Search results for: Space velocity.
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2194

Search results for: Space velocity.

2044 UB-Tree Indexing for Semantic Query Optimization of Range Queries

Authors: S. Housseno, A. Simonet, M. Simonet

Abstract:

Semantic query optimization consists in restricting the search space in order to reduce the set of objects of interest for a query. This paper presents an indexing method based on UB-trees and a static analysis of the constraints associated to the views of the database and to any constraint expressed on attributes. The result of the static analysis is a partitioning of the object space into disjoint blocks. Through Space Filling Curve (SFC) techniques, each fragment (block) of the partition is assigned a unique identifier, enabling the efficient indexing of fragments by UB-trees. The search space corresponding to a range query is restricted to a subset of the blocks of the partition. This approach has been developed in the context of a KB-DBMS but it can be applied to any relational system.

Keywords: Index, Range query, UB-tree, Space Filling Curve, Query optimization, Views, Database, Integrity Constraint, Classification.

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2043 A Preliminary Study of the Reconstruction of Urban Residential Public Space in the Context of the “Top-down” Construction Model in China: Based on Research of TianZiFang District in Shanghai and Residential Space in Hangzhou

Authors: Wang Qiaowei, Gao Yujiang

Abstract:

With the economic growth and rapid urbanization after the reform and openness, some of China's fast-growing cities have demolished former dwellings and built modern residential quarters. The blind, incomplete reference to western modern cities and the one-off construction lacking feedback mechanism have intensified such phenomenon, causing the citizen gradually expanded their living scale with the popularization of car traffic, and the peer-to-peer lifestyle gradually settled. The construction of large-scale commercial centers has caused obstacles to small business around the residential areas, leading to space for residents' interaction has been compressed. At the same time, the advocated Central Business District (CBD) model even leads to the unsatisfactory reconstruction of many historical blocks such as the Hangzhou Southern Song Dynasty Imperial Street. However, the popularity of historical spaces such as Wuzhen and Hongcun also indicates the collective memory and needs of the street space for Chinese residents. The evolution of Shanghai TianZiFang also proves the importance of the motivation of space participants in space construction in the context of the “top-down” construction model in China. In fact, there are frequent occurrences of “reconstruction”, which may redefine the space, in various residential areas. If these activities can be selectively controlled and encouraged, it will be beneficial to activate the public space as well as the residents’ intercourse, so that the traditional Chinese street space can be reconstructed in the context of modern cities.

Keywords: Rapid urbanization, traditional street space, space re-construction, bottom-up design.

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2042 A New Velocity Expression for Open Channel and its Application to Lyari River

Authors: Rana Khalid Naeem, Asif Mansoor

Abstract:

In this communication an expression for mean velocity of waste flow via an open channel is proposed which is an improvement over Manning formula. The discharges, storages and depths are computed at all locations of the Lyari river by utilizing proposed expression. The results attained through proposed expression are in good agreement with the observed data and better than those acquired using Manning formula.

Keywords: Comparison, Depth, Flow, Open Channel, Proposed Model, Storage

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2041 Kinetic Theory Based CFD Modeling of Particulate Flows in Horizontal Pipes

Authors: Pandaba Patro, Brundaban Patro

Abstract:

The numerical simulation of fully developed gas–solid flow in a horizontal pipe is done using the eulerian-eulerian approach, also known as two fluids modeling as both phases are treated as continuum and inter-penetrating continua. The solid phase stresses are modeled using kinetic theory of granular flow (KTGF). The computed results for velocity profiles and pressure drop are compared with the experimental data. We observe that the convection and diffusion terms in the granular temperature cannot be neglected in gas solid flow simulation along a horizontal pipe. The particle-wall collision and lift also play important role in eulerian modeling. We also investigated the effect of flow parameters like gas velocity, particle properties and particle loading on pressure drop prediction in different pipe diameters. Pressure drop increases with gas velocity and particle loading. The gas velocity has the same effect ((proportional toU2 ) as single phase flow on pressure drop prediction. With respect to particle diameter, pressure drop first increases, reaches a peak and then decreases. The peak is a strong function of pipe bore.

Keywords: CFD, Eulerian modeling, gas solid flow, KTGF.

