Optimization of specific energy consumption for Bomaplex Red CR-L dye removal from aqueous solution by electrocoagulation using Taguchi-neural method

In this investigation, firstly, Taguchi method was applied to determine the optimum specific energy consumption (SEC) for dye removal from aqueous solution by electrocoagulation using aluminum electrodes. An orthogonal array (OA₁₆) experimental design that allows to investigate the simultaneous variations of five parameters (Initial dye concentration, Initial pH of the solution, Supporting electrolyte concentration, Supporting electrolyte type and Current density) having four levels was employed to evaluate the effects of experimental parameters with two replicates. According to Taguchi-neural method, while the optimum conditions that dye removal efficiency equals to 62.71 % were found to be initial dye concentration 600 mg/L, initial pH of the solution 6, supporting electrolyte concentration 7.0 mM, supporting electrolyte type NaCl, and current density 0.10 mA/cm². Under these optimum conditions, energy consumption is 0.38 kW h/m³. Alternatively, it can be said that optimum conditions can be modified as follows supporting electrolyte concentration of 10.0 mM and supporting electrolyte type CaCl₂, for 600 mg/L, initial dye concentration initial pH of the solution 6, and current density 0.10 mA/cm². Under these optimum conditions, SEC and dye removal efficiency are 0.45 kW h/m³ and 69.18 %, respectively.     

Uncertainties in the prediction of flow in a long reach of the Sacramento River

The accurate prediction of the flow field in a long reach of a complex waterway is prerequisite to the evaluation to acceptable engineering accuracy of strategies for the restoration, resource management and hazard assessment. In this study, we consider some aspects of the numerical prediction of flow in a long reach of the Sacramento River in California with view to gaining a better understanding the sources and the extent of the uncertainties that are present in the predictions. The predictions were obtained using a finite‐volume method to solve the time‐averaged forms of the equations governing the conservation of mass and momentum. Body‐fitted coordinates were used to define the complex river bathymetry. Both depth‐averaged and fully three‐dimensional (3D) computations were performed. The results were compared with data obtained from a large‐scale physical model of the same reach. The outcome of the comparisons served to provide the basis for the assessment of the sensitivity of the solutions to assumptions made regarding the conditions at inlet to the solution domain, the choice of turbulence model used to close the time‐averaged equations and, for the depth‐averaged calculations, the choice of method used for prescribing the bed friction. The influence of other parameters such as the density of the computational grid, the method used to define the channel bathymetry, and the unsteadiness of the mean flow that results from vortex shedding from a bridge pier and abutments were also assessed. The results obtained form a useful addition to the growing literature on the computational modelling of flows in natural waterways.     

Analysis,design, and optimization of structures with integral compliant mechanisms for mid‐frequency response

A multi‐scale paradigm is proposed that utilizes periodic, small‐scale, integral compliant mechanisms within larger‐scale structures for the attenuation of vibro‐acoustic response. Amplification principles serve as the basis for the design of these mechanisms in achieving reduced energy transmission. The spectral finite element method is exploited for a force–velocity and energy flow analysis of the resultant truss‐like structures. A genetic algorithm is employed to optimize structure size for greatest effectiveness in the frequency range of interest. This study demonstrates that a significant decrease in structural vibration is achievable and suggests promising applications including the design of acoustic isolation panels for broadband vehicle noise reduction. Copyright © 2007 John Wiley & Sons, Ltd.     

A general framework of a Reference Model for Intelligent Integrated Manufacturing Systems (REMIMS)

Today's highly competitive business environment forces the managers to continuously make the best decisions in the shortest possible time. The ability to provide concurrency among manufacturing functions is a critical need for modern organizations as, especially, distributed environment requires synchronization of manufacturing functions. Moreover, manufacturing companies need to have strong capability of adaptation (agility) mainly because of the dynamic relationships that must be established between manufacturing units. To achieve these, there is a need for an integrated manufacturing system that will handle all interactions and interrelationships which will then be affected by the changes and create maximum gain under limited resources. In order to create and effectively manage such an integrated manufacturing system there is a need for a reference model. In this paper, such a reference model called REference Model for intelligent Integrated Manufacturing System (REMIMS) is introduced. REMIMS has hierarchical architecture with several agents responsible for different manufacturing functions. To facilitate REMIMS and allow interaction among the agents to share their knowledge, a specific knowledge exchange protocol in a knowledge network is being developed.     

Flow forecast by SWAT model and ANN in Pracana basin,Portugal

This study provides a unique opportunity to analyze the issue of flow forecast based on the soil and water assessment tool (SWAT) and artificial neural network (ANN) models. In last two decades, the ANNs have been extensively applied to various water resources system problems. In this study, the ANNs were applied to the daily flow of the Pracana basin in Portugal. The comparison of ANN models and a process-based model SWAT was established based on their prediction accuracy. The ANN model was found to be more successful than the SWAT in relation to better forecast of peak flow. Nevertheless the SWAT model results revealed a better value of mean squared error. The results of this study, in general, showed that ANNs can be powerful tools in daily flow forecasts.     

