Search results for: structural regularity
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4358

Search results for: structural regularity

4088 A Resistant-Based Comparative Study between Iranian Concrete Design Code and Some Worldwide Ones

Authors: Seyed Sadegh Naseralavi, Najmeh Bemani

Abstract:

The design in most counties should be inevitably carried out by their native code such as Iran. Since the Iranian concrete code does not exist in structural design software, most engineers in this country analyze the structures using commercial software but design the structural members manually. This point motivated us to make a communication between Iranian code and some other well-known ones to create facility for the engineers. Finally, this paper proposes the so-called interpretation charts which help specify the position of Iranian code in comparison of some worldwide ones.

Keywords: beam, concrete code, strength, interpretation charts

Procedia PDF Downloads 526
4087 Structural Equation Modeling Semiparametric in Modeling the Accuracy of Payment Time for Customers of Credit Bank in Indonesia

Authors: Adji Achmad Rinaldo Fernandes

Abstract:

The research was conducted to apply semiparametric SEM modeling to the timeliness of paying credit. Semiparametric SEM is structural modeling in which two combined approaches of parametric and nonparametric approaches are used. The analysis method in this research is semiparametric SEM with a nonparametric approach using a truncated spline. The data in the study were obtained through questionnaires distributed to Bank X mortgage debtors and are confidential. The study used 3 variables consisting of one exogenous variable, one intervening endogenous variable, and one endogenous variable. The results showed that (1) the effect of capacity and willingness to pay variables on timeliness of payment is significant, (2) modeling the capacity variable on willingness to pay also produces a significant estimate, (3) the effect of the capacity variable on the timeliness of payment variable is not influenced by the willingness to pay variable as an intervening variable, (4) the R^2 value of 0.763 or 76.33% indicates that the model has good predictive relevance.

Keywords: structural equation modeling semiparametric, credit bank, accuracy of payment time, willingness to pay

Procedia PDF Downloads 44
4086 Critical Evaluation of the Effects of Conditionalities and Structural Adjustments on the Poor and Developing Countries

Authors: Kazi Rafikoddin

Abstract:

Conditionality refers to a precondition for getting external funds from IMF or WB by giving consent for implementation of the program of economic or political reforms especially relating to open economies. These are put forth under the label of structural adjustment. It is a kind of challenge on the part of borrowing government to exercise balance between the domestic obligations and the expectations of external funding agencies. Countries have to take loans under certain criteria and regulations because better loans are often not readily available. Therefore taking loans and renewing them to pay the same with new interest rates and conditions makes the governments entangled in the circle of debt. They are forced to compete with well-established multinational companies. If their access to industrialized countries' markets is impaired through protectionism, the developed world will be condemning the indebted nations to perpetual financial crisis. On the other hand, the ability to sell their goods free in the world market is reduced through the introduction of Structural Adjustment Programmes. Although there are examples of positive effects on certain economies like India, some Third World, and poor countries have experienced the ire of these remedies. This paper tries to find out the effects of SAPs on some borrowing countries.

Keywords: IMF, world bank, conditionalities, SAPs, Third World Countries

Procedia PDF Downloads 201
4085 Study of Regulation and Registration Law of Veterinary Biological Drugs in Iran and Comparison between FDA, EMA and WHO

Authors: Hoda Dehghani, Zahra Dehghani

Abstract:

Considering the obvious growth and variety of veterinary biological product and increase consumption and also the price, it is necessary to establish the rules and serious monitoring of this products which are less expensive than the original products. The scope of this research is the study of comparing the registration criteria and procedures of veterinary biological drugs in the world's leading agencies such as EMA, FDA, and WHO. For this, purpose the rules and regulations for registration of these drugs in prestigious organizations such as the FDA, EMA and WHO were examined and compared with the existing legislation in Iran. Studies show that EMA is the forefront of the compilation and registration of drugs in the world. China is a one of the greatest country in the development of drugs and establishes very closely guidelines with creditable global guidelines, and Now, is the first country to implement the rules codified in the Far East and followed by china, India and, South Korea and Taiwan have taken incorporate the industry's top ranking in Asia. At now, Asia by creating appropriate indicators not only as a powerful center in the field of drug delivery but also as a competitor to the United States is a major source of drug discovery and creation of innovation. the activities such as clinical trials and pharmaceutical investment is the speed of technology on the continent.

