Search results for: geometrical blocks
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1017

Search results for: geometrical blocks

657 Influence of Grain Shape, Size and Grain Boundary Diffusion on High Temperature Oxidation of Metal

Authors: Sneha Samal, Iva Petrikova, Bohdana Marvalova

Abstract:

Influence of grain size, shape and grain boundary diffusion at high temperature oxidation of pure metal is investigated as the function of microstructure evolution in this article. The oxidized scale depends on the geometrical parameter of the metal-scale system and grain shape, size, diffusion through boundary layers and influence of the contamination. The creation of the inner layer and the morphological structure develops from the internal stress generated during the growth of the scale. The oxidation rate depends on the cation and anion mobile transport of the metal in the inward and outward direction of the diffusion layer. Oxidation rate decreases with decreasing the grain size of the pure metal, whereas zinc deviates from this principle. A strong correlation between the surface roughness evolution, grain size, crystalline properties and oxidation mechanism of the oxidized metal was established.

Keywords: high temperature oxidation, pure metals, grain size, shape and grain boundary

Procedia PDF Downloads 488
656 Cloning and Characterization of Uridine-5’-Diphosphate -Glucose Pyrophosphorylases from Lactobacillus Kefiranofaciens and Rhodococcus Wratislaviensis

Authors: Mesfin Angaw Tesfay

Abstract:

Uridine-5’-diphosphate (UDP)-glucose is one of the most versatile building blocks within the metabolism of prokaryotes and eukaryotes serving as an activated sugar donor during the glycosylation of natural products. It is formed by the enzyme UDP-glucose pyrophosphorylase (UGPase) using uridine-5′-triphosphate (UTP) and α-d-glucose 1-phosphate as a substrate. Herein two UGPase genes from Lactobacillus kefiranofaciens ZW3 (LkUGPase) and Rhodococcus wratislaviensis IFP 2016 (RwUGPase) were identified through genome mining approaches. The LkUGPase and RwUGPase have 299 and 306 amino acids, respectively. Both UGPase has the conserved UTP binding site (G-X-G-T-R-X-L-P) and the glucose -1-phosphate binding site (V-E-K-P). The LkUGPase and RwUGPase were cloned in E. coli and SDS-PAGE analysis showed the expression of both enzymes forming about 36 KDa of protein band after induction. LkUGPase and RwUGPase have an activity of 1549.95 and 671.53 U/mg respectively. Currently, their kinetic properties are under investigation.

Keywords: UGPase, LkUGPase, RwUGPase, UDP-glucose, Glycosylation

Procedia PDF Downloads 10
655 The Impact of Foliar Application of the Calcium-Containing Compounds in Increasing Resistance to Blue Mold on Apples

Authors: Masoud Baghalian, Musa Arshad

Abstract:

In order to investigate the effect of foliar application of calcium chloride on the resistance of fruits such as Red and Golden Lebanese apple varieties to blue mold, a split plot experiment in time and space, based on accidental blocks, with three replications under foliar application were done (Control, one in a thousand, two in thousands) and the results of the variance analysis showed that there is a significant difference between the levels of foliar and variety at 5% level and between time, there is significant difference in interaction of variety × time and three way interaction of foliar×variety×time, at 1% level. The highest resistance to the blue mold disease in foliar application was observed at two in thousands calcium (calcium chloride) level.

Keywords: apple, blue mold, foliar calcium, resistance

Procedia PDF Downloads 261
654 Numerical Analysis of Shallow Footing Rested on Geogrid Reinforced Sandy Soil

Authors: Seyed Abolhasan Naeini, Javad Shamsi Soosahab

Abstract:

The use of geosynthetic reinforcement within the footing soils is a very effective and useful method to avoid the construction of costly deep foundations. This study investigated the use of geosynthetics for soil improvement based on numerical modeling using FELA software. Pressure settlement behavior and bearing capacity ratio of foundation on geogrid reinforced sand is investigated and the effect of different parameters like as number of geogrid layers and vertical distance between elements in three different relative density soil is studied. The effects of geometrical parameters of reinforcement layers were studied for determining the optimal values to reach to maximum bearing capacity. The results indicated that the optimum range of the distance ratio between the reinforcement layers was achieved at 0.5 to 0.6 and after number of geogrid layers of 4, no significant effect on increasing the bearing capacity of footing on reinforced sandy with geogrid

Keywords: geogrid, reinforced sand, FELA software, distance ratio, number of geogrid layers

Procedia PDF Downloads 144
653 High Efficiency Class-F Power Amplifier Design

Authors: Abdalla Mohamed Eblabla

Abstract:

Due to the high increase and demand for a wide assortment of applications that require low-cost, high-efficiency, and compact systems, RF power amplifiers are considered the most critical design blocks and power consuming components in wireless communication, TV transmission, radar, and RF heating. Therefore, much research has been carried out in order to improve the performance of power amplifiers. Classes-A, B, C, D, E, and F are the main techniques for realizing power amplifiers. An implementation of high efficiency class-F power amplifier with Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) was realized in this paper. The simulation and optimization of the class-F power amplifier circuit model was undertaken using Agilent’s Advanced Design system (ADS). The circuit was designed using lumped elements.

