Image tube

An optical image is projected onto a planar surface of a photocathode that derives an electron beam replica of the image. A target electrode displaced relative to the photocathode so that it does not obstruct the optical image includes a planar surface for receiving and deriving an accurate replica of the electron beam image. The two planar surfaces are parallel. The electron beam image is focused on the target electrode by providing throughout a region that extends between the planar surfaces of the photocathode and receiving electrode, constant homogeneous dc electric and magnetic fields. The electric field extends in a direction perpendicular to the planar surfaces while the magnetic field extends along a straight line that intersects the photocathode and target electrode at an acute angle

A magnetically focused image tube employing an opaque photocathode

Image converter has been developed which uses opaque photocathode for improved efficiency. Device is easier to fabricate than previous semi-transparent photocathode converters and uses compounds from Groups 3-5 that are responsive to wave-lengths between ultraviolet (approximately 100 nm) and near infrared region (approximately 1000 nm)

Wide-angle flat field telescope

Described is an unobscured three mirror wide angle telescopic imaging system comprised of an input baffle which provides a 20 deg (Y axis) x 30 deg (X axis) field of view, a primary mirror having a convex spherical surface, a secondary mirror having a concave ellipsoidal reflecting surface, a tertiary mirror having a concave spherical reflecting surface. The mirrors comprise mirror elements which are offset segments of parent mirrors whose axes and vertices commonly lie on the system's optical axis. An iris diaphragm forming an aperture stop is located between the secondary and tertiary mirror with its center also being coincident with the optical axis and being further located at the beam waist of input light beams reflected from the primary and secondary mirror surfaces. At the system focus following the tertiary mirror is located a flat detector which may be, for example, a TV imaging tube or a photographic film. When desirable, a spectral transmission filter is placed in front of the detector in close proximity thereto

The Need for a New U.S. Policy Toward Cuba in the 1970\u27s

In light of the Castro government\u27s proven ability to survive America\u27s economic boycott, Washington would be well advised to move gradually to normalize relations with Havana as the best possible means of reducing Soviet influence in Cuba

Pituitary

Benefiting from superior tissue contrast, multi‐planar capability and lack of bone artifact, MRI readily depicts complex anatomy in and about the pituitary gland. This unit presents three basic protocols for common indications relating to pathology of the sella and parasellar region. The protocols differ in emphasis more than in concept, and share a basic theme of thin slice high‐resolution imaging including the use of gadolinium. With the possible exception of dynamic imaging, all protocols may be readily performed on any MR scanner.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145371/1/cpmia0502.pd

The Need for a New U.S. Policy Toward Cuba in the 1970\u27s

In light of the Castro government\u27s proven ability to survive America\u27s economic boycott, Washington would be well advised to move gradually to normalize relations with Havana as the best possible means of reducing Soviet influence in Cuba

Ability grouping: Year group differences in self-concept and attitudes of secondary school pupils

The vast international literature on the effects of different types of ability grouping on selfconcept and pupils? attitudes towards school has focused on pupils from single year groups. This paper aimed to explore year group differences in pupils' self concept and attitudes towards school as influenced by ability grouping. The study was cross sectional in design and measured attitudes towards school and mathematics; mathematics, general and school selfconcept and preferences for different kinds of grouping in 234 students from years 7 through 10 attending a mixed comprehensive school. The findings indicated that mathematics self concept was consistently lower than school and general self concept; all aspects of self concept increased up to year 9 and then declined in year 10; pupils in the higher sets tended to have higher self concepts; pupil preferences for setting were greater in the higher year groups, as was the extent to which the top set was perceived to be the best. A substantial proportion of pupils wanted to move set, usually to a higher set. Set placement itself did not appear to have a consistent effect on attitudes towards mathematics. This seemed to be mediated by the quality of teaching

Atmospheric X-ray emission experiment for shuttle

An experiment designed to measure the spatial, temporal, and energy distribution of X-ray aurorae produced by precipitating electrons, is presented. The experiment will provide vital data on solar-terrestrial relationships that may lead to defining the transfer mechanism that causes certain terrestrial weather events and climatological behavior. An instrument concept is discussed, and is based on a spatially sensitive multiwire proportional counter, combined with collimators to produce X-ray images of the aurorae. An instrument pointing system, on which the counter can be mounted, will provide the required altitude control, and can be operated by a Spacelab payload specialist for full control over its observing and data taking modes

The impact of instrumental music learning on attainment at age 16: a pilot study

There is increasing international evidence that playing a musical instrument has a positive impact on attainment at school but little research has been undertaken in the UK. This study addresses this drawing on data on attainment at age 11 and 16 relating to 608 students, 115 of whom played a musical instrument. The findings showed that the young people playing an instrument showed greater progress and better academic outcomes than those not playing with the greatest impact for those playing the longest. The findings are considered in relation to the possible reasons for this, and the implications for education

Dual optical detection and multivariate analysis

The application of flow injection analysis into the simultaneous determination of two or more components has been challenging for many years. Various detectors such as ultraviolet/visible absorption, fluorescence, and electrochemical detectors, have been used individually or in combination with each other. Combining two optical detectors such as fluorescence and ultraviolet/visible absorbance, however, has always been challenging due to their incompatibilities. However, the recent developments in fibre optics, solid-state light sources and miniaturised charged coupled devices (CCD), allow novel designs and most of the incompatibilities be circumvented. A flow injection manifold can now be adapted so that only one flow cell is used along with a diode array CCD detector that can detect both fluorescence and absorbance simultaneously. The initial development and testing of such dual detection system is described in this thesis. [Continues.