Video based wildfire detection at night

There has been an increasing interest in the study of video based fire detection algorithms as video based surveillance systems become widely available for indoor and outdoor monitoring applications. A novel method explicitly developed for video based detection of wildfires at night (in the dark) is presented in this paper. The method comprises four sub-algorithms: (i) slow moving video object detection, (ii) bright region detection, (iii) detection of objects exhibiting periodic motion, and (iv) a sub-algorithm interpreting the motion of moving regions in video. Each of these sub-algorithms characterizes an aspect of fire captured at night by a visible range PTZ camera. Individual decisions of the sub-algorithms are combined together using a least-mean-square (LMS) based decision fusion approach, and fire/nofire decision is reached by an active learning method.     

Combination of oxidation and dehydrogenation processes of isoamylenes in the production of isoprene on iron potassium catalyst

A theoretical model of the industrial method of the compensation of thermal energy consumed on the endothermic dehydrogenation on a fixed catalyst layer has been described. The combination of endothermic dehydrogenation with interlayer (intermediate) oxidation of produced hydrogen has been considered based on the example of the dehydrogenation of isoamylenes to isoprene. The calculated results are compared with laboratory tests.     

Energy efficient cosine similarity measures according to a convex cost function

We propose a new family of vector similarity measures. Each measure is associated with a convex cost function. Given two vectors, we determine the surface normals of the convex function at the vectors. The angle between the two surface normals is the similarity measure. Convex cost function can be the negative entropy function, total variation (TV) function and filtered variation function constructed from wavelets. The convex cost functions need not to be differentiable everywhere. In general, we need to compute the gradient of the cost function to compute the surface normals. If the gradient does not exist at a given vector, it is possible to use the sub-gradients and the normal producing the smallest angle between the two vectors is used to compute the similarity measure. The proposed measures are compared experimentally to other nonlinear similarity measures and the ordinary cosine similarity measure. The TV-based vector product is more energy efficient than the ordinary inner product because it does not require any multiplications.     

Effect of alloying elements on the contact resistance and the passivation behaviour of stainless steels

The effects of alloying elements (Cr, Mo) on the passivation and the transpassive transition behaviour of various commercial stainless steels, which are candidate materials for the bi-polar plates in polymer electrolyte membrane fuel cell, were investigated via a contact electric resistance (CER) technique with graphite counter part. The contact resistance, too high for a semi-conductor film with high donor density, is not the inherent ohmic resistance of the passive film. The CER potentials decrease linearly with the pitting resistance equivalent number (PREN). The passive films of stainless steels with high PREN are more readily removed compared to those with low PREN in terms of the charge necessary to remove the passive films. The change in transpassive transition behaviour of the stainless steels from that of iron to that of chromium went on steeply with an increase in the PREN.     

Ethanol used as an environmentally sustainable energy resource for thermal power plants

Justification of using renewable energy sources and a brief analysis of their application prospects is given. The most common renewable energy sources for mobile thermal power plants are presented. The possibilities and ways of using ethanol as an energy source for such plants with diesel engines are analyzed. It is shown that it is feasible to add small amounts of ethanol to oil diesel fuel (DF) for obtaining an environmentally sustainable energy source for diesel engines. Therewith, a stable mixture of components can be obtained by adding anhydrous (absolute) ethanol to the oil fuel. The authors studied a mixture containing 4% (by volume) of absolute ethanol and 96% of oil DF. The physicochemical properties of the mixture and each of its components are presented. Diesel engine of the type D-245.12S has been experimentally studied using the mixture of DF and ethanol. The possibility of reducing the toxicity level of the exhaust emissions when using this mixture as an energy source for diesel engines of mobile power plants is shown. Transition of the studied diesel engine from oil DF to its mixture with ethanol made it possible to reduce the smoke capacity of the exhaust gases by 15–25% and to decrease the specific mass emissions of nitrogen oxides by 17.4%. In this case, we observed a slight increase in the exhaust gas emissions of carbon monoxide and light unburned hydrocarbons, which, however, can easily be eliminated by providing the exhaust system of a diesel engine with a catalytic converter. It is noted that the studied mixture composition should be optimized. The conclusion is made that absolute ethanol is a promising ecofriendly additive to oil diesel fuel and should be used in domestic diesel engines.     