Keywords: Power Amplifier (PA), gallium nitride (GaN), Agilent’s Advanced Design System (ADS), lumped elements

Procedia PDF Downloads 436
652 Performance Study of Scraped Surface Heat Exchanger with Helical Ribbons

Authors: S. Ali, M. Baccar

Abstract:

In this work, numerical simulations were carried out using a specific CFD code in order to study the performance of an innovative Scraped Surface Heat Exchanger (SSHE) with helical ribbons for Bingham fluids (threshold fluids). The resolution of three-dimensional form of the conservation equations (continuity, momentum and energy equations) was carried out basing on the finite volume method (FVM). After studying the effect of dimensionless numbers (axial Reynolds, rotational Reynolds and Oldroyd numbers) on the hydrodynamic and thermal behaviors within SSHE, a parametric study was developed, by varying the width of the helical ribbon, the clearance between the stator wall and the tip of the ribbon and the number of turns of the helical ribbon, in order to improve the heat transfer inside the exchanger. The effect of these geometrical numbers on the hydrodynamic and thermal behaviors was discussed.

Keywords: heat transfer, helical ribbons, hydrodynamic behavior, parametric study, SSHE, thermal behavior

Procedia PDF Downloads 210
651 Exploration of Various Metrics for Partitioning of Cellular Automata Units for Efficient Reconfiguration of Field Programmable Gate Arrays (FPGAs)

Authors: Peter Tabatt, Christian Siemers

Abstract:

Using FPGA devices to improve the behavior of time-critical parts of embedded systems is a proven concept for years. With reconfigurable FPGA devices, the logical blocks can be partitioned and grouped into static and dynamic parts. The dynamic parts can be reloaded 'on demand' at runtime. This work uses cellular automata, which are constructed through compilation from (partially restricted) ANSI-C sources, to determine the suitability of various metrics for optimal partitioning. Significant metrics, in this case, are for example the area on the FPGA device for the partition, the pass count for loop constructs and communication characteristics to other partitions. With successful partitioning, it is possible to use smaller FPGA devices for the same requirements as with not reconfigurable FPGA devices or – vice versa – to use the same FPGAs for larger programs.

Keywords: reconfigurable FPGA, cellular automata, partitioning, metrics, parallel computing

Procedia PDF Downloads 264
650 Overhead Reduction by Channel Estimation Using Linear Interpolation for Single Carrier Frequency Domain Equalization Transmission

Authors: Min-Su Song, Haeng-Bok Kil, Eui-Rim Jeong

Abstract:

This paper proposes a new method to reduce the overhead by pilots for single carrier frequency domain equalization (SC-FDE) transmission. In the conventional SC-FDE transmission structure, the overhead by transmitting pilot is heavy because the pilot are transmitted at every SC-FDE block. The proposed SC-FDE structure has fewer pilots and many SC-FCE blocks are transmitted between pilots. The channel estimation and equalization is performed at the pilot period and the channels between pilots are estimated through linear interpolation. This reduces the pilot overhead by reducing the pilot transmission compared with the conventional structure, and enables reliable channel estimation and equalization.

Keywords: channel estimation, linear interpolation, pilot overhead, SC-FDE

Procedia PDF Downloads 268
649 Seismic Investigation on the Effect of Surface Structures and Twin Tunnel on the Site Response in Urban Areas

Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi

Abstract:

Site response has a profound effect on earthquake damages. Seismic interaction of urban tunnels with surface structures could also affect seismic site response. Here, we use FLAC 2D to investigate the interaction of a single tunnel and twin tunnels-surface structures on the site response. Soil stratification and properties are selected based on Line. No 7 of the Tehran subway. The effect of surface structure is considered in two ways: Equivalent surcharge and geometrical modeling of the structure. Comparison of the results shows that consideration of the structure geometry is vital in dynamic analysis and leads to the changes in the magnitude of displacements, accelerations and response spectrum. Therefore it is necessary for the surface structures to be wholly modeled and not just considered as a surcharge in dynamic analysis. The use of twin tunnel also leads to the reduction of dynamic residual settlement.

