Optimizing the Runoff Estimation with HEC-HMS Model Using Spatial Evapotranspiration by the SEBS Model

Most of the commonly used hydrological models do not account for the actual evapotranspiration (ETa) as a key contributor to water loss in semi-arid/arid regions. In this study, the HEC-HMS (Hydrologic Engineering Center Hydrologic Modeling System) model was calibrated, modified, and its performance in simulating runoff resulting from short-duration rainfall events was evaluated. The model modifications included integrating spatially distributed ETa, calculated using the surface energy balance system (SEBS), into the model. Evaluating the model’s performance in simulating runoff showed that the default HEC-HMS model underestimated the runoff with root mean squared error (RMSE) of 0.14 m³/s (R²?=?0.92) while incorporating SEBS ETa into the model reduced RMSE to 0.01 m³/s (R²?=?0.99). The integration of HECHMS and SEBS resulted in smaller and more realistic latent heat flux estimates translated into a lower water loss rate and a higher magnitude of runoff simulated by the HECHMS model. The difference between runoff simulations using the default and modified model translated into an average of 95,000 m³ runoff per rainfall event (equal to seasonal water requirement of ten-hectare winter wheat) that could be planned and triggered for agricultural purposes, flood harvesting, and groundwater recharge in the region. The effect of ETa on the simulated runoff volume is expected to be more pronounced during high evaporative demand periods, longer rainfall events, and larger catchments. The outcome of this study signifies the importance of implementing accurate estimates of evapotranspiration into a hydrological model.

     

A study on melt recycling of bio-based polypropylene/thermoplastic starch compound

The compulsion to use bioplastics has increased significantly today. One of the important aspects of plastics is their recyclability. Therefore, the important question of this research is that although bio-based compounds containing starch are sensitive to thermal-mechanical recycling processes, are such products thermally recyclable? To answer the question, polypropylene (PP)/thermoplastic starch (TPS) compound granules were extruded up to five times, and in the other part, single-extruded granules were blended at different ratios with virgin granules by extrusion. In order to characterize these samples, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, rotational disc rheometry, tensile properties, and appearance evaluation were used. The results showed that it is possible to recycle PP/TPS granules up to four times repetition of the extrusion operation and the fifth repetition also showed slight changes. There was also a blend of single-extruded granules with virgin material up to a 50:50% composition without significant variation.     

In situ synchrotron X-ray micro-tomography study of pitting corrosion in stainless steel

Pitting corrosion of stainless steel has been investigated with high-resolution in situ X-ray microtomography. The growth of pits at the tip of stainless steel pins has been observed with 3D microtomography under different conditions of applied current and cell potential. The results demonstrate how pits evolve in stainless steel, forming a characteristic “lacy” cover of perforated metal. In addition, it is shown how the shape of pits becomes modified by MnS inclusions.     

Considering rupture directivity effects,which structures should be named ‘long‐period buildings’?

Recorded accelerograms in the regions near active faults may have specific characteristics that inclusion of their effects on the response of structures is necessary. Of particular importance are permanent displacement, i.e. fling‐step, rupture directivity pulses and high‐frequency content. Several researchers have focused on the effects of rupture directivity pulses on response of structures. They have shown that long‐period structures are severely affected by these types of excitations. However, in near‐fault regions, the question ‘which building structures are long period?’ has not been clearly and quantitatively answered. In this paper, responses of 10‐, 20‐, 30‐ and 40‐story steel structures designed based on Uniform Building Code 1997 regulations are investigated under artificial pulses produced by directivity effects. It is shown that, considering rupture directivity effects, a long‐period structure is the one that has a first‐mode period–to–pulse period ratio greater than about 0.44. Furthermore, the effects of variations in the period of the near‐fault velocity pulses on the characteristics of inelastic response of structures are examined. Consequently, analysis of the structures experiencing actual near‐fault records indicates that the pattern of response spectrum obtained from artificial pulses presents the behavior of the structure under real near‐fault earthquakes rather accurately. Copyright © 2010 John Wiley & Sons, Ltd.     

NaLuF4:Yb,Tm up-conversion materials: Investigation of UV emission intensity by experimental design

NaLuF₄ doped Yb/Tm upconversion phosphor was synthesized by a facile hydrothermal method, using EDTA as a chelating agent. The influence of synthesis parameters was investigated on UV emission intensity through face-centered central composite design (CCD). Four parameters including F:RE ratio, pH value, reaction time and ethanol percent were considered as independent variables. It was found that pH value and F:RE ratio have the highest effect on emission intensity and the ethanol percent and the reaction time have mild and low influence on it. Furthermore, at pH 4, nano spherical particles with cubic phase were formed and change of other parameters had low influence on phase transformation. However, the hexagonal micro prisms with the hexagonal phase were predominant at pH?≥?6. The role of EDTA was indicated on phase transformation and aggregation of particles at the various value of pH. It was shown that the crystal phase, the surface smoothness and the particle size are influential factors on UV emission intensity.     

