Search results for: soils index properties
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 12618

Search results for: soils index properties

9198 Magnetic Fluctuations in the Terrestrial Magnetosheath

Authors: Alexandre Gurchumelia, Luca Sorriso-Valvo, David Burgess, Khatuna Elbakidze, Oleg Kharshiladze, Diana Kvaratskhelia

Abstract:

The terrestrial magnetosheath is a highly turbulent medium, with a high level of magnetic1field fluctuations throughout a broad range of scales. These often include an inertial range where a2magnetohydrodynamic turbulent cascade is observed. The multifractal properties of the turbulent3cascade, strictly related to intermittency, are observed here during the transition from quasi-parallel to4quasi-perpendicular magnetic field with respect to the bow-shock normal. The different multifractal5behavior in the two regions is analyzed. A standard coarse-graining technique has been used6to evaluate the generalized dimensions and the corresponding multifractal spectrumf(α). A7p-model fit provided a quantitative measure of multifractality and intermittency, to be compared with8standard indicators: the width of the multifractal spectrum, the peak of the kurtosis, and its scaling9exponent. Results show a clear transition and sharp differences in the intermittency properties for the two regions.

Keywords: magnetos heath, turbulence, multifractal, instabilities

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9197 Finite Element Analysis of Shape Memory Alloy Stents in Coronary Arteries

Authors: Amatulraheem Al-Abassi, K. Khanafer, Ibrahim Deiab

Abstract:

The coronary artery stent is a promising technology that can treat various coronary diseases. Materials used for manufacturing medical stents should have high biocompatible properties. Stent alloys, in particular, are remarkably promising good clinical outcomes, however, there is threaten of restenosis (reoccurring of artery narrowing due to fatty plaque), stent recoiling, or in long-term the occurrence of stent fracture. However, stents that are made of Nickel-titanium (Nitinol) can bare extensive plastic deformation and resist restenosis. This shape memory alloy has outstanding mechanical properties. Nitinol is a unique shape memory alloy as it has unique mechanical properties such as; biocompatibility, super-elasticity, and recovery to original shape under certain loads. Stent failure may cause complications in vascular diseases and possibly blockage of blood flow. Thus, studying the behaviors of the stent under different medical conditions will help the doctors and cardiologists to predict when it is necessary to change the stent in order to prevent any severe morbidity outcomes. To the best of our knowledge, there are limited published papers that analyze the stent behavior with regards to the contact surfaces of plaque layer and blood vessel. Thus, stent material properties will be discussed in this investigation to highlight the mechanical and clinical differences between various stents. This research analyzes the performance of Nitinol stent in well-known stent design to determine its bearing with stress and its dislocation in blood vessels, in comparison to stents made of different biocompatible materials. In addition, a study of its performance will be represented in the system. Finite Element Analysis is the core of this study. Thus, a physical representative model will be discussed to show the distribution of stress and strain along the interaction surface between the stent and the artery. The reaction of vascular tissue to the stent will be evaluated to predict the possibility of restenosis within the treated area.

Keywords: shape memory alloy, stent, coronary artery, finite element analysis

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9196 Shear Strength Envelope Characteristics of LimeTreated Clays

Authors: Mohammad Moridzadeh, Gholamreza Mesri

Abstract:

The effectiveness of lime treatment of soils has been commonly evaluated in terms of improved workability and increased undrained unconfined compressive strength in connection to road and airfield construction. The most common method of strength measurement has been the unconfined compression test. However, if the objective of lime treatment is to improve long-term stability of first-time or reactivated landslides in stiff clays and shales, permanent changes in the size and shape of clay particles must be realized to increase drained frictional resistance. Lime-soil interactions that may produce less platy and larger soil particles begin and continue with time under the highly alkaline pH environment. In this research, pH measurements are used to monitor chemical environment and progress of reactions. Atterberg limits are measured to identify changes in particle size and shape indirectly. Also, fully softened and residual strength measurements are used to examine an improvement in frictional resistance due to lime-soil interactions. The main variables are soil plasticity and mineralogy, lime content, water content, and curing period. Lime effect on frictional resistance is examined using samples of clays with different mineralogy and characteristics which may react with lime to various extents. Drained direct shear tests on reconstituted lime-treated clay specimens with various properties have been performed to measure fully softened shear strength. To measure residual shear strength, drained multiple reversal direct shear tests on precut specimens were conducted. This way, soil particles are oriented along the direction of shearing to the maximum possible extent and provide minimum frictional resistance. This is applicable to reactivated and part of first-time landslides. The Brenna clay, which is the highly plastic lacustrine clay of Lake Agassiz causing slope instability along the banks of the Red River, is one of the soil samples used in this study. The Brenna Formation characterized as a uniform, soft to firm, dark grey, glaciolacustrine clay with little or no visible stratification, is full of slickensided surfaces. The major source of sediment for the Brenna Formation was the highly plastic montmorillonitic Pierre Shale bedrock. The other soil used in this study is one of the main sources of slope instability in Harris County Flood Control District (HCFCD), i.e. the Beaumont clay. The shear strengths of untreated and treated clays were obtained under various normal pressures to evaluate the shear envelope nonlinearity.

