The Theory and Effect of Positive and Negative Pressure on Brewing Fermentations: Pressure Effects on Beer Fermentation

2021 ◽  
Vol 58 (3) ◽  
Keyword(s):  
Negative Pressure ◽  
Pressure Effects ◽  
Beer Fermentation

Negative pressure effects on mechanically opposing pharyngeal muscles in awake and sleeping goats

2001 ◽  
Vol 91 (5) ◽  
pp. 2289-2297 ◽  
Author(s):  
Thom R. Feroah ◽  
H. V. Forster ◽  
L. Pan ◽  
N. E. Schlick ◽  
Paul Martino ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Negative Pressure ◽  
Slow Wave Sleep ◽  
Pressure Response ◽  
Pressure Effects ◽  
Upper Airways ◽  
Tp 31 ◽  
State Dependent ◽  
Pharyngeal Muscles ◽  
Pressure Tests

Our aim was to investigate the effects of the negative pressure reflex on mechanically opposing pharyngeal muscles during wakefulness, slow-wave sleep (SWS), and rapid eye movement (REM) sleep. In four goats with isolated upper airways, we measured tracheal airflow and electrical activity of the thyropharyngeus (TP; constricting), the stylopharyngeus (SP; dilating), and the diaphragm (Dia). In the wakefulness state in response to negative pressure tests, TP decreased (65%), SP increased (198%), and tidal volume (Vt) (66%) and rate of rise of Dia (Diaslope, 69%) decreased ( P < 0.02). Similarly, during SWS, the negative pressure response of TP (31%), Vt (61%), and Diaslope (60%) decreased, whereas SP (113%) increased, relative to SWS control ( P < 0.02). In REM sleep, the negative pressure response by TP and SP were small, whereas both Vt (38%) and Diaslope (24%) were greatly decreased ( P < 0.02) compared with REM control. Inspiratory duration remained unchanged in response to negative pressure tests in all states. These data provide evidence that mechanically opposing inspiratory and expiratory pharyngeal muscles are reciprocally controlled and their response to negative pressure are state dependent.

scholarly journals Novel cavitation fluid jet polishing process based on negative pressure effects

2018 ◽  
Vol 42 ◽  
pp. 339-346 ◽  
Author(s):  
Fengjun Chen ◽  
Hui Wang ◽  
Yu Tang ◽  
Shaohui Yin ◽  
Shuai Huang ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Pressure Effects ◽  
Polishing Process

Upper airway negative-pressure effects on respiratory activity of upper airway muscles

1984 ◽  
Vol 56 (2) ◽  
pp. 500-505 ◽  
Author(s):  
O. P. Mathew
Keyword(s):  
Negative Pressure ◽  
Respiratory Activity ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Pressure Change ◽  
Pressure Effects ◽  
Rapid Decline ◽  
Airway Patency ◽  
Inspiratory Activity ◽  
Upper Airway Muscles

Influence of upper airway negative-pressure change on the respiratory activity of various upper airway muscles was investigated in 13 anesthetized rabbits. Phasic inspiratory activity increased or appeared during virtually all negative-pressure trials in nasolabial, cricothyroid, and posterior cricoarytenoid muscles. No phasic inspiratory activity was seen in the sternothyroid (ST) and sternohyoid (SH) muscles before negative-pressure applications but appeared during 80% of trials in ST and 62% of trials in SH. During maintained negative pressure, a gradual decline in activity was often observed in the nasolabial and laryngeal muscles, whereas a rapid decline in activity was seen in the cervical strap muscles. Reflex effects of negative pressure was markedly reduced or abolished by sectioning the internal branch of the superior laryngeal nerve bilaterally. Reflex augmentation of upper airway muscle activity reported here may have functional significance in the maintenance of upper airway patency. It could prevent upper airway collapse when negative pressure swings in the upper airway increase or facilitate recovery when large negative pressure swings are produced by obstructed inspiratory efforts.

scholarly journals Topical negative pressure effects on coronary blood flow in a sternal wound model

2008 ◽  
Vol 5 (4) ◽  
pp. 503-509 ◽  
Author(s):  
Sandra Lindstedt ◽  
Malin Malmsjö ◽  
Bodil Gesslein ◽  
Richard Ingemansson
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Negative Pressure ◽  
Pressure Effects ◽  
Topical Negative Pressure ◽  
Wound Model

Negative pressure effects in high-pressure oxygen-intercalatedC60

1995 ◽  
Vol 51 (21) ◽  
pp. 15552-15554 ◽  
Author(s):  
J. E. Schirber ◽  
R. A. Assink ◽  
G. A. Samara ◽  
B. Morosin ◽  
D. Loy
Keyword(s):  
High Pressure ◽  
Negative Pressure ◽  
Pressure Effects ◽  
Pressure Oxygen ◽  
High Pressure Oxygen

Short-term variability of blood pressure: effects of lower-body negative pressure and long-duration bed rest

2012 ◽  
Vol 303 (1) ◽  
pp. R77-R85 ◽  
Author(s):  
Federico Aletti ◽  
Manuela Ferrario ◽  
Da Xu ◽  
Danielle K. Greaves ◽  
J. Kevin Shoemaker ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Venous Pressure ◽  
Bed Rest ◽  
Pressure Effects ◽  
Lower Body ◽  
Arterial Baroreflex ◽  
Long Duration ◽  
Cardiopulmonary Baroreflex

Mild lower-body negative pressure (LBNP) has been utilized to selectively unload cardiopulmonary baroreceptors, but there is evidence that arterial baroreceptors can be transiently unloaded after the onset of mild LBNP. In this paper, a black box mathematical model for the prediction of diastolic blood pressure (DBP) variability from multiple inputs (systolic blood pressure, R-R interval duration, and central venous pressure) was applied to interpret the dynamics of blood pressure maintenance under the challenge of LBNP and in long-duration, head-down bed rest (HDBR). Hemodynamic recordings from seven participants in the WISE (Women's International Space Simulation for Exploration) Study collected during an experiment of incremental LBNP (−10 mmHg, −20 mmHg, −30 mmHg) were analyzed before and on day 50 of a 60-day-long HDBR campaign. Autoregressive spectral analysis focused on low-frequency (LF, ∼0.1 Hz) oscillations of DBP, which are related to fluctuations in vascular resistance due to sympathetic and baroreflex regulation of vasomotor tone. The arterial baroreflex-related component explained 49 ± 13% of LF variability of DBP in spontaneous conditions, and 89 ± 9% ( P < 0.05) on day 50 of HDBR, while the cardiopulmonary baroreflex component explained 17 ± 9% and 12 ± 4%, respectively. The arterial baroreflex-related variability was significantly increased in bed rest also for LBNP equal to −20 and −30 mmHg. The proposed technique provided a model interpretation of the proportional effect of arterial baroreflex vs. cardiopulmonary baroreflex-mediated components of blood pressure control and showed that arterial baroreflex was the main player in the mediation of DBP variability. Data during bed rest suggested that cardiopulmonary baroreflex-related effects are blunted and that blood pressure maintenance in the presence of an orthostatic stimulus relies mostly on arterial control.

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