Statistical Optimization for Production of Light Olefins in a Fluidized‐Bed Reactor

The methanol‐to‐olefins reaction (MTO) was studied in a small‐scale fluidized‐bed reactor over synthesized silicoaluminophosphate (SAPO‐34) catalysts. Mesoporous nanocrystalline SAPO‐34 molecular sieves were synthesized hydrothermally by ultrasonic and microwave‐assisted aging processes in the presence of hexadecyltrimethylammonium bromide (CTAB) and tetradecyldimethyl(3‐trimethoxysilylpropyl)ammonium chloride (TPOAC) as surfactant agents. The Box‐Behnken experimental design method was applied to determine the optimum operating parameters of this process conducted in the fluidized‐bed reactor. The optimum conditions in terms of reaction temperature, ratio of inlet gas velocity to minimum fluidizing velocity, and MeOH weight fraction were evaluated.     

Highly efficient synthesis of coumarin derivatives in the presence of H14[NaP5W30O110] as a green and reusable catalyst

A variety of heteropolyanions including: Keggin, Dawson, Preyssler, mixed addenda and sandwich types, catalyzed the formation of 4-methylnaphtho-(1,2-b)-pyran-2-one (coumarin) from the condensation of α-naphthol and ethylacetoacetate in a solvent free system and under heating conditions. Our data vividly indicate that sodium30–tungsto pentaphosphate, [NaP₅W₃₀O₁₁₀]¹⁴⁻, which so-called Preyssler’s anion, with high hydrolytic (pH 0–12) and thermal stability is the catalyst of choice. This catalyst catalyzed the synthesis of other coumarin derivatives in high yields and good selectivity.     

Water-soluble Copolymers of N-vinylpyrrolidone and Vinyl Acetate: Synthesis, Characterization, and Monomer Reactivity at High Conversions

Homogeneous copolymers of N-vinylpyrrolidone (VP) and vinyl acetate (VA) which form clear aqueous solutions were prepared by free radical polymerization in a solution of isopropanol alcohol, using 2,2-azobisisobutyronitrile as an initiator. They were characterized by FTIR, ¹H-NMR, and element analysis studies. The reactivity ratios of the monomer were computed by the Extended Kelen–Tüdós method at high conversions, using data from both ¹H-NMR and elemental analysis studies. The reactivity ratios of VP and VA in a homogenous copolymer were observed to be very different from that of a heterogeneous copolymer. Additional information was obtained by finding out the sequence length distribution for copolymers.     

Implementation of optical perfect-shuffle module

Experimental details are presented of the measured performance of a novel implementation of a cascadable module for the one-dimensional perfect shuffle of a two-dimensional array of optical signals. The design uses an anamorphic telescope to correct the difference in pitch in the two axes resulting from an image split and recombine operation performed with patterned mirrors. The performance of the cylindrical lens limits the scalability of the design.     

Components for the implementation of free-space optical crossbars

We describe an optical system developed to form the basis of a 64 × 64 free-space optical matrix-matrix crossbar switch. The design and performance of each of the main optical components is discussed: lenses, diffractive optical elements, and polarizing beamsplitters, together with the optomechanical hardware design. For these components, throughput levels of -6.9 dB have been achieved, which is compatible with full system operation at 10(-12) bit error rates at ≥270 Mbits s(-1).     

Fuzzy risk assessment of mortality after coronary surgery using combination of adaptive neuro‐fuzzy inference system and K‐means clustering

In this paper, a fuzzy expert system based on adaptive neuro‐fuzzy inference system (ANFIS) is introduced to assess the mortality after coronary bypass surgery. In preprocessing phase, the attributes were reduced using a univariant analysis in order to make the classifier system more effective. Prognostic factors with a p‐value of less than 0.05 in chi‐square or t‐student analysis were given to inputs ANFIS classifier. The correct diagnosis performance of the proposed fuzzy system was calculated in 824 samples. To demonstrate the usefulness of the proposed system, the study compared the performance of fuzzy system based on ANFIS method through the binary logistic regression with the same attributes. The experimental results showed that the fuzzy model (accuracy: 96.4%; sensitivity: 66.6%; specificity: 97.2%; and area under receiver operating characteristic curve: 0.82) consistently outperformed the logistic regression (accuracy: 89.4%; sensitivity: 47.6%; specificity: 89.4%; and area under receiver operating characteristic curve: 0.62). The obtained classification accuracy of fuzzy expert system was very promising with regard to the traditional statistical methods to predict mortality after coronary bypass surgery such as binary logistic regression model.     

A neural-network packet switch controller: scalability, performance, and network optimization

We examine a novel combination of architecture and algorithm for a packet switch controller that incorporates an experimentally implemented optically interconnected neural network. The network performs scheduling decisions based on incoming packet requests and priorities. We show how and why, by means of simulation, the move from a continuous to a discrete algorithm has improved both network performance and scalability. The system's limitations are examined and conclusions drawn as to its maximum scalability and throughput based on today's technologies.     

Integrated Fuzzy DEA-ANFIS to Measure the Success Effect of Human Resource Spirituality

Workplace spirituality has gained attention as it is proven to be a contributor to organizational performance improvement. This paper aims to assess the impact of human resource spirituality on the success of organizational strategic change projects. The success of the projects is measured by the well-known criterion of deviation from the planned budget cost. Data collection is based on a questionnaire survey of 252 personnel in 36 large and medium-scale organizational change projects in power industry. The paper proposes an integrated algorithm of fuzzy data envelopment analysis (FDEA) and adaptive network-based fuzzy inference system (ANFIS) for measuring the pure effect of human resource spirituality on the success of organizational change projects in the power industry. It also achieves a verified tool capable of addressing complexity, nonlinearity, ambiguity, and fuzziness for measuring spirituality of human resources in the projects. Results show that spirituality of the project team has a significant effect on project success.     

High molecular weight plasticizers in thermoplastic starch/polyethylene blends

In this study thermoplastic starch (TPS) was prepared with four different molecular weight polyol plasticizers: glycerol, sorbitol, diglycerol and polyglycerol. Diglycerol-TPS (DTPS) and polyglycerol-TPS (PTPS) show significantly lower moisture uptake and a higher temperature stability when compared to conventional glycerol-TPS (GTPS). TPS formulations were blended with HDPE at a concentration of 20 TPS/80 HDPE wt% and a range of interfacial modifier contents via a one-step extrusion process. The emulsification curves of the blends, which track the volume and number average diameter of the dispersed TPS domains with per cent interfacial modifier, show significantly different profiles and a non-correspondence between the d _n and d _v values at the critical concentration for interfacial saturation. The addition of small amounts of interfacial modifier to the blends prepared with diglycerol and polyglycerol results in TPS dispersed phases of wide polydispersity with droplets in the order of 200–300 nm coexisting with droplets of 5–7 µm. This wide polydispersity of TPS phase size can give insight into the mechanism of droplet formation in these systems with interfacial modifier and is indicative of an erosion-type mechanism, where small portions of the TPS droplet break off at the outer part of the droplet. Blends prepared with GTPS and sorbitol-TPS do not display this behaviour and show a more classic correspondence of d _n and d _v at the critical concentration. Dynamic mechanical analysis shows miscible behaviour for DTPS and PTPS and partially miscible behaviour for GTPS. This phenomenon was attributed to the presence of ether bonds in the chemical structure of diglycerol and polyglycerol. The increased chain flexibility and lower cohesive energy forces of diglycerol and polyglycerol lead to a more homogeneous TPS phase and consequently an erosion-type compatibilization at the interface. The mechanical properties of blends prepared with polyglycerol and diglycerol show a similar overall behaviour to glycerol.