Search results for: solid structures
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1930

Search results for: solid structures

1720 Promoting Gender Equality within Islamic Tradition via Contextualist Approach

Authors: Ali Akbar

Abstract:

The importance of advancing women’s rights is closely intertwined with the development of civil society and the institutionalization of democracy in Middle Eastern countries. There is indeed an intimate relationship between the process of democratization and promoting gender equality, since democracy necessitates equality between men and women. In order to advance the issue of gender equality, what is required is a solid theoretical framework which has its roots in the reexamination of pre-modern interpretation of certain Qurʾānic passages that seem to have given men more rights than it gives women. This paper suggests that those Muslim scholars who adopt a contextualist approach to the Qurʾānic text and its interpretation provide a solid theoretical background for improving women’s rights. Indeed, the aim of the paper is to discuss how the contextualist approach to the Qurʾānic text and its interpretation given by a number of prominent scholars is capable of promoting the issue of gender equality. The paper concludes that since (1) much of the gender inequality found in the primary sources of Islam as well as pre-modern Muslim writings is rooted in the natural cultural norms and standards of early Islamic societies and (2) since the context of today’s world is so different from that of the pre-modern era, the proposed models provide a solid theoretical framework for promoting women’s rights and gender equality.

Keywords: Contextualism, Gender equality, Islam, Women’s rights.

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1719 Use of Waste Tire Rubber Alkali-Activated-Based Mortars in Repair of Concrete Structures

Authors: Mohammad Ebrahim Kianifar, Ehsan Ahmadi

Abstract:

Reinforced concrete structures experience local defects such as cracks over their lifetime under various environmental loadings. Consequently, they are repaired by mortars to avoid detrimental effects such as corrosion of reinforcement, which in long-term may lead to strength loss of a member or collapse of structures. However, repaired structures may need multiple repairs due to changes in load distribution, and thus, lack of compatibility between mortar and substrate concrete. On the other hand, waste tire rubber alkali-activated (WTRAA)-based materials have very high potential to be used as repair mortars because of their ductility and flexibility, which may delay failure of repair mortar, and thus, provide sufficient compatibility. Hence, this work presents a study on suitability of WTRAA-based materials as mortars for repair of concrete structures through an experimental program. To this end, WTRAA mortars with 15% aggregate replacement, alkali-activated (AA) mortars, and ordinary mortars are made to repair a number of concrete beams. The WTRAA mortars are composed of slag as base material, sodium hydroxide as alkaline activator, and different gradation of waste tire rubber (fine and coarse gradations). Flexural tests are conducted on the concrete beams repaired by the ordinary, AA, and WTRAA mortars. It is found that, despite having lower compressive strength and modulus of elasticity, the WTRAA and AA mortars increase flexural strength of the repaired beams, give compatible failures, and provide sufficient mortar-concrete interface bondings. The ordinary mortars, however, show incompatible failure modes. This study demonstrates promising application of WTRAA mortars in practical repairs of concrete structures.

Keywords: Alkali-activated mortars, concrete repair, mortar compatibility flexural strength, waste tire rubber.

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1718 An E-Government Implementation Model for Peruvian State Companies Based on COBIT 5.0: Definition and Goals of the Model

Authors: M. Bruzza, M. Tupia, F. Rodríguez

Abstract:

As part of the regulatory compliance process and the streamlining of public administration, the Peruvian government has implemented the National E-Government Plan in all state institutions with the aim of providing citizens with solid services based on the use of Information and Communications Technologies (ICT). As part of the regulations, the requisites to be met by public institutions have been submitted. However, the lack of an implementation model was detected, one that can serve as a guide to such institutions in order to materialize the organizational and technological structures needed, which allow them to provide the required digital services. This paper develops an implementation model of electronic government (e-government) for Peru’s state institutions, in compliance with current regulations based on a COBIT 5.0 framework. Furthermore, the paper introduces phase 1 of this model: business and IT goals, the goals cascade and the future model of processes.

Keywords: E-government, implementation, model, COBIT 5.0, digital services, u-government, m-government.