Keywords: superstructure, tunnel, site response, surcharge, interaction

Procedia PDF Downloads 161
648 Spectroscopic, Molecular Structure and Electrostatic Potential, Polarizability, Hyperpolarizability, and HOMO–LUMO Analysis of Monomeric and Dimeric Structures of N-(2-Methylphenyl)-2-Nitrobenzenesulfonamide

Authors: A. Didaoui, N. Benhalima, M. Elkeurti, A. Chouaih, F. Hamzaoui

Abstract:

The monomer and dimer structures of the title molecule have been obtained from density functional theory (DFT) B3LYP method with 6-31G (d,p) as basis set calculations. The optimized geometrical parameters obtained by B3LYP/6-31G (d,p) method show good agreement with xperimental X-ray data. The polarizability and first order hyperpolarizabilty of the title molecule were calculated and interpreted. the intermolecular N–H•••O hydrogen bonds are discussed in dimer structure of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 03 set of quantum chemistry codes. The predicted frontier molecular orbital energies at B3LYP/6-31G(d,p) method set show that charge transfer occurs within the molecule. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the total static hyperpolarizability. The results also show that N-(2-Methylphenyl)-2-nitrobenzenesulfonamide molecule may have nonlinear optical (NLO) comportment with non-zero values.

Keywords: DFT, Gaussian 03, NLO, N-(2-Methylphenyl)-2-nitrobenzenesulfonamide

Procedia PDF Downloads 545
647 The Spectroscopic, Molecular Structure and Electrostatic Potential, Polarizability Hyperpolarizability, and Homo–Lumo Analysis of Monomeric and Dimeric Structures of 2-Chloro-N-(2 Methylphenyl) Benzamide

Authors: N. Khelloul, N. Benhalima, A. Chouaih, F. Hamzaoui

Abstract:

The monomer and dimer structures of the title molecule have been obtained from density functional theory (DFT) B3LYP method with 6-31G (d,p) as basis set calculations. The optimized geometrical parameters obtained by B3LYP/6-31G (d,p) method shows good agreement with experimental X-ray data. The polarizability and first order hyperpolarizabilty of the title molecule were calculated and interpreted. The intermolecular N–H•••O hydrogen bonds are discussed in dimer structure of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes. The predicted frontier molecular orbital energies at B3LYP/6-31G(d,p) method set show that charge transfer occurs within the molecule. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the total static hyperpolarizability. The results also show that 2-Chloro-N-(2-methylphenyl) benzamide 2 molecule may have nonlinear optical (NLO) comportment with non-zero values.

Keywords: DFT, HOMO, LUMO, NLO

Procedia PDF Downloads 336
646 Topological Analysis of Hydrogen Bonds in Pyruvic Acid-Water Mixtures

Authors: Ferid Hammami

Abstract:

The molecular geometries of the possible conformations of pyruvic acid-water complexes (PA-(H₂O)ₙ = 1- 4) have been fully optimized at DFT/B3LYP/6-311G ++ (d, p) levels of calculation. Among several optimized molecular clusters, the most stable molecular arrangements obtained when one, two, three, and four water molecules are hydrogen-bonded to a central pyruvic acid molecule are presented in this paper. Apposite topological and geometrical parameters are considered as primary indicators of H-bond strength. Atoms in molecules (AIM) analysis shows that pyruvic acid can form a ring structure with water, and the molecular structures are stabilized by both strong O-H...O and C-H...O hydrogen bonds. In large clusters, classical O-H...O hydrogen bonds still exist between water molecules, and a cage-like structure is built around some parts of the central molecule of pyruvic acid. The electrostatic potential energy map (MEP) and the HOMO-LUMO molecular orbital (highest occupied molecular orbital-lowest unoccupied molecular orbital) analysis has been performed for all considered complexes.

Keywords: pyruvic acid, PA-water complex, hydrogen bonding, DFT, AIM, MEP, HOMO-LUMO

Procedia PDF Downloads 211
645 Amino Acid Based Biodegradable Amphiphilic Polymers and Micelles as Drug Delivery Systems: Synthesis and Study

Authors: Sophio Kobauri, Vladimir P. Torchilin, David Tugushi, Ramaz Katsarava

Abstract:

Nanotherapy is an actual newest mode of treatment numerous diseases using nanoparticles (NPs) loading with different pharmaceuticals. NPs of biodegradable polymeric micelles (PMs) are gaining increased attention for their numerous and attractive abilities to be used in a variety of applications in the various fields of medicine. The present paper deals with the synthesis of a class of biodegradable micelle-forming polymers, namely ABA triblock-copolymer in which A-blocks represent amino-poly(ethylene glycol) (H2N-PEG) and B-block is biodegradable amino acid-based poly(ester amide) constituted of α-amino acid – L-phenylalanine. The obtained copolymer formed micelles of 70±4 nm size at 10 mg/mL concentration.

