Search results for: property rates
937 The Analysis of Nanoptenna for Extreme Fast Communication (XFC) over Short Distance
Authors: Shruti Taksali
Abstract:
This paper focuses on the analysis of Nanoptenna for extreme fast communication. The Nanoptenna is basically a nano antenna designed for communication at optical range of frequencies. Since, this range of frequencies includes the visible spectrum of the light, so there is a high possibility of the data transfer at high rates and extreme fast communication (XFC). The shape chosen for the analysis is a bow tie structure due to its various characteristics of electric field enhancement.
Keywords: Nanoptenna, communication, optical range, XFC.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1355936 Computer Models of the Vestibular Head Tilt Response, and Their Relationship to EVestG and Meniere's Disease
Authors: Daniel Heibert, Brian Lithgow, Kerry Hourigan
Abstract:
This paper attempts to explain response components of Electrovestibulography (EVestG) using a computer simulation of a three-canal model of the vestibular system. EVestG is a potentially new diagnostic method for Meniere's disease. EVestG is a variant of Electrocochleography (ECOG), which has been used as a standard method for diagnosing Meniere's disease - it can be used to measure the SP/AP ratio, where an SP/AP ratio greater than 0.4-0.5 is indicative of Meniere-s Disease. In EVestG, an applied head tilt replaces the acoustic stimulus of ECOG. The EVestG output is also an SP/AP type plot, where SP is the summing potential, and AP is the action potential amplitude. AP is thought of as being proportional to the size of a population of afferents in an excitatory neural firing state. A simulation of the fluid volume displacement in the vestibular labyrinth in response to various types of head tilts (ipsilateral, backwards and horizontal rotation) was performed, and a simple neural model based on these simulations developed. The simple neural model shows that the change in firing rate of the utricle is much larger in magnitude than the change in firing rates of all three semi-circular canals following a head tilt (except in a horizontal rotation). The data suggests that the change in utricular firing rate is a minimum 2-3 orders of magnitude larger than changes in firing rates of the canals during ipsilateral/backward tilts. Based on these results, the neural response recorded by the electrode in our EVestG recordings is expected to be dominated by the utricle in ipsilateral/backward tilts (It is important to note that the effect of the saccule and efferent signals were not taken into account in this model). If the utricle response dominates the EVestG recordings as the modeling results suggest, then EVestG has the potential to diagnose utricular hair cell damage due to a viral infection (which has been cited as one possible cause of Meniere's Disease).
Keywords: Diagnostic, endolymph hydrops, Meniere's disease, modeling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1517935 Assessing Complexity of Neuronal Multiunit Activity by Information Theoretic Measure
Authors: Young-Seok Choi
Abstract:
This paper provides a quantitative measure of the time-varying multiunit neuronal spiking activity using an entropy based approach. To verify the status embedded in the neuronal activity of a population of neurons, the discrete wavelet transform (DWT) is used to isolate the inherent spiking activity of MUA. Due to the de-correlating property of DWT, the spiking activity would be preserved while reducing the non-spiking component. By evaluating the entropy of the wavelet coefficients of the de-noised MUA, a multiresolution Shannon entropy (MRSE) of the MUA signal is developed. The proposed entropy was tested in the analysis of both simulated noisy MUA and actual MUA recorded from cortex in rodent model. Simulation and experimental results demonstrate that the dynamics of a population can be quantified by using the proposed entropy.
Keywords: Discrete wavelet transform, Entropy, Multiresolution, Multiunit activity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1845934 Levenberg-Marquardt Algorithm for Karachi Stock Exchange Share Rates Forecasting
Authors: Syed Muhammad Aqil Burney, Tahseen Ahmed Jilani, C. Ardil
Abstract:
Financial forecasting is an example of signal processing problems. A number of ways to train/learn the network are available. We have used Levenberg-Marquardt algorithm for error back-propagation for weight adjustment. Pre-processing of data has reduced much of the variation at large scale to small scale, reducing the variation of training data.
