WorldWideScience

Sample records for governing ventilation defects

  1. Factors governing the deep ventilation of the Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.

    2015-11-19

    A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red Sea. Historical and recent hydrographic data consistently indicate that the ventilation of the near-bottom layer in the Red Sea is a robust feature of the thermohaline circulation. Dense water capable to reach the bottom layers of the Red Sea can be regularly produced mostly inside the Gulfs of Aqaba and Suez. Occasionally, during colder than usual winters, deep water formation may also take place over coastal areas in the northernmost end of the open Red Sea just outside the Gulfs of Aqaba and Suez. However, the origin as well as the amount of deep waters exhibit considerable interannual variability depending not only on atmospheric forcing but also on the water circulation over the northern Red Sea. Analysis of several recent winters shows that the strength of the cyclonic gyre prevailing in the northernmost part of the basin can effectively influence the sea surface temperature (SST) and intensify or moderate the winter surface cooling. Upwelling associated with periods of persistent gyre circulation lowers the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme heat loss by the sea surface. In addition, the occasional persistence of the cyclonic gyre feeds the surface layers of the northern Red Sea with nutrients, considerably increasing the phytoplankton biomass.

  2. Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Svendsen, Sv Aa Højgaard

    1999-01-01

    The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger.......The note concerns ventilation in residential buildings. Describes components in ventilation systems, electric energy consumption and different ventilation systems with heat exchanger....

  3. Factors governing the deep ventilation of the Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.; Zhan, Peng; Sofianos, Sarantis S.; Raitsos, Dionysios E.; Qurban, Mohammed; Abualnaja, Yasser; Bower, Amy; Kontoyiannis, Harilaos; Pavlidou, Alexandra; Asharaf T.T., Mohamed; Zarokanellos, Nikolaos; Hoteit, Ibrahim

    2015-01-01

    A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red

  4. Spatial correspondence of 4D CT ventilation and SPECT pulmonary perfusion defects in patients with malignant airway stenosis

    Science.gov (United States)

    Castillo, Richard; Castillo, Edward; McCurdy, Matthew; Gomez, Daniel R.; Block, Alec M.; Bergsma, Derek; Joy, Sarah; Guerrero, Thomas

    2012-04-01

    To determine the spatial overlap agreement between four-dimensional computed tomography (4D CT) ventilation and single photon emission computed tomography (SPECT) perfusion hypo-functioning pulmonary defect regions in a patient population with malignant airway stenosis. Treatment planning 4D CT images were obtained retrospectively for ten lung cancer patients with radiographically demonstrated airway obstruction due to gross tumor volume. Each patient also received a SPECT perfusion study within one week of the planning 4D CT, and prior to the initiation of treatment. Deformable image registration was used to map corresponding lung tissue elements between the extreme component phase images, from which quantitative three-dimensional (3D) images representing the local pulmonary specific ventilation were constructed. Semi-automated segmentation of the percentile perfusion distribution was performed to identify regional defects distal to the known obstructing lesion. Semi-automated segmentation was similarly performed by multiple observers to delineate corresponding defect regions depicted on 4D CT ventilation. Normalized Dice similarity coefficient (NDSC) indices were determined for each observer between SPECT perfusion and 4D CT ventilation defect regions to assess spatial overlap agreement. Tidal volumes determined from 4D CT ventilation were evaluated versus measurements obtained from lung parenchyma segmentation. Linear regression resulted in a linear fit with slope = 1.01 (R2 = 0.99). Respective values for the average DSC, NDSC1 mm and NDSC2 mm for all cases and multiple observers were 0.78, 0.88 and 0.99, indicating that, on average, spatial overlap agreement between ventilation and perfusion defect regions was comparable to the threshold for agreement within 1-2 mm uncertainty. Corresponding coefficients of variation for all metrics were similarly in the range: 0.10%-19%. This study is the first to quantitatively assess 3D spatial overlap agreement between

  5. IMPACT UPON ENVIRONMENT PROTECTION DUE TO DEFECTIVELY PRODUCED AND OPERATED VENTILATION SYSTEMS IN FOOD INDUSTRY

    Directory of Open Access Journals (Sweden)

    Izabela Małecka

    2014-10-01

    Full Text Available Mechanical (air-conditioning ventilation systems and equipment in the food industry may transfer various pathogenic bacteria causing, for instance, pneumonia (Legionellosis. Microclimate parameters in manufacturing shops felt by people are affected by: human factors (health, individual temperature perception etc, and non-human factors (air physical parameters, air freshness and cleanliness etc.. Microbiological contamination of process equipment, machines and systems such as ventilation and air-conditioning equipment causes growth of pathogenic bacteria. The amount of air supplied and removed from a room depends on its use and load of odours and hazardous material. As a result of dew point formation in ventilation systems may appear the so-called air-borne condensation nuclei on which steam settles when the air gets oversaturated. The air flow rate has a material influence upon comfortable conditions in human inhabited zones. In manufacturing shops where the highest air quality is a priority, radial disinfection by means of catalytic ionization is applied. In food industry manufacturing shops of higher microbiological standard, ventilation systems based on air re-circulation should not be used.

  6. Impact of ventilation systems and energy savings in a building on the mechanisms governing the indoor radon activity concentration.

    Science.gov (United States)

    Collignan, Bernard; Powaga, Emilie

    2017-11-23

    For a given radon potential in the ground and a given building, the parameters affecting the indoor radon activity concentration (IRnAC) are indoor depressurization of a building and its air change rate. These parameters depend mainly on the building characteristics, such as airtightness, and on the nature and performances of the ventilation system. This study involves a numerical sensitivity assessment of the indoor environmental conditions on the IRnAC in buildings. A numerical ventilation model has been adapted to take into account the effects of variations in the indoor environmental conditions (depressurization and air change rate) on the radon entry rate and on the IRnAC. In the context of the development of a policy to reduce energy consumption in a building, the results obtained showed that IRnAC could be strongly affected by variations in the air permeability of the building associated with the ventilation regime. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. : ventilators for noninvasive ventilation

    OpenAIRE

    Fauroux , Brigitte; Leroux , Karl; Desmarais , Gilbert; Isabey , Daniel; Clément , Annick; Lofaso , Frédéric; Louis , Bruno

    2008-01-01

    International audience; The aim of the present study was to evaluate the performance characteristics of all the ventilators proposed for home noninvasive positive-pressure ventilation in children in France. The ventilators (one volume-targeted, 12 pressure-targeted and four dual) were evaluated on a bench which simulated six different paediatric ventilatory patterns. For each ventilator, the quality of the inspiratory and expiratory trigger and the ability to reach and maintain the preset pre...

  8. Ventilation systems

    International Nuclear Information System (INIS)

    Gossler

    1980-01-01

    The present paper deals with - controlled area ventilation systems - ventilation systems for switchgear-building and control-room - other ventilation systems for safety equipments - service systems for ventilation systems. (orig./RW)

  9. Mechanical Ventilation

    Science.gov (United States)

    ... ventilation is a life support treatment. A mechanical ventilator is a machine that helps people breathe when ... to breathe enough on their own. The mechanical ventilator is also called a ventilator , respirator, or breathing ...

  10. Anaesthesia ventilators

    Directory of Open Access Journals (Sweden)

    Rajnish K Jain

    2013-01-01

    Full Text Available Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV. PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits.

  11. Anaesthesia ventilators.

    Science.gov (United States)

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-09-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits.

  12. Anaesthesia ventilators

    Science.gov (United States)

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits. PMID:24249886

  13. Anaesthesia ventilators

    OpenAIRE

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bello...

  14. Displacement ventilation

    DEFF Research Database (Denmark)

    Kosonen, Risto; Melikov, Arsen Krikor; Mundt, Elisabeth

    The aim of this Guidebook is to give the state-of-the art knowledge of the displacement ventilation technology, and to simplify and improve the practical design procedure. The Guidebook discusses methods of total volume ventilation by mixing ventilation and displacement ventilation and it gives...... insights of the performance of the displacement ventilation. It also shows practical case studies in some typical applications and the latest research findings to create good local micro-climatic conditions....

  15. VENTILATION MODEL

    International Nuclear Information System (INIS)

    V. Chipman

    2002-01-01

    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

  16. [Anesthesia ventilators].

    Science.gov (United States)

    Otteni, J C; Beydon, L; Cazalaà, J B; Feiss, P; Nivoche, Y

    1997-01-01

    To review anaesthesia ventilators in current use in France by categories of ventilators. References were obtained from computerized bibliographic search. (Medline), recent review articles, the library of the service and personal files. Anaesthesia ventilators can be allocated into three groups, depending on whether they readminister expired gases or not or allow both modalities. Contemporary ventilators provide either constant volume ventilation, or constant pressure ventilation, with or without a pressure plateau. Ventilators readministering expired gases after CO2 absorption, or closed circuit ventilators, are either of a double- or a single-circuit design. Double-circuit ventilators, or pneumatical bag or bellows squeezers, or bag-in-bottle or bellows-in-bottle (or box) ventilators, consist of a primary, or driving circuit (bottle or box) and a secondary or patient circuit (including a bag or a bellows or membrane chambers). Bellows-in-bottle ventilators have either standing bellows ascending at expiration, or hanging bellows, descending at expiration. Ascending bellows require a positive pressure of about 2 cmH2O throughout exhalation to allow the bellows to refill. The expired gas volume is a valuable indicator for leak and disconnection. Descending bellows generate a slight negative pressure during exhalation. In case of leak or disconnection they aspirate ambient air and cannot act therefore as an indicator for integrity of the circuit and the patient connection. Closed circuit ventilators with a single-circuit (patient circuit) include a insufflating device consisting either in a bellows or a cylinder with a piston, operated by a electric or pneumatic motor. As the hanging bellows of the double circuit ventilators, they generate a slight negative pressure during exhalation and aspirate ambient air in case of leak or disconnection. Ventilators not designed for the readministration of expired gases, or open circuit ventilators, are generally stand

  17. Ventilation models

    Science.gov (United States)

    Skaaret, Eimund

    Calculation procedures, used in the design of ventilating systems, which are especially suited for displacement ventilation in addition to linking it to mixing ventilation, are addressed. The two zone flow model is considered and the steady state and transient solutions are addressed. Different methods of supplying air are discussed, and different types of air flow are considered: piston flow, plane flow and radial flow. An evaluation model for ventilation systems is presented.

  18. Industrial ventilation

    Science.gov (United States)

    Goodfellow, H. D.

    Industrial ventilation design methodology, using computers and using fluid dynamic models, is considered. It is noted that the design of a ventilation system must be incorporated into the plant design and layout at the earliest conceptual stage of the project. A checklist of activities concerning the methodology for the design of a ventilation system for a new facility is given. A flow diagram of the computer ventilation model shows a typical input, the initialization and iteration loop, and the output. The application of the fluid dynamic modeling techniques include external and internal flow fields, and individual sources of heat and contaminants. Major activities for a ventilation field test program are also addressed.

  19. Mine ventilation engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.J.

    1981-01-01

    This book on mine ventilation covers psychometrics, airflow through roadways and ducts, natural ventilation, fans, instruments, ventilation surveys, auxiliary ventilation, air quality, and planning and economics.

  20. Noninvasive ventilation.

    Science.gov (United States)

    Rabatin, J T; Gay, P C

    1999-08-01

    Noninvasive ventilation refers to the delivery of assisted ventilatory support without the use of an endotracheal tube. Noninvasive positive pressure ventilation (NPPV) can be delivered by using a volume-controlled ventilator, a pressure-controlled ventilator, a bilevel positive airway pressure ventilator, or a continuous positive airway pressure device. During the past decade, there has been a resurgence in the use of noninvasive ventilation, fueled by advances in technology and clinical trials evaluating its use. Several manufacturers produce portable devices that are simple to operate. This review describes the equipment, techniques, and complications associated with NPPV and also the indications for both short-term and long-term applications. NPPV clearly represents an important addition to the techniques available to manage patients with respiratory failure. Future clinical trials evaluating its many clinical applications will help to define populations of patients most apt to benefit from this type of treatment.

  1. 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.

  2. 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...

  3. 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.

  4. 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)

    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.

  5. 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-to-un...

  6. Behovstyret ventilation

    DEFF Research Database (Denmark)

    Afshari, Alireza; Heiselberg, Per; Reinhold, Claus

    2010-01-01

    I en nylig afsluttet undersøgelse er der udført en række målinger på otte udvalgte børneinstitutioner. Fire af disse med mekanisk ventilation og fire med naturlig ventilation. Formålet er at udvide den erfaringsbaserede viden om funktionen af naturlige og mekaniske ventilationsløsninger i...

  7. Ventilation Model

    International Nuclear Information System (INIS)

    Yang, H.

    1999-01-01

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future

  8. 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.

  9. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

    This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state-of-the-art of ventil......This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state......-of-the-art of ventilative cooling potentials and limitations, its consideration in current energy performance regulations, available building components and control strategies and analysis methods and tools. In addition, the report provides twenty six examples of operational buildings using ventilative cooling ranging from...

  10. Radioaerosol ventilation imaging in ventilator-dependent patients. Technical considerations

    International Nuclear Information System (INIS)

    Vezina, W.; Chamberlain, M.; Vinitski, S.; King, M.; Nicholson, R.; Morgan, W.K.

    1985-01-01

    The differentiation of pulmonary embolism (PE) from regional ventilatory abnormalities accompanied by reduced perfusion requires contemporary perfusion and ventilation studies. Distinguishing these conditions in ventilator-dependent patients is aided by administering a Tc-99m aerosol to characterize regional ventilation, and by performing a conventional Tc-99m MAA perfusion study. The technique uses a simple in-house constructed apparatus. Simple photographic techniques suffice, but computer subtraction of perfusion from the combined perfusion-ventilation image renders interpretation easier if aerosol administration follows perfusion imaging. Multiple defects can be examined in a single study. Excluding normal or near-normal perfusion studies, PE was thought to be present in eight of 16 patients after perfusion imaging alone, but in only one of eight after added aerosol imaging. Angiography confirmed the diagnosis in that patient. Of the eight patients who had abnormal perfusion but were thought unlikely to have PE from the perfusion study alone, two had normal ventilation, and subsequently were shown to have PE by angiography. Because angiography was only performed on patients who were thought to have a high probability of PE on sequential perfusion-ventilation imaging, the true incidence of PE may have been higher. Aerosol ventilation imaging is a useful adjunct to perfusion imaging in patients on ventilators. It requires an efficient delivery system, particularly if aerosol administration follows perfusion imaging, as it does in this study

  11. Liquid ventilation.

    Science.gov (United States)

    Sarkar, Suman; Paswan, Anil; Prakas, S

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. 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 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. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported.

  12. Personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfill the above requirements. This paper reviews...... 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...

  13. 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...

  14. 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...

  15. Ventilator-driven xenon ventilation studies

    International Nuclear Information System (INIS)

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-01-01

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

  16. 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...

  17. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as air diffuser to supply fresh air into the room. Compared with conventional ventilation systems, diffuse ceiling ventilation can significantly reduce or even eliminate draught risk due to the low...

  18. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  19. VENTILATION NEEDS DURING CONSTRUCTION

    International Nuclear Information System (INIS)

    C.R. Gorrell

    1998-01-01

    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

  20. Ventilation and filtration of active buildings

    International Nuclear Information System (INIS)

    Chapman, E.J.

    1975-12-01

    Over the last twenty years considerable practical experience has accumulated on the ventilation of buildings handling radioactive materials. It has been recognised that there is a need to establish a UKAEA code of practice in the light of this experience for the future use of designers and operators in this field. An attempt is made to lay down some of the principles governing the design of ventilation systems and, from the existing background data, to establish some of the basic design criteria. (author)

  1. Comparison of annual energy performances with different ventilation methods for cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhang; Lee, C.K.; Fong, Square; Chow, T.T.; Yao, Ting; Chan, A.L.S. [Building Energy and Environmental Technology Research Unit, School of Energy and Environment and Division of Building Science and Technology, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR (China)

    2011-01-15

    Stratum ventilation has been proposed to cope for elevated indoor temperatures recommended by governments in East Asia. TRNSYS is used for computation of the space cooling load and system energy consumption. Typical configurations of an office, a classroom and a retail shop in Hong Kong are investigated. Compared with mixing ventilation and displacement ventilation, stratum ventilation derives its energy saving potential largely from the following three factors: the reduction in ventilation and transmission loads and increased COP of chillers. The year-round energy saving is found to be substantial at 25% and 44% at least when compared with displacement ventilation and mixing ventilation, respectively. (author)

  2. Patient-Ventilator Dyssynchrony

    Directory of Open Access Journals (Sweden)

    Elvira-Markela Antonogiannaki

    2017-11-01

    Full Text Available In mechanically ventilated patients, assisted mechanical ventilation (MV is employed early, following the acute phase of critical illness, in order to eliminate the detrimental effects of controlled MV, most notably the development of ventilator-induced diaphragmatic dysfunction. Nevertheless, the benefits of assisted MV are often counteracted by the development of patient-ventilator dyssynchrony. Patient-ventilator dyssynchrony occurs when either the initiation and/or termination of mechanical breath is not in time agreement with the initiation and termination of neural inspiration, respectively, or if the magnitude of mechanical assist does not respond to the patient’s respiratory demand. As patient-ventilator dyssynchrony has been associated with several adverse effects and can adversely influence patient outcome, every effort should be made to recognize and correct this occurrence at bedside. To detect patient-ventilator dyssynchronies, the physician should assess patient comfort and carefully inspect the pressure- and flow-time waveforms, available on the ventilator screen of all modern ventilators. Modern ventilators offer several modifiable settings to improve patient-ventilator interaction. New proportional modes of ventilation are also very helpful in improving patient-ventilator interaction.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  4. Mechanical ventilator - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007240.htm Mechanical ventilator - infants To use the sharing features on this page, please enable JavaScript. A mechanical ventilator is a machine that assists with breathing. ...

  5. Learning about ventilators

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000458.htm Learning about ventilators To use the sharing features on this page, ... fixed or changed. How Does Being on a Ventilator Feel? A person receives medicine to remain comfortable ...

  6. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    Science.gov (United States)

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  7. Ventilation of nuclear facilities

    International Nuclear Information System (INIS)

    1982-01-01

    In this work an examination is made of ventilation problems in nuclear installations, of the fuel cycle or the handling of radioactive compounds. The study covers the detection of radioactive aerosols, purification, iodine trapping, ventilation equipment and its maintenance, engineering, safety of ventilation, fire efficiency, operation, regulations and normalization [fr

  8. Ventilation and ventilation/perfusion ratios

    International Nuclear Information System (INIS)

    Valind, S.O.

    1989-01-01

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

  9. Comparison of airway pressure release ventilation to conventional mechanical ventilation in the early management of smoke inhalation injury in swine.

    Science.gov (United States)

    Batchinsky, Andriy I; Burkett, Samuel E; Zanders, Thomas B; Chung, Kevin K; Regn, Dara D; Jordan, Bryan S; Necsoiu, Corina; Nguyen, Ruth; Hanson, Margaret A; Morris, Michael J; Cancio, Leopoldo C

    2011-10-01

    The role of airway pressure release ventilation in the management of early smoke inhalation injury has not been studied. We compared the effects of airway pressure release ventilation and conventional mechanical ventilation on oxygenation in a porcine model of acute respiratory distress syndrome induced by wood smoke inhalation. Prospective animal study. Government laboratory animal intensive care unit. Thirty-three Yorkshire pigs. Smoke inhalation injury. Anesthetized female Yorkshire pigs (n = 33) inhaled room-temperature pine-bark smoke. Before injury, the pigs were randomized to receive conventional mechanical ventilation (n = 15) or airway pressure release ventilation (n = 12) for 48 hrs after smoke inhalation. As acute respiratory distress syndrome developed (PaO2/Fio2 ratio conventional mechanical ventilation for 48 hrs and served as time controls. Changes in PaO2/Fio2 ratio, tidal volume, respiratory rate, mean airway pressure, plateau pressure, and hemodynamic variables were recorded. Survival was assessed using Kaplan-Meier analysis. PaO2/Fio2 ratio was lower in airway pressure release ventilation vs. conventional mechanical ventilation pigs at 12, 18, and 24 hrs (p conventional mechanical ventilation animals between 30 and 48 hrs post injury (p animals between 6 and 48 hrs (p conventional mechanical ventilation and airway pressure release ventilation pigs. In this model of acute respiratory distress syndrome caused by severe smoke inhalation in swine, airway pressure release ventilation-treated animals developed acute respiratory distress syndrome faster than conventional mechanical ventilation-treated animals, showing a lower PaO2/Fio2 ratio at 12, 18, and 24 hrs after injury. At other time points, PaO2/Fio2 ratio was not different between conventional mechanical ventilation and airway pressure release ventilation.

  10. 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.

  11. Evaluation of ventilators for mouthpiece ventilation in neuromuscular disease.

    Science.gov (United States)

    Khirani, Sonia; Ramirez, Adriana; Delord, Vincent; Leroux, Karl; Lofaso, Frédéric; Hautot, Solène; Toussaint, Michel; Orlikowski, David; Louis, Bruno; Fauroux, Brigitte

    2014-09-01

    Daytime mouthpiece ventilation is a useful adjunct to nocturnal noninvasive ventilation (NIV) in patients with neuromuscular disease. The aims of the study were to analyze the practice of mouthpiece ventilation and to evaluate the performance of ventilators for mouthpiece ventilation. Practice of mouthpiece ventilation was assessed by a questionnaire, and the performance of 6 home ventilators with mouthpiece ventilation was assessed in a bench test using 24 different conditions per ventilator: 3 mouthpieces, a child and an adult patient profile, and 4 ventilatory modes. Questionnaires were obtained from 30 subjects (mean age 33 ± 11 y) using NIV for 12 ± 7 y. Fifteen subjects used NIV for > 20 h/day, and 11 were totally ventilator-dependent. The subject-reported benefits of mouthpiece ventilation were a reduction in dyspnea (73%) and fatigue (93%) and an improvement in speech (43%) and eating (27%). The bench study showed that none of the ventilators, even those with mouthpiece ventilation software, were able to deliver mouthpiece ventilation without alarms and/or autotriggering in each condition. Alarms and/or ineffective triggering or autotriggering were observed in 135 of the 198 conditions. The occurrence of alarms was more common with a large mouthpiece without a filter compared to a small mouthpiece with a filter (P ventilator. Subjects are satisfied with mouthpiece ventilation. Alarms are common with home ventilators, although less common in those with mouthpiece ventilation software. Improvements in home ventilators are needed to facilitate the expansion of mouthpiece ventilation. Copyright © 2014 by Daedalus Enterprises.

  12. Protective garment ventilation system

    Science.gov (United States)

    Lang, R. (Inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  13. Ventilation rates and health

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  14. Ventilation of uranium mines

    International Nuclear Information System (INIS)

    Francois, Y.; Pradel, J.; Zettwoog, P.; Dumas, M.

    1975-01-01

    In the first part of the paper the authors describe the ventilation of French mines in terms of the primary ventilation system, which brings the outside air close to the working places using the overall structure of the mine to form the airways, and the secondary ventilation system, which is for the distribution of the primary air or for the ventilation of the development drifts and blind tunnels. Brief mention is made of the French regulations on the ventilation of mines in general and uranium mines in particular. The authors describe the equipment used and discuss the installed capacities and air flow per man and per working place. The difficulties encountered in properly ventilating various types of working places are mentioned, such as sub-level development drifts, reinforced stopes, and storage chambers with an artificial crown. The second part of the paper is devoted to computer calculations of the primary ventilation system. It is explained why the Commissariat a l'energie atomique has found it necessary to make these calculations. Without restating the mathematical theories underlying the methods employed, the authors demonstrate how simple measuring instruments and a small-size computer can be used to solve the ventilation problems arising in French mines. Emphasis is given to the layout of the ventilation system and to air flow and negative pressure measurements at the base of the mine. The authors show how calculations can be applied to new heading operations, a change in resistance, the replacement or addition of a ventilator, and a new air inlet or outlet. The authors come to the conclusion that since ventilation is at present the most reliable way of avoiding the pollution of mines, a thorough knowledge of the capabilities in this respect can often help improve working conditions. Despite the progress made, however, constant surveillance of the ventilation systems in uranium mines by a separate team with no responsibility for production problems is

  15. Ventilation of uranium mines

    International Nuclear Information System (INIS)

    Francois, Y.; Pradel, J.; Zettwoog, P.; Dumas, M.

