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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

    (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters......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...

  2. Method of repairing discontinuity in fiberglass structures

    Science.gov (United States)

    Gelb, L. L.; Helbert, W. B., Jr.; Enie, R. B.; Mulliken, R. F. (Inventor)

    1974-01-01

    Damaged fiberglass structures are repaired by substantially filling the irregular surfaced damaged area with a liquid, self-curing resin, preferably an epoxy resin mixed with chopped fiberglass, and then applying to the resin surface the first of several woven fiberglass swatches which has stitching in a zig-zag pattern parallel to each of its edges and a fringe of warp and fill glass fibers about the edges outward of the stitching. The method is especially applicable to repair of fiberglass rocket engine casings and is particularly advantageous since it restores the repaired fiberglass structure to substantially its original strength without any significant changes in the geometry or mass of the structure.

  3. FUNGAL POPULATION, AFLATOXIN AND FREE FATTY ACID CONTENTS OF PEANUTS PACKED IN DIFFERENT BAG TYPES

    Directory of Open Access Journals (Sweden)

    SONIA S.P. BULAONG

    2002-01-01

    Full Text Available Shelled peanuts of Gajah var. with initial moisture content of 7% were stored at 11 kg/bag in four bag types namely: jute bag, polypropylene bag, jute bag doubled with thin polyethylene (PE, and jute bag doubled with thick PE. Storage was done for six months under warehouse conditions with monitoring of relative humidity and temperature. Samples taken at the be ginning of storage and every month thereafter were analyzed for moisture content, fungal population, aflatoxin and free fatty acid contents. Statistical analyses showed that moisture content, fungal population, and free fatty acid contents were signifi cantly higher in jute and polypropylene bags than in PE-dou,bled jute bags. No significant differences were obtained in aflatoxin contents among bag types but at the end of six months storage, toxin level in jute bag exceeded the 30 ppb limit. Polypropylene had second highest toxin level at 23 ppb. The PE-doubled bags ha d 17 and 19 ppb total aflatoxins for thin and thick films, respectively. The results indicated that the immediate packag ing of dried shelled peanuts at safe moisture level in plastic films with water vapor transmission rated of 1 g/m2/24 hr or lower is recommended. This p ackaging will delay critical increases in moisture content, fungal population, aflatoxin and free fatty acid contents of peanut kernels at ambient storage conditions.

  4. Armazenamento de soja em silos tipo bolsa Soybean storage in bag type silos

    Directory of Open Access Journals (Sweden)

    Lêda R. A. Faroni

    2009-03-01

    Full Text Available Avaliaram-se as principais alterações qualitativas de soja armazenada em silos tipo bolsa e do óleo bruto extraído de soja com teores de água de 17,4% e 13,3%, armazenada em dois silos tipo bolsa, por 180 dias. Realizaram-se amostragens no dia do enchimento das bolsas, aos 30; 90 e 180 dias de armazenamento. Analisaram-se o teor de água, a condutividade elétrica, o percentual de germinação, a massa específica aparente da soja, além do teor de ácidos graxos livres e o índice de peróxido do óleo bruto extraído dela. Os teores de água da soja armazenada úmida e seca mantiveram-se próximos dos valores obtidos no início do período de armazenamento. Observou-se tendência de elevação da condutividade elétrica e decréscimo do percentual de germinação somente na soja úmida, principalmente após 90 dias de armazenamento. Não foi verificado decréscimo da massa específica aparente do material armazenado úmido e seco. Com relação aos parâmetros qualitativos do óleo bruto, observou-se que os valores obtidos se mantiveram abaixo do limite máximo exigido pela legislação para a comercialização de óleo bruto de soja. Pode-se concluir que os silos tipo bolsa representam alternativa viável do ponto de vista qualitativo para armazenagem de soja, e esse tipo de estrutura não ocasiona alterações qualitativas significativas no óleo bruto obtido desse material, em condições similares àquelas deste estudo.This study reports major qualitative changes in the soybean grains and the extracted crude oil when stored in bag type silos. Grains with moisture content of 17.4 or 13.3% were stored in two bag type silos. Samples were taken 30, 90 and 180 days of storage , to determine moisture content, electric conductivity of the grain leachate, germination percentage, apparent specific grain mass, and free fatty acid content, and peroxide index of the crude oil extracted from these grains. The wet and dry grains remained with

  5. 喷射泵排尘袋式除尘器设计%Bag Type Duster Design withSpraying Pump for Dust Exhausting

    Institute of Scientific and Technical Information of China (English)

    刘兴车

    2000-01-01

    The bag type duster which uses spraying pump principle for dust exhausting and applies to domestic and import asphalt mixing plant has got ideal result .Economic benifit is obvious. It can replace the duster of import asphalt mixing plant to reduce the investment.

  6. 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...

  7. 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.

  8. 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.

  9. 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

  10. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    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.

  11. Ventilation effectiveness

    CERN Document Server

    Mathisen, Hans Martin; Nielsen, Peter V; Moser, Alfred

    2004-01-01

    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-to-understand descriptions of the indices used to mesure the performance of a ventilation system and which indices to use in different cases.

  12. Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    Displacement ventilation is an interesting new type of air distribution principle which should be considered in connection with design of comfort ventilation in both smal1 and large spaces. Research activities on displacement ventilation are large all over the world and new knowledge of design...... methods appears continuously. This book gives an easy introduction to the basis of displacement ventilation and the chapters are written in the order which is used in a design procedure. The main text is extended by five appendices which show some of the new research activities taking place at Aalborg...

  13. 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.

  14. 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...

  15. 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.

  16. 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

  17. 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.

  18. Mechanical Ventilation

    Science.gov (United States)

    ... cared for in a hospital’s intensive care unit (ICU). People who need a ventilator for a longer time may be in a regular unit of a hospital, a rehabilitation facility, or cared for at home. Why are ...

  19. [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.

  20. Endotoxin exposure-response in a fiberglass manufacturing facility.

    Science.gov (United States)

    Milton, D K; Wypij, D; Kriebel, D; Walters, M D; Hammond, S K; Evans, J S

    1996-01-01

    Peak expiratory flow (PEF) and workplace exposure to endotoxin, phenolic resin, and formaldehyde were measured to investigate asthma symptoms and medication use among employees in a fiberglass wool manufacturing plant. Self-recorded PEF was obtained from 37 workers, for a total of 181 days off work and 187 days at work with concurrent personal exposure monitoring. Pre- and post-shift spirometry were obtained on at least 2 days. The 8 hr time-weighted average personal exposure ranges were endotoxin; 0.4-759 ng/m3; phenolic resin, 5.7-327 micrograms/m3; and formaldehyde, 1.2-265 micrograms/m3. Amplitude percent mean peak flow was associated with years since starting regular work in the highest endotoxin exposure area, although current assignment in that area was associated with reduced amplitude--evidence for a healthy worker effect. Exposure-response was analyzed by regression of lung function change on exposure using generalized estimating equations with robust variance estimates. Endotoxin exposure above 4 ng/m3 (8 hr time-weighted average) was associated with a decline in lung function across the work shift, and with drops in lung function 16-20 hr after exposure. Phenolic resin exposure was not consistently associated with decrements, and formaldehyde was not associated with decrements in lung function.

  1. 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 of ...

  2. 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...

  3. 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...

  4. 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...

  5. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Peter N Cox

    1996-01-01

    Full Text Available There has been a recent explosion of interest in the use of liquid ventilation. Over time humans have lost the physiological attributes necessary for respiration in water. However, perfluorocarbons have high solubilities for oxygen and carbon dioxide, as well as a low surface tension. These characteristics allow them to be used as a medium to assist gas exchange and recruit atelectatic-dependent lung zones in respiratory distress syndrome. Current trials may prove perfluorocarbon to be a useful adjunct in lung protective strategies in respiratory distress syndrome.

  6. Fiberglass distribution poles: A technical-economic solution for electric energy transport lines

    Energy Technology Data Exchange (ETDEWEB)

    Souto Rodriguez, E.L. [Norpost S.A., Lugones (Spain). Poligono Industrial de Silvota; Balust, J.S. [Union Electrica Fenosa, Madrid (Spain)

    1995-11-01

    In Spain, building on the experiences from the more developed nations, a research project on an economic fiberglass distribution pole for electric energy transport lines was started. The paper describes the studies carried out in three phases: general survey, characteristics and properties, and economic aspects. The characteristics of the poles which are described are: light weight, electrical properties, easy installation, safety, low maintenance, longevity, vibration damping, environmental impacts, and mechanical properties. The economic analysis showed that although fiberglass reinforced composites cost more to procure, their life-cycle cost is less due to low maintenance.

  7. Effect of Bagging Time and Bag Type on the Quality of Yunhongli 1%不同套袋时期和果袋类型对云红梨1号果实品质的影响

    Institute of Scientific and Technical Information of China (English)

    李林; 苏俊; 陈霞; 舒群

    2011-01-01

    [Objective] The aim was to make sure the suitable bagging time and bag type of red skinned pear in Yunnan province. [Method] Taken red skin pear Yunhongli 1 for materials, bagging experiment was carried out in two stages with four kinds of fruits bags. [Result] The suitable bagging time in Yunnan province was the 25th of April. The coloration index and the soluble solid content of fruit were significantly improved with external grey and internal black double-plastic bag. Bagging with external yellow and internal black dual-smooth wax bag reduced the arising of fruit rust and improved the coloration index of fruit significantly. The suitable bag type was external yellow and internal black dualsmooth wax bag. [Conclusion] The suitable bagging time and bag type were beneficial to improve the fruit quality.%【目的】明确云南地区红色砂梨适宜的套袋时间和果袋类型。【方法】以红色砂梨品种云红梨1号为试材,以4种果袋分2个时期对云红梨1号进行套袋试验.【结果]云红梨1号在云南地区适宜的套袋时间为4月25日。用外灰内黑薄膜双层袋套袋可显著提高梨果的着色指数和果实可溶性固形物,用外黄内黑双光蜡袋套袋能减少果锈的形成,显著提高梨果的着色指数。适宜的纸袋类型为外黄内黑双光蜡袋。【结论】适宜的套袋时期和果袋类型有利于果品质量的提高。

  8. Artificial Icing Test CH-47C Helicopter with Fiberglass Rotor Blades.

    Science.gov (United States)

    1979-07-01

    fiberglass rotor blades and the intake and exhaust ports for the prototype de-ice system generator . The following general aircraft information is...shut off valve was provided in the tubing run to the generator set fuel inlet. 22 0~0 zgI ogoo j 000 LiJ 2I Photo 3. De-ice System Generator Installation

  9. 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

  10. 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.

  11. Extraterrestrial fiberglass production using solar energy. [lunar plants or space manufacturing facilities

    Science.gov (United States)

    Ho, D.; Sobon, L. E.

    1979-01-01

    A conceptual design is presented for fiberglass production systems in both lunar and space environments. The raw material, of lunar origin, will be plagioclase concentrate, high silica content slag, and calcium oxide. Glass will be melted by solar energy. The multifurnace in the lunar plant and the spinning cylinder in the space plant are unique design features. Furnace design appears to be the most critical element in optimizing system performance. A conservative estimate of the total power generated by solar concentrators is 1880 kW; the mass of both plants is 120 tons. The systems will reproduce about 90 times their total mass in fiberglass in 1 year. A new design concept would be necessary if glass rods were produced in space.

  12. 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

  13. 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

  14. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    with conventional ventilation systems (mixing or displacement ventilation), diffuse ceiling ventilation can significantly reduce or even eliminate draught risk in the occupied zone. Moreover, this ventilation system presents a promising opportunity for energy saving, because of the low pressure loss, extended free......Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as an air diffuser to supply fresh air into the room. Due to the large opening area, air is delivered to the room with very low velocity and no fixed direction, therefore the name ‘diffuse’. Compared......-cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...

  15. Impact of the temperature dependency of fiberglass insulation R-value on cooling energy use in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, R.; Akbari, H.; Gartland, L.

    1996-08-01

    Building energy models usually employ a constant, room-temperature-measured value for the thermal resistance of fiberglass roof insulation. In summer, however, the mean temperature of roof insulation can rise significantly above room temperature, lowering the insulation`s thermal resistance by 10% to 20%. Though the temperature dependence of the thermal resistance of porous materials like fiberglass has been extensively studied, it is difficult to theoretically predict the variation with temperature of a particular fiberglass blanket, from first principles. Heat transfer within fiberglass is complicated by the presence of three significant mechanisms - conduction through air, conduction through the glass matrix, and radiative exchange within the matrix - and a complex, unknown internal geometry. Purely theoretical models of fiberglass heat transfer assume highly simplified matrix structures and require typically-unavailable information about the fiberglass, such as its optical properties. There is also a dearth of useful experimental data. While the thermal resistances of many individual fiberglass samples have been measured, there is only one practical published table of thermal resistance vs. both temperature and density. Data from this table was incorporated in the DOE-2 building energy model. DOE-2 was used to simulate the roof surface temperature, roof heat flux, and cooling energy consumption of a school bungalow whose temperature and energy use had been monitored in 1992. The DOE-2 predictions made with and without temperature variation of thermal conductivity were compared to measured values. Simulations were also run for a typical office building. Annual cooling energy loads and annual peak hourly cooling powers were calculated for the office building using both fixed and variable thermal conductivities, and using five different climates. The decrease in the R-value of the office building`s roof led to a 2% to 4% increase in annual cooling energy load.

  16. 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.

  17. 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

  18. 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.

  19. 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.)

  20. 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....

  1. Mechanical ventilation in children.

    Science.gov (United States)

    Kendirli, Tanil; Kavaz, Asli; Yalaki, Zahide; Oztürk Hişmi, Burcu; Derelli, Emel; Ince, Erdal

    2006-01-01

    Mechanical ventilation can be lifesaving, but > 50% of complications in conditions that require intensive care are related to ventilatory support, particularly if it is prolonged. We retrospectively evaluated the medical records of patients who had mechanical ventilation in the Pediatric Intensive Care Unit (PICU) during a follow-up period between January 2002-May 2005. Medical records of 407 patients were reviewed. Ninety-one patients (22.3%) were treated with mechanical ventilation. Ages of all patients were between 1-180 (median: 8) months. The mechanical ventilation time was 18.8 +/- 14.1 days. Indication of mechanical ventilation could be divided into four groups as respiratory failure (64.8%), cardiovascular failure (19.7%), central nervous system disease (9.8%) and safety airway (5.4%). Tracheostomy was performed in four patients. The complication ratio of mechanically ventilated children was 42.8%, and diversity of complications was as follows: 26.3% atelectasia, 17.5% ventilator-associated pneumonia, 13.1% pneumothorax, 5.4% bleeding, 4.3% tracheal edema, and 2.1% chronic lung disease. The mortality rate of mechanically ventilated patients was 58.3%, but the overall mortality rate in the PICU was 12.2%. In conclusion, there are few published epidemiological data on the follow-up results and mortality in infants and children who are mechanically ventilated.

  2. 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....

  3. Review of Residential Ventilation Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Armin Rudd

    2005-08-30

    This paper reviews current and potential ventilation technologies for residential buildings, including a variety of mechanical systems, natural ventilation, and passive ventilation. with particular emphasis on North American climates and construction.

  4. 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 provider injects ...

  5. On the Behavior of Fiberglass Epoxy Composites under Low Velocity Impact Loading

    Directory of Open Access Journals (Sweden)

    Gautam S. Chandekar

    2010-01-01

    Full Text Available Response of fiberglass epoxy composite laminates under low velocity impact loading is investigated using LS-DYNA®, and the results are compared with experimental analysis performed using an instrumented impact test setup (Instron dynatup 8250. The composite laminates are manufactured using H-VARTM© process with basket weave E-Glass fabrics. Epon 862 is used as a resin system and Epicure-W as a hardening agent. Composite laminates, with 10 layers of fiberglass fabrics, are modeled using 3D solid elements in a mosaic fashion to represent basket weave pattern. Mechanical properties are calculated by using classical micromechanical theory and assigned to the elements using ORTHOTROPIC ELASTIC material model. The damage occurred since increasing impact energy is incorporated using ADVANCED COMPOSITE DAMAGE material model in LS-DYNA®. Good agreements are obtained with the failure damage results in LS-DYNA® and experimental results. Main considerations for comparison are given to the impact load carrying capacity and the amount of impact energy absorbed by the laminates.

  6. 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.

  7. 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...

  8. 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.

  9. High Strength Wood-based Sandwich Panels Reinforced with Fiberglass and Foam

    Directory of Open Access Journals (Sweden)

    Jinghao Li

    2014-02-01

    Full Text Available Mechanical analysis is presented for new high-strength sandwich panels made from wood-based phenolic impregnated laminated paper assembled with an interlocking tri-axial ribbed core. Four different panel configurations were tested, including panels with fiberglass fabric bonded to both outside faces with self-expanding urethane foam used to fill the ribbed core. The mechanical behaviors of the sandwich panels were strength tested via flatwise compression, edgewise compression, and third-point load bending. Panels with fiberglass exhibited significantly increased strength and apparent MOE in edgewise compression and bending, but there were no noticeable effects in flatwise compression. The foam provided improved support that resisted both rib buckling and face buckling for both compression and bending tests. Post-failure observation indicated that core buckling dominated the failures for all configurations used. It is believed that using stiffer foam or optimizing the dimension of the core might further improve the mechanical performance of wood-based sandwich panels.

  10. 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.

  11. 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.

  12. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    both thermal comfort and energy efficient aspects. The present study aims to characterize the air distribution and thermal comfort in the rooms with diffuse ceiling ventilation. Both the stand-alone ventilation system and its integration with a radiant ceiling system are investigated. This study also...

  13. 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.

  14. CFD and Ventilation Research

    DEFF Research Database (Denmark)

    Li, Y.; Nielsen, Peter V.

    2011-01-01

    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 of scienti......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...... 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...... analysis in ventilation research, rather it has become an increasingly important partner....

  15. Ventilation rates and health

    DEFF Research Database (Denmark)

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

    2011-01-01

    The scientific literature through 2005 on the effects of ventilation rates on health in indoor environments has been reviewed by a multidisciplinary group. The group judged 27 papers published in peer-reviewed scientific journals as providing sufficient information on both ventilation rates...... and health effects to inform the relationship. Consistency was found across multiple investigations and different epidemiologic designs for different populations. Multiple health endpoints show similar relationships with ventilation rate. There is biological plausibility for an association of health outcomes...... 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...

  16. Derivative pipelines in the power plant construction. Fiberglass and steel in cooperation; Triebwasserleitungen im Kraftwerksbau. GFK und Stahl in Teamarbeit

    Energy Technology Data Exchange (ETDEWEB)

    Bissinger, Karl

    2010-07-01

    Nowhere, higher technical demands on water pipelines under pressure are met at the construction of hydroelectric power plants. In practice, increasingly optimized combinations of the materials fiberglass and steel have been proven. Particular experiences with the implementation of these concepts have been made in Austria and Switzerland. Under this aspect, the author of the contribution under consideration reports on recent projects from the Alps.

  17. A prospective study comparing attempted weight bearing in fiberglass below-knee casts and prefabricated pneumatic braces.

    Science.gov (United States)

    Mason, Lyndon W; Dodds, Alex

    2010-04-01

    Partial weight bearing is commonly advised after fracture of the lower extremity. Research has determined this to be inaccurate both in its instruction and its reproducibility. Many trauma departments are commonly using alternatives to plaster in the splintage of fractures, such as fiberglass and the prefabricated pneumatic braces. This study's null hypothesis is that there is no difference between partial weight bearing through a fiberglass cast as compared with a pneumatic walker. A prospective study was conducted in our department including all patients who had metatarsal or ankle fractures and could partially weight bear. Patients were excluded if they were not allowed to bear weight, had received operative fixation of their fracture, or were younger than age 16 years. The patients' total weight was measured first, and then they were trained to place 50% of their weight through the splinted limb. Three measurements were taken of their attempted weight bearing at 50%, and they were blinded to the results. Over a 16-month period, 117 patients were enrolled for this study: 72 in the pneumatic walker group and 45 in the fiberglass group. There was no significant difference in sex, age, or fracture type. There was a significant difference in percentage of weight placed through the splinted limb, with the pneumatic brace group placing much greater force than the fiberglass group. This may have been caused by altered proprioception from the walker. It is important to realize this when prescribing partial weight bearing in a particular splint as this may result in avoidable complications.

  18. 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:...

  19. Deproteinization technique stabilizes the adhesion of the fiberglass post relined with resin composite to root canal.

    Science.gov (United States)

    Cecchin, Doglas; Almeida, José F A; Gomes, Brenda P F A; Zaia, Alexandre A; Ferraz, Caio C R

    2012-02-01

    To evaluate the effects of pretreatment of root dentin by 5.25% sodium hypochlorite (NaOCl) alone, associated with 2% chlorhexidine in gel base (CHX) and/or ethanol (EtOH), and the air-drying technique (Air) on the bond strength and adhesive durability of fiberglass post relined with resin composite to root dentin. A total of 100 bovine incisor roots were divided into 10 groups: G1 (control), irrigation with physiologic solution; G2, Air; G3, NaOCl; G4, NaOCl + Air; G5, NaOCl + EtOH; G6, NaOCl + EtOH + Air; G7, NaOCl + CHX; G8, NaOCl + CHX + Air; G9, NaOCl + CHX + EtOH; G10, NaOCl + CHX + EtOH + Air. Fiberglass post relined with resin composite was cemented and each group was randomly divided into two subgroups: 24 h of water storage and 12 months of water storage. The push-out test was performed and bond strength values were analyzed by ANOVA and Tukey's test. The use of NaOCl alone or associated with CHX had the highest values of bond strength with or without Air in the immediate and stored groups, being statistically similar to the immediate control group (p > 0.05). The groups using EtOH or Air alone had lower bond strength in the immediate and stored groups (p 0.05). The use of NaOCl or NaOCl associated with CHX preserved the bond strength immediate and for 12 months. The air-drying technique and the other associations decreased the immediate bond strength values.

  20. 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.

  1. Home Ventilator Guide

    Science.gov (United States)

    ... fit the ventilator under the seat in front. Second, its protected electronic panel prevents the settings from being changed inadvertently. Third, the Trilogy has six hours of battery life – three hours of internal battery and three hours ...

  2. 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.

  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. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  5. 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.

  6. 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)

  7. 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.

  8. High energy, low inductance, high current fiberglass energy storage capacitor for the Atlas Machine Marx modules

    CERN Document Server

    Cooper, R A; Ennis, J B; Cochrane, J C; Reass, W A; Parsons, W M

    1999-01-01

    The Los Alamos National Laboratory's Atlas Marx design team envisioned a double ended plastic case 60 kV, 15 nH, 650 kA, energy storage capacitor. A design specification was established and submitted to various vendors. Maxwell Energy Products drew from its development of large fiberglass case, high voltage, low inductance "FASTCAP" capacitors manufactured for Maxwell Technologies' ACE II, ACE III and ACE IV machines. This paper discusses the LANL specification and Maxwell Energy Products' successful design, Model No. 39232, 34.1 mu F, 60 kV, 13*29*27", the only capacitor qualified by LANL for the 23 Mega Joule Atlas application. Maxwell's past experience in this type of capacitor is covered. The performance data is reviewed and the life test data compared to the original calculated design life. Challenges included Maxwell's "keep it simple " design goal which was maintained to minimize the effort required to create and manufacture a nearly 600 pound capacitor. (1 refs).

  9. Ventilator and viral induced inflammation

    NARCIS (Netherlands)

    Hennus, M.P.

    2013-01-01

    This thesis expands current knowledge on ventilator induced lung injury and provides insights on the immunological effects of mechanical ventilation during viral respiratory infections. The experimental studies in the first part of this thesis improve our understanding of how mechanical ventilation

  10. 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...

  11. Elforbrug til mekanisk ventilation

    DEFF Research Database (Denmark)

    Olufsen, P.

    I Energi 2000 er ventilationsområdet udpeget som et af de områder, hvor der bør tages initiativ til at fremme elbesparelser. I rapporten beskrives og analyseres målinger af elforbruget til ventilation i 12 bygninger, der alle anvendes til administration eller lignende formål. På grundlag af...

  12. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    -cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...

  13. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    The performance of ductless personalized ventilation (DPV) in conjunction with displacement ventilation was studied and compared with displacement ventilation alone and mixing ventilation. Thirty subjects were exposed in a climate chamber to environmental conditions representing three levels...... 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...... movement decreased with DPV compared to corresponding conditions with displacement ventilation alone and reached the same level as mixing or displacement ventilation at 23 °C. Subjects were able to control the volume and speed of the personalized air flow in order to avoid eye irritation. However...

  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. 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....

  17. 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

  18. 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.

  19. Fiberglass goes green: Developing phosphate glass for use in biodegradable composites

    Science.gov (United States)

    Arendt, Christina Lee

    Composite materials, such as the glass fiber reinforced polyester thermosets known as "fiberglass," are used in many applications. However, recycling processes for these materials are inefficient and not widely available. Specially engineered degradable polymers offer an opportunity to redesign these composites. Additionally, the composite could be tailored to be multi-use, such that upon degradation, the resulting products could be used as part of a zeoponic substrate (artificial soil) for growing plants. Such a material would be beneficial for long-duration space missions, terraforming, or in other agricultural applications. The research presented in this dissertation focuses on developing phosphate glass for use as the fiber reinforcement for such a composite. Due to the under-utilization of phosphate systems, there is a lack of thermodynamic data on these systems. The modified associate species method of phase diagram calculation was used in an attempt to gain more information about the desired system, as it is a good predictor of the phase relations in oxide melts, slags, and glasses and requires less data than other methods. Further research into the thermodynamic properties of phosphates is still needed to develop accurate phase diagrams and melting temperatures for this system. Seventeen glass formulations were developed and melted. Six of these formulations were chosen for dissolution testing. Of these six, Glass 17 was chosen for intensive testing and characterization. This glass was tested in water, hydrochloric acid solutions, and citric acid solutions. The weight loss was measured and ICP-OES was performed on the leachate solution. Scanning electron microscopy (SEM) and X-ray diffraction were performed on the tested specimens. Shrinking-core models were fit to the dissolution data. Fibers were drawn from the glass and characterized using SEM. The data shows that this glass is not dissolving congruently, as is expected of phosphate glasses. Instead

  20. Pretest Predictions for Ventilation Tests

    Energy Technology Data Exchange (ETDEWEB)

    Y. Sun; H. Yang; H.N. Kalia

    2007-01-17

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, concrete pipe walls, and insulation that will be developed during the ventilation tests involving various test conditions. The results will be used as input to the following three areas: (1) Decisions regarding testing set-up and performance. (2) Assessing how best to scale the test phenomena measured. (3) Validating numerical approach for modeling continuous ventilation. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the ventilation tests, and develop and describe numerical methods that can be used to calculate the effects of continuous ventilation. Sensitivity studies to assess the impact of variation of linear power densities (linear heat loads) and ventilation air flow rates are included. The calculation is limited to thermal effect only.

  1. 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....

  2. 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.

  3. 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)

  4. Pulmonary mechanics during mechanical ventilation.

    Science.gov (United States)

    Henderson, William R; Sheel, A William

    2012-03-15

    The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management.

  5. 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.

  6. Displacement ventilation in lecture halls

    OpenAIRE

    Egorov, Artem

    2013-01-01

    This thesis considers several important goals. The main purpose is to see how displacement ventilation sys-tem works in the lecture hall of M-building and compare obtained results with D2 and Indoor Climate Classi-fication. The second one is to analyze the function of the ventilation system. The last one is to realize when displacement ventilation is preferable to mixing ventilation. Analysis of the system was carried out with instruments from MUAS HVAC laboratory. In lecture hall were me...

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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....

  14. 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...

  15. Inhalation therapy in mechanical ventilation

    Science.gov (United States)

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

    2015-01-01

    Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients. PMID:26578139

  16. Ventilation and respiratory mechanics.

    Science.gov (United States)

    Sheel, Andrew William; Romer, Lee M

    2012-04-01

    During dynamic exercise, the healthy pulmonary system faces several major challenges, including decreases in mixed venous oxygen content and increases in mixed venous carbon dioxide. As such, the ventilatory demand is increased, while the rising cardiac output means that blood will have considerably less time in the pulmonary capillaries to accomplish gas exchange. Blood gas homeostasis must be accomplished by precise regulation of alveolar ventilation via medullary neural networks and sensory reflex mechanisms. It is equally important that cardiovascular and pulmonary system responses to exercise be precisely matched to the increase in metabolic requirements, and that the substantial gas transport needs of both respiratory and locomotor muscles be considered. Our article addresses each of these topics with emphasis on the healthy, young adult exercising in normoxia. We review recent evidence concerning how exercise hyperpnea influences sympathetic vasoconstrictor outflow and the effect this might have on the ability to perform muscular work. We also review sex-based differences in lung mechanics.

