Search results for: rational trigonometric Bézier curves
767 Investigation of Stoneley Waves in Multilayered Plates
Authors: Bing Li, Tong Lu, Lei Qiang
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Stoneley waves are interface waves that propagate at the interface between two solid media. In this study, the dispersion characteristics and wave structures of Stoneley waves in elastic multilayered plates are displayed and investigated. With a perspective of bulk wave, a reasonable assumption of the potential function forms of the expansion wave and shear wave in nth layer medium is adopted, and the characteristic equation of Stoneley waves in a three-layered plate is given in a determinant form. The dispersion curves and wave structures are solved and presented in both numerical and simulation results. It is observed that two Stoneley wave modes exist in a three-layered plate, that conspicuous dispersion occurs on low frequency band, that the velocity of each Stoneley wave mode approaches the corresponding Stoneley wave velocity at interface between two half infinite spaces. The wave structures reveal that the in-plane displacement of Stoneley waves are relatively high at interfaces, which shows great potential for interface defects detection.Keywords: characteristic equation, interface waves, potential function, Stoneley waves, wave structure
Procedia PDF Downloads 319766 An Investigation into the Interaction of Concrete Frames and Infilled Masonry Walls with Emphasis on the Connections
Authors: Hamid Fazlollahi, Behzad Rafezy, Hassan Afshin
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There masonry infill increases the stiffness of reinforced concrete frames, thus increasing the force of the earthquake also the interaction between the frame and infill, which can have devastating effects on structures. In contrast presence of infill to increase the structural strength and stability. What is seen in the construction and design of structures has largely ignored the effects of infill and regardless infill structure and its positive and negative effects analyzes and designs, that it is not economically justified and the positive effects of positive infill to be increased and almost all of the useful capacity of moment frames used for infill. In this paper, by using ABAQUS software, reinforced concrete frame with masonry infill will be modeled, then add a mechanical rubber element to modify the interaction between the frame and infill and thus reduce the losses caused by the presence of infill explains. Finally, by comparing the analytical curves, benefits of this approach we will study and to present the results of the interaction between the frame and infill masonry needs modification and methods it will provide.Keywords: masonry infill, mechanical rubber, reinforced concrete frame, interaction, ductility
Procedia PDF Downloads 454765 Photoelectrochemical Study of Nanostructured Acropora-Like Lead Sulfide Thin Films
Authors: S. Kaci, A. Keffous, O. Fellahi, I. Bozetine, H. Menari
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In this paper, we report the fabrication and characterization of Acropora-like lead sulfide nanostructured thin films using chemical bath deposition. The method has the strong points of low temperature and no surfactant, comparing with the other method. The preferential growth directions of the broad branches were indexed as along (200) directions. The photoelectrochemical property of the as-deposited thin films was also investigated. Photoelectrochemical characterization was performed in the aim to determine the flat band potential (Vfb) and to confirm the n-type character of PbS, elucidated from the J(V) curves both in the dark and under illumination. The apparition of the photocurrent Jph started at a potential VON of −0.41 V/ECS and increased towards the anodic direction, which is typical of n-type behavior. The near infrared absorbance spectrum displayed an absorbance edge at 1959 nm, showing blue shift comparing to bulk PbS (3020 nm). These nanostructured lead sulfide thin films may have potential application as dispersed photoelectrode capable of generating H2 under visible light.Keywords: lead sulfide, nanostructures, photo-conversion, thin films
Procedia PDF Downloads 362764 S-N-Pf Relationship for Steel Fibre Reinforced Concrete Made with Cement Additives
Authors: Gurbir Kaur, Surinder Pal Singh
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The present study is a part of the research work on the effect of limestone powder (LP), silica fume (SF) and metakaolin (MK), on the flexural fatigue performance of steel fibre reinforced concrete (SFRC). Corrugated rectangular steel fibres of size 0.6x2.0x35 mm at a constant volume fraction of 1.0% have been incorporated in all mix combinations as the reinforcing material. Three mix combinations were prepared by replacing 30% of ordinary Portland cement (OPC) by weight with these cement additives in binary and ternary fashion to demonstrate their contribution. An experimental programme was conducted to obtain the fatigue lives of all mix combinations at various stress levels. The fatigue life data have been analysed as an attempt to determine the relationship between stress level ‘S’, number of cycles to failure ‘N’ and probability of failure ‘Pf’ for all mix combinations. The experimental coefficients of the fatigue equation have also been obtained from the fatigue data to represent the S-N-Pf curves analytically.Keywords: cement additives, fatigue life, probability of failure, steel fibre reinforced concrete
Procedia PDF Downloads 413763 A Critical Analysis of Cognitive Explanations of Afterlife Belief