Keywords: veterinary biological product, regulation of registration, biological products, regularity authorities

Procedia PDF Downloads 364
4084 Identification of Shocks from Unconventional Monetary Policy Measures

Authors: Margarita Grushanina

Abstract:

After several prominent central banks including European Central Bank (ECB), Federal Reserve System (Fed), Bank of Japan and Bank of England employed unconventional monetary policies in the aftermath of the financial crisis of 2008-2009 the problem of identification of the effects from such policies became of great interest. One of the main difficulties in identification of shocks from unconventional monetary policy measures in structural VAR analysis is that they often are anticipated, which leads to a non-fundamental MA representation of the VAR model. Moreover, the unconventional monetary policy actions may indirectly transmit to markets information about the future stance of the interest rate, which raises a question of the plausibility of the assumption of orthogonality between shocks from unconventional and conventional policy measures. This paper offers a method of identification that takes into account the abovementioned issues. The author uses factor-augmented VARs to increase the information set and identification through heteroskedasticity of error terms and rank restrictions on the errors’ second moments’ matrix to deal with the cross-correlation of the structural shocks.

Keywords: factor-augmented VARs, identification through heteroskedasticity, monetary policy, structural VARs

Procedia PDF Downloads 348
4083 A Methodology for Seismic Performance Enhancement of RC Structures Equipped with Friction Energy Dissipation Devices

Authors: Neda Nabid

Abstract:

Friction-based supplemental devices have been extensively used for seismic protection and strengthening of structures, however, the conventional use of these dampers may not necessarily lead to an efficient structural performance. Conventionally designed friction dampers follow a uniform height-wise distribution pattern of slip load values for more practical simplicity. This can lead to localizing structural damage in certain story levels, while the other stories accommodate a negligible amount of relative displacement demand. A practical performance-based optimization methodology is developed to tackle with structural damage localization of RC frame buildings with friction energy dissipation devices under severe earthquakes. The proposed methodology is based on the concept of uniform damage distribution theory. According to this theory, the slip load values of the friction dampers redistribute and shift from stories with lower relative displacement demand to the stories with higher inter-story drifts to narrow down the discrepancy between the structural damage levels in different stories. In this study, the efficacy of the proposed design methodology is evaluated through the seismic performance of five different low to high-rise RC frames equipped with friction wall dampers under six real spectrum-compatible design earthquakes. The results indicate that compared to the conventional design, using the suggested methodology to design friction wall systems can lead to, by average, up to 40% reduction of maximum inter-story drift; and incredibly more uniform height-wise distribution of relative displacement demands under the design earthquakes.

Keywords: friction damper, nonlinear dynamic analysis, RC structures, seismic performance, structural damage

Procedia PDF Downloads 226
4082 Density functional (DFT), Study of the Structural and Phase Transition of ThC and ThN: LDA vs GGA Computational

Authors: Hamza Rekab Djabri, Salah Daoud

Abstract:

The present paper deals with the computational of structural and electronic properties of ThC and ThN compounds using density functional theory within generalized-gradient (GGA) apraximation and local density approximation (LDA). We employ the full potential linear muffin-tin orbitals (FP-LMTO) as implemented in the Lmtart code. We have used to examine structure parameter in eight different structures such as in NaCl (B1), CsCl (B2), ZB (B3), NiAs (B8), PbO (B10), Wurtzite (B4) , HCP (A3) βSn (A5) structures . The equilibrium lattice parameter, bulk modulus, and its pressure derivative were presented for all calculated phases. The calculated ground state properties are in good agreement with available experimental and theoretical results.

Keywords: DFT, GGA, LDA, properties structurales, ThC, ThN

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4081 The Impact of Scaffolding on Motivation of Vocational Special Education Students in Kakamega Program for Persons with Hearing Impaired in Kenya

Authors: J. W. Mbogani, B. A. Bunyasi

Abstract:

The special skills for five students in the vocational class in Kakamega program for Hearing impaired were identified within one term period of the Kenyan education system. Three students were identified as having a liking for tailoring. The remaining two students did not show any interest in any vocational subject. The three students were attached to two professionals in practicing general tailors within the school vicinity for scaffolding purposes. The students were allowed to attend general classes under the normal curriculum and were withdrawn after eleven in the morning for tailoring classes. The students were then monitored with the guideline of a checklist. The purpose of monitoring was to establish whether the behavior of the students reflected a motivated student. It was established that two of them improved in their school attendance in terms of regularity, punctuality and responsibility accomplishment. The third student ended up attending only tailoring classes. The socialization aspect of the two students improved a lot. They also tended to identify more with the teachers than their fellow students. We recommend that learners with special needs in education should be subjected to the normal curriculum. They may benefit more and attain a skill that could help them economically. Further study should also be done to in several institutions involving learners in other classes.