Keywords: Gradient descent method, jacobian matrix.Levenberg-Marquardt algorithm, quadratic error surfaces,
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2474933 A Hybrid CamShift and l1-Minimization Video Tracking Algorithm
Authors: Clark Van Dam, Gagan Mirchandani
Abstract:
The Continuously Adaptive Mean-Shift (CamShift) algorithm, incorporating scene depth information is combined with the l1-minimization sparse representation based method to form a hybrid kernel and state space-based tracking algorithm. We take advantage of the increased efficiency of the former with the robustness to occlusion property of the latter. A simple interchange scheme transfers control between algorithms based upon drift and occlusion likelihood. It is quantified by the projection of target candidates onto a depth map of the 2D scene obtained with a low cost stereo vision webcam. Results are improved tracking in terms of drift over each algorithm individually, in a challenging practical outdoor multiple occlusion test case.Keywords: CamShift, l1-minimization, particle filter, stereo vision, video tracking.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2043932 Studying Effects of Alternative Biodiesel Fuel in Performance and Pollutants of Diesel Engines
Authors: Shakila Motamedi, Seyed Azizollah Ghotb, Fatemeh Torfi, Najaf Hedayat
Abstract:
Since injection engines have a considerable portion, in consumption of energy and environmental pollution, using an alternative source of energy with lower pollutant effects in this regard is necessary. Biodiesel fuel is a suitable alternative for gasoline in diesel engines. In this research the property of biodiesel, the function and the pollution effects of diesel engine, when using 100% biodiesel, using 100% gasoline and mixing ratio of both fuels for comparing them, have been investigated. The researches have shown, using biodiesel fuel in prevalent diesel engine, will reduce the pollutants such as Co, half burned carbohydrate and suspended particles and a little increase in oxidation will achieve while power consumption, particularly fuel and thermal efficiency of diesel fuel has the same.Keywords: Biodiesel, Diesel Engine, Environment, Gasoline
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1593931 A Watermarking Signature Scheme with Hidden Watermarks and Constraint Functions in the Symmetric Key Setting
Authors: Yanmin Zhao, Siu Ming Yiu
Abstract:
To claim the ownership for an executable program is a non-trivial task. An emerging direction is to add a watermark to the program such that the watermarked program preserves the original program’s functionality and removing the watermark would heavily destroy the functionality of the watermarked program. In this paper, the first watermarking signature scheme with the watermark and the constraint function hidden in the symmetric key setting is constructed. The scheme uses well-known techniques of lattice trapdoors and a lattice evaluation. The watermarking signature scheme is unforgeable under the Short Integer Solution (SIS) assumption and satisfies other security requirements such as the unremovability security property.
Keywords: Short integer solution problem, signatures, the symmetric-key setting, watermarking schemes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 563930 Influence and Interaction of Temperature, H2S and pH on Concrete Sewer Pipe Corrosion
Authors: Anna Romanova, Mojtaba Mahmoodian, Morteza A. Alani
Abstract:
Concrete sewer pipes are known to suffer from a process of hydrogen sulfide gas induced sulfuric acid corrosion. This leads to premature pipe degradation, performance failure and collapses which in turn may lead to property and health damage. The above work reports on a field study undertaken in working sewer manholes where the parameters of effluent temperature and pH as well as ambient temperature and concentration of hydrogen sulfide were continuously measured over a period of two months. Early results suggest that effluent pH has no direct effect on hydrogen sulfide build up; on average the effluent temperature is 3.5°C greater than the ambient temperature inside the manhole and also it was observed that hydrogen sulfate concentration increases with increasing temperature.
