Integrated irradiance modelling in the urban environment based on remotely sensed data

The complexity of built form and land cover has often limited detailed model estimates of solar irradiance in the urban canopy. These limitations arise largely from difficulties in generating contiguous detailed spatial representations of solar obstructing features such as buildings and trees. This study presents a method that integrates remotely sensed datasets across spatial scales for estimating irradiance in urban areas. The method draws largely on airborne Light Detection and Ranging (LiDAR) technology with specific focus on estimating radiation transmission through urban vegetation. The incoming irradiance above the urban canopy is determined using atmospheric transmission derived from geostationary satellite imagery to provide a long-term record of seasonal fluctuations in cloud cover, and the associated direct and diffuse irradiance. Individual model components are analyzed for three urban study areas to assess the interactions between input model parameters and patterns of different urban form. Results indicate that representations of trees as opaque objects substantially underestimate solar irradiance across urban form types, demonstrating up to a 18% underestimate of direct irradiance in treed residential areas. Both atmospheric transmittance and urban form are also shown to be critical model parameters, and are discussed with reference to unique considerations for generating estimates of urban irradiance.     

Exergoeconomic analysis of a combined heat and power (CHP) system

This study deals with exergoeconomic analysis of a combined heat and power (CHP) system along its main components installed in Eskisehir City of Turkey. Quantitative exergy cost balance for each component and the whole CHP system is considered, while exergy cost generation within the system is determined. The exergetic efficiency of the CHP system is obtained to be 38.33% with 51 475.90 kW electrical power and the maximum exergy consumption between the components of the CHP system is found to be 51 878.82 kW in the combustion chamber. On the other hand, the exergoeconomic analysis results indicate that the unit exergy cost of electrical power produced by the CHP system accounts for 18.51 US$ GW^?1. This study demonstrates that exergoeconomic analysis can provide extra information than exergy analysis, and the results from exergoeconomic analysis provide cost‐based information, suggesting potential locations for the CHP system improvement. Copyright © 2007 John Wiley & Sons, Ltd.     

A primal decomposition method for the integrated design of multi-period production–distribution systems

We study the integrated design of strategic supply chain networks and the determination of tactical production-distribution allocations in the case of customer demands with seasonal variations. Given a set of potential suppliers, potential manufacturing facilities and distribution centers with multiple possible configurations, and customers with seasonal demands, the goal is to determine the configuration of the production-distribution system with the lowest sum of supply, production, transportation, inventory, and facility costs such that seasonal customer demands are met. We develop a mixed integer programming formulation and an integrated design methodology based on primal (Benders) decomposition. For a case study in the packaging industry, specialized acceleration techniques reduced the running times by a factor of 480. The company projects savings of 2% or $8.3 million by using the integrated rather than the optimal hierarchical configuration.     

Removal of toxic metal ions with magnetic hydrogels

Hydrogels, based on 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) were synthesized via photopolymerization technique and used for the preparation of magnetic responsive composite hydrogels. These composite hydrogels with magnetic properties were further utilized for the removal of toxic metal ions such as Cd(II), Co(II), Fe(II), Pb(II), Ni(II), Cu(II) and Cr(III) from aqueous environments. It was revealed that hydrogel networks with magnetic properties can effectively be utilized in the removal of pollutants. The results verified that magnetic iron particle containing p(AMPS) hydrogel networks provide advantageous over conventional techniques. Langmuir and Freundlich adsorption isotherms were applied for toxic metal removal and both isotherms were fit reasonably well for the metal ion absorptions.     

Isolators, polarizers, and other optical waveguide devices using a resonant-layer effect

This paper investigates the effect of a high-refractive-index layer added onto the clad layer of an optical waveguide. With proper design, the value of the fundamental mode's confinement factor in the added layer can exhibit a resonance. This resonance depends on the added layer's location, thickness, complex index, and wavelength of operation. If loss is incorporated into this added layer, relatively small changes in waveguide properties can result in large changes in loss. This phenomenon is referred to in this paper as the resonant-layer effect (RLE). A number of devices, including isolators, polarizers, and modulators, can be made and/or improved by using the RLE. As examples, this paper describes an integratable isolator giving 240-dB/cm isolation and 13-dB/cm insertion loss, an integratable polarizer with 90-dB/cm rejection and about 0.8-dB/cm insertion loss, and a 300-/spl mu/m-long modulator requiring electric fields of /spl plusmn/5 V//spl mu/m for /spl sim/45% intensity modulation. In general, the resonant layer need not be epitaxial with the waveguide, allowing for integration with a variety of material systems.     

