Numerical study of compressible convective heat transfer with variations in all fluid properties

The effects of property variations in single-phase laminar forced micro-convection with constant wall heat flux boundary condition are investigated in this work. The fully-developed flow through micro-sized circular (axisymmetric) geometry is numerically studied using two-dimensional continuum-based conservation equations. The non-dimensional governing equations show significance of momentum transport in radial direction due to μ(T) variation and energy transport by fluid conduction due to k(T) variation. For the case of heated air, variation in C_p(T) and k(T) causes increase in Nu. This is owing to: (i) reduction in T_w, (T_w ? T_m), and (?T/?r)_w and (ii) change in ?T_m/?z results in axial conduction along the flow. The effects of ρ(p,T) and μ(T) variation on convective-flow are indirect and lead to: (i) induce radial velocity which alters u(r) profile significantly and (ii) change in (?u/?r)_w along the flow. It is proposed that the deviation in convection with C_p(T), k(T) variation is significant through temperature field than ρ(p,T), μ(T) variation on velocity field. It is noted that Nu due to variation in properties differ from invariant properties (Nu = 48/11) for low subsonic flow.     

Mercury wet deposition and coal-fired power station contributions: An Australian study

Regions that have large coal-fired power station regions may be prone to elevated mercury (Hg) deposition fluxes. Total mercury (THg) in daily rainfall samples at a near-field sampling site (Hunter Valley) and a far-field station (Sydney) has been monitored in this study employing ultra-clean sampling techniques and Cold Vapour Atomic Fluorescence Spectrometry (CVAFS) analysis.     

The effects of adverse condition warning system characteristics on driver performance: an investigation of alarm signal type and threshold level

This study addresses the issues concerning the design of adverse condition warning systems (ACWS). ACWS are designed to sense adverse road and weather conditions as well as system states that can negatively impact driving performance leading to skids or accidents, and alert drivers to these conditions. In this case, an ACWS was designed to sense when a car was likely to skid. A virtual-driving environment was used to test two levels of alarm sensitivity (low and high) and two types of auditory alarm signal (Binary ON/OFF and Graded) along with a no-alarm control group. Dependent measures reflected driver performance, response to the alarm signal and trust in the alerting system. Results indicated that participants had fewer skids in the low sensitivity and graded alarm signal condition compared to some other alerting system configurations. Participants in the graded alarm signal condition also had a greater degree of lateral control over the vehicle. Additionally, trust was found to be lower for the high vs. low sensitivity alarm condition, indicating a reduction in trust when the alerting system activated more often, perhaps because participants did not feel the system was accurately reflecting a dangerous condition. This simulator-based research emphasizes the fact that while ACWS may provide an advantage in terms of vehicle control, characteristics of both the alerting signal and system configuration should be considered.     

Use of aqueous solutions of two basic dyes for the demonstration of DNA

This paper presents informations as to the ability of aqueous solutions of two basic dyes, such as Dahlia and Victoria blue, belonging to aminotriarylmethane group for the staining of DNA-aldehyde molecules as well as DNA-phosphate groups. It has been found that sections of rat tissues stained with aqueous solutions of these dyes after acid hydrolysis followed by drying between folds of filter paper and treatment in n-butanol for a minute and then by a very brief treatment in a mixture consisting of equal parts of n-butanol and absolute ethanol reveal well-stained nuclei. Tissue sections after acid hydrolysis when stained with aqueous solutions of these dyes and then treated with SO2 water do not reveal any colouration of the nuclei. Since both the dyes are without any primary amino group in their molecules, it has been concluded that the imino group of Dahlia and the tertiary amino group of Victoria blue with cold concentrated phosphoric acid and then stained with any of these dyes also exhibit well-stained nuclei. The absorption spectra of nuclei stained with these dyes for DNA-aldehyde molecules as well as DNA-phosphate groups reveal positions of the peaks of maximum absorption at the same wavelength, which, however, are different in the case of nuclei stained with the two dyes. The implications of these findings have been discussed.     

