Dewatering of Copper Flotation Tailings: Effect of Feed Dilution on the Thickener Performance

Aqueous slurries’ dewatering using gravity-driven thickeners is an essential unit operation in mineral processing. Thickener feed dilution is often used for enhanced flocculation and sediment compressibility. This work investigated the effect of feed dilution on thickener performance for copper flotation tailings. Furthermore, the performance of the feed dilution system (eductor) was investigated from theoretical and practical perspectives. The results indicated that reducing eductor discharge solid loading increased thickener underflow solid loading. Higher thickener feed flow rate also affected eductor performance, reducing its discharge solid loading by 4 wt.%. Finally, a smart thickener dilution system was proposed to maintain optimum dilution.     

The Effects of Properties of Waves on the Recovery of Ultrasonic Stimulated Waterflooding

The authors studied effects of wave frequency and power output on recovery of oil in an ultrasonic stimulated waterflooding process. A series of ultrasonic stimulated waterflooding experiments was conducted on conventional sand pack saturated with vaseline and kerosene (to represent oil). The frequency and power output of waves were varied in each experiment and the effects on oil recovery were studied. Increasing power output (intensity) of waves increased oil recovery. On the other hand, increasing frequency of the waves accelerates recovery of oil; however, the total amount of oil recovered was almost the same for waves of different frequencies. In addition to that effect of increasing power outputs of the waves on increasing the temperature was investigated.     

Blind signal-type classification using a novel robust feature subset selection method and neural network classifier

Automatic modulation recognition plays an important role for many novel computer and communication technologies. Most of the proposed systems can only identify a few kinds of digital signal and/or low order of them. They usually require high levels of signal-to-noise ratio. In this paper, we present a novel hybrid intelligent system that automatically recognizes a variety of digital signals. In this recognizer, a multilayer perceptron neural network with resilient back propagation learning algorithm is proposed as the classifier. For the first time, a combination set of spectral features and higher order moments up to eighth and higher order cumulants up to eighth are proposed as the effective features. Then we have optimized the classifier design by bees algorithm (BA) for selection of the best features that are fed to the classifier. This optimization method is new for this area. Simulation results show that the proposed technique has very high recognition accuracy with seven features selected by BA.     

Occupational dose assessment and National Dose Registry System in Iran

This report presents status of external and internal dose assessment of workers and introducing the structure of National Dose Registry System of Iran (NDRSI). As well as types of individual dosemeters in use, techniques for internal dose assessment are presented. Results obtained from the International Atomic Energy Agency intercomparison programme on measurement of personal dose equivalent H(p) (10) and consistency of the measured doses with the delivered doses are shown. Also, implementation of dosimetry standards, establishment of quality management system, authorisation and approval procedure of dosimetry service providers are discussed.     

Microstructure and thermoelectric performance evaluation of p-type (Bi,Sb)2Te3 materials synthesized using mechanical alloying and spark plasma sintering process

Journal of Materials Science: Materials in Electronics - In this paper, three p-type thermoelectric compounds, namely Bi0.5Sb1.5Te3, Bi0.3Sb1.7Te3, and Bi0.2Sb1.8Te3 were manufactured by mechanical...     

Effect of synthesis conditions on performance of a hydrogen selective nano-composite ceramic membrane

A hydrogen-selective nano-composite ceramic membrane was prepared by depositing a dense layer composed of SiO₂ and Al₂O₃ on top of a graded multilayer substrate using co-current chemical vapor deposition (CVD) method. The multilayer substrate was made by dip-coating a macroporous α-alumina tubular support by a series of boehmite solutions to get a graded structure. Using DLS analysis, it was concluded that decreasing hydrolysis time and increasing acid concentration lead to smaller particle size of boehmite sols. XRD analysis was carried out to investigate the structure of intermediate layer and an optimized calcination temperature of 973 K was obtained. SEM images indicated the formation of a graded membrane with a porous intermediate layer having a thickness of about 2 μm and a dense top selective layer with a thickness of 80–100 nm. Permeation tests showed that H₂ permeance flux decreased from 5 × 10⁻⁵ mol m⁻² s⁻¹ Pa⁻¹ for a fresh substrate to 6.30 × 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹ after 6 h of deposition, but H₂ selectivity over N₂ increased considerably from 5.6 to 203.     

Optimal steganography with blind detection based on Bayesian optimization algorithm

Pattern Analysis and Applications - An optimal steganography method is provided to embed the secret data into the low-order bits of host pixels. The main idea of the proposed method is that before...     

Correction to: Efficient cooperative multicarrier underwater acoustic communication over the Persian Gulf channel

Wireless Networks - The original version of this article unfortunately contained a mistake in the author group, where Dr. Seyed Mehdi Hosseini Andargoli was not included as a co-author of the...     

Game-theory-based lifetime maximization of multi-channel cooperative spectrum sensing in wireless sensor networks

Wireless Networks - Accurate and efficient detection of the radio-frequency spectrum is a challenging issue in wireless sensor networks (WSNs), which are used for multi-channel cooperative spectrum...     

Mapping Groundwater Potential Using a Novel Hybrid Intelligence Approach

Water Resources Management - Identifying areas with high groundwater potential is important for groundwater resources management. The main objective of this study is to propose a novel classifier...