LaMg11 with a giant unit cell synthesized by hydrogen metallurgy: Crystal structure and hydrogenation behavior

We have successfully applied a hydrogen metallurgy synthesis to yield LaMg_12?x intermetallic at 500 °C. During a vacuum thermal desorption from the LaH₃–MgH₂ nanocomposite prepared by reactive ball milling in H₂, hydrogen desorption from the La dihydride occurred via a mechanism of cooperative phase transformation at temperatures being 400° lower than the desorption from pure LaH₂. The crystal structure of the intermetallic was determined by synchrotron X-ray diffraction (SR XRD). The orthorhombic LaMg_12?x has a giant unit cell, the volume of which exceeds 8000 Å³. In situ SR XRD studies showed the fine details of the hydrogen desorption process with several parallel and consecutive transformation steps.     

Nanostructured rapidly solidified LaMg11Ni alloy: Microstructure,crystal structure and hydrogenation properties

In our earlier publication (Poletaev et al., J Alloys Compd., 509S (2011) S633) we reported a drastic variation of the structural and hydrogenation properties of LaMg_∼12 intermetallic alloy caused by Rapid Solidification (RS). In present work we have probed the effect of nickel during the chemical modification of LaMg₁₂, in combination with RS, on the structure, microstructure and hydrogen absorption–desorption properties of the alloys.     

The relationship between mental rotation and representational momentum.

Two experiments explored a possible relationship between mental rotation and representational momentum, a task in which participants were asked to remember an object's position following a sequence of images implying motion. Typically, participants misremember the position as distorted forward along the implied trajectory. If representational momentum relies on mental imagery, the magnitude of memory distortion in a representational momentum task should be positively correlated with the rate of mental rotation. As predicted, faster mental rotation rates and larger memory distortions for object position were observed for rotational axes aligned with the viewers' coordinate system. In addition, participants with slower mental rotation rates produced smaller memory distortions in the implied-event task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective hydrogen absorption from gaseous mixtures by BCC Ti-V alloys

Hydrogen absorption behaviour of the BCC Ti-V alloys has been studied as related to their potential application for the selective hydrogen absorption from mixtures with active gases containing CO and steam at high temperatures. Alloys and their hydrides were characterised using Scanning Electron Microscopy (SEM), Thermal Desorption Spectroscopy (TDS), Temperature Programmed Reaction (TPR) and in situ synchrotron X-ray powder diffraction (SR-XRD). BCC Ti_0.8V_0.2 and Ti_0.9V_0.1 were able to absorb 3.95 wt.% H by forming a FCC type hydride γ−(Ti,V)H₂. Nanoparticles of Pd and Pd/Pt were electroless deposited on the surface of the hydrides to catalyse hydrogen absorption. TPR tests showed that such alloys were capable of absorbing hydrogen even when substantial amounts of CO and H₂O were present in the gas stream. Nanoparticles of Pd/Pt provide a better performance as compared to Pd alone. In situ SR-XRD has been used to probe the mechanisms of hydrogenation and dehydrogenation.     

The gene encoding the catalytic subunit C alpha of cAMP-dependent protein kinase (locus PRKACA) localizes to human chromosome region 19p13.1

OBJECTIVE: The importance of portal hypertensive gastropathy, as a potentially bleeding lesion in cirrhotics with portal hypertension, has recently been appreciated. Histologically, dilation of the mucosal and submucosal vessels of the stomach is noted in this entity. The possibility of nitric oxide acting as a mediator for this mucosal vascular dilation has not been explored. METHODS: We determined, in a group of 10 male cirrhotic patients with esophageal varices and endoscopic changes consistent with severe portal hypertensive gastropathy (Group A), the gastric mucosal nitric oxide synthase activity. This was determined by measuring the rate of conversion of [3H]-arginine to [3H]-citrulline. Serum levels of nitrates and nitrites, the end products of nitric oxide, were also measured. The results were compared with those of a group of 10 male controls with no liver disease (Group B). RESULTS: Gastric mucosal constitutive and inducible nitric oxide synthase levels were significantly higher in group A (125.4 +/- 4.3 and 259.7 +/- 5.5 pmol/mg protein/minute, respectively) than in group B (88 +/- 8.6 and 130.8 +/- 6.6 pmol/mg protein/minute, respectively) ( p < 0.002 and < 0.0001, respectively). Serum nitrate/nitrite levels were 30.1 +/- 3.2 nmol/ml in group A and 15.5 +/- 0.09 nmol/ml in group B (p < 0.001). CONCLUSIONS: We conclude that the significantly increased gastric mucosal nitric oxide synthase activity, in patients with portal hypertensive gastropathy, suggests an important role for nitric oxide in the pathogenesis of this mucosal lesion.     

"Family dysfunction, parental attachment, and career search self-efficacy among community college students": Correction.

Reports an error in the original article by N. E. Ryan et al (Journal of Counseling Psychology, 1996, Vol 43[1], 84–89). In Table 2 on page 87, the scale labels for the Inventory of Parent and Peer Attachment Father subscale and the Family Structure Survey were inadvertently reversed in the 2nd and 3rd sections of the table. A corrected version of the table is provided. (The following abstract of this article originally appeared in record 1996-00407-009.) The relationship between family dysfunction, parental attachment, and career search self-efficacy was examined using a sample of 220 community college students. For the total sample, attachment to mother and father, and career search self-efficacy. Data were analyzed separately for men and women, which yielded results consistent with the literature. For women, attachment to mother and degree of family dysfunction combined to account for 17% of the variance in career search self-efficacy. For men, attachment to mother was the only significant predictor and accounted for 9% of the variance in career search self-efficacy. Implications for research and practice are described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A bayesian approach to classification of multiresolution remote sensing data

Several earth observation satellites acquire image bands with different spatial resolutions, e.g., a panchromatic band with high resolution and spectral bands with lower resolution. Likewise, we often face the problem of different resolutions when performing joint analysis of images acquired by different satellites. This work presents models and methods for classification of multiresolution images. The approach is based on the concept of a reference resolution, corresponding to the highest resolution in the dataset. Prior knowledge about the spatial characteristics of the classes is specified through a Markov random field model at the reference resolution. Data at coarser scales are modeled as mixed pixels by relating the observations to the classes at the reference resolution. A Bayesian framework for classification based on this multiscale model is proposed. The classification is realized by an iterative conditional modes (ICM) algorithm. The parameter estimation can be based both on a training set and on pixels with unknown class. A computationally efficient scheme based on a combination of the ICM and the expectation-maximization algorithm is proposed. Results obtained on simulated and real satellite images are presented.     

Flixborough revisited - an explosion simulation approach

A literature study of explosion estimation reports from the Flixborough accident was performed and commented. The results from this survey were compared to the results obtained from explosion simulations. The simulations were done with a computer model of the Flixborough plant using the EXSIM software simulation tool. The comparison showed that explosion magnitude estimates in the literature based on visual inspection are much lower than the simulated results, while the estimates based on calculations to a large degree conform with the simulations. The simulations also showed that the exact location of the ignition source does not seem to be significant for the magnitude of the explosion.     

Tributyrate as a substrate for the determination of lipase activity in milk.

A procedure is described for the determination of the lipolytic activity in milk using tributyrate as substrate. The method is based on the titration of liberated butyric acid in a diethyl ether: light petroleum (2-75:1, v/v) extract of the incubation mixture. Some of the fundamental factors involved in the procedure are discussed.