Keywords: Concrete corrosion, hydrogen sulphide gas, temperature, sewer pipe.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4946929 Cultural Effects on the Performance of Non- Profit and For-Profit Microfinance Institutions
Authors: Patrick M. Stanton, William R. McCumber
Abstract:
Using a large dataset of more than 2,400 individual microfinance institutions (MFIs) from 120 countries from 1999 to 2016, this study finds that nearly half of the international MFIs operate as for-profit institutions. Formal institutions (business regulatory environment, property rights, social protection, and a developed financial sector) impact the likelihood of MFIs being for-profit across countries. Cultural differences across countries (power distance, individualism, masculinity, and indulgence) seem to be a factor in the legal status of the MFI (non-profit or for-profit). MFIs in countries with stronger formal institutions, a greater degree of power distance, and a higher degree of collectivism experience better financial and social performance.Keywords: Hofstede cultural dimensions, international finance, microfinance institutions, non-profit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 999928 Burst on Hurst Algorithm for Detecting Activity Patterns in Networks of Cortical Neurons
Authors: G. Stillo, L. Bonzano, M. Chiappalone, A. Vato, F. Davide, S. Martinoia
Abstract:
Electrophysiological signals were recorded from primary cultures of dissociated rat cortical neurons coupled to Micro-Electrode Arrays (MEAs). The neuronal discharge patterns may change under varying physiological and pathological conditions. For this reason, we developed a new burst detection method able to identify bursts with peculiar features in different experimental conditions (i.e. spontaneous activity and under the effect of specific drugs). The main feature of our algorithm (i.e. Burst On Hurst), based on the auto-similarity or fractal property of the recorded signal, is the independence from the chosen spike detection method since it works directly on the raw data.
Keywords: Burst detection, cortical neuronal networks, Micro-Electrode Array (MEA), wavelets.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1558927 Combined Effect of Heat Stimulation and Delay Addition of Superplasticizer with Slag on Fresh and Hardened Property of Mortar
Authors: Antoni Wibowo, Harry Pujianto, Dewi Retno Sari Saputro
Abstract:
The stock market can provide huge profits in a relatively short time in financial sector; however, it also has a high risk for investors and traders if they are not careful to look the factors that affect the stock market. Therefore, they should give attention to the dynamic fluctuations and movements of the stock market to optimize profits from their investment. In this paper, we present a nonlinear autoregressive exogenous model (NARX) to predict the movements of stock market; especially, the movements of the closing price index. As case study, we consider to predict the movement of the closing price in Indonesia composite index (IHSG) and choose the best structures of NARX for IHSG’s prediction.
Keywords: NARX, prediction, stock market, time series.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 817926 Normalized Cumulative Spectral Distribution in Music
Authors: Young-Hwan Song, Hyung-Jun Kwon, Myung-Jin Bae
Abstract:
As the remedy used music becomes active and meditation effect through the music is verified, people take a growing interest about psychological balance or remedy given by music. From traditional studies, it is verified that the music of which spectral envelop varies approximately as 1/f (f is frequency) down to a frequency of low frequency bandwidth gives psychological balance. In this paper, we researched signal properties of music which gives psychological balance. In order to find this, we derived the property from voice. Music composed by voice shows large value in NCSD. We confirmed the degree of deference between music by curvature of normalized cumulative spectral distribution. In the music that gives psychological balance, the curvature shows high value, otherwise, the curvature shows low value.Keywords: Cognitive Psychology, Normalized Cumulative Spectral Distribution, Curvature.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2201925 A Hamiltonian Decomposition of 5-star
Authors: Walter Hussak, Heiko Schröder
Abstract:
Star graphs are Cayley graphs of symmetric groups of permutations, with transpositions as the generating sets. A star graph is a preferred interconnection network topology to a hypercube for its ability to connect a greater number of nodes with lower degree. However, an attractive property of the hypercube is that it has a Hamiltonian decomposition, i.e. its edges can be partitioned into disjoint Hamiltonian cycles, and therefore a simple routing can be found in the case of an edge failure. The existence of Hamiltonian cycles in Cayley graphs has been known for some time. So far, there are no published results on the much stronger condition of the existence of Hamiltonian decompositions. In this paper, we give a construction of a Hamiltonian decomposition of the star graph 5-star of degree 4, by defining an automorphism for 5-star and a Hamiltonian cycle which is edge-disjoint with its image under the automorphism.
