Viscous-shock-layer analysis of hypersonic flows over long slender vehicles

An efficient and accurate method for solving the viscous shock layer equations for hypersonic flows over long slender bodies is presented. The two first order equations, continuity and normal momentum, are solved simultaneously as a coupled set. The flow conditions included are from high Reynolds numbers at low altitudes to low Reynolds numbers at high altitudes. For high Reynolds number flows, both chemical nonequilibrium and perfect gas cases are analyzed with surface catalytic effects and different turbulence models, respectively. At low Reynolds number flow conditions, corrected slip models are implemented with perfect gas case. Detailed comparisons are included with other predictions and experimental data

Use Of Data Mining In Business Analytics To Support Business Competitiveness

Inthis paper, the use of data mining and text mining techniques in businessanalytics and how they support the use of business intelligence in e-businessesare discussed.  The distinction betweendata mining, business analytics and business intelligence is presented.  Suggestions on how electronic businesses canleverage on data mining to enhance their competitiveness are discussed

KINDERGARTEN TEACHERS’ UNDERSTANDING OF THE AIMS OF GIVING STUDENTS “FEEDBACK” AND ITS IMPLEMENTATION: THE STUDY OF HONG KONG

This study explores kindergarten teachers’ understanding of, comments on their actual practice of giving feedback to children in Hong Kong. The research employed a combination of quantitative and qualitative methods, with data being collected through questionnaires and interviews. The sample was chosen from the in-service kindergarten teachers who were enrolled in the teacher certificate course offered at Hong Kong Institute of Education during the academic year 2015-2016. Questionnaires were sent to 150 in-service kindergarten teachers and six teachers were interviewed. Finding indicates that many teachers have the basic understanding of using feedback. They can analyze the aims of giving students feedback not only from the perspectives of students, but also the interaction between teachers and students. However, they seldom explore it through the views from teachers. Teachers’ aims of giving students feedback are mostly for encouraging and it is mainly positive and appreciation. It is common for teachers to give motivational feedback in kindergartens, however, over-emphasize has its disadvantage. It is found that teachers encountered two problems. Firstly, teachers do not have adequate training about giving students feedback. Secondly, teachers lack follow-up work after giving feedback to students. Some suggestions for teachers’ development are made at the end of the paper.  Article visualizations

Viscous Shock Layer Analysis of Hypersonic Flows Over Long Slender Vehicles

A method for solving the viscous shock-layer equations for hypersonic flows over long slender bodies is presented. The governing equations are solved by employing a spatial-marching implicit finite-difference technique. The two first-order equations, continuity and normal momentum, are solved simultaneously as a coupled set. This method yields a simple and computationally efficient technique. Flows past hyperboloids and sphere cones with body half angles of five to 35 degrees are considered. The flow conditions included are from high Reynolds numbers at low altitudes to low Reynolds numbers at high altitudes. Detailed comparisons have been made with other predictions and experimental data for slender body flows. The results show that the coupling between the continuity and normal momentum equations is essential and adequate to obtain stable and accurate solutions past long slender bodies. Both the Cebeci-Smith and Baldwin-Lomax turbulence models are found to be adequate for application to long slender bodies. Using the corrected slip models, the viscous shock-layer predictions compare quite favorably with experimental data. Under chemical nonequilibrium conditions, the surface catalytic effects can significantly influence the surface heat transfer