    1975-01-01

    In the first part of the paper the authors describe the ventilation of French mines in terms of the primary ventilation system, which brings the outside air close to the working places using the overall structure of the mine to form the airways, and the secondary ventilation system, which is for the distribution of the primary air or for the ventilation of the development drifts and blind tunnels. Brief mention is made of the French regulations on the ventilation of mines in general and uranium mines in particular. The authors describe the equipment used and discuss the installed capacities and air flow per man and per working place. The difficulties encountered in properly ventilating various types of working places are mentioned, such as sublevel development drifts, reinforced stopes, and storage chambers with an artificial crown. The second part of the paper is devoted to computer calculations of the primary ventilation system. It is explained why the Commissariat a l'energie atomique has found it necessary to make these calculations. Without restating the mathematical theories underlying the methods employed, the authors demonstrate how simple measuring instruments and a small-size computer can be used to solve the ventilation problems arising in French mines. Emphasis is given to the layout of the ventilation system and to air flow and negative pressure measurements at the base of the mine. The authors show how calculations can be applied to new heading operations, a change in resistance, the replacement or addition of a ventilator, and a new air inlet or outlet. The authors come to the conclusion that since ventilation is at present the most reliable way of avoiding the pollution of mines, a thorough knowledge of the capabilities in this respect can often help improve working conditions. Despite the progress made, however, constant surveillance of the ventilation systems in uranium mines by a separate team with no responsibility for production problems is

  16. 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....

  17. 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....

  18. Pulmonary ventilation studies of asthmatic children with Kr-81m

    International Nuclear Information System (INIS)

    Uchiyama, Guio; Hotta, Toshiko; Arimizu, Noboru; Sugimoto, Kazuo.

    1979-01-01

    Krypton-81 m gas was eluted from the 81 Rb-sup(81m)Kr generator by using compressed air or oxygen as an eluting agent. The continuous inhalation of mixed gas of sup(81m)Kr and air or oxygen with the use of a scintillation camera produced a pulmonary image of which density was proportional to regional ventilation. Because of short half life of sup(81m)Kr (13 seconds), exhaled gas was not necessary to be trapped by the charcoal filter, and the several pulmonary views of a patient could readily be available in a short period of time. The great advantage of sup(81m)Kr generator was found in use for the studies of small children who were not usually cooperative to medical examination. Thirty seven patients with bronchial asthma of any state were so far studied. Their ages ranged from 3 to 15 years old. Studies revealed the definite ventilation defects in scans of patients with asthmatic attack. Re-scans right after the use of bronchodilators showed marked improvement of the ventilation defects. Exercise-induced asthma (EIA) was easily identified by the sup(81m)Kr ventilation study. After premedications for EIA with disodium cromoglicate, the next exercises produced less or no ventilation defects, and the preventive effect could be individually examined. The sup(81m)Kr ventilation study was also used for estimating the patient's sensitivity to provokative substances of bronchial asthma. House dust was continuously inhaled with sup(81m)Kr gas by patients. The threshold dose of house dust of disclosing ventilation defects in scans was definitely less than that of provokating the symptom of asthmatic attack. The sensitive sup(81m)Kr ventilation study could be another provokative test which induces no clinical symptoms. (author)

  19. Pulmonary ventilation studies of asthmatic children with Kr-81m

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, G; Hotta, T; Arimizu, N [Chiba Univ. (Japan). School of Medicine; Sugimoto, K

    1979-05-01

    Krypton-81 m gas was eluted from the /sup 81/Rb-sup(81m)Kr generator by using compressed air or oxygen as an eluting agent. The continuous inhalation of mixed gas of sup(81m)Kr and air or oxygen with the use of a scintillation camera produced a pulmonary image of which density was proportional to regional ventilation. Because of short half life of sup(81m)Kr (13 seconds), exhaled gas was not necessary to be trapped by the charcoal filter, and the several pulmonary views of a patient could readily be available in a short period of time. The great advantage of sup(81m)Kr generator was found in use for the studies of small children who were not usually cooperative to medical examination. Thirty seven patients with bronchial asthma of any state were so far studied. Their ages ranged from 3 to 15 years old. Studies revealed the definite ventilation defects in scans of patients with asthmatic attack. Re-scans right after the use of bronchodilators showed marked improvement of the ventilation defects. Exercise-induced asthma (EIA) was easily identified by the sup(81m)Kr ventilation study. After premedications for EIA with disodium cromoglicate, the next exercises produced less or no ventilation defects, and the preventive effect could be individually examined. The sup(81m)Kr ventilation study was also used for estimating the patient's sensitivity to provokative substances of bronchial asthma. House dust was continuously inhaled with sup(81m)Kr gas by patients. The threshold dose of house dust of disclosing ventilation defects in scans was definitely less than that of provokating the symptom of asthmatic attack. The sensitive sup(81m)Kr ventilation study could be another provokative test which induces no clinical symptoms. (author).

  20. Birth Defects

    Science.gov (United States)

    A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

  1. Norwegian Pitched Roof Defects

    Directory of Open Access Journals (Sweden)

    Lars Gullbrekken

    2016-06-01

    Full Text Available The building constructions investigated in this work are pitched wooden roofs with exterior vertical drainpipes and wooden load-bearing system. The aim of this research is to further investigate the building defects of pitched wooden roofs and obtain an overview of typical roof defects. The work involves an analysis of the building defect archive from the research institute SINTEF Building and Infrastructure. The findings from the SINTEF archive show that moisture is a dominant exposure factor, especially in roof constructions. In pitched wooden roofs, more than half of the defects are caused by deficiencies in design, materials, or workmanship, where these deficiencies allow moisture from precipitation or indoor moisture into the structure. Hence, it is important to increase the focus on robust and durable solutions to avoid defects both from exterior and interior moisture sources in pitched wooden roofs. Proper design of interior ventilation and vapour retarders seem to be the main ways to control entry from interior moisture sources into attic and roof spaces.

  2. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis

    International Nuclear Information System (INIS)

    Bourke, S.J.; Hawkins, T.; Keavey, P.M.; Gascoigne, A.D.; Corris, P.A.

    1993-01-01

    There is increasing interest in ventilation perfusion (V/Q) imaging in cryptogenic fibrosing alveolitis because of the data these scans provide on the dynamic V/Q relationships in such patients undergoing single lung transplantation. We analysed the V/Q scans of 45 consecutive patients with advanced cryptogenic fibrosing alveolitis being considered for single lung transplantation. Scans were classified according to the presence, severity and degree of matching of defects in ventilation and perfusion images and the results were compared with the data obtained from lung function tests. Ventilation images showed defects in 13 (29%) and ''washout delay'' in 15 (33%) patients; 10 (22%) patients had asymmetric distribution of ventilation with one lung receiving >60% of total ventilation. Perfusion images showed normal perfusion in 8 (18%), mild defects in 18 (40%) and major defects in 19 (42%) patients. The distribution of perfusion between lungs was significantly asymmetric in 20 (45%) patients. V/Q images were matched in 15 (33%), mildly mismatched in 15 (33%) and severely mismatched in 15 (33%) patients, but the degree of V/Q mismatch did not show a relationship to KCO, PaO 2 or A-aO 2 gradient. The appearances were atypical of pulmonary embolism in eight patients. (Author)

  3. Styret naturlig ventilation

    DEFF Research Database (Denmark)

    Morsing, S.; Strøm, J.S.

    Publikationen præsenterer et generelt dimensioneringsgrundlag for naturlig ventilation i husdyrstalde. Det er kontrolleret ved forsøg i slagtesvinestalde, hvor det ligeledes er undersøgt hvilken temperaturstabilitet, der kan opnås ved naturlig ventilation, samt produktions- og adfærdsmæssige...

  4. 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.

  5. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

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

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role...

  6. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

    1983-01-01

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

  7. Realtime mine ventilation simulation

    International Nuclear Information System (INIS)

    McDaniel, K.H.

    1997-01-01

    This paper describes the development of a Windows based, interactive mine ventilation simulation software program at the Waste Isolation Pilot Plant (WIPP). To enhance the operation of the underground ventilation system, Westinghouse Electric Corporation developed the program called WIPPVENT. While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC and uses the same subroutine to calculate airflow distributions, the user interface has been completely rewritten as a Windows application with screen graphics. WIPPVENT is designed to interact with WIPP ventilation monitoring systems through the sitewise Central monitoring System. Data can be continuously collected from the Underground Ventilation Remote Monitoring and Control System (e.g., air quantity and differential pressure) and the Mine Weather Stations (psychrometric data). Furthermore, WIPPVENT incorporates regulator characteristic curves specific to the site. The program utilizes this data to create and continuously update a REAL-TIME ventilation model. This paper discusses the design, key features, and interactive capabilities of WIPPVENT

  8. Ventilating Air-Conditioner

    Science.gov (United States)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  9. Defect modelling

    International Nuclear Information System (INIS)

    Norgett, M.J.

    1980-01-01

    Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK)

  10. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    OpenAIRE

    Sherman, Max H.

    2011-01-01

    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 outd...

  11. 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.

  12. What Is a Ventilator?

    Science.gov (United States)

    ... who are on ventilators for shorter periods. The advantage of this tube is that it can be ... other disease or condition. VAP is treated with antibiotics. You may need special antibiotics if the VAP ...

  13. Uranium mine ventilation

    International Nuclear Information System (INIS)

    Katam, K.; Sudarsono

    1982-01-01

    Uranium mine ventilation system aimed basically to control and decreasing the air radioactivity in mine caused by the radon emanating from uranium ore. The control and decreasing the air ''age'' in mine, with adding the air consumption volume, increasing the air rate consumption, closing the mine-out area; using closed drainage system. Air consumption should be 60m 3 /minute for each 9m 2 uranium ore surfaces with ventilation rate of 15m/minute. (author)

  14. Fire, safety and ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, D.

    1999-02-01

    Correct ventilation in tunnel environments is vital for the comfort and safety of the people passing through. This article gives details of products from several manufacturers of safety rescue and fire fighting equipment, fire and fume detection equipment, special fire resistant materials, fire resistant hydraulic oils and fire dampers, and ventilation systems. Company addresses and fax numbers are supplied. 4 refs., 5 tabs., 10 photos.

  15. 'Good Governance' dan 'Governability'

    Directory of Open Access Journals (Sweden)

    - Pratikno

    2005-03-01

    Full Text Available The article endeavors to trace the outset of governance concept, its dominant meanings and discourse, and its implication towards governability. The central role of government in the governing processes has predominantly been adopted. The concept of governance was emerged precisely in the context of the failure of government as key player in regulation, economic redistribution and political participation. Governance is therefore aimed to emphasize pattern of governing which are based both on democratic mechanism and sound development management. However, practices of such good governance concept –which are mainly adopted and promoted by donor states and agencies– tend to degrade state and/or government authority and legitimacy. Traditional function of the state as sole facilitator of equal societal, political and legal membership among citizens has been diminished. The logic of fair competition has been substituted almost completely by the logic of free competition in nearly all sectors of public life. The concept and practices of good governance have resulted in decayed state authority and failed state which in turn created a condition for "ungovernability". By promoting democratic and humane governance, the article accordingly encourages discourse to reinstall and bring the idea of accountable state back in.

  16. Demand Controlled Ventilation in a Combined Ventilation and Radiator System

    OpenAIRE

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    With growing concerns for efficient and sustainable energy treatment in buildings there is a need for balanced and intelligent ventilation solutions. This paper presents a strategy for demand controlled ventilation with ventilation radiators, a combined heating and ventilation system. The ventilation rate was decreased from normal requirements (per floor area) of 0.375 l·s-1·m-2 to 0.100 l·s-1·m-2 when the residence building was un-occupied. The energy saving potential due to decreased ventil...

  17. Clinical challenges in mechanical ventilation.

    Science.gov (United States)

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

    2016-04-30

    Mechanical ventilation supports gas exchange and alleviates the work of breathing when the respiratory muscles are overwhelmed by an acute pulmonary or systemic insult. Although mechanical ventilation is not generally considered a treatment for acute respiratory failure per se, ventilator management warrants close attention because inappropriate ventilation can result in injury to the lungs or respiratory muscles and worsen morbidity and mortality. Key clinical challenges include averting intubation in patients with respiratory failure with non-invasive techniques for respiratory support; delivering lung-protective ventilation to prevent ventilator-induced lung injury; maintaining adequate gas exchange in severely hypoxaemic patients; avoiding the development of ventilator-induced diaphragm dysfunction; and diagnosing and treating the many pathophysiological mechanisms that impair liberation from mechanical ventilation. Personalisation of mechanical ventilation based on individual physiological characteristics and responses to therapy can further improve outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Regional ventilation/perfusion mismatch pattern in patient with Swyer James (MacLeod′s syndrome

    Directory of Open Access Journals (Sweden)

    Sait Sager

    2014-01-01

    Full Text Available Swyer James (McLeod′s syndrome (SJMS is an uncommon disease, which occurs as a result of childhood bronchiolitis obliterans. Patients may not be diagnosed until later in their life. A 46-year-old man underwent ventilation/perfusion scintigraphy for acute onset of dyspnea. The scan showed markedly diminished ventilation and perfusion unilaterally on the right middle and inferior lobes. However, mismatched ventilation-perfusion pattern was shown on the upper right lobe, which was consistent with pulmonary embolism. Unilaterally matched ventilation/perfusion defect can see in SJMS in lung scintigraphy; however, when pulmoner embolism may accompany, scintigraphy should be carefully examined.

  19. Ventilation of radioactive enclosures

    International Nuclear Information System (INIS)

    Caminade, F.; Laurent, H.

    1957-01-01

    Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m 3 ). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author) [fr

  20. Mechanical ventilation strategies.

    Science.gov (United States)

    Keszler, Martin

    2017-08-01

    Although only a small proportion of full term and late preterm infants require invasive respiratory support, they are not immune from ventilator-associated lung injury. The process of lung damage from mechanical ventilation is multifactorial and cannot be linked to any single variable. Atelectrauma and volutrauma have been identified as the most important and potentially preventable elements of lung injury. Respiratory support strategies for full term and late preterm infants have not been as thoroughly studied as those for preterm infants; consequently, a strong evidence base on which to make recommendations is lacking. The choice of modalities of support and ventilation strategies should be guided by the specific underlying pathophysiologic considerations and the ventilatory approach must be individualized for each patient based on the predominant pathophysiology at the time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. [Ventilator associated pneumonia].

    Science.gov (United States)

    Bellani, S; Nesci, M; Celotto, S; Lampati, L; Lucchini, A

    2003-04-01

    Ventilator associated pneumonia (VAP) is a nosocomial lower respiratory tract infection that ensues in critically ill patients undergoing mechanical ventilation. The reported incidence of VAP varies between 9% and 68% with a mortality ranging between 33% and 71%. Two key factors are implicated in the pathogenesis of VAP: bacterial colonization of the upper digestive-respiratory tract and aspiration of oral secretions into the trachea. Preventive measurements are advocated to reduce the incidence of VAP, such as selective decontamination of the digestive tract (SDD), supraglottic aspiration and positioning. Prompt recognition and treatment of established VAP has also been demostrated to affect outcome. Therefore, the knowledge of risk factors associated with the development of VAP and the implementation of strategies to prevent, diagnose and treat VAP are mainstems in the nursing of mechanically ventilated patients.

  2. 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 scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize...... the growing need for CFD verification and validation, suggest on-going needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical...

  3. Auxiliary mine ventilation manual

    International Nuclear Information System (INIS)

    Workplace Safety North

    2010-01-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  4. Auxiliary mine ventilation manual

    Energy Technology Data Exchange (ETDEWEB)

    Workplace Safety North

    2010-07-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  5. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  6. Behovstyret ventilation til enfamiliehuse

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian; Hansen, Mads Peter Rudolph

    Muligheden for behovsstyret ventilation i enfamiliehuse er undersøgt. To strategier er afprøvet i praksis: En relativ simpel og billig strategi og en relativ avanceret og dyr strategi. Den simple strategi regulerer luftskiftet ensartet for alle rum mellem et lavt eller højt niveau. Den avancerede...... ventilation efter gældende krav. Desuden kræver den simple regulering kun få sensorer og er således væsentlig billigere og enklere at implementere end den avancerede strategi....

  7. Bench performance of ventilators during simulated paediatric ventilation.

    Science.gov (United States)

    Park, M A J; Freebairn, R C; Gomersall, C D

    2013-05-01

    This study compares the accuracy and capabilities of various ventilators using a paediatric acute respiratory distress syndrome lung model. Various compliance settings and respiratory rate settings were used. The study was done in three parts: tidal volume and FiO2 accuracy; pressure control accuracy and positive end-expiratory pressure (PEEP) accuracy. The parameters set on the ventilator were compared with either or both of the measured parameters by the test lung and the ventilator. The results revealed that none of the ventilators could consistently deliver tidal volumes within 1 ml/kg of the set tidal volume, and the discrepancy between the delivered volume and the volume measured by the ventilator varied greatly. The target tidal volume was 8 ml/kg, but delivered tidal volumes ranged from 3.6-11.4 ml/kg and the volumes measured by the ventilator ranged from 4.1-20.6 ml/kg. All the ventilators maintained pressure within 20% of the set pressure, except one ventilator which delivered pressures of up to 27% higher than the set pressure. Two ventilators maintained PEEP within 10% of the prescribed PEEP. The majority of the readings were also within 10%. However, three ventilators delivered, at times, PEEPs over 20% higher. In conclusion, as lung compliance decreases, especially in paediatric patients, some ventilators perform better than others. This study highlights situations where ventilators may not be able to deliver, nor adequately measure, set tidal volumes, pressure, PEEP or FiO2.

  8. 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)

  9. Battery life of portable home ventilators: effects of ventilator settings.

    Science.gov (United States)

    Falaize, Line; Leroux, Karl; Prigent, Hélène; Louis, Bruno; Khirani, Sonia; Orlikowski, David; Fauroux, Brigitte; Lofaso, Frédéric

    2014-07-01

    The battery life (BL) of portable home ventilator batteries is reported by manufacturers. The aim of this study was to evaluate the effects of ventilator mode, breathing frequency, PEEP, and leaks on the BL of 5 commercially available portable ventilators. The effects of the ventilator mode (volume controlled-continuous mandatory ventilation [VC-CMV] vs pressure support ventilation [PSV]), PEEP 5 cm H2O, breathing frequency (10, 15, and 20 breaths/min), and leaks during both volume-targeted ventilation and PSV on the BL of 5 ventilators (Elisée 150, Monnal T50, PB560, Vivo 50, and Trilogy 100) were evaluated. Each ventilator was ventilated with a test lung at a tidal volume of 700 ml and an inspiratory time of 1.2 s in the absence of leaks. Switching from PSV to VC-CMV or the addition of PEEP did not significantly change ventilator BL. The increase in breathing frequency from 10 to 20 breaths/min decreased the BL by 18 ± 11% (P = .005). Leaks were associated with an increase in BL during the VC-CMV mode (18 ± 20%, P = .04) but a decrease in BL during the PSV mode (-13 ± 15%, P = .04). The BL of home ventilators depends on the ventilator settings. BL is not affected by the ventilator mode (VC-CMV or PSV) or the addition of PEEP. BL decreases with an increase in breathing frequency and during leaks with a PSV mode, whereas leaks increase the duration of ventilator BL during VC-CMV. Copyright © 2014 by Daedalus Enterprises.

  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. 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

  12. How to Plan Ventilation Systems.

    Science.gov (United States)

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  13. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, P.; Nielsen, Peter Vilhelm

    The main objective of ventilation is to provide good air quality for the occupants. For this purpose the necessary ventilating air change rate must be determined. Within displacement ventilation the estimation is closely related to the air flow rate in the thermal plumes when an air quality based...

  14. The amazing Minivent ventilator

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia is co-published by Medpharm Publications, NISC (Pty) Ltd and Cogent, ... Respiratory rate was obtained by counting the clicking noise ... was appointed as a part-time lecturer to the University of the ... The Minivent became the first of three miniature ventilators that.

  15. Omnidirectional ventilated acoustic barrier

    Science.gov (United States)

    Zhang, Hai-long; Zhu, Yi-fan; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-chun

    2017-11-01

    As an important problem in acoustics, sound insulation finds applications in a great variety of situations. In the existing schemes, however, there has always been a trade-off between the thinness of sound-insulating devices and their ventilating capabilities, limiting their potentials in the control of low-frequency sound in high ventilation environments. Here, we design and experimentally implement an omnidirectional acoustic barrier with a planar profile, subwavelength thickness ( 0.18 λ ), yet high ventilation. The proposed mechanism is based on the interference between the resonant scattering of discrete states and the background scattering of continuous states which induces a Fano-like asymmetric transmission profile. Benefitting from the binary-structured design of the coiled unit and hollow pipe, it maximally simplifies the design and fabrication while ensuring the ventilation for all the non-resonant units with open tubes. The simulated and measured results agree well, showing the effectiveness of our proposed mechanism to block low frequency sound coming from various directions while allowing 63% of the air flow to pass. We anticipate our design to open routes to design sound insulators and to enable applications in traditionally unattainable cases such as those calling for noise reduction and cooling simultaneously.

  16. Mechanical ventilation of mice

    NARCIS (Netherlands)

    Schwarte, L. A.; Zuurbier, C. J.; Ince, C.

    2000-01-01

    Due to growing interest in murine functional genomics research, there is an increasing need for physiological stable in vivo murine models. Of special importance is support and control of ventilation by artificial respiration, which is difficult to execute as a consequence of the small size of the

  17. Lavt elforbrug til ventilation

    DEFF Research Database (Denmark)

    Jagemar, L.; Bergsøe, Niels Christian

    Rapporten giver gode råd om mulige energibesparelser og praktiske projekteringshensyn, som er forbundet med udformning af energieffektiv ventilation i ikke blot kontorbygninger, men i alle bygninger med komfortventilationsanlæg. I forbindelse med projektering af ventilationsanlæg har interessen...

  18. Understanding mechanical ventilators.

    Science.gov (United States)

    Chatburn, Robert L

    2010-12-01

    The respiratory care academic community has not yet adopted a standardized system for classifying and describing modes of ventilation. As a result, there is enough confusion that patient care, clinician education and even ventilator sales are all put at risk. This article summarizes a ventilator mode taxonomy that has been extensively published over the last 15 years. Specifically, the classification system has three components: a description of the control variables within breath; a description of the sequence of mandatory and spontaneous breaths; and a specification for the targeting scheme. This three-level specification provides scalability of detail to make the mode description appropriate for the particular need. At the bedside, we need only refer to a mode briefly using the first or perhaps first and second components. To distinguish between similar modes and brand names, we would need to include all components. This taxonomy uses the equation of motion for the respiratory system as the underlying theoretical framework. All terms relevant to describing modes of mechanical ventilation are defined in an extensive appendix.

  19. 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...

  20. Ventilation of nuclear power plants

    International Nuclear Information System (INIS)

    Madoyan, A.A.; Vlasik, V.F.

    1984-01-01

    Foundations and calculation methods of ventilation of rooms with different degree of heat and gas release with the change of operation mode of NPP main equipment, as well as problems of NPP site and adjoining area aerodynamics, have been presented. Systems of air ventilation and conditioning, cooling equipment, are considered. The main points of designing are described and determination of economic efficiency of the ventilation systems are made. Technical characteristics of the ventilators, conditioners, filters and air heaters used, are presented. Organization of adjustment, tests, operation and maintenance of the ventilation systems of NPP with RBMK and WWER-type reactors, is described

  1. 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....

  2. 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

  3. Defects and defect processes in nonmetallic solids

    CERN Document Server

    Hayes, W

    2004-01-01

    This extensive survey covers defects in nonmetals, emphasizing point defects and point-defect processes. It encompasses electronic, vibrational, and optical properties of defective solids, plus dislocations and grain boundaries. 1985 edition.

  4. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  5. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

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

    cooling capacity, energy saving, low investment cost and low noise level; while the limitations include condensation risk and the limit on the room geometry. Furthermore, the crucial design parameters are summarized and their effects on the system performance are discussed. In addition to the stand...... is not well structured with this system. These become the motivations in developing the design guide. This design guide aims to establish a systematic understanding of diffuse ceiling ventilation and provide assistance in designing of such a system. The guide is targeted at design engineers, architects...... and manufacturers and the users of diffuse ceiling technology. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation. It provides an overview of potential benefit and limitations of this technology. The benefits include high thermal comfort, high...

  6. Harnessing natural ventilation benefits.

    Science.gov (United States)

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers.

  7. Purge ventilation operability

    International Nuclear Information System (INIS)

    Marella, J.R.

    1995-01-01

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions

  8. Ventilation i industrien

    DEFF Research Database (Denmark)

    Valbjørn, O.

    I en række afsnit belyses problemer med træk, kulde, varme, og luftforurening på industriens arbejdspladser, og hvordan man ved ventilation og bygningsudformning kan bekæmpe disse gener. Hvert afsnit kan i princippet læses for sig, og anvisningen kan derfor bruges som håndbog, både af de der er...

