Search results for: short fiber composites
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4893

Search results for: short fiber composites

3933 Physico-Mechanical Properties of Wood-Plastic Composites Produced from Polyethylene Terephthalate Plastic Bottle Wastes and Sawdust of Three Tropical Hardwood Species

Authors: Amos Olajide Oluyege, Akpanobong Akpan Ekong, Emmanuel Uchechukwu Opara, Sunday Adeniyi Adedutan, Joseph Adeola Fuwape, Olawale John Olukunle

Abstract:

This study was carried out to evaluate the influence of wood species and wood plastic ratio on the physical and mechanical properties of wood plastic composites (WPCs) produced from polyethylene terephthalate (PET) plastic bottle wastes and sawdust from three hardwood species, namely, Terminalia superba, Gmelina arborea, and Ceiba pentandra. The experimental WPCs were prepared from sawdust particle size classes of ≤ 0.5, 0.5 – 1.0, and 1.0 – 2.0 mm at wood/plastic ratios of 40:60, 50:50 and 60:40 (percentage by weight). The WPCs for each study variable combination were prepared in 3 replicates and laid out in a randomized complete block design (RCBD). The physical properties investigated water absorption (WA), linear expansion (LE) and thickness swelling (TS) while the mechanical properties evaluated were Modulus of Elasticity (MOE) and Modulus of Rupture (MOR). The mean values for WA, LE and TS ranged from 1.07 to 34.04, 0.11 to 1.76 and 0.11 to 4.05 %, respectively. The mean values of the three physical properties increased with decrease in wood plastic ratio. Wood plastic ratio of 40:60 at each particle size class generally resulted in the lowest values while wood plastic ratio of 60:40 had the highest values for each of the three species. For each of the physical properties, T. superba had the least mean values followed by G. arborea, while the highest values were observed C. pentandra. The mean values for MOE and MOR ranged from 458.17 to 1875.67 and 2.64 to 18.39 N/mm2, respectively. The mean values of the two mechanical properties decreased with increase in wood plastic ratio. Wood plastic ratio of 40:60 at each wood particle size class generally had the highest values while wood plastic ratio of 60:40 had the least values for each of the three species. For each of the mechanical properties, C. pentandra had the highest mean values followed by G. arborea, while the least values were observed T. superba. There were improvements in both the physical and mechanical properties due to decrease in sawdust particle size class with the particle size class of ≤ 0.5 mm giving the best result. The results of the Analysis of variance revealed significant (P < 0.05) effects of the three study variables – wood species, sawdust particle size class and wood/plastic ratio on all the physical and mechanical properties of the WPCs. It can be concluded from the results of this study that wood plastic composites from sawdust particle size ≤ 0.5 and PET plastic bottle wastes with acceptable physical and mechanical properties are better produced using 40:60 wood/plastic ratio, and that at this ratio, all the three species are suitable for the production of wood plastic composites.

Keywords: polyethylene terephthalate plastic bottle wastes, wood plastic composite, physical properties, mechanical properties

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3932 Donoho-Stark’s and Hardy’s Uncertainty Principles for the Short-Time Quaternion Offset Linear Canonical Transform

Authors: Mohammad Younus Bhat

Abstract:

The quaternion offset linear canonical transform (QOLCT), which isa time-shifted and frequency-modulated version of the quaternion linear canonical transform (QLCT), provides a more general framework of most existing signal processing tools. For the generalized QOLCT, the classical Heisenberg’s and Lieb’s uncertainty principles have been studied recently. In this paper, we first define the short-time quaternion offset linear canonical transform (ST-QOLCT) and drive its relationship with the quaternion Fourier transform (QFT). The crux of the paper lies in the generalization of several well-known uncertainty principles for the ST-QOLCT, including Donoho-Stark’s uncertainty principle, Hardy’s uncertainty principle, Beurling’s uncertainty principle, and the logarithmic uncertainty principle.

Keywords: Quaternion Fourier transform, Quaternion offset linear canonical transform, short-time quaternion offset linear canonical transform, uncertainty principle

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3931 Evaluation of Short-Term Load Forecasting Techniques Applied for Smart Micro-Grids

Authors: Xiaolei Hu, Enrico Ferrera, Riccardo Tomasi, Claudio Pastrone

Abstract:

Load Forecasting plays a key role in making today's and future's Smart Energy Grids sustainable and reliable. Accurate power consumption prediction allows utilities to organize in advance their resources or to execute Demand Response strategies more effectively, which enables several features such as higher sustainability, better quality of service, and affordable electricity tariffs. It is easy yet effective to apply Load Forecasting at larger geographic scale, i.e. Smart Micro Grids, wherein the lower available grid flexibility makes accurate prediction more critical in Demand Response applications. This paper analyses the application of short-term load forecasting in a concrete scenario, proposed within the EU-funded GreenCom project, which collect load data from single loads and households belonging to a Smart Micro Grid. Three short-term load forecasting techniques, i.e. linear regression, artificial neural networks, and radial basis function network, are considered, compared, and evaluated through absolute forecast errors and training time. The influence of weather conditions in Load Forecasting is also evaluated. A new definition of Gain is introduced in this paper, which innovatively serves as an indicator of short-term prediction capabilities of time spam consistency. Two models, 24- and 1-hour-ahead forecasting, are built to comprehensively compare these three techniques.