Cell/Gene Therapy For Diabetic Wound Healing

Wounds in diabetes are difficult to heal. Current standard strategy employs series of medical treatments to clean and remove the infected tissue, and keep moisture with adequate blood supply. However, the standard treatments may not be sufficient enough. According to ADA, there are an increasing number of amputation cases in diabetes. In this thesis, recent development of therapies in wound healing is reviewed and results of using a TGF-ƒÒ1 plasmid DNA or stem cells in genetically diabetic mouse model are reported. In previous study, we have found that the diabetic wound healing has been improved by intradermally injecting TGF-ƒÒ1 plasmid DNA. This finding supports the feasibility of using naked DNA as a therapeutic approach for treating diabetic wounds. Since naked DNA approach yields low efficiency of gene transfer, we seek strategies that can enhance the gene expression. Hydrogel as well as electroporation which involves an application of electric pulses has been shown to enhance gene transfection. On the other hand, electrical stimulation (ES) which involves the application of a different condition of electric pulses from electroporation or hydrogel wound dressing has been shown to improve wound healing. In this thesis project, we develop a more effective strategy to improve diabetic wound healing by combining the available wound therapy and gene therapy.However, application of exogenous single cytokine gene may not be sufficient for severe wound problems. Owing to the self renewal and multipotent characteristics of stem cells, stem cells may have the potential to differentiate into some of the essential cells in wound healing such as macrophages, keratinocytes and fibroblasts. We develop a strategy to topically apply three different types of stem cells individually with the thermosensitive hydrogel in an attempt to improve wound repair. Three new strategies in this thesis project are reported. (1) Intradermal injection of TGFƒÒ-1 plasmid DNA followed by electroporation or (2) Topical application of TGFƒÒ-1 plasmid DNA with themosensitive hydrogel made of PEG-PLGA-PEG triblock copolymer. (3) Topically application of the thermosensitive hydrogel with three different types of stem cells: muscle derived stem cell, meschenymal stem cells or heamotopoietic stem cells

Computer codes for the evaluation of thermodynamic properties, transport properties, and equilibrium constants of an 11-species air model

The computer codes developed provide data to 30000 K for the thermodynamic and transport properties of individual species and reaction rates for the prominent reactions occurring in an 11-species nonequilibrium air model. These properties and the reaction-rate data are computed through the use of curve-fit relations which are functions of temperature (and number density for the equilibrium constant). The curve fits were made using the most accurate data believed available. A detailed review and discussion of the sources and accuracy of the curve-fitted data used herein are given in NASA RP 1232

Computer codes for the evaluation of thermodynamic and transport properties for equilibrium air to 30000 K

The computer codes developed here provide self-consistent thermodynamic and transport properties for equilibrium air for temperatures from 500 to 30000 K over a temperature range of 10 (exp -4) to 10 (exp -2) atm. These properties are computed through the use of temperature dependent curve fits for discrete values of pressure. Interpolation is employed for intermediate values of pressure. The curve fits are based on mixture values calculated from an 11-species air model. Individual species properties used in the mixture relations are obtained from a recent study by the present authors. A review and discussion of the sources and accuracy of the curve fitted data used herein are given in NASA RP 1260

Speech variability and accuracy in Cantonese-speaking children with hearing impairment : comparison with normal-hearing peers

This study compared speech accuracy and variability between children with hearing impairment and normal-hearing children. Twenty-seven participants were recruited, including nine children with cochlear-implants (CI), nine children with hearing aids (HA) and nine normal-hearing children (NH). Participants were asked to name each targets from Cantonese Segmental Phonology Test (CSPT) in three separate trials. Speech accuracy and variability were analyzed in different conditions (i.e. vowels, consonants, tones and whole-words) and in different sets of initial consonants (i.e. set 1, set 2 and set 3). The results showed relatively higher accuracy and lower variability in tones and vowels than in consonants and whole-words, and also in earlier acquired initial consonants than those acquired later. The HA group had higher variability and lower accuracy than the CI and NH groups. It was concluded that, with similar duration of hearing experience, using cochlear implants was more effective than using hearing aids in assisting children with profound hearing impairment in catching up with normal children in speech accuracy and variability. Acquisitional order of phonological features was also found to affect accuracy and variability of speech.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

Reaction rate coefficients and thermodynamic and transport properties are reviewed and supplemented for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium up to temperatures of 3000 K. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Curve fits are given for the various species properties for their efficient computation in flowfield codes. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in a high energy environment. Limitations of the approximate mixing laws are discussed for a mixture of ionized species. An electron number-density correction for the transport properties of the charged species is obtained. This correction has been generally ignored in the literature