Guidance of a low l/d vehicle entering the earth's atmosphere at speeds up to 50,000 feet per second

Guidance of low lift-drag ratio vehicle during earth atmosphere reentr

Estimation of Rotary Stability Derivatives at Subsonic and Transonic Speeds

The first part of this paper pertains to the estimation of subsonic rotary stability derivatives of wings. The unsteady potential flow problem is solved by a superposition of steady flow solutions. Numerical results for the damping coefficients of triangular wings are presented as functions of aspect ratio and Mach number, and are compared with experimental results over the Mach number range 0 to 1. In the second part, experimental results are used. to point out a close correlation between the nonlinear variations with angle of attack of the static pitching-moment curve slope and the damping-in-pitch coefficient. The underlying basis for the correlation is found as a result of an analysis in which the indicial function concept and. the principle of super-position are adapted to apply to the nonlinear problem. The form of the result suggests a method of estimating nonlinear damping coefficients from results of static wind-tunnel measurements

Teachers’ perceptions of the influence of learners’ undisciplined behaviour on their working life and of the support of role-players

Unacceptable behaviour by learners in South African schools is a major concern for all stakeholders in the teaching profession. This explains the increased interest in the role and responsibility of teachers in managing problem behaviour and the effect of this behaviour on educators’ quality of life in the workplace. This research posed the following questions: Does inappropriate student behaviour affect teachers’ working life, and if so, to what extent? Is the prevalence of undisciplined behaviour higher amongst boys and in multicultural schools? What is the influence of learners’ disruptive behaviour on teachers? How do teachers experience support from role-players? A questionnaire was used to obtain information for answering these questions. Although the findings of this research indicated that not all teachers experience excessive emotional reactions that may contribute to stress, it appeared that undisciplined behaviour was the source of irritation, made demands on teachers’ temper and caused aggression. The majority of teachers reported that they enjoyed sufficient support from the school’s governing body, but they were not satisfied with the support from parents and the department of education. In spite of the high percentage of teachers who indicated that undisciplined behaviour impacted on their job satisfaction, the majority do not consider leaving the teaching profession

Wind-Tunnel Investigation at Subsonic and Supersonic Speeds of the Static and Dynamic Stability Derivatives of an Airplane Model with an Unswept Wing and a High Horizontal Tail

Results are presented of a wind-tunnel investigation to evaluate the static and dynamic stability derivatives of a model with a low-aspect-ratio unswept wing and a high horizontal tail. In addition to results for the complete model, results were also obtained of the body alone, body and wing, and body and tail. Data were obtained in the Mach number range from 0.65 to 2.2, at a Reynolds number of 2 million based on the wing mean aerodynamic chord. The angle-of-attack range for most of the data was -11.5 deg to 18 deg. A limited amount of data was obtained with fixed transition. A correspondence between the damping in pitch and the static stability, previously noted in other investigations, was also observed in the present results. The effect observed was that a decrease (or increase) in the static stability was accompanied by an increase (or decrease) in the damping in pitch. A similar correspondence was observed between the damping in yaw and the static-directional stability. Results from similar tests of the same model configuration in two other facilities over different speed ranges are presented for comparison. It was found that most of the results from the three investigations correlated reasonably well. Estimates of the rotary derivatives were made using available procedures. Comparison with the experimental results indicates the need for development of more precise estimation procedures

Die persoonlikheidsamestelling van die beskeie leerling in die senior sekondêre skoolfase

Text in AfrikaansDie studie handel oor die persoonlikheidsamestelling van die beskeie leerling in die senior sekondere skoolfase. Twee sienings van beskeidenheid blyk uit die literatuur, naamlik beskeidenheid as 'n deug en beskeidenheid as manifestasie van innerlike onsekerheid. Daar is in diepte gekyk na beskeidenheid as persoonlikheidseienskap en die invloed van beskeidenheid op die relasievorming en selfaktualisering van die kind. Beskeidenheid gaan gepaard met persoonlikheidseienskappe soos terughoudendheid, beskroomdheid, geinhibeerdheid, ontoereikende assertiwiteit en vry van aanmatiging en dit behels 'n onvermoe tot selfbevordering. Verder manifesteer sake soos sosiale angstigheid, openbare selfbewustheid, vrees vir sukses en swak selfevaluering ook in beskeidenheid. Die leerling se relasievorming en selfaktualisering word deur beskeidenheid gekortwiek. Die Hoerskool Persoonlikheidsvraelys is in 'n empiriese ondersoek op 'n aantal standerd 9-leerlinge afgeneem. Geen tipiese perrsoonlikheidsprofiel kon vir beskeidenheid saamgestel word nie. 'n Aantal persoonlikheidseienskappe wat met beskeidenheid verband kan hou, het egter in die ondersoek na vore gekom.This study concerns the personality composition of the modest pupil in the senior secondary school. Two views of modesty are discussed in the literature, namely that it is a virtue and that it is a sign of inner uncertainty. An in-depth study is made of modesty as a personality characteristic and its influence on the pupil's relationship formation and self-actualisation. Modesty is associated with such personality characteristics as reserve, timidity, inhibition, unassertiveness and lack of arrogance. It implies an inability to promote oneself. Modesty is also a manifestation of social anxiety, self-conciousness, a fear of success and low self-evaluation. It handicaps the relationship formation and self-actualisation of pupils. The High School Personality Questionnaire was administered to a group of Standard 9 pupils in an empirical study. No typical personality profile could be compiled for modest pupils. Several personality 'characteristics emerged from the study which may be associated with modesty.Educational StudiesM. Ed. (met spesialisering in Voorligting