WorldWideScience

Sample records for bag-type fiberglass ventilation

  1. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Fadeyi, M.O.; Clausen, Geo;

    2009-01-01

    As ventilation filters accumulate particles removed from the airstream, they become emitters of sensory pollutants that degrade indoor air quality. Previously we demonstrated that an F7 bag-type filter that incorporates activated carbon (a "combination filter") reduces this adverse effect compared...... to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had...... filter and three modifications of a bag-type fiberglass combination filter: the "Heavy" corresponded to a commercially available filter containing 400 g of carbon per square meter of filter area, the "Medium" contained half as much carbon (200 g/m(2)), and the "Light" contained a quarter as much carbon...

  2. Application of fiberglass sucker rods

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, S.G. (Nabla Corporation (US))

    1991-05-01

    Fiberglass sucker rods are assuming a place in artificial-lift technology. This paper briefly describes the manufacturing process and gives some design and operational hints for practical applications. It also describes some mathematical modeling modifications needed for fiberglass wave-equation design programs.

  3. Application of fiberglass sucker rods

    International Nuclear Information System (INIS)

    Fiberglass sucker rods are assuming a place in artificial-lift technology. This paper briefly describes the manufacturing process and gives some design and operational hints for practical applications. It also describes some mathematical modeling modifications needed for fiberglass wave-equation design programs

  4. Chemical properties of reinforcing fiberglass in aggressive media

    Directory of Open Access Journals (Sweden)

    Avdeeva Arina

    2016-01-01

    Full Text Available In this article describe reinforced fiberglass. Fiberglass – fiber or complex yarn, formed from glass. The main application area of fiberglass and fiberglass textile materials is their use as reinforcing elements of fiberglass plastics and composites. For its consideration, conducted laboratory tests were conducted. As a result of the research was chosen the best of the characteristics of fiberglass.

  5. Reinforcement of concrete structures by fiberglass rods

    OpenAIRE

    Avdeeva Arina; Shlykova Inga; Antonova Maria; Barabanschikov Yuri; Belyaeva Svetlana

    2016-01-01

    In this article we introduced conducted experiments to determine the basic characteristics of composite reinforcement fiberglass reinforcement on the example of the same diameter, but with a different number of rovings. We have established strength along the reinforcing fiber and the corresponding class of the steel reinforcement.

  6. Mechanical performance of fiberglass sucker-rod strings

    Energy Technology Data Exchange (ETDEWEB)

    Tripp, H.A.

    1988-08-01

    The natural frequencies of fiberglass sucker-rod strings can be calculated by treating the rod strings as modified spring/mass vibration systems. The ratio of the pumping-unit operating speed to the rod-string natural frequency can then be used as a basis for understanding fiberglass-rod performance and for predicting downhole pump stroke lengths.

  7. New technology for separating resin powder and fiberglass powder from fiberglass-resin powder of waste printed circuit boards.

    Science.gov (United States)

    Li, Jia; Gao, Bei; Xu, Zhenming

    2014-05-01

    New recycling technologies have been developed lately to enhance the value of the fiberglass powder-resin powder fraction (FRP) from waste printed circuit boards. The definite aim of the present paper is to present some novel methods that use the image forces for the separation of the resin powder and fiberglass powder generated from FRP during the corona electrostatic separating process. The particle shape charactization and particle trajectory simulation were performed on samples of mixed non-metallic particles. The simulation results pointed out that particles of resin powder and particles of fiberglass powder had different detach trajectories at the conditions of the same size and certain device parameters. An experiment carried out using a corona electrostatic separator validated the possibility of sorting these particles based on the differences in their shape characteristics. The differences in the physical properties of the different types of particles provided the technical basis for the development of electrostatic separation technologies for the recycling industry. PMID:24678800

  8. 76 FR 78872 - National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing

    Science.gov (United States)

    2011-12-20

    ... Fiberglass Manufacturing AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule; notice of... Pollutants: Mineral Wool Production and Wool Fiberglass Manufacturing.'' The EPA was asked to hold a public... hearing for the proposed Wool Fiberglass Manufacturing rule will be held on January 4, 2012 in Kansas...

  9. Effect of electrospun nanofibers on flexural properties of fiberglass composites

    Science.gov (United States)

    White, Fatima T.

    In the present study, sintered electrospun TEOS nanofibers were interleaved in S2 fiberglass woven fabric layers, and composite panels were fabricated using the heated vacuum assisted resin transfer molding (H-VARTM) process. Cured panels were water jet cut to obtain the flexural test coupons. Flexural coupons were then tested using ASTM D7264 standard. The mechanical properties such as flexural strength, ultimate flexural failure strains, flexural modulus, and fiber volume fraction were measured. The S-2 fiberglass composite with the sintered TEOS electrospun nanofibers displayed lower flexural stiffness and strength as compared to the composites that were fabricated using S-2 fiberglass composite without the TEOS electrospun nanofibers. The present study also indicated that the composites fabricated with sintered TEOS electrospun nanofibers have larger failure strains as compared to the ones that were fabricated without the presence of electrospun nanofibers. The study indicates that the nanoengineered composites have better energy absorbing mechanism under flexural loading as compared to conventional fiberglass composites without presence of nanofibers.

  10. Assisted Ventilation.

    Science.gov (United States)

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  11. Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, I. S.; Bezrukov, A. A.; Pischugin, A. B. [Sredne-Nevskiy Shipyard (SNSZ), 10 Zavodskaya str., c. Pontonniy, Saint-Petersburg (Russian Federation); Bursikov, A. S.; Klimchenko, Y. A.; Marushin, E. L.; Mednikov, A. A.; Rodin, I. Y.; Stepanov, D. B. [The D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), 3 Doroga na Metallostroy, Metallostroy, Saint-Petersburg (Russian Federation)

    2014-01-29

    The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests at room and cryogenic temperatures. Some results of the tests are also given in this paper.

  12. Using fiberglass volumes for VPI of superconductive magnetic systems' insulation

    Science.gov (United States)

    Andreev, I. S.; Bezrukov, A. A.; Bursikov, A. S.; Klimchenko, Y. A.; Marushin, E. L.; Mednikov, A. A.; Pischugin, A. B.; Rodin, I. Y.; Stepanov, D. B.

    2014-01-01

    The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor's PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests at room and cryogenic temperatures. Some results of the tests are also given in this paper.

  13. THE USE OF COMPOSIT MATERIALS ALTERNATIVE FIBERGLASS (COCO FIBERS & RAGS ON FIBERGLASS SHIP IN TRADITIONAL SHIPYARDS BENGKALIS REGENCY

    Directory of Open Access Journals (Sweden)

    Romadhoni Oni

    2015-08-01

    Full Text Available The limitations of the current wood raw material nowadays is  a threat to the traditional shipbuilding business. Besides the material is expensive, it is also about the difficulty in bringing the major raw materials, fiberglass, suchas wood fiber MAT and WR ( Woven Roofing. There is plan issues to ban on the use of the fiber within a certain period  that accelerate the research in making the solution to be environment- free fiber. By doing the mechanical testing of coco fibre and rags, then gained streghth the bending and optimal impact and eligible BKI standard and ASTM D- 790 and ASTM D 638 and also the use of fiberglass reinforcement material fiber alternative is expected to save expenses in making that fiberglass. To reduce the environmental waste product that do not decompose in maintaining our health (avoiding toxic substances against syntetic fiber. The result of bending test of composit and coir fabric is getting by using Bending Elasticity Modulus with average rags of hijab 12,88 Mpa, coco fibre 2,69 Mpa and fiber fabric undershirt 6, 57 Mpa, whereas  for testing the impact obtained average value of rags hijab 0,0808 kg/mm2 coco fibiers-0,16533 kg/mm2 and fiber fabric undershit 0, 00427 kg/mm2

  14. Liquid Ventilation

    OpenAIRE

    Tawfic, Qutaiba A.

    2011-01-01

    Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixt...

  15. THE USE OF COMPOSIT MATERIALS ALTERNATIVE FIBERGLASS (COCO FIBERS & RAGS) ON FIBERGLASS SHIP IN TRADITIONAL SHIPYARDS BENGKALIS REGENCY

    OpenAIRE

    Romadhoni Oni

    2015-01-01

    The limitations of the current wood raw material nowadays is  a threat to the traditional shipbuilding business. Besides the material is expensive, it is also about the difficulty in bringing the major raw materials, fiberglass, suchas wood fiber MAT and WR ( Woven Roofing). There is plan issues to ban on the use of the fiber within a certain period  that accelerate the research in making the solution to be environment- free fiber. By doing the mechanical testing of coco fibre and rags, then ...

  16. An automated method for the layup of fiberglass fabric

    Science.gov (United States)

    Zhu, Siqi

    This dissertation presents an automated composite fabric layup solution based on a new method to deform fiberglass fabric referred to as shifting. A layup system was designed and implemented using a large robotic gantry and custom end-effector for shifting. Layup tests proved that the system can deposit fabric onto two-dimensional and three-dimensional tooling surfaces accurately and repeatedly while avoiding out-of-plane deformation. A process planning method was developed to generate tool paths for the layup system based on a geometric model of the tooling surface. The approach is analogous to Computer Numerical Controlled (CNC) machining, where Numerical Control (NC) code from a Computer-Aided Design (CAD) model is generated to drive the milling machine. Layup experiments utilizing the proposed method were conducted to validate the performance. The results show that the process planning software requires minimal time or human intervention and can generate tool paths leading to accurate composite fabric layups. Fiberglass fabric samples processed with shifting deformation were observed for meso-scale deformation. Tow thinning, bending and spacing was observed and measured. Overall, shifting did not create flaws in amounts that would disqualify the method from use in industry. This suggests that shifting is a viable method for use in automated manufacturing. The work of this dissertation provides a new method for the automated layup of broad width composite fabric that is not possible with any available composite automation systems to date.

  17. Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Mundt, M.; Mathisen, H. M.; Moser, M.;

    Improving the ventilation effectiveness allows the indoor air quality to be significantly enhanced without the need for higher air changes in the building, thereby avoiding the higher costs and energy consumption associated with increasing the ventilation rates. This Guidebook provides easy...

  18. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  19. Ventilation Model

    International Nuclear Information System (INIS)

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post

  20. Ventilation Model

    Energy Technology Data Exchange (ETDEWEB)

    V. Chipman

    2002-10-05

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to

  1. Fiberglass-reinforced glulam beams: mechanical properties and theoretical model

    Directory of Open Access Journals (Sweden)

    Juliano Fiorelli

    2006-09-01

    Full Text Available The glued-laminated lumber (glulam technique is an efficient process for making rational use of wood. Fiber-Reinforced Polymers (FRPs associated with glulam beams provide significant gains in terms of strength and stiffness, and also alter the mode of rupture of these structural elements. In this context, this paper presents a theoretical model for designing reinforced glulam beams. The model allows for the calculation of the bending moment, the hypothetical distribution of linear strains along the height of the beam, and considers the wood has a linear elastic fragile behavior in tension parallel to the fibers and bilinear in compression parallel to the fibers, initially elastic and subsequently inelastic, with a negative decline in the stress-strain diagram. The stiffness was calculated by the transformed section method. Twelve non-reinforced and fiberglass reinforced glulam beams were evaluated experimentally to validate the proposed theoretical model. The results obtained indicate good congruence between the experimental and theoretical values.

  2. Mechanical characterization of composite repairs for fiberglass wind turbine blades

    Science.gov (United States)

    Chawla, Tanveer Singh

    While in service, wind turbine blades experience various modes of loading. An example is impact loading in the form of hail or bird strikes, which might lead to localized damage or formation of cracks a few plies deep on the blade surface. One of the methods to conduct repairs on wind turbine blades that are damaged while in service is hand lay-up of the repair part after grinding out the damaged portion and some of its surrounding area. The resin used for such repairs usually differs from the parent plate resin in composition and properties such as gel time, viscosity, etc. As a result the properties of the repaired parts are not the same as that of the undamaged blades. Subsequent repetitive loading can be detrimental to weak repairs to such an extent so as to cause delamination at the parent-repair bondline causing the repairs to eventually fall off the blade. Thus the strength and toughness of the repair are of critical importance. Initial part of this work consists of an effort to increase repair strength by identifying an optimum hand layup repair resin for fiberglass wind turbine blades currently being manufactured by a global company. As delamination of the repair from the parent blade is a major concern and unidirectional glass fibers along with a polymer resin are used to manufacture blades under consideration, testing method detailed in ASTM D 5528 (Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites) was followed to determine propagation fracture toughness values of the prospective vinyl ester repair resin candidates. These values were compared to those for a base polyester repair resin used by the company. Experimental procedure and results obtained from the above mentioned testing using double cantilever beam (DCB) specimens are detailed. Three new repair resins were shortlisted through mode I testing. It was also found that variation in the depth of the ground top ply of the parent part

  3. [The fiberglass dressing with a hinge and its value in the care of ski injuries].

    Science.gov (United States)

    Schnitzler, M; Hipp, R

    1976-01-22

    Casts for immobilisation of a limb with an artificial external joint can be made light and stable using fiberglass material, because the application of a joint is possible with less material as it is possible using a conventional cast.

  4. The effects on tensile, shear, and adhesive mechanical properties when recycled epoxy/fiberglass is used as an alternative for glass microballoons in fiberglass foam core sandwiches

    Science.gov (United States)

    Wilson, Dru Matthew

    The problem of this study was to determine whether fiberglass foam core sandwiches made with recycled epoxy/fiberglass have equal or better flatwise tension, shear, and peel (adhesion) mechanical properties when compared with composite sandwiches made with industry standard glass microballoons. Recycling epoxy/fiberglass could save money by: (1) reusing cured composite materials, (2) consuming less virgin composite materials, (3) spending less on transportation and disposing of unusable composites, and (4) possibly enabling companies to sell their recycled composite powder to other manufacturers. This study used three mechanical property tests, which included: flatwise tensile test, shear test, and peel (adhesion) test. Each test used 300 samples for a combined total of 900 sandwich test samples for this study. A factorial design with three independent variables was used. The first variable, filler type, had three levels: no filler, microballoon filler, and recycled epoxy/fiberglass filler. The second variable, foam density, had four levels: 3 lb/ft³, 4 lb/ft³, 5 lb/ft³, and 6 lb/ft³. The third variable, filler percentage ratio, had eight levels: 0%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. The results of this study revealed two primary conclusions. The first conclusion was that sandwich test panels produced with recycled epoxy/fiberglass powder were equal or significantly better in tensile, shear, and peel (adhesion) strength than sandwiches produced with hollow glass microballoons. The second conclusion was that sandwich test panels produced with recycled epoxy/fiberglass powder were equal or significantly lighter in weight than sandwiches produced with hollow glass microballoons.

  5. CALCULATION ASSESSMENT OF ANCHORAGE IN CONCRETE FOR FIBERGLASS REINFORCEMENT MANUFACTURED IN THE REPUBLIC OF BELARUS

    OpenAIRE

    E. Ya. Sadin

    2016-01-01

    The paper analyzes advantages and disadvantages of composite reinforcement while reinforcing concrete structures. Results of experimental investigations on adhesion strength of fiberglass reinforcement manufactured in the Republic of Belarus with concrete have been given in the paper. The paper contains an analysis pertaining to the influence of concrete contact diameter and length of fiberglass reinforcing bars on strength and deformability of adhesion with concrete. Failure behavior of prot...

  6. Fiberglass wastes/polyester resin composites: mechanical properties and water sorption

    OpenAIRE

    Edcleide M. Araújo; Kasselyne D. Araújo; Osanildo D. Pereira; Pollyana C. Ribeiro; Tomás J. A. de Melo

    2006-01-01

    The mechanical properties of polyester/fiberglass composites were studied. The aim of this work was to evaluate the possibility of reusing the wastes taken from spray-up processing of Paraíba state Industries as reinforcement in polyester matrix composites. Composites with 20, 30, 40, 50 and 60 wt. (%) of recycled fiberglass were prepared by compression molding and compared with polyester/ virgin glass fiber composites. The mechanical properties and water sorption behavior were evaluated. The...

  7. Synthesis and characterization of silver-nanoparticle-impregnated fiberglass and utility in water disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Nangmenyi, Gordon; Yue Zhongren; Economy, James [Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, 1304 West Green Street, Urbana, IL 61801 (United States); Mehrabi, Sharifeh; Mintz, Eric, E-mail: nameni@alumni.brown.ed [Department of Chemistry, Clark Atlanta University, 223 James P Brawley Drive SW, Atlanta GA 20214 (United States)

    2009-12-09

    A number of researchers have deployed silver (Ag) nanoparticles through a number of techniques on various substrates including carbon, zeolites and polymers for water disinfection applications. However, Ag impregnated on an inorganic fiberglass surface through a simple electroless process was only recently reported for the first time. Fiberglass impregnated with Ag nanoparticles displays superior performance over carbon-based silver support systems but little is known about the factors that affect the architecture of the system, its interfacial properties and its consequent bactericidal activity. In this study, Ag content and particle size on a fiberglass substrate were manipulated by adjusting the AgNO{sub 3} concentration, immersion time, temperature, solution pH and reduction temperature. The reduction chemistry of the Ag-nanoparticle-impregnated fiberglass is described and supported with thermal gravimetric analysis (TGA) and photoelectron spectroscopy (XPS) measurements. The Ag content along with the particle size and particle size distribution were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). The Ag content on the fiberglass mats ranged from 0.04 to 4.7 wt% Ag/g-fiber with a size distribution of 10-900 nm under standard processing conditions. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Ag desorption from the fiberglass substrate, while the bactericidal properties were evaluated against Escherichia coli (E. coli).

  8. Structural integrity tests on cement fiberglass/asbestos panels

    International Nuclear Information System (INIS)

    During the seismic upgrade walkdowns of some of the Savannah River Site (SRS) facilities, a number of partition walls were encountered. These walls are constructed from 1/4 inch cement fiberglass or cement asbestos wallboard panels. Some of the partition walls are located in close proximity to safety related equipment like relay cabinets containing essential relays. Light weight safety related equipment like electric conduits and panels are commonly attached to these walls. Occasionally, heavier equipment such as a transformer may also be found. To maintain functionality of the safety related equipment during a seismic event, structural integrity of the walls is required. Additionally, any structural failure of the walls could pose an interaction hazard to adjacently located relay cabinets resulting in spurious actuation of essential relays. In the absence of published structural capacities specific to SRS construction characteristics, a series of tests were performed to assess the capacity of various wall features. This paper discusses the different types of tests performed to measure the structural capacity of various wall features. The results of the tests are presented

  9. Displacement Ventilation

    DEFF Research Database (Denmark)

    Bjørn, Erik; Mattsson, Magnus; Sandberg, Mats;

    Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment...... influence on contaminant distributions and personal exposures....

  10. Personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analyzed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  11. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor;

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  12. Ventilator-driven xenon ventilation studies

    International Nuclear Information System (INIS)

    A modification of a common commerical Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilator rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration

  13. Naturlig ventilation med varmegenvinding

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2006-01-01

    Naturlig ventilation i kontorbyggerier har været et alternativ til me-kanisk ventilation i små 10 år. Naturlig ventilation har den klare fordel, at der ikke forbruges elenergi ved ventilering af bygningen, fordi ventilatorer ikke er påkrævet. Imidlertid lider naturlig ventila-tion under de ulemper...

  14. Spectrum Fatigue Lifetime and Residual Strength for Fiberglass Laminates; TOPICAL

    International Nuclear Information System (INIS)

    This report addresses the effects of spectrum loading on lifetime and residual strength of a typical fiberglass laminate configuration used in wind turbine blade construction. Over 1100 tests have been run on laboratory specimens under a variety of load sequences. Repeated block loading at two or more load levels, either tensile-tensile, compressive-compressive, or reversing, as well as more random standard spectra have been studied. Data have been obtained for residual strength at various stages of the lifetime. Several lifetime prediction theories have been applied to the results. The repeated block loading data show lifetimes that are usually shorter than predicted by the most widely used linear damage accumulation theory, Miner's sum. Actual lifetimes are in the range of 10 to 20 percent of predicted lifetime in many cases. Linear and nonlinear residual strength models tend to fit the data better than Miner's sum, with the nonlinear providing a better fit of the two. Direct tests of residual strength at various fractions of the lifetime are consistent with the residual strength models. Load sequencing effects are found to be insignificant. The more a spectrum deviates from constant amplitude, the more sensitive predictions are to the damage law used. The nonlinear model provided improved correlation with test data for a modified standard wind turbine spectrum. When a single, relatively high load cycle was removed, all models provided similar, though somewhat non-conservative correlation with the experimental results. Predictions for the full spectrum, including tensile and compressive loads were slightly non-conservative relative to the experimental data, and accurately captured the trend with varying maximum load. The nonlinear residual strength based prediction with a power law S-N curve extrapolation provided the best fit to the data in most cases. The selection of the constant amplitude fatigue regression model becomes important at the lower stress, higher

  15. Numerical-analytical study of orthotropic viscoelasticity of fiberglass illustrated by repair layer of main pipeline

    OpenAIRE

    Львов, Г. I.; Мартиненко, В. Г.

    2014-01-01

    In this paper a numerical-analytical study on a stress-strain state of a steel pipeline section with a repair fiberglass viscoelastic layer is described. The layer is considered long enough that allows to solve the problem in a flat axisymmetric statement. A mathematical model of viscoelastic behavior of a fiber-glass is proposed, moreover this model allows to simulate an order of anisotropy of viscoelastic proper-ties that exceeds an order of anisotropy of elastic ones. To mirror viscoelasti...

  16. 40 CFR 63.5787 - What if I also manufacture fiberglass boats or boat parts?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What if I also manufacture fiberglass boats or boat parts? 63.5787 Section 63.5787 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic...

  17. Analysis of Energy Saving Potential and Optimization of Thermally Broken Fiberglass Window Frames

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    2011-01-01

    This paper elaborates on the energy saving potential and development process of fiberglass window frames, with intention for application in cold climates. A method is presented, where different means of improving thermal performance of a window frame are evaluated. Firstly, very simple geometries...

  18. Characterization of polyester with fiberglass materials as reinforcement in interior dividing walls

    OpenAIRE

    Santos, Tiago; Velosa, J. C.; Ramos, Luís F.; Fangueiro, Raúl; Mendonça, Paulo

    2012-01-01

    Some synthetic fibers present better mechanical performance compared with the natural fibers. Therefor research works were carried out to focus the characterization of polyester and glass fibers to be used as reinforcements in the internal dividing walls. Results from polyester fabrics made of compression with or without fiberglass were obtained.

  19. A method for designing fiberglass sucker-rod strings with API RP 11L

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, J.W.; Laine, R.E. (Texas A and M University (US))

    1991-02-01

    This paper presents a method for using the API recommended practice for the design of sucker-rod pumping systems with fiberglass composite rod strings. The API method is useful for obtaining quick, approximate, preliminary design calculations. Equations for calculating all the composite material factors needed in the API calculations are given.

  20. A method for designing fiberglass sucker-rod strings with API RP 11L

    International Nuclear Information System (INIS)

    This paper presents a method for using the API recommended practice for the design of sucker-rod pumping systems with fiberglass composite rod strings. The API method is useful for obtaining quick, approximate, preliminary design calculations. Equations for calculating all the composite material factors needed in the API calculations are given

  1. Fatigue testing of low-cost fiberglass composite wind turbine blade materials

    Science.gov (United States)

    Hofer, K. E.; Bennett, L. C.

    1981-01-01

    The static and fatigue behavior of transverse filament tape (TFT) fiberglass/epoxy and TFT/polyester composites was established by the testing of specimens cut from panels fabricated by a filament winding process used for the construction of large experimental wind turbine blades.

  2. VENTILATION NEEDS DURING CONSTRUCTION

    Energy Technology Data Exchange (ETDEWEB)

    C.R. Gorrell

    1998-07-23

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

  3. CALCULATION ASSESSMENT OF ANCHORAGE IN CONCRETE FOR FIBERGLASS REINFORCEMENT MANUFACTURED IN THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    E. Ya. Sadin

    2016-01-01

    Full Text Available The paper analyzes advantages and disadvantages of composite reinforcement while reinforcing concrete structures. Results of experimental investigations on adhesion strength of fiberglass reinforcement manufactured in the Republic of Belarus with concrete have been given in the paper. The paper contains an analysis pertaining to the influence of concrete contact diameter and length of fiberglass reinforcing bars on strength and deformability of adhesion with concrete. Failure behavior of prototypes and maximum loading that does cause breakage in adhesion of fiberglass reinforcement with the concrete have been controlled in order to study the influence of diameter and length of fiberglass reinforcing bar contact with the concrete on strength and deformability of concrete adhesion for composite reinforcement produced by various manufacturers. Displacement of non-loaded (free and loaded ends of the reinforcing bars with regard to concrete exposed face on both specimen ends has been also controlled. The experiments have shown that destruction of the prototypes occurred due to initiation of one of the following three reasons: reinforcement sliding in reference to concrete, cleaving of a protective concrete layer or breakage of composite reinforcement. Start-up moments for reinforcing bar slip in relation to the concrete have been determined with the help of two methods. The paper provides proposals for calculation assessment of anchorage in the concrete for fiberglass reinforcement manufactured by the following enterprises and companies “Stroykompozit” (Gomel, Republic of Belarus, Research and Production Company (RPC “Biznes-Kontinent” (Brest, Republic of Belarus and Private Eenterprise (PE “Minplast” (Minsk, Republic of Belarus.

  4. Mechanical properties of a fiberglass prepreg system at cryogenic and other temperatures

    Science.gov (United States)

    Klich, P. J.; Cockrell, C. E.

    1982-01-01

    The compressor driving the flow in the National Transonic Facility, which is nearing completion at the Langley Research Center, has 25 fiberglass blades. E-glass cloth with a pre-impregnated epoxy resin has been selected as the material for the fan blades because of its low cost, high damping, and fatigue resistance. A complete characterization is presented of this fan blade fiberglass system at temperatures of 367 K, room temperature, and 89 K. The characterization test results suggest that the material follows the general trends of metals and other glass-reinforced plastics at cryogenic temperatures. A slight diminution in strength was observed at the elevated temperature. The tests included the following: tensile, compression, fatigue, inplane shear, interlaminar shear, thermal expansion, creep, and thermal cycle.

  5. Evaluation of intake efficiencies and associated sediment-concentration errors in US D-77 bag-type and US D-96-type depth-integrating suspended-sediment samplers

    Science.gov (United States)

    Sabol, Thomas A.; Topping, David J.

    2013-01-01

    of flume and tow tests alone. This study has three interrelated goals. First, the intake efficiencies of the older US D-77 bag-type and newer, FISP-approved US D-96-type1 depth-integrating suspended‑sediment samplers are evaluated at multiple cross‑sections under a range of actual-river conditions. The intake efficiencies measured in these actual-river tests are then compared to those previously measured in flume and tow tests. Second, other physical effects, mainly water temperature and the duration of sampling at a vertical, are examined to determine whether these effects can help explain observed differences in intake efficiency both between the two types of samplers and between the laboratory and field tests. Third, the signs and magnitudes of the likely errors in suspendedsand concentration in measurements made with both types of samplers are predicted based the intake efficiencies of these two types of depth-integrating samplers. Using the relative difference in isokinetic sampling observed between the US D-77 bag-type and D-96-type samplers during river tests, measured differences in suspended-sediment concentration in a variety of size classes were evaluated between paired equal-discharge-increment (EDI) and equal-width-increment (EWI) measurements made with these two types of samplers to determine whether these differences in concentration are consistent with the differences in concentrations expected on the basis of the 1940s FISP laboratory experiments. In addition, sequential single-vertical depth-integrated samples were collected (concurrent with velocity measurements) with the US D-96-type bag sampler and two different rigidcontainer samplers to evaluate whether the predicted errors in suspended-sand concentrations measured with the US D-96- type sampler are consistent with those expected on the basis of the 1940s FISP laboratory experiments. Results from our study indicate that the intake efficiency of the US D-96-type sampler is superior to that

  6. Factors contributing to the temperature beneath plaster or fiberglass cast material

    Directory of Open Access Journals (Sweden)

    Hutchinson Mark R

    2008-02-01

    Full Text Available Abstract Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints, brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period. Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of

  7. DEMAND CONTROLLED VENTILATION AND CLASSROOM VENTILATION

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits

  8. Ventilation and ventilation/perfusion ratios

    International Nuclear Information System (INIS)

    The thesis is based on five different papers. The labelling of specific tracer compounds with positron emitting radionuclides enables a range of structural, physiological and biochemical parameters in the lung to be measured non-invasively, using positron emission tomography. This concept affords a unique opportunity for in vivo studies of different expressions of pulmonary pathophysiology at the regional level. The present thesis describes the application of positron emission tomography to the measurements of ventilation and ventilation/perfusion ratios using inert gas tracers, neon-19 and nitrogen-13 respectively. The validity of the methods applied was investigated with respect to the transport of inert gas tracers in the human lung. Both ventilation and the ventilation/perfusion ratio may be obtained with errors less than 10 % in the normal lung. In disease, however, errors may increase in those instances where the regional ventilation is very low or the intra-regional gas flow distribution is markedly nonuniform. A 2-3 fold increase in ventilation was demonstrated in normal nonsmoking subjects going from ventral to dorsal regions in the supine posture. These large regional differences could be well explained by the intrinsic elastic properties of lung tissue, considering the gravitational gradient in transpulmonary pressure. In asymptomatic smokers substantial regional ventilatroy abnormalities were found whilst the regional gas volume was similar in smokers and nonsmokers. The uncoupling between ventilation and gas volume probably reflects inflammatory changes in the airways. The regional differences in dV/dt/dQ/dt were relatively small and blood flow was largely matched to ventilation in the supine posture. However, small regions of lung with very low ventilation, unmatched by blood flow commonly exists in the most dependent parts of the lung in both smokers and nonsmokers. (29 illustrations, 7 tables, 113 references)

  9. Complications of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Drašković Biljana

    2011-01-01

    Full Text Available Mechanical ventilation of the lungs, as an important therapeutic measure, cannot be avoided in critically ill patients. However, when machines take over some of vital functions there is always a risk of complications and accidents. Complications associated with mechanical ventilation can be divided into: 1 airway-associated complications; 2 complications in the response of patients to mechanical ventilation; and 3 complications related to the patient’s response to the device for mechanical ventilation. Complications of artificial airway may be related to intubation and extubation or the endotracheal tube. Complications of mechanical ventilation, which arise because of the patient’s response to mechanical ventilation, may primarily cause significant side effects to the lungs. During the last two decades it was concluded that mechanical ventilation can worsen or cause acute lung injury. Mechanical ventilation may increase the alveolar/capillary permeability by overdistension of the lungs (volutrauma, it can exacerbate lung damage due to the recruitment/derecruitment of collapsed alveoli (atelectrauma and may cause subtle damages due to the activation of inflammatory processes (biotrauma. Complications caused by mechanical ventilation, beside those involving the lungs, can also have significant effects on other organs and organic systems, and can be a significant factor contributing to the increase of morbidity and mortality in critically ill of mechanically ventilated patients. Complications are fortunately rare and do not occur in every patient, but due to their seriousness and severity they require extensive knowledge, experience and responsibility by health-care workers.

  10. Ventilation Model Report

    International Nuclear Information System (INIS)

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. Revision 01 ICN 01 included the results of the unqualified software code MULTIFLUX to assess the influence of moisture on the ventilation efficiency. The purposes of Revision 02 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of

  11. Behavior of plywood and fiberglass steel composite tube structures subjected to impact loading

    Science.gov (United States)

    Armaghani, Seyamend Bilind

    Paratransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research done on steel subjected to static loads, but more research is needed for steel applied under dynamic loading and high speeds in order to improve crashworthiness in events such as rollovers and side impacts. Bare steel Hollow Structural Section (HSS) tubing are used a lot as structural members of Paratransit buses because of their lightness and progressive buckling under loading. The research will be conducted on quantifying the tubing's behavior under bending by conducting static three point bending and impact loading tests. In addition to the bare tubing, plywood and fiberglass composites are investigated because they are both strong and lightweight and their behavior under dynamic loading hasn't been quantified. As a result, the main purpose of this research is to quantify the differences between the dynamic and static behavior of plywood steel composite and fiberglass steel composite tubing and compare these findings with those of bare steel tubing. The differences will be quantified using detailed and thorough experiments that will examine the composites behavior under both static and dynamic loading. These tests will determine if there are any advantages of using the composite materials and thus allow for recommendations to be made to the FDOT with the goal of improving the safety of Paratransit busses. Tensile tests were conducted to determine the material properties of the tested specimens. Before the static and dynamic experiments are run to investigate the differences

  12. Mechanical Characteristics of Rattan Reinforced Fiberglass and Epoxy Composites for Shank Prosthesis Application

    Directory of Open Access Journals (Sweden)

    Agustinus Purna Irawan

    2016-06-01

    Full Text Available This research aims to develop a rattan laminated fiberglass epoxy resin materials (RLFERM to increase of mechanical strength especially in tensile, compressive, impact and flexural strength. The RLFERM will be used as an alternative material for shank prosthesis endoskeletal type and another use in engineering design. This research is related to the utilization of the natural potential of Indonesia especially of rattan. The method used to produce the endoskeletal material by using laminated process of rattan with fiberglass and epoxy resin. The test conducted involves the tensile, compressive, impact and flexural strength. The result showed that there was an increase in strength of RLFERM compared with rattan without lamination (Natural Rattan, NR. Tensile strength of RLFERM (80.2 MPa and E = 8.6 GPa increased by 67.8% when compared to the tensile strength of NR (47.8 MPa and E = 6.4 GPa. Compressive strength of RLFERM increased 47.2%, from 31.8 MPa to 46.8 MPa, impact strength of RLFERM increased 64%, from 39 kJ/m2 to 64 kJ/m2, and flexural strength of RLFERM increased on average by 53% from 54.1 MPa to 82.3 MPa. Increasing strength of RLFERM is obtained from good interface between surface of rattan with fiberglass and epoxy resin as laminate. The first prototype of lower limb prosthesis with a shank prosthesis endoskeletal type of RLFERM, have been made with good results and tested for use by patient. The test results indicate that the lower limb prosthesis with a shank prosthesis components made from RLFERM can be used by patients to walk properly and has good strength. This result will be a reference for further research in the development of a shank prosthesis made from rattan and another use in engineering design.

  13. Design Principles for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system -Hybrid Ventilation....... The hybrid ventilation concepts, design challenges and - principles are discussed and illustrated by four building examples....

  14. Recycling of glass fibers from fiberglass polyester waste composite for manufacture glass-ceramic materials

    OpenAIRE

    López Gómez, Félix Antonio; Martín, M. Isabel; García Díaz, Irene; Rodríguez, O.; Alguacil, Francisco José; Romero, M.

    2012-01-01

    This work presents the feasibility of reusing a glass fiber resulting from the thermolysis and gasification of waste composites to obtain glass-ceramic tiles. Polyester fiberglass (PFG) waste was treated at 550˚C for 3 h in a 9.6 dm3 thermolytic reactor. This process yielded an oil (≈24 wt%), a gas (≈8 wt%) and a solid residue (≈68 wt%). After the polymer has been removed, the solid residue is heated in air to oxidize residual char and remove surface contamination. The cleaning fibers were co...

  15. Development of steel head joints with fiberglass sucker rod on the base of contact stresses investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kopey, B.V.; Kopey, L.B. [Ivano-Frankivsk State Technical Oil and Gas University (Ukraine); Maksymuk, A.V.; Shcherbyna, N.M. [National Ukrainian Academy of Sciences (Ukraine)

    1998-12-31

    The methods of calculation of contact stresses during cylinder shell tube - steel bandage interaction are presented. Tymoshenko`s generalized theory of shells serves as a basis for investigating steel head to fiberglass sucker rod joint strength. This theory allows to consider mechanical performance of composite materials. The problem is reduced to solving Fredholm integral equation of second degree. The numeric analysis is performed. Several joints of composite body with steel head are proposed. The full-size sucker rod fatigue tests are performed to determine the fatigue limit under the bending and axial cyclic loads in the medium of oil well fluids. (orig.)

  16. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  17. Ventilation-perfusion scintigraphy

    International Nuclear Information System (INIS)

    A historical review of different investigation methods measuring lung function (perfusion and gas exchange) is given. The principles and handling of some ventilation methods using radioxenon, radiokrypton or radiolabelled aerosols, and the injection method of xenon are explained. The clinical applicability of these studies is evaluated considering ventilation and perfusion lung defects and congestive heart failure. The combination of the three principal techniques (perfusion scintigraphy using MAA, ventilation scintigraphy using radioxenon or radiokrypton, perfusion and ventilation scientigraphy after injection of radioxenon) lead to typical patterns of differential diagnosis of perfusion defects. (TRV)

  18. Noninvasive ventilation in trauma.

    Science.gov (United States)

    Karcz, Marcin K; Papadakos, Peter J

    2015-02-01

    Trauma patients are a diverse population with heterogeneous needs for ventilatory support. This requirement depends mainly on the severity of their ventilatory dysfunction, degree of deterioration in gaseous exchange, any associated injuries, and the individual feasibility of potentially using a noninvasive ventilation approach. Noninvasive ventilation may reduce the need to intubate patients with trauma-related hypoxemia. It is well-known that these patients are at increased risk to develop hypoxemic respiratory failure which may or may not be associated with hypercapnia. Hypoxemia in these patients is due to ventilation perfusion mismatching and right to left shunt because of lung contusion, atelectasis, an inability to clear secretions as well as pneumothorax and/or hemothorax, all of which are common in trauma patients. Noninvasive ventilation has been tried in these patients in order to avoid the complications related to endotracheal intubation, mainly ventilator-associated pneumonia. The potential usefulness of noninvasive ventilation in the ventilatory management of trauma patients, though reported in various studies, has not been sufficiently investigated on a large scale. According to the British Thoracic Society guidelines, the indications and efficacy of noninvasive ventilation treatment in respiratory distress induced by trauma have thus far been inconsistent and merely received a low grade recommendation. In this review paper, we analyse and compare the results of various studies in which noninvasive ventilation was applied and discuss the role and efficacy of this ventilator modality in trauma. PMID:25685722

  19. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health care ...

  20. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  1. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-04-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as material alternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforced plastics single skin. The weakness of this FRP was heavy construction and requires many production time. Therefore, will be checked comparison between single skin with sandwich constructions for shell. In this research, the way for making composite is hand lay up method with three various thickness of skin there are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin, must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesia rules for the fiberglass ship. Based on the result, indicates that optimization skin thickness of sandwich construction applies Coremat which tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes 23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT. Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  2. NEURAL NETWORK ANALYSIS APPLICATION TO PERMEABILITY DETERMINATION OF FIBERGLASS AND CARBON PREFORMS

    Institute of Scientific and Technical Information of China (English)

    Hossein Golestanian; Mehrdad Poursina

    2009-01-01

    Preform permeability is an important process parameter in liquid injection molding of composite parts.This parameter is currently determined with time consuming and expensive experimental procedures.This paper presents the application of a back-propagation neural network to predicting fiber bed permeability of three types of reinforcement mats.Resin flow experiments were performed to simulate the injection cycle of a resin transfer molding process.The results of these experiments were used to prepare a training set for the back propagation neural network program.The reinforcements consisted of plain-weave carbon,plain-weave fiberglass,and chopped fiberglass mats.The effects of reinforcement type,porosity and injection pressure on fiber bed permeability in the preform principal directions were investigated.Therefore,in the training of the neural network reinforcement type,these process parameters were used as the input data.Fiber bed permeability values were the specified output of the program.As a result of the specified parameters,the program was able to estimate fiber bed permeability in the preform principal directions for any given processing condition.The results indicate that neural network may be used to predict preform permeability.

  3. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-02-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as materialalternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforcedplastics single skin. The weakness of this FRP was heavy construction and requires many production time.Therefore, will be checked comparison between single skin with sandwich constructions for shell.In this research, the way for making composite is hand lay up method with three various thickness of skinthere are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin,must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesiarules for the fiberglass ship.Based on the result, indicates that optimization skin thickness of sandwich construction applies Corematwhich tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT.Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  4. Standard practice for examination of fiberglass reinforced plastic fan blades using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examinations of fiberglass reinforced plastic (FRP) fan blades of the type used in industrial cooling towers and heat exchangers. 1.2 This practice uses simulated service loading to determine structural integrity. 1.3 This practice will detect sources of acoustic emission in areas of sensor coverage that are stressed during the course of the examination. 1.4 This practice applies to examinations of new and in-service fan blades. 1.5 This practice is limited to fan blades of FRP construction, with length (hub centerline to tip) of less than 3 m [10 ft], and with fiberglass content greater than 15 % by weight. 1.6 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to evaluate the significance of AE sources. Procedures for other NDE methods are beyond the scope of this practice. 1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as sta...

  5. Diallyl phthalate prepolymer characterization and testing in fiberglass filled molding compounds

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.B.; Schneider, R.E.; Schumacher, R.J.

    1983-02-21

    A program was undertaken to identify an acceptable alternative to Dapon 35, an o-diallyl phthalate (DAP) prepolymer no longer available. Three o-DAP prepolymers from the Osaka Soda Company and four laboratory-scale prepolymers from Bendix-Kansas city were characterized and evaluated in DAP-fiberglass molding compounds. Gel permeation chromatography results for the Osaka prepolymers showed all three to be very close to one another in molecular weights (mw) and mw distributions, but slightly lower in both than Dapon 35. They are also slightly higher in monomer content. All three processed readily into DAP-fiberglass molding compounds and passed required physical property tests. One Osaka prepolymer was compounded into both asbestos and Orlon-DAP compounds on a production scale. Both compounds have passed all certification tests. The Bendix prepolymers were deliberately varied in mw and mw distribution and higher in monomer content than Dapon 35. Processing difficulties were encountered with both the lowest and highest molecular weight compounds, and the lowest molecular weight compound failed a number of physical property tests. The two intermediate molecular weight compounds processed readily and passed property tests. Guidelines were established for acceptable o-DAP prepolymers: (1) weight average mw (relative to polystyrene standards): 30,000 to 150,000; (2) mw distribution: 3.0 to less than or equal to 18.0; and (3) DAP monomer content: 1.0 to less than or equal to 6.0%. 5 figures, 6 tables.

  6. Ventilation rates and health

    DEFF Research Database (Denmark)

    Sundell, Jan; Levin, H; Nazaroff, W W;

    2011-01-01

    studies of the relationship between ventilation rates and health, especially in diverse climates, in locations with polluted outdoor air and in buildings other than offices. PRACTICAL IMPLICATIONS: Ventilation with outdoor air plays an important role influencing human exposures to indoor pollutants...

