Search results for: Nayak Amar
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 133

Search results for: Nayak Amar

103 Cognition of Driving Context for Driving Assistance

Authors: Manolo Dulva Hina, Clement Thierry, Assia Soukane, Amar Ramdane-Cherif

Abstract:

In this paper, we presented our innovative way of determining the driving context for a driving assistance system. We invoke the fusion of all parameters that describe the context of the environment, the vehicle and the driver to obtain the driving context. We created a training set that stores driving situation patterns and from which the system consults to determine the driving situation. A machine-learning algorithm predicts the driving situation. The driving situation is an input to the fission process that yields the action that must be implemented when the driver needs to be informed or assisted from the given the driving situation. The action may be directed towards the driver, the vehicle or both. This is an ongoing work whose goal is to offer an alternative driving assistance system for safe driving, green driving and comfortable driving. Here, ontologies are used for knowledge representation.

Keywords: cognitive driving, intelligent transportation system, multimodal system, ontology, machine learning

Procedia PDF Downloads 335
102 An Experimental Analysis of Squeeze Casting Parameters for 2017 a Wrought Al Alloy

Authors: Mohamed Ben Amar, Najib Souissi, Chedly Bradai

Abstract:

A Taguchi design investigation has been made into the relationship between the ductility and process variables in a squeeze cast 2017A wrought aluminium alloy. The considered process parameters were: squeeze pressure, melt temperature and die preheating temperature. An orthogonal array (OA), main effect, signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) are employed to analyze the effect of casting parameters. The results have shown that the selected parameters significantly affect the ductility of 2017A wrought Al alloy castings. Optimal squeeze cast process parameters were provided to illustrate the proposed approach and the results were proven to be trustworthy through practical experiments.

Keywords: Taguchi method, squeeze casting, process parameters, ductility, microstructure

Procedia PDF Downloads 362
101 Assessing the Perception of Indian Youths towards Poverty

Authors: Antarjeeta Nayak, Jalandhar Pradhan, Ramakrishna Biswal

Abstract:

Poverty is a complex phenomenon influenced by a large number of factors and which can be studied from many different perspectives. Most of the poverty assessments can be divided into three broad categories- construction of poverty profile (who the poor are), causes of poverty (why people are poor) and poverty alleviation strategies (what to do about poverty). In this regard, we need to know more about poverty, the factors that drive it and those that maintain it. Specifically, how people perceive and experience poverty will generate a body of knowledge that would enable government and poverty alleviation agencies to better target their interventions and understand the stigma associated with poverty. In the Indian context, the perceptions of the causes of poverty are particularly relevant because of the persistent higher percent of people below poverty line and wider economic-social inequalities despite the continuing decline of poverty in the present times. In this study we investigated the perceived attributions for poverty among youths (University students) in India. A questionnaire having 35 questions was administered to a sample of 200 University students (n=200). Findings showed that Indian youth were more inclined to attribute poverty to Structural factors; supporting system-blame hypothesis.

Keywords: poverty, perception of the causes of poverty, Indian youth, social sciences and humanities

Procedia PDF Downloads 395
100 Recovery of Fried Soybean Oil Using Bentonite as an Adsorbent: Optimization, Isotherm and Kinetics Studies

Authors: Prakash Kumar Nayak, Avinash Kumar, Uma Dash, Kalpana Rayaguru

Abstract:

Soybean oil is one of the most widely consumed cooking oils, worldwide. Deep-fat frying of foods at higher temperatures adds unique flavour, golden brown colour and crispy texture to foods. But it brings in various changes like hydrolysis, oxidation, hydrogenation and thermal alteration to oil. The presence of Peroxide value (PV) is one of the most important factors affecting the quality of the deep-fat fried oil. Using bentonite as an adsorbent, the PV can be reduced, thereby improving the quality of the soybean oil. In this study, operating parameters like heating time of oil (10, 15, 20, 25 & 30 h), contact time ( 5, 10, 15, 20, 25 h) and concentration of adsorbent (0.25, 0.5, 0.75, 1.0 and 1.25 g/ 100 ml of oil) have been optimized by response surface methodology (RSM) considering percentage reduction of PV as a response. Adsorption data were analysed by fitting with Langmuir and Freundlich isotherm model. The results show that the Langmuir model shows the best fit compared to the Freundlich model. The adsorption process was also found to follow a pseudo-second-order kinetic model.

