Search results for: Non sinusoidal and unbalanced voltage conditions.
1927 Organic Contribution on Particles Formed on Pacific Ocean: From Phytoplankton Blooms to Climate
Authors: Petri Vaattovaara, Luke Cravigan, Zoran Ristovski, Marc Mallet, Ari Laaksonen, Sarah Lawson, Nick Talbot, Gustavo Olivares, Mike Harvey, Cliff Law
Abstract:
These SOAP project Pacific Ocean measurements reveal that phytoplankton blooms with sunny conditions make possible secondary organic contribution to ultrafine particles size and composition, and thus on cloud formation ability, and finally on climate. This is in agreement with other biologically active region observations about the presence of secondary organics even the exact fraction is also depending on the local marine life (e.g. plankton blooms, seaweeds, corals). An organic contribution is clearly needed to add to CLAW hypothesis.
Keywords: Climate, marine aerosols, phytoplankton, secondary organics, CLAW hypothesis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18341926 Analysis of a Double Pipe Heat Exchanger Performance by Use of Porous Baffles and Nanofluids
Authors: N. Targui, H. Kahalerras
Abstract:
The present work is a numerical simulation of nanofluids flow in a double pipe heat exchanger provided with porous baffles. The hot nanofluid flows in the inner cylinder, whereas the cold nanofluid circulates in the annular gap. The Darcy- Brinkman-Forchheimer model is adopted to describe the flow in the porous regions, and the governing equations with the appropriate boundary conditions are solved by the finite volume method. The results reveal that the addition of metallic nanoparticles enhances the rate of heat transfer in comparison to conventional fluids but this augmentation is accompanied by an increase in pressure drop. The highest heat exchanger performances are obtained when nanoparticles are added only to the cold fluid.
Keywords: Double pipe heat exchanger, Nanofluids, Nanoparticles, Porous baffles.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 35181925 Multiple Positive Periodic Solutions of a Delayed Predatory-Prey System with Holling Type II Functional Response
Authors: Kaihong Zhao, Jiuqing Liu
Abstract:
In this letter, we considers a delayed predatory-prey system with Holling type II functional response. Under some sufficient conditions, the existence of multiple positive periodic solutions is obtained by using Mawhin’s continuation theorem of coincidence degree theory. An example is given to illustrate the effectiveness of our results.
Keywords: Multiple positive periodic solutions, Predatory-prey system, Coincidence degree, Holling type II functional response.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14971924 Vehicle Position Estimation for Driver Assistance System
Authors: Hyun-Koo Kim, Sangmoon Lee, Ho-Youl Jung, Ju H. Park
Abstract:
We present a system that finds road boundaries and constructs the virtual lane based on fusion data from a laser and a monocular sensor, and detects forward vehicle position even in no lane markers or bad environmental conditions. When the road environment is dark or a lot of vehicles are parked on the both sides of the road, it is difficult to detect lane and road boundary. For this reason we use fusion of laser and vision sensor to extract road boundary to acquire three dimensional data. We use parabolic road model to calculate road boundaries which is based on vehicle and sensors state parameters and construct virtual lane. And then we distinguish vehicle position in each lane.Keywords: Vehicle Detection, Adaboost, Haar-like Feature, Road Boundary Detection
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16411923 Educational Plan and Program of the Subject Maintenance of Electric Power Equipment
Authors: Rade Ciric, Sasa Mandic
Abstract:
Students of Higher Education Technical School of Professional Studies in Novi Sad follow the subject ‘Maintenance of Electric Power Equipment’ at the Electrotechnical Department. This paper presents educational plan and program of the subject Maintenance of Electric Power Equipment. The course deals with the problems of preventive and investing maintenance of transformer stations (TS), performing and maintenance of grounding of TS and pillars, as well as tracing and detection the location of the cables failure. There is a special elaborated subject concerning the safe work conditions for the electrician during network maintenance, as well as the basics of making and keeping technical documentation of the equipment.
