ANFIS pattern for molecular membranes separation optimization

In this work, molecular separation of aqueous-organic was simulated by using combined soft computing-mechanistic approaches. The considered separation system was a microporous membrane contactor for separation of benzoic acid from water by contacting with an organic phase containing extractor molecules. Indeed, extractive separation is carried out using membrane technology where complex of solute-organic is formed at the interface. The main focus was to develop a simulation methodology for prediction of concentration distribution of solute (benzoic acid) in the feed side of the membrane system, as the removal efficiency of the system is determined by concentration distribution of the solute in the feed channel. The pattern of Adaptive Neuro-Fuzzy Inference System (ANFIS) was optimized by finding the optimum membership function, learning percentage, and a number of rules. The ANFIS was trained using the extracted data from the CFD simulation of the membrane system. The comparisons between the predicted concentration distribution by ANFIS and CFD data revealed that the optimized ANFIS pattern can be used as a predictive tool for simulation of the process. The R2 of higher than 0.99 was obtained for the optimized ANFIS model. The main privilege of the developed methodology is its very low computational time for simulation of the system and can be used as a rigorous simulation tool for understanding and design of membrane-based systems. Highlights are, Molecular separation using microporous membranes. Developing hybrid model based on ANFIS-CFD for the separation process, Optimization of ANFIS structure for prediction of separation proces

Comparative study of conventional and unconventional designs of cathode flow fields in PEM fuel cell

The choice of an appropriate flow field distributor is crucial to circumvent mass and charge transfer resistance-related issues in proton exchange membrane fuel cells (PEMFCs). In this work, incorporating all the anisotropic nature of the gas diffusion layers (GDLs), a three-dimensional, multiphase CFD model is built to perform a comparative study of several types of cathode flow field designs. Three conventional (i.e. parallel, serpentine and interdigitated) and two recently-introduced (i.e. parallel with blocks and the metal foam) flow field designs were considered for the cathode side. The results showed that the best fuel cell performance is obtained with the metal foam flow field as it induces the lowest water saturation, the lowest values and more uniform distribution of current density and temperature as well as relatively medium pressure drop. Compared with the parallel flow field case, the peak power density increases by about 50% when using the metal foam flow field and by about 10% when using the other three investigated flow fields (i.e. serpentine, interdigitated and parallel with blocks). The parametric analysis reveals that the metal foam outperforms other designs at intermediate and high humidity conditions whereas the interdigitated flow field design outperforms other designs at low humidity conditions

Sweat permeable and ultrahigh strength 3D PVDF piezoelectric nanoyarn fabric strain sensor

Commercial wearable piezoelectric sensors possess excellent anti-interference stability due to their electronic packaging. However, this packaging renders them barely breathable and compromises human comfort. To address this issue, we develop a PVDF piezoelectric nanoyarns with an ultrahigh strength of 313.3 MPa, weaving them with different yarns to form three-dimensional piezoelectric fabric (3DPF) sensor using the advanced 3D textile technology. The tensile strength (46.0 MPa) of 3DPF exhibits the highest among the reported flexible piezoelectric sensors. The 3DPF features anti-gravity unidirectional liquid transport that allows sweat to move from the inner layer near to the skin to the outer layer in 4 s, resulting in a comfortable and dry environment for the user. It should be noted that sweating does not weaken the piezoelectric properties of 3DPF, but rather enhances. Additionally, the durability and comfortability of 3DPF are similar to those of the commercial cotton T-shirts. This work provides a strategy for developing comfortable flexible wearable electronic devices

Trace ammonium removal by liquid-liquid membrane contactors as water polishing step of water electrolysis for hydrogen production from a wastewater treatment plant effluent