  7. VENTILATION MODEL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    V. Chipman

    2002-10-31

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses.

  8. Multifamily Ventilation Retrofit Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K. [Building Science Corporation (BSC), Somerville, MA (United States); Lstiburek, J. [Building Science Corporation (BSC), Somerville, MA (United States); Bergey, D. [Building Science Corporation (BSC), Somerville, MA (United States)

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  9. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  10. High-frequency ventilation.

    Science.gov (United States)

    Crawford, M R

    1986-08-01

    Over the last six years high-frequency ventilation has been extensively evaluated both in the clinical and laboratory settings. It is now no longer the great mystery it once was, and it is now no longer believed (as many had hoped), that it will solve all the problems associated with mechanical pulmonary ventilation. Although the technique is safe and appears to cause no harm even in the long term, it has not yet been shown to offer any major advantages over conventional mechanical ventilation. PMID:3530042

  11. EVALUATION OF FUNGAL GROWTH ON FIBERGLASS DUCT MATERIALS FOR VARIOUS MOISTURE, SOIL, USE, AND TEMPERATURE CONDITIONS (JOURNAL)

    Science.gov (United States)

    The paper gives results of a series of experiments, each lasing 6 weeks, conducted in static environmental chambers to assess some of the conditions that may impact the ability of a variety of fiberglass materials to support the growth of a fungus, Penicillium chrysogenum. (NOTE:...

  12. Holographic nondestructive tests performed on composite samples of ceramic-epoxy-fiberglass sandwich structure

    Science.gov (United States)

    Kurtz, R. L.; Liu, H. K.

    1974-01-01

    When a hologram storing more than one wave is illuminated with coherent light, the reconstructed wave fronts interfere with each other or with any other phase-related wave front derived from the illuminating source. This multiple wave front comparison is called holographic interferometry, and its application is called holographic nondestructive testing (HNDT). The theoretical aspects of HNDT techniques and the sensitivity of the holographic system to the geometrical placement of the optical components are briefly discussed. A unique HNDT system which is mobile and possesses variable sensitivity to stress amplitude is discribed, the experimental evidence of the application of this system to the testing of the hidden debonds in a ceramic-epoxy-fiberglass structure used for sample testing of the radome of the Pershing missile system is presented.

  13. Interaction of surface waves induced by IDT sensors with flaws in fiberglass composite panels

    Science.gov (United States)

    Na, Jeong K.; Nalladega, Vijay; Druffner, Carl

    2011-04-01

    Polyester resin based glass fiber reinforced composite panels obtained from a local windmill turbine blade part manufacturing company are used to evaluate the performance of inter-digital transducer (IDT) surface wave transducers. Interaction of surface waves with fiberglass layers is addressed in this work. Additionally, artificially created flaws such as cracks, impact damage and delamination are also studied in terms of amplitude changes in order to attempt to quantify the size, location and severity of damage in the test panels. As a potential application to the structural health monitoring (SHM) of windmill turbine blades, the coverage distance within the width of the sound field is estimated to be over 80 cm when a set of IDT sensors consisted of one transmitter and two receivers in a pitch-catch mode.

  14. A Semi-Empirical Airborne Particle Erosion Model for Polyesteric Matrix Fiberglass Composites

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2013-12-01

    Full Text Available The paper deals with the mathematical modeling of the airborne solid particle erosion rate of composite materials, in particular non-oriented fiberglass reinforced polyesteric matrices. Using the mathematical tool of non-linear regression, based on experimental data available in the state of the art, an algebraic equation has been determined to estimate the relative erosion rate of such composites. The formulation is tailored so that it relates to classical erosion models such as Finnie’s, Bitter’s or Tulsa angle dependent model which can be implemented into commercial computational fluid dynamics software. Although the implementation - per se - is not described herein, the model proposed can be useful in estimating the global effect of solid particle erosion on composite materials in this class. Further theoretical developments may add to the model the capacity to evaluate the erosion rate for a wider class of matrices as well as more types of weavings.

  15. Why We Ventilate

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  16. Isotope ventilation diagnosis

    International Nuclear Information System (INIS)

    Nuclear ventilation examinations inform the physician about the regional lung function in cases of localized or generalized lung diseases, thus supplementing the accurate global findings of ventilation physiology. In practice, ventilation examinations are always combined with perfusion examinations as this combination of methods has a higher specificity for certain lung diseases. Indications for nuclear lung examinations are an early detection of lung obstructions, course control, and the judgement of the therapeutic success. To the surge on, combined ventilation-perfusion scintiscanning is a help in deciding about the operability of lung diseases with regard to the residual function after surgery; to the clinician, it is an ideal - non-invasive and non-exerting routine method for the diagnosis of embolisms with a specificity that is similar to that of pulmonary angiography. This facilities a quick therapy and reduces the risk of unnecessary therapeutical interventions. (orig.)

  17. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    and numerical studies on diffuse ceiling ventilation. Performance in terms of thermal comfort, air quality, pressure drop as well as radiant cooling potential are examined. Finally, a discussion on the proper design of the suspended ceiling and plenum to achieve a uniform air distribution and surface......As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role on...... thermal comfort in the occupant zone. Another characteristic of this system is its lower pressure drop compared with conventional ventilation systems, which reduces the noise problem and, at the same time, the energy consumption of the fan can be reduced. This review is based on a number of experimental...

  18. Noninvasive ventilation in trauma

    OpenAIRE

    Karcz, Marcin K; Peter J. Papadakos

    2015-01-01

    Trauma patients are a diverse population with heterogeneous needs for ventilatory support. This requirement depends mainly on the severity of their ventilatory dysfunction, degree of deterioration in gaseous exchange, any associated injuries, and the individual feasibility of potentially using a noninvasive ventilation approach. Noninvasive ventilation may reduce the need to intubate patients with trauma-related hypoxemia. It is well-known that these patients are at increased risk to develop ...

  19. Conventional mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Tobias Joseph

    2010-01-01

    Full Text Available The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU. Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

  20. Clinical challenges in mechanical ventilation.

    Science.gov (United States)

    Goligher, Ewan C; Ferguson, Niall D; Brochard, Laurent J

    2016-04-30

    Mechanical ventilation supports gas exchange and alleviates the work of breathing when the respiratory muscles are overwhelmed by an acute pulmonary or systemic insult. Although mechanical ventilation is not generally considered a treatment for acute respiratory failure per se, ventilator management warrants close attention because inappropriate ventilation can result in injury to the lungs or respiratory muscles and worsen morbidity and mortality. Key clinical challenges include averting intubation in patients with respiratory failure with non-invasive techniques for respiratory support; delivering lung-protective ventilation to prevent ventilator-induced lung injury; maintaining adequate gas exchange in severely hypoxaemic patients; avoiding the development of ventilator-induced diaphragm dysfunction; and diagnosing and treating the many pathophysiological mechanisms that impair liberation from mechanical ventilation. Personalisation of mechanical ventilation based on individual physiological characteristics and responses to therapy can further improve outcomes. PMID:27203509

  1. CFD and Ventilation Research

    DEFF Research Database (Denmark)

    Li, Y.; Nielsen, Peter V.

    2011-01-01

    of scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize...... the growing need for CFD verification and validation, suggest on-going needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical......There has been a rapid growth of scientific literature on the application of computational fluid dynamics (CFD) in the research of ventilation and indoor air science. With a 1000–10,000 times increase in computer hardware capability in the past 20 years, CFD has become an integral part...

  2. Ventilation of radioactive enclosures

    International Nuclear Information System (INIS)

    Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m3). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author)

  3. Ventilator Circuits, Humidification and Ventilator-Associated Pneumonia

    Directory of Open Access Journals (Sweden)

    Dean Hess

    1996-01-01

    Full Text Available Technical issues in the care of mechanically ventilated patients include those related to the ventilator circuit, humidification and ventilator-associated pneumonia. Principal issues related to ventilator circuits include leaks and compression volume. Circuit compression volume affects delivered tidal volume as well as measurements of auto-positive end-expiratory pressure and mixed expired PCO2. Resistance through the ventilator circuit contributes to patient-ventilator dyssynchrony during assisted modes of mechanical ventilation. Adequate humidification of inspired gas is necessary to prevent heat and moisture loss. Common methods of humidification of inspired gas during mechanical ventilation include use of active heated humidifiers and passive artificial noses. Artificial noses are less effective than active humidifiers and are best suited to short term use. With active humidifiers, the circuit can be heated to avoid condensate formation. However, care must be exercised when heated circuits are used to avoid delivery of a low relative humidity and subsequent drying of secretions in the artificial airway. Although pneumonia is a complication of mechanical ventilation, these pneumonias are usually the result of aspiration of pharyngeal secretions and are seldom related to the ventilator circuit. Ventilator circuits do not need to be changed more frequently than weekly for infection control purposes, and the incidence of ventilator-associated pneumonia may be greater with more frequent circuit changes.

  4. 短切玻璃纤维改性PBT的研究%STUDY ON FIBERGLASS CHOPPED STRAND REINFORCED PBT COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    张志坚; 费振宇; 章建忠; 陆建明

    2011-01-01

    The surface treated fiberglass chopped strand reinforced PBT composite was prepared, and the effects of fiberglass on the mechanical properties, color and dimensional stability of the composites were discussed. The results showed that the mechanical properties of PBT were improved, and the composite had good color and dimensional stability. Therefore, the application of PBT was extended.%采用表面处理的短切玻璃纤维改性聚对苯二甲酸丁二酯(PBT),探讨了短切玻璃纤维对PBT力学性能、制品颜色及尺寸的影响.结果表明,短切玻璃纤维可极大地提高PBT的力学性能,改善制品颜色,提高尺寸稳定性,扩大PBT的应用领域.

  5. Demand controlled ventilation; Behovsstyrt ventilasjon

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Henning Holm

    2006-07-01

    The terms CAV and VAV have been known terms for many years in the ventilation business. The terms are also included in building regulations, but the time is now right to focus on demand controlled ventilation (DCV). The new building regulations and the accompanying energy framework underline the need for a more nuanced thinking when it comes to controlling ventilation systems. Descriptions and further details of the ventilation systems are provided (ml)

  6. Experimental analysis of artificial dragonfly wings using black graphite and fiberglass for use in Biomimetic Micro Air Vehicles (BMAVs

    Directory of Open Access Journals (Sweden)

    Nair Praveena

    2015-01-01

    Full Text Available This article examines the suitability of two different materials which are black graphite carbon fiber and red pre-impregnated fiberglass from which to fabricate artificial dragonfly wing frames. These wings could be of use in Biomimetic Micro Aerial Vehicles (BMAV. BMAV are a new class of unmanned micro-sized air vehicles that mimic flying biological organisms. Insects, such as dragonflies, possess corrugated and complex vein structures that are difficult to mimic. Simplified dragonfly wing frames were fabricated from these materials and then a nano-composite film was adhered to them, which mimics the membrane of an actual dragonfly. Experimental analysis of these results showed that although black graphite carbon fiber and red pre-impregnated fiberglass offer some structural advantages, red pre-impregnated fiberglass was a less preferred option due to its warpage and shrinking effects. Black graphite carbon fiber with its high load bearing capability is a more suitable choice for consideration in future BMAV applications.

  7. Lung Ventilation/Perfusion Scan

    Science.gov (United States)

    ... two types of scans: ventilation and perfusion. The ventilation scan shows where air flows in your lungs. The perfusion scan shows where blood flows in your lungs. Both scans use radioisotopes (a low-risk radioactive substance). For the ventilation scan, you ...

  8. Hybrid Ventilation Air Flow Process

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols

    The scope of this annex is therefore to obtain better knowledge of the use of hybrid ventilation technologies. The annex focus on development of control strategies for hybrid ventilation, on development of methods to predict hybrid ventilation performance in office buildings and on implementation...

  9. Synthesis on the durability of composite fiberglass/epoxy resin structures

    International Nuclear Information System (INIS)

    The purpose of this paper is to collect together in a systematic way information and results relating to the durability of composite fiberglass/ epoxy resin structures. First it is a matter of assessing the average level of understanding the long term behaviour of these structures which change under the combined effects of varied mechanical loading and stresses of a physico-chemical type linked to the environment. Looking at phenomena encountered and facts from current analyses, it will then be advisable to specify a methodology which can be applied to industrial piping used in PWR cooling systems for transporting raw water under pressure. In fact assessment of their service life is at present based on long and costly testing (ASTM D 2992 B standard), the appearance of which is inherited from metal piping testing.. Therefore it appears essential to study substitution test procedures, more composite specific and at the same time which can be conducted in reasonable time. For this purpose, by coherently accelerating and combining them in order not to underestimate their effects, ageing tests shall reproduce mechanisms representative of operating conditions. (author)

  10. Non-destructive Evaluation of Bonds Between Fiberglass Composite and Metal

    Science.gov (United States)

    Zhao, Selina; Sonta, Kestutis; Perey, Daniel F.; Cramer, K. E.; Berger, Libby

    2015-01-01

    To assess the integrity and reliability of an adhesive joint in an automotive composite component, several non-destructive evaluation (NDE) methodologies are correlated to lap shear bond strengths. A glass-fabric-reinforced composite structure was bonded to a metallic structure with a two-part epoxy adhesive. Samples were subsequently cut and tested in shear, and flaws were found in some areas. This study aims to develop a reliable and portable NDE system for service-level adhesive inspection in the automotive industry. The results of the experimental investigation using several NDE methods are presented and discussed. Fiberglass-to-metal bonding is the ideal configuration for NDE via thermography using excitation with induction heating, due to the conductive metal and non-conductive glass-fiber-reinforced composites. Excitation can be either by a research-grade induction heater of highly defined frequency and intensity, or by a service-level heater, such as would be used for sealing windshields in a body shop. The thermographs thus produced can be captured via a high-resolution infrared camera, with principal component analysis and 2D spatial Laplacian processing. Alternatively, the thermographs can be captured by low resolution thermochromic microencapsulated liquid crystal film imaging, which needs no post-processing and can be very inexpensive. These samples were also examined with phased-array ultrasound. The NDE methods are compared to the lap shear values and to each other for approximate cost, accuracy, and time and level of expertise needed.

  11. A bench scale study of a one-step dissolution process for treating contaminated fiberglass filters

    International Nuclear Information System (INIS)

    High efficiency mist eliminators (HEME) and high efficiency particulate air filters (HEPA) made of High fiberglass will be used at the Savannah River Site (SRS) to remove particulate matter from offgases generated during melter feed preparation and vitrification of high-level radioactive waste (HLW) at the Defense Waste Processing Facility (DWPF). These filters will be contaminated with high-level, radioactive species and also with various high-boiling organic compounds. For this reason, a process was developed at the Savannah River Technology Center (SRTC) that will dissolve the spent filters so that the residues may be recycled to the HLW tanks for eventual vitrification. This process involves boiling the filters sequentially in NaOH, HN03 and NaOH, while contained in a stainless steal wire mesh frame assembly. The objective of this communication is to present some of the original preliminary work done by Ritter on the simple one-step dissolution process. The results from six bench-scale experiments are reported for the dissolution of an organically-fouled sample of HEME obtained from the Integrated DWPF Melter (IDMS) offgas filtration system. The preliminary effects of filter packing density, air sparging versus rotating basket agitation, fouling, and adding Triton X-405 as a dispersing agent are reported

  12. Defect Detection of Fiberglass Composite Laminates (FGCL) with Ultrasonic A-Scan Signal Measurement

    Science.gov (United States)

    Mahmod, M. F.; Abu Bakar, Elmi; Othman, A. R.

    2016-02-01

    Fiberglass composite laminates are widely used in many industries, due to its advantages of high specific strength and high specific modulus. Invisible defect such as delamination and inclusion may cause composite structural failure. Therefore, several research on ultrasonic testing for composite material defect detection have been done for the past few years. However, improper parameter setup may lead to significant error to determine the behavior of defects. In this paper, the intensive study on defect detection with ultrasonic single crystal immersion transducer has been conducted. In general, the defects detection thru acquired signal is determine the behavior of defects through the certain ultrasonic parameter setup such as sound velocity, pulse width, gain, sampling rate and transducer distance with specimen surface. Furthermore, an A-scan signal interpretation for FGCL defect detection is demonstrated and illustrated. This research is focusing on for FGCL with maximum thickness up to 10 mm in ambient temperature. The result shows an appropriate ultrasonic parameter will result better signal interpretation analysis.

  13. Space station ventilation study

    Science.gov (United States)

    Colombo, G. V.; Allen, G. E.

    1972-01-01

    A ventilation system design and selection method which is applicable to any manned vehicle were developed. The method was used to generate design options for the NASA 33-foot diameter space station, all of which meet the ventilation system design requirements. System characteristics such as weight, volume, and power were normalized to dollar costs for each option. Total system costs for the various options ranged from a worst case $8 million to a group of four which were all approximately $2 million. A system design was then chosen from the $2 million group and is presented in detail. A ventilation system layout was designed for the MSFC space station mockup which provided comfortable, efficient ventilation of the mockup. A conditioned air distribution system design for the 14-foot diameter modular space station, using the same techniques, is also presented. The tradeoff study resulted in the selection of a system which costs $1.9 million, as compared to the alternate configuration which would have cost $2.6 million.

  14. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  15. Human response to ductless personalized ventilation coupled with displacement ventilation

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Veselý, Michal; Melikov, Arsen K.

    2012-01-01

    A human subject experiment was carried out to investigate the extent to which ductless personalized ventilation (DPV) in conjunction with displacement ventilation can improve perceived air quality (PAQ) and thermal comfort at elevated room air temperature in comparison with displacement ventilation...... alone. The experimental conditions comprised displacement ventilation alone (room air temperature of 23 °C, 26 °C, 29 °C) and DPV with displacement ventilation (26 °C, 29 °C), both operating at supply air temperatures 3, 5 or 6K lower than room air temperature, as well as mixing ventilation (23 °C, 3 K......). During one hour exposure participants answered questionnaires regarding PAQ and thermal comfort. PAQ was significantly better with DPV than without DPV at the same background conditions. Thermal comfort improved when DPV was used. Combining DPV with displacement ventilation showed the potential...

  16. Ventilation-perfusion emission tomography

    International Nuclear Information System (INIS)

    The ventilation-perfusion research with SPECT is discussed. With SPECT three dimensional activity distribution can be made. Perfusion scintigraphy can be done with 99m-Tc labeled particles, ventilation scintigraphy can only be done with 81m-Kr or labeled aerosols. A disadvantage in using 99m-Tc is interference with labeled perfusion tracers. For a reliable quantification the ventilation and perfusion pictures should be registered at the same time, the energies of both tracers must lay far apart and in quantification of regional ventilation from 81m-Kr activity distribution correction must be made for differences in regional specific ventilation. 4 refs.; 3 figs

  17. Optimizing patient-ventilator synchrony.

    Science.gov (United States)

    Epstein, S K

    2001-01-01

    Mechanical ventilation assumes the work of breathing, improves gas exchange, and unloads the respiratory muscles, all of which require good synchronization between the patient and the ventilator. Causes for patient-ventilator dyssynchrony include both patient factors (abnormalities of respiratory drive and abnormal respiratory mechanics) and ventilator factors (triggering, flow delivery, breath termination criteria, the level and mode of ventilator support, and imposed work of breathing). Although patient-ventilator dyssynchrony can often be detected on physical exam, careful analysis of ventilator waveforms (pressure-time, flow-time) allows for more precise definition of the underlying cause. Patient-ventilator interaction can be improved by reversing patient factors that alter respiratory drive or elevate patient ventilatory requirements and by correcting factors that contribute to dynamic hyperinflation. Proper setting of the ventilator using sensitive triggering mechanisms, satisfactory flow rates, adequate delivered minute ventilation, matching machine T(I) to neural T(I), and applying modes that overcome the imposed work of breathing, further optimize patient-ventilator synchrony. PMID:16088669

  18. Design Procedure for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Tjelflaat, Per Olaf

    Mechanical and natural ventilation systems have developed separately during many years. The natural next step in this development is development of ventilation concepts that utilises and combines the best features from each system into a new type of ventilation system - Hybrid Ventilation....... Buildings with hybrid ventilation often include other sustainable technologies and an energy optimisation requires an integrated approach in the design of the building and its mechanical systems. Therefore, the hybrid ventilation design procedure differs from the design procedure for conventional HVAC....... The first ideas on a design procedure for hybrid ventilation is presented and the different types of design methods, that is needed in different phases of the design process, is discussed....

  19. ASHRAE and residential ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the

  20. Ventilator-associated lung injury during assisted mechanical ventilation.

    Science.gov (United States)

    Saddy, Felipe; Sutherasan, Yuda; Rocco, Patricia R M; Pelosi, Paolo

    2014-08-01

    Assisted mechanical ventilation (MV) may be a favorable alternative to controlled MV at the early phase of acute respiratory distress syndrome (ARDS), since it requires less sedation, no paralysis and is associated with less hemodynamic deterioration, better distal organ perfusion, and lung protection, thus reducing the risk of ventilator-associated lung injury (VALI). In the present review, we discuss VALI in relation to assisted MV strategies, such as volume assist-control ventilation, pressure assist-control ventilation, pressure support ventilation (PSV), airway pressure release ventilation (APRV), APRV with PSV, proportional assist ventilation (PAV), noisy ventilation, and neurally adjusted ventilatory assistance (NAVA). In summary, we suggest that assisted MV can be used in ARDS patients in the following situations: (1) Pao(2)/Fio(2) >150 mm Hg and positive end-expiratory pressure ≥ 5 cm H(2)O and (2) with modalities of pressure-targeted and time-cycled breaths including more or less spontaneous or supported breaths (A-PCV [assisted pressure-controlled ventilation] or APRV). Furthermore, during assisted MV, the following parameters should be monitored: inspiratory drive, transpulmonary pressure, and tidal volume (6 mL/kg). Further studies are required to determine the impact of novel modalities of assisted ventilation such as PAV, noisy pressure support, and NAVA on VALI. PMID:25105820

  1. ANALYSIS OF VAPORS FROM METHYLENE CHLORIDE EXTRACTS OF NUCLEAR GRADE HEPA FILTER FIBERGLASS SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    FRYE JM; ANASTOS HL; GUTIERREZ FC

    2012-06-07

    While several organic compounds were detected in the vapor samples used in the reenactment of the preparation of mounts from the extracts of nuclear grade high-efficiency particulate air filter fiberglass samples, the most significant species present in the samples were methylene chloride, phenol, phenol-d6, and 2-fluorophenol. These species were all known to be present in the extracts, but were expected to have evaporated during the preparation of the mounts, as the mounts appeared to be dry before any vapor was collected. These species were present at the following percentages of their respective occupational exposure limits: methylene chloride, 2%; phenol, 0.4%; and phenol-d6, 0.6%. However, there is no established limit for 2-fluorophenol. Several other compounds were detected at low levels for which, as in the case of 2-fluorophenol, there are no established permissible exposure limits. These compounds include 2-chlorophenol; N-nitroso-1-propanamine; 2-fluoro-1,1{prime}-biphenyl; 1,2-dihydroacenaphthylene; 2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimethylethyl); trimethyl oxirane; n-propylpropanamine; 2-(Propylamino)ethanol; 4-methoxy-1-butene; 6-methyl-5-hepten-2-one; and 3,4-dimethylpyridine. Some of these were among those added as surrogates or spike standards as part ofthe Advanced Technologies and Laboratories International, Inc. preparation ofthe extract of the HEPA filter media and are indicated as such in the data tables in Section 2, Results; other compounds found were not previously known to be present. The main inorganic species detected (sulfate, sodium, and sulfur) are also consistent with species added in the preparation of the methylene chloride extract of the high-efficiency particulate air sample.

  2. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...... an acceptable efficiency. Furthermore, solutions to secure the air tightness of the building envelope are suggested. The paper does not address problems with condensate of water in the exchanger that may freeze in cold climate conditions. This complex of problem is dealt with in a separate paper....

  3. Conventional mechanical ventilation

    OpenAIRE

    Tobias Joseph

    2010-01-01

    The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU). Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the ...

  4. Design Principles for Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation....... The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples....

  5. Mechanical ventilation in neurosurgical patients

    OpenAIRE

    Keshav Goyal; Ranadhir Mitra; Shweta Kedia

    2013-01-01

    Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical pa...

  6. Mechanical ventilation in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Keshav Goyal

    2013-01-01

    Full Text Available Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical patient requiring artificial support of the respiration.

  7. Design of 9-meter carbon-fiberglass prototype blades : CX-100 and TX-100 : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Derek (TPI Composites, Inc., Warren, RI)

    2007-09-01

    TPI Composites, Inc. (TPI), Global Energy Concepts, LLC (GEC), and MDZ Consulting (MDZ) have collaborated on a project to design, manufacture, and test prototype carbon-fiberglass hybrid wind turbine blades of 9-m length. The project, funded by Sandia National Laboratories, involves prototype blades in both conventional (unidirectional spar fibers running along the blade span) and ''adaptive'' (carbon fibers in off-axis orientation to achieve bend-twist-coupling) configurations. After manufacture, laboratory testing is being conducted to determine the static and fatigue strength of the prototypes, in conjunction with field testing to evaluate the performance under operational conditions.

  8. Reduction in the thermal resistance (R-value) of loose-fill insulation and fiberglass batts due to compression

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, D.W.; Wright, J.H.

    1981-04-01

    A method is presented for calculating the thickness reduction of loose-fill insulations and fiberglass batts that result from compressive forces exerted by additional insulation. The thickness reduction is accompanied by an increase in density and a reduction in the R value of the compressed layer. Calculations for thermal resistance of two layers of insulation are given. Information in 4 appendices includes: identification of products tested (products from 3 companies); experimental values for thickness as a function of loading; Fortran programs and output; and calculated R values for stacked insulations. (MCW)

  9. Field measurement of ventilation rates.

    Science.gov (United States)

    Persily, A K

    2016-02-01

    Ventilation rates have significant impacts on building energy use and indoor contaminant concentrations, making them key parameters in building performance. Ventilation rates have been measured in buildings for many decades, and there are mature measurement approaches available to researchers and others who need to know actual ventilation rates in buildings. Despite the fact that ventilation rates are critical in interpreting indoor concentration measurements, it is disconcerting how few Indoor Air Quality field studies measure ventilation rates or otherwise characterize the ventilation design of the study building(s). This paper summarizes parameters of interest in characterizing building ventilation, available methods for quantifying these parameters, and challenges in applying these methods to different types of buildings and ventilation systems. These parameters include whole-building air change rates, system outdoor air intake rates, and building infiltration rates. Tracer gas methods are reviewed as well as system airflow rate measurements using, for example, duct traverses. Several field studies of ventilation rates conducted over the past 75 years are described to highlight the approaches employed and the findings obtained. PMID:25689218

  10. Fatigue test of a fiberglass based composite panel. Increasing the lifetime of freight wagon

    Science.gov (United States)

    Sobek, M.; Baier, A.; Grabowski, Ł.; Majzner, M.

    2016-08-01

    In the XXI century transportation of goods plays a key role in the economy. Due to a good logistics the economy is able to grow fluently. Although land transportation is carried out mainly through trucks for the last several years there has been noted an increase in the percentage share of rail transport in the freight transport. The main goods transported by railways are mineral fuels, mining and quarrying products. They constitute the greater part of 70% of total transported goods. Transportation of material of such high weight, high hardness and with different shapes involves increased and accelerated wear and tear of the cargo space of the wagon. This process is also magnified by substances used to prevent overheating or goods theft. Usually they are in the form of chemical compounds powder, eg. Calcium. A very large impact on the wear of the freight wagons hull is made because of mechanical damage. Their source comes mostly from loading cargo with impetus and using heavy machines during unloading. A large number of cycles of loading and unloading during the working period causes abrasion of body and as a result after several years a wagon car qualifies for a major maintenance. Possibility of application composite panels in the process of renovating the wagons body could reduce the weight of whole train and prolong the service life between mandatory technical inspection. The Paper "Fatigue test of a fiberglass based composite panel. Increasing the lifetime of freight wagon" presents the research process and the results of the endurance test of the composite panel samples fixed to a metal plate. As a fixing method a stainless steel rivet nut and a stainless steel button head socket screws were chosen. Cyclic and multiple load were applied to test samples using a pneumatic cylinder. Such a methodology simulated the forces resulting from loading and unloading of the wagon and movement of the cargo during transport. In the study a dedicated stand equipped with a

  11. Monitoring during Mechnical Ventilation

    Directory of Open Access Journals (Sweden)

    Dean Hess

    1996-01-01

    Full Text Available Monitoring is a continuous, or nearly continuous, evaluation of the physiological function of a patient in real time to guide management decisions, including when to make therapeutic interventions and assessment of those interventions. Pulse oximeters pass two wavelengths of light through a pulsating vascular bed and determine oxygen saturation. The accuracy of pulse oximetry is about ±4%. Capnography measures carbon dioxide at the airway and displays a waveform called the capnogram. End-tidal PCO2 represents alveolar PCO2 and is determined by the ventilation-perfusion quotient. Use of end-tidal PCO2 as an indication of arterial PCO2 is often deceiving and incorrect in critically ill patients. Because there is normally very little carbon dioxide in the stomach, a useful application of capnography is the detection of esophageal intubation. Intra-arterial blood gas systems are available, but the clinical impact and cost effectiveness of these is unclear. Mixed venous oxygenation (PvO2 or SvO2 is a global indicator of tissue oxygenation and is affected by arterial oxygen content, oxygen consumption and cardiac output. Indirect calorimetry is the calculation of energy expenditure and respiratory quotient by the measurement of oxygen consumption and carbon dioxide production. A variety of mechanics can be determined in mechanically ventilated patients including resistance, compliance, auto-peak end-expiratory pressure (PEEP and work of breathing. The static pressure-volume curve can be used to identify lower and upper infection points, which can be used to determine the appropriate PEEP setting and to avoid alveolar overdistension. Although some forms of monitoring have become a standard of care during mechanical ventilation (eg, pulse oximetry, there is little evidence that use of any monitor affects patient outcome.

  12. Plane Stratified Flow in a Room Ventilated by Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Nickel, J.; Baron, D. J. G.

    2004-01-01

    The air movement in the occupied zone of a room ventilated by displacement ventilation exists as a stratified flow along the floor. This flow can be radial or plane according to the number of wall-mounted diffusers and the room geometry. The paper addresses the situations where plane flow...

  13. 玻纤布上胶车间通风及净化处理%Ventilation and purification for a fiberglass fabric workshop

    Institute of Scientific and Technical Information of China (English)

    马立

    2005-01-01

    介绍了某玻纤布上胶车间有机溶剂废气处理方案.认为对碳氢化合物有机溶剂先采用局部排风方式收集,再利用现有锅炉进行直接燃烧是较好的净化处理方法.

  14. Permeability and compression of fibrous porous media generated from dilute suspensions of fiberglass debris during a loss of coolant accident

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Saya, E-mail: sayalee@tamu.edu; Abdulsattar, Suhaeb S.; Vaghetto, Rodolfo; Hassan, Yassin A.

    2015-09-15

    Highlights: • Experimental investigation on fibrous debris buildup was conducted. • Head loss through fibrous media was recorded at different approach velocities. • A head loss model through fibrous media was proposed for high porosity (>0.99). • A compression model of fibrous media was developed. - Abstract: Permeability of fibrous porous media has been studied for decades in various engineering applications, including liquid purifications, air filters, and textiles. In nuclear engineering, fiberglass has been found to be a hazard during a Loss-of-Coolant Accident. The high energy steam jet from a break impinges on surrounding fiberglass insulation materials, producing a large amount of fibrous debris. The fibrous debris is then transported through the reactor containment and reaches the sump strainers. Accumulation of such debris on the surface of the strainers produces a fibrous bed, which is a fibrous porous medium that can undermine reactor core cooling. The present study investigated the buildup of fibrous porous media on two types of perforated plate and the pressure drop through the fibrous porous media without chemical effect. The development of the fibrous bed was visually recorded in order to correlate the pressure drop, the approach velocity, and the thickness of the fibrous porous media. The experimental results were compared to semi-theoretical models and theoretical models proposed by other researchers. Additionally, a compression model was developed to predict the thickness and the local porosity of a fibrous bed as a function of pressure.

  15. Permeability and compression of fibrous porous media generated from dilute suspensions of fiberglass debris during a loss of coolant accident

    International Nuclear Information System (INIS)

    Highlights: • Experimental investigation on fibrous debris buildup was conducted. • Head loss through fibrous media was recorded at different approach velocities. • A head loss model through fibrous media was proposed for high porosity (>0.99). • A compression model of fibrous media was developed. - Abstract: Permeability of fibrous porous media has been studied for decades in various engineering applications, including liquid purifications, air filters, and textiles. In nuclear engineering, fiberglass has been found to be a hazard during a Loss-of-Coolant Accident. The high energy steam jet from a break impinges on surrounding fiberglass insulation materials, producing a large amount of fibrous debris. The fibrous debris is then transported through the reactor containment and reaches the sump strainers. Accumulation of such debris on the surface of the strainers produces a fibrous bed, which is a fibrous porous medium that can undermine reactor core cooling. The present study investigated the buildup of fibrous porous media on two types of perforated plate and the pressure drop through the fibrous porous media without chemical effect. The development of the fibrous bed was visually recorded in order to correlate the pressure drop, the approach velocity, and the thickness of the fibrous porous media. The experimental results were compared to semi-theoretical models and theoretical models proposed by other researchers. Additionally, a compression model was developed to predict the thickness and the local porosity of a fibrous bed as a function of pressure

  16. A study of resonant-cavity and fiberglass-filled parallel baffles as duct silencers. [for wind tunnels

    Science.gov (United States)

    Soderman, P. T.

    1982-01-01

    Acoustical performance and pressure drop were measured for two types of splitters designed to attenuate sound propagating in ducts - resonant-cavity baffles and fiberglass-filled baffles. Arrays of four baffles were evaluated in the 7- by 10-foot wind tunnel number 1 at Ames Research Center at flow speeds from 0 to 41 m/sec. The baffles were 2.1 m high, 305 to 406 mm thick, and 3.1 to 4.4 m long. Emphasis was on measurements of silencer insertion loss as affected by variations of such parameters as baffle length, baffle thickness, perforated skin geometry, cavity size and shape, cavity damping, wind speed, and acoustic field directivity. An analytical method for predicting silencer performance is described and compared with measurements. With the addition of cavity damping in the form of 25-mm foam linings, the insertion loss above 250 Hz of the resonant-cavity baffles was improved 2 to 7 db compared with the undamped baffles; the loss became equal to or greater than the insertion loss of comparable size fiberglass baffles at frequencies above 250 Hz. Variations of cavity size and shape showed that a series of cavities with triangular cross-sections (i.e., variable depth) were superior to cavities with rectangular cross sections (i.e., constant depth). In wind, the undamped, resonant-cavity baffles generated loud cavity-resonance tones; the tones could be eliminated by cavity damping.

  17. Recent updates in mechanical ventilation

    OpenAIRE

    Bergamaschi, Valentina; Paolo, Navalesi

    2009-01-01

    Recently, several studies have been performed to better outline the pathophysiology of acute respiratory failure and evaluate the therapeutic profile of different modes of ventilation and ventilator settings. Here we briefly report those we consider most relevant for daily intensive care unit clinical practice.

  18. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... to be the only possible approach to obtain the volume flow in: thermal plumes in ventilated rooms....

  19. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  20. Transtracheal ventilation in oral surgery.

    OpenAIRE

    Terry, R M

    1983-01-01

    The use of transtracheal ventilation as a routine method of ventilation during anaesthesia for 60 patients with gross pathology requiring oral surgery is reported. Theoretical hazards of the technique and protection of the airway are discussed. There were no serious complications in this series. The technique is recommended as a simple and safe alternative to blind nasal intubation.

  1. Lecture Notes on Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The main task of the ventilation system or the air-conditioning system is to supply· and remove air and airborne materials and to supply or remove heat from a room. The necessary level of fresh air will be supplied to· a room by a ventilation system, and heat from equipment or solar radiation can...

  2. Influence of Persons' Movements on Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Brohus, Henrik; Hyldig, Mikkel; Kamper, Simon;

    2008-01-01

    Most often the ventilation effectiveness of a ventilated room is determined without considering the influence of persons´ movements. Even though the main reason for supplying the ventilation may be to create a healthy and productive environment for the occupants, their own influence on the ventil......Most often the ventilation effectiveness of a ventilated room is determined without considering the influence of persons´ movements. Even though the main reason for supplying the ventilation may be to create a healthy and productive environment for the occupants, their own influence...... of different kinds of movement compared with the case of no movements. It is found that mixing ventilation is considerably more robust compared with displacement ventilation. At the same time it is found that displacement ventilation on average is more effective than mixing ventilation when movements prevail...

  3. Solar ventilation and tempering

    Science.gov (United States)

    Adámek, Karel; Pavlů, Miloš; Bandouch, Milan

    2014-08-01

    The paper presents basic information about solar panels, designed, realized and used for solar ventilation of rooms. Used method of numerical flow simulation gives good overview about warming and flowing of the air in several kinds of realized panels (window, facade, chimney). Yearlong measurements give a good base for calculations of economic return of invested capital. The operation of the system in transient period (spring, autumn) prolongs the period without classical heating of the room or building, in winter the classical heating is supported. In the summer period the system, furnished with chimney, can exhaust inner warm air together with necessary cooling of the system by gravity circulation, only. System needs not any invoiced energy source; it is supplied entirely by solar energy. Large building systems are supported by classical electric fan respectively.

  4. Estimation of Lung Ventilation

    Science.gov (United States)

    Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

    Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

  5. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-25

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  6. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-12

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  7. Lecture Notes on Mixing Ventilation

    OpenAIRE

    Nielsen, Peter Vilhelm

    1995-01-01

    The main task of the ventilation system or the air-conditioning system is to supply· and remove air and airborne materials and to supply or remove heat from a room. The necessary level of fresh air will be supplied to· a room by a ventilation system, and heat from equipment or solar radiation can be removed by an air-conditioning system. An industrial ventilation system may both take care of the occupants' comfort and the industrial processes in the area.

  8. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, P.; Nielsen, Peter Vilhelm

    The main objective of ventilation is to provide good air quality for the occupants. For this purpose the necessary ventilating air change rate must be determined. Within displacement ventilation the estimation is closely related to the air flow rate in the thermal plumes when an air quality based...... design method is used. The vertical volume flux in a plume is influenced by many factors. Placement of the flow in relation to surrounding walls is one of them. This reduces the entrainment and is the subject of this article....

  9. Reversal of underground mine ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Ray, S.K.; Sahay, N.; Singh, R.P.; Singh, A.K.; Bhowmick, B.C. [Central Mining Research Institute, Dhanbad (India)

    2002-09-01

    Reversal of main ventilation is one of the important means to isolate a fire during emergency. In America, it has been reported that by fan reversal lives have been saved in underground coal mines. Indian coal mines have so far not come forward to adopt this method. Not much research work has so far been carried out in India. This paper deals with international review of the work carried out in other countries. Laws relating to the reversal of ventilation in different countries of the world is discussed. The effect of reversal on goaf gases and adjustment of ventilation flow is also outlined. 17 refs., 1 fig., 2 tabs.

  10. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Science.gov (United States)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  11. The Use of Fiberglass and Ceramic Cylinders to Support the Root Pass in C-Steel Welds with a Double-V Groove

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes Gurgel

    2015-09-01

    Full Text Available Abstract The aim of this work is to evaluate the effectiveness of fiberglass and ceramic fiber cylinders as root-pass weld backing for a double-V groove in 16 mm-thick carbon steel. Three different cylinder diameters were tested: 4.8, 9.5 mm (fiberglass and 6.4 mm (ceramic fiber. The welding process used was GMAW. The welding technique and the following process variables were investigated: root opening, current and travel speed. The results show that cylindrical fiberglass and ceramic fiber backings not only have excellent refractory properties, but also seal the root opening and contain the weld pool sufficiently to produce a root bead free of discontinuities and with a satisfactory shape and geometry. Working points were defined, together with a possible operating range for the welding parameters. It was concluded that cylindrical fiberglass and ceramic fiber weld backings hold great promise for use in root-pass welds in double-V grooves in applications in the naval and metallurgical industry.

  12. Contaminant Distribution Around Persons in Rooms Ventilated by Displacement Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.

    An optimal design of the ventilation system needs a proper prediction of the velocity, temperature and contaminant distribution in the room. Traditionally this is done either by the use of simplified models or by a somewhat more comprehensive CFD-simulation. Common to both methods is usually the ...... the lack of consideration for the persons present in the room. This paper deals with some of the effects of persons present in a displacement ventilated room, especially the effect on the contaminant distribution....

  13. 46 CFR 168.15-50 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately ventilated in a manner suitable to the purpose of the space and route of the vessel. (b) When mechanical ventilation is provided for... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping...

  14. 30 CFR 57.8520 - Ventilation plan.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation plan. 57.8520 Section 57.8520... Underground Only § 57.8520 Ventilation plan. A plan of the mine ventilation system shall be set out by the... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments...

  15. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  16. A computerized aid in ventilating neonates

    DEFF Research Database (Denmark)

    Arrøe, M

    1991-01-01

    A computer program for ventilating neonates using a volume controlled ventilator is presented. The program proposes directions for changes of ventilator settings decided from the actual arterial blood gas samples and ventilator settings. The program deals with up to six babies at the same time an...

  17. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Power ventilation systems except machinery space ventilation systems. Each power ventilation system...

  18. Newer nonconventional modes of mechanical ventilation.

    Science.gov (United States)

    Singh, Preet Mohinder; Borle, Anuradha; Trikha, Anjan

    2014-07-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient's demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support), Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP), neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief. PMID:25114434

  19. Equivalence in Ventilation and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  20. Newer nonconventional modes of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Preet Mohinder Singh

    2014-01-01

    Full Text Available The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient′s demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support, Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP, neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief.

  1. ENERGY STAR Certified Ventilating Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of...

  2. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

    and with as little energy consumption as 41.1 kWh/m2/year including heating and all building services with no use of renewable energy such as PVcells or solar heating. One of the key means of reaching the objectives was to implement mechanical ventilation with low pressure loss and therefore low energy consumption....... The project consists of two buildings, building one is 6 stories high, and building two is 4 stories high. The buildings have a gross area of 50,500 m2 including underground parking. The ventilation and indoor climate concept was to use mechanical ventilation together with mechanical cooling and fanassisted......, with an average of 1.1 kJ/m3. The yearly mean SFP based on estimated runtime is approx. 0.8 kJ/m3. The case shows the unlocked potential that lies within mechanical ventilation for nearzero energy consuming buildings....

