Why do we build the wall?

2019 ◽  
Vol 28 (1) ◽  
pp. 37-38 ◽  
Author(s):  
Ezequiel A Di Paolo
Keyword(s):  
Air Bubbles ◽  
Trapped Air ◽  
Good Move ◽  
Autopoietic Theory

I discuss the notion of bodies proposed by Villalobos and Razeto-Barry. I consider it a good move in a direction away from overly formal aspects of autopoietic theory, but in need of refinement. I suggest that because organismic boundaries are dialectical processes and not immanent walls, some autopoietic bodies can extend by incorporating parts of their environment as in the case of insects that use trapped air bubbles to breathe underwater.

Leveling Device for Forming X-Ray Specimen

1980 ◽  
Vol 24 ◽  
pp. 369-370
Author(s):  
Vann Y. Won
Keyword(s):  
Air Bubbles ◽  
Plastic Film ◽  
X Ray ◽  
Trapped Air ◽  
Specimen Holder ◽  
Specimen Material ◽  
Accurate Definition ◽  
Analysis Window ◽  
Definition Of ◽  
Open Face

A device was made for preparing accurate definition of surface, depth and volume of liquid x-ray fluorescence specimens.The apparatus used in conjunction with a specimen holder and plastic film window material accurately and consistently forms a flat bobble-free analysis window on the open face of the specimen holder. The specimen holder in the form of a shallow cylinderical cup is slightly over filled and covered by the plastic film. Placement of the mating leveling apparatus over the film squeezes out trapped air bubbles, levels the exposed face of the specimen, draws the plastic film tightly over the exposed face of the specimen and allows easy installation of a film retaining O-ring to maintain the specimen material in a level state within the holder.

Effects of trapped air bubbles on frequency responses of the piezo-driven inkjet printheads and visualization of the bubbles using synchrotron X-ray

2009 ◽  
Vol 154 (1) ◽  
pp. 132-139 ◽  
Author(s):  
Byung-Hun Kim ◽  
Tae-Gyun Kim ◽  
Tae-Kyung Lee ◽  
Sungwook Kim ◽  
Seung-Joo Shin ◽  
...  
Keyword(s):  
Air Bubbles ◽  
X Ray ◽  
Trapped Air ◽  
Frequency Responses

Bubble-Induced Relaxation in High-Pressure Microfluidic Systems

2013 ◽  
Vol 562-565 ◽  
pp. 581-584
Author(s):  
Bao Jun Wang ◽  
Fei Xie ◽  
Wei Wang ◽  
Wen Gang Wu ◽  
Zhi Hong Li
Keyword(s):  
High Pressure ◽  
Flow Resistance ◽  
Relaxation Times ◽  
Air Bubbles ◽  
Microfluidic Systems ◽  
Design Guideline ◽  
Pressure Relaxation ◽  
Air Bubble ◽  
Trapped Air

This work reported an analysis of a noticeable relaxation phenomenon caused by undesirable air bubbles in high-pressure microfluidic systems. A model with compression of air bubble considered was established to address the experimental observed pressure relaxation. The results indicated that the dominative factors were flow rate, flow resistance and initial diameter of the trapped air bubble. Meanwhile, the calculated relaxation times in different cases provided a design guideline for high-pressure microfluidic chip to avoid the long-term pressure relaxation.

scholarly journals Towards orbital dating of the EPICA Dome C ice core using δO<sub>2</sub>/N<sub>2</sub>

2012 ◽  
Vol 8 (1) ◽  
pp. 191-203 ◽  
Author(s):  
A. Landais ◽  
G. Dreyfus ◽  
E. Capron ◽  
K. Pol ◽  
M. F. Loutre ◽  
...  
Keyword(s):  
Ice Core ◽  
Air Bubbles ◽  
Before Present ◽  
Data Filtering ◽  
Tuning Method ◽  
Trapped Air ◽  
Measurement Series ◽  
Orbital Tuning ◽  
Gas Loss ◽  
Grain Properties

