Search results for: thermally modified wood
2373 Biodiesel Synthesis Using Animal Excreta-Based Biochar and Waste Cooking Oil
Authors: Sang-Ryong Lee, Min-Woon Jung, Deugwoo Han, Kiyong Kim
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This study laid an emphasis on the possible employment of biochar generated from pyrolysis of animal excreta to establish a green platform for producing biodiesel. To this end, the pseudo-catalytic transesterification reaction using chicken manure biochar and waste cooking oil was investigated. Compared with a commercial porous material (SiO2), chicken manure biochar generated from 350 C showed better performance, resulting in 95.6% of the FAME yield at 350C. The Ca species in chicken manure biochar imparted strong catalytic capability by providing the basicity for transesterification. The identified catalytic effect also led to the thermal cracking of unsaturated FAMEs, which decreased the overall FAME yield. For example, 40–60% of converted FAMEs were thermally degraded. To avoid undesirable thermal cracking arising from the high content of the Ca species in chicken manure biochar, the fabrication of chicken manure biochar at temperatures ≥350C was highly recommended.Keywords: Trasesterification, Animal excreta, FAME, Biochar, Chicken manure
Procedia PDF Downloads 1882372 Centrifuge Testing to Determine the Effect of Temperature on the Adhesion Strength of Ice
Authors: Zaid A. Janjua, Barbara Turnbull, Kwing-So Choi
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The adhesion of glaze ice on power infrastructure, ships and aerofoils cause monetary and structural damage. Here we investigate the influence of temperature as an important parameter affecting adhesion strength of ice. Two terms are defined to investigate this: 'freezing temperature', the temperature at which glaze ice forms; and 'ambient temperature', the temperature of the surrounding during the test. Using three metal surfaces, the adhesion strength of ice has been calculated as a value of shear stress at the point of detachment on a spinning centrifuge. Findings show that the ambient temperature has a greater influence than the freezing temperature on the adhesion strength of ice. This is because there exists an amorphous liquid-like layer at the ice-surface interface, whose bond with the surface increases in strength at lower ambient temperatures when the substrate conducts heat much faster than the ice and acts as a heat sink. The results will help us to measure the actual adhesion strength of ice to metal surfaces based on data from weather monitoring devices. Future tests envisaged focus on thermally non-conducting substrates and their influence on adhesion strength.Keywords: ice adhesion, centrifuge, glaze ice, freezing temperature, ambient temperature
Procedia PDF Downloads 3312371 A Hybrid-Evolutionary Optimizer for Modeling the Process of Obtaining Bricks
Authors: Marius Gavrilescu, Sabina-Adriana Floria, Florin Leon, Silvia Curteanu, Costel Anton
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Natural sciences provide a wide range of experimental data whose related problems require study and modeling beyond the capabilities of conventional methodologies. Such problems have solution spaces whose complexity and high dimensionality require correspondingly complex regression methods for proper characterization. In this context, we propose an optimization method which consists in a hybrid dual optimizer setup: a global optimizer based on a modified variant of the popular Imperialist Competitive Algorithm (ICA), and a local optimizer based on a gradient descent approach. The ICA is modified such that intermediate solution populations are more quickly and efficiently pruned of low-fitness individuals by appropriately altering the assimilation, revolution and competition phases, which, combined with an initialization strategy based on low-discrepancy sampling, allows for a more effective exploration of the corresponding solution space. Subsequently, gradient-based optimization is used locally to seek the optimal solution in the neighborhoods of the solutions found through the modified ICA. We use this combined approach to find the optimal configuration and weights of a fully-connected neural network, resulting in regression models used to characterize the process of obtained bricks using silicon-based materials. Installations in the raw ceramics industry, i.e., bricks, are characterized by significant energy consumption and large quantities of emissions. Thus, the purpose of our approach is to determine by simulation the working conditions, including the manufacturing mix recipe with the addition of different materials, to minimize the emissions represented by CO and CH4. Our approach determines regression models which perform significantly better than those found using the traditional ICA for the aforementioned problem, resulting in better convergence and a substantially lower error.Keywords: optimization, biologically inspired algorithm, regression models, bricks, emissions
Procedia PDF Downloads 762370 Rheological and Morphological Properties of Investment Casting Pattern Material Based on Paraffin Wax Fortified with Linear Low-Density Polyethylene and Filled with Poly Methyl Methacrylate
Authors: Robert Kimutai Tewo, Hilary Limo Rutto, Tumisang Seodigeng
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The rheological and morphological properties of paraffin wax, linear low-density polyethylene (LLDPE), and poly (methyl methacrylate) (PMMA) microbeads formulations were prepared via an extrusion process. The blends were characterized by rheometry, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The results indicated that the viscosity of the blends increased as compared to that of neat wax. SEM confirmed that LLDPE alters the wax crystal habit at higher concentrations. The rheological experimental data fitted with predicted data using the modified Krieger and Dougherty expression. The SEM micrograph of wax/LLDPE/PMMA revealed a near-perfect spherical nature for the filler particles in the wax/EVA polymer matrix. The FT-IR spectra show the deformation vibrations stretch of a long-chain aliphatic hydrocarbon (C-H) and also the presence of carbonyls absorption group denoted by -C=O- stretch.Keywords: investment casting pattern, paraffin wax, LLDPE, PMMA, rheological properties, modified Krieger and Dougherty expression
Procedia PDF Downloads 1592369 Measurement of Thermal Protrusion Profile in Magnetic Recording Heads via Wyko Interferometry
Authors: Joseph Christopher R. Ragasa, Paolo Gabriel P. Casas, Nemesio S. Mangila, Maria Emma C. Villamin, Myra G. Bungag
