Prediction of diesel fuel cold properties using artificial neural networks

In this paper, two neural networks, multilayer perceptron and networks with radial-basis function, were used to predict important cold properties of commercial diesel fuels, namely cloud point and cold filter plugging point. The developed models predict the named properties using cetane number, density, viscosity, contents of total aromatics, and distillation temperatures at 10, 50, and 90 vol. % recovery as input data. The training algorithms, number of hidden layer neurons, and number of training data points were optimized in order to obtain a model with optimal predictive ability. The results indicated better prediction of cloud and cold filter plugging points in the case of multilayer perceptron networks. The obtained absolute error mean for the optimal neural network models (0.58°C for the cloud point and 1.46°C for the cold filter plugging point) are within the range of repeatability of standard cold properties determination methods.     

Effect of the cerium (III) chloride heptahydrate on the corrosion inhibition of aluminum alloy

In the present work, the corrosion protection of aluminum alloy AA2024-T3 has been studied in NaCl solution, with and without the addition of cerium (III) chloride heptahydrate. The corrosion inhibitor efficiency after immersion into 10 mM NaCl, with or without 3 mM of CeCl₃·7H₂O at 20°C, 40°C, and 60°C was investigated. The performed quantitative tests include electrochemical techniques, such as the method of quasipotentiostatic polarization (Tafel extrapolation), cyclic polarization, and electrochemical impedance s pectroscopy to determine corrosion rate (v_corr), inhibition efficiency (η %), protective ability (γ), degree of coverage (ϑ), and pitting nucleation resistance. The samples were analyzed with scanning electron microscopy and energy dispersive X-ray analysis to evaluate and characterize the precipitates formed on the surface of aluminum samples and to determine dominant type of corrosion. The formation of Ce³⁺ precipitates occurred on cathodic intermetallic sites and the surface, in general, resulting in improved corrosion resistance. Tested cerium (III) chloride heptahydrate proved to be an effective inorganic corrosion inhibitor for AA2024-T3 in chloride solution, which, by the action of cerium ions, reduced corrosion on the surface of the studied aluminum alloy.     

Answer to the remarks on superconductivity in PdH

In this paper, the effect of heating rate on the microwave sintered 90W–7Ni–3Fe heavy alloys was investigated, with the heating rate in the range from 10 to 112 °C/min. When the alloys were sintered at the heating rate from 20 to 105 °C/min, they exhibit excellent properties with the relative density over 99%, tensile strength between 850 and 922 MPa and elongation around 20%. It has been shown that a faster heating rate results in smaller W grain size and larger W–W contiguity. The heating rate of 80 °C/min has the best combination of the microstructure and mechanical performance. Sintering under an optimized condition leads to the enhanced mechanical properties of 1020 MPa in tensile strength and 21% in elongation.     

The influence of constant axial compression pre-stress on the fatigue failure of torsion loaded tube springs

This paper reports the results of a series of biaxial static compression and torsion experiments performed to evaluate the effects of static compression stress on the fatigue life those smooth tubes made of high strength spring steel. Compression pre-stress was introduced by a solid steel bar inserted into a hollow spring and loaded with a screw-joint. The experimentally obtained results show a significant extension of fatigue strain life as a result of combining axial compression loading with torsion. Cracking behavior was observed and it was noted that compression pre-stresses contribute to retardation of the fatigue crack initiation process and, consequently, contribute to the extension of fatigue life. The fatigue shear crack initiated in a transverse direction. This crack continues to propagate in the same direction until it starts to propagate as a macro-crack on the maximum shear plane.     

An empirical confinement model for ANFO explosive

Ammonium-nitrate-fuel-oil (ANFO) explosive, one of the most used mining explosives, exhibits highly non-ideal behaviour. The non-ideality of the detonation is manifested in the strong dependence of the detonation velocity on the charge radius and existence and the characteristics of confinement. This can lead to the detonation velocities as low as one-third of the ideal velocity. The literature reported experimental detonation velocities of cylindrical ANFO charges confined in different confiners (aluminium, copper, steel, polymethyl methacrylate, and polyvinyl chloride) are analysed in this paper. An empirical confinement model, which relates the detonation velocity to the charge radius and the mass of the confiner to the mass of explosive ratio per unit length, is proposed. The model predicts the detonation velocity of unconfined and confined ANFO charges with a mean average percentage error of 8.8 %.     

