Search results for: organic photovoltaic materials

Authors: Darko Babic, Maja Modric, Dario Babic, Mario Fiolic

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For road markings as a part of traffic control plan, it is considered to have a positive impact on road safety. Their importance is particularly evident in low visibility conditions when the field of vision and the driver's visual acuity are significantly reduced. The aim of this article is to analyze how road marking retroreflectivity affects the frequency of traffic accidents in low visibility conditions. For this purpose, 10,417.4 km single carriageway roads were analysed across Croatia in the period from 2012 to 2016. The research included accidents that may be significantly affected by marking retroreflectivity: head-on collisions, running off the road, hitting a stationary object on the road and hitting a stationary roadside object. The results have shown that the retroreflectivity level is negatively correlated to the total number of accidents and the number of casualties and injuries, which ultimately means that the risk of traffic accidents and deaths and/or injuries of participants will be lower with the increase of road markings retroreflectivity. These results may assist in defining minimum values of retroreflectivity that the markings must meet at any time as well as the suitable technologies and materials for their implementation.

Keywords: retroreflectivity, road markings, traffic accidents, traffic safety

Procedia PDF Downloads 136

Authors: Ella C. Linganiso, Bonex W. Mwakikunga, Trilock Singh, Sanjay Mathur, Odireleng M. Ntwaeaborwa

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The use of nanostructured semiconducting material to catalyze degradation of environmental pollutants still receives much attention to date. One of the desired characteristics for pollutant degradation under ultra-violet visible light is the materials with extended carrier charge separation that allows for electronic transfer between the catalyst and the pollutants. In this work, zinc oxide n-type semiconductor vertically aligned structures were fabricated on silicon (100) substrates using the chemical bath deposition method. The as-synthesized structures were treated with nickel and sulphur. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy were used to characterize the phase purity, structural dimensions and elemental composition of the obtained structures respectively. Photoluminescence emission measurements showed a decrease in both the near band edge emission as well as the defect band emission upon addition of nickel and sulphur with different concentrations. This was attributed to increased charger-carrier-separation due to the presence of Ni-S material on ZnO surface, which is linked to improved charge transfer during photocatalytic reactions.

Keywords: Carrier-charge-separation, nickel, photoluminescence, sulphur, zinc oxide

Procedia PDF Downloads 288

Authors: Sonny Yip Hong Choy

Abstract:

With the ubiquity of 3D printing technology in the last decade, a wide array of material choices are available for Fused Deposition Modelling (FDM) 3D printing technology. Exploration into creating printable bio-polymers has also seen progress recently in attempts to further the sustainability agenda and circular economy. By tackling waste and pollution via recycling and reusing, food by-products resulting from mass food production may see opportunities for renewed value and alternate applications through 3D printing. To date, many pure polymers, blends, as well as composites have been developed specifically for FDM printing contexts to heighten the physical performance of final printed products. This review article covers general information on various FDM printed polymers and composites while exploring experiments designed to create printable biopolymers made from reused food by-products. The biopolymer-based composites preparation is described in detail, while their advantages and disadvantages are also discussed. In addition, this article shares knowledge and highlights experimentation that aims to achieve acceptable 3D-printed biopolymer composite properties that may address the functional requirements of different application contexts. Furthermore, the article describes a brief overview of the potential applications of such bio-polymers and the future scope in this field.

Keywords: food by-products, bio-polymers, FDM, 3d printing

Procedia PDF Downloads 62

Authors: Prathmesh Vikas Patil, Yashaswini Lomte Patil

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Laminated composite materials have considerable attention in various engineering applications due to their exceptional strength-to-weight ratio and mechanical properties. The analysis of laminated composite plates in three-dimensional (3D) elasticity is a complex problem, as it requires accounting for the orthotropic anisotropic nature of the material and the interactions between multiple layers. Conventional approaches, such as the classical plate theory, provide simplified solutions but are limited in performing exact analysis of the plate. To address such a challenge, the state space method emerges as a powerful numerical technique for modeling the behavior of laminated composites in 3D. The state-space method involves transforming the governing equations of elasticity into a state-space representation, enabling the analysis of complex structural systems in a systematic manner. Here, an effort is made to perform a 3D elasticity analysis of plates with cross-ply and angle-ply laminates using the state space approach. The state space approach is used in this study as it is a mixed formulation technique that gives the displacements and stresses simultaneously with the same level of accuracy.

Keywords: cross ply laminates, angle ply laminates, state space method, three-dimensional elasticity analysis

Procedia PDF Downloads 79

Authors: Sandy Ng

Abstract:

This study explores how women asserted their identities through vanity case design that increased their visibility and affirmed their sense of self. It discusses a history of vanity case design intersected with women as agents of social changes, represented in images that express the modern lifestyle created in the twentieth century. The discussion will emphasize how consumption transformed women’s appearances and mentality and whether vanity cases mediated the ways they perceived and presented themselves. Consumption in modern material culture imparted a sense of respectability to the modern woman while she introduced modern lifestyle and good taste through creativity and specific materials in the designs she carried that redefined her social status. Visual evidence, such as advertisements and photographs, as well as designs including vanity cases and jewelry worn by women, will be examined in the context of Pierre Bourdieu’s concept of cultural capital, enhancing understanding of women’s cultural and social roles in the modern era. Creativity articulated in fashion accessories specifically designed for women was instrumental in asserting their identities and ornamentation on design served vital cultural and social functions in the modern epoch.