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A procedure in measuring the thermal protrusion profiles of magnetic recording heads was developed using a Wyko HD-8100 optical interference-based instrument. The protrusions in the heads were made by the application of a constant power through the thermal flying height controller pads. It was found that the thermally-induced bubble is confined to form in the same head locations, primarily in the reader and writer regions, regardless of the direction of approach of temperature. An application of power to the thermal flying height control pads ranging from 0 to 50 milliWatts showed that the protrusions demonstrate a linear dependence with the supplied power. The efficiencies calculated using this method were compared to that obtained through Guzik and found to be 19.57% greater due to the static testing environment used in the testing.Keywords: thermal protrusion profile, magnetic recording heads, wyko interferometry, thermal flying height control
Procedia PDF Downloads 4622368 Efficient Pre-Concentration of As (III) Using Guanidine-Modified Magnetic Mesoporous Silica in the Food Sample
Authors: Majede Modheji, Hamid Emadi, Hossein Vojoudi
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An efficient magnetic mesoporous structure was designed and prepared for the facile pre-concentration of As(III) ions. To prepare the sorbent, a core-shell magnetic silica nanoparticle was covered by MCM-41 like structure, and then the surface was modified by guanidine via an amine linker. The prepared adsorbent was investigated as an effective and sensitive material for the adsorption of arsenic ions from the aqueous solution applying a normal batch method. The imperative variables of the adsorption were studied to increase efficiency. The dynamic and static processes were tested that matched a pseudo-second order of kinetic model and the Langmuir isotherm model, respectively. The sorbent reusability was investigated, and it was confirmed that the designed product could be applied at best for six cycles successively without any significant efficiency loss. The synthesized product was tested to determine and pre-concentrate trace amounts of arsenic ions in rice and natural waters as a real sample. A desorption process applying 5 mL of hydrochloric acid (0.5 mol L⁻¹) as an eluent exhibited about 98% recovery of the As(III) ions adsorbed on the GA-MSMP sorbent.Keywords: arsenic, adsorption, mesoporous, surface modification, MCM-41
Procedia PDF Downloads 1432367 Hyperspectral Image Classification Using Tree Search Algorithm
Authors: Shreya Pare, Parvin Akhter
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Remotely sensing image classification becomes a very challenging task owing to the high dimensionality of hyperspectral images. The pixel-wise classification methods fail to take the spatial structure information of an image. Therefore, to improve the performance of classification, spatial information can be integrated into the classification process. In this paper, the multilevel thresholding algorithm based on a modified fuzzy entropy function is used to perform the segmentation of hyperspectral images. The fuzzy parameters of the MFE function have been optimized by using a new meta-heuristic algorithm based on the Tree-Search algorithm. The segmented image is classified by a large distribution machine (LDM) classifier. Experimental results are shown on a hyperspectral image dataset. The experimental outputs indicate that the proposed technique (MFE-TSA-LDM) achieves much higher classification accuracy for hyperspectral images when compared to state-of-art classification techniques. The proposed algorithm provides accurate segmentation and classification maps, thus becoming more suitable for image classification with large spatial structures.Keywords: classification, hyperspectral images, large distribution margin, modified fuzzy entropy function, multilevel thresholding, tree search algorithm, hyperspectral image classification using tree search algorithm
Procedia PDF Downloads 1652366 The Effect of Penalizing Wrong Answers in the Computerized Modified Multiple Choice Testing System
Authors: Min Hae Song, Jooyong Park
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Even though assessment using information and communication technology will most likely lead the future of educational assessment, there is little research on this topic. Computerized assessment will not only cut costs but also measure students' performance in ways not possible before. In this context, this study introduces a tool which can overcome the problems of multiple choice tests. Multiple-choice tests (MC) are efficient in automatic grading, however structural problems of multiple-choice tests allow students to find the correct answer from options even though they do not know the answer. A computerized modified multiple-choice testing system (CMMT) was developed using the interactivity of computers, that presents questions first, and options later for a short time when the student requests for them. This study was conducted to find out whether penalizing for wrong answers in CMMT could lower random guessing. In this study, we checked whether students knew the answers by having them respond to the short-answer tests before choosing the given options in CMMT or MC format. Ninety-four students were tested with the directions that they will be penalized for wrong answers, but not for no response. There were 4 experimental conditions: two conditions of high or low percentage of penalizing, each in traditional multiple-choice or CMMT format. In the low penalty condition, the penalty rate was the probability of getting the correct answer by random guessing. In the high penalty condition, students were penalized at twice the percentage of the low penalty condition. The results showed that the number of no response was significantly higher for the CMMT format and the number of random guesses was significantly lower for the CMMT format. There were no significant between the two penalty conditions. This result may be due to the fact that the actual score difference between the two conditions was too small. In the discussion, the possibility of applying CMMT format tests while penalizing wrong answers in actual testing settings was addressed.Keywords: computerized modified multiple choice test format, multiple-choice test format, penalizing, test format
Procedia PDF Downloads 1642365 Application of the Bionic Wavelet Transform and Psycho-Acoustic Model for Speech Compression
Authors: Chafik Barnoussi, Mourad Talbi, Adnane Cherif