  3. Gas-phase plume from laser-irradiated fiberglass-reinforced polymers via imaging fourier transform spectroscopy.

    Science.gov (United States)

    Acosta, Roberto I; Gross, Kevin C; Perram, Glen P; Johnson, Shane M; Dao, Ly; Medina, David F; Roybal, Robert; Black, Paul

    2014-01-01

    Emissive plumes from laser-irradiated fiberglass-reinforced polymers (FRP) were investigated using a mid-infrared imaging Fourier transform spectrometer, operating at fast framing rates (50 kHz imagery and 2.5 Hz hyperspectral imagery) with adequate spatial (0.81 mm(2) per pixel) and spectral resolution (2 cm(-1)). Fiberglass-reinforced polymer targets were irradiated with a 1064 nm continuous wave neodymium-doped yttrium aluminum garnet (Nd:YAG) laser for 60 s at 100 W in air. Strong emissions from H(2)O, CO, CO(2), and hydrocarbons were observed between 1800 and 5000 cm(-1). A single-layer radiative transfer model was developed for the spectral region from 2000 to 2400 cm(-1) to estimate spatial maps of temperature and column densities of CO and CO(2) from the hyperspectral imagery. The spectral model was used to compute the absorption cross sections of CO and CO(2) using spectral line parameters from the high-temperature extension of the HITRAN. The analysis of pre-combustion spectra yields effective temperatures rising from ambient to 1200 K and suddenly increasing to 1515 K upon combustion. The peak signal-to-noise ratio for a single spectrum exceeds 60:1, enabling temperature and column density determinations with low statistical error. For example, the spectral analysis for a single pixel within a single frame yields an effective temperature of 1019 ± 6 K, and CO and CO(2) column densities of 1.14 ± 0.05 and 1.11 ± 0.03 × 10(18) molec/cm(2), respectively. Systematic errors associated with the radiative transfer model dominate, yielding effective temperatures with uncertainties of >100 K and column densities to within a factor of 2-3. Hydrocarbon emission at 2800 to 3200 cm(-1) is well correlated with CO column density. PMID:25014838

  4. Clinical review: Liberation from mechanical ventilation

    OpenAIRE

    El-Khatib, Mohamad F; Bou-Khalil, Pierre

    2008-01-01

    Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated p...

  5. Reverse ventilation--perfusion mismatch

    Energy Technology Data Exchange (ETDEWEB)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients.

  6. Ventilation Model and Analysis Report

    International Nuclear Information System (INIS)

    This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the host rock thermal conductivity

  7. Mechanical ventilation for severe asthma.

    Science.gov (United States)

    Leatherman, James

    2015-06-01

    Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting. PMID:26033128

  8. Comparison of Pressure Support Ventilation and Proportional Assist Ventilation Modes in Chronic Obstructive Pulmonary Disease Exacerbation

    OpenAIRE

    ŞENGÜL, Aysun; Başyiğit, İlknur; Boyacı, Haşim; Yıldız, Füsun; Ilgazlı, Ahmet

    2013-01-01

    Objective: To compare the effectiveness of pressure support ventilation and proportional assist ventilation which is two modes of non-invasive mechanical ventilation used in the treatment of chronic obstructive pulmonary disease exacerbation. Material and Methods: Total of 20 patients was included in the study. Mean age was 63±7 years. Patients were randomized as proportional assist ventilation and pressure support ventilation groups. Non-invasive mechanical ventilation was per...

  9. Contaminants in ventilated filling boxes

    Science.gov (United States)

    Bolster, D. T.; Linden, P. F.

    While energy efficiency is important, the adoption of energy-efficient ventilation systems still requires the provision of acceptable indoor air quality. Many low-energy systems, such as displacement or natural ventilation, rely on temperature stratification within the interior environment, always extracting the warmest air from the top of the room. Understanding buoyancy-driven convection in a confined ventilated space is key to understanding the flow that develops with many of these modern low-energy ventilation schemes. In this work we study the transport of an initially uniformly distributed passive contaminant in a displacement-ventilated space. Representing a heat source as an ideal sourced of buoyancy, analytical and numerical models are developed that allow us to compare the average efficiency of contaminant removal between traditional mixing and modern low-energy systems. A set of small-scale analogue laboratory experiments was also conducted to further validate our analytical and numerical solutions.We find that on average traditional and low-energy ventilation methods are similar with regard to pollutant flushing efficiency. This is because the concentration being extracted from the system at any given time is approximately the same for both systems. However, very different vertical concentration gradients exist. For the low-energy system, a peak in contaminant concentration occurs at the temperature interface that is established within the space. This interface is typically designed to sit at some intermediate height in the space. Since this peak does not coincide with the extraction point, displacement ventilation does not offer the same benefits for pollutant flushing as it does for buoyancy removal.

  10. Intraoperative mechanical ventilation strategies for one-lung ventilation.

    Science.gov (United States)

    Şentürk, Mert; Slinger, Peter; Cohen, Edmond

    2015-09-01

    One-lung ventilation (OLV) has two major challenges: oxygenation and lung protection. The former is mainly because the ventilation of one lung is stopped while the perfusion continues; the latter is mainly because the whole ventilation is applied to only one lung. Recommendations for maintaining the oxygenation and methods of lung protection can contradict each other (such as high vs. low inspiratory oxygen fraction (FiO2), high vs. low tidal volume (TV), etc.). In light of the (very few) randomized clinical trials, this review focuses on a recent strategy for OLV, which includes a possible decrease in FiO2, lower TVs, positive end-expiratory pressure (PEEP) to the dependent lung, continuous positive airway pressure (CPAP) to the non-dependent lung and recruitment manoeuvres. Other applications such as anaesthetic choice and fluid management can affect the success of ventilatory strategy; new developments have changed the classical approach in this respect. PMID:26643100

  11. Ventilation abnormalities in pulmonary embolus

    International Nuclear Information System (INIS)

    The ventilation scans of 11 patients with angiographically-proven PE were reviewed. All patients had one or more lung perfusion defects. The chest roentgenograph was abnormal in 11 of the patients. The ventilation studies were performed in the posterior positron prior to the perfusion lung scan using Xe-133. The ventilation study consists of washin, equilibrium, and washout images. In four patients with normal washin there was retention of the Xe-133 (delayed washout) at the site of the perfusion defect. All had roentgenographic abnormalities. Another pattern was observed at the sites of some perfusion defects in six patients. In these, there was decreased washin at the perfusion defect location. Two patients had both decreased washin and delayed washout. In only one case was the typical ventilation pattern of normal washin and normal washout. The method of retention is unclear, but may be due to decreased clearance of Xe-133 secondary to decreased blood flow in the area or deposition of some fat soluble component left at the site of embolization. The etiology of the reduced washin is unclear, but may be due to reduced surfactant production. This study suggests that more attention must be paid to the ventilation study, where there may be additional clues to the diagnosis of pulmonary embolus

  12. Residential ventilation standards scoping study

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Sherman, Max H.

    2003-10-01

    The goals of this scoping study are to identify research needed to develop improved ventilation standards for California's Title 24 Building Energy Efficiency Standards. The 2008 Title 24 Standards are the primary target for the outcome of this research, but this scoping study is not limited to that timeframe. We prepared this scoping study to provide the California Energy Commission with broad and flexible options for developing a research plan to advance the standards. This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the ventilation needs of California residences, determining the bases for setting residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and corresponding levels of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  13. Meclofenamate increases ventilation in lambs.

    Science.gov (United States)

    Guerra, F A; Savich, R D; Clyman, R I; Kitterman, J A

    1989-01-01

    To investigate the effects of the prostaglandin synthetase inhibitor, meclofenamate, on postnatal ventilation, we studied 11 unanaesthetised, spontaneously-breathing lambs at an average age of 7.9 +/- 1.1 days (SEM; range 5-14 days) and an average weight of 4.9 +/- 0.5 kg (range 3.0-7.0 kg). After a 30-min control period we infused 4.23 mg/kg meclofenamate over 10 min and then gave 0.23 mg/h per kg for the remainder of the 4 h. Ventilation increased progressively from a control value of 515 +/- 72 ml/min per kg to a maximum of 753 +/- 100 ml/min per kg after 3h of infusion (P less than 0.05) due to an increased breathing rate; the effects were similar during both high- and low-voltage electrocortical activity. There were no significant changes in tidal volume, heart rate, blood pressure, arterial pH or PaCO2, the increased ventilation resulted from either an increase in dead space ventilation or an increase in CO2 production. This study indicates that meclofenamate causes an increase in ventilation in lambs but no changes in pH of PaCO2. The mechanism and site of action remain to be defined. PMID:2507622

  14. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    Directory of Open Access Journals (Sweden)

    Eduardo Mireles-Cabodevila

    2012-01-01

    Full Text Available Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes. Two examples are adaptive support ventilation (ASV and mid-frequency ventilation (MFV. We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70 kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario’s respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3 mL/kg for the clinician, 6.7 to 11.9 mL/kg for ASV, and 3.5 to 9.9 mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme.

  15. Probabilistic Analysis Methods for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Frier, Christian; Heiselberg, Per

    This paper discusses a general approach for the application of probabilistic analysis methods in the design of ventilation systems. The aims and scope of probabilistic versus deterministic methods are addressed with special emphasis on hybrid ventilation systems. A preliminary application...

  16. Physical parameters of the ventilated filter cigarette

    Directory of Open Access Journals (Sweden)

    Đurđanović O.D.

    2003-01-01

    Full Text Available The main physical parameter of all ventilated filter cigarettes is the filter ventilation. It has been known for many years that these cigarettes have a possibility to achieve major reductions in all noxious smoke components including those in the gas phase, and that filter ventilation is a practical tool for controlling smoke deliveries. The term filter ventilation in this case describes the supply of diluting air to the main-stream smoke via the ventilated cigarette filter. Smoking of a lit cigarette is a nonlinear dynamic process, and filter ventilation depends on the interrelationship between a number of factors. Fortunately, the total ventilation measured on an unlit cigarette during constant and standard air flow at mouth end is somewhat lower than for a lit cigarette. It was shown that linear models used here make it possible to estimate filter ventilation degree for various commercial unlit cigarettes from nondestructive pressure measurements and geometrical data.

  17. The practice of mine ventilation engineering

    Institute of Scientific and Technical Information of China (English)

    Wallace Keith; Prosser Brian; Stinnette J. Daniel

    2015-01-01

    The practice of ventilation is continually evolving with new technological advances developed in the mining industry. In recent years the advances in diesel engine technologies, ventilation modeling software, and ventilation management capacities have redefined the historical methods used to evaluate systems. The advances re-evaluate previous methods used to calculate the airflow requirements for the dilution of diesel exhaust fumes. Modeling software has become an integral part of planning and devel-oping ventilation systems in partnership with graphical mine design software packages to generate realistic representations of the mine. Significant advances in ventilation control strategies through remote sensors and monitoring capabilities have been developed to results in cost savings. Though there has been much advancement in mine ventilation technology, the practices and basic ventilation princi-pals enacted through the ventilation engineer cannot be placated with technological advances only.

  18. Speech for People with Tracheostomies or Ventilators

    Science.gov (United States)

    ... Swallowing / Disorders and Diseases Speech for People With Tracheostomies or Ventilators [ en Español ] What is a tracheostomy ? ... people with tracheostomies or ventilators ? What is a tracheostomy? A tracheostomy is a surgical opening in the ...

  19. Performance of ductless personalized ventilation in conjunction with displacement ventilation

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Melikov, Arsen Krikor; Vesely, Michal

    2014-01-01

    perception of the environment. The subjects could control the position of the DPV supply diffuser and the personalized air flow (air velocity). The use of DPV improved perceived air quality and thermal comfort compared to displacement ventilation alone. At 26 °C and 29 °C the percentage dissatisfied with air...

  20. Ventilation effectiveness : health benefits of heat recovery ventilators

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-08-15

    Studies have shown that the installation of a heat recovery ventilator (HRV) in homes in northern Canada could improve indoor air quality and the respiratory health of inhabitants. Low ventilation rates are common in many homes in the North because the climate is severe, homes are smaller and lack basements, and occupancies are higher, leading to unhealthy indoor air quality. Northern communities also have a high rate of respiratory infections. HRVs recover much of the energy used to ventilate, which is desirable in cold regions with high heating costs. For the study, the test sample was divided into two types of houses, notably houses with active HRVs and those with control HRVs that were installed and operated but that did not function. The study results showed that HRVs provided increased ventilation. Complaints by residents about HRV noise, discomfort, or low humidity were common but equally spread between those with active and placebo HRVs. The study showed that the system design needs to be improved to better suit the needs of Inuit families. The nature of northern housing presents installation and maintenance challenges. It is hard to retrofit HRV ducting inside small, existing houses, and building supplies arrive infrequently, so detailed planning and careful take-offs of all supplies and materials must be done well in advance of construction. In addition, contractors are hard to locate and have variable expertise, and there is little technical follow-up. Robust technical support by local contractors and housing authorities is therefore important. 2 refs.

  1. Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm

    OpenAIRE

    Powers, Scott K.; Decramer, Marc; Gayan-Ramirez, Ghislaine; Levine, Sanford

    2008-01-01

    Common medical conditions that require mechanical ventilation include chronic obstructive lung disease, acute lung injury, sepsis, heart failure, drug overdose, neuromuscular disorders, and surgery. Although mechanical ventilation can be a life saving measure, prolonged mechanical ventilation can also present clinical problems. Indeed, numerous well-controlled animal studies have demonstrated that prolonged mechanical ventilation results in diaphragmatic weakness due to both atrophy and contr...

  2. Newer nonconventional modes of mechanical ventilation

    OpenAIRE

    Preet Mohinder Singh; Anuradha Borle; Anjan Trikha

    2014-01-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient′s demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. ...

  3. Ventilation-induced Alterations in Lung Development

    OpenAIRE

    Kroon, André

    2011-01-01

    textabstractMechanical ventilation is a lifesaving treatment in critically ill neonates. However, mechanical ventilation is also one of the most important risk factors (Table 1) of Bronchopulmonary dysplasia (BPD), the most common chronic lung disease in infancy with long-term pulmonary and neurological complications (1). Exposure of immature lungs to positive pressure ventilation results in oxidative stress and ventilator-induced lung injury. The resulting injury and inflammation lead to abn...

  4. Iatrogenic pneumothorax related to mechanical ventilation

    OpenAIRE

    Hsu, Chien-Wei; Sun, Shu-Fen

    2014-01-01

    Pneumothorax is a potentially lethal complication associated with mechanical ventilation. Most of the patients with pneumothorax from mechanical ventilation have underlying lung diseases; pneumothorax is rare in intubated patients with normal lungs. Tension pneumothorax is more common in ventilated patients with prompt recognition and treatment of pneumothorax being important to minimize morbidity and mortality. Underlying lung diseases are associated with ventilator-related pneumothorax with...

  5. Evaluation of Security of Mine Ventilation Systems

    Institute of Scientific and Technical Information of China (English)

    何书建; 彭担任; 翟成

    2002-01-01

    A mine ventilation system has a deterministic function for the safety of coal production and for the control of mine accidents. So, it has an importa nt meaning to evaluate the security of a mine ventilation system. This paper studied the evaluation index system of the security of a mine ventilation system, and the security of a mine ventilation system was described quantitatively in the saf ety degree. Finally, an example of the security evaluation was given .

  6. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    OpenAIRE

    H. Asilian Mahabady; Omidvar, M; A. Rezaee; A. Khavanin; S. B. Mortazavi

    2007-01-01

    A Microsoft Windows based ventilation software package is developed to reduce time-consuming and boring procedure of exhaust ventilation system design. This program Assure accurate and reliable air pollution control related calculations. Herein, package is tentatively named Exhaust Ventilation Design Software which is developed in VB6 programming environment. Most important features of Exhaust Ventilation Design Software that are ignored in formerly developed packages are Collector design and...

  7. Ventilation in Commercial and Residential Buildings

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    A number of areas have to be considered in connection with indoor air quality and ventilation. The selection of ventilation principle and components in the ventilation system will have influence on the indoor air quality and this subject will be discussed on the following pages. The main object o...

  8. 46 CFR 194.10-25 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... magazines. (1) All integral magazines shall be provided with natural or mechanical ventilation. Design... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.10-25 Section 194.10-25 Shipping...

  9. 46 CFR 98.25-75 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... provided with mechanical ventilation of sufficient capacity to assure a change of air every 3 minutes... shall be fitted with efficient natural or mechanical ventilation. (b) Enclosed compartments in which... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping...

  10. 9 CFR 91.21 - Ventilation.

    Science.gov (United States)

    2010-01-01

    ... mechanical ventilation that will furnish a complete change of air in each compartment every 2 minutes when... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ventilation. 91.21 Section 91.21... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.21 Ventilation. Each...

  11. Decisional responsibility for mechanical ventilation and weaning

    DEFF Research Database (Denmark)

    Rose, Louise; Blackwood, Bronagh; Egerod, Ingrid;

    2011-01-01

    Optimal management of mechanical ventilation and weaning requires dynamic and collaborative decision making to minimize complications and avoid delays in the transition to extubation. In the absence of collaboration, ventilation decision making may be fragmented, inconsistent, and delayed. Our...... objective was to describe the professional group with responsibility for key ventilation and weaning decisions and to examine organizational characteristics associated with nurse involvement....

  12. Why this crisis in residential ventilation

    NARCIS (Netherlands)

    Hasselaar, E.

    2008-01-01

    Ventilation is the cornerstone of good indoor air quality. Ventilation requirements have major attention in building regulations, but ventilation in practice is often poor, resulting in increased concentration of pollutants and hence exposure to health risk. Inspection of 500 houses with interviews

  13. Standard practice for acoustic emission examination of pressurized containers made of fiberglass reinforced plastic with balsa wood cores

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers guidelines for acoustic emission (AE) examinations of pressurized containers made of fiberglass reinforced plastic (FRP) with balsa cores. Containers of this type are commonly used on tank trailers for the transport of hazardous chemicals. 1.2 This practice is limited to cylindrical shape containers, 0.5 m [20 in.] to 3 m [120 in.] in diameter, of sandwich construction with balsa wood core and over 30 % glass (by weight) FRP skins. Reinforcing material may be mat, roving, cloth, unidirectional layers, or a combination thereof. There is no restriction with regard to fabrication technique or method of design. 1.3 This practice is limited to containers that are designed for less than 0.520 MPa [75.4 psi] (gage) above static pressure head due to contents. 1.4 This practice does not specify a time interval between examinations for re-qualification of a pressure container. 1.5 This practice is used to determine if a container is suitable for service or if follow-up NDT is needed before that...

  14. A WOOD REPLACEMENT MATERIAL OF SANDWICH STRUCTURE USING COIR FIBER MATS AND FIBERGLASS FABRICS AS CORE LAYER

    Directory of Open Access Journals (Sweden)

    Jia Yao,

    2011-12-01

    Full Text Available The tensile strength and bending strength of natural coir fiber are lower than many other natural fibers. Therefore, coir fiber is unsuitable for many fiber reinforcement applications. This study exploits the better shock resistance and toughness of coir fiber, which suggest that coir fiber can be used as a type of replacement material in plywood. Fast-growing poplar was chosen as the surface material, and coir fiber was selected as the core layer material for their buffering ability and toughness, and fiberglass fabrics were added in the core layer as strengthening components. The optimization of this plywood structure was carried out with an orthogonal experiment and the intuitive analysis method. The mechanical performance of some samples even exceeded that of natural wood. Through analysis of test results and scanning electron microscope (SEM observations, the buffering and toughening mechanisms of the coir fiber mats were revealed. This new material can be used to replace wood in plywood and in the transportation industry as a packaging material and as platform floors for freight vehicles.

  15. Impacts of the manufacturing process using fiberglass reinforced plastic composite on the environment and occupational health: the automotive industry case

    Directory of Open Access Journals (Sweden)

    Cíntia Madureira Orth

    2012-06-01

    Full Text Available The production of fiberglass reinforced plastic composite parts may cause serious damages to the health of workers and/or the environment, especially due to the generation of process trimmings, noise level and gas emission.  In view of that, this essay aims at assessing the main impacts of the Molding and Finish processes of an automotive plant on the environment and occupational health. It was observed that the open molding method adopted by the studied plant is the main cause of the generation of residues and that the waste of raw materials as trimmings may reach up to 30%. The final destination of those trimmings, which represent 45% of all the residues generated by the factory, is the industrial landfill. It was also observed that, due to the use of open molds, the levels of styrene and fiber dust were above the tolerance limits, presenting risks to the health of the workers.  Therefore, the studied company should consider the possibility of adopting less aggressive technologies, such as that used in closed molds. The reduction of the negative impacts of the productive processes in their source should be part of the company’s policy. Furthermore, the prevention must be continuous and improved every day.

  16. Displacement Ventilation in Hospital Environments

    DEFF Research Database (Denmark)

    Li, Yuguo; Nielsen, Peter V.; Sandberg, Mats

    2011-01-01

    Hospital differ from conventional buildings in terms of ventilation needs. Exhaled infectious droplets or droplet nuclei of an infected patient need to be removed in general wards, waiting areas and isolation rooms to minimize transmission to health-care workers, other patients and visitors...

  17. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects....

  18. Optimized structure of ventilated facades

    Directory of Open Access Journals (Sweden)

    V.A. Emelianova

    2014-10-01

    Full Text Available Today, one of the most universal types of lining, in terms of the value for money, is rightly believed to be suspended facade systems. Ventilated facade is characterized by the presence of the vertical air gap. If the system has been installed with violations, unventilated areas appear. Insufficient ventilation leads to decreasing heat-shielding properties of the structure. It has to be clearly understood how the ventilated air gap works and how its width affects the performance of the entire system. If the dependence between the size of the channel (height L and width h and the average speed of free-convective flows is determined it is possible to choose an optimal width of the air gap. This will allow the system to work as efficiently as possible and thus pay off the costs related with installation of the system. The aim of this work was to enhance the structure of the ventilated facade, find methods to define a hydraulically optimal air gap and estimate savings for the system with maximum efficiency. As a result it has been proved that it is reasonable to apply a hydraulically optimal facade.

  19. Xenon ventilation and perfusion studies

    International Nuclear Information System (INIS)

    Xenon ventilation and perfusion techniques were developed to view pulmonary function dynamically. Background from previous studies and from the xenon given the patient can interfere with the visual and computer analysis of the data. A computer program was developed to subtract the various background contributions. The protocol for the studies, the computer program and the results are described. (author)

  20. International Ventilation Cooling Application Database

    DEFF Research Database (Denmark)

    Holzer, Peter; Psomas, Theofanis Ch.; OSullivan, Paul

    2016-01-01

    The currently running International Energy Agency, Energy and Conservation in Buildings, Annex 62 Ventilative Cooling (VC) project, is coordinating research towards extended use of VC. Within this Annex 62 the joint research activity of International VC Application Database has been carried out, ...

  1. Cardiogenic oscillation induced ventilator autotriggering

    Directory of Open Access Journals (Sweden)

    Narender Kaloria

    2015-01-01

    Full Text Available Cardiogenic oscillation during mechanical ventilation can auto-trigger the ventilator resembling patient initiated breadth. This gives a false sense of intact respiratory drive and determination brain death, even if other tests are positive, is not appropriate in such a situation. It will prolong the ICU stay and confound the brain-death determination. In this case report, we describe a 35 year old man who was brought to the hospital after many hours of critical delay following multiple gun shot injuries. The patient suffered a cardiac arrest while on the way from another hospital. After an emergency laparotomy, patient was shifted to Intensive Care Unit (ICU with Glasgow Coma Scale (GCS score of E1VTM1 and was mechanically ventilated. Despite absence of brainstem reflexes, the ventilator continued to be triggered on continuous positive airway pressure (CPAP mode and the patient maintained normal oxygen saturation and acceptable levels of carbon dioxide. An apnoea test confirmed absent respiratory drive. Ventilatory waveform graph analysis, revealed cardiogenic oscillation as the cause for autotrigerring.

  2. Chest Compression Synchronized Ventilation versus Intermitted Positive Pressure Ventilation during Cardiopulmonary Resuscitation in a Pig Model

    OpenAIRE

    Kill, Clemens; Galbas, Monika; Neuhaus, Christian; Hahn, Oliver; Wallot, Pascal; Kesper, Karl; Wulf, Hinnerk; Dersch, Wolfgang

    2015-01-01

    Background Guidelines recommend mechanical ventilation with Intermitted Positive Pressure Ventilation (IPPV) during resuscitation. The influence of the novel ventilator mode Chest Compression Synchronized Ventilation (CCSV) on gas exchange and arterial blood pressure compared with IPPV was investigated in a pig model. Methods In 12 pigs (general anaesthesia/intubation) ventricular fibrillation was induced and continuous chest compressions were started after 3min. Pigs were mechanically ventil...

  3. Analyze of Ventilator Associated Pneumonia

    Directory of Open Access Journals (Sweden)

    Aysel Sunnetcioglu

    2014-03-01

    Full Text Available Aim: Ventilator-associated pneumonia (VAP is the infection that is an important cause of morbidity and mortality developed in patients whom the invasive mechanical ventilation (MV were performed in intensive care units (ICU. In this study, the factors of VAP developing in patients whom the mechanical ventilation of ICU performed, antibiotic susceptibility to these factors and determining the risk factors were aimed. Material and Method: Between January 2009 and March 2013, 79 cases, followed with the mechanical ventilation for at least for 48 hours and developed VAP, were retrospectively reviewed at Anesthesiology and Intensive Care Unit of Reanimation at Faculty of Medicine at Yuzuncu Yil University, performing endotracheal intubation. The cases were evaluated in terms of microorganisms, antibiotic susceptibility and risk factors. Results: The rate of our VAP speed was calculated to be 19.68 on the day of 1000 ventilator. While a single microorganism could be isolated in 81.1% of the 74 VAP cases whose the active pathogen could be isolated, two or more than two microorganisms were isolated in 18.9% of them.While 83 of the strains (90.2% were gram-negative bacteria, 7 of them (7.6% were gram-positive bacteria. Acinetobacter spp. (40.2% was most commonly isolated as a gram-negative factor, but methicillin-resistant S. aureus (4.3% was isolated as a gram-positive factor. It was determined that the isolated factors in VAP cases were significantly resistant to the broad-spectrum antibiotics. Discussion: As a result, in patients with high-risk factors for the development of VAP, early and appropriate empirical antibiotic treatment should be started according to the results of the sensitivity of the unit and for the multi-drug-resistant microorganisms with common and high mortality.

  4. Night ventilation control strategies in office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaojun; Yi, Lingli; Gao, Fusheng [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2009-10-15

    In moderate climates night ventilation is an effective and energy-efficient approach to improve the indoor thermal environment for office buildings during the summer months, especially for heavyweight construction. However, is night ventilation a suitable strategy for office buildings with lightweight construction located in cold climates? In order to answer this question, the whole energy-consumption analysis software EnergyPlus was used to simulate the indoor thermal environment and energy consumption in typical office buildings with night mechanical ventilation in three cities in northern China. The summer outdoor climate data was analyzed, and three typical design days were chosen. The most important factors influencing night ventilation performance such as ventilation rates, ventilation duration, building mass and climatic conditions were evaluated. When night ventilation operation time is closer to active cooling time, the efficiency of night ventilation is higher. With night ventilation rate of 10 ach, the mean radiant temperature of the indoor surface decreased by up to 3.9 C. The longer the duration of operation, the more efficient the night ventilation strategy becomes. The control strategies for three locations are given in the paper. Based on the optimized strategies, the operation consumption and fees are calculated. The results show that more energy is saved in office buildings cooled by a night ventilation system in northern China than ones that do not employ this strategy. (author)

  5. Effect of Coulping Agent on Paper Sludge Fiberboard Reinforced by Fiberglass%偶联剂对玻璃纤维增强造纸污泥纤维板的影响

    Institute of Scientific and Technical Information of China (English)

    刘贤淼; 费本华; 江泽慧

    2011-01-01

    Paper sludge fiberboard reinforced by fiberglass was studied. The influence of adding content of coupling agent and length of fiberglass on mechanical performance paper sludge fiberboard was investigated. Mechanism of reinforcement for fiberglass reinforced paper sludge fiberboard was studied. The results show that the performances are improved by the coupling agent and increase of length of fiberglass. The performances meet the national standard when coupling agent exceeds 0. 5%(by mass) and the length of fiberglass exceeds 4 cm. FT-IR study shows that fiberglass surface polarity is enhanced by adding coupling agent as covalent bond between fiberglass and PF is formed. The coupling agent can improve coarseness of fiberglass surface because fiberglass surface can be wetted by PF, and thus the wettability of fiberglass surface is improved. It is favorable for bonding.%在研制玻璃纤维增强造纸污泥纤维板的基础上,分析了偶联剂施加量和玻璃纤维长度对该板材物理力学性能的影响,并研究了这种板材的复合机理.结果表明:随着偶联剂施加量的增大,玻璃纤维长度的增加,玻璃纤维增强造纸污泥纤维板的各项性能均有所提高,当玻璃纤维长度为4 cm,偶联剂施加量≥0.5%(质量分数)时,其各项力学性能均可达到国家标准.红外光谱分析发现,偶联剂可改善玻璃纤维表面极性,使其与酚醛树脂胶形成共价连接.扫描电镜观察发现偶联剂能增加玻璃纤维表面粗糙度,这可进一步改善玻璃纤维表面的润湿性,有利于胶合.

  6. Ventilation of radioactive enclosures; Ventilation des enceintes radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Caminade, F.; Laurent, H. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m{sup 3}). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author) [French] Les manipulations oceaniques, physiques et chimiques sur des produits radioactifs doivent s'effectuer dans des enceintes convenablement ventilees. L'air extrait ne peut etre rejete dans l'atmosphere qu'apres une filtration correcte. La puissance des installations de ventilation est fonction des dimensions de l'enceinte et de son utilisation. Le choix des types de filtres est determine par l'etat physique et la nature ehimique des corps radioactifs manipules. Notre etude porte sur l'equipement individuel d'installations de petites dimensions: boites a gants, boites a pinces et, a la rigueur, enceintes de production (volume maximum utilisable 5 m{sup 3}). Nous mesurons et comparons les performances de trois types de 'ventilateurs' et les modifications apportees par l'adjonction de filtres. (auteur)

  7. Summary of human responses to ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli A.; Fisk, William J.

    2004-06-01

    The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually

  8. Free Convection Personalized Ventilation (FCPV)

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Normally we supply fresh air to a room with a diffuser, and this air is distributed in the room according to different principles as: mixing ventilation, displacement ventilation etc. That means we have to supply a very large amount of air to the whole room, although a person in the room totally...... only need a small amount of air. It is usual to supply 1-5 times the volume of the room per hour, but a person only need (in his/her inhalation) about 0.6 m3 per hour. Therefore, if people have a rather fixed position during the work, there is a possibility to supply air more directly to the breathing...

  9. Ventilation system with spiral recuperator

    Energy Technology Data Exchange (ETDEWEB)

    Adamski, Mariusz [Technical University of Bialystok, Department of Heat Engineering, ul. Wiejska 45E, PL-15-351 Bialystok (Poland)

    2010-05-15

    A new kind of longitudinal flow spiral recuperator for the heat recovery in ventilation systems of buildings was studied experimentally and analytically. The aim of this work is to analyze the possibility of using air handling units with new type of spiral recuperator in order to recover heat in ventilation systems of buildings. For the reason that the air flows are parallel to the symmetry axis of the longitudinal flow spiral recuperator, in this unit pressure drops are smaller than in commonly known spiral exchangers. Because of the counter flow, a greater value of thermal effectiveness {epsilon} is reached for the same value of the number of transfer units in comparison to cross-flow recuperators. The exploitation of the new type of spiral recuperator in winter periods brings significant savings. The results obtained from computations are very encouraging for a widespread use of these devices. (author)

  10. Development of a Residential Integrated Ventilation Controller

    Energy Technology Data Exchange (ETDEWEB)

    Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

    2011-12-01

    The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

  11. Deep underground mine without ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Czubak, A. (Akademia Gorniczo-Hutnicza, Cracow (Poland))

    1991-09-01

    Considers the possibility of creating local air-conditioned spaces for reduced numbers of miners in deep mines instead of ventilating the whole mine space. Application of air-conditioned chambers (for rest) at depths of 600-1,400 m and work performed in individually cooled suits or executed with the aid of manipulators controlled from air-conditioned chambers at depths below 1,400 m is suggested. Advantages of operating a coal mine without ventilation are reviewed (simple mine structure, power savings, fire and explosion prevention by filling the whole mine space with nitrogen without the necessity of explosion-proof mining equipment). However, operating a mine without ventilation will require a high degree of mechanization, automatic machine control and application of robots. Miners could wear special cooled exposure suits. The method suggested is considered to be a solution to the problem of the thermal barrier in deep mining and to be cheaper than classical cooling of workings at depth. 5 refs.

  12. Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters.

    Science.gov (United States)

    Stephens, B; Siegel, J A

    2013-12-01

    This work uses an in situ filter test method to measure the size-resolved removal efficiency of indoor-generated ultrafine particles (approximately 7-100 nm) for six new commercially available filters installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC filters were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel filters (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media filters (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine particles (UFP) sizes with the lowest rated filters (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated filter (MERV 16). The deeper bed filters generally achieved higher removal efficiencies than the panel filters, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new filters and other inputs from real buildings shows that MERV 13-16 filters could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency filters, depending in part on particle size.

  13. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  14. A NUMERICAL ANALYSIS OF THE VENTILATION PERFORMANCE FOR DIFFERENT VENTILATION STRATEGIES IN A SUBWAY TUNNEL

    Institute of Scientific and Technical Information of China (English)

    HUANG Yuan-dong; LI Chan; KIM Chang Nyung

    2012-01-01

    An unsteady three-dimensional analysis of the ventilation performance is carried out for different ventilation strategies to find out a ventilation method with a high performance in a subway tunnel.The natural ventilation performance associated with a train-induced air flow in a subway tunnel is examined.The dynamic layering method is used to consider the moving boundary of a train in the current CFD method.The geometries of the modeled tunnel and the subway train are partially based on those of the Seoul subway.The effects of the structure of the ventilation duct and the geometry of the partitions on the ventilation performance are evaluated.The results show that the combined ventilation ducts (to be designed),and the partitioning blocks installed along the middle of tunnel (already in existences) are helpful for air exchange.This study can provide some guidance for the design of ventilation ducts in a subway system.

  15. Clinical Practice Guidelines for Early Weaning from Mechanical Ventilation.

    OpenAIRE

    Eddy Pereira Valdés

    2009-01-01

    Clinical Practice Guidelines for Early Weaning from Mechanical Ventilation. Weaning is the process, gradual or rapid, that leads to the turn off of mechanical ventilation and allows restoring spontaneous ventilation. The guidelines describe the procedure for rapid weaning from mechanical ventilation and emphasizes on spontaneous ventilation test. It includes assessment guidelines focused on the most important aspects to be accomplished.

  16. Naturlig ventilation kombineret med varmegenvinding og natkøling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker

    2007-01-01

    Naturlig ventilation i kontorbyggerier har været et alternativ til mekanisk ventilation i små 10 år. Ventilation med naturlige drivkræfter har den klare fordel, at der ikke forbruges elenergi ved ventilering af bygningen, fordi ventilatorer ikke er påkrævet. Imidlertid lider naturlig ventilation...

  17. Theoretical analysis of flying ability of E-fiberglass weft%E-玻璃纤维纬纱飞走性的理论分析

    Institute of Scientific and Technical Information of China (English)

    金世伟; 毕松梅; 汪学骞; 李长龙

    2001-01-01

    无碱玻璃纤维在喷气织机上织造的工艺研究是国内电子级玻璃纤维布生产厂家非常关注的核心技术问题之一.喷气织机在引纬过程中张力峰值与玻纤纱品质的关系,在什么条件下能够使纬纱在梭口中安全通过,以适应高速喷气织机的高效运转,减少织疵,降低断头率,是本课题研究的中心问题,通过科学分析、试验,其结果对科学合理地确定玻纤纱引纬参数具有一定的实用价值.%The technological research of non-alkali fiberglass weaving onair-jet loom is one of the key matters concerned deeply by the domestic electronic-grade fiberglass cloth manufacturers. The technical points are the relationship between strain peak value and fiberglass yarn quality in the cause of weft inserting on the jet loom, the conditions we can make the weft pass through the shuttle opening safely for high-speed jet loom to run effectively, reduce float, decrease end breaking rate. The experiment results and their analysis have some practical value for deciding weft inserting data.

  18. Can heterogeneity in ventilation be good?

    OpenAIRE

    Costa, Eduardo LV; Amato, Marcelo BP

    2010-01-01

    Selection of the optimal positive end-expiratory pressure (PEEP) to avoid ventilator-induced lung injury in patients under mechanical ventilation is still a matter of debate. Many methods are available, but none is considered the gold standard. In the previous issue of Critical Care, Zhao and colleagues applied a method based on electrical impedance tomography to help select the PEEP that minimized ventilation inhomogeneities. Though promising when alveolar collapse and overdistension are pre...

  19. Pneumothorax after Mechanical Ventilation in Newborns

    OpenAIRE

    Abdolreza Malek; Nargess Afzali; Mojtaba Meshkat; Nadieh Yazdi Hosseini

    2011-01-01

    Objective:Air leak syndromes including pneumothorax, pneumomediastinum and pulmonary interstitial emphysema are frequent in neonatal period. Mechanical ventilation with positive pressure is one of the most common causes of these syndromes. The aim of this study was to evaluate predisposing factors and incidence of pneumothorax in newborns under mechanical ventilation. Methods:This descriptive cross sectional study was performed in 400 newborns under mechanical ventilation in intensive care un...

  20. Assisted ventilation in severe acute asthma.

    OpenAIRE

    Higgins, B; Greening, A P; Crompton, G K

    1986-01-01

    During the period 1973-85 assisted ventilation was used for the treatment of severe asthma on 48 occasions in 18 patients (one patient was ventilated 29 times). On each occasion arterial blood gas abnormalities were restored to normal as quickly as possible irrespective of peak inflation pressures. One patient was thought to be brain dead on transfer from another hospital but was ventilated for 48 hours while this diagnosis was confirmed. There was one episode of mediastinal emphysema. There ...

  1. Implementation of ventilation in existing schools

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Petersen, Steffen

    Present paper analyses the best-practice solutions for classrooms’ ventilation that fit the objective of quick and inexpensive implementation. The paper decomposes the relations between ventilation and building into manageable elements and analyzes them. The analyses are performed qualitatively......; they evaluate both scientific and practical implementation The analyses lead to a list of criteria associated with the implementation of ventilation in existing schools. Generic retrofitting scenarios which prioritize energy savings, indoor climate and building/facade integration are assembled and illustrated...

  2. 46 CFR 194.15-5 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194... minutes based upon the volume of the compartment. (1) Power ventilation units shall have...

  3. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Pedersen, D.N.; Nielsen, Peter V.;

    2001-01-01

    Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order...... that the air is fully mixed. The objective of this work is to determine the influence of the location of a pollutant, temperature differences and whether the room is furnished or not. It is also investigated if it is sufficient to determine the mean concentration in the room to determine the personal exposure...

  4. Numerical simulation of ventilation in blinding heading

    Institute of Scientific and Technical Information of China (English)

    CHANG De-qiang; LIU Jing-xian; CHEN Bao-zhi

    2008-01-01

    The way of ventilation in all its forms and characteristics in the blinding heading was studied.On the basis of computational fluid dynamics (CFD) the turbulence model of restrained ventilation in blinding heading was set up,and the calculation boundary conditions were analyzed.According to the practice application the three-dimensional flow field of ventilation in blinding heading was simulated by the computational fluid dynamics software.The characteristics of the ventilation flow field such as the temperature field zone and the flow filed zone and the rule of the flow velocity were obtained.The ventilation in blinding heading under certain circumstances was calculated and simulated for optimization.The optimal ventilation form and related parameters under given condition were obtained.The rule of the ventilation in blinding heading was theoretical analyzed,which provided reference for the research on the process of mass transfer,the rule of hazardous substances transportation and ventilation efficiency,provided a new method for the study of reasonable and effective ventilation in blinding heading.

  5. Numerical simulation of ventilation in blinding heading

    Institute of Scientific and Technical Information of China (English)

    CHANG De-qiang; LIU Jing-xian; CHEN Bao-zhi

    2008-01-01

    The way of ventilation in all its forms and characteristics in the blinding heading was studied. On the basis of computational fluid dynamics (CFD) the turbulence model of restrained ventilation in blinding heading was set up, and the calculation boundary condi-tions were analyzed. According to the practice application the three-dimensional flow field of ventilation in blinding heading was simulated by the computational fluid dynamics soft-ware. The characteristics of the ventilation flow field such as the temperature field zone and the flow filed zone and the rule of the flow velocity were obtained. The ventilation in blinding heading under certain circumstances was calculated and simulated for optimiza-tion. The optimal ventilation form and related parameters under given condition were ob-tained. The rule of the ventilation in blinding heading was theoretical analyzed, which pro-vided reference for the research on the process of mass transfer, the rule of hazardous substances transportation and ventilation efficiency, provided a new method for the study of reasonable and effective ventilation in blinding heading.

  6. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    Directory of Open Access Journals (Sweden)

    H. Asilian Mahabady

    2007-09-01

    Full Text Available A Microsoft Windows based ventilation software package is developed to reduce time-consuming and boring procedure of exhaust ventilation system design. This program Assure accurate and reliable air pollution control related calculations. Herein, package is tentatively named Exhaust Ventilation Design Software which is developed in VB6 programming environment. Most important features of Exhaust Ventilation Design Software that are ignored in formerly developed packages are Collector design and fan dimension data calculations. Automatic system balance is another feature of this package. Exhaust Ventilation Design Software algorithm for design is based on two methods: Balance by design (Static pressure balance and design by Blast gate. The most important section of software is a spreadsheet that is designed based on American Conference of Governmental Industrial Hygienists calculation sheets. Exhaust Ventilation Design Software is developed so that engineers familiar with American Conference of Governmental Industrial Hygienists datasheet can easily employ it for ventilation systems design. Other sections include Collector design section (settling chamber, cyclone, and packed tower, fan geometry and dimension data section, a unit converter section (that helps engineers to deal with units, a hood design section and a Persian HTML help. Psychometric correction is also considered in Exhaust Ventilation Design Software. In Exhaust Ventilation Design Software design process, efforts are focused on improving GUI (graphical user interface and use of programming standards in software design. Reliability of software has been evaluated and results show acceptable accuracy.

