Investigation of Rainfall Forecast System Characteristics in Real-Time Optimal Operation of Urban Drainage Systems

This study investigates the role of rainfall forecast system characteristics in predictive real-time optimal operation (PRTOP) of urban drainage systems (UDSs). A simulation-optimization model is proposed integrating the stormwater management rainfall-runoff simulator, the harmony search optimization algorithm, and a rainfall forecasting module. This module generates different rainfall forecast scenarios depending on the forecast (time) horizon (FH) and the forecast type (perfect or imperfect). Five adaptive PRTOP models are compared to evaluate the relationships between the FH, forecast type, and the system’s relative regulating capacity (SRRC). The models are tested in a part of UDS of Tehran, capital of Iran. Results indicate that for the studied system, perfect knowledge of future rainfall is more beneficial for a specific range of the SRRC, equal to 80–90% of its upper bound. Besides, the performance of the PRTOP model improves with increasing the FH up to a certain point, and then having no further positive effect. Finally, the PRTOP model equipped with a hypothetical forecasting model where the forecast error is a nonlinear function of the forecast lead time still performs better than both a zero-FH reactive RTOP model and short forecast horizon PRTOP models.

     

Robust nonlinear control schemes for finite-time tracking objective of a 5-DOF robotic exoskeleton

This paper investigates the finite-time robust tracking problem for a 5-DOF (degrees of freedom) upper-limb exoskeleton robot subjected to parametric uncertainties, unmodelled dynamics, and unknown human efforts. By developing the non-singular terminal sliding mode control approach, three innovative schemes of robust torques are proposed to steer configuration variables (angular displacements of joints) of the 5-DOF robotic exoskeleton to the reference trajectories within adjustable finite times. Based on mathematical analysis, it is proven that all suggested schemes of control inputs (input torques) accomplish and provide the mentioned tracking objective accurately. In addition, several new formulas (in the form of inequalities) are derived to determine and tune the needed finite times for achieving the tracking objective. Finally, three numerical examples are given to show the appropriate performance and the acceptable effectiveness of the proposed finite-time robust control schemes.     

Optimization and application of dry film photoresist for rapid fabrication of high-aspect-ratio microfluidic devices

Fabrication of high-aspect-ratio PDMS microfluidic devices with conventional SU-8 based soft photolithography is challenging, and often, the thickness of the master from which PDMS replicas are molded is non-uniform. Here, we present an optimized, low cost, fast prototyping microfabrication technique to make deep (up to 500 μm) and high-aspect-ratio (up to 10) microfluidic channels by producing masters by laminating a single or multiple layers of a thin dry film photoresist onto metal wafers. In particular, we explore the required exposure energy for different film thicknesses as well as the highest achievable channel depths and aspect ratios. The homogeneity of the depth of PDMS channels formed using these masters is quantified and found to be remarkably uniform over distances of 20 mm or more. The importance of the processing parameters, such as the exposure energy and development time on final feature size, wall angle, and channel aspect ratio, is investigated. In addition, we report some failure cases, the potential reasons, and strategies for making optimized devices. Potentially, deep microfluidic channels with a wide range of aspect ratios can be used to make long, homogenous separation devices that can be used in cell sorting, filtration, and flow cytometry. We believe the protocols we outline here will be of great utility to the microfluidics community.     

Synthesis of mesoporous flower-like iron oxide nanostructures from iron alkoxide precursor and their application in the catalytic reduction of 4-nitrophenol

Journal of Porous Materials - Mesoporous flower-like FeOOH nanostructure was synthesized via hydrolysis of flower-like iron glycolate in aqueous methylamine solution and ethanol as a solvent with a...     

Influence of Graphene Oxide on Thermally Induced Shape Memory Behavior of PLA/TPU Blends: Correlation with Morphology,Creep Behavior,Crystallinity, and Dynamic Mechanical Properties

In this study, shape memory is thermally induced in a series of graphene oxide (GO) filled poly(lactic acid)/thermoplastic polyurethane (PLA/TPU) blends, prepared via melt mixing process, and their shape recovery and shape fixity are measured, and the results are correlated with morphology, dynamic mechanical properties, crystallinity and creep recovery behavior. Morphological analysis by scanning and transmission electron microscopy reveals that the blends are immiscible, and GO platelets are mainly localized in the TPU phase of the blends, which lead to smaller and more elongated TPU droplets with improved interfacial adhesion being responsible for the improved shape recovery performance compared to the unfilled blend. A systematic enhancement found in storage and Young's modulus, tensile strength, creep resistance and creep recovery, and cold crystallinity as a result of GO inclusion are in agreement with the improved shape recovery, shape fixity and overall shape memory performance of the filled systems. The developed PLA/TPU/GO nanocomposites with highly improved mechanical properties can be utilized as a new class of environmentally friendly shape memory materials for a broad range of applications.     

Time Dependent Behavior of Neutron Emission in Dena Plasma Focus

The paper reports on some experimental studies carried out on Dena plasma focus (25 kV, 288 μF, 90 kJ) device with the deuterium filling gas. Time dependent neutron energy spectrum for each discharge, is obtained using an extended time of flight method by five fast neutron scintillators detectors. Temporal change of the neutron emission and the related pinch phases are found and discussed.     