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In this paper we propose a new speech compression system based on the application of the Bionic Wavelet Transform (BWT) combined with the psychoacoustic model. This compression system is a modified version of the compression system using a MDCT (Modified Discrete Cosine Transform) filter banks of 32 filters each and the psychoacoustic model. This modification consists in replacing the banks of the MDCT filter banks by the bionic wavelet coefficients which are obtained from the application of the BWT to the speech signal to be compressed. These two methods are evaluated and compared with each other by computing bits before and bits after compression. They are tested on different speech signals and the obtained simulation results show that the proposed technique outperforms the second technique and this in term of compressed file size. In term of SNR, PSNR and NRMSE, the outputs speech signals of the proposed compression system are with acceptable quality. In term of PESQ and speech signal intelligibility, the proposed speech compression technique permits to obtain reconstructed speech signals with good quality.Keywords: speech compression, bionic wavelet transform, filterbanks, psychoacoustic model
Procedia PDF Downloads 3742364 Steepest Descent Method with New Step Sizes
Authors: Bib Paruhum Silalahi, Djihad Wungguli, Sugi Guritman
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Steepest descent method is a simple gradient method for optimization. This method has a slow convergence in heading to the optimal solution, which occurs because of the zigzag form of the steps. Barzilai and Borwein modified this algorithm so that it performs well for problems with large dimensions. Barzilai and Borwein method results have sparked a lot of research on the method of steepest descent, including alternate minimization gradient method and Yuan method. Inspired by previous works, we modified the step size of the steepest descent method. We then compare the modification results against the Barzilai and Borwein method, alternate minimization gradient method and Yuan method for quadratic function cases in terms of the iterations number and the running time. The average results indicate that the steepest descent method with the new step sizes provide good results for small dimensions and able to compete with the results of Barzilai and Borwein method and the alternate minimization gradient method for large dimensions. The new step sizes have faster convergence compared to the other methods, especially for cases with large dimensions.Keywords: steepest descent, line search, iteration, running time, unconstrained optimization, convergence
Procedia PDF Downloads 5372363 Removal of Textile Dye from Industrial Wastewater by Natural and Modified Diatomite
Authors: Hakim Aguedal, Abdelkader Iddou, Abdallah Aziz, Djillali Reda Merouani, Ferhat Bensaleh, Saleh Bensadek
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The textile industry produces high amount of colored effluent each year. The management or treatment of these discharges depends on the applied techniques. Adsorption is one of wastewater treatment techniques destined to treat this kind of pollution, and the performance and efficiency predominantly depend on the nature of the adsorbent used. Therefore, scientific research is directed towards the development of new materials using different physical and chemical treatments to improve their adsorption capacities. In the same perspective, we looked at the effect of the heat treatment on the effectiveness of diatomite, which is found in abundance in Algeria. The textile dye Orange Bezaktiv (SRL-150) which is used as organic pollutants in this study is provided by the textile company SOITEXHAM in Oran city (west Algeria). The effect of different physicochemical parameters on the adsorption of SRL-150 on natural and modified diatomite is studied, and the results of the kinetics and adsorption isotherms were modeled.
Keywords: wastewater treatment, diatomite, adsorption, dye pollution, kinetic, isotherm
Procedia PDF Downloads 2712362 DFT Study of Half Sandwich of Vanadium (IV) Cyclopentadienyl Complexes
Authors: Salem El-Tohami Ashoor
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A novel new vanadium (IV) complexes incorporating the chelating diamido cyclopentadienyl {ArN(CH2)3NAr)}2-((ηn-Cp)Cp)} (Ar = 2,6-Pri2C6H3)(Cp = C5H5 and n = 1,2,3,4 and 5) have been studied with calculation of the properties of species involved in various of cyclopentadienyl reaction. These were carried out under investigation of density functional theory (DFT) calculation, and comparing together. Other methods, explicitly including electron correlation, are necessary for more accurate calculations; MB3LYP (Becke) (Lee–Yang–Parr) level of theory often being used to obtain more exact results. These complexes were estimated of electronic energy for molecular system, because it accounts for all electron correlation interactions. The optimised of [V(ArN(CH2)3NAr)2Cl(η5-Cp)] (Ar = 2,6-Pri2C6H3 and Cp= C5H5) was found to be thermally more stable than others of vanadium cyclopentadienyl. In the meantime the complex [V(ArN(CH2)3NAr)2Cl(η1-Cp)] (Ar = 2,6-Pri2C6H3 and Cp= C5H5) which is showed a low thermal stability in case of the just one carbon of cyclopentadienyl can be insertion with vanadium metal centre. By using Dewar-Chatt-Duncanson model, as a basis of the molecular orbital (MO) analysis and showed the highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital LUMO.Keywords: vanadium (IV) cyclopentadienyl complexes, DFT, MO, HOMO, LUMO
Procedia PDF Downloads 4062361 A Comparison of the Adsorption Mechanism of Arsenic on Iron-Modified Nanoclays
Authors: Michael Leo L. Dela Cruz, Khryslyn G. Arano, Eden May B. Dela Pena, Leslie Joy Diaz
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Arsenic adsorbents were continuously being researched to ease the detrimental impact of arsenic to human health. A comparative study on the adsorption mechanism of arsenic on iron modified nanoclays was undertaken. Iron intercalated montmorillonite (Fe-MMT) and montmorillonite supported zero-valent iron (ZVI-MMT) were the adsorbents investigated in this study. Fe-MMT was produced through ion-exchange by replacing the sodium intercalated ions in montmorillonite with iron (III) ions. The iron (III) in Fe-MMT was later reduced to zero valent iron producing ZVI-MMT. Adsorption study was performed by batch technique. Obtained data were fitted to intra-particle diffusion, pseudo-first order, and pseudo-second-order models and the Elovich equation to determine the kinetics of adsorption. The adsorption of arsenic on Fe-MMT followed the intra-particle diffusion model with intra-particle rate constant of 0.27 mg/g-min0.5. Arsenic was found to be chemically bound on ZVI-MMT as suggested by the pseudo-second order and Elovich equation. The derived pseudo-second order rate constant was 0.0027 g/mg-min with initial adsorption rate computed from the Elovich equation was 113 mg/g-min.Keywords: adsorption mechanism, arsenic, montmorillonite, zero valent iron
