Automatic Calibration for CE-QUAL-W2 Model Using Improved Global-Best Harmony Search Algorithm

CE-QUAL-W2 is widely used for simulating hydrodynamics and water quality of the aquatic environments. Currently, the model calibration is mainly based on trial and error, and therefore it is subject to the knowledge and experience of users. The Particle Swarm Optimization (PSO) algorithm has been tested for automatic calibration of CE-QUAL-W2, but it has an issue of prematurely converging to a local optimum. In this study, we proposed an Improved Global-Best Harmony Search (IGHS) algorithm to automatically calibrate the CE-QUAL-W2 model to overcome these shortcomings. We tested the performance of the IGHS calibration method by simulating water temperature of Devils Lake, North Dakota, which agreed with field observations with R2 = 0.98, and RMSE = 1.23 and 0.77 °C for calibration (2008–2011) and validation (2011–2016) periods, respectively. The same comparison, but with the PSO-calibrated CE-QUAL-W2 model, produced R2 = 0.98 and Root Mean Squared Error (RMSE) = 1.33 and 0.91 °C. Between the two calibration methods, the CE-QUAL-W2 model calibrated by the IGHS method could lower the RMSE in water temperature simulation by approximately 7–15%

Fabrication and properties of PVA-TiO2 hydrogel composites

AbstractThe preparation and properties of PVA-TiO2 hydrogel composites have been studied in this research. The results show that tensile strength and compression modulus of PVA-TiO2 hydrogel composites increased significantly, but the elongation did not changed obviously compared with the PVA hydrogel, indicating the good interaction between inorganic nanoparticles and organic polymer. Friction performance of the hydrogels was discussed, the friction of PVA-TiO2 hydrogel composites decrease than the PVA hydrogel and friction coefficient up to 0.001. The possible mechanism of friction was discussed

Light-emitting diodes enhanced by localized surface plasmon resonance

Light-emitting diodes [LEDs] are of particular interest recently as their performance is approaching fluorescent/incandescent tubes. Moreover, their energy-saving property is attracting many researchers because of the huge energy crisis we are facing. Among all methods intending to enhance the efficiency and intensity of a conventional LED, localized surface plasmon resonance is a promising way. The mechanism is based on the energy coupling effect between the emitted photons from the semiconductor and metallic nanoparticles fabricated by nanotechnology. In this review, we describe the mechanism of this coupling effect and summarize the common fabrication techniques. The prospect, including the potential to replace fluorescent/incandescent lighting devices as well as applications to flat panel displays and optoelectronics, and future challenges with regard to the design of metallic nanostructures and fabrication techniques are discussed

Water–Soil–Vegetation Dynamic Interactions in Changing Climate

Previous studies of land degradation, topsoil erosion, and hydrologic alteration typically focus on these subjects individually, missing important interrelationships among these important aspects of the Earth\u27s system. However, an understanding of water–soil–vegetation dynamic interactions is needed to develop practical and effective solutions to sustain the globe\u27s eco-environment and grassland agriculture, which depends on grasses, legumes, and other fodder or soil-building crops. This special issue is intended to be a platform for a discussion of the relevant scientific findings based on experimental and/or modeling studies. Its 12 peer-reviewed articles present data, novel analysis/modeling approaches, and convincing results of water–soil–vegetation interactions under historical and future climates. Two of the articles examine how lake/pond water quality is related to human activity and climate. Overall, these articles can serve as important references for future studies to further advance our understanding of how water, soil, and vegetation interactively affect the health and productivity of the Earth\u27s ecosystem. © 2017 by the authors

Automultiscopic Displays based on Orbital Angular Momentum of Light

Orbital angular momentum (OAM) of light has drawn increasing attention due to its intriguingly rich physics and potential for a variety of applications. Having an unbounded set of orthogonal states, OAM has been used to enhance the channel capacity of data transmission. We propose and demonstrate the viability of using OAM to create an automultiscopic 3D display. Multi-view image information is encoded using an OAM beam array, then sorted into different view directions using coordinate transformation elements. A three-view demonstration was achieved to encode and decode 9 by 9 pixel images. These demonstrations suggest that OAM could potentially serve as an additional platform for future 3D display systems.This research was performed under a joint collaboration between Disney Research and the University of Cambridge through the CAPE consortium. XL, JC and DC would like to thank the UK Engineering and Physical Sciences Research Council (EPSRC) for the support through the Platform Grant for Liquid Crystal Photonics (EP/F00897X/1).This is the author accepted manuscript. The final version is available from Institute of Physics via http://dx.doi.org/10.1088/2040-8978/18/8/085608

Sox10+ adult stem cells contribute to biomaterial encapsulation and microvascularization.