Abstract. Based on a composite of several measurement series performed on ice samples stored at −25 °C or −50 °C, we present and discuss the first δO2/N2 record of trapped air from the EPICA Dome C (EDC) ice core covering the period between 300 and 800 ka (thousands of years before present). The samples stored at −25 °C show clear gas loss affecting the precision and mean level of the δO2/N2 record. Two different gas loss corrections are proposed to account for this effect, without altering the spectral properties of the original datasets. Although processes at play remain to be fully understood, previous studies have proposed a link between surface insolation, ice grain properties at close-off, and δO2/N2 in air bubbles, from which orbitally tuned chronologies of the Vostok and Dome Fuji ice core records have been derived over the last four climatic cycles. Here, we show that limitations caused by data quality and resolution, data filtering, and uncertainties in the orbital tuning target limit the precision of this tuning method for EDC. Moreover, our extended record includes two periods of low eccentricity. During these intervals (around 400 ka and 750 ka), the matching between δO2/N2 and the different insolation curves is ambiguous because some local insolation maxima cannot be identified in the δO2/N2 record (and vice versa). Recognizing these limitations, we restrict the use of our δO2/N2 record to show that the EDC3 age scale is generally correct within its published uncertainty (6 kyr) over the 300–800 ka period.

Distribution of the free and oil-trapped air bubbles in simulated broths containing fungal biomass

2002 ◽  
Vol 80 (3) ◽  
pp. 491-494 ◽  
Author(s):  
C. Patricia Larralde-Corona ◽  
Ma. Soledad Córdova ◽  
Enrique Galindo
Keyword(s):  
Fungal Biomass ◽  
Air Bubbles ◽  
Trapped Air

Effect of the Cross-Sectional Shape of Recirculation Channel on Expelling Air Bubbles in the FDBs of HDD Spindle Motors

2014 ◽  
Author(s):  
Y. H. Jung ◽  
G. H. Jang ◽  
C. H. Kang ◽  
H. H. Shin ◽  
J. Y. Jeong
Keyword(s):  
Fluid Dynamic ◽  
Hard Disk Drives ◽  
Navier Stokes ◽  
Air Bubbles ◽  
Navier Stokes Equation ◽  
Cross Sectional ◽  
Air Bubble ◽  
Trapped Air ◽  
Large Pressure ◽  
Fast Flow

Fluid dynamic bearings (FDBs) are applied to most of the spindle motors of computer hard disk drives (HDDs) since FDBs provide better dynamic characteristics, such as lower vibration and noise, than ball bearings. However, a weakness of FBDs is instability arising from air bubbles in the oil lubricant of FDBs. One possible solution to expel the trapped air bubbles out of FDBs is to include recirculation channel (RC). RC is designed to balance the pressures between upper and lower parts of FDBs and to circulate the oil lubricant as well as to expel air bubbles out of FDBs. This paper experimentally and numerically investigates the behavior of the air bubble in oil lubricant of operating FDBs due to the design of the RC. We created the FDBs with transparent cover and performed the experiment to visually observe the behavior of trapped air bubbles. Also, we numerically studied the phenomena of expelling the air bubble. The flow field of FDBs is calculated by the Navier-Stokes equation and the continuity equation. And we numerically explained that large pressure difference between upper and lower regions of RC and fast flow velocity along RC expel the air bubble out of FDBs. This research can be effectively utilized to develop robust FDBs by expelling the air bubbles out of FDBs.

scholarly journals A review of the brittle ice zone in polar ice cores

2014 ◽  
Vol 55 (68) ◽  
pp. 72-82 ◽  
Author(s):  
Peter D. Neff
Keyword(s):  
Atmospheric Pressure ◽  
Accumulation Rate ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Air Bubbles ◽  
Polar Ice ◽  
Overburden Pressure ◽  
Trapped Air ◽  
Borehole Temperatures

