Growth of ZnO Nanostructures by Wet Oxidation of Zn Thin Film Deposited on Heat-Resistant Flexible Substrates at Low Temperature

Semiconductors - Coral-like ZnO nanostructures were successfully grown onto heat-resistant flexible substrates by the oxidation of Zn thin films. At a relatively low temperature (100°C), Zn...     

Impact of finite wavy wall thickness on entropy generation and natural convection of nanofluid in cavity partially filled with non-Darcy porous layer

Neural Computing and Applications - This paper investigates the natural convection inside a partially layered porous cavity with a heated wavy solid wall; the geometry is encountered in compact...     

Sorting methods and adaptive thresholding for histogram based reversible data hiding

Multimedia Tools and Applications - This paper presents a histogram based reversible data hiding (RDH) scheme, which divides image pixels into different cell frequency bands to sort them for data...     

Effect of High-Temperature Air Exposure on the Microstructure and Mechanical Properties of β-Ti Honeycomb Sandwich Panels

Metallurgical and Materials Transactions A - Ti-β-21S honeycomb sandwich panels are used for aeroengine exhaust components due to its light density, high specific strength, and great...     

Designing new hybrid artificial intelligence model for CFST beam flexural performance prediction

Engineering with Computers - A substantial number of experimental studies have reported on the flexural performance of concrete-filled steel tube (CFST) beams. Due to the problem complexity,...     

An experimental investigation to augment the efficiency of photovoltaic panels by using longitudinal fins

The temperature of a photovoltaic (PV) panel has a negative effect on the generated power. As the solar irradiance that falls on the PV increases, the operating PV temperature rises, which leads to a decrease in electrical efficiency. Therefore, there arises a need to introduce a cooling system to minimize PV temperature. In this study, the simple passive cooling method of extending its surfaces with fins was used to reduce the PV temperature. Different numbers of longitudinal aluminum fins were attached to the bottom surface of a PV panel and their effects were examined under realistic weather conditions for Baghdad, Iraq. Results show that the use of the passive cooling method under natural convection will be more effective in reducing PV temperature before solar noon than after solar noon. The maximum power enhancement was about 2.5 W and occurred at solar noon when using 10 aluminum fins. The peak efficiency value of the PV panel with fin cooling was about 15.3% against 14% for the unfinned PV panel.     

Evaluation of hydrogen concentration effect on the natural gas properties and flow performance

The natural gas flowing through transmission pipeline is impure and has a wide range of non-hydrocarbons components at different concentrations like hydrogen. The presence of hydrogen in the natural gas mixture influences its properties and flow performance. The effect of hydrogen concentration on the natural gas flowing through a transportation pipeline has not been adequately investigated and widely comprehended. In this paper, several mixtures flow through pipeline include typical natural gas and hydrogen at different concentrations up to 10% are evaluated to demonstrate their impact on the flow assurance and the natural gas properties. The string Ruswil – Griespass part from the Transitgas project with 94 km length is simulated applying Aspen Hysys Version 9 and validated using Aspen Plus. The simulation specifications were 1.228 1 10⁶ kg/h mass flowrate, 1200 mm and 1164 mm the outer and inner diameters, and 75 bar and 29.4 °C operating pressure, and temperature. The effect of different hydrogen concentrations has been examined and the differences from the typical mixture are estimated. The results show that the presence of hydrogen in the natural gas mixture reduces its density, 10% hydrogen content records 11.78% reduction in the density of typical natural gas. Interestingly, it has been found that up to 2% of hydrogen concentration turns in elevating the viscosity of the typical natural gas while the viscosity decreases at the point that hydrogen content increases above 2%. In addition, the pressure losses over the transmission pipeline increases due to the presence of hydrogen, 10% hydrogen concentration turns in 5.39% increase in the pressure drop of the natural gas mixture. Also, the temperature drop across the pipeline decreases as the hydrogen concentration increases; 10% hydrogen content can result in a 6.14% reduction in the temperature drop across the pipeline. As well as, the findings prove that the hydrogen strongly impacts the phase envelope by changing from size symmetric to size asymmetric diagram. The effect of pipeline elevations has been investigated by changing the elevation up to 25 m uphill and 25 m downhill. The results state that increase the pipeline elevation turns in increasing the pressure losses over the pipeline length. Along with this, the results illustrate that the presence of hydrogen in the mixture elevates the critical pressure and reduces the critical temperature.     

An auto-learning approach for network intrusion detection

In this paper, we propose a novel intrusion detection technique with a fully automatic attack signatures generation capability. The proposed approach exploits a honeypot traffic data analysis to build an attack scenarios database, used to detect potential intrusions. Furthermore, for an effective and efficient intrusion detection mechanism, we introduce several new or adapted algorithms for signature generation, signature comparison, etc. Finally, we use DARPA’99 and UNSW-NB15 traffic to evaluate the proposed approach. The results indicate that the generated attack signatures are of high quality with low rates of false negatives and false positives.     

Natural products as a source of environmentally friendly corrosion inhibitors of mild steel in dilute sulphuric acid: Experimental and computational studies

Protection of Metals and Physical Chemistry of Surfaces - The inhibitory effect of Acacia cyanophylla leaves extract (ACLE) on Mild steel corrosion in 1 M H2SO4 solution was investigated using...