Whole Body

The value of the impedance between two skin surface electrodes is usually dominated by the contribution of the skin. However, the skin impedance may be negligible if 

The voltage is high enough for skin electrical breakdown 

The effective skin contact area is very large 

Without the skin and with the living body tissue considered purely resistive, the resistance, R, of a body segment is determined by the mean resistivity, p mean length, L and mean cross-sectional area. A, according to R = pL/A. The resistance can be measured by a four-electrode technique (Freiberger, 1933 Grimnes, 1983a). 

When skin electrical protection has been broken down during an electrical accident, the volume segment resistance is the current Umiting factor (cf.. Section 9.14). A description of the body immittance data used for the estimation of body composition is found in 

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In principle, mesoscale methods can provide a means for connecting one type of simulation to another. For example, a molecular simulation can be used to describe a lipid. One can then derive the parameters for a lipid-lipid potential. These parameters can then be used in a simulation that combines lipids to form a membrane, which, in turn, can be used to compute parameters describing a membrane as a flexible sheet. Such parameters could be used for a simulation with many cells in order to obtain parameters that describe an organ, which could be used for a whole-body biological simulation. Each step, in theory, could be modeled in a different way using parameters derived not from experiment but from a more low-level form of simulation. This situation has not yet been realized, but it is representative of one trend in computational technique development. 

The growth of animals can be defined as an increase in mass of whole body, tissue(s), organ(s), or ceU(s) with time. This type of growth can be characterized by morphometric measurements eg, skeletal muscle or adipose tissue growth can be described by observing temporal changes in ceU number, ie, hyperplasia, and ceU size, ie, hypertrophy. Growth also includes developmental aspects of function and metaboHsm of cells and tissues from conception to maturity. 

The dB/d/is limited to 6 T/s out of concern that larger values could cause nerve stimulation. The r-f exposure is limited to a specific absorption rate (SAR) of 0.4 W/kg for the whole body, 0.32 W/kg averaged over the head, and less than 8.0 W/kg spatial peakia any one gram of tissue. These numbers are designed to limit the temperature rise to less than 1°C and localized temperature of no greater than 38°C head, 39°C tmnk, and 40°C ia the extremities. 

The nonquantitative detection of radioactive emission often is required for special experimental conditions. Autoradiography, which is the exposure of photographic film to radioactive emissions, is a commonly used technique for locating radiotracers on thin-layer chromatographs, electrophoresis gels, tissue mounted on sHdes, whole-body animal sHces, and specialized membranes (13). After exposure to the radiolabeled emitters, dark or black spots or bands appear as the film develops. This technique is especially useful for tritium detection but is also widely used for P, P, and 1. 

Bde salts, cholesterol, phosphoHpids, and other minor components are secreted by the Hver. Bile salts serve three significant physiological functions. The hydrophilic carboxylate group, which is attached via an alkyl chain to the hydrophobic steroid skeleton, allows the bile salts to form water-soluble micelles with cholesterol and phosphoHpids in the bile. These micelles assist in the solvation of cholesterol. By solvating cholesterol, bile salts contribute to the homeostatic regulation of the amount of cholesterol in the whole body. Bile salts are also necessary for the intestinal absorption of dietary fats and fat-soluble vitamins (24—26). 

Immersed Bodies When flow occurs over immersed bodies such that the boundaiy layer is completely laminar over the whole body, laminar flow is said to exist even though the flow in the mainstream is turbulent. The following reladonships are apphcable to single bodies immersed in an infinite flmd and are not valid for a.s.semhlage.s of bodies. 

Equipment may get washed with a steam jenny and allowed to air dry on plastic in a more remote area. We need to keep in mind that steam cleaners have the potential to cause substantial physical harm. The combination of high-pressure water and high temperatures can be dangerous. Wlien this is coupled with a worker standing on visquine or plastic, it becomes a slip, trip, and fall situation. Situations compounded with respiratory and whole-body protection, such as saranex or rubber suits and gloves, add in the potential for poor vision, heat stress, and the lack of physical dexterity. Keep these issues in mind prior to steam cleaner activity. 

In Figure 9-11 two workers in level D proteetion are pietured overseeing work aetivity on a platform. One appears to be a supervisor, the other a worker. Both are wearing level D, but the whole body proteetion and hand and head proteetion are different. 

In general, when a person is thermally comfortable, the person s thermal sensation for the whole body is at or near neutral as depicted in Fig. 5.7a. As we have seen, the thermal conditions necessary for comfort are affected by clothing insulation. Figure 5.7b shows the range of temperatures and humidities... 

Conditions that are warmer than the applicable still-air comfort zone of Fig. 5.7b can often be made comfortable by increasing the air speed. If the conditions are 1 to 6 °C warmer than the still-air comfort zone of Fig. 5.7b, the necessary air speed v) to restore thermal balance and comfort can be estimated from Fig. 5.8, where Tis the temperature difference between the environment and the still-air comfort temperature. Though the increased air speed will bring the whole-body thermal sensation to the comfort level, air motions above 0.8 m/s or so may cause other kinds of discomfort frojn... 

The importance of respiratory heat and water losses is not confined to the respiratory structures. Inspiration of cold, hot, or dry air poses the potential threats of thermal injury or desiccation to the airway epithelium" - T8,69 g challenge to whole-body thermoregulation. 

Under certain conditions, such as hyperbaria,airway heat losses can account for a considerable percentage of total body heat production (in some cases > 100%). Normally these threats are ameliorated by rapid moderation of inspired air temperature and humidity by exchanging heat and water vapor between the mucus and airstream in the upper airway. Recovering much of the heat and water vapor contained in expired air minimizes heat and water losses to the ambient environment and aids in whole-body thermoregulation. 

For < 0.05 m s, use t, - 0.05 m s b For DR > 100%, use DR = 100%, The model applies to people at light, mainly sedentary activity with a thermal sensation for the whole body close to neutral. The sensation of draft is lower at activities higher than sedentary and for people feeling warmer than neutral. 

Based on the pressure and impulse of the incident blast wave, the maximum velocity can be calculated of a human body during transportation by the explosion wind. Figure C-4 shows the impact velocity for the lethality criterion for whole body impact as a function of side-on overpressure and impulse... 

Pleuromamma xiphias Ostracod whole body 0.010b... 

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