Fluidized Bed Granulation with Pvp K90 and Pvp K120

The characteristics and growth mechanisms of fluidized bed granules are dependent both on process variables and the grades of PVP binders used. Generally, an increase in the concentration, spraying rate and volume of binder solution caused an increase in granule size and a decrease in size distribution. These two factors will in turn affect the poured and tapped densities of granules. Granules prepared with PVP K90 solution appeared to grow by primary and secondary agglomeration to give an aggregate structure. Granules prepared with PVP K120 solution were formed through snowballing as the primary agglomeration process. This occurred at low binder solution concentration with secondary agglomeration taking place when the concentration of PVP K120 solution was increased.     

A comparison of computational color constancy Algorithms. II. Experiments with image data

For pt.I see ibid., vol. 11, no.9, p.972-84 (2002). We test a number of the leading computational color constancy algorithms using a comprehensive set of images. These were of 33 different scenes under 11 different sources representative of common illumination conditions. The algorithms studied include two gray world methods, a version of the Retinex method, several variants of Forsyth's (1990) gamut-mapping method, Cardei et al.'s (2000) neural net method, and Finlayson et al.'s color by correlation method (Finlayson et al. 1997, 2001; Hubel and Finlayson 2000). We discuss a number of issues in applying color constancy ideas to image data, and study in depth the effect of different preprocessing strategies. We compare the performance of the algorithms on image data with their performance on synthesized data. All data used for this study are available online at http://www.cs.sfu.ca//spl sim/color/data, and implementations for most of the algorithms are also available (http://www.cs.sfu.ca//spl sim/color/code). Experiments with synthesized data (part one of this paper) suggested that the methods which emphasize the use of the input data statistics, specifically color by correlation and the neural net algorithm, are potentially the most effective at estimating the chromaticity of the scene illuminant. Unfortunately, we were unable to realize comparable performance on real images. Here exploiting pixel intensity proved to be more beneficial than exploiting the details of image chromaticity statistics, and the three-dimensional (3-D) gamut-mapping algorithms gave the best performance.     

A comparison of subcellular element concentrations in frozen-dried, plastic-embedded, dry-cut sections and frozen-dried cryosections

Biological X-ray microanalysis of diffusible elements within cellular and subcellular compartments requires preparation methods to retain electrolytes in the compartments they occupied in vivo. X-ray microanalysis of frozen-dried, plastic-embedded samples has been used to quantitate electrolytes at the cellular level. We have compared the subcellular elemental distribution in dry cut sections from such samples with that in ultrathin frozen-dried cryosections. Rat pancreases were quench-frozen onto a helium-vapor-cooled copper block. Cryosections were cut at 130-150 K, transferred using a Gatan cold stage, frozen-dried in the column and analysed at 190 K. Tissue fragments were frozen-dried at 190 K, and cut on a dry knife at 293 K. Both samples provided images permitting unambiguous identification of all major compartments except the Golgi complex. Intracellular potassium-to-sodium ratios obtained on frozen-dried plastic-embedded sections were lower than for cryosections (e.g. 1.77 in basal cytoplasm in plastic sections as compared to 4.34 for cryosections) and varied with the pre-embedding procedure (e.g. 1.77 in formaldehyde-fixed as compared to 2.87 in osmium-fixed plastic sections). Potassium gradients between adjacent organelles were large in cryosections and insignificant in plastic-embedded material. Higher cytoplasmic phosphorus, potassium and sulfur concentrations were observed in cryosections. Therefore, a redistribution of electrolytes and covalently bound elements occurred subcellularly in the plastic sections. Calcium was quantifiable in most organelles in cryosections but the plastic lowered sensitivity too much to permit routine calcium quantification. We conclude that in our hands frozen-dried, plastic-embedded samples were compromised and provided lower sensitivity than cryosections.(ABSTRACT TRUNCATED AT 250 WORDS)     

Controlling the Er content of porous silicon using the doping current intensity

The results of an investigation on the Er doping of porous silicon are presented. Electrochemical impedance spectroscopy, optical reflectivity, and spatially resolved energy dispersive spectroscopy (EDS) coupled to scanning electron microscopy measurements were used to investigate on the transient during the first stages of constant current Er doping. Depending on the applied current intensity, the voltage transient displays two very different behaviors, signature of two different chemical processes. The measurements show that, for equal transferred charge and identical porous silicon (PSi) layers, the applied current intensity also influences the final Er content. An interpretative model is proposed in order to describe the two distinct chemical processes. The results can be useful for a better control over the doping process.