  17. 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.

  18. Metabolism, temperature, and ventilation.

    Science.gov (United States)

    Mortola, Jacopo P; Maskrey, Michael

    2011-10-01

    In mammals and birds, all oxygen used (VO2) must pass through the lungs; hence, some degree of coupling between VO2 and pulmonary ventilation (VE) is highly predictable. Nevertheless, VE is also involved with CO2 elimination, a task that is often in conflict with the convection of O2. In hot or cold conditions, the relationship between VE and VO2 includes the participation of the respiratory apparatus to the control of body temperature and water balance. Some compromise among these tasks is achieved through changes in breathing pattern, uncoupling changes in alveolar ventilation from VE. This article examines primarily the relationship between VE and VO2 under thermal stimuli. In the process, it considers how the relationship is influenced by hypoxia, hypercapnia or changes in metabolic level. The shuffling of tasks in emergency situations illustrates that the constraints on VE-VO2 for the protection of blood gases have ample room for flexibility. However, when other priorities do not interfere with the primary goal of gas exchange, VE follows metabolic rate quite closely. The fact that arterial CO2 remains stable when metabolism is changed by the most diverse circumstances (moderate exercise, cold, cold and exercise combined, variations in body size, caloric intake, age, time of the day, hormones, drugs, etc.) makes it unlikely that VE and metabolism are controlled in parallel by the condition responsible for the metabolic change. Rather, some observations support the view that the gaseous component of metabolic rate, probably CO2, may provide the link between the metabolic level and VE.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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...

  4. 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...... 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....

  5. Mechanical ventilation of the premature neonate.

    Science.gov (United States)

    Brown, Melissa K; DiBlasi, Robert M

    2011-09-01

    Although the trend in the neonatal intensive care unit is to use noninvasive ventilation whenever possible, invasive ventilation is still often necessary for supporting pre-term neonates with lung disease. Many different ventilation modes and ventilation strategies are available to assist with the optimization of mechanical ventilation and prevention of ventilator-induced lung injury. Patient-triggered ventilation is favored over machine-triggered forms of invasive ventilation for improving gas exchange and patient-ventilator interaction. However, no studies have shown that patient-triggered ventilation improves mortality or morbidity in premature neonates. A promising new form of patient-triggered ventilation, neurally adjusted ventilatory assist (NAVA), was recently FDA approved for invasive and noninvasive ventilation. Clinical trials are underway to evaluate outcomes in neonates who receive NAVA. New evidence suggests that volume-targeted ventilation modes (ie, volume control or pressure control with adaptive targeting) may provide better lung protection than traditional pressure control modes. Several volume-targeted modes that provide accurate tidal volume delivery in the face of a large endotracheal tube leak were recently introduced to the clinical setting. There is ongoing debate about whether neonates should be managed invasively with high-frequency ventilation or conventional ventilation at birth. The majority of clinical trials performed to date have compared high-frequency ventilation to pressure control modes. Future trials with premature neonates should compare high-frequency ventilation to conventional ventilation with volume-targeted modes. Over the last decade many new promising approaches to lung-protective ventilation have evolved. The key to protecting the neonatal lung during mechanical ventilation is optimizing lung volume and limiting excessive lung expansion, by applying appropriate PEEP and using shorter inspiratory time, smaller tidal

  6. Climate control of natural ventilated pig houses

    NARCIS (Netherlands)

    Bontsema, J.; Straten, van G.; Salomons, L.; Klooster, van 't C.E.

    1996-01-01

    Ventilation in pig houses is important for maintaining a good climate for the welfare of animals and humans and for an optimal production. Mechanical ventilation has a good performance, since the ventilation rate can easily be controlled, but it is energy demanding, whereas natural ventilation is ch

  7. 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.

  8. 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...

  9. 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...

  10. Research of long-term properties of high-strength fiberglasses by means of the built-in FBG sensors

    Directory of Open Access Journals (Sweden)

    Mikheev Peter V.

    2016-01-01

    Full Text Available In this work the possibility of use of the built-in fiber-optical sensors (Bragg's sensors of deformation for control of a condition of polymeric fiberglasses on epoxy polymer matrix ED-I cured at the increased temperature was investigated. Sensors were inserted in different layers of the layered plastic reinforced by biaxial fiber glass fabric. The package of layers had quasiisotropic structure. The sample made by method of vacuum impregnation was affected by saturated steam (90 °C within 6 months. Operability of system of measurement has been as a result shown and swelling parameters in different layers of FGRP were recorded. For measurement measuring systems of two types — on a superbright light-emitting diode and on the tunable laser were used.

  11. Painted Fiberglass-Reinforced Contemporary Sculpture: Investigating Composite Materials, Techniques and Conservation Using a Multi-Analytical Approach.

    Science.gov (United States)

    Salvadori, Barbara; Cantisani, Emma; Colombini, Maria Perla; Tognon, Cecilia Gaia Rachele

    2016-01-01

    A multi-analytical approach was used to study the constituent materials, manufacturing technique, and state of conservation of a contemporary sculpture. This sculpture, entitled Nuredduna, was created by Aligi Sassu in 1995 and is located in the "Bellariva garden" in Florence (Italy). Fourier transform infrared spectroscopy (FT-IR), optical and electronic microscopy (OM and SEM-EDS), X-ray diffraction (XRD), and portable X-ray fluorescence (XRF) highlighted the multi-layered structure of the statue: fiberglass and an overlay of different layers (gel coat) applied with an unsaturated polyester resin added with aggregate materials and bromine compounds. A top-coat in acrylic black varnish, used as a finish, was also found. The combination of these materials with their different compositions, environmental impact, and even vandalism have negatively affected the state of conservation of Nuredduna, causing the loss of strata in its lower parts (legs and feet).

  12. 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.

  13. Mechanical ventilation in rural ICUs.

    Science.gov (United States)

    Fieselmann; Bock; Hendryx; Wakefield; Helms; Bentler

    1999-01-01

    BACKGROUND: In recent years, rural hospitals have expanded their scope of specialized services, which has led to the development and staffing of rural intensive care units (ICUs). There is little information about the breadth, quality or outcomes of these services. This is particularly true for specialized ICU services such as mechanical ventilation, where little, if any, information exists specifically for rural hospitals. The long-term objectives of this project were to evaluate the quality of medical care provided to mechanically ventilated patients in rural ICUs and to improve patient care through an educational intervention. This paper reports baseline data on patient and hospital characteristics for both rural and rural referral hospitals. RESULTS: Twenty Iowa hospitals were evaluated. Data collected on 224 patients demonstrated a mean age of 70 years and a mean ICU admission Acute Physiology and Chronic Health Evaluation (APACHE) II score of 22, with an associated 36% mortality. Mean length of ICU stay was 10 days, with 7.7 ventilated days. Significant differences were found in both institutional and patient variables between rural referral hospitals and rural hospitals with more limited resources. A subgroup of patients with diagnoses associated with complex ventilation had higher mortality rates than patients without these conditions. Patients who developed nosocomial events had longer mean ventilator and ICU days than patients without nosocomial events. This study also found ICU practices that frequently fell outside the guidelines recommended by a task force describing minimum standards of care for critically ill patients with acute respiratory failure on mechanical ventilation. CONCLUSIONS: Despite distinct differences in the available resources between rural referral and rural hospitals, overall mortality rates of ventilated patients are similar. Considering the higher mortality rates observed in patients with complicated medical conditions requiring

  14. Ventilation Model and Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    V. Chipman

    2003-07-18

    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.

  15. Determinants of ventilation behavior in naturally ventilated dwellings: Identification and quantification of relationships

    NARCIS (Netherlands)

    Levie, D.; Kluizenaar, Y. de; Hoes-van Oeffelen, E.C.M.; Hofstetter, H.; Janssen, S.A.; Spiekman, M.E.; Koene, F.G.H.

    2014-01-01

    Background: Ventilation in dwellings is essential for well-being and health. However, insight in determinants of ventilation behavior is still limited. Aim: Identifying determinants of ventilation behavior and quantifying relationships. Secondly, identifying households characteristics associated wit

  16. Assessment of the potential of roof turbine ventilators for bathroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Ishiow Kuo [National United Univ., Dept. of Architecture, Miao-li City (Taiwan); Chiming Lai [Leader Univ., Dept. of Construction Technology, Tainan City (Taiwan)

    2005-06-15

    This study set out to investigate the potential of installing a new common roof turbine ventilator on to an existing bathroom ventilation system which serves 14 bathrooms in the first dormitory block of Leader University in Taiwan, and evaluate the overall ventilation performance of this new combination. Field measurements of airflow in the ventilation ducts and low-speed wind tunnel experiments for this turbine ventilator were carried out. The results showed that the combination of the roof turbine ventilator and bathroom ventilation were successful in achieving sufficient air change rate in bathrooms, and this ventilation design alternative is now proposed as a method of improving the indoor air environment in bathrooms. (Author)

  17. Influence of Persons' Movements on Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Brohus, Henrik; Hyldig, Mikkel; Kamper, Simon

    2008-01-01

    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......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 ventilation is usually disregarded. This paper presents results from a systematic investigation of the movements´ influence on the ventilation effectiveness using human subjects combined with tracer gas measurements. Several typical "movements" are defined and carefully repeated to determine the influence...

  18. 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.

  19. 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.......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...

  20. 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).

  1. Air Distribution in a Furnished Room Ventilated by Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, June Richter; Nielsen, Peter V.; Svidt, Kjeld

    Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations of the furnit......Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations...

  2. 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.

  3. 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.

  4. Intraoperative mechanical ventilation for the pediatric patient.

    Science.gov (United States)

    Kneyber, Martin C J

    2015-09-01

    Invasive mechanical ventilation is required when children undergo general anesthesia for any procedure. It is remarkable that one of the most practiced interventions such as pediatric mechanical ventilation is hardly supported by any scientific evidence but rather based on personal experience and data from adults, especially as ventilation itself is increasingly recognized as a harmful intervention that causes ventilator-induced lung injury. The use of low tidal volume and higher levels of positive end-expiratory pressure became an integral part of lung-protective ventilation following the outcomes of clinical trials in critically ill adults. This approach has been readily adopted in pediatric ventilation. However, a clear association between tidal volume and mortality has not been ascertained in pediatrics. In fact, experimental studies have suggested that young children might be less susceptible to ventilator-induced lung injury. As such, no recommendations on optimal lung-protective ventilation strategy in children with or without lung injury can be made.

  5. The School Advanced Ventilation Engineering Software (SAVES)

    Science.gov (United States)

    The School Advanced Ventilation Engineering Software (SAVES) package is a tool to help school designers assess the potential financial payback and indoor humidity control benefits of Energy Recovery Ventilation (ERV) systems for school applications.

  6. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

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

    2001-01-01

    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......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...... to ensure that the ventilation system meets the demands it is important to know which parameters that influence the performance of the system. In this work the mixing ventilation principle was investigated. When the mixing ventilation principle is used for the design of a ventilation system it is assumed...

  7. 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...

  8. 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.

  9. 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 .

  10. Iatrogenic pneumothorax related to mechanical ventilation

    OpenAIRE

    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...

  11. 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...

  12. 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.

  13. 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....

  14. 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...

  15. 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

  16. 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....

  17. 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.

  18. 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...

  19. Computational Fluid Dynamics in Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Allard, Francis; Awbi, Hazim B.;

    2008-01-01

    Computational Fluid Dynamics in Ventilation Design is a new title in the is a new title in the REHVA guidebook series. The guidebook is written for people who need to use and discuss results based on CFD predictions, and it gives insight into the subject for those who are not used to work with CFD...

  20. 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.

  1. Minute ventilation at different compression to ventilation ratios, different ventilation rates, and continuous chest compressions with asynchronous ventilation in a newborn manikin

    Directory of Open Access Journals (Sweden)

    Solevåg Anne L

    2012-10-01

    Full Text Available Abstract Background In newborn resuscitation the recommended rate of chest compressions should be 90 per minute and 30 ventilations should be delivered each minute, aiming at achieving a total of 120 events per minute. However, this recommendation is based on physiological plausibility and consensus rather than scientific evidence. With focus on minute ventilation (Mv, we aimed to compare today’s standard to alternative chest compression to ventilation (C:V ratios and different ventilation rates, as well as to continuous chest compressions with asynchronous ventilation. Methods Two investigators performed cardiopulmonary resuscitation on a newborn manikin with a T-piece resuscitator and manual chest compressions. The C:V ratios 3:1, 9:3 and 15:2, as well as continuous chest compressions with asynchronous ventilation (120 compressions and 40 ventilations per minute were performed in a randomised fashion in series of 10 × 2 minutes. In addition, ventilation only was performed at three different rates (40, 60 and 120 ventilations per minute, respectively. A respiratory function monitor measured inspiration time, tidal volume and ventilation rate. Mv was calculated for the different interventions and the Mann–Whitney test was used for comparisons between groups. Results Median Mv per kg in ml (interquartile range was significantly lower at the C:V ratios of 9:3 (140 (134–144 and 15:2 (77 (74–83 as compared to 3:1 (191(183–199. With ventilation only, there was a correlation between ventilation rate and Mv despite a negative correlation between ventilation rate and tidal volumes. Continuous chest compressions with asynchronous ventilation gave higher Mv as compared to coordinated compressions and ventilations at a C:V ratio of 3:1. Conclusions In this study, higher C:V ratios than 3:1 compromised ventilation dynamics in a newborn manikin. However, higher ventilation rates, as well as continuous chest compressions with asynchronous

  2. 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)

  3. Short-term airing by natural ventilation

    DEFF Research Database (Denmark)

    Perino, Marco; Heiselberg, Per

    2009-01-01

    traditional mechanical ventilation components with natural ventilation devices, such as motorized windows and louvers. Among the various ventilation strategies that are currently available, buoyancy driven single-sided natural ventilation has proved to be very effective and can provide high air change rates......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...... that was aimed at developing and validating numerical models for the analysis of buoyancy driven single-sided natural ventilation systems. Once validated, these models can be used to optimize control strategies in order to achieve satisfactory indoor comfort conditions and IAQ....

  4. 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

  5. Simplified modelling of displacement ventilation

    OpenAIRE

    Mateus, Nuno André Marques, 1987-

    2016-01-01

    Tese de doutoramento, Energia e Ambiente (Energia e Desenvolvimento Sustentável), Universidade de Lisboa, Faculdade de Ciências, 2016 With the aim of creating adequate indoor conditions, modern buildings use energy for space heating, ventilation and air conditioning (HVAC). The environmental impact of this energy use creates an urgent need to develop strategies to reduce HVAC related energy consumption. This thesis contributes to this goal by testing and developing simplified models for hi...

  6. 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.

  7. 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.

  8. 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

  9. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

    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 μm 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 the

  10. 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...

  11. Single-lung ventilation in pediatric anesthesia.

    Science.gov (United States)

    Choudhry, Dinesh K

    2005-12-01

    Single-lung ventilation is requested for an increasing spectrum of surgical procedures in infants and children. A clear understanding of the physiology of single-lung ventilation, the techniques of lung separation, and the technical skill necessary to apply these techniques are essential for an anesthesiologist practicing thoracic anesthesia. This article focuses on various devices available for single-lung ventilation in the pediatric age group, the relevant respiratory physiology, and the strategies that optimize oxygenation during one-lung anesthesia.

  12. Luftkvalitet i nyere skoler uden mekanisk ventilation

    DEFF Research Database (Denmark)

    Aggerholm, Søren

    I skoler uden mekanisk ventilation må der udluftes konsekvent for at forbedre luftkvaliteten. Rapporten viser resultatet af målinger af kuldioxidkoncentrationen i fire skoler uden mekanisk ventilation og én skole med mekanisk udsugning. Kuldioxidkoncentrationen er brugt som indikator...... for luftkvaliteten. Rapporten beskriver desuden de energimæssige konsekvenser ved at etablere mekanisk ventilation. Resultaterne har især interesse for skoleforvaltninger og rådgivende teknikere....

  13. 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...

  14. 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.

  15. 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.

  16. Lung-protective ventilation in neonatology.

    Science.gov (United States)

    van Kaam, Anton

    2011-01-01

    Ventilator-induced lung injury (VILI) is considered an important risk factor in the development of bronchopulmonary dysplasia (BPD) and is primarily caused by overdistension (volutrauma) and repetitive opening and collapse (atelectrauma) of terminal lung units. Lung-protective ventilation should therefore aim to reduce tidal volumes, and recruit and stabilize atelectatic lung units (open lung ventilation strategy). This review will summarize the available evidence on lung-protective ventilation in neonatology, discussing both high-frequency ventilation (HFV) and positive pressure ventilation (PPV). It shows that HFV does not appear to have a clear benefit over PPV, although most studies failed to apply a true open lung ventilation strategy during HFV. The evidence on the optimal tidal volume, positive end-expiratory pressure and the role for lung recruitment during lung-protective PPV is extremely limited. Volume-targeted ventilation seems to be a promising mode in terms of lung protection, but more studies are needed. Due to the lack of convincing evidence, lung-protective ventilation and modes seem to be implemented in daily clinical practice at a slow pace.

  17. Potential of Natural Ventilation in Shopping Centres

    DEFF Research Database (Denmark)

    Diederichsen, Alice; Friis, Kristina; Brohus, Henrik;

    2008-01-01

    The indoor environmental quality (IEQ) is a fundamental requirement for a well performing shopping centre. This paper contains a pilot study of the potential of using hybrid ventilation (a combination of automatically controlled natural and mechanical ventilation - respectively NV and MV......) in shopping centres with focus on both the achieved IEQ and energy consumptions for air movement. By thermal building simulations it is found that there exists an interesting potential for hybrid ventilation of shopping centres, which can lead to great savings in the electrical energy consumptions...... for ventilation and cooling without compromising IEQ....

  18. 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...

  19. Frequently Asked Questions about Ventilator-Associated Pneumonia

    Science.gov (United States)

    ... Submit Button Frequently Asked Questions about Ventilator-associated Pneumonia Recommend on Facebook Tweet Share Compartir What is a Ventilator-associated Pneumonia (VAP)? Ventilator-associated pneumonia (VAP) is a lung ...

  20. 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.

  1. 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...

  2. 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.

  3. Improvement in ventilation at Stara Jama mine (Yugoslavia) on the introduction of the new Turmag ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Elezovic, V.; Sucevic, L.

    1977-01-01

    The improvement effected in the mine ventilation on the installation of the Turmag system ZEL 22-500 in a new ventilation shaft is described. Several previous bottlenecks were eliminated by revising the ventilation network.

  4. 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...

  5. 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...

  6. 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.

  7. 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

  8. YMP Engineered Barrier Systems Scaled Ventilation Testing

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Dunn; B. Lowry; B. Walsh; J.D. Mar; C. Howard; R. Johnston; T. Williams

    2002-11-22

    Yucca Mountain, approximately 100 miles northwest of Las Vegas, Nevada, has been selected as the site for the nation's first geologic repository for high level nuclear waste. The Yucca Mountain Project (YMP) is currently developing the design for the underground facilities. Ventilation is a key component of the design as a way to maintain the desired thermal conditions in the emplacement drifts prior to closure. As a means of determining the effects of continuous ventilation on heat removal from the emplacement drifts two series of scaled ventilation tests have been performed. Both test series were performed in the DOE/North Las Vegas Atlas facility. The tests provided scaled (nominally 25% of the full scale emplacement drift design) thermal and flow process data that will be used to validate YMP heat and mass transport codes. The Phase I Ventilation Test series evaluated the ability of ambient ventilation air to remove energy under varying flow and input power conditions. The Phase II Ventilation Test series evaluated the ability of pre-conditioned ventilation air to remove energy under varying flow, input temperature and moisture content, and simulated waste package input power conditions. Twenty-two distinct ventilation tests were run.

  9. 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...

  10. Commissioning Ventilated Containment Systems in the Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    2008-08-01

    This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.

  11. 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

  12. 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.

  13. New modes of assisted mechanical ventilation.

    Science.gov (United States)

    Suarez-Sipmann, F

    2014-05-01

    Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes.

  14. 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

  15. Hybrid ventilation systems and high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Utzinger, D.M. [Wisconsin Univ., Milwaukee, WI (United States). School of Architecture and Urban Planning

    2009-07-01

    This paper described hybrid ventilation design strategies and their impact on 3 high performance buildings located in southern Wisconsin. The Hybrid ventilation systems combined occupant controlled natural ventilation with mechanical ventilation systems. Natural ventilation was shown to provide adequate ventilation when appropriately designed. Proper control integration of natural ventilation into hybrid systems was shown to reduce energy consumption in high performance buildings. This paper also described the lessons learned from the 3 buildings. The author served as energy consultant on all three projects and had the responsibility of designing and integrating the natural ventilation systems into the HVAC control strategy. A post occupancy evaluation of building energy performance has provided learning material for architecture students. The 3 buildings included the Schlitz Audubon Nature Center completed in 2003; the Urban Ecology Center completed in 2004; and the Aldo Leopold Legacy Center completed in 2007. This paper included the size, measured energy utilization intensity and percentage of energy supplied by renewable solar power and bio-fuels on site for each building. 6 refs., 2 tabs., 6 figs.

  16. A computerized aid in ventilating neonates

    DEFF Research Database (Denmark)

    Arrøe, M

    1991-01-01

    and contains a continuous evaluation of the last six values of pCO2 and pO2 resulting in statements and warnings in potentially harmful situations. The program is consistent with the written instructions of the department. The ventilator treatment of 30 premature babies is evaluated retrospectively using......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...... the program, showing a total agreement of 37.5%, lowest among the babies who died in respiratory insufficiency. The advantage of the use of the program is discussed....

  17. 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.

  18. 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.

  19. Mechanisms of natural ventilation in livestock buildings

    DEFF Research Database (Denmark)

    Rong, Li; Bjerg, Bjarne Schmidt; Batzanas, Thomas;

    2016-01-01

    Studies on the mechanisms of natural ventilation in livestock buildings are reviewed and influences on discharge and pressure coefficients are discussed. Compared to studies conducted on buildings for human occupation and industrial buildings which focus on thermal comfort, ventilation systems......, indoor air quality, building physics and energy etc., our understanding of the mechanisms involved in natural ventilation of livestock buildings are still limited to the application of the orifice equation. It has been observed that the assumptions made for application of the orifice equation...... are not valid for wind-induced cross ventilation through large openings. This review identifies that the power balance model, the concept of stream tube and the local dynamic similarity model has helped in the fundamental understanding of wind-induced natural ventilation in buildings for human occupation...

  20. 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...

  1. 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...... European and international Low Energy buildings. Still it’s not really widespread. Obstacles are challenges as regards noise, dust, weather and burglary, proving the research efforts of the Annex being necessary. The VC database forms a worthwhile basis for both dissemination and further research targets......., systematically investigating the distribution of technologies and strategies within VC. The database is structured as both a ticking-list-like building-spreadsheet and a collection of building-datasheets. The content of both closely follows Annex 62 State-Of-The- Art-Report. The database has been filled, based...

  2. Infiltration as Ventilation: Weather-Induced Dilution

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Turner, William J.N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-06-01

    The purpose of outdoor air ventilation is to dilute or remove indoor contaminants to which occupants are exposed. It can be provided by mechanical or natural means. In most homes, especially older homes, weather-driven infiltration provides the dominant fraction of the total ventilation. As we seek to provide good indoor air quality at minimum energy cost, it is important to neither over-ventilate nor under-ventilate. Thus, it becomes critically important to evaluate correctly the contribution infiltration makes to the total outdoor air ventilation rate. Because weather-driven infiltration is dependent on building air leakage and weather-induced pressure differences, a given amount of air leakage will provide different amounts of infiltration. Varying rates of infiltration will provide different levels of contaminant dilution and hence effective ventilation. This paper derives these interactions and then calculates the impact of weather-driven infiltration for different climates. A new “N-factor” is introduced to provide a convenient method for calculating the ventilation contribution of infiltration for over 1,000 locations across North America. The results of this work could be used in indoor air quality standards (specifically ASHRAE 62.2) to account for the contribution of weather-driven infiltration towards the dilution of indoor pollutants.

  3. 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.

  4. 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.

  5. 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

  6. Mechanical ventilation in neurological and neurosurgical patients.

    Science.gov (United States)

    Swain, Amlan; Bhagat, Hemant; Sahni, Neeru; Salunke, Pravin

    2016-01-01

    Approximately 20% of all patients requiring mechanical ventilation suffer from neurological dysfunction. It is imperative in the ventilatory management of such patients to have a thorough understanding of the disease pathology that may require institution of mechanical ventilation as well as in realizing its effects on the injured brain. These patients have unique challenges pertaining to the assessment and securing of the airway, maintenance of mechanical ventilation, as well as weaning and extubation readiness. This manuscript aims to present the current evidence in ventilatory management of the important subset of patients with neuronal injury. The indications for ventilatory management include both neurological and neurosurgical causes.

  7. 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...

  8. 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...... in the lower part of the room close to the occupant. A personal exposure model for displacement ventilated rooms is proposed. The model takes the influence of gradients and the human thermal boundary layer into account. Two new quantities describing the interaction between a person and the ventilation...

  9. 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...

  10. 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...

  11. 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.

  12. 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...

  13. Adaptive support ventilation with percutaneous dilatational tracheotomy: a clinical study.

    Science.gov (United States)

    Veelo, Denise P; Dongelmans, Dave A; Middelhoek, Pauline; Korevaar, Johanna C; Schultz, Marcus J

    2008-09-01

    We determined the need for changes in minute ventilation with adaptive support ventilation after percutaneous dilatational tracheotomy under endoscopic guidance in 34 intensive care unit patients. During the procedure, minute ventilation was not changed; only maximum pressure limits were adjusted, if necessary. After insertion of the tracheotomy, cannula minute ventilation was adjusted only if Paco(2)-values changed >or=0.5 kPa from baseline. In 74% of patients, adaptive support ventilation was unable to maintain minute ventilation during the use of the endoscope, mandating pressure limitation adjustments. In a minority of patients (26%), minute ventilation had to be adjusted to achieve similar Paco(2) values.

  14. Control strategies for demand controlled ventilation in dwellings

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2011-01-01

    Ventilation of Danish and many other European dwellings has in the past mainly been achieved by natural ventilation or mechanical exhaust systems. Requirements for energy efficiency is changing this picture and mechanical ventilation with balanced exhaust and supply, efficient heat recovery...... high. Too low ventilation rate results in poor air quality for the occupants and moisture risk. Too high ventilation rate results in unnecessary energy consumption. This paper presents results from a study where demand controlled ventilation was installed in an existing single family house...... was possible. The results showed that the ventilation rate in periods can be reduced significantly without significant increase in moisture or CO2-concentration....

  15. 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...... of the investigated PV/MV systems has similar performance to pure MV systems. This means that optimised PV/MV systems have the potential to generate energy savings....

  16. Respiratory care year in review 2010: part 2. Invasive mechanical ventilation, noninvasive ventilation, pediatric mechanical ventilation, aerosol therapy.

    Science.gov (United States)

    Macintyre, Neil R; Nava, Stefano; Diblasi, Robert M; Restrepo, Ruben D; Hess, Dean R

    2011-05-01

    The purpose of this paper is to review the recent literature related to invasive mechanical ventilation, NIV, pediatric mechanical ventilation, and aerosol therapy. Topics covered related to invasive mechanical ventilation topics include the role of PEEP in providing lung protection during mechanical ventilation, unconventional modes for severe hypoxemia, and strategies to improve patient-ventilator interactions. Topics covered related to NIV include real-life NIV use, NIV and extubation failure, and NIV and pandemics. For pediatric mechanical ventilation, the topics addressed are NIV, invasive respiratory support, and inhaled nitric oxide. Topics covered related to aerosol therapy include short-acting β-adrenergic agents, long-acting β-adrenergic agents, long-acting antimuscarinic agents, inhaled corticosteroid therapy, phosphodiesterase type 4 (PDE4) inhibitors, long-acting β-adrenergic plus inhaled corticosteroid, long-acting antimuscarinic plus inhaled corticosteroid, nebulized hypertonic saline, inhaled mannitol, and inhaled antibiotic therapy. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.

  17. 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.

  18. Design of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    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......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...... 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...