© 2016 Society of Chemical Industry. BACKGROUND: This work evaluates hollow fiber liquid-liquid membrane contactors (HFMC) as a polishing step for the removal of low levels of ammonium from water purified by (or being supplied to) a membrane distillation unit in order to fulfil the conductivity requirements of hydrogen production by water electrolysis. RESULTS: The influence of the operating conditions (flow, pH, ammonium concentration, buffer capacity) were evaluated under a closed-loop setup in order to achieve a reduction of total ammonia concentration in water, from 15 to 1mgL-1 to assure the production of water in the membrane distillation with a conductivity lower than 1 µS cm-1. These values were used to validate a numerical algorithm describing the system performance. In order to reach the ammonia concentration requirements and considering the low concentration of bicarbonate (low pH buffer capacity) in the treated water a buffer agent was added to the working solution. CONCLUSIONS: HFMC technology is a suitable solution to remove low levels of ammonium from water to values as low as 1mgL- 1NH3 through appropriate control of pH. The ammonium removal efficiency of the HFMC was improved by raising the pH or the flow rate. Finally, the model proposed provides a good description of the membrane contactor performance with minimal deviations when compared with experimental results.Peer ReviewedPostprint (published version

Applicability of BaTiO 3 /graphene oxide (GO) composite for enhanced photodegradation of methylene blue (MB) in synthetic wastewater under UV–vis irradiation

Abstract(#br)Methylene blue (MB) is a dye pollutant commonly present in textile wastewater. We investigate and critically evaluate the applicability of BaTiO 3 /GO composite for photodegradation of MB in synthetic wastewater under UV–vis irradiation. To enhance its performance, the BaTiO 3 /GO composite is varied based on the BaTiO 3 weight. To compare and evaluate any changes in their morphologies and crystalline structures before and after treatment, BET (Brunauer–Emmett–Teller), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) tests are conducted, while the effects of reaction time, pH, dose of photocatalyst and initial MB concentration on its photodegradation by the composite are also investigated under identical conditions. The degradation pathways and removal mechanisms of MB by the BaTiO 3 /GO are elaborated. It is evident from this study that the BaTiO 3 /GO composite is promising for MB photodegradation through ·OH. Under optimized conditions (0.5 g/L of dose, pH 9.0, and 5 mg/L of MB concentration), the composite with 1:2 dose ratio of BaTiO 3 /GO has the highest MB degradation rate (95%) after 3 h of UV vis irradiation. However, its treated effluents still could not comply with the discharge standard limit of less than 0.2 mg/L imposed by national environmental legislation. This suggests that additional biological treatments are still required to deal with the remaining oxidation by-products of MB, still present in the wastewater samples such as 3,7-bis (dimethyl-amino)-10H-phenothiazine 5-oxide

Applicability of BaTiO3/graphene oxide (GO) composite for enhanced photodegradation of methylene blue (MB) in synthetic wastewater under UV-vis irradiation.

Methylene blue (MB) is a dye pollutant commonly present in textile wastewater. We investigate and critically evaluate the applicability of BaTiO3/GO composite for photodegradation of MB in synthetic wastewater under UV-vis irradiation. To enhance its performance, the BaTiO3/GO composite is varied based on the BaTiO3 weight. To compare and evaluate any changes in their morphologies and crystalline structures before and after treatment, BET (Brunauer-Emmett-Teller), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) tests are conducted, while the effects of reaction time, pH, dose of photocatalyst and initial MB concentration on its photodegradation by the composite are also investigated under identical conditions. The degradation pathways and removal mechanisms of MB by the BaTiO3/GO are elaborated. It is evident from this study that the BaTiO3/GO composite is promising for MB photodegradation through ·OH. Under optimized conditions (0.5 g/L of dose, pH 9.0, and 5 mg/L of MB concentration), the composite with 1:2 dose ratio of BaTiO3/GO has the highest MB degradation rate (95%) after 3 h of UV vis irradiation. However, its treated effluents still could not comply with the discharge standard limit of less than 0.2 mg/L imposed by national environmental legislation. This suggests that additional biological treatments are still required to deal with the remaining oxidation by-products of MB, still present in the wastewater samples such as 3,7-bis (dimethyl-amino)-10H-phenothiazine 5-oxide

Modelling Temperature Variation of Mushroom Growing Hall Using Artificial Neural Networks