Ultimate capacity prediction of axially loaded CFST short columns

Composite columns have superior strength and ductility performance, and they have become more widely accepted in the engineering applications. However, the filled tubular columns require more attention. This study aims to present a new formulation for the axial load carrying capacity (N _u ) of circular concrete filled steel tubular (CFST) short columns having various geometrical and material properties. Although there have been some empirical relations for predicting N _u in the literature, genetic algorithm based explicit formulation is not available. In the current study, 314 comprehensive experimental data samples presented in the previous studies were examined to prepare a data set for training and testing of the prediction model. The prediction parameters were selected as outer diameter of column (D), wall thickness (t), length of column (L), compressive strength of concrete (f _c ), and yield strength of steel (f _y ). The prediction model was obtained by means of gene expression programming (GEP). The proposed model was compared with available ones presented in the current design codes (ACI, Australian Standards, AISC, AIJ, Eurocode 4, DL/T, and CISC) and some existing empirical models proposed by researchers. The prediction performance of all models were also evaluated by the statistical parameters. The results indicated that the GEP model was much better than the available formulae, yielding higher correlation coefficient and lower error.     

Synthesis,electrochemistry, spectroelectrochemistry and electrocolorimetry of phthalocyanine–anthraquinone hybrids

The tetra substituted metallophthalocyanines 2 and 3, soluble in common organic solvents, bearing four 2-(9,10-dioxo-9,10-dihydro-anthracen-2-yl-methyl)-malonic acid diethyl ester functionalities were synthesized from the corresponding phthalodinitrile 1 and divalent metal salts at 170 °C in fused state. Reaction of with manganese (2+) acetate in n-pentanol led to the manganese (3+) phthalocyanine 4. Furthermore, the unsymmetrical copper phthalocyanine 5 containing one 2-(9,10-dioxo-9,10-dihydro-anthracen-2-yl-methyl)-malonic acid diethyl ester moiety was synthesized using a statistical approach. The new compounds were characterized by elemental analysis together with FT-IR, ¹H-NMR, ¹³C-NMR, and UV–vis spectroscopy and via mass spectrometric analysis. The electrochemical, in situ spectroelectrochemical, and in situ electrocolorimetric measurements represent that while MPcs give common ring-based and/or metal-based electron transfer processes, these processes were considerably affected with the redox processes of the AQ units attached to the phthalocyanine ring. At the same time attachments of the AQ units to the phthalocyanine rings improve the reversibility of the AQ units due to the electron donor–acceptor interaction between the AQ units and phthalocyanine ring. The AQ units also alter the color states of the phthalocyanines.     

Practical ways of evaluating wind speed persistence

Wind speed persistence is a measure of the mean wind speed duration over a given period of time at any location. This definition implies that wind speed persistence means a positive serial correlation in time series. The wind speed persistence provides useful information about the general climatological characteristics of the wind persisting at a given location. Therefore, wind speed persistence should be taken into account in many studies such as weather forecast, site selection for wind turbines and synthetic generation of the wind speed data. On the other hand, if wind direction information is considered together with the wind speed then this type of persistence can be used for additional purposes such as forest fires, dispersion of the air pollutants, building ventilation, etc. In this study, three different methods with some modifications of the previous methods have been applied to the wind speed data obtained from the meteorology stations located at the northwest part of Turkey. These methods are based on autocorrelation function, conditional probability and the wind speed duration curves. It has been shown that the proposed methods clearly reflect the persistence properties of the wind speed in the study area.