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2040 Mathematical Modeling of an Avalanche Release and Estimation of Flow Parameters by Numerical Method

Authors: Mahmoud Zarrini

Abstract:

Avalanche release of snow has been modeled in the present studies. Snow is assumed to be represented by semi-solid and the governing equations have been studied from the concept of continuum approach. The dynamical equations have been solved for two different zones [starting zone and track zone] by using appropriate initial and boundary conditions. Effect of density (ρ), Eddy viscosity (η), Slope angle (θ), Slab depth (R) on the flow parameters have been observed in the present studies. Numerical methods have been employed for computing the non linear differential equations. One of the most interesting and fundamental innovation in the present studies is getting initial condition for the computation of velocity by numerical approach. This information of the velocity has obtained through the concept of fracture mechanics applicable to snow. The results on the flow parameters have found to be in qualitative agreement with the published results.

Keywords: Snow avalanche, fracture mechanics, avalanche velocity, avalanche zones.

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2039 The Relations between Seismic Results and Groundwater near the Gokpinar Damp Area, Denizli, Turkey

Authors: Mahmud Gungor, Ali Aydin, Erdal Akyol, Suat Tasdelen

Abstract:

The understanding of geotechnical characteristics of near-surface material and the effects of the groundwater is very important problem in such as site studies. For showing the relations between seismic data and groundwater, we selected about 25 km2 as the study area. It has been presented which is a detailed work of seismic data and groundwater depths of Gokpinar Damp area. Seismic waves velocity (Vp and Vs) are very important parameters showing the soil properties. The seismic records were used the method of the multichannel analysis of surface waves near area of Gokpinar Damp area. Sixty sites in this area have been investigated with survey lines about 60 m in length. MASW (Multichannel analysis of surface wave) method has been used to generate onedimensional shear wave velocity profile at locations. These shear wave velocities are used to estimate equivalent shear wave velocity in the study area at every 2 and 5 m intervals up to a depth of 45 m. Levels of equivalent shear wave velocity of soil are used the classified of the study area. After the results of the study, it must be considered as components of urban planning and building design of Gokpinar Damp area, Denizli and the application and use of these results should be required and enforced by municipal authorities.

Keywords: Seismic data, Gokpinar Damp, urban planning, Denizli.

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2038 “Context” Thinking of Contemporary Urban History Space under the Basis of Enlightenment of Chinese Traditional Cultural Philology - Taking West Expansion Plan of Tianyi Pavilion as an Example

Authors: Wei Yan, Wei Dong

Abstract:

Facing the understanding problem of update and preservation of urban history space under background of rapid Chinese urbanization, so at first there is a need to dig the philosophic principles of “antithesis” and “unification” which are contained in the traditional Chinese literature known as “antithesis” and do the job of planning translation by personal understanding in order to form understanding and value systems of dialectical urban history space under the foundation of “antithesis”. Then we could put forward a “context” concept for urban history space under the foregoing basis. After that, we will take the update and preservation of Ningbo Tianyi Pavilion’s historical district as an example to discuss problems related to understanding of urban history area under the basis of Chinese tradition culture, improvement of value system, construction of urban trait space and Chinese “localization” of planning theory.

Keywords: Antithesis, traditional values, City renewal and conservation, the “context” of city history space.

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2037 Modeling Residential Space Heating Energy for Romania

Authors: Ion Smeureanu, Adriana Reveiu, Marian Dardala, Titus Felix Furtuna, Roman Kanala

Abstract:

This paper proposes a linear model for optimizing domestic energy consumption in Romania. The particularity of the model is that it is putting in competition both tangible technologies and thermal insulation projects with different financing modes. The model is optimizing the energy system by minimizing the global discounted cost in household sector, by integrating residential lighting, space heating, hot water, combined space heating – hot water, as well as space cooling, in a monolithic model. Another demand sector included is the passenger transport. This paper focuses on space heating part, analyzing technical and economic issues related to investment decisions to envelope and insulate buildings, in order to minimize energy consumption.

Keywords: Consumer behavior, energy modelling, Open Source Energy Modeling System (OSeMOSYS), MARKAL/TIMES Romanian energy model.

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2036 Residual Stress in Ground WC-Co Coatings

Authors: M. Jalali Azizpour, H. Mohammadi Majd

Abstract:

High velocity oxygen fuel (HVOF) spray technique is one of the leading technologies that have been proposed as an alternative to the replacement of electrolytic hard chromium plating in a number of engineering applications. In this study, WC-Co powder was coated on AISI1045 steel using high velocity oxy fuel (HVOF) method. The sin2ψ method was used to evaluate the through thickness residual stress by means of XRD after mechanical layer removal process (only grinding). The average of through thickness residual stress using X-Ray diffraction was -400 MPa.

Keywords: Grinding, HVOF, Thermal spray, WC-Co.

