Thoracoscopic pulmonary segmentectomy with collateral ventilation method

When a research ship sails at a high speed, there is relative motion between the ship and fluid. The ship is slammed by the fluid. To reduce the direct impact of the fluid, sonar is installed in the moonpool, and acoustic detection equipment is installed along the research ship bottom behind the moonpool. However, during high-speed sailing, a large number of bubbles form in the moonpool. Some bubbles escape from the moonpool and flow backward along the bottom of the ship. When a large number of bubbles are around the sonar and acoustic detection equipment, the equipment malfunctions. However, there have been few studies on bubble formation in the moonpool with sonar and distribution along the ship bottom behind the moonpool. Therefore, a related model was developed and prototype tests were carried out in this study. The appropriate similarity criteria were selected and verified to ensure the reliability of the experiment. Considering the influences of speed, sonar, moonpool shape, and draft, the reason and mechanism of bubble formation in a sonar moonpool were studied. An artificial ventilation method was used to simulate a real navigation environment. Because the bubbles are in a bright state under laser irradiation, the bubbles can be used as tracer particles. A high-speed camera captured illuminated bubbles. The distribution mechanism of bubbles along the ship bottom behind the moonpool was investigated using particle image velocimetry under the influence of the moonpool shape and sailing speed. The model experimental results agreed well with those of the prototype test. The air sucked into the water was the dominant factor in bubble formation in the moonpool. The bubbles were distributed in a W shape under the ship bottom.

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Case study on ventilation method development for Bar-Boljare highway tunnels construction in Montenegro

Tehnika ◽

10.5937/tehnika1705667c ◽

2017 ◽

Vol 72 (5) ◽

pp. 667-674 ◽

Cited By ~ 1

Author(s):

Aleksandar Cvjetic ◽

Nikola Lilic ◽

Vojin Cokorilo ◽

Vladimir Milisavljevic

Keyword(s):

Method Development ◽

Ventilation Method

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Ventilation Method Assessment of the Average Permeability of the Fractured Granite Rock Mass around Tunnel

Proceedings of the 5th International Conference on Information Engineering for Mechanics and Materials ◽

10.2991/icimm-15.2015.89 ◽

2015 ◽

Author(s):

Shuguang Wang ◽

Jincai Zhu ◽

Jinchao Yang ◽

Jianhua Chen ◽

Wei Yang

Keyword(s):

Rock Mass ◽

Granite Rock ◽

Fractured Granite ◽

Ventilation Method

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Experimental Investigation on Heat Transfer Performance in an Underground Dam Tunnel of Hydropower Station

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.374-377.494 ◽

2011 ◽

Vol 374-377 ◽

pp. 494-497

Author(s):

Yi Rong Dang ◽

An Gui Li ◽

Hai Guo Yin

Keyword(s):

Heat Transfer ◽

Surface Roughness ◽

Air Temperature ◽

Heat Transfer Performance ◽

Transfer Characteristic ◽

Hydropower Station ◽

Transfer Performance ◽

Air Velocity ◽

Underground Dam ◽

Ventilation Method

This paper presents an energy efficient ventilation method—dam tunnel air handling for hydropower station ventilation. The heat transfer characteristic between supply air and the dam tunnel is studied by model experiment. Supply air velocity, air temperature and dam tunnel surface roughness are chosen as the mainly influencing factors, the air temperature distribution along airflow direction are measured and analyzed in detail. The results show that the heat transfer performance in dam tunnel is improved as the increased of supply air temperature and the dam tunnel surface roughness, or maintained the supply air velocity at a lower level. This experimental study and its results are helpful to develop alternative and efficient systems for hydropower station ventilation.

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Collateral ventilation and the sloping alveolar plateaus of He and SF6: A model study

Respiration Physiology ◽

10.1016/0034-5687(92)90077-a ◽

1992 ◽

Vol 90 (2) ◽

pp. 145-158 ◽

Cited By ~ 5

Author(s):

D.P.J. Six ◽

W.R. de Vries ◽

S.C.M. Luijendijk

Keyword(s):

Model Study ◽

Collateral Ventilation

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Respiratory Effect on the Blood Volume of Pulmonary Capillaries

Journal of Biomechanical Engineering ◽

10.1115/1.3108420 ◽

1988 ◽

Vol 110 (2) ◽

pp. 150-154 ◽

Cited By ~ 2

Author(s):

Jen-shih Lee ◽

Timothy Fallon ◽

Margaret Hunter ◽

Qiang Ye ◽

Lian-pin Lee

Keyword(s):