  19. Noninvasive ventilation in hypoxemic respiratory failure

    Directory of Open Access Journals (Sweden)

    Raja Dhar

    2016-01-01

    Full Text Available Noninvasive ventilation (NIV refers to positive pressure ventilation delivered through a noninvasive interface (nasal mask, facemask, or nasal plugs etc. Over the past decade its use has become more common as its benefits are increasingly recognized. This review will focus on the evidence supporting the use of NIV in various conditions resulting in acute hypoxemic respiratory failure (AHRF, that is, non-hypercapnic patients having acute respiratory failure in the absence of a cardiac origin or underlying chronic pulmonary disease. Outcomes depend on the patient's diagnosis and clinical characteristics. Patients should be monitored closely for signs of noninvasive ventilation failure and promptly intubated before a crisis develops. The application of noninvasive ventilation by a trained and experienced team, with careful patient selection, should optimize patient outcomes.

  20. [The choice of a pediatric anesthesia ventilator].

    Science.gov (United States)

    Kern, D; Larcher, C; Cottron, N; Ait Aissa, D; Fesseau, R; Alacoque, X; Delort, F; Masquère, P; Agnès, E; Visnadi, G; Fourcade, O

    2013-12-01

    The technology of anesthesia ventilators has substantially progressed during last years. The choice of a pediatric anesthesia ventilator needs to be led by multiple parameters: requirement, technical (pneumatic performance, velocity of halogenated or oxygen delivery), cost (purchase, in operation, preventive and curative maintenance), reliability, ergonomy, upgradability, and compatibility. The demonstration of the interest of pressure support mode during maintenance of spontaneous ventilation anesthesia makes this mode essential in pediatrics. In contrast, the financial impact of target controlled inhalation of halogenated has not be studied in pediatrics. Paradoxically, complex and various available technologies had not been much prospectively studied. Anesthesia ventilators performances in pediatrics need to be clarified in further clinical and bench test studies.

  1. 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...

  2. 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.

  3. 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...... continuously by a mass spectrometer. Signals from this instrument, together with gas-volume signals from the ventilator, were fed to a computer for calculation of VO2 and VCO2. Twenty to 120 min were required to reach a stable level, depending on the patient's size and circulatory response. Similar results...... were obtained by computer simulation using a five-compartment model of CO2 stores. These experiments indicate that measuring VO2 (for calculation of metabolic respiratory quotient [RQ]) in ventilated patients should occur after the patients maintain a 60-min period of stable body temperature...

  4. 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....... Full scale experiments along with a breathing thermal manikin (BTM) have been used. The results show that the location of the sources is of great importance, just as well as temperature differences. Furthermore, the concentration in the breathing zone showed large differences throughout the room....

  5. 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...

  6. 'Elective' ventilation: an unethical and harmful misnomer?

    Science.gov (United States)

    Stammers, Trevor

    2013-01-01

    The demand for organs prompted the first use of elective ventilation in the UK in the 1990s. Recently the shortfall in supply of organs has once again prompted calls for elective ventilation to be instituted even in patients who are not brain dead. This paper proposes that the term 'elective' ventilation is a misnomer and the term non-therapeutic ventilation (NTV) should be used instead. It is further argued that the practice of NTV in cases of severe stroke is unethical and has the potential of causing a variety of harms to the patient, their relatives, and the healthcare professionals working in transplant teams and this may result in a backlash of reductions in the number of organ donations.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

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

    NARCIS (Netherlands)

    G.F. Vazquez de Anda; R.A. Lachmann; S.J.C. Verbrugge (Serge); D.A.M.P.J. Gommers (Diederik); J.J. Haitsma (Jack); B.F. 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 l

  13. Study of Coal Mine Ventilation System Optimization based on Ventsim

    Directory of Open Access Journals (Sweden)

    Zhang Jing Gang

    2016-01-01

    Full Text Available This article is based on the situation of too large coal mine ventilation resistance in the Majiagou coal mine. According to Majiagou coal mine late production plans, it measures resistance comprehensively, analyses the resistance distributions and the problems exist in the ventilation systems and comes up with targeted optimization programs. By studying the ventilation system model, as well as adjusting the system parameters, Ventsim software is applied to study ventilation system in Majiagou coal mine. Design of mine ventilation is proved practical in the mine ventilation system optimizations, thus Ventsim software can not only be used in the ventilation network calculation and merry-demand simulation and dynamic of wind flow, but also can be used to assist in the short-term and long-term planning for ventilation system, it is of a certain significance of guidance to find the problems in the mine management and optimizations of the ventilation network.

  14. Regenerative Blower for EVA Suit Ventilation Fan

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  15. Comparison of gaseous contaminant diffusion under stratum ventilation and under displacement ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Lin; Wang, Qiuwang [State Key Lab of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Lin, Zhang [Building Energy and Environmental Technology Research Unit, Division of Building Science and Technology, City University of Hong Kong, Hong Kong SAR (China)

    2010-09-15

    The gaseous contaminant diffusion under stratum ventilation is investigated by numerical method which is validated by experiments carried out. The concentration of gaseous contaminants along the supply air jet is found to be lower than the other parts of the room. Compared with displacement ventilation, the formaldehyde concentration in breathing zone is lower when a contaminant source locates close to the occupant. The concentration is at the same level when the contaminant source locates up-steam to the occupant. The concentration in the occupied zone (<1.9 m from the floor) is also lower when the contaminant source locates on the floor. At supply air temperature optimized for displacement ventilation, the toluene concentration in breathing zone for stratum ventilation is higher than that for displacement ventilation when the area source locates on the four surrounding walls of the room. (author)

  16. Hydrostatic Hyperbaric Chamber Ventilation System

    Science.gov (United States)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  17. 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.

  18. 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.

  19. 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)

  20. VENTILATION SYSTEM WITH GROUND HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Vyacheslav Pisarev

    2016-11-01

    Full Text Available Ventilation systems consume more and more energy because of the often complex treatment of the air supplied to closed spaces. Looking for sources of energy allow for significant savings costs, which often translate into renewable energy sources. One of the more popular solutions is to use energy from the ground by various methods. Known and relatively common solutions are based on ground heat exchanger and ground collector cooperating with a heat pump. The paper presents the possibility of cooperation ventilation system with ground air heat exchanger and heat pump both in summer and winter period. A number solutions of this type of system, supported by calculation examples and moist air transformation in the Moliere chart have been presented. Support ventilation system with renewable energy sources allows significant savings in operating as shown in the article.

  1. 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 .

  2. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

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

    2008-01-01

    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...... of the DCV system was slightly improved in the case with the sealed shower cubicle compared to the unsealed cubicle. The study indicated that indoor climate and energy optimizations of DCV systems should not be limited to considerations of the control system, but should also include considerations......In residential buildings moisture is a dominant pollution source removed by the ventilation system. The Danish building code requires a minimum air change rate of 0.5h-1 in residential buildings to avoid moisture related problems. However a constant ventilation rate results in unnecessary energy...

  3. Modelling of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    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...... 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......-energy approach. These lecture notes focus on modelling of natural and hybrid ventilation driven by thermal buoyancy, wind and/or mechanical driving forces for a single zone with one, two or several openings....

  4. Performance of displacement ventilation in practice

    DEFF Research Database (Denmark)

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

    2002-01-01

    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 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 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 underlying...

  5. 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...

  6. 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...

  7. 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.

  8. Noninvasive ventilation in acute respiratory failure

    Directory of Open Access Journals (Sweden)

    Mas A

    2014-08-01

    Full Text Available 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 ventilation at the end of the 20th century, this became the main modality. Both techniques, and some others that have been recently introduced and which integrate some technological innovations, have extensively demonstrated a faster improvement of acute respiratory failure in different patient populations, avoiding endotracheal intubation and facilitating the release of conventional invasive mechanical ventilation. In acute settings, NIV is currently the first-line treatment for moderate-to-severe chronic obstructive pulmonary disease exacerbation as well as for acute cardiogenic pulmonary edema and should be considered in immunocompromised patients with acute respiratory insufficiency, in difficult weaning, and in the prevention of postextubation failure. Alternatively, it can also be used in the postoperative period and in cases of pneumonia and asthma or as a palliative treatment. NIV is currently used in a wide range of acute settings, such as critical care and emergency departments, hospital wards, palliative or pediatric units, and in pre-hospital care. It is also used as a home care therapy in patients with chronic pulmonary or sleep disorders. The appropriate selection of patients and the adaptation to the technique are the keys to success. This review essentially analyzes the evidence of benefits of NIV in different populations with acute respiratory failure and describes the main modalities, new devices, and some practical aspects of the use of this technique. Keywords

  9. The Application of High Performance Fiberglass Multiaxial Fabrics in Megawatt Wind Blades%高性能玻纤多轴向织物在兆瓦级风电叶片中的应用

    Institute of Scientific and Technical Information of China (English)

    李卫东; 刘洪刚; 孙仲平; 岳荣良; 石明国

    2011-01-01

    为提高风能资源利用效率,降低风力发电成本,在传统E玻纤多轴向织物的基础上,玻纤增强材料供应商泰山玻纤开发了新型高性能玻纤及其多轴向织物。本文主要探讨兆瓦级风电叶片对玻纤增强材料的选择。%In order to improve the wind resource utilization and reduce the cost of wind power generation, Taishan Fiberglass, a fiberglass reinforcements supplier, has developed a new type high performance glass fiber and multiaxial fabrics made therewith on the basis of conventional E-glass multiaxial fabrics. This paper discusses the choice of high performance glass fiber reinforcements for making megawatt wind turbine blades.

  10. 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...

  11. 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....

  12. Early Mobilization of Mechanically Ventilated Patients.

    Science.gov (United States)

    Hruska, Pam

    2016-12-01

    Critically ill patients requiring mechanical ventilation are least likely to be mobilized and, as a result, are at-risk for prolonged complications from weakness. The use of bed rest and sedation when caring for mechanically ventilated patients is likely shaped by historical practice; however, this review demonstrates early mobilization, with little to no sedation, is possible and safe. Assessing readiness for mobilization in context of progressing patients from passive to active activities can lead to long-term benefits and has been achievable with resource-efficient implementations and team work.

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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...

  18. 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.

  19. Elective ventilation for organ donation: law, policy and public ethics.

    Science.gov (United States)

    Coggon, John

    2013-03-01

    This paper examines questions concerning elective ventilation, contextualised within English law and policy. It presents the general debate with reference both to the Exeter Protocol on elective ventilation, and the considerable developments in legal principle since the time that that protocol was declared to be unlawful. I distinguish different aspects of what might be labelled elective ventilation policies under the following four headings: 'basic elective ventilation'; 'epistemically complex elective ventilation'; 'practically complex elective ventilation'; and 'epistemically and practically complex elective ventilation'. I give a legal analysis of each. In concluding remarks on their potential practical viability, I emphasise the importance not just of ascertaining the legal and ethical acceptability of these and other forms of elective ventilation, but also of assessing their professional and political acceptability. This importance relates both to the successful implementation of the individual practices, and to guarding against possible harmful effects in the wider efforts to increase the rates of posthumous organ donation.

  20. Efficient ventilation in school buildings. Design guidebook; Ventilation performante dans les ecoles. Guide de conception

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This guidebook aims at giving practical advices for the design of ventilation systems for school buildings in order to maintain air quality levels and energy consumptions conformable with the real needs: 1 - the specific problem of schools (various types of rooms, particular indoor pollutions); 2 - main criteria to consider (air quality and hygiene, hygro-thermal comfort, ventilation efficiency, acoustic comfort, energy mastery); 3 - main existing solutions (simple-flux blow-off or blow-in mechanical ventilation systems, dual-flux systems, air conditioning systems); 4 - choice of an adapted solution (selection criteria, global solution for the school); setting-up and follow-up (rules, training, maintenance). (J.S.)

  1. 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.

  2. 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.

  3. 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)...

  4. 21 CFR 868.5915 - Manual emergency ventilator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual emergency ventilator. 868.5915 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5915 Manual emergency ventilator. (a) Identification. A manual emergency ventilator is a device, usually incorporating a bag and valve, intended...

  5. 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...

  6. [Monitorization of respiratory mechanics in the ventilated patient].

    Science.gov (United States)

    García-Prieto, E; Amado-Rodríguez, L; Albaiceta, G M

    2014-01-01

    Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation.

  7. 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...

  8. Study on the applicability of the desk replacement ventilation concept

    NARCIS (Netherlands)

    Loomans, M.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 displace-ment ventilation (DDV) concept. The study uses steady-state and transient results to discuss the applicability of the DDV co

  9. 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

  10. 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...

  11. 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 ...

  12. Proceedings of the 7th international mine ventilation congress

    Energy Technology Data Exchange (ETDEWEB)

    Wasilewski, S. (ed.)

    2001-07-01

    The proceedings contains 139 papers covering the topics: ventilation analysis; heat assessment; methane emission and drainage; human factors; health and contaminations; fans and systems; dust generation and control; ventilation network and simulation systems and virtual reality; mine explosions; ventilation studies; mine fire determination planning; mine fires prevention studies; diesels; and case studies. Selected papers have been abstracted for IEA Coal Research coal abstract database.

  13. 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

    The present study investigated different combinations of floor/ceiling heating with mixing/displacement ventilation and their impacts on the indoor air distribution and ventilation effectiveness. Measurements were performed in a room during heating season in December. The results show that indoor...... 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...... 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 increased by non-uniform indoor air distribution and small ventilation effectiveness, there should be an optimal...

  14. 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......% at the highest nominal air change rate of 4.5h-1, even for an occupant sitting 1 meter in front of the supply diffuser, the local thermal discomfort occasioned by the excessive vertical temperature differences gives chilled ceilings the advantage over chilled floors for use with displacement ventilation....

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. Ventilator associated pneumonia and infection control

    NARCIS (Netherlands)

    Alp, E.; Voss, A.

    2006-01-01

    Ventilator associated pneumonia (VAP) is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20-75% according to the study population. Aspiration of colonized pathogenic microorganisms on th

  20. Ventilators in ICU: A boon or burden

    Directory of Open Access Journals (Sweden)

    Man Mohan Mehndiratta

    2016-01-01

    Full Text Available Background and Aims: Ventilator-associated pneumonia (VAP is a major challenge in intensive care units (ICUs. This challenge is even more discernible in a neurological setting owing to the predispositions of patients. Data on VAP in the neurology and neurosurgery ICUs (NNICUs are scanty in developing countries. This study was conducted to find out the occurrence of VAP, its risk factors, microbiological profile, and antibiotic resistance in patients admitted to the NNICU of a tertiary care institute in India. Materials and Methods: Endotracheal aspirate and blood samples were collected from 100 patients admitted to the NNICU. Complete blood count, microscopic examination, culture and sensitivity testing of aspirate were done. Chest x-ray was also performed to aid in the diagnosis of VAP. Results: Incidence rate of VAP was found to be 24%. Acinetobacter baumannii was the most common pathogen (24.3% isolated from patients with VAP, and all of these isolates were sensitive to meropenem. Duration of mechanical ventilation (P < 0.0001 and associated comorbid illness (P = 0.005 were found to be significantly associated with VAP, and the duration of mechanical ventilation was found to be the only independent risk factor (P < 0.0001. Conclusions: This study highlights the risks and microbiological perspective of ventilator use among neurology patients so that adequate preventive strategies can be adopted on time.

  1. Monitoring Patient/Ventilator Interactions: Manufacturer's Perspective.

    Science.gov (United States)

    Evers, Gerard; Loey, Carl Van

    2009-03-12

    The introduction of reduced and more powerful electronics has allowed the transition of medical equipment such as respiratory support devices from the hospital to the patient's home environment. Even if this move could be beneficial for the patient, the clinician ends up in a delicate situation where little or no direct supervision is possible on the delivered treatment.Progress in technologies led to an improved handling of patient-device interaction: manufacturers are promoting new or improved ventilation modes or cycling techniques for better patient-ventilator coupling. Even though these ventilation modes have become more responsive to patient efforts, adversely they might lead to events such as false triggering, autotriggering, delayed triggering.In addition, manufacturers are developing tools to enhance the follow-up, remotely or offline, of the treatment by using embedded memory in the respiratory devices. This logging might be beneficial for the caregiver to review and document the treatment and tune the settings to the patient's need and comfort. Also, remote telemedicine has been raised as a potential solution for many years without yet overall acceptance due to legal, technical and ethical problems.Benefits of new technologies in respiratory support devices give the technical foundation for the transition from hospital to home and reducing patient/ventilator asynchronies. Healthcare infrastructure has to follow this trend in terms of cost savings versus hospital stays.

  2. 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

  3. A Novel Model for Sewer Ventilation

    DEFF Research Database (Denmark)

    Fuglsang, Emil Dietz; Nielsen, Asbjørn Haaning; Vollertsen, Jes

    2013-01-01

    Based on the naturally occurring gas CO2 the dynamics of natural ventilation and gas flow was studied in an intercepting sewer receiving wastewater from a pressure main. A deterministic physiochemical model including description of release of CO2 into the sewer gas phase was built and validated a...... against field measurements....

  4. Modeling ventilation time in forage tower silos.

    Science.gov (United States)

    Bahloul, A; Chavez, M; Reggio, M; Roberge, B; Goyer, N

    2012-10-01

    The fermentation process in forage tower silos produces a significant amount of gases, which can easily reach dangerous concentrations and constitute a hazard for silo operators. To maintain a non-toxic environment, silo ventilation is applied. Literature reviews show that the fermentation gases reach high concentrations in the headspace of a silo and flow down the silo from the chute door to the feed room. In this article, a detailed parametric analysis of forced ventilation scenarios built via numerical simulation was performed. The methodology is based on the solution of the Navier-Stokes equations, coupled with transport equations for the gas concentrations. Validation was achieved by comparing the numerical results with experimental data obtained from a scale model silo using the tracer gas testing method for O2 and CO2 concentrations. Good agreement was found between the experimental and numerical results. The set of numerical simulations made it possible to establish a simple analytical model to predict the minimum time required to ventilate a silo to make it safe to enter. This ventilation time takes into account the headspace above the forage, the airflow rate, and the initial concentrations of O2 and CO2. The final analytical model was validated with available results from the literature.

  5. Sensory source strength of used ventilation filters

    DEFF Research Database (Denmark)

    Clausen, Geo; Alm, Ole Martin; Fanger, Povl Ole

    2002-01-01

    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...

  6. Sedation and Analgesia in Mechanical Ventilation

    DEFF Research Database (Denmark)

    Strøm, Thomas; Toft, Palle

    2014-01-01

    Traditionally, critically ill patients undergoing mechanical ventilation (MV) have received sedation. Over the last decade, randomized controlled trials have questioned continued use of deep sedation. Evidence shows that a nurse-driven sedation protocol reduces length of MV compared with standard...

  7. High-Frequency Percussive Ventilation Revisited

    Science.gov (United States)

    2010-01-01

    riched gas from the ventilator flowing through the cen- Table 2. Proposed approach to HFPV/VDR-4 management Oxygenation Goal: PaO2 : >65 mm Hg or SpO2...FiO2 down from initial settings every 10 minutes as permitted to sustain clinically acceptable PaO2 or SpO2. Then change frequency and pressure

  8. 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

  9. Physiological Effects of Positive Pressure Ventilation.

    Science.gov (United States)

    1992-05-01

    CVP, and the use of PEEP up to 15cm H20 ( Teba , Dedhia, Schiebel, Blehschmidt, & Linder, 1990). Infection Nosocomial infections of the respiratory...1989). Nutritional support of the ventilator-dependent patient. Nursing Clinics of North America, 24, 407-414. Teba , L., Dedhia, H. V., Schiebel, F

  10. 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....

  11. Psychosocial problems arising from home ventilation

    NARCIS (Netherlands)

    van Kesteren, RG; Velthuis, B; van Leyden, LW

    2001-01-01

    Objective: To study psychosocial questions and problems of patients, who are chronically dependent on artificial ventilation, and their families. Design: A total of 38 patients and family members (n = 43) were randomly selected. Several patients (n = 12) received respiratory support by nasal mask; t

  12. 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...

  13. A RESEARCH ON VENTILATION EFFICIENCY OF PIPED VENTILATION SYSTEMS IN GEOTHERMALLY HEATED GREENHOUSES

    Directory of Open Access Journals (Sweden)

    İbrahim Örüng

    2016-07-01

    Full Text Available Greenhouse play significant roles in human nutrition. Vegetable and fruit consumption at certain amounts is the basic pre-condition for a well nutrition. It is possible to produce sufficient quantities of fruits and vegetables in places with available climate conditions. However, fruits and vegetables should be grown in special buildings to have a year-long production in places without available climate conditions. These places include under-cover production facilities, greenhouses, low and high tunnel facilities. Environmental conditions are adjusted are adjusted in greenhouses as to provide proper conditions for plant growth and development. Ventilation is used to remove excess heat, moisture and carbon dioxide from the greenhouses. Either natural or mechanical ventilation is used in greenhouses. Mechanical ventilation systems have various advantages over natural systems. However, mostly natural ventilation systems are preferred because of their low installation and operational costs. Both systems operates based on negative pressure. Air exchange rates are usually low in winters and it is quite hard to evenly distribute cold fresh air within the greenhouse. Air inlets are usually placed over side walls and outlets are commonly placed along the ridge. In this study an alternative natural ventilation system was proposed for more efficient ventilation of the greenhouses. In this system, fresh air gets into the greenhouse through ventilation pipes installed beneath the greenhouse floor. The incoming fresh air also heated with geothermal hot water lines, thus direct contact of cold fresh air is prevented. The design and efficiency of piped ventilation systems were provided in this paper.

  14. The cost of ventilation in birds measured via unidirectional artificial ventilation.

    Science.gov (United States)

    Markley, Jessamyn S; Carrier, David R

    2010-02-01

    The highly derived mechanism birds use to ventilate their lungs relies on dorsoventral excursions of their heavily muscled sternum and abdominal viscera. Our expectation of the level of mechanical work involved in this mechanism led us to hypothesize that the metabolic cost of breathing is higher in birds than in other tetrapods. To test this theory, we used unidirectional artificial ventilation (UDV) to stop normal ventilatory movements in guinea fowl (Numida meleagris L.) at rest and during treadmill locomotion at three speeds. Oxygen consumption was measured during normal breathing and UDV, and the difference was used to approximate the cost of ventilation. Contrary to our prediction, metabolism increased when ventilatory movements ceased during UDV at rest. Although we do not understand why this occurred we suspect that UDV induced a homeostatic mechanism to counteract the loss of carbon dioxide. Nevertheless, across all running speeds, metabolism decreased significantly with UDV, indicating a minimum cost of ventilation during running of 1.43+/-0.62% of total running metabolism or 0.48+/-0.21 mL O(2) (L ventilated)(-1). These results suggest that the metabolic cost of ventilation is low in birds and that it is within the range of costs reported previously for other amniotes.

  15. 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.

  16. Perceived Air Quality in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Brohus, Henrik; Knudsen, Henrik Nellemose; Nielsen, Peter V.

    In a displacement ventilated room the non-uniform contaminant distribution causes an improved indoor air quality in the occupied zone compared with conventional mixing ventilation. This has been demonstrated in numerous studies by chemical measurements. In this study the air quality...... in a displacement ventilated room was determined directly by asking humans about how they perceived the air quality. A trained sensory panel comprising 12 subjects assessed the perceived air quality immediately after entering a climate chamber. The experiments showed that the perceived air quality...... in the displacement ventilated chamber was substantially better than in the case of mixing ventilation....

  17. [Ventilation during cardiopulmonary resuscitation (CPR). A literature study and analysis of ventilation strategies].

    Science.gov (United States)

    Wenzel, V; Lindner, K H; Prengel, A W

    1997-02-01

    In a recently published German multicenter study, 25% of the patients with witnessed cardiac arrest outside the hospital were resuscitated successfully and discharged from the hospital. Approximately 100,000 people suffer a fatal cardiac arrest in Germany annually, which is approximately tenfold the number of deaths from motor vehicle accidents. Cardiopulmonary resuscitation (CPR) performed by bystanders is an important part of the chain of survival to minimize the time interval without artificial circulation and ventilation in a cardiac arrest victim. This is especially important in areas with long response times of the emergency medical service (EMS). Early examples of ventilation have been described throughout history. References to mouth-to-mouth ventilation (MTMV) are found in the Bible, in a description of the resuscitation of a coal miner in 1744, and in an experiment in 1796 demonstrating that exhaled gas was safe for breathing. In 1954, Elam and colleagues described artificial respiration with the exhaled gas of a rescuer using a mouth-to-mask ventilation method. The modern CPR era started with the combination of MTMV and chest compressions 35 years ago. However, the value of MTMV is currently under discussion because of a widespread fear of transmission of infectious diseases. Healthcare professionals have stated in several studies that they may withhold MTMV when confronted with a cardiac arrest in a stranger. Although an infection with Mycobacterium tuberculosis is more likely than one with HIV via MTMV, the fear of the public is understandable. An expert committee of the American Heart Association stated that MTMV may be omitted in the initial phase of cardiac arrest, and considered recommending chest compressions only if the EMS will arrive rapidly. In paralyzed volunteers, however, ventilation induced by chest compressions was not able to provide sufficient gas exchange, especially when the airway was not protected. Laboratory investigations studying

  18. Ventilation efficiencies and thermal comfort results of a desk-edge-mounted task ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, D.; Fisk, W.J.; Sullivan, D.P.; Lee, S.M.

    2003-09-01

    In chamber experiments, we investigated the ventilation effectiveness and thermal comfort of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin or a human volunteer seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15{sup o} to 45{sup o} from horizontal), and the supply flow rate of (3.5 to 6.5 L s{sup -1}). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air in the breathing zone) in experiments with the mannequin ranged from 1.4 to 2.7 (median, 1.8), whereas with human subjects the air change effectiveness ranged from 1.3 to 2.3 (median, 1.6). The majority of the air change effectiveness values with the human subjects were less than values with the mannequin at comparable tests. Similarly, the tests run with supply air temperature equal to the room air temperature had lower air change effectiveness values than comparable tests with the supply air temperature lower ({approx}5 C) than the room air temperature. The air change effectiveness values are higher than typically reported for commercially available task ventilation or displacement ventilation systems. Based on surveys completed by the subjects, operation of the task ventilation system did not cause thermal discomfort.

  19. 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.

  20. 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。

  1. 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.

  2. Moisture Transfer in Ventilated Facade Structures

    Directory of Open Access Journals (Sweden)

    Olshevskyi Vyacheslav

    2016-01-01

    Full Text Available This article discusses the phenomenon of moisture transfer in the designs of ventilated facades (VF. The main ways of moisture transfer are defined. The negative factors connected with moisture accumulation and excessive moistening of insulation are given. The physical processes occurring in the gap of the building envelope due to saturation of air with water vapor are described. The dependence of the intensity of the mass transfer on the air velocity in the layer is considered. Much attention is paid to the selection of the optimum design of the facade, namely a system with or without grooved lines. The dependence of velocity and temperature on the width of the ventilated gap is established empirically for the constructions with open and closed grooves. Expediency of a design without grooves to effectively remove moisture is determined.

  3. Simplified analysis of naturally ventilated desert buildings

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, E.H.; Richards, P.G.; Rousseau, P.G. (Pretoria Univ. (South Africa). Dept. of Mechanical Engineering); Etzion, Y.; Erell, E. (Ben-Gurion Univ. of the Negev, Sede Boqer (Israel). J. Blaustein Inst. for Desert Research)

    1992-10-01

    The verification of a simplified thermal analysis procedure and its application to naturally ventilated desert buildings are discussed. Measurements for buildings in the Negev Desert, made independently by the Desert Architecture Unit of the Jacob Blaustein Institute for Desert Research, were inter alia used to verify the simplified thermal analysis procedure QUICK, developed by the Centre for Experimental and Numerical Thermoflow. As detailed information for validation purposes is not always readily available to researchers, the measurements as well as the buildings' descriptions are given in detail in this paper. The effect of natural ventilation strategies on the indoor air temperatures is also investigated for the desert buildings. A simplified but novel procedure to calculate the air change rates through the building from the measured wind speeds, building geometry and surroundings is proposed. Hourly air change rates determined with the proposed procedure are employed in the simulations with QUICK. (author)

  4. Ventilator associated pneumonia and infection control

    Directory of Open Access Journals (Sweden)

    Alp Emine

    2006-04-01

    Full Text Available Abstract Ventilator associated pneumonia (VAP is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20–75% according to the study population. Aspiration of colonized pathogenic microorganisms on the oropharynx and gastrointestinal tract is the main route for the development of VAP. On the other hand, the major risk factor for VAP is intubation and the duration of mechanical ventilation. Diagnosis remains difficult, and studies showed the importance of early initiation of appropriate antibiotic for prognosis. VAP causes extra length of stay in hospital and intensive care units and increases hospital cost. Consequently, infection control policies are more rational and will save money.

