A hybrid FRTOC-SA algorithm for product mix problems with fuzzy processing time and capacity

Identification and determination of products and their quantities according to available resources is called product mix problem in manufacturing plants. One of the efficient and easy to use algorithms for solving product mix problems in uncertainty conditions is Fuzzy Revised Theory of Constraints (FRTOC) that was proposed by Azadegan et al. (2011). Their algorithm had a complete neighborhood search. So, it needed a long process to calculate the best result when demands of products were too much. Therefore, according to abilities of simulated annealing (SA) algorithm, we proposed a hybrid algorithm based on FRTOC and SA. In other words, the SA method is used instead of searching all neighbors in FRTOC. Also, a numerical example is used to show the capabilities of the proposed algorithm in comparison with the FRTOC.     

Discharge characteristics of a modified oblique side weir in subcritical flow

Side weirs are frequently used in many water projects. Due to their position with respect to the flow direction, side weirs are categorized as plain, oblique and labyrinth. One of the advantages of an oblique side weir is the increase in the effective length of the weir for overflowing and, therefore, diverting more discharge with the same channel opening, weir height and flow properties (i.e., upstream discharge, upstream Froude number and so on). In this paper, an experimental set-up of a new design of an oblique side weir with asymmetric geometry has been studied. The hydraulic behavior of this kind of oblique side weir, with a constant opening length, different weir heights and asymmetric oblique angle, has been investigated in a subcritical situation. The results from over 200 test measurements show that this kind of weir is up to 2.33 times more efficient with respect to the conventional side weir in a rectangular channel among the tested conditions. Finally, the discharge coefficient as a function of geometrical and flow variables are presented for design engineers. In addition, a more precise relation has been obtained for flow with Froude numbers less than 0.4.     

Selective etching of polylactic acid in poly(styrene)‐block‐poly(d,l)lactide diblock copolymer for nanoscale patterning

Self‐assembled thin films of a lamellar forming polystyrene‐block‐poly(d,l )lactide (PS‐b‐PLA) block copolymer (BCP) contain a “reactive” block that can be readily removed to provide a template for substrate pattern formation. Various methods of PLA removal were studied here with a view to develop the system as an on‐chip etch mask for substrate patterning. Solvo‐microwave annealing was used to induce microphase separation in PS‐b‐PLA BCP with a periodicity of 34 nm (L_o) on silicon and silicon on insulator (SOI) substrates. Wet etches based on alkaline and enzymatic solutions were studied in depth. Fourier transform‐infrared (FT‐IR) analysis showed that basic hydrolysis using sodium hydroxide (NaOH) or ammonium hydroxide (NH₄OH) solutions resulted in greater PLA removal in comparison to an enzymatic approach using Proteinase K in a Tris‐HCl buffer solution. However, in the enzymatic approach, the characteristic self‐assembled fingerprint patterns were retained with less damage. Comparison to a dry etch procedure using a reactive ion etch (RIE) technique was made. A detailed study of the etch rate of PS and PLA homopolymer and PS‐b‐PLA shows depending on DC bias, the etch selectivity of PLA and PS can be almost doubled from 1.7 at DC bias 145 V to 3 at DC bias 270 V. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40798. Together with Krebs et al., J. Appl. Polym. Sci. (2014) 131 , 40795, doi: 10.1002/app.40795 , this article is part of a Special Issue on Polymers for Microelectronics. The remaining articles appear in J. Appl. Polym. Sci. (2014) volume 131 , issue 24. This note was added on 1st July 2014.     

Enhanced optical properties of ZnS–rGO nanocomposites for ultraviolet detection applications

In this research, fabrication and characterization of ultraviolet (UV) detectors based on zinc sulfide–reduced graphene oxide (rGO) nanocomposite with the focus on the wurtzite structure of zinc sulfide was carried out. The nanoparticles of ZnS were synthesized using chemical deposition method and annealed at 500?°C under flow of argon. X-ray diffraction pattern showed that ZnS with the wurtzite phase was formed at 500?°C. Here, rGO as a unique material with similar properties to graphene such as high electron transport was used in order to improve the optical properties of ZnS. For this purpose, rGO was added to ZnS with three different weight percentages of 5, 10 and 15. Scanning electron microscopy showed that ZnS nanoparticles were well placed in rGO sheets. The UV–visible spectra of the synthesized composites showed that with increasing rGO in composite, light absorption is increased. Photoluminescence (PL) spectra also showed that with increasing the percentage of rGO the generation of electron-hole in composite was increased and PL peak was enhanced. The effect of elevated generation of electron-hole pairs was apparent in optoelectrical properties of fabricated UV detectors based on the sample with higher concentration of rGO in composite. For this sample, the response time was decreased to 310 ms, and the sensitivity to UV irradiation was increased by 7.7 times.     