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2035 Einstein’s General Equation of the Gravitational Field

Authors: A. Benzian

Abstract:

The generalization of relativistic theory of gravity based essentially on the principle of equivalence stipulates that for all bodies, the grave mass is equal to the inert mass which leads us to believe that gravitation is not a property of the bodies themselves, but of space, and the conclusion that the gravitational field must curved space-time what allows the abandonment of Minkowski space (because Minkowski space-time being nonetheless null curvature) to adopt Riemannian geometry as a mathematical framework in order to determine the curvature. Therefore the work presented in this paper begins with the evolution of the concept of gravity then tensor field which manifests by Riemannian geometry to formulate the general equation of the gravitational field.

Keywords: Inertia, principle of equivalence, tensors, Riemannian geometry.

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2034 Steering Velocity Bounded Mobile Robots in Environments with Partially Known Obstacles

Authors: Reza Hossseynie, Amir Jafari

Abstract:

This paper presents a method for steering velocity bounded mobile robots in environments with partially known stationary obstacles. The exact location of obstacles is unknown and only a probability distribution associated with the location of the obstacles is known. Kinematic model of a 2-wheeled differential drive robot is used as the model of mobile robot. The presented control strategy uses the Artificial Potential Field (APF) method for devising a desired direction of movement for the robot at each instant of time while the Constrained Directions Control (CDC) uses the generated direction to produce the control signals required for steering the robot. The location of each obstacle is considered to be the mean value of the 2D probability distribution and similarly, the magnitude of the electric charge in the APF is set as the trace of covariance matrix of the location probability distribution. The method not only captures the challenges of planning the path (i.e. probabilistic nature of the location of unknown obstacles), but it also addresses the output saturation which is considered to be an important issue from the control perspective. Moreover, velocity of the robot can be controlled during the steering. For example, the velocity of robot can be reduced in close vicinity of obstacles and target to ensure safety. Finally, the control strategy is simulated for different scenarios to show how the method can be put into practice.

Keywords: Steering, obstacle avoidance, mobile robots, constrained directions control, artificial potential field.

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2033 The Effect Particle Velocity on the Thickness of Thermally Sprayed Coatings

Authors: M. Jalali Azizpour, H. Mohammadi Majd

Abstract:

In this paper, the effect of WC-12Co particle velocity in HVOF thermal spraying process on the coating thickness has been studied. The statistical results show that the spray distance and oxygen-to-fuel ratio are more effective factors on particle characterization and thickness of HVOF thermal spraying coatings. Spray Watch diagnostic system, scanning electron microscopy (SEM), X-ray diffraction and thickness measuring system were used for this purpose.

Keywords: Grinding, HVOF, Thermal spray, WC-Co.

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2032 Understanding Charge Dynamics in Elastomers Adopting Pulsed Electro Acoustic (PEA) Technique

Authors: R. Sarathi, M. G. Danikas, Y. Chen, T. Tanaka

Abstract:

In the present work, Pulsed Electro Acoustic (PEA) technique was adopted to understand the space charge dynamics in elastomeric material. It is observed that the polarity of the applied DC voltage voltage and its magnitude alters the space charge dynamics in insulation structure. It is also noticed that any addition of compound to the base material/processing technique have characteristic variation in the space charge injection process. It could be concluded based on the present work that the plasticizer could inject heterocharges into the insulation medium. Also it is realized that space charge magnitude is less with the addition of plasticizer. In the PEA studies, it is observed that local electric field in the insulating material can be much more than applied electric field due to space charge formation. One of the important conclusions arrived at based on PEA technique is that one could understand the safe operating electric field of an insulation material and the charge trap sites.

Keywords: Pulsed electro acoustic technique, space charge, DCvoltage, elastomers, Electric field, high voltage.

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2031 On the Dynamic Behaviour of a Four-Bar Linkage Driven by a Velocity Controlled DC Motor

Authors: Giovanni Incerti

Abstract:

The dynamic behaviour of a four-bar linkage driven by a velocity controlled DC motor is discussed in the paper. In particular the author presents the results obtained by means of a specifically developed software, which implements the mathematical models of all components of the system (linkage, transmission, electric motor, control devices). The use of this software enables a more efficient design approach, since it allows the designer to check, in a simple and immediate way, the dynamic behaviour of the mechanism, arising from different values of the system parameters.

Keywords: Four-bar linkage, Speed control, Dynamic analysis.

