Search results for: local thermal non-equilibrium
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8645

Search results for: local thermal non-equilibrium

4505 Adaptive Architecture: Reformulation of Socio-Ecological Systems

Authors: Pegah Zamani

Abstract:

This multidisciplinary study interrogates the reformulation of socio-ecological systems by bringing different disciplines together and incorporating ecological, social, and technological components to the sustainable design. The study seeks for a holistic sustainable system to understand the multidimensional impact of the evolving innovative technologies on responding to the variable socio-environmental conditions. Through a range of cases, from the vernacular built spaces to the sophisticated optimized systems, the research unfolds how far the environmental elements would impact the performance of a sustainable building, its micro-climatic ecological requirements, and its human inhabitation. As a product of the advancing technologies, an optimized and environmentally responsive building offers new identification, and realization of the built space through reformulating the connection to its internal and external environments (such as solar, thermal, and airflow), as well as its dwellers. The study inquires properties of optimized buildings, by bringing into the equation not only the environmental but also the socio-cultural, morphological, and phenomenal factors. Thus, the research underlines optimized built space as a product and practice which would not be meaningful without addressing and dynamically adjusting to the diversity and complexity of socio-ecological systems.

Keywords: ecology, morphology, socio-ecological systems, sustainability

Procedia PDF Downloads 199
4504 Performance Evaluation and Dear Based Optimization on Machining Leather Specimens to Reduce Carbonization

Authors: Khaja Moiduddin, Tamer Khalaf, Muthuramalingam Thangaraj

Abstract:

Due to the variety of benefits over traditional cutting techniques, the usage of laser cutting technology has risen substantially in recent years. Hot wire machining can cut the leather in the required shape by controlling the wire by generating thermal energy. In the present study, an attempt has been made to investigate the effects of performance measures in the hot wire machining process on cutting leather specimens. Carbonization and material removal rates were considered as quality indicators. Burning leather during machining might cause carbon particles, reducing product quality. Minimizing the effect of carbon particles is crucial for assuring operator and environmental safety, health, and product quality. Hot wire machining can efficiently cut the specimens by controlling the current through it. Taguchi- DEAR-based optimization was also performed in the process, which resulted in a required Carbonization and material removal rate. Using the DEAR approach, the optimal parameters of the present study were found with 3.7% prediction error accuracy.

Keywords: cabronization, leather, MRR, current

Procedia PDF Downloads 58
4503 “Double Layer” Theory of Hydrogenation

Authors: Vaclav Heral

Abstract:

Ideas about the mechanism of heterogeneous catalytic hydrogenation are diverse. The Horiuti-Polanyi mechanism is most often referred to, based on the idea of a semi-hydrogenated state. In our opinion, it does not represent a satisfactory explanation of the hydrogenation mechanism, because, for example: (1) It neglects the fact that the bond of atomic hydrogen to the metal surface is strongly polarized, (2) It does not explain why a surface deprived of atomic hydrogen (by thermal desorption or by alkyne) loses isomerization capabilities, but hydrogenation capabilities remain preserved, (3) It was observed that during the hydrogenation of 1-alkenes, the reaction can be of the 0th order to hydrogen and to the alkene at the same time, which is excluded during the competitive adsorption of both reactants on the catalyst surface. We offer an alternative mechanism that satisfactorily explains many of the ambiguities: It is the idea of an independent course of olefin isomerization, catalyzed by acidic atomic hydrogen bonded on the surface of the catalyst, in addition to the hydrogenation itself, in which a two-layer complex appears on the surface of the catalyst: olefin bound to the surface and molecular hydrogen bound to it in the second layer. The rate-determining step of hydrogenation is the conversion of this complex into the final product. We believe that the Horiuti-Polanyi mechanism is flawed and we naturally think that our two-layer theory better describes the experimental findings.

Keywords: acidity of hydrogenation catalyst, Horiuti-Polanyi, hydrogenation, two-layer hydrogenation

Procedia PDF Downloads 65
4502 A3 Strategy Deployment: A Case Study Applied to a City Government Department for Healthcare in Brazil

Authors: Samuel Bonato, Cineia Santos, Roberta Leite, Carla Ten Caten

Abstract:

This paper aims to apply the A3 strategy deployment in a local department for healthcare. As a literature review, it was evaluated articles related to the period 2009 - 2018, considering the key-words A3, healthcare, public services and strategy deployment. The methodology used was action research, involving all the actors inside the secretary, beginning with the top management and deploying it through meetings and evaluation conferences with the participation of all secretary coordination. As main results, it is possible to highlight the development of 8 A3, one as the "mother A3" and 7 as "son A3", each one related to each coordination. In each A3, past results, new goals, new projects to achieve these goals and control deadlines were defined and implemented to a management strategy. In addition to this result, this paper is planning to present the use of this A3 during 6 months in 2019.