  5. 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....

  6. 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.

  7. 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.

  8. Cooling airflow design tool for displacement ventilation.

    OpenAIRE

    Schiavon, Stefano; Bauman, Fred

    2009-01-01

    These user notes describe how to use a spreadsheet-based (Excel 2007) version of the ASHRAE method (Chen and Glicksman 2003) for calculating the amount of design cooling airflow required for a displacement ventilation (DV) system that is providing all sensible cooling for a conditioned space. The design tool has been developed by CBE and is available on the CBE Partner website: http://www.cbe.berkeley.edu/partners/downloads.php

  9. Degree of dependence on the ventilator according to sleep states in artificially ventilated premature infants.

    Science.gov (United States)

    Curzi-Dascalova, L; Relier, J P; Peirano, P; Castex, M; Vasseur, O

    1986-07-01

    Polygraphic recordings were performed in 14 sleeping premature infants receiving ventilation for respiratory distress syndrome. All were clinically stabilized, with normal EEG and neurologic status and differentiated sleep states (coded according to EEG and REM criteria). They all had two respiratory patterns: passive, completely dependent on the ventilator, and active, with autonomous respiratory movements and/or inspiratory diaphragmatic activity added to passive respiration. We found that in infants ventilated at the rate of 18-54/min, respiration was more active and autonomous in active REM sleep and more passive and dependent on the machine in quiet NREM sleep (P less than 0.005). Within the limits of the values observed in our study, differences between sleep states were not due to other factors that could possibly interfere with and modify the degree of respiratory autonomy. We found no significant correlation between the percentage of time passed with active respiration on one hand and age (gestational, postnatal, conceptional) or diagnostic or physical parameters of artificial ventilation and blood gas levels on the other hand. Our results suggest that in artificially ventilated but neurologically normal premature infants, differences between respiratory control in both sleep states exist as early as 28 weeks conceptional age (lower limit of our study).

  10. 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.

  11. Advanced Controls for Residential Whole-House Ventilation Systems

    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); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    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.

  12. 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.

  13. Respiratory mechanics in mechanically ventilated patients.

    Science.gov (United States)

    Hess, Dean R

    2014-11-01

    Respiratory mechanics refers to the expression of lung function through measures of pressure and flow. From these measurements, a variety of derived indices can be determined, such as volume, compliance, resistance, and work of breathing. Plateau pressure is a measure of end-inspiratory distending pressure. It has become increasingly appreciated that end-inspiratory transpulmonary pressure (stress) might be a better indicator of the potential for lung injury than plateau pressure alone. This has resulted in a resurgence of interest in the use of esophageal manometry in mechanically ventilated patients. End-expiratory transpulmonary pressure might also be useful to guide the setting of PEEP to counterbalance the collapsing effects of the chest wall. The shape of the pressure-time curve might also be useful to guide the setting of PEEP (stress index). This has focused interest in the roles of stress and strain to assess the potential for lung injury during mechanical ventilation. This paper covers both basic and advanced respiratory mechanics during mechanical ventilation.

  14. 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.

  15. 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.

  16. 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.

  17. Technology for noninvasive mechanical ventilation: looking into the black box

    Directory of Open Access Journals (Sweden)

    Ramon Farré

    2016-03-01

    Full Text Available Current devices for providing noninvasive respiratory support contain sensors and built-in intelligence for automatically modifying ventilation according to the patient's needs. These devices, including automatic continuous positive airway pressure devices and noninvasive ventilators, are technologically complex and offer a considerable number of different modes of ventilation and setting options, the details of which are sometimes difficult to capture by the user. Therefore, better predicting and interpreting the actual performance of these ventilation devices in clinical application requires understanding their functioning principles and assessing their performance under well controlled bench test conditions with simulated patients. This concise review presents an updated perspective of the theoretical basis of intelligent continuous positive airway pressure and noninvasive ventilation devices, and of the tools available for assessing how these devices respond under specific ventilation phenotypes in patients requiring breathing support.

  18. 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.

  19. Mechanical ventilation in patients subjected to extracorporeal membrane oxygenation (ECMO).

    Science.gov (United States)

    Sánchez, M L

    2017-02-07

    Mechanical ventilation (MV) is a crucial element in the management of acute respiratory distress syndrome (ARDS), because there is high level evidence that a low tidal volume of 6ml/kg (protective ventilation) improves survival. In these patients with refractory respiratory insufficiency, venovenous extracorporeal membrane oxygenation (ECMO) can be used. This salvage technique improves oxygenation, promotes CO2 clearance, and facilitates protective and ultraprotective MV, potentially minimizing ventilation-induced lung injury. Although numerous trials have investigated different ventilation strategies in patients with ARDS, consensus is lacking on the optimal MV settings during venovenous ECMO. Although the concept of "lung rest" was introduced years ago, there are no evidence-based guidelines on its use in application to MV in patients supported by ECMO. How MV in ECMO patients can promote lung recovery and weaning from ventilation is not clear. The purpose of this review is to describe the ventilation strategies used during venovenous ECMO in clinical practice.

  20. Effect of forced ventilation on the dust concentration of partially ventilated mine worksites

    Energy Technology Data Exchange (ETDEWEB)

    Vekeny, H.

    1985-01-01

    The stone drifts and about two-thirds of the roadways in coal seams of the Mecsek Coal Mines, Hungary, are driven by forced ventilation which, in addition to its numerous merits, causes also air velocities significantly higher than optimum resulting in delivering dust particles and rock material produced by breaking of mineral and rock material into the atmosphere of worksites. This also increases the risk of silicosis of miners. A new device called a wind rose was developed and applied to the blow-out end of the ventilation duct leading to a better distribution of the discharged air stream in the drift.

  1. 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.

  2. Mechanical ventilation and respiratory mechanics during equine anesthesia.

    Science.gov (United States)

    Moens, Yves

    2013-04-01

    The mechanical ventilation of horses during anesthesia remains a crucial option for optimal anesthetic management, if the possible negative cardiovascular side effects are managed, because this species is prone to hypercapnia and hypoxemia. The combined use of capnography and pitot-based spirometry provide complementary information on ventilation and respiratory mechanics, respectively. This facilitates management of mechanical ventilation in conditions of changing respiratory system compliance (ie, laparoscopy) and when investigating new ventilatory strategies including alveolar recruitment maneuvers and optimization of positive expiratory pressure.

  3. 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.

  4. 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.

  5. [Ventilation in acute respiratory distress. Lung-protective strategies].

    Science.gov (United States)

    Bruells, C S; Rossaint, R; Dembinski, R

    2012-11-01

    Ventilation of patients suffering from acute respiratory distress syndrome (ARDS) with protective ventilator settings is the standard in patient care. Besides the reduction of tidal volumes, the adjustment of a case-related positive end-expiratory pressure and preservation of spontaneous breathing activity at least 48 h after onset is part of this strategy. Bedside techniques have been developed to adapt ventilatory settings to the individual patient and the different stages of ARDS. This article reviews the pathophysiology of ARDS and ventilator-induced lung injury and presents current evidence-based strategies for ventilator settings in ARDS.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Incidence and predictors of difficult mask ventilation and intubation

    Directory of Open Access Journals (Sweden)

    Prerana N Shah

    2012-01-01

    Conclusions: The predictive score may lead to a better anticipation of difficult airway management, potentially deceasing the morbidity and mortality resulting from hypoxia or anoxia with failed ventilation.

  11. 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.

  12. 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.)

  13. 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).

  14. 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

  15. Patient experiences during awake mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Danille Prime

    2016-02-01

    Full Text Available Background: Sedation practices in an ICU have shifted significantly in the past 20 years toward the use of minimizing sedation in mechanically ventilated patients. While minimizing sedation is clearly in the best interest of patients, data are lacking about how this approach affects patients’ experiences. Methods: We interviewed mechanically ventilated patients receiving minimal sedation, over a 6-month period in an ICU, in order to explore their emotional, comfort, and communication experiences. Their responses were compared with the responses of their available family members regarding their attitudes and perceptions of the patients’ experiences. Results: Seventy-five percent of the patients agreed or strongly agreed that they experienced pain, and 50% agreed or strongly agreed that they were comfortable. Half of the patients agreed or strongly agreed that they preferred to be kept awake. Five patients (31% indicated that they were frustrated while 17 relatives (89% agreed or strongly agreed that the patients were frustrated. When controlling for age and gender of respondents, family members perceived higher levels of patient pain (least square [LS] mean [95% CI]: 4.2 [3.7, 4.7] vs. 3.1 [2.5, 3.8]; p=0.022, frustration (LS mean [95% CI]: 4.2 [3.7, 4.6] vs. 3.2 [2.6, 3.9]; p=0.031, and adequate communication with nurses and doctors (LS mean [95% CI]: 3.9 [3.5, 4.4] vs. 3.1 [2.4, 3.7]; p=0.046 than the patients themselves. Conclusion: Patients tolerated minimal sedation without significant frustration while mechanically ventilated despite experiencing discomfort. Patient and family member perceptions of the patient experience may differ, especially in regards to pain and frustration. The use of a communication tool can facilitate understanding of patient experiences and preferences.

  16. 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......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 displacement flow with a downward direction in areas of the room where no thermal load is present. The system was extended by a personalized ventilation system to study the improved Protection of people in a room. The investigation involved full-scale experiments with two breathing thermal manikins. One...... in the room with increased protection of the occupants. It is shown that personalized ventilation improves the protection of occupants by increasing the personal exposure index....

  17. 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

    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...

  18. 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.

  19. 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.

  20. Design Features of Modern Mechanical Ventilators.

    Science.gov (United States)

    MacIntyre, Neil

    2016-12-01

    A positive-pressure breath ideally should provide a VT that is adequate for gas exchange and appropriate muscle unloading while minimizing any risk for injury or discomfort. The latest generation of ventilators uses sophisticated feedback systems to sculpt positive-pressure breaths according to patient effort and respiratory system mechanics. Currently, however, these new control strategies are not totally closed-loop systems. This is because the automatic input variables remain limited, some clinician settings are still required, and the specific features of the perfect breath design still are not entirely clear. Despite these limitations, there are some rationale for many of these newer feedback features.

  1. 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...

  2. Performance of personalized ventilation combined with chilled ceiling in an office room: inhaled air quality and contaminant distribution

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    In a simulated two persons’ office room inhaled air quality and contaminant distribution provided with personalized ventilation combined with chilled ceiling, mixing ventilation only, chilled ceiling with mixing ventilation and chilled ceiling with mixing and personalized ventilation was studied...

  3. Practice of Producing New Type Fiberglass Leno Fabric with GA747 Loom%GA747织机生产新型玻璃纤维纱罗网布的实践

    Institute of Scientific and Technical Information of China (English)

    曹爱军; 王洁静

    2014-01-01

    新型玻璃纤维纱罗网布的地经和纬纱采用玻璃纤维无捻直接纱,绞经采用涤纶丝生产,取代传统网布使用的有捻纱线,并去除传统纺织中的整经工序,在GA747织机上安装绞综综框且采用合理的织造工艺,有效降低原料成本,提高产品品质。%A new type fiberglass leno fabric was woven with fiberglass direct roving as normal warp and weft and polyester fiber as crossing warp to replace twisted yarn used in traditional mesh fabrics and eliminate the warping step used in the traditional weaving process. GA747 loom was equipped with leno heald frame and operated with a reasonable weaving process technology,resulting in significant reduction of material cost and improvement of product quality.

  4. Increasing natural ventilation using solar chimney

    Directory of Open Access Journals (Sweden)

    Nakielska Magdalena

    2017-01-01

    Full Text Available At a time when much attention is paid to the problem of energy saving is looking for new technical solutions, among others in the construction industry. At present, searching new solutions is a worldwide trend in creating buildings. Those solutions enable a comfortable use of building structures in harmony with natural environment and ensure reducing energy consumption. Solar chimneys, which facilitate the gravity ventilation by using solar energy, may be a solution to the problem. In hot climates solar chimney has been applied in the process of passive cooling of a building. In temperate zones and cold is used to assist natural ventilation. The problem of the solar chimney is not popular in Poland. Construction in Bydgoszcz two research positions, enabled the analysis of the impact of solar chimneys on the thermal comfort of rooms. This article presents experimental studies on solar chimney located in Poland. The analysis of the flow of air in the room during the day have been measured using two testmodels situated on the 3.1 building of UTP University of Science and Technology at 7 Kaliska street in Bydgoszcz.

  5. CDC releases ventilator-associated events criteria

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2017-01-01

    Full Text Available No abstract available. Article truncated at 150 words. A new term has been coined by the CDC, ventilator-associated events (VAEs (1. In 2011, the CDC convened a working group composed of members of several stakeholder organizations to address the limitations of the definition of ventilator-associated pneumonia (VAP definition (2. The organizations represented in the Working Group include: the Critical Care Societies Collaborative (the American Association of Critical-Care Nurses, the American College of Chest Physicians, the American Thoracic Society, and the Society for Critical Care Medicine; the American Association for Respiratory Care; the Association of Professionals in Infection Control and Epidemiology; the Council of State and Territorial Epidemiologists; the Healthcare Infection Control Practices Advisory Committee’s Surveillance Working Group; the Infectious Diseases Society of America; and the Society for Healthcare Epidemiology of America. VAEs are defined by an increase oxygen (>0.2 in FiO2 or positive end-expiratory pressure (PEEP (≥3 cm H2O, after a previous stable baseline of at least 2 …

  6. 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

  7. Mixing Ventilation System in a Single-Aisle Aircraft Cabin

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Zhang, Chen; Wojcik, Kamil

    2014-01-01

    and present a design procedure of the system. Finally, a personalised ventilation system will be described, which can be used together with the mixing ventilation system. The experiments are made in a full-scale, left side mock-up of a single-aisle (Boeing 737) cabin with four seats. The four passengers...

  8. 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...

  9. 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.

  10. A particle detector for use in ventilation engineering.

    Science.gov (United States)

    Clark, R P

    1973-09-01

    An electronic particle counting device is described, based on a constant-temperature hot-wire anemometer probe. The device has found application in tracing the motions of droplets and measuring their concentration within ventilated areas when subjected to different types of ventilation. In this way the effectiveness of various systems may be determined.

  11. 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.

  12. 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,…

  13. 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”....

  14. 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

  15. 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

  16. Differential ventilation with spontaneous respiration for bilateral emphysema.

    Science.gov (United States)

    Chakravarthy, Murali; Jawali, Vivek

    2007-06-01

    In patients with bilateral bullous disease and empyema in one lung, controlled ventilation may be hazardous and result in severe hypoxia. A 50-year-old man with bullous disease and thoracic empyema on the left side was operated on under general anesthesia with spontaneous respiration using differential lung ventilation.

  17. TLR2 deficiency aggravates lung injury caused by mechanical ventilation

    NARCIS (Netherlands)

    Kuipers, Maria Theresa; Jongsma, Geartsje; Hegeman, Maria A; Tuip-de Boer, Anita M; Wolthuis, Esther K; Choi, Goda; Bresser, Paul; van der Poll, Tom; Schultz, Marcus J; Wieland, Catharina W

    2014-01-01

    Innate immunity pathways are found to play an important role in ventilator-induced lung injury. We analyzed pulmonary expression of Toll-like receptor 2 (TLR2) in humans and mice and determined the role of TLR2 in the pathogenesis of ventilator-induced lung injury in mice. Toll-like receptor 2 gene

  18. 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.

  19. 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...

  20. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    NARCIS (Netherlands)

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ven

  1. 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.

  2. 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

  3. 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

  4. 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....

  5. 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...

  6. 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....

  7. [The study of noninvasive ventilator impeller based on ANSYS].

    Science.gov (United States)

    Hu, Zhaoyan; Lu, Pan; Xie, Haiming; Zhou, Yaxu

    2011-06-01

    An impeller plays a significant role in the non-invasive ventilator. This paper shows a model of impeller for noninvasive ventilator established with the software Solidworks. The model was studied for feasibility based on ANSYS. Then stress and strain of the impeller were discussed under the external loads. The results of the analysis provided verification for the reliable design of impellers.

  8. 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...

  9. 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...

  10. Investigation of Ventilator Associated Pneumoniae in Intensive Care Patients

    Directory of Open Access Journals (Sweden)

    Hakan Tağrıkulu,

    2016-04-01

    Full Text Available Objective: Mechanical ventilator associated pneumonia is a serious infection occurred frequently in intensive care units and associated with high mortality. In this study we aimed to investigate the incidence of ventilator associated pneumonia, the duration of mechanical ventilation, length of intensive care unit stay, complication occurrence and mortality rates on patients undergoing mechanical ventilation for more than 48 hours. Material and Method: Two hundred twenty patients were included in the study. Demographic data at the time of the admission to intensive care unit (age, sex, height, weight and body mass index, intensive care admission diagnosis and systemic diseases were all recorded. The clinical pulmonary infection score was used for ventilator associated pneumonia diagnosis. Antibiotic usage, duration of stay in intensive care unit, duration of mechanical ventilation stay and mortality were all recorded. Results: Ventilator-associated pneumonia was detected in 51.36% (n=113 of the 220 patients. Clinical pulmonary infection score was found as 8.04±1.03 in patients with ventilator-associated pneumonia and 1.75±1.88 in non- ventilatorassociated pneumonia patients (p=0.001. Higher age was detected in ventilator-associated pneumonia group (58±12.79 years and 51.37±15.87 years, p=0.001. Also hypertension and diabetes mellitus were observed more frequently (p=0.001. Development of enteral nutrition in patients with ventilator-associated pneumonia were significantly higher than those of parenterally fed patients (enteral: by 36.4% and 25.5% p=0.006; parenteral: 25% and 19.1%, p=0.042. The length of stay in intensive care unit (12.38±5.81 and 10.79±5.91 days, p=0.045, duration of mechanical ventilation (9.67±4.84 days and 6.7±3.87 days, p=0.001 and mortality rates (24.5% and 15.5% p=0.019 were significantly higher in the ventilator-associated pneumonia group. Conclusion: Ventilator-associated pneumonia increases the duration of

  11. 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...

  12. Mechanical ventilation with heat recovery in cold climates

    DEFF Research Database (Denmark)

    Kragh, Jesper; Rose, Jørgen; Svendsen, Svend

    2005-01-01

    like the Northern Europe or in arctic climate like in Greenland or Alaska these ventilation systems will typically face problems with ice formation in the heat exchanger. When the warm humid room air comes in contact with the cold surfaces inside the exchanger (cooled by the outside air), the moisture......Building ventilation is necessary to achieve a healthy and comfortable indoor environment, but as energy prices continue to rise it is necessary to reduce the energy consumption. Using mechanical ventilation with heat recovery reduces the ventilation heat loss significantly, but in cold climates...... freezes to ice. The analysis of measurements from existing ventilation systems with heat recovery used in single-family houses in Denmark and a test of a standard heat recovery unit in the laboratory have clearly shown that this problem occurs when the outdoor temperature gets below approximately –5º...

  13. 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.

  14. Energy efficient demand controlled ventilation in single family houses

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2010-01-01

    This paper presents a strategy for a simple demand controlled ventilation system for single family houses where all sensors and controls are located in the air handling unit. The strategy is based on sensing CO2-concentration and moisture content in the outdoor air and exhaust air. The CO2......-concentration is used to ensure adequate ventilation during occupancy and the moisture content is used to ensure adequate removal of moisture produced in the house. The ventilation rate can be switched between two flow rates: a high rate and a low rate. The high flow rate is based on existing requirements...... in the Danish building regulations and the low flow rate is based on minimum requirements in indoor air quality standards. Measurements were performed on an existing single family house where the controls were installed on the existing mechanical ventilation system. The results showed that the ventilation can...

  15. Investigation of Ventilation Strategies for the Day-Care Institutions

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Afshari, Alireza; Heiselberg, Per

    2011-01-01

    Two existing nursery buildings, a mechanically and a naturally ventilated one, were chosen for investigations of energy saving potential and IAQ, using the different from present ventilation strategies and their control principles. These investigations are carried out applying a dynamic building...... simulation tool BSim. Each building is modelled separately and each of these models is “calibrated” using the detailed experimental data. Calibrated models are then used to evaluate different ventilation strategies for these particular buildings. This paper is aimed to illustrate the differences...... in assumptions for building operation on the design stage and actual building operation. Finally, it is not argued in favour to one or another ventilation principle, but in favour of demand controlled ventilation....

  16. 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.

  17. Distribution of ventilation in American alligator Alligator mississippiensis

    Energy Technology Data Exchange (ETDEWEB)

    Bickler, P.E.; Spragg, R.G.; Hartman, M.T.; White, F.N.

    1985-10-01

    The regional distribution of ventilation in the multicameral lung of spontaneously ventilating alligators (Alligator mississippiensis) was studied with TTXe scintigraphy. Frequent gamma camera images of TTXe washin and washout were obtained and processed to allow evaluation of regional ventilation. Washin of TTXe 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 TTXe 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.

  18. 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.

  19. Experimental evaluation of air distribution in mechanically ventilated residential rooms

    DEFF Research Database (Denmark)

    Tomasi, R.; Krajčík, M.; Simone, A.

    2013-01-01

    The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventilation effectiveness was experimentally studied in a simulated residential room equipped with radiant floor heating/cooling and mixing ventilation systems. The tests were performed for various positions...... removal effectiveness (CRE) and local air change index was measured in order to characterize ventilation effectiveness in the occupied zone. Acceptable thermal comfort was found in most experiments; however, air temperature differences higher than 3 °C occurred when floor cooling was combined...... with unconditioned outdoor air supply, i.e. at the supply air temperatures higher than the room air temperature. Moreover, low floor temperatures were needed to maintain the desired reference temperature in the stratified thermal environment. Mainly in cooling conditions the ventilation effectiveness depended...

  20. 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.

  1. 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.

  2. Comparison of patient-ventilator asynchrony during pressure support ventilation and proportional assist ventilation modes in surgical Intensive Care Unit: A randomized crossover study

    Directory of Open Access Journals (Sweden)

    Parshotam Lal Gautam

    2016-01-01

    Full Text Available Background: The patient-ventilator asynchrony is almost observed in all modes of ventilation, and this asynchrony affects lung mechanics adversely resulting in deleterious outcome. Innovations and advances in ventilator technology have been trying to overcome this problem by designing newer modes of ventilation. Pressure support ventilation (PSV is a commonly used flow-cycled mode where a constant pressure is delivered by ventilator. Proportional assist ventilation (PAV is a new dynamic inspiratory pressure assistance and is supposed to be better than PSV for synchrony and tolerance, but reports are still controversial. Moreover, most of these studies are conducted in chronic obstructive pulmonary disease patients with respiratory failure; the results of these studies may not be applicable to surgical patients. Thus, we proposed to do compare these two modes in surgical Intensive Care Unit (ICU patients as a randomized crossover study. Aims: Comparison of patient-ventilator asynchrony between PSV and PAV plus (PAV+ in surgical patients while weaning. Subjects and Methods: After approval by the Hospital Ethics Committee, we enrolled twenty patients from surgical ICU of tertiary care institute. The patients were ventilated with pressure support mode (PSV and PAV+ for 12 h as a crossover from one mode to another after 6 h while weaning. Results: Average age and weight of patients were 41.80 ± 15.20 years (mean ± standard deviation [SD] and 66.50 ± 12.47 (mean ± SD kg, respectively. Comparing the asynchronies between the two modes, the mean number of total asynchronous recorded breaths in PSV was 7.05 ± 0.83 and 4.35 ± 5.62, respectively, during sleep and awake state, while the same were 6.75 ± 112.24 and 10.85 ± 11.33 in PAV+. Conclusion: Both PSV and PAV+ modes of ventilation performed similarly for patient-ventilator synchrony in surgical patients. In surgical patients with acute respiratory failure, dynamic inspiratory pressure

  3. 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.

  4. Pulmonary levels of high-mobility group box 1 during mechanical ventilation and ventilator-associated pneumonia

    NARCIS (Netherlands)

    van Zoelen, Marieke A D; Ishizaka, Akitoshi; Wolthuls, Esther K; Choi, Goda; van der Poll, Tom; Schultz, Marcus J

    2008-01-01

    High-mobility group box (HMGB) 1 is a recently discovered proinflammatory mediator that contributes to acute lung injury. We determined HMGB-1 levels in bronchoalveolar lavage fluid of patients during mechanical ventilation (MV) and ventilator-associated pneumonia (VAP). Bronchoalveolar lavage fluid

  5. 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...... office room with two workstations positioned one behind the other was arranged in a full-scale room. Each workstation consisted of a table with an installed “ductless” PV system, PC, desk lamp and seated breathing thermal manikin. The “ductless” PV system sucked the clean and cool displacement air...... supplied over the floor at four different heights, i.e. 2, 5, 10 and 20 cm and transported it direct to the breathing level. Moreover, two displacement airflow rates were used with a supply temperature adjusted in order to maintain an exhaust air temperature of 26 °C. Two pollution sources, namely air...

  6. Where to perform long-term ventilation.

    Science.gov (United States)

    Ambrosino, Nicolino; Vianello, Andrea

    2002-09-01

    Given that most VAI prefer to be cared for at home and that their return home is the desire of families, health care professionals, and others concerned with LTMV, the effort to transform prolonged mechanical ventilation from a hospital-centered to a home-centered treatment needs to be continued and further developed. Nevertheless, the future of high-technology home care will undoubtedly be influenced by improvements in quality and containment of costs, as in its current status treatment of VAI at home too often leads to family disruption and presents a dramatically increasing cost burden. Careful selection of patients, closer attention to education and training, and collection of outcome data are all factors that presumably will facilitate the development of better-quality and cost-saving home care.

  7. 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...

  8. 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.

  9. [Intermediate care units and noninvasive ventilation].

    Science.gov (United States)

    Becker, Heinrich F; Schönhofer, Bernd; Vogelmeier, Claus

    2006-04-15

    Intermediate care units (IMC) have been introduced to provide optimal patient management according to disease severity and to bridge the gap between intensive care (ICU) and general wards. Most patients that are referred to an IMC need monitoring and intensive analgetic treatment. Over the past years noninvasive ventilation (NIV) and weaning have emerged as important new forms of active treatment in the IMC. Most studies that have been published so far demonstrate that an IMC improves patient outcome and lowers costs, although randomized controlled trials are missing. NIV reduces mortality, the need for intubation as well as ICU and hospital length of stay in patients with chronic obstructive pulmonary disease (COPD) and other disorders that cause respiratory failure. In many cases NIV can be performed in the IMC, a fact that reduces the number of ICU admissions, lowers costs and improves patient care. The high prevalence of pulmonary diseases and NIV emphasizes the importance of pneumologists as directors of both ICU and IMC.

  10. Evaluation of an Incremental Ventilation Energy Model for Estimating Impacts of Air Sealing and Mechanical Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Turner, Willliam JN [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-01

    Changing the rate of airflow through a home affects the annual thermal conditioning energy. Large-scale changes to airflow rates of the housing stock can significantly alter the energy consumption of the residential energy sector. However, the complexity of existing residential energy models hampers the ability to estimate the impact of policy changes on a state or nationwide level. The Incremental Ventilation Energy (IVE) model developed in this study was designed to combine the output of simple airflow models and a limited set of home characteristics to estimate the associated change in energy demand of homes. The IVE model was designed specifically to enable modelers to use existing databases of home characteristics to determine the impact of policy on ventilation at a population scale. In this report, we describe the IVE model and demonstrate that its estimates of energy change are comparable to the estimates of a wellvalidated, complex residential energy model when applied to homes with limited parameterization. Homes with extensive parameterization would be more accurately characterized by complex residential energy models. The demonstration included a range of home types, climates, and ventilation systems that cover a large fraction of the residential housing sector.

  11. Gas transfer model to design a ventilator for neonatal total liquid ventilation.

    Science.gov (United States)

    Bonfanti, Mirko; Cammi, Antonio; Bagnoli, Paola

    2015-12-01

    The study was aimed to optimize the gas transfer in an innovative ventilator for neonatal Total Liquid Ventilation (TLV) that integrates the pumping and oxygenation functions in a non-volumetric pulsatile device made of parallel flat silicone membranes. A computational approach was adopted to evaluate oxygen (O2) and carbon dioxide (CO2) exchanges between the liquid perfluorocarbon (PFC) and the oxygenating gas, as a function of the geometrical parameter of the device. A 2D semi-empirical model was implemented to this purpose using Comsol Multiphysics to study both the fluid dynamics and the gas exchange in the ventilator. Experimental gas exchanges measured with a preliminary prototype were compared to the simulation outcomes to prove the model reliability. Different device configurations were modeled to identify the optimal design able to guarantee the desired gas transfer. Good agreement between experimental and simulation outcomes was obtained, validating the model. The optimal configuration, able to achieve the desired gas exchange (ΔpCO2 = 16.5 mmHg and ΔpO2 = 69 mmHg), is a device comprising 40 modules, 300 mm in length (total exchange area = 2.28 m(2)). With this configuration gas transfer performance is satisfactory for all the simulated settings, proving good adaptability of the device.

