Wire coils

Before starting the realisation of silicium coils, we construct a simpler probe with a 27 mm long excitation coil and 16 wired coil sensors, with 1 mm diameter and 1 mm long. We cannot hope any reconstruction with such a probe, but this allows to validate the whole approach. We tried it with test tubes with longitudinal or circonferential notches, external or internal, 100 pm wide, 100%, 60%, 40%, 20% and 10% deep. Our attention has been especially focused on circonferential notches, which are difficult to detect with usual probes. For example, the measurement signals at 240 kHz standard frequency are shown figure 6 7. 

Recommended methods for assessing the corrosivity of waters, including flowing potable waters, are described in ASTM 02688 1983. Three procedures are described in which test specimens in the form of wires, sheets or tubes are placed in pipes, tanks or other equipment. The test assembly for the first of these consists of three helical wire coils mounted in series on, and electrically insulated from, a supporting frame. The assembly must be installed so that flow is not disturbed and turbulence and high velocities, e.g. of more than 1 -53 ms , are avoided. A minimum test period of 30 days is recommended. Procedures for the other specimen forms are given in the standard. 

Inside the probe is a wire coil that surrounds the sample tube. This wire transmits the radiofrequency pulses to the sample and then receives... 

Om choice among heating elements is limited to the R.F.- coil, a hot-wire coil or perhaps the MoSi2 "hairpin" element. The reason is that we must... 

We use the same approach to classify the different nanostructures for Titania. The term one-dimensional (ID) nanostructures indicate nanocrystals in which elongation only in one direction is above this threshold (about 10 nm). This class of ID nanostructures comprises different types of nano-ordered materials, such as nanorods, -wires, -coils, -fibers, -pillars (or -columns) and -tubes. We prefer to use the term quasi one-dimensional nanostructures, because often the dimensions are larger than the indicated threshold, although elongation along one main axis still exists. When the diameter of the nanorod, nanowire or nanotube becomes smaller, there is often a significant change in the properties with respect to crystalline solids or even two-dimensional systems. A bismuth nanowire is an excellent example, which transforms into a semiconductor, as the wire diameter becomes smaller.145... 

The two most convenient procedures for preparing ketene are the present one and the pyrolysis of acetone over a hot wire. The latter procedure can give ketene at a faster rate (0.45 mole per hr. versus 0.2 mole per hr.), but it takes considerable adjustment to get optimum conditions, and trouble is sometimes caused by the wire getting coated with carbon. Furthermore, because the efl ciency of a given wire coil varies with time, passing throu a maximum, frequent calibration of the apparatus is necessary. The present method is more reliable and is the method of choice, when diketene is available. 

Elias et al.43 observed that the heat liberated on a silver-coated platinum wire coil was about 10% higher than that expected from the known concentration of atomic oxygen in a discharge flow system, and they ascribed the effect to appreciable concentrations of 02(1A5) in the discharge products. It was then shown that some heat was released even after all the atomic oxygen had been removed by reaction with ethylene. 

Heating elements operating <760°C are almost always of a chrome—nickel resistance alloy and are in the form of ribbon, cast alloy, open wire coils, or sheathed construction. Several alloys are suitable in this temperature range and all are satisfactory if propedy applied. In general, the more expensive alloys are used when physical space limitations dictate higher watts per area dissipation from the element. 

The lowest cost means of controlling temperature is to regulate the power applied to a heater (wire coil) by means of a variable transformer. Since there is no feedback, there is no means to compensate for changes in line voltage fluctuations or changes in ambient temperature, both of which usually are considerable. 

Fig. 19. An emf of about 25 mV exists between titanium and TiNi electrodes at temperatures above TTR. A TiNi wire coiled outside the electrolytic bath below TTR. When this coiled wire is inserted into the bath at temperature above TTR the wire will instantly straighten out due to memory effect. By letting the uncoiling TiNi wire to come in contact with the TiNi electrode, an emf of more than 500 mV is registered.- reference [49],...

Vrolix M, Grollier G, Legrand V et al. Heparin-coated wire coil (Wiktor) for elective stent placement-The MENTOR trial (abstract), Eur Heart J 1997 18 155. 

Although two reactors are shown in Figure 1, they were not used simultaneously. The reactor shown in the center was the fixed bed reactor which is of primary interest in this contribution. It consisted of a 12.7 mm diameter X 250 mm long steel tube packed with 40/50 mesh catalyst (0.3 mm average particle diameter). The reactor was heated by a nichrome wire coil and was well insulated. The coil spacing was adjusted and was packed in insulation with the intent of making the reactor crudely adiabatic. A variac controlled heater on the reactor inlet and a thermocouple sensor kept the feed to the reactor at the nominal reaction (or feed inlet) temperature of 400°C. The tube of the fixed-bed, reactor was fitted with 12 thermocouples to record the axial temperature profile in the bed (Figure 1). 

PURPOSE AND RATIONALE A classical method to produce thrombosis is based on the insertion of wire coils into the lumen of blood vessels. The model was first described by Stone and Lord (1951) in an aorta of a dog and was further modified to be used in arterial coronary vessels of opened-chest dogs. The use in venous vessels was described by Kumada et al. (1980). 

Venous thrombosis is produced in rats by insertion of a stainless steel wire coil into the inferior caval vein. Platelets as well as plasmatic coagulation are activated on the wire coil. Thrombus formation onto the wire is quantitated by measuring the protein content of the thrombotic material isolated. The kinetics of thrombus formation show an increase in weight and protein content within the first 30 min followed by a steady state between thrombus formation and endogenous thrombolysis leading to a constant protein content of thrombi between 1 and up to 48 h following implantation of the wire coil. Thrombosis incidence in untreated control animals in this model is 100%. The test is used to evaluate antithrombotic and thrombolytic properties of compounds in an in vivo-model of venous thrombosis in rats. 

In addition to the described preparation, for continuous infusion of a thrombolytic test solution a polyethylene catheter is inserted in the jugular vein. One and a half hours after implantation of the wire coil, the test compound or the vehicle (controls) is infused for up to 2.5 h. The wire coil is then removed and the protein content of thrombi is determined (see above). Bernat et al. (1986) demonstrated the fibrinolytic activity of urokinase and streptokinase-human plasminogen complex in this model. 

Current balance — Historic instrument to measure currents by measuring the repulsive force between metal wire coils through which currents flow. The electromagnetic force is balanced by gravity acting on a known mass. Such instruments have been used for the absolute determination of the ampere (-> SI base units). 

Inductance (L) is the magnetic field generated when a current is passed through an inductor, typically a wire coil. The strength of the magnetic field is measured in henries (H). The impedance of an inductor (Z, (co)) is given as... 

Using your penknife, remove inch of insulation from both ends of each piece of copper wire. Connect one of the 6-inch lengths of wire to one of the dry cells at the outside terminal. Make the connection by winding the wire coils around the terminal. Connect the central terminal of the same dry cell to the outside terminal of the second dry cell with the 4-inch length of wire. Connect the second 6-inch length of wire to the central terminal of the second... 

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