Keywords: A3 Strategy, strategy deployment, healthcare, Public services

Procedia PDF Downloads 140
4501 Long Term Variability of Temperature in Armenia in the Context of Climate Change

Authors: Hrachuhi Galstyan, Lucian Sfîcă, Pavel Ichim

Abstract:

The purpose of this study is to analyze the temporal and spatial variability of thermal conditions in the Republic of Armenia. The paper describes annual fluctuations in air temperature. Research has been focused on case study region of Armenia and surrounding areas, where long–term measurements and observations of weather conditions have been performed within the National Meteorological Service of Armenia and its surrounding areas. The study contains yearly air temperature data recorded between 1961-2012. Mann-Kendal test and the autocorrelation function were applied to detect the change trend of annual mean temperature, as well as other parametric and non-parametric tests searching to find the presence of some breaks in the long term evolution of temperature. The analysis of all records reveals a tendency mostly towards warmer years, with increased temperatures especially in valleys and inner basins. The maximum temperature increase is up to 1,5 °C. Negative results have not been observed in Armenia. The patterns of temperature change have been observed since the 1990’s over much of the Armenian territory. The climate in Armenia was influenced by global change in the last 2 decades, as results from the methods employed within the study.

Keywords: air temperature, long-term variability, trend, climate change

Procedia PDF Downloads 292
4500 Habitat Model Review and a Proposed Methodology to Value Economic Trade-Off between Cage Culture and Habitat of an Endemic Species in Lake Maninjau, Indonesia

Authors: Ivana Yuniarti, Iwan Ridwansyah

Abstract:

This paper delivers a review of various methodologies for habitat assessment and a proposed methodology to assess an endemic fish species habitat in Lake Maninjau, Indonesia as a part of a Ph.D. project. This application is mainly aimed to assess the trade-off between the economic value of aquaculture and the fisheries. The proposed methodology is a generalized linear model (GLM) combined with GIS to assess presence-absence data or habitat suitability index (HSI) combined with the analytical hierarchy process (AHP). Further, a cost of habitat replacement approach is planned to be used to calculate the habitat value as well as its trade-off with the economic value of aquaculture. The result of the study is expected to be a scientific consideration in local decision making and to provide a reference for other areas in the country.

Keywords: AHP, habitat, GLM, HSI, Maninjau

Procedia PDF Downloads 143
4499 A Study on Mesh Size Dependency on Bed Expansion Zone in a Three-Phase Fluidized Bed Reactor

Authors: Liliana Patricia Olivo Arias

Abstract:

The present study focused on the hydrodynamic study in a three-phase fluidized bed reactor and the influence of important aspects, such as volume fractions (Hold up), velocity magnitude of gas, liquid and solid phases (hydrogen, gasoil, and gamma alumina), interactions of phases, through of drag models with the k-epsilon turbulence model. For this purpose was employed a Euler-Euler model and also considers the system is constituted of three phases, gaseous, liquid and solid, characterized by its physical and thermal properties, the transport processes that are developed within the transient regime. The proposed model of the three-phase fluidized bed reactor was solved numerically using the ANSYS-Fluent software with different mesh refinements on bed expansion zone in order to observe the influence of the hydrodynamic parameters and convergence criteria. With this model and the numerical simulations obtained for its resolution, it was possible to predict the results of the volume fractions (Hold ups) and the velocity magnitude for an unsteady system from the initial and boundaries conditions were established.

Keywords: three-phase fluidized bed system, CFD simulation, mesh dependency study, hydrodynamic study

Procedia PDF Downloads 159
4498 Understanding the Role of Gas Hydrate Morphology on the Producibility of a Hydrate-Bearing Reservoir

Authors: David Lall, Vikram Vishal, P. G. Ranjith

Abstract:

Numerical modeling of gas production from hydrate-bearing reservoirs requires the solution of various thermal, hydrological, chemical, and mechanical phenomena in a coupled manner. Among the various reservoir properties that influence gas production estimates, the distribution of permeability across the domain is one of the most crucial parameters since it determines both heat transfer and mass transfer. The aspect of permeability in hydrate-bearing reservoirs is particularly complex compared to conventional reservoirs since it depends on the saturation of gas hydrates and hence, is dynamic during production. The dependence of permeability on hydrate saturation is mathematically represented using permeability-reduction models, which are specific to the expected morphology of hydrate accumulations (such as grain-coating or pore-filling hydrates). In this study, we demonstrate the impact of various permeability-reduction models, and consequently, different morphologies of hydrate deposits on the estimates of gas production using depressurization at the reservoir scale. We observe significant differences in produced water volumes and cumulative mass of produced gas between the models, thereby highlighting the uncertainty in production behavior arising from the ambiguity in the prevalent gas hydrate morphology.