Keywords: Brenna clay, friction resistance, lime treatment, residual

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9195 Study of Bis(Trifluoromethylsulfonyl)Imide Based Ionic Liquids by Gas Chromatography

Authors: F. Mutelet, L. Cesari

Abstract:

Development of safer and environmentally friendly processes and products is needed to achieve sustainable production and consumption patterns. Ionic liquids, which are of great interest to the chemical and related industries because of their attractive properties as solvents, should be considered. Ionic liquids are comprised of an asymmetric, bulky organic cation and a weakly coordinating organic or inorganic anion. A large number of possible combinations allows for the ability to ‘fine tune’ the solvent properties for a specific purpose. Physical and chemical properties of ionic liquids are not only influenced by the nature of the cation and the nature of cation substituents but also by the polarity and the size of the anion. These features infer to ionic liquids numerous applications, in organic synthesis, separation processes, and electrochemistry. Separation processes required a good knowledge of the behavior of organic compounds with ionic liquids. Gas chromatography is a useful tool to estimate the interactions between organic compounds and ionic liquids. Indeed, retention data may be used to determine infinite dilution thermodynamic properties of volatile organic compounds in ionic liquids. Among others, the activity coefficient at infinite dilution is a direct measure of solute-ionic liquid interaction. In this work, infinite dilution thermodynamic properties of volatile organic compounds in specific bis(trifluoromethylsulfonyl)imide based ionic liquids measured by gas chromatography is presented. It was found that apolar compounds are not miscible in this family of ionic liquids. As expected, the solubility of organic compounds is related to their polarity and hydrogen-bond. Through activity coefficients data, the performance of these ionic liquids was evaluated for different separation processes (benzene/heptane, thiophene/heptane and pyridine/heptane). Results indicate that ionic liquids may be used for the extraction of polar compounds (aromatics, alcohols, pyridine, thiophene, tetrahydrofuran) from aliphatic media. For example, 1-benzylpyridinium bis(trifluoromethylsulfonyl) imide and 1-cyclohexylmethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide are more efficient for the extraction of aromatics or pyridine from aliphatics than classical solvents. Ionic liquids with long alkyl chain length present important capacity values but their selectivity values are low. In conclusion, we have demonstrated that specific bis(trifluoromethylsulfonyl)imide based ILs containing polar chain grafted on the cation (for example benzyl or cyclohexyl) increases considerably their performance in separation processes.

Keywords: interaction organic solvent-ionic liquid, gas chromatography, solvation model, COSMO-RS

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9194 Amelioration of Stability and Rheological Properties of a Crude Oil-Based Drilling Mud

Authors: Hammadi Larbi, Bergane Cheikh

Abstract:

Drilling for oil is done through many mechanisms. The goal is first to dig deep and then, after arriving at the oil source, to simply suck it up. And for this, it is important to know the role of oil-based drilling muds, which had many benefits for the drilling tool and for drilling generally, and also and essentially to know the rheological behavior of the emulsion system in particular water-in-oil inverse emulsions (Water/crude oil). This work contributes to the improvement of the stability and rheological properties of crude oil-based drilling mud by organophilic clay. Experimental data from steady-state flow measurements of crude oil-based drilling mud are classically analyzed by the Herschel-Bulkley model. The effects of organophilic clay type VG69 are studied. Microscopic observation showed that the addition of quantities of organophilic clay type VG69 less than or equal to 3 g leads to the stability of inverse Water/Oil emulsions; on the other hand, for quantities greater than 3g, the emulsions are destabilized.

Keywords: drilling, organophilic clay, crude oil, stability

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9193 The Effect of Salinity and Bentonite on the Hydrous Behaviors and Sodium Content of the Broad Bean Vicia faba var. Semilla violeta

Authors: T. Nouri, Y. H. A. Reguieg, A. Latigui, A. Ouaini

Abstract:

Salinity is considered as the most important abiotic factor. It limits growth and productivity of plants and degrades agricultural soils and ecosystem in arid and semi arid area. The study was conducted on Vicia faba L.’Semilla violeta’. Sowing was realized in plastic pots containing sandy substrates of bentonite 0, 3, 5, 7, and 10% associated with abiotic stresses of salinity corresponding to doses of NaCl, MgCl2 and MgSO4 20, 40, and 60 mmol/l respectively. The purpose of this work is to study the combined effect of salinity and of bentonite on a plant commonly cultivated in Algeria the broad bean Vicia faba has through the chemical and hydrous parameter. The results show that the combined action of strong concentration salt (40 and 60 mmol/l) and of bentonite a reduction of the relative content water reveals, against an increase in the content of hydrous deficit and of sodium. The growth of broad bean is significant in the substrate amended to 5 % of bentonite.

Keywords: salinity, bentonite, Vicia faba L, sodium content, hydrous parameters

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9192 Effects of Daily Temperature Changes on Transient Heat and Moisture Transport in Unsaturated Soils

Authors: Davood Yazdani Cherati, Ali Pak, Mehrdad Jafarzadeh

Abstract:

This research contains the formulation of a two-dimensional analytical solution to transient heat, and moisture flow in a semi-infinite unsaturated soil environment under the influence of daily temperature changes. For this purpose, coupled energy conservation and mass fluid continuity equations governing hydrothermal behavior of unsaturated soil media are presented in terms of temperature and volumetric moisture content. In consideration of the soil environment as an infinite half-space and by linearization of the governing equations, Laplace–Fourier transformation is conducted to convert differential equations with partial derivatives (PDEs) to ordinary differential equations (ODEs). The obtained ODEs are solved, and the inverse transformations are calculated to determine the solution to the system of equations. Results indicate that heat variation induces moisture transport in both horizontal and vertical directions.