Keywords: creativity, design, femininity, modern women, vanity case

Procedia PDF Downloads 62

Authors: Ali Ashraf Hamedi Oghul Beyk

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This research is aimed in order to demonstrate the factors affecting on effectiveness of animal artificial insemination training courses in Zanjan province. The research method is descriptive and correlation. Research tools a questionnaire and research sample are 104 persons who participated in animal artificial insemination training courses. The data resulted from this procedure was analysed by using SPSS software under windows system.independent variables include :individual, sociological, technical, and organizational, dependent variable is: affecting factors on effectiveness of animal artificial insemination training courses the finding of this study indicates that there is a significant correlation(99/0) between individual variables such as motivation and interest and experiment and effectiveness of animal artificial insemination training courses. There is significant correlation (95/0) between sociological variables such as job and education and effectiveness of animal artificial insemination training course. There is significant correlation (99/0) between techn ical variables such as training quality media and instructional materials. Moreover, effectiveness of animal artificial insemination training course there is significant correlation(0/95) between organizational variables such as trainers combination,place conditions.

Keywords: animal artificial insemination, effect, effectiveness, training courses, Zanjan

Procedia PDF Downloads 364

Authors: Taif Rocky, Uttam Saha, Mahobul Islam

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With a rapid urbanisation in Bangladesh, waste management remains one of the core challenges. Turning municipal waste into biogas for mass usage is a solution that Bangladesh needs to adopt urgently. Practical Action with its commitment to challenging poverty with technological justice has piloted such idea in Gaibandha. The initiative received immense success and drew the attention of policy makers and practitioners. We believe, biogas from waste can highly contribute to meet the growing demand for energy in the country at present and in the future. Practical Action has field based experience in promoting small scale and innovative technologies. We have proven track record in integrated solid waste management. We further utilized this experience to promote waste to biogas at end users’ level. In 2011, we have piloted a project on waste to biogas in Gaibandha, a northern secondary town of Bangladesh. With resource and support from UNICEF and with our own innovative funds we have established a complete chain of utilizing waste to the renewable energy source and organic fertilizer. Biogas is produced from municipal solid waste, which is properly collected, transported and segregated by private entrepreneurs. The project has two major focuses, diversification of biogas end use and establishing a public-private partnership business model. The project benefits include Recycling of Wastes, Improved institutional (municipal) capacity, Livelihood from improved services and Direct Income from the project. Project risks include Change of municipal leadership, Traditional mindset, Access to decision making, Land availability. We have observed several outcomes from the initiative. Up scaling such an initiative will certainly contribute for sustainable cleaner and healthier urban environment and urban poverty reduction. - It reduces the unsafe disposal of wastes which improve the cleanliness and environment of the town. -Make drainage system effective reducing the adverse impact of water logging or flooding. -Improve public health from better management of wastes. -Promotes usage of biogas replacing the use of firewood/coal which creates smoke and indoor air pollution in kitchens which have long term impact on health of women and children. -Reduce the greenhouse gas emission from the anaerobic recycling of wastes and contributes to sustainable urban environment. -Promote the concept of agroecology from the uses of bio slurry/compost which contributes to food security. -Creates green jobs from waste value chain which impacts on poverty alleviation of urban extreme poor. -Improve municipal governance from inclusive waste services and functional partnership with private sectors. -Contribute to the implementation of 3R (Reduce, Reuse, Recycle) Strategy and Employment Creation of extreme poor to achieve the target set in Vision 2021 by Government of Bangladesh.

Keywords: kitchen waste, secondary town, biogas, segregation

Procedia PDF Downloads 204

Authors: Elnaz Dabiri, Somayeh Hamidnezhad

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Background and Objective: This study aims at investigating the effect of whole word method on Mean Length of Utterance (MLU) of 3 to 6 years old children with cochlear implants having normal IQ. Materials and Methods: In this quasi-experimental and interventional study, 20 children with cochlear implants, aged between 3and 6 years, and normal IQ were selected from Tabriz cochlear implants center using convenience sampling. Afterward, they were randomly bifurcated. The first group was educated by whole-word reading method along with traditional methods and the second group by traditional methods. Both groups had three sessions of 45-minutes each, every week continuously for a period of 3 months. Pre-test and post-test language abilities of both groups were assessed using the TOLD test. Results: Both groups before training have the same age, IQ, and MLU, but after training the first group shows a considerable improvement in MLU in comparison with the second group. Conclusions: Reading training by the whole word method have more effect on MLU of children with cochlear implants in comparison of the traditional method.