Keywords: short-term load forecasting, smart micro grid, linear regression, artificial neural networks, radial basis function network, gain

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3930 Study of Biodegradable Composite Materials Based on Polylactic Acid and Vegetal Reinforcements

Authors: Manel Hannachi, Mustapha Nechiche, Said Azem

Abstract:

This study focuses on biodegradable materials made from Poly-lactic acid (PLA) and vegetal reinforcements. Three materials are developed from PLA, as a matrix, and : (i) olive kernels (OK); (ii) alfa (α) short fibers and (iii) OK+ α mixture, as reinforcements. After processing of PLA pellets and olive kernels in powder and alfa stems in short fibers, three mixtures, namely PLA-OK, PLA-α, and PLA-OK-α are prepared and homogenized in Turbula®. These mixtures are then compacted at 180°C under 10 MPa during 15 mn. Scanning Electron Microscopy (SEM) examinations show that PLA matrix adheres at surface of all reinforcements and the dispersion of these ones in matrix is good. X-ray diffraction (XRD) analyses highlight an increase of PLA inter-reticular distances, especially for the PLA-OK case. These results are explained by the dissociation of some molecules derived from reinforcements followed by diffusion of the released atoms in the structure of PLA. This is consistent with Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analysis results.

Keywords: alfa short fibers, biodegradable composite, olive kernels, poly-lactic acid

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3929 Characterization of Aluminium Alloy 6063 Hybrid Metal Matrix Composite by Using Stir Casting Method

Authors: Balwinder Singh

Abstract:

The present research is a paper on the characterization of aluminum alloy-6063 hybrid metal matrix composites using three different reinforcement materials (SiC, red mud, and fly ash) through stir casting method. The red mud was used in solid form, and particle size range varies between 103-150 µm. During this investigation, fly ash is received from Guru Nanak Dev Thermal Plant (GNDTP), Bathinda. The study has been done by using Taguchi’s L9 orthogonal array by taking fraction wt.% (SiC 5%, 7.5%, and 10% and Red Mud and Fly Ash 2%, 4%, and 6%) as input parameters with their respective levels. The study of the mechanical properties (tensile strength, impact strength, and microhardness) has been done by using Analysis of Variance (ANOVA) with the help of MINITAB 17 software. It is revealed that silicon carbide is the most significant parameter followed by red mud and fly ash affecting the mechanical properties, respectively. The fractured surface morphology of the composites using Field Emission Scanning Electron Microscope (FESEM) shows that there is a good mixing of reinforcement particles in the matrix. Energy-dispersive X-ray spectroscopy (EDS) was performed to know the presence of the phases of the reinforced material.

Keywords: reinforcement, silicon carbide, fly ash, red mud

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3928 Photocatalytic Activity of Polypyrrole/ZnO Composites for Degradation of Dye Reactive Red 45 in Wastewater

Authors: Ljerka Kratofil Krehula, Vanja Gilja, Andrea Husak, Sniježana Šuka, Zlata Hrnjak-Murgić

Abstract:

Zinc oxide (ZnO) can be used as photocatalysts for water purification. However, one particular interest is given on the integration of inorganic ZnO nanoclusters with conducting polymers because the resulting nanocomposites may possess unique properties and enhanced photocatalytic activity in comparison to pure ZnO, using UV and also visible light. It is needed to explore the appropriate structure of polypyrrole that can induce activation of ZnO photocatalyst since the synthesis of organic/inorganic hybrid materials can result in a synergistic and complementary feature, increasing ZnO photocatalytic efficiency. In this paper several different composites of polypyrrole/zinc oxide (ZnO) were studied. Composite samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and scanning electron microscopy (SEM). The photocatalytic efficiency of prepared samples was studied as a decomposition of Reactive Red 45 (RR 45) dye, which was monitored by UV-Vis spectroscopy as a change in absorbance of characteristic wavelength at 542 nm. Results show good photocatalytic efficiency of all nanocomposite samples.

Keywords: photocatalysis, polypyrrole, wastewater, zinc oxide

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3927 The Contribution of SMES to Improve the Transient Stability of Multimachine Power System

Authors: N. Chérif, T. Allaoui, M. Benasla, H. Chaib

Abstract:

Industrialization and population growth are the prime factors for which the consumption of electricity is steadily increasing. Thus, to have a balance between production and consumption, it is necessary at first to increase the number of power plants, lines and transformers, which implies an increase in cost and environmental degradation. As a result, it is now important to have mesh networks and working close to the limits of stability in order to meet these new requirements. The transient stability studies involve large disturbances such as short circuits, loss of work or production group. The consequence of these defects can be very serious, and can even lead to the complete collapse of the network. This work focuses on the regulation means that networks can help to keep their stability when submitted to strong disturbances. The magnetic energy storage-based superconductor (SMES) comprises a superconducting coil short-circuited on it self. When such a system is connected to a power grid is able to inject or absorb the active and reactive power. This system can be used to improve the stability of power systems.

Keywords: short-circuit, power oscillations, multiband PSS, power system, SMES, transient stability

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3926 Mechanical Tests and Analyzes of Behaviors of High-Performance of Polyester Resins Reinforced With Unifilo Fiberglass

Authors: Băilă Diana Irinel, Păcurar Răzvan, Păcurar Ancuța

Abstract:

In the last years, composite materials are increasingly used in automotive, aeronautic, aerospace, construction applications. Composite materials have been used in aerospace in applications such as engine blades, brackets, interiors, nacelles, propellers/rotors, single aisle wings, wide body wings. The fields of use of composite materials have multiplied with the improvement of material properties, such as stability and adaptation to the environment, mechanical tests, wear resistance, moisture resistance, etc. The composite materials are classified concerning type of matrix materials, as metallic, polymeric and ceramic based composites and are grouped according to the reinforcement type as fibre, obtaining particulate and laminate composites. Production of a better material is made more likely by combining two or more materials with complementary properties. The best combination of strength and ductility may be accomplished in solids that consist of fibres embedded in a host material. Polyester is a suitable component for composite materials, as it adheres so readily to the particles, sheets, or fibres of the other components. The important properties of the reinforcing fibres are their high strength and high modulus of elasticity. For applications, as in automotive or in aeronautical domain, in which a high strength-to-weight ratio is important, non-metallic fibres such as fiberglass have a distinct advantage because of their low density. In general, the glass fibres content varied between 9 to 33% wt. in the composites. In this article, high-performance types of composite materials glass-epoxy and glass-polyester used in automotive domain will be analyzed, performing tensile and flexural tests and SEM analyzes.

