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Experiment Data (experiment + data)
Selected AbstractsA novel self-consistent Nıvlt-like equation for metastable zone width determined by the polythermal methodCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2009K. Sangwal Abstract Using a power-law relation between three-dimensional nucleation rate J and dimensionless supersaturation ratio S, and the theory of regular solutions to describe the temperature dependence of solubility, a novel Nıvlt-like equation of metastable zone width of solution relating maximum supercooling ,Tmax with cooling rate R is proposed in the form: ln(,Tmax/T0) = , + , lnR, with intercept , = {(1,m)/m }ln(,Hs/RGTlim) + (1/m)ln(f/KT0) and slope , = 1/m. Here T0 is the initial saturation temperature of solution in a cooling experiment, ,Hs is the heat of dissolution, RG is the gas constant, Tlim is the temperature of appearance of first nuclei, m is the nucleation order, and K is a new nucleation constant connected with the factor f defined as the number of particles per unit volume. It was found that the value of the term , for a system at saturation temperature T0 is essentially determined by the constant m and the factor f. The value of the factor f for a solute,solvent system at initial saturation temperature T0 is determined by solute concentration c0. Analysis of the experiment data for four different solute-water systems according to the above equation revealed that: (1) the values of , and m for a system at a given temperature depend on the method of detection of metstable zone width, and (2) the value of slope , = 1/m for a system is practically a temperature-independent constant characteristic of the system, but the value of , increases with an increase in saturation temperature T0, following an Arrhenius-type equation with an activation energy Esat. The results showed, among others, that solubility of a solute is an important factor that determines the value of the nucleation order m and the activation energy Esat for diffusion. In general, the lower the solubility of a solute in a given solvent, the higher is the value of m and lower is the value of Esat. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Numerical simulation of rime ice accretion process on an airfoilHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 4 2005Zhang Da-lin Abstract To simulate the ice accretion on an airfoil, a boundary moving technique is proposed to deal with the distortion of the airfoil surface due to ice accretion on the leading edge. Incorporating the two-phase model of air-supercooled droplets in the Eulerian coordinate system, this technique is applied to simulate the process of the rime ice accretion (the droplets freeze at the instant impinging on the airfoil) on the NACA 0012 airfoil, and the ice profile after ice accretion is achieved successfully. A brief comparison between the results of this paper and the experiment data indicates that the current method is applicable and effective. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(4): 226,234, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20064 [source] Numerical simulation of a dam break for an actual river terrain environmentHYDROLOGICAL PROCESSES, Issue 4 2007C. B. Liao Abstract A two-dimensional (2D) finite-difference shallow water model based on a second-order hybrid type of total variation diminishing (TVD) approximate solver with a MUSCL limiter function was developed to model flooding and inundation problems where the evolution of the drying and wetting interface is numerically challenging. Both a minimum positive depth (MPD) scheme and a non-MPD scheme were employed to handle the advancement of drying and wetting fronts. We used several model problems to verify the model, including a dam break in a slope channel, a dam break flooding over a triangular obstacle, an idealized circular dam-break, and a tide flow over a mound. Computed results agreed well with the experiment data and other numerical results available. The model was then applied to simulate the dam breaking and flooding of Hsindien Creek, Taiwan, with the detailed river basin topography. Computed flooding scenarios show reasonable flow characteristics. Though the average speed of flooding is 6,7 m s,1, which corresponds to the subcritical flow condition (Fr < 1), the local maximum speed of flooding is 14·12 m s,1, which corresponds to the supercritical flow condition (Fr , 1·31). It is necessary to conduct some kind of comparison of the numerical results with measurements/experiments in further studies. Nevertheless, the model exhibits its capability to capture the essential features of dam-break flows with drying and wetting fronts. It also exhibits the potential to provide the basis for computationally efficient flood routing and warning information. Copyright © 2006 John Wiley & Sons, Ltd. [source] Numerical simulation of turbulent impinging jet on a rotating diskINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2007A. Abdel-Fattah, Article first published online: 25 OCT 200 Abstract The calculations of quasi-three-dimensional momentum equations were carried out to study the influence of wall rotation on the characteristics of an impinging jet. The pressure coefficient, the mean velocity distributions and the components of Reynolds stress are calculated. The flow is assumed to be steady, incompressible and turbulent. The finite volume scheme is used to solve the continuity equation, momentum equations and k,, model equations. The flow characteristics were studied by varying rotation speed , for 0,,,167.6 rad/s, the distance from nozzle to disk (H/d) was (3, 5, 8 and 10) and the Reynolds number Re base on VJ and d was 1.45 × 104. The results showed that, the radial velocity and turbulence intensity increase by increasing the rotation speed and decrease in the impingement zone as nozzle to disk spacing increases. When the centrifugal force increases, the radial normal stresses and shear stresses increase. The location of maximum radial velocity decreases as the local velocity ratio (,) increases. The pressure coefficient depends on the centrifugal force and it decreases as the distance from nozzle to plate increases. In impingement zone and radial wall jet, the spread of flow increases as the angular velocity decreases The numerical results give good agreement with the experiment data of Minagawa and Obi (Int. J. of Heat and Fluid Flow 2004; 25:759,766). Copyright © 2006 John Wiley & Sons, Ltd. [source] Kinetic and heat transfer modeling of rubber blends' sulfur vulcanization with N - t -butylbenzothiazole-sulfenamide and N,N -di- t -butylbenzothiazole-sulfenamideJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Likozar Abstract Vulcanization kinetics and heat transfer for various blends of natural (NR) and polybutadiene (BR) rubber were studied simultaneously using a mechanistic approach when developing vulcanization model kinetics. Rubber process analyzer (RPA), dynamic scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) methods were used for the study. The model reaction scheme was based on one of the best possible proposed individual reaction mechanisms. Molecular modeling was applied to distinguish between the reactivity of chemically similar species. The kinetics of N - t -butylbenzothiazole-sulfenamide (TBBS) and N,N -di- t -butylbenzothiazole-sulfenamide (TBSI) were treated separately using FTIR experiment data, and then incorporated in a model suitable for two-accelerator vulcanization. The proposed model quite well describes the thermal equilibration during the induction period despite a few simplifications. During cure and over-cure periods the course of vulcanization was described using a rigorous kinetic model. Physical and chemical model parameters were calculated from experimental data. Average heat transfer coefficient minimum during induction period was found to be at a weight ratio of BR and NR 1 : 1. The activation energy of significant reactions between rubber and other species was found to vary linearly with vulcanization compound composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 293,307, 2007 [source] Targeted driving using visual tracking on Mars: From research to flightJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3 2009Won S. Kim This paper presents the development, validation, and deployment of the visual target tracking capability onto the Mars Exploration Rover (MER) mission. Visual target tracking enables targeted driving, in which the rover approaches a designated target in a closed visual feedback loop, increasing the target position accuracy by an order of magnitude and resulting in fewer ground-in-the-loop cycles. As a result of an extensive validation, we developed a reliable normalized cross-correlation visual tracker. To enable tracking with the limited computational resources of a planetary rover, the tracker uses the vehicle motion estimation to scale and roll the template image, compensating for large image changes between rover steps. The validation showed that a designated target can be reliably tracked within several pixels or a few centimeters of accuracy over a 10-m traverse using a rover step size of 10% of the target distance in any direction. It also showed that the target is not required to have conspicuous features and can be selected anywhere on natural rock surfaces excluding rock boundary and shadowed regions. The tracker was successfully executed on the Opportunity rover near Victoria Crater on four distinct runs, including a single-sol instrument placement. We present the flight experiment data of the tracking performance and execution time. © 2009 Wiley Periodicals, Inc. [source] Text-based video content classification for online video-sharing sitesJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 5 2010Chunneng Huang With the emergence of Web 2.0, sharing personal content, communicating ideas, and interacting with other online users in Web 2.0 communities have become daily routines for online users. User-generated data from Web 2.0 sites provide rich personal information (e.g., personal preferences and interests) and can be utilized to obtain insight about cyber communities and their social networks. Many studies have focused on leveraging user-generated information to analyze blogs and forums, but few studies have applied this approach to video-sharing Web sites. In this study, we propose a text-based framework for video content classification of online-video sharing Web sites. Different types of user-generated data (e.g., titles, descriptions, and comments) were used as proxies for online videos, and three types of text features (lexical, syntactic, and content-specific features) were extracted. Three feature-based classification techniques (C4.5, Naïve Bayes, and Support Vector Machine) were used to classify videos. To evaluate the proposed framework, user-generated data from candidate videos, which were identified by searching user-given keywords on YouTube, were first collected. Then, a subset of the collected data was randomly selected and manually tagged by users as our experiment data. The experimental results