Integration of time series forecasting in a dynamic decision support system for multiple reservoir management to conserve water sources

In most of arid and semi-arid regions, there are limited sources of available fresh water for different domestic and environmental demands. Strategic and parsimonious fresh water-use in water-scarce areas such as Southern New Mexico is crucially important. Elephant Butte and Caballo reservoirs are two integrated reservoirs in this region that provide water supply for many water users in downstream areas. Since Elephant Butte Reservoir is in a semi-arid region, it would be rational to utilize other energy sources such as wind energy to produce electricity and use the water supply to other critical demands in terms of time and availability. This study develops a strategy of optimal management of two integrated reservoirs to quantify the savable volume of water sources through optimal operation management. To optimize operations for the Elephant Butte and Caballo reservoirs as an integrated reservoir operation in New Mexico, the authors in this case study utilized two autoregressive integrated moving average models, one non-seasonal (daily, ARIMA model) and one seasonal (monthly, SARIMA model), to predict daily and monthly inflows to the Elephant Butte Reservoir. The coefficient of determination between predicted and observed daily values and the normalized mean of absolute error (NMAE) were 0.97 and 0.09, respectively, indicating that the daily ARIMA prediction model was significantly reliable and accurate for a univariate based streamflow forecast model. The developed time series prediction models were incorporated in a decision support system, which utilizes the predicted values for a day and a month ahead and leads to save significant amount of water volume by providing the optimal release schedule from Elephant Butte into the Caballo Reservoir. The predicted daily and monthly values from the developed ARIMA prediction models were integrated successfully with the dynamic operation model, which provides the optimal operation plans. The optimal operation plan significantly minimizes the total evaporation loss from both reservoirs by providing the optimal storage levels in both reservoirs. The saved volume of the water would be considered as a significant water supply for environmental conservation actions in downstream of the Caballo Reservoir. Providing an integrated optimal management plan for two reservoirs led to save significant water sources in a region that water shortage has led to significant environmental consequences. Finally, since the models are univariate, they demonstrate an approach for reliable inflow prediction when information is limited to only streamflow values. We find that hydroelectric power generation forces the region to lose significant amount of water to evaporation and therefore hinder the optimal use of freshwater. Based on these findings, we conclude that a water scarce region like Southern New Mexico should gain independence from hydroelectric power and save the freshwater for supporting ecosystem services and environmental purposes.     

Highly Porous NiTi with Isotropic Pore Morphology Fabricated by Self-Propagated High-Temperature Synthesis

Highly porous NiTi with isotropic pore morphology has been successfully produced by self-propagating high-temperature synthesis of elemental Ni/Ti metallic powders. The effects of adding urea and NaCl as temporary pore fillers were investigated on pore morphology, microstructure, chemical composition, and the phase transformation temperatures of specimens. These parameters were studied by optical microscopy, scanning electron microscopy, x-ray diffraction, and differential scanning calorimetry (DSC). Highly porous specimens were obtained with up to 83% total porosity and pore sizes between 300 and 500 μm in diameter. Results show pore characteristics were improved from anisotropic to isotropic and pore morphology was changed from channel-like to irregular by adding pore filler powders. Furthermore, the highly porous specimens produced when using urea as a space holder, were of more uniform composition in comparison to NaCl. DSC results showed that a two-step martensitic phase transformation takes place during the cooling cycles and the austenite finish temperature (A _f) is close to human body temperature. Compression test results reveal that the compressive strength of highly porous NiTi is about 155 MPa and recoverable strain about 6% in superelasticity regime.     