Keywords: analytical solution, heat conduction, hydrothermal analysis, laplace–fourier transformation, two-dimensional

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9191 Single Item Presenteeism Question Reliability and Validity of Persian Version in Low Back Pain Patients

Authors: Mohammadreza Khanmohammadi, Noureddin Nakhostin Ansari, Soofia Naghdi

Abstract:

Purpose: Our study aimed to validate single item presenteeism question (SIPQ) into the Persian language for patients with low back pain. Background information: low back pain is a common health problem, and it is one of the most prevalent disorder in working people. There are the different subjective way to evaluate the effect of back pain on work productivity that one of them is by implementing single item presenteeism question. This question has not been validated into the Persian language. Method: Patients were asked to answer SIPQ and pain from 0 to 10 according to numerical rating scale (NRS). The functional rating index was administrated to evaluate construct validity. For test-retest reliability, almost 50 patients re-completed the Persian SIPQ. The construct validity of SIPQ was assessed by analyzing Spearman rank correlation between this question and the Persian version of Functional rating index questionnaire. To analyze test-retest reliability, we assessed intraclass correlation coefficient (agreement) (ICC agreement) (two-way random effects model, single measure). Results: The SIPQ score of two groups of patients (84 males, 16 females, mean age ±SD: 33.85±11.16 years, range: 19-67 years) and healthy subjects (48 male, 2 female ones, mean age ±SD: 24.24 ±8.07 years) was statistically significant. (Mann-Whitney U =198.00, P<.001). The Spearman correlation of data showed that there is a significant correlation between Persian SIPQ score and Persian FRI band (r= .559, P<.001). The ICC was .62. So, the analysis indicated good, test-retest reliability. Conclusion: This study showed that Persian version of SIPQ is reliable and valid when applied to back pain patients.

Keywords: cross cultural adaptation, economic burden, low back pain, Persian language, translation

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9190 Enhancing of Paraffin Wax Properties by Adding of Low Density Polyethylene (LDPE)

Authors: Siham Mezher Yousif, Intisar Yahiya Mohammed, Salma Nagem Mouhy

Abstract:

Low Density Polyethylene is a thermoplastic resin extracted from petroleum based, whereas the wax is an oily organic component that is contains of alkanes, ester, polyester, and hydroxyl ester. The purpose of this research is to find out the optimum conditions of the wax produced by inducing with LDPE. The experiments were carried out by mixing different percentages of wax and LDPE to produce different polymer/wax compositions, in which lower values of the penetration, thickness, and electrical conductivity are obtained with increasing of mixing ratio of LDPE/wax which showed results of 19 mm penetration, 692 micron thickness and 5.9 mA electrical conductivity for 90 wt % of LDPE/wax) maximum mixing ratio (. It’s found that the optimum results regarding penetration, enamel thickness, and electrical conductivity “according to the enamel hardness, insulation properties, and economic aspects” are 20 mm, 276 micron, and 6.2 mA respectively.

Keywords: paraffin wax, low density polyethylene, blending, mixing ratio, bleaching

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9189 Numerical Simulation of Bio-Chemical Diffusion in Bone Scaffolds

Authors: Masoud Madadelahi, Amir Shamloo, Seyedeh Sara Salehi

Abstract:

Previously, some materials like solid metals and their alloys have been used as implants in human’s body. In order to amend fixation of these artificial hard human tissues, some porous structures have been introduced. In this way, tissues in vicinity of the porous structure can be attached more easily to the inserted implant. In particular, the porous bone scaffolds are useful since they can deliver important biomolecules like growth factors and proteins. This study focuses on the properties of the degradable porous hard tissues using a three-dimensional numerical Finite Element Method (FEM). The most important studied properties of these structures are diffusivity flux and concentration of different species like glucose, oxygen, and lactate. The process of cells migration into the scaffold is considered as a diffusion process, and related parameters are studied for different values of production/consumption rates.

Keywords: bone scaffolds, diffusivity, numerical simulation, tissue engineering

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9188 A Frictional-Collisional Closure Model for the Saturated Granular Flow: Experimental Evidence and Two Phase Modelling

Authors: Yunhui Sun, Qingquan Liu, Xiaoliang Wang

Abstract:

Dense granular flows widely exist in geological flows such as debris flow, landslide, or sheet flow, where both the interparticle and solid-liquid interactions are important to modify the flow. So, a two-phase approach with both phases correctly modelled is important for a better investigation of the saturated granular flows. However, a proper closure model covering a wide range of flowing states for the solid phase is still lacking. This study first employs a chute flow experiment based on the refractive index matching method, which makes it possible to obtain internal flow information such as velocity, shear rate, granular fluctuation, and volume fraction. The granular stress is obtained based on a steady assumption. The kinetic theory is found to describe the stress dependence on the flow state well. More importantly, the granular rheology is found to be frictionally dominated under weak shear and collisionally dominated under strong shear. The results presented thus provide direct experimental evidence on a possible frictional-collisional closure model for the granular phase. The data indicates that both frictional stresses exist over a wide range of the volume fraction, though traditional theory believes it vanishes below a critical volume fraction. Based on the findings, a two-phase model is used to simulate the chute flow. Both phases are modelled as continuum media, and the inter-phase interactions, such as drag force and pressure gradient force, are considered. The frictional-collisional model is used for the closure of the solid phase stress. The profiles of the kinematic properties agree well with the experiments. This model is further used to simulate immersed granular collapse, which is unsteady in nature, to study the applicability of this model, which is derived from steady flow.

Keywords: closure model, collision, friction, granular flow, two-phase model

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9187 Experimental Study and Numerical Simulation of the Reaction and Flow on the Membrane Wall of Entrained Flow Gasifier

Authors: Jianliang Xu, Zhenghua Dai, Zhongjie Shen, Haifeng Liu, Fuchen Wang

Abstract:

In an entrained flow gasifier, the combustible components are converted into the gas phase, and the mineral content is converted into ash. Most of the ash particles or droplets are deposited on the refractory or membrane wall and form a slag layer that flows down to the quenching system. The captured particle reaction process and slag flow and phase transformation play an important role in gasifier performance and safe and stable operation. The reaction characteristic of captured char particles on the molten slag had been studied by applied a high-temperature stage microscope. The gasification process of captured chars with CO2 on the slag surface was observed and recorded, compared to the original char gasification. The particle size evolution, heat transfer process are discussed, and the gasification reaction index of the capture char particle are modeled. Molten slag layer promoted the char reactivity from the analysis of reaction index, Coupled with heat transfer analysis, shrinking particle model (SPM) was applied and modified to predict the gasification time at carbon conversion of 0.9, and results showed an agreement with the experimental data. A comprehensive model with gas-particle-slag flow and reaction models was used to model the different industry gasifier. The carbon conversion information in the spatial space and slag layer surface are investigated. The slag flow characteristic, such as slag velocity, molten slag thickness, slag temperature distribution on the membrane wall and refractory brick are discussed.