Keywords: Educational plan and program, electric power equipment, maintenance, technical documentation, safe work.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13701922 Recovering the Boundary Data in the Two Dimensional Inverse Heat Conduction Problem Using the Ritz-Galerkin Method
Authors: Saeed Sarabadan, Kamal Rashedi
Abstract:
This article presents a numerical method to find the heat flux in an inhomogeneous inverse heat conduction problem with linear boundary conditions and an extra specification at the terminal. The method is based upon applying the satisfier function along with the Ritz-Galerkin technique to reduce the approximate solution of the inverse problem to the solution of a system of algebraic equations. The instability of the problem is resolved by taking advantage of the Landweber’s iterations as an admissible regularization strategy. In computations, we find the stable and low-cost results which demonstrate the efficiency of the technique.Keywords: Inverse problem, parabolic equations, heat equation, Ritz-Galerkin method, Landweber iterations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11941921 A High Order Theory for Functionally Graded Shell
Authors: V. V. Zozulya
Abstract:
New theory for functionally graded (FG) shell based on expansion of the equations of elasticity for functionally graded materials (GFMs) into Legendre polynomials series has been developed. Stress and strain tensors, vectors of displacements, traction and body forces have been expanded into Legendre polynomials series in a thickness coordinate. In the same way functions that describe functionally graded relations has been also expanded. Thereby all equations of elasticity including Hook-s law have been transformed to corresponding equations for Fourier coefficients. Then system of differential equations in term of displacements and boundary conditions for Fourier coefficients has been obtained. Cases of the first and second approximations have been considered in more details. For obtained boundary-value problems solution finite element (FE) has been used of Numerical calculations have been done with Comsol Multiphysics and Matlab.
Keywords: Shell, FEM, FGM, legendre polynomial.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15911920 Principal Component Analysis using Singular Value Decomposition of Microarray Data
Authors: Dong Hoon Lim
Abstract:
A series of microarray experiments produces observations of differential expression for thousands of genes across multiple conditions. Principal component analysis(PCA) has been widely used in multivariate data analysis to reduce the dimensionality of the data in order to simplify subsequent analysis and allow for summarization of the data in a parsimonious manner. PCA, which can be implemented via a singular value decomposition(SVD), is useful for analysis of microarray data. For application of PCA using SVD we use the DNA microarray data for the small round blue cell tumors(SRBCT) of childhood by Khan et al.(2001). To decide the number of components which account for sufficient amount of information we draw scree plot. Biplot, a graphic display associated with PCA, reveals important features that exhibit relationship between variables and also the relationship of variables with observations.
Keywords: Principal component analysis, singular value decomposition, microarray data, SRBCT
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32501919 Nanofibrous Ion Exchangers
Authors: Jaromír Marek, Jakub Wiener, Yan Wang
Abstract:
The main goal of this study was to find simple and industrially applicable production of ion exchangers based on nanofibrous polystyrene matrix and characterization of prepared material. Starting polystyrene nanofibers were sulfonated and crosslinked under appropriate conditions at the same time by sulfuric acid. Strongly acidic cation exchanger was obtained in such a way. The polymer matrix was made from polystyrene nanofibers prepared by NanospiderTM technology.
Various types postpolymerization reactions and other methods of crosslinking were studied. Greatly different behavior between nano- and microsize materials was observed. The final nanofibrous material was characterized and compared to common granular ion exchangers and available microfibrous ion exchangers. The sorption properties of nanofibrous ion exchangers were compared with the granular ion exchangers. For nanofibrous ion exchangers of comparable ion exchange capacity was observed considerably faster adsorption kinetics.