Keywords: amino acids, biodegradable poly (ester amide), amphiphilic triblock-copolymer, micelles

Procedia PDF Downloads 188
644 Analyzing the Heat Transfer Mechanism in a Tube Bundle Air-PCM Heat Exchanger: An Empirical Study

Authors: Maria De Los Angeles Ortega, Denis Bruneau, Patrick Sebastian, Jean-Pierre Nadeau, Alain Sommier, Saed Raji

Abstract:

Phase change materials (PCM) present attractive features that made them a passive solution for thermal comfort assessment in buildings during summer time. They show a large storage capacity per volume unit in comparison with other structural materials like bricks or concrete. If their use is matched with the peak load periods, they can contribute to the reduction of the primary energy consumption related to cooling applications. Despite these promising characteristics, they present some drawbacks. Commercial PCMs, as paraffines, offer a low thermal conductivity affecting the overall performance of the system. In some cases, the material can be enhanced, adding other elements that improve the conductivity, but in general, a design of the unit that optimizes the thermal performance is sought. The material selection is the departing point during the designing stage, and it does not leave plenty of room for optimization. The PCM melting point depends highly on the atmospheric characteristics of the building location. The selection must relay within the maximum, and the minimum temperature reached during the day. The geometry of the PCM container and the geometrical distribution of these containers are designing parameters, as well. They significantly affect the heat transfer, and therefore its phenomena must be studied exhaustively. During its lifetime, an air-PCM unit in a building must cool down the place during daytime, while the melting of the PCM occurs. At night, the PCM must be regenerated to be ready for next uses. When the system is not in service, a minimal amount of thermal exchanges is desired. The aforementioned functions result in the presence of sensible and latent heat storage and release. Hence different types of mechanisms drive the heat transfer phenomena. An experimental test was designed to study the heat transfer phenomena occurring in a circular tube bundle air-PCM exchanger. An in-line arrangement was selected as the geometrical distribution of the containers. With the aim of visual identification, the containers material and a section of the test bench were transparent. Some instruments were placed on the bench for measuring temperature and velocity. The PCM properties were also available through differential scanning calorimeter (DSC) tests. An evolution of the temperature during both cycles, melting and solidification were obtained. The results showed some phenomena at a local level (tubes) and on an overall level (exchanger). Conduction and convection appeared as the main heat transfer mechanisms. From these results, two approaches to analyze the heat transfer were followed. The first approach described the phenomena in a single tube as a series of thermal resistances, where a pure conduction controlled heat transfer was assumed in the PCM. For the second approach, the temperature measurements were used to find some significant dimensionless numbers and parameters as Stefan, Fourier and Rayleigh numbers, and the melting fraction. These approaches allowed us to identify the heat transfer phenomena during both cycles. The presence of natural convection during melting might have been stated from the influence of the Rayleigh number on the correlations obtained.

Keywords: phase change materials, air-PCM exchangers, convection, conduction

Procedia PDF Downloads 173
643 The Spectroscopic, Molecular Structure and Electrostatic Potential, Polarizability, Hyperpolarizability, and HOMO–LUMO Analysis of Monomeric and Dimeric Structures of N-(2-Methylphenyl)-2-Nitrobenzenesulfonamide

Authors: A. Didaoui, N. Benhalima, M. Elkeurti, A. Chouaih, F. Hamzaoui

Abstract:

The monomer and dimer structures of the title molecule have been obtained from density functional theory (DFT) B3LYP method with 6-31G(d,p) as basis set calculations. The optimized geometrical parameters obtained by B3LYP/6-31G(d,p) method show good agreement with experimental X-ray data. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. The intermolecular N–H•••O hydrogen bonds are discussed in dimer structure of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 03 set of quantum chemistry codes. The predicted frontier molecular orbital energies at B3LYP/6-31G(d,p) method set show that charge transfer occurs within the molecule. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the total static hyperpolarizability. The results also show that N-(2-Methylphenyl)-2-nitrobenzenesulfonamide molecule may have nonlinear optical (NLO) comportment with non-zero values.

