dimensions before vapour smoothing with maximum impact of orientation angle. The vapour smoothing process caused shrinkage in both linear and radial dimensions with maximum effect of smoothing time. The process parameters and their levels are optimized and confirmatory experiments indicated reduced deviations in dimensional features with consistency in IT grades
Graphene as biomedical sensing element: State of art review and potential engineering applications
No full textNano graphene (Gr) particles are of abundant methodical and scientific interest as having the astonishing prospective to usage as the sensors element in the miniaturized and biomedical sensor device. The nano Gr particles have been appeared on the life science and health platform due to their interesting material performance like; excellent biocompatibility, conductivity, super para magnetism, thermal, chemical, mechanical and metallurgical properties to use as a sensor component. In recent years, Gr as nanoparticles has acquired powerful technological and scientific attention and having potential applications like; for fabrication of super-capacitors, batteries, solar or fuel cells, miniaturized and biomedical sensors. Gr is one of the most influential nano composites with endowment of use in the sensing mechanism like; bio-sensing, bio-imaging and diagnostic of diseases due to stimulating material behavior like; biocompatibility, cell growing properties, excellent surface behavior thermally and chemically etc. The present discussion explores the state of art review and prospective of the Gr in the miniaturized and biomedical sensors. The sensing mechanism for each of the sensors has been discussed for betters understanding of the functionality and prospective of the Gr in the sensors
Investigations for Thermal and Electrical Conductivity of ABS-Graphene Blended Prototypes
Get PDFThe thermoplastic materials such as acrylonitrile-butadiene-styrene (ABS) and Nylon have large applications in three-dimensional printing of functional/non-functional prototypes. Usually
these polymer-based prototypes are lacking in thermal and electrical conductivity. Graphene (Gr) has attracted impressive enthusiasm in the recent past due to its natural mechanical, thermal, and
electrical properties. This paper presents the step by step procedure (as a case study) for development of an in-house ABS-Gr blended composite feedstock filament for fused deposition modelling (FDM)
applications. The feedstock filament has been prepared by two different methods (mechanical and chemical mixing). For mechanical mixing, a twin screw extrusion (TSE) process has been used, and
for chemical mixing, the composite of Gr in an ABS matrix has been set by chemical dissolution, followed by mechanical blending through TSE. Finally, the electrical and thermal conductivity of
functional prototypes prepared from composite feedstock filaments have been optimize
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