Design of airfoils in incompressible viscous flows by numerical optimization

A method is outlined for the design of airfoils in incompressible viscous flows by numerical optimization wherein a reduced number of design coordinates are used to define the airfoil shape. The optimization problem is formulated as a nongradient search in a finite constrained parameter space. The approach is to define the airfoil as a linear combination of basic shapes which may be analytically or numerically defined. The design problem is to determine the participation of each of these basic shapes in defining the optimum airfoil. The aerodynamic analysis program is specially developed to fit the requirements of the optimization program and is based on the vortex singularity method for inviscid flow analysis and the momentum integral method for boundary layer analysis. Four examples have been worked out to illustrate the proposed design method. In these, modifications to four different airfoil geometries are made to achieve either a minimum drag coefficient or a minimum pitching moment coefficient under prescribed constraints. The results show that significant drag or pitching moment reduction is possible through shape manipulation alone.     

Neuro-fuzzy MIMO nonlinear control for ceramic roller kiln

Artificial neural networks (ANNs) and neuro-fuzzy systems (NFSs) have been widely used in modeling and control of many practical industrial nonlinear processes. However, most of them have concentrated on single-output systems only. In this paper, we present a comparative study using ANNs and co-active neuro-fuzzy inference system (CANFIS) in modeling a real, complicated multi-input–multi-output (MIMO) nonlinear temperature process of roller kiln used in ceramic tile manufacturing line. Using this study, we prove that CANFIS is better suited for modeling the temperature process in control phase. After that, a neural network (NN) controller has been developed to control the above mentioned temperature process due to a feedback control diagram. The designed controller performance is tested by a Visual C++ project and the resulting numerical data shows that this controller can work accurately and reliably when the roller kiln set-point temperature set changes.     

Text extraction and document image segmentation using matched wavelets and MRF model.

In this paper, we have proposed a novel scheme for the extraction of textual areas of an image using globally matched wavelet filters. A clustering-based technique has been devised for estim ating globally matched wavelet filters using a collection of groundtruth images. We have extended our text extraction scheme for the segmentation of document images into text, background, and picture components (which include graphics and continuous tone images). Multiple, two-class Fisher classifiers have been used for this purpose. We also exploit contextual information by using a Markov random field formulation-based pixel labeling scheme for refinement of the segmentation results. Experimental results have established effectiveness of our approach.     

Development of spectral band cloning techniques for soil nutrients estimation

Satellite‐based monitoring is an indispensable tool to guide soil‐specific crop management. However, it has attained little success in the estimation of soil nutrients due to the limitations incurred from inherent spectral characteristics. In this study, spectral band cloning (SBC) is developed and proposed to augment the soil nutrient predictive capabilities of broadband satellite data. Fine‐spectral channels of spectrometers were synchronized with coarse resolution of IRS satellite data to generate nutrient‐sensitive cloned IRS bands. Soil samples, collected at the time of satellite image acquisition in Lop Buri, Thailand, were analyzed both spectrally and chemically, viz., soil organic matter (OM), phosphorus, potassium and iron. The resulting SBC‐based models showed acceptable correlations, which otherwise were unattainable from raw IRS bands through prevailing models. Accuracy and validation measures showed good agreements between the measured and estimated nutrient surfaces. It is concluded that the SBC is a promising method of quantitative soil nutrient mapping, and could further be used for identification and mapping of other indiscernible biophysical parameters.     

Linear-code multicast on parallel architectures

Parallel architectures involve communication with the aim of fast receiving of complete information at each node. Several architectures have been proposed to overcome the problem of high communicational and computational time complexity for transferring and receiving information. To reduce the complexity of such communication, we have implemented Linear Network Coding (LNC) in the parallel environment. For verification of our approach, we have considered some parallel architecture for implementing network coding approach and examined our results on these networks in a generic environment. We have formulated a standard approach for parallel networks, showing that by applying this approach effect of faulty nodes, information size and communication complexity exponentially decreases with code length.