Keywords: general tailoring, scaffolding, term, vocational class

Procedia PDF Downloads 139
4080 Hysteretic Behavior of the Precast Concrete Column with Head Splice Sleeve Connection

Authors: Seo Soo-Yeon, Kim Sang-Ku, Noh Sang-Hyun, Lee Ji-Eun, Kim Seol-Ki, Lim Jong-Wook

Abstract:

This paper presents a test result to find the structural capacity of Hollow-Precast Concrete (HPC) column with Head-Splice Sleeve (HSS) for the connection of bars under horizontal cyclic load. Two Half-scaled HPC column specimens were made with the consideration of construction process in site. The difference between the HPC specimens is the location of HSS for bar connection. The location of the first one is on the bottom slab or foundation while the other is above the bottom slab or foundation. Reinforced concrete (RC) column was also made for the comparison. In order to evaluate the hysteretic behavior of the specimens, horizontal cyclic load was applied to the top of specimen under constant axial load. From the test, it is confirmed that the HPC columns with HSS have enough structural capacity that can be emulated to RC column. This means that the HPC column with HSS can be used in the moment resisting frame system.

Keywords: structural capacity, hollow-precast concrete column, head-splice sleeve, horizontal cyclic load

Procedia PDF Downloads 373
4079 A Comparison between Different Segmentation Techniques Used in Medical Imaging

Authors: Ibtihal D. Mustafa, Mawia A. Hassan

Abstract:

Tumor segmentation from MRI image is important part of medical images experts. This is particularly a challenging task because of the high assorting appearance of tumor tissue among different patients. MRI images are advance of medical imaging because it is give richer information about human soft tissue. There are different segmentation techniques to detect MRI brain tumor. In this paper, different procedure segmentation methods are used to segment brain tumors and compare the result of segmentations by using correlation and structural similarity index (SSIM) to analysis and see the best technique that could be applied to MRI image.

Keywords: MRI, segmentation, correlation, structural similarity

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4078 Structural Behavior of Composite Hollow RC Column under Combined Loads

Authors: Abdul Qader Melhm, Hussein Elrafidi

Abstract:

This paper is dealing with studying the structural behavior of a steel-composite hollow reinforced concrete (RC) column model under combined eccentric loading. The composite model consists of an inner steel tube surrounded via a concrete core with longitudinal and circular transverse reinforcement. The radius of gyration according to American and Euro specifications be calculated, in order to calculate the thinnest ratio for this type of composite column model, in addition to the flexural rigidity. Formulas for interaction diagram is given for this type of model, which is a general loading conditions in which an element is exposed to an axial load with bending at the same time. The structural capacity of this model, elastic, plastic loads and strains will be computed and compared with experimental results. The total eccentric axial load of the column model is calculated based on the effective length KL available from several relationships provided in the paper. Furthermore, the inner tube experiences buckling failure after reaching its maximum strength will be investigated.

Keywords: column, composite, eccentric, inner tube, interaction, reinforcement

Procedia PDF Downloads 192
4077 Optimized Real Ground Motion Scaling for Vulnerability Assessment of Building Considering the Spectral Uncertainty and Shape

Authors: Chen Bo, Wen Zengping

Abstract:

Based on the results of previous studies, we focus on the research of real ground motion selection and scaling method for structural performance-based seismic evaluation using nonlinear dynamic analysis. The input of earthquake ground motion should be determined appropriately to make them compatible with the site-specific hazard level considered. Thus, an optimized selection and scaling method are established including the use of not only Monte Carlo simulation method to create the stochastic simulation spectrum considering the multivariate lognormal distribution of target spectrum, but also a spectral shape parameter. Its applications in structural fragility analysis are demonstrated through case studies. Compared to the previous scheme with no consideration of the uncertainty of target spectrum, the method shown here can make sure that the selected records are in good agreement with the median value, standard deviation and spectral correction of the target spectrum, and greatly reveal the uncertainty feature of site-specific hazard level. Meanwhile, it can help improve computational efficiency and matching accuracy. Given the important infection of target spectrum’s uncertainty on structural seismic fragility analysis, this work can provide the reasonable and reliable basis for structural seismic evaluation under scenario earthquake environment.