Structural and Mechanical Properties of Al/B4C Composites Fabricated by Wet Attrition Milling and Hot Extrusion

In this study,Al matrix composites reinforced by 7.5 and 15 vol.%B₄C particles and also monolithic Al（Al without the B₄C particles） were produced by wet attrition milling and subsequent hot forward extrusion processes.The microstructure of the composites,evaluated by scanning electron microscopy（SEM）,showed that the B₄C particles were properly distributed in the Al matrix.Mechanical properties of the AI/B₄C composites and monolithic Al were investigated by tensile,wear and hardness tests.The results revealed that with increasing content of B₄C particles,the tensile strength and microhardness of composites increased but the elongation decreased.In addition,the tensile strength and microhardness of composite samples were higher than those of monolithic Al.The density measurements revealed that the density of composites decreased with increasing content of the B₄C particles.     

Computing the Szeged and PI Indices of VC5C7[p,q] and HC5C7[p,q] Nanotubes

In this paper we give a GAP program for computing the Szeged and the PI indices of any graph. Also we compute the Szeged and PI indices of VC₅C₇ [ p,q] and HC₅C₇ [ p,q] nanotubes by this program.     

BM3D frames and variational image deblurring

A family of the block matching 3-D (BM3D) algorithms for various imaging problems has been recently proposed within the framework of nonlocal patchwise image modeling , . In this paper, we construct analysis and synthesis frames, formalizing BM3D image modeling, and use these frames to develop novel iterative deblurring algorithms. We consider two different formulations of the deblurring problem, i.e., one given by the minimization of the single-objective function and another based on the generalized Nash equilibrium (GNE) balance of two objective functions. The latter results in the algorithm where deblurring and denoising operations are decoupled. The convergence of the developed algorithms is proved. Simulation experiments show that the decoupled algorithm derived from the GNE formulation demonstrates the best numerical and visual results and shows superiority with respect to the state of the art in the field, confirming a valuable potential of BM3D-frames as an advanced image modeling tool.     

Experimental and numerical study on lead-bismuth heat transfer in a fuel rod simulator

As a task of the EU project IP EUROTRANS towards development of an Accelerator Driven System (ADS) dedicated to the transmutation of long-lived fission products, experiments and simulations were performed on the TALL test facility at KTH to investigate thermal hydraulics along a single fuel rod simulator cooled by lead-bismuth eutectic (LBE). The fuel rod simulator is concentrically inserted in a tube, so that an annular channel is formed for LBE flow. This paper presents the measured temperature profiles in the annular channel, and the comparisons with the simulation results of the CFX code. The primary objective is to help understanding the LBE heat transfer characteristics and qualifying the turbulence and heat transfer modeling for LBE application. The quantitative comparison between the calculated and measured temperatures of the LBE indicates that the simulation underestimates the experiment at most radial and axial positions. Finally the uncertainties in measurement and the deficiency in turbulence models resulting in such a disagreement were discussed, which will be directive and beneficial to future work in the field.     

Preparation of thermally stable,low dielectric constant,pyridine‐based polyimide and related nanofoams

Reaction of 6‐chloronicotinoyl chloride with p‐phenylene diamine resulted in preparation of a dichloro diamide compound. Subsequently, chloro displacement of this compound with 4‐amino phenoxy groups led to production of a new pyridine‐based ether diamine named as N,N′‐(1,4‐phenylene)bis(6‐(4‐aminophenoxy) nicotinamide). Novel polyimide was prepared through polycondensation reaction of the diamine with hexafluoroisopropylidene diphthalic anhydride (6‐FDA) via two‐step imidization method. In addition, new nanoporous polyimide films were produced through graft copolymerization of polyimide as the continuous phase with a thermally labile poly (propylene glycol) oligomer as the labile phase. The grafted copolymers were synthesized using reaction of the diamine and 6‐FDA in the presence of poly (propylene glycol) 2‐bromoacetate as thermally labile constituent via a poly(amic acid) precursor process. The labile block was decomposed via thermal treatment to release inert molecules that diffused out of the matrix to leave pores with diameters between 30 and 60 nm. The structures and properties of polyimide and polyimide nanofoams were characterized by different techniques including ¹H‐NMR, FTIR, TGA, DMTA, SEM, TEM, dielectric constant, and tensile strength measurement. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013