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1717 Design Development of Floating Performance Structure for Coastal Areas in the Maltese Islands

Authors: Rebecca E. Dalli Gonzi, Joseph Falzon

Abstract:

Background: Islands in the Mediterranean region offer opportunities for various industries to take advantage of the facilitation and use of versatile floating structures in coastal areas. In the context of dense land use, marine structures can contribute to ensure both terrestrial and marine resource sustainability. Objective: The aim of this paper is to present and critically discuss an array of issues that characterize the design process of a floating structure for coastal areas and to present the challenges and opportunities of providing such multifunctional and versatile structures around the Maltese coastline. Research Design: A three-tier research design commenced with a systematic literature review. Semi-structured interviews with stakeholders including a naval architect, a marine engineer and civil designers were conducted. A second stage preceded a focus group with stakeholders in design and construction of marine lightweight structures. The three tier research design ensured triangulation of issues. All phases of the study were governed by research ethics. Findings: Findings were grouped into three main themes: excellence, impact and implementation. These included design considerations, applications and potential impacts on local industry. Literature for the design and construction of marine structures in the Maltese Islands presented multiple gaps in the application of marine structures for local industries. Weather conditions, depth of sea bed and wave actions presented limitations on the design capabilities of the structure. Conclusion: Water structures offer great potential and conclusions demonstrate the applicability of such designs for Maltese waters. There is still no such provision within Maltese coastal areas for multi-purpose use. The introduction of such facilities presents a range of benefits for visiting tourists and locals thereby offering wide range of services to tourism and marine industry. Costs for construction and adverse weather conditions were amongst the main limitations that shaped design capacities of the water structures.

Keywords: Coastal areas, lightweight, marine structure, multipurpose, versatile, floating device.

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1716 An Evaluation of Sag Detection Techniques for Fast Solid-State Electronic Transferring to Alternate Electrical Energy Sources

Authors: M. N. Moschakis, I. G. Andritsos, V. V. Dafopoulos, J. M. Prousalidis, E. S. Karapidakis

Abstract:

This paper deals with the evaluation of different detection strategies used in power electronic devices as a critical element for an effective mitigation of voltage disturbances. The effectiveness of those detection schemes in the mitigation of disturbances such as voltage sags by a Solid-State Transfer Switch is evaluated through simulations. All critical parameters affecting their performance is analytically described and presented. Moreover, the effect of fast detection of sags on the overall performance of STS is analyzed and investigated.

Keywords: Faults (short-circuits), industrial engineering, power electronics, power quality, static transfer switch, voltage sags (or dips).

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1715 Osmotic Dehydration of Apricot using Saltsucrose Solutions

Authors: M. Manafi, J. Hesari, H. Peighambardoust, M. Rahimzade Khoyi

Abstract:

Fruit drying is a well known process mostly used for preservation of fruits. Osmotic dehydration of apricot slices were carried out in three different salt-sucrose concentrations and four different temperatures. Also three different weight ratios of solution to sample were conducted to one set of experiments. The dehydration curves were constructed using Peleg-s model. Increasing the solution volume increased the mass transfer rate and hence the solid gain increased rapidly. Increasing the volume of osmotic media caused an increase in overall mass transfer but a 'solution to sample' ratio of 5:1 gave the best product quality. The best temperature and concentration that had a high water loss to solid gain ratio and an acceptable taste were 40°C and 5%, respectively.

Keywords: Apricot, Effective diffusivities, Osmotic dehydration

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1714 Micromechanics Modeling of 3D Network Smart Orthotropic Structures

Authors: E. M. Hassan, A. L. Kalamkarov

Abstract:

Two micromechanical models for 3D smart composite with embedded periodic or nearly periodic network of generally orthotropic reinforcements and actuators are developed and applied to cubic structures with unidirectional orientation of constituents. Analytical formulas for the effective piezothermoelastic coefficients are derived using the Asymptotic Homogenization Method (AHM). Finite Element Analysis (FEA) is subsequently developed and used to examine the aforementioned periodic 3D network reinforced smart structures. The deformation responses from the FE simulations are used to extract effective coefficients. The results from both techniques are compared. This work considers piezoelectric materials that respond linearly to changes in electric field, electric displacement, mechanical stress and strain and thermal effects. This combination of electric fields and thermo-mechanical response in smart composite structures is characterized by piezoelectric and thermal expansion coefficients. The problem is represented by unitcell and the models are developed using the AHM and the FEA to determine the effective piezoelectric and thermal expansion coefficients. Each unit cell contains a number of orthotropic inclusions in the form of structural reinforcements and actuators. Using matrix representation of the coupled response of the unit cell, the effective piezoelectric and thermal expansion coefficients are calculated and compared with results of the asymptotic homogenization method. A very good agreement is shown between these two approaches.