Keywords: cochlear implants, reading training, traditional methods, language therapy, whole word method, Mean Length of Utterance (MLU)

Procedia PDF Downloads 320

Authors: Benallou Yassine, Amara Kadda, Bouazza Boubakar, Soudini Belabbes, Arbouche Omar, M. Zemouli

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The study of the pressure effect on the materials, their functionality and their properties is very important, insofar as it provides the opportunity to identify others applications such the optical properties in the alkaline earth chalcogenides, as like the SrS. Here we present the first-principles calculations which have been performed using the full potential linearized augmented plane wave method (FP-LAPW) within the Generalized Gradient Approximation developed by Perdew–Burke–Ernzerhor for solids (PBEsol). The calculated structural parameters like the lattice parameters, the bulk modulus B and their pressure derivative B' are in reasonable agreement with the available experimental and theoretical data. In addition, the elastic properties such as elastic constants (C11, C12, and C44), the shear modulus G, the Young modulus E, the Poisson’s ratio ν and the B/G ratio are also given. The treatments of exchange and correlation effects were done by the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential for the electronic. The pressure effect on the electronic properties was visualized by calculating the variations of the gap as a function of pressure. The obtained results are compared to available experimental data and to other theoretical calculations

Keywords: SrS, GGA-PBEsol+TB-MBJ, density functional, Perdew–Burke–Ernzerhor, FP-LAPW, pressure effect

Procedia PDF Downloads 549

Authors: Faci Youcef, Ahmed Mebtouche, Djillali Allou, Maalem Badredine

Abstract:

The inclination of the bolt in a fastened joint of composite material during a tensile test can be influenced by several parameters, including material properties, bolt diameter and length, the type of composite material being used, the size and dimensions of the bolt, bolt preload, surface preparation, the design and configuration of the joint, and finally testing conditions. These parameters should be carefully considered and controlled to ensure accurate and reliable results during tensile testing of composite materials with fastened joints. Our work focuses on the effect of the stacking sequence and the geometry of specimens. An experimental test is carried out to obtain the inclination of a bolt during a tensile test of a composite material using acoustic emission and digital image correlation. Several types of damage were obtained during the load. Digital image correlation techniques permit the obtaining of the inclination of bolt angle value during tensile test. We concluded that the inclination of the bolt during a tensile test of a composite material can be related to the damage that occurs in the material. It can cause stress concentrations and localized deformation in the material, leading to damage such as delamination, fiber breakage, matrix cracking, and other forms of failure.

Keywords: damage, inclination, analyzed, carbon

Procedia PDF Downloads 40

Authors: C. P. Providakis, G. M. Angeli, M. J. Favvata, N. A. Papadopoulos, C. E. Chalioris, C. G. Karayannis

Abstract:

An effort for the detection of damages in the reinforcement bars of reinforced concrete members using PZTs is presented. The damage can be the result of excessive elongation of the steel bar due to steel yielding or due to local steel corrosion. In both cases the damage is simulated by considering reduced diameter of the rebar along the damaged part of its length. An integration approach based on both electromechanical admittance methodology and guided wave propagation technique is used to evaluate the artificial damage on the examined longitudinal steel bar. Two actuator PZTs and a sensor PZT are considered to be bonded on the examined steel bar. The admittance of the Sensor PZT is calculated using COMSOL 3.4a. Fast Furrier Transformation for a better evaluation of the results is employed. An effort for the quantification of the damage detection using the root mean square deviation (RMSD) between the healthy condition and damage state of the sensor PZT is attempted. The numerical value of the RSMD yields a level for the difference between the healthy and the damaged admittance computation indicating this way the presence of damage in the structure. Experimental measurements are also presented.

Keywords: concrete reinforcement, damage detection, electromechanical admittance, experimental measurements, finite element method, guided waves, PZT

Procedia PDF Downloads 237

Authors: Konstantinos G. Dassios, Guillaume Bonnefont, Gilbert Fantozzi, Theodore E. Matikas, Costas Galiotis

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We report herein the development and preliminary mechanical characterization of fully-dense multi-wall carbon nanotube (MWCNT)-reinforced ceramics and glasses based on a completely new methodology termed High Shear Compaction (HSC). The tubes are introduced and bound to the matrix grains by aid of polymeric binders to form flexible green bodies which are sintered and densified by spark plasma sintering to unprecedentedly high densities of 100% of the pure-matrix value. The strategy was validated across a PyrexTM glass / MWCNT composite while no identifiable factors limit application to other types of matrices. Non-destructive evaluation, based on ultrasonics, of the dynamic mechanical properties of the materials including elastic, shear and bulk modulus as well as Poisson’s ratio showed optimum property improvement at 0.5 %wt tube loading while evidence of nanoscale-specific energy dissipative characteristics acting complementary to nanotube bridging and pull-out indicate a high potential in a wide range of reinforcing and multifunctional applications.

Keywords: ceramic matrix composites, carbon nanotubes, toughening, ultrasonics

Procedia PDF Downloads 354

Authors: Shalini Rajput, Dinesh Mohan

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Water is the most important and essential resources for existing of life on the earth. Water quality is gradually decreasing due to increasing urbanization and industrialization and various other developmental activities. It can pose a threat to the environment and public health therefore it is necessary to remove hazardous contaminants from wastewater prior to its discharge to the environment. Recently, magnetic iron oxide nanoparticles have been arise as significant materials due to its distinct properties. This article focuses on the synthesis method with a possible mechanism, structure and application of magnetic iron oxide nanoparticles. The various characterization techniques including X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray, Fourier transform infrared spectroscopy and vibrating sample magnetometer are useful to describe the physico-chemical properties of nanoparticles. Nanosized iron oxide particles utilized for remediation of contaminants from aqueous medium through adsorption process. Due to magnetic properties, nanoparticles can be easily separate from aqueous media. Considering the importance and emerging trend of nanotechnology, iron oxide nanoparticles as nano-adsorbent can be of great importance in the field of wastewater treatment.