Keywords: char, slag, numerical simulation, gasification, wall reaction, membrane wall

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9186 Influence of Thermal Ageing on Microstructural Features and Mechanical Properties of Reduced Activation Ferritic/Martensitic Grades

Authors: Athina Puype, Lorenzo Malerba, Nico De Wispelaere, Roumen Petrov, Jilt Sietsma

Abstract:

Reduced Activation Ferritic/Martensitic (FM) steels like EUROFER are of interest for first wall application in the future demonstration (DEMO) fusion reactor. Depending on the final design codes for the DEMO reactor, the first wall material will have to function in low-temperature mode or high-temperature mode, i.e. around 250-300°C of above 550°C respectively. However, the use of RAFM steels is limited up to a temperature of about 550°C. For the low-temperature application, the material suffers from irradiation embrittlement, due to a shift of ductile-to-brittle transition temperature (DBTT) towards higher temperatures upon irradiation. The high-temperature response of the material is equally insufficient for long-term use in fusion reactors, due to the instability of the matrix phase and coarsening of the precipitates at prolonged high-temperature exposure. The objective of this study is to investigate the influence of thermal ageing for 1000 hrs and 4000 hrs on microstructural features and mechanical properties of lab-cast EUROFER. Additionally, the ageing behavior of the lab-cast EUROFER is compared with the ageing behavior of standard EUROFER97-2 and T91. The microstructural features were investigated with light optical microscopy (LOM), electron back-scattered diffraction (EBSD) and transmission electron microscopy (TEM). Additionally, hardness measurements, tensile tests at elevated temperatures and Charpy V-notch impact testing of KLST-type MCVN specimens were performed to study the microstructural features and mechanical properties of four different F/M grades, i.e. T91, EUROFER97-2 and two lab-casted EUROFER grades. After ageing for 1000 hrs, the microstructures exhibit similar martensitic block sizes independent on the grain size before ageing. With respect to the initial coarser microstructures, the aged microstructures displayed a dislocation structure which is partially fragmented by polygonization. On the other hand, the initial finer microstructures tend to be more stable up to 1000hrs resulting in similar grain sizes for the four different steels. Increasing the ageing time to 4000 hrs, resulted in an increase of lath thickness and coarsening of M23C6 precipitates leading to a deterioration of tensile properties.

Keywords: ageing experiments, EUROFER, ferritic/martensitic steels, mechanical properties, microstructure, T91

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9185 Design and Analysis of a Rear Bumper of an Automobile with a Hybrid Polymer Composite of Oil Palm Empty Fruit Bunch Fiber/Banana Fibres

Authors: S. O. Ologe, U. P. Anaidhuno, Duru C. A.

Abstract:

This research investigated the design and analysis of a rear bumper of an automobile with a hybrid polymer composite of OPEBF/Banana fibre. OPEBF/Banana fibre hybrid polymers composite is of low cost, lightweight, as well as possesses satisfactory mechanical properties. In this research work, hybrid composites have been developed using the hand layup technique based on the percentage combination of OPEBF/Banana fibre at 10:90, 20:80, 30:70, 40:60, 50:50. 60:40, 70:30. 20:80, 90:10, 95:5. The mechanical properties in the context of compressive strength of 65MPa, a flexural strength of 20MPa, and impact strength of 3.25Joule were observed, and the simulation analysis on the induction of 500N load at the factor of safety of 3 was observed to have displayed a good strength suitable for automobile bumper with the advantages of weight reduction.

Keywords: OPEBF, Banana, fibre, hybrid

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9184 Fatigue Behavior of Dissimilar Welded Monel400 and SS316 by Friction Stir Welding

Authors: Aboozar Aghaei, Kamran Dehghani

Abstract:

In the present work, the dissimilar Monel400 and SS316 were joined by friction stir welding (FSW). The applied rotating speed was 400 rpm, whereas the traverse speed varied between 50 and 150 mm/min. At a constant rotating speed, the sound welds were obtained at the welding speeds of 50 and 100 mm/min. However, a groove-like defect was formed when the welding speed exceeded 100 mm/min. The mechanical properties of the joints were evaluated using tensile and fatigue tests. The fatigue strength of dissimilar FSWed specimens was higher than that of both Monel400 and SS316. To study the failure behavior of FSWed specimens, the fracture surfaces were analyzed using a scanning electron microscope (SEM). The failure analysis indicates that different mechanisms may contribute to the fracture of welds. This was attributed to the dissimilar characteristics of dissimilar materials exhibiting different failure behaviors.

Keywords: frictions stir welding, stainless steel, Monel400, mechanical properties

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9183 The Effect of Biochar, Inoculated Biochar and Compost Biological Component of the Soil

Authors: Helena Dvořáčková, Mikajlo Irina, Záhora Jaroslav, Elbl Jakub

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Biochar can be produced from the waste matter and its application has been associated with returning of carbon in large amounts into the soil. The impacts of this material on physical and chemical properties of soil have been described. The biggest part of the research work is dedicated to the hypothesis of this material’s toxic effects on the soil life regarding its effect on the soil biological component. At present, it has been worked on methods which could eliminate these undesirable properties of biochar. One of the possibilities is to mix biochar with organic material, such as compost, or focusing on the natural processes acceleration in the soil. In the experiment has been used as the addition of compost as well as the elimination of toxic substances by promoting microbial activity in aerated water environment. Biochar was aerated for 7 days in a container with a volume of 20 l. This way modified biochar had six times higher biomass production and reduce mineral nitrogen leaching. Better results have been achieved by mixing biochar with compost.