Keywords: Asymptotic Homogenization Method, Effective Piezothermoelastic Coefficients, Finite Element Analysis, 3D Smart Network Composite Structures.

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1713 A ±0.5V BiCMOS Class-A Current Conveyor

Authors: Subodh Thankachan, Manisha Pattanaik, S. S. Rajput

Abstract:

In this paper, a new BiCMOS CCII and CCCII, capable of operate at ±0.5V and having wide dynamic range with achieved bandwidth of 480MHz and 430MHz respectively have been proposed. The structures have been found to be insensitive to the threshold voltage variations. The proposed circuits are suitable for implementation using 0.25μm BiCMOS technology. Pspice simulations confirm the performance of the proposed structures.

Keywords: BiCMOS, Current conveyor, Compound current conveyor, Low supply voltage, Threshold voltage variation.

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1712 Data Structures and Algorithms of Intelligent Web-Based System for Modular Design

Authors: Ivan C. Mustakerov, Daniela I. Borissova

Abstract:

In recent years, new product development became more and more competitive and globalized, and the designing phase is critical for the product success. The concept of modularity can provide the necessary foundation for organizations to design products that can respond rapidly to market needs. The paper describes data structures and algorithms of intelligent Web-based system for modular design taking into account modules compatibility relationship and given design requirements. The system intelligence is realized by developed algorithms for choice of modules reflecting all system restrictions and requirements. The proposed data structure and algorithms are illustrated by case study of personal computer configuration. The applicability of the proposed approach is tested through a prototype of Web-based system.

Keywords: Data structures, algorithms, intelligent web-based system, modular design.

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1711 Boundary Effect on the Onset of Marangoni Convection with Internal Heat Generation

Authors: Norihan Md Arifin, Norfifah Bachok

Abstract:

The onset of Marangoni convection in a horizontal fluid layer with internal heat generation overlying a solid layer heated from below is studied. The upper free surface of a fluid is nondeformable and the bottom boundary are rigid and no-slip. The resulting eigenvalue problem is solved exactly. The critical values of the Marangoni numbers for the onset of Marangoni convection are calculated and the latter is found to be critically dependent on the internal heating, depth ratio and conductivity ratio. The effects of the thermal conductivity and the thickness of the solid plate on the onset of convective instability with internal heating are studied in detail.

Keywords: Linear stability, Marangoni convection, Internal Heatgeneration.

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1710 Analysis of Dust Particles in Snow Cover in the Surroundings of the City of Ostrava: Particle Size Distribution, Zeta Potential and Heavy Metal Content

Authors: Roman Marsalek

Abstract:

In this paper, snow samples containing dust particles from several sampling points around the city of Ostrava were analyzed. The pH values of sampled snow were measured and solid particles analyzed. Particle size, zeta potential and content of selected heavy metals were determined in solid particles. The pH values of most samples lay in the slightly acid region. Mean values of particle size ranged from 290.5 to 620.5 nm. Zeta potential values varied between -5 and -26.5 mV. The following heavy metal concentration ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g, manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest values of copper and lead were found in the vicinity of busy crossroads, and on the contrary, the highest levels of manganese and iron were detected close to a large steelworks. The proportion between pH values, zeta potentials, particle sizes and heavy metal contents was established. Zeta potential decreased with rising pH values and, simultaneously, heavy metal content in solid particles increased. At the same time, higher metal content corresponded to lower particle size.

Keywords: Dust, snow, zeta potential, particles size distribution, heavy metals.