Performance of Multi-Antenna Signaling Strategies Using Dual-Polarized Antennas: Measurement Results and Analysis

Multiple-input multiple-output (MIMO) wireless systems employ spatialmultiplexingto increase spectral efficiency or transmit diversity (space-time coding)techniques to improve link reliability.The performance of these signaling techniques is highly dependent on channelcharacteristics whichin turn depend on antenna height and spacing and richness of scattering. Theuse ofdual-polarized antennas is a cost- and space-effective alternative where twospatially separated uni-polarized antennas can be replaced by a singledual-polarizedantenna element. In this paper, we use fixed-wireless experimental datacollected in atypical suburban environment at 2.5 GHz to investigate the performance ofspatialmultiplexing and transmit diversity (Alamouti scheme) for a dual-polarizedantennasetup. Channel measurements were conducted over a cell of radius 7 km andchannel statistics such as K-factor, cross-polarizationdiscrimination (XPD), and fading signal correlation were extracted fromthe gathered data. At each location, differentcombinations of these parametersyield different performance (measured in terms of average uncoded bit errorrate)of spatial multiplexing and the Alamouti scheme.The results indicate that proper selection of the transmissionmode through feedback, if possible, can reduce thebit error rate by several orders of magnitude. Furthermore, the resultshint at the existence of a preferred-mode switching distance within a cell– above/below which one mode of transmission exhibits generally superiorperformance.     

Noise analysis of the UHF RFID system

Noise is one of the most important parameters in designing a radio frequency (RF) system. Especially in ultra-high frequency (UHF) RF identification (RFID) systems noise plays and important role. This is because the noise performance of the receiver chain is defined not only by the intrinsic noise of the receiver, but also by the large self-jammer signal. This self-jammer signal on the one hand requires that the receiver is designed for high input dynamic range which increases the intrinsic noise of the receiver. On the other hand this self-jammer signal through the effects of reciprocal mixing and range correlation contributes significantly to the total noise of the receiver. To our knowledge this is the first work that deals in detail with the amplitude and phase noise in a UHF RFID system.     

AC electrical resistance measurements of PdHx samples versus composition x

Electrical and optical properties of SnO₂ film deposited on indium tin oxide substrate by dip coating have been investigated. The electrical conductivity of the SnO₂ film exhibits the extrinsic conductivity mechanism with two shallow and deep donor levels. The current voltage characteristics of SnO₂ film confirm the presence of space charge limited conduction. The density of states at the Fermi level N(E_F) for the SnO₂ film was determined using current–voltage characteristics and was found to be 1.63 × 10¹⁶ eV⁻¹ m⁻³. The Seebeck coefficient of the SnO₂ at room temperature indicates the n-type electrical conductivity. The Seebeck coefficient suggests that the electrical conductivity of the SnO₂ film varies from n-type conductivity to p-type conductivity with increasing temperature. The optical constants, such refractive index as dielectric constants, were determined from the reflectance, transmittance and absorption spectra. The refractive index dispersion behavior of the SnO₂ film obeys the single oscillator model. The fundamental absorption edge in SnO₂ film is formed by the direct allowed transitions with band gap of 3.40 eV.     

Impact of Fusarium infection and fungicide treatment on wheat malt wort quality

Two wheat genotypes varying in susceptibility to infection by Fusarium species were assessed by four different treatments in the field: (a) control, (b) treated with fungicide (Prosaro®), (c) inoculated with Fusarium culmorum spores and treated with fungicide and (d) inoculated with F. culmorum spores. Wort quality indicators (saccharification time, speed of filtration, wort colour, pH, extract, air dried extract and dried extract) were determined using standard methods. The results indicate that infection with F. culmorum affected wort quality, particularly wort colour and significantly extended (or stopped) saccharification and rate of filtration. Treatment with fungicide reduced the extent of quality deterioration, even with samples infected with F. culmorum. The wheat type which was less susceptible to Fusarium infection produced less compromised worts, confirming its superiority to the more susceptible wheat genotype. Further study is suggested at a commercial scale to determine the interrelationship between Fusarium infection, fungicide treatment and wheat malt quality. © 2018 The Institute of Brewing & Distilling