Binary freezing point behavior of some saturated and unsaturated fatty acid methyl esters with methyl heptadecanoate

The binary freezing point behavior of methyl heptadecanoate with methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl elaidate and methyl petroselaidate have been determined. Both stable and metastable polymorphic forms were observed. Methyl laurate formed a simple eutectic with a region of metastable equilibrium. Methyl myristate formed a simple eutectic of stable equilibrium and a solid solution of metastable equilibrium. Methyl palmitate exhibited a solid solution of metastable equilibrium terminating in a eutectic and a region of discontinuous stable equilibrium. Methyl stearate formed a solid solution of metastable wquilibrium and also continuous stable equilibrium which formed an incongruently melting molecular compound that terminated in a eutectic point. Methyl heptadecanonate with the unsaturated eighteen carbon atom acid methyl esters exhibited only simple eutectic points and a small region of metastable equilibrium. The binary freezing point behavior of the methyl esters in general resemble that of the corresponding ethyl esters. The limited results of mixtures of methyl esters of an odd carbon acid with unsaturated acids indicate an induced stabilizing effect caused by unsaturation in the carbon chain. So. Utiliz. Res. Dev. Div., ARS, USDA.     

A developmental study of efficiency in differential galvanic skin response conditioning.

Hypothesized that in a differential galvanic-skin-response (GSR) conditioning situation, differential sets would be increasingly effective with increasing age in producing differential rates of conditioning. The GSRs of 193 children from kindergarten and Grades 1, 2, 4, and 6 were conditioned under inhibiting and facilitating sets. Support for the hypothesis was found in a significant Grade * Set interaction. Ability to verbalize the positive-conditioned-stimulus-unconditioned-stimulus relation was also a function of the Grade * Set interaction, as well as the interaction of Grade * Successful vs Unsuccessful Conditioning. Data also indicate the importance of cognitive factors in classical conditioning paradigms with human Ss. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electroluminescence from nanocrystals in an electromigrated gap composed of two different metals

We present a technique for making nanoscale gaps with work function offsets based on electromigrating leads composed of two different metals. Electroluminescence spectra from plain metal gaps with and without CdSe/ZnS (core/shell) nanocrystals are qualitatively very similar and exhibit features that are much broader than the photoluminescence spectra obtained from the same nanocrystals. These observations can be explained by inelastic scattering of conduction electrons in the metal leads or by electroluminescence from small metallic clusters that can form during the fabrication process. However, electroluminescence that spectrally coincides with nanocrystal photoluminescence can be observed in devices containing nanocrystals formed by electromigrating Pt leads bridged with small indium islands. This suggests that electromigrating leads made of different metals is a promising route to fabricating nanoscale gaps with work function offsets for optoelectronic devices.     

Detection of karst cavities by geophysical methods

Bulletin of Engineering Geology and the Environment - At two dam construction sites in Central America geophysical tests were conducted in a karstic environment in order to evaluate the...     

Cortical surface shape analysis based on spherical wavelets

In vivo quantification of neuroanatomical shape variations is possible due to recent advances in medical imaging and has proven useful in the study of neuropathology and neurodevelopment. In this paper, we apply a spherical wavelet transformation to extract shape features of cortical surfaces reconstructed from magnetic resonance images (MRIs) of a set of subjects. The spherical wavelet transformation can characterize the underlying functions in a local fashion in both space and frequency, in contrast to spherical harmonics that have a global basis set. We perform principal component analysis (PCA) on these wavelet shape features to study patterns of shape variation within normal population from coarse to fine resolution. In addition, we study the development of cortical folding in newborns using the Gompertz model in the wavelet domain, which allows us to characterize the order of development of large-scale and finer folding patterns independently. Given a limited amount of training data, we use a regularization framework to estimate the parameters of the Gompertz model to improve the prediction performance on new data. We develop an efficient method to estimate this regularized Gompertz model based on the Broyden-Fletcher-Goldfarb-Shannon (BFGS) approximation. Promising results are presented using both PCA and the folding development model in the wavelet domain. The cortical folding development model provides quantitative anatomic information regarding macroscopic cortical folding development and may be of potential use as a biomarker for early diagnosis of neurologic deficits in newborns.     

Changes in microstructures and physical properties of polymer-modified mortars during wet storage

The decrease in strength of tile adhesive mortars during wet storage was investigated. In a first approach, the water resistance of the polymer phases was tested on structures isolated from the mortar and in situ. It was observed that cellulose ether and polyvinyl alcohol structures are water-soluble. Subsequent investigations on polymer mobility within the mortar showed that the migrating pore water transports cellulose ether and polyvinyl alcohol during periods of water intrusion and drying. This leads to enrichments at the mortar-substrate interface. In contrast, latices interacting with the cement are water-resistant, and therefore, immobile in the mortar. Further experiments revealed that the mortar underwent considerable volume changes depending on the storage condition. Cracking occurred mainly close to the mortar-tile interface, cement hydrates grew within these shrinkage or expansion cracks. Test results revealed that the strength decrease of wet stored tile adhesives is caused by different mechanisms related to cement hydration, volume changes of the mortar, and reversible swelling of latex films.     

MODELING OF SUPERPLASTIC FORMING PROCESS FOR ALUMINUM ALLOYS WITH STRAIN HARDENING EFFECT

ＭＯＤＥＬＩＮＧＯＦＳＵＰＥＲＰＬＡＳＴＩＣＦＯＲＭＩＮＧＰＲＯＣＥＳＳＦＯＲＡＬＵＭＩＮＵＭＡＬＬＯＹＳＷＩＴＨＳＴＲＡＩＮＨＡＲＤＥＮＩＮＧＥＦＦＥＣＴＹ．Ｎ．ＫｗｏｎａｎｄＹ．－Ｗ．Ｃｈａｎｇ（ＣｅｎｔｅｒｆｏｒＡｄｖａｎｃｅｄＡｅｒｏｓｐａｃ...     

Retrograde labeling of single neurons in conjunction with MALDI high-energy collision-induced dissociation MS/MS analysis for peptide profiling and structural characterization

To reveal the peptide contents of the visually nonidentifiable neurons from a neuronal circuit of interest, we combined retrograde labeling of neurons with mass spectrometric single cell analysis. We used the neuronal circuit involved in the copulation behavior of a freshwater snail, Lymnaea stagnalis, as a model. Central neurons that control this behavior are known to send their axons to the penis nerve and innervate the penis complex. By retrograde filling from the penis nerve with nickel-lysine, these neurons were selectively labeled darkish blue. Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometric analyses of single stained neurons in the parietal ganglion from different animals reveal consistently the presence of several molecular ion species in the range of 800-1200 Da. From a single neuron, six molecular ion species were further characterized with MALDI time-of-flight/time-of-flight mass spectrometry, which demonstrates that the peptides are derived from a previously reported -FLRFamide precursor.