9 research outputs found

    Efficient surface water flow simulation on static Cartesian grid with local refinement according to key topographic features

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    Aiming at improving the computational efficiency without accuracy losses for surface water flow simulation, this paper presents a structured but non-uniform grid system incorporated into a Godunov-type finite volume scheme. The proposed grid system can detect the key topographic features in the computational domain where high-resolution mesh is in need for reliably solving the shallow water equations. The mesh refinement is automatically carried out in these areas while the mesh in the rest of the domain remains coarse. The criterion determining the refinement is suggested by a dimensionless number with a fixed value of 0.2 after sensitivity analysis. Three laboratory and field-scale test cases are employed to demonstrate the performance of the model for flow simulations on the new non-uniform grids. In all of the tests, the grid system is shown to successfully generate high-resolution mesh only in those areas with abruptly changing topographic features that dominate the flooding processes. To produce numerical solutions of similar accuracy, the non-uniform grid based model is able to accelerate by about two times comparing with the fine uniform grid based counterpart

    Tuning and Designing the Self-Assembly of Surfactants: The Magic of Carbon Nanotube Arrays

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    Controlling the self-assembly and polymorphic transition of surfactants is a challenging but meaningful topic for chemists and materials scientists, which is significant for the preparation of advanced nanomaterials. We presented coarse-grained (CG) molecular dynamics (MD) simulations on the self-assembly of surfactants confined within the carbon nanotube (CNT) arrays. Under the effect of confinement, an intriguing “rod-double helix-hexagon-worm” polymorphic transition was observed with varying the size of the confining space. The simulations also showed that the confinement of CNT arrays does not break the characteristic of surfactant assemblies at certain concentration. Based on these results, a plausible strategy for designing complex assemblies was presented. And then, “nano-drill” and “dartboard” assemblies were created with the strategy. This work demonstrated that the confinement of CNT arrays may be an efficient method to tune and design the self-assembly of surfactants, shedding light on the development of nanotechnology and advanced materials

    Association of caffeine intake with erectile dysfunction among normal weight and overweight/obese men in NHANES 2001–2004.

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    <p><sup>†</sup>Adjusted for age, vigorous and moderate physical activity, smoking status, education, race/ethnicity, obesity (BMI ≥ 30 kg/m<sup>2</sup>), total water intake (plain and tap), total energy (continuous), alcohol (continuous). Error bars represent 95% confidence intervals. <i>P</i><sub><i>trend</i></sub><i>= 0</i>.<i>08 and P</i><sub><i>interaction</i></sub><i>= 0</i>.<i>09</i>. <sup>*</sup>Erectile dysfunction was defined as “sometimes” or “never” able to maintain an erection for satisfactory sexual intercourse. <sup>‡</sup> Approximately 170–375 mg/day of caffeine intake is equivalent to 2–3 cups of coffee. <sup>a</sup>Overweight/obesity = body mass index ≥ 25 kg/m<sup>2</sup>.</p

    Association of caffeine intake with erectile dysfunction in NHANES 2001–2004 (n = 3724).

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    <p><sup>†</sup>Adjusted for age, vigorous and moderate physical activity, smoking status, education, race/ethnicity, obesity (BMI ≥ 30 kg/m<sup>2</sup>), total water intake (plain and tap), total energy (continuous), alcohol (continuous). Error bars represent 95% confidence intervals. <i>P</i><sub><i>trend</i></sub><i>= 0</i>.<i>19</i>. <sup>*</sup>Erectile dysfunction was defined as “sometimes” or “never” able to maintain an erection for satisfactory sexual intercourse. <sup>‡</sup>Approximately 170–375 mg/day of caffeine intake is equivalent to 2–3 cups of coffee.</p

    Self-Healing Chameleon Skin Functioning in the Air Environments

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    Chameleons are famous for their uncommon ability to change skin colors rapidly by tuning the lattice distance of guanine nanocrystals within the dermal iridophores. This mechanism has inspired various artificial photonic crystal (PC) films with tunable structural colors. However, the structural colors of most reported films are facile to be destroyed by external factors such as friction, impact, or water evaporation. Herein, an artificial intelligent skin, which has an elastomer–colloidal photonic crystal–hydrogel sandwich structure, is presented in this work. The outer modified polydimethylsiloxane layer acts as the cuticle to protect the hydrogel layer from water evaporation and endows the skin with self-healing ability. The inner hydrophilic hydrogel layer embedded with the colloidal photonic crystals acts as the dermis layer, and the polystyrene colloids layer plays the role of the guanine nanocrystals. A programmed color change can be easily controlled by varying the elongation of the artificial skin, covering the full visible spectrum range. Moreover, skin with patterned stripes, which is similar to the panther chameleon skin that can manipulate multiple colors, has also been achieved. The present artificial skin will offer fresh perspectives on the preparation of artificial chameleon skin similar to the real dynamic flexible skin, which would promote the application of PCs in optical devices