Anchoring of Copper(II) Schiff Base Complex into Aminopropyl-Functionalised MCM-41: A Novel,Efficient and Reusable Catalyst for Selective Oxidation of Alcohols

A copper(II) complex containing tetradentate N₂O₂ Schiff base ligand immobilized into aminopropyl-functionalised MCM-41 (mobile crystalline material number 41), was prepared and characterized by Fourier-transform infrared, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, N₂ adsorption–desorption and inductively coupled plasma analysis techniques. The novel heterogeneous catalyst, MCM-41-pr-NH₂-CuL, can be successfully applied for efficient and selective oxidation of different primary and secondary alcohols to the corresponding carbonyl compounds using hydrogen peroxide as an oxidant in acetonitrile at 60 °C. The effect of reaction parameters such as solvent, amount of catalyst, temperature and kind of oxidant on the oxidation of benzyl alcohol was also studied. The prepared catalyst could be recovered and reused four times without important loss of its catalytic performance. The heterogeneous MCM-41-pr-NH₂-CuL catalyst was found to be catalytically more active in the oxidation of alcohols compared to the similar type of copper(II) Schiff base complex in homogeneous media under the same reaction conditions.     

A walk around the decarboxylative C-S cross-coupling reactions

This review highlights a number of recent discoveries and advances in the construction of carbon-sulfur bonds through decarboxylative cross-coupling reactions between carboxylic acids and sulfur-containing coupling partners. Particular emphasis is placed on the mechanistic aspects of the reactions.     

Hydrophobicity of fluorocarbon-finished electrospun poly (acrylonitrile) nanofibrous webs

This article reports the hydrophobicity of fluorocarbon-finished nanofibrous webs composed of electrospun poly (acrylonitrile) nanofibers with fiber diameter in the range of about 100–3000 nm. The results obtained from sliding angle and contact angle measurements tests are reported. It was found that the contact angle of unfinished samples with average fiber diameters of about 700, 980 , and 3050 nm lies between 132° and 134°, indicating a rather high and at the same time not much different hydrophobicity for the webs. However, after finishing the electrospun nano- and microfibrous webs, the contact angle increased by a considerable amount to 138°–157° for the webs with average fiber diameter in the range of about 100–3050 nm, respectively. Sliding angle test of the finished nanofibrous webs showed a minimum angle of about 3° for the web with average fiber diameter of 3055 nm. To the best of authors’ knowledge, the rolling angle of 3° is the smallest rolling angle ever reported in the literature. The result of this work showed also that sliding angle test may be more sensitive than contact angle test. It was also ascertained that none of the Wenzel model and Cassie–Baxter model can represent the superhydrophobicity of the fluorocarbon-finished nano- and microfibrous webs.     

Development of a complete and straightforward hybrid model for gray water treatment

Clean Technologies and Environmental Policy - One of the most essential methods for preserving water resources is water reuse. The present study has been aimed at adjusting a gray water treatment...     

Multiple Protective Roles of Nanoliposome-Incorporated Baicalein against Alpha-Synuclein Aggregates

Nanoparticles are useful for increasing drug stability, solubility, and availability. The small molecule baicalein inhibits fibrillation, and detoxifies aggregates of α-synuclein (αSN) associated with Parkinson's disease (PD), but it suffers from instability, low solubility and consequent low availability. Here it is demonstrated that incorporation of baicalein into zwitterionic nanoliposomes (NLP-Ba) addresses these problems. NLP-Ba inhibits αSN fibril initiation, elongation, secondary nucleation, and also depolymerizes mature fibrils more effectively than free baicalein and prevents soluble αSN aggregates from seeding new fibrils. Importantly, NLP-Ba perturbs oligomers’ capacity to permeabilize the membrane. The interaction between NLP-Ba and αSN is confirmed by different biophysical techniques. This nanosystem crosses the blood-brain barrier in vitro and is effective against rotenone neurotoxicity in vivo. The effect of NLP-Ba on αSN fibrillation/cytotoxicity is attributed to a combination of free baicalein and empty NLPs. The results indicate a neuroprotective role for NLP-Ba in decreasing αSN pathogenicity in PD and highlight the use of nanoliposomes to mobilize poorly soluble hydrophobic drugs.     

Effect of defects and loading on prediction of Young��s modulus of SWCNTs

In this paper, the influence of various vacancy and Stone-Wales defects on the Young??s modulus of single-walled carbon nanotubes is investigated via a structural model. Dispersion in experimental results is the motivation for this work. Our results show that the type of method used (loading and boundary condition) for the prediction of the Young??s modulus of SWCNTs is very important for the results. The effect of different types of defects on the Young??s modulus is also studied for zigzag and armchair nanotubes with various aspect ratios (length/diameter). A comparison of our results with those of experimental methods indicates that for the exact prediction of the Young??s modulus of SWCNTs we need to apply the correct conditions.