Warm-cool feeling

The computer display then shows the steady-state values for characteristics such as the thermal conductivity k [W/(mK)], thermal resistance R [m K/W] and thickness of the sample s [mm], but also the transient (non-stationary) parameters like thermal diffusivity and so called thermal absorptivity b [Ws1/2/(jti2K)], Thus it characterizes the warm-cool feeling of textile fabrics during the first short contact of human skin with a fabric. It is defined by the equation b = (Xpc)l, however, this parameter is depicted under some simplifying conditions of the level of heat flow q [ W/m2] which passes between the human skin of infinite thermal capacity and temperature T The textile fabric contact is idealized to a semi-infinite body of the finite thermal capacity and initial temperature, T, using the equation, = b (Tj - To)/(n, ... 

In case of steady state heat conduction, the material property is the conductivity which can be calculated once the heat loss from the body is known and the boundary temperature is measured. In case of transient heat flow, the main factor is the diffusivity a which is equal to the ratio of the conductivity and the heat content of the body. Hence equation 10.8 is the basic governing equation of transient heat transfer with boundary conditions relevant for textile materials. Transient state heat conduction is related to instantaneous conduction of heat fi-om the surface of the body to the clothing. Instantaneous heat transfer can be related to the warmth or coolness to touch and the warm-cool feeling of any clothing can be quantified. 

We often describe physical objects as being warm, cool, cold, hot, etc. What is interesting is that we may describe different objects that are at the same temperature as feeling different. This is due to the amount of heat, the thermal energy, that is transferred between those objects and our skin. The amount of heat transferred is dependent on the total amount of contact (the surface area) and the thermal conductivity coefficient (TCC) of the object. An object that has high TCC, such as most metals, will transfer heat much faster than an object with a low TCC, such as wood or thermoplastic. Below is a table with TCC values for a number of common materials (Table 7.2). 

The temperatures monitored in Fig. 5.2 are used by the brain to regulate shivering, blood flow to the skin, and sweating. The sensed temperatures also contribute to our overall feelings of warmth and other thermal sensations. 7 hermal sensation (TS) can be predicted over a wide range of activities (0.8 to 4 met) from simple deviations in the mean body temperature (T j,) from the mean bodv temperature when the person feels neither warm or cool but neutral (Fig. 5.2). 

The PMV index predicts the mean value of the thermal preferences of a large group of people exposed to the same environment. But individual votes are scattered around this mean value, and it is useful to predict the number of people likely to feel uncomfortably warm or cool. The PPD (predicted percentage of dissatisfied) index establishes a quantitative prediction of the number of thermally dissatisfied people. The PPD predicts the percentage of a large group of people likely to feel too warm or cool, i.e., voting hot (-t-. , warm (4-2), cool (-2), or cold (-3) on the 7-point thermal sensation scale. 

If the floor is too warm or too cool, occupants may feel uncomfortable due to warm or cool feet. For people wearing light indoor shoes, it is the temperature of the floor rather than the material of the floor covering that is important to comfort. Figure 6.4 shows the percentage of dissatisfied for seated or standing people as a function of floor temperature. 

Affected area of skin may feel warm (or cool) and boggy (or firm) when compared with the skin on an opposing area of the body. The patient may complain of pain or itching in the area. 

Bai Wei is bitter, salty and cold, and enters the Lung, Stomach and Kidney meridians. It can reduce deficient heat and cool the blood. The strong point of this herb is that it can be used not only for acute febrile diseases, but also for chronic disorders, such as postpartum fever, lingering fever, night sweats and a warm feeling in the palms and soles in febrile diseases. 

This extra water vapor in the air makes it harder for humans to utilize their natural evaporative cooling method sweat. Flumans sweat in the intense heat of a sauna, but the sweat cannot evaporate easily because the air is already filled with water vapor. As a result, the human body loses its ability to regulate its own body temperature. This explains why sitting in a sauna can feel extremely warm even when temperatures are not that high. 

As you observed in the DISCOVERY LAB at the beginning of this chapter, some solutions release energy as they form, whereas others absorb energy during formation. For example, after ammonium nitrate dissolves in water, its container feels cool. In contrast, after calcium chloride dissolves in water, its container feels warm. You will learn more about the heat of solution in the next chapter. 

I would be feeling the migraines coming and had to get these down pat, always planning ahead. Set and setting are paramount. The body can over heat on LSD if the air temperature is too hot. In the winter, I would wear warm clothes outside. During the summer, I would only have a session outside if the temperature was not hot. Usually, in the summer, sessions were conducted outside on a cool sunny day. 

Warm baths and showers are great for warming and moistening cool, dry vata, especially when the weather is cold or when you re feeling out of balance. 

The strongly acidic HCl solution of ZrOCl3 8HgO is evaporated on a water bath until crystallization is incipient and is then treated with an equal volume of cone, hydrochloric acid the mixture is heated (do not allow too much HCl to escape) and. If necessary, 25% hydrochloric acid is added to the warm mixture until solution is complete and the mixture contains, at most, 39 g. of o Q chloride, I.e., 15 g. of ZrOg per 100 ml. The solution is mechanically stirred and its temperature is allowed to drop to a point where it still feels warm to the hand it is then cooled with ice. After stirring for 30 minutes at 0°C, the product is filtered through a medium-porosity fritted glass and washed with 25% hydrochloric acid precooled to 0°C. 

I know, she whispered, giving his hand a squeeze. Herman thought she looked like a goddess in the glorious explosion of rosy light. Her hand felt warm, and he could almost feel a cool, tender breeze. Let s go, she said, tenderly guiding him into her craft. 

She had then continued to be sick, or at least have the stomach spasms, after they floated through the airlock tube into the starship s tiny lounge. Endron, the ship s systems specialist who doubled as medical officer, had towed her into the sick bay cubicle. Twenty minutes later when the horrid warm itch inside her stomach faded, and some kind of cool fluid was sprayed into her mouth to rinse away the taste of vomit, she began to take stock for the first time. Her ears felt funny, and when she touched one she could feel something hard cupped around the back of it. 

The experiment can be adapted in a simplified manner to everyday life We touch a thick rubber band with the upper lip and after waiting a short while for equalization of temperature, it is stretched quickly and powerfully and immediately pressed again against the upper lip. The band feels noticeably warm. When the stretched band is allowed to contract to its original length and then quickly pressed against the upper lip, there is a noticeable cooling. 

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