Mobile Web Browsing with Aural Flows: An Exploratory Study

Existing web applications force users focus their visual attention on mobile devices while browsing content and services while on the go. To support eyes-free, mobile experiences, designers can minimize interaction with a device by leveraging the auditory channel. Whereas acoustic interfaces have proven to be effective in reducing visual attention, a perplexing challenge is designing aural information architectures for the web. To address this problem, techniques to remodel existing information architectures as linear, aural flows were introduced and evaluated. Mobile web browsing with aural flows is exemplified in ANFORA News, a semiaural mobile site designed to browse large collections of news stories. An exploratory study involving frequent news readers (n?=?20) investigated the usability and navigation experience with ANFORA News in a mobile setting. Initial evidence suggests that aural flows are a promising paradigm to support eyes-free mobile navigation while on the go, but users still require assistance and additional learning to fully master the aural mechanics of the flows while on the go. Future work will improve on the mechanisms to customize content and control the aural navigation.     

Synthesis of ZnS–Mn nano-luminescent pigment for ink applications

In the present study, ZnS–Mn nano-luminescent pigments were synthesized, using co-precipitation method. Polyvinylpyrrolidine (PVP) surface modifier and Mn dopant concentrations were considered as affecting parameters. The luminescent ink was loaded with two different concentrations of pigments. The obtained ink was silk-screened on different types of fabrics mainly treated cotton, cotton and nylon. Structure, microstructure, luminescent properties of nano-pigments, inks and fabrics and also rheological properties of the inks were investigated. The results showed that the ceramic ink prepared with nano-luminescent pigment had high photoluminescence (PL) intensity. Moreover, the optimum concentrations of Mn and PVP for obtaining maximum PL intensity were found as 2 and 5 wt%, respectively. SEM images of fabrics indicated that nanoparticles were loaded, nonuniformly, on the fibers. The treated linen and nylon fabrics showed maximum and minimum PL intensity, respectively, due to ink penetration depth in the fabrics. Furthermore, washing fastness estimated for all fabrics was in the proper range.     

Use of inkjet printing to deposit magnesium chloride salt patterns for investigation of atmospheric corrosion of 304 stainless steel

Inkjet printing was used to deposit MgCl₂ salt patterns on 304 stainless steel foils to investigate atmospheric corrosion. Results were found to be more consistent if initial hydration (1 h at ∼90% RH) of the printed salt pattern was carried out. The pit diameter following exposure at 45% RH and 300 K for 24 h was found to increase with the diameter of the original salt deposit, which is consistent with the idea of cathodic limitation of the pit current. For a constant deposition area, the pit diameter increases with increased salt deposition density, which may be associated with a lower ohmic drop resulting from a higher droplet, or could be influenced by enhanced corrosion during the initial hydration stage.     

Solution combustion synthesis of FeCr2O4 powders for pigment applications: Effect of fuel type

Solution combustion synthesis of iron chromite was reported using iron(III) nitrate nonahydrate and chromium(III) nitrate nonahydrate as starting materials, as well as glycine, urea, citric acid, and ethylene glycol as fuels. The influence of fuel type on the structure, molecular, microstructure as well as chromatic properties of samples was investigated. The X-ray diffraction (XRD) patterns showed that unlike themodynamical prediction, glycine fuel led to strongest combustion and consequent highest XRD peak intensities and lower lattice parameters. Moreover, the change of fuel type and mixing of fuels affected XRD data. Fourier transform infrared analysis showed that the band position of Cr–O and Fe–O bonds were shifted to higher frequencies by using of fuels with weaker combustion reactions. In addition, scanning electron micrographs showed that different morphologies of FeCr₂O₄ particles were obtained depending on the fuel type and ratios. Energy-dispersive X-ray spectroscopy analysis of the samples showed that oxygen concentration of samples was less than that of stoichiometric ratio of FeCr₂O₄ due to local reducing atmosphere. Furthermore, chromatic properties of the powders showed that the pigment synthesized with glycine fuel has a better and lighter grayish brown color than the other ones and can be used as a suitable industrial candidate to create a brown color in the ceramic glaze.     

Solution combustion synthesis of FeCr2O4:Zn,Al pigment powders

FeCr₂O₄:Zn,Al pigment powders were prepared via a solution combustion synthesis method. Effects of Zn and Al dopants and less/extra Fe content on the structure, molecular bonds, and optical properties of powders were studied. Results showed that addition of dopants as well as extra/less content of Fe led to weaker combustion and consequently lower X-ray diffraction peak intensities, lattice parameters, and differential thermal analysis peak intensities. Moreover, Fourier transform infrared analysis illustrated that the band position of Cr–O and Fe–O bonds were shifted to higher frequencies with moving away from stoichiometry. In addition, scanning electron micrographs showed that in all samples, porous spongy microstructures were formed with highly flake-like agglomerated particles. Furthermore, there was a significant difference between the powder samples and the tiles colored with in glaze powders due to the partial dissolution of pigments in contact with the molten glaze of tiles. In comparison to the tile colored with the stoichiometric FeCr₂O₄ pigments without dopants, the color difference (ΔE) in the tiles colored by the iron chromite pigments doped with Zn and Al dopants and less/extra Fe content reached the high values as large as ΔE = 36.19. The solar reflectance values (R_s) in near-infrared region were above 50% in all samples. Near 80% R_s in the tile colored by the iron chromite pigment doped with 3 mol% Zn and the yellowish brown appearance (L* = 43.44, a* = 6.77, b* = 18.38, c* = 19.59, h = 69.79) showed that the sample was a good candidate for cool building materials such as roof tiles.