Search results for: Wind Energy Conversion Systems

Authors: Jafar Akbari, Masoud Rismanchian, Samira Ramezani

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Purpose: The photocatalytic degradation of pollutants is a novel technology with various advantages such as high efficiency and energy saving. In this research, the effects of operational variables on the photocatalytic efficiency of TiO₂ coated on nickel foam in the removal of toluene from the simulated indoor air have been investigated. Methods: TiO₂ film were prepared via the sol-gel method and coated on nickel foam. The characteristics and morphology were found using XRD, SEM, and BET technique. Then, the effects of relative humidity, UV-A intensity, the initial toluene concentration, TiO₂ loading, and the air circulation velocity on the photocatalytic degradation rate have been evaluated. Results: The optimal degradation of toluene has been achieved with loading 4.35 g TiO2 on the foam, 30% RH, 5.4 µW.cm−2 UV-A intensity, and 20 ppm initial concentration in the air circulation velocity of 0.15 fpm. Conclusion: The changes of toluene photocatalytic degradation rate have been studied at various times. Also, the kinetic behavior of toluene photocatalytic degradation has been investigated using Langmuir-Hinshelwood (L-H) model.

Keywords: photocatalytic degradation, operational variables, tio₂, nickel foam, gaseous toluene, nanotechnology

Procedia PDF Downloads 67

Authors: K. M. Seddik

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This paper explores the implementation of 5S elements in the Egyptian garment enterprises. The paper depended on a survey questionnaire (established from Summit Business Solutions, New York) and observations to collect data from the respondents. The observations are based on the on-site visits and interviews with the managers, supervisors and labors. The enterprises divided into three groups according to the nature activity. The first group of enterprises encompassed 49.52% of the total samples, the second and third group of enterprises represented 50.48% The results of this research indicated to the influence of the nature activity in implementing 5S systems and conclude that sustain is a difficult element which involve encourage workers for developing and practicing a highly discipline. In addition the results demonstrate that although the enterprises may achieve a higher executing of 5S elements but it may realize a low coherence in implementation.

Keywords: 5S elements, garment enterprises, implementation, lean manufacturing

Procedia PDF Downloads 241

Authors: Sadiq Sani, Muhammad B. Ibrahim

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Watermelon rinds powder (WRP) and neem-tree leaves powder (NLP) were used as adsorbents for equilibrium adsorption isotherms studies for detoxification of methyl orange dye (MO) from simulated wastewater. The applicability of the process to various isotherm models was tested. All isotherms from the experimental data showed excellent linear reliability (R2: 0.9487-0.9992) but adsorptions onto WRP were more reliable (R2: 0.9724-0.9992) than onto NLP (R2: 0.9487-0.9989) except for Temkin’s Isotherm where reliability was better onto NLP (R2: 0.9937) than onto WRP (R2: 0.9935). Dubinin-Radushkevich’s monolayer adsorption capacities for both WRP and NLP (qD: 20.72 mg/g, 23.09 mg/g) were better than Langmuir’s (qm: 18.62 mg/g, 21.23 mg/g) with both capacities higher for adsorption onto NLP (qD: 23.09 mg/g; qm: 21.23 mg/g) than onto WRP (qD: 20.72 mg/g; qm: 18.62 mg/g). While values for Langmuir’s separation factor (RL) for both adsorbents suggested unfavourable adsorption processes (RL: -0.0461, -0.0250), Freundlich constant (nF) indicated favourable process onto both WRP (nF: 3.78) and NLP (nF: 5.47). Adsorption onto NLP had higher Dubinin-Radushkevich’s mean free energy of adsorption (E: 0.13 kJ/mol) than WRP (E: 0.08 kJ/mol) and Temkin’s heat of adsorption (bT) was better onto NLP (bT: -0.54 kJ/mol) than onto WRP (bT: -0.95 kJ/mol) all of which suggested physical adsorption.

Keywords: adsorption isotherms, methyl orange, neem leaves, watermelon rinds

Procedia PDF Downloads 253

Authors: Mohamed Amine Ben Abdallah, Imed Khemili, Nizar Aifaoui

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This work denotes an insight into dynamic synthesis of multibody systems. A set of mechanism parameters design variable are synthetized based on a desired mechanism response, such as, velocity, acceleration and bodies deformations. Moreover, knowing the work space, for a robot, and mechanism response allow defining optimal parameters mechanism handling with the desired target response. To this end, evolutionary genetic algorithm has been deployed. A demonstrative example for imperfect mechanism has been treated, mainly, a slider crank mechanism with a flexible connecting rod. The transversal deflection of the connecting rod has been chosen as response to identify the mechanism design parameters.

