scholarly journals A SIMPLE DEVICE FOR AUTOMATIC PRESSURE CONTROL DURING ALTERNATING POSITIVE-NEGATIVE PRESSURE VENTILATION

1957 ◽  
Vol 29 (2) ◽  
pp. 84-85
Author(s):  
LOTHAR BARTH
Keyword(s):  
Negative Pressure ◽  
Pressure Control ◽  
Simple Device ◽  
Negative Pressure Ventilation ◽  
Automatic Pressure

Sustained Improvement in Gas Exchange After Negative Pressure Ventilation for 8 Hours Per Day on 2 Successive Days in Chronic Airflow Limitation

1991 ◽  
Vol 144 (2) ◽  
pp. 390-394 ◽  
Author(s):  
Enrique Fernandez ◽  
Paltiel Weiner ◽  
Ephraim Meltzer ◽  
Mary M. Lutz ◽  
David B. Badish ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Negative Pressure ◽  
Airflow Limitation ◽  
Sustained Improvement ◽  
Negative Pressure Ventilation

Negative pressure ventilation decreases inflammation and lung edema during normothermic ex-vivo lung perfusion

2018 ◽  
Vol 37 (4) ◽  
pp. 520-530 ◽  
Author(s):  
Nader S. Aboelnazar ◽  
Sayed Himmat ◽  
Sanaz Hatami ◽  
Christopher W. White ◽  
Mohamad S. Burhani ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Ex Vivo ◽  
Lung Perfusion ◽  
Lung Edema ◽  
Ex Vivo Lung Perfusion ◽  
Negative Pressure Ventilation

Augmentation of phrenic neural activity by increased rates of lung inflation

1981 ◽  
Vol 50 (1) ◽  
pp. 149-161 ◽  
Author(s):  
A. I. Pack ◽  
R. G. DeLaney ◽  
A. P. Fishman
Keyword(s):  
Tidal Volume ◽  
Volume Change ◽  
Neural Activity ◽  
Negative Pressure ◽  
Spontaneous Breathing ◽  
Moving Average ◽  
Constant Flow ◽  
Lung Inflation ◽  
Negative Pressure Ventilation ◽  
Single Breath

Studies were conducted in anesthetized paralyzed dogs using a cycle-triggered constant-flow ventilator, which ventilated the animal in phase with the recorded phrenic neural activity. Intermittently tests were performed in which the animal was ventilated with a different airflow for a single breath. Increased airflows, within the range generated during spontaneous breathing, caused an increased rate of rise of the moving average phrenic neurogram and a shortening of the duration of the nerve burst. The magnitude of the increase in the rate of rise of the neurogram was related to the level of inspiratory airflow. Tests with brief pulses of airflow showed that an increase in the rate of rise of the phrenic neurogram could be produced without inflating the lung above the resting tidal volume of the animal. Similar results were obtained with negative-pressure ventilation and the effects were abolished by vagotomy. This vagally mediated augmentation of phrenic neural output may accelerate the inspiratory volume change in the lung during spontaneous breathing at hyperpneic levels.

scholarly journals Diagnosis and validation by computational fluid dynamics of poultry house with negative pressure ventilation

2019 ◽  
Vol 23 (10) ◽  
pp. 761-767
Author(s):  
Gisele C. de A. Cunha ◽  
José P. Lopes Neto ◽  
Dermeval A. Furtado ◽  
Valéria P. Borges ◽  
Elias A. Freire ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Negative Pressure ◽  
Environmental Variables ◽  
Fluid Dynamic ◽  
Air Velocity ◽  
Cfd Simulations ◽  
Heterogeneous Distribution ◽  
Poultry House ◽  
Mean Values ◽  
Negative Pressure Ventilation

ABSTRACT Negative pressure ventilation in poultry houses has been used to enable the correction of their internal microclimates, and studies point to the heterogeneous distribution of air along the aviaries and the inadequacy of the environmental variables to the recommended ranges for thermal comfort of adult birds, especially in the hottest hours of the day. This study aimed to diagnose the facilities of a poultry house in the state of Paraíba, Brazil, regarding the distribution of environmental variables and thermal comfort; develop a computational model and validate it for Computational Fluid Dynamic - CFD simulations. Air temperature (Tair), air relative humidity (RH) and air velocity (Vair) data allowed characterizing the internal environment by comparison with the recommended ranges for each variable and by the temperature-humidity-velocity index (THVI). The poultry house does not provide comfort for the housed adult birds, between 12 and 14 h, with THVI indicating alert and Tair, RH and Vair values outside the recommended ranges; the CFD model for the poultry house was validated with Tair averages collected in the field of 27.75 ± 1.35 ºC and simulated of 27.85 ± 0.55 ºC, mean values of RH collected of 83 ± 12% and simulated of 78 ± 3%, and means of Vair collected of 2.35 ± 1.35 m s-1 and simulated of 2.50 ± 1.50 m s-1.

Negative Pressure Ventilation

CHEST Journal ◽  
1989 ◽  
Vol 95 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Robert D. Levy ◽  
T. Douglas Bradley ◽  
Stephen L. Newman ◽  
Peter T. Macklem ◽  
James G. Martin
Keyword(s):  
Negative Pressure ◽  
Negative Pressure Ventilation

Research on Negative Pressure Control Technology in NPP Reactor Building and its Application

2013 ◽  
Author(s):  
Jianghong Xie
Keyword(s):  
Power Unit ◽  
Negative Pressure ◽  
Nuclear Power ◽  
Pressure Control ◽  
Control Technology ◽  
Annular Space ◽  
Pressure System ◽  
Nuclear Power Unit ◽  
Reactor Building ◽  
Double Wall

The paper mainly elaborates the negative pressure control technology and commissioning approaches for double-wall containment of Russian WWER-1000 nuclear power units. It also carries out an analysis and research on the layered negative pressure technology in the containment. It mainly includes the following three parts: A Russian WWER-1000 nuclear power unit adopts the structure of double-wall containment for its Reactor building, with independent negative pressure systems for the containment and the annular space between the two walls. The paper mainly elaborates the control methods and limits requirements for the negative pressure in the containment and the annular space under the normal operation condition and in case of design basis accidents, with analysis and argumentation on the design function and operation requirements of the negative pressure system for the containment and the annular space. In the paper, the design philosophy of layered negative pressure and its feasibility study are analyzed from the aspects of radiated partition, air distribution of the negative pressure system and containment separator for layered negative pressure. The commissioning methods and technical requirements of negative pressure system in the Reactor building are described in the paper. Problems encountered during commissioning are also addressed and analyzed. Operations practices prove that the negative pressure control technology for double-wall containment of WWER-1000 nuclear power unit is advanced and reliable, which meets the requirements on nuclear air decontamination emission and radiation protection, and is worthy of study, research and reference.

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