  12. Vortex ventilation in the laboratory environment.

    Science.gov (United States)

    Meisenzahl, Lawrence R

    2014-01-01

    Assured containment at low airflow has long eluded the users of ventilated enclosures including chemical fume hoods used throughout industry. It is proposed that containment will be enhanced in a hood that has a particular interior shape that causes a natural vortex to occur. The sustained vortex improves the containment of contaminants within the enclosure at low airflow. This hypothesis was tested using the ASHRAE 110 tracer gas test. A known volume of tracer gas was emitted in the hood. A MIRAN SapphIRe infrared spectrometer was used to measure the concentration of tracer gas that escapes the enclosure. The design of the experiment included a written operating procedure, data collection plan, and statistical analysis of the data. A chemical fume hood of traditional design was tested. The hood interior was then reconstructed to enhance the development of a vortex inside the enclosure. The hood was retested using the same method to compare the performance of the traditional interior shape with the enhanced vortex shape. In every aspect, the vortex hood showed significant improvement over the traditional hood design. Use of the Hood Index characterizing the dilution of gas in an air stream as a logarithmic function indicates a causal relationship between containment and volumetric airflow through an enclosure. Use of the vortex effect for ventilated enclosures can provide better protection for the user and lower operating cost for the owner. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a data collection spreadsheet, data analysis, and data collection procedure.].

  13. Fire protection countermeasures for containment ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Alvares, N.; Beason, D.; Bergman, V.; Creighton, J.; Ford, H.; Lipska, A.

    1980-08-25

    The goal of this project is to find countermeasures to protect High Efficiency Particulate Air (HEPA) filters, in exit ventilation ducts, from the heat and smoke generated by fire. Initially, methods were developed to cool fire-heated air by fine water spray upstream of the filters. It was recognized that smoke aerosol exposure to HEPA filters could also cause disruption of the containment system. Through testing and analysis, several methods to partially mitigate the smoke exposure to the HEPA filters were identified. A continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. The technique is capable of protecting HEPA filters over the total time duration of the test fires. The reason for success involved the modification of the prefiltration media. Commercially available filter media has particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, rolling filter media were laminated with the desired properties. The approach was Edisonian, but truncation in short order to a combination of prefilters was effective. The application of this technique was qualified, since it is of use only to protect HEPA filters from fire-generated smoke aerosols. It is not believed that this technique is cost effective in the total spectrum of containment systems, especially if standard fire protection systems are available in the space. But in areas of high-fire risk, where the potential fuel load is large and ignition sources are plentiful, the complication of a rolling prefilter in exit ventilation ducts to protect HEPA filters from smoke aerosols is definitely justified.

  14. Displacement ventilation and passive cooling strategies

    Energy Technology Data Exchange (ETDEWEB)

    Carew, P.; Bekker, B. [PJCarew Consulting, Cape Town (South Africa)

    2009-07-01

    Displacement ventilation (DV) is widely used a passive cooling strategy because it requires less air supply for cooling compared to conventional mixing ventilation (MV). DV introduces air at low level and low velocity, and at high supply air temperature, usually around 18 degrees C. The slightly cooler air runs along the floor of a room until it reaches a heat load. The heat load induces a plume of warmer air that rises due to lower density. This induces stratification in room temperature with the occupied area of the room. The air near the ceiling is continually exhausted to prevent a build up of warm air into the occupied zone. This paper demonstrated the impacts of using DV in comparison to MV on the peak capacity, size and humidity levels associated with various passive cooling strategies, informed by the ASHRAE DV guidelines. A generic office building in Johannesburg, South Africa, was used as a model. The paper illustrated the extent to which DV can be used as a passive cooling strategy in spaces that were previously considered as having too high a heat load when calculated using MV system guidelines. A comparison of DV and MV also highlighted the risk of over-design when conventional MV guidelines are used to design cooling sources for DV applications. The DV was shown to significantly lower the amount of supply air needed to serve a room's heat load when compared to MV at the same temperatures. This reduction in air supply impacts the feasibility of using passive cooling strategies in evaporative cooling, 2-stage evaporative cooling, thermal storage and air to ground heat exchangers. However, passive cooling strategies are unlikely to be widely implemented until design guidelines are created by organizations such as ASHRAE. 8 refs., 2 tabs., 15 figs.

  15. Noninvasive positive pressure ventilation in unplanned extubation

    Directory of Open Access Journals (Sweden)

    Eryuksel Emel

    2009-01-01

    Full Text Available Background: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. Materials and Methods: 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. Results: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. Conclusions: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.

  16. Sensitivity analysis on parameter changes in underground mine ventilation systems

    Institute of Scientific and Technical Information of China (English)

    LI Gary; KOCSIS Charles; HARDCASTLE Steve

    2011-01-01

    A more efficient mine ventilation system,the ventilation-on-demand (VOD) system,has been proposed and tested in Canadian mines recently.In order to supply the required air volumes to the production areas of a mine,operators need to know the cause and effect of any changes requested from the VOD system.The sensitivity analysis is developed through generating a cause and effect matrix of sensitivity factors on given parameter changes in a ventilation system.This new utility,which was incorporated in the 3D-CANVENT mine ventilation simulator,is able to predict the airflow distributions in a ventilation network when underground conditions and ventilation controls are changed.For a primary ventilation system,the software can determine the optimal operating speed of the main fans to satisfy the airflow requirements in underground workings without necessarily using booster fans and regulators locally.An optimized fan operating speed time-table would assure variable demand-based fresh air delivery to the production areas effectively,while generating significant savings in energy consumption and operating cost.

  17. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Charlotte J. Beurskens

    2014-01-01

    Full Text Available Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2 diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen. A fixed protective ventilation protocol (6 mL/kg was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P<0.017. Results. During heliox ventilation, respiratory rate decreased (25±4 versus 23±5 breaths min−1, P=0.010. Minute volume ventilation showed a trend to decrease compared to baseline (11.1±1.9 versus 9.9±2.1 L min−1, P=0.026, while reducing PaCO2 levels (5.0±0.6 versus 4.5±0.6 kPa, P=0.011 and peak pressures (21.1±3.3 versus 19.8±3.2 cm H2O, P=0.024. Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

  18. Control of Airborne Infectious Diseases in Ventilated Spaces

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2009-01-01

    We protect ourselves from airborne cross-infection in the indoor environment by supplying fresh air to a room by natural or mechanical ventilation. The air is distributed in the room according to different principles: mixing ventilation, displacement ventilation, etc. A large amount of air...... is supplied to the room to ensure a dilution of airborne infection. Analyses of the flow in the room show that there are a number of parameters that play an important role in minimizing airborne cross-infection. The air flow rate to the room must be high, and the air distribution pattern can be designed...

  19. Guidelines For Health-Based Ventilation In Europe

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Carrer, Paolo; de Oliveira Fernandes, Eduardo;

    2014-01-01

    The burden of disease (BoD) associated with major air exposures indoors in 26 European countries was recently accounted for loss of two million healthy life years annually expressed as disability adjusted life years (DALYs) (Jantunen et al., 2011). The development of health-based ventilation...... guidelines has been recommended as one of the strategic priorities to reduce this BoD (de Oliveira-Fernandes et al., 2009), also because the current ventilation standards in Europe provide different categories of comfort, not health, as the main criteria for designing ventilation requirements (EN 13779, 2007...

  20. Appropriate Ventilation Solutions for the Iconographic Buildings from the Fifties

    DEFF Research Database (Denmark)

    Vestergaard, Inge; Blyt, Henrik

    2016-01-01

    will show a development to the introduction of mechanical ventilation in the building stock with a particular focus on decentralized ventilation systems. To evaluate the retrofitting initiatives a cross-disciplinary corporation between the professions of architecture and engineering are required...... inform the evaluation. Cases are chosen from earlier research projects and brought into the analysis in order to either see a development or to see more clearly how integrated evaluations of the ventilation and the preserving strategies can lead to a better understanding of an optimized intervention...

  1. Airflow and Temperature Distribution in Rooms with Displacement Ventilation

    DEFF Research Database (Denmark)

    Jacobsen, T. V.

    This thesis deals with air flow and temperature distribution in a room ventilated by the displacement principle. The characteristic features of the ventilation system are treated in the whole room but main emphasis is laid on the analysis of the stratified flow region in front of the inlet device....... After a prefatory description of the background and the fundamentals of displacement ventilation the objectives of the current study are specified. The subsequent sections describe the measurements of velocity and temperature profiles carried out in a full scale test room. Based on experimental data...

  2. Human Response to Personalized Ventilation Combined with Chilled Ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Marcol, Bartosz;

    2014-01-01

    Personalized ventilation (PV) improves inhaled air quality, because it provides fresh air to each workstation and directly to occupant’s breathing zone. Previous research was focused on combining PV with additional total volume air distribution, i.e. mixing ventilation or displacement ventilation...... temperature for chilled ceiling was 15,5/16,8°C at room air temperature of 26°C and 19,5/20,6°C at 28°C. During the experiment the subjects were performing typical office tasks at workstations with computers. Exposure included also increased activity level office work for a period of 25 min...

  3. Validation of a Human Exhalation Flow Simulation in a Room with Vertical Ventilation

    DEFF Research Database (Denmark)

    Olmedo, Inés; Nielsen, Peter V.; Adana, M. Ruiz de

    2012-01-01

    We protect ourselves from airborne cross-infection in our indoor environment by supplying fresh air to the room by natural or mechanical ventilation. The air is distributed in the room according to different principles as e.g. mixing ventilation, downward ventilation, displacement ventilation, et...

  4. 46 CFR 116.620 - Ventilation of machinery and fuel tank spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation of machinery and fuel tank spaces. 116.620... AND ARRANGEMENT Ventilation § 116.620 Ventilation of machinery and fuel tank spaces. In addition to the requirements of this subpart, ventilation systems for spaces containing machinery or fuel...

  5. Comparative study on the ventilation mode of the residential building in Beijing area in winter

    Science.gov (United States)

    Wang, G. J.; Li, Q. P.; Guo, Y.; Hu, Y. H.

    2016-08-01

    With the development of residential energy conservation technology, the air tightness requirement of the window is higher and higher. So in winter the cold penetration wind cannot satisfy the requirement of indoor personnel to fresh air. The common ventilation mode includes natural ventilation, natural inlet and mechanical exhaust, wall type ventilator with heat exchange, ventilation unit with heat exchange. Looking for energy saving, comfortable way of ventilation, the application effect of the way of ventilation is evaluated in air distribution and comfort performance and the initial investment by FLUENT software. The conclusion is that the mode of ventilation unit with heat exchange has higher superiority compared with the others.

  6. Polyester matrix composite reinforced by fiberglass: how far can have contact with oil; Composito de matriz poliester e reforco de fibra de vidro: ate onde pode ter contato com petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, C.M.; Masieiro, F.R.S.; Felipe, R.C.T.S.; Felipe, R.N.B.; Medeiros, G.G. [Centro Federal de Educacao Tecnologica (CEFET), Natal, RN (Brazil)], e-mail: k1000_rn@hotmail.com

    2008-07-01

    The use of reinforced plastics (PR) in the petroleum industry is very incipient when compared to conventional materials such as steel, for example. PR are already being used in floorings and handrails, but still there is not studies about the behavior of these materials when they come into contact with oil. In this context, this work aims to obtain a composite using a matrix of polyester resin, and the fiberglass (E Glass) as material of reinforcement. After the obtention of the composite, proof bodies will be made for the determination of the mechanical properties related to the traction and bending. Some of these proof bodies will be immersed in oil for a period of 120 days. At the end of this period, they will be tested. Thus, the traction and bending of the proof bodies which was immersed will be compared to the other ones, seeking to verify the influence of this immersion on the mechanical properties of the material. (author)

  7. Integrated Bulding Heating, Cooling and Ventilation Control

    Science.gov (United States)

    Dong, Bing

    Current research studies show that building heating, cooling and ventilation energy consumption account for nearly 40% of the total building energy use in the U.S. The potential for saving energy through building control systems varies from 5% to 20% based on recent market surveys. In addition, building control affects environmental performances such as thermal, visual, air quality, etc., and occupancy such as working productivity and comfort. Building control has been proven to be important both in design and operation stages. Building control design and operation need consistent and reliable static and dynamic information from multiple resources. Static information includes building geometry, construction and HVAC equipment. Dynamic information includes zone environmental performance, occupancy and outside weather information during operation. At the same time, model-based predicted control can help to optimize energy use while maintaining indoor set-point temperature when occupied. Unfortunately, several issues in the current approach of building control design and operation impede achieving this goal. These issues include: a) dynamic information data such as real-time on-site weather (e.g., temperature, wind speed and solar radiation) and occupancy (number of occupants and occupancy duration in the space) are not readily available; b) a comprehensive building energy model is not fully integrated into advanced control for accuracy and robustness; c) real-time implementation of indoor air temperature control are rare. This dissertation aims to investigate and solve these issues based on an integrated building control approach. This dissertation introduces and illustrates a method for integrated building heating, cooling and ventilation control to reduce energy consumption and maintain indoor temperature set-point, based on the prediction of occupant behavior patterns and weather conditions. Advanced machine learning methods including Adaptive Gaussian Process

  8. Experimental Study of Tunnel Fire with Natural Ventilation

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhong-yuan; LEI Bo; CHEN Peng-Yun

    2009-01-01

    The 1/15 reduced-scale experiments using Froude scaling were designed to study the effect on the smoke control efficiency for subway tunnel fires with natural ventilation mode.The propane gas fires with heat release rate 11.48 kW was used,which corresponds to the heat release rate 10 MW in the full-scale tunnel.The temperature distributions under the ceiling were measured by K-type thermocouples to investigate smoke move-ment,and the velocity of smoke in shafts was measured by hot-wire anemometer to obtain the smoke extract amount of ventilation shafts.The results show that the smoke temperature under the ceiling varies with the lon-gitudinal different distance from fire Source.The results also show that the smoke temperature distributions and the smoke control efficiency in tunnel vary with the space between ventilation shafts and vary with the area and the height of ventilation shaft.

  9. Chest trauma: A case for single lung ventilation.

    Science.gov (United States)

    Pandharikar, Nagaraj; Sachdev, Anil; Gupta, Neeraj; Gupta, Suresh; Gupta, Dhiren

    2016-04-01

    Chest trauma is one of the important causes of mortality and morbidity in pediatric trauma patients. The complexity, magnitude, and type of lung injury make it extremely challenging to provide optimal oxygenation and ventilation while protecting the lung from further injury due to mechanical ventilation. Independent lung ventilation is used sporadically in these patients who do not respond to these conventional ventilatory strategies using double-lumen endotracheal tubes, bronchial blocker balloons, etc. However, this equipment may not be easily available in developing countries, especially for pediatric patients. Here, we present a case of severe chest trauma with pulmonary contusion, flail chest, and bronchopleural fistula, who did not respond to conventional lung protective strategies. She was successfully managed with bronchoscopy-guided unilateral placement of conventional endotracheal tube followed by single lung ventilation leading to resolution of a chest injury.

  10. Personal Exposure to Contaminant Sources in Ventilated Rooms

    DEFF Research Database (Denmark)

    Brohus, Henrik

    on the two major room ventilation principles. A personal exposure model for a displacement ventilated room is proposed. Two new quantities describing the interaction between a person and the ventilation are defined. The findings clearly stress the need for an improved exposure assessment in cases where......Three different tools for personal exposure assessment are presented. They are all able to consider the local influence of persons in ventilated rooms where concentration gradients prevail: A Breathing Thermal Manikin, a Computer Simulated Person, and a Trained Sensory Panel. The tools are applied...... a contaminant source is located in the vicinity of persons. It is also shown that it is not sufficient to know the local concentration level of an empty room, the local impact of a person is distinct and should be considered in the exposure assessment....

  11. Passive ventilation systems with heat recovery and night cooling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2008-01-01

    In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept...... with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical University...... simulation program ESP-r to model the heat and air flows and the results show the feasibility of the proposed ventilation concept in terms of low energy consumption and good indoor climate....

  12. Energy Saving by Novel Bed-Integrated Local Exhaust Ventilation

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Kehayova, Nushka; Melikov, Arsen Krikor

    2016-01-01

    to suck the human bio-effluents at the area of the body where they are generated before they spread in the room. The air polluted with released bio-effluents is exhausted into the mattress near the body and is either cleaned and released back in the room or is removed from the room by connecting......High quality indoor environment in hospitals is important for patients’ healing and performance of the personnel. A novel method for minimizing spread of bio-effluents generated from hospitalized patients lying in bed was developed. The method consists of ventilated mattress (VM) which is able...... the mattress to the exhaust of the room background ventilation system. Comprehensive research reveals that the method is highly efficient for removal of bio-effluents. The energy saving potential of the VM combined with constant air volume (CAV) ventilation operating at reduced ventilation rate in a single...

  13. Passive Cooling of buildings by night-time ventilation

    DEFF Research Database (Denmark)

    Artmann, Nikolai; Manz, Heinrich; Heiselberg, Per

    Due to an overall trend towards an increasing cooling energy demand in buildings in many European countries over the last few decades, passive cooling by night-time ventilation is seen as a promising concept. However, because of uncertainties in thermal comfort predictions, architects and engineers...... are still hesitant to apply passive cooling techniques. As night-time ventilation is highly dependent on climatic conditions, a method for quantifying the climatic cooling potential was developed and the impact of climate warming was investigated. Although a clear decrease was found, significant potential...... will remain, especially if night-time ventilation is applied in combination with other cooling methods. Building energy simulations showed that the performance of night-time ventilation is also affected by the heat transfer at internal room surfaces, as the cooling effect is very limited for heat transfer...

  14. Chair with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...... with those systems is the fact that the jet entrains air from the surroundings and, therefore, reduces the amount of fresh air which reaches the breathing zone. The entrainment is minimized in the system discussed here, especially when the source of clean air is located in the boundary layer close......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...

  15. Bed with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jiang, Hao; Polak, Marcin

    2007-01-01

    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 with those systems is the fact that the jet entrains air from the surroundings and, therefore, reduces the amount of fresh air which reaches the breathing zone. The entrainment is minimized in the system discussed here, especially when the source of clean air is located in the boundary layer close......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...

  16. Post-Polio Health International including International Ventilator Users Network

    Science.gov (United States)

    ... Place Explore the past, the present and help build a promising future for the world’s polio survivors. ... Polio Health International (PHI) Including International Ventilator Users Network 4207 Lindell Blvd., #110, Saint Louis, MO 63108- ...

  17. Chest trauma: A case for single lung ventilation

    Directory of Open Access Journals (Sweden)

    Nagaraj Pandharikar

    2016-01-01

    Full Text Available Chest trauma is one of the important causes of mortality and morbidity in pediatric trauma patients. The complexity, magnitude, and type of lung injury make it extremely challenging to provide optimal oxygenation and ventilation while protecting the lung from further injury due to mechanical ventilation. Independent lung ventilation is used sporadically in these patients who do not respond to these conventional ventilatory strategies using double-lumen endotracheal tubes, bronchial blocker balloons, etc. However, this equipment may not be easily available in developing countries, especially for pediatric patients. Here, we present a case of severe chest trauma with pulmonary contusion, flail chest, and bronchopleural fistula, who did not respond to conventional lung protective strategies. She was successfully managed with bronchoscopy-guided unilateral placement of conventional endotracheal tube followed by single lung ventilation leading to resolution of a chest injury.

  18. Energy-saving strategies with personalized ventilation in cold climates

    DEFF Research Database (Denmark)

    Shiavon, Stefano; Melikov, Arsen Krikor

    2009-01-01

    In this study the influence of the personalized supply air temperature control strategy on energy consumption and the energy-saving potentials of a personalized ventilation system have been investigated by means of simulations with IDA-ICE software. GenOpt software was used to determine the optimal...... supply air temperature. The simulated office room was located in a cold climate. The results reveal that the supply air temperature control strategy has a marked influence on energy consumption. The energy consumption with personalized ventilation may increase substantially (in the range: 61......–268%) compared to mixing ventilation alone if energy-saving strategies are not applied. The results show that the best supply air temperature control strategy is to provide air constantly at 20 °C. The most effective way of saving energy with personalized ventilation is to extend the upper room operative...

  19. Partial Liquid Ventilation: Animal Studies on Lung Function

    NARCIS (Netherlands)

    A.S. Tutuncu

    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 applicatio

  20. Perceived decisional responsibility for mechanical ventilation and weaning

    DEFF Research Database (Denmark)

    Haugdahl, Hege S; Storli, Sissel; Rose, Louise;

    2014-01-01

    AIM: To explore variability in perceptions of nurse managers and physician directors regarding roles, responsibilities and clinical-decision making related to mechanical ventilator weaning in Norwegian intensive care units (ICUs). BACKGROUND: Effective teamwork is crucial for providing optimal...... patient care in ICU. More knowledge on nurses' and physicians' perceptions of responsibility in clinical decision-making for mechanical ventilation is needed. METHODS: Self-administered survey of mechanical ventilation and weaning responsibilities was sent to nurse managers and physician directors...... of Norwegian adult ICUs. Nurses' decisional influence and autonomy were estimated on a numeric rating scale (NRS) from 0 to 10 (least to most). RESULTS: Response rate was 38/60 (63%) nurses and 38/52 (73%) physicians. On the NRS nurse managers perceived the autonomy and influence of nurses' ventilator...

  1. Comparison of three methods in improving bag mask ventilation

    Directory of Open Access Journals (Sweden)

    Samad EJ Golzari

    2014-01-01

    Conclusions: Leaving dentures in place in edentulous patients after inducing anesthesia improves bag-mask ventilation. However, placing folded compressed gauze in buccal space leads to more significant improvement in BMV compared to leaving dentures in place.

  2. Measure Guideline: Selecting Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2014-02-01

    This report, developed by Building America research team CARB, addresses adding or improving mechanical ventilation systems to existing homes. The goal of this report is to assist decision makers and contractors in making informed decisions when selecting ventilation systems for homes. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability. 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 examination of relevant codes and standards. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors.

  3. Nursing strategies to prevent ventilator-associated pneumonia.

    Science.gov (United States)

    Hixson, S; Sole, M L; King, T

    1998-02-01

    Critically ill patients who require mechanical ventilation are at high risk for development of pneumonia during the course of treatment. Ventilator-associated pneumonia leads to higher rates of mortality and morbidity, increased length of hospital stay, and higher hospital costs. The intubation that is necessary for mechanical ventilation impairs the patient's normal defense mechanisms for fighting infection. Impaired defenses, along with such risk factors as age of the patient, equipment used, and failure of the staff to wash hands increase the likelihood of colonization of the lower airways. Colonization and subsequent pneumonia commonly occurs from microaspiration of secretions from the oropharynx and gastrointestinal tract. In this article, the mechanism of microaspiration, diagnosis of ventilator-associated pneumonia, and nursing strategies to reduce the incidence of pneumonia are described.

  4. Displacement and air distribution ventilation systems; Verdringingsventilatie- en luchtverdeelsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Van Holten, P. [Solid Air, Amsterdam (Netherlands)

    2009-06-15

    Since an evaporative cooling system uses 100% clean outdoor air; it is ideal for positive displacement ventilation. By using the overpressure inside the building or room, windows and doors can be opened without affecting the controlled room temperature. The combination of positive displacement ventilation/balance ventilation with heat recovery is a very attractive solution. In this article you will find a brief explanation of the operation, application and basic principles of positive displacement ventilation. [Dutch] Verdampingskoeling leent zich in het bijzonder voor verdringingsventilatie dankzij het gebruik van 100% buitenlucht. Gebruikmakend van overdruk kunnen daarbij ramen en deuren worden geopend zonder dat de temperatuur hierdoor sterk wordt beinvloed. De combinatie verdringingsventilatie/balansventilatie met WTW, zoals in De Vijfhoek, is daarbij een voor de hand liggende optie. In dit artikel worden de basisprincipes van verdringingsventilatie, alsmede de werking en toepassing hiervan, toegelicht.

  5. Experimental Assessment of Moisture Transfer in the Vertical Ventilated Channel

    Directory of Open Access Journals (Sweden)

    Musorina Tatyana

    2016-01-01

    Full Text Available This article considers the moisture transfer phenomenon in the vertical ventilated channel. Also the article considers innovative structures for the vertical ventilated channel.The negative factors connected with moisture accumulation and excessive moistening of a heat insulation are given. Optimum design parameters for definition of the most intensive moisture transfer are discovered: systems with and without grooved lines. Influence that existence of technological gaps (grooved lines has on the speed of air flows in a gap is investigated. Dependence of speed on width of the ventilated gap for a design with the opened and closed grooved lines is established empirically. The dehumidification properties of the vertical ventilated channel are described, as well as dependence of mass evaporation rate on time is established. Processes of drying-out in various conditions are compared.

  6. 46 CFR 111.33-9 - Ventilation exhaust.

    Science.gov (United States)

    2010-10-01

    ... REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-9 Ventilation exhaust. The exhaust of each forced-air semiconductor rectifier system must: (a) Terminate in a location other than a hazardous...

  7. Research of Application of Passive Natural Ventilated Strategies of High-Density Urban Area

    Institute of Scientific and Technical Information of China (English)

    DeXuan Song; ShaoYu Liu; SiJie Liu

    2014-01-01

    High⁃density development is becoming an inevitable tendency in Chinese urbanization. In this study, the application of natural ventilation in high⁃density urban development is discussed. Based on the domestic and foreign study on natural ventilation, indoor and outdoor natural ventilated strategies, and the application on natural ventilation in underground space development are analyzed. From the study, the relationship between passive and active ventilated technologies is interpreted into what is described to be synergistic, complementary and additive.

  8. Ventilation strategies in burn intensive care: A retrospective observational study

    Directory of Open Access Journals (Sweden)

    Stefano Palazzo

    2014-01-01

    Full Text Available Consensus regarding optimal burns intensive care (BICU patient management is lacking. This study aimed to assess whether ventilation strategies, cardiovascular support and sedation in BICU patients have changed over time, and whether this affects outcome. A retrospective observational study comparing two 12-patient BICU cohorts (2005/06 and 2010/11 was undertaken. Demographic and admission characteristics, ventilation parameters, sedation, fluid resuscitation, cardiovascular support and outcome (length of stay, mortality data were collected from patient notes. Data was analysed using T-tests, Fisher's exact and Mann-Whitney U tests. In our study cohort groups were equivalent in demographic and admission parameters. There were equal ventilator-free days in the two cohorts 10 ± 12.7 vs. 13.3 ± 12.2 ventilator free days; P = 0.447. The 2005/06 cohort were mechanically ventilated more often than in 2010/11 cohort (568 ventilator days/1000 patient BICU days vs. 206 ventilator days/1000 patient BICU days; P = 0.001. The 2005/06 cohort were ventilated less commonly in tracheostomy group/endotracheal tube spontaneous (17.8% vs. 26%; P = 0.001 and volume-controlled modes (34.4% vs. 40.8%; P = 0.001. Patients in 2010/11 cohort were more heavily sedated (P = 0.001 with more long-acting sedative drug use (P = 0.001 than the 2005/06 cohort, fluid administration was equivalent. Patient outcome did not vary. Inhalational injury patients were ventilated in volume-controlled (44.5% vs. 28.1%; P = 0.001 and pressure-controlled modes (18.2% vs. 9.5%; P = 0.001 more frequently than those without. Outcome did not vary. This study showed there has been shift away from mechanical ventilation, with increased use of tracheostomy/tracheal tube airway spontaneous ventilation. Inhalation injury patients require more ventilatory support though patient outcomes do not differ. Prospective trials are required to establish which strategies confer benefit.

  9. Personal Exposure in a Ventilated Room with Concentration Gradients

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.

    This paper deals with personal exposure in rooms with concentration gradients and persons present. Results from case studies including a breathing thermal manikin in a displacement ventilated room and in a wind channel are presented.......This paper deals with personal exposure in rooms with concentration gradients and persons present. Results from case studies including a breathing thermal manikin in a displacement ventilated room and in a wind channel are presented....