PACS

81.05.Rm; 82.45.Rr     

Housing quality and resilience in New Zealand

There is extensive research on the negative health impacts of poor housing quality. However, little is known about the potential health benefits of high-quality housing in poor neighbourhoods. Neighbourhoods with unexpectedly good health outcomes despite high levels of deprivation have been deemed resilient places and housing quality in these areas may be a contributor to this resilience. This study aimed to evaluate whether an indicator of neighbourhood housing quality was associated with a previously quantified resilience index (RINZ) in New Zealand. It was found that areas with high housing quality tended to have higher median income, greater proportions of partnered people and shorter-term residents, and very low proportions of Māori. A positive association was found between housing quality and resilience, after adjustment for deprivation. There was no indication of differences by heterogeneity in housing quality within the aggregate unit of analysis. These findings pose the hypothesis that improving housing quality in similarly deprived areas that have poor health outcomes could potentially boost health. To extend this understanding, further development of a more sophisticated housing quality indicator is recommended.     

Somatotropic axis and concentrate supplementation in grazing dairy cows of genetically diverse origin

Supplementing pasture-fed dairy cows with concentrates in early lactation was hypothesized to result in an earlier postpartum recoupling of the somatotropic axis in New Zealand (NZ)-type Holstein-Friesian dairy cows than in North American (NA)-type cows. To test this hypothesis, NA (n = 30) and NZ (n = 30) cows were allocated to 1 of 3 supplementation strategies (0, 3, or 6 kg of dry matter concentrate/d) for the first 12 wk of lactation in a completely randomized design and a 2 × 3 factorial arrangement. Production traits and characteristics of the somatotropic axis were studied at phenotypic, hormonal, and gene expression levels. Milk production and plasma metabolite concentrations were measured weekly, and liver was biopsied in wk 1, 4, 8, and 12 postcalving. North American cows produced more milk and displayed a larger degree of somatotropic axis uncoupling than did NZ cows. This was evident in strain differences in body condition score, blood growth hormone, and insulin-like growth factor-1 concentrations, and hepatic expression of growth hormone receptor-1a. No strain × diet interactions were observed for any characteristic of the somatotropic axis at either the blood metabolite or gene expression level; however, blood insulin concentrations during wk 7 to 11 postpartum increased with concentrate supplementation in NZ but not NA cows. These results demonstrate that feeding supplements does not result in an earlier recoupling of the somatotropic axis; however, the greater blood insulin concentrations with concentrate feeding in NZ cows from wk 7 may result in an earlier recoupling in this genetic strain, after the period investigated in this study. Further research is required to understand differences in insulin control between these genetic strains.     

Observations of wind turbine wakes and surface roughness effects on wind flow variability

Wind data collected at nine meteorological towers at the Goodnoe Hills MOD-2 wind turbine site were analyzed to characterize the wind flow over the site both in the absence and presence of wind turbine wakes. Free-flow characteristics examined were the variability of wind speed and turbulence intensity across the site as a function of wind direction and surface roughness. The nine towers' data revealed that scattered areas of trees upwind of the site caused pronounced variations in the wind flow over the site. At two towers that were frequently downwind of an extensive grove of trees, up to 30% reductions in wind speed and a factor of 2 to 3 increase in turbulence intensity were measured. A substantial increase in the magnitude of the wind gusts, as well as a considerable decrease in the mean wind speed, was observed when a tower was downwind of the trees.Wind turbine wake characteristics analyzed included the average velocity deficits, wake turbulence, wake width, wake trajectory, vertical profile of the wake, and the stratification of wake properties as a function of the ambient wind speed and turbulence intensity. The wind turbine rotor disk spanned a height of 15 m to 107 m. The nine towers' data permitted a detailed analysis of the wake behavior at a height of 32 m at various downwind distances from 2 to 10 rotor diameters (D). The relationship between velocity deficit and downwind distance was surprisingly linear, with average maximum deficits ranging from 34% at 2 D to 7% at 10 D. Largest deficits were at low wind speeds and low turbulence intensities. Average wake widths were 2.8 D at a downwind distance of 10 D. Implications for turbine spacing are that, for a wind farm with a 10-D row separation, array losses would be significantly greater for a 2-D than a 3-D spacing because of incremental effects caused by overlapping wakes. Other interesting wake properties observed were the wake turbulence (which was greatest along the flanks of the wake). the vertical variation of deficits (which were greater below hub height than above), and the trajectory of the wake (which was essentially straight).     

Training issues.