  7. Ventilation strategies and outcome in randomised trials of high frequency ventilation

    OpenAIRE

    Thome, U; Carlo, W; Pohlandt, F

    2005-01-01

    Objective: Randomised controlled trials comparing elective use of high frequency ventilation (HFV) with conventional mechanical ventilation (CMV) in preterm infants have yielded conflicting results. We hypothesised that the variability of results may be explained by differences in study design, ventilation strategies, delay in initiation of HFV, and use of permissive hypercapnia.

  8. Boundary conditions for the use of personal ventilation over mixing ventilation in open plan offices

    DEFF Research Database (Denmark)

    Petersen, Steffen; Hviid, Christian Anker

    2013-01-01

    This paper investigates the boundary conditions for choosing a combined Personal Ventilation (PV) and Mixing Ventilation (MV) over conventional mixing ventilation in an office with multiple workers. A simplified procedure for annual performance assessment of PV/MV systems in terms of air quality,...

  9. Performance of Ductless Personalized Ventilation in Conjunction with Displacement Ventilation: Impact of Workstations Layout and Partitions

    DEFF Research Database (Denmark)

    Halvonova, Barbara; Melikov, Arsen Krikor

    2010-01-01

    The performance of a new personalized ventilation system, referred to as ductless personalized ventilation (DPV), was studied in full-scale room experiments in conjunction with displacement ventilation (DV). The idea behind DPV is to utilize clean and cool air supplied via DV. In the experiment, ...

  10. Hypercapnia attenuates ventilator-induced diaphragm atrophy and modulates dysfunction

    NARCIS (Netherlands)

    Schellekens, W.J.M.; Hees, H.W.H. van; Kox, M.; Linkels, M.; Acuna, G.L.; Dekhuijzen, P.N.R.; Scheffer, G.J.; Hoeven, J.G. van der; Heunks, L.M.A.

    2014-01-01

    INTRODUCTION: Diaphragm weakness induced by prolonged mechanical ventilation may contribute to difficult weaning from the ventilator. Hypercapnia is an accepted side effect of low tidal volume mechanical ventilation, but the effects of hypercapnia on respiratory muscle function are largely unknown.

  11. Cage RACK ventilation options for laboratory animal facilities.

    Science.gov (United States)

    Stakutis, Richard E

    2003-09-01

    Individually ventilated cage systems have become the method of choice for housing rodents. The author describes the various options for cage ventilation, from using supply and exhaust fans to directly connecting the racks to the building ventilation system. PMID:12966448

  12. Thermal comfort of seated occupants in rooms with personalized ventilation combined with mixing or displacement ventilation

    DEFF Research Database (Denmark)

    Forejt, L.; Melikov, Arsen Krikor; Cermak, Radim;

    2004-01-01

    The performance of two personalized ventilation systems combined with mixing or displacement ventilation was studied under different conditions in regard to thermal comfort of seated occupants. The cooling performance of personalized ventilation was found to be independent of room air distribution....... Differences between the personalized air terminal devices were identified in terms of the cooling distribution over the manikin¿s body. The personalized ventilation supplying air from the front towards the face provided a more uniform cooling of the body than the personalized ventilation supplying air from...

  13. Dynamic Behaviour of Ventilated Hydrofoils.

    Science.gov (United States)

    Kjeldsen, Morten; Arndt, Roger; Wosnik, Martin

    2006-11-01

    In certain types of pumping applications oscillations are induced by operation with liquids containing a free gas load. In order to understand the physics of this process, a series of tests with a ventilated A 2D NACA 0015 hydrofoil were performed in the water tunnel at the St. Anthony Falls Laboratory of the University of Minnesota. The special bubble removal feature of the water tunnel allowed continuous ventilation without experiencing visible bubbles upstream the hydrofoil. These studies build on previous work on cavitation-induced oscillations. Gas injection studies were made over a range of gas flow rates and test section pressure. The results clearly show that lift oscillations increase in intensity when the gas load is increased. The point of maximum unsteadiness is also associated the rapid decline of the foil performance as measured as average lift. Further increase of the gas injection load gives a steady behaviour with almost no lift. These experiments are compared with traditional cavitation experiments. The similarities between gas injection- and cavitation induced unsteadiness on the hydrofoil are many, but the amplitude of lift oscillations found on the foil with gas injection corresponds to about 50% of that found for cavitating hydrofoils. The fact that the oscillations are periodic leads to the consideration of both passive and active control.

  14. Design Specification for Fiberglass Roving Size Applicator and Its Application%玻璃纤维粗纱涂油器设计规范与应用

    Institute of Scientific and Technical Information of China (English)

    穆允广; 陈宗勇; 柳丽娜

    2011-01-01

    从玻璃纤维粗纱涂油器的使用环境和基本要求出发,论述了该设备的基本设计规范,主要包括制作材料选择;涂油盒、涂油盒盖、保持架与涂油辊结构设计;传动机构的设计;涂油转速的相关计算与减速电机的选择标准,对提高稳定玻璃纤维粗纱的浸润剂涂覆效率意义较大。%Based on the operation environment and requirements for fiberglass roving size applicator, the basic specification for designing it are stated, including the selection of materials, the structural design of size box, box cover, cage and sizing roller, the design of driving device, the calculation of sizing roller rotation and the selection of geared motor. All these are of great significance to improve and stabilize the sizing of fiberglass roving

  15. A cost-effectiveness analysis of reducing ventilator-associated pneumonia at a Danish ICU with ventilator bundle

    DEFF Research Database (Denmark)

    Møller, Anders Holmen; Hansen, Louise; Jensen, Morten Sall;

    2012-01-01

    -based routine treatment or standard procedures. OBJECTIVE: To determine cost-effectiveness of implementing the Ventilator bundle (VB), thereby reducing ventilator-associated pneumonia (VAP), when treating a ventilated patient, compared to standard procedure. SETTING AND PATIENTS: A hypothetical population...

  16. Evaporation Controlled Emission in Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Nielsen, Peter V.; Heiselberg, Per

    -scale ventilated room when the emission is fully or partly evaporation controlled. The objective of the present research work has been to investigate the change of emission rates from small-scale experiments to full-scale ventilated rooms and to investigate the influence of the local air velocity field near...

  17. Echocardiographic evaluation during weaning from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Luciele Medianeira Schifelbain

    2011-01-01

    Full Text Available INTRODUCTION: Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation. OBJECTIVES: To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T-tube; and comparing patient subgroups: success vs. failure in weaning. METHODS: Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T-tube. Pressure support ventilation vs. T-tube and weaning success vs. failure were compared using ANOVA and Student's t-test. The level of significance was p<0.05. RESULTS: Twenty-four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T-tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation. CONCLUSION: No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T-tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients

  18. 14 CFR 252.9 - Ventilation systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC... as to provide the level and quality of ventilation specified and designed by the manufacturer for...

  19. Preoperational test report, primary ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  20. Ductless personalized ventilation with local air cleaning

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Vesely, Michal; Melikov, Arsen Krikor

    2012-01-01

    An experiment with 28 human subjects was performed to examine effects of using a local air cleaning device combined with ductless personalized ventilation (DPV) on perceived air quality. Experiments were performed in a test room with displacement ventilation. The DPV at one of two desks...

  1. Clinical analysis of ventilator-associated pneumonia

    Institute of Scientific and Technical Information of China (English)

    Bing-Qu Deng; Yong Liang

    2015-01-01

    Objective:To investigate the clinical analysis associated pneumonia in elderly ventilator. Methods:Through January 2011 to December 2013 in our hospital 165 cases of ventilator therapy in elderly patients with clinical data were retrospectively analyzed, discussed ventilator-associated pneumonia in the elderly risk factors, clinical symptoms, and the distribution of pathogens analysis of drug resistance.Results: The patient's age, sex, APACHE score, the incidence of aspiration, sedation and antacids, ventilator time were higher in patients (P<0.05); pathogens of ventilator-associated pneumonia in the elderly by high to low order of Pseudomonas aerations, Acinetobacter sop, etc.; pathogens commonly used in clinical antimicrobial drug resistance is higher.Conclusion:Take the risk factors associated pneumonia ventilator for elderly corresponding measures to reduce the incidence of ventilator-associated pneumonia, which Gram-negative bacteria as cause of ventilator-associated pneumonia in the elderly is an important pathogen occurs, the clinical course of treatment should be combined with a reasonable choice of antimicrobial susceptibility testing.

  2. Ventilation-induced Alterations in Lung Development

    NARCIS (Netherlands)

    A.A. Kroon (André)

    2011-01-01

    textabstractMechanical ventilation is a lifesaving treatment in critically ill neonates. However, mechanical ventilation is also one of the most important risk factors (Table 1) of Bronchopulmonary dysplasia (BPD), the most common chronic lung disease in infancy with long-term pulmonary and neurolog

  3. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo;

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

  4. Ventilation in low energy housing retrofits

    NARCIS (Netherlands)

    Mlecnik, E.

    2008-01-01

    According to the definition, passive houses in Europe meet a target energy demand for heating of less than 15 kWh per square meter and per year. This low level for the heating demand is based on heating by a small post-heater in the hygienic ventilation system at 52 °C maximum, while the ventilation

  5. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T;

    1987-01-01

    studied CO2 production (VCO2) and oxygen consumption (VO2) in mechanically ventilated ICU patients, where CO2 stores were altered by: a) changing minute ventilation by 15%, b) reducing body temperature, and c) changing the level of sedation. Expired gases went through a mixing chamber and were analyzed...

  6. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  7. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo;

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  8. Ventilation-perfusion scintigram in diabetics

    International Nuclear Information System (INIS)

    We carried out ventilation and perfusion scintigraphies and pulmonary function tests in 20 diabetics under 50 years of age. 99mTc-MAA perfusion scintigrams showed evidence of minimal nonuniformity (MNU) in four cases (20%) and nonsegmental defect (NSD) in eight cases (40%). There was a ventilation defect in the single-breath image in one case (5%) and a delayed washout in three cases (15%) upon 133Xe ventilation scintigram. In the NSD group, the mean diffusing capacity value was abnormally low and the mean duration of the diabetes was long compared with other groups. The frequency of perfusion defects was higher than that of ventilation abnormalities; moreover, abnormal findings on ventilation scintigrams were very mild compared with those of perfusion defects. Perfusion defects correlated significantly with a decrease in diffusing capacity. These findings suggest that the disturbance in pulmonary arterial perfusion caused a decrease in diffusing capacity in diabetics. (author)

  9. Ventilated facades: review of main problems

    Directory of Open Access Journals (Sweden)

    D.V. Nemova

    2010-08-01

    Full Text Available The design of ventilated facades becomes more and more popular.Ventilated facades are installed on erected and reconstructed public, office and residential buildings.In this article the basic problems relating to the ventilated facade system are considered. The design, installation process, thermotechnical properties, fire safety, economic efficiency are considered. The purpose of the article is the prevention in practice the most often errors which arise in time of installation, operation and dismantle of such systems.After the analysis following basic problems of systems with ventilated facades have been allocated:calculation of necessary air gap;selection of qualitative materials and installation;fire safety;maintenance of required hermal resistance.Application of ventilated facades systems for warming of buildings and increasing of their power efficiency demands the thought over and complex approach. Such systems are not so economic, energy effective and durable as it is considered to be.

  10. Functionality of Ventilated Facades: Protection of Insulation

    Directory of Open Access Journals (Sweden)

    Petrichenko Mikhail

    2016-01-01

    Full Text Available This article discusses about methods of construction of the ventilated facades. The ventilated facade is not only the element of facing, it is the supporting structure. Their main objective - creation of air ventilating space between a facade and an external wall of the building. Moving of air in this gap protects a heater from destruction, interfering with a moisture congestion. In addition, the ventilated facade protect the building from aggressive influence of external environment, have a sound and thermal insulation properties. There are several problems of systems of the ventilated facades connected with an application of a heater. For more effective using it is necessary to minimize contact of a heater with environment.

  11. Pneumothorax After Mechanical Ventilation in Newborns

    Directory of Open Access Journals (Sweden)

    Nadieh Yazdi Hosseini

    2011-03-01

    Full Text Available Objective:Air leak syndromes including pneumothorax, pneumomediastinum and pulmonary interstitial emphysema are frequent in neonatal period. Mechanical ventilation with positive pressure is one of the most common causes of these syndromes. The aim of this study was to evaluate predisposing factors and incidence of pneumothorax in newborns under mechanical ventilation. Methods:This descriptive cross sectional study was performed in 400 newborns under mechanical ventilation in intensive care unit of a teaching hospital in Iran from April 2004 to December 2008. Predisposing factors leading to ventilation and incidence of air leak syndromes were studied. Sex, gestational age, birth weight, type of delivery, history of surfactant replacement therapy, ventilator settings and mortality rate were recorded. Statistical analysis was done using SPSS software. Univariate analysis and regression analysis were considered. Findings:Among 400 patients under mechanical ventilation, 102 neonates developed pneumothorax (26%. Fifty six (54.9% of them were boys and 46 (45.1% girls. 54.9% of newborns with pneumothorax were preterm and 45.1% term. Birth weight less than 2500g was recorded in 59.8%. Fifty two percent of these neonates were born by cesarean section vs. 32% of newborns without pneumothorax. The most common type (62.7% of ventilation leading to pneumothorax was Inspiratory Positive Pressure Ventilation (IPPV. Surfactant replacement therapy was recorded in 32.4% of cases with pneumothorax compared to 60.4% of neonates under ventilation without pneumothorax, which was significantly different (P= 0.017. Conclusion:In newborns surfactant replacement therapy can reduce the risk of pneumothorax caused by mechanical ventilation.

  12. Quantification of ventilation characteristics of a helmet.

    Science.gov (United States)

    Van Brecht, A; Nuyttens, D; Aerts, J M; Quanten, S; De Bruyne, G; Berckmans, D

    2008-05-01

    Despite the augmented safety offered by wearing a cyclist crash helmet, many cyclists still refuse to wear one because of the thermal discomfort that comes along with wearing it. In this paper, a method is described that quantifies the ventilation characteristics of a helmet using tracer gas experiments. A Data-Based Mechanistic model was applied to provide a physically meaningful description of the dominant internal dynamics of mass transfer in the imperfectly mixed fluid under the helmet. By using a physical mass balance, the local ventilation efficiency could be described by using a single input-single output system. Using this approach, ventilation efficiency ranging from 0.06 volume refreshments per second (s(-1)) at the side of the helmet to 0.22s(-1) at the rear ventilation opening were found on the investigated helmet. The zones at the side were poorly ventilated. The influence of the angle of inclination on ventilation efficiency was dependent on the position between head and helmet. General comfort of the helmet can be improved by increasing the ventilation efficiency of fresh air at the problem zones.

  13. Natural Ventilation Performance of Kedah Vernacular House

    Directory of Open Access Journals (Sweden)

    Izudinshah Abd. Wahab

    2014-10-01

    Full Text Available As processed energy becoming more expensive, people have started to look for natural sources for option to provide their needs and comfort. Natural ventilation is one of the passive approaches that have recently become one of the important approaches in building design. However, architecturally, this approach is not considered new as a lot of previous buildings before industry era are totally depending on natural sources to ventilate their indoor spaces. Therefore this study was done to look into how these architectural details in Malay vernacular houses may affect the air movement performance around them. Two case studies of vernacular houses were chosen with design elements identified as natural ventilation attributes. Several points were identified inside and outside of the house where the wind speed of their surrounding were taken hourly in daytime for three days. The data were than compared to the building elements of the spaces. Both houses shows how building orientation and position of ventilation openings play the major role in determine the indoor air movement performance. However due to having other unintentionally openings such as gaps on roof design and gaps in flooring construction installation may also allow air flow to sip into the building despite of not having proper opening facing the cross ventilation. Besides that, by having openings at high level at the high roof may also encourage natural air flow via stack effect ventilation. Wide and full height window design may also become one of the most significant element to allow ventilation as proven in this research.

  14. Electrical Impedance Tomography During Mechanical Ventilation.

    Science.gov (United States)

    Walsh, Brian K; Smallwood, Craig D

    2016-10-01

    Electrical impedance tomography (EIT) is a noninvasive, non-radiologic imaging modality that may be useful for the quantification of lung disorders and titration of mechanical ventilation. The principle of operation is based on changes in electrical conductivity that occur as a function of changes in lung volume during ventilation. EIT offers potentially important benefits over standard imaging modalities because the system is portable and non-radiologic and can be applied to patients for long periods of time. Rather than providing a technical dissection of the methods utilized to gather, compile, reconstruct, and display EIT images, the present article seeks to provide an overview of the clinical application of this technology as it relates to monitoring mechanical ventilation and providing decision support at the bedside. EIT has been shown to be useful in the detection of pneumothoraces, quantification of pulmonary edema and comparison of distribution of ventilation between different modes of ventilation and may offer superior individual titration of PEEP and other ventilator parameters compared with existing approaches. Although application of EIT is still primarily done within a research context, it may prove to be a useful bedside tool in the future. However, head-to-head comparisons with existing methods of mechanical ventilation titration in humans need to be conducted before its application in general ICUs can be recommended. PMID:27682815

  15. 玻璃纤维增强连续塑料复合管道的应用性能%Performances of fiberglass reinforced composite plastic pipeline

    Institute of Scientific and Technical Information of China (English)

    夏平原; 李诗春; 陈斌

    2013-01-01

    Characterized by light weight,superior corrosion resistance,high pressure-beating capacities,longer extension,flexibility,easiness in fabrication,energy conservation and higher safety factors,fiberglass reinforced composite plastic pipeline of high-performance flexible composite pipe with multi-layer structures will gradually replace steel pipe for development and transportation of hydrocarbons due to their overall low costs.Through a model,the mechanical property of fiberglass reinforced composite plastic pipe is analyzed.In addition,six types of fiberglass reinforced composite plastic pipes have been produced and explosion tested in accordance with different design requirements.Research results show that actual bursting pressures are basically the same with designed theoretical pressure with pressure extent of 5.5 to 25 MPa.These products can fulfill requirements presented by actual production process.%玻璃纤维增强连续塑料复合管是一种多层结构高性能柔性复合管,具有质量轻、抗腐蚀能力强、承压能力强、制作长度长、可弯曲、施工简易、维护方便、节能环保、使用安全系数高的优点,因此整体使用成本较低,有望逐步取代钢制管道,用于石油天然气的开采和输送.建模分析了玻璃纤维增强连续塑料复合管的力学性能,根据不同要求设计了6种玻璃纤维增强连续塑料复合管道,并实施爆破试验,结果表明:实际爆破压力与理论设计压力基本相同,压力范围为5.5~25 MPa,可以满足实际生产需求.

  16. Cellulosic building insulation versus mineral wool, fiberglass or perlite: installer's exposure by inhalation of fibers, dust, endotoxin and fire-retardant additives.

    Science.gov (United States)

    Breum, N O; Schneider, T; Jørgensen, O; Valdbjørn Rasmussen, T; Skibstrup Eriksen, S

    2003-11-01

    A task-specific exposure matrix was designed for workers installing building insulation materials. A priori, a matrix element was defined by type of task (installer or helper), type of work area (attic spaces or wall cavities) and type of insulation material (slabs from mineral wool, fiberglass or flax; loose-fill cellulosic material or perlite). In the laboratory a mock-up (full scale) of a one-family house was used for simulated installation of insulation materials (four replicates per matrix element). Personal exposure to dust and fibers was measured. The dust was analyzed for content of endotoxin and some trace elements (boron and aluminum) from fire-retardant or mold-resistant additives. Fibers were characterized as WHO fibers or non-WHO fibers. In support of the exposure matrix, the dustiness of all the materials was measured in a rotating drum tester. For installers in attic spaces, risk of exposure was low for inhalation of dust and WHO fibers from slab materials of mineral wool or fiberglass. Slab materials from flax may cause high risk of exposure to endotoxin. The risk of exposure by inhalation of dust from loose-fill materials was high for installers in attic spaces and for some of the materials risk of exposure was high for boron and aluminum. Exposure by inhalation of cellulosic WHO fibers was high but little is known about the health effects and a risk assessment is not possible. For the insulation of walls, the risk of installers' exposure by inhalation of dust and fibers was low for the slab materials, while a high risk was observed for loose-fill materials. The exposure to WHO fibers was positively correlated to the dust exposure. A dust level of 6.1 mg/m3 was shown to be useful as a proxy for screening exposure to WHO fibers in excess of 10(6) fibers/m3. In the rotating drum, slabs of insulation material from mineral wool or fiberglass were tested as not dusty. Cellulosic loose-fill materials were tested as very dusty, and perlite proved to be

  17. Fixture of Alkali-resistant Fiberglass Mesh%耐碱玻璃纤维网格布拉伸夹具研究

    Institute of Scientific and Technical Information of China (English)

    杨乐; 尹晓江; 任云丽; 马洪涛; 张勇亭; 孙海勇

    2014-01-01

    耐碱玻璃纤维网格布作为外墙外保温系统中重要的组成部分,其断裂强力的好坏直接影响到外墙外保温系统的优劣,影响外墙保温系统的保温及装饰效果。 GB/T7689.5-2013作为指导耐碱玻璃纤维网格布断裂强力检测的方法标准对拉伸试样的制备及试验进行了规定,基于提高网格布与夹具之间摩擦力,同时保证使耐碱玻璃纤维网格布不在夹具夹持处断裂的原则,设计出一种针对类似耐碱玻璃纤维网格布等软性材料进行拉伸试验所需的新型夹具,利用该夹具对试样进行试验,在保证检测结果准确性的同时,能够有效提高产品的检测效率。%Being one important part of exterior wall external insulation systems, alkali-resistant fiber-glass mesh’s breaking force influences directly performance of those systems, together with their effect of insulation and decoration. Using GB/T7689.5-2013, we carry on fiberglass mesh’s preparation and experi-mental studies on breaking force. A new fixture is designed in order to avoid founding of breakings at clamping based on promotion of fiberglass mesh with fixture’s friction. With the fixture, the experiment on breaking force of the soft material can achieve accurate result and efficient detection.

  18. Simulating People Moving in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Mattsson, M.; Bjørn, Erik; Sandberg, M.;

    A displacement ventilation system works better the more uni-directional the air flow through the ventilated room is: from floor to ceiling. Thus, from an air quality point of view, there should be as little vertical mixing of the room air as possible. It is therefore comprehensible that physical...... activity in the room -like peoples movements -in previous studies has been shown to influence the effectiveness of the ventilation. In this study we have compared results from previous tests, where a cylindrical person simulator was used, to results obtained when using a person simulator of more human...

  19. Energy Analysis of the Ductless Personalized Ventilation

    DEFF Research Database (Denmark)

    Lelong, Cyril; Dalewski, Mariusz; Melikov, Arsen Krikor

    2013-01-01

    This study explores the impact of different occupancy profiles on the potential energy savings due to using ductless personalized ventilation (DPV) combined with displacement ventilation. Energy simulations were performed with the dynamic simulation software IDA-ICE in order to investigate optimal...... energy efficient strategies for implantation of DPV in practice. The impact of using DPV on annual energy use has been studied for different occupancy profiles in cold climates. The results suggest that using DPV combined with displacement ventilation may significantly reduce building energy use while...

  20. Position paper - primary ventilation system configuration

    International Nuclear Information System (INIS)

    The purpose of this paper is to develop and document a position on the configuration of the primary ventilation system. This configuration will be used on the waste storage tanks currently being designed for the Multi-Function Waste Tank Facility. The primary ventilation system provides a single treatment train and exhaust fan for each waste storage tank. The ventilation systems from each of two tanks are grouped with an additional treatment train and exhaust fan that function as backup to either of the two systems

  1. The research analysis and application of stability of ventilation system

    Institute of Scientific and Technical Information of China (English)

    卢国斌; 陈长华; 葛少成

    2002-01-01

    The stability of ventilation system includes stabilities of branch, network and main fan. The ventilation system is a dynamic process. The parameters in the ventilation system vary with time. In the paper, a group of mathematical models of quantitative analysis are set up, and the mathematical models are suitable to any ventilation system.

  2. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  3. 24 CFR 3280.103 - Light and ventilation.

    Science.gov (United States)

    2010-04-01

    ... combination passive and mechanical system. The ventilation system or provisions for ventilation must not... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Light and ventilation. 3280.103... Light and ventilation. (a) Lighting. Each habitable room shall be provided with exterior windows...

  4. 46 CFR 111.103-3 - Machinery space ventilation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  5. Partial liquid ventilation improves lung function in ventilation-induced lung injury

    OpenAIRE

    Vazquez de Anda, G.F.; Lachmann, R A; Verbrugge, Serge; Gommers, Diederik; Haitsma, J.J.; Lachmann, Burkhard

    2001-01-01

    textabstractDisturbances in lung function and lung mechanics are present after ventilation with high peak inspiratory pressures (PIP) and low levels of positive end-expiratory pressure (PEEP). Therefore, the authors investigated whether partial liquid ventilation can re-establish lung function after ventilation-induced lung injury. Adult rats were exposed to high PIP without PEEP for 20 min. Thereafter, the animals were randomly divided into five groups. The first group was killed immediately...

  6. Analysis of trials comparing High Frequency Ventilation with Conventional Mechanical Ventilation : Clinical Epidemiology in Intensive Care

    OpenAIRE

    Bollen, C W

    2006-01-01

    An abundance of experimental and clinical evidence indicates that mechanical ventilation can cause ventilator induced lung damage (VILI). Primary mechanisms leading to VILI are volutrauma, i.e. use of large tidal volumes resulting in over-distension, and atelectotrauma, i.e. repetitive closing and opening of alveoli, causing shear stress. Ideally, mechanical ventilation should supply enough airway pressure, even in the end-expiratory phase of breathing, to prevent collapse of the lungs. On th...

  7. Using a Ventilation Controller to Optimize Residential Passive Ventilation For Energy and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    One way to reduce the energy impact of providing residential ventilation is to use passive and hybrid systems. However, these passive and hybrid (sometimes called mixed-mode) systems must still meet chronic and acute health standards for ventilation. This study uses a computer simulation approach to examine the energy and indoor air quality (IAQ) implications of passive and hybrid ventilation systems, in 16 California climate zones. Both uncontrolled and flow controlled passive stacks are assessed. A new hybrid ventilation system is outlined that uses an intelligent ventilation controller to minimise energy use, while ensuring chronic and acute IAQ standards are met. ASHRAE Standard 62.2-2010 – the United States standard for residential ventilation - is used as the chronic standard, and exposure limits for PM2.5, formaldehyde and NO2 are used as the acute standards.The results show that controlled passive ventilation and hybrid ventilation can be used in homes to provide equivalent IAQ to continuous mechanical ventilation, for less use of energy.

  8. Adaptive Intelligent Ventilation Noise Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA needs for quiet crew volumes in a space habitat, Physical Optics Corporation (POC) proposes to develop a new Adaptive Intelligent Ventilation Noise...

  9. Adaptive Intelligent Ventilation Noise Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA need for quiet on-orbit crew quarters (CQ), Physical Optics Corporation (POC) proposes to develop a new Adaptive Intelligent Ventilation Noise...

  10. Modelling of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... as well as influence the air content (dust, pollution etc.). Architects and engineers need to acquire qualitative and quantitative information about the interactions between building characteristics and natural ventilation in order to design buildings and systems consistent with a passive low...... be installed in existing buildings after a few modifications. In contrast, ventilation systems using only natural forces such as wind and thermal buoyancy need to be designed together with the building, since the building itself and its components are the elements that can reduce or increase air movement...

  11. Design of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... as well as influence the air content (dust, pollution etc.). Architects and engineers need to acquire qualitative and quantitative information about the interactions between building characteristics and natural ventilation in order to design buildings and systems consistent with a passive low...... be installed in existing buildings after a few modifications. In contrast, ventilation systems using only natural forces such as wind and thermal buoyancy need to be designed together with the building, since the building itself and its components are the elements that can reduce or increase air movement...

  12. Short-term airing by natural ventilation

    DEFF Research Database (Denmark)

    Perino, Marco; Heiselberg, Per

    2009-01-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates traditio......The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates...... for temperature and IAQ control. However, in order to promote a wider applications of these systems, an improvement in the knowledge of their working principles and the availability of new design and simulation tools is necessary. In this context, the paper analyses and presents the results of a research...

  13. Building cooling by night-time ventilation

    Institute of Scientific and Technical Information of China (English)

    卢军; 王曦; 甘灵丽

    2009-01-01

    Nowadays,the world is short of energy source,and larger proportion of building energy consumption is occupied by air conditioning system. It is urgent that not only importance should be attached on energy saving but also arcology energy technology based on green and sustainable thought should be advocated. Considering the ever growing energy consumption of residential buildings,intermittent ventilation is a solution to saving energy consumption and improving indoor thermal comfort. Aiming at reducing indoor air temperature by intermittent ventilation and decrease energy consumption of air conditioning system,with the help of DeST (Designer’s Simulation Toolkit) this paper analyzes the characteristics of air conditioning load and year round air conditioning time in Chongqing located in hot summer and cold winter zone,obtains the amount of energy consumption saved at different ventilation rates,and recommends suitable ventilation rate in hot summer and cold winter zone.

  14. Inspiratory times when weaning from mechanical ventilation.

    OpenAIRE

    Greenough, A; Greenall, F; Gamsu, H R

    1987-01-01

    Two inspiratory times (0.5 and 1.0 seconds) were compared when weaning infants from mechanical ventilation. The shorter inspiratory time was associated with significant increases in minute volume and reduction in active expiration.

  15. Improved ventilation of open top greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Kats, G.; Thompson, C.R.; Kuby, W.C.

    1976-11-01

    In an attempt to reduce the greenhouse effect found when experiments are carried out in greenhouses, a new type of plant growth chamber was designed. Cylindrical chambers, 240 cm in height and 300 cm in diameter were constructed from Filon, a translucent corrugated acrylic fiberglass plastic sheet. A squirrel cage blower provided air at a rate of about 2.5 changes per minute. Activated charcoal filters were installed in the incoming air stream to remove photochemical oxidants to produce clean air. A 45/sup 0/ baffle was installed to displace the trailing edge mixing layer above the top of the chamber and thus sweep it clear by utilizing the vertical momentum component of the wind which is created locally.

  16. Healthcare Technology Management (HTM) of mechanical ventilators by clinical engineers

    OpenAIRE

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

    Mechanical ventilator failures expose patients to unacceptable risks, and maintaining mechanical ventilator safety is an important issue. We examined the usefulness of maintaining mechanical ventilators by clinical engineers (CEs) using a specialized calibrator. These evaluations and the ability to make in-house repairs proved useful for obviating the need to rent ventilators which, in turn, might prove faulty themselves. The CEs' involvement in maintaining mechanical ventilators is desirable...

  17. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    OpenAIRE

    2014-01-01

    Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of...

  18. Patient-ventilator interaction: the last 40 years.

    Science.gov (United States)

    Branson, Richard D

    2011-01-01

    Patient-ventilator synchrony is a complex issue affected by ventilator performance, patient characteristics, and the patient-ventilator interface. The history of patient-ventilator interaction includes avoidance of pharmacalogic paralysis, the development of spontaneous breathing systems, microprocessor technology to maximize interaction, and closed-loop control. While most clinicians agree that patient-ventilator synchrony is desirable, there remain no cause-and-effect data that asynchrony is associated with poor outcome.

  19. Evaluating Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  20. Secretion management in the mechanically ventilated patient

    OpenAIRE

    Mantellini E.; Perrero L.; Provenzano G.; Petrozzino S.

    2012-01-01

    Purpose: the aim of this work is to highlight the importance of a correct management of the secretions in the patient submitted to mechanical ventilation (MV). Methods: analysis of the current bibliography related to respiratory infections and secretion in patients with mechanically ventilation. We focus on the use of in-ex suflator achine (cough machine) associated with High Frequency Chest Wall Oscillation (HFCWO).Results: we observe a reduction of pulmonary infection and a better managemen...

  1. Ventilated Facades: Insulation Materials of Different Manufacturers

    OpenAIRE

    Shatornaya Alexandra; Chislova Maria; Chislova Anna; Drozdetskaya Marina; Trubina Daria

    2016-01-01

    The article analyzes the various manufacturers of thermal insulation materials that are used in hinged ventilated facades and there is a comparison them by the same criteria for identifying the advantages and disadvantages of their using in civil engineering. In the article there are the results of the carrying out calculations of wall construction with ventilated faсade to resistance of heat transfer by using materials from different manufacturers for identical wall construction. As a result...

  2. Noninvasive ventilation in acute respiratory failure

    OpenAIRE

    Masip, Josep

    2014-01-01

    Arantxa Mas, Josep MasipCritical Care Department, Consorci Sanitari Integral (CSI), Hospital Sant Joan Despí Moisès Broggi and Hospital General de l’Hospitalet, University of Barcelona, Barcelona, SpainAbstract: After the institution of positive-pressure ventilation, the use of noninvasive ventilation (NIV) through an interface substantially increased. The first technique was continuous positive airway pressure; but, after the introduction of pressure support v...

  3. Outcome of mechanical ventilation in Sri Lanka.

    OpenAIRE

    Rajapakse, V. P.; Wijesekera, S

    1989-01-01

    The outcome of mechanical ventilation is reported in a series of 43 patients managed in an intensive care unit in Sri Lanka. Eighteen patients (42%) survived. Of these, all except one were discharged from hospital. Patients with organophosphate poisoning and Guillain-Barré polyneuritis had a mortality of 47% and 50% respectively. Patients who were ventilated postoperatively as a result of anaesthetic complications during surgery had a mortality rate of 20%. Patients with tetanus and myastheni...

  4. Quantifying the performance of natural ventilation windcatchers

    OpenAIRE

    Jones, B

    2010-01-01

    This thesis was submitted for the degree of Doctor of Doctor of Environmental Technology and awarded by Brunel University, 2010. The significant energy consumption of non- domestic buildings has led to renewed interest in natural ventilation strategies that utilise the action of the wind, and the buoyancy of hot air. One natural ventilation element is the Windcatcher, a roof mounted device that works by channelling air into a room under the action of wind pressure, whilst simultaneously dr...

  5. Perioperative lung protective ventilation in obese patients

    OpenAIRE

    Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F.; Repine, John E.

    2015-01-01

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increa...

  6. Aerodynamic investigations of ventilated brake discs.

    OpenAIRE

    Parish, D.; MacManus, David G.

    2005-01-01

    The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometrie...

  7. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  8. A historical perspective on ventilator management.

    Science.gov (United States)

    Shapiro, B A

    1994-02-01

    Paralysis via neuromuscular blockade in ICU patients requires mechanical ventilation. This review historically addresses the technological advances and scientific information upon which ventilatory management concepts are based, with special emphasis on the influence such concepts have had on the use of neuromuscular blocking agents. Specific reference is made to the scientific information and technological advances leading to the newer concepts of ventilatory management. Information from > 100 major studies in the peer-reviewed medical literature, along with the author's 25 yrs of clinical experience and academic involvement in acute respiratory care is presented. Nomenclature related to ventilatory management is specifically defined and consistently utilized to present and interpret the data. Pre-1970 ventilatory management is traced from the clinically unacceptable pressure-limited devices to the reliable performance of volume-limited ventilators. The scientific data and rationale that led to the concept of relatively large tidal volume delivery are reviewed in the light of today's concerns regarding alveolar overdistention, control-mode dyssynchrony, and auto-positive end-expiratory pressure. Also presented are the post-1970 scientific rationales for continuous positive airway pressure/positive end-expiratory pressure therapy, avoidance of alveolar hyperxia, and partial ventilatory support techniques (intermittent mandatory ventilation/synchronized intermittent mandatory ventilation). The development of pressure-support devices is discussed and the capability of pressure-control techniques is presented. The rationale for more recent concepts of total ventilatory support to avoid ventilator-induced lung injury is presented. The traditional techniques utilizing volume-preset ventilators with relatively large tidal volumes remain valid and desirable for the vast majority of patients requiring mechanical ventilation. Neuromuscular blockade is best avoided in these

  9. Clinical review: Long-term noninvasive ventilation

    OpenAIRE

    Robert, Dominique; Argaud, Laurent

    2007-01-01

    Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase...

  10. Sensor-based demand controlled ventilation

    Energy Technology Data Exchange (ETDEWEB)

    De Almeida, A.T. [Universidade de Coimbra (Portugal). Dep. Eng. Electrotecnica; Fisk, W.J. [Lawrence Berkeley National Lab., CA (United States)

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  11. Seismic qualification of ventilation stack

    International Nuclear Information System (INIS)

    This paper describes the method to be used to qualify the 105 K ventilation stack at the US Department of Energy's Hanford Site, near Richland, Washington, under seismic and wind loadings. The stack stands at 175 ft (53.34 m), with a diameter tapering from 22 ft (6.71 m) at the foundation to 12.83 ft (3.91 m) at the top. Although the stack is classified as Safety Class 3 (low hazard), it is treated as a Safety Class 1 (high hazard) component, as failure could damage a Safety Class 1 facility (the irradiated fuel storage basin). The evaluation used US Department of Energy criteria specified in UCRL 15910 (1990). The seismic responses of the stack under earthquake loading were obtained from modal analyses with response spectrum input that used the ANSYS (1989) finite-element computer code. The moments and shear forces from the results of seismic analysis were used to qualify the reinforcement capacity of the stack structure by the ultimate-strength method. The wind forces acting on the stack in both along-wind and are evaluations of the soil bearing pressure, the moment, and the shear capacity of the stack foundation

  12. Effect of spontaneous breathing on ventilator-induced lung injury in mechanically ventilated healthy rabbits: a randomized, controlled, experimental study

    OpenAIRE

    Xia, Jingen; Sun, Bing; He, Hangyong; Zhang, Heng; Wang, Chunting; Zhan, Qingyuan

    2011-01-01

    Introduction Ventilator-induced lung injury (VILI), one of the most serious complications of mechanical ventilation (MV), can impact patients' clinical prognoses. Compared to control ventilation, preserving spontaneous breathing can improve many physiological features in ventilated patients, such as gas distribution, cardiac performance, and ventilation-perfusion matching. However, the effect of spontaneous breathing on VILI is unknown. The goal of this study was to compare the effects of spo...

  13. CT ventilation functional image-based IMRT treatment plans are comparable to SPECT ventilation functional image-based plans

    OpenAIRE

    Kida, S.; Bal, M; Kabus, S; Negandar, M; Shan, X.; Jr, LBW; Keall, PJ; Yamamoto, T.

    2016-01-01

    To investigate the hypothesis that CT ventilation functional image-based IMRT plans designed to avoid irradiating highly-functional lung regions are comparable to single-photon emission CT (SPECT) ventilation functional image-based plans.Three IMRT plans were created for eight thoracic cancer patients using: (1) CT ventilation functional images, (2) SPECT ventilation functional images, and (3) anatomic images (no functional images). CT ventilation images were created by deformable image regis...

  14. Mechanical ventilation in emergency departments: Non invasive or invasive mechanical ventilation. Where is the answer?

    OpenAIRE

    Esquinas Rodriguez Antonio M; Cosentini Roberto; Papadakos Peter J

    2012-01-01

    The Emergency Department length of stay for patients requiring mechanical ventilation paper in this issue is very illustrative of many variables that still confound the way we treat patients that may not require endotracheal intubation (ETI) but may benefit from non-invasive mechanical ventilation (NIV) [1].

  15. Changes in lung volume and ventilation during surfactant treatment in ventilated preterm infants

    NARCIS (Netherlands)

    M. Miedema; F.H. de Jongh; I. Frerichs; M.B. van Veenendaal; A.H. van Kaam

    2011-01-01

    The immediate and regional effects of exogenous surfactant in open lung high-frequency oscillatory ventilated (HFOV) preterm infants are unknown. To assess regional changes in lung volume, mechanics, and ventilation during and after surfactant administration in HFOV preterm infants with respiratory

  16. Ventilator versus manual hyperinflation in clearing sputum in ventilated intensive care unit patients.

    Science.gov (United States)

    Dennis, Diane; Jacob, Wendy; Budgeon, Charley

    2012-01-01

    The aim of hyperinflation in the ventilated intensive care unit patient is to increase oxygenation, reverse lung collapse and clear sputum. The efficacy and consistency of manual hyperventilation is well supported in the literature, but there is limited published evidence supporting hyperventilation utilising a ventilator. Despite this, a recent survey established that almost 40% of Australian tertiary intensive care units utilise ventilator hyperinflation. The aim of this non-inferiority cross-over study was to determine whether ventilator hyperinflation was as effective as manual hyperinflation in clearing sputum from patients receiving mechanical ventilation using a prescriptive ventilator hyperinflation protocol. Forty-six patients received two randomly ordered physiotherapy treatments on the same day by the same physiotherapist. The efficacy of the hyperinflation modes was measured by sputum wet weight. Secondary measures included compliance, tidal volume, airway pressure and PaO2/FiO2 ratio. There was no difference in wet weight of sputum cleared using ventilator hyperinflation or manual hyperinflation (mean 3.2 g, P=0.989). Further, no difference in compliance (P=0.823), tidal volume (P=0.219), heart rate (P=0.579), respiratory rate (P=0.929) or mean arterial pressure (P=0.593) was detected. A statistically significant difference was seen in mean airway pressure (P=0.002) between techniques. The effect of techniques on the PaO2/FiO2 response ratio was dependent on time (interaction P=0.024). Physiotherapy using ventilator hyperinflation cleared a comparable amount of sputum and was as safe as manual hyperinflation. This research describes a ventilator hyperinflation protocol that will serve as a platform for continued discussion, research and development of its application in ventilated patients.