Keywords: dynamic response, evolutionary genetic algorithm, flexible bodies, optimization

Procedia PDF Downloads 298

Authors: Pavol Tanuska, Pavel Vazan, Michal Kebisek, Dominika Jurovata

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The paper gives the results of the project that was oriented on the usage of knowledge discoveries from production systems for needs of the hierarchical process control. One of the main project goals was the proposal of knowledge discovery model for process control. Specifics data mining methods and techniques was used for defined problems of the process control. The gained knowledge was used on the real production system, thus, the proposed solution has been verified. The paper documents how it is possible to apply new discovery knowledge to be used in the real hierarchical process control. There are specified the opportunities for application of the proposed knowledge discovery model for hierarchical process control.

Keywords: hierarchical process control, knowledge discovery from databases, neural network, process control

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Authors: N. Yaiphaba, Elizabeth C. H.

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YPO₄ nanoparticles codoped with Eu³⁺(5 at.%) and Bi³⁺(0, 1, 3, 5, 7, 10, 12, 15, 20 at.%) have been prepared in poly acrylic acid (PAA)-H₂O medium by hydrothermal synthesis by maintaining a temperature of 180oC. The crystalline structure of as-prepared and 500oC annealed samples transforms from tetragonal (JCPDS-11-0254) to hexagonal phase (JCPDS-42-0082) with increasing concentration of Bi³⁺ ions. However, 900oC annealed samples exhibit tetragonal structure. The crystallite size of the particles varies from 19-50 nm. The luminescence intensity increases at lower concentration of Bi³⁺ ions and then decreases with increasing Bi3+ ion concentrations. The luminescence intensity further increases on annealing at 500oC and 900oC. Further, 900oC annealed samples show sharp increase in luminescence intensity. Moreover, the samples follow bi-exponential decay indicating energy transfer from donor to the activator or non-uniform distribution of ions in the samples. The samples on excitation at 318 nm exhibit near white emission while at 394 nm excitation show emission in the red region. The as-prepared samples are redispersible and have potential applications in display devices, metal ion sensing, biological labelling, etc.

Keywords: charge transfer, sensitizer, activator, annealing

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Authors: Matthew C. Best

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Linear Multi-Input Multi-Output (MIMO) dynamic models can be identified, with no a priori knowledge of model structure or order, using a new Generalised Identifying Filter (GIF). Based on an Extended Kalman Filter, the new filter identifies the model iteratively, in a continuous modal canonical form, using only input and output time histories. The filter’s self-propagating state error covariance matrix allows easy determination of convergence and conditioning, and by progressively increasing model order, the best fitting reduced-order model can be identified. The method is shown to be resistant to noise and can easily be extended to identification of smoothly nonlinear systems.

Keywords: system identification, Kalman filter, linear model, MIMO, model order reduction

Procedia PDF Downloads 579

Authors: Athar Imtiaz, Abduljalil S. Al-Mudhary, Taha Mirhashemi, Roslina Ibrahim

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Information Technology (IT) is being used by almost all organizations throughout the world. However, its success at supporting and improving business is debatable. There is always the risk of IT project failure and studies have proven that a large number of IT projects indeed do fail. There are many components that further the success of IT projects; these have been studied in previous studies. Studies have found the most necessary components for success in software development projects, executive information systems etc. In this study, previous literature that has looked into these success promoting factors have been critically reviewed and analyzed. Fifteen critical Success Factors (CSF) of IT projects were enlisted and examined. These factors can be applied to all IT projects and is not specific to a particular type of IT/IS project. A hypothesis was also generated after the evaluation of the factors.