  9. Noninvasive Ventilation in Premature Neonates.

    Science.gov (United States)

    Flanagan, Keri Ann

    2016-04-01

    The use of noninvasive ventilation is a constantly evolving treatment option for respiratory disease in the premature infant. The goals of these noninvasive ventilation techniques are to improve gas exchange in the premature infant's lungs and to minimize the need for intubation and invasive mechanical ventilation. The goals of this article are to consider various uses of nasal interfaces, discuss skin care and developmental positioning concerns faced by the bedside nurse, and discuss the medical management aimed to reduce morbidity and mortality. This article explores the nursing role, the advances in medical strategies for noninvasive ventilation, and the team approach to noninvasive ventilation use in this population. Search strategy included a literature review on medical databases, such as EBSCOhost, CINAHL, PubMed, and NeoReviews. Innovative products, nursing research on developmental positioning and skin care, and advanced medical management have led to better and safer outcomes for premature infants requiring noninvasive ventilation. The medical focus of avoiding long-term mechanical ventilation would not be possible without the technology to provide noninvasive ventilation to these premature infants and the watchful eye of the nurse in terms of careful positioning, preventing skin breakdown and facial scarring, and a proper seal to maximize ventilation accuracy. This article encourages nursing-based research to quantify some of the knowledge about skin care and positioning as well as research into most appropriate uses for noninvasive ventilation devices.

  10. Performance evaluation of ventilation radiators

    International Nuclear Information System (INIS)

    Myhren, Jonn Are; Holmberg, Sture

    2013-01-01

    A ventilation radiator is a combined ventilation and heat emission unit currently of interest due to its potential for increasing energy efficiency in exhaust-ventilated buildings with warm water heating. This paper presents results of performance tests of several ventilation radiator models conducted under controlled laboratory conditions. The purpose of the study was to validate results achieved by Computational Fluid Dynamics (CFD) in an earlier study and identify possible improvements in the performance of such systems. The main focus was on heat transfer from internal convection fins, but comfort and health aspects related to ventilation rates and air temperatures were also considered. The general results from the CFD simulations were confirmed; the heat output of ventilation radiators may be improved by at least 20% without sacrificing ventilation efficiency or thermal comfort. Improved thermal efficiency of ventilation radiators allows a lower supply water temperature and energy savings both for heating up and distribution of warm water in heat pumps or district heating systems. A secondary benefit is that a high ventilation rate can be maintained all year around without risk for cold draught. -- Highlights: ► Low temperature heat emitters are currently of interest due to their potential for increasing energy efficiency. ► A ventilation radiator is a combined ventilation and heat emission unit which can be adapted to low temperature heating systems. ► We examine how ventilation radiators can be made to be more efficient in terms of energy consumption and thermal comfort. ► Current work focuses on heat transfer mechanisms and convection fin configuration of ventilation radiators

  11. MR-based assessment of pulmonary ventilation-perfusion in animal models

    International Nuclear Information System (INIS)

    Yang Jian; Wan Mingxi; Guo Youmin

    2003-01-01

    Objective: To show the feasibility and value in the diagnosis of airway obstruction and pulmonary embolism with MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging. Methods: Eight canines were implemented for peripheral pulmonary embolism by intravenous injection of gelfoam granules at pulmonary segmental arterial level, and five of them were formed airway obstruction models by inserting self-made balloon catheter at second-bronchia. The oxygen-enhanced MR ventilation imaging was introduced by subtracting the images of pre- and post- inhaled pure oxygen. The MR pulmonary perfusion imaging was achieved by the first-pass contrast agent method. Moreover, the manifestation of MR ventilation and perfusion imaging was observed and contradistinguished with that of general pathologic anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results: The manifestations of airway obstruction regions in MR ventilation and perfusion imaging were matched, but those of pulmonary embolism regions were dismatched. The defect range of airway obstruction in MR ventilation image was smaller than that in ventilation scintigraphy. The abnormal perfusion regions of pulmonary embolism were divided into defect regions and reduce regions based on the time courses of signal intensity changes. The sensitivity and specificity of diagnosis on pulmonary embolism by MR ventilation combined with perfusion technique were 75.0% and 98.1%. The diagnostic results were in good coherence with ventilation-perfusion scintigraphy and pulmonary angiography (K=0.743, 0.899). Conclusion: The MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging can be used to diagnose the airway and vascular abnormity in lung. This technique resembles the ventilation-perfusion scintigraphy. It can provide quantitative functional information and better spatial and temporal resolution, and possesses the value of clinical application

  12. Pretest Predictions for Ventilation Tests

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  13. 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.......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...

  14. 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.

  15. Mechanical Ventilation and Bronchopulmonary Dysplasia.

    Science.gov (United States)

    Keszler, Martin; Sant'Anna, Guilherme

    2015-12-01

    Mechanical ventilation is an important potentially modifiable risk factor for the development of bronchopulmonary dysplasia. Effective use of noninvasive respiratory support reduces the risk of lung injury. Lung volume recruitment and avoidance of excessive tidal volume are key elements of lung-protective ventilation strategies. Avoidance of oxidative stress, less invasive methods of surfactant administration, and high-frequency ventilation are also important factors in lung injury prevention. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Design Principles for Natural and Hybrid Ventilation

    OpenAIRE

    Heiselberg, Per

    2000-01-01

    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.

  17. 46 CFR 42.15-45 - Ventilators.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Ventilators. 42.15-45 Section 42.15-45 Shipping COAST... Conditions of Assignment of Freeboard § 42.15-45 Ventilators. (a) Ventilators in position 1 or 2 to spaces... any ventilator exceeds 351/2 inches in height it shall be specially supported. (b) Ventilators passing...

  18. Naturlig ventilation i enfamiliehuse

    DEFF Research Database (Denmark)

    Bergsøe, N.C.

    Meddelelsen beskriver resultaterne af en række beregninger foretaget ved anvendelse af et computerprogram. Beregningerne har til formål at belyse forskellige parametres indvirkning på funktionen af et naturligt ventilationssystem. Blandt andet belyses systemets afhængighed af aftrækskanalernes di...... dimension, udeluftventilarealet og placeringen af aftrækskanalernes udmunding i tagfladen. Derudover gengives i kortfattet form de væsentligste konklusioner af udvalgte publikationer, som behandler særlige forhold vedrørende naturlig ventilation i praksis....

  19. 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...

  20. [Lung protective ventilation. Ventilatory modes and ventilator parameters].

    Science.gov (United States)

    Schädler, Dirk; Weiler, Norbert

    2008-06-01

    Mechanical ventilation has a considerable potential for injuring the lung tissue. Therefore, attention has to be paid to the proper choice of ventilatory mode and settings to secure lung-protective ventilation whenever possible. Such ventilator strategy should account for low tidal volume ventilation (6 ml/kg PBW), limited plateau pressure (30 to 35 cm H2O) and positive end-expiratory pressure (PEEP). It is unclear whether pressure controlled or volume controlled ventilation with square flow profile is beneficial. The adjustment of inspiration and expiration time should consider the actual breathing mechanics and anticipate the generation of intrinsic PEEP. Ventilatory modes with the possibility of supporting spontaneous breathing should be used as soon as possible.

  1. Improved Performance With Ventilation

    Science.gov (United States)

    Kawakami, Ellison; Lee, Seung Jae; Karn, Ashish; Hong, Jiarong; Arndt, Roger

    2013-11-01

    Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. Various aspects of the flow physics of a supercavitating vehicle have been under investigation for several years at Saint Anthony Falls Laboratory. Both steady flow and simulated flow below a wave train have been studied. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity to permit an in-depth study of unsteadiness. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are reviewed in light of new studies that focused on various closure mechanisms. Sponsored by ONR.

  2. Ventilator-associated pneumonia.

    Science.gov (United States)

    Shaw, Michael Jan

    2005-05-01

    This review summarises some of the notable papers on ventilator-associated pneumonia (VAP) from January 2003 to October 2004. Ventilator-associated pneumonia remains an important drain on hospital resources. All population groups are affected, but patients with VAP are more likely to be older, sicker, and male, with invasive medical devices in situ. Early VAP diagnosis is desirable to reduce VAP mortality and to retard emergence of multidrug-resistant microbes. This may be possible using preliminary culture results or intracellular organism in polymorphonuclear cells. In most intensive care units, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii are the commonest organisms isolated in VAP. However, causative organisms vary between and within hospitals. Consequently, individual intensive care units should develop empirical antibiotic policies to target the pathogenic bacteria prevalent in their patient populations. Preventative strategies aimed at reducing aerodigestive tract colonisation by pathogenic organisms, and also their subsequent aspiration, are becoming increasingly important. Educating medical staff about these simple measures is therefore pertinent. To reduce the occurrence of multidrug-resistant organisms, limiting the duration of antibiotic treatment to 8 days and antimicrobial rotation should be contemplated. Empirical therapy with antipseudomonal penicillins plus beta-lactamase inhibitors should be considered. If methicillin-resistant Staphylococcus aureus VAP is a possibility, linezolid may be better than vancomycin. Prevention remains the key to reducing VAP prevalence.

  3. Embedded defects

    International Nuclear Information System (INIS)

    Barriola, M.; Vachaspati, T.; Bucher, M.

    1994-01-01

    We give a prescription for embedding classical solutions and, in particular, topological defects in field theories which are invariant under symmetry groups that are not necessarily simple. After providing examples of embedded defects in field theories based on simple groups, we consider the electroweak model and show that it contains the Z string and a one-parameter family of strings called the W(α) string. It is argued that although the members of this family are gauge equivalent when considered in isolation, each member becomes physically distinct when multistring configurations are considered. We then turn to the issue of stability of embedded defects and demonstrate the instability of a large class of such solutions in the absence of bound states or condensates. The Z string is shown to be unstable for all values of the Higgs boson mass when θ W =π/4. W strings are also shown to be unstable for a large range of parameters. Embedded monopoles suffer from the Brandt-Neri-Coleman instability. Finally, we connect the electroweak string solutions to the sphaleron

  4. 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 ...

  5. Innovation in home mechanical ventilation

    NARCIS (Netherlands)

    Hazenberg, Andrea

    2017-01-01

    Patients on home mechanical ventilation (HMV) are ventilator dependent, usually for the rest of their lives. In the past decades, the number of patients on HMV increased to nearly 3,000 in 2016 in the Netherlands. Current indications for HMV are patients diagnosed with either neuromuscular disease,

  6. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  7. Ventilation of an hydrofoil wake

    Science.gov (United States)

    Arndt, Roger; Lee, Seung Jae; Monson, Garrett

    2013-11-01

    Ventilation physics plays a role in a variety of important engineering applications. For example, hydroturbine ventilation is used for control of vibration and cavitation erosion and more recently for improving the dissolved oxygen content of the flow through the turbine. The latter technology has been the focus of an ongoing study involving the ventilation of an hydrofoil wake to determine the velocity and size distribution of bubbles in a bubbly wake. This was carried out by utilizing particle shadow velocimetry (PSV). This technique is a non-scattering approach that relies on direct in-line volume illumination by a pulsed source such as a light-emitting diode (LED). The data are compared with previous studies of ventilated flow. The theoretical results of Hinze suggest that a scaling relationship is possible that can lead to developing appropriate design parameters for a ventilation system. Sponsored by ONR and DOE.

  8. Natural ventilation for free stall dairy barns

    OpenAIRE

    Gay, Susan Wood

    2009-01-01

    Natural ventilation is a result of a combination good construction, correct temperature, humidity control, air exchange. This publication discusses how to achieve natural ventilation in your structure.

  9. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments......, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors also...

  10. [Oesophagitis during mechanical ventilation].

    Science.gov (United States)

    Gastinne, H; Canard, J M; Pillegand, B; Voultoury, J C; Catanzano, A; Claude, R; Gay, R

    1982-10-16

    Twenty-one patients whose condition required mechanical ventilation with nasogastric intubation were investigated for oesophagitis before the 3rd day and on the 15th day of treatment, including endoscopy and biopsy. Lesions of oesophagitis were detected in 14 cases during the initial examination and in 19 cases on the second endoscopy. The course of the lesions varied from one patient to another and appeared to be unrelated to the course of the primary disease. Oesophagitis in these patients is probably due to frequent episodes of gastro-oesophageal reflux encouraged by cough, impaired consciousness and the presence of a tube. Reflux may also be the cause of inapparent and recurrent lung aspiration.

  11. Cardiac gated ventilation

    International Nuclear Information System (INIS)

    Hanson, C.W. III; Hoffman, E.A.

    1995-01-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart

  12. 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.

  13. Mechanical ventilation in abdominal surgery.

    Science.gov (United States)

    Futier, E; Godet, T; Millot, A; Constantin, J-M; Jaber, S

    2014-01-01

    One of the key challenges in perioperative care is to reduce postoperative morbidity and mortality. Patients who develop postoperative morbidity but survive to leave hospital have often reduced functional independence and long-term survival. Mechanical ventilation provides a specific example that may help us to shift thinking from treatment to prevention of postoperative complications. Mechanical ventilation in patients undergoing surgery has long been considered only as a modality to ensure gas exchange while allowing maintenance of anesthesia with delivery of inhaled anesthetics. Evidence is accumulating, however, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary function and clinical outcome in patients undergoing abdominal surgery. Non-protective ventilator settings, especially high tidal volume (VT) (>10-12mL/kg) and the use of very low level of positive end-expiratory pressure (PEEP) (PEEPventilator-associated lung injury in patients with healthy lungs. Stimulated by previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung protective mechanical ventilation. In this review, we aimed at providing the most recent and relevant clinical evidence regarding the use of mechanical ventilation in patients undergoing abdominal surgery. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  14. 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.

  15. 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.

  16. 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....

  17. Regional Ventilation Changes in Severe Asthma after Bronchial Thermoplasty with 3He MR Imaging and CT

    Science.gov (United States)

    Thomen, Robert P.; Sheshadri, Ajay; Quirk, James D.; Kozlowski, Jim; Ellison, Henry D.; Szczesniak, Rhonda D.; Castro, Mario

    2015-01-01

    Purpose To quantify regional lung ventilation in healthy volunteers and patients with severe asthma (both before and after thermoplasty) by using a combination of helium 3 (3He) magnetic resonance (MR) imaging and computed tomography (CT), with the intention of developing more effective image-guided treatments for obstructive lung diseases. Materials and Methods With approval of the local institutional review board, informed consent, and an Investigational New Drug Exemption, six healthy volunteers and 10 patients with severe asthma were imaged in compliance with HIPAA regulations by using both multidetector CT and 3He MR imaging. Individual bronchopulmonary segments were labeled voxel by voxel from the CT images and then registered to the 3He MR images by using custom software. The 3He signal intensity was then analyzed by evaluating the volume-weighted fraction of total-lung signal intensity present in each segment (segmental ventilation percentage [SVPsegmental ventilation percentage]) and by identifying the whole-lung defect percentage and the segmental defect percentage. Of the 10 patients with asthma, seven received treatment with bronchial thermoplasty and were imaged with 3He MR a second time. Changes in segmental defect percentages and whole-lung defect percentages are presented. Results Ventilation measures for healthy volunteers yielded smaller segment-to-segment variation (mean SVPsegmental ventilation percentage, 100% ± 18 [standard deviation]) than did the measures for patients with severe asthma (mean SVPsegmental ventilation percentage, 97% ± 23). Patients with asthma also demonstrated larger segmental defect percentages (median, 13.5%; interquartile range, 8.9%–17.8%) than healthy volunteers (median, 6%; interquartile range, 5.6%–6.3%). These quantitative results confirm what is visually observed on the 3He images. A Spearman correlation of r = −0.82 was found between the change in whole-lung defect percentage and the number of days between

  18. 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 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....

  19. Interactive Governance

    DEFF Research Database (Denmark)

    Bang, Henrik

    2016-01-01

    Governance analysis has exploded in recent years, and it has become nearly impossible to tell what difference the concept and practice of governance makes from those of government and state. In addition governance analysis has been placed more and more in the shadow of the new institutionalisms and...... and growth. However, interactive governance is not a property or effect of institutions; nor does it apply solely to those individuals who seek success above everything else. It is connective more than individualistic or collectivistic in nature; and it manifests a governability capacity which...

  20. 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......[Mechanical and natural ventilation] into a new type of ventilation system- Hybrid Ventilation....

  1. 21 CFR 868.5975 - Ventilator tubing.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventilator tubing. 868.5975 Section 868.5975 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5975 Ventilator tubing. (a) Identification. Ventilator tubing is a device intended for use as a conduit for gases between a ventilator and a patient...

  2. Preoperational test report, vent building ventilation system

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    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

  3. 46 CFR 45.131 - Ventilators.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Ventilators. 45.131 Section 45.131 Shipping COAST GUARD....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures must have coamings of steel or equivalent material at the freeboard deck. (b) Ventilators in position 1...

  4. 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 must...

  5. The role of ventilation. 2 v. Proceedings

    International Nuclear Information System (INIS)

    1994-01-01

    The 78 papers which constitute the proceedings of the conference are presented in two volumes. The papers in the first volume cover sessions dealing with the following broad topics: ventilation strategies; indoor air quality; energy impact of ventilation; building design for optimum ventilation; ventilation and energy. Volume 2 also covers ventilation strategies and ventilation and energy, and in addition: calculation, measurement and design tools; measurement and modelling. Separate abstract have been prepared for 4 papers in Volume 1 which deal with the role of ventilation in mitigating the hazard of radon in buildings. (UK)

  6. Proceedings of the 13. U.S./North American mine ventilation symposium

    International Nuclear Information System (INIS)

    Hardcastle, S.; McKinnon, D.L.

    2010-01-01

    This biannual symposium has become a major international forum for presenting technical papers in the field of underground mine ventilation. Participants included members of industry, academia and government organizations. The presentations dealt with underground coal and metal mining issues, including fire prevention, air quality control, heat and refrigeration and innovations in fan technology. The papers reflected the issues that underground mine ventilation professionals are currently facing to ensure the health and safety of miners. The sessions 7 were entitled: air quality; metal mine ventilation; coal mine ventilation; heat issues; mine fires; ventilation modeling; and fan technology. All 72 presentations featured at this conference have been catalogued separately for inclusion in this database. refs., tabs., figs.

  7. Mine engineering and ventilation problems unique to the control of radon daughters

    International Nuclear Information System (INIS)

    Rock, R.L.

    1975-01-01

    Quality and quantity of ventilation are the two interrelated but key factors in any radon-daughter control programme. The better the intake air quality (little or no contamination from radon and its daughters), the less are the total air requirements for ventilation of active mining areas. Engineering principles for quantity distribution of air through underground working areas are straightforward and the formulae and theories governing forced ventilation are not within the scope of this paper. Rather, this paper discusses the principal methods of utilizing mine planning to facilitate radon-daughter control and also treats the more subtle features of mine ventilation which are especially critical in the ventilation of mines where radon gas constitutes an environmental contamination problem. (author)

  8. Newer nonconventional modes of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Preet Mohinder Singh

    2014-01-01

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

  9. 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.

  10. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

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

  11. Pulsed ventilation in mines. II

    Energy Technology Data Exchange (ETDEWEB)

    Krause, D

    1975-06-01

    Using test results, an attempt is made to determine the form of the free jet and to derive design data for pulsed fans. The most suitable placing of these fans for the ventilation of headings is discussed.

  12. ENERGY STAR Certified Ventilating Fans

    Data.gov (United States)

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

  13. A comparative analysis of pulmonary ventilation-perfusion imaging with pulmonary angiography in the diagnosis of pulmonary embolism

    International Nuclear Information System (INIS)

    Wang Jincheng; Mi Hongzhi; Wang Qian; Zhang Weijun; Lu Biao; Yang Hao; Ding Jian; Lu Yao

    2001-01-01

    Objective: To assess the value of ventilation-perfusion imaging in the diagnosis of pulmonary embolism (PE). Methods: Thirty consecutive patients with clinically suspected pulmonary embolism were studied, male: female 15:15, mean age was (36.2 +- 13.9) years. The chest radiograms were obtained in all 30 patients. All patients underwent radionuclide ventilation-perfusion imaging and pulmonary angiography. Results: Of the 30 patients, 22 with lobe, multiple segment or multi-subsegment perfusion defects and normal or nearly normal ventilation images were reported as PE. 20 of them were confirmed to be with PE by pulmonary angiography, 2 patients were not confirmed. Eight of 30 patients with multiple perfusion defects, ventilative abnormalities were reported as non-PE and the diagnoses were confirmed by pulmonary angiography. The sensitivity, specificity and accuracy of diagnosis of PE by ventilation-perfusion imaging was 100%, 80.0% and 93.3% respectively. Conclusions: (1) Ventilation-perfusion imaging is one of the most valuable methods in the diagnosis of PE. (2) The results suggest that pulmonary embolism can be diagnosed non-invasively in most patients on the basis of clinical manifestation, chest radiograms and ventilation-perfusion imaging findings. (3) Pulmonary angiography is required while clinical manifestation and ventilation-perfusion imaging findings are discordant with each other

  14. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e-government/e-governance...

  15. Leadership, Governance

    Science.gov (United States)

    : Environmental Documents, Reports LANL Home Calendar Search Contacts About » Leadership, Governance Leadership national security and energy challenges. Leadership, Governance Ethics, Accountability Los Alamos National . Director's Office terry wallace in leadership, governance Director Terry C. Wallace, Jr. Terry C. Wallace, Jr

  16. Stakeholder Governance

    DEFF Research Database (Denmark)

    Flak, Leif Skiftenes; Rose, Jeremy

    2005-01-01

    to e-Government. Originally a management theory, stakeholder theory advocates addressing the concerns of all stakeholders in a firm, as opposed to concentration on the interests of senior managers and stockholders. Apart from the original profit focus, there is no serious conceptual mismatch between...... of governance. Finally, the paper makes recommendations for future work in adapting ST to the e-government context....

  17. Wind Extraction for Natural Ventilation

    Science.gov (United States)

    Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan

    2017-11-01

    Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.

  18. TS LOOP ALCOVE VENTILATION ANALYSIS

    International Nuclear Information System (INIS)

    T.M. Lahnalampi

    2000-01-01

    The scope of this analysis is to examine the existing, constructor installed, physical ventilation installations located in each of the Exploratory Studies Facility (ESF) Topopah Springs (TS) Loop Alcoves No.1, No.2, No.3, No.4, No.6, and No.7. Alcove No.5 is excluded from the scope of this analysis since it is an A/E design system. Each ventilation installation will be analyzed for the purpose of determining if requirements for acceptance into the A/E design technical baseline have been met. The ventilation installations will be evaluated using Occupational Safety and Health Administration (OSHA) standards and Exploratory Studies Facility Design Requirements (ESFDR) (YMP 1997) requirements. The end product will be a technical analysis that will define ventilation installation compliance issues, any outstanding field changes, and use-as-is design deviations that are required to bring the ventilation installations into compliance with requirements for acceptance into the A/E design technical baseline. The analysis will provide guidance for alcove ventilation component design modifications to be developed to correct any deficient components that do not meet minimum requirements and standards

  19. Ventilation Model and Analysis Report

    International Nuclear Information System (INIS)

    Chipman, V.

    2003-01-01

    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

  20. Mechanical ventilation for severe asthma.

    Science.gov (United States)

    Leatherman, James

    2015-06-01

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

  1. Endotracheal tube defects: Hidden causes of airway obstruction

    Directory of Open Access Journals (Sweden)

    Sofi Khalid

    2010-01-01

    Full Text Available Manufacturing defects of endotracheal tube (ETT are still encountered in anesthesia practice. Many such defects go unnoticed during routine inspection prior to their use. Such defects in ETT may lead to partial or complete airway obstruction in an intubated patient. We report a case of partial airway obstruction with a prepacked, single use, uncuffed ETT due to a manufacturing defect in the form of a plastic meniscus at the distal end of the tube. This case report highlights the significance of standard monitoring of ventilation and the role of a vigilant clinician in detecting such defects in avoiding critical events as can arise from the use of such defective ETTs. It also emphasizes the need for double checking ETTs prior to their use.

  2. Program governance

    CERN Document Server

    Khan, Muhammad Ehsan

    2014-01-01

    FOUNDATION OF GOVERNANCEGovernanceDefining GovernanceGovernance at Multiple LevelsSummaryReferencesTransaction Cost EconomicsTransactions-Core Elements and Attributes     Behavioral Assumptions     Governance Structure AttributesHazards of Concern     Incomplete Contracting     Bilateral Dependency and Fundamental Transformation     Adaptation or MaladaptationLinking Governance, Governance Structures, and ContractsThe Impact of Asset Specificity and Behavioral Assumptions on ContractsAp

  3. Plural Governance

    DEFF Research Database (Denmark)

    Mols, Niels Peter; Menard, Claude

    2014-01-01

    Plural governance is a form of governance where a firm both makes and buys similar goods or services. Despite a widespread use of plural governance there are no transaction cost models of how plural governance affects performance. This paper reviews the literature about plural forms and proposes...... a model relating transaction cost and resource-based variables to the cost of the plural form. The model is then used to analyze when the plural form is efficient compared to alternative governance structures. We also use the model to discuss the strength of three plural form synergies....