Keywords: bentonite, Langmuir isotherm, peroxide value, RSM, soybean oil

Procedia PDF Downloads 338
99 Radiative Reactions Analysis at the Range of Astrophysical Energies

Authors: A. Amar

Abstract:

Analysis of the elastic scattering of protons on 10B nuclei has been done in the framework of the optical model and single folding model at the beam energies up to 17 MeV. We could enhance the optical potential parameters using Esis88 Code, as well as SPI GENOA Code. Linear relationship between volume real potential (V0) and proton energy (Ep) has been obtained. Also, surface imaginary potential WD is proportional to the proton energy (Ep) in the range 0.400 and 17 MeV. The radiative reaction 10B(p,γ)11C has been analyzed using potential model. A comparison between 10B(p,γ)11C and 6Li(p,γ)7Be has been made. Good agreement has been found between theoretical and experimental results in the whole range of energy. The radiative resonance reaction 7Li(p,γ)8Be has been studied.

Keywords: elastic scattering of protons on 10B nuclei, optical potential parameters, potential model, radiative reaction

Procedia PDF Downloads 183
98 Introduction of the Harmfulness of the Seismic Signal in the Assessment of the Performance of Reinforced Concrete Frame Structures

Authors: Kahil Amar, Boukais Said, Kezmane Ali, Hannachi Naceur Eddine, Hamizi Mohand

Abstract:

The principle of the seismic performance evaluation methods is to provide a measure of capability for a building or set of buildings to be damaged by an earthquake. The common objective of many of these methods is to supply classification criteria. The purpose of this study is to present a method for assessing the seismic performance of structures, based on Pushover method, we are particularly interested in reinforced concrete frame structures, which represent a significant percentage of damaged structures after a seismic event. The work is based on the characterization of seismic movement of the various earthquake zones in terms of PGA and PGD that is obtained by means of SIMQK_GR and PRISM software and the correlation between the points of performance and the scalar characterizing the earthquakes will be developed.

Keywords: seismic performance, pushover method, characterization of seismic motion, harmfulness of the seismic

Procedia PDF Downloads 353
97 Electrokinetic Transport of Power Law Fluid through Hydrophobic Micro-Slits

Authors: Ainul Haque, Ameeye Kumar Nayak

Abstract:

Flow enhancement and species transport in a slit hydrophobic microchannel is studied for non-Newtonian fluids with the externally imposed electric field and pressure gradient. The incompressible Poisson-Nernst-Plank equations and the Navier-Stokes equations are approximated by lubrication theory to quantify the flow structure due to hydrophobic and hydrophilic surfaces. The analytical quantification of velocity and pressure of electroosmotic flow (EOF) is made with the numerical results due to the staggered grid based finite volume method for flow governing equations. The resistance force due to fluid friction and shear force along the surface are decreased by the hydrophobicity, enables the faster movement of fluid particles. The resulting flow enhancement factor Ef is increased with the low viscous fluid and provides maximum species transport. Also, the analytical comparison of EOF with pressure driven EOF justifies the flow enhancement due to hydrophobicity and shear impact on flow variation.

Keywords: electroosmotic flow, hydrophobic surface, power-law fluid, shear effect

Procedia PDF Downloads 339
96 Garment Industry Development in South East Asia and Competitiveness

Authors: P. Nayak, Shakeel Shaikh

Abstract:

In this paper, we analyse the apparel export performance of Southeast Asian Nations (ASEAN) in the world market. The study covers the 2003-2012 period at the sector as well as product levels (6 digit HS) and analysis is based HS 2002 nomenclature. We measure export similarity among Southeast Asian nations for the apparel sector (two digit HS-61 & 62), besides analysing the products performance in the world through Revealed Comparative Advantage (RCA) technique. Coupled with RCA, the price as a factor of competitiveness was examined from the available Unit Value Realizations (UVR). Further to this, the resource availability or outsourced from the region was considered as an extension to the analysis of competitiveness between the nations. With the help of these methodologies, we examine the degree of competition between the exports of southeast nations in the world market. Our results show that Cambodia, Indonesia, Thailand, and Vietnam are well performing states within ASEAN. The paper further delves into sustainability of the export performing countries within ASEAN.

