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A number of procedures for fluorescent X-ray analysis have been introduced to accommodate the samples that are produced from research on the recovery of values from secondary metal sources. For some applications, standards are conveniently available such as those that can be purchased from the National Bureau of Standards. For other applications, secondary standards must be prepared and analyzed by independent methods. The sample preparation procedures vary considerably. For monitoring process efficiency, sample preparation is often kept at a minimum such as simply pouring loose powders into disposable cups. For the most accurate analyses, sample preparatton requires casting the alloys and finishing the surfaces. Matrix correction procedures are employed where concentrations of major constituents vary over wide ranges.
A time-sharing computer was used in conjunction with a semiconductor detector and radioisotopic sources to evaluate energy dispersion x-ray analysis for the rapid analysis of copper base alloys. The time-sharing computer served two purposes: to aid in the development of the analytical method and to simulate the action of a dedicated computer that would eventually be used as part of an on-line analytical device. Some of the general capabilities of time-sharing computers are discussed in this paper with some emphasis on the differences between the computer requirements of energy dispersive x-ray methods and conventional x-ray spectrography.
An annular source of americium 24l was used with a secondary fluorescer to excite 23 brass and bronze alloys. The 400 channel spectrum from a multichannel analyzer was recorded on paper tape. A telephone coupled teletype was used to transmit the X-ray spectrum to the central processing facility. Curve fitting and statistical analysis programs similar to those available from most commercial time-sharing computer operations were utilised as well as other programs written at this laboratory for processing digitized spectra.
This study investigated patient characteristics in paediatric hospitalisations for hypertrophic cardiomyopathy. We used Nationwide Inpatient Sample, which is the largest all-payer inpatient database in the United States, yielding nationally representative estimates, from 2001 to 2014. ICD-9-CM diagnostic codes identified hospitalisations for patients with hypertrophic cardiomyopathy and <18 years. Outcomes included yearly rate of hospitalisation, death, admission via emergency department, and need for surgery. Predictors of interest were age groups (<1, 1–9, and ⩾10 y/o), sex, and race/ethnicity. Logistic regression modelled associations, adjusted by patient- and hospital-level variables. With 2302 weighted hospitalisations, hospitalisation rates were 0.22 per 100,000 children/year, with higher rates for <1 y/o (0.42) and ⩾10 y/o (0.31). Male-to-female ratios were more prominent in the oldest age group; 2.7:1 in ⩾10 y/o versus less than 1.7:1 for <10 y/o. In-hospital mortality was 1.5%, with highest mortality rates among the <1 y/o (6.3%). Children ⩾10 y/o had 5.59 times higher risk of admission from the emergency department than 1–9 y/o age group. Both ⩾10 and <1 y/o age groups had lower risk of surgical intervention compared to the 1–9 y/o group with odds ratio 0.56 and 0.26, respectively. Black children had higher risk of admission from the emergency department than White children with odds ratio 2.78. A relation between age group and sex was observed, with sex-based differences in prevalence and treatment of hypertrophic cardiomyopathy becoming more pronounced with age. Further studies are needed to clarify mechanisms behind age and racial disparity in hospitalisation, especially admission source.
Valentine (1, Theorems 2 and 3) has defined a three-point property which he called P3 and has shown that a closed subset of the euclidean plane possessing this property is expressible as the union of at most three convex sets. He also showed that if the number of isolated points of local non-convexity of such a set is one, finite and even, or infinite, the set is the union of two convex sets. In this paper we give properties which, together with Valentine's results, characterize those subsets of a plane which may be represented as a union of two closed, convex sets.