Keywords: nanoparticles, adsorption, iron oxide, nanotechnology

Procedia PDF Downloads 541

Authors: Ye Ling, Jiang Yuting, Ruan Haihui

Abstract:

Zinc ion capacitors (ZICs) have garnered tremendous interest recently from researchers due to the perfect integration of batteries and supercapacitors (SC). However, ZICs are currently still facing two major challenges, one is low specific capacitance because of the limited capacity of capacitive cathode materials. In this work, TiN/CNC composites were obtained by a creative method composed of simple mixing and calcination treatment of tetrabutyl titanate (TBOT) and ZIF-8. The formed TiN particles are of ultra-small size and distributed uniformly on the nanoporous carbon matrix, which enhances the conductivity of the composites and the micropores caused by the evaporation of zinc during the calcination process and can serve as the reservoir of electrolytes; both are beneficial to zinc ion storage. When it was used as a cathode with zinc metal and 2M ZnSO₄ as the anode and electrolyte, respectively, in a ZIC device, the assembled device delivered a maximum energy density as high as 153 Wh kg-¹ at a power density of 269.4 W kg-¹, which is superior to many ZICs as reported. Also, it can maintain an energy density of 83.7 Wh kg-¹ at a peak power density of 8.6 kW kg-¹, exhibiting good rate performance. Moreover, when it was charged/discharged for 5000 cycles at a current density of 5 A g-¹, it remained at 85.8% of the initial capacity with a Coulombic efficiency (CE) of nearly 100%.

Keywords: zinc ion capacitor, metal nitride, zif-8, supercapacitor

Procedia PDF Downloads 21

Authors: H. A. J. Nguyen, V. A. Pham

Abstract:

RE:SOUNDING is an ongoing research project and artwork seeking to return the sound and knowledge of Dong Son bronze drums back to contemporary musicians. Colonial collections of ethnographic instruments are problematic in how they commit acts of conceptual, cultural, and acoustic silencing. The collection (or more honestly), the plagiarism, and pillaging of these instruments have systemically separated them from living and breathing cultures. This includes diasporic communities, who have come to resettle in close proximity - but still have little access - to the museums and galleries that display their cultural objects. Despite recent attempts to 'open up' and 'recognise' the tensions and violence of these ethnographic collections, many museums continue to structurally organize and reproduce knowledge with the same procedural distance and limitations of imperial condescension. Impatient with the slowness of these museums, our diaspora led collaborations participated in the opaque economy of the auction market to gain access and begin the process of digitally recording and archiving the actual sounds of the ancient Dong Son drum. This self-directed, self-initiated artwork not only acoustically reinvigorated an ancient instrument but redistributed these sonic materials back to contemporary musicians, composers, and their diasporic communities throughout Vietnam, South East Asia, and Australia. Our methodologies not only highlight the persistent inflexibility of museum infrastructures but demand that museums refrain from their paternalistic practice of risk-averse ownership, to seriously engage with new technologies and political formations that require all public institutions to be held accountable for the ethical and intellectual viability of their colonial collections. The integrated and practical resolve of diasporic artists and their communities are more than capable of working with new technologies to reclaim and reinvigorate what is culturally and spiritually theirs. The motivation to rematriate – as opposed to merely repatriate – the acoustic legacies of these instruments to contemporary musicians and artists is a new model for decolonial and restorative practices. Exposing the inadequacies of western scholarship that continues to treat these instruments as discreet, disembodied, and detached artifacts, these collaborative strategies have thus far produced a wealth of new knowledge – new to the west perhaps – but not that new to these, our own communities. This includes the little-acknowledged fact that the Dong Son drum were political instruments of war and technology, rather than their simplistic description in the museum and western academia as agrarian instruments of fertility and harvest. Through the collective and continued sharing of knowledge and sound materials produced from this research, these drums are gaining a contemporary relevance beyond the cultural silencing of the museum display cabinet. Acknowledgement: We acknowledge the Wurundjeri and Boon Wurrung of the Kulin Nation and the Gadigal of the Eora Nation where we began this project. We pay our respects to the Peoples, Lands, Traditional Custodians, Practices, and Creator Ancestors of these Great Nations, as well as those First Nations peoples throughout Australia, Vietnam, and Indonesia, where this research continues, and upon whose stolen lands and waterways were never ceded.

Keywords: acoustic archaeology, decolonisation, museum collections, rematriation, repatriation, Dong Son, experimental music, digital recording

Procedia PDF Downloads 125

Authors: Abdulmajeed Dabwan, Saqib Anwar, Ali Al-Samhan

Abstract:

Electron Beam Melting (EBM) is a metal powder bed-based Additive Manufacturing (AM) technology, which uses computer-controlled electron beams to create fully dense three-dimensional near-net-shaped parts from metal powder. It gives the ability to produce any complex parts directly from a computer-aided design (CAD) model without tools and dies, and with a variety of materials. However, the quality of the surface finish in EBM process has limitations to meeting the performance requirements of additively manufactured components. The aim of this study is to investigate the cutting forces induced during milling Ti6Al4V produced by EBM as well as the surface quality of the milled surfaces. The effects of cutting speed and radial depth of cut on the cutting forces, surface roughness, and surface morphology were investigated. The results indicated that the cutting speed was found to be proportional to the resultant cutting force at any cutting conditions while the surface roughness improved significantly with the increase in cutting speed and radial depth of cut.