Functionalisation of carbon nanotubes by methotrexate and study of synchronous photothermal effect of carbon nanotube and anticancer drug on cancer cell death

Carboxylated functionalised multi‐walled carbon nanotubes (f‐MWCNT) were synthesised. Furthermore, folic acid (FA) and methotrexate (MTX) through ethylenediamine (ED) were attached to the surface of f‐MWCNT to synthesise MWCNT–ED–FA and MWCNT–ED–MTX. Release studies of MTX as free drug and in MWCNT–ED–MTX were performed. These studies showed that MTX release rate from MWCNT–ED–MTX decreased in comparison with free MTX, which is due to the MTX attachment on the MWCNT. The anticancer effect of MWCNT–ED–FA and MWCNT–ED–MTX on the breast cancer cell line (MCF‐7) was studied. Studies have shown that MWCNT–ED–MTX cytotoxicity is more than that of MWCNT–ED–FA, which is due to the presence of MTX. Furthermore, the anticancer effects of MWCNT–ED–FA and MWCNT–ED–MTX in the presence of infrared laser radiation on the MCF7 cell were studied. The experiments showed that in the presence of the laser, the cytotoxicities of MWCNT–ED–FA and MWCNT–ED–MTX were the same and increased in comparison with laser absence, which indicates that the photothermal effect is stronger than other factors and mask their effects. This effect can be related to laser radiation absorption by MWCNT and its conversion to heat which can induce cancer cell death. Targeting studies have shown that MWCNT–ED–FA is targeted to the cancer cells due to the presence of FA.Inspec keywords: nanoparticles, nanomedicine, nanocomposites, drug delivery systems, tumours, carbon nanotubes, photothermal effects, toxicology, drugs, cancer, cellular biophysics, nanofabricationOther keywords: MWCNT–ED–FA, MWCNT–ED–MTX cytotoxicity, f‐MWCNT, synchronous photothermal effect, carbon nanotube, anticancer drug, cancer cell death     

Plasma Focus Device as a Breeder of Proton to Produce Short Lived Radioisotope <Superscript>18</Superscript>F

In a plasma focus device, the nuclear fusion products are created through the thermal and non-thermal (beam-target) mechanisms. The beam target character of the pinched plasma is used to determine the yield of 3.02 Mev protons (when deuterium filling gas is used) at the optimized regime. For this situation, a combination of “moving boiler” model and a shock wave theory are employed. The numerical simulations for the production of the positron emitter nuclide, ¹⁸F (T _1/2 = 110 min; widely used in positron emission tomography), for two Mather type devices (NX2 and PF1000) show that, the rules of the drift velocity as well as the drive parameters have an high impact on the final yields.     

Effect of Maillard‐based conjugation with dextran on the functional properties of lysozyme and casein

The purpose of this research was to find the best experimental conditions for glycosylation of lysozyme and casein with dextran, and to investigate the effect of glycosylation on the functional properties of these proteins. Glycosylation was performed by allowing proteins to react with dextran under Maillard reaction conditions. The extent of glycosylation was determined by sugar analysis, SDS‐PAGE, gel filtration and cation‐exchange chromatography. Glycosylation of lysozyme with a 1:5 weight ratio of protein to dextran, held at 60 °C for one week under a relative humidity of 79% resulted in coupling of 3.0 mole dextran to one mole lysozyme. In the case of casein, at 60 °C, 48 h and 79% relative humidity, 0.1 and 0.13 mole dextran was attached to one mole of casein when a weight ratio of protein to dextran of 1:5 and 1:7.5 was used, respectively. A decrease in the degree of glycosylation occurred when samples were incubated for 72 h. Enzymatic activity of glycosylated lysozyme was reduced by 20% compared with unmodified lysozyme (P < 0.05). Both proteins exhibited improved solubility at different pH values (3, 7 and 9), different temperatures (25, 40 and 60 °C) and increased heat stability, with a better emulsion activity and emulsion stability than with un‐modified proteins (P < 0.05). These changes might increase the applicability of lysozyme as a natural antimicrobial and casein as a protein ingredient in different food systems. Copyright © 2005 Society of Chemical Industry     

Do web sites change customers’ beliefs? A study of prior–posterior beliefs in e-commerce

Web sites are the main interface between online merchants and their customers. Despite the consequent importance of web-site design, there is little theoretical foundation that can be used to assess how web-design factors lead e-customers to revise their earlier beliefs. Our study examined web customers’ salient beliefs and the role of web-design elements in altering customers’ existing beliefs after their exposure to an e-commerce web site. Using salient beliefs and categories of web-design elements identified previously, we developed a conceptual model of belief revisions due to exposure to web-design elements and internal cues. The empirical analysis of the model indicated that web customers were influenced by the external cues from the design factors as well as the internal ones from their prior beliefs. Our findings have implications in designing web sites for e-commerce.