Informal (unpaid) care-givers of older people with dementia experience stress and isolation, causing physical and psychiatric morbidity. Comprehensive geriatric assessment clinics represent an important geriatrician-led model of dementia care. Our qualitative study examined the educational and support needs of care-givers of people diagnosed with dementia at a geriatric assessment clinic, resources used to address those needs and challenges experienced in doing so. We conducted structured thematic analysis of interviews with 18 informal care-givers. Participants’ narratives reflected four themes. First, care-givers sought information from varied sources, including the Alzheimer Society, the internet and clinic staff. Responsive behaviours, the expected progression of dementia and system navigation were topics of particular interest. Second, care-givers obtained assistance from public, for-profit and voluntary sources. Third, care-givers received little assistance. Two-thirds received fewer than four hours of help weekly from all sources combined, and none more than 15. Several received no assistance whatsoever. Publicly funded support workers’ tasks, and their timing, were often unhelpful. Finally, while numerous care-givers felt physical and emotional strain, and worried about how poor health impaired their care-giving, many hesitated to seek help. The needs of this unique population of informal care-givers can be met by improved home-care service flexibility, and access to trustworthy information about the expected progression of dementia and skills for managing behavioural and psychological symptoms.
We have mapped the nearby (z=0.018), active galaxy NGC 1275 (3C84) at 6 different epochs from 1981 to 1986 at 1.3 cm (22.3 GHz) with a global VLBI array of seven telescopes. We find a long-lived knot of emission separating from the brightest radio component with a projected velocity = 0.4 6±0.12 h−1 c. This knot moves through diffuse emission that also moves away from the main component with a slower projected velocity of 0.33±0.12 h−1 c. We show that the knot and diffuse emission result from two separate events that occurred around 1959 and 1968.
We report aperture synthesis observations of the HCO+ and HCN J=1–0 molecular lines towards the Galactic center. These data complement existing HCN data and trace a dense molecular ring surrounding the ionized central 2 pc of the Galaxy. The new data are consistent with the model of a clumpy, almost complete ring which is inclined to the line of sight at 50 to 75 degrees. The same structure is seen in HCO+ and in HCN with the exception of an HCN feature at 60 to 100 km/s in the western part of the ring, which is not detected in HCO+ emission. The HCN and HCO+ are collisionally excited in clumps with densities around 10 cm and volume filling factor 1/3 to 1/30. H13 CN emission from the ring was detected at about 1/7 of the intensity of the HCN; the latter is optically thick and is mapping a combination of surface density and excitation temperature. The HCO+ emission shows deep absorption features associated with galactic structure along the line of sight. Absorption features corresponding to the 3 kpc arm, the inner disk and an expanding ring at −195 km/s can be seen in absorption against the Sgr A radio continuum.
I report here centimeter–wavelength observations carried out at the Very Large Array (VLA) to help resolve two questions. First, what is the source of the far infrared (FIR) emission in infrared-luminous IRAS galaxies, active nuclei or more widely distributed star formation? And what physics underlies the tight correlation (Helou et al., 1985) between FIR and radio flux? To test potential answers to these questions, we believe it is important to study the most luminous IRAS galaxies. We selected 39 for study from the ultraluminous catalog of Strauss et al.(1990 and 1992). All sources had FIR luminosity ≥ 1011.4 L⊙. Radio wavelength observations of these systems provide several advantages. First, in the radio there is no obscuration, so we can “see” the active galactic nuclei, if present. Radio spectral indices can distinguish between synchrotron and thermal emission. And finally, observations at the VLA provide sub–kpc resolution. We observed these sources with the VLA in its C configuration. At 1460 MHz, the effective resolution was ≃ 15″; and ≃ 4″ at 4860 MHz. We made follow-up observations on 24 sources in the A configuration with resolution at 4860 MHz of ≃ 0″.5 (or 300–800 h–1 pc for these sources).
The radio source 0108 + 388 is a canonical example of a class of extragalactic radio sources, referred to as Gigahertz-Peaked Spectrum (GPS) sources, whose spectra peak at high frequencies. There are two competing models for the cause of the high frequency turnover: free-free absorption (f-f) of the lower frequency radiation by ionized gas in the host galaxies (e.g. van Breugel 1984), or synchrotron self-absorption (SSA) due to exceptionally large magnetic fields, (e.g. Hodges, Mutel, & Phillips 1984).