  17. The effect of mechanical ventilator settings during ventilator hyperinflation techniques: a bench-top analysis.

    Science.gov (United States)

    Thomas, P J

    2015-01-01

    Ventilator hyperinflations are used by physiotherapists for the purpose of airway clearance in intensive care. There is limited data to guide the selection of mechanical ventilator modes and settings that may achieve desired flow patterns for ventilator hyperinflation. A mechanical ventilator was connected to two lung simulators and a respiratory mechanics monitor. Peak inspiratory (PIFR) and expiratory flow rates (PEFR) were measured during manipulation of ventilator modes (pressure support ventilation [PSV], volume-controlled synchronised intermittent mandatory ventilation [VC-SIMV] and pressure-controlled synchronised intermittent mandatory ventilation [PC-SIMV]) and ventilator settings (including set tidal volume, positive end-expiratory pressure, inspiratory flow rate, inspiratory pause, pressure support, inspiratory time and/or inflation pressure). Additionally, each trial was conducted with high (0.05 l/cmH2O) and low (0.01 l/cmH2O) compliance settings on the lung simulators. Each trial was dichotomised into success or failure under three categories (attainment of PIFR-PEFR less than or equal to 0.9, PEFR/PIFR greater than 17 l/min, PEFR greater than or equal to 40 l/min). A total of 232 trials were conducted (96 VC-SIMV, 96 PC-SIMV, 40 PSV). A greater proportion of VC-SIMV trials were ceased due to high peak inspiratory pressures (35%). However, VC-SIMV trials were more likely to be successful at meeting all three outcome measures (26 VC-SIMV trials, 7 PC-SIMV trials, 0 PSV trials). It was found that manipulation of settings in VC-SIMV mode appears more successful than PSV and PC-SIMV for ventilator hyperinflations. PMID:25579293

  18. Closed-loop control of respiratory drive using pressure-support ventilation: target drive ventilation.

    Science.gov (United States)

    Spahija, Jadranka; Beck, Jennifer; de Marchie, Michel; Comtois, Alain; Sinderby, Christer

    2005-05-01

    By using diaphragm electrical activity (multiple-array esophageal electrode) as an index of respiratory drive, and allowing such activity above or below a preset target range to indicate an increased or reduced demand for ventilatory assistance (target drive ventilation), we evaluated whether the level of pressure-support ventilation can be automatically adjusted in response to exercise-induced changes in ventilatory demand. Eleven healthy individuals breathed through a circuit (18 cm H2O/L/second inspiratory resistance at 1 L/second flow; 0.5-1.0 L/second expiratory flow limitation) connected to a modified ventilator. Subjects breathed for 6-minute periods at rest and during 20 and 40 W of bicycle exercise, with and without target drive ventilation (the target was set to 60% of the increase in diaphragm electrical activity observed between rest and 20 W of unassisted exercise). With target drive ventilation during exercise, the level of pressure-support ventilation was automatically increased, reaching 13.3 +/- 4.0 and 20.3 +/- 2.8 cm H2O during 20- and 40-W exercise, respectively, whereas diaphragm electrical activity was reduced to a level within the target range. Both diaphragmatic pressure-time product and end-tidal CO2 were significantly reduced with target drive ventilation at the end of the 20- (p < 0.01) and 40-W (p < 0.001) exercise periods. Minute ventilation was not altered. These results demonstrate that target drive ventilation can automatically adjust pressure-support ventilation, maintaining a constant neural drive and compensating for changes in respiratory demand. PMID:15665323

  19. WASTE TREATMENT BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    P.A. Kumar

    2000-06-22

    The Waste Treatment Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Treatment Building (WTB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for personnel comfort and equipment operation, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WTB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement area ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination with the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WTB. The Waste Treatment Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits, The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Treatment Building Ventilation System interfaces with the Waste Treatment Building System by being located in the WTB, and by maintaining specific pressure, temperature, and humidity environments within the building

  20. WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    P.A. Kumar

    2000-06-21

    The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is

  1. Indoor radon remediation : effect of ventilation

    International Nuclear Information System (INIS)

    Radon and its progeny are the major contributors to the natural radiation dose received by human beings. As per the ICRP recommendations, it becomes necessary to take remedial steps for the reduction of radon daughters in a dwelling place if the level is found to be more than 200 Bqm-3. Ventilation process can simulate the conditions generated through advection or diffusion, therefore it may be major factors that control the indoor radon concentration is the room. In the present investigations, the effects of natural ventilation in a room having an external source of radon have been studied. The variation in radon concentration with operative time of exhaust fan has also been studied. For radon concentration measurement the LR-115 type II solid state nuclear track detectors (SSNTDs) were use. The radon reduction factor, which is the ratio of radon concentrations before and after remediation has been calculated. The radon reduction factor was found to vary 1.08 to 1.17 due to natural ventilation where as 1.17 to 3.01 due to forced ventilation. The results indicate that optimized ventilation (natural or forced) can be simple mean of radon remediation in dwellings. (author)

  2. Cardiopulmonary effects of intermittent mandatory ventilation.

    Science.gov (United States)

    Douglas, M E; Downs, J B

    1980-01-01

    IMV is a combination of spontaneous and mechanical ventilation. For numerous reasons, IMV is potentially more advantageous than conventional techniques. By maintaining spontaneous breathing, mechanical augmentation can be titrated to adjust alveolar minute ventilation levels to normal, thereby decreasing the incidence of respiratory alkalemia. There are major differences between the cardiopulmonary effects of IMV and conventional mechanical ventilation. Spontaneous inspiration decreases Ppl and results in better distribution of inspired gas, a better V/Q, and less physiological dead space. In addition, transmural filling pressures, venous return, and cardiac output are more normal than during conventional mechanical ventilation. Maintenance of spontaneous ventilation lowers mean Paw and pulmonary vascular resistance. If venous admixture occurs, it can be minimized by titrating PEEP. Thus, more effective therapy for hypoxemia is possible. If spontaneous breathing is to persist and be efective, work-of-breathing must be minimized. This can be accomplished best when a continuous flow of gas provides optimal CPAP to maintain FRC and to minimize the effects of decreased compliance without depressing cardiac function. PMID:7007253

  3. Tunnel Ventilation Control Using Reinforcement Learning Methodology

    Science.gov (United States)

    Chu, Baeksuk; Kim, Dongnam; Hong, Daehie; Park, Jooyoung; Chung, Jin Taek; Kim, Tae-Hyung

    The main purpose of tunnel ventilation system is to maintain CO pollutant concentration and VI (visibility index) under an adequate level to provide drivers with comfortable and safe driving environment. Moreover, it is necessary to minimize power consumption used to operate ventilation system. To achieve the objectives, the control algorithm used in this research is reinforcement learning (RL) method. RL is a goal-directed learning of a mapping from situations to actions without relying on exemplary supervision or complete models of the environment. The goal of RL is to maximize a reward which is an evaluative feedback from the environment. In the process of constructing the reward of the tunnel ventilation system, two objectives listed above are included, that is, maintaining an adequate level of pollutants and minimizing power consumption. RL algorithm based on actor-critic architecture and gradient-following algorithm is adopted to the tunnel ventilation system. The simulations results performed with real data collected from existing tunnel ventilation system and real experimental verification are provided in this paper. It is confirmed that with the suggested controller, the pollutant level inside the tunnel was well maintained under allowable limit and the performance of energy consumption was improved compared to conventional control scheme.

  4. Low resource ventilation unit; Ressourcebesparende ventilationsenhed

    Energy Technology Data Exchange (ETDEWEB)

    Drivsholm, C.

    2012-03-15

    In the project a resource-saving ventilation device was developed which is based on the use of a regenerator and a reversible air flow. The regenerator is placed in the building envelope, and the concept works in the way that the heat in the air during ventilation is stored in the regenerator and brought back into the building by a reversible air change. The heated air is blown from inside the building out through the regenerator. In this way the regenerator accumulates the heat in the air. Over a period of 30-120 seconds, the regenerator capacity is utilized. When the regenerator cannot be further heated, the air flow is reversed and there is now blown cold air through the regenerator. Thereby the heat from the regenerator is released to the cold fresh air. Thus, the fresh air brings heat back into the building, whereby the air is replaced with a limited heat loss. Ventilation with a regenerator is described as micro-ventilation. The developed micro-ventilation unit was tested by the Danish Technological Institute. The test results shows that the unit performs according to expectations: 1) The heat recovery is 85%; 2) The flow through the unit is 80m3 per hour in a 5 section unit; 3) The noise level is 30 db(A) in a representative room; 4) The energy consumption is <300 J/m3. The unit is introduced into the market, and the first plants have been sold. (LN)

  5. Ventilator associated pneumonia in major paediatric burns.

    Science.gov (United States)

    Rogers, Alan David; Deal, Cailin; Argent, Andrew Charles; Hudson, Donald Anthony; Rode, Heinz

    2014-09-01

    More than three-quarters of deaths related to major burns are a consequence of infection, which is frequently ventilator associated pneumonia (VAP). A retrospective study was performed, over a five-year period, of ventilated children with major burns. 92 patients were included in the study; their mean age was 3.5 years and their mean total body surface area burn was 30%. 62% of the patients sustained flame burns, and 31% scalds. The mean ICU stay was 10.6 days (range 2-61 days) and the mean ventilation time was 8.4 days (range 2-45 days). There were 59 documented episodes of pneumonia in 52 patients with a rate of 30 infections per 1000 ventilator days. Length of ventilation and the presence of inhalational injury correlate with the incidence of VAP. 17.4% of the patients died (n=16); half of these deaths may be attributed directly to pneumonia. Streptococcus pneumonia, Pseudomonas aeruginosa, Acinetobacter baumanii and Staphylococcus aureus were the most prominent aetiological organisms. Broncho-alveolar lavage was found to be more specific and sensitive at identifying the organism than other methods. This study highlights the importance of implementing strictly enforced strategies for the prevention, detection and management of pneumonia in the presence of major burns. PMID:24468505

  6. Ventilator associated pneumonia in major paediatric burns.

    Science.gov (United States)

    Rogers, Alan David; Deal, Cailin; Argent, Andrew Charles; Hudson, Donald Anthony; Rode, Heinz

    2014-09-01

    More than three-quarters of deaths related to major burns are a consequence of infection, which is frequently ventilator associated pneumonia (VAP). A retrospective study was performed, over a five-year period, of ventilated children with major burns. 92 patients were included in the study; their mean age was 3.5 years and their mean total body surface area burn was 30%. 62% of the patients sustained flame burns, and 31% scalds. The mean ICU stay was 10.6 days (range 2-61 days) and the mean ventilation time was 8.4 days (range 2-45 days). There were 59 documented episodes of pneumonia in 52 patients with a rate of 30 infections per 1000 ventilator days. Length of ventilation and the presence of inhalational injury correlate with the incidence of VAP. 17.4% of the patients died (n=16); half of these deaths may be attributed directly to pneumonia. Streptococcus pneumonia, Pseudomonas aeruginosa, Acinetobacter baumanii and Staphylococcus aureus were the most prominent aetiological organisms. Broncho-alveolar lavage was found to be more specific and sensitive at identifying the organism than other methods. This study highlights the importance of implementing strictly enforced strategies for the prevention, detection and management of pneumonia in the presence of major burns.

  7. Air Distribution and Ventilation Effectiveness in a room with Floor/Ceiling Heating and Mixing/Displacement Ventilation

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.;

    2014-01-01

    combined with floor/ceiling heating systems is approximately equal to 1.0, and ventilation effectiveness of displacement ventilation system combined with floor/ceiling heating systems ranges from 1.0 to 1.2. The floor/ceiling heating systems combined with mixing ventilation system have more uniform indoor.......0 to 1.2. The floor/ceiling heating systems combined with mixing ventilation system have more uniform indoor air distribution but smaller ventilation effectiveness compared with the floor/ceiling heating systems combined with displacement ventilation system. With regard to the building heat loss...

  8. Secretion management in the mechanically ventilated patient

    Directory of Open Access Journals (Sweden)

    Mantellini E.

    2012-01-01

    Full Text Available Purpose: the aim of this work is to highlight the importance of a correct management of the secretions in the patient submitted to mechanical ventilation (MV. Methods: analysis of the current bibliography related to respiratory infections and secretion in patients with mechanically ventilation. We focus on the use of in-ex suflator achine (cough machine associated with High Frequency Chest Wall Oscillation (HFCWO.Results: we observe a reduction of pulmonary infection and a better management of bronchial secretion in patient undergone to the use of in-ex suflator machine (cough machine associated with High Frequency Chest Wall Oscillation (HFCWO.Conclusions: the correct approach to patients submitted to mechanical ventilation (MV expect the use of High Frequency Chest Wall Oscillation (HFCWO (VEST and in-ex suflator machine (cough machine to decrease pulmonary infection thank to a reduction of permanence of bronchial secretions in the lungs .

  9. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    climate and energy consumption of a Constant Air Volume (CAV) system and a Demand Controlled Ventilation (DCV) system for two different bathroom designs. The air change rate of the CAV system corresponded to 0.5h-1. The ventilation rate of the DCV system was controlled by occupancy and by the relative...... humidity in the bathroom. The two designs differed by the construction of the shower cubicle which in one case was sealed and in the other case unsealed. The construction influenced the relative humidity within the bathroom during a shower, i.e. the pollution source the ventilation rate was controlled by....... The indoor climate and the energy consumption were estimated based on a simplified calculation of the variation of the water content within the bathroom during a day. The results showed that the DCV system controlled by occupancy and relative humidity had an improved energy performance and an improved...

  10. Heating, ventilation and air conditioning system modelling

    Energy Technology Data Exchange (ETDEWEB)

    Whalley, R.; Abdul-Ameer, A. [British University in Dubai (United Arab Emirates)

    2011-03-15

    Heating, ventilation and air conditioning modelling methods, for large scale, spatially dispersed systems are considered. Existing techniques are discussed and proposals for the application of novel analysis approaches are outlined. The use of distributed-lumped parameter procedures enabling the incorporation of the relatively concentrated and significantly dispersed, system element characteristics, is advocated. A dynamic model for a heating, ventilation and air conditioning system comprising inlet and exhaust fans, with air recirculation, heating/cooling and filtration units is presented. Pressure, airflow and temperature predictions within the system are computed following input, disturbance changes and purging operations. The generalised modelling advancements adopted and the applicability of the model for heating, ventilation and air conditioning system simulation, re-configuration and diagnostics is emphasised. The employment of the model for automatic, multivariable controller design purposes is commented upon. (author)

  11. Performance of displacement ventilation in practice

    DEFF Research Database (Denmark)

    Naidenov, K.; Pitchurov, G.; Langkilde, Gunnar;

    2002-01-01

    the major local discomfort in the rooms with displacement ventilation. Twenty-three percent of the occupants were daily bothered by draught. In some buildings the maintenance personnel tried to improve occupants´ thermal comfort by raising the supply air temperature or office workers themselves......This paper presents results of a field study in offices with displacement ventilation. It comprises detailed physical measurements of the thermal environment and collection of occupants´ response at 227 workplaces. The results, both physical measurements and human response, identified draught as...... blocked the diffusers by rearranging the furniture. Half of the surveyed occupants were not satisfied with the indoor air quality. The main conclusion is that displacement ventilation needs careful design and room furnishing in order to ensure a comfortable environment. Occupants must understand the...

  12. Flow measurement in mechanical ventilation: a review.

    Science.gov (United States)

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. PMID:25659299

  13. Study of the Human Breathing Flow Profile in a Room with three Different Ventilation Strategies

    DEFF Research Database (Denmark)

    Olmedo, Ines; Nielsen, Peter V.; de Adana, Manuel Ruiz;

    2010-01-01

    This study investigates the characteristics of human exhalation through the mouth with three different ventilation strategies: displacement ventilation, mixing ventilation and without ventilation. Experiments were conducted with one breathing thermal manikin in a full scale test room where the ex...

  14. Study of the Human Breathing Flow Profile with Three Different Ventilation Strategies

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Cortes, Ines Olmedo; Ruiz de Adana, Manuel

    2011-01-01

    This study investigates the characteristics of human exhalation through the mouth with three different ventilation strategies: displacement ventilation, mixing ventilation and without ventilation. Experiments were conducted with one breathing thermal manikin in a full scale test room where the ex...

  15. Advanced design of local ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Kulmala, I. [VTT Manufacturing Technology, Espoo (Finland). Safety Technology

    1997-12-31

    Local ventilation is widely used in industry for controlling airborne contaminants. However, the present design practices of local ventilation systems are mainly based on empirical equations and do not take quantitatively into account the various factors affecting the performance of these systems. The aim of this study was to determine the applicability and limitations of more advanced fluid mechanical methods to the design and development of local ventilation systems. The most important factors affecting the performance of local ventilation systems were determined and their effect was studied in a systematic manner. The numerical calculations were made with the FLUENT computer code and they were verified by laboratory experiments, previous measurements or analytical solutions. The results proved that the numerical calculations can provide a realistic simulation of exhaust openings, effects of ambient air flows and wake regions. The experiences with the low-velocity local supply air showed that these systems can also be modelled fairly well. The results were used to improve the efficiency and thermal comfort of a local ventilation unit and to increase the effective control range of exhaust hoods. In the simulation of the interaction of a hot buoyant source and local exhaust, the predicted capture efficiencies were clearly higher than those observed experimentally. The deviations between measurements and non-isothermal flow calculations may have partly been caused by the inability to achieve grid independent solutions. CFD simulations is an advanced and flexible tool for designing and developing local ventilation. The simulations can provide insight into the time-averaged flow field which may assist us in understanding the observed phenomena and to explain experimental results. However, for successful calculations the applicability and limitations of the models must be known. (orig.) 78 refs.

  16. The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation.

    Science.gov (United States)

    Hess, Dean R

    2012-06-01

    For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the

  17. Evaluation of pressure support ventilation with seven different ventilators using Active Servo Lung 5000

    Directory of Open Access Journals (Sweden)

    Nagano,Osamu

    2008-04-01

    Full Text Available In modern emergency and critical care, physicians tend to choose the mode of mechanical ventilation based on spontaneous breathing for the purpose of promoting discharge of pulmonary secretion and preventing atelectasis in patients with acute respiratory insufficiency. However, we often observe "differences in recovery" among patients treated using the same PSV settings beyond "differences in individual characteristics." We evaluated the Pressure Support Ventilation (PSV mode aiming to certify the difference among 7 representative mechanical ventilators using the Active Servo Lung 5000 (ASL5000 respiratory simulation system. The following parameters were measured: The time delay that resulted in the lowest inspiratory pressure from the point at which the ventilator recognized spontaneous breathing (TD, the lowest inspiratory airway pressure (cmH2O generated prior to the initiation of PSV (DeltaPaw, the work of breathing while triggering required to achieve the lowest inspiratory negative pressure from the beginning of inspiratory support (WOBtrig, and the inspiratory work of breathing (WOBi. The mean TD of the Puritan-Bennett type 840 (PB840 was signifi cantly shorter than those of other ventilators (p0.01. The WOBtrig of the PB840 was significantly lower than those of others (p0.01. However, the WOBi values of the Servo-I and T-Bird were greater than the others, with the Evita series showing the smallest WOBi of the 7 ventilators tested. According to this simulation study using ASL 5000, we concluded that PB840 was the most rapid response ventilator, but the Evita series was the gentlest mechanical ventilator among 7 ventilators from the standpoint of the total work of breathing during the inspiration phase in the setting of PSV.

  18. Ductless personalized ventilation with local air cleaning

    OpenAIRE

    Dalewski, Mariusz; Vesely, Michal; Melikov, Arsen Krikor

    2012-01-01

    An experiment with 28 human subjects was performed to examine effects of using a local air cleaning device combined with ductless personalized ventilation (DPV) on perceived air quality. Experiments were performed in a test room with displacement ventilation. The DPV at one of two desks was equipped with an activated carbon filter installed at the air intake, while the DPV at the second desk was without such a filter. The air temperature in the occupied zone (1.1 m above the floor) was 29 °C....

  19. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  20. Ventilation-perfusion imaging in pulmonary papillomatosis

    International Nuclear Information System (INIS)

    Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment

  1. Methods of evaluating cleanliness of ventilation ducts

    Institute of Scientific and Technical Information of China (English)

    曹勇; 罗运有; 于丹; 甘丽斯

    2009-01-01

    A testing system for evaluating cleanliness of ventilation ducts was constructed. Comparisons of four evaluation methods for quantifying the amount of dust on the inner surface of ventilation ducts are presented. The experimental results show that the wiping by solvent method is more efficient than that by the wiping method,especially used on low cleanliness duct surface. The gravimetric tape method is an efficient method of collecting dust samples on the duct surface with low amounts of dust,particularly used to check the cleanliness level after the cleaning work. The optical method can be set up rapidly and is useful for fieldwork measurements.

  2. Short Term Airing by Natural Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Perino, M.

    2010-01-01

    principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected...... airflow rate, ventilation efficiency, thermal comfort and dynamic temperature conditions. A suitable laboratory test rig was developed to perform extensive experimental analyses of the phenomenon under controlled and repeatable conditions. The results showed that short-term window airing is very effective...... and can provide both acceptable IAQ and thermal comfort conditions in buildings....

  3. Preoperational test report, recirculation ventilation systems

    International Nuclear Information System (INIS)

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  4. Achieving Natural and Hybrid Ventilation in Practice

    DEFF Research Database (Denmark)

    Liddament, Martin; Axley, James; Heiselberg, Per;

    2006-01-01

    Case studies provide essential evidence about the performance of buildings. They also illustrate the methods by which a technology can be implemented as well as highlighting problems. Various case study buildings (both new and retrofit) that incorporate mixed mode, natural ventilation and low...... energy cooling are reviewed in this paper. An outline of the tasks that ventilation is required to perform is also presented. The results show that many buildings perform well and can provide good thermal comfort and air quality for much of the occupied period. Various solutions have been introduced...

  5. Ventilation-perfusion distribution in normal subjects

    OpenAIRE

    Beck, Kenneth C.; Johnson, Bruce D.; Olson, Thomas P.; Wilson, Theodore A.

    2012-01-01

    Functional values of LogSD of the ventilation distribution (σV̇) have been reported previously, but functional values of LogSD of the perfusion distribution (σq̇) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σV̇, σq̇, and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations o...

  6. Design of Energy Efficient Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The focus in the development has for both systems been to minimise energy consumption while maintaining a comfortable and healthy indoor environment. The natural next step in this development is to develop ventilation concepts that utilises and combines the best features from each system[Mechanic......The focus in the development has for both systems been to minimise energy consumption while maintaining a comfortable and healthy indoor environment. The natural next step in this development is to develop ventilation concepts that utilises and combines the best features from each system...

  7. Design av bladprofil for en stor ventilator

    OpenAIRE

    Hjetland, Even

    2009-01-01

    Institutt for Energi- og Prosessteknikk ved NTNU gikk, for en tid tilbake, til innkjøp av en fullskala ventilator av typen som Vegdirektoratet i Norge benytter til ventilering i tunneler. Motivasjonen bak innkjøpet var et ønske om å drive utviklingsarbeid rundt impellerdesign, da Vegdirektoratet ved flere anledninger opplevde at innkjøpte ventilatorer ikke overholdt produsentens egne spesifikasjoner. Denne oppgaven er et ledd i dette arbeidet, og har som målsetning å utvikle bladgeometri spes...

  8. VENTILATION INFLUENCE UPON INDOOR AIR RADON LEVEL

    Institute of Scientific and Technical Information of China (English)

    田德源

    1995-01-01

    Levels of indoor radon in air are studied by a continuous electrostatic radon monitor under normal living conditions to evaluate the influence of air conditioned ventilation on indoor air radon level.Results show that the indoor air radon concentrations are not much more than those without household conditioner living condition.although using household conditioner requires a sealed room which should lead to a higher radon level.Turning on air conditioner helps lower indoor radon level.Therefore.the total indoor air Rn levels are normal>ventilation>exhaust or indraft> exhaust plus indraft.

  9. No-sedation during mechanical ventilation

    DEFF Research Database (Denmark)

    Laerkner, Eva; Stroem, Thomas; Toft, Palle

    2016-01-01

    BACKGROUND: Evidence is growing that less or no-sedation is possible and beneficial for patients during mechanical ventilation. AIM: To investigate if there was a difference in patient consciousness and nursing workload comparing a group of patients receiving no-sedation with a group of sedated...... patients with daily wake up, and also to estimate economic consequences of a no-sedation strategy. DESIGN AND METHODS: Data were collected during a prospective trial of 140 mechanically ventilated patients randomized to either no-sedation or to sedation with daily wake up. From day 1 to 7 in the intensive...

  10. The Effects of Ventilation in Homes on Health

    DEFF Research Database (Denmark)

    Wargocki, Pawel

    2013-01-01

    and to reduce emissions. Often, especially in existing buildings, this strategy is difficult to implement, in which case exposures are controlled by providing sufficient, presumably clean, outdoor ventilation air to dilute and remove the contaminants. The present paper attempts to find out how much ventilation...... in existing homes. No data were found indicating that buildings having dedicated natural ventilation systems perform less well than the dwellings in which mechanical ventilation systems are installed. Newly installed mechanical ventilation systems were observed to improve health conditions. In homes...... Guidelines for Indoor Air Quality and improving ventilation measurements). Exposures should also be controlled using different ventilation methods for comparison. Future studies should also advance the understanding of how ventilation systems should be operated to achieve optimal performance. These data...

  11. Hypoxia in a neonate caused by intermittent positive pressure ventilation.

    OpenAIRE

    Beddis, I R; Silverman, M

    1980-01-01

    A newborn baby receiving mechanical ventilation was noted to have an extremely variable degree of hypoxia, despite the administration of 100% oxygen. The hypoxia was relieved rapidly when mechanical ventilation was withdrawn.

  12. High frequency jet ventilation in fat embolism syndrome.

    Science.gov (United States)

    Lee, A; Simpson, D

    1986-11-01

    The use of high frequency jet ventilation in the management of a patient with fat embolism syndrome is described. Its principal advantage over conventional intermittent positive pressure ventilation is a reduction in the amount of sedation necessary. PMID:3789371

  13. Adaptive support ventilation: State of the art review

    Directory of Open Access Journals (Sweden)

    Jaime Fernández

    2013-01-01

    Full Text Available Mechanical ventilation is one of the most commonly applied interventions in intensive care units. Despite its life-saving role, it can be a risky procedure for the patient if not applied appropriately. To decrease risks, new ventilator modes continue to be developed in an attempt to improve patient outcomes. Advances in ventilator modes include closed-loop systems that facilitate ventilator manipulation of variables based on measured respiratory parameters. Adaptive support ventilation (ASV is a positive pressure mode of mechanical ventilation that is closed-loop controlled, and automatically adjust based on the patient′s requirements. In order to deliver safe and appropriate patient care, clinicians need to achieve a thorough understanding of this mode, including its effects on underlying respiratory mechanics. This article will discuss ASV while emphasizing appropriate ventilator settings, their advantages and disadvantages, their particular effects on oxygenation and ventilation, and the monitoring priorities for clinicians.

  14. 环氧树脂玻璃钢防腐在丰特果蔬汁污水处理工程中的应用%Application of Epoxy Fiberglass-reinforced Plastics Anticorrosion in Sewage Treatment Project of Fengte Fruit and Vegetable Juice Company

    Institute of Scientific and Technical Information of China (English)

    李晓民

    2012-01-01

    This article describes the anticorrosion construction technique,control process and control index of epoxy fiberglass-reinforced plastics,and summarizes the advantages of anticorrosion of epoxy fiberglass-reinforced plastics.%介绍环氧树脂玻璃钢防腐施工工艺、控制过程及控制指标,总结环氧树脂玻璃钢防腐的优点。

  15. Automated analysis of Xe-133 pulmonary ventilation (AAPV) in children

    Science.gov (United States)

    Cao, Xinhua; Treves, S. Ted

    2011-03-01

    In this study, an automated analysis of pulmonary ventilation (AAPV) was developed to visualize the ventilation in pediatric lungs using dynamic Xe-133 scintigraphy. AAPV is a software algorithm that converts a dynamic series of Xe- 133 images into four functional images: equilibrium, washout halftime, residual, and clearance rate by analyzing pixelbased activity. Compared to conventional methods of calculating global or regional ventilation parameters, AAPV provides a visual representation of pulmonary ventilation functions.

  16. Frequency of hypoxic events in patients on a mechanical ventilator

    OpenAIRE

    Mahmood, Nader A; Chaudry, Fawad A.; Azam, Hamad; Ali, M. Imran; Khan, M. Anees

    2013-01-01

    Background: Mechanical ventilation is an important tool in the management of respiratory failure in the critically ill patient. Although mechanical ventilation can be a life-saving intervention, it is also known to carry several side-effects and risks. Adequate oxygenation is one of the primary goals of mechanical ventilation. However, while on mechanical ventilation, patients frequently experience hypoxic events resulting from various causes, which need to be properly evaluated and treated. ...

  17. Simvastatin attenuates ventilator-induced lung injury in mice

    OpenAIRE

    Müller, Holger C; Hellwig, Katharina; Rosseau, Simone; Tschernig, Thomas; Schmiedl, Andreas; Gutbier, Birgitt; Schmeck, Bernd; Hippenstiel, Stefan; Peters, Harm; Morawietz, Lars; Suttorp, Norbert; Witzenrath, Martin

    2010-01-01

    Introduction Mechanical ventilation (MV) is a life saving intervention in acute respiratory failure without alternative. However, particularly in pre-injured lungs, even protective ventilation strategies may evoke ventilator-induced lung injury (VILI), which is characterized by pulmonary inflammation and vascular leakage. Adjuvant pharmacologic strategies in addition to lung protective ventilation to attenuate VILI are lacking. Simvastatin exhibited anti-inflammatory and endothelial barrier s...

  18. Partial Liquid Ventilation: Animal Studies on Lung Function

    OpenAIRE

    Tutuncu, A.S.

    1995-01-01

    textabstractVarious mechanical ventilation techniques have been investigated, both experimentally and clinically, to improve outcome from acute respiratory failure. As an alternative means of respiratory support, perfluorocarbon (PFC) liquids have gained Interest first in liquid breathing applications, and then have formed the basis for the liquid ventilation technique. Combining the liquid and gas ventilation techniques, a new ventilatory support technique, namely partial liquid ventilation,...

  19. Effects of passive limb movement on pulmonary ventilation.

    OpenAIRE

    Waisbren, S. J.; Whiting, C. S.; Nadel, E R

    1990-01-01

    This study was undertaken to determine if the observed increase in ventilation during passive limb movement was a reflex hyperventilation or a response to an increased metabolic need for oxygen. Experiments on human volunteers were designed to test the hypothesis that the rapid increase of ventilation at the onset of exercise was due to stimulation of the joints. Results of these studies showed significant increases in ventilation, oxygen consumption, carbon dioxide production, ventilation/ox...

  20. Patient triggered ventilation using a flow triggered system.

    OpenAIRE

    Hird, M F; Greenough, A

    1991-01-01

    The role of patient triggered ventilation (PTV) for the newborn was assessed using a new patient triggered ventilator, the Draeger Bablylog 8000, which incorporates significant improvements in both ventilator performance and the triggering system. Thirty three infants, median gestational age 30 weeks and postnatal age 2.5 days, were entered into the study to compare blood gases obtained during conventional and patient triggered ventilation. Oxygenation did not improve with PTV in the group ov...

  1. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    Science.gov (United States)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  2. The Application of the Computer Control in the Device of Producing Fiberglass%计算机监控系统在制备丝装置中的应用

    Institute of Scientific and Technical Information of China (English)

    陈楚楠; 胡连旭

    2014-01-01

    实验证实:拉丝温度、拉丝张力、预制棒下降速度(棒速)和制备丝的走速(简称丝速)是影响拉丝质量的四大关键因素。为了提高成丝品质,就必须控制好以上关键参数。基于此目的,我们应用光电等较先进的检测技术手段,全面引进计算机监控系统,取得了较好的控制效果。%It was confirmed by tests that there were four pivotal factors including the temperature, the tension, the prepared-bar speed and the fiberglass velocity which influenced the quality of producing fiberglass. In order to improve the quality of the fiberglass,we must control them well. Basing on the purpose we applied the advanced optical & electrics techniques and the system of the computer controlling from aspects. Then we obtained a satisfactory effect.

  3. Experimental Analysis and Model Validation of an Opaque Ventilated Facade

    DEFF Research Database (Denmark)

    López, F. Peci; Jensen, Rasmus Lund; Heiselberg, Per;

    2012-01-01

    Natural ventilation is a convenient way of reducing energy consumption in buildings. In this study an experimental module of an opaque ventilated façade (OVF) was built and tested for assessing its potential of supplying free ventilation and air preheating for the building. A numerical model was ...

  4. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted...

  5. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868.5955 Section 868.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  6. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  7. 46 CFR 127.260 - Ventilation for accommodations.

    Science.gov (United States)

    2010-10-01

    ... vessel of 100 or more gross tons must be provided with a mechanical ventilation system unless the... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for accommodations. 127.260 Section 127.260... ARRANGEMENTS Particular Construction and Arrangements § 127.260 Ventilation for accommodations. (a)...

  8. Airway Strain during Mechanical Ventilation in an Intact Animal Model

    OpenAIRE

    Sinclair, Scott E.; Molthen, Robert C.; Haworth, Steve T.; Dawson, Christopher A.; Waters, Christopher M.

    2007-01-01

    Rationale: Mechanical ventilation with large tidal volumes causes ventilator-induced lung injury in animal models. Little direct evidence exists regarding the deformation of airways in vivo during mechanical ventilation, or in the presence of positive end-expiratory pressure (PEEP).

  9. Academic Emergency Medicine Physicians’ Knowledge of Mechanical Ventilation

    OpenAIRE

    Wilcox, Susan R.; Tania D. Strout; Jeffrey I. Schneider; Mitchell, Patricia M.; Smith, Jessica; Lutfy-Clayton, Lucienne; Marcolini, Evie G.; Aydin, Ani; Seigel, Todd A.; Jeremy B. Richards

    2016-01-01

    Introduction: Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) education or clinical practice. The objective of this study was to quantify EM attendings’ education, experience, and knowledge regarding mechanical ventilation in the emergency department. Methods: We developed a survey of academic EM attendings’ educational experiences with ventilators and a knowledge assessme...

  10. Academic Emergency Medicine Physicians’ Knowledge of Mechanical Ventilation

    OpenAIRE

    Wilcox, Susan R.; Tania D. Strout; Jeffrey I. Schneider; Mitchell, Patricia M.; Jessica Smith; Lucienne Lutfy-Clayton; Marcolini, Evie G.; Ani Aydin; Seigel, Todd A.; Jeremy B. Richards

    2016-01-01

    Introduction: Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) education or clinical practice. The objective of this study was to quantify EM attendings’ education, experience, and knowledge regarding mechanical ventilation in the emergency department. Methods: We developed a survey of academic EM attendings’ educational experiences with ventilators and a knowledge assessment tool with nine ...

  11. Hybrid Ventilation in New and Retrofitted Office Buildings

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The scope of this annex is to obtain better knowledge of the use of hybrid ventilation technologies. The annex will focus on development of control strategies for hybrid ventilation, on development of methods to predict hybrid ventilation performance in office buildings and on development...

  12. 46 CFR 58.01-45 - Machinery space, ventilation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery space, ventilation. 58.01-45 Section 58.01-45... MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-45 Machinery space, ventilation. Each machinery space must be ventilated to ensure that, when machinery or boilers are operating at full power in...

  13. Study on the applicability of the desk displacement ventilation concept

    NARCIS (Netherlands)

    Loomans, Marcel G.L.C.

    1999-01-01

    This paper summarizes an experimental and numerical study into a ventilation concept that combines displacement ventilation with task conditioning, the so-called desk displacement ventilation (DDV) concept. The study uses steady-state and transient results to discuss the applicability of the DDV con

  14. Numerical analysis of heat transfer by conduction and natural convection in loose-fill fiberglass insulation--effects of convection on thermal performance

    Energy Technology Data Exchange (ETDEWEB)

    Delmas, A.A.; Wilkes, K.E.

    1992-04-01

    A two-dimensional code for solving equations of convective heat transfer in porous media is used to analyze heat transfer by conduction and convection in the attic insulation configuration. The particular cases treated correspond to loose-fill fiberglass insulation, which is characterized by high porosity and air permeability. The effects of natural convection on the thermal performance of the insulation are analyzed for various densities, permeabilities, and thicknesses of insulation. With convection increasing the total heat transfer through the insulation, the thermal resistance was found to decrease as the temperature difference across the insulating material increases. The predicted results for the thermal resistance are compared with data obtained in the large-scale climate simulator at the Roof Research Center using the attic test module, where the same phenomenon has already been observed. The way the wood joists within the insulation influence the start of convection is studied for differing thermophysical and dynamic properties of the insulating material. The presence of wood joists induces convection at a lower temperature difference.

  15. Synthesis on the durability of composite fiberglass/epoxy resin structures; Synthese sur la durabilite des structures composites en fibres de verre/resine epoxide

    Energy Technology Data Exchange (ETDEWEB)

    Thevenin, P. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

    1997-12-31

    The purpose of this paper is to collect together in a systematic way information and results relating to the durability of composite fiberglass/ epoxy resin structures. First it is a matter of assessing the average level of understanding the long term behaviour of these structures which change under the combined effects of varied mechanical loading and stresses of a physico-chemical type linked to the environment. Looking at phenomena encountered and facts from current analyses, it will then be advisable to specify a methodology which can be applied to industrial piping used in PWR cooling systems for transporting raw water under pressure. In fact assessment of their service life is at present based on long and costly testing (ASTM D 2992 B standard), the appearance of which is inherited from metal piping testing.. Therefore it appears essential to study substitution test procedures, more composite specific and at the same time which can be conducted in reasonable time. For this purpose, by coherently accelerating and combining them in order not to underestimate their effects, ageing tests shall reproduce mechanisms representative of operating conditions. (author). 113 refs.

  16. Dynamic Mechanical Analysis and High Strain-Rate Energy Absorption Characteristics of Vertically Aligned Carbon Nanotube Reinforced Woven Fiber-Glass Composites

    Directory of Open Access Journals (Sweden)

    Kiyun Kim

    2015-01-01

    Full Text Available The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT forests grown on woven fiber-glass (FG layer and embedded within 10 layers of woven FG, with polyester (PE and polyurethane (PU resin systems (FG/PE/VACNT and FG/PU/VACNT are investigated and compared with the baseline materials, FG/PE and FG/PU (i.e., without VACNT. A Dynamic Mechanical Analyzer (DMA was used for obtaining the mechanical properties. It was found that FG/PE/VACNT exhibited a significantly lower flexural stiffness at ambient temperature along with higher damping loss factor over the investigated temperature range compared to the baseline material FG/PE. For FG/PU/VACNT, a significant increase in flexural stiffness at ambient temperature along with a lower damping loss factor was observed with respect to the baseline material FG/PU. A Split Hopkinson Pressure Bar (SHPB was used to evaluate the energy absorption and strength of specimens under high strain-rate compression loading. It was found that the specific energy absorption increased with VACNT layers embedded in both FG/PE and FG/PU. The compressive strength also increased with the addition of VACNT forest layers in FG/PU; however, it did not show an improvement for FG/PE.

  17. Ventilation in medium-sized and large boiler houses; Ventilation i medelstora och stoerre pannhus

    Energy Technology Data Exchange (ETDEWEB)

    Grotherus, Dan [AaF Installation AB, Oerebro (Sweden); Larsson, Tord [Oerebro Univ. (Sweden). Dept. of Technology

    2005-04-01

    The purpose of this report is to exemplify and clarify the need for ventilation in medium-sized and large boiler houses. We will furthermore present some recommendations, guidelines and advice for the design and construction of a boiler house ventilation system to the plant owners and suppliers of equipment. Boiler house ventilation can be performed in different ways using mechanical or natural ventilation. The solution to be chosen depends on the following factors: Working environment requirements and a necessity to control temperature and pressure in the boiler house; The design of the boiler plant and house; The need for combustion air; The investment expenditure as well as operation and maintenance costs. Mechanical ventilation should be chosen if the aim is a controllable 'climate'. The mechanical ventilation can be either centrally situated or distributed with many aggregates in the boiler house. Centrally situated ventilation equipment will give a higher accessibility and lower maintenance costs than a distributed ventilation system. If the boiler house is designed with natural ventilation the air and flue gas fans will be the only ones installed. In this case temperature and pressure inside the boiler house will be difficult to control. The design factor for the ventilation plant in a boiler house is in most cases the demand to cool the air inside the boiler house to approximately 45 deg C. This is the highest temperature allowed by the Occupational Safety and Health Act in a work environment where the boiler operator is working alone. The air flow which is required for the combustion is normally less than the air flow needed to cool the air in the boiler house. The supply air which is cooling the air inside the boiler house should be supplied on several different levels to attain an efficient cooling. If the combustion air is taken from the heated indoor air the boiler house will work as a heat reclaimer. The difference between outdoor and indoor

  18. A Medical Student Workshop in Mechanical Ventilation.

    Science.gov (United States)

    And Others; Kushins, Lawrence G.

    1980-01-01

    In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)

  19. Infection Route Analysis of Ventilator Associated Pneumonia

    Institute of Scientific and Technical Information of China (English)

    Wei; Guo; Jie; Zhang; Jing-yun; Li; Yue; Ma; Sheng-hui; Cui

    2012-01-01

    Objective A prospective study was conducted in a tertiary care center to identify the risk factors of ventilator associated pneumonia(VAP) through phenotypic and molecular biological methods. Methods The patients who were mechanically ventilated in the respiratory intensive care unit(RICU) and the neurological internal intensive care unit(NICU) were enrolled in our study, and samples were collected from the lower respiratory tract, oropharynx and stomach. Other samples, including the environmental air, swabs of nurses’ hands, subglottic secretion and ventilator circuit, were also collected. Microorganisms in the collected samples were recovered and identified at species level by biochemical detection. Genetic relationship of dominant species was further characterized by pulsed field gel electrophoresis(PFGE). Results Out of 48 enrolled patients, 22 cases developed VAP and bacterial cultures were recovered from the lower respiratory tract samples of 14 cases. The average hospitalization time with VAP was significantly longer than that of patients without VAP(P < 0.05). Among the recovered bacteria cultures, multidrug-resistant Pseudomonas aeruginosa and Stenotrophomonas maltophilia were dominant. It was more likely that subglottic secretion and gastric juice samples contained the same isolates as recovered in the lower respiratory tract by PFGE analysis. Conclusions Mechanical ventilation in RICU and NICU was a high risk factor for VAP development. Special emphasis of VAP prophylaxis should be paid on subglottic secretion and gastric juice reflux.

  20. Enhanced natural ventilation method for atrium space

    NARCIS (Netherlands)

    An, H.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. Energy saving is a relevant issue nowadays. Heating, ventilation and air conditioning (HVAC) occupies the largest portion both in residential and non-residential field. This consumption goes with the demand for ther

  1. 29 CFR 1926.57 - Ventilation.

    Science.gov (United States)

    2010-07-01

    ... downdraft booths are provided with doors, such doors shall be closed when spray painting. (7) Make-up air. (i) Clean fresh air, free of contamination from adjacent industrial exhaust systems, chimneys, stacks... exhaust ventilation when used as described in (a) shall be designed to prevent dispersion into the air...

