Nonlinear mathematical modeling of butterfly valves driven by solenoid actuators

This paper describes high fidelity modeling and analysis of the opening and closing processes of butterfly valves driven by solenoid actuators using multiphysics models. The equations are derived and solved numerically. The variable of primary interest is the butterfly valve rotation angle. The coupled model for electromagnetics, fluid dynamics and mechanical dynamics are derived by making some simplifying assumptions. It is shown that the behavior of hydrodynamic torque plays an important role in the closing and opening processes. A discussion is presented with an explanation of the results and a comparison has been made for both the processes.     

A rapid, one-pot, four-component route to 2H-indazolo[2,1-b]phthalazine-triones

A new, efficient, and environmentally benign protocol for the one-pot, four-component synthesis of 2,2-dimethyl-13-phenyl-2,3-dihydro-1H-indazolo[2,1-b]phthalazine-1,6,11(13H)-trione by condensation of phthalic anhydride, hydrazinium hydroxide, aromatic aldehydes, and dimedone catalyzed by Ce(SO₄)₂·4H₂O as an ecofriendly catalyst with high catalytic activity and reusability at 125 °C under solvent-free conditions is reported. The reaction proceeds to completion within 5-10 min in 71-95% yield. To the best of our knowledge, this new procedure provides the first example of an efficient synthetic method for 2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-trione via a four-component reaction.     

ZrOCl2·8H2O as an efficient and recyclable catalyst for the clean synthesis of xanthenedione derivatives under solvent-free conditions

ZrOCl₂·8H₂O was found to be an efficient and recyclable catalyst for the reaction of aromatic aldehydes with dimedone to afford 1,8-dioxo-1,2,3,4,5,6,7,8-octahydroxanthenes under solvent-free conditions. Short reaction time, excellent yields and simple work-up are the advantages of this procedure. The interaction obtained from XRD studies was shown that the catalyst loses H₂O during the reaction but it did not affect catalytic activity of the catalyst and the catalyst could be reused several times.     

以蛋壳为原料制备的纳米氧化钙用于高效催化合成吡喃并[4,3-b]吡喃(英文)

Nano-CaO was prepared by calcination of ball-milled chicken eggshell waste.This novel,bioactive,heterogeneous catalyst,which had high catalytic activity and reusability,was used in the green synthesis of pyrano[4,3-b]pyrans via condensation of various aromatic aldehydes,malononitrile,and 4-hydroxy-6-methyl-2H-pyran-2-one at 120 °C under solvent-free conditions.The reaction proceeded to completion within 5–45 min in 93%–98% yield.The nano-CaO was fully characterized by scanning electron microscopy,X-ray powder diffraction,infrared spectroscopy,X-ray fluorescence spectroscopy,and thermal gravimetric,surface area,and elemental analyses.     

Synthesis,single crystal structure determination,and solution behavior of an 8-hydroxyquinoline derivative of niobium(V) ethoxide

An 8-hydroxyquinoline derivative of niobium(V) ethoxide was synthesized and characterized by elemental analysis, mass spectrometry, infrared, electronic, and ¹H, ¹³C, and ⁹³NMR spectroscopies. Tetraethoxy(8-quinolinato)niobium(V), as shown by the single crystal structure determination, exists as an octahedral compound in the solid state in which the 8-quinolinato group chelates to the metal atom. In solution, this group partially becomes unidentate; the six-coordinate species is in equilibrium with the five-coordinate species, as shown by ⁹³Nb and variable-temperature ¹H NMR spectroscopy.     

An efficient synthesis of spiro[dibenzo[b,i]xanthene-13,3′-indoline]-pentaones and 5H-dibenzo[b,i]xanthene-tetraones

Spiro[dibenzo[b,i]xanthene-13,3′-indoline]-pentaones and 5H-dibenzo[b,i]xanthene-tetraones are synthesized from the condensation of 2-hydroxynaphthalene-1,4-dione with isatins or aldehydes.     

Effect of Sorbent Additives to Copper-Contaminated Soils on Seed Germination and Early Growth of Grass Seedlings

Heavy metal and metalloid-contaminated soil is a serious barrier to colonization for many plant species. The problem of the elimination of toxic waste accumulated in technogenous soils in many highly transformed regions is extremely important. Hence, another attempt was made to analyze the effect of the addition of sorbents (BCH—biochar, B—bentonite, ChM—chicken manure, OS—organo-zeolitic substrate) to contaminated copper soil on the germination and early growth of Eurasian common grass species (Agrostis capillaris, A. stolonifera, Festuca rubra and Poa pratensis), which could potentially be used in recultivation. This experiment was based on the laboratory sandwich method. Standard germination indexes, morphometry and biomass analysis were used. The percentage of germinating seeds was lower in each of the soil variants and sorbents used compared to the control. Dry mass was positively stimulated by all sorbents. The response to the addition of sorbents, expressed as the electrolyte leakage of seedlings, was different depending on the species and type of sorbent. Among all sorbents, the most positive effects on germination and growth were observed in the case of OS. Overall, the response to the addition of sorbents was different in the studied species, depending on their stage of development.     

Transient chaos and crisis phenomena in butterfly valves driven by solenoid actuators

Chilled water systems used in the industry and on board ships are critical for safe and reliable operation. It is hence important to understand the fundamental physics of these systems. This paper focuses in particular on a critical part of the automation system, namely, actuators and valves that are used in so-called “smart valve” systems. The system is strongly nonlinear, and necessitates a nonlinear dynamic analysis to be able to predict all critical phenomena that affect effective operation and efficient design. The derived mathematical model includes electromagnetics, fluid mechanics, and mechanical dynamics. Nondimensionalization has been carried out in order to reduce the large number of parameters to a few critical independent sets to help carry out a broad parametric analysis. The system stability analysis is then carried out with the aid of the tools from nonlinear dynamic analysis. This reveals that the system is unstable in a certain region of the parameter space. The system is also shown to exhibit crisis and transient chaotic responses; this is characterized using Lyapunov exponents and power spectra. Knowledge and avoidance of these dangerous regimes is necessary for successful and safe operation.     

Ce(SO4)2·4H2O as a Recyclable Catalyst for an Efficient,Simple, and Clean Synthesis of 4H-Benzo[b]pyrans

An efficient method for the synthesis of 4H-benzo[b]pyrans has been developed by the use of Ce(SO₄)₂·4H₂O (2.5 mol%) as a catalyst. Heating the mixture of an appropriate aldehyde, malononitrile, and dimedone in the presence of the catalyst at 45°C in a mixture of water:ethanol (1:1) as solvent for about 9–55 min resulted excellent yields of the corresponding products. Short experimental time of the reaction, excellent yields, simple workup, not using cumbersome apparatus for purification of the products, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.