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2030 Soliton Interaction in Birefringent Fibers with Third-Order Dispersion

Authors: Dowluru Ravi Kumar, Bhima Prabhakara Rao

Abstract:

Propagation of solitons in single-mode birefringent fibers is considered under the presence of third-order dispersion (TOD). The behavior of two neighboring solitons and their interaction is investigated under the presence of third-order dispersion with different group velocity dispersion (GVD) parameters. It is found that third-order dispersion makes the resultant soliton to deviate from its ideal position and increases the interaction between adjacent soliton pulses. It is also observed that this deviation due to third-order dispersion is considerably small when the optical pulse propagates at wavelengths relatively far from the zerodispersion. Modified coupled nonlinear Schrödinger-s equations (CNLSE) representing the propagation of optical pulse in single mode fiber with TOD are solved using split-step Fourier algorithm. The results presented in this paper reveal that the third-order dispersion can substantially increase the interaction between the solitons, but large group velocity dispersion reduces the interaction between neighboring solitons.

Keywords: Birefringence, Group velocity dispersion, Polarization mode dispersion, Soliton interaction, Third order dispersion.

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2029 Positive Solutions for Three-Point Boundary Value Problems of Third-Order Nonlinear Singular Differential Equations in Banach Space

Authors: Li Xiguang

Abstract:

In this paper, by constructing a special set and utilizing fixed point index theory, we study the existence of solution for singular differential equation in Banach space, which improved and generalize the result of related paper.

Keywords: Banach space, cone, fixed point index, singular differential equation.

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2028 Super Harmonic Nonlinear Lateral Vibration of an Axially Moving Beam with Rotating Prismatic Joint

Authors: M. Najafi, S. Bab, F. Rahimi Dehgolan

Abstract:

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: Axially moving beam, Galerkin method, non-linear vibration, super harmonic resonances.

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2027 Free Convection in an Infinite Porous Dusty Medium Induced by Pulsating Point Heat Source

Authors: K. Kannan, V. Venkataraman

Abstract:

Free convection effects and heat transfer due to a pulsating point heat source embedded in an infinite, fluid saturated, porous dusty medium are studied analytically. Both velocity and temperature fields are discussed in the form of series expansions in the Rayleigh number, for both the fluid and particle phases based on the mean heat generation rate from source and on the permeability of the porous dusty medium. This study is carried out by assuming the Rayleigh number small and the validity of Darcy-s law. Analytical expressions for both phases are obtained for second order mean in both velocity and temperature fields and evolution of different wave patterns are observed in the fluctuating part. It has been observed that, at the vicinity of the origin, the second order mean flow is influenced only by relaxation time of dust particles and not by dust concentration.

Keywords: Pulsating point heat source, azimuthal velocity, porous dusty medium, Darcy's law.

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2026 On Frenet-Serret Invariants of Non-Null Curves in Lorentzian Space L5

Authors: Melih Turgut, José Luis López-Bonilla, Süha Yılmaz

Abstract:

The aim of this paper is to determine Frenet-Serret invariants of non-null curves in Lorentzian 5-space. First, we define a vector product of four vectors, by this way, we present a method to calculate Frenet-Serret invariants of the non-null curves. Additionally, an algebraic example of presented method is illustrated.

Keywords: Lorentzian 5-space, Frenet-Serret Invariants, Nonnull Curves

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2025 Hotel Design and Energy Consumption

Authors: Bin Su

Abstract:

A hotel mainly uses its energy on water heating, space heating, refrigeration, space cooling, cooking, lighting and other building services. A number of 4-5 stars hotels in Auckland city are selected for this study. Comparing with the energy used for others, the energy used for the internal space thermal control (e.g. internal space heating) is more closely related to the hotel building itself. This study not only investigates relationship between annual energy (and winter energy) consumptions and building design data but also relationships between winter extra energy consumption and building design data. This study is to identify the major design factors that significantly impact hotel energy consumption for improving the future hotel design for energy efficient.

Keywords: Hotel building design, building energy, building passive design, energy efficiency.

