Jian Jun Shu

Developing classification indices for Chinese pulse diagnosis

AIM To develop classification criteria for Chinese pulse diagnosis and to objectify the ancient diagnostic technique. METHODS Chinese pulse curves are treated as wave signals. Multidimensional variable analysis is performed to provide the best curve fit between the recorded Chinese pulse waveforms and the collective Gamma density functions. RESULTS Chinese pulses can be recognized quantitatively by the newly-developed four classification indices, that is, the wave length, the relative phase difference, the rate parameter, and the peak ratio. The new quantitative classification not only reduces the dependency of pulse diagnosis on Chinese physicians experience, but also is able to interpret pathological wrist-pulse waveforms more precisely. CONCLUSIONS Traditionally, Chinese physicians use fingertips to feel the wrist-pulses of patients in order to determine their health conditions. The qualitative theory of the Chinese pulse diagnosis is based on the experience of Chinese physicians for thousands of years. However, there are no quantitative theories to relate these different wrist-pulse waveforms to the health conditions of patients. In this paper, new quantified classification indices have been introduced to interpret the Chinese pulse waveform patterns objectively.

Modelling vaporous cavitation on fluid transients

A comprehensive study of the problem of modelling vaporous cavitation in transmission lines is presented. The two-phase homogeneous equilibrium vaporous cavitation model which has been developed is compared with the conventional column separation model. The latter predicts unrealistically high pressure spikes because of a conflict arising from the prediction of negative cavity sizes if the pressure is not permitted to fall below the vapour pressure, or the prediction of negative absolute pressures if the cavity size remains positive. This is verified by a comparison of predictions with previously published experimental results on upstream, midstream and downstream cavitation. The new model has been extended to include frequency-dependent friction. The characteristics predicted by the frequency-dependent friction model show close correspondence with experimental data.

Heat transfer in the flow of a cold, two-dimensional vertical liquid jet against a hot, horizontal plate

Abstract A cold, thin film of liquid impinging on an isothermal hot, horizontal surface is modelled as a two-dimensional jet of prescribed uniform velocity, film thickness and temperature. An approximate solution for the velocity and temperature distributions in the flow along the horizontal surface is developed, which exploits the Watson hydrodynamic similarity solution for thin film flow. A numerical solution of high accuracy has also been obtained. Comparisons indicate that the approximate solution may provide a valuable basis for assessing flow and heat transfer in more complex settings modelled by jet impingement such as cylinder inundation flows.

On thermal boundary layers on a flat plate subjected to a variable heat flux

Abstract The problem of a steady forced convection thermal boundary-layer past a flat plate with a prescribed surface heat flux proportional to (1+ x 2 ) m ( m a constant) is investigated both analytically and numerically. In view of the present formulation, the governing equations reduce to the well-known Blasius similarity equation and to the full boundary-layer energy equation with two parameters: the wall flux exponent m and Prandtl number Pr. The range of existence of solutions is considered, it being shown that solutions for both x small and x large exist only for m >−1/2. However, for m ⩽−1/2 the asymptotic structure for x large is found to be different for m m =−1/2, respectively. These asymptotic solutions for large x are derived and compared with numerical solutions of the full boundary-layer equation. A very good agreement between these asymptotic solutions and numerical simulations are found in the range of Prandtl numbers considered.

Mixed-convection laminar film condensation on a semi-infinite vertical plate

A comprehensive study of the problem of laminar film condensation with both a gravitational type body force and a moving vapour concurrent and parallel to the surface has been presented here. It demonstrates where both the body force and vapour velocity are significant through a comprehensive numerical solution obtained by a modified Keller box method. Important parameters governing condensation and heat transfer of pure vapour are determined. A perturbation analysis is applied in the leading edge and downstream regimes. The thin film approximations for the both regimes are obtained and compared with exact numerical solutions.

Pairwise alignment of the DNA sequence using hypercomplex number representation.

A new set of DNA base-nucleic acid codes and their hypercomplex number representation have been introduced for taking the probability of each nucleotide into full account. A new scoring system has been proposed to suit the hypercomplex number representation of the DNA base-nucleic acid codes and incorporated with the method of dot matrix analysis and various algorithms of sequence alignment. The problem of DNA sequence alignment can be processed in a rather similar way to pairwise alignment of the protein sequence.

An Improved Scoring Matrix for Multiple Sequence Alignment

The way for performing multiple sequence alignment is based on the criterion of the maximum-scored information content computed from a weight matrix, but it is possible to have two or more alignments to have the same highest score leading to ambiguities in selecting the best alignment. This paper addresses this issue by introducing the concept of joint weight matrix to eliminate the randomness in selecting the best multiple sequence alignment. Alignments with equal scores are iteratively rescored with the joint weight matrix of increasing level (nucleotide pairs, triplets, and so on) until one single best alignment is eventually found. This method for resolving ambiguity in multiple sequence alignment can be easily implemented by use of the improved scoring matrix.

A Finite Element Model and Electronic Analogue of Pipeline Pressure Transients With Frequency-Dependent Friction

A finite element model and its equivalent electronic analogue circuit has been developed for fluid transients in hydraulic transmission lines with laminar frequency-dependent friction. Basic equations are approximated to be a set of ordinary differential equations that can be represented in state-space form. The accuracy of the model is demonstrated by comparison with the method of characteristics

Thermal interaction between free convection and forced convection along a vertical conducting wall

Abstract A theoretical study is presented in this paper to investigate the conjugate heat transfer across a vertical finite wall separating two forced and free convection flows at different temperatures. It is assumed that the heat conduction in the wall is only in the transversal direction. We also assume that countercurrent boundary layers are formed on the both sides of the wall. The governing equations of this problem and their corresponding boundary conditions are all cast into a dimensionless form by using a non-similarity transformation. These resulting equations, which are singular at the points ξc=0 and 1, are solved numerically using a very efficient singular perturbation method. The effects of the resistance parameters and of the Prandtl numbers on heat transfer characteristics are investigated and presented in a table and ten figures.

Generalized fundamental solutions for unsteady viscous flows

A number of closed-form fundamental solutions for generalized unsteady Oseen and Stokes flows associated with arbitrary time-dependent translational and rotational motions have been developed. These solutions are decomposed into two parts corresponding to a longitudinal wave and a transversal wave. As examples of application, the hydrodynamic forces acting on a sphere and on a circular cylinder translating in an unsteady rotating flow field at low Reynolds numbers are calculated using the generalized fundamental solutions.