Keywords: critical success factors, CSF, IT projects, IS projects, software development projects

Procedia PDF Downloads 379

Authors: Samira Cherid, Samir Bentata, F. Zahira Meghoufel, Sabria Terkhi, Yamina Sefir, Fatima Bendahma, Bouabdellah Bouadjemi, Ali Z. Itouni

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In this work, we examined the propagation of light in one-dimensional systems is examined by means of the random dimer model. The introduction of defect elements, randomly in the studied system, breaks down the Anderson localization and provides a set of propagating delocalized modes at the corresponding conventional dimer resonances. However, tuning suitably the defect dimer resonance on the host ones (or vice versa), the transmission magnitudes can be enhanced providing the optimized ballistic transmission regime as an average response. Hence, ballistic optical filters can be conceived at desired wavelengths.

Keywords: photonic crystals, random dimer model, ballistic resonance, localization and transmission

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Authors: Vahid Bayrami Rad

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Ever since humans developed a collective way of life to the development of urbanization, the concern of security has always been considered one of the most important challenges of life. To protect property, locks have always been a practical tool. With the advancement of technology, the form of locks has changed from mechanical to electric. One of the most widely used fields of using artificial intelligence is its application in the technology of surveillance security systems. Currently, the technologies used in smart anti-theft door handles are one of the most potential fields for using artificial intelligence. Artificial intelligence has the possibility to learn, calculate, interpret and process by analyzing data with the help of algorithms and mathematical models and make smart decisions. We will use Arduino board to process data.

Keywords: arduino board, artificial intelligence, image processing, solenoid lock

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Authors: Abbes Lounis, Kahina Louadj, Mohamed Aidene

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This paper presents an optimal control problem applied to a robot; the problem is to determine a command which makes it possible to reach a final state from a given initial state in record time. The approach followed to solve this optimization problem with constraints on the control starts by presenting the equations of motion of the dynamic system then by applying Pontryagin's maximum principle (PMP) to determine the optimal control, and Picard's successive approximation method combined with the shooting method to solve the resulting differential system.

Keywords: robotics, Pontryagin's Maximum Principle, PMP, Picard's method, shooting method, non-linear differential systems

Procedia PDF Downloads 243

Authors: Mohamed Amine Ferhat, Mohamed Nadjib Bouhatem, Farid Chemat

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One of the principal aims of sustainable and green processing development remains the dissemination and teaching of green chemistry to both developed and developing nations. This paper describes one attempt to show that “north-south” collaborations yield innovative sustainable and green technologies which give major benefits for both nations. In this paper we present early results from a solvent free microwave extraction (SFME) of essential oils using fresh orange peel, a byproduct in the production of orange juice. SFME is performed at atmospheric pressure without added any solvent or water. SFME increases essential oil yield and eliminate wastewater treatment. The procedure is appropriate for the teaching laboratory, and allows the students to learn extraction, chromatographic and spectroscopic analysis skills, and are expose to dramatic visual example of rapid, sustainable and green extraction of essential oil, and are introduced to commercially successful sustainable and green chemical processing with microwave energy.

Keywords: essential oil, extraction, green processing, microwave

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Authors: Pijitra Jomsri

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Currently, the sources of cultures and tourist attractions are presented in online documentary form only. In order to make them more virtual, the researcher then collected and presented them in the form of Virtual Temple. The prototype, which is a replica of the actual location, was developed to the website and allows people who are interested in Rattanakosin Island can see in form of Panorama Pan View. By this way, anyone can access the data and appreciate the beauty of Rattanakosin Island in the virtual model like the real place. The result from the experiment showed that the levels of the knowledge on Thai temples in Rattanakosin Island increased; moreover, the users were highly satisfied with the systems. It can be concluded that virtual temples can support to publicize Thai arts, cultures and travels, as well as it can be utilized effectively.

Keywords: virtual sight-seeing, Rattanakosin Island, Thai temples, virtual temple

Procedia PDF Downloads 322

Authors: Mohamed Noureldin, Jinkoo Kim

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In this study, a genetic algorithm was used to find out the optimum locations of the slit dampers satisfying a target displacement. A seismic retrofit scheme for a building structure was presented using steel plate slit dampers. A cyclic loading test was used to verify the energy dissipation capacity of the slit damper. The seismic retrofit of the model structure using the slit dampers was compared with the retrofit with enlarging shear walls. The capacity spectrum method was used to propose a simple damper distribution scheme proportional to the inter-story drifts. The validity of the simple story-wise damper distribution procedure was verified by comparing the results of the genetic algorithm. It was observed that the proposed simple damper distribution pattern was in a good agreement with the optimum distribution obtained from the genetic algorithm. Acknowledgment: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03032809).