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1709 Void-Free Bonding of Si/Ti/Ni Power Integrated Circuit Chips with Direct Bonding Copper Alumina Substrates through Ag3Sn Intermetallic Interlayer

Authors: Kuan-Yu Chiu, Yin-Hsuan Chen, Tung-Han Chuang

Abstract:

Ti/Ni/Ag/Sn-metallized Si chips were bonded to Ni/Pd/Au-surface finished DBC (Direct Bonding Copper) alumina substrate through the formation of an Ag3Sn intermetallic interlayer by solid–liquid interdiffusion bonding method. The results indicated that the holes and gaps at the bonding interface could be effectively prevented. The intermetallic phases at the bonding interface between the Si/Ti/Ni/Ag/Sn wafer and the DBC substrate were identified as Ag3Sn, Ni3Sn4, and Ni3Sn2. The average bonding strength was about 19.75 MPa, and the maximum bonding strength reached 35.24 MPa.

Keywords: BGBM, Backside Grinding and Backside Metallization, SLID bonding, Solid–liquid Interdiffusion Bonding, Si/Ti/Ni/Sn, Si/Ti/Ni/Ag/Sn, intermetallic compound.

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1708 Ethanol Production from Sugarcane Bagasse by Means of Enzymes Produced by Solid State Fermentation Method

Authors: Nasim Shaibani, Saba Ghazvini, Mohammad R. Andalibi, Soheila Yaghmaei

Abstract:

Nowadays there is a growing interest in biofuel production in most countries because of the increasing concerns about hydrocarbon fuel shortage and global climate changes, also for enhancing agricultural economy and producing local needs for transportation fuel. Ethanol can be produced from biomass by the hydrolysis and sugar fermentation processes. In this study ethanol was produced without using expensive commercial enzymes from sugarcane bagasse. Alkali pretreatment was used to prepare biomass before enzymatic hydrolysis. The comparison between NaOH, KOH and Ca(OH)2 shows NaOH is more effective on bagasse. The required enzymes for biomass hydrolysis were produced from sugarcane solid state fermentation via two fungi: Trichoderma longibrachiatum and Aspergillus niger. The results show that the produced enzyme solution via A. niger has functioned better than T. longibrachiatum. Ethanol was produced by simultaneous saccharification and fermentation (SSF) with crude enzyme solution from T. longibrachiatum and Saccharomyces cerevisiae yeast. To evaluate this procedure, SSF of pretreated bagasse was also done using Celluclast 1.5L by Novozymes. The yield of ethanol production by commercial enzyme and produced enzyme solution via T. longibrachiatum was 81% and 50% respectively.

Keywords: Alkali pretreatment, bioethanol, cellulase, simultaneous saccharification and fermentation, solid statefermentation, sugarcane bagasse

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1707 Effect of Polymer Molecular Structures on Properties of Dental Cement Restoratives

Authors: Dong Xie, Jun Zhao, Yiming Weng

Abstract:

The objective of this study was to synthesize and characterize the poly(alkenoic acid)s with different molecular structures, use these polymers to formulate a dental cement restorative, and study the effect of molecular structures on reaction kinetics, viscosity, and mechanical strengths of the formed polymers and cement restoratives. In this study, poly(alkenoic acid)s with different molecular structures were synthesized. The purified polymers were formulated with commercial Fuji II LC glass fillers to form the experimental cement restoratives. The reaction kinetics was studied via 1HNMR spectroscopy. The formed restoratives were evaluated using compressive strength, diametral tensile strength, flexural strength, hardness and wear-resistance tests. Specimens were conditioned in distilled water at 37oC for 24 h prior to testing. Fuji II LC restorative was used as control. The results show that the higher the arm number and initiator concentration, the faster the reaction was. It was also found that the higher the arm number and branching that the polymer had, the lower the viscosity of the polymer in water and the lower the mechanical strengths of the formed restorative. The experimental restoratives were 31-53% in compressive strength, 37- 55% in compressive modulus, 80-126% in diametral tensile strength, 76-94% in flexural strength, 4-21% in fracture toughness and 53-96% in hardness higher than Fuji II LC. For wear test, the experimental restoratives were only 5.4-13% of abrasive and 6.4-12% of attritional wear depths of Fuji II LC in each wear cycle. The aging study also showed that all the experimental restoratives increased their strength continuously during 30 days, unlike Fuji II LC. It is concluded that polymer molecular structures have significant and positive impact on mechanical properties of dental cement restoratives.

Keywords: Poly(alkenoic acid)s, molecular structures, dental cement, mechanical strength.