Blood Volume ◽

Positive Pressure Ventilation ◽

Transpulmonary Pressure ◽

Intermittent Positive Pressure Ventilation ◽

Positive Pressure ◽

Respiratory Effect ◽

Negative Pressure Ventilation ◽

Aortic Blood ◽

Pulmonary Capillaries ◽

Ventilation Method

We measured the density variations of aortic blood from rabbits ventilated by a positive end inspiratory pressure of 6 mmHg or a negative box pressure of the same magnitude. When calculated from the density variations, the fluctuations in blood volume of the pulmonary capillaries within one cycle as induced by an intermittent positive pressure ventilation were found to be similar to the ones induced by an intermittent negative pressure ventilation. Using these volumetric fluctuations as a means to assess the transpulmonary pressure and the transmural pressure across the pulmonary capillaries, we conclude that the switching of the ventilation method did not alter the cyclic fluctuations of these pressures.

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Interventional Bronchoscopy in the Management of Chronic Obstructive Lung Disease

Current Respiratory Medicine Reviews ◽

10.2174/1573398x15666190211155026 ◽

2019 ◽

Vol 15 (2) ◽

pp. 133-139 ◽

Cited By ~ 1

Author(s):

Semra Bilaçeroğlu

Keyword(s):

Management Strategies ◽

Chronic Obstructive Lung Disease ◽

Lifestyle Changes ◽

Airflow Limitation ◽

Chronic Obstructive ◽

Interventional Bronchoscopy ◽

Obstructive Pulmonary Disease ◽

Mucosal Regeneration ◽

Therapeutic Modalities ◽

Collateral Ventilation

Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, hyperinflation and reduced gas exchange that lead to progressive dyspnea. Pulmonary rehabilitation, lifestyle changes, pharmacotherapy, long-term oxygen therapy, noninvasive ventilation and surgical therapeutic approaches are the basic management strategies. Purpose: In the last 15 years, various bronchoscopic therapeutic modalities have emerged for severe COPD. The aim of this review is to summarize the effects of these bronchoscopic treatments compared with lung rehabilitation and pharmacological therapies. Methods: A PubMed search for the eligible studies and reviews on interventional bronchoscopy and COPD has been conducted. Results: Bronchoscopic lung volume reduction (LVR) techniques are targeted to reduce hyperinflation. The efficacy of reversible valve implantation has been confirmed in several randomized controlled trials. It provides clinical benefit in the absence of interlobar collateral ventilation. Nonblocking bronchoscopic LVR with coils, thermal vapor or sealants is independent of collateral ventilation but has not been studied sufficiently. Partially irreversible coil implantation leads to parenchymal compression while irreversible LVR with thermal vapor or sealants induce an inflammatory reaction. Targeted lung denervation ablates parasympathetic pulmonary nerves in COPD for sustainable bronchodilation, and liquid nitrogen metered cryospray destroys hyperplastic goblet cells and excessive submucous glands in the central airways to induce mucosal regeneration in chronic bronchitis. Conclusion: The best-examined bronchoscopic LVR method is the valve therapy. The data from the other modalities are still limited. Further studies are required to select the patients that will optimally benefit from a particular treatment and to predict and treat the procedure-related complications.

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Size of pores of Kohn: influence of transpulmonary and vascular pressures

Journal of Applied Physiology ◽

10.1152/jappl.1981.51.3.739 ◽

1981 ◽

Vol 51 (3) ◽

pp. 739-745 ◽

Cited By ~ 3

Author(s):

R. W. Mazzone ◽

S. Kornblau

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Pore Size ◽

Minimum Diameter ◽

Transmission Electron ◽

Zone Ii ◽

The Mean ◽

Alveolar Septa ◽

Collateral Ventilation

We investigated the influence of transpulmonary (Ptp) and vascular pressures on the size of the pores of Kohn in primary alveolar septa. Dogs lungs, perfused and ventilated in situ, were rapidly frozen with Freon 22 in zone II or III conditions following deflation to Ptp of 5, 15, or 25 cmH2O. Frozen samples were freeze-substituted for transmission electron microscopy. Five fields containing at least one pore each were selected randomly from each section of tissue, and the minimum diameter visible in the cut section was measured. For both zone II and III conditions, as Ptp increased, mean pore size increased. The mean pore size under zone III conditions was 1.2015, 1.788, and 2.249 micrometer for Ptp of 5, 15, and 25 cmH2O, respectively. For zone 2 conditions, the corresponding values were 1.1438, 1,8757, and 2.08 micrometer. For both zones II and III, increasing capillary hydrostatic pressure had no significant effect on pore size. The results support the notion that alveolar pores can increase collateral ventilation by dynamically stretching as Ptp increases. Capillary pressure does not influence pore size probably because of collagen fibers, which surround the pore lumen. Presumably, these fibers resist encroachment of capillaries on the pore lumen as vascular pressures increase.

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