Keywords: leaching of nitrogen, soil, biochar, compost

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9182 Influence of Building Orientation and Post Processing Materials on Mechanical Properties of 3D-Printed Parts

Authors: Raf E. Ul Shougat, Ezazul Haque Sabuz, G. M. Najmul Quader, Monon Mahboob

Abstract:

Since there are lots of ways for building and post processing of parts or models in 3D printing technology, the main objective of this research is to provide an understanding how mechanical characteristics of 3D printed parts get changed for different building orientations and infiltrates. Tensile, compressive, flexure, and hardness test were performed for the analysis of mechanical properties of those models. Specimens were designed in CAD software, printed on Z-printer 450 with five different build orientations and post processed with four different infiltrates. Results show that with the change of infiltrates or orientations each of the above mechanical property changes and for each infiltrate the highest tensile strength, flexural strength, and hardness are found for such orientation where there is the lowest number of layers while printing.

Keywords: 3D printing, building orientations, infiltrates, mechanical characteristics, number of layers

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9181 Optimum Design of Hybrid (Metal-Composite) Mechanical Power Transmission System under Uncertainty by Convex Modelling

Authors: Sfiso Radebe

Abstract:

The design models dealing with flawless composite structures are in abundance, where the mechanical properties of composite structures are assumed to be known a priori. However, if the worst case scenario is assumed, where material defects combined with processing anomalies in composite structures are expected, a different solution is attained. Furthermore, if the system being designed combines in series hybrid elements, individually affected by material constant variations, it implies that a different approach needs to be taken. In the body of literature, there is a compendium of research that investigates different modes of failure affecting hybrid metal-composite structures. It covers areas pertaining to the failure of the hybrid joints, structural deformation, transverse displacement, the suppression of vibration and noise. In the present study a system employing a combination of two or more hybrid power transmitting elements will be explored for the least favourable dynamic loads as well as weight minimization, subject to uncertain material properties. Elastic constants are assumed to be uncertain-but-bounded quantities varying slightly around their nominal values where the solution is determined using convex models of uncertainty. Convex analysis of the problem leads to the computation of the least favourable solution and ultimately to a robust design. This approach contrasts with a deterministic analysis where the average values of elastic constants are employed in the calculations, neglecting the variations in the material properties.

Keywords: convex modelling, hybrid, metal-composite, robust design

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9180 Biocontrol Effectiveness of Indigenous Trichoderma Species against Meloidogyne javanica and Fusarium oxysporum f. sp. radicis lycopersici on Tomato

Authors: Hajji Lobna, Chattaoui Mayssa, Regaieg Hajer, M'Hamdi-Boughalleb Naima, Rhouma Ali, Horrigue-Raouani Najet

Abstract:

In this study, three local isolates of Trichoderma (Tr1: T. viride, Tr2: T. harzianum and Tr3: T. asperellum) were isolated and evaluated for their biocontrol effectiveness under in vitro conditions and in greenhouse. In vitro bioassay revealed a biopotential control against Fusarium oxysporum f. sp. radicis lycopersici and Meloidogyne javanica (RKN) separately. All species of Trichoderma exhibited biocontrol performance and (Tr1) Trichoderma viride was the most efficient. In fact, growth rate inhibition of Fusarium oxysporum f. sp. radicis lycopersici (FORL) was reached 75.5% with Tr1. Parasitism rate of root-knot nematode was 60% for juveniles and 75% for eggs with the same one. Pots experiment results showed that Tr1 and Tr2, compared to chemical treatment, enhanced the plant growth and exhibited better antagonism against root-knot nematode and root-rot fungi separated or combined. All Trichoderma isolates revealed a bioprotection potential against Fusarium oxysporum f. sp. radicis lycopersici. When pathogen fungi inoculated alone, Fusarium wilt index and browning vascular rate were reduced significantly with Tr1 (0.91, 2.38%) and Tr2 (1.5, 5.5%), respectively. In the case of combined infection with Fusarium and nematode, the same isolate of Trichoderma Tr1 and Tr2 decreased Fusarium wilt index at 1.1 and 0.83 and reduced the browning vascular rate at 6.5% and 6%, respectively. Similarly, the isolate Tr1 and Tr2 caused maximum inhibition of nematode multiplication. Multiplication rate was declined at 4% with both isolates either tomato infected by nematode separately or concomitantly with Fusarium. The chemical treatment was moderate in activity against Meloidogyne javanica and Fusarium oxysporum f. sp. radicis lycopersici alone and combined.

Keywords: trichoderma spp., meloidogyne javanica, Fusarium oxysporum f.sp.radicis lycopersici, biocontrol

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9179 Application of Regularized Spatio-Temporal Models to the Analysis of Remote Sensing Data

Authors: Salihah Alghamdi, Surajit Ray

Abstract:

Space-time data can be observed over irregularly shaped manifolds, which might have complex boundaries or interior gaps. Most of the existing methods do not consider the shape of the data, and as a result, it is difficult to model irregularly shaped data accommodating the complex domain. We used a method that can deal with space-time data that are distributed over non-planner shaped regions. The method is based on partial differential equations and finite element analysis. The model can be estimated using a penalized least squares approach with a regularization term that controls the over-fitting. The model is regularized using two roughness penalties, which consider the spatial and temporal regularities separately. The integrated square of the second derivative of the basis function is used as temporal penalty. While the spatial penalty consists of the integrated square of Laplace operator, which is integrated exclusively over the domain of interest that is determined using finite element technique. In this paper, we applied a spatio-temporal regression model with partial differential equations regularization (ST-PDE) approach to analyze a remote sensing data measuring the greenness of vegetation, measure by an index called enhanced vegetation index (EVI). The EVI data consist of measurements that take values between -1 and 1 reflecting the level of greenness of some region over a period of time. We applied (ST-PDE) approach to irregular shaped region of the EVI data. The approach efficiently accommodates the irregular shaped regions taking into account the complex boundaries rather than smoothing across the boundaries. Furthermore, the approach succeeds in capturing the temporal variation in the data.