  2. Computational Fluid Dynamics in Ventilation Design

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2008-01-01

    This paper is based on the new REHVA Guidebook Computational Fluid  Dynamics in Ventilation Design (Nielsen et al. 2007) written by Peter V. Nielsen, Francis(Nielsen 2007) written by Peter V. Nielsen, Francis Allard, Hazim B. Awbi, Lars Davidson and Alois Schälin. The guidebook is made for people...

  3. Improving comfort and health with personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analysed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  4. Dispersion mechanics in underground mine ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Standish, P.N.

    1988-01-01

    Application of Dispersion Mechanics to mine ventilation surveys is studied using C/sub 2/H/sub 2/ tracer release and detection on the 2 Drill level at Elura Mine, Cobar, NSW. Preliminary calibration work of the measuring systems in the laboratory and in a large test rig together with the results obtained is reported. It is found that the results in these non-mining systems closely follow the results of Dispersion Mechanics theory for a dispersed plug flow model. For the underground conditions studied the results of tracer studies show that the ventilating air flow is layered or segregated in a tube bundle pattern. These tracer results are reproduced by the results of traditional anemometer readings obtained under the same flow conditions. The results also show that the ventilating air flow under actual underground conditions is characterized by transient behavior which appears to be normal behavior of the ventilating air in underground workings. Application of the results to practice is included.

  5. Ventilator-associated pneumonia and mortality

    NARCIS (Netherlands)

    Melsen, W.G.

    2012-01-01

    Ventilator-associated Pneumonia (VAP) is one of the most common nosocomial infections among patients admitted to the intensive care unit. It is generally believed that VAP increases the mortality of patients, however exact determination of the attributable mortality of VAP is challenging. This thesi

  6. VRML Programs for Room Ventilation Applications

    DEFF Research Database (Denmark)

    Nielsen, Anker

    Cheap 3D models for visualization of room ventilation applications are now available. VRML (Virtu~l Reality Modelling Language) is found to be a good format to describe buildings, rooms and furniture. A 3D model in VRML can be placed on a World Wide Web (www) page and others can see the model in ...

  7. Displacement Ventilation by Different Types of Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Hoff, Lars; Pedersen, Lars Germann

    The paper describes measuring results of the air movement from three different types of diffusers for displacement ventilation. Two of the diffusers are lowlevel wall mounted diffusers, one with a low and one with a high initial entrainment. The third diffuser is of the floor mounted type....

  8. Gas exchange and intrapulmonary distribution of ventilation during continuous-flow ventilation

    International Nuclear Information System (INIS)

    In 12 anesthetized paralyzed dogs, pulmonary gas exchange and intrapulmonary inspired gas distribution were compared between continuous-flow ventilation (CFV) and conventional mechanical ventilation (CMV). Nine dogs were studied while they were lying supine, and three dogs were studied while they were lying prone. A single-lumen catheter for tracheal insufflation and a double-lumen catheter for bilateral endobronchial insufflation [inspired O2 fraction = 0.4; inspired minute ventilation = 1.7 +/- 0.3 (SD) 1.kg-1.min-1] were evaluated. Intrapulmonary gas distribution was assessed from regional 133Xe clearances. In dogs lying supine, CO2 elimination was more efficient with endobronchial insufflation than with tracheal insufflation, but the alveolar-arterial O2 partial pressure difference was larger during CFV than during CMV, regardless of the type of insufflation. By contrast, endobronchial insufflation maintained both arterial PCO2 and alveolar-arterial O2 partial pressure difference at significantly lower levels in dogs lying prone than in dogs lying supine. In dogs lying supine, the dependent lung was preferentially ventilated during CMV but not during CFV. In dogs lying prone, gas distribution was uniform with both modes of ventilation. The alveolar-arterial O2 partial pressure difference during CFV in dogs lying supine was negatively correlated with the reduced ventilation of the dependent lung, which suggests that increased ventilation-perfusion mismatching was responsible for the increase in alveolar-arterial O2 partial pressure difference. The more efficient oxygenation during CFV in dogs lying prone suggests a more efficient matching of ventilation to perfusion, presumably because the distribution of blood flow is also nearly uniform

  9. Protective Mechanical Ventilation in Inflammatory and Ventilator-Associated Pneumonia Models

    OpenAIRE

    Sperber, Jesper

    2016-01-01

    Severe infections, trauma or major surgery can each cause a state of systemic inflammation. These causes for systemic inflammation often coexist and complicate each other. Mechanical ventilation is commonly used during major surgical procedures and when respiratory functions are failing in the intensive care setting. Although necessary, the use of mechanical ventilation can cause injury to the lungs and other organs especially under states of systemic inflammation. Moreover, a course of mecha...

  10. Numerical and experimental analysis of the energy saving and potential of ventilation of opaque ventilates facades

    OpenAIRE

    Peci López, Fernando

    2013-01-01

    Nowadays the efficient use of energy is a crucial necessity. Buildings are among the greater energy consumers in a country and the ventilation and HVAC systems account for a high percentage of this consumption. A way of reducing the energy consumption of these systems is taking advantage of the renewable energies available. In this document an opaque ventilated façade (OVF) was studied. An OVF takes advantage of the wind force and solar radiation to provide the indoor space wit...

  11. Pressure-controlled versus volume-controlled ventilation during one-lung ventilation in elderly patients with poor pulmonary function

    OpenAIRE

    2014-01-01

    Objective: The aim was to investigate the effects of two different ventilatory strategies: Pressure-controlled ventilation (PCV) versus volume-controlled ventilation (VCV) in elderly patients with poor pulmonary function during one-lung ventilation (OLV). Patients and Methods: The patients were enrolled into the study having poor pulmonary function (forced expiratory volume in 1 s

  12. History of neonatal resuscitation. Part 1: Artificial ventilation.

    Science.gov (United States)

    Obladen, Michael

    2008-01-01

    The construction of manual ventilators by Hunter, Chaussier, and Gorcy seemed to set the stage for artificial ventilation of the neonate at the end of the 18th century. When Leroy d'Etiolles recognized pneumothorax as a complication of ventilation in 1828, the Paris Academy of Science advised against positive pressure ventilation. Indirect techniques like that of Silvester or the Schultze swingings gained widespread acceptance and prevailed until the First World War. Modern ventilators were developed following the poliomyelitis epidemics in the 20th century.

  13. Ventilation imaging with 99m technetium labeled aerosols

    International Nuclear Information System (INIS)

    The major clinical use of ventilation perfusion scintigraphy is for the diagnosis of pulmonary embolism (PE). Accurate diagnosis of PE is essential since effective treatment if available. The scintigraphic characteristic of PE are segmental perfusion defects in lung that is normally ventilated. The inherent shortcoming of perfusion scintigraphy is its lack of specificity. Combining a ventilation study with perfusion imaging improves the diagnostic specificity of lungs scintigraphy. This article describes clinical use of simple same day ventilation and perfusion imaging technique. The technique is based on a low dose ventilation procedure using 99m Tc labelled aerosol immediately followed by a standard dose perfusion procedure. (author)

  14. SY Tank Farm ventilation isolation option risk assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Powers, T.B.; Morales, S.D.

    1994-03-01

    The safety of the 241-SY Tank Farm ventilation system has been under extensive scrutiny due to safety concerns associated with tank 101-SY. Hydrogen and other gases are generated and trapped in the waste below the liquid surface. Periodically, these gases are released into the dome space and vented through the exhaust system. This attention to the ventilation system has resulted in the development of several alternative ventilation system designs. The ventilation system provides the primary means of mitigation of accidents associated with flammable gases. This report provides an assessment of various alternatives ventilation system designs.

  15. Continuous distributions of specific ventilation recovered from inert gas washout

    Science.gov (United States)

    Lewis, S. M.; Evans, J. W.; Jalowayski, A. A.

    1978-01-01

    A new technique is described for recovering continuous distributions of ventilation as a function of tidal ventilation/volume ratio from the nitrogen washout. The analysis yields a continuous distribution of ventilation as a function of tidal ventilation/volume ratio represented as fractional ventilations of 50 compartments plus dead space. The procedure was verified by recovering known distributions from data to which noise had been added. Using an apparatus to control the subject's tidal volume and FRC, mixed expired N2 data gave the following results: (a) the distributions of young, normal subjects were narrow and unimodal; (b) those of subjects over age 40 were broader with more poorly ventilated units; (c) patients with pulmonary disease of all descriptions showed enlarged dead space; (d) patients with cystic fibrosis showed multimodal distributions with the bulk of the ventilation going to overventilated units; and (e) patients with obstructive lung disease fell into several classes, three of which are illustrated.

  16. Academic Emergency Medicine Physicians’ Knowledge of Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Susan R. Wilcox

    2016-05-01

    Full Text Available Introduction: Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM education or clinical practice. The objective of this study was to quantify EM attendings’ education, experience, and knowledge regarding mechanical ventilation in the emergency department. Methods: We developed a survey of academic EM attendings’ educational experiences with ventilators and a knowledge assessment tool with nine clinical questions. EM attendings at key teaching hospitals for seven EM residency training programs in the northeastern United States were invited to participate in this survey study. We performed correlation and regression analyses to evaluate the relationship between attendings’ scores on the assessment instrument and their training, education, and comfort with ventilation. Results: Of 394 EM attendings surveyed, 211 responded (53.6%. Of respondents, 74.5% reported receiving three or fewer hours of ventilation-related education from EM sources over the past year and 98 (46% reported receiving between 0-1 hour of education. The overall correct response rate for the assessment tool was 73.4%, with a standard deviation of 19.9. The factors associated with a higher score were completion of an EM residency, prior emphasis on mechanical ventilation during one’s own residency, working in a setting where an emergency physician bears primary responsibility for ventilator management, and level of comfort with managing ventilated patients. Physicians’ comfort was associated with the frequency of ventilator changes and EM management of ventilation, as well as hours of education. Conclusion: EM attendings report caring for mechanically ventilated patients frequently, but most receive fewer than three educational hours a year on mechanical ventilation, and nearly half receive 0-1 hour. Physicians’ performance on an assessment tool for mechanical ventilation is

  17. Impacts of Ventilation Ratio and Vent Balance on Cooling Load and Air Flow of Naturally Ventilated Attics

    Directory of Open Access Journals (Sweden)

    Zhigang Shen

    2012-08-01

    Full Text Available The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields are characterized by thermal stratification, except for the soffit regions. It is demonstrated that an increase in ventilation ratio will reduce attic cooling load. Compared with unbalanced vent configurations, balanced attic ventilation is shown to be the optimal solution in both maximizing ventilating flow rate and minimizing cooling load for attics with ventilation ratio lower than 1/100. For attics with ventilation ratios greater than 1/67, a configuration of large ridge vent with small soffit vent favors ventilating air flow enhancement, while a configuration of small ridge vent with large soffit vent results in the lowest cooling energy consumption.

  18. Comparison of 4-Dimensional Computed Tomography Ventilation With Nuclear Medicine Ventilation-Perfusion Imaging: A Clinical Validation Study

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradskiy, Yevgeniy, E-mail: yevgeniy.vinogradskiy@ucdenver.edu [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Koo, Phillip J. [Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado (United States); Castillo, Richard [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Castillo, Edward; Guerrero, Thomas [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Computational and Applied Mathematics, Rice University, Houston, Texas (United States); Gaspar, Laurie E.; Miften, Moyed; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)

    2014-05-01

    Purpose: Four-dimensional computed tomography (4DCT) ventilation imaging provides lung function information for lung cancer patients undergoing radiation therapy. Before 4DCT-ventilation can be implemented clinically it needs to be validated against an established imaging modality. The purpose of this work was to compare 4DCT-ventilation to nuclear medicine ventilation, using clinically relevant global metrics and radiologist observations. Methods and Materials: Fifteen lung cancer patients with 16 sets of 4DCT and nuclear medicine ventilation-perfusion (VQ) images were used for the study. The VQ-ventilation images were acquired in planar mode using Tc-99m-labeled diethylenetriamine-pentaacetic acid aerosol inhalation. 4DCT data, spatial registration, and a density-change-based model were used to compute a 4DCT-based ventilation map for each patient. The percent ventilation was calculated in each lung and each lung third for both the 4DCT and VQ-ventilation scans. A nuclear medicine radiologist assessed the VQ and 4DCT scans for the presence of ventilation defects. The VQ and 4DCT-based images were compared using regional percent ventilation and radiologist clinical observations. Results: Individual patient examples demonstrate good qualitative agreement between the 4DCT and VQ-ventilation scans. The correlation coefficients were 0.68 and 0.45, using the percent ventilation in each individual lung and lung third, respectively. Using radiologist-noted presence of ventilation defects and receiver operating characteristic analysis, the sensitivity, specificity, and accuracy of the 4DCT-ventilation were 90%, 64%, and 81%, respectively. Conclusions: The current work compared 4DCT with VQ-based ventilation using clinically relevant global metrics and radiologist observations. We found good agreement between the radiologist's assessment of the 4DCT and VQ-ventilation images as well as the percent ventilation in each lung. The agreement lessened when the data were

  19. Comparison of 4-Dimensional Computed Tomography Ventilation With Nuclear Medicine Ventilation-Perfusion Imaging: A Clinical Validation Study

    Science.gov (United States)

    Vinogradskiy, Yevgeniy; Koo, Phillip J.; Castillo, Richard; Castillo, Edward; Guerrero, Thomas; Gaspar, Laurie E.; Miften, Moyed; Kavanagh, Brian D.

    2014-01-01

    Purpose Four-dimensional computed tomography (4DCT) ventilation imaging provides lung function information for lung cancer patients undergoing radiation therapy. Before 4DCT-ventilation can be implemented clinically it needs to be validated against an established imaging modality. The purpose of this work was to compare 4DCT-ventilation to nuclear medicine ventilation, using clinically relevant global metrics and radiologist observations. Methods and Materials Fifteen lung cancer patients with 16 sets of 4DCT and nuclear medicine ventilation-perfusion (VQ) images were used for the study. The VQ-ventilation images were acquired in planar mode using Tc-99m-labeled diethylenetriamine-pentaacetic acid aerosol inhalation. 4DCT data, spatial registration, and a density-change-based model were used to compute a 4DCT-based ventilation map for each patient. The percent ventilation was calculated in each lung and each lung third for both the 4DCT and VQ-ventilation scans. A nuclear medicine radiologist assessed the VQ and 4DCT scans for the presence of ventilation defects. The VQ and 4DCT-based images were compared using regional percent ventilation and radiologist clinical observations. Results Individual patient examples demonstrate good qualitative agreement between the 4DCT and VQ-ventilation scans. The correlation coefficients were 0.68 and 0.45, using the percent ventilation in each individual lung and lung third, respectively. Using radiologist-noted presence of ventilation defects and receiver operating characteristic analysis, the sensitivity, specificity, and accuracy of the 4DCT-ventilation were 90%, 64%, and 81%, respectively. Conclusions The current work compared 4DCT with VQ-based ventilation using clinically relevant global metrics and radiologist observations. We found good agreement between the radiologist’s assessment of the 4DCT and VQ-ventilation images as well as the percent ventilation in each lung. The agreement lessened when the data were analyzed

  20. CANISTER HANDLING FACILITY - VENTILATION AIR CALCULATION

    International Nuclear Information System (INIS)

    The purpose of this analysis is to establish the preliminary Ventilation Confinement Zone for the Canister Handling Facility (CHF). The results of this document will be used to determine the air quantities for each VCZ that will eventually be reflected in the development of the Ventilation Flow Diagrams. The analyses contained in this document are developed by D and E/Mechanical HVAC and are intended solely for the use of the D and E/Mechanical HVAC in its work regarding Confinement Zoning Analysis for the Canister Handling Facility. Yucca Mountain Project personnel from D and E/Mechanical HVAC should be consulted before use of the analyses for purposes other than those stated herein or used by individuals other than authorized personnel in D and E/Mechanical HVAC

  1. Dead space: the physiology of wasted ventilation.

    Science.gov (United States)

    Robertson, H Thomas

    2015-06-01

    An elevated physiological dead space, calculated from measurements of arterial CO2 and mixed expired CO2, has proven to be a useful clinical marker of prognosis both for patients with acute respiratory distress syndrome and for patients with severe heart failure. Although a frequently cited explanation for an elevated dead space measurement has been the development of alveolar regions receiving no perfusion, evidence for this mechanism is lacking in both of these disease settings. For the range of physiological abnormalities associated with an increased physiological dead space measurement, increased alveolar ventilation/perfusion ratio (V'A/Q') heterogeneity has been the most important pathophysiological mechanism. Depending on the disease condition, additional mechanisms that can contribute to an elevated physiological dead space measurement include shunt, a substantial increase in overall V'A/Q' ratio, diffusion impairment, and ventilation delivered to unperfused alveolar spaces. PMID:25395032

  2. Bicycle helmet ventilation and comfort angle dependence.

    Science.gov (United States)

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  3. Bilateral Scapulohumeral Ankylosis after Prolonged Mechanical Ventilation.

    Science.gov (United States)

    van Lotten, Manon L; Schreinemakers, J Rieneke; van Noort, Arthur; Rademakers, Maarten V

    2016-09-01

    This case demonstrates a rarely reported bilateral scapulohumeral bony ankylosis. A young woman developed extensive heterotopic ossifications (HOs) in both shoulder joints after being mechanically ventilated for several months at the intensive care unit in a comatose status. She presented with a severe movement restriction of both shoulder joints. Surgical resection of the bony bridges was performed in 2 separate sessions with a significant improvement of shoulder function afterwards. No postoperative complications, pain, or recurrence of HOs were noted at 1-year follow-up. Mechanical ventilation, immobilization, neuromuscular blockage, and prolonged sedation are known risk factors for the development of HOs in the shoulder joints. Relatively early surgical resection of the HOs can be performed safely in contrary to earlier belief. Afterwards, nonsteroidal anti-inflammatory drugs and/or radiation therapy can be possible treatment modalities to prevent recurrence of HOs. PMID:27583120

  4. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... quite well with the Epstein's formula ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed....

  5. 玻璃钢-聚氨酯泡沫夹层板弯曲失效研究%The bending failure of fiberglass-polyurethane foam sandwich panel

    Institute of Scientific and Technical Information of China (English)

    张雁; 杨树兴; 魏传锋

    2014-01-01

    In order to study the bending failure mechanism of composite sandwich panels, the fiberglass-polyurethane foam sandwich panel is designed and manufactured by vacuum infusion. A theoretical model for its failure is built and the bending test is carried out, as well as the numerical simulation. The failure load is obtained, and two failure modes are revealed during the bending process. An explanation of two inflexion points observed in the load-deflection curve of the glass fiber-polyurethane foam sandwich panel is made. It is concluded that the first inflexion point, corresponding to the first failure mode, is owing to the tensile splitting of the surface glass fiber, and the second one, corresponding to the second failure mode, is due to the shear force splitting of the middle foam.%采用真空灌注方法研制了玻璃纤维-聚氨酯泡沫夹层板,通过理论推导、数值仿真及试验验证对该夹层板的弯曲失效特性进行了研究,得到了实际失效载荷以及两种失效模式。研究表明,玻璃纤维-聚氨酯泡沫夹层板的载荷变形曲线中会出现2处拐点:第一拐点对应第一失效模式,其表征为表层玻璃纤维被拉伸断裂;第二拐点对应第二失效模式,其表征为芯体泡沫被剪切开裂。

  6. Preparation of emulsion adhesive for fiberglass mesh%玻璃纤维网格布用乳液胶粘剂的研制

    Institute of Scientific and Technical Information of China (English)

    于忠英

    2011-01-01

    A styrene-acrylate emulsion adhesive for fiberglass mesh was prepared by polymerization method of pre-emulsified monomers. The effects of monomcr.emulsifier, initiator and reaction temperature were studied on the stsbility.water resistance,adhesion,viscosity and polymerization process.The optimum process conditions were determined. The results showed that when the miss ratio of soft and hard monomer was 47/53,the emulsifier and APS were 3% and 0.4% by weight of monomer respectively,SDS/OP -10 was 2/1.the polymerization temperature was 82~84 ℃ and reaction time was 2.5 hr,the porperties of styrene-acrylate emulsion were better.%采用予乳化聚合方法制备了玻璃纤维网格布用苯丙乳液胶粘剂.探讨了单体、乳化剂、引发剂、聚合反应温度等对乳液的稳定性、耐水性、粘接性、黏度及聚合反应过程的影响.确定了最佳的工艺条件.结果表明,当软硬单体质量比为47/53、乳化剂占单体的3%,mSDS/mOP-10=2/1,APS占单体的0.4%,聚合反应温度为82~84℃、反应时间为2.5 h时,制备的苯丙乳液综合性能最佳.

  7. Association of compliance of ventilator bundle with incidence of ventilator-associated pneumonia and ventilator utilization among critical patients over 4 years

    Directory of Open Access Journals (Sweden)

    Majid S Al-Thaqafy

    2014-01-01

    Full Text Available Background: Several studies showed that the implementation of the Institute for Healthcare Improvement (IHI ventilator bundle alone or with other preventive measures are associated with reducing Ventilator-Associated Pneumonia (VAP rates. However, the association with ventilator utilization was rarely examined and the findings were conflicting. The objectives were to validate the bundle association with VAP rate in a traditionally high VAP environment and to examine its association with ventilator utilization. Materials and Methods: The study was conducted at the adult medical-surgical intensive care unit (ICU at King Abdulaziz Medical City, Saudi Arabia, between 2010 and 2013. VAP data were collected by a prospective targeted surveillance as per Centers for Disease Control and Prevention (CDC/National Healthcare Safety Network (NHSN methodology while bundle data were collected by a cross-sectional design as per IHI methodology. Results: Ventilator bundle compliance significantly increased from 90% in 2010 to 97% in 2013 (P for trend < 0.001. On the other hand, VAP rate decreased from 3.6 (per 1000 ventilator days in 2010 to 1.0 in 2013 (P for trend = 0.054 and ventilator utilization ratio decreased from 0.73 in 2010 to 0.59 in 2013 (P for trend < 0.001. There were negative significant correlations between the trends of ventilator bundle compliance and VAP rate (cross-correlation coefficients −0.63 to 0.07 and ventilator utilization (cross-correlation coefficients −0.18 to −0.63. Conclusion: More than 70% improvement of VAP rates and approximately 20% improvement of ventilator utilization were observed during IHI ventilator bundle implementation among adult critical patients in a tertiary care center in Saudi Arabia. Replicating the current finding in multicenter randomized trials is required before establishing any causal link.

  8. Simulacije dihanja: Simulation of pulmonary ventilation:

    OpenAIRE

    Dolenšek, Janez

    2008-01-01

    In addition to animal experiments, digital and analogue simulations are also used in medical research as well in medical education. In this way, various physiological systems can be studied and, if suitably presented, simulations can greatly improve the understanding of underlying processes. In initial simulations of pulmonary ventilation, mechanical models were used. Recently, these have been replaced by computer-assisted digital approaches. Our method involved the construction of a model of...

  9. Ventilation-perfusion scintigraphy in pneumology

    International Nuclear Information System (INIS)

    Perfusion scintigraphy belongs to the most efficient and important techniques available for routine diagnostics in pneumology. Its main field of indication however is restricted to relatively small sectors of the non-invasive exploration of structural and functional lung conditions and interactions, as for instance the diagnosis of pulmonary artery embolism, assessment of the ventilation/perfusion ratio in case of central location of a tumour, and pre-operative pulmonary functional diagnostics. (orig.)

  10. Ultra-protective ventilation and hypoxemia

    OpenAIRE

    Gattinoni, Luciano

    2016-01-01

    Partial extracorporeal CO2 removal allows a decreasing tidal volume without respiratory acidosis in patients with acute respiratory distress syndrome. This, however, may be associated with worsening hypoxemia, due to several mechanisms, such as gravitational and reabsorption atelectasis, due to a decrease in mean airway pressure and a critically low ventilation-perfusion ratio, respectively. In addition, an imbalance between alveolar and artificial lung partial pressures of nitrogen may accel...

  11. CFD design analysis of ventilated disc brakes

    OpenAIRE

    Pulugundla, Gautam

    2008-01-01

    This thesis reports the numerical investigation of the automotive ventilated disc brake rotor. Disc brakes operate on the principle of friction by converting kinetic energy into heat energy. The main objective of a disc brake rotor is to store this heat energy and dissipate it as soon as possible. This work is carried out in a area where there is very limited understanding. Commercial CFD code FLUENT was used for carrying out the simulations with the rotor rotating in still ...

  12. Pseudomonas aeruginosa ventilator-associated pneumonia management

    OpenAIRE

    Ramírez-Estrada S; Borgatta B; Rello J.

    2016-01-01

    Sergio Ramírez-Estrada,1 Bárbara Borgatta,1,2 Jordi Rello3,4 1Critical Care Department, Vall d'Hebron University Hospital, 2CRIPS, Vall d'Hebron Institute of Research (VHIR), 3Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, 4Centro de Investigación Biomédica en Red Enfermedad Respiratoria – CIBERES, Madrid, Spain Abstract: Ventilator-associated pneumonia is the most common infection i...

  13. Fractal ventilation enhances respiratory sinus arrhythmia

    Directory of Open Access Journals (Sweden)

    Girling Linda G

    2005-05-01

    Full Text Available Abstract Background Programming a mechanical ventilator with a biologically variable or fractal breathing pattern (an example of 1/f noise improves gas exchange and respiratory mechanics. Here we show that fractal ventilation increases respiratory sinus arrhythmia (RSA – a mechanism known to improve ventilation/perfusion matching. Methods Pigs were anaesthetised with propofol/ketamine, paralysed with doxacurium, and ventilated in either control mode (CV or in fractal mode (FV at baseline and then following infusion of oleic acid to result in lung injury. Results Mean RSA and mean positive RSA were nearly double with FV, both at baseline and following oleic acid. At baseline, mean RSA = 18.6 msec with CV and 36.8 msec with FV (n = 10; p = 0.043; post oleic acid, mean RSA = 11.1 msec with CV and 21.8 msec with FV (n = 9, p = 0.028; at baseline, mean positive RSA = 20.8 msec with CV and 38.1 msec with FV (p = 0.047; post oleic acid, mean positive RSA = 13.2 msec with CV and 24.4 msec with FV (p = 0.026. Heart rate variability was also greater with FV. At baseline the coefficient of variation for heart rate was 2.2% during CV and 4.0% during FV. Following oleic acid the variation was 2.1 vs. 5.6% respectively. Conclusion These findings suggest FV enhances physiological entrainment between respiratory, brain stem and cardiac nonlinear oscillators, further supporting the concept that RSA itself reflects cardiorespiratory interaction. In addition, these results provide another mechanism whereby FV may be superior to conventional CV.

  14. COMPARISON OF HIGH-FREQUENCY OSCILLATION VENTILATION WITH CONVENTIONAL MANDATORY VENTILATION IN ANIMAL ARDS MODEL

    Institute of Scientific and Technical Information of China (English)

    SHI Guo-chao; HUANG Shao-guang; LI Min; DENG Wei-wu; WAN Huan-ying

    2005-01-01

    Objective To compare effect of high-frequency oscillation ventilation (HFOV) and conventional mandatory ventilation (CMV) on lung injury development in rabbit with acute respiratory distress syndrome (ARDS). Methods Animals that underwent saline lung lavage to produce lung injury were randomized to one of the two treatment groups (HFOV or CMV, n=6). PaCO2 was maintained between 35-45mmHg and arterial oxygen saturation (SaO2) was maintain >88% by adjusting corresponding ventilator parameters. Ventilation period was 6h. Lung fluids were aspirated before and at the end of ventilation for cell analysis. Then the animals were euthanized, lung tissue was removed for wet/dry weight measurement, light and electron microscopic examination.Results The difference of artery blood gas analyses(pH, PaO2, PaCO2) between HFOV and CMV was insignificant. The difference between HFOV and CMV in cytological examination of lung fluids, wet/dry weight measurement was also insignificant. But compared with CMV,HFOV not only reduced the area of lung injury, but also reduced lung injury score in light and electron microscopic examination. Conclusion When same artery blood gas analysis was obtained, HFOV significantly reduced lung injury development in ARDS animal than CMV. As a lung protection strategy, HFOV can be used in the treatment of ARDS.

  15. Why we ventilate our houses - An historical look

    Energy Technology Data Exchange (ETDEWEB)

    Matson, Nance E.; Sherman, Max H.

    2004-05-14

    The knowledge of how to ventilate buildings, and how much ventilation is necessary for human health and comfort, has evolved over centuries of trial and error. Humans and animals have developed successful solutions to the problems of regulating temperature and removing air pollutants through the use of ventilation. These solutions include ingenious construction methods, such as engineered passive ventilation (termite mounds and passive stacks), mechanical means (wing-powered, fans), and an evolving effort to identify problems and develop solutions. Ventilation can do more than help prevent building occupants from getting sick; it can provide an improved indoor environment. Codes and standards provide minimum legal requirements for ventilation, but the need for ventilation goes beyond code minima. In this paper we will look at indoor air pollutant sources over time, the evolution of ventilation strategies, current residential ventilation codes and standards (e.g., recently approved ASHRAE Standard 62.2), and briefly discuss ways in which we can go beyond the standards to optimize residential ventilation, reduce indoor air quality problems, and provide corresponding social and economic benefit.

  16. Advanced Controls for Residential Whole-House Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William; Walker, Iain; Sherman, Max

    2014-08-01

    Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.

  17. Sustained ventilation: perfusion imbalance during hemodialysis.

    Science.gov (United States)

    Milner, L S; Rothberg, A D; Thomson, P D; Stothart, M

    1983-06-01

    Five children between the ages of 6 and 15 years, who required chronic hemodialysis (HD) for renal failure, were studied to evaluate the central and pulmonary effects of HD on gas exchange. Acetate dialysate was used, and dialysate pO2 and pCO2, arterial pO2 and pCO2, endtidal CO2 and minute ventilation were measured pre-HD and 15, 30, 60, 120 and 240 minutes after commencement of HD. Arterial-alveolar CO2 gradient (aADCO2) was calculated to determine the ventilation: perfusion (V/Q) status. Minute ventilation did not change significantly from the pre-HD value of 8.9 +/- 1.1 l/min (mean +/- SD). The aADCO2 increased significantly from 3.2 +/- 3.7 mmHg to 8.4 +/- 2.4 mmHg at 15 mins (p less than .01) and was still elevated at 120 mins. (9.1 +/- 3.4 mmHg, p less than .02). There was a weak but significant inverse relationship between aADCO2 and arterial pO2 (r -0.42, p less than 0.05). The results suggest that, in these children, dialysed at altitude, dialysis-related hypoxemia appears to be the result of a sustained V/Q mismatch, possibly related to a decrease in pulmonary perfusion. PMID:6413444

  18. Collective fluid mechanics of honeybee nest ventilation

    Science.gov (United States)

    Gravish, Nick; Combes, Stacey; Wood, Robert J.; Peters, Jacob

    2014-11-01

    Honeybees thermoregulate their brood in the warm summer months by collectively fanning their wings and creating air flow through the nest. During nest ventilation workers flap their wings in close proximity in which wings continuously operate in unsteady oncoming flows (i.e. the wake of neighboring worker bees) and near the ground. The fluid mechanics of this collective aerodynamic phenomena are unstudied and may play an important role in the physiology of colony life. We have performed field and laboratory observations of the nest ventilation wing kinematics and air flow generated by individuals and groups of honeybee workers. Inspired from these field observations we describe here a robotic model system to study collective flapping wing aerodynamics. We microfabricate arrays of 1.4 cm long flapping wings and observe the air flow generated by arrays of two or more fanning robotic wings. We vary phase, frequency, and separation distance among wings and find that net output flow is enhanced when wings operate at the appropriate phase-distance relationship to catch shed vortices from neighboring wings. These results suggest that by varying position within the fanning array honeybee workers may benefit from collective aerodynamic interactions during nest ventilation.

  19. Volumetric capnography in the mechanically ventilated patient.

    Science.gov (United States)

    Blanch, L; Romero, P V; Lucangelo, U

    2006-06-01

    Expiratory capnogram provides qualitative information on the waveform patterns associated with mechanical ventilation and quantitative estimation of expired CO2. Volumetric capnography simultaneously measures expired CO2 and tidal volume and allows identification of CO2 from 3 sequential lung compartments: apparatus and anatomic dead space, from progressive emptying of alveoli and alveolar gas. Lung heterogeneity creates regional differences in CO2 concentration and sequential emptying contributes to the rise of the alveolar plateau and to the steeper the expired CO2 slope. The concept of dead space accounts for those lung areas that are ventilated but not perfused. In patients with sudden pulmonary vascular occlusion due to pulmonary embolism, the resultant high V/Q mismatch produces an increase in alveolar dead space. Calculations derived from volumetric capnography are useful to suspect pulmonary embolism at the bedside. Alveolar dead space is large in acute lung injury and when the effect of positive end-expiratory pressure (PEEP) is to recruit collapsed lung units resulting in an improvement of oxygenation, alveolar dead space may decrease, whereas PEEP-induced overdistension tends to increase alveolar dead space. Finally, measurement of physiologic dead space and alveolar ejection volume at admission or the trend during the first 48 hours of mechanical ventilation might provide useful information on outcome of critically ill patients with acute lung injury or acute respiratory distress syndrome. PMID:16682932

  20. Tomographic display of ventilation-perfusion ratio

    International Nuclear Information System (INIS)

    Tomographic displays of the distribution of ventilation-perfusion ratio in six subjects with a single photon radionuclide computed tomography (RCT) were obtained. The distribution of ventilation (V) and perfusion (Q) were measured separately with continuous breathing of Kr-81m and with intravenous administration of Tc-99m labelled macroaggregates of human serum albumin (MAA). V/Q was calculated pixel-by-pixel and the distributions of V/Q were displayed in a logarithmic scale with the surrounding thoracic cage obtained from transmission CT. The number of voxel, ventilation and perfusion were plotted against log(V/Q). They had almost log normal distributions with smaller variances in healthy subjects than those with emphysema or bronchitis. In the former, much coincidence between V and Q was observed, whereas in the latter, dissociation was seen between them. This noninvasive technique provided not only the visualization of the distribution of V/Q in a transaxial images, but also the quantifications of the V-Q mismatch

  1. Ventilation imaging with Kr-81m

    International Nuclear Information System (INIS)

    Sixty-five patients with suspected pulmonary embolism were studied prospectively with both Kr-81m and Xe-133 ventilation imaging and Tc-99m MAA perfusion imaging. The krypton images, perfusion scintigrams and chest radiographs were read independently of the xenon images, perfusion scintigrams and chest radiographs by three observers. The studies of 53 patients were interpreted as normal or as indicative of a low or intermediate probability for pulmonary embolism with both gases. One study indicated intermediate probability with Xe-133 due to diffuse, severe xenon retention but low probability with Kr-81m because of close ventilation-perfusion correspondence. The studies of 9 patients indicated a high probability of embolism with both gases, while those of two additional patients (one with emboli at angiography) indicated a high probability only with Kr-81m. While essential agreement between Xe-133 and Kr-81m ventilation imaging was found in most patients, the significant difference in interpretation in 2 of 11 patients with probable pulmonary embolism suggests that a controlled, prospective trial with pulmonary angiography is warranted before Kr-81m is employed for routine clinical use. (orig.)

  2. Ventilation-perfusion study using radioactive xenon

    International Nuclear Information System (INIS)

    In the framework of research concerning the physiopathology of the lung of aged subjects, studies were performed utilizing radioactive xenon. Subjects generally undergo three tests, two serving to evaluate ventilation. The patient is placed in a spirometric circuit containing a mixture of radioactive xenon. An initial measurement is performed after a forced inspiration preceded by a forced expiration. The second measurement is effected after the patient has respired for several minutes in the spirometer, this ensuring the equilibrium between radioactivity in the lungs and the spirometric circuit. The curves thus obtained express the distribution of gas in respiratory capacity and in total pulmonary capacity, respectively. The differences between the two curves thus represents the distribution of residual capacity. The third test, that of perfusion, is done by an intravenous injection of 133Xe in physiological solution. In normal young subjects, perfusion and ventilation are more pronounced in basal than in apical areas, but the apical-basal gradient is lower for ventilation as compared to perfusion. The spirometric examination has confirmed ventilatory alterations of old age: a slight reduction of vital capacity concerning the reduction of reserve expiratory volume; a progressive increase in residual volume and, consequently, an intrapulmonary stagnation of air; a slight increase of the time of intrapulmonary gas mixture; a slight reduction of the maximum expiratory volume per second

  3. Thermal comfort and ventilation effectiveness in an office room with radiant floor cooling and displacement ventilation

    DEFF Research Database (Denmark)

    Krajcik, Michal; Tomasi, Roberta; Simone, Angela;

    2016-01-01

    The influence of displacement ventilation and a cooled floor on indoor climate in the cooling season were experimentally studied in a room representing an office with a shaded window, occupied by two simulated employees. The aim was to investigate whether the combination of these two systems can...... retain the favorable air and temperature distribution patterns and high ventilation effectiveness that are typically attained by displacement ventilation, while exploiting the energy conservation advantages of a high temperature cooling system. The tests were performed under a range of boundary.......5h-1. However, for a broad range of boundary conditions, decreasing the floor temperature resulted in vertical air temperature differences of up to 6K and vertical equivalent temperature differences of up to 8K for a seated person. Thus although the maximum draught rating at ankle level was 21...

  4. The influence of music during mechanical ventilation and weaning from mechanical ventilation: A review.

    Science.gov (United States)

    Hetland, Breanna; Lindquist, Ruth; Chlan, Linda L

    2015-01-01

    Mechanical ventilation (MV) causes many distressing symptoms. Weaning, the gradual decrease in ventilator assistance leading to termination of MV, increases respiratory effort, which may exacerbate symptoms and prolong MV. Music, a non-pharmacological intervention without side effects may benefit patients during weaning from mechanical ventilatory support. A narrative review of OVID Medline, PsychINFO, and CINAHL databases was conducted to examine the evidence for the use of music intervention in MV and MV weaning. Music intervention had a positive impact on ventilated patients; 16 quantitative and 2 qualitative studies were identified. Quantitative studies included randomized clinical trials (10), case controls (3), pilot studies (2) and a feasibility study. Evidence supports music as an effective intervention that can lesson symptoms related to MV and promote effective weaning. It has potential to reduce costs and increase patient satisfaction. However, more studies are needed to establish its use during MV weaning.

  5. Personal exposure between people in a room ventilated by textile terminals - with and without personalized ventilation

    DEFF Research Database (Denmark)

    Nielsen, P. V.; Hyldgaard, C.E.; Melikov, Arsen Krikor;

    2005-01-01

    The investigation is made in a room ventilated by an air distribution system based on a textile terminal. The air distribution in the room is mainly controlled by buoyancy forces from the heat sources, although the flow from the textile terminal can be characterized as a passive displacement flow...... with a downward direction in areas without thermal load. The system is extended by a personalized ventilation system to study the improved protection of people in a room. The investigation involves full-scale experiments with two breathing thermal manikins. One manikin is the source and the other the target....... In general it is found that when the air is supplied from the textile terminal alone, the flow in the room is fully mixed with a limited protection of the occupants. It is shown that the personalized ventilation improves the protection of occupants by increasing the personal exposure index....

  6. The influence of music during mechanical ventilation and weaning from mechanical ventilation: A review.

    Science.gov (United States)

    Hetland, Breanna; Lindquist, Ruth; Chlan, Linda L

    2015-01-01

    Mechanical ventilation (MV) causes many distressing symptoms. Weaning, the gradual decrease in ventilator assistance leading to termination of MV, increases respiratory effort, which may exacerbate symptoms and prolong MV. Music, a non-pharmacological intervention without side effects may benefit patients during weaning from mechanical ventilatory support. A narrative review of OVID Medline, PsychINFO, and CINAHL databases was conducted to examine the evidence for the use of music intervention in MV and MV weaning. Music intervention had a positive impact on ventilated patients; 16 quantitative and 2 qualitative studies were identified. Quantitative studies included randomized clinical trials (10), case controls (3), pilot studies (2) and a feasibility study. Evidence supports music as an effective intervention that can lesson symptoms related to MV and promote effective weaning. It has potential to reduce costs and increase patient satisfaction. However, more studies are needed to establish its use during MV weaning. PMID:26227333

  7. Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.

    Science.gov (United States)

    Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

    2011-07-01

    In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

  8. Hybrid Ventilation with Innovative Heat Recovery—A System Analysis

    Directory of Open Access Journals (Sweden)

    Bengt Hellström

    2013-02-01

    Full Text Available One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with heat recovery. The system also includes a ground source storage and waste water heat recovery system. The result of the analysis shows that the annual energy gain from ground source storage is limited. However, this is partly a consequence of the fact that the well functioning hybrid ventilation system leaves little room for improvements. The analysis shows that the hybrid ventilation system has potential to be an attractive solution for low energy buildings with a very low need for electrical energy.

  9. Aerosol ventilation scintigraphy in mechanically ventilated patients in the intensive care unit

    International Nuclear Information System (INIS)

    A simple economical apparatus was constructed to permit 99m technetium aerosol lung scanning in intubated patients requiring mechanical ventilation. A study was then undertaken which showed the technique to be feasible, reliable and to provide information leading to changes in diagnosis and management in patients in the Intensive Care Unit (ICU). The technique can identify pure ventilatory abnormalities particularly endobronchial obstruction. The technique does not require computer manipulation of images and allows the ready acquisition of ventilation scans in multiple projections which is a distinct advantage over radio xenon scanning

  10. Performance of "ductless" personalized ventilation in conjunction with displacement ventilation: Impact of intake height

    DEFF Research Database (Denmark)

    Halvonova, B.; Melikov, Arsen Krikor

    2010-01-01

    The importance of the intake positioning height above the floor level on the performance of “ductless” personalized ventilation (“ductless” PV) in conjunction with displacement ventilation (DV) was examined with regard to the quality of inhaled air and of the thermal comfort provided. A typical...... exhaled by one of the manikins and passive pollution on the table in front of the same manikin were simulated by constant dosing of tracer gases. The results show that the positioning of a “ductless” PV intake height up to 0.2 m above the floor will not significantly influence the quality of inhaled air...

