Slagging and fouling characteristics of seam 32/33, Panian coalfield, Semirara Island, Philippines

Twenty samples of seam 32/33, the main seam of Panian coalfield in Semirara Island, Antique Province, Philippines, were collected from a borehole drilled at the northeastern edge of the coalfield. The samples were analyzed to characterize the coal geochemistry of the seam and understand why the coals of Semirara Island exhibit a high tendency for slagging and fouling despite its low average ash content. Analysis of the slagging and fouling characteristics of this seam is important because it supplies five electric power utilities and several cement plants in the Philippines. Proximate analyses and vitrinite reflectance measurements designate the rank of the seam as sub-bituminous C, based on ASTM coal classification. H/C versus O/C ratios indicate that the seam is made up largely of huminite, denoting early stages of coalification. Chemical analysis of the ash reveals high contents of Na, Mg, Fe, Ca, Ba and Sr. The strongly negative correlation of these elements with the ash content indicates an organic affinity of the chemical elements of the seam. Owing to enrichment in alkali and alkali-earth elements, slagging and fouling indices indicate that the seam has medium to high propensity for slagging and a severe tendency for fouling. The detrimental characteristics of coal feedstock from Panian mine is mitigated by modifications to the boiler design and operational conditions and by blending with coals imported from Indonesia, China and Australia.     

Optic flow estimation by a Hopfield neural network using geometrical constraints

Sparse optic flow maps are general enough to obtain useful information about camera motion. Usually, correspondences among features over an image sequence are estimated by radiometric similarity. When the camera moves under known conditions, global geometrical constraints can be introduced in order to obtain a more robust estimation of the optic flow. In this paper, a method is proposed for the computation of a robust sparse optic flow (OF) which integrates the geometrical constraints induced by camera motion to verify the correspondences obtained by radiometric-similarity-based techniques. A raw OF map is estimated by matching features by correlation. The verification of the resulting correspondences is formulated as an optimization problem that is implemented on a Hopfield neural network (HNN). Additional constraints imposed in the energy function permit us to achieve a subpixel accuracy in the image locations of matched features. Convergence of the HNN is reached in a small enough number of iterations to make the proposed method suitable for real-time processing. It is shown that the proposed method is also suitable for identifying independently moving objects in front of a moving vehicle. Received: 26 December 1995 / Accepted: 20 February 1997     

Post-stress interface trap generation induced by oxide-field stresswith FN injection

Interface trap generation in nMOS transistors during both stressing and post-stress periods under the conditions of oxide field (dynamic and dc) stress with FN injection is investigated with charge pumping technique. In contrast to the post-stress interface trap generation induced by hot carrier stress which is a logarithmical function of post-stress time, the post-stress interface trap generation induced by oxide-field stress with FN injection first increases with post-stress time but then becomes saturated. The mechanisms for the interface trap generation in both stressing and post-stress periods are described     

Large and medium sized artery abnormalities in untreated and treated hypothyroidism

BACKGROUND: Hypothyroidism is frequently accompanied by cardiac dysfunction, increased vascular resistance and a greater prevalence of hypertension. Whether this condition is also accompanied by alterations of large artery function and structure is not known, however. PATIENTS AND METHODS: We investigated radial artery compliance and wall thickness as well as carotid artery compliance in 11 normotensive recently diagnosed and never treated hypothyroid patients. Fifteen euthyroid healthy age- and sex-matched subjects served as controls. No subject had evidence of large artery atherosclerotic lesions. Carotid artery diameter was evaluated continuously by a B-M mode device and carotid compliance obtained by the Reneman formula. Radial artery diameter and wall thickness were continuously acquired over the systodiastolic blood pressure range (beat-to-beat finger measurement) by an echo-tracking device, and compliance (Langewouters formula) was expressed as the integral of the area under the compliance/blood pressure curve normalized for pulse pressure. RESULTS: Patients with hypothyroidism showed greater radial wall thickness (+109%, P < 0.01) and compliance (+58%, P < 0.03) than controls. Carotid artery compliance was not different in the two groups. In 10 hypothyroid patients L- tiroxine therapy for 9.0 +/- 2.3 months did not change carotid artery function but markedly reduced radial artery wall thickness (-36%, P < 0.05) and compliance (-20%, P < 0.05). CONCLUSIONS: Hypothyroidism is associated with early arterial structural and functional alterations, which involve more muscular than elastic arteries. These alterations, however, are reversible by hormonal replacement therapy.     