Keywords: irregularly shaped domain, partial differential equations, finite element analysis, complex boundray

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9178 Effect of Gamma Irradiation on Structural and Optical Properties of ZnO/Mesoporous Silica Nanocomposite

Authors: K. Sowri Babu, P. Srinath, N. Rajeswara Rao, K. Venugopal Reddy

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The effect of gamma ray irradiation on morphology and optical properties of ZnO/Mesoporous silica (MPS) nanocomposite was studied. The ZnO/MPS nanocomposite was irradiated with gamma rays of doses 30, 60, and 90 kGy and dose-rate of irradiation was 0.15 kGy/hour. Irradiated samples are characterized with FE-SEM, FT-IR, UV-vis, and Photoluminescence (PL) spectrometers. SEM pictures showed that morphology changed from spherical to flake like morphology. UV-vis analysis showed that the band gap increased with increase of gamma ray irradiation dose. This enhancement of the band gap is assigned to the depletion of oxygen vacancies with irradiation. The intensity of PL peak decreased gradually with increase of gamma ray irradiation dose. The decrease in PL intensity is attributed to the decrease of oxygen vacancies at the interface due to poor interface and improper passivation between ZnO/MPS.

Keywords: ZnO nanoparticles, nanocomposites, mesoporous silica, photoluminescence

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9177 Crystallized Colored Towels Obtained by Special Coloration of Yarns

Authors: Hasan Eskin, Gizem Özmen, A. Nazmi Çeler

Abstract:

When we examine the home textile development process, it follows a parallel line with the other textile products especially in the garment fabrics in terms of raw materials, production technologies and pattern characteristics. As a result, the expectations of people regarding textile, comfort, pattern (texture) and color properties are increasing. One of the places where comfort is most sought after is bath, pool, sea and baths. In addition to the material and technique that make up the physical structure in woven fabrics, color has an impressive importance with its strong effects. Color is the most prominent element in the fabric, and the color and texture are visually reinforcing. Evaluation of color in fabric is a personal phenomenon. Factors that determine color determination in fabric are the amount of color used, color ratio and its relationship with other colors. In this project; Considering the effect of color dimensions on human, we are talking about the crystallized colored towel that we developed in terms of comfort and texture properties. The basis of the effect created in the towel; It is formed by bending the yarn from its own special blend and the harmonious appearance of the natural crystallized rainbow colors with the pattern effect it determines on the warp yarns by using the weft yarns in the weaving. In addition, by using different weaving techniques and colors, alternatives can be created and personalized patterns can be created. One side of the towel determines the properties related to color, while the pile part determines the comfort characteristics with its soft touch and water absorbency.

Keywords: color effect, comfort, towel, weaving technique

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9176 Study of the Suitability for the Use of Gravel in the Regions around Araz River in Karabakh as a Concrete Aggregate

Authors: S. B. Shahmarova, F. N. Iskandarli, J. T. Zeynalov, F. N. Mammadov, M. M. Mirzayev, F. Y. Bayramov

Abstract:

The physical, mechanical, and chemical properties of aggregates play an important role in the production of ready-mixed concrete. Furthermore, the alkali-silicate reaction of aggregates is one of the essential factors in construction projects for the durability and longer service life of buildings and construction structures to be built. It is necessary to use the aggregates from the liberated regions of Karabakh and East Zangazur in the preparation of concretes to be produced for reconstruction and renovation projects in those regions. In this regard, the study of the physical and mechanical properties of aggregates in the regions around the Araz River (Fuzuli, Jabrayil, and Zangilan) became a significant issue. So, gravel samples were taken from seven different sources located in the regions around Araz River, where the quarries are planned to be built. The chemical oxide composition of the samples was determined, water absorption and specific gravity tests, chloride, alkali-silicate reaction tests, aggregate crushing strength test, Los Angeles, and frost resistance (into the solution of MgSO₄ and Na₂SO₄) tests were performed, and the results were evaluated in accordance with the relevant standards. As a result, it was determined that the aggregates in the regions around the Araz River (Fuzuli, Jabrayil, and Zangilan) conform to the relative standards and can be used effectively in the production of various concretes to be used for the projects in Karabakh.

Keywords: aggregates of the regions around Araz River (Fuzuli, Jabrayil, and Zangilan), physical and mechanical properties, alkali-silicate reaction, Karabakh, Azerbaijan

Procedia PDF Downloads 87
9175 Sensitivity Enhancement of Photonic Crystal Fiber Biosensor

Authors: Mohamed Farhat O. Hameed, Yasamin K. A. Alrayk, A. A Shaalan, S. S. A. Obayya

Abstract:

