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Several objective functions have been proposed in the literature to adjust the input parameters of a node in constructive networks. Furthermore, many researchers have focused on the universal approximation capability of the network based on the existing objective functions. In this brief, we use a correntropy measure based on the sigmoid kernel in the objective function to adjust the input parameters of a newly added node in a cascade network. The proposed network is shown to be capable of approximating any continuous nonlinear mapping with probability one in a compact input sample space. Thus, the convergence is guaranteed. The performance of our method was compared with that of eight different objective functions, as well as with an existing one hidden layer feedforward network on several real regression data sets with and without impulsive noise. The experimental results indicate the benefits of using a correntropy measure in reducing the root mean square error and increasing the robustness to noise.

AbstractThis study investigated the effects of ultrasound (US) and gas bubbling (GB) on permeate flux and membrane fouling. The ultrafiltration process of 1% skimmed milk was performed under various ultrasonic frequencies (37, 80 kHz, and tandem), irradiation modes (pulsed and sweeping), two-phase flow patterns (bubble and slug), and gas flow rates. The results showed that the US treatment improves the permeate flux up to 180%. The highest cleaning effect was obtained in the pulsed mode at 37 kHz. In the tandem frequency, the results showed that the fouling percentage significantly decreased with reduction in the frequency switching time. The GB injection treatment improved the mean of permeate flux up to 72% after 30 min. The slug pattern at medium gas flow rate was more effective than the other treatments. Best result was achieved in combination of the US (pulsed mode—37 kHz) and the GB (slug pattern—medium flow rate). In this condition, the permeate flux was significantly improved up to 384% in comparison with the control. Furthermore, the hydrodynamic resistance results showed the higher ability of the US in cleaning of membrane pores during ultrafiltration.

AbstractFouling phenomenon is well known as a main obstacle in membrane separation technology. In this study, the effects of bubbling with various hydrodynamic factors and gas–liquid solubility were evaluated on fouling control and permeation flux in ultrafiltration of skimmed milk solution. Direct gas injection and carbonated feed, as a new bubbling method, were used for bubbling. In the direct gas injection technique, various two-phase flow patterns (slug and bubble), gas flow rates, and bubbling modes (continuous and intermittent) were investigated during a cross-flow ultrafiltration. The results showed that the both of gas bubbling methods improved the permeation flux during 30-min filtration. The permeation flux was enhanced up to 72 and 40% by direct injecting of N2and CO2, respectively, while it was only enhanced up to 58% with carbonated feed. The evaluation of hydrodynamic resistance of membranes indicated that the gas bubbling by carbonated feed was more effective on the fouling resistance, while the cake resistance was affected by the gas injection during infiltration. In addition, the slug flow pattern was more effective than the bubble flow pattern on decline of membrane fouling. In the slug flow pattern, the permeate flux increased when medium flow rate was applied. Furthermore, ultrafiltration performance was improved using the intermittent gas bubbling mode. This study indicated that slug flow pattern with insoluble gas has a higher performance than the other ones in preventing fouling and flux enhancement during ultrafiltration processing.

AbstractMembrane processing has found many applications in various industries as an advanced method of separating materials in liquid or gas. The greatest obstacle in using membrane filtration technology is fouling, particularly in porous membranes. The fouling phenomenon is the result of organic and inorganic materials depositing on the surface and pores of membrane. In this study, the effect of ultrasound frequency (37, 80 kHz, and tandem) and amplitude of sonication (30, 60, and 90%) were evaluated on flux recovery during and after microfiltration. Results showed that the 37 kHz and tandem frequencies significantly improved the permeate flux at earlier minutes, particularly when tandem frequency was applied. In addition, the permeate flux was increased as the sonication power increased. However, the interaction effects between frequency and sonication power showed that the ultrasound frequencies were more effective than sonication power on flux recovery. Furthermore, the calculation of fouling percentage showed that both low frequencies and high amplitude together significantly reduced the fouling agents during the cleaning process. However, there were no remarkable statistical effects among the same levels of sonication power during the cleaning process. The interaction effects of various frequencies and powers of ultrasound on cleaning membranes were evaluated and more cleaning efficiency was observed in comparison to sonication power when low frequency applied.

•Effect of four sonication irradiation modes were studied on ultrafiltration process.•Interactions of ultrasound irradiation modes and US frequencies waves were studied.•Creating alternative mode by power intensity changings was more effective than frequency.•We have decreased fouling percentage to 10% by ultrasound assisted during 30min.•The best condition for ultrasound assisted ultrafiltration were introduced.

There has been a growing tendency for cooperation among Gulf Cooperation Council (GCC) countries in the development of economic and financial institutions. This has led to an increasing need for the standardisation of accounting regulations in order to improve cooperation and enhance the efficiency of the financial institutions amongst these. In this paper, an attempt has been made to investigate the accounting standards followed by the financial institutions in five selected GCC countries (Bahrain, Saudi Arabia, Oman, Qatar and the United Arab Emirates) with some policy prescriptions for harmonisation of the accounting regulations. This paper provides a comparative analysis of various accounting policies and practices, including loans and provisions, assets, investments, taxation, liabilities, foreign exchange, revenue recognition, and consolidation of each GCC countries banking and other financial institutions.