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1706 Serviceability of Fabric-Formed Concrete Structures

Authors: Yadgar Tayfur, Antony Darby, Tim Ibell, Mark Evernden, John Orr

Abstract:

Fabric form-work is a technique to cast concrete structures with a great advantage of saving concrete material of up to 40%. This technique is particularly associated with the optimized concrete structures that usually have smaller cross-section dimensions than equivalent prismatic members. However, this can make the structural system produced from these members prone to smaller serviceability safety margins. Therefore, it is very important to understand the serviceability issue of non-prismatic concrete structures. In this paper, an analytical computer-based model to optimize concrete beams and to predict load-deflection behaviour of both prismatic and non-prismatic concrete beams is presented. The model was developed based on the method of sectional analysis and integration of curvatures. Results from the analytical model were compared to load-deflection behaviour of a number of beams with different geometric and material properties from other researchers. The results of the comparison show that the analytical program can accurately predict the load-deflection response of concrete beams with medium reinforcement ratios. However, it over-estimates deflection values for lightly reinforced specimens. Finally, the analytical program acceptably predicted load-deflection behaviour of on-prismatic concrete beams.

Keywords: Concrete beams, deflections, fabric formwork, optimisation, serviceability.

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1705 Assessment of the Energy Balance Method in the Case of Masonry Domes

Authors: M. M. Sadeghi, S. Vahdani

Abstract:

Masonry dome structures had been widely used for covering large spans in the past. The seismic assessment of these historical structures is very complicated due to the nonlinear behavior of the material, their rigidness, and special stability configuration. The assessment method based on energy balance concept, as well as the standard pushover analysis, is used to evaluate the effectiveness of these methods in the case of masonry dome structures. The Soltanieh dome building is used as an example to which two methods are applied. The performance points are given from superimposing the capacity, and demand curves in Acceleration Displacement Response Spectra (ADRS) and energy coordination are compared with the nonlinear time history analysis as the exact result. The results show a good agreement between the dynamic analysis and the energy balance method, but standard pushover method does not provide an acceptable estimation.

Keywords: Energy balance method, pushover analysis, time history analysis, masonry dome.

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1704 Up Scaling of Highly Transparent Quasi-Solid State, Dye-Sensitized Solar Devices Composed of Nanocomposite Materials

Authors: Dimitra Sygkridou, Andreas Rapsomanikis, Elias Stathatos, Polycarpos Falaras, Evangelos Vitoratos

Abstract:

At the present work, highly transparent strip type quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated through inkjet printing using nanocomposite TiO2 inks as raw materials and tested under outdoor illumination conditions. The cells, which can be considered as the structural units of large area modules, were fully characterized electrically and electrochemically and after the evaluation of the received results a large area DSSC module was manufactured. The module design was a sandwich Z-interconnection where the working electrode is deposited on one conductive glass and the counter electrode on a second glass. Silver current collective fingers were printed on the conductive glasses to make the internal electrical connections and the adjacent cells were connected in series and finally insulated using a UV curing resin to protect them from the corrosive (I-/I3-) redox couple of the electrolyte. Finally, outdoor tests were carried out to the fabricated dye-sensitized solar module and its performance data were collected and assessed.

Keywords: Dye-sensitized solar devices, inkjet printing, quasi-solid state electrolyte, transparency, up scaling.

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1703 Effect of Aging Condition on Semisolid Cast 2024 Aluminum Alloy

Authors: Wisutmethangoon S., Pannaray S., Plookphol T., Wannasin J.

Abstract:

2024 Aluminum alloy was squeezed cast by the Gas Induced Semi Solid (GISS) process. Effect of artificial aging on microstructure and mechanical properties of this alloy was studied in the present work. The solutionized specimens were aged hardened at temperatures of 175°C, 200°C, and 225°C under various time durations. The highest hardness of about 77.7 HRE was attained from specimen aged at the temperature of 175°C for 36h. Upon investigation the microstructure by using transmission electron microscopy (TEM), the S’ phase was mainly attributed to the strengthening effect in the aged alloy. The apparent activation energy for precipitation hardening of the alloy was calculated as 133,805 J/mol.