Keywords: Electrospinning, ion exchangers, nanofibers, polystyrene.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20301918 An Experimental Study of the Effect of Coil Step on Heat Transfer Coefficient in Shell- Side of Shell-and-Coil Heat Exchanger
Authors: Mofid Gorji Bandpy, Hasan Sajjadi
Abstract:
In this study the mixed convection heat transfer in a coil-in-shell heat exchanger for various Reynolds numbers and various dimensionless coil pitch was experimentally investigated. The experiments were conducted for both laminar and turbulent flow inside coil and the effects of coil pitch on shell-side heat transfer coefficient of the heat exchanger were studied. The particular difference in this study in comparison with the other similar studies was the boundary conditions for the helical coils. The results indicate that with the increase of coil pitch, shell-side heat transfer coefficient is increased.Keywords: Coil pitch, Shell-and-Coil heat exchanger, Mixed convection, Experimental investigation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24581917 An Accurate Computation of Block Hybrid Method for Solving Stiff Ordinary Differential Equations
Authors: A. M. Sagir
Abstract:
In this paper, self-starting block hybrid method of order (5,5,5,5)T is proposed for the solution of the special second order ordinary differential equations with associated initial or boundary conditions. The continuous hybrid formulations enable us to differentiate and evaluate at some grids and off – grid points to obtain four discrete schemes, which were used in block form for parallel or sequential solutions of the problems. The computational burden and computer time wastage involved in the usual reduction of second order problem into system of first order equations are avoided by this approach. Furthermore, a stability analysis and efficiency of the block method are tested on stiff ordinary differential equations, and the results obtained compared favorably with the exact solution.Keywords: Block Method, Hybrid, Linear Multistep Method, Self – starting, Special Second Order.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14821916 Thermoplastic Composites with Reduced Discoloration and Enhanced Fire-Retardant Property
Authors: Peng Cheng, Liqing Wei, Hongyu Chen, Ruomiao Wang
Abstract:
This paper discusses a light-weight reinforced thermoplastic (LWRT) composite with superior fire retardancy. This porous LWRT composite is manufactured using polyolefin, fiberglass, and fire retardant additives via a wet-lay process. However, discoloration of the LWRT can be induced by various mechanisms, which may be a concern in the building and construction industry. It is commonly understood that discoloration is strongly associated with the presence of phenolic antioxidant(s) and NOx. The over-oxidation of phenolic antioxidant(s) is probably the root-cause of the discoloration (pinking/yellowing). Hanwha Azdel, Inc. developed a LWRT with fire-retardant property of ASTM E84-Class A specification, as well as negligible discoloration even under harsh conditions. In addition, this thermoplastic material is suitable for secondary processing (e.g. compression molding) if necessary.Keywords: Discoloration, fire-retardant, thermoplastic composites, wet-lay process.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7921915 Forced Vibration of a Fiber Metal Laminated Beam Containing a Delamination
Authors: Sh. Mirhosseini, Y. Haghighatfar, M. Sedighi
Abstract:
Forced vibration problem of a delaminated beam made of fiber metal laminates is studied in this paper. Firstly, a delamination is considered to divide the beam into four sections. The classic beam theory is assumed to dominate each section. The layers on two sides of the delamination are constrained to have the same deflection. This hypothesis approves the conditions of compatibility as well. Consequently, dynamic response of the beam is obtained by the means of differential transform method (DTM). In order to verify the correctness of the results, a model is constructed using commercial software ABAQUS 6.14. A linear spring with constant stiffness takes the effect of contact between delaminated layers into account. The attained semi-analytical outcomes are in great agreement with finite element analysis.
Keywords: Delamination, forced vibration, finite element modelling, natural frequency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8321914 Mechanical Properties of Recycled Plasticized PVB/PVC Blends
Authors: Michael Tupý, Dagmar Měřínská, Alice Tesaříková-Svobodová, Christian Carrot, Caroline Pillon, Vít Petránek
Abstract:
The mechanical properties of blends consisting of plasticized poly(vinyl butyral) (PVB) and plasticized poly(vinyl chloride) (PVC) are studied, in order to evaluate the possibility of using recycled PVB waste derived from windshields. PVC was plasticized with 38% of diisononyl phthalate (DINP), while PVB was plasticized with 28% of triethylene glycol, bis(2-ethylhexanoate) (3GO). The optimal process conditions for the PVB/PVC blend in 1:1 ratio were determined. Entropy was used in order to theoretically predict the blends miscibility. The PVB content of each blend composition used was ranging from zero to 100%. Tensile strength and strain were tested. In addition, a comparison between recycled and original PVB, used as constituents of the blend, was performed.