Keywords: glass-polyester composite, glass fibre, traction and flexion tests, SEM analyzes

Procedia PDF Downloads 158
3925 Implication of Multi-Walled Carbon Nanotubes on Polymer/MXene Nanocomposites

Authors: Mathias Aakyiir, Qunhui Zheng, Sherif Araby, Jun Ma

Abstract:

MXene nanosheets stack in polymer matrices, while multi-walled carbon nanotubes (MWCNTs) entangle themselves when used to form composites. These challenges are addressed in this work by forming MXene/MWCNT hybrid nanofillers by electrostatic self-assembly and developing elastomer/MXene/MWCNTs nanocomposites using a latex compounding method. In a 3-phase nanocomposite, MWCNTs serve as bridges between MXene nanosheets, leading to nanocomposites with well-dispersed nanofillers. The high aspect ratio of MWCNTs and the interconnection role of MXene serve as a basis for forming nanocomposites of lower percolation threshold of electrical conductivity from the hybrid fillers compared with the 2-phase composites containing either MXene or MWCNTs only. This study focuses on discussing into detail the interfacial interaction of nanofillers and the elastomer matrix and the outstanding mechanical and functional properties of the resulting nanocomposites. The developed nanocomposites have potential applications in the automotive and aerospace industries.

Keywords: elastomers, multi-walled carbon nanotubes, MXenes, nanocomposites

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3924 Modelling and Numerical Analysis of Thermal Non-Destructive Testing on Complex Structure

Authors: Y. L. Hor, H. S. Chu, V. P. Bui

Abstract:

Composite material is widely used to replace conventional material, especially in the aerospace industry to reduce the weight of the devices. It is formed by combining reinforced materials together via adhesive bonding to produce a bulk material with alternated macroscopic properties. In bulk composites, degradation may occur in microscopic scale, which is in each individual reinforced fiber layer or especially in its matrix layer such as delamination, inclusion, disbond, void, cracks, and porosity. In this paper, we focus on the detection of defect in matrix layer which the adhesion between the composite plies is in contact but coupled through a weak bond. In fact, the adhesive defects are tested through various nondestructive methods. Among them, pulsed phase thermography (PPT) has shown some advantages providing improved sensitivity, large-area coverage, and high-speed testing. The aim of this work is to develop an efficient numerical model to study the application of PPT to the nondestructive inspection of weak bonding in composite material. The resulting thermal evolution field is comprised of internal reflections between the interfaces of defects and the specimen, and the important key-features of the defects presented in the material can be obtained from the investigation of the thermal evolution of the field distribution. Computational simulation of such inspections has allowed the improvement of the techniques to apply in various inspections, such as materials with high thermal conductivity and more complex structures.

Keywords: pulsed phase thermography, weak bond, composite, CFRP, computational modelling, optimization

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3923 Evaluation of the Use of U-Wrap Anchorage Systems for Strengthening Concrete Members Reinforced by Fiber Reinforced-Polymer Laminate

Authors: Mai A. Aljaberi

Abstract:

The anchorage of fibre-reinforced polymer (FRP) sheets is the most effective solution to prevent or delay debonding failure; this system has proven to get better levels of FRP utilization. Unfortunately, the related design information is still unclear. This shortcoming limits the widespread use of the anchorage system. In order to minimize the knowledge gap about the design of U-wrap anchors, this paper reports the results of tested beams which were strengthened with carbon fiber-reinforced polymer (CFRP) sheets at their tension sides and secured with U-wrap anchors at each end of the longitudinal CFRP. The beams were tested under four-point loading until failure. The parameters examined include the compressive strength of the concrete and the number of longitudinal CFRP. It is concluded that these parameters have a considerable effect on the debonding of the strain. The greatest improvement in the strain was 55.8% over the control beam.

Keywords: CFRP, concrete strengthening, debonding failure, debonding strain, U-wrap anchor

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3922 Effect of Different Levels of Fibrolytic Enzyme on Feed Digestibility and Production Performance in Lactating Dairy Cows

Authors: Hazrat Salman Sidique, Muhammad Tahir Khan, Haq Aman Ullah, Muhammad Mobashar, Muhammad Ishtiaq Sohail Mehmood

Abstract:

The poor quality conventional feed for the livestock production in Pakistan are wheat straw, tops of sugar cane and tree leaves. To enhance the nutritive value of feed, this study focused on investigating the effects of fibrolytic enzyme (Fibrozyme®, Alltech Inc. Company, USA) at different levels i.e. 0, 5, 10, and 15g/kg of total mix ration on feed intake, digestibility, milk yield and composition, and economics of the ration in Holstein Friesians cows. Twelve Holstein Friesians cows of almost the same age, and lactation stage were randomly allocated into 4 equal groups i.e. A, B, C, and D. Four experimental rations supplemented with Fibrozyme® 0g, 5g, 10g, and 15g/Kg of total mix ration were assigned to these sets correspondingly. The dry matter intake was linearly and significantly (P<0.05) improved. A significant effect of Fibrozyme® was observed for organic matter digestibility, ether extract digestibility, crude fiber digestibility, nitrogen free extract digestibility, and acid detergent fiber digestibility while the results were statistically non-significant for crude protein digestibility, neutral detergent fiber digestibility, and ash digestibility. Milk yield and composition except fat were significantly (P<0.05) increased in all Fibrozyme® treated groups. This study concludes that supplementation of Fibrozyme® at the rate of 15g/Kg total mix ration improved the dry matter intake, nutrients digestibility, and milk production and constituents like protein, lactose, and solid not fat. Therefore, treatment of total mix ration with Fibrozyme® was desirably reasonable and profitable.

