Characterizations of electrical properties of highT(sub c) superconducting materials

The automated data acquisition system developed in the Space Science Laboratory at Marshall Space Flight Center for measuring electrical properties of high temperature superconductors is described. The acquisition system, consisting of a computer and computer-controlled hardware, allows large numbers of voltage, current, temperature, and magnetic measurements to be performed on bulk and thin film samples. Typical results are shown characterizing transition temperature (T sub c), critical current density (J sub c), and magnetic properties of bulk high T(sub c) materials as a function of temperature

Development of low-temperature transistor modules to improve the MSFC mid-infrared array

This report describes the low-temperature transistor modules designed for use with the MSFC mid-infrared array. The modules were developed in the Space Science Laboratory at Marshall Space Flight Center with Center Director's Discretionary Funds. The transistors (JFETs), which operate at a temperature of 77 K, are epoxied to a copper surface attached to a Teflon substrate. The module substrate insulates the JFETs from the 1.5K detector work surfaces and provides a convenient mounting structure for additional components such as solder pins. These modules have maintained their structural integrity during repeated temperature cycling, and they have to be convenient during maintenance and servicing of the infrared array

Smoking, dementia and cognitive decline in the elderly, a systematic review.

Background. Nicotine may aid reaction time, learning and memory, but smoking increases cardiovascular risk. Cardiovascular risk factors have been linked to increased risk of dementia. A previous meta-analysis found that current smokers were at higher risk of subsequent dementia, Alzheimers disease, vascular dementia and cognitive decline. Methods. In order to update and examine this further a systematic review and meta-analysis was carried out using different search and inclusion criteria, database selection and more recent publications. Both reviews were restricted to those aged 65 and over. Results. The review reported here found a significantly increased risk of Alzheimers disease with current smoking and a likely but not significantly increased risk of vascular dementia, dementia unspecified and cognitive decline. Neither review found clear relationships with former smoking. Conclusion. Current smoking increases risk of Alzheimers disease and may increase risk of other dementias. This reinforces need for smoking cessation, particularly aged 65 and over. Nicotine alone needs further investigation. © 2008 Peters et al; licensee BioMed Central Ltd

The Way We Measure: Comparison of Methods to Derive Radial Surface Brightness Profiles

The breaks and truncations in the luminosity profile of face-on spiral galaxies offer valuable insights in their formation history. The traditional method of deriving the surface photometry profile for face-on galaxies is to use elliptical averaging. In this paper, we explore the question whether elliptical averaging is the best way to do this. We apply two additional surface photometry methods, one new: principle axis summation, and one old that has become seldom used: equivalent profiles. These are compared to elliptically averaged profiles using a set of 29 face-on galaxies. We find that the equivalent profiles match extremely well with elliptically averaged profiles, confirming the validity of using elliptical averaging. The principle axis summation offers a better comparison to edge-on galaxies.Comment: Accepted for publication by Monthly Notices of the R.A.S. A hi-res version is available at http://www.astro.rug.nl/~vdkruit/Petersetal-VI.pd

The Shape of Dark Matter Haloes II. The Galactus HI Modelling & Fitting Tool

We present a new HI modelling tool called \textsc{Galactus}. The program has been designed to perform automated fits of disc-galaxy models to observations. It includes a treatment for the self-absorption of the gas. The software has been released into the public domain. We describe the design philosophy and inner workings of the program. After this, we model the face-on galaxy NGC2403, using both self-absorption and optically thin models, showing that self-absorption occurs even in face-on galaxies. It is shown that the maximum surface brightness plateaus seen in Paper I of this series are indeed signs of self-absorption. The apparent HI mass of an edge-on galaxy can be drastically lower compared to that same galaxy seen face-on. The Tully-Fisher relation is found to be relatively free from self-absorption issues.Comment: Accepted for publication by Monthly Notices RAS. Hi-res. version available at www.astro.rug.nl/~vdkruit/Petersetal-II.pd

A Nonclassical Dihydrogen Adduct of S = ½ Fe(I)

We have exploited the capacity of the “(SiP^(iPr)_3)Fe(I)” scaffold to accommodate additional axial ligands and characterized the mononuclear S = 1/2 H_2 adduct complex (SiP^(iPr)_3)Fe^I(H_2). EPR and ENDOR data, in the context of X-ray structural results, revealed that this complex provides a highly unusual example of an open-shell metal complex that binds dihydrogen as a ligand. The H2 ligand at 2 K dynamically reorients within the ligand-binding pocket, tunneling among the energy minima created by strong interactions with the three Fe–P bonds

Network ST radar and related measurements at Pennsylvania State University

Mesoscale meteorological measurements, analysis and prediction are some of the principal areas of research in the Department of Meteorology at Penn State. In anticipation of a staged turn-on of the three systems during the Summer and Fall of 1984, the nonconstruction-related efforts have focused on the software development necessary to allow essentially immediate use of network data. A 16-bit microcomputer has been programmed to serve as the network controller, communications interface and, at least for real-time purposes, the operational display system. Insofar as possible we have in this task built upon our substantial accumulated experience in working with the processing and display of Doppler sodar system signals. Once the radar-derived wind and turbulence profiles are communicated to the various interconnected Departmental computers they become just one component of a comprehensive data base which can be applied to a diverse set of ongoing basic and operational research programs

Protein-energy malnutrition and the home environment : a study among children in Coast Province, Kenya

Abr. abstr.: This is an account of a study concerning the occurrence of childhood malnutrition in Kilifi District, Kenya. The socioeconomic characteristics of women with malnourished children who attended Kilifi Family Life Training Centre in the year 1984/1985 were analysed. Next, the possible influence of intra-household factors on the occurrence of childhood malnutrition was examined. A comparison of two groups of ten mother/child pairs, focusing on feeding and weaning patterns, hygiene, parental care and home stimulation, revealed important variations as regards child/caretaker relationships. In households where no malnutrition had occurred, children were fed more regularly and were provided with more types of stimulation. The question remains whether a malnourished child generates a lower level of stimulation on the caretaker's part, or whether lack of stimulation by the caretaker leads to an increased risk of malnutrition. However, the present findings indicate not only that a relationship between childhood malnutrition and home stimulation exists, but that it persists beyond the acute episode and subsequent rehabilitation. Consequently, it is recommended that emphasis during rehabilitation should not only be on nutritional requirements and general child care, but also on individual attention and stimulation given to the chil