The recent developments of computer and electronic systems have made the use of intelligent systems for the automation of agricultural industries. In this study, the temperature variation of the mushroom growing room was modeled by multi-layered perceptron and radial basis function networks based on independent parameters including ambient temperature, water temperature, fresh air and circulation air dampers, and water tap. According to the obtained results from the networks, the best network for MLP was in the second repetition with 12 neurons in the hidden layer and in 20 neurons in the hidden layer for radial basis function network. The obtained results from comparative parameters for two networks showed the highest correlation coefficient (0.966), the lowest root mean square error (RMSE) (0.787) and the lowest mean absolute error (MAE) (0.02746) for radial basis function. Therefore, the neural network with radial basis function was selected as a predictor of the behavior of the system for the temperature of mushroom growing halls controlling system

Comparison of flat and hollow-fiber mixed-matrix composite membranes for CO2 separation with temperature

Zeolite A/poly (1-trimethylsilyl-1-propyne) (zeoliteA/PTMSP) and [emim][Ac]/chitosan (IL/CS) are mixed-matrix membrane (MMM) materials with enhanced CO2/N2 permselectivity even at higher temperature. The scalability to asymmetric flat and hollow-fiber geometry by a simple dip-coating method was analyzed. The CO2/N2 separation performance was evaluated at different temperatures. The resulting composite membranes exhibit a significantly enhanced CO2permeation flux because the MMM layer thickness is reduced by 97?% from flat to hollow-fiber geometries in IL-CS composite membranes, while the selectivity is maintained similar to the self-standing membranes, thus proving that compatibility between the membrane component materials leads to a defect-free composite membrane, regardless the geometry and temperature.Financial support from the Spanish Ministry of Economyand Competitiveness (MINECO) under project CTQ2012-31229 at the Universidad de Cantabria is gratefully acknowl-edged. A.F.B. and C.C.C. also thank the MINECO for theEarly Stage Researcher (BES2013-064266) and ‘‘Ramón yCajal’’ (RYC2011-0855) contracts, respectively. The authorsthank F. Noboru Ramirez-Matsumoto for his contribution inthe synthesis and permeation experiments of the CS andIL-CS composite flat membranes by the modified IP method

Permselectivity improvement in membranes for CO2/N2 separation

In this work, small-pore zeolites of different topology (CHA, LTA5, Rho), all with Si/Al ratio of 5, have been added to highly permeable poly(1-trimethylsilyl-1-propyne) (PTMSP) to increase its selectivity and thermal and mechanical stability. Membranes were characterized by TGA, XRD, SEM and CO2 and N2 single gas permeation measurements at different temperatures. TGA reveal that the thermal resistance of the mixed matrix membranes (MMM) is as good as that of pure PTMSP polymer membranes. XRD and SEM results reflect that there is good interaction between the fillers and the membrane matrix, at 5 and 10 wt.% zeolite loadings, while at 20 wt.% a dual layer structure is formed, when Rho zeolite is the filler, because the particle size of Rho is higher than those of LTA5 or CHA, and voids appear that limit the permselectivity performance. In single gas permeation of N2 and CO2, the influence of temperature, zeolite loading and type is analyzed. The selectivity of pure PTMSP is considerably enhanced with the addition of the zeolites and the increase of temperature, and the MMM loaded with 5 wt.% zeolite surpassed the Robeson's upper bound for CO2/N2 separation, without decreasing the permeability too much. Upon increasing temperature from 298 to 333 K, the permselectivity is enhanced even further without loss of permeability. The 5 wt.% loaded membranes were tested in CO2/N2 mixed gas separation experiments at 333 K and 12.5 wt.% CO2 in the feed, and the permselectivity of LTA5- and Rho-PTMSP membranes was further enhanced, compared with the single gas permeation experiments.Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under project CTQ2012-31229 at the Universidad de Cantabria and MAT2012-38567-C02-01 and Severo Ochoa SEV-2012-0267 at the ITQ (UPV-CSIC) are gratefully acknowledged. A.F.B. and C.C.C. also thank the MINECO for the Early Stage Researcher (BES2013-064266) and ‘‘Ramón y Cajal’’ tenure-track (RYC2011-0855) contracts, respectively