Procedia PDF Downloads 4072360 Effect of Rice Husk Ash on Properties of Cold Bituminous Emulsion Mix
Authors: Sampada Katekar, Namdeo Hedaoo
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Cold Bituminous Emulsion Mixtures (CBEMs) are generally produced by mixing unheated aggregate, binder and filler at ambient temperature. Cold bituminous emulsion mixtures have several environmental and cost-effective benefits. But CBEMs offer poor early life properties too and they require long curing time to achieve maximum strength. The main focus of this study is to overcome inferiority of CBEMs by incorporating Rice Husk Ash (RHA) and Ordinary Portland Cement (OPC). In this study, RHA and OPC are substituted for conventional mineral filler in an increased percentage from 0 to 3% with an increment of 1%. Marshall stability, retained stability and tensile strength tests were conducted to evaluate the enhancement in performance of CBEMs. The experimental results have shown that Marshall stability and tensile strength of CBEMs increased significantly by replacing the conventional mineral filler with RHA and OPC. The addition of RHA and OPC in CBEMs result in a reduction in moisture induced damages. However, stability and tensile strength values of RHA modified CBEMs are higher than that of OPC modified CBEMs.Keywords: cold bituminous emulsion mixtures, Marshall stability test, ordinary Portland cement, rice husk ash
Procedia PDF Downloads 1622359 Effect of Modified Layered Silicate Nanoclay on the Dynamic Viscoelastic Properties of Thermoplastic Polymers Nanocomposites
Authors: Benalia Kouini, Aicha Serier
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This work aims to investigate the structure–property relationship in ternary nanocomposites consisting of polypropylene as the matrix, polyamide 66 as the minor phase and treated nanoclay DELLITE 67G as the reinforcement. All PP/PA66/Nanoclay systems with polypropylene grafted maleic anhydride PP-g-MAH as a compatibilizer were prepared via melt compounding and characterized in terms of nanoclay content. Morphological structure was investigated by scanning electron microscopy. The rheological behavior of the nanocomposites was determined by various methods, viz melt flow index (MFI) and parallel plate rheological measurements. The PP/PP-g-MAH/PA66 nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PP, PA66 and nanoclay. SEM results revealed the formation of nanocomposites as the nanoclay was intercalated and exfoliated. In the ternary nanocomposites, the rheological behavior showed that, the complex viscosity is increased with increasing the nanoclay content; however, at low frequencies this increase is governed by the content of nanofiller while at high frequencies it is mainly determined by talc content. A similar trend was also observed for the variations of storage modulus (G′) and loss modulus (G″) with frequency. The results showed that the use of nanoclay considerably affects the melt elasticity.Keywords: nanocomposites, polypropylene, polyamide66, modified nanoclay, rheology
Procedia PDF Downloads 3762358 Existence and Stability of Periodic Traveling Waves in a Bistable Excitable System
Authors: M. Osman Gani, M. Ferdows, Toshiyuki Ogawa
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In this work, we proposed a modified FHN-type reaction-diffusion system for a bistable excitable system by adding a scaled function obtained from a given function. We study the existence and the stability of the periodic traveling waves (or wavetrains) for the FitzHugh-Nagumo (FHN) system and the modified one and compare the results. The stability results of the periodic traveling waves (PTWs) indicate that most of the solutions in the fast family of the PTWs are stable for the FitzHugh-Nagumo equations. The instability occurs only in the waves having smaller periods. However, the smaller period waves are always unstable. The fast family with sufficiently large periods is always stable in FHN model. We find that the oscillation of pulse widths is absent in the standard FHN model. That motivates us to study the PTWs in the proposed FHN-type reaction-diffusion system for the bistable excitable media. A good agreement is found between the solutions of the traveling wave ODEs and the corresponding whole PDE simulation.Keywords: bistable system, Eckhaus bifurcation, excitable media, FitzHugh-Nagumo model, periodic traveling waves
Procedia PDF Downloads 1802357 Applying the Crystal Model Approach on Light Nuclei for Calculating Radii and Density Distribution
Authors: A. Amar
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A new model, namely the crystal model, has been modified to calculate the radius and density distribution of light nuclei up to ⁸Be. The crystal model has been modified according to solid-state physics, which uses the analogy between nucleon distribution and atoms distribution in the crystal. The model has analytical analysis to calculate the radius where the density distribution of light nuclei has obtained from analogy of crystal lattice. The distribution of nucleons over crystal has been discussed in a general form. The equation that has been used to calculate binding energy was taken from the solid-state model of repulsive and attractive force. The numbers of the protons were taken to control repulsive force, where the atomic number was responsible for the attractive force. The parameter has been calculated from the crystal model was found to be proportional to the radius of the nucleus. The density distribution of light nuclei was taken as a summation of two clusters distribution as in ⁶Li=alpha+deuteron configuration. A test has been done on the data obtained for radius and density distribution using double folding for d+⁶,⁷Li with M3Y nucleon-nucleon interaction. Good agreement has been obtained for both the radius and density distribution of light nuclei. The model failed to calculate the radius of ⁹Be, so modifications should be done to overcome discrepancy.Keywords: nuclear physics, nuclear lattice, study nucleus as crystal, light nuclei till to ⁸Be
Procedia PDF Downloads 1702356 Diamond-Like Carbon-Based Structures as Functional Layers on Shape-Memory Alloy for Orthopedic Applications
Authors: Piotr Jablonski, Krzysztof Mars, Wiktor Niemiec, Agnieszka Kyziol, Marek Hebda, Halina Krawiec, Karol Kyziol