This interesting set of articles, taken as a group, suggests that we have come a long way toward the integration of family therapy into the training of psychologists. The question is no longer "Should psychologists be trained in family therapy?" but "How can such training best be accomplished, in what settings, with what approaches, and how related to other elements of the graduate or postdoctoral program?" The articles by Ribordy (see record 1989-13401-001) and by Lebow (see record 1989-13365-001) address the central issues in training from different vantages (the family institute versus the academic program) but converge on many points. I will comment mainly on these two articles, but first I want to take note of some of the ideas raised by Berger and Jurkovic (see record 1989-12730-001). They describe and persuasively illustrate a contextual approach to family work that emphasizes the varying settings in which therapy may occur. Thus they are concerned with a "supersystem" that incorporates these extra therapeutic systems as well as clinicians and family. It will be no great surprise to the readers of this Journal that many of these same points emerge from Ribordy's and Lebow's more general discussions of training issues. They explore the separate territories of the academic graduate program and the family institute as settings for training and ably outline the advantages and disadvantages of each. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expression of growth hormone-binding protein with a hydrophilic carboxyl terminus by the mouse placenta: studies in vivo and in vitro

GH-binding protein (GHBP) or GH receptor is present in numerous extrahepatic tissues in the rodent. From mid- to late gestation in the mouse, the maternal serum concentration of GHBP increases 30- to 50-fold. We have investigated whether the placenta might synthesize GHBP and potentially contribute to this increase. RNA was isolated from placentas and subjected to Northern analysis using a cDNA probe to the shared region of GHBP and GH receptor-encoding mRNAs. From day 8 to day 18 of gestation, the GHBP-encoding mRNA (1.4 kb) increased 45-fold in quantity. The GH receptor-encoding mRNA (4.2 kb) increased sixfold by day 14 and then remained steady until day 18. These changes which were not co-ordinated parallel reported changes in the steady-state concentrations of 1.4 and 4.2 kb mRNAs in maternal liver, suggesting shared regulatory factors. Extracts of freshly isolated trophoblasts were assayed for GHBP with a radioimmunoassay specific for GHBP with a hydrophilic carboxyl terminus. The cytosolic content of immunoreactive GHBP increased fourfold from mid- to late gestation. Trophoblasts were isolated from placentas and cultured for 2 days on collagen gels in defined medium. Cultured cells were at least 90% viable and secreted mouse placental lactogen-II (mPL-II). Immunocytochemistry was carried out simultaneously on cells cultured from day 7 to day 17 of gestation using a monoclonal antibody (MAb 4.3), which recognizes the hydrophilic C-terminus of GHBP. Cell-localized GHBP was present in trophoblasts cultured for 2 days, but GHBP was not detectable by radioimmunoassay or by immunoprecipitation in concentrated culture media from cultures treated with 100 ng mouse GH/ml or 100 ng mPL-II/ml or from untreated cultures. RNA was isolated from cells cultured in an identical manner to those analysed by immunocytochemistry. Three GH receptor/GHBP mRNA species of 8, 4.2 and 1.4 kb were observed. The quantity of 4.2 and 1.4 kb mRNAs did not change significantly in cultures from day 7 to day 15 of gestation but, in cultures from day 17 of gestation, the amount of 1.4 kb mRNA dropped significantly, while that of the 4.2 kb mRNA remained unchanged. GHBP- and GH receptor-encoding mRNAs are not co-ordinately regulated in vivo or in vitro. Although mPL-II was secreted into the medium by cultured trophoblasts, secretion of GHBP could not be detected. The culture medium may not contain the specific factors required for secretion of placental GHBP, or placental GHBP may not be destined for secretion.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of Ar gas pressure on growth, structure, and mechanical properties of sputtered Ti, Al, TiAl, and Ti3Al films

Single layers of Ti, Al, TiAl and Ti₃Al were sputter deposited on to 2″ oxidized Si 111 wafers and 7059 Corning Glass to study the effect of film thickness, temperature, and sputtering gas pressure on the mechanical and physical properties. In the present investigation, sputtering gas pressure was varied from 2 mT to 10 mT. The film thickness was varied from 1000 Å to 2 μm. The as-deposited Ti, Al and Ti₃Al films are well crystallized over the entire thickness range. Ti and Ti₃Al films show preferred orientation in the 0002 direction. On the other hand, Al films are random polycrystalline. TiAl films are nearly amorphous for all the thicknesses under consideration. TiAl films show formation of Ti (Al) solid solution phase with increasing Ar pressure. All the materials under consideration, show average film stress to be independent of thickness for thicker films. The nature of the stress (compressive or tensile) depends upon working gas pressure, sputtering power and the target material used. A definite trend is observed in the film stress as a function of Ar gas pressure. Both power and gas pressure influence the energetic bombardment of ions/atoms which in turn influence the average film stress. The nature of the intrinsic stress is explained by the atomic peening model. The Young's modulus of thin films is calculated by using the slope of the stress-temperature plots. The E values seem to change with deposition conditions, however, there is no obvious trend between the sputtering gas pressure and the Young's modulus of these thin films.