Keywords: interconnection networks, paths and cycles, graphs andgroups.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1746924 Fuzzy Expert System Design for Determining Wearing Properties of Nitrided and Non Nitrided Steel
Authors: Serafettin Ekinci, Kursat Zuhtuogullari
Abstract:
This paper proposes a Fuzzy Expert System design to determine the wearing properties of nitrided and non nitrided steel. The proposed Fuzzy Expert System approach helps the user and the manufacturer to forecast the wearing properties of nitrided and non nitrided steel under specified laboratory conditions. Surfaces of the engineering components are often nitrided for improving wear, corosion, fatigue specifications. A major property of nitriding process is reducing distortion and wearing of the metalic alloys. A Fuzzy Expert System was developed for determining the wearing and durability properties of nitrided and non nitrided steels that were tested under different loads and different sliding speeds in the laboratory conditions.Keywords: Fuzzy Expert System Design, Rule Based Systems, Fatigue, Corrosion
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1615923 Elastic Stress Analysis of Annular Bi-Material Discs with Variable Thickness under Mechanical and Thermomechanical Loads
Authors: E. Çetin, A. Kurşun, Ş. Aksoy, M. Tunay Çetin
Abstract:
The closed form study deals with elastic stress analysis of annular bi-material discs with variable thickness subjected to the mechanical and thermomechanical loads. Those discs have many applications in the aerospace industry, such as gas turbines and gears. Those discs normally work under thermal and mechanical loads. Their life cycle can increase when stress components are minimized. Each material property is assumed to be isotropic. The results show that material combinations and thickness of profiles play an important role in determining the responses of bi-material discs and an optimal design of those structures. Stress distribution is investigated and results are shown as graphs.
Keywords: Bi-material discs, elastic stress analysis, mechanical loads, rotating discs.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2429922 Valuing Environmental Impact of Air Pollution in Moscow with Hedonic Prices
Authors: V. Komarova
Abstract:
The main purpose of this research is the calculation of implicit prices of the environmental level of air quality in the city of Moscow on the basis of housing property prices. The database used contains records of approximately 20 thousand apartments and has been provided by a leading real estate agency operating in Russia. The explanatory variables include physical characteristics of the houses, environmental (industry emissions), neighbourhood sociodemographic and geographic data: GPS coordinates of each house. The hedonic regression results for ecological variables show «negative» prices while increasing the level of air contamination from such substances as carbon monoxide, nitrogen dioxide, sulphur dioxide, and particles (CO, NO2, SO2, TSP). The marginal willingness to pay for higher environmental quality is presented for linear and log-log models.
Keywords: Air pollution, environment, hedonic prices, real estate, willingness to pay.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1973921 Epoxidized-Transesterified Cotton Seed Oil for Temperature-Dependent Austempering Process
Authors: R. M. Dodo, Z. Musa, K. A. Bello, U. Abdullahi, G. A. Faruna
Abstract:
Temperature dependent austempering of high carbon steel using epoxidized-transesterified cotton seed oil (ETO) was examined. Five sets of samples were heated to 850 oC and held for one hour and then quenched in an oil bath of ETO at 250 oC for one hour. The same procedure was performed on the remaining samples, which were austempered at 270 oC, 290 oC, 310 oC, and 330 oC. Next, mechanical property tests were conducted. The austempered samples were then analyzed for microstructure using a scanning electron microscope (SEM). The results indicate that tensile strength and hardness decrease with increasing temperature, while impact strength improved with rising temperature. It was observed that 270 oC is the best austempering temperature, as it produces austempered samples with the best combination of mechanical properties.