Keywords: DFT, Gaussian 03, NLO, N-(2-Methylphenyl)-2-nitrobenzenesulfonamide, polarizability

Procedia PDF Downloads 322
642 Reversible and Adaptive Watermarking for MRI Medical Images

Authors: Nisar Ahmed Memon

Abstract:

A new medical image watermarking scheme delivering high embedding capacity is presented in this paper. Integer Wavelet Transform (IWT), Companding technique and adaptive thresholding are used in this scheme. The proposed scheme implants, recovers the hidden information and restores the input image to its pristine state at the receiving end. Magnetic Resonance Imaging (MRI) images are used for experimental purposes. The scheme first segment the MRI medical image into non-overlapping blocks and then inserts watermark into wavelet coefficients having a high frequency of each block. The scheme uses block-based watermarking adopting iterative optimization of threshold for companding in order to avoid the histogram pre and post processing. Results show that proposed scheme performs better than other reversible medical image watermarking schemes available in literature for MRI medical images.

Keywords: adaptive thresholding, companding technique, data authentication, reversible watermarking

Procedia PDF Downloads 291
641 A Review on the Use of Plastic Waste with Viable Materials in Composite Construction Block

Authors: Mohan T. Harish, Masson Lauriane, Sreevalsa Kolathayar

Abstract:

Environmental issues raise alarm in the constructional field which implies a need for exploring new construction materials derived from the waste and residual products. This paper presents a detailed review of the alternatives approaches employed in the construction field using plastic waste in mixture with mixed with fillers. A detailed analysis of the plastic waste used in concrete, with soil, sand, clay and natural residues like sawdust, rice husk etc are presented. The different process carried forward was also discussed along with the scrutiny of the change in mechanical properties. The effect of coupling agents in the proposed mixture has been appraised in detail which gives implications for its future application in the field of plastic waste with viable materials in composite construction blocks.

Keywords: plastic waste, composite materials, construction block, concrete, natural residue, coupling agent

Procedia PDF Downloads 246
640 Calibration of a Large Standard Step Height with Low Sampled Coherence Scanning Interferometry

Authors: Dahi Ghareab Abdelsalam Ibrahim

Abstract:

Scanning interferometry is commonly used for measuring the three-dimensional profiling of surfaces. Here, we used a scanning stage calibrated with standard gauge blocks to measure a standard step height of 200μm. The stage measures precisely the envelope of interference at the platen and at the surface of the step height. From the difference between the two envelopes, we measured the step height of the sample. Experimental measurements show that the measured value matches well with the nominal value of the step height. A light beam of 532nm from a Tungsten Lamp is collimated and incident on the interferometer. By scanning, two envelopes were produced. The envelope at the platen surface and the envelope at the object surface were determined precisely by a written program code, and then the difference between them was measured from the calibrated scanning stage. The difference was estimated to be in the range of 198 ± 2 μm.

Keywords: optical metrology, digital holography, interferometry, phase unwrapping

Procedia PDF Downloads 69
639 Behavior of Current in a Semiconductor Nanostructure under Influence of Embedded Quantum Dots

Authors: H. Paredes Gutiérrez, S. T. Pérez-Merchancano

Abstract:

Motivated by recent experimental and theoretical developments, we investigate the influence of embedded quantum dot (EQD) of different geometries (lens, ring and pyramidal) in a double barrier heterostructure (DBH). We work with a general theory of quantum transport that accounts the tight-binding model for the spin dependent resonant tunneling in a semiconductor nanostructure, and Rashba spin orbital to study the spin orbit coupling. In this context, we use the second quantization theory for Rashba effect and the standard Green functions method. We calculate the current density as a function of the voltage without and in the presence of quantum dots. In the second case, we considered the size and shape of the quantum dot, and in the two cases, we worked considering the spin polarization affected by external electric fields. We found that the EQD generates significant changes in current when we consider different morphologies of EQD, as those described above. The first thing shown is that the current decreases significantly, such as the geometry of EQD is changed, prevailing the geometrical confinement. Likewise, we see that the current density decreases when the voltage is increased, showing that the quantum system studied here is more efficient when the morphology of the quantum dot changes.

Keywords: quantum semiconductors, nanostructures, quantum dots, spin polarization

Procedia PDF Downloads 266
638 The Flow Separation Delay on the Aircraft Wing

Authors: Ishtiaq A. Chaudhry, Z. R. Tahir, F. A. Siddiqui, Z. Anwar, F. Valenzuelacalva

Abstract:

A series of experiments involving the particle image velocimetry technique are carried out to analyse the quantitative effectiveness of the synthesized vortical structures towards actual flow separation control. The streamwise vortices are synthesized from the synthetic jet actuator and introduced into the attached and separating boundary layer developed on the flat plate surface. Two types of actuators with different geometrical set up are used to analyse the evolution of vortical structures in the near wall region and their impact towards achieving separation delay on the actual aircraft wing. Firstly a single circular jet is synthesized at varying actuator operating parameters and issued into the boundary layer to evaluate the dynamics of the interaction between the vortical structures and the near wall low momentum fluid in the separated region. Secondly, an array of jets has been issued into the artificially separated region to assess the effectiveness of various vortical structures towards achieving the reattachment of the separated flow in the streamwise direction.