Effect of steaming time on surface roughness of beech veneer

The objective of this study was to investigate effect of steaming time on surface roughness of beech (Fagus orientalis L.) veneer produced using the rotary cutting method. Three roughness parameters, average roughness (R_a), mean peak-to-valley height (R_z), and maximum roughness (R_max) obtained from a stylus type profilometer were used to evaluate the roughness of the veneer sheets. Surface roughness of the samples cut from the inner portion of the logs showed a significant dependence on steaming time. Among the specimens 20 h steaming time showed the smoothest surface . Surface roughness of veneer samples taken from both outer and middle portion of the logs did not show any statistically significant difference as steaming time was changed. Based on the findings in this study, it appears that steaming time should be approximately 20 h to have an ideal surface quality of the veneer with a minimum cost of production.     

99mTc-citrate versus 67Ga-citrate for the scintigraphic visualization of inflammatory lesions

Citric acid was labeled with 99mTc with an efficiency of > 99%. The biodistribution of 99mTc-citrate was studied in mice with turpentine-induced abscesses in comparison to 67Ga-citrate. The max. abscess/muscle concentration ratios were 4.61 +/- 1.92 (3 h) for 99mTc-citrate and 4.76 +/- 2.04 (4 h) for 67Ga-citrate. Arthritis was induced in 10 rabbits by intra-articular injection of ovalbumin Scintigrams obtained 4 days later and at 3 h post-injection of 99mTc-citrate showed increased activity involving the synovium. The max. arthritic/contralateral knee ratio was 3.19 +/- 1.29 (3 h) and 6.47 +/- 3.71 (24 h) for 99mTc- and 67Ga-citrate, respectively. The blood clearance curve of 99mTc-citrate in rabbits was biexponential with a fast (T1/2 = 36 min) and a slow (T1/2 = 18 h) component, compared to mono-exponential clearance of 67Ga-citrate (T1/2 = 23 h). In 10 patients with rheumatoid arthritis whole-body scintigrams and spot images of involved joints indicated localization of the tracer in inflamed tissues. The mean target-to-soft tissue ratios were 3.04 +/- 0.81 and 4.95 +/- 2.56 for 99mTc-citrate and 99mTc-MDP, respectively. Renal clearance of radioactivity was evident from the scintigrams. Our results demonstrated that 99mTc-citrate is effective as a radiopharmaceutical for the visualization of inflammatory lesions and may be preferred to 67Ga-citrate due to the ideal physical characteristics of the radionuclide, easy preparation, low cost, early accumulation and the preference for the renal route of excretion.     

Compressive moduli and network parameters of N‐isopropylacrylamide hydrogels copolymerized by monoesters of itaconic acid and crosslinked with tetraallylammonium bromide

The present study focuses on the mechanical properties of hydrophilically or hydrophobically modified poly(N‐isopropylacrylamide) (PNIPAAm) hydrogels, and all discussions on their improved mechanical strengths are based on the conformational effects of hydrophobic side chains attached to the comonomers and the structural differences between the crosslinkers. Three different types of monoalkyl itaconates, bearing octyl (Oc), cetyl (Ce), and cyclohexyl (CH) groups as comonomers, were used to prepare the copolymeric PNIPAAm hydrogels crosslinked with N,N′‐methylenebisacrylamide (BIS) and tetraallylammonium bromide (TAB) as neutral tetrafunctional and ionic octafunctional crosslinkers, respectively. The most striking result is the compressive E modulus of TAB‐crosslinked PNIPAAm hydrogel containing 10 mol % of mOcI. It reaches nearly 1.0 MPa and is independent of the temperature and pH of the swelling/shrinking medium. The result was discussed in terms of the inter/intramolecular interactions between hydrophobic octyl groups adopting a rod‐like conformation in the case of 25 °C/distilled deionized water (DDW) and 37 °C/DDW combinations. Further, it was observed that the electrostatic repulsive forces between the carboxylate groups on mOcI units could be suppressed even at 37 °C and pH 9 due to the rod‐like conformations of C₈H₁₇ groups. Its micrographs under bright‐field and polarized light supported the presence of an ordered anisotropic phase and multiple associations of extended, hydrophobic side chains. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45039.     

An effective synthesis route for improving the catalytic activity of carbon-supported Co–B catalyst for hydrogen generation through hydrolysis of NaBH4

A novel method for synthesis of carbon-supported cobalt boride catalyst was developed for hydrogen generation from catalytic hydrolysis of NaBH₄ solution. The activated carbon and carbon black supported catalysts prepared by “reduction–precipitation” method were found to be much more active than those prepared by conventional “impregnation–reduction” method inspite of the same Co content. A maximum hydrogen generation was achieved using carbon black supported Co–B, which lowers the activation energy to 56.7 kJ mol⁻¹. The effects of NaOH concentration (1–15 wt.%), NaBH₄ concentration (5–20 wt.%) and reaction temperature (25–40 °C) on the performance of the most active catalyst (Co–B/C_B) were investigated in detail. The results indicated that this catalyst can be used in a hydrogen generator for mobile applications such as PEMFC systems due to its high catalytic activity and simple preparation method.