showed that the proposed approach was able to classify online videos based on users' interests with accuracy rates up to 87.2%, and all three types of text features contributed to discriminating videos. Support Vector Machine outperformed C4.5 and Naïve Bayes techniques in our experiments. In addition, our case study further demonstrated that accurate video-classification results are very useful for identifying implicit cyber communities on video-sharing Web sites. [source] An experimental examination of demand reduction in multi-unit versions of the Uniform-price, Vickrey, and English auctionsMANAGERIAL AND DECISION ECONOMICS, Issue 6 2006David Porter Demand reduction in Uniform-price and English auctions are strategic reactions by participants to reduce price and thus increase potential profits. Laboratory experiments similar to the field experiments performed by List and Reiley (Am. Econ. Rev. 2000; 9(4): 961,972) in which two individuals with demands for two units vie for two units through a Uniform-price, English or Vickrey auction are conducted. We find strong support for demand reduction in both the English and Uniform-price auctions, with significantly more dramatic reductions in the English auction. However, there is significant overbidding in both the Vickrey and Uniform-price auction. This overbidding solves a puzzle found by List and Reiley in their field experiment data. Copyright © 2006 John Wiley & Sons, Ltd. [source] Modeling And Solving An Engine Intake Manifold With Turbo Charger For Predictive ControlASIAN JOURNAL OF CONTROL, Issue 3 2006Long Xie ABSTRACT In this paper, we build the intake manifold model of an engine with a turbo charger and develop a high speed calculation algorithm for model-based predictive control in real time. The model is built according to the analysis of its thermodynamic and hydrodynamic characteristics and the sampled experiment data. The model equations are presented as a set of differential equations with condition selection (bifurcation) on the right hand side. The switching surface is divided into two parts, sliding and crossing. The sliding mode on the switching surface is analyzed in detail, and a calculation algorithm is proposed to remove illegal crossing caused by the numerical errors on this surface. Also, the control formula and the condition guiding the bifurcation between these two parts are demonstrated. Using this method, we can solve this model over the entire region of input throttle angles, the stability is greatly increased, and the calculation time is greatly reduced for real time control systems. [source] Study on the inhibitory mechanism and binding mode of the hydroxycoumarin compound NSC158393 to HIV-1 integrase by molecular modelingBIOPOLYMERS, Issue 9 2009Ming Liu Abstract Human immunodeficiency virus type 1 integrase (IN) is an essential enzyme in the life cycle of this virus and also an important target for the study of anti-HIV drugs. In this work, the binding modes of the wild type IN core domain and the two mutants, that is, W132G and C130S, with the 4-hydroxycoumarin compound NSC158393 were evaluated by using the "relaxed complex" molecular docking approach combined with molecular dynamics (MD) simulations. Based on the monomer MD simulations, both of the two substitutions affect not only the stability of the 128,136 peptides, but also the flexibility of the functional 140s loop. In principle, NSC158393 binds the 128,136 peptides of IN; however, the specific binding modes for the three systems are various. According to the binding mode of NSC158393 with WT, NSC158393 can effectively interfere with the stability of the IN dimer by causing a steric hindrance around the monomer interface. Additionally, through the comparative analysis of the MD trajectories of the wild type IN and the IN-NSC158393 complex, we found that NSC15893 may also exert its inhibitory function by diminishing the mobility of the function loop of IN. Three key binding residues, that is, W131, K136, and G134, were discovered by energy decomposition calculated with the Molecular Mechanics Generalized Born Surface Area method. Characterized by the largest binding affinity, W131 is likely to be indispensable for the ligand binding. All the above results are consistent with experiment data, providing us some helpful information for understanding the mechanism of the coumarin-based inhibitors. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 700,709, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Structure,property relationships for azo disperse dyes on polyurethane fibreCOLORATION TECHNOLOGY, Issue 3 2009Hong-Fei Qian Using two series of monoazo disperse dyes, the relationships between the molecular structure of dye and its dyeing properties, such as adsorption behaviour, fastness properties and distribution on polyurethane,polyester blends, were thoroughly investigated. Correlation analysis of experiment data revealed that the partition coefficient between octanol and water (CLogP) is the main factor affecting dye sorption. A greater level of CLogP tends to have a greater isotherm coefficient and better rubbing and washing fastness on polyurethane fibre, as well as a greater distribution ratio between the components of the blend. The dye dipole moment is negatively correlated with various degrees of washing fastness. The dye with two terminal hydroxy groups exhibited notable sorption on the polyurethane component and has the largest partition ratio on polyurethane,polyester in the blend. Corresponding regression analysis equations were identified. [source] | |||||||||||||