Keywords: boundary layer, flow separation, streamwise vortices, synthetic jet actuator

Procedia PDF Downloads 461
637 The Effect of Geometrical Ratio and Nanoparticle Reinforcement on the Properties of Al-based Nanocomposite Hollow Sphere Structures

Authors: Mostafa Amirjan

Abstract:

In the present study, the properties of Al-Al2O3 nanocomposite hollow sphere structures were investigated. For this reason, the Al-based nanocomposite hollow spheres with different amounts of nano alumina reinforcement (0-10wt %) and different ratio of thickness to diameter (t/D: 0.06-0.3) were prepared via a powder metallurgy method. Then, the effect of mentioned parameters was studied on physical and quasi static mechanical properties of their related prepared structures (open/closed cell) such as density, hardness, strength and energy absorption. It was found that as the t/D ratio increases the relative density, compressive strength and energy absorption increase. The highest values of strength and energy absorption were obtained from the specimen with 5 wt. % of nanoparticle reinforcement, t/D of 0.3 (t=1 mm, D=400µm) as 22.88 MPa and 13.24 MJ/m3, respectively. The moderate specific strength of prepared composites in the present study showed the good consistency with the properties of others low carbon steel composite with similar structure.

Keywords: hollow sphere structure foam, nanocomposite, thickness and diameter (t/D ), powder metallurgy

Procedia PDF Downloads 449
636 A Technical Solution for Micro Mixture with Micro Fluidic Oscillator in Chemistry

Authors: Brahim Dennai, Abdelhak Bentaleb, Rachid Khelfaoui, Asma Abdenbi

Abstract:

The diffusion flux given by the Fick’s law characterizethe mixing rate. A passive mixing strategy is proposed to enhance mixing of two fluids through perturbed jet low. A numerical study of passive mixers has been presented. This paper is focused on the modeling of a micro-injection systems composed of passive amplifier without mechanical part. The micro-system modeling is based on geometrical oscillators form. An asymmetric micro-oscillator design based on a monostable fluidic amplifier is proposed. The characteristic size of the channels is generally about a few hundred of microns. The numerical results indicate that the mixing performance can be as high as 99 % within a typical mixing chamber of 0.20 mm diameter inlet and 2.0 mm distance of nozzle - spliter. In addition, the results confirm that self-rotation in the circular mixer significantly enhances the mixing performance. The novel micro mixing method presented in this study provides a simple solution to mixing problems in microsystem for application in chemistry.

Keywords: micro oscillator, modeling, micro mixture, diffusion, size effect, chemical equation

Procedia PDF Downloads 426
635 Numerical Solution Speedup of the Laplace Equation Using FPGA Hardware

Authors: Abbas Ebrahimi, Mohammad Zandsalimy

Abstract:

The main purpose of this study is to investigate the feasibility of using FPGA (Field Programmable Gate Arrays) chips as alternatives for the conventional CPUs to accelerate the numerical solution of the Laplace equation. FPGA is an integrated circuit that contains an array of logic blocks, and its architecture can be reprogrammed and reconfigured after manufacturing. Complex circuits for various applications can be designed and implemented using FPGA hardware. The reconfigurable hardware used in this paper is an SoC (System on a Chip) FPGA type that integrates both microprocessor and FPGA architectures into a single device. In the present study the Laplace equation is implemented and solved numerically on both reconfigurable hardware and CPU. The precision of results and speedups of the calculations are compared together. The computational process on FPGA, is up to 20 times faster than a conventional CPU, with the same data precision. An analytical solution is used to validate the results.

Keywords: accelerating numerical solutions, CFD, FPGA, hardware definition language, numerical solutions, reconfigurable hardware

Procedia PDF Downloads 378
634 Evaluation of Competency Training Effectiveness in Chosen Sales Departments

Authors: L. Pigon, S. Kot, J. K. Grabara

Abstract:

Nowadays, with organizations facing the challenges of increasing competitiveness, human capital accumulated by the organization is one of the elements that strongly differentiate between companies. Efficient management in the competition area requires to manage the competencies of their employees to be suitable to the market fluctuations. The aim of the paper was to determine how employee training to improve their competencies is verified. The survey was conducted among 37 respondents involved in selection of training providers and training programs in their enterprises. The results showed that all organizations use training survey as a basic method for evaluation of training effectiveness. Depending on the training contents and organization, the questionnaires contain various questions. Most of these surveys are composed of the three basic blocks: the trainer's assessment, the evaluation of the training contents, the assessment of the materials and the place of the organisation. None of the organization surveys conducted regular job-related observations or examined the attitudes of the training participants.