Keywords: electron beam melting, additive manufacturing, Ti6Al4V, surface morphology

Procedia PDF Downloads 97

Authors: C. P. Providakis, G. M. Angeli, M. J. Favvata, N. A. Papadopoulos, C. E. Chalioris, C. G. Karayannis

Abstract:

An effort for the detection of damages in the reinforcement bars of reinforced concrete members using PZTs is presented. The damage can be the result of excessive elongation of the steel bar due to steel yielding or due to local steel corrosion. In both cases the damage is simulated by considering reduced diameter of the rebar along the damaged part of its length. An integration approach based on both electro-mechanical admittance methodology and guided wave propagation technique is used to evaluate the artificial damage on the examined longitudinal steel bar. Two actuator PZTs and a sensor PZT are considered to be bonded on the examined steel bar. The admittance of the Sensor PZT is calculated using COMSOL 3.4a. Fast Furrier Transformation for a better evaluation of the results is employed. An effort for the quantification of the damage detection using the root mean square deviation (RMSD) between the healthy condition and damage state of the sensor PZT is attempted. The numerical value of the RSMD yields a level for the difference between the healthy and the damaged admittance computation indicating this way the presence of damage in the structure. Experimental measurements are also presented.

Keywords: concrete reinforcement, damage detection, electromechanical admittance, experimental measurements, finite element method, guided waves, PZT

Procedia PDF Downloads 274

Authors: Lenka Morávková, Zuzana Sedláková, Jiří Vejražka, Věra Jandová, Pavel Izák

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The need to minimize the costs of biogas upgrading leads to a continuous search for new and more effective membrane materials. The improvement of biogas combustion efficiency is connected with polar gases removal from a feed stream. One of the possibilities is the use of water–swollen polyamide layer of thin film composite reverse osmosis membrane for simultaneous carbon dioxide and hydrogen sulphide removal. Transport properties and basic characteristics of a thin film composite membrane were compared in the term of appropriate water-swollen membrane choice for biogas upgrading. SEM analysis showed that the surface of the best performing composites changed significantly upon swelling by water. The surface changes were found to be a proof that the selective skin polyamide layer was swollen well. Further, the presence of a sufficient number of associative centers, namely amido groups, inside the upper layer of the hydrophilic thin composite membrane can play an important role in the polar gas separation from a non-polar gas. The next key factor is a high porosity of the membrane support.

Keywords: biogas upgrading, carbon dioxide separation, hydrogen sulphide separation, water-swollen membrane

Procedia PDF Downloads 327

Authors: Mohammed Berka, Khaled Merit

Abstract:

Recent works on microwave filters show that the constituent materials such filters are very important in the design and realization. Several solutions have been proposed to improve the qualities of filtering. In this paper, we propose a new dual band-pass filter based on the coupling of a composite (CRLH) coplanar waveguide with complementary split ring resonators (CSRRs). The (CRLH) CPW is composed of two resonators, each one has an interdigital capacitor (CID) and two short-circuited stubs parallel to top ground plane. On the lower ground plane, we use defected ground structure technology (DGS) to engrave two (CSRRs) offered with different shapes and dimensions. Between the top ground plane and the substrate, we place a ferrite layer to control the electromagnetic coupling between (CRLH) CPW and (CSRRs). The global filter that has coplanar access will have a dual band-pass behavior around the magnetic resonances of (CSRRs). Since there’s no scientific or experimental result in the literature for this kind of complicated structure, it was necessary to perform simulation using HFSS Ansoft designer.

Keywords: complementary split ring resonators, coplanar waveguide, ferrite, filter, stub.

Procedia PDF Downloads 389

Authors: Natia Jalagonia, Tinatin Kuchukhidze

Abstract:

