A recent research paper described how student throughput variables and properties combine to explain the behaviour of stationary or simplified throughput systems. Such behaviour can be understood in terms of the locus of a point in the triangular admissible region of the H-S plane, where H represents headcounts and S successful credits, each depending on the system properties at that point. The efficiency of the student throughput process is given by the ratio S/H. Simplified throughput systems are characterised by stationary graduation and dropout patterns of students as well as by annual intakes of student cohorts of equal size. The effect of varying the size of the annual intakes of student cohorts is reported on here. The observations made lead to the establishment of a more generalised student throughput theory which includes the simplified theory as a special case. The generalised theory still retains the notion of a triangular admissible region in the H-S plane but with the size and shape of the triangle depending on the size of the student cohorts. The ratio S/H again emerges as the process efficiency measure for throughput systems in general with unchanged roles assigned to important system properties. This theory provides for a more fundamental understanding of student throughput systems encountered in real life. SIGNIFICANCE: •A generalised stationary student throughput theory through varying cohort sizes allows for a far better understanding of real student throughput systems.

Many different models have been designed to describe the plethora of factors that influence student throughput and success and how these factors affect throughput system variables and properties. System variables include headcounts (H) and successful credits (S) of throughput systems; some examples of system properties are the percentage of the new student intake graduating annually, and the average number of years to graduate or to drop out of a degree. However, no past study has defined the analytical relationships between these variables and properties from a process perspective - which was the purpose of this study. Three simple analytical equations were derived for 4-year degrees, and then geometrically interpreted. The behaviour of a simplified throughput system can be described by the position of a point in the admissible region of the H-S plane, with each point relating to a specific set of system properties. The successful credits ratio (S/H) is shown to be the ideal process efficiency ratio for throughput systems. The results were also extended to degrees of shorter duration. The behaviour of real throughput systems is broadly found to be similar to the behaviour of simplified throughput systems. In this study, only the mathematical foundations for the general relationships between throughput properties and throughput variables for a degree were established. The way in which this mathematical basis finds application in practice is illustrated for a few selected cases only, because of the specific focus of this paper.

Espectros de perda de energia de elétrons foram obtidos para a molécula de hexafluoreto de enxofre na região da camada de valência (0 a 100 eV) com uma variação angular de 1.0° - 15.0°. Os espectros foram medidos para uma energia de impacto de 1 keV. O estudo com variação angular sugere a presença de três transições proibidas na região de energia abaixo de 40 eV. Acima de 40 eV, estruturas interessantes aparecem para maiores ângulos de espalhamento podendo estar associadas a processos multieletrônicos proibidos. Uma nova estrutura foi observada em 76 eV. A seção de choque elástica absoluta foi obtida através de normalização dos dados relativos com valores experimentais encontrados na literatura. As seções de choque diferenciais inelásticas absolutas foram obtidas para as transições em 11,5 eV e 13,2 eV. A força do oscilador generalizada (FOG) foi determinada para a transição em 11,5 eV no intervalo de K² entre 0,05 e 1,3 u.a.. O valor experimental da força do oscilador óptica (0,312) para o pico em 11,5 eV, obtido através de extrapolação da curva da FOG, mostra boa concordância com dados da literatura.

Electron-energy-loss spectra of the SF6 molecule have been measured in the valence-shell region (0 - 100 eV) covering an angular range of 1.0° - 15.0°. The spectra have been measured at an impact energy of 1.0 keV. The angular dependence of the spectra showed the presence of three forbidden transitions in the region below 40 eV. Above 40 eV interesting features appear at higher scattering angles, which can be associated to nondipole many-body processes. A new feature was observed at 76 eV. The absolute elastic differential cross section has been obtained through normalization of the relative data to the experimental values found in the literature. The absolute inelastic differential cross sections for the 11.5 eV and 13.2 eV transitions have been determined. The generalized oscillator strength (GOS) for the 11.5 eV peak has been also determined in the 0.05 to 1.3 a.u. K² range. The experimentally determined value for the optical oscillator strength(0.312) for the 11.5 eV peak obtained through extrapolation of the GOS curve showed good agreement with the data found in the literature.