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NiTi alloys, possessing unique mechanical properties such as pseudoelasticity and shape memory effect (SME), are suitable for many applications, including implanthology and biomedical devices. Additionally, these alloys have similar values of elastic modulus to those of human bones, what is very important in orthopedics. Unfortunately, the environment of physiological fluids in vivo causes unfavorable release of Ni ions, which in turn may lead to metalosis as well as allergic reactions and toxic effects in the body. For these reasons, the surface properties of NiTi alloys should be improved to increase corrosion resistance, taking into account biological properties, i.e. excellent biocompatibility. The prospective in this respect are layers based on DLC (Diamond-Like Carbon) structures, which are an attractive solution for many applications in implanthology. These coatings (DLC), usually obtained by PVD (Physical Vapour Deposition) and PA CVD (Plasma Activated Chemical Vapour Deposition) methods, can be also modified by doping with other elements like silicon, nitrogen, oxygen, fluorine, titanium and silver. These methods, in combination with a suitably designed structure of the layers, allow the possibility co-decide about physicochemical and biological properties of modified surfaces. Mentioned techniques provide specific physicochemical properties of substrates surface in a single technological process. In this work, the following types of layers based on DLC structures (incl. Si-DLC or Si/N-DLC) were proposed as prospective and attractive approach in surface functionalization of shape memory alloy. Nitinol substrates were modified in plasma conditions, using RF CVD (Radio Frequency Chemical Vapour Deposition). The influence of plasma treatment on the useful properties of modified substrates after deposition DLC layers doped with silica and/or nitrogen atoms, as well as only pre-treated in O2 NH3 plasma atmosphere in a RF reactor was determined. The microstructure and topography of the modified surfaces were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Furthermore, the atomic structure of coatings was characterized by IR and Raman spectroscopy. The research also included the evaluation of surface wettability, surface energy as well as the characteristics of selected mechanical and biological properties of the layers. In addition, the corrosion properties of alloys after and before modification in the physiological saline were also investigated. In order to determine the corrosion resistance of NiTi in the Ringer solution, the potentiodynamic polarization curves (LSV – Linear Sweep Voltamperometry) were plotted. Furthermore, the evolution of corrosion potential versus immersion time of TiNi alloy in Ringer solution was performed. Based on all carried out research, the usefullness of proposed modifications of nitinol for medical applications was assessed. It was shown, inter alia, that the obtained Si-DLC layers on the surface of NiTi alloy exhibit a characteristic complex microstructure, increased surface development, which is an important aspect in improving the osteointegration of an implant. Furthermore, the modified alloy exhibits biocompatibility, the transfer of the metal (Ni, Ti) to Ringer’s solution is clearly limited.Keywords: bioactive coatings, corrosion resistance, doped DLC structure, NiTi alloy, RF CVD
Procedia PDF Downloads 2292355 Preparation Nanocapsules of Chitosan Modified With Selenium Extracted From the Lactobacillus Acidophilus and Their Anticancer Properties
Authors: Akbar Esmaeili, Mahnoosh Aliahmadi
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This study synthesized a modified imaging of gallium@deferoxamine/folic acid/chitosan/polyaniline/polyvinyl alcohol (Ga@DFA/FA/CS/PANI/PVA). It contains Morus nigra extract by selenium nanoparticles prepared from Lactobacillus acidophilus. Using the impregnation method, Se nanoparticles were then deposited on (Ga@DFA/FA/ CS/PANI/PVA). The modified contrast agents were mixed with M. nigra extract, and investigated their antibacterial activities by applying to L929 cell lines. The influence of variable factors, including 1. surfactant, 2. solvent, 3. aqueous phase, 4. pH, 5. buffer, 6. minimum Inhibitory concentration (MIC), 7. minimum bactericidal concentration (MBC), 8. cytotoxicity on cancer cells., 9. antibiotic, 10. antibiogram, 11. release and loading, 12. the emotional effect, 13. the concentration of nanoparticles, 14. olive oil, and 15. they have investigated thermotical methods. The structure and morphology of the synthesized contrast agents were characterized by zeta potential sizer analysis (ZPS), X-Ray diffraction (XRD), Fourier-transform infrared (FT-IR), energy dispersive X-ray (EDX), ultraviolet–visible (UV–Vis) spectra, and scanning electron microscope (SEM). The experimental section was conducted and monitored by response surface methods (RSM), MTT, MIC, MBC, and cancer cytotoxic conversion assay. Antibiogram testing of NCs on Pseudomonas aeruginosa bacteria was successful and obtained MIC = 2 factors with less harmful effect. All experimental sections confirmed that our synthesized particles have potent antioxidant properties. Antibiogram testing revealed that NPS could kill P. aeruginosa and P. aeruginosa. A variety of synthetic conditions were done by diffusion emulsion method by varying parameters, the optimum state of DFA release Ga@DFA/FA/CS/PANI/PVA NPs (6 ml) with pH = 5.5, time = 3 h, NCs and DFA (3 mg), and achieved buffer (20 ml). DFA in Ga@DFA/FA/ CS/PANI/PVA was released and showed an absorption peak at 378 nm by applying a 300-rpm magnetic rate. In this report, Ga decreased the harmful effect on the human body.Keywords: nanocapsules, technolgy, biology, nano
Procedia PDF Downloads 322354 The Batch Method Approach for Adsorption Mechanism Processes of Some Selected Heavy Metal Ions and Methylene Blue by Using Chemically Modified Luffa Cylindrica
Authors: Akanimo Emene, Mark D. Ogden, Robert Edyvean
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Adsorption is a low cost, efficient and economically viable wastewater treatment process. Utilization of this treatment process has not been fully applied due to the complex and not fully understood nature of the adsorption system. To optimize its process is to choose a sufficient adsorbent and to study further the experimental parameters that influence the adsorption design system. Chemically modified adsorbent, Luffa cylindrica, was used to adsorb heavy metal ions and an organic pollutant, methylene blue, from aqueous environmental solution at varying experimental conditions. Experimental factors, adsorption time, initial metal ion or organic pollutant concentration, ionic strength, and pH of solution were studied. The experimental data were analyzed with kinetic and isotherm models. The antagonistic effect of the methylene and some heavy metal ions were recorded. An understanding of the use of this treated Luffa cylindrica for the removal of these toxic substances will establish and improve the commercial application of the adsorption process in treatment of contaminated waters.Keywords: adsorption, heavy metal ions, Luffa cylindrica, wastewater treatment