Keywords: digestibility, fibrozyme, TMR, digestibility, lactating cow

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3921 Synthesis, Characterization, and Physico–Chemical Properties of Nano Zinc Oxide and PVA Composites

Authors: S. H. Rashmi, G. M. Madhu, A. A. Kittur, R. Suresh

Abstract:

Polymer nanocomposites represent a new class of materials in which nanomaterials act as the reinforcing material in composites, wherein small additions of nanomaterials lead to large enhancements in thermal, optical, and mechanical properties. A boost in these properties is due to the large interfacial area per unit volume or weight of the nanoparticles and the interactions between the particle and the polymer. Micro-sized particles used as reinforcing agents scatter light, thus, reducing light transmittance and optical clarity. Efficient nanoparticle dispersion combined with good polymer–particle interfacial adhesion eliminates scattering and allows the exciting possibility of developing strong yet transparent films, coatings and membranes. This paper aims at synthesizing zinc oxide nanoparticles which are reinforced in poly vinyl alcohol (PVA) polymer. The mechanical properties showed that the tensile strength of the PVA nanocomposites increases with the increase in the amount of nanoparticles.

Keywords: glutaraldehyde, polymer nanocomposites, poly vinyl alcohol, zinc oxide

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3920 Investigation on the Properties of Particulate Reinforced AA2014 Metal Matrix Composite Materials Produced by Vacuum Infiltration Method

Authors: Isil Kerti, Onur Okur, Sibel Daglilar, Recep Calin

Abstract:

Particulate reinforced aluminium matrix composites have gained more importance in automotive, aeronautical and defense industries due to their specific properties like as low density, high strength and stiffness, good fatigue strength, dimensional stability at high temperature and acceptable tribological properties. In this study, 2014 Aluminium alloy used as a matrix material and B₄C and SiC were selected as reinforcements components. For production of composites materials, vacuum infiltration method was used. In the experimental studies, the reinforcement volume ratios were defined by mixing as totally 10% B₄C and SiC. Aging treatment (T6) was applied to the specimens. The effect of T6 treatment on hardness was determined by using Brinell hardness test method. The effects of the aging treatment on microstructure and chemical structure were analysed by making XRD, SEM and EDS analysis on the specimens.

Keywords: metal matrix composite, vacumm infiltration method, aluminum metal matrix, mechanical feature

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3919 Prediction of the Lateral Bearing Capacity of Short Piles in Clayey Soils Using Imperialist Competitive Algorithm-Based Artificial Neural Networks

Authors: Reza Dinarvand, Mahdi Sadeghian, Somaye Sadeghian

Abstract:

Prediction of the ultimate bearing capacity of piles (Qu) is one of the basic issues in geotechnical engineering. So far, several methods have been used to estimate Qu, including the recently developed artificial intelligence methods. In recent years, optimization algorithms have been used to minimize artificial network errors, such as colony algorithms, genetic algorithms, imperialist competitive algorithms, and so on. In the present research, artificial neural networks based on colonial competition algorithm (ANN-ICA) were used, and their results were compared with other methods. The results of laboratory tests of short piles in clayey soils with parameters such as pile diameter, pile buried length, eccentricity of load and undrained shear resistance of soil were used for modeling and evaluation. The results showed that ICA-based artificial neural networks predicted lateral bearing capacity of short piles with a correlation coefficient of 0.9865 for training data and 0.975 for test data. Furthermore, the results of the model indicated the superiority of ICA-based artificial neural networks compared to back-propagation artificial neural networks as well as the Broms and Hansen methods.

Keywords: artificial neural network, clayey soil, imperialist competition algorithm, lateral bearing capacity, short pile

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3918 Reducing Antimicrobial Resistance Using Biodegradable Polymer Composites of Mof-5 for Efficient and Sustained Delivery of Cephalexin and Metronidazole

Authors: Anoff Anim, Lila Mahmound, Maria Katsikogianni, Sanjit Nayak

Abstract:

Sustained and controlled delivery of antimicrobial drugs have been largely studied recently using metal organic frameworks (MOFs)and different polymers. However, much attention has not been given to combining both MOFs and biodegradable polymers which would be a good strategy in providing a sustained gradual release of the drugs. Herein, we report a comparative study of the sustained and controlled release of widely used antibacterial drugs, cephalexin and metronidazole, from zinc-based MOF-5 incorporated in biodegradable polycaprolactone (PCL) and poly-lactic glycolic acid (PLGA) membranes. Cephalexin and metronidazole were separately incorporated in MOF-5 post-synthetically, followed by their integration into biodegradable PLGA and PCL membranes. The pristine MOF-5 and the loaded MOFs were thoroughly characterized by FT-IR, SEM, TGA and PXRD. Drug release studies were carried out to assess the release rate of the drugs in PBS and distilled water for up to 48 hours using UV-Vis Spectroscopy. Four bacterial strains from both the Gram-positive and Gram-negative types, Staphylococus aureus, Staphylococuss epidermidis, Escherichia coli, Acinetobacter baumanii, were tested against the pristine MOF, pure drugs, loaded MOFs and the drug-loaded MOF-polymer composites. Metronidazole-loaded MOF-5 composite of PLGA (PLGA-Met@MOF-5) was found to show highest efficiency to inhibit the growth of S. epidermidis compared to the other bacteria strains while maintaining a sustained minimum inhibitory concentration (MIC). This study demonstrates that the combination of biodegradable MOF-polymer composites can provide an efficient platform for sustained and controlled release of antimicrobial drugs, and can be a potential strategy to integrate them in biomedical devices.