Authors: Mahdi Biabanaki
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Religion is present in all human societies and has been for tens of thousands of years. What is noteworthy is that although religious traditions vary in different societies, there are considerable similarities in their religious beliefs. In all human cultures, for example, there is a widespread belief in the afterlife. Cognitive science of Religion (CSR), an emerging branch of cognitive science, searches for the root of these widespread similarities and the widespread prevalence of beliefs such as beliefs in the afterlife in common mental structures among humans. Accordingly, the cognitive architecture of the human mind has evolved to produce such beliefs automatically and non-reflectively. For CSR researchers, belief in the afterlife is an intuitive belief resulting from the functioning of mental tools. Our purpose in this article is to extract and evaluate the cognitive explanations presented in the CSR field for explaining beliefs in the afterlife. Our research shows that there are two basic theories in this area of CSR, namely "intuitive dualism" and "simulation constraint" theory. We show that these two theories face four major challenges and limitations in explaining belief in the afterlife: inability to provide a causal explanation, inability to explain cultural/religious differences in afterlife belief, the lack of distinction between the natural and the rational foundations of belief in the afterlife and disregarding the supernatural foundations of the afterlife belief.Keywords: afterlife, cognitive science of religion, intuitive dualism, simulation constraint
Procedia PDF Downloads 213762 Skin Care through Ayurveda
Authors: K. L. Virupaksha Gupta
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Ayurveda offers a holistic outlook regarding skin care. Most Initial step in Ayurveda is to identify the skin type and care accordingly which is highly personalized. Though dermatologically there are various skin type classifications such Baumann skin types (based on 4 parameters i) Oily Vs Dry ii) Sensitive Vs Resistant iii) Pigmented Vs Non-Pigmented iv) Wrinkled Vs Tight (Unwrinkled) etc but Skin typing in Ayurveda is mainly determined by the prakriti (constitution) of the individual as well as the status of Doshas (Humors) which are basically of 3 types – i.e Vata Pitta and Kapha,. Difference between them is mainly attributed to the qualities of each dosha (humor). All the above said skin types can be incorporated under these three types. The skin care modalities in each of the constitution vary greatly. Skin of an individual of Vata constitution would be lustreless, having rough texture and cracks due to dryness and thus should be given warm and unctuous therapies and oil massage for lubrication and natural moisturizers for hydration. Skin of an individual of Pitta constitution would look more vascular (pinkish), delicate and sensitive with a fair complexion, unctuous and tendency for wrinkles and greying of hair at an early age and hence should be given cooling and nurturing therapies and should avoid tanning treatments. Skin of an individual of kapha constitution will have oily skin, they are delicate and look beautiful and radiant and hence these individuals would require therapies to mainly combat oily skin. Hence, the skin typing and skin care in Ayurveda is highly rational and scientific.Keywords: Ayurveda, dermatology, Dosha, skin types
Procedia PDF Downloads 407761 A Dynamic Column Adsorption Study of Methyl Blue on Synthesis onto Synthesized Chitosan Immobilized Sawdust Cellulose Nanocrystals
Authors: Opeyemi A. Oyewo, Seshibe Makgato
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This paper presents the synthesis, characterization, and application of pelletized chitosan immobilized sawdust cellulose nanocrystals (PCCN) in a fixed-bed column for the continuous adsorption of methyl blue (MB) from water. The product was characterized using FT-IR, XRD, and SEM analysis. Microstructural examination revealed that the pellets are porous and spherical. XRD examination revealed phases that can be attributed to the presence of chitosan in PCCN. The effects of starting concentration, bed depth, and flow rate on synthetic water were explored. To identify MB breakthrough behaviour, performance indices such as bed volume, adsorbent exhaustion rate, and service time were investigated. Furthermore, the breakthrough data were incorporated into both the Thomas and Bohart-Adams models. The Thomas model was suitable for describing MB breakthrough curves. However, more research with diverse water matrices may be required to assess the resilience of PCCN.Keywords: adsorption, dynamic, methyl blue, pelletization
Procedia PDF Downloads 31760 Measuring Investigation and Computational Simulation of Cavitation Phenomenon Effects on the Industrial Centrifugal Pump Vibration
Authors: Mahdi Hamzehei, Homan Alimoradzadeh, Mahdi Shahriyari
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In this paper, vibration of the industrial centrifugal pumps studied by measuring analysis and computational simulation. Effects of different parameters on pump vibration were investigated. Also, simulation of cavitation in the centrifugal pump was down. First, via CF-TURBO software, the pump impeller and the fluid passing through the pump is modelled and finally, the phenomenon of cavitation in the impeller has been modelled by Ansys software. Also, the effects of changes in the amount of NPSH and bubbles generation in the pump impeller were investigated. By simulation of piping with pipe flow software, effect of fluid velocity and pressure on hydraulics and vibration were studied computationally by applying Computational Fluid Dynamic (CFD) techniques, fluent software and experimentally. Furthermore, this comparison showed that the model can predict hydraulics and vibration behaviour.Keywords: cavitation, vibration, centrifugal pumps, performance curves, NPSH