Polymer electrolytes (PE) play an important part in electrochemical devices such as batteries and fuel cells. To achieve optimal performance, the PE must maintain a high ionic conductivity and mechanical stability at both high and low relative humidity. The polymer electrolyte also needs to have excellent chemical stability for long and robustness. According to the prevailing theory, ionic conduction in polymer electrolytes is facilitated by the large-scale segmental motion of the polymer backbone, and primarily occurs in the amorphous regions of the polymer electrolyte. Crystallinity restricts polymer backbone segmental motion and significantly reduces conductivity. Consequently, polymer electrolytes with high conductivity at room temperature have been sought through polymers which have highly flexible backbones and have largely amorphous morphology. The interest in polymer electrolytes was increased also by potential applications of solid polymer electrolytes in high energy density solid state batteries, gas sensors and electrochromic windows. Conductivity of 10-3 S/cm is commonly regarded as a necessary minimum value for practical applications in batteries. At present, polyethylene oxide (PEO)-based systems are most thoroughly investigated, reaching room temperature conductivities of 10-7 S/cm in some cross-linked salt in polymer systems based on amorphous PEO-polypropylene oxide copolymers.. It is widely accepted that amorphous polymers with low glass transition temperatures Tg and a high segmental mobility are important prerequisites for high ionic conductivities. Another necessary condition for high ionic conductivity is a high salt solubility in the polymer, which is most often achieved by donors such as ether oxygen or imide groups on the main chain or on the side groups of the PE. It is well established also that lithium ion coordination takes place predominantly in the amorphous domain, and that the segmental mobility of the polymer is an important factor in determining the ionic mobility. Great attention was pointed to PEO-based amorphous electrolyte obtained by synthesis of comb-like polymers, by attaching short ethylene oxide unit sequences to an existing amorphous polymer backbone. The aim of presented work is to obtain of solid polymer electrolyte membranes using PMHS as a matrix. For this purpose the hydrosilylation reactions of α,ω-bis(trimethylsiloxy)methyl¬hydrosiloxane with allyl triethylene-glycol mo¬nomethyl ether and vinyltriethoxysilane at 1:28:7 ratio of initial com¬pounds in the presence of Karstedt’s catalyst, platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon catalyst in 50% solution of anhydrous toluene have been studied. The synthesized olygomers are vitreous liquid products, which are well soluble in organic solvents with specific viscosity ηsp ≈ 0.05 - 0.06. The synthesized olygomers were analysed with FTIR, 1H, 13C, 29Si NMR spectroscopy. Synthesized polysiloxanes were investigated with wide-angle X-ray, gel-permeation chromatography, and DSC analyses. Via sol-gel processes of doped with lithium trifluoromethylsulfonate (triflate) or lithium bis¬(trifluoromethylsulfonyl)¬imide polymer systems solid polymer electrolyte membranes have been obtained. The dependence of ionic conductivity as a function of temperature and salt concentration was investigated and the activation energies of conductivity for all obtained compounds are calculated

Keywords: synthesis, PMHS, membrane, electrolyte

Procedia PDF Downloads 236

Authors: B. Kahouadji, L. Guerbous, L. Lamiri, A. Mendoud

Abstract:

Recently, nanomaterials are developed in the form of nano-films, nano-crystals and nano-pores. Lanthanide phosphates as a material find extensive application as laser, ceramic, sensor, phosphor, and also in optoelectronics, medical and biological labels, solar cells and light sources. Among the different kinds of rare-earth orthophosphates, yttrium orthophosphate has been shown to be an efficient host lattice for rare earth activator ions, which have become a research focus because of their important role in the field of light display systems, lasers, and optoelectronic devices. It is in this context that the 4fn- « 4fn-1 5d transitions of rare earth in insulating materials, lying in the UV and VUV, are the aim of large number of studies .Though there has been a few reports on Eu3+, Nd3+, Pr3+,Er3+, Ce3+, Tm3+ doped YPO4. The 4fn- « 4fn-1 5d transitions of the rare earth dependent to the host-matrix, several matrices ions were used to study these transitions, in this work we are suggesting to study on a very specific class of inorganic material that are orthophosphate doped with rare earth ions. This study focused on the effect of Ce3+ concentration on the structural and optical properties of Ce3+ doped YPO4 yttrium orthophosphate with powder form prepared by the Sol Gel method.

Keywords: YPO4, Ce3+, 4fn- <->4fn-1 5d transitions, scintillator

Procedia PDF Downloads 325

Authors: Mojtaba Ghodsi, Hamidreza Ziaifar, Morteza Mohammadzaheri, Payam Soltani

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This article presents an analytical model to estimate the harvested power from a Magnetostrictive cantilevered beam with tip excitation. Furthermore, the effects of internal and external damping on harvested power are investigated. The magnetostrictive material in this harvester is Galfenol. In comparison to other popular smart materials like Terfenol-D, Galfenol has higher strength and machinability. In this article, first, a mechanical model of the Euler-Bernoulli beam is employed to calculate the deflection of the harvester. Then, the magneto-mechanical equation of Galfenol is combined with Faraday's law to calculate the generated voltage of the Magnetostrictive cantilevered beam harvester. Finally, the beam model is incorporated in the aforementioned combination. The results show that a 30×8.5×1 mm Galfenol cantilever beam harvester with 80 turn pickup coil can generate up to 3.7 mV and 9 mW. Furthermore, sensitivity analysis made by Response Surface Method (RSM) shows that the harvested power is only sensitive to the internal damping coefficient.

Keywords: internal damping coefficient, external damping coefficient, euler-bernoulli, energy harvester, galfenol, magnetostrictive, response surface method

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Authors: Andrea Scapolo, Zaya Rustamova, Arturo Matute Castro

Abstract:

The “Voices in Dissent” initiative aims at collecting and making available in a digital format, testimonies, letters, and other narratives produced by victims of political oppression from different geographical spaces across the Atlantic. By recovering silenced voices behind the official narratives, this open-access online database will provide indispensable tools for rewriting the history of authoritarian regimes from the margins as memory debates continue to provoke controversy among academic and popular transnational circles. In providing an extensive database of non-hegemonic discourses in a variety of political and social contexts, the project will complement the existing European and Latin-American studies, and invite further interdisciplinary and trans-national research. This digital resource will be available to academic communities and the general audience and will be organized geographically and chronologically. “Voices in Dissent” will offer a first comprehensive study of these personal accounts of persecution and repression against determined historical backgrounds and their impact on collective memory formation in contemporary societies. The digitalization of these texts will allow to run metadata analyses and adopt comparatist approaches for a broad range of research endeavors. Most of the testimonies included in our archive are testimonies of trauma: the trauma of exile, imprisonment, torture, humiliation, censorship. The research on trauma has now reached critical mass and offers a broad spectrum of critical perspectives. By putting together testimonies from different geographical and historical contexts, our project will provide readers and scholars with an extraordinary opportunity to investigate how culture shapes individual and collective memories and provides or denies resources to make sense and cope with the trauma. For scholars dealing with the epistemological and rhetorical analysis of testimonies, an online open-access archive will prove particularly beneficial to test theories on truth status and the formation of belief as well as to study the articulation of discourse. An important aspect of this project is also its pedagogical applications since it will contribute to the creation of Open Educational Resources (OER) to support students and educators worldwide. Through collaborations with our Library System, the archive will form part of the Digital Commons database. The texts collected in this online archive will be made available in the original languages as well as in English translation. They will be accompanied by a critical apparatus that will contextualize them historically by providing relevant background information and bibliographical references. All these materials can serve as a springboard for a broad variety of educational projects and classroom activities. They can also be used to design specific content courses or modules. In conclusion, the desirable outcomes of the “Voices in Dissent” project are: 1. the collections and digitalization of political dissent testimonies; 2. the building of a network of scholars, educators, and learners involved in the design, development, and sustainability of the digital archive; 3. the integration of the content of the archive in both research and teaching endeavors, such as publication of scholarly articles, design of new upper-level courses, and integration of the materials in existing courses.

Keywords: digital archive, dissent, open educational resources, testimonies, transatlantic studies

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Authors: Tarikayehu Amanuel, Abraham Mohammed

Abstract:

The production of biodiesel from waste materials is becoming an increasingly important research area in the field of renewable energy. One potential waste material source is avocado, a fruit with a large seed and peel that are typically discarded after consumption. This research aims to investigate the feasibility of using avocado waste as a feedstock for the production of biodiesel. The study focuses on extracting oil from the waste material using the transesterification technique and then characterizing the properties of oil to determine its suitability for conversion to biodiesel. The study was conducted experimentally, and a maximum oil yield of 11.583% (150g of oil produced from 1.295kg of avocado waste powder) was obtained from avocado waste powder at an extraction time of 4hr. An 87% fatty acid methyl ester (biodiesel) conversion was also obtained using a methanol/oil ratio of 6:1, 1.3g NaOH, reaction time 60min, and 65°C reaction temperature. Furthermore, from 145 ml of avocado waste oil, 126.15 ml of biodiesel was produced, indicating a high percentage of conversion (87%). Conclusively, the produced biodiesel showed comparable physical and chemical characteristics to that of standard biodiesel samples considered for the study. The results of this research could help to identify a new source of biofuel production while also addressing the issue of waste disposal in the food industry.

Keywords: biodiesel, avocado, transesterification, soxhlet extraction

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Authors: Kamil Dydek, Szymon Demski, Kamil Majchrowicz, Paulina Kozera, Bogna Sztorch, Dariusz Brząkalski, Zuzanna Krawczyk, Robert Przekop, Anna Boczkowska

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Thanks to their excellent properties, i.e. high stiffness and strength in relation to their weight, corrosion resistance, and low thermal expansion, Carbon Fiber Reinforced Polymers (CFRPs) are a group of materials readily used in many industrial sectors, e.g. aviation, automotive, wind energy. Conventional CFRPs also have their disadvantages, namely, relatively low electrical conductivity and brittle cracking. To counteract this, a thermoplastic acrylic resin was proposed, which was further modified by the addition of organosilicon compounds and multi-walled carbon nanotubes (MWCNTs). The addition of the organosilicon compounds was aimed at improving the dispersion of the MWCNTs and obtaining good adhesion between the resin and the carbon fibre, where the MWCNTs were used as a conductive filler. In addition, during the fabrication of laminates using the infusion method, thermoplastic nonwovens doped with MWCNTs were placed between the carbon reinforcement layers to achieve a synergistic effect with an increase in electrical and mechanical properties.

Keywords: CFRP, acrylic resin, organosilicon compounds, mechanical properties, electrical properties

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Authors: Khaled Own Mohaisen, Md. Hasan Zahir, Salah U. Al-Dulaijan, Shamsad Ahmad, Mohammed Maslehuddin

Abstract:

Shape-stabilized phase change materials (ss-PCMs) for energy storage systems were developed using perlite, scoria, and oil ash as a carrier, with polyethylene glycol (PEG) with a molecular weight of 6000 as phase change material (PCM). Physical mixing using simple impregnation of ethanol evaporation technique method was carried out to fabricate the form stabilized PCM. The fabricated PCMs prevent leakage, reduce the supercooling effect and minimize recalescence problems of the PCM. The differential scanning calorimetry (DSC) results show that perlite composite (ExPP) has the highest latent heat of melting and freezing values of (141.6 J/g and 143.7 J/g) respectively, compared with oil ash (OAP) and scoria (SCP) composites. Moreover, ExPP has the highest impregnation ratio, energy storage efficiency, and energy storage capacity compared with OAP and SCP. However, OAP and SCP have higher thermal conductivity values compared to ExPP composites which accelerate the thermal storage response in the composite. These results were confirmed with DSC, and the characteristic of the PCMs was investigated by using XRD and FE-SEM techniques.