Keywords: export competitiveness, export similarity index, revealed comparative advantage, unit value realisation

Procedia PDF Downloads 258
95 In situ Polymerization and Properties of Biobased Polyurethane/Epoxy Interpenetrating Network Nanocomposites

Authors: Aiswarea Mathew, Smita Mohanty, Jr., S. K. Nayak

Abstract:

Polyurethane networks based on castor oil (CO) as a renewable resource polyol were synthesized. Polyurethane/epoxy resin interpenetrating network nanocomposites containing modified montmorillonite organoclay (C30B-PU/EP nanocomposites) were prepared by an in situ intercalation method. The conventional spectroscopic characterization of the synthesized samples using FT-IR confirms the existence of the proposed castor oil based PU structure and also showed that strong interactions existed between C30B and EP/PU matrix. The dispersion degree of C30B in EP/PU matrix was characterized by X-Ray diffraction (XRD) method. Scanning electronic microscopy analysis showed that the interpenetrating process of PU and EP increases the exfoliation degree of C30B, and it improves the compatibility and the phase structure of polyurethane/epoxy resin interpenetrating polymer networks (PU/EP IPNs). The thermal stability improves compared to the polyurethane when the PU/EP IPN is formed. Mechanical properties including the Young’s modulus and tensile strength reflected marked improvement with addition of C30B.

Keywords: castor oil, epoxy, montmorillonite, polyurethane

Procedia PDF Downloads 372
94 Performance and Emissions Analysis of Diesel Engine with Bio-Diesel of Waste Cooking Oils

Authors: Mukesh Kumar, Onkar Singh, Naveen Kumar, Amar Deep

Abstract:

The waste cooking oil is taken as feedstock for biodiesel production. For this research, waste cooking oil is collected from many hotels and restaurants, and then biodiesel is prepared for experimentation purpose. The prepared biodiesel is mixed with mineral diesel in the proportion of 10%, 20%, and 30% to perform tests on a diesel engine. The experimental analysis is carried out at different load conditions to analyze the impact of the blending ratio on the performance and emission parameters. When the blending proportion of biodiesel is increased, then the highest pressure reduces due to the fall in the calorific value of the blended mixture. Experimental analysis shows a promising decrease in nitrogen oxides (NOx). A mixture of 20% biodiesel and mineral diesel is the best negotiation, mixing ratio, and beyond that, a remarkable reduction in the outcome of the performance has been observed.

Keywords: alternative sources, diesel engine, emissions, performance

Procedia PDF Downloads 146
93 In vitro Synergistic Antioxidant Activity of Honey-Mentha Spicata Combination

Authors: Yuva Bellik, Selles Mohamed Amar

Abstract:

The beneficial health effects including antioxidant properties of mint (Mentha spicata) and honey bees (Apis mellifera) have been extensively studied. However, there is no data about the effects of their associated use. In this study the total phenolic and flavonoid contents for individual extracts of mint and honey and their combination were determined. The antioxidant activity was investigated by using reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2´- azinobis-(3-ethylbenzothiazoline-6-sulphonic acid diamonium salt (ABTS), and chelating power methods. The results showed that individual extracts contained important quantity of phenolics and flavonoids and their combination was found to produce best antioxidant activity. A significant linear correlation between the phenolic/flavonoid contents and antioxidant activity, especially with reducing power and free radical scavenging abilities, was observed.

Keywords: honey, mint, synergy, antioxidant activity

Procedia PDF Downloads 355
92 Sub-Saharan Africa: Role of Global Fashion System in Turbo-Charging Growth of Apparel Industry

Authors: Rajkishore Nayak, Tarun Panwar, Majo George

Abstract:

The study focuses on investigating the factors that influence the growth of fashion and textile manufacturing in the Sub-Saharan Africa (SSA) countries. This paper endeavours to identify, analyse and evaluate the critical factors associated with the growth of fashion and textile manufacturing in SSA countries. This research has done a Strength, Weakness, Opportunity, and Threat (SWOT) analysis based on the available literature and the knowledge of authors in garment manufacturing and export. It was found that the SSA countries have shown little growth in fashion and textile manufacturing and export from the starting of the year 2000. Unlike the developing countries such as Vietnam and Bangladesh, the total export to the US, the EU and other parts of the world has declined. On the other hand, the total supply of fashion and textiles to the domestic market has been in rise. However, the local communities still need to rely on other countries to meet their demand. Availability of cheaper imported clothes from other countries such as Bangladesh, China and Vietnam have made it difficult for the local manufacturers to produce at a cheaper price.

