The system parameters of the polars MR Ser and ST LMi

We obtain the NaI 8183,8195 absorption line radial velocity curves for the polars ST LMi and MR Ser, from which we find the semi-amplitudes to be K_abs=329=+/-6 kms-1 and K_abs=289+/-9 kms-1 respectively. We find that for both systems the effects on the \NaI absorption lines due to X-rays heating the inner face of the secondary are negligible, and so the values obtained for K_abs can be taken as the true semi-amplitude of the secondary star. We then determine the projected rotational velocities, vsini, to be 104+/-9 kms-1 and 66+/-13 kms-1 for ST LMi and MR Ser respectively which enables their mass ratios to be calculated. For ST LMi and MR Ser we find the mass ratio to be 0.22+/-0.04 and 0.10+/-0.05 respectively; values which are significantly different only at the 94 percent level. We show that ``spike'' in the orbital period distribution of polars is a significant feature, although the discovery of only one more system with a period outside the ``spike'' would decrease its significance below a 99 percent confidence level. We conclude that, even if the limb darkening coefficients for the secondary stars in ST LMi and MR Ser are the same, we cannot rule out the two systems having identical parameters. Therefore our observations are compatible with the theory explaining the ``spike'' in the period distribution of the AM Hers.Comment: 6 pages, accepted for MNRAS, use mn.sty, 9 postscript figures, 3 table

Some studies concerning the isolation of spectral lines in analytical flame atomic spectroscopy

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Modeling and testing of stitched composite laminates for enhanced interlaminar strength

This research assesses the effects of stitching a four-layer E-glass/Epoxy cross-ply laminate with translaminar reinforcement consisting of E-glass yarns. Both experimental characterization and finite element analysis have been employed to accurately predict and analyze the properties of the stitched material.;Tensile and Double Cantilever Beam testing indicated that translaminar stitching degrades the effective extensional modulus of the laminate by about 15.9 percent, while it enhances the opening Mode I interlaminar fracture toughness. This degradation in the effective in-plane stiffness is attributed to the localized damage inflicted on the fiber plies by the needle penetration of the sewing machine used to insert the transversely reinforcing stitch.;The finite element model predicted a more rigid effective extensional modulus of 2.44 MSI, which is approximately 2.9 percent higher than the corresponding experimental value of 2.37 MSI. This difference can be attributed to slippage effects along the fiber-matrix interfaces being prevented in the model

Remedial Mathematics Students Entering Community College: A Phenomenological Study Designed to Discover Shared Learning Characteristics and Needs

Over the course of several decades, a large body of research written with a focus on community colleges has accumulated based on the high need for remediation in mathematics, and has been associated with high attrition rates at that level. Reform efforts have been largely unsuccessful. This qualitative study was conducted so that the phenomenon of the requirement of remedial coursework in math could be examined. Each of the thirteen participants in the study took part in one open-ended interview in which they shared their experiences, including their backgrounds and beliefs about learning mathematics throughout their years of school prior to, and including their enrollment in remedial mathematics coursework at the community college level. A conceptual framework that blended adult learning theories, or andragogy, with current research about the effect of mindset on learning mathematics was utilized to interpret information gathered. Delimitations of the study were the exclusion of students who signed up for remedial math by choice without requirement and students in need of special education services. The data gathered from the participant narratives led to conclusions that common experiences existed among remedial math students including a negative mindset about mathematics, a distorted view of mathematics as a discipline, and negative perceptions about community college structures including advising, course structure, and course pathways. Conclusions gleaned from this study contributed to the body of research on this topic based on alignment with recommendations from researchers that the community college experience for remedial studies be changed to include explicit work on self-regulation and metacognitive strategies, as well as increased use of active learning strategies, and changes in policy regarding course placement and pathways

Historical Skeletal Remains from Dundas County, Ontario: A Cautionary Tale Concerning Individual Identification

A single burial dating to the historic period was unexpectedly discovered on a farm in rural Dundas County, Ontario. Based on a preliminary investigation, the remains were believed to be those of Margaret Ellen Bellway, an 8-year-old girl who lived on the property and who died in the year 1881. The objectives of this article are to demonstrate that establishing individual identification of historical remains is possible, to demonstrate the importance of exploring all relevant avenues of research prior to finalizing individual identification, and to demonstrate the means by which this is done. Skeletal analysis of the remains indicated a child of 5 to 6 years of age and coffin hardware analysis indicated a burial date between 1860 and 1871. The latter information was used to restrict the search of land registry, census, vital statistic, and parish records. Information derived from these sources strongly supports the identification fo the remains as those of Daniel Veitch, whose family lived on the property from 1866 to 1874, and who died at the age of 6 in 1870

Building a Framework for Change

Change is never easy. Sustained change in education is particularly difficult. To get the desired results, all of the stakeholders must have a shared vision for learning. It is a process not a destination. Brewer Elementary School has been in the process of change in the past several years. Brewer is in the heart of Columbus, Georgia. The school opened in 1991. The building itself is a welcome focal point in a community of apartments, low rent housing, trailer parks and businesses. It is a safe, clean, happy place for children to learn. The school currently has approximately 520 students in pre-kindergarten thru fifth grade. There is a high population of special education students served at the school in the mildly intellectually disabled, severe/profound, learning disabled and behavior disordered programs. Ninety-two percent of the children are African American, four percent Caucasian, two percent Hispanic and two percent are of mixed race. There is an even distribution of male and female students

Impulse

https://openprairie.sdstate.edu/coe_impulse/1044/thumbnail.jp

Optical and ROSAT X-ray observations of the dwarf nova OY Carinae in superoutburst and quiescence

We present ROSAT X-ray and optical light curves of the 1994 February superoutburst of the eclipsing SU UMa dwarf nova OY Carinae. There is no eclipse of the flux in the ROSAT HRI light curve. Contemporaneous `wide B' band optical light curves show extensive superhump activity and dips at superhump maximum. Eclipse mapping of these optical light curves reveals a disc with a considerable physical flare, even three days into the superoutburst decline. We include a later (1994 July) ROSAT PSPC observation of OY Car that allows us to put constraints on the quiescent X-ray spectrum. We find that while there is little to choose between OY Car and its fellow high inclination systems with regard to the temperature of the emitting gas and the emission measure, we have difficulties reconciling the column density found from our X-ray observation with the column found in HST UV observations by Horne et al. (1994). The obvious option is to invoke time variability.Comment: 16 pages, 14 figures, accepted for publication in MNRA