Keywords: gas hydrate morphology, multi-scale modeling, THMC, fluid flow in porous media

Procedia PDF Downloads 213
4497 Feasibility Study to Enhance the Heat Transfer in a Typical Pressurized Water Reactor by Ribbed Spacer Grids

Authors: A. Ghadbane, M. N. Bouaziz, S. Hanini, B. Baggoura, M. Abbaci

Abstract:

The spacer grids are used to fix the rods bundle in a nuclear reactor core also act as turbulence-enhancing devices to improve the heat transfer from the hot surfaces of the rods to the surrounding coolant stream. Therefore, the investigation of thermal-hydraulic characteristics inside the rod bundles is important for optima design and safety operation of a nuclear reactor power plant. This contribution presents a feasibility study to use the ribbed spacer grids as mixing devices. The present study evaluates the effects of different ribbed spacer grids configurations on flow pattern and heat transfer in the downstream of the mixing devices in a 2 x 2 rod bundle array. This is done by obtaining velocity and pressure fields, turbulent intensity and the heat transfer coefficient using a three-dimensional CFD analysis. Numerical calculations are performed by employing K-ε turbulent model. The computational results obtained are promising and the comparison with standard spacer grids shows a clear difference which required the experimental approach to validate.

Keywords: PWR fuel assembly, spacer grid, mixing vane, swirl flow, turbulent heat transfer, CFD

Procedia PDF Downloads 484
4496 Studies on Microstructure and Mechanical Properties of Simulated Heat Affected Zone in a Micro Alloyed Steel

Authors: Sanjeev Kumar, S. K. Nath

Abstract:

Proper selection of welding parameters for getting excellent weld is a challenge. HAZ simulation helps in identifying suitable welding parameters like heating rate, cooling rate, peak temperature, and energy input. In this study, the influence of weld thermal cycle of heat affected zone (HAZ) is simulated for Submerged Arc Welding (SAW) using Gleeble ® 3800 thermomechanical simulator. A (Micro-alloyed) MA steel plate of thickness 18 mm having yield strength 450MPa is used for making test specimens. Determination of the mechanical properties of weld simulated specimens including Charpy V-notch toughness and hardness is performed. Peak temperatures of 1300°C, 1150°C, 1000°C, 900°C, 800°C, heat energy input of 22KJ/cm and preheat temperatures of 30°C have been used with Rykalin-3D simulation model. It is found that the impact toughness (75J) is the best for the simulated HAZ specimen at the peak temperature 900ºC. For parent steel, impact toughness value is 26.8J at -50°C in transverse direction.

Keywords: HAZ simulation, mechanical properties, peak temperature, ship hull steel, weldability

Procedia PDF Downloads 560
4495 Penetration Analysis for Composites Applicable to Military Vehicle Armors, Aircraft Engines and Nuclear Power Plant Structures

Authors: Dong Wook Lee

Abstract:

This paper describes a method for analyzing penetration for composite material using an explicit nonlinear Finite Element Analysis (FEA). This method may be used in the early stage of design for the protection of military vehicles, aircraft engines and nuclear power plant structures made of composite materials. This paper deals with simple ballistic penetration tests for composite materials and the FEA modeling method and results. The FEA was performed to interpret the ballistic field test phenomenon regarding the damage propagation in the structure subjected to local foreign object impact.