Keywords: Sub-Saharan Africa, developing countries, apparel industry, fashion and textile, sustainable fashion

Procedia PDF Downloads 97
91 Risk Assessment and Management Using Machine Learning Models

Authors: Lagnajeet Mohanty, Mohnish Mishra, Pratham Tapdiya, Himanshu Sekhar Nayak, Swetapadma Singh

Abstract:

In the era of global interconnectedness, effective risk assessment and management are critical for organizational resilience. This review explores the integration of machine learning (ML) into risk processes, examining its transformative potential and the challenges it presents. The literature reveals ML's success in sectors like consumer credit, demonstrating enhanced predictive accuracy, adaptability, and potential cost savings. However, ethical considerations, interpretability issues, and the demand for skilled practitioners pose limitations. Looking forward, the study identifies future research scopes, including refining ethical frameworks, advancing interpretability techniques, and fostering interdisciplinary collaborations. The synthesis of limitations and future directions highlights the dynamic landscape of ML in risk management, urging stakeholders to navigate challenges innovatively. This abstract encapsulates the evolving discourse on ML's role in shaping proactive and effective risk management strategies in our interconnected and unpredictable global landscape.

Keywords: machine learning, risk assessment, ethical considerations, financial inclusion

Procedia PDF Downloads 28
90 Numerical Modeling of Structural Failure of a Ship During the Collision Event

Authors: Adjal Yassine, Semmani Amar

Abstract:

During the last decades, The risk of collision has been increased, especially in high maritime traffic. As the consequence, the demand is required for safety at sea and environmental protection. For this purpose, the consequences prediction of ship collisions is recommended in order to minimize structural failure. additionally, at the design stage of the ship, damage generated during the collision event must be taken into consideration. This structural failure, in some cases, can develop into the progressive collapse of other structural elements and generate catastrophic consequences. The present study investigates the progressive collapse of ships damaged by collisions using the Non -linear finite element method. The failure criteria are taken into account. The impacted area has a refined mesh in order to have more reliable results. Finally, a parametric study was conducted in this study to highlight the effect of the ship's speed, as well as the different impacted areas of double-bottom ships.

Keywords: collsion, strucural failure, ship, finite element analysis

Procedia PDF Downloads 71
89 The Effect of COVID-19 Transmission, Lockdown Measures, and Vaccination on Stock Market Returns

Authors: Belhouchet Selma, Ben Amar Anis

Abstract:

We examine the impact of COVID-19 transmission, containment measures, and vaccination growth on daily stock market returns for the G7 countries (Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States) from January 22, 2020, to August 31, 2021, more than a year and a half after COVID-19. For this objective, we use panel pooled ordinary least squares regressions. Our findings indicate that the spread of the pandemic has a negative impact on the daily performance of the world's seven main stock markets. Government measures to improve stock market returns are no longer successful. Furthermore, our findings demonstrate that immunization efforts in G7 nations do not increase stock market performance in these countries. A variety of robustness tests back up our conclusions. Our findings have far-reaching implications for investors, governments, and regulators not only in the G7 countries but also in all developed countries and all countries globally.

Keywords: COVID-19, G7 stock market, containment measures, vaccination

Procedia PDF Downloads 69
88 Mixed Treatment (Physical-Chemical and Biological) of Ouled Fayet Landfill Leachates

Authors: O. Balamane-Zizi, L. M. Rouidi, A. Boukhrissa, N. Daas, H. Ait-amar

Abstract:

The objective of this study was to test the possibility of a mixed treatment (physical-chemical and biological) of Ouled Fayet leachates which date of 10 years and has a large fraction of hard COD that can be reduced by coagulation-flocculation. Previous batch tests showed the possibility of applying the physical-chemical and biological treatments separately; the removal efficiencies obtained in this case were not interesting. We propose, therefore, to test the possibility of a combined treatment, in order to improve the quality of the leachates. Estimation of the treatment’s effectiveness was done by analysis of some pollution parameters such as COD, suspended solids, and heavy metals (particularly iron and nickel). The main results obtained after the combination of treatments, show reduction rate of about 63% for COD, 73% for suspended solids and 80% for iron and nickel. We also noted an improvement in the turbidity of treated leachates.