  4. Impact of Fire Ventilation on General Ventilation in the Building

    Science.gov (United States)

    Zender-Świercz, Ewa; Telejko, Marek

    2017-10-01

    The fire of building is a threat to its users. The biggest threat is generation, during lifetime of fire, hot gases and smoke. The purpose of quick and efficient evacuation from the area covered by the fire, at first step the escape routes have to be secured from smokiness. The smoke ventilation systems are used for this purpose. The proper design and execution of smoke ventilation is important not only because of the safety, but also of the maintenance of comfort in the building at a time when there is no fire. The manuscript presents the effect of incorrectly realized smoke ventilation in the stairwell of the medium building. The analysis shows that the flaps of smoke ventilation located in the stairwell may have a significant impact on the proper functioning of mechanical ventilation in the period when there is no fire. The improperly installed or incorrect insulated components cause perturbation of air flow and they change pressure distribution in the building. The conclusion of the analysis is the need to include the entire technical equipment of the building during the design and realization of its individual elements. The impact of various installations at each other is very important, and the omission of any of them can cause disturbances in the proper work of another.

  5. Sulpyrine inhalation challenge test monitored continuously by respiratory impedance and 81mKr ventilation image

    International Nuclear Information System (INIS)

    Suenaga, Naoto; Nakamura, Hitoshi; Shiratsuki, Natsuo; Nishioka, Yasuhiro; Kitada, Osamu; Sugita, Minoru

    1993-01-01

    Continuous changes of respiratory impedance by the oscillation method using Asthograph and 81m Kr ventilation image during saline and sulpyrine solution (100 mg/ml, 250 mg/ml) provocation were simultaneously measured in 15 adult asthmatics and 7 normal individuals. Estimation of airway obstruction by respiratory impedance using Asthograph was difficult during sulpyrine inhalation, since respiratory impedance increased gradually. In addition to the measurement of respiratory impedance, images of 81m Kr ventilation were also obtained to estimate the regional ventilatory distribution. Estimation of the airway obstruction was easily obtained. Another advantage of 81m Kr ventilation image is that it can estimate the regional ventilatory distribution. The site of airway obstruction provoked by sulpyrine was observed predominantly in the lower lung field. The results of our present study were as follows. In 3 patients, increase of respiratory impedance and defect of 81m Kr ventilation image were observed. Two cases in this group were clinically diagnosed as having aspirin-induced asthma. In 7 patients, a defect of 81m Kr ventilation image was observed, but no increase of respiratory impedance was observed. Five cases in this group could not be clinically diagnosed as having aspirin-induced asthma. In 5 patients, neither defect of 81m Kr ventilation image nor increase of respiratory impedance could be detected. These results suggest that 81m Kr ventilation image on sulpyrine inhalation challenge test is a useful method for evaluating regional ventilatory distribution, but should be further investigated for application to aspirin-induced asthma. (author)

  6. 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.

  7. Trigger performance of mid-level ICU mechanical ventilators during assisted ventilation: a bench study.

    Science.gov (United States)

    Ferreira, Juliana C; Chipman, Daniel W; Kacmarek, Robert M

    2008-09-01

    To compare the triggering performance of mid-level ICU mechanical ventilators with a standard ICU mechanical ventilator. Experimental bench study. The respiratory care laboratory of a university-affiliated teaching hospital. A computerized mechanical lung model, the IngMar ASL5000. Ten mid-level ICU ventilators were compared to an ICU ventilator at two levels of lung model effort, three combinations of respiratory mechanics (normal, COPD and ARDS) and two modes of ventilation, volume and pressure assist/control. A total of 12 conditions were compared. Performance varied widely among ventilators. Mean inspiratory trigger time was ventilators. The mean inspiratory delay time (time from initiation of the breath to return of airway pressure to baseline) was longer than that for the ICU ventilator for all tested ventilators except one. The pressure drop during triggering (Ptrig) was comparable with that of the ICU ventilator for only two ventilators. Expiratory Settling Time (time for pressure to return to baseline) had the greatest variability among ventilators. Triggering differences among these mid-level ICU ventilators and with the ICU ventilator were identified. Some of these ventilators had a much poorer triggering response with high inspiratory effort than the ICU ventilator. These ventilators do not perform as well as ICU ventilators in patients with high ventilatory demand.

  8. Tidal ventilation distribution during pressure-controlled ventilation and pressure support ventilation in post-cardiac surgery patients.

    Science.gov (United States)

    Blankman, P; VAN DER Kreeft, S M; Gommers, D

    2014-09-01

    Inhomogeneous ventilation is an important contributor to ventilator-induced lung injury. Therefore, this study examines homogeneity of lung ventilation by means of electrical impedance tomography (EIT) measurements during pressure-controlled ventilation (PCV) and pressure support ventilation (PSV) using the same ventilation pressures. Twenty mechanically ventilated patients were studied after cardiac surgery. On arrival at the intensive care unit, ventilation distribution was measured with EIT just above the diaphragm for 15 min. After awakening, PCV was switched to PSV and EIT measurements were again recorded. Tidal impedance variation, a measure of tidal volume, increased during PSV compared with PCV, despite using the same ventilation pressures (P = 0.045). The distribution of tidal ventilation to the dependent lung region was more pronounced during PSV compared with PCV, especially during the first half of the inspiration. An even distribution of tidal ventilation between the dependent and non-dependent lung regions was seen during PCV at lower tidal volumes (tidal volumes (≥ 8 ml/kg). In addition, the distribution of tidal ventilation was predominantly distributed to the dependent lung during PSV at low tidal volumes. In post-cardiac surgery patients, PSV showed improved ventilation of the dependent lung region due to the contribution of the diaphragm activity, which is even more pronounced during lower assist levels. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  9. Facts about Birth Defects

    Science.gov (United States)

    ... label> Information For… Media Policy Makers Facts about Birth Defects Language: English (US) Español (Spanish) Recommend on ... having a baby born without a birth defect. Birth Defects Are Common Every 4 ½ minutes, a ...

  10. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  11. 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).

  12. 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...

  13. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

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

    2008-01-01

    consumption during periods where the demand for ventilation is low and poor indoor climate during periods where the demand for ventilation is high. Controlling the ventilation rate by demand can improve the energy performance of the ventilation system and the indoor climate. This paper compares the indoor...... climate and energy consumption of a Constant Air Volume (CAV) system and a Demand Controlled Ventilation (DCV) system for two different bathroom designs. The air change rate of the CAV system corresponded to 0.5h-1. The ventilation rate of the DCV system was controlled by occupancy and by the relative...

  14. Air ventilation/controlling facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro

    1997-12-12

    When all electricity supply from the outside of a power plant are lost, a power generator directly connected to an emergency steam turbine which is driven by steams introduced from a nuclear reactor is driven to supply electricity required in the power plant. Cool water prepared by a refrigerator is used as cooling water in an air ventilation/controlling facility of a room equipped with the power generating facility. As the refrigerator, a refrigerator of an existent emergency air cooling water system for an auxiliary air ventilation/controlling equipment is used. This can extend the period of time till the temperature of the room where the power generator is disposed exceeds the temperature range capable of keeping the integrity of the power generator even when all the AC power supply are lost to inactivate the function of the air ventilation/controlling system. (I.S.)

  15. Regulatory Governance

    DEFF Research Database (Denmark)

    Kjær, Poul F.; Vetterlein, Antje

    2018-01-01

    Regulatory governance frameworks have become essential building blocks of world society. From supply chains to the regimes surrounding international organizations, extensive governance frameworks have emerged which structure and channel a variety of social exchanges, including economic, political...... by the International Transitional Administrations (ITAs) in Kosovo and Iraq as well as global supply chains and their impact on the garment industry in Bangladesh....

  16. Experimentalist governance

    NARCIS (Netherlands)

    Sabel, C.F.; Zeitlin, J.; Levi-Faur, D.

    2012-01-01

    A secular rise in volatility and uncertainty is overwhelming the capacities of conventional hierarchical governance and ‘command-and-control’ regulation in many settings. One significant response is the emergence of a novel, ‘experimentalist’ form of governance that establishes deliberately

  17. Remaking Governance.

    Science.gov (United States)

    Carver, John

    2000-01-01

    The Policy Governance model's philosophical foundations lie in Rousseau's social contract, Greenleaf's servant-leadership, and modern management theory. Policy Governance stresses primacy of the owner-representative role; full-board authority; superintendents as chief executive officers; authoritative prescription of "ends," bounded…

  18. [Pressure support ventilation and proportional assist ventilation during weaning from mechanical ventilation].

    Science.gov (United States)

    Aguirre-Bermeo, H; Bottiroli, M; Italiano, S; Roche-Campo, F; Santos, J A; Alonso, M; Mancebo, J

    2014-01-01

    To compare tolerance, duration of mechanical ventilation (MV) and clinical outcomes during weaning from MV in patients subjected to either pressure support ventilation (PSV) or proportional assist ventilation (PAV). A prospective, observational study was carried out. Intensive Care Unit. A total of 40 consecutive subjects were allocated to either the PSV or the PAV group until each group contained 20 patients. Patients were included in the study when they met the criteria to begin weaning and the attending physician decided to initiate the weaning process. The physician selected the modality and set the ventilatory parameters. None. Demographic data, respiratory mechanics, ventilatory parameters, duration of MV, and clinical outcomes (reintubation, tracheostomy, mortality). Baseline characteristics were similar in both groups. No significant differences were observed between the PSV and PAV groups in terms of the total duration of MV (10 [5-18] vs. 9 [7-19] days; P=.85), reintubation (5 [31%] vs. 3 [19%]; P=.69), or mortality (4 [20%] vs. 5 [25%] deaths; P=1). Eight patients (40%) in the PSV group and 6 patients (30%) in the PAV group (P=.74) required a return to volume assist-control ventilation due to clinical deterioration. Tolerance, duration of MV and clinical outcomes during weaning from mechanical ventilation were similar in PSV and PAV. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  19. Membrane modules for building ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Kistler, K.R.; Cussler, E.L.

    2002-01-01

    Hollow fibre and flat sheet membranes with an interfacially polymerized coating of polyamide have a permeance for water vapour of about 0.16 m sec{sup -1}. These membranes can serve as a basis for building ventilation which provides fresh air while recovering about 70% of the specific heat and 60% of the latent heat. Because these membranes are selective for water vapour, the air is exhausted with internal pollutants like carbon monoxide, formaldehyde, and radon. The expense of the ventilator should be recovered in reduced heating costs in about three years. (Author)

  20. Limiting volume with modern ventilators.

    Science.gov (United States)

    Wing, Thomas J; Haan, Lutana; Ashworth, Lonny J; Anderson, Jeff

    2015-06-01

    The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may

  1. 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.

  2. Ventilation of radioactive enclosures; Ventilation des enceintes radioactives

    Energy Technology Data Exchange (ETDEWEB)

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

    1957-07-01

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

  3. 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.

  4. 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...

  5. Perioperative lung protective ventilation in obese patients

    NARCIS (Netherlands)

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

    2015-01-01

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent

  6. 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.

  7. Improvements of uranium mine ventilation system

    International Nuclear Information System (INIS)

    Liu Changrong; Zhou Xinghuo; Liu Zehua; Wang Zhiyong

    2007-01-01

    Ventilation has been proved to be a main method to eliminate radon and its daughters in uranium mines. According to the practical rectifications of uranium mine ventilation system, the improved measures are summarized. (authors)

  8. Ventilation area measured with eit in order to optimize peep settings in mechanically ventilated patients

    NARCIS (Netherlands)

    Blankman, P; Groot Jebbink, E; Preis, C; Bikker, I.; Gommers, D.

    2012-01-01

    INTRODUCTION. Electrical Impedance Tomography (EIT) is a non-invasive imaging technique, which can be used to visualize ventilation. Ventilation will be measured by impedance changes due to ventilation. OBJECTIVES. The aim of this study was to optimize PEEP settings based on the ventilation area of

  9. Initial ventilator settings for critically ill patients

    OpenAIRE

    Kilickaya, Oguz; Gajic, Ognjen

    2013-01-01

    The lung-protective mechanical ventilation strategy has been standard practice for management of acute respiratory distress syndrome (ARDS) for more than a decade. Observational data, small randomized studies and two recent systematic reviews suggest that lung protective ventilation is both safe and potentially beneficial in patients who do not have ARDS at the onset of mechanical ventilation. Principles of lung-protective ventilation include: a) prevention of volutrauma (tidal volume 4 to 8 ...

  10. Building ventilation, state of the art, prospective

    International Nuclear Information System (INIS)

    1995-10-01

    This conference is composed of 21 communications and 21 posters in the domain of building ventilation and indoor air quality; the main themes are: indoor air quality assessment and optimization; performance enhancement and optimization of ventilation systems and equipment; ventilation systems for renovated and rehabilitated buildings; French and European regulations, standardizations and certifications; experimental and numerical simulation studies concerning ventilation systems, air flow, temperature distribution, air quality, radon decontamination, thermal comfort and acoustic levels in buildings

  11. Artificial humidification for the mechanically ventilated patient

    OpenAIRE

    Selvaraj, Nelson

    2010-01-01

    Caring for patients who are mechanically ventilated poses many\\ud challenges for critical care nurses. It is important to humidify the\\ud patient’s airways artificially to prevent complications such as\\ud ventilator-associated pneumonia. There is no gold standard to\\ud determine which type of humidification is best for patients who\\ud are artificially ventilated. This article provides an overview of\\ud commonly used artificial humidification for mechanically ventilated\\ud patients and discuss...

  12. Artificial humidification for the mechanically ventilated patient.

    Science.gov (United States)

    Selvaraj, N

    Caring for patients who are mechanically ventilated poses many challenges for critical care nurses. It is important to humidify the patient's airways artificially to prevent complications such as ventilator-associated pneumonia. There is no gold standard to determine which type of humidification is best for patients who are artificially ventilated. This article provides an overview of commonly used artificial humidification for mechanically ventilated patients and discusses nurses' responsibilities in caring for patients receiving artificial humidification.

  13. High-Frequency Percussive Ventilation Revisited

    Science.gov (United States)

    2010-01-01

    be implemented. ‡ Follow the reverse of the ventilation sequence if respiratory alkalosis develops—however, start at ventilation goal sequence 1 not at...High-frequency percussive ventilation (HFPV) has demonstrated a potential role as a rescue option for refractory acute respiratory distress syndrome...frequency percussive ventilation (HFPV) has demon- strated a potential role as a salvage option for refrac- tory acute respiratory distress syndrome

  14. Performance comparison of 15 transport ventilators.

    Science.gov (United States)

    Chipman, Daniel W; Caramez, Maria P; Miyoshi, Eriko; Kratohvil, Joseph P; Kacmarek, Robert M

    2007-06-01

    Numerous mechanical ventilators are designed and marketed for use in patient transport. The complexity of these ventilators differs considerably, but very few data exist to compare their operational capabilities. Using bench and animal models, we studied 15 currently available transport ventilators with regard to their physical characteristics, gas consumption (duration of an E-size oxygen cylinder), battery life, ease of use, need for compressed gas, ability to deliver set ventilation parameters to a test lung under 3 test conditions, and ability to maintain ventilation and oxygenation in normal and lung-injured sheep. Most of the ventilators tested were relatively simple to operate and had clearly marked controls. Oxygen cylinder duration ranged from 30 min to 77 min. Battery life ranged from 70 min to 8 hours. All except 3 of the ventilators were capable of providing various F(IO2) values. Ten of the ventilators had high-pressure and patient-disconnect alarms. Only 6 of the ventilators were able to deliver all settings as specifically set on the ventilator during the bench evaluation. Only 4 of the ventilators were capable of maintaining ventilation, oxygenation, and hemodynamics in both the normal and the lung-injured sheep. Only 2 of the ventilators met all the trial targets in all the bench and animal tests. With many of the ventilators, certain of the set ventilation parameters were inaccurate (differed by > 10% from the values from a cardiopulmonary monitor). The physical characteristics and high gas consumption of some of these ventilators may render them less desirable for patient transport.

  15. Renewing governance.

    Science.gov (United States)

    Loos, Gregory P

    2003-01-01

    Globalization's profound influence on social and political institutions need not be negative. Critics of globalization have often referred to the "Impossible Trinity" because decision-making must 1. respect national sovereignty, 2. develop and implement firm regulation, and 3. allow capital markets to be as free as possible. To many, such goals are mutually exclusive because history conditions us to view policy-making and governance in traditional molds. Thus, transnational governance merely appears impossible because current forms of governance were not designed to provide it. The world needs new tools for governing, and its citizens must seize the opportunity to help develop them. The rise of a global society requires a greater level of generality and inclusion than is found in most policy bodies today. Politicians need to re-examine key assumptions about government. States must develop ways to discharge their regulatory responsibilities across borders and collaborate with neighboring jurisdictions, multilateral bodies, and business. Concepts such as multilateralism and tripartism show great promise. Governments must engage civil society in the spirit of shared responsibility and democratic decision-making. Such changes will result in a renewal of the state's purpose and better use of international resources and expertise in governance.

  16. Ventilation and cardiac related impedance changes in children undergoing corrective open heart surgery

    International Nuclear Information System (INIS)

    Schibler, Andreas; Pham, Trang M T; Moray, Amol A; Stocker, Christian

    2013-01-01

    Electrical impedance tomography (EIT) can determine ventilation and perfusion relationship. Most of the data obtained so far originates from experimental settings and in healthy subjects. The aim of this study was to demonstrate that EIT measures the perioperative changes in pulmonary blood flow after repair of a ventricular septum defect in children with haemodynamic relevant septal defects undergoing open heart surgery. In a 19 bed intensive care unit in a tertiary children's hospital ventilation and cardiac related impedance changes were measured using EIT before and after surgery in 18 spontaneously breathing patients. The EIT signals were either filtered for ventilation (ΔZV) or for cardiac (ΔZQ) related impedance changes. Impedance signals were then normalized (normΔZV, normΔZQ) for calculation of the global and regional impedance related ventilation perfusion relationship (normΔZV/normΔZQ). We observed a trend towards increased normΔZV in all lung regions, a significantly decreased normΔZQ in the global and anterior, but not the posterior lung region. The normΔZV/normΔZQ was significantly increased in the global and anterior lung region. Our study qualitatively validates our previously published modified EIT filtration technique in the clinical setting of young children with significant left-to-right shunt undergoing corrective open heart surgery, where perioperative assessment of the ventilation perfusion relation is of high clinical relevance. (paper)

  17. Ventilation and cardiac related impedance changes in children undergoing corrective open heart surgery.

    Science.gov (United States)

    Schibler, Andreas; Pham, Trang M T; Moray, Amol A; Stocker, Christian

    2013-10-01

    Electrical impedance tomography (EIT) can determine ventilation and perfusion relationship. Most of the data obtained so far originates from experimental settings and in healthy subjects. The aim of this study was to demonstrate that EIT measures the perioperative changes in pulmonary blood flow after repair of a ventricular septum defect in children with haemodynamic relevant septal defects undergoing open heart surgery. In a 19 bed intensive care unit in a tertiary children's hospital ventilation and cardiac related impedance changes were measured using EIT before and after surgery in 18 spontaneously breathing patients. The EIT signals were either filtered for ventilation (ΔZV) or for cardiac (ΔZQ) related impedance changes. Impedance signals were then normalized (normΔZV, normΔZQ) for calculation of the global and regional impedance related ventilation perfusion relationship (normΔZV/normΔZQ). We observed a trend towards increased normΔZV in all lung regions, a significantly decreased normΔZQ in the global and anterior, but not the posterior lung region. The normΔZV/normΔZQ was significantly increased in the global and anterior lung region. Our study qualitatively validates our previously published modified EIT filtration technique in the clinical setting of young children with significant left-to-right shunt undergoing corrective open heart surgery, where perioperative assessment of the ventilation perfusion relation is of high clinical relevance.

  18. Implementation of natural ventilation in pig houses

    NARCIS (Netherlands)

    Klooster, van 't C.E.

    1994-01-01

    A description of experimental work and discussion on implementation of natural ventilation in pig houses is given. A literature review describes the state of the art, animal growth data are given. It includes characterization of ventilation openings, a technique to estimate the ventilation

  19. 46 CFR 98.25-75 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... shall be fitted with efficient natural or mechanical ventilation. (b) Enclosed compartments in which... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST... Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom outlet connections shall be...

  20. 46 CFR 194.10-25 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... magazines. (1) All integral magazines shall be provided with natural or mechanical ventilation. Design... vans shall be provided with natural ventilation sufficient to maintain the inside air temperature below... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.10-25 Section 194.10-25 Shipping COAST...

  1. 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...

  2. 14 CFR 252.9 - Ventilation systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating so...

  3. Ventilation strategies and indoor environment in classrooms

    DEFF Research Database (Denmark)

    Zhang, Chen; Liu, Li

    2017-01-01

    Compared with the other building types, the school building has much higher occupancy density and ventilation demand. In Demark, most of the school buildings are ventilated by natural manner. There is a risk of poor indoor environment associated with the lack of ventilation system or insufficient...

  4. Intelligent ventilation in the intensive care unit

    Directory of Open Access Journals (Sweden)

    Sigal Sviri

    2012-08-01

    Full Text Available Objectives. Automated, microprocessor-controlled, closed-loop mechanical ventilation has been used in our Medical Intensive Care Unit (MICU at the Hadassah Hebrew-University Medical Center for the past 15 years; for 10 years it has been the primary (preferred ventilator modality. Design and setting. We describe our clinical experience with adaptive support ventilation (ASV over a 6-year period, during which time ASV-enabled ventilators became more readily available and were used as the primary (preferred ventilators for all patients admitted to the MICU. Results. During the study period, 1 220 patients were ventilated in the MICU. Most patients (84% were ventilated with ASV on admission. The median duration of ventilation with ASV was 6 days. The weaning success rate was 81%, and tracheostomy was required in 13%. Sixty-eight patients (6% with severe hypoxia and high inspiratory pressures were placed on pressure-controlled ventilation, in most cases to satisfy a technical requirement for precise and conservative administration of inhaled nitric oxide. The overall pneumothorax rate was less than 3%, and less than 1% of patients who were ventilated only using ASV developed pneumothorax. Conclusions. ASV is a safe and acceptable mode of ventilation for complicated medical patients, with a lower than usual ventilation complication rate.

  5. 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

  6. 21 CFR 868.5895 - Continuous ventilator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continuous ventilator. 868.5895 Section 868.5895...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5895 Continuous ventilator. (a) Identification. A continuous ventilator (respirator) is a device intended to mechanically control or assist...

  7. 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...

  8. Ventilation system in fire modelization

    International Nuclear Information System (INIS)

    Cordero Garcia, S.

    2012-01-01

    There is a model of fire in an enclosure formed by two rooms. In one of them, it will cause the fire and check how the system of ventilation in different configurations responds. In addition, the behavior of selected targets, which will be a configuration of cables similar to those found in nuclear power stations will be analyzed.

  9. 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.

  10. Design ventilátoru

    OpenAIRE

    Macháčková, Petra

    2013-01-01

    Předmětem této bakalářské práce je návrh designu stolního ventilátoru. Hlavní myšlenkou je inovativní přístup a dodržení technických, estetických a ergonomických požadavků a současně splnění psychologických a ekonomických funkcí. Navržený ventilátor by měl využívat inovativní technologie bezlopatkových ventilátorů. Ventilátor by měl působit jako vhodný doplněk do moderního interiéru. Cílem je propojit originální design s modernizací přístroje při splnění obecných předpokladů průmyslového desi...

  11. 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....

  12. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    Ventilation systems with vertical displacement flow have been used in industrial areas with extensive heat loads for many years. Hot and contaminant air is carried directly from the occupied zone towards the ceiling by hot processes and other activities which create a natural convection flow....

  13. ENERGY STAR Certified Ventilating Fans

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of October 1, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=vent_fans.pr_crit_vent_fans

  14. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    ... to stop eating (fast), be on a special diet, or take any medicines before the test. A chest x-ray is usually done before or after a ventilation and perfusion scan. You wear a hospital gown or comfortable clothing that does not have ...

  15. Organizational governance

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Klein, Peter G.

    This chapter reviews and discusses rational-choice approaches to organizational governance. These approaches are found primarily in organizational economics (virtually no rational-choice organizational sociology exists), particularly in transaction cost economics, principal-agent theory...

  16. Waste governance

    CSIR Research Space (South Africa)

    Oelofse, Suzanna HH

    2018-06-01

    Full Text Available of governance in Africa. The next section focuses on regulation, and the status of the regulatory frameworks in different African countries. Shortcomings in the regulatory framework are highlighted through examples in various countries. Specific policy...

