RESUMO
An understanding of electrolyte stratification behaviours in lead-acid battery electrolytes during battery operation is important for optimal operation and design of lead-acid batteries for vehicle applications. In this paper, we present an in operando phase-contrast X-ray imaging technique for quantitatively visualizing electrolyte stratification dynamics that arise in electrolytes during battery operation.
RESUMO
Multilayers of gold nanoclusters (GNCs) coated with a thin Pd layer were constructed using GNCs modified with self-assembled monolayers (SAMs) of mercaptoundecanoic acid and a polyallylamine hydrochloride (PAH) multilayer assembly, which has been reported to act as a three-dimensional electrode. SAMs were removed from GNCs by electrochemical anodic decomposition and then a small amount of Pd was electrochemically deposited on the GNCs. The kinetics of the oxygen reduction reaction (ORR) on the Pd modified GNC/PAH multilayer assembly was studied using a rotating disk electrode, and a significant increase in the ORR rate was observed after Pd deposition. Electrocatalytic activities in alkaline and acidic solutions were compared both for the GNC multilayer electrode and Pd modified GNC electrode.
RESUMO
It is important to increase the iodine delivery rate (I), that is the iodine concentration of the contrast material (C) x the flow rate of the contrast material (Q), through microcatheters to obtain arteriograms of the highest contrast. It is known that C is an important factor that influences I. The purpose of this study is to establish a method of hydrodynamic calculation of the optimum iodine concentration (i.e., the iodine concentration at which I becomes maximum) of the contrast material and its flow rate through commercially available microcatheters. Iopamidol, ioversol and iohexol of ten iodine concentrations were used. Iodine delivery rates (I meas) of each contrast material through ten microcatheters were measured. The calculated iodine delivery rate (I cal) and calculated optimum iodine concentration (calculated C opt) were obtained with spreadsheet software. The agreement between I cal and I meas was studied by correlation and logarithmic Bland-Altman analyses. The value of the calculated C opt was within the optimum range of iodine concentrations (i.e. the range of iodine concentrations at which I meas becomes 90% or more of the maximum) in all cases. A good correlation between I cal and I meas (I cal = 1.08 I meas, r = 0.99) was observed. Logarithmic Bland-Altman analysis showed that the 95% confidence interval of I cal/I meas was between 0.82 and 1.29. In conclusion, hydrodynamic calculation with spreadsheet software is an accurate, generally applicable and cost-saving method to estimate the value of the optimum iodine concentration and its flow rate through microcatheters.