Keywords: landfill leachates, COD, physical-chemical treatment, biological treatment

Procedia PDF Downloads 444
87 Characterization and Evaluation of LD Slag and Fly Ash Mixture for Their Possible Utilization in Different Sectors

Authors: Jagdeep Nayak, Biswajit Paul, Anup Gupta

Abstract:

Characterization of coal refuses to fly ash, and steel slag from steel industries have been performed to develop a mixture of both these materials to enhance strength properties of their utilization in other sectors like mine fill, construction work, etc. A large amount of Linz-Donawitz (LD) slag and fly ash waste are generated from steel and thermal power industries respectively. Management of these wastes is problematic, and their reutilization may provide a sustainable waste management option. LD slag and fly ash mixed in different proportions were tested to analyse the micro structural improvement and hardening rate of the matrix. Mixing of activators such as sodium hydroxide and potassium silicate with silica-alumina of LD slag-fly ash mixture, geopolymeric structure were found to be developed. The effect of geo-polymerization behaviour and subsequent structural rearrangement has been studied using compressibility; shear strength and permeability tests followed by micro-graphical analysis. Densification in the mixture was observed along with an improvement of geotechnical properties due to the addition of LD slag. Due to suitable strength characteristics of these two waste materials as mixture, it can be used in the various construction field or may be used as a filling material in mine voids.

Keywords: LD slag, fly-ash, geopolymer, strength property, compressibility

Procedia PDF Downloads 360
86 WO₃-SnO₂ Sensors for Selective Detection of Volatile Organic Compounds for Breath Analysis

Authors: Arpan Kumar Nayak, Debabrata Pradhan

Abstract:

A simple, single-step and one-pot hydrothermal method was employed to synthesize WO₃-SnO₂ mixed nanostructured metal oxides at 200°C in 12h. The SnO₂ nanoparticles were found to be uniformly decorated on the WO₃ nanoplates. Though it is widely known that noble metals such as Pt, Pd doping or decoration on metal oxides improve the sensing response and sensitivity, we varied the SnO₂ concentration in the WO₃-SnO₂ mixed oxide and demonstrated their performance in ammonia, ethanol and acetone sensing. The sensing performance of WO₃-(x)SnO₂ [x = 0.27, 0.54, 1.08] mixed nanostructured oxides was found to be not only superior to that of pristine oxides but also higher/better than that of reported noble metal-based sensors. The sensing properties (selectivity, limit of detection, response and recovery times) are measured as a function of operating temperature (150-350°C). In particular, the gas selectivity is found to be highly temperature-dependent with optimum performance obtained at 200°C, 300°C and 350°C for ammonia, ethanol, and acetone, respectively. The present results on cost effective WO₃-SnO₂ sensors can find potential application in human breath analysis by noninvasive detection.

Keywords: gas sensing, mixed oxides, nanoplates, ammonia, ethanol, acetone

Procedia PDF Downloads 216
85 Effects of Applied Pressure and Heat Treatment on the Microstructure of Squeeze Cast Al-Si Alloy Were Examined

Authors: Mohamed Ben Amar, Henda Barhoumi, Hokia Siala, Foued Elhalouani

Abstract:

The present contribution consists of a purely experimental investigation on the effect of Squeeze casting on the micro structural and mechanical propriety of Al-Si alloys destined to automotive industry. Accordingly, we have proceeding, by ourselves, to all the thermal treatment consisting of solution treatment at 540°C for 8h and aging at 160°C for 4h. The various thermal treatment, have been carried out in order to monitor the processes of formation and dissolution accompanying the solid state phase transformations as well as the resulting changes in the mechanical proprieties. The examination of the micrographs of the aluminum alloys reveals the dominant presence of dendrite. Concerning the mechanical characteristic the Vickers micro-hardness curve an increase as a function of the pressure. As well as the heat treatment increase mechanical propriety such that pressure and micro hardness. The curves have been explained in terms of structural hardening resulting from the various compounds formation.

