1,720,972 research outputs found
Cavum septi pellucidi (CSP) ratio: a marker for partial agenesis of the fetal corpus callosum.
No full textWeak Interaction of Oxygen with Refractory Carbides
No full textThe Electrochemical Soc., (P.Y. Hou, M.J. McNallan, R. Otra, E.J. Opila, D.A. Shores, Eds
The role of sintering time on reversibility of Ni(s)-NiO(s) electrodes for high-temperature solid oxide-electrolyte galvanic cells
No full textThe reversibility of solid-electrolyte galvanic cells such as, Mo|Ni(s)-NiO(s)|CSZ|Fe(s)-Fe1-δO(s)|Mo, (CSZ = CaO-contg. ZrO2) was studied with respect to the sintering time of the active powders. Pellets from short (7 h) and long (14 h) sintering times were prepd. and assembled to give the above cells. Each of them was thermally cycled and only the cells contg. Ni(s)-NiO(s) electrodes prepd. with a long sintering time gave emf. vs. T curves which were independent of cycle. These values agreed closely with the literature. For the cell reaction, NiO(s) + (1 - δ)Fe(s) = Ni(s) + Fe1-δO(s), ΔG = -(27.85 ± 0.06) - (0.02157 ± 0.00004)T kJ mol-1 at 977-1350 K. To check the electrochem. reversibility, cyclic voltammetry was also used. On the basis of these results and of SEM anal. of the electrode pellets, a mechanism is proposed whereby only at long sintering time would a triple phase contact at the electrode/electrolyte interface be produced
Conductivity of commercial zirconia electrolytes. II. n-Type conductivity of 15 m/o CSZ and 7.5 m/o MSZ at oxygen pressures of solid nickel-solid nickel oxide mixture
No full textThe n-type cond. of the com. 7.5 m/o MgO-stabilized ZrO2 and 15 m/o CaO-stabilized ZrO2 electrolytes was measured at O pressures of the Ni(s)-NiO(s) mixt. at 1073-1423 K by using the blocking electrode technique. The exptl. values of the activation energies were, resp., 1.58 and 1.38 eV for CaO-stabilized and MgO-stabilized ZrO2. The O ion transport no. was also measured as function of temp. and its value at 1273 K was 91%. The significance of the activation energy and PO2 dependence of the partial cond. in the particular exptl. conditions was emphasized
Conductivity of commercial zirconia electrolytes. I. Ionic and n-type conductivities of 15 m/o CSZ at oxygen pressures of solid chromium-solid chromium oxide mixture
No full textThe total and n-type conductivities of com. 15 m/o CaO-stabilized ZrO2 electrolyte were measured. The ionic and n-cond. activation energies are reported at 1195-1917 K as is the n-type cond. dependence on the equil. O partial pressure of the Cr(s)-Cr2O3(s) mixt. electrodes. Values of conduction were detd. and a chronoamperometric technique to measure it is reported. The physicochem. behavior of the Cr(s)-Cr2O3(s) mixt. deriving from certain anomalies obsd. in the cond. trends at the highest temp. values is considered
Some evidence on the instability of a chromium-chromium(III) oxide electrode in electrochemical oxygen sensors at steelmaking temperatures
No full textAnomalies were obsd. in measurements of emf. and elec. cond. measurements of solid oxide electrolyte cells involving Cr(s)-Cr2O3(s) electrodes. Transformation in the system at ∼1653 K explains the anomalies mentioned above on the basis of measured temp. dependence of emf. and total and electronic conductivities of the cells
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Preoperative work-up for definition of lymph node risk involvement in early stage endometrial cancer: 5-year follow-up
No full textThis prospective cohort study aimed to analyze the accuracy of magnetic resonance imaging (MRI) and hysteroscopic excisional biopsy (HEB) for predicting the low- and high-risk patients with endometrial carcinoma for nodal involvement at preoperative evaluation. From January 2005 to December 2006, all patients with a diagnosis of endometrial carcinoma were prospectively included in the study and underwent pelvic MRI and HEB. The pelvic MRI (without contrast) was aimed to evaluate the extent of myometrial invasion (MI < 50%, MI ≥ 50%), the possible involvement of cervical stroma, the ovarian, and lymph nodes status. HEB was performed under general anesthesia, retrieving multiple biopsies through a 5-mm, monopolar, loop electrode. According to our data analysis, the integration of MRI and HEB showed an elevated accuracy and high rates of sensitivity (85.0%), specificity (88.5%), negative predictive value (91.9%) and positive predictive value (79.0%) in identifying low-risk patients who do not need comprehensive surgical staging
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