Keywords: slit dampers, seismic retrofit, genetic algorithm, optimum design

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Authors: Sh. Hamada

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The current work aims to study the rainbow like-structure observed in the elastic scattering of alpha particles on both ¹²C and ¹⁶O nuclei. We reanalyzed the experimental elastic scattering angular distributions data for α+¹²C and α+¹⁶O nuclear systems at different energies using both optical model and double folding potential of different interaction models such as: CDM3Y1, DDM3Y1, CDM3Y6 and BDM3Y1. Potential created by BDM3Y1 interaction model has the shallowest depth which reflects the necessity to use higher renormalization factor (N_r). Both optical model and double folding potential of different interaction models fairly reproduce the experimental data.

Keywords: density distribution, double folding, elastic scattering, nuclear rainbow, optical model

Procedia PDF Downloads 223

Authors: Ramanpreet Kaur, Upasana Sharma

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The purpose of this paper is to address the challenges faced by MLDB system at the piston foundry plant due to interruption in supply of water. For the MLDB system to work in Model, two sub-units must be connected to the robotic main unit. The system cannot function without robotics and water supply by the fan (WSF). Insufficient water supply is the cause of system failure. The system operates at top performance using two sub-units. If one sub-unit fails, the system capacity is reduced. Priority of repair is given to the main unit i.e. Robotic and WSF. To solve the problem, semi-Markov process and regenerative point technique are used. Relevant graphs are also included to particular case.

Keywords: MLDB system, robotic, semi-Markov process, regenerative point technique

Procedia PDF Downloads 59

Authors: John N. Idenyi, Hadimundeen Abdallah, Abigeal D. Adeyemi, Jonathan C. Eya

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Gut microbiomes play a significant role in the growth, metabolism, and health of fish. However, we know very little about the interactive effects of variations in dietary composition and temperature on rainbow trout gut microbiota. Exactly 288 rainbow trout weighing 45.6g ± 0.05 (average ± SD) were fed four isocaloric, isolipidic, and isonitrogenous diets comprising 40% crude protein and 20% crude lipid and formulated as 100 % animal-based protein (AP) and a blend of 50 fish oil (FO)/50 camelina oil (CO), 100 % AP and100 % CO, 100 % plant-based protein (PP) and a blend of 50FO/50CO or 100 % PP and 100 % CO in 14 or 18°C for 150 days. Gut content was analyzed using 16S rRNA gene and shotgun sequencing. The most abundant phyla identified regardless of diet were Tenericutes, Firmicutes, Proteobacteria, Spirochaetes, Bacteroidetes, and Actinobacteria, while Aeromonadaceae and Enterobacteriaceae were dominant families in 18°C. Moreover, gut microbes were dominated by genes relating to an amino acid, carbohydrate, fat, and energy metabolisms and influenced by temperature. The shared functional profiles for all the diets suggest that plant protein sources in combination with CO could be as good as the fish meal with 50/50 FO & CO in rainbow trout farming.