Keywords: computer aided engineering, finite element analysis, impact analysis, penetration analysis, composite material

Procedia PDF Downloads 117
4494 Anthocyanin Complex: Characterization and Cytotoxicity Studies

Authors: Sucharat Limsitthichaikoon, Kedsarin Saodaeng, Aroonsri Priprem, Teerasak Damrongrungruang

Abstract:

Complexation of anthocyanins to mimic natural copigmentation process was investigated. Cyanidin-rich extracts from Zea mays L. CeritinaKulesh. anddelphinidin-rich extracts from ClitoriaternateaL. were used to form 4 anthocyanin complexes, AC1, AC2, AC3, and AC4, in the presence of several polyphenols and a trace metal. Characterizations of the ACs were conducted by UV, FTIR, DSC/TGA and morphological observations. Bathochromic shifts of the UV spectra of 4 formulas of ACs were observed at peak wavelengths of about 510-620 nm by 10 nm suggesting complex formation.FTIR spectra of the ACs indicate shifts of peaks from 1,733 cm-1 to 1,696 cm-1 indicating interactions and a decrease in the peak areas within the wavenumber of 3,400-3,500 cm-1 indicating changes in hydrogen bonding.Thermal analysis of all of the ACs suggests increases in melting temperature after complexation. AC with the highest melting temperature was morphologically observed by SEM and TEM to be crystal-like particles within a range of 50 to 200 nm. Particle size analysis of the AC by laser diffraction gave a range of 50-600 nm, indicating aggregation. This AC was shown to have no cytotoxic effect on cultured HGEPp0.5 and HGF (all p> 0.05) by MTT. Therefore, complexation of anthocyanins was simple and self-assembly process, potentially resulting in nanosized particles of anthocyanin complex.

Keywords: anthocyanins, complexation, purple corn cops, butterfly pea, physicochemical characteristics, cytotoxicity

Procedia PDF Downloads 358
4493 Thermomechanical Behaviour of Various Pressurized Installations Subjected to Thermal Load Due to the Combustion of Metal Particles

Authors: Khaled Ayfi, Morgan Dal, Frederic Coste, Nicolas Gallienne, Martina Ridlova, Philippe Lorong

Abstract:

In the gas industry, contamination of equipment by metal particles is one of the feared phenomena. Indeed, particles inside equipment can be driven by the gas flow and accumulate in places where the velocity is low. As they constitute a potential ignition hazard, particular attention is paid to the presence of particles in the oxygen industry. Indeed, the heat release from ignited particles may damage the equipment and even result in a loss of integrity. The objective of this work is to support the development of new design criteria. Studying the thermomechanical behavior of this equipment, thanks to numerical simulations, allows us to test the influence of various operating parameters (oxygen pressure, wall thickness, initial operating temperature, nature of the metal, etc.). Therefore, in this study, we propose a numerical model that describes the thermomechanical behavior of various pressurized installations heated locally by the combustion of small particles. This model takes into account the geometric and material nonlinearity and has been validated by the comparison of simulation results with experimental measurements obtained by a new device developed in this work.

Keywords: ignition, oxygen, numerical simulation, thermomechanical behaviour

Procedia PDF Downloads 147
4492 Axisymmetric Rotating Flow over a Permeable Surface with Heat and Mass Transfer Effects

Authors: Muhammad Faraz, Talat Rafique, Jang Min Park

Abstract:

In this article, rotational flow above a permeable surface with a variable free stream angular velocity is considered. Main interest is to solve the associated heat/mass transport equations under different situations. Firstly, heat transport phenomena occurring in generalized vortex flow are analyzed under two altered heating processes, namely, the (i) prescribed surface temperature and (ii) prescribed heat flux. The vortex motion imposed at infinity is assumed to follow a power-law form 〖(r/r_0)〗^((2n-1)) where r denotes the radial coordinate, r_0 the disk radius, and n is a power-law parameter. Assuming a similar solution, the governing Navier-Stokes equations transform into a set of coupled ODEs which are treated numerically for the aforementioned thermal conditions. Secondly, mass transport phenomena accompanied by activation energy are incorporated into the generalized vortex flow situation. After finding self-similar equations, a numerical solution is furnished by using MATLAB's built-in function bvp4c.

Keywords: bödewadt flow, vortex flow, rotating flows, prescribed heat flux, permeable surface, activation energy

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4491 The Impact of Modeling Method of Moisture Emission from the Swimming Pool on the Accuracy of Numerical Calculations of Air Parameters in Ventilated Natatorium

Authors: Piotr Ciuman, Barbara Lipska

Abstract:

The aim of presented research was to improve numerical predictions of air parameters distribution in the actual natatorium by the selection of calculation formula of mass flux of moisture emitted from the pool. Selected correlation should ensure the best compliance of numerical results with the measurements' results of these parameters in the facility. The numerical model of the natatorium was developed, for which boundary conditions were prepared on the basis of measurements' results carried out in the actual facility. Numerical calculations were carried out with the use of ANSYS CFX software, with six formulas being implemented, which in various ways made the moisture emission dependent on water surface temperature and air parameters in the natatorium. The results of calculations with the use of these formulas were compared for air parameters' distributions: Specific humidity, velocity and temperature in the facility. For the selection of the best formula, numerical results of these parameters in occupied zone were validated by comparison with the measurements' results carried out at selected points of this zone.