Keywords: Epoxidized-transesterified cotton seed oil, austempering temperature, high carbon steel, bainitic structures.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28920 Oil Refineries Emissions: Source and Impact: A Study using AERMOD
Authors: Amir. AL-Haddad, Hisham. Ettouney, Samiya. Saqer
Abstract:
The main objectives of this paper are to measure pollutants concentrations in the oil refinery area in Kuwait over three periods during one year, obtain recent emission inventory for the three refineries of Kuwait, use AERMOD and the emission inventory to predict pollutants concentrations and distribution, compare model predictions against measured data, and perform numerical experiments to determine conditions at which emission rates and the resulting pollutant dispersion is below maximum allowable limits.Keywords: Emissions, ISCST3 model, Modeling, Pollutants, Refinery
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1618919 A Dual Digital-Image Watermarking Technique
Authors: Maha Sharkas, Dahlia ElShafie, Nadder Hamdy
Abstract:
Image watermarking has become an important tool for intellectual property protection and authentication. In this paper a watermarking technique is suggested that incorporates two watermarks in a host image for improved protection and robustness. A watermark, in form of a PN sequence (will be called the secondary watermark), is embedded in the wavelet domain of a primary watermark before being embedded in the host image. The technique has been tested using Lena image as a host and the camera man as the primary watermark. The embedded PN sequence was detectable through correlation among other five sequences where a PSNR of 44.1065 dB was measured. Furthermore, to test the robustness of the technique, the watermarked image was exposed to four types of attacks, namely compression, low pass filtering, salt and pepper noise and luminance change. In all cases the secondary watermark was easy to detect even when the primary one is severely distorted.Keywords: DWT, Image watermarking, watermarkingtechniques, wavelets.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2711918 A Practical Method for Load Balancing in the LV Distribution Networks Case Study: Tabriz Electrical Network
Authors: A. Raminfard, S. M. Shahrtash
Abstract:
In this paper, a new efficient method for load balancing in low voltage distribution systems is presented. The proposed method introduces an improved Leap-frog method for optimization. The proposed objective function includes the difference between three phase currents, as well as two other terms to provide the integer property of the variables; where the latter are the status of the connection of loads to different phases. Afterwards, a new algorithm is supplemented to undertake the integer values for the load connection status. Finally, the method is applied to different parts of Tabriz low voltage network, where the results have shown the good performance of the proposed method.
Keywords: Load balancing, improved leap-frog method, optimization algorithm, low voltage distribution systems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3424917 Measuring the Effect of Ventilation on Cooking in Indoor Air Quality by Low-Cost Air Sensors
Authors: Andres Gonzalez, Adam Boies, Jacob Swanson, David Kittelson
Abstract:
The concern of the indoor air quality (IAQ) has been increasing due to its risk to human health. The smoking, sweeping, and stove and stovetop use are the activities that have a major contribution to the indoor air pollution. Outdoor air pollution also affects IAQ. The most important factors over IAQ from cooking activities are the materials, fuels, foods, and ventilation. The low-cost, mobile air quality monitoring (LCMAQM) sensors, is reachable technology to assess the IAQ. This is because of the lower cost of LCMAQM compared to conventional instruments. The IAQ was assessed, using LCMAQM, during cooking activities in a University of Minnesota graduate-housing evaluating different ventilation systems. The gases measured are carbon monoxide (CO) and carbon dioxide (CO2). The particles measured are particle matter (PM) 2.5 micrometer (µm) and lung deposited surface area (LDSA). The measurements are being conducted during April 2019 in Como Student Community Cooperative (CSCC) that is a graduate housing at the University of Minnesota. The measurements are conducted using an electric stove for cooking. The amount and type of food and oil using for cooking are the same for each measurement. There are six measurements: two experiments measure air quality without any ventilation, two using an extractor as mechanical ventilation, and two using the extractor and windows open as mechanical and natural ventilation. 3The results of experiments show that natural ventilation is most efficient system to control particles and CO2. The natural ventilation reduces the concentration in 79% for LDSA and 55% for PM2.5, compared to the no ventilation. In the same way, CO2 reduces its concentration in 35%. A well-mixed vessel model was implemented to assess particle the formation and decay rates. Removal rates by the extractor were significantly higher for LDSA, which is dominated by smaller particles, than for PM2.5, but in both cases much lower compared to the natural ventilation. There was significant day to day variation in particle concentrations under nominally identical conditions. This may be related to the fat content of the food. Further research is needed to assess the impact of the fat in food on particle generations.Keywords: Cooking, indoor air quality, low-cost sensor, ventilation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1017916 Synthesis of SnO Novel Cabbage Nanostructure and Its Electrochemical Property as an Anode Material for Lithium Ion Battery
Authors: Yongkui Cui, Fengping Wang, Hailai Zhao, Muhammad Zubair Iqbal, Ziya Wang, Yan Li, Pengpeng L. V.