Keywords: Poly(vinyl butyral), poly(vinyl chloride), windshield, polymer waste, mechanical properties.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 47311913 A Constructive Proof of the General Brouwer Fixed Point Theorem and Related Computational Results in General Non-Convex sets
Authors: Menglong Su, Shaoyun Shi, Qing Xu
Abstract:
In this paper, by introducing twice continuously differentiable mappings, we develop an interior path following following method, which enables us to give a constructive proof of the general Brouwer fixed point theorem and thus to solve fixed point problems in a class of non-convex sets. Under suitable conditions, a smooth path can be proven to exist. This can lead to an implementable globally convergent algorithm. Several numerical examples are given to illustrate the results of this paper.
Keywords: interior path following method, general Brouwer fixed point theorem, non-convex sets, globally convergent algorithm
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14461912 Self-Organizing Control Systems for Unstable and Deterministic Chaotic Processes
Authors: M. A. Beisenbi, N. M. Kissikova, S. E. Beisembina, S. T. Suleimenova, S. A. Kaliyeva
Abstract:
The paper proposes a method for constructing a self-organizing control system for unstable and deterministic chaotic processes in the class of catastrophe “hyperbolic umbilic” for objects with m-inputs and n-outputs. The self-organizing control system is investigated by the universal gradient-velocity method of Lyapunov vector-functions. The conditions for self-organization of the control system in the class of catastrophes “hyperbolic umbilic” are shown in the form of a system of algebraic inequalities that characterize the aperiodic robust stability in the stationary states of the system.
Keywords: Gradient-velocity method of Lyapunov vector-functions, hyperbolic umbilic, self-organizing control system, stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4611911 Collaborative Mobile Device based Data Collection and Dissemination using MIH for Effective Emergency Management
Authors: Aiswaria Ramachandran, Balaji Haiharan
Abstract:
The importance of our country-s communication system is noticeable when a disaster occurs. The communication system in our country includes wired and wireless telephone networks, radio, satellite system and more increasingly internet. Even though our communication system is most extensive and dependable, extreme conditions can put a strain on them. Interoperability between heterogeneous wireless networks can be used to provide efficient communication for emergency first response. IEEE 802.21 specifies Media Independent Handover (MIH) services to enhance the mobile user experience by optimizing handovers between heterogeneous access networks. This paper presents an algorithm to improve congestion control in MIH framework. It is analytically shown that by including time factor in network selection we can optimize congestion in the network.Keywords: Vertical Handoff, Heterogeneous Networks, MIH
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15481910 Sub-Impact Phenomenon of Elasto-Plastic Free-Free Beam during a Strike
Authors: H. Rong, X. C. Yin, J. Yang, Y. N. Shen
Abstract:
Based on Rayleigh beam theory, the sub-impacts of a free-free beam struck horizontally by a round-nosed rigid mass is simulated by the finite difference method and the impact-separation conditions. In order to obtain the sub-impact force, a uniaxial compression elastic-plastic contact model is employed to analyze the local deformation field on contact zone. It is found that the horizontal impact is a complicated process including the elastic plastic sub-impacts in sequence. There are two sub-zones of sub-impact. In addition, it found that the elastic energy of the free-free beam is more suitable for the Poisson collision hypothesis to explain compression and recovery processes.Keywords: beam, sub-impact, elastic-plastic deformation, finite difference method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18521909 Influence Analysis of Pelamis Wave Energy Converter Structure Parameters
Authors: Liu Shengnan, Sun Liping, Zhu Jianxun
Abstract:
Based on three dimensional potential flow theory and hinged rigid body motion equations, structure RAOs of Pelamis wave energy converter is analyzed. Analysis of numerical simulation is carried out on Pelamis in the irregular wave conditions, and the motion response of structures and total generated power is obtained. The paper analyzes influencing factors on the average power including diameter of floating body, section form of floating body, draft, hinged stiffness and damping. The optimum parameters are achieved in Zhejiang Province. Compared with the results of the pelamis experiment made by Glasgow University, the method applied in this paper is feasible.