Keywords: antimicrobial resistance, biodegradable polymers, cephalexin, drug release metronidazole, MOF-5, PCL, PLGA

Procedia PDF Downloads 85
3917 Preparation of Electrospun PLA/ENR Fibers

Authors: Jaqueline G. L. Cosme, Paulo H. S. Picciani, Regina C. R. Nunes

Abstract:

Electrospinning is a technique for the fabrication of nanoscale fibers. The general electrospinning system consists of a syringe filled with polymer solution, a syringe pump, a high voltage source and a grounded counter electrode. During electrospinning a volumetric flow is set by the syringe pump and an electric voltage is applied. This forms an electric potential between the needle and the counter electrode (collector plate), which results in the formation of a Taylor cone and the jet. The jet is moved towards the lower potential, the counter electrode, wherein the solvent of the polymer solution is evaporated and the polymer fiber is formed. On the way to the counter electrode, the fiber is accelerated by the electric field. The bending instabilities that occur form a helical loop movements of the jet, which result from the coulomb repulsion of the surface charge. Trough bending instabilities the jet is stretched, so that the fiber diameter decreases. In this study, a thermoplastic/elastomeric binary blend of non-vulcanized epoxidized natural rubber (ENR) and poly(latic acid) (PLA) was electrospun using polymer solutions consisting of varying proportions of PCL and NR. Specifically, 15% (w/v) PLA/ENR solutions were prepared in /chloroform at proportions of 5, 10, 25, and 50% (w/w). The morphological and thermal properties of the electrospun mats were investigated by scanning electron microscopy (SEM) and differential scanning calorimetry analysis. The SEM images demonstrated the production of micrometer- and sub-micrometer-sized fibers with no bead formation. The blend miscibility was evaluated by thermal analysis, which showed that blending did not improve the thermal stability of the systems.

Keywords: epoxidized natural rubber, poly(latic acid), electrospinning, chemistry

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3916 Comparison of Solar Radiation Models

Authors: O. Behar, A. Khellaf, K. Mohammedi, S. Ait Kaci

Abstract:

Up to now, most validation studies have been based on the MBE and RMSE, and therefore, focused only on long and short terms performance to test and classify solar radiation models. This traditional analysis does not take into account the quality of modeling and linearity. In our analysis we have tested 22 solar radiation models that are capable to provide instantaneous direct and global radiation at any given location Worldwide. We introduce a new indicator, which we named Global Accuracy Indicator (GAI) to examine the linear relationship between the measured and predicted values and the quality of modeling in addition to long and short terms performance. Note that the quality of model has been represented by the T-Statistical test, the model linearity has been given by the correlation coefficient and the long and short term performance have been respectively known by the MBE and RMSE. An important founding of this research is that the use GAI allows avoiding default validation when using traditional methodology that might results in erroneous prediction of solar power conversion systems performances.

Keywords: solar radiation model, parametric model, performance analysis, Global Accuracy Indicator (GAI)

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3915 A Geoprocessing Tool for Early Civil Work Notification to Optimize Fiber Optic Cable Installation Cost

Authors: Hussain Adnan Alsalman, Khalid Alhajri, Humoud Alrashidi, Abdulkareem Almakrami, Badie Alguwaisem, Said Alshahrani, Abdullah Alrowaished

Abstract:

Most of the cost of installing a new fiber optic cable is attributed to civil work-trenching-cost. In many cases, information technology departments receive project proposals in their eReview system, but not all projects are visible to everyone. Additionally, if there was no IT scope in the proposed project, it is not likely to be visible to IT. Sometimes it is too late to add IT scope after project budgets have been finalized. Finally, the eReview system is a repository of PDF files for each project, which commits the reviewer to manual work and limits automation potential. This paper details a solution to address the late notification of the eReview system by integrating IT Sites GIS data-sites locations-with land use permit (LUP) data-civil work activity, which is the first step before securing the required land usage authorizations and means no detailed designs for any relevant project before an approved LUP request. To address the manual nature of eReview system, both the LUP System and IT data are using ArcGIS Desktop, which enables the creation of a geoprocessing tool with either Python or Model Builder to automate finding and evaluating potentially usable LUP requests to reduce trenching between two sites in need of a new FOC. To achieve this, a weekly dump was taken from LUP system production data and loaded manually onto ArcMap Desktop. Then a custom tool was developed in model builder, which consisted of a table of two columns containing all the pairs of sites in need of new fiber connectivity. The tool then iterates all rows of this table, taking the sites’ pair one at a time and finding potential LUPs between them, which satisfies the provided search radius. If a group of LUPs was found, an iterator would go through each LUP to find the required civil work between the two sites and the LUP Polyline feature and the distance through the line, which would be counted as cost avoidance if an IT scope had been added. Finally, the tool will export an Excel file named with sites pair, and it will contain as many rows as the number of LUPs, which met the search radius containing trenching and pulling information and cost. As a result, multiple projects have been identified – historical, missed opportunity, and proposed projects. For the proposed project, the savings were about 75% ($750,000) to install a new fiber with the Euclidean distance between Abqaiq GOSP2 and GOSP3 DCOs. In conclusion, the current tool setup identifies opportunities to bundle civil work on single projects at a time and between two sites. More work is needed to allow the bundling of multiple projects between two sites to achieve even more cost avoidance in both capital cost and carbon footprint.

Keywords: GIS, fiber optic cable installation optimization, eliminate redundant civil work, reduce carbon footprint for fiber optic cable installation

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3914 Computer-Aided Teaching of Transformers for Undergraduates

Authors: Rajesh Kumar, Roopali Dogra, Puneet Aggarwal

Abstract:

In the era of technological advancement, use of computer technology has become inevitable. Hence it has become the need of the hour to integrate software methods in engineering curriculum as a part to boost pedagogy techniques. Simulations software is a great help to graduates of disciplines such as electrical engineering. Since electrical engineering deals with high voltages and heavy instruments, extra care must be taken while operating with them. The viable solution would be to have appropriate control. The appropriate control could be well designed if engineers have knowledge of kind of waveforms associated with the system. Though these waveforms can be plotted manually, but it consumes a lot of time. Hence aid of simulation helps to understand steady state of system and resulting in better performance. In this paper computer, aided teaching of transformer is carried out using MATLAB/Simulink. The test carried out on a transformer includes open circuit test and short circuit respectively. The respective parameters of transformer are then calculated using the values obtained from open circuit and short circuit test respectively using Simulink.

