humidity

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humidity

 [hu-mid´ĭ-te]
the degree of moisture in the air.
absolute humidity the actual amount of vapor in the atmosphere, expressed in milligrams per liter.
relative humidity the percentage of moisture in the air as compared to the amount necessary to cause saturation, which is taken as 100.
humidity therapy the therapeutic use of water to prevent or correct a moisture deficit in the respiratory tract. Under normal conditions the respiratory tract is kept moist by humidifying mechanisms that allow for evaporation of water from the respiratory mucosa. If these mechanisms fail to work, are bypassed (such as with an endotracheal tube), or are inadequate to overcome the drying and irritating effects of therapeutic gases and mucosal crusting, some form of humidification must be provided.

The principal reasons for employing humidity therapy are: (1) to prevent drying and irritation of the respiratory mucosa, (2) to facilitate ventilation and diffusion of oxygen and other therapeutic gases being administered, and (3) to aid in the removal of thick and viscous secretions that obstruct the air passages. Another important use of water aerosol therapy is to aid in obtaining an induced sputum specimen.

Humidity therapy may be delivered in a variety of ways. Humidifiers and vaporizers increase the water content of an environment and are limited to the treatment of upper respiratory disorders because they produce particles that are too large to penetrate deeply into the lungs. Nebulizers generate clouds or mists of particles that are extremely small and thus capable of penetrating more deeply into the bronchioles and small structures of the lower respiratory tract. Examples of these include jet instruments and ultrasonic nebulizers.

hu·mid·i·ty

(hyū-mid'i-tē),
Moisture or dampness, as of the air.
[L. humiditas, dampness]

hu·mid·i·ty

(hyū-mid'i-tē)
Moisture or dampness, as of the air.
[L. humiditas, dampness]

hu·mid·i·ty

(hyū-mid'i-tē)
Moisture or dampness, as of the air.
[L. humiditas, dampness]
References in periodicals archive ?
These regulators provide effective and efficient control, and they offer the best option for moisture problems, especially in situations where radical temperature variations exist or where high air humidity is a constant.
Calibration parameters and coefficient of determination for each method evaluated Calibration regression parameters Methods evaluated a b [R.sup.2] FAO-PM without Rs -1.1441 1.3229 0.8303 FAO-PM without WS -0.6640 1.1467 0.8525 FAO-PM without RH 0.2150 0.9851 0.9256 FAO-PM without Rs and RH -1.0474 1.3663 0.7731 FAO-PM without Rs and WS -2.3025 1.5929 0.7041 FAO-PM without RH and WS -0.0642 1.0459 0.8295 FAO-PM without Rs, WS and RH -1.5618 1.4874 0.6734 Hargreaves-Samani -1.6213 1.2367 0.6539 Jensen-Haise 0.4006 0.8556 0.7934 Hicks-Hess 0.4668 0.9793 0.7956 Priestley-Taylor 0.9833 1.5163 0.8122 Tanner-Pelton 0.3403 0.8305 0.7825 FAO-PM--FAO Penman-Monteith; Rs--Solar radiation; WS--Wind speed; RH--Relative air humidity Table 3.
The investigation aimed to determine whether air humidity and atmospheric pressure have a similar influence on [H.sub.2]S generation as air temperature does.
The production environments were meteorologically characterized using sensors of temperature and relative air humidity (SHT-75), installed in the geometric center (2 m), with wireless communication (arduino protocol), while the external environment was characterized by a weather station close to the greenhouses.
where [W.sub.air,in] in is the inlet air humidity ratio ([g.sub.v]/[kg.sub.air]), [W.sub.air,out] is the outlet air humidity ratio ([g.sub.v]/[kg.sub.air]), and [W.sub.sol,in] is the inlet desiccant solution humidity ratio (g/kg).
For applications in which the disadvantages of migrating antistatic agents cannot be accepted, non-migrating systems must be used, which are not affected by air humidity and provide permanent protection from charge build-up.
(2009) evaluated the effect of relative air humidity on the time of evaporation of droplets and observed that, as humidity increased, the evaporation time also increased.
It is especially effective for facilities seeking to control indoor air humidity, including manufacturers and supermarkets.
Although return air temperature is easily controlled by AHUs, return air humidity depends on outdoor air conditions and intake ratios, especially during the winter.
Building sensors measure carbon dioxide levels, air humidity, temperature, and flow of people to continuously fine-tune the functionality and energy consumption of the CUBIC.