Procedia PDF Downloads 543759 [Keynote Talk]: Swiss Scientific Society for Developing Countries: A Concept of Relationship
Authors: Jawad Alzeer
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Cultural setup is varied from country to country and nation to nation, but the ability to adapt successfully to the new cultural setup may pave the way toward the development of cultural intelligence. Overcoming differences may require to build up our personality with the ability to learn, exchange thoughts, and have a constructive dream. Adaptation processes can be accelerated if we effectively utilize our cultural diversity. This can be done through a unified body or society; people with common goals can collectively work to satisfy their values. Narrowing the gap between developed and developing countries is of prime importance. Many international organizations are trying to resolve these issues by rational and peaceful means. Failing to understand the cultural differences, mentalities, strengths and weaknesses of developed and developing countries led to the collapse of many partnerships. Establishment of a neutral body influenced by developed countries intellectuality and developing countries personality may offer a better understanding and reasonable solutions, suggestions, advice that may assist in narrowing gaps and promote-strengthening relationship between developed and developing countries. The key issues, goals, and potential concepts associated with initiating Swiss scientific society for developing countries as a model to facilitate integration of highly skilled scientists are discussed.Keywords: cultural diversity, developing countries, integration, Switzerland
Procedia PDF Downloads 808758 Influence of Flexural Reinforcement on the Shear Strength of RC Beams Without Stirrups
Authors: Guray Arslan, Riza Secer Orkun Keskin
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Numerical investigations were conducted to study the influence of flexural reinforcement ratio on the diagonal cracking strength and ultimate shear strength of reinforced concrete (RC) beams without stirrups. Three-dimensional nonlinear finite element analyses (FEAs) of the beams with flexural reinforcement ratios ranging from 0.58% to 2.20% subjected to a mid-span concentrated load were carried out. It is observed that the load-deflection and load-strain curves obtained from the numerical analyses agree with those obtained from the experiments. It is concluded that flexural reinforcement ratio has a significant effect on the shear strength and deflection capacity of RC beams without stirrups. The predictions of the diagonal cracking strength and ultimate shear strength of beams obtained by using the equations defined by a number of codes and researchers are compared with each other and with the experimental values.Keywords: finite element, flexural reinforcement, reinforced concrete beam, shear strength
Procedia PDF Downloads 331757 Super Harmonic Nonlinear Lateral Vibration of an Axially Moving Beam with Rotating Prismatic Joint
Authors: M. Najafi, S. Bab, F. Rahimi Dehgolan
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The motion of an axially moving beam with rotating prismatic joint with a tip mass on the end is analyzed to investigate the nonlinear vibration and dynamic stability of the beam. The beam is moving with a harmonic axially and rotating velocity about a constant mean velocity. A time-dependent partial differential equation and boundary conditions with the aid of the Hamilton principle are derived to describe the beam lateral deflection. After the partial differential equation is discretized by the Galerkin method, the method of multiple scales is applied to obtain analytical solutions. Frequency response curves are plotted for the super harmonic resonances of the first and the second modes. The effects of non-linear term and mean velocity are investigated on the steady state response of the axially moving beam. The results are validated with numerical simulations.Keywords: super harmonic resonances, non-linear vibration, axially moving beam, Galerkin method
Procedia PDF Downloads 391756 Monomial Form Approach to Rectangular Surface Modeling
Authors: Taweechai Nuntawisuttiwong, Natasha Dejdumrong
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Geometric modeling plays an important role in the constructions and manufacturing of curve, surface and solid modeling. Their algorithms are critically important not only in the automobile, ship and aircraft manufacturing business, but are also absolutely necessary in a wide variety of modern applications, e.g., robotics, optimization, computer vision, data analytics and visualization. The calculation and display of geometric objects can be accomplished by these six techniques: Polynomial basis, Recursive, Iterative, Coefficient matrix, Polar form approach and Pyramidal algorithms. In this research, the coefficient matrix (simply called monomial form approach) will be used to model polynomial rectangular patches, i.e., Said-Ball, Wang-Ball, DP, Dejdumrong and NB1 surfaces. Some examples of the monomial forms for these surface modeling are illustrated in many aspects, e.g., construction, derivatives, model transformation, degree elevation and degress reduction.Keywords: monomial forms, rectangular surfaces, CAGD curves, monomial matrix applications