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2024 Effects of Upflow Liquid Velocity on Performance of Expanded Granular Sludge Bed (EGSB) System

Authors: Seni Karnchanawong, Wachara Phajee

Abstract:

The effects of upflow liquid velocity (ULV) on performance of expanded granular sludge bed (EGSB) system were investigated. The EGSB reactor, made from galvanized steel pipe 0.10 m diameter and 5 m height, had been used to treat piggery wastewater, after passing through acidification tank. It consisted of 39.3 l working volume in reaction zone and 122 l working volume in sedimentation zone, at the upper part. The reactor was seeded with anaerobically digested sludge and operated at the ULVs of 4, 8, 12 and 16 m/h, consecutively, corresponding to organic loading rates of 9.6 – 13.0 kg COD/ (m3.d). The average COD concentrations in the influent were 9,601 – 13,050 mg/l. The COD removal was not significantly different, i.e. 93.0% - 94.0%, except at ULV 12 m/h where SS in the influent was exceptionally high so that VSS washout had occurred, leading to low COD removal. The FCOD and VFA concentrations in the effluent of all experiments were not much different, indicating the same range of treatment performance. The biogas production decreased at higher ULV and ULV of 4 m/h is suggested as design criterion for EGSB system.

Keywords: Expanded granular sludge bed system, piggery wastewater, upflow liquid velocity

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2023 Hydrogenation of Acetic Acid on Alumina-Supported Pt-Sn Catalysts

Authors: Ke Zhang, Fang Li, Haitao Zhang, Hongfang Ma, Weiyong Ying, Dingye Fang

Abstract:

Three alumina-supported Pt-Sn catalysts have been prepared by means of co-impregnation and characterized by XRD and N2 adsorption. The influence of catalyst composition and reaction conditions on the conversion and selectivity were investigated in the hydrogenation of acetic acid in an isothermal integral fixed bed reactor. The experiments were performed on the temperature interval 468-548 K, liquid hourly space velocity (LHSV) of 0.3-0.7h-1, pressures between 1.0 and 5.0Mpa. A good compromise of 0.75%Pt-1.5%Sn can act as an optimized acetic acid hydrogenation catalyst, and the conversion and selectivity can be tuned through the variation of reaction conditions.

Keywords: Acetic acid, hydrogenation, Pt-Sn catalysts, ethanol.

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2022 Social Space or the Art of Belonging: The Socio-Spatial Approach in the Field of Residential Facilities for Persons with Disabilities

Authors: Sarah Reker

Abstract:

The Convention on the Rights of Persons with Disabilities (CRPD) provides the basis of this study. For all countries which have ratified the convention since its entry into force in 2007, the effective implementation of the requirements often leads to considerable challenges. Furthermore, missing indicators make it difficult to measure progress. Therefore, the aim of the research project is to contribute to analyze the consequences of the implementation process on the inclusion and exclusion conditions for people with disabilities in Germany. Disabled People’s Organisations and other associations consider the social space to be relevant for the successful implementation of the CRPD. Against this background, the research project wants to focus on the relationship between a barrier-free access to the social space and the “full and effective participation and inclusion” (Art. 3) of persons with disabilities. The theoretical basis of the study is the sociological theory of social space (“Sozialraumtheorie”).

Keywords: Decentralisation, qualitative research, residential facilities, social space.

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2021 Comics as Third Space: An Analysis of the Continuous Negotiation of Identities in Postcolonial Philippines

Authors: Anna Camille V. Flores

Abstract:

Comics in the Philippines has taken on many uses for the Filipino people. They have been sources of entertainment, education, and political and social commentaries. History has been witnessed to the rise and fall of Philippine comics but the 21st century is seeing a revival of the medium and the industry. It is within this context that an inquiry about Filipino identity is situated. Employing the analytical framework of postcolonialism, particularly Homi K. Bhabha’s concepts of Hybridity and the Third Space, this study analyzes three contemporary Philippine comics, Trese, Filipino Heroes League, and Dead Balagtas. The study was able to draw three themes that represent how Filipinos inhabit hybrid worlds and hybridized identities. First, the third space emerged through the use of hybrid worlds in the comics. Second, (re)imagined communities are established through the use of intertextual signifiers. Third, (re)negotiated identities are expressed through visual and narrative devices such as the use of Philippine mythology, historical and contemporary contexts, and language. In conclusion, comics can be considered as Third Space where these identities have the agency and opportunity to be expressed and represented.

Keywords: Comics, hybridity and third space, Philippine comics, postcolonialism.

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2020 Natural Flickering of Methane Diffusion Flames

Authors: K. R. V. Manikantachari, Vasudevan Raghavan, K. Srinivasan

Abstract:

Present study focuses on studying the oscillatory behavior of jet diffusion flames. At a particular jet exit velocity, the flames are seen to exhibit natural flickering. Initially the flickering process is not continuous. In this transition region as well as in the continuous flickering regime, the flickering displays multiple frequency oscillations. The response of the flame to the exit velocity profile of the burner is also studied using three types of burners. The entire range of natural flickering is investigated by capturing high speed digital images and processing them using a MATLAB code.