  11. Non-invasive ventilation in acute cardiogenic pulmonary oedema

    OpenAIRE

    Agarwal, R.; Aggarwal, A.; D Gupta; S. Jindal

    2005-01-01

    Non-invasive ventilation (NIV) is the delivery of assisted mechanical ventilation to the lungs, without the use of an invasive endotracheal airway. NIV has revolutionised the management of patients with various forms of respiratory failure. It has decreased the need for invasive mechanical ventilation and its attendant complications. Cardiogenic pulmonary oedema (CPO) is a common medical emergency, and NIV has been shown to improve both physiological and clinical outcomes. From the data prese...

  12. The Use of Noninvasive Mechanical Ventilation in Myasthenic Crisis

    OpenAIRE

    Mustafa Said Aydoğan; M. Ali Erdoğan; Aytaç Yücel; Ülkü Özgül; Hüseyin Konur; Türkan Toğal; Mahmut Durmuş

    2012-01-01

    Myasthenia gravis is an autoimmune disease of the nicotinic acetylcholin receptors at the postsynaptic membrane of the neuromuscular junction. Myasthenic crisis, defined as respiratory failure requiring mechanical ventilation is a common life-threatening complication that occur approximately 15% to 20% of patients with MG. Endotracheal intubation and invasive mechanical ventilation have a number of complications and a high mortality. On the other hand, noninvasive mechanical ventilation is be...

  13. Pulmonary deposition of a nebulised aerosol during mechanical ventilation.

    OpenAIRE

    Thomas, S. H.; O'Doherty, M J; Fidler, H M; Page, C J; Treacher, D F; Nunan, T. O.

    1993-01-01

    BACKGROUND: There is increasing use of therapeutic aerosols in patients undergoing mechanical ventilation. Few studies have measured aerosol delivery to the lungs under these conditions with adequate experimental methods. Hence this study was performed to measure pulmonary aerosol deposition and to determine the reproducibility of the method of measurement during mechanical ventilation. METHODS: Nine male patients were studied during mechanical ventilation after open heart surgery and two exp...

  14. Mechanical ventilation interacts with endotoxemia to induce extrapulmonary organ dysfunction

    OpenAIRE

    O'Mahony, D. Shane; Liles, W. Conrad; William A Altemeier; Dhanireddy, Shireesha; Frevert, Charles W.; Liggitt, Denny; Martin, Thomas R.; Matute-Bello, Gustavo

    2006-01-01

    Introduction Multiple organ dysfunction syndrome (MODS) is a common complication of sepsis in mechanically ventilated patients with acute respiratory distress syndrome, but the links between mechanical ventilation and MODS are unclear. Our goal was to determine whether a minimally injurious mechanical ventilation strategy synergizes with low-dose endotoxemia to induce the activation of pro-inflammatory pathways in the lungs and in the systemic circulation, resulting in distal organ dysfunctio...

  15. Home Mechanical Ventilation: A Canadian Thoracic Society Clinical Practice Guideline

    OpenAIRE

    McKim, Douglas A.; Jeremy Road; Monica Avendano; Steve Abdool; Fabien Côté; Nigel Duguid; Janet Fraser; François Maltais; Morrison, Debra L.; Colleen O’Connell; Petrof, Basil J.; Karen Rimmer; Robert Skomro; Canadian Thoracic Society Home Mechanical Ventilation Committee

    2011-01-01

    Increasing numbers of patients are surviving episodes of prolonged mechanical ventilation or benefitting from the recent availability of user-friendly noninvasive ventilators. Although many publications pertaining to specific aspects of home mechanical ventilation (HMV) exist, very few comprehensive guidelines that bring together all of the current literature on patients at risk for or using mechanical ventilatory support are available. The Canadian Thoracic Society HMV Guideline Committee ha...

  16. Weaning from the ventilator in patients with respiratory failure

    OpenAIRE

    Berg, Bart

    1994-01-01

    textabstractWeaning from the ventilator is the gradual withdrawal of mechanical ventilatory support. Mechanical ventilation is well-accepted as rescue therapy in patients with life-threatening respiratory failure. As this treatment is associated with substantial morbidity and mortality, ventilatory support is only considered beneficial when applied during a limited period. In many patients however weaning from the ventilator is a cumbersome process. In this chapter the issues related to the w...

  17. Course of Weaning from Prolonged Mechanical Ventilation after Cardiac Surgery

    OpenAIRE

    Herlihy, James P.; Koch, Stephen M.; Jackson, Robert; Nora, Hope

    2006-01-01

    In order to determine the temporal pattern of weaning from mechanical ventilation for patients undergoing prolonged mechanical ventilation after cardiac surgery, we performed a retrospective review of 21 patients' weaning courses at our long-term acute care hospital. Using multiple regression analysis of an estimate of individual patients' percentage of mechanical ventilator support per day (%MVSD), we determined that 14 of 21 patients (67%) showed a statistically significant quadratic or cub...

  18. Trend of Maximal Inspiratory Pressure in Mechanically Ventilated Patients: Predictors

    OpenAIRE

    Pedro Caruso; Denise Simão Carnieli; Keila Harue Kagohara; Adriana Anciães; Jacqueline Santos Segarra; Daniel Deheinzelin

    2008-01-01

    INTRODUCTION: It is known that mechanical ventilation and many of its features may affect the evolution of inspiratory muscle strength during ventilation. However, this evolution has not been described, nor have its predictors been studied. In addition, a probable parallel between inspiratory and limb muscle strength evolution has not been investigated. OBJECTIVE: To describe the variation over time of maximal inspiratory pressure during mechanical ventilation and its predictors. We also stud...

  19. Systemic inflammation associated with mechanical ventilation among extremely preterm infants

    OpenAIRE

    Bose, Carl L.; Laughon, Matthew M; Allred, Elizabeth N.; O’Shea, T. Michael; Van Marter, Linda J; Ehrenkranz, Richard A.; Raina N Fichorova; Leviton, Alan

    2012-01-01

    Little evidence is available to document that mechanical ventilation is an antecedent of systemic inflammation in preterm humans. We obtained blood on postnatal day 14 from 726 infants born before the 28th week of gestation and measured the concentrations of 25 inflammation-related proteins. We created multivariable models to assess the relationship between duration of ventilation and protein concentrations in the top quartile. Compared to newborns ventilated for fewer than 7 days (N=247), th...

  20. Quantitative relationship of sick building syndrome symptoms with ventilation rates

    OpenAIRE

    Fisk, William J.

    2009-01-01

    Data from published studies were combined and analyzed to develop best-fit equations and curves quantifying the change in sick building syndrome (SBS) symptom prevalence in office workers with ventilation rate. For each study, slopes were calculated, representing the fractional change in SBS symptom prevalence per unit change in ventilation rate per person. Values of ventilation rate, associated with each value of slope, were also calculated. Linear regression equations were fitted to the res...

  1. Ventilator-induced lung injury in preterm infants

    OpenAIRE

    Carvalho, Clarissa Gutierrez; Rita C. Silveira; Procianoy, Renato Soibelmann

    2013-01-01

    In preterm infants, the need for intubation and mechanical ventilation is associated with ventilator-induced lung injuries and subsequent bronchopulmonary dysplasia. The aim of the present review was to improve the understanding of the mechanisms of injury that involve cytokine-mediated inflammation to contribute to the development of new preventive strategies. Relevant articles were retrieved from the PubMed database using the search terms "ventilator-induced lung injury preterm", "continuou...

  2. Should High-Frequency Ventilation in the Adult Be Abandoned?

    Science.gov (United States)

    Nguyen, Albert P; Schmidt, Ulrich H; MacIntyre, Neil R

    2016-06-01

    High-frequency oscillatory ventilation (HFOV) can improve ventilation-perfusion matching without excessive alveolar tidal stretching or collapse-reopening phenomenon. This is an attractive feature in the ventilation of patients with ARDS. However, two recent large multi-center trials of HFOV failed to show benefits in this patient population. The following review addresses whether, in view of these trails, HFOV should be abandoned in the adult population? PMID:27235314

  3. APRV Mode in Ventilator Induced Lung Injury (VILI)

    OpenAIRE

    Ata Mahmoodpoor; Samad EJ Golzari

    2014-01-01

    Ventilator-Induced Lung Injury (VILI), being a significant iatrogenic complication in the ICU patients, is associated with high morbidity and mortality. Numerous approaches, protocols and ventilation modes have been introduced and examined to decrease the incidence of VILI in the ICU patients. Airway pressure release ventilation (APRV), firstly introduced by Stock and Downs in 1987, applies higher Continuous Positive Airway Pressure (CPAP) levels in prolonged periods (P and T high) in order t...

  4. How we managed a difficult to ventilate patient

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Garg

    2015-01-01

    Full Text Available A 40-year-old female presented with respiratory difficulty, cough and sputum with blood streaking. Her right lung was destroyed, and trachea was shifted to the same side. On mechanical ventilation, she developed hypoxia and rise in blood pressure. Ventilator was not delivering set tidal volume. After looking into the cause, it was decided to reintubate the patient with new endotracheal tube after cutting bevel. Thereafter, there was successful ventilation.

  5. Mine site ventilation - the case for adequate training

    Energy Technology Data Exchange (ETDEWEB)

    Chalmers, D. [University of New South Wales, Sydney, NSW (Australia)

    2009-10-01

    In response to the recommendations made by the inquiry into the explosion at Moura No. 2 underground coal mine in 1994, the School of Mining Engineering at the University of New South Wales (UNSW) was approached to develop a ventilation trianing course. The School onow provides ventilation trianing and educaiotn to the coal industry in Queensland, New South Wales and New Zealand. Taining at the UNSW on euipment is non a statutory reuqirement for ventilation officers in NSW and Queensland. 1 ref.

  6. Recommended Ventilation Strategies for Energy-Efficient Production Homes

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, J.; Brown, R.; Koomey, J.; Warner, J.; Greenberg, S.

    1998-12-01

    This report evaluates residential ventilation systems for the U.S. Environmental Protection Agency's (EPA's) ENERGY STAR{reg_sign} Homes program and recommends mechanical ventilation strategies for new, low-infiltration, energy-efficient, single-family, ENERGY STAR production (site-built tract) homes in four climates: cold, mixed (cold and hot), hot humid, and hot arid. Our group in the Energy Analysis Department at Lawrence Berkeley National Lab compared residential ventilation strategies in four climates according to three criteria: total annualized costs (the sum of annualized capital cost and annual operating cost), predominant indoor pressure induced by the ventilation system, and distribution of ventilation air within the home. The mechanical ventilation systems modeled deliver 0.35 air changes per hour continuously, regardless of actual infiltration or occupant window-opening behavior. Based on the assumptions and analysis described in this report, we recommend independently ducted multi-port supply ventilation in all climates except cold because this strategy provides the safety and health benefits of positive indoor pressure as well as the ability to dehumidify and filter ventilation air. In cold climates, we recommend that multi-port supply ventilation be balanced by a single-port exhaust ventilation fan, and that builders offer balanced heat-recovery ventilation to buyers as an optional upgrade. For builders who continue to install forced-air integrated supply ventilation, we recommend ensuring ducts are airtight or in conditioned space, installing a control that automatically operates the forced-air fan 15-20 minutes during each hour that the fan does not operate for heating or cooling, and offering ICM forced-air fans to home buyers as an upgrade.

  7. Pulmonary ventilation following acclimation to a hot environment

    OpenAIRE

    Beaudin, Andrew Edward

    2007-01-01

    Human pulmonary ventilation and the hyperoxic-centrally mediated ventilatory response to CO2 were studied before and after a 10-day passive heat acclimation (HA). It was hypothesized pulmonary ventilation during a passively- or actively-induced hyperthermia would adapt similarily to thermolytic heat loss responses and that chemosensitivity would be increased following HA. Following HA, onset of increased cutaneous vasodilatation, eccrine sweating and ventilation in both passively- and activel...

  8. Comparison of triggering systems for neonatal patient triggered ventilation.

    OpenAIRE

    Hird, M F; Greenough, A

    1991-01-01

    The efficacy of two triggering systems was compared during neonatal patient triggered ventilation: the Graseby MR10 respiration monitor and airway pressure changes. Ten preterm infants were studied, median gestational age 33 weeks (range 28-35). Patient triggered ventilation was administered via the SLE ventilator at a series of inflation times (0.24, 0.3, and 0.4 seconds). Comparison was made between the trigger systems of the trigger delay, inflation volume delivered, and proportion of spon...

  9. Ventilator assessment of respiratory mechanics in paediatric intensive care

    OpenAIRE

    Harikumar, Gopinathannair; Greenough, Anne; Rafferty, Gerrard F.

    2007-01-01

    Many modern “paediatric” mechanical ventilators have in-built features for estimation of respiratory mechanics which could be useful in the management of ventilated infants and children. The aim of this study was to determine if such measurements were reproducible and accurate. Ventilator (Draeger Evita 4) displayed compliance (Cvent) and resistance (Rvent) values were assessed and compared to the results of respiratory system mechanics (respiratory system compliance (Crs) and resistance (Rrs...

  10. 环氧树脂对玻璃纤维/水泥复合材料界面性能的影响%THE INFLUENCES OF EPOXY RESIN ON THE INTERFACIAL PROPERTIES OF FIBERGLASS/CEMENT COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    马莉; 江晓禹

    2012-01-01

    在细观单纤维拔出实验基础上,利用ANSYS有限元程序,结合生死单元方法,对环氧树脂接枝处理的玻璃纤维/水泥基复合材料纤维拔出行为进行数值模拟,获得了界面理想结合/界面非理想结合下的拔出荷载-位移曲线.讨论了环氧树脂光滑接枝与粗糙接枝对玻璃纤维/水泥基复合材料界面强度的影响,研究表明,环氧树脂接枝不仅具有良好的界面结合性,还具有良好的机械嵌合性.%Based on the single fiber representative volume element of fiber reinforced composites, the single fiber pull-out test of fiberglass/cement composites were numerically simulated by using finite element code ANSYS and considering different embedment length. According to experimental data of fiberglass/cement composites, the numerical simulation is reasonable. The effect of graft on the single fiber pull-out of the composite was discussed. Moreover, based on the results of micro-experiments for fiber/matrix interfaces, the single fiber pull-out tests of fiberglass/cement composites were numerically simulated by using finite element code ANSYS and the method of element birth and death. The load-displacement curves were obtained for perfectly bonded interfaces and non-perfectly bonded interfaces. The influences of smooth and rough epoxy graft on the interfacial shear strengh of fiberglass/cement composites were discussed, compared with no graft, the interfacial shear strength results indicated that the smooth epoxy graft improves by 30% and the rough grafted epoxy resin improves by 90%. The results show that epoxy graft not only has good interfacial combination, but also has good mechanical embed effects.

  11. Flammable gas cloud build up in a ventilated enclosure

    International Nuclear Information System (INIS)

    Ventilation is frequently used as a means for preventing the build up of flammable or toxic gases in enclosed spaces. The effectiveness of the ventilation often has to be considered as part of a safety case or risk assessment. In this paper methods for assessing ventilation effectiveness for hazardous area classification are examined. The analysis uses data produced from Computational Fluid Dynamics (CFD) simulations of low-pressure jet releases of flammable gas in a ventilated enclosure. The CFD model is validated against experimental measurements of gas releases in a ventilation-controlled test chamber. Good agreement is found between the model predictions and the experimental data. Analysis of the CFD results shows that the flammable gas cloud volume resulting from a leak is largely dependent on the mass release rate of flammable gas and the ventilation rate of the enclosure. The effectiveness of the ventilation for preventing the build up of flammable gas can therefore be assessed by considering the average gas concentration at the enclosure outlet(s). It is found that the ventilation rate of the enclosure provides a more useful measure of ventilation effectiveness than considering the enclosure air change rate.

  12. Chair with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Bartholomaeussen, Niels Møller; Jakubowska, Ewa;

    2007-01-01

    Normally we protect ourselves from cross infection by supplying fresh air to a room by a diffuser, and this air is distributed in the room according to different principles as: mixing ventilation, displacement ventilation, etc. That means that it is necessary to supply a very large amount of air...... to the whole room to ensure a dilution of airborne infection. Personalized ventilation has proven to be a very efficient system to protect people from cross infection because clean air is supplied direct to the breathing zone. Most designs of personalized ventilation are based on a supply jet. The problem...

  13. Game on[Natural ventilation for the Sydney Olympics arena

    Energy Technology Data Exchange (ETDEWEB)

    Luke, A.

    2000-08-01

    The provision of design advice and computer modelling of a natural ventilation system for the Olympic Games arena in Sydney by UK consultants is reported, and the limitation of technology choices due to the advanced stage of the structural design and the need for unrestricted spectator views is noted. Details are given of the choice of natural cross-ventilation as well as passive driven ventilation, mechanical ventilation and some air conditioning, and simulation modelling indicating the effectiveness of night-time cooling for temperature control. The effects of the wind regime are considered, and the strategy to maximise energy efficiency and minimise waste is described.

  14. Humidification during invasive and noninvasive mechanical ventilation: 2012.

    Science.gov (United States)

    Restrepo, Ruben D; Walsh, Brian K

    2012-05-01

    We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and December 2011. The update of this clinical practice guideline is based on 184 clinical trials and systematic reviews, and 10 articles investigating humidification during invasive and noninvasive mechanical ventilation. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: 1. Humidification is recommended on every patient receiving invasive mechanical ventilation. 2. Active humidification is suggested for noninvasive mechanical ventilation, as it may improve adherence and comfort. 3. When providing active humidification to patients who are invasively ventilated, it is suggested that the device provide a humidity level between 33 mg H(2)O/L and 44 mg H(2)O/L and gas temperature between 34°C and 41°C at the circuit Y-piece, with a relative humidity of 100%. 4. When providing passive humidification to patients undergoing invasive mechanical ventilation, it is suggested that the HME provide a minimum of 30 mg H(2)O/L. 5. Passive humidification is not recommended for noninvasive mechanical ventilation. 6. When providing humidification to patients with low tidal volumes, such as when lung-protective ventilation strategies are used, HMEs are not recommended because they contribute additional dead space, which can increase the ventilation requirement and P(aCO(2)). 7. It is suggested that HMEs are not used as a prevention strategy for ventilator-associated pneumonia.

  15. Boundary Layer Ventilation Processes During a High Pressure Event

    Science.gov (United States)

    Gray, S. L.; Dacre, H. F.; Belcher, S. E.

    2006-12-01

    It is often assumed that ventilation of the atmospheric boundary layer is weak during high pressure events. But is this always true? Here we investigate the processes responsible for ventilation of the atmospheric boundary layer during a high pressure event that occured on the 9 May 2005 using the UK Met Office Unifed Model. Pollution sources are represented by the constant emission of a passive tracer everywhere over land. The ventilation processes observed include a sea breeze circulation, turbulent mixing across the top of the boundary layer followed by large-scale ascent, and shallow convection. Vertical distributions of tracer are validated with AMPEP (Aircraft Measurement of chemical Processing Export fluxes of Pollutants over the UK) CO aircraft measurements and are shown to agree impressively well. Budget calculations of tracers are performed in order to determine the relative importance of these ventilation processes. The sea breeze circulation was found to ventilate 26% of the boundary layer tracer by sunset of which 2% was above 2km. A combination of the sea breeze circulation and turbulent mixing ventilated 46% of the boundary layer tracer, of which 10% was above 2km. Finally, the sea breeze circulation, turbulent mixing and shallow convection processes together ventilated 52% of the tracer into the free troposphere, of which 26% was above 2km. Hence this study shows that signicant ventilation of the boundary layer can occur during high pressure events; turbulent mixing and convection processes can double the amount of pollution ventilated from the boundary layer.

  16. Ventilation and perfusion display in a single image

    International Nuclear Information System (INIS)

    A new method of ventilation and perfusion display onto a single image is presented. From the data on regions of interest of the lungs, three-dimensional histograms are created, containing as parameters X and Y for the position of the pixels, Z for the perfusion and colour for local ventilation. The perfusion value is supplied by sets of curves having Z proportional to the local perfusion count rate. Ventilation modulates colour. Four perspective views of the histogram are simultaneously displayed to allow visualization of the entire organ. Information about the normal ranges for both ventilation and perfusion is also provided in the histograms. (orig.)

  17. Calculation of Industrial Enterprise Ventilation System by Network Integral Method

    Directory of Open Access Journals (Sweden)

    Mihienkova Evgeniya I.

    2016-01-01

    Full Text Available This paper describe a ventilation system calculation of the technology building industrial enterprise. On the basis of the calculation model for the enterprise offered technical decision of ventilation systems, subject to a compliance exchange multiplicity, purification efficiency, decontamination from the work area; provided the required volume of gas extraction from process equipment according to the sanitary standards and environmental requirements. Produced selection of ventilation equipment parameters, solved the problem of the air exchange balancing between ventilation systems to prevent the emergence of parasitic flows between the rooms building. SigmaNet software package was used for the implement the calculation.

  18. Energy and IAQ Implications of Residential Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    This study evaluates the energy, humidity and indoor air quality (IAQ) implications of residential ventilation cooling in all U.S. IECC climate zones. A computer modeling approach was adopted, using an advanced residential building simulation tool with airflow, energy and humidity models. An economizer (large supply fan) was simulated to provide ventilation cooling while outdoor air temperatures were lower than indoor air temperatures (typically at night). The simulations were performed for a full year using one-minute time steps to allow for scheduling of ventilation systems and to account for interactions between ventilation and heating/cooling systems.

  19. A taxonomy for mechanical ventilation: 10 fundamental maxims.

    Science.gov (United States)

    Chatburn, Robert L; El-Khatib, Mohamad; Mireles-Cabodevila, Eduardo

    2014-11-01

    The American Association for Respiratory Care has declared a benchmark for competency in mechanical ventilation that includes the ability to "apply to practice all ventilation modes currently available on all invasive and noninvasive mechanical ventilators." This level of competency presupposes the ability to identify, classify, compare, and contrast all modes of ventilation. Unfortunately, current educational paradigms do not supply the tools to achieve such goals. To fill this gap, we expand and refine a previously described taxonomy for classifying modes of ventilation and explain how it can be understood in terms of 10 fundamental constructs of ventilator technology: (1) defining a breath, (2) defining an assisted breath, (3) specifying the means of assisting breaths based on control variables specified by the equation of motion, (4) classifying breaths in terms of how inspiration is started and stopped, (5) identifying ventilator-initiated versus patient-initiated start and stop events, (6) defining spontaneous and mandatory breaths, (7) defining breath sequences (8), combining control variables and breath sequences into ventilatory patterns, (9) describing targeting schemes, and (10) constructing a formal taxonomy for modes of ventilation composed of control variable, breath sequence, and targeting schemes. Having established the theoretical basis of the taxonomy, we demonstrate a step-by-step procedure to classify any mode on any mechanical ventilator.

  20. Imaging of ventilation/perfusion ratio by gated regional spirometry

    International Nuclear Information System (INIS)

    Gated 133Xe images of patients rebreathing into a closed system can provide images of the distribution of lung volumes, ventilation and specific ventilation. These have been shown to be accurate, precise, and do not require unusually sophisticated equipment or skills. A mathematical transformation is used to correct the images for lung movement, which does not alter the total number of counts in the image. Perfusion images are gated to remove motion blurring but not transformed. Ventilation/perfusion images showing the distribution of V/Q ratio are then generated from the individual ventilation and perfusion images. (author)

  1. Performance evaluation methods and instrumentation for mine ventilation fans

    Institute of Scientific and Technical Information of China (English)

    LI Man; WANG Xue-rong

    2009-01-01

    Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production, we instituted a research project on the measurement methods of key performance parameters such as wind pressure, amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical perform-ance and analytical results of our experiments show that it is feasible, reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.

  2. Comparison of conventional mechanical ventilation and synchronous independent lung ventilation (SILV) in the treatment of unilateral lung injury.

    Science.gov (United States)

    Hurst, J M; DeHaven, C B; Branson, R D

    1985-08-01

    Eight patients presenting with severe unilateral pulmonary injury responded poorly to conventional mechanical ventilation. Synchronous independent lung ventilation (SILV) was employed to provide support of ventilation and oxygenation without creating the ventilation/perfusion (V/Q) mismatch observed during conventional ventilation. All patients demonstrated improved oxygenation (mean increase, 80 torr) during SILV with the FIO2 unchanged from previous therapy. Invasive hemodynamic monitoring in five of eight patients showed no difference in the commonly measured cardiopulmonary parameters with the two forms of mechanical ventilation. Peak inspiratory pressure (PIP), continuous positive airway pressure (CPAP), and pressure change secondary to tidal volume delivery to the uninvolved lung were significantly less during SILV. SILV is an effective method of improving oxygenation in patients with severe unilateral pulmonary injury. PMID:3894680

  3. Low Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome: A Paradigm Shift in Mechanical Ventilation

    OpenAIRE

    Jed Lipes; Francois Lellouche; Azadeh Bojmehrani

    2012-01-01

    Protective ventilation with low tidal volume has been shown to reduce morbidity and mortality in patients suffering from acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Low tidal volume ventilation is associated with particular clinical challenges and is therefore often underutilized as a therapeutic option in clinical practice. Despite some potential difficulties, data have been published examining the application of protective ventilation in patients without lung inj...

  4. Total Liquid Ventilation Provides Superior Respiratory Support to Conventional Mechanical Ventilation in a Large Animal Model of Severe Respiratory Failure

    OpenAIRE

    Pohlmann, Joshua R.; Brant, David O; Daul, Morgan A; Reoma, Junewai L; Kim, Anne C; Osterholzer, Kathryn R.; Johnson, Kent J.; Bartlett, Robert H.; Cook, Keith E.; Hirschl, Ronald B.

    2011-01-01

    Total liquid ventilation (TLV) has the potential to provide respiratory support superior to conventional mechanical ventilation (CMV) in the acute respiratory distress syndrome (ARDS). However, laboratory studies are limited to trials in small animals for no longer than 4 hours. The objective of this study was to compare TLV and CMV in a large animal model of ARDS for 24 hours. Ten sheep weighing 53 ± 4 (SD) kg were anesthetized and ventilated with 100% oxygen. Oleic acid was injected into th...

  5. Comparison of Noninvasive Positive Pressure Ventilation and Invasive Positive Pressure Ventilation in Patients with Acute Respiratory Failure

    Institute of Scientific and Technical Information of China (English)

    Jian Li; De-hou Zhang; Xian-feng Huang; Ming Ding; Guo-rong Shu

    2005-01-01

    @@ The use of noninvasive positive pressure ventilation (NPPV)in the treatment of acute respiratory failure (ARF) has been supported by a number of randomised controlled trials. We conducted a controlled prospective randomised study to compare the efficacy of NPPV with the efficacy of invasive positive pressure ventilation (IPPV) in ARF patients whose conditions had not improved under aggressive medical therapy thus requiring mechanical ventilation (MV).

  6. Practical guidebook on the modulation of ventilation flow rates; Guide pratique sur la modulation des debits de ventilation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The modulation of ventilation flow rates aims at adapting the flow rate of ventilation systems to the real occupancy of rooms, at maintaining a good indoor air quality and at mastering the energy expenses due to air renewing in rooms. This technical guidebook presents the design of modulated ventilation systems (definition of occupancy areas in buildings, choice of presence sensors (CO{sub 2}, hygrometry, temperature, CO, VOC and other specific probes)), their principle and implementation. (J.S.)

  7. An Analysis and Study of Service Life of Fiberglass Pipeline(Ⅱ)%玻璃钢管路工程寿命的分析研究(中)

    Institute of Scientific and Technical Information of China (English)

    孔庆宝; 孔凡旭

    2001-01-01

    玻璃钢管工程寿命是管路工程设计的重要参数,是影响技术-经济竞争能力的关键因素之一。本文首先给出工程寿命的定义,并据此对制约工程寿命的三个主要因素——管材的疲劳损伤机理和疲劳特性、管材的抗介质浸蚀性能和内衬层的耐磨性进行充分论证,对确定玻璃钢管工程寿命的几种实用方法和基本原则进行了简要分析和评价。收集了国内外一系列管路实例,包括市政供水,农田灌溉、排污以及油田注水和原油输送等管线工程。理论分析和工程实践都证明了工程寿命是可以设计、检验和预测的。按照相应的产品标准和规范进行设计、制造和安装施工的玻璃钢管路,可以具有预期的工程寿命。%Service life of fiberglass pipeline is an impoitant parameter and the critical factor affecting the technical and economic competitiveness. From the analysis of three main actors - fatigue damage mechanism and characteristics, corrosion resistance to media and wear resistance of inner liners,the practical methods and basic principle to determine the in civiL construction, arm irrigation, sewage drainge and crude oil transportation and water injection are given to verify the practicability of the desiguability and prediction of Service life.

  8. Ventilation-perfusion matching during exercise

    Science.gov (United States)

    Wagner, P. D.

    1992-01-01

    In normal subjects, exercise widens the alveolar-arterial PO2 difference (P[A-a]O2) despite a more uniform topographic distribution of ventilation-perfusion (VA/Q) ratios. While part of the increase in P(A-a)O2 (especially during heavy exercise) is due to diffusion limitation, a considerable amount is caused by an increase in VA/Q mismatch as detected by the multiple inert gas elimination technique. Why this occurs is unknown, but circumstantial evidence suggests it may be related to interstitial pulmonary edema rather than to factors dependent on ventilation, airway gas mixing, airway muscle tone, or pulmonary vascular tone. In patients with lung disease, the gas exchange consequences of exercise are variable. Thus, arterial PO2 may increase, remain the same, or fall. In general, patients with advanced chronic obstructive pulmonary disease (COPD) or interstitial fibrosis who exercise show a fall in PO2. This is usually not due to worsening VA/Q relationships but mostly to the well-known fall in mixed venous PO2, which itself results from a relatively smaller increase in cardiac output than VO2. However, in interstitial fibrosis (but not COPD), there is good evidence that a part of the fall in PO2 on exercise is caused by alveolar-capillary diffusion limitation of O2 transport; in COPD (but not interstitial fibrosis), a frequent additional contributing factor to the hypoxemia of exercise is an inadequate ventilatory response, such that minute ventilation does not rise as much as does CO2 production or O2 uptake, causing arterial PCO2 to increase and PO2 to fall.

  9. [Mechanical ventilation in chronic ventilatory insufficiency].

    Science.gov (United States)

    Schucher, B; Magnussen, H

    2007-10-01

    Mechanical ventilation has become an important treatment option in chronic ventilatory failure. There are different diseases which lead to ventilatory failure and to home mechanical ventilation (HMV). A primary loss of in- and expiratory muscle strength is the reason for respiratory deterioration in neuromuscular disease. In most of these diseases ventilatory failure develops because of the progressive character of muscular damage. Initially, ventilatory failure can be found during night-time. In the case of hypercapnia at daytime, life expectancy is strongly reduced, especially in amyotrophic lateral sclerosis and Duchenne muscular dystrophy. HMV leads to a prolongation of life and to an increase in quality of life, if bulbar involvement is not severe. Impressive clinical improvements under HMV have been found in restrictive disorders of the rib cage like kyphoscoliosis or posttuberculosis sequelae, with an increase of quality of life, walking distance and a decrease in pulmonary hypertension. Only few data are published about long-term results of HMV in Obesity Hypoventilation. In terms of retrospective analyses of clinical data HMV seems to improve survival in this population. Some patients only need CPAP treatment, but most patients have to be treated with ventilatory support. The application of HMV in patients with chronic ventilatory failure due to chronic obstructive pulmonary disease (COPD) is growing, but there are controversial results in randomised clinical trials. Analysis of these data suggest better results of HMV in patients with severe hypercapnia, with the application of higher effective ventilatory pressure and a ventilator mode with a significant reduction in the work of breathing. Under such conditions HMV leads to a reduction of hypercapnia, an improvement in sleep quality, walking distance and quality of life, but until now there is no evidence in reduction of mortality in COPD. PMID:17620231

  10. VENTILATOR ASSOCIATED PNEUMONIA IN INTENSIVE CARE UNIT

    Directory of Open Access Journals (Sweden)

    Syed Ali

    2015-12-01

    Full Text Available BACKGROUND Knowledge of the incidence of ventilator-associated pneumonia (VAP and its associated risk factors is imperative for the development and use of more effective preventive measures. METHODOLOGY We conducted a prospective cohort study over a period of 12 months to determine the incidence and the risk factors for development of VAP in critically ill adult patients admitted in intensive care units (ICUs in Chalmeda Anand Rao Institute of Medical Sciences, Karimnagar, we included 150 patients, on mechanical ventilation for more than 48 hours. VAP was diagnosed according to the current diagnostic criteria. RESULTS The study cohort comprised of 150 patients of various cases of cerebrovascular accident, poisoning, neurological disorders, sepsis and others. VAP was diagnosed when a score of ≥6 was obtained in the clinical pulmonary infection scoring system having six variables and a maximum score of 12. The mean age of the patients was 40 years. Of the 150 patients, 28 patients developed VAP during the ICU stay. The incidence of VAP in our study was 18.8%. The risk factor in our study was decrease in the PaO2/FiO2 ratio, duration of mechanical ventilation, impaired consciousness, tracheostomy, re-intubation, emergency intubation, nasogastric tube, emergency intubation and intravenous sedatives were found to be the specific risk factors for early onset VAP, while tracheostomy and re-intubation were the independent predictors of late-onset VAP, The most predominant organisms in our study was Pseudomonas (39.2%. CONCLUSIONS Knowledge of these risk factors may be useful in implementing simple and effective preventive measures. Precaution during emergency intubation, minimizing the occurrence of reintubation, avoidance of tracheostomy as far as possible, and minimization of sedation. The ICU clinicians should be aware of the risk factors for VAP, which could prove useful in identifying patients at high risk for VAP, and modifying patient care to

  11. Analysis of static ventilation dynamics using MR

    International Nuclear Information System (INIS)

    This study was conducted to analyze ventilation dynamics. The images were obtained in 10 normal volunteers (non-smoker males) without breath-holding. For the pulse sequence, 2D fast SPGR was used with the following parameters: TR/TE/FA=8-10 msec/2.3 msec/20 deg., matrix x encode=256 x 128, 10 mm thickness, 2 mm pitch, 35 cm FOV. The images were obtained every 0.85 sec. The area of the lung lobe in the sagittal plane was calculated in each phase. The lung lobar volume was obtained from the total area multiplied by the thickness and pitch of the scan. Six of the ten subjects in the present study underwent the helium dilution measurements (HDM) both in sitting and supine posture to obtain their functional residual capacities (FRCs). HDM showed that the FRC obtained in supine posture was smaller than that in sitting posture by 768±391 ml. In supine posture, a significant linear relationship was observed between FRC using HDM and minimal total lung volume using MR (r=0.817, p<0.05). Finally, time-volume curves were constructed by applying Fourier analysis. Time-volume curves for each lung were parallel with no time lag in all cases. The peak of time-volume curve of middle lobe appeared earliest of those of three lobes. The peak of time-volume curve of upper lobe appeared slightly earlier than that of lower lobe. The amplitude of time-volume curve of lower lobe was larger than that of upper and middle lobe. The analysis of pulmonary dynamic ventilation using MR may be a useful technique to assess lung lobar ventilation as a non-invasive method. (author)

  12. Microbiological pattern of ventilator associated pneumonia

    International Nuclear Information System (INIS)

    Ventilator associated pneumonia (VAP) is an important and common complication of mechanically ventilated patients. It is the leading cause of morbidity and mortality in Intensive Care Units (ICU) worldwide. The aim of study was to determine the pattern of bacteria involved in VAP in intensive care unit of Jinnah hospital Lahore. Methods: It was descriptive case series study, conducted over a period of one year on mechanically ventilated 50 patients. American Thoracic Society (ATS) guidelines recommend quantitative/semi-quantitative culture of endotracheal aspirates (ETA) or bronchoscopic aspirates/washing from the infected lung segments for the diagnosis of VAP. Hence this study was conducted to identify the types of bacteria involved in VAP in our ICU. Patients enrolled were clinically and radiologically suspected VAP, admitted in the ICU of Jinnah Hospital/Allama Iqbal Medical College (AIMC) Lahore. Bronchial washings were taken with the help of Fiber optic bronchoscope. Wherever bronchoscopy was not possible, subglottic secretions were collected with the help of sterilized catheter and sucker. Collected samples were sent to the Pathology laboratory of AIMC for aerobic culture and sensitivity. Results: Major pathogenic bacteria isolated were Gram negative (74%). Among this group E. coli, Pseudomonas, Klebsiella and Acinetobacter were the commonest organisms. Gram positive bacteria were 20%, Staphylococcus aureus (MRSA) and haemolyticus streptococci were the major isolate. In 4% cases mixed growth and in 2% cases no growth was reported. Conclusion: Major pathogenic organisms of VAP in our ICU are Gram negative bacteria. The Bacteriological culture of endobroncheal aspirates is helpful in the diagnosis and management of VAP. Emperic antibiotic therapy for VAP should cover Gram negative organisms. (author)

  13. Solar ventilation: The use of solar chimneys for natural ventilation of buildings

    NARCIS (Netherlands)

    Macquoy, B.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. A very old principle is the system of the solar chimney for ventilation, which in recent years has regained interests. This essay will explore the potentials of solar chimneys in a modern application.

  14. Personal exposure between people in a room ventilated by textile terminals - with and without personalized ventilation

    DEFF Research Database (Denmark)

    Nielsen, P.V.; Hyldgaard, C.E.; Melikov, Arsen Krikor;

    2007-01-01

    This paper describes an investigation made in a room ventilated by an air distribution system based on a textile terminal. The air distribution in the room is mainly controlled by buoyancy forces from the heat sources, although the flow from the textile terminal can be characterized as a displace...

  15. Noninvasive Positive Pressure Ventilation or Conventional Mechanical Ventilation for Neonatal Continuous Positive Airway Pressure Failure

    Directory of Open Access Journals (Sweden)

    Zohreh Badiee

    2014-01-01

    Full Text Available Background: The aim of this study was to assess the success rate of nasal intermittent positive pressure ventilation (NIPPV for treatment of continuous positive airway pressure (CPAP failure and prevention of conventional ventilation (CV in preterm neonates. Methods: Since November 2012 to April 2013, a total number of 55 consecutive newborns with gestational ages of 26-35 weeks who had CPAP failure were randomly assigned to one of the two groups. The NIPPV group received NIPPV with the initial peak inspiratory pressure (PIP of 16-20 cmH 2 O and frequency of 40-60 breaths/min. The CV group received PIP of 12-20 cmH 2 O and frequency of 40-60 breaths/min. Results: About 74% of newborns who received NIPPV for management of CPAP failure responded to NIPPV and did not need intubation and mechanical ventilation. Newborns with lower postnatal age at entry to the study and lower 5 min Apgar score more likely had NIPPV failure. In addition, treatment failure was higher in newborns who needed more frequent doses of surfactant. Duration of oxygen therapy was 9.28 days in CV group and 7.77 days in NIPPV group (P = 0.050. Length of hospital stay in CV group and NIPPV groups were 48.7 and 41.7 days, respectively (P = 0.097. Conclusions: NIPPV could decrease the need for intubation and mechanical ventilation in preterm infants with CPAP failure.

  16. Guide to Closing and Conditioning Ventilated Crawlspaces

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, B.

    2013-01-01

    This how-to guide explains the issues and concerns with conventional ventilated crawlspaces and provides prescriptive measures for improvements that will create healthier and more durable spaces. The methods described in this guide are not the only acceptable ways to treat a crawlspace but represent a proven strategy that works in many areas of the United States. The designs discussed in this guide may or may not meet the local building codes and as such will need to be researched before beginning the project.

  17. Ventilation-perfusion scintigraphy in pulmonary disease

    International Nuclear Information System (INIS)

    A program for ventilation-perfusion imaging is described. It is suitable for routine use and comprises defined image masking and normalized matrix division. Three cases are reported from more than eighty in which VP imaging was performed. The findings show that the mask technique enables perfusion defects to be topographically outlined from the ventilatory distribution. Furthermore it is demonstrated that the mask technique can even be applied to sequential studies characterized by marked air trapping. The functional images are generated quickly enough even for emergency use. (Auth.)

  18. C-106 tank process ventilation test

    International Nuclear Information System (INIS)

    Project W-320 Acceptance Test Report for tank 241-C-106, 296-C-006 Ventilation System Acceptance Test Procedure (ATP) HNF-SD-W320-012, C-106 Tank Process Ventilation Test, was an in depth test of the 296-C-006 ventilation system and ventilation support systems required to perform the sluicing of tank C-106. Systems involved included electrical, instrumentation, chiller and HVAC. Tests began at component level, moved to loop level, up to system level and finally to an integrated systems level test. One criteria was to perform the test with the least amount of risk from a radioactive contamination potential stand point. To accomplish this a temporary configuration was designed that would simulate operation of the systems, without being connected directly to the waste tank air space. This was done by blanking off ducting to the tank and connecting temporary ducting and an inlet air filter and housing to the recirculation system. This configuration would eventually become the possible cause of exceptions. During the performance of the test, there were points where the equipment did not function per the directions listed in the ATP. These events fell into several different categories. The first and easiest problems were field configurations that did not match the design documentation. This was corrected by modifying the field configuration to meet design documentation and reperforming the applicable sections of the ATP. A second type of problem encountered was associated with equipment which did not operate correctly, at which point an exception was written against the ATP, to be resolved later. A third type of problem was with equipment that actually operated correctly but the directions in the ATP were in error. These were corrected by generating an Engineering Change Notice (ECN) against the ATP. The ATP with corrected directions was then re-performed. A fourth type of problem was where the directions in the ATP were as the equipment should operate, but the design of

  19. Ultra-protective ventilation and hypoxemia.

    Science.gov (United States)

    Gattinoni, Luciano

    2016-01-01

    Partial extracorporeal CO2 removal allows a decreasing tidal volume without respiratory acidosis in patients with acute respiratory distress syndrome. This, however, may be associated with worsening hypoxemia, due to several mechanisms, such as gravitational and reabsorption atelectasis, due to a decrease in mean airway pressure and a critically low ventilation-perfusion ratio, respectively. In addition, an imbalance between alveolar and artificial lung partial pressures of nitrogen may accelerate the process. Finally, the decrease in the respiratory quotient, leading to unrecognized alveolar hypoxia and monotonous low plateau pressures preventing critical opening, may contribute to hypoxemia. PMID:27170273

  20. Passive Smoking in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Bjørn, Erik; Nielsen, Peter V.

    The aim of this research is to see if the displacement ventilation principle can protect a person from exposure to passive tobacco smoking. This is done by full-scale experiments with two breathing thermal manikins, smoke visualisations, and tracer gas measurements. In some situations, exhaled...... smoke will stratify in a certain height due to the vertical temperature gradient. This horizontal layer of exhaled tobacco smoke may lead to exposure. In other situations, the smoke is mixed into the upper zone, and the passive smoker is protected to some extent by the displacement principle...