Procedia PDF Downloads 146755 Examining the Effects of Production Method on Aluminium A356 Alloy and A356-10%SiCp Composite for Hydro Turbine Bucket Application
Authors: Williams S. Ebhota, Freddie L. Inambao
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This study investigates the use of centrifugal casting method to fabricate functionally graded aluminium A356 Alloy and A356-10%SiCp composite for hydro turbine bucket application. The study includes the design and fabrication of a permanent mould. The mould was put into use and the buckets of A356 Alloy and A356-10%SiCp composite were cast, cut and machined into specimens. Some specimens were given T6 heat treatment and the specimens were prepared for different examinations accordingly. The SiCp particles were found to be more at inner periphery of the bucket. The maximum hardness of As-Cast A356 and A356-10%SiCp composite was recorded at the inner periphery to be 60 BRN and 95BRN, respectively. And these values were appreciated to 98BRN and 122BRN for A356 alloy and A356-10%SiCp composite, respectively. It was observed that the ultimate tensile stress and yield tensile stress prediction curves show the same trend.Keywords: A356 alloy, A356-10%SiCp composite, centrifugal casting, Pelton bucket, turbine blade
Procedia PDF Downloads 280754 Analysis of the Extreme Hydrometeorological Events in the Theorical Hydraulic Potential and Streamflow Forecast
Authors: Sara Patricia Ibarra-Zavaleta, Rabindranarth Romero-Lopez, Rosario Langrave, Annie Poulin, Gerald Corzo, Mathias Glaus, Ricardo Vega-Azamar, Norma Angelica Oropeza
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The progressive change in climatic conditions worldwide has increased frequency and severity of extreme hydrometeorological events (EHE). Mexico is an example; this has been affected by the presence of EHE leaving economic, social and environmental losses. The objective of this research was to apply a Canadian distributed hydrological model (DHM) to tropical conditions and to evaluate its capacity to predict flows in a basin in the central Gulf of Mexico. In addition, the DHM (once calibrated and validated) was used to calculate the theoretical hydraulic power and the performance to predict streamflow before the presence of an EHE. The results of the DHM show that the goodness of fit indicators between the observed and simulated flows in the calibration process (NSE=0.83, RSR=0.021 and BIAS=-4.3) and validation: temporal was assessed at two points: point one (NSE=0.78, RSR=0.113 and BIAS=0.054) and point two (NSE=0.825, RSR=0.103 and BIAS=0.063) are satisfactory. The DHM showed its applicability in tropical environments and its ability to characterize the rainfall-runoff relationship in the study area. This work can serve as a tool for identifying vulnerabilities before floods and for the rational and sustainable management of water resources.Keywords: HYDROTEL, hydraulic power, extreme hydrometeorological events, streamflow
Procedia PDF Downloads 341753 Design, Construction and Characterization of a 3He Proportional Counter for Detecting Thermal Neutron
Authors: M. Fares, S. Mameri, I. Abdlani, K. Negara
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Neutron detectors in general, proportional counters gas filling based isotope 3He in particular are going to be essential for monitoring and control of certain nuclear facilities, monitoring of experimentation around neutron beams and channels nuclear research reactors, radiation protection instruments and other tools multifaceted exploration and testing of materials, etc. This work consists of a measurement campaign features two Proportional Counters 3He (3He: LND252/USA CP, CP prototype: 3He LND/DDM). This is to make a comparison study of a CP 3He LND252/USA reference one hand, and in the context of routine periodic monitoring of the characteristics of the detectors for controlling the operation especially for laboratory prototypes. In this paper, we have described the different characteristics of the detectors and the experimental protocols used. Tables of measures have been developed and the different curves were plotted. The experimental campaign at stake: 2 PC 3He were thus characterized: Their characteristics (sensitivity, energy pulse height distribution spectra, gas amplification etc.) Were identified: 01 PC 3He 1'' Type: prototype DEDIN/DDM, 01 PC 3He 1'' Type: LND252/USA.Keywords: PC 3He, sensitivity, pulse height distribution spectra, gas amplification
Procedia PDF Downloads 442752 Stability Analysis of Tumor-Immune Fractional Order Model
Authors: Sadia Arshad, Yifa Tang, Dumitru Baleanu
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A fractional order mathematical model is proposed that incorporate CD8+ cells, natural killer cells, cytokines and tumor cells. The tumor cells growth in the absence of an immune response is modeled by logistic law as it was the simplest form for which predictions also agreed with the experimental data. Natural Killer Cells are our first line of defense. NK cells directly kill tumor cells through several mechanisms, including the release of cytoplasmic granules containing perforin and granzyme, expression of tumor necrosis factor (TNF) family members. The effect of the NK cells on the tumor cell population is expressed with the product term. Rational form is used to describe interaction between CD8+ cells and tumor cells. A number of cytokines are produced by NKs, including tumor necrosis factor TNF, IFN, and interleukin (IL-10). Source term for cytokines is modeled by Michaelis-Menten form to indicate the saturated effects of the immune response. Stability of the equilibrium points is discussed for biologically significant values of bifurcation parameters. We studied the treatment of fractional order system by investigating analytical conditions of tumor eradication. Numerical simulations are presented to illustrate the analytical results.Keywords: cancer model, fractional calculus, numerical simulations, stability analysis
