Parallel wire method

A common transient method is the line source technique, and such an apparatus was developed by Lobo and Cohen41 which could be used with melts. Oehmke and Wiegmann42 used the line source technique for measurements as a function of temperature and pressure. A hot wire parallel technique43 yielded conductivity and specific heat from the same transient, and then diffusivity was calculated. Zhang and Fujii44 obtained conductivity, diffusivity and the product of density and specific heat from a short hot wire method. 

The batch method is the easiest and was the first DEP technique developed. For biological DEP a batch chamber can be constructed on a microscope slide. The electrodes (two parallel wires for example) are placed in a pocket or inside a capillary tube that is mounted on the slide (Figure 7). The chamber is large enough to hold 1 or 2 drops of cell suspension and measurements of the number cells collected on the electrodes can be easily made 1 or 2 minutes after the field is applied. The chamber is then rinsed and dried and the process is repeated as often as desired. Batch methods are simple, low cost, and can accurately characterize cells, even... 

According to ASTM Cl 113 [95], the hot wire method is an absolute method for direct determination of the thermal conductivity based on the measurement of the temperature increase of a linear heat source/hot wire (cross-wire technique, according to ISO 8894-1 [96]) or at a specific distance from a linear heat source (parallel-wire technique, according to ISO 8894-2). 

Parallel hot wire method (BS EN 993-15 1998 and ISO 8894-2)— To extend the range of conductivites measured, the parallel hot wire method was devised. In this method, as its name suggests, the heater and thermocouple wires are arranged in parallel. This modified arrangement allows thermal conductivities up to 25 W/mk to be measured. 

We find that tubing in the range of 15-30 mm diameter (approximately) can be broken by a variation of the above method The tubing is scratched fairly strongly, and placed, with the scratch uppermost, so that it rests on a copper wire, about 3 mm diameter, which is opposite to the scratch and parallel to it. The scratch is moistened. 

Chapter H2 describes the measurement of textural properties of solid-like foods. The first unit in that chapter, unit H2.i, describes a general procedure commonly used to evaluate the texture of solid foods. This method involves the compression of the food material between two parallel plates. There are a number of empirical textural parameters which can be evaluated with this technique. Simple compressive measurements do not provide a complete textural picture of some foods untthi.i presents variations to the parallel plate compression method with the use of special fixtures. For example the use of a puncture probe or a wire cutting device provide data that may relate more directly to the consumer s evaluation of texture for products like apples and cheese, unit m.3 describes a general protocol for the evaluation of a number of sensory texture parameters. This protocol is... 

Cables via the powder-in-tube (PIT) method The approach is especially suited to processing Bi-2223 into leads and cables for power applications. A silver or silver alloy tube, filled with the partially reacted precursor powders formulated to yield Bi-2223, is drawn down to a wire 1-2mm diameter. The wire is rolled into a tape if that is the required form, usually with a width-to-thickness ratio of approximately 10 1. The composite is then heated to 800-900 °C when the powder partially melts. The recrystallization process is controlled and the pure Bi-2223 phase develops with large grains oriented so that the Cu-O planes lie parallel to the silver surface to optimize Jc. 

Use of fibers as reinforcements to make composites is, of course, well established. These are structural applications where, because of the characteristically long length of fibers, they are incorporated in a continuous medium, called the matrix. We describe some of these applications in subsequent chapters in more detail. Yet another common use of fibers of various kinds is in making ropes. In prehistoric times, ropes were made of braided leather strips and vines. Later, vegetable fibers such as jute, hemp, etc., were used to make ropes. More recently, ropes have been made of synthetic pol3nmers and metallic fibers. Ropes can be made by a variety of construction methods twisted, braided, plaited, parallel core and fiber, and wire rope. 

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