  17. Corporate Governance

    Directory of Open Access Journals (Sweden)

    Dragoș-Mihail Daghie

    2011-05-01

    Full Text Available The purpose of this study is to analyze and understand the recently introduced form of managementof a company limited by shares. The Law no. 441/2006, which fundamentally amended Company Law,created this form of controlling the company, the corporate governance, but the legislation does not explicitlydefine what it wants to achieve through this instrument. This topic is recent in research as the theme ofgerman-roman commercial law systems (in French corporate governance system was introduced in 1966 andin Romania in 2006 but in terms of Anglo-Saxon law, the topic has been addressed years since 1776 (AdamSmith: The Wealth of Nations The concept of corporate governance would like, as a result, to establish somerules that companies must comply in order to achieve effective governance, transparent and beneficial forboth shareholders and for the minority. Corporate governance is a key element with an aim at improvingefficiency and economic growth in full accordance with the increase of investors’ confidence. Corporategovernance assumes a series of relationship between the company management, leadership, shareholders andthe other people concerned. Also corporate governance provides for that structure by means of which thecompany’s targets are set out and the means to achieve them and also the manner how to monitor such.

  18. Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

    Science.gov (United States)

    Krieger, Tobias J; Wald, Martin

    2017-03-01

    Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

  19. Heat Transfer and Fluid Flow in Naturally Ventilated Greenhouses

    Directory of Open Access Journals (Sweden)

    M. Elashmawy

    2017-08-01

    Full Text Available In this paper, heat transfer and fluid flow in naturally ventilated greenhouses are studied numerically for tow configuration according to the number and positions of the opening. The equations governing the phenomenon are developed using the stream function-vorticity formalism and solved using the finite volume method. The aim of the study is to investigate how buoyancy forces influence airflow and temperature patterns inside the greenhouse. Rayleigh number is the main parameter which changes from 103 to 106 and Prandtl number is fixed at Pr=0.71. Results are reported in terms of stream function, isotherms and average Nusselt number. It is found that the flow structure is sensitive to the value of Rayleigh number and the number of openings. Also, that using asymmetric opening positions improve the natural ventilation and facilitate the occurrence of buoyancy induced upward cross-airflow inside the greenhouse.

  20. Ventilation system design for educational facilities

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F.; Abo Elazm, M.M. [Arab Academy for Science, Alexandria (Egypt). Technology and Maritime Transport; Safwan, M. [Arab Academy for Science, Cairo (Egypt). Technology and Maritime Transport

    2010-07-01

    In order to maintain acceptable indoor air quality levels in classrooms, high ventilation rates are needed to dilute the concentration of indoor contaminants, resulting in higher energy consumption for the operation of mechanical ventilation systems. Three factors are usually considered when determining the adequate ventilation rate for classrooms in educational facilities. These include the maximum population served in the classroom; carbon dioxide (CO{sub 2}) production rate by occupants; and outdoor air conditions. CO{sub 2} concentrations usually indicate the rate of ventilation required. This paper presented a newly developed computer software program for determining the ventilation rates needed to enhance indoor air quality and to maintain CO{sub 2} concentration within the recommended levels by ANSI/ASHRAE standards for best student performance. This paper also presented design curves for determining the ventilation rates and air changes per hour required for the ventilated educational zone. 15 refs., 2 tabs., 5 figs.

  1. Minute Ventilation Limitations of Two Field Transport Ventilators.

    Science.gov (United States)

    Szpisjak, Dale F; Horn, Gregory; Shalov, Samuel; Abes, Alvin Angelo; Van Decar, Lauren

    2017-01-01

    Knowledge of transport ventilator performance impacts patient safety. This study compared minute ventilation (V E ) of the MOVES and Uni-Vent 731 when ventilating the VentAid Training Test Lung with compliance (C) ranging from 0.02 to 0.10 L/cm H 2 O and three different airway resistances (R) (none, Rp5, or Rp20). Tidal volume (V T ) was 800 ± 25 mL. Respiratory rate was increased to ventilator's maximum or until auto-PEEP > 5 cm H 2 O. Respiratory parameters were recorded with the RSS 100HR Research Pneumotach. Data were reported as median (interquartile range). Peak inspiratory pressure (PIP) of the Uni-Vent and MOVES ranged from 22.3 (22.2-22.5) to 82.6 (82.2-83.2) and 20.8 (20.6-20.9) to 50.6 (50.2-50.9) cm H 2 O, respectively. V E of the Uni-Vent and MOVES ranged from 17.7 (17.7-17.7) to 31.5 (31.5-31.5) and 11.3 (10.5-11.3) to 20.2 (19.7-20.5) L/min, respectively. Linear regression demonstrated strong, negative correlation of V E with PIP for the MOVES (V E [L/min] = 26 - 0.31 × PIP [cm H 2 O], r = -0.97) but weak, positive correlation for the Uni-Vent (r = 0.05). Uni-Vent V E exceeded MOVES V E under each test condition (p = 0.0002). If patient V E requirements exceed those predicted by the MOVES regression equation, then using the Uni-Vent should be considered. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

  2. Selected topics in high temperature chemistry defect chemistry of solids

    CERN Document Server

    Johannesen, Ø

    2013-01-01

    The properties of materials at high temperature play a vital role in their processing and practical use. The real properties of materials at elevated temperatures are very often governed by defects in their structure. Lattice defects may consist of point defects like vacancies, interstitial atoms or substituted atoms. These classes are discussed in general and specifically for oxides, nitrides, carbides and sulfides. Defect aggregates, shear structures and adaptive structures are also described. Special attention is paid to hydrogen defects which seem to play an important role in several mater

  3. 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

  4. Tax Governance

    DEFF Research Database (Denmark)

    Boll, Karen; Brehm Johansen, Mette

    to wider international trends within tax administration, especially concerning the development of risk assessments and internal control in the corporations and a greater focus on monitoring of these elements by the tax authorities. Overall, the working paper concludes that Tax Governance as a model......This working paper presents an analysis of the experiences of Cooperative Compliance in Denmark. Cooperative Compliance denotes a specific kind of collaborative program for the regulation of large corporate taxpayers by the tax authorities. Cooperative Compliance programs have been implemented...... in several countries worldwide. In Denmark the program is called Tax Governance. Tax Governance has been studied using qualitative method and the analyses of the working paper build on an extensive base of in-depth interviews – primarily with tax directors from corporations participating in the program...

  5. Mobilizing Government

    DEFF Research Database (Denmark)

    Wang, Cancan; Medaglia, Rony; Jensen, Tina Blegind

    2016-01-01

    The nature of inter-organizational collaboration between government and other stakeholders is rapidly changing with the introduction of open social media (OSM) platforms. Characterized by a high degree of informality as well as a blurred personal/professional nature, OSM can potentially introduce...... changes and tensions in the well-established routines of the public sector. This paper aims at shedding light on such changes, presenting findings from a study on the use of an OSM platform, WeChat, in an interorganizational collaboration project between government, university, and industry stakeholders...

  6. SU-C-BRA-06: Developing Clinical and Quantitative Guidelines for a 4DCT-Ventilation Functional Avoidance Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradskiy, Y; Waxweiler, T; Diot, Q; Kavanagh, B; Schubert, L; Miften, M [University of Colorado Denver, Aurora, CO (United States); Castillo, R [University of Texas Medical Branch of Galveston, Pearland, TX (United States); Guerrero, T; Castillo, E [Beaumont Health System, Royal Oak, MI (United States)

    2015-06-15

    Purpose: 4DCT-ventilation is an exciting new imaging modality that uses 4DCTs to calculate lung ventilation. Because 4DCTs are acquired as part of routine care, calculating 4DCT-ventilation allows for lung function evaluation without additional cost or inconvenience to the patient. Development of a clinical trial is underway at our institution to use 4DCT-ventilation for thoracic functional avoidance with the idea that preferential sparing of functional lung regions can decrease pulmonary toxicity. The purpose of our work was to develop the practical aspects of a 4DCT-ventilation functional avoidance clinical trial including: 1.assessing patient eligibility 2.developing trial inclusion criteria and 3.developing treatment planning and dose-function evaluation strategies. Methods: 96 stage III lung cancer patients from 2 institutions were retrospectively reviewed. 4DCT-ventilation maps were calculated using the patient’s 4DCTs, deformable image registrations, and a density-change-based algorithm. To assess patient eligibility and develop trial inclusion criteria we used an observer-based binary end point noting the presence or absence of a ventilation defect and developed an algorithm based on the percent ventilation in each lung third. Functional avoidance planning integrating 4DCT-ventilation was performed using rapid-arc and compared to the patient’s clinically used plan. Results: Investigator-determined clinical ventilation defects were present in 69% of patients. Our regional/lung-thirds ventilation algorithm identified that 59% of patients have lung functional profiles suitable for functional avoidance. Compared to the clinical plan, functional avoidance planning was able to reduce the mean dose to functional lung by 2 Gy while delivering comparable target coverage and cord/heart doses. Conclusions: 4DCT-ventilation functional avoidance clinical trials have great potential to reduce toxicity, and our data suggest that 59% of lung cancer patients have lung

  7. Stockpiling Ventilators for Influenza Pandemics.

    Science.gov (United States)

    Huang, Hsin-Chan; Araz, Ozgur M; Morton, David P; Johnson, Gregory P; Damien, Paul; Clements, Bruce; Meyers, Lauren Ancel

    2017-06-01

    In preparing for influenza pandemics, public health agencies stockpile critical medical resources. Determining appropriate quantities and locations for such resources can be challenging, given the considerable uncertainty in the timing and severity of future pandemics. We introduce a method for optimizing stockpiles of mechanical ventilators, which are critical for treating hospitalized influenza patients in respiratory failure. As a case study, we consider the US state of Texas during mild, moderate, and severe pandemics. Optimal allocations prioritize local over central storage, even though the latter can be deployed adaptively, on the basis of real-time needs. This prioritization stems from high geographic correlations and the slightly lower treatment success assumed for centrally stockpiled ventilators. We developed our model and analysis in collaboration with academic researchers and a state public health agency and incorporated it into a Web-based decision-support tool for pandemic preparedness and response.

  8. 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...... and locations, using VC as a mean of indoor comfort improvement. The building-spreadsheet highlights distributions of technologies and strategies, such as the following. (Numbers in % refer to the sample of the database’s 91 buildings.) It may be concluded that Ventilative Cooling is applied in temporary......, 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...

  9. 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. In m....... In most health-care environments, harmful microorganisms and infectious aerosols may exist in relatively high concentration. They are particularly harmful to patients due to reduced immunity, and to those with open wounds.......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...

  10. Initial mechanical ventilator settings and lung protective ventilation in the ED.

    Science.gov (United States)

    Wilcox, Susan R; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey; Seigel, Todd A

    2016-08-01

    Mechanical ventilation with low tidal volumes has been shown to improve outcomes for patients both with and without acute respiratory distress syndrome. This study aims to characterize mechanically ventilated patients in the emergency department (ED), describe the initial ED ventilator settings, and assess for associations between lung protective ventilation strategies in the ED and outcomes. This was a multicenter, prospective, observational study of mechanical ventilation at 3 academic EDs. We defined lung protective ventilation as a tidal volume of less than or equal to 8 mL/kg of predicted body weight and compared outcomes for patients ventilated with lung protective vs non-lung protective ventilation, including inhospital mortality, ventilator days, intensive care unit length of stay, and hospital length of stay. Data from 433 patients were analyzed. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Two hundred sixty-one patients (60.3%) received lung protective ventilation, but most patients were ventilated with a low positive end-expiratory pressure, high fraction of inspired oxygen strategy. Patients were ventilated in the ED for a mean of 5 hours and 7 minutes but had few ventilator adjustments. Outcomes were not significantly different between patients receiving lung protective vs non-lung protective ventilation. Nearly 40% of ED patients were ventilated with non-lung protective ventilation as well as with low positive end-expiratory pressure and high fraction of inspired oxygen. Despite a mean ED ventilation time of more than 5 hours, few patients had adjustments made to their ventilators. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Ventilation-air conditioning system

    International Nuclear Information System (INIS)

    Kubokoya, Takashi.

    1991-01-01

    Heretofore, in ventilation-air conditioning systems in a nuclear power plant, exhaust gases from each of the ventilation-air conditioning systems of a reactor building, a turbine building, a waste processing building are joined and they are released into atmosphere from the top of a high main exhaustion stack. In order to build such a high main exhaustion stack, a considerable construction cost is required and, in addition, there is a worry of lacking balance with surrounding scenery. Then, in the present invention, exhaust gases are heated by waste heat in a turbine during their introduction from the ventilation-air conditioning facility in the building of a power plant to the main exhaust stack. With such a constitution, since the exhaust gases are heated and their temperature is elevated, they uprise by natural convection when they are released from the top of the main exhaustion stack to the atmosphere. Accordingly, they are released to a level higher than the conventional case in view of the volume of the blower which sends the exhaust gases under pressure, to diffuse them to the atmosphere more sufficiently compared with a conventional case. Further, the height of the main exhaustion stack can be reduced, enabling to minimize the cost for moving the blower. (T.M.)

  12. Bank Governance

    OpenAIRE

    Laura Ard; Alexander Berg

    2010-01-01

    Principles of good governance have been a major component of international financial standards and are seen as essential to the stability and integrity of financial systems. Over the past 10 years much energy and attention have gone to improving the ability of company boards, managers, and owners to prudently navigate rapidly changing and volatile market conditions. So, how to explain the ...

  13. Government Organizations

    DEFF Research Database (Denmark)

    Krause Hansen, Hans; Salskov-Iversen, Dorte

    2017-01-01

    , with clearly defined boundaries between the public and private; and in terms of polycentrism, where power and authority are seen as dispersed among state and nonstate organizations, including business and civil society organizations. Globalization and new media technologies imply changes in the relationship...... democracy and the public sphere; and discourse approaches to studying the intersections of government, organizational change, and information and communication technology....

  14. Corporate Governance

    International Development Research Centre (IDRC) Digital Library (Canada)

    Andy Knight; David Malone; Faith Mitchell. Finance and Audit Committee. Members: Denis Desautels (Chairman); Ahmed Galal;. Frieda Granot; Elizabeth Parr-Johnston; Andrés Rozental;. Gordon Shirley. Governance Committee. Members: The Honourable Barbara McDougall (Chairman);. Claude-Yves Charron; Denis ...

  15. 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.

  16. Craniotomy Frontal Bone Defect

    African Journals Online (AJOL)

    2018-03-01

    Mar 1, 2018 ... Defect reconstruction and fixation of the graft: The defect of ... where all loose fragments of fractured frontal bone was removed via the ... Mandible. • Ilium. • Allograft ... pediatric patients owing to skull growth. Thus, autologous ...

  17. Congenital platelet function defects

    Science.gov (United States)

    ... pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... Congenital platelet function defects are bleeding disorders that cause reduced platelet function. Most of the time, people with these disorders have ...

  18. Temperature of gas delivered from ventilators.

    Science.gov (United States)

    Chikata, Yusuke; Onodera, Mutsuo; Imanaka, Hideaki; Nishimura, Masaji

    2013-01-01

    Although heated humidifiers (HHs) are the most efficient humidifying device for mechanical ventilation, some HHs do not provide sufficient humidification when the inlet temperature to the water chamber is high. Because portable and home-care ventilators use turbines, blowers, pistons, or compressors to inhale in ambient air, they may have higher gas temperature than ventilators with piping systems. We carried out a bench study to investigate the temperature of gas delivered from portable and home-care ventilators, including the effects of distance from ventilator outlet, fraction of inspiratory oxygen (FIO2), and minute volume (MV). We evaluated five ventilators equipped with turbine, blower, piston, or compressor system. Ambient air temperature was adjusted to 24°C ± 0.5°C, and ventilation was set at FIO2 0.21, 0.6, and 1.0, at MV 5 and 10 L/min. We analyzed gas temperature at 0, 40, 80, and 120 cm from ventilator outlet and altered ventilator settings. While temperature varied according to ventilators, the outlet gas temperature of ventilators became stable after, at the most, 5 h. Gas temperature was 34.3°C ± 3.9°C at the ventilator outlet, 29.5°C ± 2.2°C after 40 cm, 25.4°C ± 1.2°C after 80 cm and 25.1°C ± 1.2°C after 120 cm (P < 0.01). FIO2 and MV did not affect gas temperature. Gas delivered from portable and home-care ventilator was not too hot to induce heated humidifier malfunctioning. Gas soon declined when passing through the limb.

  19. Mechanical ventilators in US acute care hospitals.

    Science.gov (United States)

    Rubinson, Lewis; Vaughn, Frances; Nelson, Steve; Giordano, Sam; Kallstrom, Tom; Buckley, Tim; Burney, Tabinda; Hupert, Nathaniel; Mutter, Ryan; Handrigan, Michael; Yeskey, Kevin; Lurie, Nicole; Branson, Richard

    2010-10-01

    The supply and distribution of mechanical ventilation capacity is of profound importance for planning for severe public health emergencies. However, the capability of US health systems to provide mechanical ventilation for children and adults remains poorly quantified. The objective of this study was to determine the quantity of adult and pediatric mechanical ventilators at US acute care hospitals. A total of 5,752 US acute care hospitals included in the 2007 American Hospital Association database were surveyed. We measured the quantities of mechanical ventilators and their features. Responding to the survey were 4305 (74.8%) hospitals, which accounted for 83.8% of US intensive care unit beds. Of the 52,118 full-feature mechanical ventilators owned by respondent hospitals, 24,204 (46.4%) are pediatric/neonatal capable. Accounting for nonrespondents, we estimate that there are 62,188 full-feature mechanical ventilators owned by US acute care hospitals. The median number of full-feature mechanical ventilators per 100,000 population for individual states is 19.7 (interquartile ratio 17.2-23.1), ranging from 11.9 to 77.6. The median number of pediatric-capable device full-feature mechanical ventilators per 100,000 population younger than 14 years old is 52.3 (interquartile ratio 43.1-63.9) and the range across states is 22.1 to 206.2. In addition, respondent hospitals reported owning 82,755 ventilators other than full-feature mechanical ventilators; we estimate that there are 98,738 devices other than full-feature ventilators at all of the US acute care hospitals. The number of mechanical ventilators per US population exceeds those reported by other developed countries, but there is wide variation across states in the population-adjusted supply. There are considerably more pediatric-capable ventilators than there are for adults only on a population-adjusted basis.

  20. Defect of the Eyelids.

    Science.gov (United States)

    Lu, Guanning Nina; Pelton, Ron W; Humphrey, Clinton D; Kriet, John David

    2017-08-01

    Eyelid defects disrupt the complex natural form and function of the eyelids and present a surgical challenge. Detailed knowledge of eyelid anatomy is essential in evaluating a defect and composing a reconstructive plan. Numerous reconstructive techniques have been described, including primary closure, grafting, and a variety of local flaps. This article describes an updated reconstructive ladder for eyelid defects that can be used in various permutations to solve most eyelid defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Improving the energy and IAQ performance of ventilation systems in Dutch dwellings

    NARCIS (Netherlands)

    Holsteijn, R.C.A. van; Li, W.L.; Valk, H.J.J.; Kornaat, W.

    2016-01-01

    MONICAIR - MONItoring & Control of Air quality in Individual Rooms - is a pre-competitive field research project of a broad consortium of Dutch ventilation unit manufacturers and research institutes, supported by the Dutch government. The first aim of the project is to investigate and compare the

  2. 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

  3. Point defects in solids

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The principal properties of point defects are studied: thermodynamics, electronic structure, interactions with etended defects, production by irradiation. Some measuring methods are presented: atomic diffusion, spectroscopic methods, diffuse scattering of neutron and X rays, positron annihilation, molecular dynamics. Then points defects in various materials are investigated: ionic crystals, oxides, semiconductor materials, metals, intermetallic compounds, carbides, nitrides [fr

  4. Fibrous metaphyseal defects

    International Nuclear Information System (INIS)

    Ritschl, P.; Hajek, P.C.; Pechmann, U.

    1989-01-01

    Sixteen patients with fibrous metaphyseal defects were examined with both plain radiography and magnetic resonance (MR) imaging. Depending on the age of the fibrous metaphyseal defects, characteristic radiomorphologic changes were found which correlated well with MR images. Following intravenous Gadolinium-DTPA injection, fibrous metaphyseal defects invariably exhibited a hyperintense border and signal enhancement. (orig./GDG)

  5. Birth Defects (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Birth Defects KidsHealth / For Parents / Birth Defects What's in ... Prevented? Print en español Anomalías congénitas What Are Birth Defects? While still in the womb, some babies ...

  6. Clinical studies on combined ventilation (sup(81m)Kr)/perfusion (sup(99m)Tc-MAA) scintigraphy

    International Nuclear Information System (INIS)

    Yamamoto, Keiichiro; Miyamae, Tatsuya

    1983-01-01

    One hundred fifty patients having pulmonary disease underwent pulmonary scintigraphy sequentially with sup(99m)Tc-MAA and sup(81m)Kr gases. Scintigrams of matched defect were obtained from 113 (75.3%) of the 150 patients, considered to be nonspecific universal pattern of a pulmonary disease. Scintigrams of mismatched defect (absent perfusion and homogeneous ventilation) were obtained from 20 patients (13.3%), including 6 with lung carcinoma, 3 with pulmonary embolism, 3 with connective tissue disease, 2 with aortitis syndrome and 6 with other diseases. Scintigrams of mismatch with impaired ventilation and normal perfusion were mainly seen in chronic obstructive lung diseases. Of the 10 patients with bronchial asthma, 5 had scintigrams of improved ventilation after intravenous injection of 250 mg aminophilline, but none of patients with emphysema. The combined scintigraphy has made significant contributions to diagnosis and management of patients with pulmonary disease where the chest X-ray is unhelpful. (author)

  7. Pulmonary edema following transcatheter closure of atrial septal defect

    Directory of Open Access Journals (Sweden)

    Keerthi Chigurupati

    2015-01-01

    Full Text Available We describe an incident of development of acute pulmonary edema after the device closure of a secundum atrial septal defect in a 52-year-old lady, which was treated with inotropes, diuretics and artificial ventilation. Possibility of acute left ventricular dysfunction should be considered after the defect closure in the middle-aged patients as the left ventricular compliance may be reduced due to increased elastic stiffness and diastolic dysfunction. Baseline left atrial pressure may be > 10 mmHg in these patients. Associated risk factors for the left ventricular dysfunction are a large Qp:Qs ratio, systemic hypertension, severe pulmonary hypertension and paroxysmal atrial fibrillation.

  8. Value of chest X-ray combined with perfusion scan versus ventilation/perfusion scan in acute pulmonary embolism

    NARCIS (Netherlands)

    de Groot, M. R.; Turkstra, F.; van Marwijk Kooy, M.; Oostdijk, A. H.; van Beek, E. J.; Büller, H. R.

    2000-01-01

    The main purpose of ventilation scanning, as adjunct to perfusion lung scintigraphy, in acute pulmonary embolism is to allow for the classification of segmental perfusion defects as mismatched, which is generally accepted as proof for the presence of pulmonary embolism. We examined whether this

  9. Detection of early subclinical lung disease in children with cystic fibrosis by lung ventilation imaging with hyperpolarised gas MRI.

    Science.gov (United States)

    Marshall, Helen; Horsley, Alex; Taylor, Chris J; Smith, Laurie; Hughes, David; Horn, Felix C; Swift, Andrew J; Parra-Robles, Juan; Hughes, Paul J; Norquay, Graham; Stewart, Neil J; Collier, Guilhem J; Teare, Dawn; Cunningham, Steve; Aldag, Ina; Wild, Jim M

    2017-08-01

    Hyperpolarised 3 He ventilation-MRI, anatomical lung MRI, lung clearance index (LCI), low-dose CT and spirometry were performed on 19 children (6-16 years) with clinically stable mild cystic fibrosis (CF) (FEV 1 >-1.96), and 10 controls. All controls had normal spirometry, MRI and LCI. Ventilation-MRI was the most sensitive method of detecting abnormalities, present in 89% of patients with CF, compared with CT abnormalities in 68%, LCI 47% and conventional MRI 22%. Ventilation defects were present in the absence of CT abnormalities and in patients with normal physiology, including LCI. Ventilation-MRI is thus feasible in young children, highly sensitive and provides additional information about lung structure-function relationships. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  10. Comparative performances analysis of neonatal ventilators.

    Science.gov (United States)

    Baldoli, Ilaria; Tognarelli, Selene; Scaramuzzo, Rosa T; Ciantelli, Massimiliano; Cecchi, Francesca; Gentile, Marzia; Sigali, Emilio; Ghirri, Paolo; Boldrini, Antonio; Menciassi, Arianna; Laschi, Cecilia; Cuttano, Armando

    2015-02-08

    Mechanical ventilation is a therapeutic action for newborns with respiratory diseases but may have side effects. Correct equipment knowledge and training may limit human errors. We aimed to test different neonatal mechanical ventilators' performances by an acquisition module (a commercial pressure sensor plus an isolated chamber and a dedicated software). The differences (ΔP) between peak pressure values and end-expiration pressure were investigated for each ventilator. We focused on discrepancies among measured and imposed pressure data. A statistical analysis was performed. We investigated the measured/imposed ΔP relation. The ΔP do not reveal univocal trends related to ventilation setting parameters and the data distributions were non-Gaussian. Measured ΔP represent a significant parameter in newborns' ventilation, due to the typical small volumes. The investigated ventilators showed different tendencies. Therefore, a deep specific knowledge of the intensive care devices is mandatory for caregivers to correctly exploit their operating principles.