Procedia PDF Downloads 315751 Exploring the Applications of Modular Forms in Cryptography
Authors: Berhane Tewelday Weldhiwot
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This research investigates the pivotal role of modular forms in modern cryptographic systems, particularly focusing on their applications in secure communications and data integrity. Modular forms, which are complex analytic functions with rich arithmetic properties, have gained prominence due to their connections to number theory and algebraic geometry. This study begins by outlining the fundamental concepts of modular forms and their historical development, followed by a detailed examination of their applications in cryptographic protocols such as elliptic curve cryptography and zero-knowledge proofs. By employing techniques from analytic number theory, the research delves into how modular forms can enhance the efficiency and security of cryptographic algorithms. The findings suggest that leveraging modular forms not only improves computational performance but also fortifies security measures against emerging threats in digital communication. This work aims to contribute to the ongoing discourse on integrating advanced mathematical theories into practical applications, ultimately fostering innovation in cryptographic methodologies.Keywords: modular forms, cryptography, elliptic curves, applications, mathematical theory
Procedia PDF Downloads 16750 Numerical Investigation of Two Turbulence Models for Predicting the Temperature Separation in Conical Vortex Tube
Authors: M. Guen
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A three-dimensional numerical study is used to analyze the behavior of the flow inside a vortex tube. The vortex tube or Ranque-Hilsch vortex tube is a simple device which is capable of dividing compressed air from the inlet nozzle tangentially into two flow with different temperatures warm and cold. This phenomenon is known from literature by temperature separation. The K ω-SST and K-ε turbulence models are used to predict the turbulent flow behaviour inside the tube. The vortex tube is an Exair 708 slpm (25 scfm) commercial tube. The cold and hot exits areas are 30.2 and 95 mm2 respectively. The vortex nozzle consists of 6 straight slots; the height and the width of each slot are 0.97 mm and 1.41 mm. The total area normal to the flow associated with six nozzles is therefore 8.15 mm 2. The present study focuses on a comparison between two turbulence models K ω-SST, K-ε by using a new configuration of vortex tube (Conical Vortex Tube). The performance curves of the temperature separation versus cold outlet mass fraction were calculated and compared with experimental and numerical study of other researchers.Keywords: conical vortex tube, temperature separation, cold mass fraction, turbulence
Procedia PDF Downloads 249749 Analysis of Q-Learning on Artificial Neural Networks for Robot Control Using Live Video Feed
Authors: Nihal Murali, Kunal Gupta, Surekha Bhanot
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Training of artificial neural networks (ANNs) using reinforcement learning (RL) techniques is being widely discussed in the robot learning literature. The high model complexity of ANNs along with the model-free nature of RL algorithms provides a desirable combination for many robotics applications. There is a huge need for algorithms that generalize using raw sensory inputs, such as vision, without any hand-engineered features or domain heuristics. In this paper, the standard control problem of line following robot was used as a test-bed, and an ANN controller for the robot was trained on images from a live video feed using Q-learning. A virtual agent was first trained in simulation environment and then deployed onto a robot’s hardware. The robot successfully learns to traverse a wide range of curves and displays excellent generalization ability. Qualitative analysis of the evolution of policies, performance and weights of the network provide insights into the nature and convergence of the learning algorithm.Keywords: artificial neural networks, q-learning, reinforcement learning, robot learning
Procedia PDF Downloads 372748 Textile Firms Response to the Restriction of Nonylphenol and Its Ethoxylates: Looking from the Perspectives of Attitude and the Perceptions of Technical and Organizational Adaptabilities, Risks, Benefits, and Barriers
Authors: Hien T. T. Ho, Tsunemi Watanabe
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The regulatory and market pressures on the restriction of nonylphenol and its ethoxylates in textile articles have confronted the textile manufacturers, particularly those in developing countries. This study aimed to examine the tentative behavior of the textile manufacturers in Vietnam from the perspectives of attitude and the perceptions of technical and organizational adaptabilities, risks, benefits, and barriers. Personal interviews were conducted with five technical specialists from four textile firms and one chemical supplier. The environmental regulatory and market situations regarding the chemical use in Vietnam were also described. The findings revealed two main opposing trends of chemical substitution depending on the market orientation of firms that governed the patterns of risk and benefit perception. The indirect influence of perceived adaptabilities on firm tentative behavior through perceived risks was elucidated, which initiated a conceptual model of firm’s behavior combining the organizational-based and the rational-based relationships. The intermediary role of non-governmental textile and garment industrial/ trade associations is highlighted to strengthen private firm’s informative capacity.Keywords: firm behavior, institutional analysis, organizational adaptation, technical adaptation
