Fabrication of high-aspect-ratio Prussian blue nanotubes using a porous alumina template

Prussian blue nanotubes were fabricated by using a sequential deposition technique inside the 60-nm well-ordered pores of anodic alumina. By varying the deposition parameters and the dimensions of the template, we could tailor the length and the outer as well as the inner diameter of the tubes. The nanotubes were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD).     

Evaluation of an ultrasonic echo-tracking method for measurements of arterial wall movements in two dimensions

The longitudinal movement of blood vessel walls has so far gained little or no attention, as it has been presumed that these movements are of a negligible magnitude. However, modern high-resolution ultrasound scanners can demonstrate that the inner layers of the arterial wall exhibit considerable movements in the longitudinal direction. This paper evaluates a new, noninvasive, echo-tracking technique, which simultaneously can track both the radial and the longitudinal movements of the arterial wall with high resolution in vivo. Initially, the method is evaluated in vitro using a specially designed ultrasound phantom, which is attached to and moved by an X-Y system, the movement of which was compared with two high-resolution triangulation lasers. The results show an inaccuracy of 2.5% full scale deflection (fsd), reproducibility of 12 microm and a resolution of 5 microm, which should be more than sufficient for in vivo studies. The ability of the method is also demonstrated in a limited in vivo study in which a preselected part of the inner vessel wall of the right common carotid artery of a healthy volunteer is tracked in two dimensions over many cardiac cycles. The results show well reproducible x-y movement loops in which the recorded radial and longitudinal movements both are of the magnitude millimetre.     

The indirect electrochemical epoxldation of butenes and ethylene in a bipolar trickle tower

1-Butene,cis-2-butene,trans-2-butene and ethylene have been epoxidized under conditions which give reasonable results for propylene. In all cases the selectivities are high, but the current efficiencies are low (< 65%) due to the bulk phase chemical reactions being slower than the electrochemical generation of oxidant. Under conditions where the rates of the chemical and electrochemical reactions match, the figures of merit would be comparable to those for propylene. In the epoxidation the conformation of each butene isomer is preserved.     

Application of the trickle tower to problems of pollution control. I. The scavenging of metal ions

The theory of metal deposition in a bipolar trickle tower is reviewed briefly and applied to the scavenging of copper, silver, lead and calcium from dilute streams. Measurements of reference potential and mass-transfer coefficients for the copper system in one tower allow estimates ofθ _L, the fractional active length, to be made and subsequently allow data from different towers to be collapsed into a universal plot, thus substantiating the theory at least to a first approximation. In the co-deposition of copper, lead and cadmium, the data for copper and lead can be collapsed, but for cadmium cannot, probably because cadmium's reference potential is very negative under the conditions of the experiments. A scaling law is proposed which can be used in the design of practical systems.     

Mass transfer in capillary gap and pump cells with radial inflow

Overall and local mass transfer rate have been measured in capillary gap and pump cells for radial inflow, and for successive outflow in one channel and inflow in the next. These data have been compared with those for the normal, radial outflow. It is suggested that flow direction is a useful additional parameter in adjusting the environment in a cell to the needs of the overall reaction.     

The rotating electrolyser. II. Transport properties and design equations

It is shown that mass transfer in the rotating electrolyser is controlled by the rotational Reynolds number (Re _φ) and that species electrogenerated at the wall are confined to a thin layer close to the wall. The radial dispersion coefficient is of the same order as that of a non-rotational, capillary gap cell. Criteria for scale-up are discussed briefly.     

HOPS LIAISON COMMITTEE*: INTERNATIONAL HOP VARIETY TRIALS 1965–1967

This report covers a series of International Hop Variety Trials for the final 3 years for which they were carried out. The results generally confirm those obtained for the first 5 years. The object, history and organization of the trials are described and the results are discussed.     

The dehydrodimerisation of diethyl malonate in six different designs of cell

The dehydrodimerisation of diethyl malonate to ethyl-1,1,2,2, ethane tetracarboxylate has been studied in six varieties of cell — a pump cell, a capillary gap cell, a bipolar trickle tower, a paralled plate cell, a parallel plate cell with turbulence promoters and a poorly stirred tank — with potassium iodide as electrolyte. At low conversion the simplest cells give the most ideal performance, since the anolyte and catholyte layers are naturally segregated from the bulk and the stable malonate anion reacts with electrogenerated iodine in the reactor loop where mixing is good. At higher conversions, the segregation leads to the formation of a sequential product, ethyl-1,1,2,2, ethene tetracarboxylate, and it is the cells with greater mixing that give the greater specificity.     

Optimization of off-null ellipsometry in sensor applications

The optimization of azimuth angle settings of a polarizer-compensator-sample-analyzer off-null ellipsometric sensor system to obtain maximum intensity changes with respect to changes in the properties of a sensing layer, with and without considering changes in s reflectance, is studied. Optimal conditions in the two cases are derived analytically under the assumption that linear relationships exist among the changes in the parameters of the sensing layer. The validity of these optimal conditions is verified by numerical examples. The advantage of using ellipsometry compared with reflectometry to readout sensing information for some sensing samples is also discussed.