Study of the inhibitory effect of hydrophobic fluorescent markers on the enzymic coagulation of bovine casein micelles: action of TNS

The interaction of 2-(p-toluidinyl) naphthalene-6-sulfonate (TNS) with casein micelles (CM) was studied by fluorescence spectroscopy. Fluorescence emission spectra of the complex showed blue shift and intensity enhancement of TNS fluorescence, suggesting the insertion of the marker in low polarity regions of CM. An energy transfer process between the proteins and the marker was detected, showing that most of the TNS binding sites were in the proximity of CM fluorescent residues. TNS inhibited the aggregation step of CM enzymic coagulation, producing probably a decrease of size and amount of aggregates formed. This effect could not be related only to changes in CM net charge, but also possibly to the occupancy of surface hydrophobic regions by the marker. About a 20% decrease in the TNS fluorescence intensity was observed during the proteolytic step of coagulation which could be attributed to release of the marker from its binding sites located in the CM external layer. A bound TNS release was also observed during the initial time of the aggregation step, probably by removal of the bound marker from contact regions between aggregating particles upon their collisions. A further increase, related to the aggregation step, could indicate the uptake of the marker by new hydrophobic sites created in the complex structure of the clusters. The results pointed to the participation of surface hydrophobic regions of renneted CM in their aggregation process.     

Dissolution kinetics of phenylbutazone

This study investigated the possible effects of simultaneous, noninstantaneous, reversible chemical ionization of carbon acids on the dissolution of a typical pharmaceutical carbon acid, phenylbutazone, and its deutero analog. The dissolution rate versus pH profile for phenylbutazone was consistent with phenylbutazone acting as if it were an acid where the ionization can be considered instantaneous. In view of the dissolution behavior of phenylbutazone under various conditions, it is unlikely that the noninstantaneous ionization kinetics demonstrated for this compound play a major role in determining the dissolution rate, either in vitro or in vivo, since the average residence time in a typical aqueous diffusion layer for phenylbutazone dissolution is longer than the reaction time for its ionization. Slowing the reaction time with a primary isotope effect by deuterium substitution for the ionizable proton caused significant deviation from classical behavior for d-phenylbutazone.     

Dose for minimal sympathetic response to a painful stimulation for alphaxolone and thiopentone in man (author's transl)

The dose that prevents the sympathetic response to a painful stimulation has been determined for alphaxolone and thiopentone (DRSM). The stimulation was the tracheal intubation and the sympathetic response has been evaluated as the percentual change of heart rate from the basal level. The DRSM has been determined as the dose that assures no percentual change of H.R. after intubation. The alphaxolone showed a DRSM very low (0.489) on the contrary the dose of thiopentone required to obtain no sympathetic response is high (7.776).     

Empathic accuracy in a clinically relevant setting.

This study addressed 3 questions regarding empathic accuracy in a clinically relevant setting. First, does the empathic accuracy of a perceiver improve with increased exposure to a target individual? Second, can empathic accuracy be enhanced by providing the perceiver with feedback about the target's actual thoughts and feelings? Third, are there stable individual differences in empathic accuracy that generalize across different targets? The results indicated that although absolute performance levels varied from 1 target to another, empathic accuracy generally improved with increased exposure to the target. In addition, feedback concerning the target's actual thoughts and feelings accelerated the rate at which the perceivers' empathic accuracy improved. Finally, cross-target consistency in responding (α?=?.86) revealed stable individual differences in the perceivers' empathic ability. Implications of these findings for clinical training and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composition and antioxidant activity of essential oils from Oregano plants grown wild in Greece

In this study, four samples of essential oils obtained from plant species with a wide distribution in Greece and economic importance for the world-wide spice market and also carvacrol and thymol were tested for their possible antioxidant activity. The four plant species wereOriganum vulgare subsp.hirtum, O. onites, Coridothymus capitatus andSatureja thymbra. The essential oils were chemically characterised by gas chromatography-ion trap detection. All the essential oils examined and also carvacrol and thymol were found to have antioxidant activity when tested on TLC plates and by measuring peroxide values of lard stored at 35° C. The results indicate that the antioxidant effect may be related to the presence of carvacrol and thymol in essential oils.