Implanted biomaterials and biomedical devices generally induce foreign body reaction and end up with encapsulation by a dense avascular fibrous layer enriched in extracellular matrix. Fibroblasts/myofibroblasts are thought to be the major cell type involved in encapsulation, but it is unclear whether and how stem cells contribute to this process. Here we show, for the first time, that Sox10+ adult stem cells contribute to both encapsulation and microvessel formation. Sox10+ adult stem cells were found sparsely in the stroma of subcutaneous loose connective tissues. Upon subcutaneous biomaterial implantation, Sox10+ stem cells were activated and recruited to the biomaterial scaffold, and differentiated into fibroblasts and then myofibroblasts. This differentiation process from Sox10+ stem cells to myofibroblasts could be recapitulated in vitro. On the other hand, Sox10+ stem cells could differentiate into perivascular cells to stabilize newly formed microvessels. Sox10+ stem cells and endothelial cells in three-dimensional co-culture self-assembled into microvessels, and platelet-derived growth factor had chemotactic effect on Sox10+ stem cells. Transplanted Sox10+ stem cells differentiated into smooth muscle cells to stabilize functional microvessels. These findings demonstrate the critical role of adult stem cells in tissue remodeling and unravel the complexity of stem cell fate determination

High-birefringence nematic liquid crystal for broadband THz applications

Liquid crystals (LCs) have been studied extensively in the visible range for their dielectric tunability, and the characterisation in the terahertz (THz) range has gained increasing interest due to the need for active THz modulation and switching devices. In this paper, we use THz time-domain spectroscopy to measure the frequency-dependent birefringence and the absorption coefficient of a number of commercial and non-commercial nematic LCs, including E7, BL037, MDA-98-1602, LCMS-107, GT3-23001 and 1825, over a range of bias voltages at room temperature. Furthermore, several basic components of LC mixture are analysed to establish their contributions to birefringence and theoretical model is used to fit the absorption spectra. The large tunability and low loss measured for a range of samples show that the LCs are useful tunable dielectrics for compact, efficient and broadband THz devices.The authors would like to thank the UK Engineering and Physical Sciences Research Council (EPSRC) for the support through the Platform Grant for Liquid Crystal Photonics (EP/F00897X/1).This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/10.1080/02678292.2016.115373

Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events

SWAT Modeling of Non-Point Source Pollution in Depression-Dominated Basins under Varying Hydroclimatic Conditions

Non-point source (NPS) pollution from agricultural lands is the leading cause of various water quality problems across the United States. Particularly, surface depressions often alter the releasing patterns of NPS pollutants into the environment. However, most commonly-used hydrologic models may not be applicable to such depression-dominated regions. The objective of this study is to improve water quantity/quality modeling and its calibration for depression-dominated basins under wet and dry hydroclimatic conditions. Specifically, the Soil and Water Assessment Tool (SWAT) was applied for hydrologic and water quality modeling in the Red River of the North Basin (RRB). Surface depressions across the RRB were incorporated into the model by employing a surface delineation method and the impacts of depressions were evaluated for two modeling scenarios, MS1 (basic scenario) and MS2 (depression-oriented scenario). Moreover, a traditional calibration scheme (CS1) was compared to a wet-dry calibration scheme (CS2) that accounted for the effects of hydroclimatic variations on hydrologic and water quality modeling. Results indicated that the surface runoff simulation and the associated water quality modeling were improved when topographic characteristics of depressions were incorporated into the model (MS2). The Nash–Sutcliffe efficiency (NSE) coefficient indicated an average increase of 30.4% and 19.6% from CS1 to CS2 for the calibration and validation periods, respectively. Additionally, the CS2 provided acceptable simulations of water quality, with the NSE values of 0.50 and 0.74 for calibration and validation periods, respectively. These results highlight the enhanced capability of the proposed approach for simulating water quantity and quality for depression-dominated basins under the influence of varying hydroclimatic conditions