A new VOF‐based numerical scheme for the simulation of fluid flow with free surface. Part II: application to the cavity filling and sloshing problems

Finite element analysis of fluid flow with moving free surface has been performed in 2‐D and 3‐D. The new VOF‐based numerical algorithm that has been proposed by the present authors (Int. J. Numer. Meth. Fluids, submitted) was applied to several 2‐D and 3‐D free surface flow problems. The proposed free surface tracking scheme is based on two numerical tools; the orientation vector to represent the free surface orientation in each cell and the baby‐cell to determine the fluid volume flux at each cell boundary. The proposed numerical algorithm has been applied to 2‐D and 3‐D cavity filling and sloshing problems in order to demonstrate the versatility and effectiveness of the scheme. The proposed numerical algorithm resolved successfully the free surfaces interacting with each other. The simulated results demonstrated applicability of the proposed numerical algorithm to the practical problems of large free surface motion. It has been also demonstrated that the proposed free surface tracking scheme can be easily implemented in any irregular non‐uniform grid systems and can be extended to 3‐D free surface flow problems without additional efforts. Copyright © 2003 John Wiley & Sons, Ltd.     

Infine Functions, Nonsmooth Alternative Theorems and Vector Optimization Problems

In this paper we introduce a new notion of infine nonsmooth functions and give several characterizations of infineness property. We prove alternative theorems with mixed constraints (i.e., inequality and equality constraints) being described by invex-infine nonsmooth functions. We establish a necessary and sufficient condition for a solution of a vector optimization problem involving mixed constraints to be a properly efficient solution.     

Synthesis of some chiral liquid crystals and study of the effect of intramolecular hydrogen bonding on the phase behaviour

The synthesis of three new series of chiral Schiff's bases containing benzilideneaniline and 2-hydroxybenzilideneaniline moieties as mesogenic cores is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements were used to study the phase transition temperatures and behaviour. The results reveal that most of these materials show chiral smectic mesomorphism.     

Role of Na(+)-Ca2+ exchange system in the pathogenesis of myocardial ischemia-reperfusion damage

Results from a systematic experiment on isolated perfused rat heart and isolated myocytes of adult rat showed that the mechanism of calcium influx during myocardial ischemia-reperfusion is due to the development of intracellular sodium overload during ischemic period; on reperfusion, the high intracellular Na+ content activated the reverse direction of Na(+)-Ca2+ exchange over myocardial sarcolemma (SL), thus a large quantity of extracellular Ca2+ fluxed over the SL to the intracellular space, forming a condition of intracellular Ca2+ overload, which leads to irreversible damage of the myocardium.     

Studies on the chemical constituents of the South China Sea sponge Phacellia fusca

Three pyrrololactam alkaloids have been isolated from the marine sponge Phacellia fusca Schmidt collected from the South China Sea, and their structures were determined as 1–3 , on the grounds of spectral data. This is the first report of these compounds from this sponge. The structure of 1 was confirmed by X-ray analysis.     

Controllable synthesis of ZnS/PMMA nanocomposite hybrids generated from functionalized ZnS quantum dots nanocrystals

We reported controllable synthesis of ZnS nanocrystal-polymer transparent hybrids by using polymethylmethacrylate (PMMA) as a polymer matrix. In a typical run, the appropriate amounts of zinc chloride (ZnCl₂) and sodium sulfide (Na₂S) in the presence of 2-mercaptoethanol (ME) as the organic ligand were well dispersed in H₂O/dimethylformamide solution without any aggregation. In addition, the Mn-doped ZnS nanocrystals (NCs) were synthesized with similar method. Then, ZnS-PMMA hybrids were obtained via free radical polymerization in situ by using ZnS NCs functionalized with methacryloxypropyltrimethoxysilane (MPS). FT-IR characterization indicates the formation of robust bonding between ZnS NCs and the organic ligand. The TEM images show that ZnS NCs are well dispersed in PMMA matrix, and particle size of as-prepared ZnS NCs is about 2.6 nm, in agreement with the computing results of Brus’s model and Debye–Scherrer formula. The photoluminescence measurements present that ZnS NCs, Mn-doped ZnS NCs, and ZnS/PMMA hybrid show good optical properties.     

Experimental verification of drop/impact simulation for a cellular phone

Conducting drop tests to investigate impact behavior and identify failure mechanisms of small-size electronic products is generally expensive and time-consuming. Nevertheless, strict drop/impact performance criteria for hand-held electronic products such as cellular phones play a decisive role in the design because they must withstand unexpected shocks. The design of product durability on impact has heavily relied on the designer's intuition and experience. In this study, a reliable drop/impact simulation for a cellular phone is carried out using the explicit code LS-DYNA. Subsequently globallocal experimental verification is accomplished by means of high-speed photography and impact response measurement. Using this methodology, we predict potential damage locations in a cellular phone and compare them with real statistical data. It is envisaged that development of a reliable methodology of drop/impact simulation will provide us with a powerful and efficient vehicle for improvement of the design quality and reduction of the product development cycle.     

Numerical methods for computations of nonequilibrium hypersonic flow around bodies

In this paper we present numerical methods for computations of nonequilibrium hypersonic flow of air around bodies including chemical reaction effects and present numerical result of the flow over concave corners. We developed implicit finite difference method to overcome numerical difficulties associated with the lack of resolution behind the shock and near the body. Using our method we were able to find details of the flow properties near the shock and body and were able to continue the computation of the flow for a long distance from the corner of the body.