Keywords: ground motion selection, scaling method, seismic fragility analysis, spectral shape

Procedia PDF Downloads 293
4076 The Meaning of Stillness: Based on the Errand Boy Project in Tibet during the Pandemic Quarantine in Shanghai in the Mayday Holiday

Authors: Mingyuan Duan

Abstract:

Many scholars have paid attention to the relationship between mobility and stillness, but most of them focus on stillness from the perspective of serving mobility. This study believes that more attention should be paid to the importance of stillness, and we suggest reexamining the meaning of stillness in terms of the value of stillness to people. The Errand Boy Project was launched by a social innovation enterprise called Bottle Dream during the May Day holiday in 2022. It linked volunteers from all over the world online to help people who are trapped at home due to the epidemic realize their outdoor wishes: get closer to nature and relieve their anxious mood. Taking Errand Boy in Tibet as a case study, this paper analyzes the emotional expressions and comments of people with limited mobility in the face of nature in the webcast room and explains the importance of stillness to humans from a non-human perspective. This study points out that the significance of stillness to human beings during the pandemic is composed of three aspects: the sense of solidity established by a steady mobile phone network connection, the stable possibility of wish fulfillment predicted by the periodic regularity of plant growth, and the transcendent spiritual power from the stable sacred mountain.

Keywords: stillness, non-human, pandemic, mobility

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4075 Structural and Optical Properties of Pr3+ Doped ZnO and PVA:Zn98Pr2O Nanocomposites Free Standing Film

Authors: Pandiyarajan Thangaraj, Mangalaraja Ramalinga Viswanathan, Karthikeyan Balasubramanian, Héctor D. Mansilla, José Ruiz, David Contreras

Abstract:

We report a systematic study of structural and optical properties of Pr-doped ZnO nanostructures and PVA:Zn98Pr2O polymer matrix nanocomposites free standing films are performed. These particles are synthesized through simple wet chemical route and solution casting technique at room temperature, respectively. Structural studies carried out by X-ray diffraction method, confirms that the prepared pure ZnO and Pr-doped ZnO nanostructures are in hexagonal wurtzite structure and the microstrain is increased upon doping. TEM analysis reveals that the prepared materials are in the sheet-like nature. Absorption spectra show free excitonic absorption band at 370 nm and red shift for the Pr-doped ZnO nanostructures. The PVA:Zn98Pr2O composite film exhibits both free excitonic and PVA absorption bands at 282 nm. Fourier transform infrared spectral studies confirm the presence of A1 (TO) and E1 (TO) modes of Zn-O bond vibration and the formation of polymer composite materials.

Keywords: Pr doped ZnO, polymer nanocomposites, optical properties, free standing film

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4074 Structural Behavior of Non-Prismatic Mono-Symmetric Beam

Authors: Nandini B. Nagaraju, Punya D. Gowda, S. Aishwarya, Benjamin Rohit

Abstract:

This paper attempts to understand the structural behavior of non-prismatic channel beams subjected to bending through finite element (FE) analysis. The present study aims at shedding some light on how tapered channel beams behave by studying the effect of taper ratio on structural behavior. As a weight reduction is always desired in aerospace structures beams are tapered in order to obtain highest structural efficiency. FE analysis has been performed to study the effect of taper ratio on linear deflection, lateral torsional buckling, non-linear parameters, stresses and dynamic parameters. Taper ratio tends to affect the mechanics of tapered beams innocuously and adversely. Consequently, it becomes important to understand and document the mechanics of channel tapered beams. Channel beams generally have low torsional rigidity due to the off-shear loading. The effect of loading type and location of applied load have been studied for flange taper, web taper and symmetric taper for different conditions. Among these, as the taper ratio is increased, the torsional angular deflection increases but begins to decrease when the beam is web tapered and symmetrically tapered for a mid web loaded beam. But when loaded through the shear center, an increase in the torsional angular deflection can be observed with increase in taper ratio. It should be considered which parameter is tapered to obtain the highest efficiency.

Keywords: channel beams, tapered beams, lateral torsional bucking, shear centre

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4073 Designing and Formulating Action Plan for Development of Corporate Citizenship in Producing Units in Iran

Authors: Freyedon Ahmadi

Abstract:

Corporate citizenship is considered as one of the most discussed topics in the developed countries, in which a citizen considers a Corporate just like a usual citizen with every civil right as respectful for corporate as for actual citizens, and in return citizens expect that corporate would pay a reciprocal respect to them. The current study’s purpose is to identify the impact of the current state of corporate citizenship along effective factors on its condition on industrial producing units, in order to find an accession plane for corporate citizenship development. In this study corporate citizenship is studied in four dimensions like legal corporate, economical corporate, ethical corporate and voluntary corporate. Moreover, effective factors’ impact on corporate citizenship is explored based on threefold dimensional model: behavioral, structural, and content factors, as well. In this study, 50 corporate of Food industry and of petrochemical industry, along with 200 selected individuals from directors’ board on Tehran province’s scale with stratified random sampling method, are chosen as actuarial sample. If based on functional goal and compilation methods, the present study is a description of correlation type; questionnaire is used for accumulation of initial Data. For Instrument Validity expert’s opinion is used and structural equations and its reliability is qualified by using Cronbach Alpha. The results of this study indicate that close to 70 percent of under survey corporate have not a good condition in corporate citizenship. And all of structural factors, behavioral factors, contextual factors, have a great deal of impression and impact on the advent corporate citizenship behavior in the producing Units. Among the behavioral factors, social responsibility; among structural factors, organic structure and human centered orientation, medium size, high organizational capacity; and among the contextual factors, the clientele’s positive viewpoints toward corporate had the utmost importance in impression on under survey Producing units.

Keywords: corporate citizenship, structural factors, behavioral factors, contextual factors, producing units

Procedia PDF Downloads 230
4072 Detect Cable Force of Cable Stayed Bridge from Accelerometer Data of SHM as Real Time

Authors: Nguyen Lan, Le Tan Kien, Nguyen Pham Gia Bao

Abstract:

The cable-stayed bridge belongs to the combined system, in which the cables is a major strutual element. Cable-stayed bridges with large spans are often arranged with structural health monitoring systems to collect data for bridge health diagnosis. Cables tension monitoring is a structural monitoring content. It is common to measure cable tension by a direct force sensor or cable vibration accelerometer sensor, thereby inferring the indirect cable tension through the cable vibration frequency. To translate cable-stayed vibration acceleration data to real-time tension requires some necessary calculations and programming. This paper introduces the algorithm, labview program that converts cable-stayed vibration acceleration data to real-time tension. The research results are applied to the monitoring system of Tran Thi Ly cable-stayed bridge and Song Hieu cable-stayed bridge in Vietnam.

Keywords: cable-stayed bridge, cable fore, structural heath monitoring (SHM), fast fourie transformed (FFT), real time, vibrations

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4071 Prediction of Structural Response of Reinforced Concrete Buildings Using Artificial Intelligence

Authors: Juan Bojórquez, Henry E. Reyes, Edén Bojórquez, Alfredo Reyes-Salazar

Abstract:

This paper addressed the use of Artificial Intelligence to obtain the structural reliability of reinforced concrete buildings. For this purpose, artificial neuronal networks (ANN) are developed to predict seismic demand hazard curves. In order to have enough input-output data to train the ANN, a set of reinforced concrete buildings (low, mid, and high rise) are designed, then a probabilistic seismic hazard analysis is made to obtain the seismic demand hazard curves. The results are then used as input-output data to train the ANN in a feedforward backpropagation model. The predicted values of the seismic demand hazard curves found by the ANN are then compared. Finally, it is concluded that the computer time analysis is significantly lower and the predictions obtained from the ANN were accurate in comparison to the values obtained from the conventional methods.

Keywords: structural reliability, seismic design, machine learning, artificial neural network, probabilistic seismic hazard analysis, seismic demand hazard curves

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4070 Experimental Study of the Infill Masonry Walls Response Subjected to Out-Of-Plane Static Loadings

Authors: André Furtado, Hugo Rodrigues, António Arêde, Humberto Varum

Abstract:

Besides characterized as non-structural elements, infill masonry (IM) walls have an important contribute in the structural response of reinforced concrete structures as proved by the damages observed recent earthquakes. In particular, the out-of-plane (OOP) collapse has been one of the most observed failure mechanism. The aim of this research is to contribute to the increase of understanding regarding the OOP behaviour of full-scale infill panels considering different variables such as panel support width and axial load on the top of columns. For this, it was carried out in the Laboratory of Earthquake and Structural Engineering (LESE) an experimental campaign of five full-scale IM walls subjected to OOP distributed cyclic loadings. Specimens with different variables such as previous in-plane damage, support conditions, axial load on the top of the columns were studied. The results will be presented and discussed along the manuscript in terms of force-displacement hysteretic curves, cracking pattern, initial stiffness, stiffness degradation and accumulative energy dissipation.