Abstract:
The novel 3D SnO cabbages self-assembled by nanosheets were successfully synthesized via template-free hydrothermal growth method under facile conditions. The XRD results manifest that the as-prepared SnO is tetragonal phase. The TEM and HRTEM results show that the cabbage nanosheets are polycrystalline structure consisted of considerable single-crystalline nanoparticles. Two typical Raman modes A1g=210 and Eg=112 cm-1 of SnO are observed by Raman spectroscopy. Moreover, galvanostatic cycling tests has been performed using the SnO cabbages as anode material of lithium ion battery and the electrochemical results suggest that the synthesized SnO cabbage structures are a promising anode material for lithium ion batteries.Keywords: Hydrothermal process, lithium ion battery, Raman spectroscopy, stannous oxide.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2107915 Regular Data Broadcasting Plan with Grouping in Wireless Mobile Environment
Authors: John T. Tsiligaridis
Abstract:
The broadcast problem including the plan design is considered. The data are inserted and numbered at predefined order into customized size relations. The server ability to create a full, regular Broadcast Plan (RBP) with single and multiple channels after some data transformations is examined. The Regular Geometric Algorithm (RGA) prepares a RBP and enables the users to catch their items avoiding energy waste of their devices. Moreover, the Grouping Dimensioning Algorithm (GDA) based on integrated relations can guarantee the discrimination of services with a minimum number of channels. This last property among the selfmonitoring, self-organizing, can be offered by servers today providing also channel availability and less energy consumption by using smaller number of channels. Simulation results are provided.Keywords: Broadcast, broadcast plan, mobile computing, wireless networks, scheduling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1453914 IFS on the Multi-Fuzzy Fractal Space
Authors: Nadia M. G. AL-Sa'idi, Muhammad Rushdan Md. Sd., Adil M. Ahmed
Abstract:
The IFS is a scheme for describing and manipulating complex fractal attractors using simple mathematical models. More precisely, the most popular “fractal –based" algorithms for both representation and compression of computer images have involved some implementation of the method of Iterated Function Systems (IFS) on complete metric spaces. In this paper a new generalized space called Multi-Fuzzy Fractal Space was constructed. On these spases a distance function is defined, and its completeness is proved. The completeness property of this space ensures the existence of a fixed-point theorem for the family of continuous mappings. This theorem is the fundamental result on which the IFS methods are based and the fractals are built. The defined mappings are proved to satisfy some generalizations of the contraction condition.
Keywords: Fuzzy metric space, Fuzzy fractal space, Multi fuzzy fractal space.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1973913 Relating Interface Properties with Crack Propagation in Composite Laminates
Authors: Tao Qu, Chandra Prakash, Vikas Tomar
Abstract:
The interfaces between organic and inorganic phases in natural materials have been shown to be a key factor contributing to their high performance. This work analyzes crack propagation in a 2-ply laminate subjected to uniaxial tensile mode-I crack propagation loading that has laminate properties derived based on biological material constituents (marine exoskeleton- chitin and calcite). Interfaces in such laminates are explicitly modeled based on earlier molecular simulations performed by authors. Extended finite element method and cohesive zone modeling based simulations coupled with theoretical analysis are used to analyze crack propagation. Analyses explicitly quantify the effect that interface mechanical property variation has on the delamination as well as the transverse crack propagation in examined 2-ply laminates.