Keywords: squeeze casting, process parameters, heat treatment, ductility, microstructure

Procedia PDF Downloads 401
84 Ultimate Strength Prediction of Shear Walls with an Aspect Ratio between One and Two

Authors: Said Boukais, Ali Kezmane, Kahil Amar, Mohand Hamizi, Hannachi Neceur Eddine

Abstract:

This paper presents an analytical study on the behavior of rectangular reinforced concrete walls with an aspect ratio between one and tow. Several experiments on such walls have been selected to be studied. Database from various experiments were collected and nominal wall strengths have been calculated using formulas, such as those of the ACI (American), NZS (New Zealand), Mexican (NTCC), and Wood equation for shear and strain compatibility analysis for flexure. Subsequently, nominal ultimate wall strengths from the formulas were compared with the ultimate wall strengths from the database. These formulas vary substantially in functional form and do not account for all variables that affect the response of walls. There is substantial scatter in the predicted values of ultimate strength. New semi empirical equation are developed using data from tests of 46 walls with the objective of improving the prediction of ultimate strength of walls with the most possible accuracy and for all failure modes.

Keywords: prediction, ultimate strength, reinforced concrete walls, walls, rectangular walls

Procedia PDF Downloads 312
83 Performance Optimization of Low-Cost Solar Dryer Using Modified PI Controller

Authors: Rajesh Kondareddy, Prakash Kumar Nayak, Maunash Das, Vrinatri Velentina Boro

Abstract:

Today, there is a huge global concern for sustainable development which would include minimizing the consumption of non-renewable energies without affecting the basic global economy. Solar drying is one of the important processes used for extending the shelf life of agricultural products. The performance of a low cost automated solar dryer fitted with cascade control scheme and modified PI controller for drying chilli was investigated. The dryer was composed of designed solar collector (air heater) fitted with cylindrical pipes to improve the air velocity and a solar drying chamber containing rack of two cheese cloth (net) trays both being integrated together. The air allowed in through air inlet is heated up in the solar collector and channelled through the drying chamber where it is utilized in drying (removing the moisture content from the food substance or agricultural produce loaded). Here, to maintain the temperature in the heating chambers and to improve performance, a modified PI (Proportional–Integral) controller was used due its simplicity and robustness. Drying time for drying chilli from the initial moisture content of 88.5% (wb) to 7.3% (wb) was estimated to be 14 hours in solar dryer whereas 32 h was observed in the open sun drying.

Keywords: cascade control, chilli, PI controller, solar dryer

Procedia PDF Downloads 263
82 New Stress Instability Workability Criteria for Internal Ductile Failure in Steel Cold Heading

Authors: Amar Sabih, James Nemes

Abstract:

The occurrence of internal ductile failure within the Adiabatic Shear Band (ASB) in cold-headed products presents a significant barrier in the fast-expanding cold-heading (CH) industry. The presence of internal ductile failure in cold-headed products may lead to catastrophic fracture under tensile loads despite the ductile nature of the material causing expensive industrial recalls. Therefore, this paper presents a new workability criterion that uses stress instability as an indicator to accurately reveal the locus of initiation of internal ductile failures. The concept of the instability criterion is to use the stress ratio at failure as a weighting function to indicate the initiation of ductile failure inside the ASBs. This paper presents a comprehensive experimental, metallurgical, and finite element simulation study to calculate the material constants used in this criterion.

Keywords: adiabatic sher band, ductile failure, stress instability, workability criterion

Procedia PDF Downloads 56
81 Critical Buckling Load of Carbon Nanotube with Non-Local Timoshenko Beam Using the Differential Transform Method

Authors: Tayeb Bensattalah, Mohamed Zidour, Mohamed Ait Amar Meziane, Tahar Hassaine Daouadji, Abdelouahed Tounsi

Abstract:

In this paper, the Differential Transform Method (DTM) is employed to predict and to analysis the non-local critical buckling loads of carbon nanotubes with various end conditions and the non-local Timoshenko beam described by single differential equation. The equation differential of buckling of the nanobeams is derived via a non-local theory and the solution for non-local critical buckling loads is finding by the DTM. The DTM is introduced briefly. It can easily be applied to linear or nonlinear problems and it reduces the size of computational work. Influence of boundary conditions, the chirality of carbon nanotube and aspect ratio on non-local critical buckling loads are studied and discussed. Effects of nonlocal parameter, ratios L/d, the chirality of single-walled carbon nanotube, as well as the boundary conditions on buckling of CNT are investigated.

