Portable devices

The hand-held comparative Brinell tester is the most portable device. With this device a hammer blow is substituted for the static load which is transmitted first through a standard bar of known hardness and then through the indenter into the workpiece. The indentations in both the standard bar and the workpiece are measured and from the ratio of the diameters the HBN is derived. The loss in accuracy is made up for by the exceUent portabUity. 

A steady-state rocket-type combustion spray unit has been developed, called high velocity oxy fuel (HVOF), that creates a steady state, continuous, supersonic spray stream (1.2—3 mm dia) resembling a rocket motor exhaust. The portable device injects and accelerates the particles inside a barrel (rocket nozzle). It produces coating quaHty and particle velocities equal to the D-gun at 5—10 times the spray rate with significantly reduced coating costs. 

A method of detecting herbicides is proposed the photosynthetic herbicides act by binding to Photosystem II (PS II), a multiunit chlorophyll-protein complex which plays a vital role in photosynthesis. The inhibition of PS II causes a reduced photoinduced production of hydrogen peroxide, which can be measured by a chemiluminescence reaction with luminol and the enzyme horseradish peroxidase (HRP). The sensing device proposed combines the production and detection of hydrogen peroxide in a single flow assay by combining all the individual steps in a compact, portable device that utilises micro-fluidic components. 

This section provides information needed to understand and solve the majority of balancing problems using a vibration/balance analyzer, a portable device that detects the level of imbalance, misalignment, etc., in a rotating part based on the measurement of vibration signals. 

This technique detects substances qualitatively and quantitatively. The chromatogram retention time is compound-specific, and peak-height indicates the concentration of pollutant in the air. Detection systems include flame ionization, thermal conductivity and electron capture. Traditionally gas chromatography is a laboratory analysis but portable versions are now available for field work. Table 9.4 lists conditions for one such portable device. 

Schematic diagram and examples of alkaline dry cells. These batteries provide electrical current for many portable devices.

This technique is medically attractive as well as economical and has achieved commercial success. Initially, the devices were very heavy and required so much electrical power that they were not portable. Later work (Guzelsu et al., 1994) provided a more elfective pulse characteristic that was also energy saving, which led to battery-powered portable devices. Figure 24.2 indicates the earlier and later PEMF characteristics. 

The Leclanche cell (also known as the dry cell) is frequently used to power flashlights, watches, calculators, and a number of other portable devices. Despite the name dry cell, this battery does contain an electrolyte solution but only in the form of dense paste. There are two versions of this cell, the acid version and the alkaline version. 

Air-Zn primary and air A1 mechanically rechargeable batteries with carbonaceous air electrodes were designed and tested. Air Zn batteries are mostly used in the hearing aids, while air-Al batteries find wider range of applications in the portable devices. Electrically rechargeable air electrodes with pyropolymer catalyst have been developed. 

Korovin N.V., Kleimenov B.V., Dyachkov E.V., Vohgova I.V. Aluminium-air batteries for portable devices.Ext Abstr. 1997 Joint. Intern. Meeting ES and ISE. Paris. 1997.P. 88. 

Historically, respirometers have been used for wastewater biodegradability evaluation. More recently [52], a mobile on-line respirometer was proposed and tested for monitoring the activated sludge inhibition due to industrial discharges in a sewer network. A derived portable device called a Baroxymeter [53], based on monitoring the respiration of a bacterial culture by pressure measurements and using respiration inhibition as a toxicity alert, was proposed for the rapid detection of the toxicity effect of some toxic substances. 

Direct Reading Instrument A portable device that measures, and displays, in a short period of time, the concentration of a contaminant in the environment. 

In recent years, research into wireless networking has been dominated by the perceived need for high bandwidth access to data intensive files with extensive graphical, video and audio content. Bluetooth has been heralded as the low-power wireless standard of the future, but it is very much a high-bandwidth technology, designed to integrate portable devices into this communications infrastructure, and is relatively power... 

Fuel cells can be used to power a variety of portable devices, from handheld electronics such as cell phones and radios to larger equipment such as portable generators. Other potential applications include laptop computers, personal digital assistants (PDAs), and handheld video cameras—almost any application that has traditionally used batteries. These fuel cells have the potential to last more than three times as long as batteries between refueling. 

A sensitive ELISA procedure was developed for the determination of TNT (221) and other nitroaromatic compounds. TNT can be detected within the range of 0.02-20 ng/L in water samples462. A simplified immunofiltration prepacked portable device for field screening tests of TNT in water and soil was also developed. A quantitative color response to concentrations of TNT in the range 1-30 ng/L in water and 50-1000 pg/g in soil was demonstrated463. 

For obvious reasons, lemon batteries are not a convenient way to power a portable device, such as a cell phone. Scientists and inventors have worked to develop a variety of batteries that are inexpensive, compact, and easy to store and to carry. Our society uses vast numbers of batteries. 

A button battery is much smaller than an alkaline battery. Button batteries are commonly used in watches, as shown in Figure 11.9. Because of its small size, the button battery is also used for hearing aids, pacemakers, and some calculators and cameras. The development of smaller batteries has had an enormous impact on portable devices, as shown in Figure 11.10. 

Technical progress as well as investments in PEMFCs for transportation, stationary, portable, and micro fuel cell applications has been dramatic in recent years. The present view is ophmistic for fuel cell power generation the status is presently at the field trial level, or early commercialization stage, moving into volume commercialization. Although commercially viable, niche PEMFC applicahons exist today, the first commercial mass markets for fuel cells are expected to be for handheld electronic devices, PCs, and other portable devices. 

Hammett acidity function chem An expression for the acidity of a medium, defined as ho = Kbh+ BH / B, where Kbh+ is the dissociation constant of the acid form of the Indicator, and BH+ and B are the concentrations of the protonated base and the unprotonated base respectively. ham at a sid ad e. faijk shan ) hand sugar refractometer analy chem Portable device to read refractive Indices of sugar solutions. Also known as protelnometer. hand shCig ar. re.frak tam-3d-3r1... 

Practical FTIR solutions have been developed by paying attention to the fundamental design of the instrument. Moving an FTIR instrument out of the benign enviromnent of a laboratory to the more alien environment of either a process line or that of a portable device is not straightforward. A major emphasis on the instrument design in terms of both ruggedness and fundamental reliability of components is critical. Furthermore, issues such as enviromnental contamination, humidity, vibration and temperature are factors... 

Paper subject diaries are notoriously poor in their legibility, completeness and accuracy. Electronic diaries are small, portable devices that can present text and graphics to the subject. They allow the subject to record and store responses, which can be time-stamped for each entry made. 

The metal has very little commercial use. In elemental form it is a laser source, a portable x-ray source, and as a dopant in garnets. When added to stainless steel, it improves grain refinement, strength, and other properties. Some other applications, particularly in oxides mixed with other rare earths, are as carbon rods for industrial hghting, in titanate insulated capacitors, and as additives to glass. The radioactive isotope ytterbium-169 is used in portable devices to examine defects in thin steel and aluminum. The metal and its compounds are used in fundamental research. 

Insulin pumps are small, portable devices worn externally that deliver a continuous supply of insuhn subcutaneously through a hypodermic needle. The pumps provide a basal rate of insuhn between meals and can be manually adjusted to facilitate glycemic control at... 

---