Keywords: Chitin, composites, interfaces, fracture.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1406912 Effects of Gamma Irradiation on Chemical and Antioxidant Properties of Iranian Native Fresh Barberry Fruit
Authors: Samira Berenji Ardestani, Hamid Reza Akhavan
Abstract:
Gamma irradiation greatly reduces the potential microbiological risk of fresh fruits, resulting in improved microbial safety as well as extending their shelf life. The effects of 0.5-2 kGy gamma doses on some physicochemical, microbial and sensory properties of fresh barberry fruits (Berberis vulgaris) during refrigerated storage for 40 days were evaluated. The total anthocyanin and total phenolic contents of barberry fruits decreased in a dose-dependent manner immediately after irradiation and after subsequent storage. In general, it is recommended that, according to the effect of gamma radiation on physicochemical, microbial and sensorial characteristics, doses of 1.25-2 kGy could be used.Keywords: Antioxidant property, barberry fruit, chemical properties, gamma irradiation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 723911 Determination of Required Ion Exchange Solution for Stabilizing Clayey Soils with Various PI
Authors: R. Ziaie Moayed, F. Allahyari
Abstract:
Soil stabilization has been widely used to improve soil strength and durability or to prevent erosion and dust generation. Generally to reduce problems of clayey soils in engineering work and to stabilize these soils additional materials are used. The most common materials are lime, fly ash and cement. Using this materials, although improve soil property , but in some cases due to financial problems and the need to use special equipment are limited .One of the best methods for stabilization clayey soils is neutralization the clay particles. For this purpose we can use ion exchange materials. Ion exchange solution like CBR plus can be used for soil stabilization. One of the most important things in using CBR plus is determination the amount of this solution for various soils with different properties. In this study a laboratory experiment is conduct to evaluate the ion exchange capacity of three soils with various plasticity index (PI) to determine amount or required CBR plus solution for soil stabilization.Keywords: CBR plus, clayey soils, ion exchange, soil stabilization
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2450910 Reliability-Based Topology Optimization Based on Evolutionary Structural Optimization
Authors: Sang-Rak Kim, Jea-Yong Park, Won-Goo Lee, Jin-Shik Yu, Seog-Young Han
Abstract:
This paper presents a Reliability-Based Topology Optimization (RBTO) based on Evolutionary Structural Optimization (ESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. Deterministic Topology Optimization (DTO) is obtained without considering of the uncertainties related to the uncertainty parameters. However, RBTO involves evaluation of probabilistic constraints, which can be done in two different ways, the reliability index approach (RIA) and the performance measure approach (PMA). Limit state function is approximated using Monte Carlo Simulation and Central Composite Design for reliability analysis. ESO, one of the topology optimization techniques, is adopted for topology optimization. Numerical examples are presented to compare the DTO with RBTO.Keywords: Evolutionary Structural Optimization, PerformanceMeasure Approach, Reliability-Based Topology Optimization, Reliability Index Approach.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2801909 Morphology of Machined Surfaces from Electro Discharge Sawing and Sinking Electro Discharge Machining
Authors: N. Nagabhushana Ramesh, Kalley Harinarayana, T. Raghavender Reddy, B. Balu Naik
Abstract:
Electro Discharge Sawing is a hybrid process combining the features of SEDM and ECM. Its major characteristic is extremely fast erosion rate compare to either of the above processes. This paper brings out its relative feature of SEDM and EDS about their erosion rates, surface roughness, and morphology of machined surfaces.Keywords: Electro Chemical Machining (ECM), Electro Discharge Sawing (EDS), Sinking Electro Discharge Machining (SEDM).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2167908 A Compact Quasi-Zero Stiffness Vibration Isolator Using Flexure-Based Spring Mechanisms Capable of Tunable Stiffness
Authors: Thanh-Phong Dao, Shyh-Chour Huang
Abstract:
This study presents a quasi-zero stiffness (QZS) vibration isolator using flexure-based spring mechanisms which afford both negative and positive stiffness elements, which enable self-adjustment. The QZS property of the isolator is achieved at the equilibrium position. A nonlinear mathematical model is then developed, based on the pre-compression of the flexure-based spring mechanisms. The dynamics are further analyzed using the Harmonic Balance method. The vibration attention efficiency is illustrated using displacement transmissibility, which is then compared with the corresponding linear isolator. The effects of parameters on performance are also investigated by numerical solutions. The flexure-based spring mechanisms are subsequently designed using the concept of compliant mechanisms, with evaluation by ANSYS software, and simulations of the QZS isolator.Keywords: Vibration isolator, quasi-zero stiffness, flexure-based spring mechanisms, compliant mechanism.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2150