Procedia PDF Downloads 164747 Analysis of Lightweight Register Hardware Threat
Authors: Yang Luo, Beibei Wang
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In this paper, we present a design methodology of lightweight register transfer level (RTL) hardware threat implemented based on a MAX II FPGA platform. The dynamic power consumed by the toggling of the various bit of registers as well as the dynamic power consumed per unit of logic circuits were analyzed. The hardware threat was designed taking advantage of the differences in dynamic power consumed per unit of logic circuits to hide the transfer information. The experiment result shows that the register hardware threat was successfully implemented by using different dynamic power consumed per unit of logic circuits to hide the key information of DES encryption module. It needs more than 100000 sample curves to reduce the background noise by comparing the sample space when it completely meets the time alignment requirement. In additional, an external trigger signal is playing a very important role to detect the hardware threat in this experiment.Keywords: side-channel analysis, hardware Trojan, register transfer level, dynamic power
Procedia PDF Downloads 279746 Application of a Hybrid Modified Blade Element Momentum Theory/Computational Fluid Dynamics Approach for Wine Turbine Aerodynamic Performances Prediction
Authors: Samah Laalej, Abdelfattah Bouatem
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In the field of wind turbine blades, it is complicated to evaluate the aerodynamic performances through experimental measurements as it requires a lot of computing time and resources. Therefore, in this paper, a hybrid BEM-CFD numerical technique is developed to predict power and aerodynamic forces acting on the blades. Computational fluid dynamics (CFD) simulation was conducted to calculate the drag and lift forces through Ansys software using the K-w model. Then an enhanced BEM code was created to predict the power outputs generated by the wind turbine using the aerodynamic properties extracted from the CFD approach. The numerical approach was compared and validated with experimental data. The power curves calculated from this hybrid method were in good agreement with experimental measurements for all velocity ranges.Keywords: blade element momentum, aerodynamic forces, wind turbine blades, computational fluid dynamics approach
Procedia PDF Downloads 64745 Wind Turbine Powered Car Uses 3 Single Big C-Section Blades
Authors: K. Youssef, Ç. Hüseyin
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The blades of a wind turbine have the most important job of any wind turbine component; they must capture the wind and convert it into usable mechanical energy. The objective of this work is to determine the mechanical power of single big C-section of vertical wind turbine for wind car in a two-dimensional model. The wind car has a vertical axis with 3 single big C-section blades mounted at an angle of 120°. Moreover, the three single big C-section blades are directly connected to wheels by using various kinds of links. Gears are used to convert the wind energy to mechanical energy to overcome the load exercised on the main shaft under low speed. This work allowed a comparison of drag characteristics and the mechanical power between the single big C-section blades with the previous work on 3 C-section and 3 double C-section blades for wind car. As a result obtained from the flow chart the torque and power curves of each case study are illustrated and compared with each other. In particular, drag force and torque acting on each types of blade was taken at an airflow speed of 4 m/s, and an angular velocity of 13.056 rad/s.Keywords: blade, vertical wind turbine, drag characteristics, mechanical power
Procedia PDF Downloads 520744 The Role of Trust in International Relations– Examining India’s Gujaral Doctrine and South Asian Politics
Authors: Bhavana Mahajan
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International Relations is a discipline of paradoxes. The State is the dominant political institution, yet little attention has been accorded to why individual countries behave the way they do with the theoretical analysis dismissing the State as a reactionary monolith – thus States either play to “quest for power” or to “systemic” forces. However, States do behave as and are influenced by agents when interacting with international structures as well as with other states. While questions on “competitive power politics” and “trust” have been examined and developed to a fair extent by International Relations theorists in the post 1990s period, their application to the domain of South Asian politics is limited and little research, if any, examines the conduct of foreign policy beyond rational choice. This paper is an initial attempt to marry these theoretical insights with the foreign policy exercised by India especially the case of the “Gujral Doctrine, as one of “non-reciprocal accommodation”. Ignoring the view that such a policy move can be viewed as political “feinting” or deception, it is noteworthy that India even made the first move in terms of defining its role as one who “trusts” rather than one who “seeks” to trust, given the country’s geo-strategic context and threat perceptions.Keywords: India’s foreign policy, South Asia, social constructivism, English school, trusting relationships, Gujral Doctrine, rationality