  11. Application of CPM procedures in mine ventilation

    International Nuclear Information System (INIS)

    Wang, Y.J.; Mutmansky, J.M.

    1982-01-01

    Mine ventilation analysis is an engineering discipline that can be considered a branch of the body of science known as network analysis. Likewise, the group of engineering procedures known as the critical path method (CPM) is considered a branch of network analysis. It is therefore not surprising that mine ventilation network analysis and CPM have many similarities. These similarities are useful in analyzing several types of mine ventilation problems and will be utilized in this paper. The analogy between the free split in a ventilation circuit and the critical path in a scheduling network has been recognized by Owili-Eger (1973). While this was recognized as a property of a general ventilation network, many important applications to controlled-splitting problems also exist. The mathematical procedures necessary to apply CPM and network methods have previously been presented (Wang, 1981; Wang, 1982). This paper will illustrate the implementation of these methods by application to mine ventilation networks

  12. Plural Governance

    DEFF Research Database (Denmark)

    Mols, Niels Peter; Hansen, Jesper Rosenberg; Villadsen, Anders Ryom

    We suggest that both making and buying the same product or service has several effects on market performance. A model is developed and tested by use of 170 answers gathered from the Danish municipalities. The results support the hypotheses that both making and buying: (1) moderates the negative r...... on how the plurality is measured. The results indicate that internal production may facilitate effective governance of the relationships with suppliers. Implications for research on firm boundaries and for practice are also discussed....

  13. IT Governance

    OpenAIRE

    Šimková, Hana

    2008-01-01

    IT governance (control of information technology) is a frequently discussed topic today which represents current needs to take control of IT, judge impacts of all resolutions and lead up investments running to the information technology. It is very important for both small and large organizations to have IT which encourages business strategy and helps to meet objectives of a company. The theoretical part of this paper is focused on characterization of the main areas, benefits, rules and vario...

  14. Dirichlet topological defects

    International Nuclear Information System (INIS)

    Carroll, S.M.; Trodden, M.

    1998-01-01

    We propose a class of field theories featuring solitonic solutions in which topological defects can end when they intersect other defects of equal or higher dimensionality. Such configurations may be termed open-quotes Dirichlet topological defects,close quotes in analogy with the D-branes of string theory. Our discussion focuses on defects in scalar field theories with either gauge or global symmetries, in 3+1 dimensions; the types of defects considered include walls ending on walls, strings on walls, and strings on strings. copyright 1998 The American Physical Society

  15. Synthetic Defects for Vibrothermography

    Science.gov (United States)

    Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

    2010-02-01

    Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

  16. Defect production in ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States); Kinoshita, C. [Kyushu Univ. (Japan)

    1997-08-01

    A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

  17. Modelling of Natural and Hybrid Ventilation

    OpenAIRE

    Heiselberg, Per

    2006-01-01

    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,...

  18. Prevention of ventilator-associated pneumonia

    OpenAIRE

    J. Oliveira; C. Zagalo; P. Cavaco-Silva

    2014-01-01

    Invasive mechanical ventilation (IMV) represents a risk factor for the development of ventilator-associated pneumonia (VAP), which develops at least 48 h after admission in patients ventilated through tracheostomy or endotracheal intubation. VAP is the most frequent intensive-care-unit (ICU)-acquired infection among patients receiving IMV. It contributes to an increase in hospital mortality, duration of MV and ICU and length of hospital stay. Therefore, it worsens the condition of the critica...

  19. 46 CFR 153.312 - Ventilation system standards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ventilation system standards. 153.312 Section 153.312... Handling Space Ventilation § 153.312 Ventilation system standards. A cargo handling space ventilation system must meet the following: (a) A ventilation system exhaust duct must discharge no less than 10 m...

  20. Ventilation Inception and Washout, Scaling, and Effects on Hydrodynamic Performance of a Surface Piercing Strut

    Science.gov (United States)

    Harwood, Casey; Young, Yin Lu; Ceccio, Steven

    2014-11-01

    High-lift devices that operate at or near a fluid free surface (such as surface-piercing or shallowly-submerged propellers and hydrofoils) are prone to a multiphase flow phenomenon called ventilation, wherein non-condensable gas is entrained in the low-pressure flow, forming a cavity around the body and dramatically altering the global hydrodynamic forces. Experiments are being conducted at the University of Michigan's towing tank using a canonical surface-piercing strut to investigate atmospheric ventilation. The goals of the work are (i) to gain an understanding of the dominant physics in fully wetted, partially ventilated, and fully ventilated flow regimes, (ii) to quantify the effects of governing dimensionless parameters on the transition between flow regimes, and (iii) to develop scaling relations for the transition between flow regimes. Using theoretical arguments and flow visualization techniques, new criteria are developed for classifying flow regimes and transition mechanisms. Unsteady transition mechanisms are described and mapped as functions of the governing non-dimensional parameters. A theoretical scaling relationship is developed for ventilation washout, which is shown to adequately capture the experimentally-observed washout boundary. This material is based upon work supported by the National Science Foundation Graduate Student Research Fellowship under Grant No. DGE 1256260. Support also comes from the Naval Engineering Education Center (Award No. N65540-10-C-003).

  1. On holographic defect entropy

    International Nuclear Information System (INIS)

    Estes, John; Jensen, Kristan; O’Bannon, Andy; Tsatis, Efstratios; Wrase, Timm

    2014-01-01

    We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions

  2. Short-term airing by natural ventilation

    DEFF Research Database (Denmark)

    Perino, Marco; Heiselberg, Per

    2009-01-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates traditio......The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates...... 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...... 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....

  3. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    Directory of Open Access Journals (Sweden)

    H. Asilian Mahabady

    2007-09-01

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

  4. Defect Chemistry of Oxides for Energy Applications.

    Science.gov (United States)

    Schweke, Danielle; Mordehovitz, Yuval; Halabi, Mahdi; Shelly, Lee; Hayun, Shmuel

    2018-05-31

    Oxides are widely used for energy applications, as solid electrolytes in various solid oxide fuel cell devices or as catalysts (often associated with noble metal particles) for numerous reactions involving oxidation or reduction. Defects are the major factors governing the efficiency of a given oxide for the above applications. In this paper, the common defects in oxide systems and external factors influencing the defect concentration and distribution are presented, with special emphasis on ceria (CeO 2 ) based materials. It is shown that the behavior of a variety of oxide systems with respect to properties relevant for energy applications (conductivity and catalytic activity) can be rationalized by general considerations about the type and concentration of defects in the specific system. A new method based on transmission electron microscopy (TEM), recently reported by the authors for mapping space charge defects and measuring space charge potentials, is shown to be of potential importance for understanding conductivity mechanisms in oxides. The influence of defects on gas-surface reactions is exemplified on the interaction of CO 2 and H 2 O with ceria, by correlating between the defect distribution in the material and its adsorption capacity or splitting efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Unusual ventilation perfusion scintigram in a case of immunologic pulmonary edema clinically simulating pulmonary embolism

    International Nuclear Information System (INIS)

    Campeau, R.J.; Faust, J.M.; Ahmad, S.

    1987-01-01

    A case of immunologic pulmonary edema secondary to hydrochlorothiazide allergy developed in a 55-year-old woman that clinically simulated pulmonary embolism. The patient had abnormal washin images with normal washout images on an Xe-133 ventilation study. On the perfusion study, large bilateral central and posterior perfusion defects were present that showed an unusual mirror image pattern on the lateral and posterior oblique views. Resolution of radiographic and scintigraphic abnormalities occurred over a 3-day period in conjunction with corticosteroid therapy

  6. [Alveolar ventilation and recruitment under lung protective ventilation].

    Science.gov (United States)

    Putensen, Christian; Muders, Thomas; Kreyer, Stefan; Wrigge, Hermann

    2008-11-01

    Goal of mechanical ventilation is to improve gas exchange and reduce work of breathing without contributing to further lung injury. Besides providing adequate EELV and thereby arterial oxygenation PEEP in addition to a reduction in tidal volume is required to prevent cyclic alveolar collapse and tidal recruitment and hence protective mechanical ventilation. Currently, there is no consensus if and if yes at which price alveolar recruitment with high airway pressures should be intended ("open up the lung"), or if it is more important to reduce the mechanical stress and strain to the lungs as much as possible ("keep the lung closed"). Potential of alveolar recruitment differs from patient to patient but also between lung regions. Potential for recruitment depends probably more on regional lung mechanics - especially on lung elastance - than on the underlying disease. Based on available data neither high PEEP nor other methods used for alveolar recruitment could demonstrate a survival benefit in patients with ARDS. These results may support an individualized titration of PEEP or other manoeuvres used for recruitment taking into consideration the regional effects. Bedside imaging techniques allowing titration of PEEP or other manoeuvres to prevent end-expiratory alveolar collapse (tidal recruitment) and inspiratory overinflation may be a promising development.

  7. 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...

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

    DEFF Research Database (Denmark)

    Petersen, Steffen; Hviid, Christian Anker

    2013-01-01

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

  9. Genital and Urinary Tract Defects

    Science.gov (United States)

    ... conditions > Genital and urinary tract defects Genital and urinary tract defects E-mail to a friend Please fill ... and extra fluids. What problems can genital and urinary tract defects cause? Genital and urinary tract defects affect ...

  10. Ventil

    OpenAIRE

    Schmidt, U.; Schuetz, H.G.; Meinel, M.; Buehling, H.

    1998-01-01

    The valve, especially as an overload safety valve for a mechanical press, has a mechanical lock on the valve piston (1) in the pressure medium flow path between an entry (7) and outlet (9) opening. The lock is a screw which is broken by a pyrotechnic or explosive action. The valve piston (1) has the structure of a step piston, where it is under loading from the pressure medium. USE - The safety valve is for protection of a mechanical press from damage through overloading. ADVANTAGE - The stru...

  11. Ventilation equations for improved exothermic process control.

    Science.gov (United States)

    McKernan, John L; Ellenbecker, Michael J

    2007-04-01

    Exothermic or heated processes create potentially unsafe work environments for an estimated 5-10 million American workers each year. Excessive heat and process contaminants have the potential to cause acute health effects such as heat stroke, and chronic effects such as manganism in welders. Although millions of workers are exposed to exothermic processes, insufficient attention has been given to continuously improving engineering technologies for these processes to provide effective and efficient control. Currently there is no specific occupational standard established by OSHA regarding exposure to heat from exothermic processes, therefore it is important to investigate techniques that can mitigate known and potential adverse occupational health effects. The current understanding of engineering controls for exothermic processes is primarily based on a book chapter written by W. C. L. Hemeon in 1955. Improvements in heat transfer and meteorological theory necessary to design improved process controls have occurred since this time. The research presented involved a review of the physical properties, heat transfer and meteorological theories governing buoyant air flow created by exothermic processes. These properties and theories were used to identify parameters and develop equations required for the determination of buoyant volumetric flow to assist in improving ventilation controls. Goals of this research were to develop and describe a new (i.e. proposed) flow equation, and compare it to currently accepted ones by Hemeon and the American Conference of Governmental Industrial Hygienists (ACGIH). Numerical assessments were conducted to compare solutions from the proposed equations for plume area, mean velocity and flow to those from the ACGIH and Hemeon. Parameters were varied for the dependent variables and solutions from the proposed, ACGIH, and Hemeon equations for plume area, mean velocity and flow were analyzed using a randomized complete block statistical

  12. Performances of domiciliary ventilators compared by using a parametric procedure

    Directory of Open Access Journals (Sweden)

    Fresnel Emeline

    2016-12-01

    Performances of domiciliary ventilators strongly depend not only on the breathing dynamics but also on the ventilator strategy. One given ventilator may be more adequate than another one for a given patient.

  13. History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

    Science.gov (United States)

    Slutsky, Arthur S

    2015-05-15

    Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure.

  14. Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

    Directory of Open Access Journals (Sweden)

    Raffaele L. Dellaca’

    2017-06-01

    To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice. To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients. To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment. To better understand and classify ventilation modes. To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms.

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

    Science.gov (United States)

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

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

  16. 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...

  17. Preoperational test report, primary ventilation system

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    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

  18. Naturlig ventilation og træk

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2002-01-01

    Nye ventilationsprincipper som naturlig ventilation er med til at sætte fokus på de strømningselementer, der skal anvendes til dimensionering af luftfordelingen i et rum. Artiklen anviser, hvordan træk fra vinduer og tagåbninger i rum med naturlig ventilation kan beregnes ved hjælp af...

  19. Preoperational test report, primary ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

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

  20. [Mechanical ventilation in acute asthma crisis].

    Science.gov (United States)

    Barbas, Carmen Sílvia Valente; Pinheiro, Bruno do Valle; Vianna, Arthur; Magaldi, Ricardo; Casati, Ana; José, Anderson; Okamoto, Valdelis Novis

    2007-06-01

    The II Brazilian Consensus Conference on Mechanical Ventilation was published in 2000. Knowledge on the field of mechanical ventilation evolved rapidly since then, with the publication of numerous clinical studies with potential impact on the ventilatory management of critically ill patients. Moreover, the evolving concept of evidence - based medicine determined the grading of clinical recommendations according to the methodological value of the studies on which they are based. This explicit approach has broadened the understanding and adoption of clinical recommendations. For these reasons, AMIB - Associação de Medicina Intensiva Brasileira and SBPT - Sociedade Brasileira de Pneumologia e Tisiologia - decided to update the recommendations of the II Brazilian Consensus. Mechanical ventilation in the asthma attack has been one of the updated topics. Describe the most important topics on the mechanical ventilation during the asthma attack and suggest the main therapeutic approaches. Systematic review of the published literature and gradation of the studies in levels of evidence, using the key words "mechanical ventilation" and "asthma". We present recommendations on the ventilatory modes and settings to be adopted when ventilating a patient during an asthma attack, as well as the recommended monitoring. Alternative ventilation techniques are also presented. Protective ventilatory strategies are recommended when ventilating a patient during a severe asthma attack.

  1. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Lung-protective ventilation in abdominal surgery.

    Science.gov (United States)

    Futier, Emmanuel; Jaber, Samir

    2014-08-01

    To provide the most recent and relevant clinical evidence regarding the use of prophylactic lung-protective mechanical ventilation in abdominal surgery. Evidence is accumulating, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary complications in patients undergoing abdominal surgery. Nonprotective ventilator settings, especially high tidal volume (>10-12 ml/kg), very low level of positive end-expiratory pressure (PEEP, ventilator-associated lung injury in patients with healthy lungs. Stimulated by the previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung-protective mechanical ventilation. Recent data provide compelling evidence that prophylactic lung-protective mechanical ventilation using lower tidal volume (6-8 ml/kg of predicted body weight), moderate PEEP (6-8 cm H2O), and recruitment maneuvers is associated with improved functional or physiological and clinical postoperative outcome in patients undergoing abdominal surgery. The use of prophylactic lung-protective ventilation can help in improving the postoperative outcome.

  3. Review of operating room ventilation standards

    NARCIS (Netherlands)

    Melhado, M.D.A.; Hensen, J.L.M.; Loomans, M.G.L.C.

    2006-01-01

    This article reviews standards applied to operating room ventilation design used by European, South and North American countries. Required environmental parameters are compared with regard to type of surgery, and ventilation system. These requirements as well as their relation to infection control

  4. Lung-protective ventilation in neonatology

    NARCIS (Netherlands)

    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

  5. 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

  6. 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

  7. 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...

  8. 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. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  9. Ventilation of gloveboxes and containment shells

    International Nuclear Information System (INIS)

    Guetron, R.

    1984-01-01

    In this paper are defined fundamental principles for the ventilation of containment enclosures and gloveboxes, and examined criteria required to maintain containment in normal or accidental conditions. Dimensioning of ventilation network and associated equipment (adjustement and filtering devices). Some examples are given [fr

  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. Standardization of pulmonary ventilation technique using volume-controlled ventilators in rats with congenital diaphragmatic hernia

    Directory of Open Access Journals (Sweden)

    Rodrigo Melo Gallindo

    Full Text Available OBJECTIVE: To standardize a technique for ventilating rat fetuses with Congenital Diaphragmatic Hernia (CDH using a volume-controlled ventilator. METHODS: Pregnant rats were divided into the following groups: a control (C; b exposed to nitrofen with CDH (CDH; and c exposed to nitrofen without CDH (N-. Fetuses of the three groups were randomly divided into the subgroups ventilated (V and non-ventilated (N-V. Fetuses were collected on day 21.5 of gestation, weighed and ventilated for 30 minutes using a volume-controlled ventilator. Then the lungs were collected for histological study. We evaluated: body weight (BW, total lung weight (TLW, left lung weight (LLW, ratios TLW / BW and LLW / BW, morphological histology of the airways and causes of failures of ventilation. RESULTS: BW, TLW, LLW, TLW / BW and LLW / BW were higher in C compared with N- (p 0.05. The morphology of the pulmonary airways showed hypoplasia in groups N- and CDH, with no difference between V and N-V (p <0.05. The C and N- groups could be successfully ventilated using a tidal volume of 75 ìl, but the failure of ventilation in the CDH group decreased only when ventilated with 50 ìl. CONCLUSION: Volume ventilation is possible in rats with CDH for a short period and does not alter fetal or lung morphology.

  12. Assisted Ventilation in Patients with Acute Respiratory Distress Syndrome: Lung-distending Pressure and Patient-Ventilator Interaction

    NARCIS (Netherlands)

    Doorduin, J.; Sinderby, C.A.; Beck, J.; Hoeven, J.G. van der; Heunks, L.M.

    2015-01-01

    BACKGROUND: In patients with acute respiratory distress syndrome (ARDS), the use of assisted mechanical ventilation is a subject of debate. Assisted ventilation has benefits over controlled ventilation, such as preserved diaphragm function and improved oxygenation. Therefore, higher level of

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    perception of the environment. The subjects could control the position of the DPV supply diffuser and the personalized air flow (air velocity). The use of DPV improved perceived air quality and thermal comfort compared to displacement ventilation alone. At 26 °C and 29 °C the percentage dissatisfied with air......, increased eye dryness sensation was reported by 30% of subjects. The personalized air flow selected by nearly 80% of the subjects at 26 °C was between 10 and 20 l/s corresponding to the target air velocity of 1.2–1.7 m/s. At 29 °C almost 90% of subjects chose a personalized air flow between 15 and 20 l/s (1...

  14. Short Term Airing by Natural Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Perino, M.

    2010-01-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available 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 for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working...... 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...

  15. 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...

  16. Mechanical Ventilation: State of the Art.

    Science.gov (United States)

    Pham, Tài; Brochard, Laurent J; Slutsky, Arthur S

    2017-09-01

    Mechanical ventilation is the most used short-term life support technique worldwide and is applied daily for a diverse spectrum of indications, from scheduled surgical procedures to acute organ failure. This state-of-the-art review provides an update on the basic physiology of respiratory mechanics, the working principles, and the main ventilatory settings, as well as the potential complications of mechanical ventilation. Specific ventilatory approaches in particular situations such as acute respiratory distress syndrome and chronic obstructive pulmonary disease are detailed along with protective ventilation in patients with normal lungs. We also highlight recent data on patient-ventilator dyssynchrony, humidified high-flow oxygen through nasal cannula, extracorporeal life support, and the weaning phase. Finally, we discuss the future of mechanical ventilation, addressing avenues for improvement. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  17. [Lung protective ventilation - pathophysiology and diagnostics].

    Science.gov (United States)

    Uhlig, Stefan; Frerichs, Inéz

    2008-06-01

    Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography.

  18. Pandemic ventilator rationing and appeals processes.

    Science.gov (United States)

    Patrone, Daniel; Resnik, David

    2011-06-01

    In a severe influenza pandemic, hospitals will likely experience serious and widespread shortages of patient pulmonary ventilators and of staff qualified to operate them. Deciding who will receive access to mechanical ventilation will often determine who lives and who dies. This prospect raises an important question whether pandemic preparedness plans should include some process by which individuals affected by ventilator rationing would have the opportunity to appeal adverse decisions. However, the issue of appeals processes to ventilator rationing decisions has been largely neglected in state pandemic planning efforts. If we are to devise just and effective plans for coping with a severe influenza pandemic, more attention to the issue of appeals processes for pandemic ventilator rationing decisions is needed. Arguments for and against appeals processes are considered, and some suggestions are offered to help efforts at devising more rational pandemic preparedness plans.

  19. 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 shop......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...

  20. Mechanisms of natural ventilation in livestock buildings

    DEFF Research Database (Denmark)

    Rong, Li; Bjerg, Bjarne; 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...

  1. 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.

  2. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  3. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

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

  4. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2012-01-01

    Most people agree that our world face daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel dominant...... perspectives in challenge per-ception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping of engineering education...... and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter strives to elicit the bodies...

  5. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2011-01-01

    Abstract: Most people agree that our world faces daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel...... dominant perspectives in challenge perception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping...... of engineering education and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter...

  6. Bilevel vs ICU ventilators providing noninvasive ventilation: effect of system leaks: a COPD lung model comparison.

    Science.gov (United States)

    Ferreira, Juliana C; Chipman, Daniel W; Hill, Nicholas S; Kacmarek, Robert M

    2009-08-01

    Noninvasive positive-pressure ventilation (NPPV) modes are currently available on bilevel and ICU ventilators. However, little data comparing the performance of the NPPV modes on these ventilators are available. In an experimental bench study, the ability of nine ICU ventilators to function in the presence of leaks was compared with a bilevel ventilator using the IngMar ASL5000 lung simulator (IngMar Medical; Pittsburgh, PA) set at a compliance of 60 mL/cm H(2)O, an inspiratory resistance of 10 cm H(2)O/L/s, an expiratory resistance of 20 cm H(2)O/ L/s, and a respiratory rate of 15 breaths/min. All of the ventilators were set at 12 cm H(2)O pressure support and 5 cm H(2)O positive end-expiratory pressure. The data were collected at baseline and at three customized leaks. At baseline, all of the ventilators were able to deliver adequate tidal volumes, to maintain airway pressure, and to synchronize with the simulator, without missed efforts or auto-triggering. As the leak was increased, all of the ventilators (except the Vision [Respironics; Murrysville, PA] and Servo I [Maquet; Solna, Sweden]) needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation, and some transitioned to backup ventilation. Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators. The Vision and Servo I were the only ventilators that required no adjustments as they adapted to increasing leaks. There were differences in performance between these two ventilators, although the clinical significance of these differences is unclear. Clinicians should be aware that in the presence of leaks, most ICU ventilators require adjustments to maintain an adequate tidal volume.

  7. Mechanical ventilation during extracorporeal membrane oxygenation.

    Science.gov (United States)

    Schmidt, Matthieu; Pellegrino, Vincent; Combes, Alain; Scheinkestel, Carlos; Cooper, D Jamie; Hodgson, Carol

    2014-01-21

    The timing of extracorporeal membrane oxygenation (ECMO) initiation and its outcome in the management of respiratory and cardiac failure have received considerable attention, but very little attention has been given to mechanical ventilation during ECMO. Mechanical ventilation settings in non-ECMO studies have been shown to have an effect on survival and may also have contributed to a treatment effect in ECMO trials. Protective lung ventilation strategies established for non-ECMO-supported respiratory failure patients may not be optimal for more severe forms of respiratory failure requiring ECMO support. The influence of positive end-expiratory pressure on the reduction of the left ventricular compliance may be a matter of concern for patients receiving ECMO support for cardiac failure. The objectives of this review were to describe potential mechanisms for lung injury during ECMO for respiratory or cardiac failure, to assess the possible benefits from the use of ultra-protective lung ventilation strategies and to review published guidelines and expert opinions available on mechanical ventilation-specific management of patients requiring ECMO, including mode and ventilator settings. Articles were identified through a detailed search of PubMed, Ovid, Cochrane databases and Google Scholar. Additional references were retrieved from the selected studies. Growing evidence suggests that mechanical ventilation settings are important in ECMO patients to minimize further lung damage and improve outcomes. An ultra-protective ventilation strategy may be optimal for mechanical ventilation during ECMO for respiratory failure. The effects of airway pressure on right and left ventricular afterload should be considered during venoarterial ECMO support of cardiac failure. Future studies are needed to better understand the potential impact of invasive mechanical ventilation modes and settings on outcomes.