Keywords: Pelamis, Hinge, Floating multibody, Wave energy
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32621908 Improved Asymptotic Stability Analysis for Lure Systems with Neutral Type and Time-varying Delays
Authors: Changchun Shen, Shouming Zhong
Abstract:
This paper investigates the problem of absolute stability and robust stability of a class of Lur-e systems with neutral type and time-varying delays. By using Lyapunov direct method and linear matrix inequality technique, new delay-dependent stability criteria are obtained and formulated in terms of linear matrix inequalities (LMIs) which are easy to check the stability of the considered systems. To obtain less conservative stability conditions, an operator is defined to construct the Lyapunov functional. Also, the free weighting matrices approach combining a matrix inequality technique is used to reduce the entailed conservativeness. Numerical examples are given to indicate significant improvements over some existing results.
Keywords: Lur'e system, linear matrix inequalities, Lyapunov, stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17911907 Experimental Investigation on Over-Cut in Ultrasonic Machining of WC-Co Composite
Authors: Ravinder Kataria, Jatinder Kumar, B. S. Pabla
Abstract:
Ultrasonic machining is one of the most widely used non-traditional machining processes for machining of materials that are relatively brittle, hard, and fragile such as advanced ceramics, refractories, crystals, quartz etc. Present article has been targeted at investigating the impact of different experimental conditions (power rating, cobalt content, tool material, thickness of work piece, tool geometry, and abrasive grit size) on over cut in ultrasonic drilling of WC-Co composite material. Taguchi’s L-36 orthogonal array has been employed for conducting the experiments. Significant factors have been identified using analysis of variance (ANOVA) test. The experimental results revealed that abrasive grit size and tool material are most significant factors for over cut.
Keywords: ANOVA, Abrasive grit size, Taguchi, WC-Co, ultrasonic machining.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16881906 Geochemical Study of Natural Bitumen, Condensate and Gas Seeps from Sousse Area, Central Tunisia
Authors: A. Belhaj Mohamed, M. Saidi, N. Boucherb, N. Ourtani, A. Soltani, I. Bouazizi, M. Ben Jrad
Abstract:
Natural hydrocarbon seepage has helped petroleum exploration as a direct indicator of gas and/or oil subsurface accumulations. Surface macro-seeps are generally an indication of a fault in an active Petroleum Seepage System belonging to a Total Petroleum System. This paper describes a case study in which multiple analytical techniques were used to identify and characterize trace petroleum-related hydrocarbons and other volatile organic compounds in groundwater samples collected from Sousse aquifer (Central Tunisia). The analytical techniques used for analyses of water samples included gas chromatography-mass spectrometry (GCMS), capillary GC with flame-ionization detection, Compound Specific Isotope Analysis, Rock Eval Pyrolysis. The objective of the study was to confirm the presence of gasoline and other petroleum products or other volatile organic pollutants in those samples in order to assess the respective implication of each of the potentially responsible parties to the contamination of the aquifer. In addition, the degree of contamination at different depths in the aquifer was also of interest. The oil and gas seeps have been investigated using biomarker and stable carbon isotope analyses to perform oil-oil and oil-source rock correlations. The seepage gases are characterized by high CH4 content, very low δ13CCH4 values (-71,9 ‰) and high C1/C1–5 ratios (0.95–1.0), light deuterium–hydrogen isotope ratios (- 198 ‰) and light δ13CC2 and δ13CCO2 values (-23,8‰ and-23,8‰ respectively) indicating a thermogenic origin with the contribution of the biogenic gas. An organic geochemistry study was carried out on the more ten oil seep samples. This study includes light hydrocarbon and biomarkers analyses (hopanes, steranes, n-alkanes, acyclic isoprenoids, and aromatic steroids) using GC and GC-MS. The studied samples show at least two distinct families, suggesting two different types of crude oil origins: the first oil seeps appears to be highly mature, showing evidence of chemical and/or biological degradation and was derived from a clay-rich source rock deposited in suboxic conditions. It has been sourced mainly by the lower Fahdene (Albian) source rocks. The second oil seeps was derived from a carbonate-rich source rock deposited in anoxic conditions, well correlated with the Bahloul (Cenomanian-Turonian) source rock.
