Man's transportation to space

Saturn i, saturn ib, and saturn v launch vehicle

Understanding reflective practice: encouraging better student engagement. First person action inquiry

The purpose of this research project is to examine my own engagement with reflective practice in my capacity as teacher and practitioner. This process of examination aims to improve attention to reflective practice within the student nutritional therapist environment where I teach. Research was conducted using a first-person action approach, with data acquired via critical self-observation and non-inquisitorial involvement in work-based situations feeding into action-reflection cycles. Conclusions highlighted strengths and areas for development as teacher and practitioner which may impact on student engagement with reflective practice on the course. Wider staff training and improvement to the curriculum were also identified with actions and recommendations including the adoption of new reflective practice teaching methods, further training for staff, adjustments to personal reflective practices and curriculum-wide developments. The proposed dissemination of findings and outcomes more widely will be via the nutritional therapy regulatory body and amongst fellow training providers

Afterglow lightcurves, viewing angle and the jet structure of gamma-ray bursts

Gamma ray bursts are often modelled as jet-like outflows directed towards the observer; the cone angle of the jet is then commonly inferred from the time at which there is a steepening in the power-law decay of the afterglow. We consider an alternative model in which the jet has a beam pattern where the luminosity per unit solid angle (and perhaps also the initial Lorentz factor) decreases smoothly away from the axis, rather than having a well-defined cone angle within which the flow is uniform. We show that the break in the afterglow light curve then occurs at a time that depends on the viewing angle. Instead of implying a range of intrinsically different jets - some very narrow, and others with similar power spread over a wider cone - the data on afterglow breaks could be consistent with a standardized jet, viewed from different angles. We discuss the implication of this model for the luminosity function.Comment: Corrected typo in Eq. 1

Adaptation of a general circulation model to ocean dynamics

A primitive-variable general circulation model of the ocean was formulated in which fast external gravity waves are suppressed with rigid-lid surface constraint pressires which also provide a means for simulating the effects of large-scale free-surface topography. The surface pressure method is simpler to apply than the conventional stream function models, and the resulting model can be applied to both global ocean and limited region situations. Strengths and weaknesses of the model are also presented

Predictions for The Very Early Afterglow and The Optical Flash

According to the internal-external shocks model for $\gamma$-ray bursts (GRBs), the GRB is produced by internal shocks within a relativistic flow while the afterglow is produced by external shocks with the ISM. We explore the early afterglow emission. For short GRBs the peak of the afterglow will be delayed, typically, by few dozens of seconds after the burst. For long GRBs the early afterglow emission will overlap the GRB signal. We calculate the expected spectrum and the light curves of the early afterglow in the optical, X-ray and $\gamma$-ray bands. These characteristics provide a way to discriminate between late internal shocks emission (part of the GRB) and the early afterglow signal. If such a delayed emission, with the characteristics of the early afterglow, will be detected it can be used both to prove the internal shock scenario as producing the GRB, as well as to measure the initial Lorentz factor of the relativistic flow. The reverse shock, at its peak, contains energy which is comparable to that of the GRB itself, but has a much lower temperature than that of the forward shock so it radiates at considerably lower frequencies. The reverse shock dominates the early optical emission, and an optical flash brighter than 15th magnitude, is expected together with the forward shock peak at x-rays or $\gamma$-rays. If this optical flash is not observed, strong limitations can be put on the baryonic contents of the relativistic shell deriving the GRBs, leading to a magnetically dominated energy density.Comment: 23 pages including 4 figure

Family Effects in Youth Employment

The authors begin with the hypothesis that parental contacts play a major role in finding jobs for youth. This hypothesis is tested with a model of youth employment that includes characteristics of other family members in addition to a large set of control variables. Particular attention is paid to parental characteristics that might indicate a parent's ability to assist the youth in finding a job, including occupation, industry and education. The effects of such variables are generally not significant and do not support the initial hypothesis. However, the employment probability of a youth is significantly affected by the presence of employed siblings, indicating the presence of some intrafamily effects.

Analysis of pressure distortion testing

The development of a distortion methodology, method D, was documented, and its application to steady state and unsteady data was demonstrated. Three methodologies based upon DIDENT, a NASA-LeRC distortion methodology based upon the parallel compressor model, were investigated by applying them to a set of steady state data. The best formulation was then applied to an independent data set. The good correlation achieved with this data set showed that method E, one of the above methodologies, is a viable concept. Unsteady data were analyzed by using the method E methodology. This analysis pointed out that the method E sensitivities are functions of pressure defect level as well as corrected speed and pattern

Importance of an Astrophysical Perspective for Textbook Relativity

The importance of a teaching a clear definition of the ``observer'' in special relativity is highlighted using a simple astrophysical example from the exciting current research area of ``Gamma-Ray Burst'' astrophysics. The example shows that a source moving relativistically toward a single observer at rest exhibits a time ``contraction'' rather than a ``dilation'' because the light travel time between the source and observer decreases with time. Astrophysical applications of special relativity complement idealized examples with real applications and very effectively exemplify the role of a finite light travel time.Comment: 5 pages TeX, European Journal of Physics, in pres

Pentalogy of Cantrell : the first Maltese case with successful outcome

Pentalogy of Cantrell is a rare disorder which was first described by Cantrell and his colleagues in 1958. It is comprised of congenital heart disease and midline defects. Surgical treatment is possible with internalisation of the heart, repair of associated intracardiac anomalies and repair of the thoraco-abdominal defect. In this article the authors describe the first Maltese case, with a successful outcome.peer-reviewe