The surface plasmon resonance (SPR) sensors are widely used due to its high sensitivity with molecular labels free. The commercial SPR sensors depend on the conventional prism-coupled configuration. However, this type of configuration suffers from miniaturization and integration. Therefore, the search for compact, portable and highly sensitive SPR sensors becomes mandatory.In this paper, sensitivity enhancement of a novel photonic crystal fiber biosensoris introduced and studied. The suggested design has microstructure of air holes in the core region surrounded by two large semicircular metallized channels filled with the analyte. The inner surfaces of the two channels are coated by a silver layer followed by a gold layer.The simulation results are obtained using full vectorial finite element methodwith perfect matched layer (PML) boundary conditions. The proposed design depends on bimetallic configuration to enhance the biosensor sensitivity. Additionally, the suggested biosensor can be used for multi-channel/multi-analyte sensing. In this study, the sensor geometrical parameters are studied to maximize the sensitivity for the two polarized modes. The numerical results show that high refractive index sensitivity of 4750 nm/RIU (refractive index unit) and 4300 nm/RIU can be achieved for the quasi (transverse magnetic) TM and quasi (transverse electric) TE modes of the proposed biosensor, respectively. The reportedbiosensor has advantages of integration of microfluidics setup, waveguide and metallic layers into a single structure. As a result, compact biosensor with better integration compared to conventional optical fiber SPR biosensors can be obtained.

Keywords: photonic crystal fibers, gold, silver, surface plasmon, biosensor

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9174 Advertising Disability Index: A Content Analysis of Disability in Television Commercial Advertising from 2018

Authors: Joshua Loebner

Abstract:

Tectonic shifts within the advertising industry regularly and repeatedly present a deluge of data to be intuited across a spectrum of key performance indicators with innumerable interpretations where live campaigns are vivisected to pivot towards coalescence amongst a digital diaspora. But within this amalgam of analytics, validation, and creative campaign manipulation, where do diversity and disability inclusion fit in? In 2018 several major brands were able to answer this question definitely and directly by incorporating people with disabilities into advertisements. Disability inclusion, representation, and portrayals are documented annually across a number of different media, from film to primetime television, but ongoing studies centering on advertising have not been conducted. Symbols and semiotics in advertising often focus on a brand’s features and benefits, but this analysis on advertising and disability shows, how in 2018, creative campaigns and the disability community came together with the goal to continue the momentum and spark conversations. More brands are welcoming inclusion and sharing positive portrayals of intersectional diversity and disability. Within the analysis and surrounding scholarship, a multipoint analysis of each advertisement and meta-interpretation of the research has been conducted to provide data, clarity, and contextualization of insights. This research presents an advertising disability index that can be monitored for trends and shifts in future studies and to provide further comparisons and contrasts of advertisements. An overview of the increasing buying power within the disability community and population changes among this group anchors the significance and size of the minority in the US. When possible, viewpoints from creative teams and advertisers that developed the ads are brought into the research to further establish understanding, meaning, and individuals’ purposeful approaches towards disability inclusion. Finally, the conclusion and discussion present key takeaways to learn from the research, build advocacy and action both within advertising scholarship and the profession. This study, developed into an advertising disability index, will answer questions of how people with disabilities are represented in each ad. In advertising that includes disability, there is a creative pendulum. At one extreme, among many other negative interpretations, people with disables are portrayed in a way that conveys pity, fosters ableism and discrimination, and shows that people with disabilities are less than normal from a societal and cultural perspective. At the other extreme, people with disabilities are portrayed with a type of undue inspiration, considered inspiration porn, or superhuman, otherwise known as supercrip, and in ways that most people with disabilities could never achieve, or don’t want to be seen for. While some ads reflect both extremes, others stood out for non-polarizing inclusion of people with disabilities. This content analysis explores television commercial advertisements to determine the presence of people with disabilities and any other associated disability themes and/or concepts. Content analysis will allow for measuring the presence and interpretation of disability portrayals in each ad.

Keywords: advertising, brand, disability, marketing

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9173 Effects of Particle Size Distribution on Mechanical Strength and Physical Properties in Engineered Quartz Stone

Authors: Esra Arici, Duygu Olmez, Murat Ozkan, Nurcan Topcu, Furkan Capraz, Gokhan Deniz, Arman Altinyay

Abstract:

Engineered quartz stone is a composite material comprising approximately 90 wt.% fine quartz aggregate with a variety of particle size ranges and `10 wt.% unsaturated polyester resin (UPR). In this study, the objective is to investigate the influence of particle size distribution on mechanical strength and physical properties of the engineered stone slabs. For this purpose, granular quartz with two particle size ranges of 63-200 µm and 100-300 µm were used individually and mixed with a difference in ratios of mixing. The void volume of each granular packing was measured in order to define the amount of filler; quartz powder with the size of less than 38 µm, and UPR required filling inter-particle spaces. Test slabs were prepared using vibration-compression under vacuum. The study reports that both impact strength and flexural strength of samples increased as the mix ratio of the particle size range of 63-200 µm increased. On the other hand, the values of water absorption rate, apparent density and abrasion resistance were not affected by the particle size distribution owing to vacuum compaction. It is found that increasing the mix ratio of the particle size range of 63-200 µm caused the higher porosity. This led to increasing in the amount of the binder paste needed. It is also observed that homogeneity in the slabs was improved with the particle size range of 63-200 µm.

Keywords: engineered quartz stone, fine quartz aggregate, granular packing, mechanical strength, particle size distribution, physical properties.