Procedia PDF Downloads 341743 6,402: On the Aesthetic Experience of Facticity
Authors: Nicolás Rudas
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Sociologists have brought to light the fascination of contemporary societies with numbers but fall short of explaining it. In their accounts, people generally misunderstand the technical intricacies of statistical knowledge and therefore accept numbers as unassailable “facts”. It is due to such pervasive fascination, furthermore, that both old and new forms of social control find fertile ground. By focusing on the process whereby the fetishization of numbers reaches its zenith, i.e., when specific statistics become emblematic of an entire society, it is asserted that numbers primarily function as moral symbols with immense potential for galvanizing collective action. Their “facticity” is not solely a cognitive problem but one that is deeply rooted in myth and connected with social experiences of epiphany and ritual. Evidence from Colombia is used to illustrate how certain quantifications become canonical. In 2021, Colombia’s Peace Court revealed that the national army had executed 6,402 innocent civilians to later report them as members of illegal armed groups. Rapidly, “6,402” transformed into a prominent item in the country’s political landscape. This article reconstructs such a process by following the first six months of the figure’s circulation, both in traditional and social media. In doing so, it is developed a new cultural-sociological conceptualization of numbers as “fact-icons” that departs from traditional understandings of statistics as “technical” objects. Numbers are icons whose appropriation is less rational than aesthetic.Keywords: culture, statistics, collective memory, social movements
Procedia PDF Downloads 71742 Numerical Implementation and Testing of Fractioning Estimator Method for the Box-Counting Dimension of Fractal Objects
Authors: Abraham Terán Salcedo, Didier Samayoa Ochoa
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This work presents a numerical implementation of a method for estimating the box-counting dimension of self-avoiding curves on a planar space, fractal objects captured on digital images; this method is named fractioning estimator. Classical methods of digital image processing, such as noise filtering, contrast manipulation, and thresholding, among others, are used in order to obtain binary images that are suitable for performing the necessary computations of the fractioning estimator. A user interface is developed for performing the image processing operations and testing the fractioning estimator on different captured images of real-life fractal objects. To analyze the results, the estimations obtained through the fractioning estimator are compared to the results obtained through other methods that are already implemented on different available software for computing and estimating the box-counting dimension.Keywords: box-counting, digital image processing, fractal dimension, numerical method
Procedia PDF Downloads 83741 Analysis of Rainfall Hazard in North East of Algeria
Authors: Imene Skhakhfa, Lahbaci Ouerdachi
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The design of sewerage systems is directly related to rainfall, which has a highly random character. Showers are usually described by three characteristics: intensity, volume and duration. Several studies considered only in two of the three models. The objective of our work is to perform an analysis of the impact of three variables on put in charge of sewerage system, responsible for misbehavior, origin of urban flooding. 30 events were considered events for the longest, most rushed and most intense period which runs from 1986 -2001. We built the IDF curves and heavy projects double symmetrical triangles associated with this selection. A simulation of the operation, with the model canoe, sewage from the city of Annaba (Algeria) in the three rain solicitation project, double triangles associated with events considered. It appears that the sewage of the city of Annaba, in terms of charging, is much more sensitive to rain most precipitous, and the more intense causing loadings and last the longest. Further analysis of all the rain and the field measurements are underway to confirm the test simulations.Keywords: intensity, volume, duration, sewerage, design, simulation
Procedia PDF Downloads 445740 Governance of the Waters in the Upper Iguazu Watershed: Case Study in Passaúna and Miringuava Watersheds
Authors: Matheus Fonseca Durães, Bruno da Silva Pereira, Bruna Stewart