Synthesis and characterization of novel pH‐responsive poly(2‐hydroxylethyl methacrylate‐co‐N‐allylsuccinamic acid) hydrogels for drug delivery

In this study, N‐allylsuccinamic acid (NASA) was synthesized in a single step with a yield of 85%. Carboxylic acid containing NASA was characterized through Fourier transform infrared (FTIR) radiation and ¹H‐NMR and ¹³C‐NMR analysis, and then it was used for synthesis of poly(2‐hydroxylethyl methacrylate‐co‐N‐allylsuccinamic acid) [p(HEMA‐co‐NASA)] hydrogels. The structure of the obtained pH‐responsive p(HEMA‐co‐NASA) hydrogels were characterized with FTIR spectroscopy and scanning electron microscopy analysis, and their swelling characterization was carried out under different drug‐release conditions. In the application step of the study, the hydrogels were used for the in vitro release of vitamin B12 and Rhodamine 6G, which were selected as model drugs. We determined that the hydrogels used as a drug‐delivery matrix could release the drug they had absorbed under different release conditions (phosphate‐buffered saline, 0.9% NaCl, and pH 1.2) at high rates for time periods of up to 24 h. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39660.     

Prediction of Discharge Coefficient for Trapezoidal Labyrinth Side Weir Using a Neuro-Fuzzy Approach

Adaptive neuro-fuzzy inference system (ANFIS) is considered for flow over trapezoidal labyrinth side weirs located on a straight channel as a substantial part of distribution channels in irrigation systems and treatment units. To estimate the outflow over a trapezoidal labyrinth side weir, the discharge coefficient in the side weir equation needs to be determined in according with the effective dimensionless parameters which is Froude number, the sidewall angle, the ratios of weir length to channel width, weir length to total crest length and weir height to flow depth. 670 laboratory test results are used for determining discharge coefficient of trapezoidal labyrinth side weirs. The performance of the ANFIS model is compared with artificial neural networks (ANN), non-linear regression (NLR) and multi-linear regression (MLR) models. The comparing criteria used for the evaluation of the models’ performances are root mean square errors (RMSE), mean absolute errors (MAE) and determination coefficient (R²) statistics. Comparison results indicated that the ANFIS technique could be successfully employed in modeling discharge coefficient. It is found that the ANFIS model with RMSE of 0.090 in test period is superior in estimation of discharge coefficient than the nonlinear and linear regression models with RMSE of 0.124 and 0.279, respectively.     

Exergetic performance evaluation of a combined heat and power (CHP) system in Turkey

This study deals with the exergetic performance assessment of a combined heat and power (CHP) system installed in Eskisehir city of Turkey. Quantitative exergy balance for each component and the whole CHP system was considered, while exergy consumptions in the system were determined. The performance characteristics of this CHP system were evaluated using exergy analysis method. The exergetic efficiency of the CHP system was accounted for 38.16% with 49 880 kW as electrical products. The exergy consumption occurred in this system amounted to 80 833.67 kW. The ways of improving the exergy efficiency of this system were also analysed. As a result of these, a simple way of increasing the exergy efficiency of the available CHP system was suggested that the valves‐I–III and the MPSC could be replaced by a 3500 kW‐intermediate pressure steam turbine (IPST). If the IPST is installed to the CHP system (called the modified CHP (MCHP) system), the exergetic efficiency of the MCHP system is calculated to be 40.75% with 53 269.53 kW as electrical products. The exergy consumption is found to be 77 444.14 kW in the MCHP system. Copyright © 2006 John Wiley & Sons, Ltd.