Rural communities in South Africa are becoming increasingly reliant on freshwater fish to supplement their dietary protein requirement. Rising costs of other protein sources, increasing rural poverty and escalating rural populations are resulting in increasing consumption of fish from contaminated river systems. The Olifants River, Limpopo Basin, Eastern South Africa, has been systemically impaired and is now one of the most polluted rivers in South Africa. We measured the concentrations of metals in fish muscle tissue from two impoundments in the Olifants River (Flag Boshielo Dam and the Phalaborwa Barrage) and conducted a human health risk assessment following Heath et al., (2004) to investigate whether consumption of Oreochromis mossambicus from these impoundments posed a risk to the health of rural communities. Our results show that metals are accumulating in the muscle tissue of O. mossambicus even though the populations appear to be healthy. No patterns were observed in the ratios of the metals accumulated in the muscle tissue of O. mossambicus at each impoundment. The human health risk assessment identified that lead, antimony and chromium at Flag Boshielo Dam and lead at the Phalaborwa Barrage were above acceptable levels for the safe consumption based on a weekly 150 g fish meal. We conclude that consuming O. mossambicus from these impoundments could pose an unacceptable risk to the health of rural communities.
The market town of St. Neots is situated a mile or so off the Great North Road, and on the right bank of the Great Ouse just where it forms the boundary between Huntingdonshire and Bedfordshire. It lies at an average height of 55 feet above O.D.
For some years I have visited the pits which are worked in the low level gravels in and near this town and have been successful in obtaining from them a number of Palæolithic implements and flakes, as well as mammalian remains. Nearly all the implements and flakes were found by myself on heaps of gravel recently raised from the pits, but a few, together with all the bones, were found by the workmen, who in some cases were able to give me the level of derivation.
The first pit to be considered is in the town of St. Neots, and is situated in the grounds of Hall Place, Cambridge Street, about 150 yards east of the Vicarage. It is not very extensively worked and gravel is dug to a depth of 9 feet. The surface, which is approximately 50 feet above O.D., is less than ten feet above the level of the river. I have only one definite implement from this site (Plate II., fig. c), which I found on a heap of gravel on the edge of the pit. Flakes, however, number ten. They are mostly rather thick and coarse, and five show some crust. Most of them have little patination except a faint bluish stain near the crust. One is of a dark honey colour, and another has an ochreous patination. Several of these might have been used as scrapers, and four seem to have been struck from a prepared platform. Red Deer, Rhinocerus tichorhinus and Bos or Bison have been discovered in this pit.
The discovery of late Palæolithic relics in East Anglia has aroused the interest of students of prehistoric remains, and the paper by Dr. A. Sturge in Vol. I., Part II., of the Proceedings of the Prehistoric Society of East Anglia may be regarded as the starting-point from which much will be done in the near future.
I have for some time held on theoretical grounds that Late Palæolithic relics should occur in East Anglia, and collected specimens from Wretham Heath in support of that view: it was, therefore, with peculiar interest that I learned of Dr. Sturge's discoveries. I wish to thank Dr. Sturge and the Abbé Breuil for their kindness in examining my specimens, and Mr. W. B. R. King, B.A., of Jesus College, Cambridge, for much help in collecting.
For many years the post-glacial age of palæolithic man in this country was generally accepted, though it was denied by some, especially by Prof. James Geikie and Mr. S. B. J. Skertchly. The latter based his views upon the distribution of the superficial deposits on the western borders of Norfolk and Suffolk, of which more anon.
Of recent years, the work of various continental geologists has shewn that palæolithic man lived in western Europe before the latest glacial episode, and it seems very unlikely therefore, that the same was not the case in our own country. We determined, therefore, to open some sections in the well-known locality of High Lodge, Mildenhall, in order to try to obtain evidence upon this point. We would wish to record our cordial thanks to Sir Henry Bunbury, upon whose estates the High Lodge deposits are found, for giving us permission to make excavations, and affording us every facility during the operations. We also took advantage of a recently opened exposure at Warren Hill, to note the section exposed at that place.
