Heat transfer characteristics of hypersonic waveriders with an emphasis on the leading edge effects

The heat transfer characteristics in surface radiative equilibrium and the aerodynamic performance of blunted hypersonic waveriders are studied along two constant dynamic pressure trajectories for four different Mach numbers. The inviscid leading edge drag was found to be a small (4 to 8 percent) but not negligible fraction of the inviscid drag of the vehicle. Although the viscous drag at the leading edge can be neglected, the presence of the leading edge will influence the transition pattern of the upper and the lower surfaces and therefore affect the viscous drag of the entire vehicle. For an application similar to the National Aerospace Plane (NASP), the present study demonstrates that the waverider remains a valuable concept at high Mach numbers if a state-of-the-art active cooling device is used along the leading edge. At low Mach number (less than 5), the study shows the surface radiative cooling might be sufficient. In all cases, radiative cooling is sufficient for the upper and lower surfaces of the vehicle if ceramic composites are used as thermal protection

The Lagrangian and Hamiltonian Aspects of the Electrodynamic Vacuum-Field Theory Models

We review the modern classical electrodynamics problems and present the related main fundamental principles characterizing the electrodynamical vacuum-field structure. We analyze the models of the vacuum field medium and charged point particle dynamics using the developed field theory concepts. There is also described a new approach to the classical Maxwell theory based on the derived and newly interpreted basic equations making use of the vacuum field theory approach. In particular, there are obtained the main classical special relativity theory relations and their new explanations. The well known Feynman approach to Maxwell electromagnetic equations and the Lorentz type force derivation is also discussed in detail. A related charged point particle dynamics and a hadronic string model analysis is also presented. We also revisited and reanalyzed the classical Lorentz force expression in arbitrary non-inertial reference frames and present some new interpretations of the relations between special relativity theory and its quantum mechanical aspects. Some results related with the charge particle radiation problem and the magnetic potential topological aspects are discussed. The electromagnetic Dirac-Fock-Podolsky problem of the Maxwell and Yang-Mills type dynamical systems is analyzed within the classical Dirac-Marsden-Weinstein symplectic reduction theory. The problem of constructing Fock type representations and retrieving their creation-annihilation operator structure is analyzed. An application of the suitable current algebra representation to describing the non-relativistic Aharonov-Bohm paradox is presented. The current algebra coherent functional representations are constructed and their importance subject to the linearization problem of nonlinear dynamical systems in Hilbert spaces is demonstrated.Comment: 70 p, revie

The Lagrangian and Hamiltonian Aspects of the Electrodynamic Vacuum-Field Theory Models

The  important classical  Ampère’s and Lorentz laws derivations  are revisited and their relationships with  the modern vacuum field theory approach to modern relativistic electrodynamics are demonstrated.  The relativistic models of the vacuum field medium and charged point particle dynamics as well as  related classical electrodynamics problems  jointly with the fundamental principles, characterizing the electrodynamical vacuum-field structure,  based on  the developed field theory concepts are reviewed and analyzed detail. There is also described a new approach to the classical Maxwell theory based on the derived and newly interpreted basic equations making use of the vacuum field theory approach. There are obtained the main classical special relativity theory relationships and their new explanations. The well known Feynman approach to Maxwell electromagnetic equations and the Lorentz type force derivation is also. A related charged point particle dynamics and a hadronic string model analysis is also presented. We also revisited and reanalyzed the classical Lorentz force expression in arbitrary non-inertial reference frames and present some new interpretations of the relations between special relativity theory and its quantum mechanical aspects. Some results related with the charge particle radiation problem and the magnetic potential topological aspects are discussed. The electromagnetic Dirac-Fock-Podolsky problem of the Maxwell and Yang-Mills type dynamical systems is analyzed within the classical Dirac-Marsden-Weinstein symplectic reduction theory. Based on the Gelfand-Vilenkin representation theory of infinite dimensional groups and the Goldin-Menikoff-Sharp theory of generating Bogolubov type functionals the problem of constructing Fock type representations and retrieving their creation-annihilation operator structure is analyzed. An application of the suitable current algebra representation to describing the non-relativistic Aharonov-Bohm paradox is demonstrated. The current algebra coherent functional representations are constructed and their importance subject to the linearization problem of nonlinear dynamical systems in Hilbert spaces is also presented

The Score Reliability Of Draw-A-Person Intellectual Ability Test (DAP: IQ) For Rural Malawi Students

In this brief article, the reliability of scores for the Draw-A-Person Intellectual Ability Test for Children, Adolescents, and Adults (DAP: IQ; Reynolds & Hickman, 2004) was examined through several analyses with a sample of 147 children from rural Malawi, Africa using a Chichewa translation of instructions. Cronbach alpha coefficients for the 23 test items were calculated for the total sample, the six age groups represented in the sample, and gender. The interscorer reliability of test scores was also calculated.  The obtained alpha coefficients for the 23 items for total sample (.81), the six age groups represented (.68 - .92), and gender (male .79, female .83) were comparable to those listed in the examiner’s manual.  The coefficient for interscorer reliability was .85.

STUDENTS’ MATHEMATICS ATTITUDES AND METACOGNITIVE PROCESSES IN MATHEMATICAL PROBLEM SOLVING

Mathematical problem solving is considered as one of the many endpoints in teaching Mathematics to students. This study looked into the performance in mathematics problem solving among fourth year students of Central Mindanao University Laboratory High School and their relationship with students’ attitudes towards Mathematics. The attitudes measured were Attitude towards success in Math, Mother’s mathematics attitude, Father’s mathematics attitude, Motivation, Usefulness of Math, Teacher’s mathematics attitude, Confidence in learning math, and mathematics anxiety. It also investigated the metacognitive processes of students considering varying levels of their mathematics anxiety. It used the responses of 127 students. Of the 127, (nine) 9 were selected according to their mathematics anxiety levels to determine and compare their metacognitive processes. Results showed that students consider Mathematics as useful and they have a positive attitude towards success in Mathematics. The students’ fathers, mothers, and teachers also have positive attitudes towards their mathematics learning. However, overall, the students’ performance in mathematics problem solving is considered poor. Among the eight (8) mathematics attitudes only confidence in learning Math and mathematics anxiety were correlated with performance in mathematics problem solving. Confidence in learning Math was positively correlated, while mathematics anxiety was negatively correlated with performance in mathematics problem solving. Students with high mathematics anxiety tend to confirm their solutions with their classmates. Students with moderate anxiety are test-anxious and those with low anxiety are distracted by external factors, but can readily shift their focus back to problem solving. The three (3) cases showed that students with low, moderate, and high mathematics anxiety employed mostly orientation and execution procedures. There were only few instances of verification and lesser instances of organization procedures. Self-questioning was the most observed metacognitive skill. Furthermore, students from the three (3) cases were unable to correctly answer two (2) problems, both of which are non-routine due to unfamiliarity and “experiential interference”.  Article visualizations