Keywords: 2024 aluminum alloy, Gas induced semi solid, T6 heat treatment, Aged hardening, Transmission electron microscopy.

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1702 Preparation and Conductivity Measurements of LSM/YSZ Composite Solid Oxide Electrolysis Cell Anode Materials

Authors: Christian C. Vaso, Rinlee Butch M. Cervera

Abstract:

One of the most promising anode materials for solid oxide electrolysis cell (SOEC) application is the Sr-doped LaMnO3 (LSM) which is known to have a high electronic conductivity but low ionic conductivity. To increase the ionic conductivity or diffusion of ions through the anode, Yttria-stabilized Zirconia (YSZ), which has good ionic conductivity, is proposed to be combined with LSM to create a composite electrode and to obtain a high mixed ionic and electronic conducting anode. In this study, composite of lanthanum strontium manganite and YSZ oxide, La0.8Sr0.2MnO3/Zr0.92Y0.08O2 (LSM/YSZ), with different wt.% compositions of LSM and YSZ were synthesized using solid-state reaction. The obtained prepared composite samples of 60, 50, and 40 wt.% LSM with remaining wt.% of 40, 50, and 60, respectively for YSZ were fully characterized for its microstructure by using powder X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and Scanning electron microscope/Energy dispersive spectroscopy (SEM/EDS) analyses. Surface morphology of the samples via SEM analysis revealed a well-sintered and densified pure LSM, while a more porous composite sample of LSM/YSZ was obtained. Electrochemical impedance measurements at intermediate temperature range (500-700 °C) of the synthesized samples were also performed which revealed that the 50 wt.% LSM with 50 wt.% YSZ (L50Y50) sample showed the highest total conductivity of 8.27x10-1 S/cm at 600 oC with 0.22 eV activation energy.

Keywords: Ceramics, microstructure, fuel cells, electrochemical impedance spectroscopy.

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1701 Finite Element Analysis of Low-Velocity Impact Damage on Stiffened Composite Panels

Authors: Xuan Sun, Mingbo Tong

Abstract:

To understand the factors which affect impact damage on composite structures, particularly the effects of impact position and ribs. In this paper, a finite element model (FEM) of low-velocity impact damage on the composite structure was established via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS software. The structural elements chosen for the investigation comprised a series of stiffened composite panels, representative of real aircraft structure. By impacting the panels at different positions relative to the ribs, the effect of relative position of ribs was found out. Then the simulation results and the experiments data were compared. Finally, the factors which affect impact damage on the structures were discussed. The paper was helpful for the design of stiffened composite structures.

Keywords: Stiffened, Low-velocity, Impact, Abaqus, Impact Energy.

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1700 Coupled Dynamics in Host-Guest Complex Systems Duplicates Emergent Behavior in the Brain

Authors: Sergio Pissanetzky

Abstract:

The ability of the brain to organize information and generate the functional structures we use to act, think and communicate, is a common and easily observable natural phenomenon. In object-oriented analysis, these structures are represented by objects. Objects have been extensively studied and documented, but the process that creates them is not understood. In this work, a new class of discrete, deterministic, dissipative, host-guest dynamical systems is introduced. The new systems have extraordinary self-organizing properties. They can host information representing other physical systems and generate the same functional structures as the brain does. A simple mathematical model is proposed. The new systems are easy to simulate by computer, and measurements needed to confirm the assumptions are abundant and readily available. Experimental results presented here confirm the findings. Applications are many, but among the most immediate are object-oriented engineering, image and voice recognition, search engines, and Neuroscience.

Keywords: AI, artificial intelligence, complex system, object oriented, OO, refactoring.

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1699 Quantum Dot Cellular Automata Based Effective Design of Combinational and Sequential Logical Structures

Authors: Hema Sandhya Jagarlamudi, Mousumi Saha, Pavan Kumar Jagarlamudi

Abstract:

The use of Quantum dots is a promising emerging Technology for implementing digital system at the nano level. It is effecient for attractive features such as faster speed , smaller size and low power consumption than transistor technology. In this paper, various Combinational and sequential logical structures - HALF ADDER, SR Latch and Flip-Flop, D Flip-Flop preceding NAND, NOR, XOR,XNOR are discussed based on QCA design, with comparatively less number of cells and area. By applying these layouts, the hardware requirements for a QCA design can be reduced. These structures are designed and simulated using QCA Designer Tool. By taking full advantage of the unique features of this technology, we are able to create complete circuits on a single layer of QCA. Such Devices are expected to function with ultra low power Consumption and very high speeds.

