Numerical Simulations for Nonlinear Waves Interaction with Multiple Perforated Quasi-Ellipse Caissons

A three-dimensional numerical flume is developed to study cnoidal wave interaction with multiple arranged perforated quasi-ellipse caissons. The continuity equation and the Navier-Stokes equations are used as the governing equation, and the VOF method is adopted to capture the free surface elevation. The equations are discretized on staggered cells and then solved using a finite difference method. The generation and propagation of cnoidal waves in the numerical flume are tested first. And the ability of the present model to simulate interactions between waves and structures is verified by known experimental results. Then cnoidal waves with varying incident wave height and period are generated and interact with multiple quasi-ellipse caissons with and without perforation. It is found that the perforation plays an effective role in reducing wave runup/rundown and wave forces on the caissons. The wave forces on caissons reduce with the decreasing incident wave period. The influence of the transverse distance of multiple caissons on wave forces is also investigated. A closer transverse distance between caissons can produce larger wave forces. But when relative adjacent distance L/D (L is the transverse distance and D is the width of the quasi-ellipse caisson) is larger than 3, the effect of adjacent distance is limited

Optical Lossy-mode-resonance Relative Humidity Sensor on a Fiber Tip

Real-time measurement of relative humidity (RH) is important to many physical, chemical, and biological processes. However, in processes that involve harsh conditions such as high temperatures, strong electromagnetic interferences, and complex spatial constraints, conventional electrical sensors often fall short due to their intrinsic limitations. Here, we developed an optical lossy-mode-resonance (LMR) RH sensor based on the SnO2 film coated D-shaped fiber tip. Thanks to the high-temperature endurance and electromagnetic interference immunity, the developed optical fiber-tip sensor is ideal for RH sensing in critical environments, such as in the microwave drying process. Furthermore, unlike other reported in-line LMR sensors, our sensor is located at the D-shaped fiber tip with a probe-like form factor, allowing it to be readily implemented in a spatially confined environment. We have developed a custom fabrication setup for the novel D-shaped LMR fiber-tip sensor. The LMR signal from the sensor was experimentally characterized. The lossy mode resonances are understood by the finite element analysis, the results of which agree well with the experimental measurements. The fiber-tip sensor had a linear RH response between 6.1% to 75.0% and a resolution better than 4.0% RH. The fiber-tip sensor demonstrated a response time and reversibility comparable to that of commercial electrical sensors. The novel D-shaped fiber-tip LMR RH sensor developed in this work will benefit many applications that require RH monitoring in a harsh environment. Furthermore, our innovative D-shaped fiber tip design can be readily applied to LMR-based fiber sensors in general. This will allow the design's advantages of small footprint and agile maneuverability to benefit a wide range of LMR fiber sensing applications beyond RH sensing.Comment: 9 pages, 5 figure

Synthesis of Indole-3-Acetic Acid Derivatives and a Urea Carboxylic Acid Derivative by Propylphosphonic Anhydride (T3P)

The purpose of medicinal chemistry is to efficiently create a variety of compounds with potential for pharmacological efficacy. To promote this diversity, indole-3-acetic acid, a common plant hormone, was used as the starting material for various reactions. The coupling reagent used for these reactions was propylphosphonic anhydride, or T3P, since it has demonstrated efficiency in selective amide formation under mild conditions and it is readily soluble. In the case of multiple viable reaction sites, the intended product will dimerize, as was the case in the synthesis of the compound labeled amide 2 when T3P coupled with both sites of piperazine. N-Hydroxysuccinimide, also referred to as HOSu and NHS, was used to decrease the reactivity of the carboxylic acid—T3P mixed anhydride, so it less readily formed the dimer. This increased the yield of the monomer. Pharmacological efficacy is more probable when synthesizing a chemotype with a known structure-activity relationship, or SAR. Urea carboxylic acid has been found to have antischistosomal activity. In an effort to synthesize a drug candidate with greater likelihood of pharmacological activity, a compound was synthesized from a urea carboxylic acid using T3P by the same method used to synthesize products from indole-3-acetic acid. Five compounds were synthesized using the T3P reagent in an attempt to expand the repository of potential drug candidates. The method for each compound was made largely similar, but it differed in the work-up and purification stages, as the acidity and polarity of the systems varied.https://digitalcommons.unmc.edu/surp2021/1061/thumbnail.jp

Numerical Simulations for Nonlinear Waves Interaction with Multiple Perforated Quasi-Ellipse Caissons

A three-dimensional numerical flume is developed to study cnoidal wave interaction with multiple arranged perforated quasiellipse caissons. The continuity equation and the Navier-Stokes equations are used as the governing equation, and the VOF method is adopted to capture the free surface elevation. The equations are discretized on staggered cells and then solved using a finite difference method. The generation and propagation of cnoidal waves in the numerical flume are tested first. And the ability of the present model to simulate interactions between waves and structures is verified by known experimental results. Then cnoidal waves with varying incident wave height and period are generated and interact with multiple quasi-ellipse caissons with and without perforation. It is found that the perforation plays an effective role in reducing wave runup/rundown and wave forces on the caissons. The wave forces on caissons reduce with the decreasing incident wave period. The influence of the transverse distance of multiple caissons on wave forces is also investigated. A closer transverse distance between caissons can produce larger wave forces. But when relative adjacent distance L/D (L is the transverse distance and D is the width of the quasi-ellipse caisson) is larger than 3, the effect of adjacent distance is limited