Keywords: aquafeed, aquaculture, microbiome, rainbow trout

Procedia PDF Downloads 76

Authors: M. Balordi, G. Santucci de Magistris, F. Pini, P. Marcacci

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The increasing of extreme meteorological events represents the most important causes of damages and blackouts of the whole electric system. In particular, the icing on ground-wires and overheads lines, due to snowstorms or harsh winter conditions, very often gives rise to the collapse of cables and towers both in cold and warm climates. On the other hand, the high concentration of contaminants in the air, due to natural and/or antropic causes, is reflected in high levels of pollutants layered on glass and ceramic insulators, causing frequent and unpredictable flashover events. Overheads line and insulator failures lead to blackouts, dangerous and expensive maintenances and serious inefficiencies in the distribution service. Inducing superhydrophobic (SHP) properties to conductors, ground-wires and insulators, is one of the ways to face all these problems. Indeed, in some cases, the SHP surface can delay the ice nucleation time and decrease the ice nucleation temperature, preventing ice formation. Besides, thanks to the low surface energy, the adhesion force between ice and a superhydrophobic material are low and the ice can be easily detached from the surface. Moreover, it is well known that superhydrophobic surfaces can have self-cleaning properties: these hinder the deposition of pollution and decrease the probability of flashover phenomena. Here this study presents three different studies to impart superhydrophobicity to aluminum, zinc and glass specimens, which represent the main constituent materials of conductors, ground-wires and insulators, respectively. The route to impart the superhydrophobicity to the metallic surfaces can be summarized in a three-step process: 1) sandblasting treatment, 2) chemical-hydrothermal treatment and 3) coating deposition. The first step is required to create a micro-roughness. In the chemical-hydrothermal treatment a nano-scale metallic oxide (Al or Zn) is grown and, together with the sandblasting treatment, bring about a hierarchical micro-nano structure. By coating an alchilated or fluorinated siloxane coating, the surface energy decreases and gives rise to superhydrophobic surfaces. In order to functionalize the glass, different superhydrophobic powders, obtained by a sol-gel synthesis, were prepared. Further, the specimens were covered with a commercial primer and the powders were deposed on them. All the resulting metallic and glass surfaces showed a noticeable superhydrophobic behavior with a very high water contact angles (>150°) and a very low roll-off angles (<5°). The three optimized processes are fast, cheap and safe, and can be easily replicated on industrial scales. The anti-icing and self-cleaning properties of the surfaces were assessed with several indoor lab-tests that evidenced remarkable anti-icing properties and self-cleaning behavior with respect to the bare materials. Finally, to evaluate the anti-snow properties of the samples, some SHP specimens were exposed under real snow-fall events in the RSE outdoor test-facility located in Vinadio, western Alps: the coated samples delay the formation of the snow-sleeves and facilitate the detachment of the snow. The good results for both indoor and outdoor tests make these materials promising for further development in large scale applications.

Keywords: superhydrophobic coatings, anti-icing, self-cleaning, anti-snow, overheads lines

Procedia PDF Downloads 173

Authors: Junhong Feng, Wenyu Lu, Xinhong Cheng, Li Zheng, Yuehui Yu

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The effects of proton irradiation on the properties of gate oxide were evaluated by monitoring the static parameters (such as threshold voltage and on-resistance) and dynamic parameters (Miller plateau time) of 1700V SiC VDMOS before and after proton irradiation. The incident proton energy was 3MeV, and the doses were 5 × 10¹² P / cm², 1 × 10¹³ P / cm², respectively. The results show that the threshold voltage of MOS exhibits negative drift under proton irradiation, and the near-interface traps in the gate oxide layer are occupied by holes generated by the ionization effect of irradiation, thus forming more positive charges. The basis for selecting TMiller is that the change time of Vgs is the time when Vds just shows an upward trend until it rises to a stable value. The degradation of the turn-off time of the Miller platform verifies that the capacitance Cgd becomes larger, reflecting that the gate oxide layer is introduced into the trap by the displacement effect caused by proton irradiation, and the interface state deteriorates. As a more sensitive area in the irradiation process, the gate oxide layer will be optimized for its parameters (such as thickness, type, etc.) in subsequent studies.

Keywords: SiC VDMOS, proton radiation, Miller time, gate oxide

Procedia PDF Downloads 72

Authors: Zhou Xiaowen China, Zhang Sanming China

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Neighbourhood space as a very important part of city spaces, is an organic combination of material environment and spiritual achievement in people’ daily life, and has a real impact upon the sustainable development of the whole city. Looking back on the past 2014 World Architecture Festival (WAF), 4 out of 35winning buildings were neighbourhood designs, and all of them mentioned about space-sharing and sustainable development. In this paper, three award-winning cases were studied, including the world building of the year—the chapel (Vietnam, A21 studio), The Carve (Norway, A-Lab) and House for Trees (Vietnam, Vo Trong Nghia Architects). Urban context, planning, space construction and sustainable technology were discussed. Based on those, it was discovered that passive energy-saving technologies have been paid more and more attention, sharing space has been designed ingeniously, and the architectural forms of them reflect social inclusion and equity. This paper is aimed at summarizing the excellent works on the Festival and providing reference for the future design.