  10. A novel rescue technique for difficult intubation and difficult ventilation.

    Science.gov (United States)

    Zestos, Maria M; Daaboul, Dima; Ahmed, Zulfiqar; Durgham, Nasser; Kaddoum, Roland

    2011-01-17

    We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit. Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation. A 13 year old patient was taken to the operating room for incision and drainage of a neck abscess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

  11. Capture and Use of Coal Mine Ventilation Air Methane

    Energy Technology Data Exchange (ETDEWEB)

    Deborah Kosmack

    2008-10-31

    CONSOL Energy Inc., in conjunction with MEGTEC Systems, Inc., and the U.S. Department of Energy with the U.S. Environmental Protection Agency, designed, built, and operated a commercial-size thermal flow reversal reactor (TFRR) to evaluate its suitability to oxidize coal mine ventilation air methane (VAM). Coal mining, and particularly coal mine ventilation air, is a major source of anthropogenic methane emissions, a greenhouse gas. Ventilation air volumes are large and the concentration of methane in the ventilation air is low; thus making it difficult to use or abate these emissions. This test program was conducted with simulated coal mine VAM in advance of deploying the technology on active coal mine ventilation fans. The demonstration project team installed and operated a 30,000 cfm MEGTEC VOCSIDIZER oxidation system on an inactive coal mine in West Liberty, WV. The performance of the unit was monitored and evaluated during months of unmanned operation at mostly constant conditions. The operating and maintenance history and how it impacts the implementation of the technology on mine fans were investigated. Emission tests showed very low levels of all criteria pollutants at the stack. Parametric studies showed that the equipment can successfully operate at the design specification limits. The results verified the ability of the TFRR to oxidize {ge}95% of the low and variable concentration of methane in the ventilation air. This technology provides new opportunities to reduce greenhouse gas emissions by the reduction of methane emissions from coal mine ventilation air. A large commercial-size installation (180,000 cfm) on a single typical mine ventilation bleeder fan would reduce methane emissions by 11,000 to 22,100 short tons per year (the equivalent of 183,000 to 366,000 metric tonnes carbon dioxide).

  12. The State-of-the-Art for Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols

    2016-01-01

    Ventilative cooling for buildings may lead to cooling energy savings and improvements in thermal comfort, especially in seasonally temperate and warm climates. But, codes and regulations need to better quantify its benefits.......Ventilative cooling for buildings may lead to cooling energy savings and improvements in thermal comfort, especially in seasonally temperate and warm climates. But, codes and regulations need to better quantify its benefits....

  13. Spontaneous blood pressure oscillations in mechanically ventilated patients with sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R; Greve, Anders M;

    2016-01-01

    OBJECTIVE: In the present hypothesis-generating study, we investigated whether spontaneous blood pressure oscillations are suppressed to lower frequencies, and whether abolished oscillations are associated with an adverse outcome in mechanically ventilated patients with sepsis. METHODS: We...... retrospectively subjected invasive steady-state blood pressure recordings from 65 mechanically ventilated patients with sepsis to spectral analysis. Modified spectral bands were visually identified by plotting spectral power against frequency. RESULTS: Modified middle-frequency and low-frequency (MF' and LF...

  14. Noninvasive ventilation in status asthmaticus in children: levels of evidence

    OpenAIRE

    Silva,Paula de Souza; Barreto,Sérgio Saldanha Menna

    2015-01-01

    Objective To evaluate the quality of available evidence to establish guidelines for the use of noninvasive ventilation for the management of status asthmaticus in children unresponsive to standard treatment. Methods Search, selection and analysis of all original articles on asthma and noninvasive ventilation in children, published until September 1, 2014 in all languages in the electronic databases PubMed, Web of Science, Cochrane Library, Scopus and SciELO, located using the search terms: "a...

  15. Demand controlled ventilation in single-family homes; Behovstyret ventilation til enfamiliehuse

    Energy Technology Data Exchange (ETDEWEB)

    Rammer Nielsen, T.; Drivsholm, C.; Rudolph Hansen, M.P.; Kragh, J.

    2009-12-15

    This project investigated two different control strategies: A simple and cheap strategy and an advanced and expensive strategy: 1. Simple control: The ventilation rate is varied only on the whole building level giving an average ventilation rate of either 0.1 l/(s m{sup 2}) or 0.35 l/(s m{sup 2}). The air change rate is controlled by sensors in the air handling unit measuring relative humidity, temperature and CO{sub 2}. The control is based on the CO{sub 2}-concentration and absolute humidity in the supply air and exhaust air. A fixed set point for the difference in CO{sub 2}-concentration between the exhaust and supply is used to decide if the ventilation rate is low or high. As supplement to the CO{sub 2} control the difference in absolute humidity between exhaust and supply is used to assure that the ventilation remain at the high level if there is a high level of humidity in the house. 2. Advanced control: The air change rate is varied dynamically for all living rooms giving an average air change for the house between 0.1 l/(s m{sup 2}) and 0.35 l/(s m{sup 2}). The air change rate in the living rooms is controlled by CO{sub 2}-sensors in each room and dampers in the room supply duct. Relative humidity is measured in the rooms with high moisture production to ensure that the highest air exchange is activated if the relative humidity in one of these rooms is too high. Even though the two strategies have been implemented and tested for a long period of time, only the simple control can be recommended. The simple control ensures that the air quality is almost the same as if the house was ventilated constantly at the high ventilation rate. Also the simple control only requires two CO{sub 2} sensors, two relative humidity sensors and two temperature sensors in the air handling unit. These sensors should be checked from time to time e.g. when filters are exchanged. The simple control is today used in meeting rooms, office rooms and daycare facilities in a modified

  16. Experimental Study of Air Distribution and Ventilation Effectiveness in a Room with a Combination of Different Mechanical Ventilation and Heating/Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Simone, Angela; Krajcik, Michal;

    2011-01-01

    Mixing and displacement ventilation are common systems in commercial buildings, while mixing ventilation is used in residential buildings. Displacement ventilation provides fresh air to the occupied zone in a more efficient way than mixing ventilation but it is important to know how well it works...... with a floor system for heating or cooling. Can, for example, a floor heating system warm up the supply air too fast and destroy the displacement effect? Will floor cooling, combined with displacement ventilation, result in too high a vertical temperature difference and too low a temperature at feet level......? The required amount of ventilation depends on the ventilation effectiveness. In standards, the recommended values for ventilation effectiveness depend on the position of the supply and exhaust device and on the difference between supply and room air temperature. Among others, for warm air heating...

  17. Hypervirulent Klebsiella pneumoniae induced ventilator-associated pneumonia in mechanically ventilated patients in China.

    Science.gov (United States)

    Yan, Q; Zhou, M; Zou, M; Liu, W-e

    2016-03-01

    The purpose of this study was to investigate the clinical characteristics of hypervirulent K. pneumoniae (hvKP) induced ventilator-associated pneumonia (VAP) and the microbiological characteristics and epidemiology of the hvKP strains. A retrospective study of 49 mechanically ventilated patients with K. pneumoniae induced VAP was conducted at a university hospital in China from January 2014 to December 2014. Clinical characteristics and K. pneumoniae antimicrobial susceptibility and biofilm formation were analyzed. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57 and virulence factors plasmid rmpA(p-rmpA), iroB, iucA, mrkD, entB, iutA, ybtS, kfu and allS were also evaluated. Multilocus sequence typing (MLST) and random amplified polymorphic DNA (RAPD) analyses were used to study the clonal relationship of the K. pneumoniae strains. Strains possessed p-rmpA and iroB and iucA were defined as hvKP. Of 49 patients, 14 patients (28.6 %) were infected by hvKP. Antimicrobial resistant rate was significantly higher in cKP than that in hvKP. One ST29 K54 extended-spectrum-beta-lactamase (ESBL) producing hvKP strain was detected. The prevalence of K1 and K2 in hvKP was 42.9 % and 21.4 %, respectively. The incidences of K1, K2, K20, p-rmpA, iroB, iucA, iutA, Kfu and alls were significantly higher in hvKP than those in cKP. ST23 was dominant among hvKP strains, and all the ST23 strains had identical RAPD pattern. hvKP has become a common pathogen of VAP in mechanically ventilated patients in China. Clinicians should increase awareness of hvKP induced VAP and enhance epidemiologic surveillance.

  18. Assessment of mechanical ventilation parameters on respiratory mechanics.

    Science.gov (United States)

    Pidaparti, Ramana M; Koombua, Kittisak; Ward, Kevin R

    2012-01-01

    Better understanding of airway mechanics is very important in order to avoid lung injuries for patients undergoing mechanical ventilation for treatment of respiratory problems in intensive-care medicine, as well as pulmonary medicine. Mechanical ventilation depends on several parameters, all of which affect the patient outcome. As there are no systematic numerical investigations of the role of mechanical ventilation parameters on airway mechanics, the objective of this study was to investigate the role of mechanical ventilation parameters on airway mechanics using coupled fluid-solid computational analysis. For the airway geometry of 3 to 5 generations considered, the simulation results showed that airflow velocity increased with increasing airflow rate. Airway pressure increased with increasing airflow rate, tidal volume and positive end-expiratory pressure (PEEP). Airway displacement and airway strains increased with increasing airflow rate, tidal volume and PEEP form mechanical ventilation. Among various waveforms considered, sine waveform provided the highest airflow velocity and airway pressure while descending waveform provided the lowest airway pressure, airway displacement and airway strains. These results combined with optimization suggest that it is possible to obtain a set of mechanical ventilation strategies to avoid lung injuries in patients.

  19. Numerical investigation of pulmonary drug delivery under mechanical ventilation conditions

    Science.gov (United States)

    Banerjee, Arindam; van Rhein, Timothy

    2012-11-01

    The effects of mechanical ventilation waveform on fluid flow and particle deposition were studied in a computer model of the human airways. The frequency with which aerosolized drugs are delivered to mechanically ventilated patients demonstrates the importance of understanding the effects of ventilation parameters. This study focuses specifically on the effects of mechanical ventilation waveforms using a computer model of the airways of patient undergoing mechanical ventilation treatment from the endotracheal tube to generation G7. Waveforms were modeled as those commonly used by commercial mechanical ventilators. Turbulence was modeled with LES. User defined particle force models were used to model the drag force with the Cunningham correction factor, the Saffman lift force, and Brownian motion force. The endotracheal tube (ETT) was found to be an important geometric feature, causing a fluid jet towards the right main bronchus, increased turbulence, and a recirculation zone in the right main bronchus. In addition to the enhanced deposition seen at the carinas of the airway bifurcations, enhanced deposition was also seen in the right main bronchus due to impaction and turbulent dispersion resulting from the fluid structures created by the ETT. Authors acknowledge financial support through University of Missouri Research Board Award.

  20. Links between the mechanics of ventilation and spine stability.

    Science.gov (United States)

    Wang, Simon; McGill, Stuart M

    2008-05-01

    Spine stability is ensured through isometric coactivation of the torso muscles; however, these same muscles are used cyclically to assist ventilation. Our objective was to investigate this apparent paradoxical role (isometric contraction for stability or rhythmic contraction for ventilation) of some selected torso muscles that are involved in both ventilation and support of the spine. Eight, asymptomatic, male subjects provided data on low back moments, motion, muscle activation, and hand force. These data were input to an anatomically detailed, biologically driven model from which spine load and a lumbar spine stability index was obtained. Results revealed that subjects entrained their torso stabilization muscles to breathe during demanding ventilation tasks. Increases in lung volume and back extensor muscle activation coincided with increases in spine stability, whereas declines in spine stability were observed during periods of low lung inflation volume and simultaneously low levels of torso muscle activation. As a case study, aberrant ventilation motor patterns (poor muscle entrainment), seen in one subject, compromised spine stability. Those interested in rehabilitation of patients with lung compromise and concomitant back troubles would be assisted with knowledge of the mechanical links between ventilation during tasks that impose spine loading.

  1. Ventilation as mitigation of PCB contaminated air in buildings

    DEFF Research Database (Denmark)

    Lyng, Nadja; Trap, Niels; Andersen, Helle Vibeke;

    2014-01-01

    The effect of ventilation on indoor concentrations was evaluated in 9 buildings constituting a total of 30 rooms. All cases had interior and/or exterior sealants containing PCB as primary source. Criteria for inclusion in the evaluation were that the indoor concentrations of PCBtotal In the remai......The effect of ventilation on indoor concentrations was evaluated in 9 buildings constituting a total of 30 rooms. All cases had interior and/or exterior sealants containing PCB as primary source. Criteria for inclusion in the evaluation were that the indoor concentrations of PCBtotal...... In the remaining four cases, the pressure difference between the room measured and the surroundings showed a tremendous effect on the concentration as opposed to the effect of ventilation. Pressure differences might affect the emission of PCB by motion of air through gaps and cracks along the PCB sealants. were...... measured in the same room at least twice and under different ventilation conditions. In general, PCB concentrations decrease with increased ventilation making the effect of ventilation to reduce human exposure feasible. In 26 case rooms, the mean reduction of the concentration was found to be 51% (median...

  2. New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

    Energy Technology Data Exchange (ETDEWEB)

    Sidheswaran, Meera; Destaillats, Hugo; Sullivan, Douglas P.; Fisk, William J.

    2010-10-27

    Approximately ten percent of the energy consumed in U.S. commercial buildings is used by HVAC systems to condition outdoor ventilation air. Reducing ventilation rates would be a simple and broadly-applicable energy retrofit option, if practical counter measures were available that maintained acceptable concentrations of indoor-generated air pollutants. The two general categories of countermeasures are: 1) indoor pollutant source control, and 2) air cleaning. Although pollutant source control should be used to the degree possible, source control is complicated by the large number and changing nature of indoor pollutant sources. Particle air cleaning is already routinely applied in commercial buildings. Previous calculations indicate that particle filtration consumes only 10percent to 25percent of the energy that would otherwise be required to achieve an equivalent amount of particle removal with ventilation. If cost-effective air cleaning technologies for volatile organic compounds (VOCs) were also available, outdoor air ventilation rates could be reduced substantially and broadly in the commercial building stock to save energy. The research carried out in this project focuses on developing novel VOC air cleaning technologies needed to enable energy-saving reductions in ventilation rates. The minimum required VOC removal efficiency to counteract a 50percent reduction in ventilation rate for air cleaning systems installed in the HVAC supply airstream is modest (generally 20percent or less).

  3. Delirium during Weaning from Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Marcela Aparecida Leite

    2014-01-01

    Full Text Available Background. We compare the incidence of delirium before and after extubation and identify the risk factors and possible predictors for the occurrence of delirium in this group of patients. Methods. Patients weaned from mechanical ventilation (MV and extubated were included. The assessment of delirium was conducted using the confusion assessment method for the ICU and completed twice per day until discharge from the intensive care unit. Results. Sixty-four patients were included in the study, 53.1% of whom presented with delirium. The risk factors of delirium were age (P=0.01, SOFA score (P=0.03, APACHE score (P=0.01, and a neurological cause of admission (P=0.01. The majority of the patients began with delirium before or on the day of extubation. Hypoactive delirium was the most common form. Conclusion. Acute (traumatic or medical neurological injuries were important risk factors in the development of delirium. During the weaning process, delirium developed predominantly before or on the same day of extubation and was generally hypoactive (more difficult to detect. Therefore, while planning early prevention strategies, attention must be focused on neurological patients who are receiving MV and possibly even on patients who are still under sedation.

  4. Prone ventilation in acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Claude Guérin

    2014-06-01

    Full Text Available Prone positioning has been used for many years in patients with acute lung injury (ALI/acute respiratory distress syndrome (ARDS, with no clear benefit for patient outcome. Meta-analyses have suggested better survival in patients with an arterial oxygen tension (PaO2/inspiratory oxygen fraction (FIO2 ratio <100 mmHg. A recent randomised controlled trial was performed in ARDS patients after a 12–24 h stabilisation period and severity criteria (PaO2/FIO2 <150 mmHg at a positive end-expiratory pressure ≥5 cmH2O. This trial has demonstrated a significant reduction in mortality from 32.8% in the supine group to 16% in the prone group (p<0.001. The reasons for this dramatic effect are not clear but probably involves a reduction in ventilator-induced lung injury due to prone positioning, for which there is ample evidence in experimental and clinical studies. The aims of this article are to discuss: the rationale of prone positioning in patients with ALI/ARDS; the evidence of its use based on trial analysis; and the limitations of its use as well as the current place of prone positioning in the management of patients with ALI/ARDS. From the currently available data, prone positioning should be used as a first-line therapy in patients with severe ALI/ARDS.

  5. Where should noninvasive ventilation be delivered?

    Science.gov (United States)

    Hill, Nicholas S

    2009-01-01

    Noninvasive ventilation (NIV) has assumed an important role in the management of certain types of respiratory failure in acute-care hospitals. However, the optimal location for NIV has been a matter of debate. Some have argued that all patients begun on NIV in the acute-care setting should go to an intensive care unit (ICU), but this is impractical because ICU beds are often unavailable, and it may not be a sensible use of resources. Also, relatively few studies have examined the question of location for NIV. One problem is that various units' capabilities to deliver NIV differ substantially, even in the same hospital. Choosing the appropriate environment for NIV requires consideration of the patient's need for monitoring, the monitoring capabilities of the unit, including both technical and personnel resources (nursing and respiratory therapy), and the staff's skill and experience. In some hospitals NIV is begun most often in the emergency department, but is most often managed in an ICU. Step-down units are often good locations for NIV, but many institutions do not have step-down units. With ICU beds at a premium, many hospitals are forced to manage some NIV patients on general wards, which can be safely done with more stable patients if the ward is suitably monitored and experienced. When deciding where to locate the patient, clinicians must be familiar with the capabilities of the units in their facility and try to match the patient's need for monitoring and the unit's capabilities.

  6. Effective sample size estimation for a mechanical ventilation trial through Monte-Carlo simulation: Length of mechanical ventilation and Ventilator Free Days.

    Science.gov (United States)

    Morton, S E; Chiew, Y S; Pretty, C; Moltchanova, E; Scarrott, C; Redmond, D; Shaw, G M; Chase, J G

    2017-02-01

    Randomised control trials have sought to seek to improve mechanical ventilation treatment. However, few trials to date have shown clinical significance. It is hypothesised that aside from effective treatment, the outcome metrics and sample sizes of the trial also affect the significance, and thus impact trial design. In this study, a Monte-Carlo simulation method was developed and used to investigate several outcome metrics of ventilation treatment, including 1) length of mechanical ventilation (LoMV); 2) Ventilator Free Days (VFD); and 3) LoMV-28, a combination of the other metrics. As these metrics have highly skewed distributions, it also investigated the impact of imposing clinically relevant exclusion criteria on study power to enable better design for significance. Data from invasively ventilated patients from a single intensive care unit were used in this analysis to demonstrate the method. Use of LoMV as an outcome metric required 160 patients/arm to reach 80% power with a clinically expected intervention difference of 25% LoMV if clinically relevant exclusion criteria were applied to the cohort, but 400 patients/arm if they were not. However, only 130 patients/arm would be required for the same statistical significance at the same intervention difference if VFD was used. A Monte-Carlo simulation approach using local cohort data combined with objective patient selection criteria can yield better design of ventilation studies to desired power and significance, with fewer patients per arm than traditional trial design methods, which in turn reduces patient risk. Outcome metrics, such as VFD, should be used when a difference in mortality is also expected between the two cohorts. Finally, the non-parametric approach taken is readily generalisable to a range of trial types where outcome data is similarly skewed.

  7. Comparative Study of pressure-control ventilation and volume-control ventilation in treating traumatic acute respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    杨云梅; 黄卫东; 沈美亚; 徐哲荣

    2005-01-01

    Objective: To observe the clinical therapeutic effect and side effect of pressure-control ventilation (PCV) on traumatic acute respiratory distress syndrome (ARDS) compared with volume-control ventilation (VCV).Methods: Forty patients with traumatic ARDS were hospitalized in our department from June 1996 to December 2002. Twenty were treated with PCV (PCV group) and 20 with VCV (VCV group). The changes of the peak inflating pressure and the mean pressure of the airway were observed at the very beginning of the mechanical ventilation and the following 12 and 24 hours, respectively. The transcutaneous saturation of oxygen pressure, the pressure of oxygen in artery, the mean blood pressure, the central venous pressure, the heart rate and the incidence of the pressure injury were also monitored before ventilation and 12 hours after ventilation.Results: The pressure of oxygen in artery, the transcutaneous saturation of oxygen pressure, the heart rate and the respiratory rate in the PCV group were obviously improved after ventilation treatment. The peak inflating pressure, the mean pressure of the airway and the central venous pressure in the PCV group were lower than in the VCV group. The incidence of pressure injury was 0 in the PCV group while 10% in the VCV group. Conclusions: The clinical effect of PCV on traumatic ARDS is better and the incidence rate of pressure injury is lower than that of VCV. PCV has minimal effects on the hemodynamics.

  8. Advanced lung ventilation system (ALVS) with linear respiratory mechanics assumption for waveform optimization of dual-controlled ventilation.

    Science.gov (United States)

    Montecchia, F; Guerrisi, M; Canichella, A

    2007-03-01

    The present paper describes the functional features of an advanced lung ventilation system (ALVS) properly designed for the optimization of conventional dual-controlled ventilation (DCV), i.e. with pressure-controlled ventilation with ensured tidal or minute volume. Considering the particular clinical conditions of patients treated with controlled ventilation the analysis and synthesis of ALVS control have been performed assuming a linear respiratory mechanics. Moreover, new airways pressure waveforms with more physiological shape can be tested on simulators of respiratory system in order to evaluate their clinical application. This is obtained through the implementation of a compensation procedure making the desired airways pressure waveform independent on patient airways resistance and lung compliance variations along with a complete real-time monitoring of respiratory system parameters leading the ventilator setting. The experimental results obtained with a lung simulator agree with the theoretical ones and show that ALVS performance is useful for the research activity aiming at the improvement of both diagnostic evaluation and therapeutic outcome relative to mechanical ventilation treatments.

  9. Modelling aerosol transfer in a ventilated room; Modelisation du transfert des aerosols dans un local ventile

    Energy Technology Data Exchange (ETDEWEB)

    Nerisson, Ph.

    2009-02-15

    When particulate radioactive contamination is likely to become airborne in a ventilated room, assessment of aerosol concentration in every point of this room is important, in order to ensure protection of operators and supervision of workspaces. Thus, a model of aerosol transport and deposition has been developed as part of a project started with IRSN, EDF and IMFT. A simplified Eulerian model, called 'diffusion-inertia model' is used for particle transport. It contains a single transport equation of aerosol concentration. The specific study of deposition on walls has permitted to develop a boundary condition approach, which determines precisely the particle flux towards the wall in the boundary layer, for any deposition regime and surface orientation.The final transport and deposition models retained have been implemented in a CFD code called Code-Saturne. These models have been validated according to literature data in simple geometries and tracing experiments in ventilated rooms, which have been carried out in 30 m{sup 3} and 1500 m{sup 3} laboratory rooms. (author)

  10. 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

  11. "Bundle" Practices and Ventilator-Associated Events: Not Enough.

    Science.gov (United States)

    O'Horo, John C; Lan, Haitao; Thongprayoon, Charat; Schenck, Louis; Ahmed, Adil; Dziadzko, Mikhail

    2016-12-01

    OBJECTIVE Ventilator-associated events (VAEs) are nosocomial events correlated with length of stay, costs, and mortality. Current ventilator bundle practices target the older definition of ventilator-associated pneumonia and have not been systematically evaluated for their impact on VAEs. DESIGN Retrospective cohort study. SETTING Tertiary medical center between January 2012 and August 2014. PARTICIPANTS All adult patients ventilated for at least 24 hours at our institution. INTERVENTIONS We conducted univariate analyses for compliance with each element; we focused on VAEs occurring within a 2-day window of failure to meet any ventilator bundle element. We used Cox proportional hazard models to assess the effect of stress ulcer prophylaxis, deep vein thrombosis (DVT) prophylaxis, oral care, and sedation breaks on VAEs. We adjusted models for gender, age, and Acute Physiology and Chronic Health Evaluation (APACHE) III scores. RESULTS Our cohort comprised 2,660 patients with 16,858 ventilator days and 77 VAEs. Adjusting for APACHE score and gender, only oral care was associated with a reduction in the risk of VAE (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.26-0.77). The DVT prophylaxis and sedation breaks did not show any significant impact on VAEs. Stress ulcer prophylaxis trended toward an increased risk of VAE (HR, 1.59; 95% CI, 1.00-2.56). CONCLUSION Although limited by a low baseline rate of VAEs, existing ventilator bundle practices do not appear to target VAEs well. Oral care is clearly important, but the impact of DVT prophylaxis, sedation breaks, and especially stress ulcer prophylaxis are questionable at best. Infect Control Hosp Epidemiol 2016;1453-1457.

  12. Trend of maximal inspiratory pressure in mechanically ventilated patients: predictors

    Directory of Open Access Journals (Sweden)

    Pedro Caruso

    2008-01-01

    Full Text Available 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 studied the possible relationship between the evolution of maximal inspiratory pressure and limb muscle strength. METHODS: A prospective observational study was performed in consecutive patients submitted to mechanical ventilation for > 72 hours. The maximal inspiratory pressure trend was evaluated by the linear regression of the daily maximal inspiratory pressure and a logistic regression analysis was used to look for independent maximal inspiratory pressure trend predictors. Limb muscle strength was evaluated using the Medical Research Council score. RESULTS: One hundred and sixteen patients were studied, forty-four of whom (37.9% presented a decrease in maximal inspiratory pressure over time. The members of the group in which maximal inspiratory pressure decreased underwent deeper sedation, spent less time in pressure support ventilation and were extubated less frequently. The only independent predictor of the maximal inspiratory pressure trend was the level of sedation (OR=1.55, 95% CI 1.003 - 2.408; p = 0.049. There was no relationship between the maximal inspiratory pressure trend and limb muscle strength. CONCLUSIONS: Around forty percent of the mechanically ventilated patients had a decreased maximal inspiratory pressure during mechanical ventilation, which was independently associated with deeper levels of sedation. There was no relationship between the evolution of maximal inspiratory pressure and the muscular strength of the limb.

  13. Indoor Air Quality and Ventilation in Residential Deep Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan; Walker, Iain

    2014-06-01

    Because airtightening is a significant part of Deep Energy Retrofits (DERs), concerns about ventilation and Indoor Air Quality (IAQ) have emerged. To investigate this, ventilation and IAQ were assessed in 17 non-smoking California Deep Energy Retrofit homes. Inspections and surveys were used to assess household activities and ventilation systems. Pollutant sampling performed in 12 homes included six-day passive samples of nitrogen dioxide (NO2), formaldehyde and air exchange rate (AER); time-resolved data loggers were used to measure particle counts. Half of the homes provided continuous mechanical ventilation. Despite these homes being twice as airtight (3.0 and 7.6 ACH50, respectively), their median AER was indistinguishable from naturally vented homes (0.36 versus 0.37 hr--1). Numerous problems were found with ventilation systems; however, pollutant levels did not reach levels of concern in most homes. Ambient NO2 standards were exceeded in some gas cooking homes that used legacy ranges with standing pilots, and in Passive House-style homes without range hoods exhausted to outside. Cooking exhaust systems were installed and used inconsistently. The majority of homes reported using low-emitting materials, and formaldehyde levels were approximately half those in conventional new CA homes (19.7 versus 36 ?g/m3), with emissions rates nearly 40percent less (12.3 versus 20.6 ?g/m2/hr.). Presence of air filtration systems led to lower indoor particle number concentrations (PN>0.5: 8.80E+06 PN/m3 versus 2.99E+06; PN>2.5: 5.46E+0.5 PN/m3 versus 2.59E+05). The results indicate that DERs can provide adequate ventilation and IAQ, and that DERs should prioritize source control, particle filtration and well-designed local exhaust systems, while still providing adequate continuous ventilation.

  14. The role of invasive ventilation in exacerbations of chronic obstructive pulmonary disease causing respiratory failure.

    Science.gov (United States)

    Kosky, Christopher; Turton, Charles

    2006-01-01

    Acute hypercapnic respiratory failure in chronic obstructive pulmonary disease can usually be managed initially with medical treatment and non- invasive ventilation. In circumstances where non- invasive ventilation cannot be used or has failed, intubation and invasive ventilation may be lifesaving. The outcome of patients with an exacerbation of COPD requiring invasive ventilation is better than often thought, with a hospital survival of 70-89%. Decisions regarding invasive ventilation made by physicians and patients with COPD are unpredictable and vary with the individual. This article reviews the role of invasive ventilation in exacerbations of COPD to assist decision making.