Keywords: computer aided teaching, open circuit test, short circuit test, simulink, transformer

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3913 Preparation on Sentimental Analysis on Social Media Comments with Bidirectional Long Short-Term Memory Gated Recurrent Unit and Model Glove in Portuguese

Authors: Leonardo Alfredo Mendoza, Cristian Munoz, Marco Aurelio Pacheco, Manoela Kohler, Evelyn Batista, Rodrigo Moura

Abstract:

Natural Language Processing (NLP) techniques are increasingly more powerful to be able to interpret the feelings and reactions of a person to a product or service. Sentiment analysis has become a fundamental tool for this interpretation but has few applications in languages other than English. This paper presents a classification of sentiment analysis in Portuguese with a base of comments from social networks in Portuguese. A word embedding's representation was used with a 50-Dimension GloVe pre-trained model, generated through a corpus completely in Portuguese. To generate this classification, the bidirectional long short-term memory and bidirectional Gated Recurrent Unit (GRU) models are used, reaching results of 99.1%.

Keywords: natural processing language, sentiment analysis, bidirectional long short-term memory, BI-LSTM, gated recurrent unit, GRU

Procedia PDF Downloads 159
3912 Effects of the Coagulation Bath and Reduction Process on SO2 Adsorption Capacity of Graphene Oxide Fiber

Authors: Özge Alptoğa, Nuray Uçar, Nilgün Karatepe Yavuz, Ayşen Önen

Abstract:

Sulfur dioxide (SO2) is a very toxic air pollutant gas and it causes the greenhouse effect, photochemical smog, and acid rain, which threaten human health severely. Thus, the capture of SO2 gas is very important for the environment. Graphene which is two-dimensional material has excellent mechanical, chemical, thermal properties, and many application areas such as energy storage devices, gas adsorption, sensing devices, and optical electronics. Further, graphene oxide (GO) is examined as a good adsorbent because of its important features such as functional groups (epoxy, carboxyl and hydroxyl) on the surface and layered structure. The SO2 adsorption properties of the fibers are usually investigated on carbon fibers. In this study, potential adsorption capacity of GO fibers was researched. GO dispersion was first obtained with Hummers’ method from graphite, and then GO fibers were obtained via wet spinning process. These fibers were converted into a disc shape, dried, and then subjected to SO2 gas adsorption test. The SO2 gas adsorption capacity of GO fiber discs was investigated in the fields of utilization of different coagulation baths and reduction by hydrazine hydrate. As coagulation baths, single and triple baths were used. In single bath, only ethanol and CaCl2 (calcium chloride) salt were added. In triple bath, each bath has a different concentration of water/ethanol and CaCl2 salt, and the disc obtained from triple bath has been called as reference disk. The fibers which were produced with single bath were flexible and rough, and the analyses show that they had higher SO2 adsorption capacity than triple bath fibers (reference disk). However, the reduction process did not increase the adsorption capacity, because the SEM images showed that the layers and uniform structure in the fiber form were damaged, and reduction decreased the functional groups which SO2 will be attached. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) analyzes were performed on the fibers and discs, and the effects on the results were interpreted. In the future applications of the study, it is aimed that subjects such as pH and additives will be examined.

Keywords: coagulation bath, graphene oxide fiber, reduction, SO2 gas adsorption

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3911 Effect of Formulated Insect Enriched Sprouted Soybean /Millet Based Food on Gut Health Markers in Albino Wistar Rats

Authors: Gadanya, A.M., Ponfa, S., Jibril, M.M., Abubakar, S. M.

Abstract:

Background: Edible insects such as grasshopper are important sources of food for humans, and have been consumed as traditional foods by many indigenous communities especially in Africa, Asia, and Latin America. These communities have developed their skills and techniques in harvesting, preparing, consuming, and preserving edible insects, widely contributing to the role played by the use of insects in human nutrition. Aim/ objective: This study was aimed at determining the effect of insect enriched sprouted soyabean /millet based food on some gut health markers in albino rats. Methods. Four different formulations of Complementary foods (i.e Complementary Food B (CFB): sprouted millet (SM), Complementary Food C (CFC): sprouted soyabean (SSB), Complementary Food D (CFD): sprouted soybean and millet (SSBM) in a ratio of (50:50) and Complementary Food E (CFE): insect (grasshopper) enriched sprouted soybean and millet (SSBMI) in a ratio of (50:25:25)) were prepared. Proximate composition and short chain fatty acid contents were determined. Thirty albino rats were divided into5 groups of six rats each. Group 1(CDA) were fed with basal diet and served as a control group, while groups 2,3,4 and 5 were fed with the corresponding complimentary foods CFB, CFC, CFD and CFE respectively daily for four weeks. Concentrations of fecal protein, serum total carotenoids and nitric oxide were determined. DNA extraction for molecular isolation and characterization were carried out followed by PCR, the use of mega 11 software and NCBI blast for construction of the phylogenetic tree and organism identification respectively. Results: Significant increase (P<0.05) in percentage ash, fat, protein and moisture contents, as well as short chain fatty acid (acetate, butyrate and propionate) concentrations were recorded in the insect enriched sprouted composite food (CFE) when compared with the CFA, CFB, CFC and CFD composite food. Faecal protein, carotenoid and nitric oxide concentrations were significantly lower (P>0.05) in group 5 in comparison to groups 1to 4. Ruminococcus bromii and Bacteroidetes were molecularly isolated and characterized by 16s rRNA from the sprouted millet/sprouted soybean and the insect enriched sprouted soybean/sprouted millet based food respectively. The presence of these bacterial strains in the feaces of the treated rats is an indication that the gut of the treated rats is colonized by good gut bacteria, hence, an improved gut health. Conclusion: Insect enriched sprouted soya bean/sprouted millet based complementary diet showed a high composition of ash, fat, protein and fiber. Thus, could increase the availability of short chain fatty acids whose role to the host organism cannot be overemphasized. It was also found to have decrease the level of faecal protein, carotenoid and nitric oxide in the serum which is an indication of an improvement in the immune system function.