Keywords: neighbourhood design, 2014 World Architecture Festival (WAF), sustainable development, space-sharing

Procedia PDF Downloads 429

Authors: Khamael M. Abualnaja, Lidija Šiller, Benjamin R. Horrocks

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Alkylated silicon nanocrystals (C11-SiNCs) were prepared successfully by galvanostatic etching of p-Si(100) wafers followed by a thermal hydrosilation reaction of 1-undecene in refluxing toluene in order to extract C11-SiNCs from porous silicon. Erbium trichloride was added to alkylated SiNCs using a simple mixing chemical route. To the best of our knowledge, this is the first investigation on mixing SiNCs with erbium ions (III) by this chemical method. The chemical characterization of C11-SiNCs and their mixtures with Er3+ (Er/C11-SiNCs) were carried out using X-ray photoemission spectroscopy (XPS). The optical properties of C11-SiNCs and their mixtures with Er3+ were investigated using Raman spectroscopy and photoluminescence (PL). The erbium-mixed alkylated SiNCs shows an orange PL emission peak at around 595 nm that originates from radiative recombination of Si. Er/C11-SiNCs mixture also exhibits a weak PL emission peak at 1536 nm that originates from the intra-4f transition in erbium ions (Er3+). The PL peak of Si in Er/C11-SiNCs mixture is increased in the intensity up to three times as compared to pure C11-SiNCs. The collected data suggest that this chemical mixing route leads instead to a transfer of energy from erbium ions to alkylated SiNCs.

Keywords: photoluminescence, silicon nanocrystals, erbium, Raman spectroscopy

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Authors: Maria Lazari, Lorenzo Sanavia

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Mechanics of unsaturated soils has been an active field of research in the last decades. Efficient constitutive models that take into account the partial saturation of soil are necessary to solve a number of engineering problems e.g. instability of slopes and cuts due to heavy rainfalls. A large number of constitutive models can now be found in the literature that considers fundamental issues associated with the unsaturated soil behaviour, like the volume change and shear strength behaviour with suction or saturation changes. Partially saturated soils may either expand or collapse upon wetting depending on the stress level, and it is also possible that a soil might experience a reversal in the volumetric behaviour during wetting. Shear strength of soils also changes dramatically with changes in the degree of saturation, and a related engineering problem is slope failures caused by rainfall. There are several states of the art reviews over the last years for studying the topic, usually providing a thorough discussion of the stress state, the advantages, and disadvantages of specific constitutive models as well as the latest developments in the area of unsaturated soil modelling. However, only a few studies focused on the coupling between partial saturation states and time effects on the behaviour of geomaterials. Rate dependency is experimentally observed in the mechanical response of granular materials, and a viscoplastic constitutive model is capable of reproducing creep and relaxation processes. Therefore, in this work an elasto-viscoplastic constitutive model for unsaturated soils is proposed and validated on the basis of experimental data. The model constitutes an extension of an existing elastoplastic strain-hardening constitutive model capable of capturing the behaviour of variably saturated soils, based on energy conjugated stress variables in the framework of superposed continua. The purpose was to develop a model able to deal with possible mechanical instabilities within a consistent energy framework. The model shares the same conceptual structure of the elastoplastic laws proposed to deal with bonded geomaterials subject to weathering or diagenesis and is capable of modelling several kinds of instabilities induced by the loss of hydraulic bonding contributions. The novelty of the proposed formulation is enhanced with the incorporation of density dependent stiffness and hardening coefficients in order to allow the modeling of the pycnotropy behaviour of granular materials with a single set of material constants. The model has been implemented in the commercial FE platform PLAXIS, widely used in Europe for advanced geotechnical design. The algorithmic strategies adopted for the stress-point algorithm had to be revised to take into account the different approach adopted by PLAXIS developers in the solution of the discrete non-linear equilibrium equations. An extensive comparison between models with a series of experimental data reported by different authors is presented to validate the model and illustrate the capability of the newly developed model. After the validation, the effectiveness of the viscoplastic model is displayed by numerical simulations of a partially saturated slope failure of the laboratory scale and the effect of viscosity and degree of saturation on slope’s stability is discussed.

Keywords: PLAXIS software, slope, unsaturated soils, Viscoplasticity

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Authors: Yavuz Yardim

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FRP systems have been largely used to improve the performance of structural members, due to their high strength to weight ratio and corrosion resistance. Application of this strengthening procedure in circular columns has resulted quite beneficial in increasing their seismic and axial capacity. Whereas in the rectangular ones, strength enhancement was considerably less due to stress concentration in the corner. In this work three anchorage configurations are tested for their efficiency in increasing the uniformity of confinement pressure in the CFRP strengthened non-circular sections. There is a slight increase in the axial strength of specimens as a general trend. More specifically fan anchorage reached an increase of 17.5% compared to the unanchored specimens. The study shows that uniformity of confining pressure has increased by adding anchorage.