Keywords: experimental validation, indoor swimming pool, moisture emission, natatorium, numerical calculations CFD, thermal and humidity conditions, ventilation

Procedia PDF Downloads 405
4490 Effect of Particle Size on Sintering Characteristics of Injection Molded 316L Powder

Authors: H. Özkan Gülsoy, Antonyraj Arockiasamy

Abstract:

The application of powder injection molding technology for the fabrication of metallic and non-metallic components is of growing interest as the process considerably saves time and cost. Utilizing this fabrication method, full dense components are being prepared in various sizes. In this work, our effort is focused to study the densification behavior of the parts made using different size 316L stainless steel powders. The metal powders were admixed with an adequate amount of polymeric compounds and molded as standard tensile bars. Solvent and thermal debinding was carried out followed by sintering in ultra pure hydrogen atmosphere based on the differential scanning calorimetry (DSC) cycle. Mechanical property evaluation and microstructural characterization of the sintered specimens was performed using universal Instron tensile testing machine, Vicker’s microhardness tester, optical (OM) and scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction were used. The results are compared and analyzed to predict the strength and weakness of the test conditions.

Keywords: powder injection molding, sintering, particle size, stainless steels

Procedia PDF Downloads 358
4489 Study of the Behavior of Bolted Joints with and Without Reinforcement

Authors: Karim Akkouche

Abstract:

Many methods have been developed for characterizing the behavior of bolted joints. However, in the presence of a certain model of stiffeners, no orientation was given in relation to their modeling. To this end, multitude of coarse errors can arise in the reproduction of the propagation of efforts and in representation of the modes of deformations. Considering these particularities, a numerical investigation was carried out in our laboratory. In this paper we will present a comparative study between three types of assemblies. A non-linear 3D modeling was chosen, given that it takes into consideration geometric and material non-linearity, using the Finite Element calculation code ABAQUS. Initially, we evaluated the influence of the presence of each stiffener on the "global" behavior of the assemblies, this by analyzing their Moment-Rotation curves, also by referring to the classification system proposed by NF EN 1993- 1.8 which is based on the resisting moment Mj-Rd and the initial stiffness Sj.int. In a second step, we evaluated the "local" behavior of their components by referring to the stress-strain curves.

Keywords: assembly, post-beam, end plate, nonlinearity

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4488 Energy Consumption and Energy Conservation Potential for HVAC System in Commercial Buildings Sector in India

Authors: Rishabh Agrawal, S. C. Kaushik, T. S. Bhatti

Abstract:

In order to reduce energy consumption for sustainable development, continuous energy consumption tracking of building energy systems are essential. In this paper an assessment study has been done to identify the energy consumption & energy conservation potential for commercial buildings sector in Karnataka state, India. There are a total of 326 commercial buildings in the state of Karnataka who has qualified as designated consumers (i.e., having a Contract Demand ≥ 600 KVA), was consider for the study. It has estimated that the annual electricity sale to commercial sector is 3.62 Billion Units (BU) in alone Karnataka State, India, which is an account for 9.57 % of the total electricity sold. The commercial sector constitutes Government & private establishments, hospitals, hotels, restaurants, educational institutions, malls etc. Total 326 commercial buildings in the state accounting for annual energy consumption of 1295.72 Million Units (MU) which works out to about 35% of the sectoral consumption. The annual energy savings potential for 326 commercial buildings is assessed to be 0.25 BU.

Keywords: commercial buildings, connected load, energy conservation studies, energy savings, energy efficiency, energy conservation strategy, energy efficiency, thermal energy, HVAC system

Procedia PDF Downloads 576
4487 Material Flow Modeling in Friction Stir Welding of AA6061-T6 Alloy and Study of the Effect of Process Parameters

Authors: B. SahaRoy, T. Medhi, S. C. Saha

Abstract:

To understand the friction stir welding process, it is very important to know the nature of the material flow in and around the tool. The process is a combination of both thermal as well as mechanical work i.e it is a coupled thermo-mechanical process. Numerical simulations are very much essential in order to obtain a complete knowledge of the process as well as the physics underlying it. In the present work a model based approach is adopted in order to study material flow. A thermo-mechanical based CFD model is developed using a Finite Element package, Comsol Multiphysics. The fluid flow analysis is done. The model simultaneously predicts shear strain fields, shear strain rates and shear stress over the entire workpiece for the given conditions. The flow fields generated by the streamline plot give an idea of the material flow. The variation of dynamic viscosity, velocity field and shear strain fields with various welding parameters is studied. Finally the result obtained from the above mentioned conditions is discussed elaborately and concluded.