Procedia PDF Downloads 1882353 Investigating Geopolymerization Process of Aluminosilicates and its Impact on the Compressive Strength of the Produced Geopolymers
Authors: Heba Fouad, Tarek M. Madkour, Safwan A. Khedr
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This paper investigates multiple factors that impact the formation of geopolymers and their compressive strength to be utilized in construction as an environmentally-friendly material. Bentonite and Kaolinite were thermally calcinated at 750 °C to obtain Metabentonite and Metakaolinite with higher reactivity. Both source materials were activated using a solution of sodium hydroxide (NaOH). Thereafter, samples were cured at different temperatures. The samples were analyzed chemically using a host of spectroscopic techniques. The bulk density and compressive strength of the produced Geopolymer pastes were studied. Findings indicate that the ratio of NaOH solution to source material affects the compressive strength, being optimal at 0.54. Moreover, controlled heat curing was proven effective to improve compressive strength. The existence of characteristic Fourier Transform Infrared Spectroscopy (FTIR) peaks at approximately 1020 cm-1 and 460 cm-1 which corresponds to the asymmetric stretching vibration of Si-O-T and bending vibration of Si-O-Si, hence, confirming the formation of the target geopolymer.Keywords: calcination of metakaolinite, compressive strength, FTIR analysis, geopolymer, green cement
Procedia PDF Downloads 1572352 Poly(S/DVB)HIPE Filled with Cellulose from Water Hyacinth
Authors: Metinee Kawsomboon, Thanchanok Tulaphol, Manit Nithitanakul, Jitima Preechawong
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PolyHIPE is a porous polymeric material from polymerization of high internal phase emulsion (HIPE) which contains 74% of internal phase (disperse phase) and 26 % of external phase (continues phase). Typically, polyHIPE was prepared from styrene (S) and divinylbenzene (DVB) and they were used in various kind of applications such as catalyst support, gas adsorption, separation membranes, and tissue engineering scaffolds due to high specific surface areas, high porousity, ability to adsorb large quantities of liquid. In this research, cellulose from water hyacinth (Eichornia Crassipes), an aquatic plant that grows and spread rapidly in rivers and waterways in Thailand was added into polyHIPE to increase mechanical property of polyHIPE. Addition of unmodified and modified cellulose to poly(S/DVB)HIPE resulting in a decrease in the surface area and thermal stability of the resulting materials. Mechanical properties of the resulting polyHIPEs filled with both unmodified and modified cellulose exhibited higher compressive strength and Young’s modulus by 146.3% and 162.5% respectively, compared to unfilled polyHIPEs. The water adsorption capacity of filled polyHIPE was also improved.Keywords: porous polymer, PolyHIPE, cellulose, surface modification, water hyacinth
Procedia PDF Downloads 1342351 Increased Circularity in Metals Production Using the Ausmelt TSL Process
Authors: Jacob Wood, David Wilson, Stephen Hughes
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The Ausmelt Top Submerged Lance (TSL) Process has been widely applied for the processing of both primary and secondary copper, nickel, lead, tin, and zinc-bearing feed materials. Continual development and evolution of the technology over more than 30 years has resulted in a more intense smelting process with higher energy efficiency, improved metal recoveries, lower operating costs, and reduced fossil fuel consumption. This paper covers a number of recent advances to the technology, highlighting their positive impacts on smelter operating costs, environmental performance, and contribution towards increased circularity in metals production.Keywords: ausmelt TSL, smelting, circular economy, energy efficiency
Procedia PDF Downloads 2312350 Feedback from a Service Evaluation of a Modified Intrauterine Device Insertor: A First Step to a Changement of the Standard of Iud Insertion Procedure
Authors: Desjardin, Michaels, Martinez, Ulmann
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Copper IUD is one of the most efficient and cost-effective contraception. However, pain at insertion hampers the use of this method. This is especially unfortunate in nulliparous women, often younger, who are excellent candidates for this contraception, including Emergency Contraception. Standard insertion procedure of a copper IUD usually involves measurement of uterine cavity with an hysterometer and the use of a tenaculum in order to facilitate device insertion. Both procedures lead to patient pain which often constitutes a limitation of the method. To overcome these issues, we have developed a modified insertor combined with a copper IUD. The singular design of the inserter includes a flexible inflatable membrane technology allowing an easy access to the uterine cavity even in case of abnormal uterine positions or narrow cervical canal. Moreover, this inserter makes possible a direct IUD insertion with no hysterometry and no need for tenaculum. To assess device effectiveness and patient-reported pain, a study was conducted at two clinics in Fance with 31 individuals who wanted to use a copper IUD as contraceptive method. IUD insertions have been performed by four healthcare providers. Operators completed questionnaire and evaluated effectiveness of the procedure (including IUD correct fundal placement and other usability questions) as their satisfaction. Patient also completed questionnaire and pain during procedure was measured on a 10-cm Visual Analogue Scale (VAS). Analysis of the questionnaires indicates that correct IUD placement took place in more than 93% of women, which is a standard efficacy rate. It also demonstrates that IUD insertion resulted in no, light or moderate pain predominantly in nulliparous women. No insertion resulted in severe pain (none above 6cm on a 10-cm VAS). This translated by a high level of satisfaction from both patients and practitioners. In addition, this modified inserter allowed a simplification of the insertion procedure: correct fundal placement was ensured with no need for hysterometry (100%) prior to insertion nor for cervical tenaculum to pull on the cervix (90%). Avoidance of both procedures contributed to the decrease in pain during insertion. Taken together, the results of the study demonstrate that this device constitutes a significant advance in the use of copper IUDs for any woman. It allows a simplification of the insertion procedure: there is no need for pre-insertion hysterometry and no need for traction on the cervix with tenaculum. Increased comfort during insertion should allow a wider use of the method for nulliparous women and for emergency contraception. In addition, pain is often underestimated by practitioners, but fear of pain is obviously one of the blocking factors as indicated by the analysis of the questionnaire. This evaluation brings interesting information on the use of this modified inserter for standard copper IUD and promising perspectives to set up a changement in the standard of IUD insertion procedure.Keywords: contraceptio, IUD, innovation, pain
