These respiratory changes are important, particularly during mechanical ventilation, and Q should therefore be measured at a defined phase of the respiratory cycle, usually end-expiration.

Towards the end of the egg development phase, the male often makes holes in the roof and near the rim of the nest, presumably to improve ventilation of the nest during fanning at a time when the eggs are more metabolically active.

* Three phase 400 V AC for air conditioning compressor, heating, ventilation fans ( air cond.

In the preliminary design phase of the tunnel COWI established an overall concept for the electrical and mechanical systems with emphasis on safety-related functions such as electric power supply, tunnel lighting, fire fighting, tunnel ventilation and smoke extraction.

Whatever the mechanism, blood meant for the pulmonary system is not ventilated and so no gas exchange occurs ( the ventilation / perfusion ratio is decreased ).

These generally had 2 floors, with a firing level and a support / infrastructure level that provided the troops with rest and services ( power generating units, reserves of water, fuel, food, ventilation equipment, etc .).

The Apollo / Skylab A7L suit included eleven layers in all: an inner liner, a liquid cooling and ventilation garment, a pressure bladder, a restraint layer, another liner, and a thermal micrometeoroid garment consisting of five aluminized insulation layers and an external layer of white Ortho-Fabric.

Once the incision is closed, the anesthetic agents are stopped and / or reversed, and the patient is taken off ventilation and extubated ( if general anesthesia was administered ).

It can also be referred to as an Atrium style due to the common atrium / courtyard constructed in the middle of the shelter to provide adequate light and ventilation.

In this situation, the left lung may be unable to participate in ventilation, which can lead to decreased oxygen content due to ventilation / perfusion mismatch.

It is typically caused by a ventilation / perfusion ( V / Q ) mismatch ; the volume of air flowing in and out of the lungs is not matched with the flow of blood to the lungs.

That movement or flow of combustion air and flue gas is called " natural draught / draft ", " natural ventilation ", " chimney effect ", or " stack effect ".

Some systems are also equipped with compressed-gas tanks, air compressors, and / or backup batteries to provide ventilation in case of power failure or defective gas supplies, and methods to operate or call for help if their mechanisms or software fail.

In 1953, Ibsen set up what became the world's first Medical / Surgical ICU in a converted student nurse classroom in Kommunehospitalet ( The Municipal Hospital ) in Copenhagen, and provided one of the first accounts of the management of tetanus with muscle relaxants and controlled ventilation.

File: ventperf. jpg | Normal pulmonary ventilation and perfusion ( V / Q ) scan.

The entrance hole should be 1 1 / 2 " diameter for Eastern Bluebirds, and the box should have good ventilation.

Doorway flows are of interest in the domain of natural ventilation and air conditioning / refrigeration and have been extensively investigated, see for example Kiel and Wilson, Dalziel and Lane-Serff or Phillips and Woods, to name but a few.

Various pathologies and anomalies cause conditions such as diffusion limitation, ventilation / perfusion mismatch, and pulmonary shunts that can limit oxygenation of the blood and therefore oxygen distribution.

Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds ( VOC ), molds ( see mold health issues ), improper exhaust ventilation of ozone ( byproduct of some office machinery ), light industrial chemicals used within, or lack of adequate fresh-air intake / air filtration ( see Minimum Efficiency Reporting Value ).

The American Society of Heating, Refrigerating and Air-Conditioning Engineers ( ASHRAE ) recently revised its ventilation standard to provide a minimum of 15 cfm of outdoor air per person ( 20 cfm / person in office spaces ).

This is called ventilation – perfusion ( or V / Q ) mismatch.

Below-the-surface upgrades include new wiring, heating, ventilation and air conditioning systems, new audio / visual equipment in classrooms and conference areas, and an updated sprinkler system.

* Heating / ventilation / air-conditioning systems

The ventilation rate can also be expressed on a per person or per unit floor area basis, such as CFM / p or CFM / ft², or as air changes per hour.

For residential buildings, which mostly rely on infiltration for meeting their ventilation needs, the common ventilation rate measure is the number of times the whole interior volume of air is replaced per hour, and is called air changes per hour ( I or ACH ; units of 1 / h ).

When the ventilation does not match the perfusion through the paranchyema of the lung.

This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation.

Finally, the diffusing capacity does not directly measure the primary cause of hypoxemia, or low blood oxygen, namely mismatch of ventilation to perfusion:

* Pulmonary shunts exist when there is normal perfusion to an alveolus, but ventilation fails to supply the perfused region.

These responses to carbon dioxide and oxygen by pulmonary blood vessels and bronchiole airway smooth muscle aid in matching perfusion and ventilation within the lungs.

The recruitment reduces ventilation – perfusion mismatch.

Some physiological factors are having non-perfuse but ventilated alveoli, such as a pulmonary embolism or smoking, excessive ventilation of the alveoli, brought on in relation to perfusion, in people with chronic obstructive lung disease, and “ shunt dead space ,” which is a mistake between the left to right lung that moves the higher CO2 concentrations in the venous blood into the arterial side making an arterial to end tail CO2 indifferences.

This is primarily as a result of ventilation – perfusion imbalance ( see Effect of oxygen on chronic obstructive pulmonary disease ).

The most common indication for lung scintigraphy is to diagnose pulmonary embolism, e. g. with a ventilation / perfusion scan.

Capnography provides information about production, pulmonary ( lung ) perfusion, alveolar ventilation, respiratory patterns, and elimination of from the anaesthesia breathing circuit and ventilator.

This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation.

The Euler – Liljestrand mechanism describes the connection between ventilation and blood circulation ( perfusion ) of the lung.

This improves ventilation / perfusion ratio and arterial oxygenation, but is less helpful in the case in long-term whole-body hypoxia.

An altered level of consciousness indicates the need for immediate reevaluation of the patient's oxygenation, ventilation, and perfusion status.

: This decline is due to an increasingly poor match between ventilation and perfusion in the lung as we age, making ventilation-perfusion abnormalities the most common reason for a reduced arterial oxygen content.

* As a limit, a ventilation / perfusion ratio of zero is a physiological shunt.