AbstractMaintaining ice-core quality through the brittle ice zone (BIZ) remains challenging for polar ice-core studies. At depth, increasing ice overburden pressurizes trapped air bubbles, causing fracture of cores upon exposure to atmospheric pressure. Fractured ice cores degrade analyses, reducing resolution and causing contamination. BIZ encounters at 18 sites across the Greenland, West and East Antarctic ice sheets are documented. The BIZ begins at a mean depth of 545 ± 162 m (1 standard deviation), extending to depths where ductile clathrate ice is reached: an average of 1132 ± 178 m depth. Ice ages in this zone vary with snow accumulation rate and ice thickness, beginning as young as 2 ka BP at Dye-3, Greenland, affecting ice >160 ka BP in age at Taylor Dome, Antarctica, and compromising up to 90% of retrieved samples at intermediate-depth sites. Effects of pressure and temperature on the BIZ are explored using modeled firn-column overburden pressure and borehole temperatures, revealing complex associations between firn densification and BIZ depth, and qualitatively supporting expected thinning of the BIZ at low ice temperatures due to shallower clathrate stability. Mitigating techniques for drilling, transport, sampling and analysis of brittle ice cores are also discussed.

scholarly journals Newly designed solid coupling medium for reducing trapped air pockets during extracorporeal shock wave lithotripsy_ a phantom study

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chien-Sheng Wang ◽  
Ching-Chia Li ◽  
Wen-Jeng Wu ◽  
Wen-Chin Liou ◽  
Yusen Eason Lin ◽  
...  
Keyword(s):  
Shock Wave ◽  
Phantom Study ◽  
Acoustic Energy ◽  
Disintegration Rate ◽  
Measuring Device ◽  
Trapped Air ◽  
Extracorporeal Shock Wave ◽  
Air Pockets ◽  
Coupling Medium ◽  
Level 2

Abstract Introduction Air pockets between the lithotripter head and body surface are almost inevitably generated when applying a handful of gel onto the contact portion of the treatment head and that on the patient’s skin during coupling procedure. These air pockets can compromise the transmission of acoustic energy of shock wave and may significantly affect efficacy of stone disintegration. Comparing to conventional gel, this study aims to investigate efficacy of stone disintegration by using a proprietary isolation-coupling pad (“icPad”) as the coupling medium to reduce trapped air pockets during ESWL procedure. Method In this phantom study, Dornier lithotripter (Delta-2 RC, Dornier MedTech Europe GmbH Co., Germany) was used with a proprietary gel pads (icPad, Diameter = 150 mm, Thickness = 4 mm and 8 mm). The lithotripter was equipped with inline camera to observe the trapped air pockets between the contact surface of the lithotripter head. A testing and measuring device were used to observe experimental stone disintegration using icPad and semi-liquid gel. The conventional semi-liquid gel was used as control for result comparison. Results The stone disintegration rate of icPad 4 mm and 8 mm after 200 shocks of energy at level 2 were significantly higher than that of the semi-liquid gel (disintegration rate 92.3%, 85.0% vs. 45.5%, respectively, p < 0.001). The number of shocks for complete stone disintegration by icPad of 4 mm and 8 mm at the same energy level 2 were significantly lower than that of the semi-liquid gel (the number of shocks 242.0 ± 13.8, 248.7 ± 6.3 vs. 351.0 ± 54.6, respectively, p = 0.011). Furthermore, quantitative comparison of observed air pockets under Optical Coupling Control (OCC) system showed that the area of air pockets in semi-liquid group was significantly larger than that of the group using icPad (8 mm) and that of the group using icPad (8 mm) after sliding (332.7 ± 91.2 vs. 50.3 ± 31.9, 120.3 ± 21.5, respectively, p < 0.05). Conclusion The advantages of icPad includes: (1) reduced the numbers of shock wave and increased stone disintegration rate due to icPad’s superior efficacy; (2) significantly reduce trapped air pockets in ESWL coupling. Due to the study limitation, more data are needed to confirm our observations before human trials.

scholarly journals Air bubbles play a role in shear thinning of non-colloidal suspensions

2021 ◽  
Vol 33 (1) ◽  
pp. 011702
Author(s):  
Yuan Lin ◽  
Ying Wang ◽  
Zixin Weng ◽  
Dingyi Pan ◽  
Jiawang Chen
Keyword(s):  
Colloidal Suspensions ◽  
Shear Thinning ◽  
Air Bubbles
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