Keywords: rectangular columns, FRP, confinement, anchorage

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Authors: Pablo J. Valverde, Jaime E. Fernandez

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This paper shows under which conditions public corruption can emerge. The theoretical model includes variables such as the public employee wage (w), a control corruption parameter (c), and the group size of interactions (GS) between clusters of public officers and contractors. The system behavior is analyzed using phase diagrams based on combinations of such parameters (c, w, GS). Numerical simulations are implemented in order to contrast analytic results based on Nash equilibria of the theoretical model. Major findings include the functional relationship between wages and network topology, which attempts to reduce the emergence of corrupt behavior.

Keywords: public corruption, game theory, complex systems, Nash equilibrium.

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Authors: Sundus Ayyaz, Saad Rehman, Usman Qamar

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Software Architecture is the basic structure of software that states the development and advancement of a software system. Software architecture is also considered as a significant tool for the construction of high quality software systems. A clean design leads to the control, value and beauty of software resulting in its longer life while a bad design is the cause of architectural erosion where a software evolution completely fails. This paper discusses the occurrence of software architecture erosion and presents a set of methods for the detection, declaration and prevention of architecture erosion. The causes and symptoms of architecture erosion are observed with the examples of prescriptive and descriptive architectures and the practices used to stop this erosion are also discussed by considering different types of software erosion and their affects. Consequently finding and devising the most suitable approach for fighting software architecture erosion and in some way reducing its affect is evaluated and tested on different scenarios.

Keywords: software architecture, architecture erosion, prescriptive architecture, descriptive architecture

Procedia PDF Downloads 481

Authors: K. Raghuwaiya, B. Sharma, J. Vanualailai

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This paper presents a set of artificial potential field functions that improves upon; in general, the motion planning and posture control, with theoretically guaranteed point and posture stabilities, convergence and collision avoidance properties of the general 3-trailer system in a priori known environment. We basically design and inject two new concepts; ghost walls and the distance optimization technique (DOT) to strengthen point and posture stabilities, in the sense of Lyapunov, of our dynamical model. This new combination of techniques emerges as a convenient mechanism for obtaining feasible orientations at the target positions with an overall reduction in the complexity of the navigation laws. Simulations are provided to demonstrate the effectiveness of the controls laws.

Keywords: artificial potential fields, 3-trailer systems, motion planning, posture

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Authors: Zdravko Eškinja, Lovre Miljanić, Ognjen Kuljača

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This paper is an overview of simulation tools used to model specific thermal dynamics that occurs while controlling double skin façade. Research has been conducted on simplified construction with single zone where one side is glazed. Heat flow and temperature responses are simulated in three different simulation tools: IDA-ICE, EnergyPlus and HAMBASE. The excitation of observed system, used in all simulations, was a temperature step of exterior environment. Air infiltration, insulation and other disturbances are excluded from this research. Although such isolated behaviour is not possible in reality, experiments are carried out to gain novel information about heat flow transients which are not observable under regular conditions. Results revealed new possibilities for adapting the parameters of the neural network regulator. Along numerical simulations, the same set-up has been also tested in a real-time experiment with a 1:18 scaled model and thermal chamber. The comparison analysis brings out interesting conclusion about simulation accuracy in this particular case.

Keywords: double skin façade, experimental tests, heat control, heat flow, simulated tests, simulation tools

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Authors: Nayeli Camacho, Fernanda Lara-Perez, Carolina Ortega-Portilla, Diego G. Espinosa-Arbelaez, Juan M. Alvarado-Orozco, Guillermo C. Mondragon-Rodriguez