Keywords: AA6061-T6, CFD modelling, friction stir welding, material flow

Procedia PDF Downloads 518
4486 Numerical Solutions of Fractional Order Epidemic Model

Authors: Sadia Arshad, Ayesha Sohail, Sana Javed, Khadija Maqbool, Salma Kanwal

Abstract:

The dynamical study of the carriers play an essential role in the evolution and global transmission of infectious diseases and will be discussed in this study. To make this approach novel, we will consider the fractional order model which is generalization of integer order derivative to an arbitrary number. Since the integration involved is non local therefore this property of fractional operator is very useful to study epidemic model for infectious diseases. An extended numerical method (ODE solver) is implemented on the model equations and we will present the simulations of the model for different values of fractional order to study the effect of carriers on transmission dynamics. Global dynamics of fractional model are established by using the reproduction number.

Keywords: Fractional differential equation, Numerical simulations, epidemic model, transmission dynamics

Procedia PDF Downloads 591
4485 Channels Splitting Strategy for Optical Local Area Networks of Passive Star Topology

Authors: Peristera Baziana

Abstract:

In this paper, we present a network configuration for a WDM LANs of passive star topology that assume that the set of data WDM channels is split into two separate sets of channels, with different access rights over them. Especially, a synchronous transmission WDMA access algorithm is adopted in order to increase the probability of successful transmission over the data channels and consequently to reduce the probability of data packets transmission cancellation in order to avoid the data channels collisions. Thus, a control pre-transmission access scheme is followed over a separate control channel. An analytical Markovian model is studied and the average throughput is mathematically derived. The performance is studied for several numbers of data channels and various values of control phase duration.

Keywords: access algorithm, channels division, collisions avoidance, wavelength division multiplexing

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4484 First-Principles Density Functional Study of Nitrogen-Doped P-Type ZnO

Authors: Abdusalam Gsiea, Ramadan Al-habashi, Mohamed Atumi, Khaled Atmimi

Abstract:

We present a theoretical investigation on the structural, electronic properties and vibrational mode of nitrogen impurities in ZnO. The atomic structures, formation and transition energies and vibrational modes of (NO3)i interstitial or NO4 substituting on an oxygen site ZnO were computed using ab initio total energy methods. Based on Local density functional theory, our calculations are in agreement with one interpretation of bound-excition photoluminescence for N-doped ZnO. First-principles calculations show that (NO3)i defects interstitial or NO4 substituting on an Oxygen site in ZnO are important suitable impurity for p-type doping in ZnO. However, many experimental efforts have not resulted in reproducible p-type material with N2 and N2O doping. by means of first-principle pseudo-potential calculation we find that the use of NO or NO2 with O gas might help the experimental research to resolve the challenge of achieving p-type ZnO.

Keywords: DFF, nitrogen, p-type, ZnO

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4483 Modeling of Tsunami Propagation and Impact on West Vancouver Island, Canada

Authors: S. Chowdhury, A. Corlett

Abstract:

Large tsunamis strike the British Columbia coast every few hundred years. The Cascadia Subduction Zone, which extends along the Pacific coast from Vancouver Island to Northern California is one of the most seismically active regions in Canada. Significant earthquakes have occurred in this region, including the 1700 Cascade Earthquake with an estimated magnitude of 9.2. Based on geological records, experts have predicted a 'great earthquake' of a similar magnitude within this region may happen any time. This earthquake is expected to generate a large tsunami that could impact the coastal communities on Vancouver Island. Since many of these communities are in remote locations, they are more likely to be vulnerable, as the post-earthquake relief efforts would be impacted by the damage to critical road infrastructures. To assess the coastal vulnerability within these communities, a hydrodynamic model has been developed using MIKE-21 software. We have considered a 500 year probabilistic earthquake design criteria including the subsidence in this model. The bathymetry information was collected from Canadian Hydrographic Services (CHS), and National Oceanic Atmospheric and Administration (NOAA). The arial survey was conducted using a Cessna-172 aircraft for the communities, and then the information was converted to generate a topographic digital elevation map. Both survey information was incorporated into the model, and the domain size of the model was about 1000km x 1300km. This model was calibrated with the tsunami occurred off the west coast of Moresby Island on October 28, 2012. The water levels from the model were compared with two tide gauge stations close to the Vancouver Island and the output from the model indicates the satisfactory result. For this study, the design water level was considered as High Water Level plus the Sea Level Rise for 2100 year. The hourly wind speeds from eight directions were collected from different wind stations and used a 200-year return period wind speed in the model for storm events. The regional model was set for 12 hrs simulation period, which takes more than 16 hrs to complete one simulation using double Xeon-E7 CPU computer plus a K-80 GPU. The boundary information for the local model was generated from the regional model. The local model was developed using a high resolution mesh to estimate the coastal flooding for the communities. It was observed from this study that many communities will be effected by the Cascadia tsunami and the inundation maps were developed for the communities. The infrastructures inside the coastal inundation area were identified. Coastal vulnerability planning and resilient design solutions will be implemented to significantly reduce the risk.

Keywords: tsunami, coastal flooding, coastal vulnerable, earthquake, Vancouver, wave propagation

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4482 Bag of Words Representation Based on Weighting Useful Visual Words

Authors: Fatma Abdedayem

Abstract:

The most effective and efficient methods in image categorization are almost based on bag-of-words (BOW) which presents image by a histogram of occurrence of visual words. In this paper, we propose a novel extension to this method. Firstly, we extract features in multi-scales by applying a color local descriptor named opponent-SIFT. Secondly, in order to represent image we use Spatial Pyramid Representation (SPR) and an extension to the BOW method which based on weighting visual words. Typically, the visual words are weighted during histogram assignment by computing the ratio of their occurrences in the image to the occurrences in the background. Finally, according to classical BOW retrieval framework, only a few words of the vocabulary is useful for image representation. Therefore, we select the useful weighted visual words that respect the threshold value. Experimentally, the algorithm is tested by using different image classes of PASCAL VOC 2007 and is compared against the classical bag-of-visual-words algorithm.

Keywords: BOW, useful visual words, weighted visual words, bag of visual words

Procedia PDF Downloads 427
4481 Experimental Study of a Solar Still with Four Glass Cover

Authors: Zakaria Haddad, Azzedine Nahoui, Mohamed Salmi, Ali Djagham

Abstract:

Solar distillation is an effective and practical method for the production of drinking water in arid and semi-arid areas; however, this production is very limited. The aim of this work is to increase the latter by means of single slope solar still with four glass cover without augmenting volume and surface of a conventional solar still, using local materials and simple design. The equipment was tested under the climatic condition of Msila city (35°70′ N, 4°54′ E), Algeria. Performance of the use of four glass cover was studied, and exhaustive data were collected, analyzed, and presented. To show the effectiveness of the system, its performance was compared with that of the conventional solar still. The experimental study shows that the production of the proposed system achieves 5.3 l/m²/day and 5.8 l/m²/day respectively for the months of April and May, with an increase of 10% and 17% compared to the conventional solar still.

Keywords: drinking water, four glass cover, production, solar distillation

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4480 A Different Perspective on the Sustainability of Logistics Service Providers in City Logistics

Authors: Hugo de Tarragon, Martine Hlady-Rispal, Gauthier Casteran

Abstract:

Rooted in ethnographic research on city logistics, our paper examines how Logistics Service Providers (LSP) can move from a "subservient" posture to one of instigating the sustainable transformation of city logistics, using literature on sustainable city logistics. To do so, we start by providing a representation of the subservient posture adopted by LSPs during their interactions with stakeholders. We then mobilize ecosystem theories to analyze the follower posture LSP can adopt to ensure their financial, human, and environmental sustainability in a city logistics ecosystem. This study contributes to local authorities’ greater consideration/involvement of LSP in the definition of their city logistics strategy. It can also provide LSP with an insight into the transformations to be carried out to improve their sustainability. Finally, it encourages research projects aimed at exploring more precisely the value relationships between LSP and their stakeholders.

