Studies on vibration of some rib-stiffened cantilever plates

The vibrational mode shapes and frequencies of rib-stiffened skew cantilever plates as determined by holographic interferometry are given. The effects of varying the sweep back angle, rib stiffness and aspect ratio are studied along with the influence of varying the boundary conditions at the root chord on the vibrational behavior of the plates. The study is applicable to investigating the vibrational behavior of stiffened plates often used in the design of guided rockets and missiles

Horrocks Correspondence on a Quadric Surface

We extend the Horrocks correspondence between vector bundles and cohomology modules on the projective plane to the product of two projective lines. We introduce a set of invariants for a vector bundle on the product of two projective lines, which includes the first cohomology module of the bundle, and prove that there is a one to one correspondence between these sets of invariants and isomorphism classes of vector bundles without line bundle summands.Comment: 19 page

An investigation into poverty among domestic maids in Lusaka, Zambia

Despite tall claims of GDP growth, Zambian Poverty remained un addressed. Zambia has drafted its first Poverty Reduction Strategy Paper (PRSP) in 2002-2005 and mainstreamed the successive poverty reduction strategies into the National Development Plans beginning with the Fifth National Development Plan (FNDP) 2006-2010. Zambia after independence has progressively moved southwards in terms of GDP growth and achieved the status of Highly Indebted Poor Country (HIPC). Nevertheless, Zambia’s progress reports show some achievements in GDP growth and containing poverty during the initial years of FNDP. The midterm review reports show that there has been a growth in GDP and poverty reduction in Zambia, and more reduction in urban poverty. These claims have led me to find out “Has the GDP growth during the Fifth National Development Plan resulted in poverty reduction among the most vulnerable women workers- the domestic maids in Lusaka?” In the process of determining this, a review of Zambian Economy, the urban poverty levels; growth in GDP before and after FNDP; and living standards of randomly selected Domestic Maids from different compounds in Lusaka have been analyzed, evaluated and related to poverty reduction, growth and development theories. To support the analysis, a questionnaire (Appendix-I) was designed and data was collected from eight domestic maids. Apart from the primary data collection process, some data was recorded from the offices of Government of Zambia, FNDP, PRSP, and living standard surveys conducted by the United Nations Organization present in Zambia. From the information composed the appropriate data has been utilized effectively to analyze it and arrive at conclusions. In conclusion it is found that the growth in GDP and reduction in poverty levels have no tangible impact on the poverty levels of domestic maids in Lusaka.Domestic Maids, Poverty Reduction, Lusaka, Zambian Economy, Hingly Indebted Poor Country

Remote Sensing of Sea Surface Temperature from Earth Satellites

Techniques for measuring sea surface temperature using remote sensors in earth orbiting satellites are discussed. Specific reference is made to the infrared sensors carried by the TIROS Operational Satellite. The development of a method to examine a large number of measurements in order to differentiate the temperature effects of clouds is described. It is stated that the system used is completely objective and minimizes the influence of atmospheric absorption, cloud contamination, and instrumental noise on the inferred sea surface temperatures

Sterilisation and the work careers of women

This paper uses Canadian data to study the relationship between sterilisation and the work careers of women. The study is motivated by the observation that childbearing and child rearing are the main reasons for the intermittency of womens ’work. Sterilisation may be correlated with a change in the labour market behaviour of women because it ends childbearing.There are three main findings. First, among women with children, sterilised women are more likely to work than non-sterilised women. Second,being sterilised is found to have a positive and significant effect on the earnings of women who had stopped working in the past but has an insignifican effect on the earnings of continuously employed women.Third,sterilised women and non-sterilised women do not differ in the probability that they had previously stopped working.However,among sterilised women who are currently working, most had experienced career interruptions that were initiated and completed before they became sterilised.

The Submillimeter Array Polarimeter

We describe the Submillimeter Array (SMA) Polarimeter, a polarization converter and feed multiplexer installed on the SMA. The polarimeter uses narrow-band quarter-wave plates to generate circular polarization sensitivity from the linearly-polarized SMA feeds. The wave plates are mounted in rotation stages under computer control so that the polarization handedness of each antenna is rapidly selectable. Positioning of the wave plates is found to be highly repeatable, better than 0.2 degrees. Although only a single polarization is detected at any time, all four cross correlations of left- and right-circular polarization are efficiently sampled on each baseline through coordinated switching of the antenna polarizations in Walsh function patterns. The initial set of anti-reflection coated quartz and sapphire wave plates allows polarimetry near 345 GHz; these plates have been have been used in observations between 325 and 350 GHz. The frequency-dependent cross-polarization of each antenna, largely due to the variation with frequency of the retardation phase of the single-element wave plates, can be measured precisely through observations of bright point sources. Such measurements indicate that the cross-polarization of each antenna is a few percent or smaller and stable, consistent with the expected frequency dependence and very small alignment errors. The polarimeter is now available for general use as a facility instrument of the SMA.Comment: To appear in Proc. SPIE 7020, 'Millimeter and Submillimeter Detectors and Instrumentation'. Uses spie.cl