  8. Defect assessment procedures at high temperature

    International Nuclear Information System (INIS)

    Ainsworth, R.A.

    1991-01-01

    A comprehensive assessment procedure for the high-temperature response of structures is being produced. The procedure is referred to as R5 and is written as a series of step-by-step instructions in a number of volumes. This paper considers in detail those parts of R5 which address the behaviour of defects. The defect assessment procedures may be applied to defects found in service, postulated defects, or defects formed during operation as a result of creep-fatigue loading. In the last case, a method is described for deducing from endurance data the number of cycles to initiate a crack of a specified size. Under steady loading, the creep crack tip parameter C * is used to assess crack growth. Under cyclic loading, the creep crack growth during dwell periods is stiell governed by C * but crack growth due to cyclic excursions must also be included. This cyclic crack growth is described by an effective stress intensity factor range. A feature of the R5 defect assessment procedures in that they are based on simplified methods and approximate reference stress methods are described which enable C * in a component to be evaluated. It is shown by comparison with theoretical calculations and experimental data that reliable estimates of C * and the associated crack growth are obtained provided realistic creep strain rate date are used in the reference stress approximation. (orig./HP)

  9. 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...... above a point heat source cannot be used. This is caused either by the way of generating the plume including a long intermediate region or by the environmental conditions where vertical temperature gradients are present. The flow has a larger angle of spread and the entrainment factor is greather than...... turbulent plumes from different heated bodies are investigated. The measurements have taken place in a full-scale test room where the vertical temperature gradient have been changed. The velocity and the temperature distribution in the plume are measured. Large scale plume axis wandering is taken...

  10. Inspection and Quality Assurance in Government Contracts.

    Science.gov (United States)

    1983-01-01

    of Defective Performance . . . . . . . . .. 130 Estoppel Generally . . . . . ... 132 The Government Duty to Speak . . . .. 136 A Government Agent...of ratification of agreements or escaping the absence of inspector authority 62 under the changes clause to order changes. Estoppel Generally Once one...define the rationale for a result favoring the contractor in these cases, the courts and boards are really applying the equitable doctrine of estoppel .6

  11. General design guide for ventilation systems for fuel reprocessing plants, September 1975

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    General safety, occupied area ventilation systems, process area ventilation systems, exhaust ventilation and filtration systems, ventilation system construction and layout ventilation system testing and monitoring, and the quality assurance program are discussed

  12. Automated pulmonary lobar ventilation measurements using volume-matched thoracic CT and MRI

    Science.gov (United States)

    Guo, F.; Svenningsen, S.; Bluemke, E.; Rajchl, M.; Yuan, J.; Fenster, A.; Parraga, G.

    2015-03-01

    Objectives: To develop and evaluate an automated registration and segmentation pipeline for regional lobar pulmonary structure-function measurements, using volume-matched thoracic CT and MRI in order to guide therapy. Methods: Ten subjects underwent pulmonary function tests and volume-matched 1H and 3He MRI and thoracic CT during a single 2-hr visit. CT was registered to 1H MRI using an affine method that incorporated block-matching and this was followed by a deformable step using free-form deformation. The resultant deformation field was used to deform the associated CT lobe mask that was generated using commercial software. 3He-1H image registration used the same two-step registration method and 3He ventilation was segmented using hierarchical k-means clustering. Whole lung and lobar 3He ventilation and ventilation defect percent (VDP) were generated by mapping ventilation defects to CT-defined whole lung and lobe volumes. Target CT-3He registration accuracy was evaluated using region- , surface distance- and volume-based metrics. Automated whole lung and lobar VDP was compared with semi-automated and manual results using paired t-tests. Results: The proposed pipeline yielded regional spatial agreement of 88.0+/-0.9% and surface distance error of 3.9+/-0.5 mm. Automated and manual whole lung and lobar ventilation and VDP were not significantly different and they were significantly correlated (r = 0.77, p pulmonary structural-functional maps with high accuracy and robustness, providing an important tool for image-guided pulmonary interventions.

  13. Occupants’ Utilization of Natural Ventilation: A Study of Selected Terrace House Designs in Hot-humid Climate

    Directory of Open Access Journals (Sweden)

    Ibiyeye AI

    2015-05-01

    Full Text Available With increased time spent indoors and demand for enhanced comfort levels, energy consumption in homes is rising mostly for cooling, particularly in hot-humid regions. Natural ventilation is seen as an alternative to mechanical cooling as it is totally independent on energy and has been reported to be of high potential. However, little information is available on the utilization of natural ventilation in individual living spaces in different house designs. Therefore, this paper aims to investigate occupants’ utilization of natural ventilation in living spaces under different terrace house designs in hot-humid climate and also the relationship between the openings and occupants’ satisfaction with natural ventilation. Five (5 different terrace house types in Putrajaya, Malaysia with different opening design characteristics were selected for the study. A total of 298 households from these house types were surveyed and results show that occupants mostly open their windows during the daytime to capture breeze from outside despite the fact that they owned air-conditioners. In terms of occupants’ level of satisfaction with indoor ventilation when utilizing natural ventilation, majority rated neither satisfied nor unsatisfied. Further regression analysis reveals that this level of satisfaction is significantly related to opening sizes that are in accordance with the law, duration of opening windows and AC ownership. Findings from this study will shed more light on behavioural pattern of occupants of residential buildings towards natural ventilation provisions and highlight the importance of conforming to the law governing them.

  14. Metallography of defects

    International Nuclear Information System (INIS)

    Borisova, E.A.; Bochvar, G.A.; Brun, M.Ya.

    1980-01-01

    Different types of defects of metallurgical, technological and exploitation origin in intermediate and final products of titanium alloys, are considered. The examples of metallic and nonmetallic inclusions, chemical homogeneity, different grains, bands, cracks, places of searing, porosity are given; methods of detecting the above defects are described. The methods of metallography, X-ray spectral analysis, measuring microhardness are used

  15. Beating Birth Defects

    Centers for Disease Control (CDC) Podcasts

    Each year in the U.S., one in 33 babies is affected by a major birth defect. Women can greatly improve their chances of giving birth to a healthy baby by avoiding some of the risk factors for birth defects before and during pregnancy. In this podcast, Dr. Stuart Shapira discusses ways to improve the chances of giving birth to a healthy baby.

  16. Oral mask ventilation is more effective than face mask ventilation after nasal surgery.

    Science.gov (United States)

    Yazicioğlu, Dilek; Baran, Ilkay; Uzumcugil, Filiz; Ozturk, Ibrahim; Utebey, Gulten; Sayın, M Murat

    2016-06-01

    To evaluate and compare the face mask (FM) and oral mask (OM) ventilation techniques during anesthesia emergence regarding tidal volume, leak volume, and difficult mask ventilation (DMV) incidence. Prospective, randomized, crossover study. Operating room, training and research hospital. American Society of Anesthesiologists physical status I and II adult patients scheduled for nasal surgery. Patients in group FM-OM received FM ventilation first, followed by OM ventilation, and patients in group OM-FM received OM ventilation first, followed by FM ventilation, with spontaneous ventilation after deep extubation. The FM ventilation was applied with the 1-handed EC-clamp technique. The OM was placed only over the mouth, and the 1-handed EC-clamp technique was used again. A child's size FM was used for the OM ventilation technique, the mask was rotated, and the inferior part of the mask was placed toward the nose. The leak volume (MVleak), mean airway pressure (Pmean), and expired tidal volume (TVe) were assessed with each mask technique for 3 consecutive breaths. A mask ventilation grade ≥3 was considered DMV. DMV occurred more frequently during FM ventilation (75% with FM vs 8% with OM). In the FM-first sequence, the mean TVe was 249±61mL with the FM and 455±35mL with the OM (P=.0001), whereas in the OM-first sequence, it was 276±81mL with the FM and 409±37mL with the OM (P=.0001). Regardless of the order used, the OM technique significantly decreased the MVleak and increased the TVe when compared to the FM technique. During anesthesia emergence after nasal surgery the OM may offer an effective ventilation method as it decreases the incidence of DMV and the gas leak around the mask and provides higher tidal volume delivery compared with FM ventilation. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Defects at oxide surfaces

    CERN Document Server

    Thornton, Geoff

    2015-01-01

    This book presents the basics and characterization of defects at oxide surfaces. It provides a state-of-the-art review of the field, containing information to the various types of surface defects, describes analytical methods to study defects, their chemical activity and the catalytic reactivity of oxides. Numerical simulations of defective structures complete the picture developed. Defects on planar surfaces form the focus of much of the book, although the investigation of powder samples also form an important part. The experimental study of planar surfaces opens the possibility of applying the large armoury of techniques that have been developed over the last half-century to study surfaces in ultra-high vacuum. This enables the acquisition of atomic level data under well-controlled conditions, providing a stringent test of theoretical methods. The latter can then be more reliably applied to systems such as nanoparticles for which accurate methods of characterization of structure and electronic properties ha...

  18. Defects in dilute nitrides

    International Nuclear Information System (INIS)

    Chen, W.M.; Buyanova, I.A.; Tu, C.W.; Yonezu, H.

    2005-01-01

    We provide a brief review our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in dilute nitrides, i.e. Ga(In)NAs and Ga(Al,In)NP. Defect complexes involving intrinsic defects such as As Ga antisites and Ga i self interstitials were positively identified.Effects of growth conditions, chemical compositions and post-growth treatments on formation of the defects are closely examined. These grown-in defects are shown to play an important role in non-radiative carrier recombination and thus in degrading optical quality of the alloys, harmful to performance of potential optoelectronic and photonic devices based on these dilute nitrides. (author)

  19. The fluid mechanics of natural ventilation

    Science.gov (United States)

    Linden, Paul

    1999-11-01

    Natural ventilation of buildings is the flow generated by temperature differences and by the wind. Modern buildings have extreme designs with large, tall open plan spaces and large cooling requirements. Natural ventilation offers a means of cooling these buildings and providing good indoor air quality. The essential feature of ventilation is an exchange between an interior space and the external ambient. Recent work shows that in many circumstances temperature variations play a controlling feature on the ventilation since the directional buoyancy force has a large influence on the flow patterns within the space and on the nature of the exchange with the outside. Two forms of buoyancy-driven ventilation are discussed: mixing ventilation in which the interior is at approximately uniform temperature and displacement ventilation where there is strong internal stratification. The dynamics of these flows are considered and the effects of wind on them are examined both experimentally and theoretically. The aim behind this work is to give designers rules and intuition on how air moves within a building and the research shows a fascinating branch of fluid mechanics.

  20. Controlled ventilation in gas-heated low-energy houses. Primary energy savings in regard to the users behaviour

    International Nuclear Information System (INIS)

    Luedemann, B.; Schmitz, G.

    1999-01-01

    With the introduction of the energy savings regulation in Germany (ESVO) low-energy buildings will be the standard for new buildings at the turn of the millennium. The heating energy demand will sink around 30 % facing the actual standard. Systems for controlled Ventilation with heat-recovery are often regarded as an essential component to achieve the low-energy standard for buildings. The quota of the ventilation losses in high insulated buildings is up to far over 50 % of the heating energy demand. However, in practice ventilation systems often do not achieve the calculated energy-savings on the heat requirement. Until now, both technical defects of ventilation systems and the tightness of buildings are at the centre of discussion dealing with this problem. Therefore, in a common research project of three gas supply companies, an electricity distribution company and the Department of Technical Thermodynamics at the TUHH, the bandwidth of the possible energy-savings by ventilation systems with heat recovery was investigated by dynamic simulation of the thermal behaviour of buildings and ventilation systems. Above all, the question of the influence of the user behaviour was at the centre of attention. (author)

  1. Variation in Definition of Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Rose, Louise; McGinlay, Michael; Amin, Reshma; Burns, Karen Ea; Connolly, Bronwen; Hart, Nicholas; Jouvet, Philippe; Katz, Sherri; Leasa, David; Mawdsley, Cathy; McAuley, Danny F; Schultz, Marcus J; Blackwood, Bronagh

    2017-10-01

    Consistency of definitional criteria for terminology applied to describe subject cohorts receiving mechanical ventilation within ICU and post-acute care settings is important for understanding prevalence, risk stratification, effectiveness of interventions, and projections for resource allocation. Our objective was to quantify the application and definition of terms for prolonged mechanical ventilation. We conducted a scoping review of studies (all designs except single-case study) reporting a study population (adult and pediatric) using the term prolonged mechanical ventilation or a synonym. We screened 5,331 references, reviewed 539 full-text references, and excluded 120. Of the 419 studies (representing 38 countries) meeting inclusion criteria, 297 (71%) reported data on a heterogeneous subject cohort, and 66 (16%) included surgical subjects only (46 of those 66, 70% cardiac surgery). Other studies described COPD (16, 4%), trauma (22, 5%), neuromuscular (17, 4%), and sepsis (1, 0.2%) cohorts. A total of 741 terms were used to refer to the 419 study cohorts. The most common terms were: prolonged mechanical ventilation (253, 60%), admission to specialized unit (107, 26%), and long-term mechanical ventilation (79, 19%). Some authors (282, 67%) defined their cohorts based on duration of mechanical ventilation, with 154 studies (55%) using this as the sole criterion. We identified 37 different durations of ventilation ranging from 5 h to 1 y, with > 21 d being the most common (28 of 282, 7%). For studies describing a surgical cohort, minimum ventilation duration required for inclusion was ≥ 24 h for 20 of 66 studies (30%). More than half of all studies (237, 57%) did not provide a reason/rationale for definitional criteria used, with only 28 studies (7%) referring to a consensus definition. We conclude that substantial variation exists in the terminology and definitional criteria for cohorts of subjects receiving prolonged mechanical ventilation. Standardization of

  2. REVERSIBLE VENTILATION SYSTEM FOR ADMINISTRATIVE BUILDINGS

    Directory of Open Access Journals (Sweden)

    Valery Yu. Kravchuk

    2017-01-01

    Full Text Available Abstract. Objectives To consider the possibility of applying the principle of reversing air flows for a centralised ventilation system; to develop a specific scheme for air exchange reversible ventilation, which will take into account the peculiarities of the microclimate of administrative buildings; to select the type of filling of the air-permeable element and justify this choice; to determine the conditions for changing the direction of air movement in the ventilation system and the area of its application; to form a list of equipment necessary for the operation of such a system; to consider the influence of supply and exhaust devices on the heat and humidity regime of claddings. Methods  To achieve this goal, the published thematic material was reviewed and a patent search carried out using Russian and European databases. Data on mathematical modelling of filtration in porous media and experimental results were used. A method for ventilating rooms in administrative building using the reversal of movement of supply and exhaust air streams along the same channels was applied. Results  Schemas for reversible ventilation systems are presented and their modes of operation considered. It is established that the idea of reversing ventilation flows has not yet been applied in the development of centralised ventilation systems. Based on these published materials, it was concluded that the proposed design of supply and exhaust devices can be used in practice. An original air exchange scheme for the ventilation of administrative buildings and design of supply and exhaust devices for this system are proposed. The conditions for changing the operating modes of the system and the scope of its application are determined. Conclusion The use of the proposed ventilation system allows normative air exchange to be provided without using a supply unit during the cold season. This application of airflow reversal allows the potential of natural forces to be used

  3. Characteristics of coal mine ventilation air flows.

    Science.gov (United States)

    Su, Shi; Chen, Hongwei; Teakle, Philip; Xue, Sheng

    2008-01-01

    Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.

  4. Preoperational test report, primary ventilation condensate system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-01-29

    Preoperational test report for Primary Ventilation Condensate System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides a collection point for condensate generated by the W-030 primary vent offgas cooling system serving tanks AYIOI, AY102, AZIOI, AZI02. The system is located inside a shielded ventilation equipment cell and consists of a condensate seal pot, sampling features, a drain line to existing Catch Tank 241-AZ-151, and a cell sump jet pump. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  5. Secretion management in the mechanically ventilated patient.

    Science.gov (United States)

    Branson, Richard D

    2007-10-01

    Secretion management in the mechanically ventilated patient includes routine methods for maintaining mucociliary function, as well as techniques for secretion removal. Humidification, mobilization of the patient, and airway suctioning are all routine procedures for managing secretions in the ventilated patient. Early ambulation of the post-surgical patient and routine turning of the ventilated patient are common secretion-management techniques that have little supporting evidence of efficacy. Humidification is a standard of care and a requisite for secretion management. Both active and passive humidification can be used. The humidifier selected and the level of humidification required depend on the patient's condition and the expected duration of intubation. In patients with thick, copious secretions, heated humidification is superior to a heat and moisture exchanger. Airway suctioning is the most important secretion removal technique. Open-circuit and closed-circuit suctioning have similar efficacy. Instilling saline prior to suctioning, to thin the secretions or stimulate a cough, is not supported by the literature. Adequate humidification and as-needed suctioning are the foundation of secretion management in the mechanically ventilated patient. Intermittent therapy for secretion removal includes techniques either to simulate a cough, to mechanically loosen secretions, or both. Patient positioning for secretion drainage is also widely used. Percussion and postural drainage have been widely employed for mechanically ventilated patients but have not been shown to reduce ventilator-associated pneumonia or atelectasis. Manual hyperinflation and insufflation-exsufflation, which attempt to improve secretion removal by simulating a cough, have been described in mechanically ventilated patients, but neither has been studied sufficiently to support routine use. Continuous lateral rotation with a specialized bed reduces atelectasis in some patients, but has not been shown

  6. Position paper - primary ventilation system configuration

    International Nuclear Information System (INIS)

    Dalpiaz, E.L.

    1994-06-01

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

  7. Energy Analysis of the Ductless Personalized Ventilation

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......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...

  8. Weaning newborn infants from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Paolo Biban

    2013-06-01

    Full Text Available Invasive mechanical ventilation is a life-saving procedure which is largely used in neonatal intensive care units, particularly in very premature newborn infants. However, this essential treatment may increase mortality and cause substantial morbidity, including lung or airway injuries, unplanned extubations, adverse hemodynamic effects, analgosedative dependency and severe infectious complications, such as ventilator-associated pneumonia. Therefore, limiting the duration of airway intubation and mechanical ventilator support is crucial for the neonatologist, who should aim to a shorter process of discontinuing mechanical ventilation as well as an earlier appreciation of readiness for spontaneous breathing trials. Unfortunately, there is scarce information about the best ways to perform an effective weaning process in infants undergoing mechanical ventilation, thus in most cases the weaning course is still based upon the individual judgment of the attending clinician. Nonetheless, some evidence indicate that volume targeted ventilation modes are more effective in reducing the duration of mechanical ventilation than traditional pressure limited ventilation modes, particularly in very preterm babies. Weaning and extubation directly from high frequency ventilation could be another option, even though its effectiveness, when compared to switching and subsequent weaning and extubating from conventional ventilation, is yet to be adequately investigated. Some data suggest the use of weaning protocols could reduce the weaning time and duration of mechanical ventilation, but better designed prospective studies are still needed to confirm these preliminary observations. Finally, the implementation of short spontaneous breathing tests in preterm infants has been shown to be beneficial in some centres, favoring an earlier extubation at higher ventilatory settings compared with historical controls, without worsening the extubation failure rate. Further

  9. Special Considerations in Neonatal Mechanical Ventilation.

    Science.gov (United States)

    Dalgleish, Stacey; Kostecky, Linda; Charania, Irina

    2016-12-01

    Care of infants supported with mechanical ventilation is complex, time intensive, and requires constant vigilance by an expertly prepared health care team. Current evidence must guide nursing practice regarding ventilated neonates. This article highlights the importance of common language to establish a shared mental model and enhance clear communication among the interprofessional team. Knowledge regarding the underpinnings of an open lung strategy and the interplay between the pathophysiology and individual infant's response to a specific ventilator strategy is most likely to result in a positive clinical outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  11. Wind-induced ventilation of the giant nests of the leaf-cutting ant Atta vollenweideri

    Science.gov (United States)

    Kleineidam, Christoph; Ernst, Roman; Roces, Flavio

    2001-06-01

    To understand the significance of elaborate nest architecture for the control of nest climate, we investigated the mechanisms governing nest ventilation in a large field nest of Atta vollenweideri. Surface wind, drawing air from the central tunnels of the nest mound, was observed to be the main driving force for nest ventilation during summer. This mechanism of wind-induced ventilation has so far not been described for social insect colonies. Thermal convection, another possible force driving ventilation, contributed very little. According to their predominant airflow direction, two functionally distinct tunnel groups were identified: outflow tunnels in the upper, central region, and inflow tunnels in the lower, peripheral region of the nest mound. The function of the tunnels was independent of wind direction. Outflow of air through the central tunnels was followed by a delayed inflow through the peripheral tunnels. Leaf-cutting ants design the tunnel openings on the top of the nest with turrets which may reinforce wind-induced nest ventilation.

  12. Experimental and numerical study of smoke propagation through a vent separating two mechanically ventilated rooms

    International Nuclear Information System (INIS)

    Audouin, Laurent; Pretrel, Hugues; Vaux, Samuel

    2015-01-01

    The paper presents an experimental and numerical study about smoke propagation through a horizontal opening between two superposed compartments, as can be encountered in nuclear installations, in case of a fire taking place in the lower room. The experimental configuration proposed in this study consists in two rooms mechanically ventilated and connected each other by a horizontal opening. The fire source is simulated by a propane burner located in the lower room. The inlet ventilation duct is located in the lower room and the exhaust ventilation duct is located in the upper room. For such experimental configuration, several flow regimes at the horizontal opening connecting the two rooms can be encountered depending on the fire power, the opening size (diameter, depth) and the ventilation set-up (location of inlet/outlet ducts, flow rate). Indeed, flow at the opening is governed by buoyant forces due to the hot gases produced by the fire, the inertia effect due to the forced ventilation and the momentum effect due to smoke flow nearby the horizontal opening (for instance, ceiling jet or thermal plume from fire). Consequently, such complex mixed (natural/ forced) convective flows are still a challenge for CFD fire codes to make properly calculations of these experimental scenarios. The objective of this paper is to assess the capability of ISIS code (CFD) to simulate the behaviour of smoke propagation inside these two superposed compartments. Results of this study are presented with details (especially, thermal stratification and flow rates through the horizontal vent) and are discussed thoroughly.

  13. Experimental and numerical study of smoke propagation through a vent separating two mechanically ventilated rooms

    Energy Technology Data Exchange (ETDEWEB)

    Audouin, Laurent; Pretrel, Hugues; Vaux, Samuel [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saint Paul Lez Durance (France)

    2015-12-15

    The paper presents an experimental and numerical study about smoke propagation through a horizontal opening between two superposed compartments, as can be encountered in nuclear installations, in case of a fire taking place in the lower room. The experimental configuration proposed in this study consists in two rooms mechanically ventilated and connected each other by a horizontal opening. The fire source is simulated by a propane burner located in the lower room. The inlet ventilation duct is located in the lower room and the exhaust ventilation duct is located in the upper room. For such experimental configuration, several flow regimes at the horizontal opening connecting the two rooms can be encountered depending on the fire power, the opening size (diameter, depth) and the ventilation set-up (location of inlet/outlet ducts, flow rate). Indeed, flow at the opening is governed by buoyant forces due to the hot gases produced by the fire, the inertia effect due to the forced ventilation and the momentum effect due to smoke flow nearby the horizontal opening (for instance, ceiling jet or thermal plume from fire). Consequently, such complex mixed (natural/ forced) convective flows are still a challenge for CFD fire codes to make properly calculations of these experimental scenarios. The objective of this paper is to assess the capability of ISIS code (CFD) to simulate the behaviour of smoke propagation inside these two superposed compartments. Results of this study are presented with details (especially, thermal stratification and flow rates through the horizontal vent) and are discussed thoroughly.

  14. Formation of topological defects

    International Nuclear Information System (INIS)

    Vachaspati, T.

    1991-01-01

    We consider the formation of point and line topological defects (monopoles and strings) from a general point of view by allowing the probability of formation of a defect to vary. To investigate the statistical properties of the defects at formation we give qualitative arguments that are independent of any particular model in which such defects occur. These arguments are substantiated by numerical results in the case of strings and for monopoles in two dimensions. We find that the network of strings at formation undergoes a transition at a certain critical density below which there are no infinite strings and the closed-string (loop) distribution is exponentially suppressed at large lengths. The results are contrasted with the results of statistical arguments applied to a box of strings in dynamical equilibrium. We argue that if point defects were to form with smaller probability, the distance between monopoles and antimonopoles would decrease while the monopole-to-monopole distance would increase. We find that monopoles are always paired with antimonopoles but the pairing becomes clean only when the number density of defects is small. A similar reasoning would also apply to other defects

  15. 33 CFR 183.610 - Powered ventilation system.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Powered ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.610 Powered ventilation system... must: (1) Be open to the atmosphere, or (2) Be ventilated by an exhaust blower system. (b) Each exhaust...