Keywords: gut-health, insect, millet, soybean, sprouted

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3910 Development of 3D Printed Natural Fiber Reinforced Composite Scaffolds for Maxillofacial Reconstruction

Authors: Sri Sai Ramya Bojedla, Falguni Pati

Abstract:

Nature provides the best of solutions to humans. One such incredible gift to regenerative medicine is silk. The literature has publicized a long appreciation for silk owing to its incredible physical and biological assets. Its bioactive nature, unique mechanical strength, and processing flexibility make us curious to explore further to apply it in the clinics for the welfare of mankind. In this study, Antheraea mylitta and Bombyx mori silk fibroin microfibers are developed by two economical and straightforward steps via degumming and hydrolysis for the first time, and a bioactive composite is manufactured by mixing silk fibroin microfibers at various concentrations with polycaprolactone (PCL), a biocompatible, aliphatic semi-crystalline synthetic polymer. Reconstructive surgery in any part of the body except for the maxillofacial region deals with replacing its function. But answering both the aesthetics and function is of utmost importance when it comes to facial reconstruction as it plays a critical role in the psychological and social well-being of the patient. The main concern in developing adequate bone graft substitutes or a scaffold is the noteworthy variation in each patient's bone anatomy. Additionally, the anatomical shape and size will vary based on the type of defect. The advent of additive manufacturing (AM) or 3D printing techniques to bone tissue engineering has facilitated overcoming many of the restraints of conventional fabrication techniques. The acquired patient's CT data is converted into a stereolithographic (STL)-file which is further utilized by the 3D printer to create a 3D scaffold structure in an interconnected layer-by-layer fashion. This study aims to address the limitations of currently available materials and fabrication technologies and develop a customized biomaterial implant via 3D printing technology to reconstruct complex form, function, and aesthetics of the facial anatomy. These composite scaffolds underwent structural and mechanical characterization. Atomic force microscopic (AFM) and field emission scanning electron microscopic (FESEM) images showed the uniform dispersion of the silk fibroin microfibers in the PCL matrix. With the addition of silk, there is improvement in the compressive strength of the hybrid scaffolds. The scaffolds with Antheraea mylitta silk revealed higher compressive modulus than that of Bombyx mori silk. The above results of PCL-silk scaffolds strongly recommend their utilization in bone regenerative applications. Successful completion of this research will provide a great weapon in the maxillofacial reconstructive armamentarium.

Keywords: compressive modulus, 3d printing, maxillofacial reconstruction, natural fiber reinforced composites, silk fibroin microfibers

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3909 Forming Simulation of Thermoplastic Pre-Impregnated Textile Composite

Authors: Masato Nishi, Tetsushi Kaburagi, Masashi Kurose, Tei Hirashima, Tetsusei Kurasiki

Abstract:

The process of thermoforming a carbon fiber reinforced thermoplastic (CFRTP) has increased its presence in the automotive industry for its wide applicability to the mass production car. A non-isothermal forming for CFRTP can shorten its cycle time to less than 1 minute. In this paper, the textile reinforcement FE model which the authors proposed in a previous work is extended to the CFRTP model for non-isothermal forming simulation. The effect of thermoplastic is given by adding shell elements which consider thermal effect to the textile reinforcement model. By applying Reuss model to the stress calculation of thermoplastic, the proposed model can accurately predict in-plane shear behavior, which is the key deformation mode during forming, in the range of the process temperature. Using the proposed model, thermoforming simulation was conducted and the results are in good agreement with the experimental results.

Keywords: carbon fiber reinforced thermoplastic, finite element analysis, pre-impregnated textile composite, non-isothermal forming

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3908 Experimental Study of Hyperparameter Tuning a Deep Learning Convolutional Recurrent Network for Text Classification

Authors: Bharatendra Rai

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The sequence of words in text data has long-term dependencies and is known to suffer from vanishing gradient problems when developing deep learning models. Although recurrent networks such as long short-term memory networks help to overcome this problem, achieving high text classification performance is a challenging problem. Convolutional recurrent networks that combine the advantages of long short-term memory networks and convolutional neural networks can be useful for text classification performance improvements. However, arriving at suitable hyperparameter values for convolutional recurrent networks is still a challenging task where fitting a model requires significant computing resources. This paper illustrates the advantages of using convolutional recurrent networks for text classification with the help of statistically planned computer experiments for hyperparameter tuning.

Keywords: long short-term memory networks, convolutional recurrent networks, text classification, hyperparameter tuning, Tukey honest significant differences

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3907 Information Extraction for Short-Answer Question for the University of the Cordilleras

Authors: Thelma Palaoag, Melanie Basa, Jezreel Mark Panilo

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Checking short-answer questions and essays, whether it may be paper or electronic in form, is a tiring and tedious task for teachers. Evaluating a student’s output require wide array of domains. Scoring the work is often a critical task. Several attempts in the past few years to create an automated writing assessment software but only have received negative results from teachers and students alike due to unreliability in scoring, does not provide feedback and others. The study aims to create an application that will be able to check short-answer questions which incorporate information extraction. Information extraction is a subfield of Natural Language Processing (NLP) where a chunk of text (technically known as unstructured text) is being broken down to gather necessary bits of data and/or keywords (structured text) to be further analyzed or rather be utilized by query tools. The proposed system shall be able to extract keywords or phrases from the individual’s answers to match it into a corpora of words (as defined by the instructor), which shall be the basis of evaluation of the individual’s answer. The proposed system shall also enable the teacher to provide feedback and re-evaluate the output of the student for some writing elements in which the computer cannot fully evaluate such as creativity and logic. Teachers can formulate, design, and check short answer questions efficiently by defining keywords or phrases as parameters by assigning weights for checking answers. With the proposed system, teacher’s time in checking and evaluating students output shall be lessened, thus, making the teacher more productive and easier.