Keywords: Diffusion flames, Natural flickering, flickering frequency, intermittent flickering

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2019 Drop Impact Study on Flexible Superhydrophobic Surface Containing Micro-Nano Hierarchical Structures

Authors: Abinash Tripathy, Girish Muralidharan, Amitava Pramanik, Prosenjit Sen

Abstract:

Superhydrophobic surfaces are abundant in nature. Several surfaces such as wings of butterfly, legs of water strider, feet of gecko and the lotus leaf show extreme water repellence behaviour. Self-cleaning, stain-free fabrics, spill-resistant protective wears, drag reduction in micro-fluidic devices etc. are few applications of superhydrophobic surfaces. In order to design robust superhydrophobic surface, it is important to understand the interaction of water with superhydrophobic surface textures. In this work, we report a simple coating method for creating large-scale flexible superhydrophobic paper surface. The surface consists of multiple layers of silanized zirconia microparticles decorated with zirconia nanoparticles. Water contact angle as high as 159±10 and contact angle hysteresis less than 80 was observed. Drop impact studies on superhydrophobic paper surface were carried out by impinging water droplet and capturing its dynamics through high speed imaging. During the drop impact, the Weber number was varied from 20 to 80 by altering the impact velocity of the drop and the parameters such as contact time, normalized spread diameter were obtained. In contrast to earlier literature reports, we observed contact time to be dependent on impact velocity on superhydrophobic surface. Total contact time was split into two components as spread time and recoil time. The recoil time was found to be dependent on the impact velocity while the spread time on the surface did not show much variation with the impact velocity. Further, normalized spreading parameter was found to increase with increase in impact velocity.

Keywords: Contact angle, contact angle hysteresis, contact time, superhydrophobic.

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2018 An Iterated Function System for Reich Contraction in Complete b Metric Space

Authors: R. Uthayakumar, G. Arockia Prabakar

Abstract:

In this paper, we introduce R Iterated Function System and employ the Hutchinson Barnsley theory (HB) to construct a fractal set as its unique fixed point by using Reich contractions in a complete b metric space. We discuss about well posedness of fixed point problem for b metric space.

Keywords: Fractals, Iterated Function System, Compact set, Reich Contraction, Well posedness.

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2017 Analysis of Cascade Control Structure in Train Dynamic Braking System

Authors: B. Moaveni, S. Morovati

Abstract:

In recent years, increasing the usage of railway transportations especially in developing countries caused more attention to control systems railway vehicles. Consequently, designing and implementing the modern control systems to improve the operating performance of trains and locomotives become one of the main concerns of researches. Dynamic braking systems is an important safety system which controls the amount of braking torque generated by traction motors, to keep the adhesion coefficient between the wheel-sets and rail road in optimum bound. Adhesion force has an important role to control the braking distance and prevent the wheels from slipping during the braking process. Cascade control structure is one of the best control methods for the wide range of industrial plants in the presence of disturbances and errors. This paper presents cascade control structure based on two forward simple controllers with two feedback loops to control the slip ratio and braking torque. In this structure, the inner loop controls the angular velocity and the outer loop control the longitudinal velocity of the locomotive that its dynamic is slower than the dynamic of angular velocity. This control structure by controlling the torque of DC traction motors, tries to track the desired velocity profile to access the predefined braking distance and to control the slip ratio. Simulation results are employed to show the effectiveness of the introduced methodology in dynamic braking system.

Keywords: Cascade control, dynamic braking system, DC traction motors, slip control.

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2016 Positive Solutions for Boundary Value Problems of Fourth-Order Nonlinear Singular Differential Equations in Banach Space

Authors: Li Xiguang

Abstract:

In this paper, by constructing a special non-empty closed convex set and utilizing M¨onch fixed point theory, we investigate the existence of solution for a class of fourth-order singular differential equation in Banach space, which improved and generalized the result of related paper.

Keywords: Banach space, cone, fixed point index, singular differential equation.

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2015 Information Entropy of Isospectral Hydrogen Atom

Authors: Anil Kumar, C. Nagaraja Kumar

Abstract:

The position and momentum space information entropies of hydrogen atom are exactly evaluated. Using isospectral Hamiltonian approach, a family of isospectral potentials is constructed having same energy eigenvalues as that of the original potential. The information entropy content is obtained in position space as well as in momentum space. It is shown that the information entropy content in each level can be re-arranged as a function of deformation parameter.

Keywords: Information Entropy, BBM inequality, Isospectral Potential.

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