  15. APRV Mode in Ventilator Induced Lung Injury (VILI

    Directory of Open Access Journals (Sweden)

    Ata Mahmoodpoor

    2014-01-01

    Full Text Available 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 to preserve satisfactory lung volume and consequently alveolar recruitment. This mode benefits a time-cycled release phase to a lower set of pressure for a short period of time (P and T low i.e. release time (1,2. While some advantages have been introduced for APRV such as efficiently recruited alveoli over time, more homogeneous ventilation, less volutrauma, probable stabilization of patent alveoli and reduction in atelectrauma, protective effects of APRV on lung damage only seem to be substantial if spontaneous breathing responds to more than 30% of total minute ventilation (3. APRV in ARDS patients should be administered cautiously; T low<0.6 seconds, for recruiting collapsed alveoli; however overstretching of alveoli especially during P high should not be neglected and appropriate sedation considered. The proposed advantages for APRV give the impression of being outstanding; however, APRV, as a non-physiologic inverse ratio mode of ventilation, might result in inflammation mainly due to impaired patient-ventilator interaction explaining the negative or minimally desirable effects of APRV on inflammation (4. Consequently, continuous infusion of neuromuscular blocking drugs during ARDS has been reported to reduce mortality (5. There are insufficient confirming data on the superiority of APRV above other ventilatory methods in regard to oxygenation, hemodynamics, regional blood flow, patient comfort and length of mechanical ventilation. Based on current findings

  16. OUTCOME OF VENTILATION IN HYALINE MEMBRANE DISEASE: THE INDIAN EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Nayana Prabha

    2016-06-01

    Full Text Available OBJECTIVE To study the short-term outcome of both preterm and term babies requiring assisted ventilation for hyaline membrane disease and report the complications contributing to morbidity and mortality of these patients from a regional medical college with limited resources. DESIGN Retrospective file review. SETTING Regional Medical College. PARTICIPANTS All babies ventilated for HMD over a 6-year period from June 2008 to June 2014. OUTCOME MEASURES Outcome of ventilation and factors contributing to mortality. RESULTS Out of 100 babies with hyaline membrane disease who were ventilated, 82% survived. Increasing gestational age and birth weight was associated with survival. The commonest complication was shock (77% and the commonest cause of mortality was septicaemia (77%. Septicaemia, Disseminated Intravascular Coagulation (DIC and pulmonary haemorrhage were significantly more common complications babies who died (p<0.05. Binary logistic regression analysis showed that DIC (Odds ratio 5.2 [Confidence intervals (C.I. 1.1-27.1] and pulmonary haemorrhage (OR 18 [1.72-45.2] to be predictors of mortality. The incidence of intraventricular haemorrhage was 1% and that of pneumothorax was 2%. The initial peak inspiratory pressure administered was significantly lower (p=0.033 and maximum peak end expiratory pressure was significantly higher in those who expired (p=0.027. CONCLUSION Outcome of ventilation for hyaline membrane disease improves with increasing gestational age and birth weight. The commonest cause of mortality and morbidity were septicaemia and shock respectively.

  17. Neonatal weaning from ventilator: PSV versus SIMV mode

    Directory of Open Access Journals (Sweden)

    Nayeri F

    2009-01-01

    Full Text Available "nBackground: The use of synchronized intermittent mandatory ventilation (SIMV and pressure support ventilation (PSV have been used for older children and adults. The purpose of this study was to compare PSV and SIMV modes in weaning from mechanical ventilation in neonate with respiratory failure. "nMethods: A randomized clinical trial study carried out in NICU ward of Valiasr hospital Imam Khomeini Hospital complex, Tehran, Iran. Thirty neonates enrolled in two groups of 15. At the weaning time they randomly assigned to SIMV or PSV. They compared for tidal volume (VT, peak inspiratory pressure (PIP, incidence of pneumothorax, weaning failure and duration of weaning. For two groups to be homogeneous, maternal disease during pregnancy were also considered. "nResults: In this study, VT, PIP, incidence of pneumothorax and weaning failure did not differ between groups; duration of ventilation of the two methods (hours and duration of hospitalization (days were separately calculated. The only meaningful difference in two groups were due to weaning duration. The neonates weaned by PSV mode experienced shorter weaning time. (6.05 hours. The weaning time in SIMV mode was longer (45 hours (P=0.006. There were no other meaningful differences between the two groups "nConclusions: According to the results of this study there were no advantage using PSV over SIMV except that the weaning time were shorter in PSV. This decrease in weaning time causes less dependence of the neonate to the ventilator and as a result secure them from complications.

  18. Feedforward consequences of isometric contractions: effort and ventilation.

    Science.gov (United States)

    Luu, Billy L; Smith, Janette L; Martin, Peter G; McBain, Rachel A; Taylor, Janet L; Butler, Jane E

    2016-08-01

    The onset of voluntary muscle contractions causes rapid increases in ventilation and is accompanied by a sensation of effort. Both the ventilatory response and perception of effort are proportional to contraction intensity, but these behaviors have been generalized from contractions of a single muscle group. Our aim was to determine how these relationships are affected by simultaneous contractions of multiple muscle groups. We examined the ventilatory response and perceived effort of contraction during separate and simultaneous isometric contractions of the contralateral elbow flexors and of an ipsilateral elbow flexor and knee extensor. Subjects made 10-sec contractions at 25, 50, and 100% of maximum during normocapnia and hypercapnia. For simultaneous contractions, both muscle groups were activated at the same intensities. Ventilation was measured continuously and subjects rated the effort required to produce each contraction. As expected, ventilation and perceived effort increased proportionally with contraction intensity during individual contractions. However, during simultaneous contractions, neither ventilation nor effort reflected the combined muscle output. Rather, the ventilatory response was similar to when contractions were performed separately, and effort ratings showed a small but significant increase for simultaneous contractions. Hypercapnia at rest doubled baseline ventilation, but did not affect the difference in perceived effort between separate and simultaneous contractions. The ventilatory response and the sense of effort at the onset of muscle activity are not related to the total output of the motor pathways, or the working muscles, but arise from cortical regions upstream from the motor cortex.

  19. Respiratory dysfunction in ventilated patients: can inspiratory muscle training help?

    Science.gov (United States)

    Bissett, B; Leditschke, I A; Paratz, J D; Boots, R J

    2012-03-01

    Respiratory muscle dysfunction is associated with prolonged and difficult weaning from mechanical ventilation. This dysfunction in ventilator-dependent patients is multifactorial: there is evidence that inspiratory muscle weakness is partially explained by disuse atrophy secondary to ventilation, and positive end-expiratory pressure can further reduce muscle strength by negatively shifting the length-tension curve of the diaphragm. Polyneuropathy is also likely to contribute to apparent muscle weakness in critically ill patients, and nutritional and pharmaceutical effects may further compound muscle weakness. Moreover, psychological influences, including anxiety, may contribute to difficulty in weaning. There is recent evidence that inspiratory muscle training is safe and feasible in selected ventilator-dependent patients, and that this training can reduce the weaning period and improve overall weaning success rates. Extrapolating from evidence in sports medicine, as well as the known effects of inspiratory muscle training in chronic lung disease, a theoretical model is proposed to describe how inspiratory muscle training enhances weaning and recovery from mechanical ventilation. Possible mechanisms include increased protein synthesis (both Type 1 and Type 2 muscle fibres), enhanced limb perfusion via dampening of a sympathetically-mediated metaboreflex, reduced lactate levels and modulation of the perception of exertion, resulting in less dyspnoea and enhanced exercise capacity.

  20. The Mechanical Impact of Aerodynamic Stall on Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available This paper describes work aimed at establishing the ability of a tunnel ventilation fan to operate without risk of mechanical failure in the event of aerodynamic stall. The research establishes the aerodynamic characteristics of a typical tunnel ventilation fan when operated in both stable and stalled aerodynamic conditions, with and without an anti-stall stabilisation ring, with and without a “nonstalling” blade angle and at full, half, and one quarter design speed. It also measures the fan’s peak stress, thus facilitating an analysis of the implications of the experimental results for mechanical design methodology. The paper concludes by presenting three different strategies for tunnel ventilation fan selection in applications where the selected fan will most likely stall. The first strategy selects a fan with a low-blade angle that is nonstalling. The second strategy selects a fan with a high-pressure developing capability. The third strategy selects a fan with a fitted stabilisation ring. Tunnel ventilation system designers each have their favoured fan selection strategy. However, all three strategies can produce system designs within which a tunnel ventilation fan performs reliably in-service. The paper considers the advantages and disadvantages of each selection strategy and considered the strengths and weaknesses of each.

  1. Ventilation Behavior and Household Characteristics in NewCalifornia Houses

    Energy Technology Data Exchange (ETDEWEB)

    Price, Phillip N.; Sherman, Max H.

    2006-02-01

    A survey was conducted to determine occupant use of windows and mechanical ventilation devices; barriers that inhibit their use; satisfaction with indoor air quality (IAQ); and the relationship between these factors. A questionnaire was mailed to a stratified random sample of 4,972 single-family detached homes built in 2003, and 1,448 responses were received. A convenience sample of 230 houses known to have mechanical ventilation systems resulted in another 67 completed interviews. Some results are: (1) Many houses are under-ventilated: depending on season, only 10-50% of houses meet the standard recommendation of 0.35 air changes per hour. (2) Local exhaust fans are under-utilized. For instance, about 30% of households rarely or never use their bathroom fan. (3) More than 95% of households report that indoor air quality is ''very'' or ''somewhat'' acceptable, although about 1/3 of households also report dustiness, dry air, or stagnant or humid air. (4) Except households where people cook several hours per week, there is no evidence that households with significant indoor pollutant sources get more ventilation. (5) Except households containing asthmatics, there is no evidence that health issues motivate ventilation behavior. (6) Security and energy saving are the two main reasons people close windows or keep them closed.

  2. Coupling of Thermal Mass with Night Ventilation in Buildings

    Science.gov (United States)

    Endurthy, Akhilesh Reddy

    Passive cooling designs & technologies offer great promise to lower energy use in buildings. Though the working principles of these designs and technologies are well understood, simplified tools to quantitatively evaluate their performance are lacking. Cooling by night ventilation, which is the topic of this research, is one of the well known passive cooling technologies. The building's thermal mass can be cooled at night by ventilating the inside of the space with the relatively lower outdoor air temperatures, thereby maintaining lower indoor temperatures during the warmer daytime period. Numerous studies, both experimental and theoretical, have been performed and have shown the effectiveness of the method to significantly reduce air conditioning loads or improve comfort levels in those climates where the night time ambient air temperature drops below that of the indoor air. The impact of widespread adoption of night ventilation cooling can be substantial, given the large fraction of energy consumed by air conditioning of buildings (about 12-13% of the total electricity use in U.S. buildings). Night ventilation is relatively easy to implement with minimal design changes to existing buildings. Contemporary mathematical models to evaluate the performance of night ventilation are embedded in detailed whole building simulation tools which require a certain amount of expertise and is a time consuming approach.

  3. Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction.

    Science.gov (United States)

    Smith, Ira J; Godinez, Guillermo L; Singh, Baljit K; McCaughey, Kelly M; Alcantara, Raniel R; Gururaja, Tarikere; Ho, Melissa S; Nguyen, Henry N; Friera, Annabelle M; White, Kathy A; McLaughlin, John R; Hansen, Derek; Romero, Jason M; Baltgalvis, Kristen A; Claypool, Mark D; Li, Wei; Lang, Wayne; Yam, George C; Gelman, Marina S; Ding, Rongxian; Yung, Stephanie L; Creger, Daniel P; Chen, Yan; Singh, Rajinder; Smuder, Ashley J; Wiggs, Michael P; Kwon, Oh-Sung; Sollanek, Kurt J; Powers, Scott K; Masuda, Esteban S; Taylor, Vanessa C; Payan, Donald G; Kinoshita, Taisei; Kinsella, Todd M

    2014-07-01

    Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in CMV-mediated diaphragm wasting and weakness in rats. CMV-induced diaphragm atrophy and contractile dysfunction coincided with marked increases in STAT3 phosphorylation on both tyrosine 705 (Tyr705) and serine 727 (Ser727). STAT3 activation was accompanied by its translocation into mitochondria within diaphragm muscle and mitochondrial dysfunction. Inhibition of JAK signaling during CMV prevented phosphorylation of both target sites on STAT3, eliminated the accumulation of phosphorylated STAT3 within the mitochondria, and reversed the pathologic alterations in mitochondrial function, reduced oxidative stress in the diaphragm, and maintained normal diaphragm contractility. In addition, JAK inhibition during CMV blunted the activation of key proteolytic pathways in the diaphragm, as well as diaphragm atrophy. These findings implicate JAK/STAT3 signaling in the development of diaphragm muscle atrophy and dysfunction during CMV and suggest that the delayed extubation times associated with CMV can be prevented by inhibition of Janus kinase signaling.-Smith, I. J., Godinez, G. L., Singh, B. K., McCaughey, K. M., Alcantara, R. R., Gururaja, T., Ho, M. S., Nguyen, H. N., Friera, A. M., White, K. A., McLaughlin, J. R., Hansen, D., Romero, J. M., Baltgalvis, K. A., Claypool, M. D., Li, W., Lang, W., Yam, G. C., Gelman, M. S., Ding, R., Yung, S. L., Creger, D. P., Chen, Y., Singh, R., Smuder, A. J., Wiggs, M. P., Kwon, O.-S., Sollanek, K. J., Powers, S. K., Masuda, E. S., Taylor, V. C., Payan, D. G

  4. Preoperational test report, primary ventilation condenser cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-10-29

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  5. The Effects of Ventilation in Homes on Health

    DEFF Research Database (Denmark)

    Wargocki, Pawel

    2013-01-01

    It is estimated that people in the developed world spend more than 85-90% of their time indoors. Of this, most is spent in homes. To minimize health risks from pollutants occurring in homes, exposures should be controlled. The most effective way to achieve this is to control sources of pollutants...... and many of them suffer from deficient experimental design, as well as a lack of proper characterization of actual exposures occurring indoors. Based on the available data, in the reviewed studies, it seems likely that health risks may occur when ventilation rates are below 0.4 air changes per hour...... with existing ventilation systems this positive effect was less evident, probably due to poor performance of the system (too low ventilation rates and/or poor maintenance). Studies are recommended in which exposures are much better characterized (by for example measuring the pollutants indicated by the WHO...

  6. Investigation of Indoor Climate in a Naturally Ventilated Office Building

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Kalyanova, Olena; Jensen, Rasmus Lund;

    2008-01-01

    A measuring program in a naturally ventilated office building in Copenhagen was carried out to document the indoor climate and ventilation system performance during a year. It included a questionnaire regarding the perceived indoor environmental quality and physical measurements of thermal comfort...... to a combination of poor control of solar shading and a very high local heat load that was above the Danish recommendations for naturally ventilated office buildings. Both measured and perceived indoor air quality in the building was in general very high. The measured air flow rates was relatively high due...... to the need for cooling in the office building, while the level of infiltration was quite low indicating an airtight construction....

  7. Improvement in performance of main ventilation fan for mines

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.N. [Indian School of Mines, Dhanbad (India)

    2007-07-01

    This paper examined methods of improving the performance of main ventilation fans in mines. The basic principles of selecting and operating fans were reviewed, and methods of improving the energy efficiency of fans were evaluated. The study considered issues related to static efficiency, as well as curves and intersection points. Mine resistances were examined in relation to ventilation requirements at different phases of mine development. Flow losses and difficulties in producing accurate mathematical models of ventilation fans were also discussed. Fan operation set-points were reviewed. Details of tests conducted to determine the effects of the number of blades on fan performance were presented. The tests demonstrated the importance of incorporating cowl diffusers and guide vanes within the design of axial flow fans. The advantages of deblading were also discussed. 6 refs.

  8. Experimental Assessment of Mechanical Night Ventilation on Inner Wall Surfaces

    DEFF Research Database (Denmark)

    Wenhui, Ji; Heiselberg, Per Kvols; Wang, Houhua;

    2016-01-01

    The cooling potential of night ventilation largely depends on the heat exchange at the internal room surfaces. During night time, increased heat transfer on a vertical wall is expected due to cool supply air that flows along the internal wall surface from the top of the wall. This paper presents ...... an experimental study of the cooling of wall surfaces in a test room by mechanical night-time ventilation. Significant improvement of indoor thermal environment is presented resulting from the enhanced internal convection heat transfer.......The cooling potential of night ventilation largely depends on the heat exchange at the internal room surfaces. During night time, increased heat transfer on a vertical wall is expected due to cool supply air that flows along the internal wall surface from the top of the wall. This paper presents...

  9. Potential of Natural Ventilation in Cold Conditions Countries

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    The objective of this article is to investigate the energy performance of natural ventilation as a passive cooling method of buildings within houses located in temperate countries using Denmark as a case study. The method consists in running simulations with a thermal-airflow program of a household...... that there is a reduction of 90% of hours of a possible use of mechanical ventilation, showing the feasibility to achieve thermal comfort within the house by using passive ventilation. The conclusion is therefore that the results contribute to an assessment of the economic and environmental benefits of using natural...... located in Vejle, Denmark during the months of June, July and August calculating the indoor air temperatures during this period. The dwelling belongs to a Danish project of passive houses named Komfort Husene where its users claim there are periods of overheating during the summer time. Then, after...

  10. Humidification during mechanical ventilation in the adult patient.

    Science.gov (United States)

    Al Ashry, Haitham S; Modrykamien, Ariel M

    2014-01-01

    Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evolved. Sophisticated systems composed of reservoirs, wires, heating devices, and other elements have become part of our usual armamentarium in the intensive care unit. Therefore, basic knowledge of the mechanisms of action of each of these devices, as well as their advantages and disadvantages, becomes a necessity for the respiratory care and intensive care practitioner. In this paper, we review current methods of airway humidification during invasive mechanical ventilation of adult patients. We describe a variety of devices and describe the eventual applications according to specific clinical conditions.

  11. Humidification during Mechanical Ventilation in the Adult Patient

    Directory of Open Access Journals (Sweden)

    Haitham S. Al Ashry

    2014-01-01

    Full Text Available Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evolved. Sophisticated systems composed of reservoirs, wires, heating devices, and other elements have become part of our usual armamentarium in the intensive care unit. Therefore, basic knowledge of the mechanisms of action of each of these devices, as well as their advantages and disadvantages, becomes a necessity for the respiratory care and intensive care practitioner. In this paper, we review current methods of airway humidification during invasive mechanical ventilation of adult patients. We describe a variety of devices and describe the eventual applications according to specific clinical conditions.

  12. Cooling of the Building Structure by Night-time Ventilation

    DEFF Research Database (Denmark)

    Artmann, Nikolai

    , architects and engineers are still hesitant to apply passive cooling techniques. The basic concept of night-time ventilation involves cooling the building structure overnight in order to provide a heat sink during the occupancy period. As this requires a sufficiently high temperature difference between...... a building energy simulation program (HELIOS), and the effect of different parameters such as building construction, heat gains, air change rates, heat transfer coefficients and climatic conditions on the number of overheating degree hours (operative room temperature >26 °C) was evaluated. Besides climatic...... air flow rates and the possibility of a cold air jet flowing along the ceiling, but the magnitude of these effects is hard to predict. Heat transfer during night-time ventilation in case of mixing and displacement ventilation has been investigated in a full scale test room. The performance of night...

  13. Neonatal noninvasive ventilation techniques: do we really need to intubate?

    Science.gov (United States)

    DiBlasi, Robert M

    2011-09-01

    The current trend for supporting neonates with respiratory distress syndrome is nasal continuous positive airway pressure (CPAP). Nearly half of all neonates who are supported with CPAP will still develop respiratory failure that requires potentially injurious endotracheal intubation and invasive ventilation. Thus, the role of any neonatal clinician is to minimize invasive ventilation whenever possible, to avoid the multitude of complications that can arise when using this form of therapy. Noninvasive ventilation (NIV) is a form of respiratory assistance that provides greater respiratory support than does CPAP and may prevent intubation in a larger fraction of neonates who would otherwise fail CPAP. With the inception of nasal airway interfaces, clinicians have ushered in many different forms of NIV in neonates, often with very little experimental data to guide management. This review will explore in detail all of the different forms of neonatal NIV that are currently focused within an area of intense clinical investigation.

  14. Vertical Temperature Distribution in a Room with Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    A displacement ventilation system exploits the use of energy efficiently because it is possible to remove exhaust air from a room with a temperature that is several degrees above the temperature in the occupied zone. This process will allow a higher air inlet temperature at the same load...... to consider the temperature gradient in the occupied zone, as well as the asymmetric radiation from the ceiling, in connection with the design of a displacement ventilation system and the evaluation of thermal comfort. This paper will introduce five temperature distribution models with different levels...... in comparison with mixing ventilation. It is necessary to have a design method for the temperature distribution used for instance in connection with the tlow element method and the energy calculations. The temperature distribution is also important in connection with thermal comfort in a room. It is necessary...

  15. Floor Heating with Displacement Ventilation: An Experimental and Numerical Analysis

    DEFF Research Database (Denmark)

    Causone, Francesco; Olesen, Bjarne W.; Corgnati, S.P.

    2010-01-01

    The effect of floor heating combined with displacement ventilation (DV) on thermal indoor environments and indoor air quality (IAQ) was studied by means of CFD. The numerical model was validated with experimental data. A typical office room was simulated, and one of the occupants was considered...... to be the contaminant source. The CFD model reliably simulated air velocities and temperatures. Also ventilation effectiveness values were coherent with experimental data. The model made it possible to understand the effect oldie downdraft from a cold window on the dissemination of contaminant in the room. Although...... ventilation effectiveness at seated breathing height was always higher than one, it was not possible to visualize a defined contaminant stratification in the room. Only when the windows were not assumed to be cold, a clearly stratified flow pattern could be detected. The numerical model was then used...

  16. Hospital bed ventilation: impact of operation mode on exposure

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor; Barova, Mariya

    2014-01-01

    and droplet nuclei of less than 3 μm aerodynamic diameter. Two modes of operation of the bed incorporated ventilation unit were tested: releasing the cleaned air upwards (pull mode) or supplying it sideways over the lying patient (“push and pull” mode). The strategy to exhaust pollutants close o release...... ventilation unit was operated in the “push and pull” mode compared to the pull mode....... a second patient lying in the other bed. The doctor stood up 0.55 m from the bed facing the sick patient. Two pairs of localized ventilation units were attached near the heads of both patients alongside the beds to capture, clean and release the captured exhaled air from the lying patients. When the bed...

  17. Performance potential of mechanical ventilation systems with minimized pressure loss

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    2013-01-01

    simulations that quantify fan power consumption, heating demand and indoor environmental conditions. The system was designed with minimal pressure loss in the duct system and heat exchanger. Also, it uses state-of-the-art components such as electrostatic precipitators, diffuse ceiling inlets and demand......-control ventilation with static pressure set-point reset. All the equipment has been designed to minimize pressure losses and thereby the fan power needed to operate the system. The total pressure loss is 30-75 Pa depending on the operating conditions. The annual average specific fan power is 330 J/m3 of airflow rate......In many locations mechanical ventilation has been the most widely used principle of ventilation over the last 50 years but the conventional system design must be revised to comply with future energy requirements. This paper examines the options and describes a concept for the design of mechanical...

  18. Saving energy for ventilation using decentralised duct fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Bergsøe, Niels Christian; Afshari, Alireza

    2014-01-01

    pressure drops which in turn will increase energy use. This paper presents a novel procedure for balancing CAV-systems using decentralised duct fans instead of flat plate dampers. The procedure will result in lower pressure drops and consequently in a reduction of energy use for ventilation when compared......In conventional mechanical ventilation systems with constant air volume (CAV) airflows are often balanced using balancing flat plate dampers. The purpose of the dampers is to obtain nominal airflows to the individual zones or rooms in the building. Unfortunately, this procedure leads to increased...... to a conventional mechanical ventilation system with flat plate dampers. Theoretical calculations and experimental observations for the investigated systems show that the power demand for distribution of air can be reduced about 30%. The work carried out forms part of an ongoing PhD-project on mechanical...

  19. Nutrition considerations in the management of ventilator-dependent patients.

    Science.gov (United States)

    Ireton-Jones, C S; Borman, K R; Turner, W W

    1993-04-01

    Nutrition support of the patient with ventilatory failure is an important adjunct to recovery. Malnutrition and respiratory failure are frequently interrelated. Ventilator dependence occurs when the patient cannot independently sustain oxygenation, carbon dioxide removal, or acid-base balance. Nutrition assessment, determination of energy requirements, and provision of nutrient solutions utilizing the most appropriate route of administration should be initiated early in the ventilator-dependent patient's hospital course. Careful assessment will identify patients needing repletion along with maintenance calories, as well as special macronutrient and micronutrient needs. The nutrient prescription is designed to provide carbohydrate, protein, and fat in amounts for optimal substrate utilization. Body fluid balance, micronutrient needs, electrolyte homeostasis, and acid-base balance affect respiratory muscle function and must also be considered in developing the nutrition regimen. Properly constructed enteral or parenteral nutrition plans begun early offer the best support for ventilator-dependent patients.

  20. Pressure and volume controlled mechanical ventilation in anaesthetized pregnant sheep.

    Science.gov (United States)

    Davis, J; Musk, G C

    2014-10-01

    Optimal mechanical ventilation of the pregnant ewe during anaesthesia is of vital importance for maintaining fetal viability. This study aimed to compare peak inspiratory pressure (PIP), oxygenation and cardiovascular parameters with pressure-control (PCV) or volume-control (VCV) mechanical ventilation of anaesthetized pregnant sheep. Twenty ewes at 110 days gestation underwent general anaesthesia in dorsal recumbency for fetal surgery in a research setting. All the sheep were mechanically ventilated; one group with PCV (n = 10) and another with VCV (n = 10) to maintain normocapnia. PIP, direct arterial blood pressure, heart rate, arterial pH and arterial oxygen tension were recorded. PIP was lower in the PCV group (P sheep anaesthetized in dorsal recumbency, though PCV may provide superior oxygenation at a lower PIP.

  1. 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......The new initiatives and regulations towards nearly zero energy buildings forces designers to exploit the cooling potential of the climate to reduce the overheating occurrence and to improve thermal comfort indoors. Climate analysis is particularly useful at early design stages to support decision....... 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...