Procedia PDF Downloads 752349 Benefits of High Power Impulse Magnetron Sputtering (HiPIMS) Method for Preparation of Transparent Indium Gallium Zinc Oxide (IGZO) Thin Films
Authors: Pavel Baroch, Jiri Rezek, Michal Prochazka, Tomas Kozak, Jiri Houska
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Transparent semiconducting amorphous IGZO films have attracted great attention due to their excellent electrical properties and possible utilization in thin film transistors or in photovoltaic applications as they show 20-50 times higher mobility than that of amorphous silicon. It is also known that the properties of IGZO films are highly sensitive to process parameters, especially to oxygen partial pressure. In this study we have focused on the comparison of properties of transparent semiconducting amorphous indium gallium zinc oxide (IGZO) thin films prepared by conventional sputtering methods and those prepared by high power impulse magnetron sputtering (HiPIMS) method. Furthermore we tried to optimize electrical and optical properties of the IGZO thin films and to investigate possibility to apply these coatings on thermally sensitive flexible substrates. We employed dc, pulsed dc, mid frequency sine wave and HiPIMS power supplies for magnetron deposition. Magnetrons were equipped with sintered ceramic InGaZnO targets. As oxygen vacancies are considered to be the main source of the carriers in IGZO films, it is expected that with the increase of oxygen partial pressure number of oxygen vacancies decreases which results in the increase of film resistivity. Therefore in all experiments we focused on the effect of oxygen partial pressure, discharge power and pulsed power mode on the electrical, optical and mechanical properties of IGZO thin films and also on the thermal load deposited to the substrate. As expected, we have observed a very fast transition between low- and high-resistivity films depending on oxygen partial pressure when deposition using conventional sputtering methods/power supplies have been utilized. Therefore we established and utilized HiPIMS sputtering system for enlargement of operation window for better control of IGZO thin film properties. It is shown that with this system we are able to effectively eliminate steep transition between low and high resistivity films exhibited by DC mode of sputtering and the electrical resistivity can be effectively controlled in the wide resistivity range of 10-² to 10⁵ Ω.cm. The highest mobility of charge carriers (up to 50 cm2/V.s) was obtained at very low oxygen partial pressures. Utilization of HiPIMS also led to significant decrease in thermal load deposited to the substrate which is beneficial for deposition on the thermally sensitive and flexible polymer substrates. Deposition rate as a function of discharge power and oxygen partial pressure was also systematically investigated and the results from optical, electrical and structure analysis will be discussed in detail. Most important result which we have obtained demonstrates almost linear control of IGZO thin films resistivity with increasing of oxygen partial pressure utilizing HiPIMS mode of sputtering and highly transparent films with low resistivity were prepared already at low pO2. It was also found that utilization of HiPIMS technique resulted in significant improvement of surface smoothness in reactive mode of sputtering (with increasing of oxygen partial pressure).Keywords: charge carrier mobility, HiPIMS, IGZO, resistivity
Procedia PDF Downloads 2922348 Effective Virtual Tunnel Shape for Motion Modification in Upper-Limb Perception-Assist with a Power-Assist Robot
Authors: Kazuo Kiguchi, Kouta Ikegami
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In the case of physically weak persons, not only motor abilities, but also sensory abilities are sometimes deteriorated. The concept of perception-assist has been proposed to assist the sensory ability of the physically weak persons with a power-assist robot. Since upper-limb motion is very important in daily living, perception-assist for upper-limb motion has been proposed to assist upper-limb motion in daily living. A virtual tunnel was applied to modify the user’s upper-limb motion if it was necessary. In this paper, effective shape of the virtual tunnel which is applied in the perception-assist for upper-limb motion is proposed. Not only the position of the grasped tool but also the angle of the grasped tool are modified if it is necessary. Therefore, the upper-limb motion in daily living can be effectively modified to realize certain proper daily motion. The effectiveness of the proposed virtual tunnel was evaluated by performing the experiments.Keywords: motion modification, power-assist robots, perception-assist, upper-limb motion
Procedia PDF Downloads 2372347 Segregation Patterns of Trees and Grass Based on a Modified Age-Structured Continuous-Space Forest Model
Authors: Jian Yang, Atsushi Yagi
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Tree-grass coexistence system is of great importance for forest ecology. Mathematical models are being proposed to study the dynamics of tree-grass coexistence and the stability of the systems. However, few of the models concentrates on spatial dynamics of the tree-grass coexistence. In this study, we modified an age-structured continuous-space population model for forests, obtaining an age-structured continuous-space population model for the tree-grass competition model. In the model, for thermal competitions, adult trees can out-compete grass, and grass can out-compete seedlings. We mathematically studied the model to make sure tree-grass coexistence solutions exist. Numerical experiments demonstrated that a fraction of area that trees or grass occupies can affect whether the coexistence is stable or not. We also tried regulating the mortality of adult trees with other parameters and the fraction of area trees and grass occupies were fixed; results show that the mortality of adult trees is also a factor affecting the stability of the tree-grass coexistence in this model.Keywords: population-structured models, stabilities of ecosystems, thermal competitions, tree-grass coexistence systems