Keywords: city logistics, logistics service providers, sustainability, ecosystems, value creation

Procedia PDF Downloads 177
4479 Sinusoidal Roughness Elements in a Square Cavity

Authors: Muhammad Yousaf, Shoaib Usman

Abstract:

Numerical studies were conducted using Lattice Boltzmann Method (LBM) to study the natural convection in a square cavity in the presence of roughness. An algorithm basedon a single relaxation time Bhatnagar-Gross-Krook (BGK) model of Lattice Boltzmann Method (LBM) was developed. Roughness was introduced on both the hot and cold walls in the form of sinusoidal roughness elements. The study was conducted for a Newtonian fluid of Prandtl number (Pr) 1.0. The range of Ra number was explored from 103 to 106 in a laminar region. Thermal and hydrodynamic behavior of fluid was analyzed using a differentially heated square cavity with roughness elements present on both the hot and cold wall. Neumann boundary conditions were introduced on horizontal walls with vertical walls as isothermal. The roughness elements were at the same boundary condition as corresponding walls. Computational algorithm was validated against previous benchmark studies performed with different numerical methods, and a good agreement was found to exist. Results indicate that the maximum reduction in the average heat transfer was16.66 percent at Ra number 105.

Keywords: Lattice Boltzmann method, natural convection, nusselt number, rayleigh number, roughness

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4478 Analysis of Commercial Cow and Camel Milk by Nuclear Magnetic Resonance

Authors: Lucia Pappalardo, Sara Abdul Majid Azzam

Abstract:

Camel milk is widely consumed by people living in arid areas of the world, where it is also known for its potential therapeutic and medical properties. Indeed it has been used as a treatment for several diseases such as tuberculosis, dropsy, asthma, jaundice and leishmaniasis in India, Sudan and some parts of Russia. A wealth of references is available in literature for the composition of milk from different diary animals such as cows, goats and sheep. Camel milk instead has not been extensively studied, despite its nutritional value. In this study commercial cow and camel milk samples, bought from the local market, were analyzed by 1D 1H-NMR and multivariate statistics in order to identify the different composition of the low-molecular-weight compounds in the milk mixtures. The samples were analyzed in their native conditions without any pre-treatment. Our preliminary study shows that the two different types of milk samples differ in the content of metabolites such as orotate, fats and more.

Keywords: camel, cow, milk, Nuclear Magnetic Resonance (NMR)

Procedia PDF Downloads 559
4477 Analysis of Air-Water Two-Phase Flow in a 3x3 Rod Bundle

Authors: Pei-Syuan Ruan, Ya-Chi Yu, Shao-Wen Chen, Jin-Der Lee, Jong-Rong Wang, Chunkuan Shih

Abstract:

This study investigated the void fraction characteristics under low superficial gas velocity (Jg) and low superficial fluid velocity (Jf) conditions in a 3x3 rod bundle geometry. Three arrangements of conductivity probes were set to measure the void fraction at various cross-sectional regions, including rod-gap, sub-channel and rod-wall regions. The experimental tests were performed under the flow conditions of Jg = 0-0.236 m/s and Jf = 0-0.142 m/s, and the time-averaged void fractions were recorded at each flow condition. It was observed that while the superficial gas velocity increases, the small bubbles started to cluster together and become big bubbles. As the superficial fluid velocity increases, the local void fractions of the three test regions will get closer and the bubble distribution will be more uniform across the cross section.

Keywords: conductivity probes, rod bundles, two-phase flow, void fraction

Procedia PDF Downloads 156
4476 Thermophysical and Heat Transfer Performance of Covalent and Noncovalent Functionalized Graphene Nanoplatelet-Based Water Nanofluids in an Annular Heat Exchanger

Authors: Hamed K. Arzani, Ahmad Amiri, Hamid K. Arzani, Salim Newaz Kazi, Ahmad Badarudin

Abstract:

The new design of heat exchangers utilizing an annular distributor opens a new gateway for realizing higher energy optimization. To realize this goal, graphene nanoplatelet-based water nanofluids with promising thermophysical properties were synthesized in the presence of covalent and noncovalent functionalization. Thermal conductivity, density, viscosity and specific heat capacity were investigated and employed as a raw data for ANSYS-Fluent to be used in two-phase approach. After validation of obtained results by analytical equations, two special parameters of convective heat transfer coefficient and pressure drop were investigated. The study followed by studying other heat transfer parameters of annular pass in the presence of graphene nanopletelesbased water nanofluids at different weight concentrations, input powers and temperatures. As a result, heat transfer performance and friction loss are predicted for both synthesized nanofluids.

Keywords: heat transfer, nanofluid, turbulent flow, forced convection flow, graphene nanoplatelet

Procedia PDF Downloads 422