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Ultra-high molecular weight polyethylene (UHMWPE) has been the gold standard material for total knee replacements for almost five decades. Wear damage to UHMWPE articulating surface is inevitable due to the natural sliding and rolling movements of the knee. This generates a considerable amount of wear debris, which results in mechanical instability of the joint, reduces joint mobility, increases pain with detrimental biologic responses, and causes component loosening. The presence of wear particles has been closely related to adverse reactions in the knee joint surrounding tissue, especially for particles in the range of 0.3 to 2 μm. Carbon-based materials possess excellent mechanical properties and have shown great promise in tribological applications. In this study, diamond-like carbon coatings (DLC) and carbon nanotubes (CNTs) were used to decrease the wear rate of ultra-high molecular weight polyethylene. A titanium doped DLC (Ti-DLC) was deposited by magnetron sputtering on stainless steel precision spheres while CNTs were used as a second phase reinforcement in UHMWPE at a concentration of 1.25 wt.%. A comparative tribological analysis of the wear of UHMWPE and UHMWPE-CNTs with a stainless steel counterpart with and without Ti-DLC coating is presented. The experimental wear testing was performed on a pin-on-disc tribometer under dry conditions, using a reciprocating movement with a load of 1 N at a frequency of 2 Hz for 100,000 and 200,000 cycles. The wear tracks were analyzed with high-resolution scanning electron microscopy to determine wear modes and observe the size and shape of the wear debris. Furthermore, profilometry was used to study the depth of the wear tracks and to map the wear of the articulating surface. The wear tracks at 100,000 and 200,000 cycles on all samples were relatively shallow, and they were in the range of average roughness. It was observed that the Ti-DLC coating decreases the mass loss in the UHMWPE and the depth of the wear track. The combination of both carbon-based materials decreased the material loss compared to the system of stainless steel and UHMWPE. Burnishing of the surface was the predominant wear mode observed with all the systems, more subtle for the systems with Ti-DLC coatings. Meanwhile, in the system composed of stainless steel-UHMWPE, the intrinsic surface roughness of the material was completely replaced by the wear tracks.

Keywords: CNT reinforcement, self-lubricating materials, Ti-DLC, UHMWPE tribological performance

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Authors: Cui Long (Allen)

Abstract:

The role of the Arctic in world politics and international relations has increased significantly over the past decades. With its large natural resources, the Arctic region has important geopolitical, strategic, and economic significance. All this determines the interest in it not only of the Arctic states but also of states located far from the Arctic. One of these states is the People's Republic of China. Relations between China and Russia in recent decades have been built on the basis of strategic partnership. Joint projects in the Arctic have become the most important priority area of this partnership. These are projects in the transport and energy fields. A large number of works by Russian scientists are devoted to the Sino-Russian Arctic cooperation. Most authors consider cooperation as a guarantee of stability for China and Russia in a globalized world. However, there are authors who believe that there are separate contradictions in the relations between the Arctic and non-Arctic countries. In their opinion, China sometimes acts as a competitor, and its activities become expansionist. In general, according to the Russian authors, Sino-Russian cooperation is mutually beneficial and is under development. China and Russia have a long way to go in the issue of sustainable development of the Arctic.

Keywords: People’s Republic of China, Russian Federation, Arctic, historiography

Procedia PDF Downloads 52

Authors: Pooja Seth, Shruti Aggarwal

Abstract:

The Europium (Eu) doped (0.02-0.1 wt %) lithium fluoride (LiF) crystal in the form of multicrystalline sheet was gown by the edge defined film fed growth (EFG) technique. Crystals were grown in argon gas atmosphere using graphite crucible and stainless steel die. The systematic incorporation of Eu inside the host LiF lattice was confirmed by X-ray diffractometry. Thermoluminescence (TL) glow curve was recorded on annealed (AN) crystals after irradiation with a gamma dose of 15 Gy. The effect of different concentration of Eu in enhancing the thermoluminescence (TL) intensity of LiF was studied. The normalized peak height of the Eu-doped LiF crystal was nearly 12 times that of the LiF crystals. The optimized concentration of Eu in LiF was found to be 0.05wt% at which maximum TL intensity was observed with main TL peak positioned at 185 °C. At higher concentration TL intensity decreases due to the formation of precipitates in the form of clusters or aggregates. The nature of the energy traps in Eu doped LiF was analysed through glow curve deconvolution. The trap depth was found to be in the range of 0.2 – 0.5 eV. These results showed that doping with Eu enhances the TL intensity by creating more defect sites for capturing of electron and holes during irradiation which might be useful for dosimetry application.

Keywords: thermoluminescence, defects, gamma radiation, crystals

Procedia PDF Downloads 316