Keywords: QCA, QCA Designer, Clock, Majority Gate

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1698 Fabrication of Wearable Antennas through Thermal Deposition

Authors: Jeff Letcher, Dennis Tierney, Haider Raad

Abstract:

Antennas are devices for transmitting and/or receiving signals which make them a necessary component of any wireless system. In this paper, a thermal deposition technique is utilized as a method to fabricate antenna structures on substrates. Thin-film deposition is achieved by evaporating a source material (metals in our case) in a vacuum which allows vapor particles to travel directly to the target substrate which is encased with a mask that outlines the desired structure. The material then condenses back to solid state. This method is used in comparison to screen printing, chemical etching, and ink jet printing to indicate advantages and disadvantages to the method. The antenna created undergoes various testing of frequency ranges, conductivity, and a series of flexing to indicate the effectiveness of the thermal deposition technique. A single band antenna that is operated at 2.45 GHz intended for wearable and flexible applications was successfully fabricated through this method and tested. It is concluded that thermal deposition presents a feasible technique of producing such antennas.

Keywords: Thermal deposition, wearable antennas, Bluetooth technology, flexible electronics.

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1697 Bisymmetric, Persymmetric Matrices and Its Applications in Eigen-decomposition of Adjacency and Laplacian Matrices

Authors: Mahdi Nouri

Abstract:

In this paper we introduce an efficient solution method for the Eigen-decomposition of bisymmetric and per symmetric matrices of symmetric structures. Here we decompose adjacency and Laplacian matrices of symmetric structures to submatrices with low dimension for fast and easy calculation of eigenvalues and eigenvectors. Examples are included to show the efficiency of the method.

Keywords: Graphs theory, Eigensolution, adjacency and Laplacian matrix, Canonical forms, bisymmetric, per symmetric.

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1696 Modeling and Simulation of Practical Metamaterial Structures

Authors: Ridha Salhi, Mondher Labidi, Fethi Choubani

Abstract:

Metamaterials have attracted much attention in recent years because of their electromagnetic exquisite proprieties. We will present, in this paper, the modeling of three metamaterial structures by equivalent circuit model. We begin by modeling the SRR (Split Ring Resonator), then we model the HIS (High Impedance Surfaces), and finally, we present the model of the CPW (Coplanar Wave Guide). In order to validate models, we compare the results obtained by an equivalent circuit models with numerical simulation.

Keywords: Metamaterials, SRR, HIS, CPW, IDC.

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1695 Towards Growing Self-Organizing Neural Networks with Fixed Dimensionality

Authors: Guojian Cheng, Tianshi Liu, Jiaxin Han, Zheng Wang

Abstract:

The competitive learning is an adaptive process in which the neurons in a neural network gradually become sensitive to different input pattern clusters. The basic idea behind the Kohonen-s Self-Organizing Feature Maps (SOFM) is competitive learning. SOFM can generate mappings from high-dimensional signal spaces to lower dimensional topological structures. The main features of this kind of mappings are topology preserving, feature mappings and probability distribution approximation of input patterns. To overcome some limitations of SOFM, e.g., a fixed number of neural units and a topology of fixed dimensionality, Growing Self-Organizing Neural Network (GSONN) can be used. GSONN can change its topological structure during learning. It grows by learning and shrinks by forgetting. To speed up the training and convergence, a new variant of GSONN, twin growing cell structures (TGCS) is presented here. This paper first gives an introduction to competitive learning, SOFM and its variants. Then, we discuss some GSONN with fixed dimensionality, which include growing cell structures, its variants and the author-s model: TGCS. It is ended with some testing results comparison and conclusions.

Keywords: Artificial neural networks, Competitive learning, Growing cell structures, Self-organizing feature maps.