Keywords: boundary conditions, buckling, non-local, differential transform method

Procedia PDF Downloads 269
80 Experimental Characterization of Anisotropic Mechanical Properties of Textile Woven Fabric

Authors: Rym Zouari, Sami Ben Amar, Abdelwaheb Dogui

Abstract:

This paper presents an experimental characterization of the anisotropic mechanical behavior of 4 textile woven fabrics with different weaves (Twill 3, Plain, Twill4 and Satin 4) by off-axis tensile testing. These tests are applied according seven directions oriented by 15° increment with respect to the warp direction. Fixed and articulated jaws are used. Analysis of experimental results is done through global (Effort/Elongation curves) and local scales. Global anisotropy was studied from the Effort/Elongation curves: shape, breaking load (Frup), tensile elongation (EMT), tensile energy (WT) and linearity index (LT). Local anisotropy was studied from the measurement of strain tensor components in the central area of the specimen as a function of testing orientation and effort: longitudinal strain ɛL, transverse strain ɛT and shearing ɛLT. The effect of used jaws is also analyzed.

Keywords: anisotropy, off-axis tensile test, strain fields, textile woven fabric

Procedia PDF Downloads 332
79 Promissing Antifungal Chitinase from Marine Strain of Bacillus

Authors: Ben Amar Cheba, Taha Ibrahim Zaghloul, Mohamad Hisham El-Massry, Ahmad Rafik El-Mahdy

Abstract:

Seventy two bacterial strains with ability to degrade chitin were isolated during a screening program. One of the most potent isolates (strain R2) was identified as Bacillus sp. using conventional methods as well as 16S rRNA technique and submitted in the Gen Bank sequence database as Bacillus sp. R2 with a given accession number DQ 923161. This strain was able to produce high levels of extracellular chitinase. The chitinase of Bacillus sp. R2 hydrolyzed several chitinous substrates preferentially and showed a maximum activity toward the β chitin such as Calmar pen and squid bone chitins with the folds 1.47 and 1.23 respectively. The enzyme also exhibited a substrate binding capacity of more than 70% for squid chitin, shrimp shell colloidal chitin, chitosan and prawn shell chitin. The chitinase showed a moderate antifungal activity against many phytopathogenic fungi such as Aspergillus niger, A. flavus, Penicillium degitatum and Fusarium calmorum.This strain could be a suitable candidate for chitinase production on an industrial scale for using as promising antifungal biopestecide.

Keywords: antifungal activity, Bacillus sp. R2, chitinase, substrate specificity

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78 A Novel Stress Instability Workability Criteria for Internal Ductile Failure in Steel Cold Heading Process

Authors: Amar Sabih, James Nemes

Abstract:

The occurrence of internal ductile failure within the Adiabatic Shear Band (ASB) in cold-headed products presents a significant barrier in the fast-expanding cold-heading (CH) industry. The presence of internal ductile failure in cold-headed products may lead to catastrophic fracture under tensile loads despite the ductile nature of the material causing expensive industrial recalls. Therefore, this paper presents a workability criterion that uses stress instability as an indicator to accurately reveal the locus of initiation of internal ductile failures. The concept of the instability criterion is to use the stress ratio at failure as a weighting function to indicate the initiation of ductile failure inside the ASBs. This paper presents a comprehensive experimental, metallurgical, and finite element simulation study to calculate the material constants used in this criterion.

