Ventilation general

Ventilation can be provided as general dilution ventilation or local extraction ventilation. Dilution ventilation (general ventilation)... 

Materials of Construction Ventilation General, Local, Air intakes, Rate... 

General ventilation General ventilation distributed at ceiling level exhaust... 

GHB is rapidly absorbed from the GI tract and its onset of action is extremely rapid. Loss of consciousness may occur within 15 to 30 minutes. The duration of response is also short, typically 1 to 3 hours for normal dose and 2 to 4 hours with excessive dose. Overdose leading to coma and respiratory depression requiring assisted ventilation generally resolves in <6 hours. Frequent use of GHB in high dose may produce tolerance and dependence despite its short duration of action. A withdrawal syndrome consisting of tremor, agitation, paranoia, delirium, hallucinations, confusion, tachycardia, and hypertension may follow cessation from chronic heavy use. 

Ventilation is an important method of reducing the level of toxic airborne contaminants in the process environment. Ventilation includes general (dilution) ventilation and local exhaust (vent) ventilation. General ventilation involves dilution of air and hence the term dilution ventilation. Local exhaust ventilation is a method of removing contaminants before they enter the workplace air. Local ventilation is typically achieved by employing a hood that covers the specific area of contamination. 

A local exhaust is generally preferred over a dilution ventilation system for health hazard control because a local exhaust system removes the contaminants directly fi om the source, whereas dilution ventilation merely mixes the contaminant with uncontaminated air to reduce the contaminant concentration. Dilution ventilation may be acceptable when the contaminant concentration has a low toxicity or a threshold limit value (TLV) > 100 ppm, and the rate of contaminant emission is constant and low enough that the quantity of required dilution air is not prohibitively large. However, dilution ventilation generally is not acceptable when the TLV is less than 100 ppm. 

Ventilation general room ventilation and local exhaust ventilation to reduce the air concentration of an allergen... 

After removal of the load from the sterilizer, further dissipation of residues is a function of time, temperature, and ventilation. Generally, the rate of ethylene oxide dissipation doubles for every 10 C rise in temperature (the Q]q is... 

There are other issues with general ventilation. General ventilation does not always reach local sites in a space where concentrations may exceed safe levels for fire or health. Often distribution of air is uneven in a space. 

OHS may present with various possible sleep respiratory patterns (obstructive apneas, hypoventilation, and sometimes, central apneas, or a combined pattern) (7) and needs polysomnographic evaluation to adapt the ventilatory treatment, which is then mandatory (Fig. 3) either as nasal continuous positive airway pressure (nCPAP) or bi-level positive airway pressure ventilation, generally with oxygen supplementation if severe desaturation is present. 

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