Keywords: infill masonry walls, experimental testing, out-of-plane, full-scale

Procedia PDF Downloads 390
4069 Structural Characterization and Application of Tio2 Nano-Partical

Authors: Maru Chetan, Desai Abhilash

Abstract:

The structural characteristics & application of TiO2 powder with different phases are study by various techniques in this paper. TTIP, EG and citric acid use as Ti source and catalyst respectively synthesis for sol gel synthesis of TiO2 powder. To replace sol gel method we develop the new method of making nano particle of TiO2 powder. It is two route method one is physical and second one is chemical route. Specific aim to this process is to minimize the production cost and the large scale production of nano particle The synthesis product work characterize by EDAX, SEM, XRD tests.

Keywords: mortal and pestle, nano particle , TiO2, TTIP

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4068 A Linear Autoregressive and Non-Linear Regime Switching Approach in Identifying the Structural Breaks Caused by Anti-Speculation Measures: The Case of Hong Kong

Authors: Mengna Hu

Abstract:

This paper examines the impact of an anti-speculation tax policy on the trading activities and home price movements in the housing market in Hong Kong. The study focuses on the secondary residential property market where transactions dominate. The policy intervention substantially raised the transaction cost to speculators as well as genuine homeowners who dispose their homes within a certain period. Through the demonstration of structural breaks, our empirical results show that the rise in transaction cost effectively reduced speculative trading activities. However, it accelerated price increase in the small-sized segment by vastly demotivating existing homeowners from trading up to better homes, causing congestion in the lower-end market where the demand from first-time buyers is still strong. Apart from that, by employing regime switching approach, we further show that the unintended consequences are likely to be persistent due to this policy together with other strengthened cooling measures.

Keywords: transaction costs, housing market, structural breaks, regime switching

Procedia PDF Downloads 263
4067 A Fuzzy Structural Equation Model for Development of a Safety Performance Index Assessment Tool in Construction Sites

Authors: Murat Gunduz, Mustafa Ozdemir

Abstract:

In this research, a framework is to be proposed to model the safety performance in construction sites. Determinants of safety performance are to be defined through extensive literature review and a multidimensional safety performance model is to be developed. In this context, a questionnaire is to be administered to construction companies with sites. The collected data through questionnaires including linguistic terms are then to be defuzzified to get concrete numbers by using fuzzy set theory which provides strong and significant instruments for the measurement of ambiguities and provides the opportunity to meaningfully represent concepts expressed in the natural language. The validity of the proposed safety performance model, relationships between determinants of safety performance are to be analyzed using the structural equation modeling (SEM) which is a highly strong multi variable analysis technique that makes possible the evaluation of latent structures. After validation of the model, a safety performance index assessment tool is to be proposed by the help of software. The proposed safety performance assessment tool will be based on the empirically validated theoretical model.

Keywords: Fuzzy set theory, safety performance assessment, safety index, structural equation modeling (SEM), construction sites

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4066 Structural and Electronic Properties of the Rock-salt BaxSr1−xS Alloys

Authors: B. Bahloul, K. Babesse, A. Dkhira, Y. Bahloul, L. Amirouche

Abstract:

Structural and electronic properties of the rock-salt BaxSr1−xS are calculated using the first-principles calculations based on the density functional theory (DFT) within the generalized gradient approximation (GGA), the local density approximation (LDA) and the virtual-crystal approximation (VCA). The calculated lattice parameters at equilibrium volume for x=0 and x=1 are in good agreement with the literature data. The BaxSr1−xS alloys are found to be an indirect band gap semiconductor. Moreoever, for the composition (x) ranging between [0-1], we think that our results are well discussed and well predicted.

Keywords: semiconductor, Ab initio calculations, rocksalt, band structure, BaxSr1−xS

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4065 Application of a Model-Free Artificial Neural Networks Approach for Structural Health Monitoring of the Old Lidingö Bridge

Authors: Ana Neves, John Leander, Ignacio Gonzalez, Raid Karoumi

Abstract:

Systematic monitoring and inspection are needed to assess the present state of a structure and predict its future condition. If an irregularity is noticed, repair actions may take place and the adequate intervention will most probably reduce the future costs with maintenance, minimize downtime and increase safety by avoiding the failure of the structure as a whole or of one of its structural parts. For this to be possible decisions must be made at the right time, which implies using systems that can detect abnormalities in their early stage. In this sense, Structural Health Monitoring (SHM) is seen as an effective tool for improving the safety and reliability of infrastructures. This paper explores the decision-making problem in SHM regarding the maintenance of civil engineering structures. The aim is to assess the present condition of a bridge based exclusively on measurements using the suggested method in this paper, such that action is taken coherently with the information made available by the monitoring system. Artificial Neural Networks are trained and their ability to predict structural behavior is evaluated in the light of a case study where acceleration measurements are acquired from a bridge located in Stockholm, Sweden. This relatively old bridge is presently still in operation despite experiencing obvious problems already reported in previous inspections. The prediction errors provide a measure of the accuracy of the algorithm and are subjected to further investigation, which comprises concepts like clustering analysis and statistical hypothesis testing. These enable to interpret the obtained prediction errors, draw conclusions about the state of the structure and thus support decision making regarding its maintenance.