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9172 Microfluidic Device for Real-Time Electrical Impedance Measurements of Biological Cells

Authors: Anil Koklu, Amin Mansoorifar, Ali Beskok

Abstract:

Dielectric spectroscopy (DS) is a noninvasive, label free technique for a long term real-time measurements of the impedance spectra of biological cells. DS enables characterization of cellular dielectric properties such as membrane capacitance and cytoplasmic conductivity. We have developed a lab-on-a-chip device that uses an electro-activated microwells array for loading, DS measurements, and unloading of biological cells. We utilized from dielectrophoresis (DEP) to capture target cells inside the wells and release them after DS measurement. DEP is a label-free technique that exploits differences among dielectric properties of the particles. In detail, DEP is the motion of polarizable particles suspended in an ionic solution and subjected to a spatially non-uniform external electric field. To the best of our knowledge, this is the first microfluidic chip that combines DEP and DS to analyze biological cells using electro-activated wells. Device performance is tested using two different cell lines of prostate cancer cells (RV122, PC-3). Impedance measurements were conducted at 0.2 V in the 10 kHz to 40 MHz range with 6 s time resolution. An equivalent circuit model was developed to extract the cell membrane capacitance and cell cytoplasmic conductivity from the impedance spectra. We report the time course of the variations in dielectric properties of PC-3 and RV122 cells suspended in low conductivity medium (LCB), which enhances dielectrophoretic and impedance responses, and their response to sudden pH change from a pH of 7.3 to a pH of 5.8. It is shown that microfluidic chip allowed online measurements of dielectric properties of prostate cancer cells and the assessment of the cellular level variations under external stimuli such as different buffer conductivity and pH. Based on these data, we intend to deploy the current device for single cell measurements by fabricating separately addressable N × N electrode platforms. Such a device will allow time-dependent dielectric response measurements for individual cells with the ability of selectively releasing them using negative-DEP and pressure driven flow.

Keywords: microfluidic, microfabrication, lab on a chip, AC electrokinetics, dielectric spectroscopy

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9171 Novel Emulgel of Piroxicam for Topical Application with Mentha and Clove Oil

Authors: S. V. Patil, P. S. Dounde, S. S. Patil

Abstract:

Emulgels have emerged as one of the most interesting topical delivery system as it has dual release control system that is gel and emulsion. The major objective behind this formulation is delivery of hydrophobic drugs to systemic circulation via skin. In fact presence of a gelling agent in water phase converts a classical emulsion in to emulgel. The emulgel for dermatological use has several favorable properties such as being thixotropic, greaseless, easily spreadable, easily removable, emollient, non-staining, water-soluble, longer shelf life, bio-friendly, transparent and pleasing appearance. Various penetration enhancers can potentiate the effect. So this can be used as better topical drug delivery systems over present conventional systems available in market. Piroxicam is a non-steroidal anti-inflammatory drug that has major problems when administered orally; it is an insoluble drug and has irritant effect on gastro intestinal tract lead to ulceration and bleeding. The aim of this study was to overcoming these problems through preparation of topical emulgel of this drug. Emulgel of Piroxicam was prepared using Carbopol 940 along with mentha oil and clove oil as permeation enhancer. The prepared emulgel were evaluated for their physical appearance, pH determination, viscosity, spreadability, in vitro drug release, ex vivo permeation studies. All the prepared formulations showed acceptable physical properties, homogeneity, consistency, spreadability, viscosity and pH value. The emulgel was found to be stable with respect to physical appearance, pH, rheological properties and drug content at all temperature and conditions for three month.

Keywords: emulgel, piroxicam, menthe oil, clove oil

Procedia PDF Downloads 450
9170 Implementation of Algorithm K-Means for Grouping District/City in Central Java Based on Macro Economic Indicators

Authors: Nur Aziza Luxfiati

Abstract:

Clustering is partitioning data sets into sub-sets or groups in such a way that elements certain properties have shared property settings with a high level of similarity within one group and a low level of similarity between groups. . The K-Means algorithm is one of thealgorithmsclustering as a grouping tool that is most widely used in scientific and industrial applications because the basic idea of the kalgorithm is-means very simple. In this research, applying the technique of clustering using the k-means algorithm as a method of solving the problem of national development imbalances between regions in Central Java Province based on macroeconomic indicators. The data sample used is secondary data obtained from the Central Java Provincial Statistics Agency regarding macroeconomic indicator data which is part of the publication of the 2019 National Socio-Economic Survey (Susenas) data. score and determine the number of clusters (k) using the elbow method. After the clustering process is carried out, the validation is tested using themethodsBetween-Class Variation (BCV) and Within-Class Variation (WCV). The results showed that detection outlier using z-score normalization showed no outliers. In addition, the results of the clustering test obtained a ratio value that was not high, namely 0.011%. There are two district/city clusters in Central Java Province which have economic similarities based on the variables used, namely the first cluster with a high economic level consisting of 13 districts/cities and theclustersecondwith a low economic level consisting of 22 districts/cities. And in the cluster second, namely, between low economies, the authors grouped districts/cities based on similarities to macroeconomic indicators such as 20 districts of Gross Regional Domestic Product, with a Poverty Depth Index of 19 districts, with 5 districts in Human Development, and as many as Open Unemployment Rate. 10 districts.

Keywords: clustering, K-Means algorithm, macroeconomic indicators, inequality, national development

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9169 High-Frequency Induction Heat Sintering of Al/SiC/GNS Nanocomposites and Their Tribological Properties

Authors: Mohammad Islam, Iftikhar Ahmad, Hany S. Abdo, Yasir Khalid

Abstract:

High-frequency induction heat sintering (HFIHS) is a fast, efficient powder consolidation technique. In this work, aluminum (Al) powder was mixed with silicon carbide (SiC) and/or graphene nanosheets (GNS) in different proportions and compacted using HFIHS process to produce dense nanocomposites. The nanostructures dispersion was assessed via electron microscopy using both SEM and TEM. Tribological behavior of the nanocomposites was investigated at different loads to determine wear rate and coefficient of friction. The scratch profiles were examined under the microscope to correlate wear properties with the microstructure. While the addition of SiC nanoparticles enhances microhardness values, GNS incorporation promotes dry lubricity with strikingly different wear scratch morphologies. Such Al/SiC/GNS material compositions can be explored for use in automotive brake pad and thermal management applications.

Keywords: aluminum nanocomposites, silicon carbide, graphene nanosheets, tribology

Procedia PDF Downloads 305