  2. Enhanced deep ocean ventilation and oxygenation with global warming

    Science.gov (United States)

    Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

    2014-12-01

    Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

  3. Shrinking the room for invasive ventilation in hypercapnic respiratory failure

    Directory of Open Access Journals (Sweden)

    Scarpazza P

    2013-03-01

    Full Text Available Paolo Scarpazza,1 Cristoforo Incorvaia,2 Chiara Melacini,1 Roberta Cattaneo,1 Cristiano Bonacina,1 Gian Galeazzo Riario-Sforza,2 Walter Casali1 1Pneumology Unit, Ospedale Civile, Vimercate, 2Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy Abstract: Noninvasive ventilation (NIV was introduced as an alternative to invasive mechanical ventilation for acute respiratory failure caused from exacerbations of chronic obstructive pulmonary disease in the 1980s, and its use gradually rose worldwide. Seventy-eight patients (57 males, mean age 78.3 ± 9.2 years undergoing NIV were evaluated. Of them, 48 (62.3% had acute hypercapnic respiratory failure because of a chronic obstructive pulmonary disease exacerbation, and the remaining 30 had acute hypercapnic respiratory failure from other causes, mainly cardiac failure. All patients were treated by NIV using the bi-level positive airway pressure set up at high pressure/high backup rate. NIV was successful in 67 subjects (85.9% and the patients were discharged, 57 of whom continued NIV at home and ten had spontaneous breathing. NIV was unsuccessful in eleven patients, ten of whom died and one was successfully treated by invasive mechanical ventilation. Significant differences were detected for a higher basal Glasgow Coma Scale score in successfully treated patients (P = 0.007, a higher basal Acute Physiology and Chronic Health Evaluation score in unsuccessfully treated patients (P = 0.004, and a lower pH after 1 hour in unsuccessfully treated patients (P = 0.015. These findings show a very high rate of success of NIV in patients with acute hypercapnic respiratory failure not only from chronic obstructive pulmonary disease but also from cardiac failure. This suggests that the use of invasive mechanical ventilation may be further reduced, with a decrease in its known complications as well. Keywords: invasive ventilation, noninvasive ventilation, acute respiratory failure

  4. Brazilian recommendations of mechanical ventilation 2013. Part I

    Science.gov (United States)

    2014-01-01

    Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25210957

  5. Nonassociative learning promotes respiratory entrainment to mechanical ventilation.

    Directory of Open Access Journals (Sweden)

    Shawna M MacDonald

    Full Text Available BACKGROUND: Patient-ventilator synchrony is a major concern in critical care and is influenced by phasic lung-volume feedback control of the respiratory rhythm. Routine clinical application of positive end-expiratory pressure (PEEP introduces a tonic input which, if unopposed, might disrupt respiratory-ventilator entrainment through sustained activation of the vagally-mediated Hering-Breuer reflex. We suggest that this potential adverse effect may be averted by two differentiator forms of nonassociative learning (habituation and desensitization of the Hering-Breuer reflex via pontomedullary pathways. METHODOLOGY/PRINCIPAL FINDINGS: We tested these hypotheses in 17 urethane-anesthetized adult Sprague-Dawley rats under controlled mechanical ventilation. Without PEEP, phrenic discharge was entrained 1:1 to the ventilator rhythm. Application of PEEP momentarily dampened the entrainment to higher ratios but this effect was gradually adapted by nonassociative learning. Bilateral electrolytic lesions of the pneumotaxic center weakened the adaptation to PEEP, whereas sustained stimulation of the pneumotaxic center weakened the entrainment independent of PEEP. In all cases, entrainment was abolished after vagotomy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate an important functional role for pneumotaxic desensitization and extra-pontine habituation of the Hering-Breuer reflex elicited by lung inflation: acting as buffers or high-pass filters against tonic vagal volume input, these differentiator forms of nonassociative learning help to restore respiratory-ventilator entrainment in the face of PEEP. Such central sites-specific habituation and desensitization of the Hering-Breuer reflex provide a useful experimental model of nonassociative learning in mammals that is of particular significance in understanding respiratory rhythmogenesis and coupled-oscillator entrainment mechanisms, and in the clinical management of mechanical ventilation in

  6. Brazilian recommendations of mechanical ventilation 2013. Part 2

    Science.gov (United States)

    Barbas, Carmen Sílvia Valente; Ísola, Alexandre Marini; Farias, Augusto Manoel de Carvalho; Cavalcanti, Alexandre Biasi; Gama, Ana Maria Casati; Duarte, Antonio Carlos Magalhães; Vianna, Arthur; Serpa Neto, Ary; Bravim, Bruno de Arruda; Pinheiro, Bruno do Valle; Mazza, Bruno Franco; de Carvalho, Carlos Roberto Ribeiro; Toufen Júnior, Carlos; David, Cid Marcos Nascimento; Taniguchi, Corine; Mazza, Débora Dutra da Silveira; Dragosavac, Desanka; Toledo, Diogo Oliveira; Costa, Eduardo Leite; Caser, Eliana Bernadete; Silva, Eliezer; Amorim, Fabio Ferreira; Saddy, Felipe; Galas, Filomena Regina Barbosa Gomes; Silva, Gisele Sampaio; de Matos, Gustavo Faissol Janot; Emmerich, João Claudio; Valiatti, Jorge Luis dos Santos; Teles, José Mario Meira; Victorino, Josué Almeida; Ferreira, Juliana Carvalho; Prodomo, Luciana Passuello do Vale; Hajjar, Ludhmila Abrahão; Martins, Luiz Claudio; Malbouisson, Luis Marcelo Sá; Vargas, Mara Ambrosina de Oliveira; Reis, Marco Antonio Soares; Amato, Marcelo Brito Passos; Holanda, Marcelo Alcântara; Park, Marcelo; Jacomelli, Marcia; Tavares, Marcos; Damasceno, Marta Cristina Paulette; Assunção, Murillo Santucci César; Damasceno, Moyzes Pinto Coelho Duarte; Youssef, Nazah Cherif Mohamed; Teixeira, Paulo José Zimmermann; Caruso, Pedro; Duarte, Péricles Almeida Delfino; Messeder, Octavio; Eid, Raquel Caserta; Rodrigues, Ricardo Goulart; de Jesus, Rodrigo Francisco; Kairalla, Ronaldo Adib; Justino, Sandra; Nemer, Sergio Nogueira; Romero, Simone Barbosa; Amado, Verônica Moreira

    2014-01-01

    Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25295817

  7. A method for measuring passive elastance during proportional assist ventilation.

    Science.gov (United States)

    Younes, M; Webster, K; Kun, J; Roberts, D; Masiowski, B

    2001-07-01

    There are currently no reliable, noninvasive ways to monitor respiratory elastance (E) during assisted ventilation. We describe a method that is suited for proportional assist ventilation (PAV). In this mode, the end of the ventilator's inflation phase occurs during the declining phase of inspiratory effort (Pmus). If the opening of the exhalation valve is delayed, airway pressure (Paw) should initially rise as Pmus continues its decline. When Pmus declines to zero, a Paw plateau should appear. Paw at this point should reflect passive recoil at the prevailing volume. A cohort of 74 ventilator-dependent patients, ventilated in the PAV mode, were studied. Brief end-inspiratory occlusions were applied at random intervals. The magnitude of early change in Paw during the occlusion was inversely related to level of assist (r = 0.7, p 75%), Paw was nearly flat or declined slightly, indicating minimal residual Pmus at the onset of occlusion. At lower assist levels, Paw increased exponentially in most patients with an average time constant of 0.21 +/- 0.06 s. Extraneous events that may corrupt the measurement (e.g., behavioral responses) were extremely rare (passive E measured during controlled ventilation (ECMV); the average difference (EPAV - ECMV) was (+/- SD) -0.3 +/- 4.9 cm H2O x L(-1), corresponding to 0.9 +/- 16.4% of average E. We conclude that Paw measured at 0.25 s from the onset of end-inspiratory occlusion in the PAV mode provides a reliable estimate of passive elastic recoil.

  8. The ventilation and climate modelling of rapid development tunnel drivages

    Energy Technology Data Exchange (ETDEWEB)

    Lowndes, I.S.; Crossley, A.J.; Yang, Z.Y. [University of Nottingham, Nottingham (United Kingdom). School of Chemical Environmental & Mining Engineering

    2004-03-01

    The extraction of minerals and coal at greater depth, employing higher-powered machinery to increase production levels, has imposed an increased burden on ventilation systems to maintain an acceptable working environment. There may be an economic or practical limit to the climatic improvement that may be obtained by the sole use of ventilation air. Where this limit is identified, there may be the need to consider the selective application of air-cooling systems. This paper details the construction of a computer based climatic prediction tool developed at the University of Nottingham. The current model predicts the psychrometric and thermodynamic conditions within long rapid development single entry tunnel drivages. The model takes into account the mass and heat transfer between the strata, water, machinery and the ventilation air. The results produced by the model have been correlated against ventilation, climatic and operational data, obtained from a number of rapid tunnel developments within UK deep coalmines. The paper details the results of a series of correlation and validation studies conducted against the ventilation and climate survey data measured within 105s district Tail Gate tunnel development at Maltby Colliery, UK. The paper concludes by presenting the results of a case study that illustrate the application of the validated model to the design and operation of an integrated mine ventilation and cooling system. The case study illustrates the effect that an increased depth and hence increased virgin strata temperature has on the climate experienced within rapid tunnel developments. Further investigations were performed to identify the optimum cooling strategy that should be adopted to maintain a satisfactory climate at the head of the drivage.

  9. Intelligent predictive model of ventilating capacity of imperial smelt furnace

    Institute of Scientific and Technical Information of China (English)

    唐朝晖; 胡燕瑜; 桂卫华; 吴敏

    2003-01-01

    In order to know the ventilating capacity of imperial smelt furnace (ISF), and increase the output of plumbum, an intelligent modeling method based on gray theory and artificial neural networks(ANN) is proposed, in which the weight values in the integrated model can be adjusted automatically. An intelligent predictive model of the ventilating capacity of the ISF is established and analyzed by the method. The simulation results and industrial applications demonstrate that the predictive model is close to the real plant, the relative predictive error is 0.72%, which is 50% less than the single model, leading to a notable increase of the output of plumbum.

  10. [Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

    Science.gov (United States)

    Bellucci Sessa, R; Riccio, G

    2004-01-01

    After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

  11. Patients' experiences of being mechanically ventilated in an ICU

    DEFF Research Database (Denmark)

    Baumgarten, Mette; Poulsen, Ingrid

    2015-01-01

    patients admitted to an ICU, while they were not ventilated. RESULTS: Fifteen abstracted findings appeared from the metasynthesis and led to the synthesised finding: 'Being dependent on health professionals, without being able to communicate, causes experiences with anxiety, fear and loneliness. How......, consisting of anxiety, fear and loneliness. IMPLICATIONS FOR PRACTICE: In future practice, it is expected that patients will be more awake during mechanical ventilation. It is therefore important that health professionals have the knowledge that their presence and their support of the relationship between...

  12. Airflow characteristics in the occupied zone of ventilated spaces

    DEFF Research Database (Denmark)

    Hanzawa, H.; Melikov, Arsen Krikor; Fanger, Povl Ole

    1987-01-01

    raft is one of the most common causes of complaint in ventilated or air-conditioned spaces. Therefore, knowing the turbulent airflow in these spaces and the impact of this flow on the sensation of draft is very important. The characteristics of turbulent flow (turbulence intensity, length scales...... of turbulence, turbulence kinetic energy, etc. ) were investigated in 20 typically ventilated spaces. Relationships between these characteristics and the mean velocity were found. The turbulence energy spectra are similar to those in a fully developed turbulent flow. The spectra reveal the major contribution...

  13. Empirical Antibiotic Therapy for Ventilator-Associated Pneumonia

    Directory of Open Access Journals (Sweden)

    Diana L. Wells

    2013-07-01

    Full Text Available Ventilator-associated pneumonia (VAP is the most common infectious complication in the intensive care unit. It can increase duration of mechanical ventilation, length of stay, costs, and mortality. Improvements in the administration of empirical antibiotic therapy have potential to reduce the complications of VAP. This review will discuss the current data addressing empirical antibiotic therapy and the effect on mortality in patients with VAP. It will also address factors that could improve the administration of empirical antibiotics and directions for future research.

  14. Large Eddy Simulation of the ventilated wave boundary layer

    DEFF Research Database (Denmark)

    Lohmann, Iris P.; Fredsøe, Jørgen; Sumer, B. Mutlu

    2006-01-01

    A Large Eddy Simulation (LES) of (1) a fully developed turbulent wave boundary layer and (2) case 1 subject to ventilation (i.e., suction and injection varying alternately in phase) has been performed, using the Smagorinsky subgrid-scale model to express the subgrid viscosity. The model was found...... size. The results indicate that the large eddies develop in the resolved scale, corresponding to fluid with an effective viscosity decided by the sum of the kinematic and subgrid viscosity. Regarding case 2, the results are qualitatively in accordance with experimental findings. Injection generally...... significantly. Ventilation therefore results in a net current, even in symmetric waves....

  15. Planning an outing from hospital for ventilator-dependent children.

    Science.gov (United States)

    Gilgoff, I S; Helgren, J

    1992-10-01

    Returning ventilator-dependent children to the home environment has become a well-accepted occurrence. The success of a home program depends on careful pre-discharge planning in order to ensure the child's medical safety, and adequate preparation to ensure the child's and family's adjustment to an active community life after discharge. To achieve this, involvement in community activities must begin while the child is still in hospital. As part of a complete rehabilitation program, nine ventilator-dependent children were taken on an inpatient outing to Disneyland. The planning and goals of the outing are described.

  16. Effects of ambient conditions on multi-capillary ventilation rate

    Directory of Open Access Journals (Sweden)

    Zhang Qing

    2016-01-01

    Full Text Available As a major physical parameter for the tobacco industry, the ventilation rate of cigarette should be measured reliably. Theoretical and numerical investigation on ef-fects of ambient conditions (e. g., cumulative flux of ozone and additional pressure drop on the ventilation rate was carried out. It was found that the standards exhibited a non-linear airflow component, which explains why additional pressure drop has an effect on the calibrated value, and had low sensitivity to cumulative flux of ozone.

  17. Adequacy of oxygenation parameters in elderly patients undergoing mechanical ventilation

    OpenAIRE

    Guedes, Luana Petruccio Cabral Monteiro; Delfino,Fabrício Costa; de Faria, Flavia Perassa; de Melo, Gislane Ferreira; Carvalho, Gustavo Azevedo

    2013-01-01

    ABSTRACT Objective: To compare ideal PaO2 with PaO2 found, ideal PaO2/FiO2 of room air with the one found, and ideal FiO2 with FiO2 found in mechanically ventilated elderly patients. Methods: Cross-sectional study that evaluated elderly mechanically ventilated patients for at least 72 hours and who underwent three subsequent blood gas analyses. Results: The sample consisted of 48 elderly with mean age of 74.77±9.36 years. There was a significant difference between the ideal PaO2 and the one f...

  18. Experimental study of diffuse ceiling ventilation in classroom

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Terkildsen, Søren

    conditions a classroom was retrofitted with mechanical ventilation and a diffuse ceiling. The employed ceiling comprises active panels penetrable to air and impenetrable passive panels. The performance was studied with regard to air movements, temperatures and air change efficiency at two different air...... changes. The experiments were carried out during class to obtain realistic conditions. At both airflows did the ceiling perform satisfactorily with air movements and temperatures within the requirements of indoor climate standards. The air change efficiency is comparable to conventional mixing ventilation....

  19. Design of Local Ventilation by Full-Scale and Scale Modelling Techniques

    OpenAIRE

    Nielsen, Peter V.

    1997-01-01

    This paper will show the experiments with local ventilation of a filling machine from the paint industry, local ventilation of a film developing machine, experiments with a vortex exhaust opening and local heating of a checkout assistant's working place.

  20. Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates (Final Report, 2009)

    Science.gov (United States)

    EPA announced the availability of the final report, Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates. This report provides a revised approach for calculating an individual's ventilation rate directly from their oxygen c...

  1. Predicting Delayed Ventilator Weaning after Lung Transplantation: The Role of Body Mass Index

    Directory of Open Access Journals (Sweden)

    Sarah Soh

    2014-11-01

    CONCLUSIONS: Low BMI might be associated with delayed ventilator weaning in lung transplantation patients. In addition, instead of the traditional weaning predictors of RSBI and RR, TV might be a better predictor for ventilator weaning after lung transplantation.

  2. Bortezomib partially protects the rat diaphragm from ventilator-induced diaphragm dysfunction

    NARCIS (Netherlands)

    Agten, A.; Maes, K.; Thomas, D.; Cielen, N.; Hees, H.W. van; Dekhuijzen, R.; Decramer, M.; Gayan-Ramirez, G.

    2012-01-01

    OBJECTIVE: Controlled mechanical ventilation leads to diaphragmatic contractile dysfunction and atrophy. Since proteolysis is enhanced in the diaphragm during controlled mechanical ventilation, we examined whether the administration of a proteasome inhibitor, bortezomib, would have a protective effe

  3. Antibiotics or probiotics as preventive measures against ventilator-associated pneumonia: a literature review

    NARCIS (Netherlands)

    Schultz, M.J.; Haas, L.E.

    2011-01-01

    Mechanically ventilated critically ill patients frequently develop ventilator-associated pneumonia (VAP), a life-threatening complication. Proposed preventive measures against VAP include, but are not restricted to, selective decontamination of the digestive tract (SDD), selective oropharyngeal deco

  4. Software Configuration Management Plan for the B-Plant Canyon Ventilation Control System

    Energy Technology Data Exchange (ETDEWEB)

    MCDANIEL, K.S.

    1999-08-31

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This Software Configuration Management Plan provides instructions for change control of the CVCS.

  5. Comparison of mixing and displacement ventilation in a low energy office building during heating season

    DEFF Research Database (Denmark)

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

    2014-01-01

    The present study investigated the performance of mixing and displacement ventilation systems in a low energy office building during heating season. Measurements were performed with regard to air distribution and ventilation effectiveness. The results show that indoor air temperatures in occupied....../s for both ventilation systems. In addition, local ventilation effectiveness ranged from 0.91 to 0.94 for mixing ventilation and from 1.03 to 1.17 for displacement ventilation. Distributions of vertical air temperature and velocity and horizontal contaminant concentration were more uniform for mixing...... ventilation compared to those for displacement ventilation. Due to the heat emission from equipments and occupants, heating system was not needed in the low energy office building in a mild winter. In such a situation, indoor thermal environment was still acceptable in terms of the general thermal comfort...

  6. A control system for mechanical ventilation of passive and active subjects.

    Science.gov (United States)

    Tehrani, Fleur T

    2013-06-01

    Synchronization of spontaneous breathing with breaths supplied by the ventilator is essential for providing optimal ventilation to patients on mechanical ventilation. Some ventilation techniques such as Adaptive Support Ventilation (ASV), Proportional Assist Ventilation (PAV), and Neurally Adjusted Ventilatory Assist (NAVA) are designed to address this problem. In PAV, the pressure support is proportional to the patient's ongoing effort during inspiration. However, there is no guarantee that the patient receives adequate ventilation. The system described in this article is designed to automatically control the support level in PAV to guarantee delivery of patient's required ventilation. This system can also be used to control the PAV support level based on the patient's work of breathing. This technique further incorporates some of the features of ASV to deliver mandatory breaths for passive subjects. The system has been tested by using computer simulations and the controller has been implemented by using a prototype.

  7. Assessing the influence of mechanical ventilation on blood gases and blood pressure in rattlesnakes

    DEFF Research Database (Denmark)

    Bertelsen, Mads F.; Buchanan, Rasmus; Jensen, Heidi M.

    2015-01-01

    , randomized trial. ANIMALS: Twenty one fasted adult South American rattlesnakes (Crotalus durissus terrificus). METHODS: Snakes were anesthetized with propofol (15 mg kg(-1) ) intravenously, endotracheally intubated and assigned to one of four ventilation regimens: Spontaneous ventilation, or mechanical...

  8. Comparison of mixing and displacement ventilation in a low energy office building during heating season

    DEFF Research Database (Denmark)

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

    2014-01-01

    The present study investigated the performance of mixing and displacement ventilation systems in a low energy office building during heating season. Measurements were performed with regard to air distribution and ventilation effectiveness. The results show that indoor air temperatures in occupied...... zone was 21.0°C for mixing ventilation and 20.8°C for displacement ventilation when supply air temperature was 19°C and air change rate was 4.2 h-. Vertical air temperature difference between the head level and the foot level were all less than 3°C and local air velocity were all less than 0.2m....../s for both ventilation systems. In addition, local ventilation effectiveness ranged from 0.91 to 0.94 for mixing ventilation and from 1.03 to 1.17 for displacement ventilation. Distributions of vertical air temperature and velocity and horizontal contaminant concentration were more uniform for mixing...

  9. Low cost of pulmonary ventilation in American alligators (Alligator mississippiensis) stimulated with doxapram.

    Science.gov (United States)

    Skovgaard, Nini; Crossley, Dane A; Wang, Tobias

    2016-04-01

    To determine the costs of pulmonary ventilation without imposing severe oxygen limitations or acidosis that normally accompany exposures to hypoxia or hypercapnia, we opted to pharmacologically stimulate ventilation with doxapram (5 and 10 mg kg(-1)) in alligators. Doxapram is used clinically to alleviate ventilatory depression in response to anaesthesia and acts primarily on the peripheral oxygen-sensitive chemoreceptors. Using this approach, we investigated the hypothesis that pulmonary ventilation is relatively modest in comparison to resting metabolic rate in crocodilians and equipped seven juvenile alligators with masks for concurrent determination of ventilation and oxygen uptake. Doxapram elicited a dose-dependent and up to fourfold rise in ventilation, primarily by increasing ventilatory frequency. The accompanying rise in oxygen uptake was very small; ventilation in resting animals constitutes no more than 5% of resting metabolic rate. The conclusion that pulmonary ventilation is energetically cheap is consistent with earlier studies on alligators where ventilation was stimulated by hypoxia or hypercapnia.

  10. Performance of "ductless" personalized ventilation in conjunction with displacement ventilation: Impact of disturbances due to walking person(s)

    DEFF Research Database (Denmark)

    Halvonova, Barbara; Melikov, Arsen Krikor

    2010-01-01

    The performance of the novel "ductless" personalized ventilation in conjunction with displacement ventilation (DV) was compared with the performance of DV alone under realistic conditions involving disturbances due to walking of one or two persons. An office room with two workstations was arranged...... in a full-scale test room. Two thermal manikins were used as sedentary occupants at the workstations. Two pollution sources, namely exhaled air by one of the manikins and passive pollution on the table in front of the same manikin were simulated. The performance of the ventilation systems was evaluated...... with regard to the quality of inhaled air and thermal comfort of the seated "occupants". The walking person(s) caused mixing of the clean and cool air near the floor with the polluted and warmer air at higher levels and disturbed the displacement principle which resulted in a decrease of the inhaled air...

  11. Implications of Natural Occlusion of Ventilated Racks on Ammonia and Sanitation Practices

    OpenAIRE

    Creamer, Michelle A; Petty, Joann; Martin, Tara,; Bergdall, Valerie; Hickman-Davis, Judy M.

    2014-01-01

    Examination of ventilated rat racks prior to semiannual sanitation revealed silicone nozzles and ventilation ports that were partially or completely occluded with granular debris. We subsequently sought to document performance standards for rack sanitation and investigate the effect of ventilation port occlusion on rack function and animal husbandry practices. We hypothesized that individually ventilated cages with occluded airflow would require more frequent cage changes, comparable to those...

  12. Impact of enhanced ventilator care bundle checklist on nursing documentation in an intensive care unit.

    Science.gov (United States)

    Malouf-Todaro, Nabia; Barker, James; Jupiter, Daniel; Tipton, Phyllis Hart; Peace, Jane

    2013-01-01

    Ventilator-associated pneumonia is a hospital-acquired infection that may develop in patients 48 hours after mechanical ventilation. The project goal was to determine whether a ventilator-associated pneumonia care bundle checklist embedded into an existing electronic health record would increase completeness of nursing documentation in an intensive care unit setting. With the embedded checklist, there were significant improvements in nursing documentation and a decreased incidence of ventilator-associated pneumonia.

  13. Applied analysis of ventilation technology in residential buildings in Changjiang river valley

    Institute of Scientific and Technical Information of China (English)

    杨露露; 卢军; 王曦; 甘灵丽

    2009-01-01

    Making the use of ventilation technology may decrease building energy consumption,improve indoor thermal environment,and ameliorate indoor air quality. Combining with the meteorological characteristics in the Changjiang river valley and focusing on Chongqing,this work makes an applied analysis of the feasibility of intermittent mechanical ventilation. By comparison of various ventilation modes,it gives a summary of the suitable ventilation ways for different weather conditions with the combination of testing data and experimental data.

  14. Elective use of the Ventrain for upper airway obstruction during high-frequency jet ventilation.

    Science.gov (United States)

    Fearnley, Robert A; Badiger, Sheela; Oakley, Richard J; Ahmad, Imran

    2016-09-01

    The safety of high pressure source ventilation (jet ventilation) is dependent upon upper airway patency to facilitate adequate passive expiration and prevent increasing intrathoracic pressure and its associated deleterious sequelae. Distortions in airway anatomy may make passive expiration inadequate or impossible in some patients. We report the elective use of the Ventrain device to provide ventilation in a clinical setting of upper airway obstruction in a patient with post radiation fibrosis that had previously prevented passive expiration during attempted high pressure source ventilation.

  15. Management of critically ill patients receiving noninvasive and invasive mechanical ventilation in the emergency department

    Directory of Open Access Journals (Sweden)

    Rose L

    2012-03-01

    Full Text Available Louise RoseLawrence S Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, CanadaAbstract: Patients requiring noninvasive and invasive ventilation frequently present to emergency departments, and may remain for prolonged periods due to constrained critical care services. Emergency clinicians often do not receive the same education on management of mechanical ventilation or have similar exposure to these patients as do their critical care colleagues. The aim of this review was to synthesize the evidence on management of patients requiring noninvasive and invasive ventilation in the emergency department including indications, clinical applications, monitoring priorities, and potential complications. Noninvasive ventilation is recommended for patients with acute exacerbation of chronic obstructive pulmonary disease or cardiogenic pulmonary edema. Less evidence supports its use in asthma and other causes of acute respiratory failure. Use of noninvasive ventilation in the prehospital setting is relatively new, and some evidence suggests benefit. Monitoring priorities for noninvasive ventilation include response to treatment, respiratory and hemodynamic stability, noninvasive ventilation tolerance, detection of noninvasive ventilation failure, and identification of air leaks around the interface. Application of injurious ventilation increases patient morbidity and mortality. Lung-protective ventilation with low tidal volumes based on determination of predicted body weight and control of plateau pressure has been shown to reduce mortality in patients with acute respiratory distress syndrome, and some evidence exists to suggest this strategy should be used in patients without lung injury. Monitoring of the invasively ventilated patient should focus on assessing response to mechanical ventilation and other interventions, and avoiding complications, such as ventilator-associated pneumonia. Several key aspects of management of noninvasive

  16. The Role of Oral Care in Prevention of Ventilator Associated Pneumonia: A Literature Review

    OpenAIRE

    H Darvishi Khezri

    2014-01-01

    Introduction: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection reported among mechanical ventilation patients in intensive care units(ICU). Ventilator-associated pneumonia is associated with increased morbidity, mortality hospital, length of stay and health care costs. Oral health can be compromised by critical illness and by mechanical ventilation and thus, it deteriorates over time. A relationship exists between oral health status and VAP that is influenced by ...

  17. Mitogen-Activated Protein Kinases Regulate Susceptibility to Ventilator-Induced Lung Injury

    OpenAIRE

    2008-01-01

    BACKGROUND: Mechanical ventilation causes ventilator-induced lung injury in animals and humans. Mitogen-activated protein kinases have been implicated in ventilator-induced lung injury though their functional significance remains incomplete. We characterize the role of p38 mitogen-activated protein kinase/mitogen activated protein kinase kinase-3 and c-Jun-NH(2)-terminal kinase-1 in ventilator-induced lung injury and investigate novel independent mechanisms contributing to lung injury during ...

  18. A secondary source configuration for control of a ventilation fan noise in ducts

    OpenAIRE

    Čudina, Mirko; Prezelj, Jurij

    2015-01-01

    The main noise source in heating, ventilation, and air conditioning systems is usually a ventilating fan. Noise, generated by the ventilating fan is transmitted through the duct into the living and working environment. A typical fan noise spectrum consists of a broadband noise, which is superimposed with pure tones. Different methods are available to reduce a transmission of such noise from the ventilating fan into the living and working environment. In this article it is demonstrated how a f...

  19. Lung Injury After One-Lung Ventilation: A Review of the Pathophysiologic Mechanisms Affecting the Ventilated and the Collapsed Lung.

    Science.gov (United States)

    Lohser, Jens; Slinger, Peter

    2015-08-01

    Lung injury is the leading cause of death after thoracic surgery. Initially recognized after pneumonectomy, it has since been described after any period of 1-lung ventilation (OLV), even in the absence of lung resection. Overhydration and high tidal volumes were thought to be responsible at various points; however, it is now recognized that the pathophysiology is more complex and multifactorial. All causative mechanisms known to trigger ventilator-induced lung injury have been described in the OLV setting. The ventilated lung is exposed to high strain secondary to large, nonphysiologic tidal volumes and loss of the normal functional residual capacity. In addition, the ventilated lung experiences oxidative stress, as well as capillary shear stress because of hyperperfusion. Surgical manipulation and/or resection of the collapsed lung may induce lung injury. Re-expansion of the collapsed lung at the conclusion of OLV invariably induces duration-dependent, ischemia-reperfusion injury. Inflammatory cytokines are released in response to localized injury and may promote local and contralateral lung injury. Protective ventilation and volatile anesthesia lessen the degree of injury; however, increases in biochemical and histologic markers of lung injury appear unavoidable. The endothelial glycocalyx may represent a common pathway for lung injury creation during OLV, because it is damaged by most of the recognized lung injurious mechanisms. Experimental therapies to stabilize the endothelial glycocalyx may afford the ability to reduce lung injury in the future. In the interim, protective ventilation with tidal volumes of 4 to 5 mL/kg predicted body weight, positive end-expiratory pressure of 5 to 10 cm H2O, and routine lung recruitment should be used during OLV in an attempt to minimize harmful lung stress and strain. Additional strategies to reduce lung injury include routine volatile anesthesia and efforts to minimize OLV duration and hyperoxia.

  20. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    Directory of Open Access Journals (Sweden)

    Jícha M.

    2013-04-01

    Full Text Available The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.