Keywords: artificial neural networks, clustering analysis, model-free damage detection, statistical hypothesis testing, structural health monitoring

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4064 Wave Propagation In Functionally Graded Lattice Structures Under Impact Loads

Authors: Mahmood Heshmati, Farhang Daneshmand

Abstract:

Material scientists and engineers have introduced novel materials with complex geometries due to the recent technological advances and promotion of manufacturing methods. Among them, lattice structures with graded architectures denoted by functionally graded porous materials (FGPMs) have been developed to optimize the structural response. FGPMs are achieved by tailoring the size and density of the internal pores in one or more directions that lead to the desired mechanical properties and structural responses. Also, FGPMs provide more flexible transition and the possibility of designing and fabricating structural elements with complex and variable properties. In this paper, wave propagation in lattice structures with functionally graded (FG) porosity is investigated in order to examine the ability of shock absorbing effect. The behavior of FG porous beams with different porosity distributions under impact load and the effects of porosity distribution and porosity content on the wave speed are studied. Important conclusions are made, along with a discussion of the future scope of studies on FGPMs structures.

Keywords: functionally graded, porous materials, wave propagation, impact load, finite element

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4063 Implementation of CNV-CH Algorithm Using Map-Reduce Approach

Authors: Aishik Deb, Rituparna Sinha

Abstract:

We have developed an algorithm to detect the abnormal segment/"structural variation in the genome across a number of samples. We have worked on simulated as well as real data from the BAM Files and have designed a segmentation algorithm where abnormal segments are detected. This algorithm aims to improve the accuracy and performance of the existing CNV-CH algorithm. The next-generation sequencing (NGS) approach is very fast and can generate large sequences in a reasonable time. So the huge volume of sequence information gives rise to the need for Big Data and parallel approaches of segmentation. Therefore, we have designed a map-reduce approach for the existing CNV-CH algorithm where a large amount of sequence data can be segmented and structural variations in the human genome can be detected. We have compared the efficiency of the traditional and map-reduce algorithms with respect to precision, sensitivity, and F-Score. The advantages of using our algorithm are that it is fast and has better accuracy. This algorithm can be applied to detect structural variations within a genome, which in turn can be used to detect various genetic disorders such as cancer, etc. The defects may be caused by new mutations or changes to the DNA and generally result in abnormally high or low base coverage and quantification values.

Keywords: cancer detection, convex hull segmentation, map reduce, next generation sequencing

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4062 Sustainability of Carbon Nanotube-Reinforced Concrete

Authors: Rashad Al Araj, Adil K. Tamimi

Abstract:

Concrete, despite being one of the most produced materials in the world, still has weaknesses and drawbacks. Significant concern of the cementitious materials in structural applications is their quasi-brittle behavior, which causes the material to crack and lose its durability. One of the very recently proposed mitigations for this problem is the implementation of nanotechnology in the concrete mix by adding carbon nanotubes (CNTs) to it. CNTs can enhance the critical mechanical properties of concrete as a structural material. Thus, this paper demonstrates a state-of-the-art review of reinforcing concrete with CNTs, emphasizing on the structural performance. It also goes over the properties of CNTs alone, the present methods and costs associated with producing them, the possible special applications of concretes reinforced with CNTs, the key challenges and drawbacks that this new technology still encounters, and the most reliable practices and methodologies to produce CNT-reinforced concrete in the lab. This work has shown that the addition of CNTs to the concrete mix in percentages as low as 0.25% weight of cement could increase the flexural strength and toughness of concrete by more than 45% and 25%, respectively, and enhance other durability-related properties, given that an effective dispersion of CNTs in the cementitious mix is achieved. Since nano reinforcement for cementitious materials is a new technology, many challenges have to be tackled before it becomes practiced at the mass level.