    Self-Healing Chameleon Skin Functioning in the Air Environments

    No full text
    Chameleons are famous for their uncommon ability to change skin colors rapidly by tuning the lattice distance of guanine nanocrystals within the dermal iridophores. This mechanism has inspired various artificial photonic crystal (PC) films with tunable structural colors. However, the structural colors of most reported films are facile to be destroyed by external factors such as friction, impact, or water evaporation. Herein, an artificial intelligent skin, which has an elastomer–colloidal photonic crystal–hydrogel sandwich structure, is presented in this work. The outer modified polydimethylsiloxane layer acts as the cuticle to protect the hydrogel layer from water evaporation and endows the skin with self-healing ability. The inner hydrophilic hydrogel layer embedded with the colloidal photonic crystals acts as the dermis layer, and the polystyrene colloids layer plays the role of the guanine nanocrystals. A programmed color change can be easily controlled by varying the elongation of the artificial skin, covering the full visible spectrum range. Moreover, skin with patterned stripes, which is similar to the panther chameleon skin that can manipulate multiple colors, has also been achieved. The present artificial skin will offer fresh perspectives on the preparation of artificial chameleon skin similar to the real dynamic flexible skin, which would promote the application of PCs in optical devices

    Association of caffeine intake with erectile dysfunction among men with and without hypertension in NHANES 2001–2004.

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    <p><sup>†</sup>Adjusted for age, vigorous and moderate physical activity, smoking status, education, race/ethnicity, obesity (BMI ≥ 30 kg/m<sup>2</sup>), total water intake (plain and tap), total energy (continuous), alcohol (continuous). Error bars represent 95% confidence intervals. <i>P</i><sub><i>trend</i></sub><i>= 0</i>.<i>13 and P</i><sub><i>interaction</i></sub><i>= 0</i>.<i>30</i>. <sup>*</sup>Erectile dysfunction was defined as “sometimes” or “never” able to maintain an erection for satisfactory sexual intercourse. <sup>‡</sup> Approximately 170–375 mg/day of caffeine intake is equivalent to 2–3 cups of coffee. <sup>a</sup>Hypertension = systolic/diastolic blood pressure ≥140/90 mmHg, self-reported diagnosis, or medication treatment.</p

    Self-Healing Chameleon Skin Functioning in the Air Environments

    No full text
    Chameleons are famous for their uncommon ability to change skin colors rapidly by tuning the lattice distance of guanine nanocrystals within the dermal iridophores. This mechanism has inspired various artificial photonic crystal (PC) films with tunable structural colors. However, the structural colors of most reported films are facile to be destroyed by external factors such as friction, impact, or water evaporation. Herein, an artificial intelligent skin, which has an elastomer–colloidal photonic crystal–hydrogel sandwich structure, is presented in this work. The outer modified polydimethylsiloxane layer acts as the cuticle to protect the hydrogel layer from water evaporation and endows the skin with self-healing ability. The inner hydrophilic hydrogel layer embedded with the colloidal photonic crystals acts as the dermis layer, and the polystyrene colloids layer plays the role of the guanine nanocrystals. A programmed color change can be easily controlled by varying the elongation of the artificial skin, covering the full visible spectrum range. Moreover, skin with patterned stripes, which is similar to the panther chameleon skin that can manipulate multiple colors, has also been achieved. The present artificial skin will offer fresh perspectives on the preparation of artificial chameleon skin similar to the real dynamic flexible skin, which would promote the application of PCs in optical devices

    Association of caffeine intake with erectile dysfunction among men with and without diabetes in NHANES 2001–2004.

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    <p><sup>†</sup>Adjusted for age, vigorous and moderate physical activity, smoking status, education, race/ethnicity, obesity (BMI ≥ 30 kg/m<sup>2</sup>), total water intake (plain and tap), total energy (continuous), alcohol (continuous). Error bars represent 95% confidence intervals. <i>P</i><sub><i>trend</i></sub><i>= 0</i>.<i>57 and P</i><sub><i>interaction</i></sub><i>= 0</i>.<i>65</i>. <sup>*</sup>Erectile dysfunction was defined as “sometimes” or “never” able to maintain an erection for satisfactory sexual intercourse. <sup>‡</sup> Approximately 170–375 mg/day of caffeine intake is equivalent to 2–3 cups of coffee. <sup>a</sup>Diabetes = fasting plasma glucose ≥126 mg/dl, self-reported diagnosis, or medication treatment.</p
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