Keywords: information extraction, short-answer question, natural language processing, application

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3906 Short-Term Energy Efficiency Decay and Risk Analysis of Ground Source Heat Pump System

Authors: Tu Shuyang, Zhang Xu, Zhou Xiang

Abstract:

The objective of this paper is to investigate the effect of short-term heat exchange decay of ground heat exchanger (GHE) on the ground source heat pump (GSHP) energy efficiency and capacity. A resistance-capacitance (RC) model was developed and adopted to simulate the transient characteristics of the ground thermal condition and heat exchange. The capacity change of the GSHP was linked to the inlet and outlet water temperature by polynomial fitting according to measured parameters given by heat pump manufacturers. Thus, the model, which combined the heat exchange decay with the capacity change, reflected the energy efficiency decay of the whole system. A case of GSHP system was analyzed by the model, and the result showed that there was risk that the GSHP might not meet the load demand because of the efficiency decay in a short-term operation. The conclusion would provide some guidances for GSHP system design to overcome the risk.

Keywords: capacity, energy efficiency, GSHP, heat exchange

Procedia PDF Downloads 350
3905 Synthesis, Characterization, and Evaluation of New Series of Oil Sorbers Based on Maleate Esters

Authors: Nora A. Hamad, Ayman M. Atta, Adel A. H. Abdel-Rahman

Abstract:

Two malice anhydride esters were prepared using long chain aliphatic alcohols (C8H17OH and C12H25OH, 1:1 mole ratio). Three series of crosslinked homo and copolymers of maleate esters with octadecyl acrylate and acrylic acid were prepared respectively through suspension copolymerization. The monomers were mixed with 0.02 Wt% of BP initiator, PVA 1% (170 ml for each 100g of monomers) and different weight ratios of DVB crosslinked (1% and 4%) in cyclohexane. The prepared crosslinked homo and copolymers were characterized by SEM, TGA and FTIR spectroscopic analyses. The prepared polymers were coated onto poly (ethylene terephethalate) nonwoven fiber (NWPET). The effect of copolymerization feed composition, crosslinker wt% and reaction media or solvent on swelling properties of crosslinked polymers were studied through the oil absorption tests in toluene and 10% of diluted crude oil with toluene.

Keywords: acrylic acid, crosslinked copolymers, maleate ester, poly(ethylene terephethalate) nonwoven fiber (NWPET), oil absorbency, octadecyl acrylat

Procedia PDF Downloads 391
3904 Force Sensor for Robotic Graspers in Minimally Invasive Surgery

Authors: Naghmeh M. Bandari, Javad Dargahi, Muthukumaran Packirisamy

Abstract:

Robot-assisted minimally invasive surgery (RMIS) has been widely performed around the world during the last two decades. RMIS demonstrates significant advantages over conventional surgery, e.g., improving the accuracy and dexterity of a surgeon, providing 3D vision, motion scaling, hand-eye coordination, decreasing tremor, and reducing x-ray exposure for surgeons. Despite benefits, surgeons cannot touch the surgical site and perceive tactile information. This happens due to the remote control of robots. The literature survey identified the lack of force feedback as the riskiest limitation in the existing technology. Without the perception of tool-tissue contact force, the surgeon might apply an excessive force causing tissue laceration or insufficient force causing tissue slippage. The primary use of force sensors has been to measure the tool-tissue interaction force in real-time in-situ. Design of a tactile sensor is subjected to a set of design requirements, e.g., biocompatibility, electrical-passivity, MRI-compatibility, miniaturization, ability to measure static and dynamic force. In this study, a planar optical fiber-based sensor was proposed to mount at the surgical grasper. It was developed based on the light intensity modulation principle. The deflectable part of the sensor was a beam modeled as a cantilever Euler-Bernoulli beam on rigid substrates. A semi-cylindrical indenter was attached to the bottom surface the beam at the mid-span. An optical fiber was secured at both ends on the same rigid substrates. The indenter was in contact with the fiber. External force on the sensor caused deflection in the beam and optical fiber simultaneously. The micro-bending of the optical fiber would consequently result in light power loss. The sensor was simulated and studied using finite element methods. A laser light beam with 800nm wavelength and 5mW power was used as the input to the optical fiber. The output power was measured using a photodetector. The voltage from photodetector was calibrated to the external force for a chirp input (0.1-5Hz). The range, resolution, and hysteresis of the sensor were studied under monotonic and harmonic external forces of 0-2.0N with 0 and 5Hz, respectively. The results confirmed the validity of proposed sensing principle. Also, the sensor demonstrated an acceptable linearity (R2 > 0.9). A minimum external force was observed below which no power loss was detectable. It is postulated that this phenomenon is attributed to the critical angle of the optical fiber to observe total internal reflection. The experimental results were of negligible hysteresis (R2 > 0.9) and in fair agreement with the simulations. In conclusion, the suggested planar sensor is assessed to be a cost-effective solution, feasible, and easy to use the sensor for being miniaturized and integrated at the tip of robotic graspers. Geometrical and optical factors affecting the minimum sensible force and the working range of the sensor should be studied and optimized. This design is intrinsically scalable and meets all the design requirements. Therefore, it has a significant potential of industrialization and mass production.

Keywords: force sensor, minimally invasive surgery, optical sensor, robotic surgery, tactile sensor

Procedia PDF Downloads 230