Keywords: adiabatic shear band, workability criterion, ductile failure, stress instability

Procedia PDF Downloads 57
77 Influence of Ball Milling Time on Mechanical Properties of Porous Ti-20Nb-5Ag Alloy

Authors: M. J. Shivaram, Shashi Bhushan Arya, Jagannath Nayak, Bharat Bhooshan Panigrahi

Abstract:

Titanium and its alloys have become more significant implant materials due to their mechanical properties, excellent biocompatibility and high corrosion resistance. Biomaterials can be produce by using the powder metallurgy (PM) methods and required properties can tailored by varying the processing parameters, such as ball milling time, space holder particles, and sintering temperature. The desired properties such as, structural and mechanical properties can be obtained by powder metallurgy method.  In the present study, deals with fabrication of solid and porous Ti-20Nb-5Ag alloy using high energy ball milling for different times (5 and 20 h). The resultant powder particles were used to fabricate solid and porous Ti-20Nb-5Ag alloy by adding space holder particles (NH4HCO3). The resultant powder particles, fabricated solid and porous samples were characterized by scanning electron microscopy (SEM). The compressive strength, elastic modulus and microhardness properties were investigated. Solid and porous Ti-20Nb-5Ag alloy samples showed good mechanical properties for 20 h ball milling time as compare to 5 h ball milling.

Keywords: ball milling, compressive strengths, microstructure, porous titanium alloy

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76 Development and Characterization of Biodegradable Films Based on Biopolymer Extracted From Natural Sources

Authors: Dalila Hammiche, Lisa Klaai, Sonia Imzi, Amar Boukerrou

Abstract:

The fight against plastic pollution implies the development of polymers as alternatives to synthetic polymers. Starch is a natural polymer that can easily be plasticized by means of additives. The objective of this work is to develop and characterize biodegradable biofilms based on starch, plasticized by glycerol (20 and 30%). The elaboration of the biofilms was carried out by the casting method under simple conditions. The samples were characterized by infrared spectroscopy analysis with Fourier transform (FTIR), thermogravimetric analysis, and biodegradability test. Infrared spectral analysis showed that the 30% and 20% glycerol films have the same chemical structure and no functional group changes occurred. Thermogravimetric analysis showed that a 30% glycerol film has higher thermal stability than a 20% glycerol film. Biodegradability test showed that the lower the percentage of glycerol, the more easily the biofilm degrades.

Keywords: starch, natural sources, FTIR, thermogravimetric analysis, biodegradability test

Procedia PDF Downloads 70
75 Synthesis and Characterization of Renewable Resource Based Green Epoxy Coating

Authors: Sukanya Pradhan, Smita Mohanty, S. K Nayak

Abstract:

Plant oils are a great renewable source for being a reliable starting material to access new products with a wide spectrum of structural and functional variations. Even though petroleum products might also render the same, but it would also impose a high risk factor of environmental and health hazard. Since epoxidized vegetable oils are easily available, eco-compatible, non-toxic and renewable, hence these have drawn much of the attentions in the polymer industrial sector especially for the development of eco-friendly coating materials. In this study a waterborne epoxy coating was prepared from epoxidized soyabean oil by using triethanolamine. Because of its hydrophobic nature, it was a tough and tedius task to make it hydrophilic. The hydrophobic biobased epoxy was modified into waterborne epoxy by the help of a plant based anhydride as curing agent. Physico-mechanical, chemical resistance tests and thermal analysis of the green coating material were carried out which showed good physic-mechanical, chemical resistance properties as well as environment friendly. The complete characterization of the final material was done in terms of scratch hardness, gloss test, impact resistance, adhesion and bend test.

Keywords: epoxidized soybean oil, waterborne, curing agent, green coating

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74 Optical and Double Folding Model Analysis for Alpha Particles Elastically Scattered from 9Be and 11B Nuclei at Different Energies

Authors: Ahmed H. Amer, A. Amar, Sh. Hamada, I. I. Bondouk, F. A. El-Hussiny

Abstract:

Elastic scattering of α-particles from 9Be and 11B nuclei at different alpha energies have been analyzed. Optical model parameters (OMPs) of α-particles elastic scattering by these nuclei at different energies have been obtained. In the present calculations, the real part of the optical potential are derived by folding of nucleon-nucleon (NN) interaction into nuclear matter density distribution of the projectile and target nuclei using computer code FRESCO. A density-dependent version of the M3Y interaction (CDM3Y6), which is based on the G-matrix elements of the Paris NN potential, has been used. Volumetric integrals of the real and imaginary potential depth (JR, JW) have been calculated and found to be energy dependent. Good agreement between the experimental data and the theoretical predictions in the whole angular range. In double folding (DF) calculations, the obtained normalization coefficient Nr is in the range 0.70–1.32.

Keywords: elastic scattering, optical model, double folding model, density distribution

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