Procedia PDF Downloads 1462346 Characterization of the Ignitability and Flame Regression Behaviour of Flame Retarded Natural Fibre Composite Panel
Authors: Timine Suoware, Sylvester Edelugo, Charles Amgbari
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Natural fibre composites (NFC) are becoming very attractive especially for automotive interior and non-structural building applications because they are biodegradable, low cost, lightweight and environmentally friendly. NFC are known to release high combustible products during exposure to heat atmosphere and this behaviour has raised concerns to end users. To improve on their fire response, flame retardants (FR) such as aluminium tri-hydroxide (ATH) and ammonium polyphosphate (APP) are incorporated during processing to delay the start and spread of fire. In this paper, APP was modified with Gum Arabic powder (GAP) and synergized with carbon black (CB) to form new FR species. Four FR species at 0, 12, 15 and 18% loading ratio were added to oil palm fibre polyester composite (OPFC) panels as follows; OPFC12%APP-GAP, OPFC15%APP-GAP/CB, OPFC18%ATH/APP-GAP and OPFC18%ATH/APPGAP/CB. The panels were produced using hand lay-up compression moulding and cured at room temperature. Specimens were cut from the panels and these were tested for ignition time (Tig), peak heat released rate (HRRp), average heat release rate (HRRavg), peak mass loss rate (MLRp), residual mass (Rm) and average smoke production rate (SPRavg) using cone calorimeter apparatus as well as the available flame energy (ɸ) in driving the flame using radiant panel flame spread apparatus. From the ignitability data obtained at 50 kW/m2 heat flux (HF), it shows that the hybrid FR modified with APP that is OPFC18%ATH/APP-GAP exhibited superior flame retardancy and the improvement was based on comparison with those without FR which stood at Tig = 20 s, HRRp = 86.6 kW/m2, HRRavg = 55.8 kW/m2, MLRp =0.131 g/s, Rm = 54.6% and SPRavg = 0.05 m2/s representing respectively 17.6%, 67.4%, 62.8%, 50.9%, 565% and 62.5% improvements less than those without FR (OPFC0%). In terms of flame spread, the least flame energy (ɸ) of 0.49 kW2/s3 for OPFC18%ATH/APP-GAP caused early flame regression. This was less than 39.6 kW2/s3 compared to those without FR (OPFC0%). It can be concluded that hybrid FR modified with APP could be useful in the automotive and building industries to delay the start and spread of fire.Keywords: flame retardant, flame regression, oil palm fibre, composite panel
Procedia PDF Downloads 1242345 A Modified Periodic 2D Cellular Re-Entrant Honeycomb Model to Enhance the Auxetic Elastic Properties
Authors: Sohaib Z. Khan, Farrukh Mustahsan, Essam R. I. Mahmoud, S. H. Masood
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Materials or structures that contract laterally on the application of a compressive load and vice versa are said to be Auxetic materials which exhibit Negative Poisson’s Ratio (NPR). Numerous auxetic structures are proposed in the literature. One of the most studied periodic auxetic structure is the re-entrant honeycomb model. In this paper, a modified re-entrant model is proposed to enhance the auxetic behavior. The paper aimed to investigate the elastic behaviour of the proposed model to improve Young’s modulus and NPR by evaluating the analytical model. Finite Element Analysis (FEA) is also conducted to support the analytical results. A significant increment in Young’s modulus and NPR can be achieved in one of the two orthogonal directions of the loading at the cost of compromising these values in other direction. The proposed modification resulted in lower relative densities when compared to the existing re-entrant honeycomb structure. A trade-off in the elastic properties in one direction at low relative density makes the proposed model suitable for uni-direction applications where higher stiffness and NPR is required, and strength to weight ratio is important.Keywords: 2D model, auxetic materials, re-entrant honeycomb, negative Poisson's ratio
Procedia PDF Downloads 1302344 Ultradrawing and Ultimate Pensile Properties of Ultra-High Molecular Weight Polyethylene Nanocomposite Fibers Filled with Cellulose Nanofibers
Authors: Zhong-Dan Tu, Wang-Xi Fan, Yi-Chen Huang, Jen-Taut Yeh
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Novel ultrahigh molecular weight polyethylene (UHMWPE)/cellulose nanofiber (CNF) (F100CNFy) and UHMWPE/modified cellulose nanofiber (MCNF) (F100MCNFxy) as-prepared nanocomposite fibers were prepared by spinning F100CNFy and F100MCNFxy gel solutions, respectively. Cellulose nanofibers were successfully prepared by proper acid treatment of cotton fibers using sulfuric acid solutions. The best prepared CNF is with specific surface areas around 120 m2/g and a nanofiber diameter of 20 nm. Modified cellulose nanofiber was prepared by grafting maleic anhydride grafted polyethylene (PE-g-MAH) onto cellulose nanofibers. The achievable draw ratio (Dra) values of each F100MCNFxy as-prepared fiber series specimens approached a maximal value as their MCNF contents reached the optimal value at 0.05 phr. In which, the maximum Dra value obtained for F100MCNFx0.05 as-prepared fiber specimen prepared at the optimal MCNF content reached another maximum value as the weight ratio of PE-g-MAH to CNF approach an optimal value at 6. Similar to those found for the achievable drawing properties of the as-prepared fibers, the orientation factor, tensile strength (σ f) and initial modulus (E) values of drawn F100MCNF6y fiber series specimens with a fixed draw ratio reach a maximal value as their MCNF contents approach the optimal value, wherein the σ f and E values of the drawn F100MCNFxy fiber specimens are significantly higher than those of the drawn F100 fiber specimens and corresponding drawn F100CNFy fiber specimens prepared at the same draw ratios and CNF contents but without modification. To understand the interesting ultradrawing, thermal, orientation and tensile properties of F100CNFy and F100MCNFxy fiber specimens, Fourier transform infra-red, specific surface areas, and transmission electron microcopic analyses of the original and modified CNF nanofillers were performed in this study.Keywords: ultradrawing, cellulose nanofibers, ultrahigh molecular weight polyethylene, nanocomposite fibers
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