In 1900 an implement was found on the surface at Broom Covert, Higham, Suffolk, which has generously been presented to the Sedgwick Museum, Cambridge, by F. H. Barclay, Esq., M.A., F.G.S., the Warren, Cromer.
It is of considerable interest, and I propose briefly to describe it. It is slightly lustrous, milk-white with some light indigo-coloured mottlings, quite unworn, and presumably a true surface-find not derived from a deposit.
The specimen, which is 4½-in. long and 1½-in. across at the widest part is a well-formed lateral burin (Fig. 1). The working edge has been renewed, probably more than once. At the final renewal, after striking the burin-blow, the face then produced was modified by the removal of some small flakes at the anterior end (Fig. 1 c). The striking platform was reduced by subsequent trimming, giving the butt-end a neat semi-oval outline.
Highly as I feel the honour of having been asked to occupy this Presidential chair, I accepted that honour with some diffidence, for I recognise that my studies in Pre-history.have not been carried very far. As, however, these studies have convinced me that the application of geology to prehistoric problems is even yet fraught with many difficulties, it appears to me desirable in this address to call special attention to some of these difficulties.
Having devoted nearly half a century to geological researches of various kinds, I can state with confidence that those geological problems with which we are concerned are among the most difficult with which the geologist is confronted, and their investigation cannot be lightly undertaken.
At present, what we above all require is the collection of facts, and I therefore hailed with pleasure the foundation of this Society, and congratulate its members upon the amount of valuable work which they have already performed. Among these members the name of Dr. Allen Sturge stands out pre-eminent. He may be regarded as the Father of the Society, and all members must deeply deplore the loss which the Society has sustained by his death.
A low temperature amorphous zinc indium oxide (ZIO) thin film transistor (TFT) backplane technology for high information content flexible organic light emitting diode (OLED) displays has been developed. We have fabricated 4.1-in. diagonal OLED backplanes on the Flexible Display Center’s six-inch wafer-scale pilot line using ZIO as the active layer. The ZIO based TFTs exhibited an effective saturation mobility of 18.6 cm2/V-s and a threshold voltage shift of 2.2 Volts or less under positive and negative gate bias DC stress for 10000 seconds. We report on the critical steps in the evolution of the backplane process: the qualification of the low temperature (200°C) ZIO process, the stability of the devices under forward and reverse bias stress, the transfer of the process to flexible plastic substrates, and the fabrication of white organic light emitting diode (OLED) displays.
The heterogeneity of a-Si:H and a-Si:D films has been probed on the nano-scale by small-angle neutron scattering (SANS). Films were deposited by two techniques, plasma-enhanced chemical-vapor deposition (PECVD) and hot-wire chemical-vapor deposition (HWCVD) using conditions that yield high-quality films and devices. Four samples were examined in a light-soaked state (AM1.5, 300 h) and then re-examined after annealing (190°C, 1 h) in-situ to look for any change in SANS associated with the Staebler-Wronski effect. No changes were observed in the SANS intensity to a precision that could have readily detected the 25% change reported in 1985 (Chenevas-Paule et al). Significant differences are observed in hydrogenated and deuterated films, as well as in the PECVD versus the HWCVD materials.
Principal challenges to direct fabrication of high performance a-Si:H transistor arrays on flexible substrates include automated handling through bonding-debonding processes, substrate-compatible low temperature fabrication processes, management of dimensional instability of plastic substrates, and planarization and management of CTE mismatch for stainless steel foils. In collaboration with our industrial and academic partners, we have developed viable solutions to address these challenges, as described in this paper.
We ask if Earth-like planets (terrestrial mass and habitable-zone orbit) can be detected in multi-planet systems, using astrometric and radial velocity observations. We report here the preliminary results of double-blind calculations designed to answer this question.