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1694 Properties of Al2O3 – hBN Composites

Authors: K. Broniszewski, J. Woźniak, K. Czechowski, P. Orłowski, A. Olszyna

Abstract:

Alumina matrix composites with addition of hexagonal boron nitride (hBN), acting as solid lubricant, were produced. Main purpose of solid lubricants is to dispose the necessity of using cooling lubricants in machining process. Hot pressing was used as a consolidating process for Al2O3-x%wt.hBN (x=1/ 2,5/ 5 /7,5 /10) composites. Properties of sinters such as relative density, hardness, Young-s modulus and fracture toughness were examined. Obtained samples characterize by high relative density. Hardness and fracture toughness values allow the use of alumina – hBN composites for machining steels even in hardened condition. However it was observed that high weight content of hBN can negatively influence the mechanical properties of composites.

Keywords: Alumina. Composites, Hexagonal boron nitride, Machining

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1693 Urban Search and Rescue and Rapid Field Assessment of Damaged and Collapsed Building Structures

Authors: Abid I. Abu-Tair, Gavin M. Wilde, John M. Kinuthia

Abstract:

Urban Search and Rescue (USAR) is a functional capability that has been developed to allow the United Kingdom Fire and Rescue Service to deal with ‘major incidents’ primarily involving structural collapse. The nature of the work undertaken by USAR means that staying out of a damaged or collapsed building structure is not usually an option for search and rescue personnel. As a result there is always a risk that they themselves could become victims. For this paper, a systematic and investigative review using desk research was undertaken to explore the role which structural engineering can play in assisting search and rescue personnel to conduct structural assessments when in the field. The focus is on how search and rescue personnel can assess damaged and collapsed building structures, not just in terms of structural damage that may been countered, but also in relation to structural stability. Natural disasters, accidental emergencies, acts of terrorism and other extreme events can vary significantly in nature and ferocity, and can cause a wide variety of damage to building structures. It is not possible or, even realistic, to provide search and rescue personnel with definitive guidelines and procedures to assess damaged and collapsed building structures as there are too many variables to consider. However, understanding what implications damage may have upon the structural stability of a building structure will enable search and rescue personnel to better judge and quantify risk from a life-safety standpoint. It is intended that this will allow search and rescue personnel to make informed decisions and ensure every effort is made to mitigate risk, so that they themselves do not become victims.

Keywords: Damaged and collapsed building structures, life safety, quantifying risk, search and rescue personnel, structural assessments in the field.

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1692 Utilization of Wheat Bran as Bed Material in Solid State Bacterial Production of Lactic Acid with Various Nitrogen Sources

Authors: U.K.Ghosh, M.K.Ghosh

Abstract:

The present experimental investigation brings about a comparative study of lactic acid production by pure strains of Lactobacilli (1) L. delbreuckii (NCIM2025), (2) L. pentosus (NCIM 2912), (3) Lactobacillus sp.(NCIM 2734, (4) Lactobacillus sp. (NCIM2084) and coculture of strain-1 and Stain-2 in solid bed of wheat bran, under the influence of different nitrogen sources such as baker-s yeast, meat extract and proteose peptone. Among the pure cultures, strain-3 attained lowest pH value of 3.44, hence highest acid formation 46.41 g/L, while the coculture attained an overall maximum value 47.56 g/L lactic acid (pH 3.38) at 15 g/L and 20 g/L level of baker-s yeast, respectively.

Keywords: Eco-friendly, lactic acid, lactobacilli, wheat bran

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1691 The Influence of Substrate Bias on the Mechanical Properties of a W- and S-containing DLC-based Solid-lubricant Film

Authors: Guojia Ma, Guoqiang Lin, Shuili Gong, Gang Sun, Dawang Wang

Abstract:

A diamond-like carbon (DLC) based solid-lubricant film was designed and DLC films were successfully prepared using a microwave plasma enhanced magnetron sputtering deposition technology. Post-test characterizations including Raman spectrometry, X-ray diffraction, nano-indentation test, adhesion test, friction coefficient test were performed to study the influence of substrate bias voltage on the mechanical properties of the W- and S-doped DLC films. The results indicated that the W- and S-doped DLC films also had the typical structure of DLC films and a better mechanical performance achieved by the application of a substrate bias of -200V.

Keywords: Adhesive Strength, Coefficient of Friction, Substrate Bias, W- and S-doped DLC film

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