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The concept of Brazil’s water governance has been the topic of discussion and has undergone legal and organizational improvements due to the need to promote a more effective and sustainable relationship with natural resources and stemming from conflicts related to shortcomings in decision-making. The Waters Act has enabled Brazil to create interesting mechanisms for integrated management, but, on the other hand, it has created a challenge that involves the implementation of the principles established in this legal framework. This study aims to evaluate some challenges and opportunities for water governance in two watersheds based on data collection and analysis of concessions, the water use register, and flow data. The elements presented demonstrated, via an analysis of legally instituted criteria, that the level of commitment of water resources is high, especially to public supply, and the adoption of the reference flow constituted one of the main barriers to implementing an efficient system, demonstrating the need for a regulatory policy that considers the hydrological behavior of the watersheds. Finally, the current water management model presents challenges to be addressed to achieve the objectives proposed by the water policy, such as ensuring sustainable, rational, and integrated use of water resources.Keywords: management, hydrology, public policies, Brazil
Procedia PDF Downloads 95739 Numerical Investigation on Design Method of Timber Structures Exposed to Parametric Fire
Authors: Robert Pečenko, Karin Tomažič, Igor Planinc, Sabina Huč, Tomaž Hozjan
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Timber is favourable structural material due to high strength to weight ratio, recycling possibilities, and green credentials. Despite being flammable material, it has relatively high fire resistance. Everyday engineering practice around the word is based on an outdated design of timber structures considering standard fire exposure, while modern principles of performance-based design enable use of advanced non-standard fire curves. In Europe, standard for fire design of timber structures EN 1995-1-2 (Eurocode 5) gives two methods, reduced material properties method and reduced cross-section method. In the latter, fire resistance of structural elements depends on the effective cross-section that is a residual cross-section of uncharred timber reduced additionally by so called zero strength layer. In case of standard fire exposure, Eurocode 5 gives a fixed value of zero strength layer, i.e. 7 mm, while for non-standard parametric fires no additional comments or recommendations for zero strength layer are given. Thus designers often implement adopted 7 mm rule also for parametric fire exposure. Since the latest scientific evidence suggests that proposed value of zero strength layer can be on unsafe side for standard fire exposure, its use in the case of a parametric fire is also highly questionable and more numerical and experimental research in this field is needed. Therefore, the purpose of the presented study is to use advanced calculation methods to investigate the thickness of zero strength layer and parametric charring rates used in effective cross-section method in case of parametric fire. Parametric studies are carried out on a simple solid timber beam that is exposed to a larger number of parametric fire curves Zero strength layer and charring rates are determined based on the numerical simulations which are performed by the recently developed advanced two step computational model. The first step comprises of hygro-thermal model which predicts the temperature, moisture and char depth development and takes into account different initial moisture states of timber. In the second step, the response of timber beam simultaneously exposed to mechanical and fire load is determined. The mechanical model is based on the Reissner’s kinematically exact beam model and accounts for the membrane, shear and flexural deformations of the beam. Further on, material non-linear and temperature dependent behaviour is considered. In the two step model, the char front temperature is, according to Eurocode 5, assumed to have a fixed temperature of around 300°C. Based on performed study and observations, improved levels of charring rates and new thickness of zero strength layer in case of parametric fires are determined. Thus, the reduced cross section method is substantially improved to offer practical recommendations for designing fire resistance of timber structures. Furthermore, correlations between zero strength layer thickness and key input parameters of the parametric fire curve (for instance, opening factor, fire load, etc.) are given, representing a guideline for a more detailed numerical and also experimental research in the future.Keywords: advanced numerical modelling, parametric fire exposure, timber structures, zero strength layer
Procedia PDF Downloads 168738 Prediction of Permeability of Frozen Unsaturated Soil Using Van Genuchten Model and Fredlund-Xing Model in Soil Vision
Authors: Bhavita S. Dave, Jaimin Vaidya, Chandresh H. Solanki, Atul K.
Abstract:
To measure the permeability of a soil specimen, one of the basic assumptions of Darcy's law is that the soil sample should be saturated. Unlike saturated soils, the permeability of unsaturated soils cannot be found using conventional methods as it does not follow Darcy's law. Many empirical models, such as the Van Genuchten Model and Fredlund-Xing Model were suggested to predict permeability value for unsaturated soil. Such models use data from the soil-freezing characteristic curve to find fitting parameters for frozen unsaturated soils. In this study, soil specimens were subjected to 0, 1, 3, and 5 freezing-thawing (F-T) cycles for different degrees of saturation to have a wide range of suction, and its soil freezing characteristic curves were formulated for all F-T cycles. Changes in fitting parameters and relative permeability with subsequent F-T cycles are presented in this paper for both models.Keywords: frozen unsaturated soil, Fredlund Xing model, soil-freezing characteristic curve, Van Genuchten model
Procedia PDF Downloads 189