Keywords: expanded perlite, oil ash, scoria, energy storage material

Procedia PDF Downloads 63

Authors: Somayeh Khanjani, Hamideh Abolghasemi, Hadi Shirzad, Samaneh Nabavi

Abstract:

At world market can be currently encountered a wide range of gemological objects that are incorrectly declared, treated, or it concerns completely different materials that try to copy precious objects more or less successfully. Counterfeiting of precious commodities is a problem faced by governments in most countries. Police have seized many counterfeit coins that looked like the real coins and because the feeling to the touch and the weight were very similar to those of real coins. Most people were fooled and believed that the counterfeit coins were real ones. These counterfeit coins may have been made by big criminal organizations. To elucidate the manufacturing process, not only the quantitative analysis of the coins but also the comparison of their morphological characteristics was necessary. Several modern techniques have been applied to prevent counterfeiting of coins. The objective of this study was to demonstrate the potential of X-ray Fluorescence (XRF) technique and the other analytical techniques for example SEM/EDX/WDX, FT-IR/ATR and Raman Spectroscopy. Using four elements (Cu, Ag, Au and Zn) and obtaining XRF for several samples, they could be discriminated. XRF technique and SEM/EDX/WDX are used for study of chemical composition. XRF analyzers provide a fast, accurate, nondestructive method to test the purity and chemistry of all precious metals. XRF is a very promising technique for rapid and non destructive counterfeit coins identification in forensic science.

Keywords: counterfeit coins, X-ray fluorescence, forensic, FT-IR

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Authors: Manoj Kumar Gupta, Jayashree Bijwe

Abstract:

Additives in lubricating oils are the focus of research attention since the further reduction in friction and wear properties of oils would lead to the further saving of tribo-materials and energy apart from improving their efficiency. Remarkable tribo-performance enhancement is reported in the literature due to addition of particles of solid lubricants in lubricating oils; especially that of nano-sizes. In the present work graphite nano-particles (NPs) in various amounts (1, 2, 3 and 4 wt. %) were used to explore the possible anti-wear (AW) performance enhancement in Group III oil. Polyisobutylene succinimide (PIBSI- 1 wt. %) was used as a dispersant for dispersing these NPs and to enhance the stability of these nano-suspensions. It was observed that PIBSI inclusion enhanced the stability of oil almost by eight times. NPs in all amounts enhanced the AW performance of oil considerably. The optimum amount was three wt. %, which led to the highest enhancement under all loads. The extent of benefits, however, were dependent on load. At the lowest (392 N) and highest loads (784 N), the benefits were not profound. At moderate load (588 N), highest improvement (around 60 %) was recorded. The SEM and AFM studies were done on the worn ball surfaces to reveal the detailed features of films transferred and proved useful to correlate the wear performance of oils.

Keywords: dispersant, graphite, nano-lubricant, anti-wear additive

Procedia PDF Downloads 143

Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Zhifeng Hao, Xiang Chen

Abstract:

After the prohibition of tin-based fouling-prevention coatings in 2003, the researchers were directed toward eco-friendly coatings. Because of their nonstick, environmental, and economic benefits, foul-release nanocoatings have received a lot of attention. They use physical anti-adhesion terminology to deter any fouling attachment.Natural bioinspired surfaces have micro/nano-roughness and low surface free energy features, which may inspire the design of dynamic antifouling coatings. Graphene-based nanocomposite surfaces were designed to combat marine-fouling adhesion with ecological as well as eco-friendly effects rather than biocidal solutions. Polymer–graphenenanofiller hybrids are a novel class of composite materials in fouling-prevention applications. The controlled preparation of nanoscale orientation, arrangement, and direction along the composite building blocks would result in superior fouling prohibition. This work representsfoul-release nanocomposite top coats for marine coating applications with superhydrophobicity, surface inertness against fouling adherence, cost-effectiveness, and increased lifetime.

Keywords: foul-release nanocoatings, graphene-based nanocomposite, polymer, nanofillers

Procedia PDF Downloads 116

Authors: Elena A. Outkina, Marina V. Meledina, Aliaksandr A. Khodin

Abstract:

Nanostructured thin films of SnSₓ, Cu₂ZnSnS₄ (CZTS) semiconductors were fabricated by chemical processing to produce thin-film photoactive layers for photocells as a prospective lowest-cost and environment-friendly alternative to Si, Cu(In, Ga)Se₂, and other traditional solar cells materials. To produce SnSₓ layers, the modified successive ionic layer adsorption and reaction (SILAR) technique were investigated, including successive cyclic dipping into Na₂S solution and SnCl₂, NaCl, triethanolamine solution. To fabricate CZTS layers, the cyclic dipping into CuSO₄ with ZnSO₄, SnCl₂, and Na₂S solutions was used with intermediate rinsing in distilled water. The nano-template aluminum/alumina substrate was used to control deposition processes. Micromorphology and optical characteristics of the fabricated layers have been investigated. Analysis of 2D-like layers deposition features using nano-template substrate is presented, including the effect of nanotips in a template on surface charge redistribution and transport.

Keywords: kesterite, nanotemplate, SILAR, solar cell, tin sulphide

Procedia PDF Downloads 123