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91.
RA Arcilla R Mathew P Sodt L Lester N Cahill OG Thilenius 《Canadian Metallurgical Quarterly》1976,2(2):125-136
A combined angiocardiographic-echocardiographic method for estimating right ventricular wall mass is described. Biplane cineangiocardiograms are analyzed for ventricular volume in end-diastole, and wall thickness is determined from echocardiograms obtained with a high frequency transducer and strip chart recorder, The intracavitary and the external surface volumes of the ventricle are derived, and the difference multiplied by 1.050, the specific gravity of myocardium. Excellent correlation was observed between right ventricular wall mass and body surface area in normal children (r = 0.93). The mean right ventricular mass was 44.5 g/M2 as compared to 78.1 g/M2 for the left ventricle, corresponding mass/EDV values were 0.48 g/cm3 and 1.26 g/cm3, respectively. In isolated right ventricular pressure overload, the increase in right ventricular mass is chiefly due to the increase in wall thickness; in volume overload, it is due mostly to the increase in chamber volume, 相似文献
92.
Mathew David Mackenzie 《Neural computing & applications》1995,3(1):2-16
A novel neural network called Class Directed Unsupervised Learning (CDUL) is introduced. The architecture, based on a Kohonen self-organising network, uses additional input nodes to feed class knowledge to the network during training, in order to optimise the final positioning of Kohonen nodes in feature space. The structure and training of CDUL networks is detailed, showing that (a) networks cannot suffer from the problem of single Kohonen nodes being trained by vectors of more than one class, (b) the number of Kohonen nodes necessary to represent the classes is found during training, and (c) the number of training set passes CDUL requires is low in comparison to similar networks. CDUL is subsequently applied to the classification of chemical excipients from Near Infrared (NIR) reflectance spectra, and its performance compared with three other unsupervised paradigms. The results thereby obtained demonstrate a superior performance which remains relatively constant through a wide range of network parameters. 相似文献
93.
Mary Mathew V. Das Gupta Charlie Bethea 《Drug development and industrial pharmacy》1993,19(12):1497-1503
A stability-indicating high-performance liquid chromatography method for the quantitation of nizatidine in capsules has been developed. The method is accurate and precise with a percent relative standard deviation of 0.34 based on 6 readings. A number of inactive ingredients present in the capsules did not interfere in the assay procedure. The recovery from the synthetic mixtures was quantitative. The extraction procedure from the capsules is very simple. The drug appears to be very sensitive to bases (such as sodium hydroxide) since 100% of the drug decomposed on boiling for 35 minutes. The drug was very stable when boiled with sulfuric acid. 相似文献
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The nature and quantities of the chemical species evaporating from the surface of fluorozirconate glasses heated to above Tg were investigated. ZrF4 vaporized from a ZBLAN glass whereas ZrF3 . ZrF2 and ZrF vaporized from a ZBL glass. Other gases found include HF, HCl, O2 , CO2 , and atomic fluorine. 相似文献
98.
This work describes the effect of the speed of drum‐type rotating collector in an electrospinning process on the orientation of electrospun poly(butylene terephthalate) fiber mats, and its effect on the tensile properties. The degree of orientation increased with the increase in the drum speed (surface velocity) up to a critical level, and thereafter, wavy fibers were observed. The average diameter reduced and its distribution became narrower with increase in the velocity. The mechanical properties in a parallel direction improved about three times with increase in the surface velocity. The anisotropic mechanical behavior could be predicted with a simple classical equation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2017–2021, 2006 相似文献
99.
The complexation behaviour of dithiocarbamate functions supported on polyacrylamides with varying extents (2-20 mol%) of N,N′-methylene-bis-acrylamide (NNMBA) crosslinks was investigated. The crosslinked polyacrylamides were prepared by the free radical solution polymerization of the monomers in water at 80°C using potassium persulphate as initiator. The dithiocarbamate ligands were introduced by polymer-analogous reaction involving transamidation with ethylenediamine and dithiocarbamylation with carbon disulphide and alkali. The complexation behaviour of these dithiocarbamate resins with the ligand functions in different macromolecular environments were investigated towards Co(II), Ni(II), Cu(II), Zn(II) and Hg(II) ions by a batch equilibration technique. The metal ion intake varied with the extent of the NNMBA-crosslinking. Thus the 8% crosslinked system has the highest complexation capacity. The values for metal ion intake followed the order Hg(II)> Cu(II)> Zn(II)> Ni(II)> Co(II). The time-course of complexation, the possibility of recycling and the swelling characteristics of the uncomplexed and complexed resins were considered, and IR characterization and thermal studies were undertaken. The swelling values of the complexed resins are lower than those of the uncomplexed resins. The thermal stability of dithiocarbamates varied with the extent of NNMBA-crosslinks and with the metal ion. 相似文献
100.