Keywords: human capital, competencies, training effectiveness, sale department

Procedia PDF Downloads 168
633 An Alternative Method for Computing Clothoids

Authors: Gerardo Casal, Miguel E. Vázquez-Méndez

Abstract:

The clothoid (also known as Cornu spiral or Euler spiral) is a curve that is characterized because its curvature is proportional to its length. This property makes that it would be widely used as transition curve for designing the layout of roads and railway tracks. In this work, from the geometrical property characterizing the clothoid, its parametric equations are obtained and two algorithms to compute it are compared. The first (classical), is widely used in Surveying Schools and it is based on the use of explicit formulas obtained from Taylor expansions of sine and cosine functions. The second one (alternative) is a very simple algorithm, based on the numerical solution of the initial value problems giving the clothoid parameterization. Both methods are compared in some typical surveying problems. The alternative method does not use complex formulas and so it is conceptually very simple and easy to apply. It gives good results, even if the classical method goes wrong (if the quotient between length and radius of curvature is high), needs no subsequent translations nor rotations and, consequently, it seems an efficient tool for designing the layout of roads and railway tracks.

Keywords: transition curves, railroad and highway engineering, Runge-Kutta methods

Procedia PDF Downloads 277
632 CCK/Gastrin Immunoreactivity in Gastrointestinal Tract of Vimba vimba

Authors: Nurgül Şenol, Melda Azman

Abstract:

In this study, gastrointestinal immunohistochemistry in the Vimba vimba and the localization of CCK/gastrin were determined. Although there are a number of studies which relate to the gastrointestinal histochemistry and the localization of the peptides, a literature research in this field revealed that no histochemical or immunohistochemical study covering also the species had been found in our country. In this research, species will be provided from Vimba vimba located in Eğirdir lake. Stomach samples and intestinal samples of these fish will be exposed to routine histological tissue process, embedded in paraffin blocks, and 5-6 μ -thick sections will be taken. Using the PAP (Peroxidase anti-peroxidase) method, localization of the peptides CCK/gastrin was to be found. The densities of peptides of this species were compared, and then the findings obtained were to be evaluated through the statistical analysis methods (SPSS). Endocrine cells reactive to gastrin/CCK antiserum were demonstrated in the stomach and intestinal mucosa. There is a significant difference between gastrin and CCK when compared to regions.

Keywords: CCK, gastrin, immunoreactivity, vimba vimba

Procedia PDF Downloads 310
631 Liver Tumor Detection by Classification through FD Enhancement of CT Image

Authors: N. Ghatwary, A. Ahmed, H. Jalab

Abstract:

In this paper, an approach for the liver tumor detection in computed tomography (CT) images is represented. The detection process is based on classifying the features of target liver cell to either tumor or non-tumor. Fractional differential (FD) is applied for enhancement of Liver CT images, with the aim of enhancing texture and edge features. Later on, a fusion method is applied to merge between the various enhanced images and produce a variety of feature improvement, which will increase the accuracy of classification. Each image is divided into NxN non-overlapping blocks, to extract the desired features. Support vector machines (SVM) classifier is trained later on a supplied dataset different from the tested one. Finally, the block cells are identified whether they are classified as tumor or not. Our approach is validated on a group of patients’ CT liver tumor datasets. The experiment results demonstrated the efficiency of detection in the proposed technique.

Keywords: fractional differential (FD), computed tomography (CT), fusion, aplha, texture features.

Procedia PDF Downloads 354
630 Spatial Pattern of Farm Mechanization: A Micro Level Study of Western Trans-Ghaghara Plain, India

Authors: Zafar Tabrez, Nizamuddin Khan

Abstract:

Agriculture in India in the pre-green revolution period was mostly controlled by terrain, climate and edaphic factors. But after the introduction of innovative factors and technological inputs, green revolution occurred and agricultural scene witnessed great change. In the development of India’s agriculture, speedy, and extensive introduction of technological change is one of the crucial factors. The technological change consists of adoption of farming techniques such as use of fertilisers, pesticides and fungicides, improved variety of seeds, modern agricultural implements, improved irrigation facilities, contour bunding for the conservation of moisture and soil, which are developed through research and calculated to bring about diversification and increase of production and greater economic return to the farmers. The green revolution in India took place during late 60s, equipped with technological inputs like high yielding varieties seeds, assured irrigation as well as modern machines and implements. Initially the revolution started in Punjab, Haryana and western Uttar Pradesh. With the efforts of government, agricultural planners, as well as policy makers, the modern technocratic agricultural development scheme was also implemented and introduced in backward and marginal regions of the country later on. Agriculture sector occupies the centre stage of India’s social security and overall economic welfare. The country has attained self-sufficiency in food grain production and also has sufficient buffer stock. Our first Prime Minister, Jawaharlal Nehru said ‘everything else can wait but not agriculture’. There is still a continuous change in the technological inputs and cropping patterns. Keeping these points in view, author attempts to investigate extensively the mechanization of agriculture and the change by selecting western Trans-Ghaghara plain as a case study and block a unit of the study. It includes the districts of Gonda, Balrampur, Bahraich and Shravasti which incorporate 44 blocks. It is based on secondary sources of data by blocks for the year 1997 and 2007. It may be observed that there is a wide range of variations and the change in farm mechanization, i.e., agricultural machineries such as ploughs, wooden and iron, advanced harrow and cultivator, advanced thrasher machine, sprayers, advanced sowing instrument, and tractors etc. It may be further noted that due to continuous decline in size of land holdings and outflux of people for the same nature of works or to be employed in non-agricultural sectors, the magnitude and direction of agricultural systems are affected in the study area which is one of the marginalized regions of Uttar Pradesh, India.

Keywords: agriculture, technological inputs, farm mechanization, food production, cropping pattern

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629 Assessment of Occupational Health and Safety Conditions of Health Care Workers in Barangay Health Centers in a Selected City in Metro Manila

Authors: Deinzel R. Uezono, Vivien Fe F. Fadrilan-Camacho, Bianca Margarita L. Medina, Antonio Domingo R. Reario, Trisha M. Salcedo, Luke Wesley P. Borromeo

Abstract:

The environment of health care workers is considered one of the most hazardous settings due to the nature of their work. In developing countries especially, the Philippines, this continues to be overlooked in terms of programs and services on occupational health and safety (OHS). One possible reason for this is the existing information gap on OHS which limits data comparability and impairs effective monitoring and assessment of interventions. To address this gap, there is a need to determine the current conditions of Filipino health care workers in their workplace. This descriptive cross-sectional study assessed the occupational health and safety conditions of health care workers in barangay health centers in a selected city in Metro Manila, Philippines by: (1) determining the hazards present in the workplace; (2) determining the most common self-reported medical problems; and (3) describing the elements of an OHS system based on the six building blocks of health system. Assessment was done through walkthrough survey, self-administered questionnaire, and key informant interview. Data analysis was done using Epi Info 7 and NVivo 11. Results revealed different health hazards present in the workplace particularly biological hazards (exposure to sick patients and infectious specimens), physical hazards (inadequate space and/or lighting), chemical hazards (toxic reagents and flammable chemicals), and ergonomic hazards (activities requiring repetitive motion and awkward posture). Additionally, safety hazards (improper capping of syringe and lack of fire safety provisions) were also observed. Meanwhile, the most commonly self-reported chronic diseases among health care workers (N=336) were hypertension (20.24%, n=68) and diabetes (12.50%, n=42). Top commonly self-reported symptoms were colds (66.07%, n=222), coughs (63.10%, n=212), headache (55.65%, n=187), and muscle pain (50.60%, n=170) while other diseases were influenza (16.96%, n=57) and UTI (15.48%, n=52). In terms of the elements of the OHS system, a general policy on occupational health and safety was found to be lacking and in effect, an absence of health and safety committee overseeing the implementing and monitoring of the policy. No separate budget specific for OHS programs and services was also found to be a limitation. As a result, no OHS personnel and trainings/seminar were identified. No established information system for OHS was in place. In conclusion, health and safety hazards were observed to be present across the barangay health centers visited in a selected city in Metro Manila. Medical conditions identified as most commonly self-reported were hypertension and diabetes for chronic diseases; colds, coughs, headache, and muscle pain for medical symptoms; and influenza and UTI for other diseases. As for the elements of the occupational health and safety system, there was a lack in the general components of the six building blocks of the health system.

Keywords: health hazards, occupational health and safety, occupational health and safety system, safety hazards

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628 Research on Residential Block Fabric: A Case Study of Hangzhou West Area

Authors: Wang Ye, Wei Wei

Abstract:

Residential block construction of big cities in China began in the 1950s, and four models had far-reaching influence on modern residential block in its development process, including unit compound and residential district in 1950s to 1980s, and gated community and open community in 1990s to now. Based on analysis of the four models’ fabric, the article takes residential blocks in Hangzhou west area as an example and carries on the studies from urban structure level and block special level, mainly including urban road network, land use, community function, road organization, public space and building fabric. At last, the article puts forward semi-open sub-community strategy to improve the current fabric.

Keywords: Hangzhou west area, residential block model, residential block fabric, semi-open sub-community strategy

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