Keywords: sustainability, carbon nano tube, microsilica, concrete

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4061 Structural Analysis and Strengthening of the National Youth Foundation Building in Igoumenitsa, Greece

Authors: Chrysanthos Maraveas, Argiris Plesias, Garyfalia G. Triantafyllou, Konstantinos Petronikolos

Abstract:

The current paper presents a structural assessment and proposals for retrofit of the National Youth Foundation Building, an existing reinforced concrete (RC) building in the city of Igoumenitsa, Greece. The building is scheduled to be renovated in order to create a Municipal Cultural Center. The bearing capacity and structural integrity have been investigated in relation to the provisions and requirements of the Greek Retrofitting Code (KAN.EPE.) and European Standards (Eurocodes). The capacity of the existing concrete structure that makes up the two central buildings in the complex (buildings II and IV) has been evaluated both in its present form and after including several proposed architectural interventions. The structural system consists of spatial frames of columns and beams that have been simulated using beam elements. Some RC elements of the buildings have been strengthened in the past by means of concrete jacketing and have had cracks sealed with epoxy injections. Static-nonlinear analysis (Pushover) has been used to assess the seismic performance of the two structures with regard to performance level B1 from KAN.EPE. Retrofitting scenarios are proposed for the two buildings, including type Λ steel bracings and placement of concrete shear walls in the transverse direction in order to achieve the design-specification deformation in each applicable situation, improve the seismic performance, and reduce the number of interventions required.

Keywords: earthquake resistance, pushover analysis, reinforced concrete, retrofit, strengthening

Procedia PDF Downloads 292
4060 The Effect of Substrate Temperature on the Structural, Optical, and Electrical of Nano-Crystalline Tin Doped-Cadmium Telluride Thin Films for Photovoltaic Applications

Authors: Eman A. Alghamdi, A. M. Aldhafiri

Abstract:

It was found that the induce an isolated dopant close to the middle of the bandgap by occupying the Cd position in the CdTe lattice structure is an efficient factor in reducing the nonradiative recombination rate and increasing the solar efficiency. According to our laboratory results, this work has been carried out to obtain the effect of substrate temperature on the CdTe0.6Sn0.4 prepared by thermal evaporation technique for photovoltaic application. Various substrate temperature (25°C, 100°C, 150°C, 200°C, 250°C and 300°C) was applied. Sn-doped CdTe thin films on a glass substrate at a different substrate temperature were made using CdTe and SnTe powders by the thermal evaporation technique. The structural properties of the prepared samples were determined using Raman, x-Ray Diffraction. Spectroscopic ellipsometry and spectrophotometric measurements were conducted to extract the optical constants as a function of substrate temperature. The structural properties of the grown films show hexagonal and cubic mixed structures and phase change has been reported. Scanning electron microscopy (SEM) reviled that a homogenous with a bigger grain size was obtained at 250°C substrate temperature. The conductivity measurements were recorded as a function of substrate temperatures. The open-circuit voltage was improved by controlling the substrate temperature due to the improvement of the fundamental material issues such as recombination and low carrier concentration. All the result was explained and discussed on the biases of the influences of the Sn dopant and the substrate temperature on the structural, optical and photovoltaic characteristics.

Keywords: CdTe, conductivity, photovoltaic, ellipsometry

Procedia PDF Downloads 133
4059 Assessment of Heavy Metal Contamination in Roadside Soils along Shenyang-Dalian Highway in Liaoning Province, China

Authors: Zhang Hui, Wu Caiqiu, Yuan Xuyin, Qiu Jie, Zhang Hanpei

Abstract:

The heavy metal contaminations were determined with a detailed soil survey in roadside soils along Shenyang-Dalian Highway of Liaoning Province (China) and Pb, Cu, Cd, Ni and Zn were analyzed using the atomic absorption spectrophotometric method. The average concentration of Pb, Cu, Cd, Ni and Zn in roadside soils was determined to be 43.8, 26.5, 0.119, 32.1, 71.3 mg/kg respectively, and all of the heavy metal contents were higher than the background values. Different heavy metal distribution regularity was found in different land use type of roadside soil, there was an obvious peak of heavy concentration at 25m from road edge in the farmland, while in the forest and orchard soil, all heavy metals gradually decreased with the increase of distance from road edge and conformed to the exponential model. Furthermore, the heavy metal contents of heavy metals except Cd were markedly increased compared with those in 1999 and 2007, and the heavy metals concentrations of Shenyang- Dalian Highway were considered medium or low in comparison with those in other cities around the world. The assessment of heavy metal contamination of roadside soils illustrated a common low pollution for all heavy metal and recommended that more attention should be paid to Pb contamination in roadside soils in Shenyang-Dalian Highway.

Keywords: heavy metal contamination, roadside, highway, Nemerow Pollution Index

Procedia PDF Downloads 267