Keywords: Biomarkers, oil and gas seeps, organic geochemistry, source rock.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 34521905 Stability Analysis of Two-delay Differential Equation for Parkinson's Disease Models with Positive Feedback
Authors: M. A. Sohaly, M. A. Elfouly
Abstract:
Parkinson's disease (PD) is a heterogeneous movement disorder that often appears in the elderly. PD is induced by a loss of dopamine secretion. Some drugs increase the secretion of dopamine. In this paper, we will simply study the stability of PD models as a nonlinear delay differential equation. After a period of taking drugs, these act as positive feedback and increase the tremors of patients, and then, the differential equation has positive coefficients and the system is unstable under these conditions. We will present a set of suggested modifications to make the system more compatible with the biodynamic system. When giving a set of numerical examples, this research paper is concerned with the mathematical analysis, and no clinical data have been used.
Keywords: Parkinson's disease, stability, simulation, two delay differential equation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6631904 Enhancement of Heat Transfer Rate in a Solar Flat Plate Collector Using Twisted Tapes and Wire Coiled Turbulators
Authors: S. Vijayakumar, R. Vinoth, K. Abilash, P. Praveen
Abstract:
Effects of insertion of coiled wire in juxtaposition with twisted tapes on heat transfer rate and solar radiation without disturbing the flow inside the riser tubes in a solar flat plate collector is experimentally reconnoitered in this present work. The wire coil used as a turbulator is placed inside the riser tube while the twisted tape is inserted into the wire coil to create a continuous swirling flow along the tube wall. The results of the heat transfer have been compared well with the available results. The heat transfer rate in the collector has been found to be increased by 18% to 70%. Solar water heaters having inserts in the flow tubes perform better than the conventional plain ones. It has been observed that heat losses are reduced consequently increasing the thermal performance about 30% over the plain water heaters under the same operating conditions. The effect of twisted tape with wire coils, flow Reynolds number, and the intensity of solar radiation on the thermal performance of the solar water heater has been presented. Effects of insertion of coiled wire in juxtaposition with twisted tapes on heat transfer rate and solar radiation without disturbing the flow inside the riser tubes in a solar flat plate collector is experimentally reconnoitered in this present work. The wire coil used as a turbulator is placed inside the riser tube while the twisted tape is inserted into the wire coil to create a continuous swirling flow along the tube wall. The results of the heat transfer have been compared well with the available results. The heat transfer rate in the collector has been found to be increased by 18% to 70%. Solar water heaters having inserts in the flow tubes perform better than the conventional plain ones. It has been observed that heat losses are reduced consequently increasing the thermal performance about 30% over the plain water heaters under the same operating conditions. The effect of twisted tape with wire coils, flow Reynolds number, and the intensity of solar radiation on the thermal performance of the solar water heater has been presented.
Keywords: Solar Flat Plate Collector, Heat Transfer, Twisted tape, Wire coiled turbulators
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28711903 Optimized Weight Vector for QoS Aware Web Service Selection Algorithm Using Particle Swarm Optimization
Authors: N. Arulanand, P. M. Ananth
Abstract:
Quality of Service (QoS) attributes as part of the service description is an important factor for service attribute. It is not easy to exactly quantify the weight of each QoS conditions since human judgments based on their preference causes vagueness. As web services selection requires optimization, evolutionary computing based on heuristics to select an optimal solution is adopted. In this work, the evolutionary computing technique Particle Swarm Optimization (PSO) is used for selecting a suitable web services based on the user’s weightage of each QoS values by optimizing the QoS weight vector and thereby finding the best weight vectors for best services that is being selected. Finally the results are compared and analyzed using static inertia weight and deterministic inertia weight of PSO.Keywords: QoS, Optimization, Particle Swarm Optimization (PSO), weight vector, web services, web service selection.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20151902 Nitrogen Removal in a High-efficiency Denitrification/Oxic Filter treatment System for Advanced Treatment of Municipal Wastewater
Authors: D. W. Kim , D. J. Ryu, M. J. Go, D. Chang, S. B. Han, J. M. Hur, B. R. Chung, B. K. Kim, Yeon Hye Jin
Abstract:
Biological treatment of secondary effluent wastewater by two combined denitrification/oxic filtration systems packed with Lock type(denitrification filter) and ceramic ball (oxic filter) has been studied for 5months. Two phases of operating conditions were carried out with an influent nitrate and ammonia concentrations varied from 5.8 to 11.7mg/L and 5.4 to 12.4mg/L,respectively. Denitrification/oxic filter treatment system were operated under an EBCT (Empty Bed Contact Time) of 4h at system recirculation ratio in the range from 0 to 300% (Linear Velocity increased 19.5m/d to 78m/d). The system efficiency of denitrification , nitrification over 95% respectively. Total nitrogen and COD removal range from 54.6%(recirculation 0%) to 92.3%(recirculation 300%) and 10% to 62.5%, respectively.Keywords: Advanced treatment , Biofilter, Nitrogen removal, Two combined denitrification/oxic filter
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19911901 Ultrasound Assisted Extraction and Microwave Assisted Extraction of Carotenoids from Melon Shells
Authors: A. Brinda Lakshmi, J. Lakshmi Priya
Abstract:
Cantaloupes (muskmelon and watermelon) contain biologically active molecules such as carotenoids which are natural pigments used as food colorants and afford health benefits. ß-carotene is the major source of carotenoids present in muskmelon and watermelon shell. Carotenoids were extracted using Microwave assisted extraction (MAE) and Ultrasound assisted extraction (UAE) utilising organic lipophilic solvents such as acetone, methanol, and hexane. Extraction conditions feed-solvent ratio, microwave power, ultrasound frequency, temperature and particle size were varied and optimized. It was found that the yield of carotenoids was higher using UAE than MAE, and muskmelon had the highest yield of carotenoids when was ethanol used as a solvent for 0.5 mm particle size.Keywords: Carotenoids, extraction, muskmelon shell, watermelon shell.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9801900 A Case Study on Suitable Area and Resource for Development of Floating Photovoltaic System
Authors: Young-Kwan Choi
Abstract:
In development of floating photovoltaic generation system, finding a suitable place of installation is as important as development of economically feasible and stable structure. Especially since floating photovoltaic system has its facility floating on water surface, it is extremely important to review the effects of weather conditions such as wind, water flow and floating matters, various factors (such as fogs) that can reduce generation efficiency, possibility of connection with power system, and legal restrictions. The method of investigating suitable area and resource for development of tracking-type floating photovoltaic generation system was proposed in this paper, which can be used for development of floating and ocean photovoltaic system in the future.
Keywords: Floating PV system, On-site Survey, Resources Survey of Photovoltaic, Tracking-type Floating PV.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 33201899 A Review on Application of Chitosan as a Natural Antimicrobial
Authors: F. Nejati Hafdani, N. Sadeghinia
Abstract:
In recent years application of natural antimicrobials instead of conventional ones, due to their hazardous effects on health, has got serious attentions. On the basis of the results of different studies, chitosan, a natural bio-degradable and non-toxic biopolysaccharide derived from chitin, has potential to be used as a natural antimicrobial. Chitosan has exhibited high antimicrobial activity against a wide variety of pathogenic and spoilage microorganisms, including fungi, and Gram-positive and Gramnegative bacteria. The antimicrobial action is influenced by intrinsic factors such as the type of chitosan, the degree of chitosan polymerization and extrinsic factors such as the microbial organism, the environmental conditions and presence of the other components. The use of chitosan in food systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action. In this article we review a number of studies on the investigation of chitosan antimicrobial properties and application of them in culture and food mediums.Keywords: Antimicrobial, Chitosan, Preservative
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 67981898 Analytical Modeling of Channel Noise for Gate Material Engineered Surrounded/Cylindrical Gate (SGT/CGT) MOSFET
Authors: Pujarini Ghosh A, Rishu Chaujar B, Subhasis Haldar C, R.S Gupta D, Mridula Gupta E
Abstract:
In this paper, an analytical modeling is presentated to describe the channel noise in GME SGT/CGT MOSFET, based on explicit functions of MOSFETs geometry and biasing conditions for all channel length down to deep submicron and is verified with the experimental data. Results shows the impact of various parameters such as gate bias, drain bias, channel length ,device diameter and gate material work function difference on drain current noise spectral density of the device reflecting its applicability for circuit design applications.Keywords: Cylindrical/Surrounded gate (SGT/CGT) MOSFET, Gate Material Engineering (GME), Spectral Noise and short channeleffect (SCE).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1981