  1. Computational Fluid Dynamics and Ventilation Airflow

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2014-01-01

    Computational fluid dynamics (CFD) was first introduced in the ventilation industry in the 1970s. CFD has been increasingly used since then, as testified by the number of peer-reviewed articles, which was less than 10 per year in the 1990s, and which is now 60 to 70 per year. This article discusses......-state solutions. The article finishes with a number of different case studies such as flow in occupied spaces, smoke management in buildings, cross-infection risks from the exhalation of particles and calculation of people moving in a room. The use of benchmark tests is also addressed....

  2. Befuktning av inandningsgas i en ventilator

    OpenAIRE

    Larsson, Christian; Yang, David

    2009-01-01

    Långtidsbehandling med ventilator utan tillräcklig befuktning kan torka ut en patients luftvägar med olika komplikationer som följd. Målet för detta examensarbete var att utveckla en ny teknik för att befukta och värma inandningsgasen. Ett fungerande koncept och en prototyp som styrker konceptet skulle tas fram. Marknaden för befuktare studerades och de vanligast använda befuktningsmetoderna granskades för att hitta svagheter som behövde åtgärdas. De två vanligaste befuktartyperna är Heated H...

  3. [Non invasive ventilation in the emergency setting].

    Science.gov (United States)

    Wilhelm, Laetitia; Della Santa, Vincent; Hanhart, Walter-Alexandre

    2015-08-12

    Before the development of non invasive ventilation (NIV), endotracheal intubation was the only ventilatory therapy available in case of severe respiratory distress and acute respiratory failure. NIV used to be employed in intensive care settings only. Nowadays, the use of NIV has been democratized to include the emergency room, and the pre-hospital care setting for treatment of acute respiratory failure. Cardiogenic pulmonary edema and acute exacerbation of COPD are indications of choice, since NIV improves mortality. The efficiency of the therapy depends on early treatment; however, endotracheal intubation should not be delayed when it becomes necessary. PMID:26449102

  4. Effects of Acute Administration of Corticosteroids during Mechanical Ventilation on Rat Diaphragm

    OpenAIRE

    Maes, Karen; Testelmans, Dries; Cadot, Pascal; DeRuisseau, Keith; Powers, Scott K.; Decramer, Marc; Gayan-Ramirez, Ghislaine

    2008-01-01

    Rationale: Mechanical ventilation is known to induce ventilator-induced diaphragm dysfunction. Patients submitted to mechanical ventilation often receive massive doses of corticosteroids that may cause further deterioration of diaphragm function.

  5. Regional Pulmonary Perfusion, Inflation, and Ventilation Defects in Bronchoconstricted Patients with Asthma

    OpenAIRE

    Harris, R. Scott; Winkler, Tilo; Tgavalekos, Nora; Musch, Guido; Melo, Marcos F. Vidal; Schroeder, Tobias; Chang, Yuchiao; Venegas, José G.

    2006-01-01

    Rationale: Bronchoconstriction in asthma leads to heterogeneous ventilation and the formation of large and contiguous ventilation defects in the lungs. However, the regional adaptations of pulmonary perfusion (Q̇) to such ventilation defects have not been well studied.

  6. A rational framework for selecting modes of ventilation.

    Science.gov (United States)

    Mireles-Cabodevila, Eduardo; Hatipoğlu, Umur; Chatburn, Robert L

    2013-02-01

    Mechanical ventilation is a life-saving intervention for respiratory failure and thus has become the cornerstone of the practice of critical care medicine. A mechanical ventilation mode describes the predetermined pattern of patient-ventilator interaction. In recent years there has been a dizzying proliferation of mechanical ventilation modes, driven by technological advances and market pressures, rather than clinical data. The comparison of these modes is hampered by the sheer number of combinations that need to be tested against one another, as well as the lack of a coherent, logical nomenclature that accurately describes a mode. In this paper we propose a logical nomenclature for mechanical ventilation modes, akin to biological taxonomy. Accordingly, the control variable, breath sequence, and targeting schemes for the primary and secondary breaths represent the order, family, genus, and species, respectively, for the described mode. To distinguish unique operational algorithms, a fifth level of distinction, termed variety, is utilized. We posit that such coherent ordering would facilitate comparison and understanding of modes. Next we suggest that the clinical goals of mechanical ventilation may be simplified into 3 broad categories: provision of safe gas exchange; provision of comfort; and promotion of liberation from mechanical ventilation. Safety is achieved via optimization of ventilation-perfusion matching and pressure-volume relationship of the lungs. Comfort is provided by fostering patient-ventilator synchrony. Liberation is promoted by optimization of the weaning experience. Then we follow a paradigm that matches the technological capacity of a particular mode to achieving a specific clinical goal. Finally, we provide the reader with a comparison of existing modes based on these principles. The status quo in mechanical ventilation mode nomenclature impedes communication and comparison of existing mechanical ventilation modes. The proposed model

  7. Protective lung ventilation in operating room: a systematic review.

    Science.gov (United States)

    Futier, E; Constantin, J M; Jaber, S

    2014-06-01

    Postoperative pulmonary and extrapulmonary complications adversely affect clinical outcomes and healthcare utilization, so that prevention has become a measure of the quality of perioperative care. Mechanical ventilation is an essential support therapy to maintain adequate gas exchange during general anesthesia for surgery. Mechanical ventilation using high tidal volume (VT) (between 10 and 15 mL/kg) has been historically encouraged to prevent hypoxemia and atelectasis formation in anesthetized patients undergoing abdominal and thoracic surgery. However, there is accumulating evidence from both experimental and clinical studies that mechanical ventilation, especially the use of high VT and plateau pressure, may potentially aggravate or even initiate lung injury. Ventilator-associated lung injury can result from cyclic alveolar overdistension of non-dependent lung tissue, and repetitive opening and closing of dependent lung tissue resulting in ultrastructural damage at the junction of closed and open alveoli. Lung-protective ventilation, which refers to the use of lower VT and limited plateau pressure to minimize overdistension, and positive end-expiratory pressure to prevent alveolar collapse at end-expiration, was shown to improve outcome in critically ill patients with acute respiratory distress syndrome (ARDS). It has been recently suggested that this approach might also be beneficial in a broader population, especially in critically ill patients without ARDS at the onset of mechanical ventilation. There is, however, little evidence regarding a potential beneficial effect of lung protective ventilation during surgery, especially in patients with healthy lungs. Although surgical patients are frequently exposed to much shorter periods of mechanical ventilation, this is an important gap in knowledge given the number of patients receiving mechanical ventilation in the operating room. This review developed the benefits of lung protective ventilation during surgery

  8. Waste tank ventilation rates measured with a tracer gas method

    International Nuclear Information System (INIS)

    Passive ventilation with the atmosphere is used to prevent accumulation of waste gases and vapors in the headspaces of 132 of the 177 high-level radioactive waste Tanks at the Hanford Site in Southeastern Washington State. Measurements of the passive ventilation rates are needed for the resolution of two key safety issues associated with the rates of flammable gas production and accumulation and the rates at which organic salt-nitrate salt mixtures dry out. Direct measurement of passive ventilation rates using mass flow meters is not feasible because ventilation occurs va multiple pathways to the atmosphere (i.e., via the filtered breather riser and unsealed tank risers and pits), as well as via underground connections to other tanks, junction boxes, and inactive ventilation systems. The tracer gas method discussed in this report provides a direct measurement of the rate at which gases are removed by ventilation and an indirect measurement of the ventilation rate. The tracer gas behaves as a surrogate of the waste-generated gases, but it is only diminished via ventilation, whereas the waste gases are continuously released by the waste and may be subject to depletion mechanisms other than ventilation. The fiscal year 1998 tracer studies provide new evidence that significant exchange of air occurs between tanks via the underground cascade pipes. Most of the single-shell waste tanks are connected via 7.6-cm diameter cascade pipes to one or two adjacent tanks. Tracer gas studies of the Tank U-102/U-103 system indicated that the ventilation occurring via the cascade line could be a significant fraction of the total ventilation. In this two-tank cascade, air evidently flowed from Tank U-103 to Tank U-102 for a time and then was observed to flow from Tank U-102 to Tank U-103

  9. Andreas Vesalius' understanding of pulmonary ventilation.

    Science.gov (United States)

    Hage, J Joris; Brinkman, Romy J

    2016-09-01

    The historical evolution of understanding of the mechanical aspects of respiration is not well recorded. That the anatomist Andreas Vesalius (1515-1564) first recorded many of these mechanics in De Humani Corporis Fabrica Libri Septem has received little attention. We searched a digital copy of De Fabrica (1543) and its English translation as provided by Richardson and Carman (1998-2009) for references to aspects of pulmonary ventilation. We found that Vesalius grasped the essentials of tidal and forced respiration. He recognized that atmospheric pressure carried air into the lungs, approximately 100 years before Borelli did. He described an in vivo experiment of breathing, some 120 years before John Mayow produced his artificial model. He reported on positive pressure ventilation through a tracheotomy and on its life-saving effect, some 100 years before Robert Hook did. In publicly recording his insights over 450 years ago, Vesalius laid a firm basis for our understanding of the physiology of respiration and the management of its disorders. PMID:27238371

  10. Noninvasive positive pressure ventilation in unplanned extubation

    International Nuclear Information System (INIS)

    Unplanned extubation is quite common in intensive care unit (ICU) patients receiving mechanical ventilatory support. The present study aimed to investigate the effectiveness of noninvasive positive pressure ventilation (NPPV) in patients with unplanned extubation. A total of 15 patients (12 male, age: 57 + - 24 years, APACHE II score: 19 + - 7) monitored at the medical ICU during the year 2004 who developed unplanned extubation were included in the study. NPPV was tried in all of them following unplanned extubation. Indications for admission to the ICU were as follows: nine patients with pneumonia, three with status epilepticus, one with gastrointestinal bleeding, one with cardiogenic pulmonary edema and one with diffuse alveolar bleeding. Eleven of the patients (74%) were at the weaning period at the time of unplanned extubation. Among these 11 patients, NPPV was successful in 10 (91%) and only one (9%) was reintubated due to the failure of NPPV. The remaining four patients (26%) had pneumonia and none of them were at the weaning period at the time of extubation, but their requirement for mechanical ventilation was gradually decreasing. Unfortunately, an NPPV attempt for 6-8 h failed and these patients were reintubated. Patients with unplanned extubation before the weaning criteria are met should be intubated immediately. On the other hand, when extubation develops during the weaning period, NPPV may be an alternative. The present study was conducted with a small number of patients, and larger studies on the effectiveness of NPPV in unplanned extubation are warranted for firm conclusions. (author)

  11. Axisymmetric, Ventilated Supercavitation in Unsteady, Horizontal Flow

    Science.gov (United States)

    Kawakami, Ellison; Lee, Seung-Jae; Arndt, Roger

    2012-11-01

    Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, an artificial supercavity is required until the vehicle can reach conditions at which a natural supercavity can be sustained. Previous studies at Saint Anthony Falls Laboratory (SAFL) focused on the behavior of ventilated supercavities in steady horizontal flows. In open waters, vehicles can encounter unsteady flows, especially when traveling under waves. A study has been carried out at SAFL to investigate the effects of unsteady flow on axisymmetric supercavities. An attempt is made to duplicate sea states seen in open waters. In an effort to track cavity dimensions throughout a wave cycle, an automated cavity tracking script has been developed. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are presented. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. The supercavity volume varied with cavitation number and a possible relationship between the two is being explored. (Supported by ONR)

  12. Pseudomonas aeruginosa ventilator-associated pneumonia management

    Directory of Open Access Journals (Sweden)

    Ramírez-Estrada S

    2016-01-01

    Full Text Available Sergio Ramírez-Estrada,1 Bárbara Borgatta,1,2 Jordi Rello3,4 1Critical Care Department, Vall d'Hebron University Hospital, 2CRIPS, Vall d'Hebron Institute of Research (VHIR, 3Department of Medicine, Universitat Autònoma de Barcelona (UAB, Barcelona, 4Centro de Investigación Biomédica en Red Enfermedad Respiratoria – CIBERES, Madrid, Spain Abstract: Ventilator-associated pneumonia is the most common infection in intensive care unit patients associated with high morbidity rates and elevated economic costs; Pseudomonas aeruginosa is one of the most frequent bacteria linked with this entity, with a high attributable mortality despite adequate treatment that is increased in the presence of multiresistant strains, a situation that is becoming more common in intensive care units. In this manuscript, we review the current management of ventilator-associated pneumonia due to P. aeruginosa, the most recent antipseudomonal agents, and new adjunctive therapies that are shifting the way we treat these infections. We support early initiation of broad-spectrum antipseudomonal antibiotics in present, followed by culture-guided monotherapy de-escalation when susceptibilities are available. Future management should be directed at blocking virulence; the role of alternative strategies such as new antibiotics, nebulized treatments, and vaccines is promising. Keywords: multidrug-resistant, ICU, new-antibiotics, adjunctive-therapies, care-bundles

  13. 聚酯玻纤布在桥面防水粘结层中的应用%Application of Fiberglass Polyester Paving Mat in Waterproof Cohesive Layer on Deck

    Institute of Scientific and Technical Information of China (English)

    严恒; 战琦琦; 朱洪洲; 唐伯明

    2011-01-01

    In general coiled materials or coating materials chosen for waterproof adhesive layer in pavement of bridge deck on highways do not exhibit optimal effect. In order to improve the adhesive property between deck and asphalt pavement, the SBS modified asphalt + fiberglass polyester paving mat are selected as waterproof adhesive materials. The dosage of oil in adhesive layer is determined via shearing test, the test road is paved and the pull test is carried out. The test results show that the interlayer adhesive property of fiberglass polyester paving mat displays perfect property.%通常,公路桥梁桥面铺装防水粘结层选用的卷材或涂膜类材料效果均不佳,为了提高桥面与沥青铺装层之间的粘结性能,选用SBS改性沥青+聚酯玻纤布的形式作为防水粘结材料,通过剪切试验确定粘层油用量,铺筑试验路,并进行拉拔试验,结果表明,聚酯玻纤布的层间粘结性能良好.

  14. Energy Saving Potential by Utilizing Natural Ventilation under Warm Conditions

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    The objective of this article is to show the potential of natural ventilation as a passive cooling method within the residential sector of countries which are located in warm conditions using Mexico as a case study. The method is proposed as performing, with a simplified ventilation model, thermal...

  15. Amyotrophic Lateral Sclerosis Patients' Perspectives on Use of Mechanical Ventilation.

    Science.gov (United States)

    Young, Jenny M.; And Others

    1994-01-01

    Interviewed 13 amyotrophic lateral sclerosis patients. All believed that they alone should make decision regarding use of mechanical ventilation. Factors they considered important were quality of life, severity of disability, availability of ventilation by means of nasal mask, possible admission to long-term care facility, ability to discontinue…

  16. Quantitative relationship of sick building syndrome symptoms with ventilation rates

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Mirer, Anna G.; Mendell, Mark J.

    2009-01-01

    Data from published studies were combined and analyzed to develop best-fit equations and curves quantifying the change in sick building syndrome (SBS) symptom prevalence in office workers with ventilation rate. For each study, slopes were calculated, representing the fractional change in SBS symptom prevalence per unit change in ventilation rate per person. Values of ventilation rate, associated with each value of slope, were also calculated. Linear regression equations were fitted to the resulting data points, after weighting by study size. Integration of the slope-ventilation rate equations yielded curves of relative SBS symptom prevalence versus ventilation rate. Based on these analyses, as the ventilation rate drops from 10 to 5 L/s-person, relative SBS symptom prevalence increases approximately 23percent (12percent to 32percent), and as ventilation rate increases from 10 to 25 L/s-person, relative prevalence decreases approximately 29percent (15percent to 42percent). Variations in SBS symptom types, building features, and outdoor air quality may cause the relationship ofSBS symptom prevalence with ventilation rate in specific situations to differ from the average relationship predicted in this paper.

  17. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Science.gov (United States)

    2010-10-01

    ... duct under paragraph (a) of this section must be at least 10 m (32.8 ft.) from ventilation intakes and... have any combination of fixed or rotating components made of an aluminum or magnesium alloy and ferrous fixed or rotating components. (k) Each ventilation intake and exhaust must have a protective...

  18. Ventilatory strategy in ARDS focusing on pressure controlled ventilation

    NARCIS (Netherlands)

    J. Kesecioglu (Jozef)

    1994-01-01

    textabstractThis thesis focuses on comparison of different modes of ventilation in animals and patients with ARDS. The aim is to determine the immediate advantages of one mode over the other in terms of gas exchange, airway pressures,' hemodynamics and ventilation inhomogeneity.

  19. Mechanical ventilation drives inflammation in severe viral bronchiolitis.

    Directory of Open Access Journals (Sweden)

    Marije P Hennus

    Full Text Available INTRODUCTION: Respiratory insufficiency due to severe respiratory syncytial virus (RSV infection is the most frequent cause of paediatric intensive care unit admission in infants during the winter season. Previous studies have shown increased levels of inflammatory mediators in airways of mechanically ventilated children compared to spontaneous breathing children with viral bronchiolitis. In this prospective observational multi-center study we aimed to investigate whether this increase was related to disease severity or caused by mechanical ventilation. MATERIALS AND METHODS: Nasopharyngeal aspirates were collected <1 hour before intubation and 24 hours later in RSV bronchiolitis patients with respiratory failure (n = 18 and non-ventilated RSV bronchiolitis controls (n = 18. Concentrations of the following cytokines were measured: interleukin (IL-1α, IL-1β, IL-6, monocyte chemotactic protein (MCP-1 and macrophage inflammatory protein (MIP-1α. RESULTS: Baseline cytokine levels were comparable between ventilated and non-ventilated infants. After 24 hours of mechanical ventilation mean cytokine levels, except for MIP-1α, were elevated compared to non-ventilated infected controls: IL-1α (159 versus 4 pg/ml, p<0.01, IL-1β (1068 versus 99 pg/ml, p<0.01, IL-6 (2343 versus 958 pg/ml, p<0.05 and MCP-1 (174 versus 26 pg/ml, p<0.05. CONCLUSIONS: Using pre- and post-intubation observations, this study suggests that endotracheal intubation and subsequent mechanical ventilation cause a robust pulmonary inflammation in infants with RSV bronchiolitis.

  20. Ventilator-induced mediator release: role of PEEP and surfactant

    NARCIS (Netherlands)

    J.J. Haitsma

    2002-01-01

    textabstractLung protective ventilation such as the ARDSnet low tidal volumes strategy can reduce mortality in ARDS patients. The lmowledge that an essential therapy such as mechanical ventilation on the intensive care influences patient outcome has given rise to the re-evaluation of current ventila

  1. Weaning from the ventilator in patients with respiratory failure

    NARCIS (Netherlands)

    B.W. van den Berg (Bart)

    1994-01-01

    textabstractWeaning from the ventilator is the gradual withdrawal of mechanical ventilatory support. Mechanical ventilation is well-accepted as rescue therapy in patients with life-threatening respiratory failure. As this treatment is associated with substantial morbidity and mortality, ventilatory

  2. Energy Efficiency for Heating, Ventilating, Air-Conditioning Instructors.

    Science.gov (United States)

    Scharmann, Larry, Ed.; Lay, Gary, Ed.

    Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in heating, ventilating, and air-conditioning. The following topics are examined: how energy conservation pays, heating, ventilation, air-conditioning,…

  3. Eustachian tube function in children after insertion of ventilation tubes.

    NARCIS (Netherlands)

    Heerbeek, N. van; Ingels, K.J.A.O.; Snik, A.F.M.; Zielhuis, G.A.

    2001-01-01

    This study was performed to assess the effect of the insertion of ventilation tubes and the subsequent aeration of the middle ear on eustachian tube (ET) function in children. Manometric ET function tests were performed repeatedly for 3 months after the placement of ventilation tubes in 83 children

  4. Titin and diaphragm dysfunction in mechanically ventilated rats.

    NARCIS (Netherlands)

    Hees, H.W.H. van; Schellekens, W.J.M.; Andrade Acuna, G.L.; Linkels, M.; Hafmans, T.G.M.; Ottenheijm, C.A.C.; Granzier, H.L.; Scheffer, G.J.; Hoeven, J.G. van der; Dekhuijzen, P.N.R.; Heunks, L.M.A.

    2012-01-01

    PURPOSE: Diaphragm weakness induced by mechanical ventilation may contribute to difficult weaning from the ventilator. For optimal force generation the muscle proteins myosin and titin are indispensable. The present study investigated if myosin and titin loss or dysfunction are involved in mechanica

  5. Air Distribution in Aircraft Cabins Using Free Convection Personalized Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The aim of the ventilation system is to control cross infection in an aircraft cabin if one or a number of the passengers are “source patients” (source of airborne disease). The Personalized Ventilation described in this text is of the type mentioned in “Free Convection Personalized Ventilation”....

  6. Experimental Study of Effect of Vents in Thermal Ventilation

    Institute of Scientific and Technical Information of China (English)

    LIU Dong; LIU Xiao-yu; ZHUANG Jiang-ting; SHEN Hui

    2009-01-01

    The effects of vents on thermal ventilation to save energy in the cold roUing workshop of Baosteel were investigated.According to the scale modeling theory,a small chamber was established.The details about construction of experiment On thermal ventilation and the preparation and arrangement of apparatus were dis-cussed,and then the effects of vents on thermal ventilation were studied through experiments,which includes the temperature distribution,the volume of ventilation,the temperature difference between inlets and outlets,the neutral plane,and the effective thermal coefficient of thermal natural ventilation.Based on this,the effects of natural ventilation based on varied area of inlets and oudets and those of vents on one side and on different sides were compared.According to the experiments,the area of inlet vents and outlet vents affect the tempera-ture distribution in chamber, and their effects on ventilation volume are difierent,but the effects of vents in sin-gle side or different sides aare the same under the condition that only thermal ventilation is considered.

  7. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 56.14213... Equipment Safety Practices and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at locations where arc flash could be hazardous...

  8. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 57.14213... welding. (a) Welding operations shall be shielded when performed at locations where arc flash could be hazardous to persons. (b) All welding operations shall be well-ventilated....

  9. Bed with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jiang, Hao; Polak, Marcin

    2007-01-01

    Normally we protect ourselves from cross infection by supplying fresh air to a room by a diffuser. This air is then distributed in the room according to different principles as e.g. mixing ventilation, displacement ventilation, etc. That means that it is necessary to supply a very large amount of...

  10. 30 CFR 77.1911 - Ventilation of slopes and shafts.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation of slopes and shafts. 77.1911... COAL MINES Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All slopes and... be examined before each shift and the quantity of air in the slope or shaft measured daily by...

  11. Preventing Ventilator Associated Lung Injury: A Perioperative Perspective

    Directory of Open Access Journals (Sweden)

    Satoshi eKimura

    2016-05-01

    Full Text Available Introduction: Research into the prevention of ventilator-associated lung injury (VALI in patients with acute respiratory distress syndrome (ARDS in the intensive care unit (ICU has resulted in the development of a number of lung protective strategies, which have become commonplace in the treatment of critically ill patients. An increasing number of studies have applied lung protective ventilation in the operating room to otherwise healthy individuals. We review the history of lung protective strategies in patients with acute respiratory failure and explore their use patients undergoing mechanical ventilation during general anesthesia to provide context for a discussion of the benefits and drawbacks, as well as inform future areas of inquiry.Methods: We completed a database search and reviewed articles investigating lung protective ventilation in both the ICU and in patients receiving general anesthesia through May 2015. Results: Lung protective ventilation was associated with improved outcomes in patients with acute respiratory failure in the ICU. Clinical evidence is less clear regarding lung protective ventilation for patients undergoing surgery. Conclusion: Lung protective ventilation strategies including low tidal volume ventilation and moderate positive end-expiratory pressure (PEEP are well established therapies to minimize lung injury in critically ill patients with and without lung disease, and may provide benefit to patients undergoing general anesthesia.

  12. Experimental Investigation of Ventilation Efficiency in a Dentistry Surgical Room

    Directory of Open Access Journals (Sweden)

    Oladokun Majeed Olaide

    2016-01-01

    Full Text Available As a response to the need to provide an acceptable thermal comfort and air quality in indoor environments, various ventilation performance indicators were developed over the years. These metrics are mainly geared towards air distribution, heat and pollutant removals. Evidence exists of influencing factors on these indicators as centered on ventilation design and operations. Unlike other indoor environments, health care environment requires better performance of ventilation system to prevent an incidence of nosocomial and other hospital acquired illnesses. This study investigates, using in-situ experiments, the ventilation efficiency in a dentistry surgical room. Thermal and hygric parameters were monitored on the air terminal devices and occupied zone over a period of one week covering both occupied and unoccupied hours. The resulting time-series parameters were used to evaluate the room’s ventilation effectiveness. Also, the obtained parameters were benchmarked against ASHRAE 170 (2013 and MS1525 (2014 requirements for ventilation in health care environment and building energy efficiency respectively. The results show that the mean daily operative conditions failed to satisfy the provisions of both standards. Regarding effectiveness, the findings reveal that the surgical room ventilation is ineffective with ventilation efficiency values ranging between 0 and 0.5 indicating air distribution short-circuiting. These results suggest further investigations, through numerical simulation, on the effect of this short-circuiting on thermal comfort, infection risk assessments and possible design improvements, an endeavour that forms our next line of research inquiries.

  13. Displacement Ventilation in a Room with Low-Level Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Ventilation systems with vertical displacement flow have been used in industrial areas with high thermal loads for many years. Quite resently the vertical displacement flow systems have grown popular as comfort ventilation in rooms with thermal loads e.g. offices....

  14. 46 CFR 111.33-9 - Ventilation exhaust.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation exhaust. 111.33-9 Section 111.33-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-9 Ventilation exhaust. The exhaust of each...

  15. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). 169.315 Section 169.315 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.315 Ventilation (other than...

  16. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation of gasoline machinery spaces. 185.352 Section 185.352 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required...

  17. Lung ventilation-perfusion scintigraphy in pulmonary embolism

    International Nuclear Information System (INIS)

    In 53 patients with possible pulmonary embolism, pulmonary abnormalities of 133Xe ventilation and 99Tcsup(m) albumin microsphere perfusion scintigraphy were compared with absence or presence of pulmonary emboli documented by concurrent pulmonary angiography. It was found that patients with combined scintigraphy considered as unlikely for pulmonary embolism (ventilation defect larger than perfusion defect) or indicative of pulmonary embolism (ventilation defect smaller than perfusion defect) provide high diagnostic specificity. Patients with equal ventillation-perfusion abnormalities (possible pulmonary embolism) require further evaluation by pulmonary angiography to ascertain diagnosis. Importantly, diagnostic accuracy, using ventilation-perfusion scintigraphy and the quantified method of evaluation delineated, is preserved in patients with severe congestive heart failure. (Auth.)

  18. Ventilation Systems Operating Experience Review for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader

    1999-12-01

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection.

  19. Automated quantitative analysis of ventilation-perfusion lung scintigrams

    International Nuclear Information System (INIS)

    An automated computer analysis of ventilation (Kr-81m) and perfusion (Tc-99m) lung images has been devised that produces a graphical image of the distribution of ventilation and perfusion, and of ventilation-perfusion ratios. The analysis has overcome the following problems: the identification of the midline between two lungs and the lung boundaries, the exclusion of extrapulmonary radioactivity, the superimposition of lung images of different sizes, and the format for presentation of the data. Therefore, lung images of different sizes and shapes may be compared with each other. The analysis has been used to develop normal ranges from 55 volunteers. Comparison of younger and older age groups of men and women show small but significant differences in the distribution of ventilation and perfusion, but no differences in ventilation-perfusion ratios

  20. Current concepts of protective ventilation during general anaesthesia.

    Science.gov (United States)

    Serpa Neto, Ary; Schultz, Marcus J; Slutsky, Arthur S

    2015-01-01

    Mechanical ventilation with high tidal volumes (VT) has been common practice in operating theatres because this strategy recruits collapsed lung tissue and improves ventilation-perfusion mismatch, thus decreasing the need for high inspired oxygen concentrations. Positive end-expiratory pressure (PEEP) was not used routinely because it was thought to impair cardiovascular function. Over the past two decades there have been advances in our understanding of the causes and importance of ventilation-induced lung injury based on studies in animals with healthy lungs, and trials in critically ill patients with and without acute respiratory distress syndrome. Recent data from randomised controlled trials in patients receiving ventilation during general anaesthesia for surgery have demonstrated that lung-protective strategies (use of low VT, use of PEEP if indicated, and avoidance of excessive oxygen concentrations) are also of importance during intraoperative ventilation. PMID:26561993

  1. Distribution of ventilation in American alligator Alligator mississippiensis

    International Nuclear Information System (INIS)

    The regional distribution of ventilation in the multicameral lung of spontaneously ventilating alligators (Alligator mississippiensis) was studied with 133Xe scintigraphy. Frequent gamma camera images of 133Xe washin and washout were obtained and processed to allow evaluation of regional ventilation. Washin of 133Xe to equilibrium occurred in three to four breaths in anterior, central, and posterior compartments. Washin was most rapid in the posterior compartment and slowest in the anterior. The structure of the lungs and distribution of ventilation of inspired gas is consistent with the rapid radial spread of gas through a parallel arrangement of lung units surrounding the central intrapulmonary bronchus. Washout to equilibrium of 133Xe from all compartments occurred within three to four breaths. This rapid washin and washout of gas to all parts of the lung stands in contrast to the lungs of turtles and snakes, in which the caudal air sacs are relatively poorly ventilated

  2. Modeling and Control of Livestock Ventilation Systems and Indoor Environments

    DEFF Research Database (Denmark)

    Wu, Zhuang; Heiselberg, Per; Stoustrup, Jakob

    2005-01-01

    constraints and random disturbances is designed through system linearization. The well designed control systems are able to determine the demand ventilation rate and airflow pattern, improve and optimize the indoor Thermal Comfort (TC), Indoor Air Quality (IAQ) and energy use.......The hybrid ventilation systems have been widely used for livestock barns to provide optimum indoor climate by controlling the ventilation rate and air flow distribution within the ventilated building structure. The purpose of this paper is to develop models for livestock ventilation systems...... and indoor environments with a major emphasis on the prediction of indoor horizontal variation of temperature and concentration adapted to the design of appropriate controlling strategy and control systems. The Linear Quadratic (LQ) optimal control method taking into account of the effect of necessary...

  3. Evaluation Tool of Climate Potential for Ventilative Cooling

    DEFF Research Database (Denmark)

    Belleri, Annamaria; Psomas, Theofanis Ch.; Heiselberg, Per Kvols

    2015-01-01

    making towards cost-effective passive cooling solution e.g. ventilative cooling. As buildings with different use patterns, envelope characteristics and internal loads level do not follow equally the external climate condition, the climate analysis cannot abstract from building characteristics and use....... Within IEA Annex 62 project, national experts are working on the development of a climate evaluation tool, which aims at assessing the potential of ventilative cooling by taking into account also building envelope thermal properties, internal gains and ventilation needs. The analysis is based on a single......-zone thermal model applied to user-input climatic data on hourly basis. The tool identifies the percentage of hours when natural ventilation can be exploited to assure minimum air change rates required by state of the art research, standards and regulations and the percentage of hours when direct ventilative...

  4. Reversible ventilation and perfusion abnormalities in unilateral obstructed lung

    International Nuclear Information System (INIS)

    An intraluminal carcinoid tumor obstructing the left mainstem bronchus produced hypoxemia through alteration in ventilation/perfusion matching. Studies of regional lung function using 133-xenon (/sup 133/Xe) and a multiprobe computerized instrumentation system documented a reduction of perfusion to 22 percent and ventilation to 6 percent of the total. There was negligible washout of intravenously injected /sup 133/Xe from the left lung consistent with air trapping. Four days after left mainstem bronchial sleeve resection, perfusion, ventilation and washout of injected xenon had significantly improved and by four months postresection, all measurements were virtually normal, although complete restoration of perfusion in relation to ventilation was delayed. Regional lung function studied with a multiprobe system in this patient provided a clinical model for the study of ventilation and perfusion inter-relationships in large airway obstruction and demonstrated that a prolonged time may be required for return of perfusion to normal

  5. Radionuclide studies on ventilation and perfusion in different lung regions

    International Nuclear Information System (INIS)

    At present in the practice of radionuclide methods of investigation of the ventilation and blood flow one mistakes either a regional ventilated volume or the rate of indicator clearance from a given region for regional alveolar ventilation. The regional ventilation-perfusion ratio is obtained by dividing corresponding values expressed not in absolute but in relative units that causes erroneous results. A method proposed makes it possible to calculate regional distributions of ventilation, perfusion and their ratio as well as the values of mean time and the passage of an indicator through the alveolar-bronchial space and the vascular bed of the lungs strictly in accordance with the conditions of the clinical physiology of respiration. Measurements were taken according to an established method using either a gamma-chamber or a radiographic unit with autonomous detectors. To study the regional blood flow, 133Xe and sup(99m)Tc-MAA can be used

  6. Numerical Simulation for Ventilated Supercavitation High Speed Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    YANG Wu-gang; YANG Zhen-cai; CHU Yan; DENG Qiu-xia; LI Ya-rong; ZHANG Yu-wen

    2009-01-01

    Supercavitation is a revolutionary technique to achieve high drag reduction for underwater vehicle. It can help us to break through the conventional speed barrier. This article presents a numerical algorithm for ventilated supercavitation flow field based on mixture multiphase flow model, briefs the calculation results and compares them with that tested in high-speed water tunnel and towing tank. The mathematical model, its numerical calculation method, computational region and boundary conditions are discussed in detail. Some pertinent nondimensional parameters about the ventilated supercavitation, such as geometrical configuration of supercavity, drag coefficient and ventilation rate are investigated. Reynolds number is selected to predict gas ventilation rate instead of Froude number. Finally, based on the test and simulation results, a semi-empirical formula of the ventilation rate estimation suitable for different conical angle caritators is proposed.

  7. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.

    2014-02-01

    This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

  8. Ventilation Systems Operating Experience Review for Fusion Applications

    International Nuclear Information System (INIS)

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection

  9. Invasive home mechanical ventilation, mainly focused on neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Börger, Sandra

    2010-01-01

    Full Text Available Introduction and background: Invasive home mechanical ventilation is used for patients with chronic respiratory insufficiency. This elaborate and technology-dependent ventilation is carried out via an artificial airway (tracheal cannula to the trachea. Exact numbers about the incidence of home mechanical ventilation are not available. Patients with neuromuscular diseases represent a large portion of it. Research questions: Specific research questions are formulated and answered concerning the dimensions of medicine/nursing, economics, social, ethical and legal aspects. Beyond the technical aspect of the invasive home, mechanical ventilation, medical questions also deal with the patient’s symptoms and clinical signs as well as the frequency of complications. Economic questions pertain to the composition of costs and the differences to other ways of homecare concerning costs and quality of care. Questions regarding social aspects consider the health-related quality of life of patients and caregivers. Additionally, the ethical aspects connected to the decision of home mechanical ventilation are viewed. Finally, legal aspects of financing invasive home mechanical ventilation are discussed. Methods: Based on a systematic literature search in 2008 in a total of 31 relevant databases current literature is viewed and selected by means of fixed criteria. Randomized controlled studies, systematic reviews and HTA reports (health technology assessment, clinical studies with patient numbers above ten, health-economic evaluations, primary studies with particular cost analyses and quality-of-life studies related to the research questions are included in the analysis. Results and discussion: Invasive mechanical ventilation may improve symptoms of hypoventilation, as the analysis of the literature shows. An increase in life expectancy is likely, but for ethical reasons it is not confirmed by premium-quality studies. Complications (e. g. pneumonia are rare

  10. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.; Bergey, D.

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  11. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Somerville, MA (United States); Bergey, Daniel [Building Science Corporation, Somerville, MA (United States)

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  12. Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Miyuki Nakamura

    2014-06-01

    Full Text Available Objective: Discomfort and noncompliance with noninvasive ventilation (NIV interfaces are obstacles to NIV success. Total face masks (TFMs are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection; three worked with some problems (low PEEP or high cycling delay; and one worked properly. Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

  13. High-frequency oscillatory ventilation is not superior to conventional mechanical ventilation in surfactant-treated rabbits with lung injury

    NARCIS (Netherlands)

    D.A.M.P.J. Gommers (Diederik); A. Hartog (Anneke); R. Schnabel; A. de Jaegere (Anne); B.F. Lachmann (Burkhard)

    1999-01-01

    textabstractThe aim of this study was to compare high-frequency oscillatory ventilation (HFOV) with conventional mechanical ventilation (CMV) with and without surfactant in the treatment of surfactant-deficient rabbits. A previously described saline lung lavage model of

  14. Optimization of mine ventilation fan speeds according to ventilation on demand and time of use tariff

    International Nuclear Information System (INIS)

    Highlights: • DSM techniques are applied to an underground mine ventilation network. • A minimization model is solved to find the optimal speeds of the main mine fan. • Ventilation on demand (VOD) leads to a saving of USD 213160. • The optimal mining schedule, together with VOD, leads to a saving of USD 277035. • According to a case study, a maximum of 2 540 035 kW h can be saved per year. - Abstract: In the current situation of the energy crisis, the mining industry has been identified as a promising area for application of demand side management (DSM) techniques. This paper investigates the potential for energy-cost savings and actual energy savings, by implementation of variable speed drives to ventilation fans in underground mines. In particular, ventilation on demand is considered in the study, i.e., air volume is adjusted according to the demand at varying times. Two DSM strategies, energy efficiency (EE) and load management (LM), are formulated and analysed. By modelling the network with the aid of Kirchhoff’s laws and Tellegen’s theorem, a nonlinear constrained minimization model is developed, with the objective of achieving EE. The model is also made to adhere to the fan laws, such that the fan power at its operating points is found to achieve realistic results. LM is achieved by finding the optimal starting time of the mining schedule, according to the time of use (TOU) tariff. A case study is shown to demonstrate the effects of the optimization model. The study suggests that by combining load shifting and energy efficiency techniques, an annual energy saving of 2 540 035 kW h is possible, leading to an annual cost saving of USD 277035

  15. Deep water ventilation traced by Synechococcus cyanobacteria

    Science.gov (United States)

    Vilibić, Ivica; Šantić, Danijela

    2008-07-01

    The paper describes a finding of photoautotroph cyanobacteria Synechococcus in deep Adriatic waters during the spring of 2006. The maximum abundance in early May was positioned at 800 m, being of order of the values referred for the surface waters in the Adriatic Sea. The deep abundance maximum has been associated to the fast ventilation of deep Adriatic waters, usually occurring during wintertime strong cooling events. Two processes were detected: (1) deep convection in the South Adriatic Pit (SAP) and (2) density current going downslope. The first process was responsible for bringing the cyanobacteria down to 600-m depth in the area of convection, and the second one triggered the downslope transport of the cyanobacteria to the SAP very bottom. The depletion rate of Synechoccocus cyanobacteria in an extremely hostile environment has been computed to equal about 1 month.

  16. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... injection tracer gas technique. Smoke visualizations showed that the airflow patterns are highly transient and unstable, and that the airflow rate oscillates with time. Correlations between the Froude (Archimedes) number Fr (Ar) and the L/D ratio are presented. In some cases the measured airflow rates fit...

  17. Sensory source strength of used ventilation filters

    DEFF Research Database (Denmark)

    Clausen, Geo; Alm, Ole Martin; Fanger, Povl Ole

    2002-01-01

    the experimental space after facial exposure, without entering the space. Alternatively, the panel could enter the space and evaluate the air quality after full exposure to the air. The sensory pollution load of the filter determined from full exposure was approximately 7 times lower than when......A two-year-old filter was placed in a ventilation system recirculating the air in an experimental space. Via glass tubes supplied with a small fan it was possible to extract air upstream and downstream of the filter to an adjacent room. A panel could thus perform sensory assessments of the air from...... determined after facial exposure. Even with the lower values of the sensory pollution load found in the present study, model predictions of the perceived air quality in a typical office show that used filters may still be important sources of indoor air pollution....

  18. Street canyon ventilation and atmospheric turbulence

    Science.gov (United States)

    Salizzoni, P.; Soulhac, L.; Mejean, P.

    Operational models for pollutant dispersion in urban areas require an estimate of the turbulent transfer between the street canyons and the overlying atmospheric flow. To date, the mechanisms that govern this process remain poorly understood. We have studied the mass exchange between a street canyon and the atmospheric flow above it by means of wind tunnel experiments. Fluid velocities were measured with a Particle Image Velocimetry system and passive scalar concentrations were measured using a Flame Ionisation Detector. The mass-transfer velocity between the canyon and the external flow has been estimated by measuring the cavity wash-out time. A two-box model, used to estimate the transfer velocity for varying dynamical conditions of the external flow, has been used to interpret the experimental data. This study sheds new light on the mechanisms which drive the ventilation of a street canyon and illustrates the influence of the external turbulence on the transfer process.

  19. Personal Exposure in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter Vilhelm

    1996-01-01

    Personal exposure in a displacement ventilated room is examined. The stratified flow and the considerable concentration gradients necessitate an improvement of the widely used fully mixing compartmental approach. The exposure of a seated and a standing person in proportion to the stratification...... height is examined by means of full-scale measurements. A breathing thermal manikin is used to simulate a person. It is found that the flow in the boundary layer around a person is able to a great extent to entrain and transport air from below the breathing zone. In the case of non-passive, heated...... contaminant sources, this entrainment improves the indoor air quality. Measurements of exposure due to a passive contaminant source show a significant dependence on the flow field as well as on the contaminant source location. Poor system performance is found in the case of a passive contaminant released...

  20. Modelling thermodynamic processes for underground mine ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Klement, J.; Bajer, M.; Suchan, L.

    1979-01-01

    This paper analyzes the problem of heat and humidity transfer from the rock massif to mine air, which is important for forecasting mine environmental conditions. Various equations are presented, pointing out the thermodynamic flow of heat and humidity and the thermodynamic forces of humidity and chemical potential of rock. The equations are described as a general mathematical approach for a nonstationary field of temperature and specific moisture in a rock massif with capillary moisture and for various kinetic phases. The fields of thermal energy and humidity must be calculated with appropriate computer programs. Reliable values of hygrothermal rock properties and of the rock drying effect of ventilation are required as well as further research combined with in-situ measurements and with the development of hybrid models and simulation methods. (6 refs.) (In German)