  16. 46 CFR 153.310 - Ventilation system type.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ventilation system type. 153.310 Section 153.310... Handling Space Ventilation § 153.310 Ventilation system type. A cargo handling space must have a permanent forced ventilation system of the exhaust type. ...

  17. Modeling and Control of Livestock Ventilation Systems and Indoor Environments

    DEFF Research Database (Denmark)

    Wu, Zhuang; Heiselberg, Per; Stoustrup, Jakob

    2005-01-01

    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 i...

  18. Are lung-protective ventilation strategies worth the effort? | Slinger ...

    African Journals Online (AJOL)

    Nonphysiological ventilation in healthy lungs induces acute lung injury (ALI). Protective lung ventilation in patients with ALI improves outcome. Protective lung ventilation in noninjured lungs and in the absence of a primary pulmonary insult may initiate ventilation-induced lung injury (VILI), as evidenced by inflammatory ...

  19. Effects of different rhizosphere ventilation treatment on water and ...

    African Journals Online (AJOL)

    The objective of this study was to explore the effects of different rhizosphere ventilation treatment on water and nutrients absorption of maize. The pot experiment was conducted using three methods: no ventilation, two day ventilation and four day ventilation, under conditions of the different levels of irrigation methods.

  20. Engineering governance: introducing a governance meta framework.

    OpenAIRE

    Brand, N.; Beens, B.; Vuuregge, E.; Batenburg, R.

    2011-01-01

    There is a need for a framework that depicts strategic choices within an organisation with regard to potential governance structures. The governance meta framework provides the necessary structure in the current developments of governance. Performance as well as conformance are embedded in this framework and provide the balance for all governance domains. (aut.ref.)

  1. Discussion for management of ventilation system in uranium mines

    International Nuclear Information System (INIS)

    Li Xianjie; Ren Jianjun; Hu Penghua

    2014-01-01

    Radon exhaustion and ventilation are surely regarded as key links for safety production and radiation protection in underground uranium mines, and the crucial point to achieve safety production goals lies in timely and accurately adjusting and controlling of ventilation technical measures and ventilation system management with the changing operation conditions of mines. This paper proposes corresponding countermeasures based on the respectively systematical analysis of daily ventilation management, ventilation facilities and structures management, and ventilation system information management in uranium mines. Furthermore, standardized management approaches and suggestions are put forward to realize standardization of uranium mines' ventilation management and radon exhaustion technique. (authors)

  2. Can mechanical ventilation strategies reduce chronic lung disease?

    Science.gov (United States)

    Donn, Steven M; Sinha, Sunil K

    2003-12-01

    Chronic lung disease (CLD) continues to be a significant complication in newborn infants undergoing mechanical ventilation for respiratory failure. Although the aetiology of CLD is multifactorial, specific factors related to mechanical ventilation, including barotrauma, volutrauma and atelectrauma, have been implicated as important aetiologic mechanisms. This article discusses the ways in which these factors might be manipulated by various mechanical ventilatory strategies to reduce ventilator-induced lung injury. These include continuous positive airway pressure, permissive hypercapnia, patient-triggered ventilation, volume-targeted ventilation, proportional assist ventilation, high-frequency ventilation and real-time monitoring.

  3. Numerical investigations of buoyancy-driven natural ventilation in a simple three-storey atrium building and thermal comfort evaluation

    International Nuclear Information System (INIS)

    Hussain, Shafqat; Oosthuizen, Patrick H.

    2013-01-01

    The numerical investigations of buoyancy-driven natural ventilation and thermal comfort evaluation in a simple three-storey atrium building as a part of the passive ventilation strategy was undertaken using a validated Computational Fluid Dynamic (CFD) model. The Reynolds Averaged Navier–Stokes (RANS) modeling approach with the SST-k–ω turbulence model and the discrete transfer radiation model (DTRM) was used for the numerical investigations. The steady-state governing equations were solved using a commercial solver FLUENT©. Various flow situations of the buoyancy-driven natural ventilation in the building during day and night time were examined. The numerical results obtained for the airflow rates, airflow patterns and temperature distributions inside the building are presented in this paper. Using the numerical results, the well-known thermal comfort indices PMV (predicted mean vote) and PPD (predicted percentage of dissatisfied) were calculated for the evaluation of the thermal comfort conditions in the occupied regions of the building. It was noticed that thermal conditions prevailing in the occupied areas of the building as a result of using the buoyancy-driven ventilation were mostly in comfort zone. From the study of the night time ventilation, it was found that hot water (80 °C) circulation (heated by solar collectors during daytime) along the chimney walls during night time and heat sources present in the building can be useful in inducing night ventilation airflows in the building as a part of the passive ventilation strategy. -- Highlights: • A simple three-storey atrium building. • Numerical modeling of buoyancy-driven ventilation flow in the building. • Effect of solar intensity and geographical location on ventilation. • CFD predictions were used to calculate thermal comfort indices. • Evaluation of thermal comfort conditions for the occupants

  4. 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.

  5. Design of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... 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...

  6. Modelling of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... 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...

  7. Mechanical ventilation strategies for the surgical patient

    NARCIS (Netherlands)

    Schultz, Marcus J.; Abreu, Marcelo Gama de; Pelosi, Paolo

    2015-01-01

    Purpose of review To summarize clinical evidence for intraoperative ventilation settings, which could protect against postoperative pulmonary complications (PPCs) in surgical patients with uninjured lungs. Recent findings There is convincing evidence for protection against PPCs by low tidal volumes:

  8. Appointment, qualifications and responsibilities of ventilation officers

    International Nuclear Information System (INIS)

    1981-01-01

    The Code provides for the appointment of a ventilation officer when required by the appropriate authority. This guideline offers comment on the appointment, qualifications, training and responsibilities of that person

  9. Solar Preheated Ventilation - Innovative Solar Technology

    National Research Council Canada - National Science Library

    Gaberson, Howard

    1999-01-01

    .... This innovative technology applies to both new construction or rehabilitation projects. This TDS introduces this low maintenance solar technology for consideration in all future industrial ventilation or HVAC projects...

  10. 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....

  11. Ductless personalized ventilation with local air cleaning

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  12. 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.

  13. Intelligent ventilation in the intensive care unit

    African Journals Online (AJOL)

    Automated, microprocessor-controlled, closed-loop mechanical ventilation has been used ... Sixty-eight patients (6%) with severe hypoxia and high inspiratory pressures were ... At any breath, the controller compares target and actual data for.

  14. Comfort parameters - Ventilation of a subway wagon

    Science.gov (United States)

    Petr, Pavlíček; Ladislav, Tříska

    2017-09-01

    Research and development of a ventilation system is being carried out as a part of project TA04030774 of the Technology Agency of the Czech Republic. Name of the project is "Research and Development of Mass-optimized Components for Rail Vehicles". Problems being solved are development and testing of a new concept for ventilation systems for public transport vehicles. The main improvements should be a reduction of the mass of the whole system, easy installation and reduction of the noise of the ventilation system. This article is focused on the comfort parameters in a subway wagon (measurement and evaluation carried out on a function sample in accordance with the regulations). The input to the project is a ventilator hybrid casing for a subway wagon, which was manufactured and tested during the Ministry of Industry and Trade project TIP FR-TI3/449.

  15. Improving underground ventilation conditions in coal mines

    CSIR Research Space (South Africa)

    Meyer, CF

    1993-11-01

    Full Text Available projects could be initiated by miningtek in co-operation with different mines. This report deals with the findings of this project and also deals with the future of research within Miningtek with regard to underground ventilation....

  16. Adaptive Intelligent Ventilation Noise Control, Phase II

    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...

  17. Adaptive Intelligent Ventilation Noise Control, Phase I

    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...

  18. Ventilation Guidance for Spray Polyurethane Foam Application

    Science.gov (United States)

    Properly designed ventilation can reduce airborne levels of aerosols, mists, and vapors generated during spray application and can help protect SPF applicators, helpers, and others who may be working in adjacent areas.

  19. Perioperative lung protective ventilation in obese patients.

    Science.gov (United States)

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

    2015-05-06

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.

  20. Intraoperative mechanical ventilation: state of the art.

    Science.gov (United States)

    Ball, Lorenzo; Costantino, Federico; Orefice, Giulia; Chandrapatham, Karthikka; Pelosi, Paolo

    2017-10-01

    Mechanical ventilation is a cornerstone of the intraoperative management of the surgical patient and is still mandatory in several surgical procedures. In the last decades, research focused on preventing postoperative pulmonary complications (PPCs), both improving risk stratification through the use of predictive scores and protecting the lung adopting so-called protective ventilation strategies. The aim of this review was to give an up-to-date overview of the currently suggested intraoperative ventilation strategies, along with their pathophysiologic rationale, with a focus on challenging conditions, such as obesity, one-lung ventilation and cardiopulmonary bypass. While anesthesia and mechanical ventilation are becoming increasingly safe practices, the contribution to surgical mortality attributable to postoperative lung injury is not negligible: for these reasons, the prevention of PPCs, including the use of protective mechanical ventilation is mandatory. Mechanical ventilation should be optimized providing an adequate respiratory support while minimizing unwanted negative effects. Due to the high number of surgical procedures performed daily, the impact on patients' health and healthcare costs can be relevant, even when new strategies result in an apparently small improvement of outcome. A protective intraoperative ventilation should include a low tidal volume of 6-8 mL/kg of predicted body weight, plateau pressures ideally below 16 cmH2O, the lowest possible driving pressure, moderate-low PEEP levels except in obese patients, laparoscopy and long surgical procedures that might benefit of a slightly higher PEEP. The work of the anesthesiologist should start with a careful preoperative visit to assess the risk, and a close postoperative monitoring.

  1. Perioperative lung protective ventilation in obese patients

    OpenAIRE

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

    2015-01-01

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

  2. Computer codes for ventilation in nuclear facilities

    International Nuclear Information System (INIS)

    Mulcey, P.

    1987-01-01

    In this paper the authors present some computer codes, developed in the last years, for ventilation and radioprotection. These codes are used for safety analysis in the conception, exploitation and dismantlement of nuclear facilities. The authors present particularly: DACC1 code used for aerosol deposit in sampling circuit of radiation monitors; PIAF code used for modelization of complex ventilation system; CLIMAT 6 code used for optimization of air conditioning system [fr

  3. 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.

  4. Iatrogenic pneumothorax related to mechanical ventilation

    Science.gov (United States)

    Hsu, Chien-Wei; Sun, Shu-Fen

    2014-01-01

    Pneumothorax is a potentially lethal complication associated with mechanical ventilation. Most of the patients with pneumothorax from mechanical ventilation have underlying lung diseases; pneumothorax is rare in intubated patients with normal lungs. Tension pneumothorax is more common in ventilated patients with prompt recognition and treatment of pneumothorax being important to minimize morbidity and mortality. Underlying lung diseases are associated with ventilator-related pneumothorax with pneumothoraces occurring most commonly during the early phase of mechanical ventilation. The diagnosis of pneumothorax in critical illness is established from the patients’ history, physical examination and radiological investigation, although the appearances of a pneumothorax on a supine radiograph may be different from the classic appearance on an erect radiograph. For this reason, ultrasonography is beneficial for excluding the diagnosis of pneumothorax. Respiration-dependent movement of the visceral pleura and lung surface with respect to the parietal pleura and chest wall can be easily visualized with transthoracic sonography given that the presence of air in the pleural space prevents sonographic visualization of visceral pleura movements. Mechanically ventilated patients with a pneumothorax require tube thoracostomy placement because of the high risk of tension pneumothorax. Small-bore catheters are now preferred in the majority of ventilated patients. Furthermore, if there are clinical signs of a tension pneumothorax, emergency needle decompression followed by tube thoracostomy is widely advocated. Patients with pneumothorax related to mechanical ventilation who have tension pneumothorax, a higher acute physiology and chronic health evaluation II score or PaO2/FiO2 < 200 mmHg were found to have higher mortality. PMID:24834397

  5. A historical perspective on ventilator management.

    Science.gov (United States)

    Shapiro, B A

    1994-02-01

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

  6. Humidification of inspired gases during mechanical ventilation.

    Science.gov (United States)

    Gross, J L; Park, G R

    2012-04-01

    Humidification of inspired gas is mandatory for all mechanically ventilated patients to prevent secretion retention, tracheal tube blockage and adverse changes occurring to the respiratory tract epithelium. However, the debate over "ideal" humidification continues. Several devices are available that include active and passive heat and moisture exchangers and hot water humidifiers Each have their advantages and disadvantages in mechanically ventilated patients. This review explores each device in turn and defines their role in clinical practice.

  7. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    Zwijnenburg, A.

    1989-01-01

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

  8. 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...... of stochastic differential equations is presented comprising a general heat balance for an arbitrary number of loads and zones in a building to determine the thermal behaviour under random conditions....

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

    OpenAIRE

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

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

  10. Ventricular Septal Defect (VSD)

    Science.gov (United States)

    ... Call your doctor if your baby or child: Tires easily when eating or playing Is not gaining ... heart procedures. Risk factors Ventricular septal defects may run in families and sometimes may occur with other ...

  11. Birth Defects: Cerebral Palsy

    Science.gov (United States)

    ... Loss > Birth defects & other health conditions > Cerebral palsy Cerebral palsy E-mail to a friend Please fill in ... this page It's been added to your dashboard . Cerebral palsy (also called CP) is a group of conditions ...

  12. Endocardial cushion defect

    Science.gov (United States)

    ... Philadelphia, PA: Elsevier; 2016:chap 426. Kouchoukos NT, Blackstone EH, Hanley FL, Kirklin JK. Atrioventricular septal defect. In: Kouchoukos NT, Blackstone EH, Hanley FL, Kirklin JK, eds. Kirklin/Barratt- ...

  13. Repairing Nanoparticle Surface Defects

    NARCIS (Netherlands)

    Marino, Emanuele; Kodger, Thomas E.; Crisp, R.W.; Timmerman, Dolf; MacArthur, Katherine E.; Heggen, Marc; Schall, Peter

    2017-01-01

    Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We

  14. Point defects in platinum

    International Nuclear Information System (INIS)

    Piercy, G.R.

    1960-01-01

    An investigation was made of the mobility and types of point defect introduced in platinum by deformation in liquid nitrogen, quenching into water from 1600 o C, or reactor irradiation at 50 o C. In all cases the activation energy for motion of the defect was determined from measurements of electrical resistivity. Measurements of density, hardness, and x-ray line broadening were also made there applicable. These experiments indicated that the principal defects remaining in platinum after irradiation were single vacant lattice sites and after quenching were pairs of vacant lattice sites. Those present after deformation In liquid nitrogen were single vacant lattice sites and another type of defect, perhaps interstitial atoms. (author)

  15. Tracer dating and ocean ventilation

    International Nuclear Information System (INIS)

    Thiele, G.; Sarmiento, J.L.

    1990-01-01

    The interpretation of transient tracer observations depends on difficult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. The authors use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. The authors define an idealized ventilation age tracer that is conservative with respect to mixing, and they explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters

  16. Ventilation criteria for IDMS facility

    International Nuclear Information System (INIS)

    Lambert, D.P.

    1996-01-01

    Both Facility Evaluation Board (FEB) reviews of the Integrated DWPF Melter System (IDMS) have identified the inconsistency of the current IDMS Process Hazards Review (PHR) versus actual IDMS practice as regards the criteria to contain air borne pollutants that may be present in the Process Room (e.g. benzene and mercury). The PHR states that a 1.0 in. wc pressure differential be maintained between the IDMS Process Room and Building 672-T. In addition, the PHR further specifies that the linear velocity through openings into the Process Room (e.g. open doors) be equal to or greater than 150 fpm. Finally, the PHR recommended that mercury vapor and benzene monitors be installed in the Process Room ventilation exhaust to alert personnel to the presence of vapors of benzene and/or mercury before entering the Process Room. This report summarizes the results of reassessment of these criteria and the specific recommendation for permanent installation of mercury and benzene vapor monitors in the vapor exhaust of the Process Room

  17. Ventilator in nuclear power plant

    International Nuclear Information System (INIS)

    Goto, Hiroshi.

    1980-01-01

    Purpose: To fabricate a compact ventilator by arranging separate pipelines communicating the operating stage range and contaminated range in a building, and arranging cleaning means commonly used for these ranges. Constitution: A pipeline to be connected to the operating stage range is connected via an exhaust fan and a damper to the stack, and a pipeline to be connected to the contaminated range is connected via another exhaust fan and another damper to the above described pipeline. The exhaust sides of both exhaust fans are connected by means of separate pipelines, and two dampers are disposed in the intermediate of the pipeline. A pipeline is led out from the intermediate of the dampers, and connected to the terminal end of the pipeline from the contaminated range via a filter train and a booster fan. Since the exhaust volume of the operating stage range is substantially equal to that of the contaminated range, the installation capacity of the filter train is reduced to half. (Sekiya, K.)

  18. Pretest Predictions for Phase II Ventilation Tests

    International Nuclear Information System (INIS)

    Yiming Sun

    2001-01-01

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, and concrete pipe walls that will be developed during the Phase II ventilation tests involving various test conditions. The results will be used as inputs to validating numerical approach for modeling continuous ventilation, and be used to support the repository subsurface design. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the Phase II ventilation tests, and describe numerical methods that are used to calculate the effects of continuous ventilation. The calculation is limited to thermal effect only. This engineering work activity is conducted in accordance with the ''Technical Work Plan for: Subsurface Performance Testing for License Application (LA) for Fiscal Year 2001'' (CRWMS M and O 2000d). This technical work plan (TWP) includes an AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', activity evaluation (CRWMS M and O 2000d, Addendum A) that has determined this activity is subject to the YMP quality assurance (QA) program. The calculation is developed in accordance with the AP-3.12Q procedure, ''Calculations''. Additional background information regarding this activity is contained in the ''Development Plan for Ventilation Pretest Predictive Calculation'' (DP) (CRWMS M and O 2000a)

  19. Histochemical alterations in one lung ventilation.

    Science.gov (United States)

    Yin, Kingsley; Gribbin, Elizabeth; Emanuel, Steven; Orndorff, Rebecca; Walker, Jean; Weese, James; Fallahnejad, Manucher

    2007-01-01

    One lung ventilation is a commonly performed surgical procedure. Although there have been several reports showing that one-lung ventilation can cause pathophysiological alterations such as pulmonary hypoxic vasoconstriction and intrapulmonary shunting, there have been virtually no reports on the effects of one-lung ventilation on lung histology. Yorkshire pigs (11-17 kg) were anesthetized, a tracheotomy performed and a tracheal tube inserted. The chest was opened and one lung ventilation (OLV), was induced by clamping of the right main bronchus. OLV was continued for 60 min before the clamp was removed and two lung ventilation (TLV) started. TLV was continued for 30 to 60 min. Blood and lung biopsies were taken immediately before OLV, 30 min and 60 min of OLV and after restoration of TLV. Histological analyses revealed that the non-ventilated lung was totally collapsed during OLV. On reventilation, there was clear evidence of vascular congestion and alveolar wall thickening at 30 min after TLV. At 60 min of TLV, there was still vascular congestion. Serum nitrite levels (as an index of nitric oxide production) showed steady decline over the course of the experimental period, reaching a significantly low level on reventilation (compared with baseline levels before OLV). Lung MPO activity (marker of neutrophil sequestration) and serum TNFalpha levels were not raised during the entire experimental period. These results suggest that there was lung vascular injury after OLV, which was associated with reduced levels of nitric oxide production and not associated with an inflammatory response.

  20. Thallium myocardial tomoscintigraphy: detection of ischemia during weaning from mechanical ventilation in patients with chronic obstructive pulmonary disease. Tomoscintigraphie myocardique au thallium: detection de l'ischemie provoquee par le sevrage de la ventilation assistee chez le bronchiteux chronique

    Energy Technology Data Exchange (ETDEWEB)

    Andre, L; Valette, H; Obama, S; Archambaud, F; Richard, C; Teboul, J L; Hebert, J L; Auzepy, P; Desgrez, A [Hopital de Bicetre, 94 - Le Kremlin-Bicetre (FR)

    1990-01-01

    In order to evidence myocardial ischemia-leading to ventricular dysfunction-during weaning from mechanical ventilation in patients with chronic obstructive pulmonary disease, thallium myocardial tomography and gated blood pool studies were performed in 9 patients during mechanical ventilation and during weaning from mechanical ventilation. During the latter, results of gated blood pool studies showed a diffuse homogeneous left ventricular dysfunction. A fixed lower thallium uptake in the septum than in the lateral wall was found with the quantitative analysis of myocardial tomograms. Partial volume effect is likely the cause of this septal defect. The hypothesis of a diffuse ischemia cannot be excluded; but, without the absolute quantification of tomographic data, it cannot be proven.

  1. 3 Level Ventilation: the First Clinical Experience

    Directory of Open Access Journals (Sweden)

    P. Torok

    2008-01-01

    Full Text Available Considering the issues of artificial ventilation (AV in non-homogenous pathological lung processes (acute lung injury (ALI, acute respiratory distress syndrome (ARDS, pneumonia, etc., the authors applied the three-level lung ventilation to a group of 12 patients with non-homogenous lung injury. Three-level ventilation was defined as a type (modification of AV whose basic ventilation level was produced by the modes CMV, PCV or PS (ASB and add-on level, the so-called background ventilation was generated by two levels of PEEP. PEEP (constant and PEEPh (PEEP high with varying frequency and duration of transition between the individual levels of PEEP. Objective: to elucidate whether in cases of considerably non-homogenous gas distribution in acute pathological disorders, three-level ventilation (3LV can correct gas distribution into the so-called slow bronchoalveolar compartments, by decreasing the volume load of the so-called fast compartments and to improve lung gas exchange, by following the principles of safe ventilation. Results. 3LV was applied to 12 patients with severe non-homogenous lung injury/disorder (atypic pneumonia and ARDS/ALI and low-success PCV ventilation after recruitment manoeuvre (PaO2 (kPA /FiO2 = 5—6. There were pronounced positive changes in pulmonary gas exchange within 1—4 hours after initiation of 3LV at a fPCV of 26±4 breaths/min-1 and PEEPh at a fPEEPH of 7±2 breaths/min-1 with a minute ventilation of 12±4 l/min. 3LV reduced a intrapulmonary shunt fraction 50±5 to 30±5%, increased CO2 elimination, with PaCO2 falling to the values below 6±0.3 kPa, and PaO2 to 7.5±1.2 kPa, with FiO2 being decreased to 0.8—0.4. Lung recruitment also improved gas exchange: with PEEP=1.2±0.4 kPa, static tho-racopulmonary compliance (Cst elevated from 0.18±0.02 l/kPa to 0.3±0.02 l/kPa and then to 0.38±0.05 l/kPa. Airways resistance (Raw decreased by more than 30%. Improved lung aeration was also estimated as a manifestation of

  2. Nasal mask ventilation is better than face mask ventilation in edentulous patients.

    Science.gov (United States)

    Kapoor, Mukul Chandra; Rana, Sandeep; Singh, Arvind Kumar; Vishal, Vindhya; Sikdar, Indranil

    2016-01-01

    Face mask ventilation of the edentulous patient is often difficult as ineffective seating of the standard mask to the face prevents attainment of an adequate air seal. The efficacy of nasal ventilation in edentulous patients has been cited in case reports but has never been investigated. Consecutive edentulous adult patients scheduled for surgery under general anesthesia with endotracheal intubation, during a 17-month period, were prospectively evaluated. After induction of anesthesia and administration of neuromuscular blocker, lungs were ventilated with a standard anatomical face mask of appropriate size, using a volume controlled anesthesia ventilator with tidal volume set at 10 ml/kg. In case of inadequate ventilation, the mask position was adjusted to achieve best-fit. Inspired and expired tidal volumes were measured. Thereafter, the face mask was replaced by a nasal mask and after achieving best-fit, the inspired and expired tidal volumes were recorded. The difference in expired tidal volumes and airway pressures at best-fit with the use of the two masks and number of patients with inadequate ventilation with use of the masks were statistically analyzed. A total of 79 edentulous patients were recruited for the study. The difference in expiratory tidal volumes with the use of the two masks at best-fit was statistically significant (P = 0.0017). Despite the best-fit mask placement, adequacy of ventilation could not be achieved in 24.1% patients during face mask ventilation, and 12.7% patients during nasal mask ventilation and the difference was statistically significant. Nasal mask ventilation is more efficient than standard face mask ventilation in edentulous patients.

  3. Clinical studies on combined ventilation (sup(81m)Kr)/perfusion (sup(99m)Tc-MAA) scintigraphy. With special reference to the 'mismatch' patterns and their significance

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Keiichiro; Miyamae, Tatsuya [Saitama Medical School (Japan)

    1983-01-01

    One hundred fifty patients having pulmonary disease underwent pulmonary scintigraphy sequentially with sup(99m)Tc-MAA and sup(81m)Kr gases. Scintigrams of matched defect were obtained from 113 (75.3%) of the 150 patients, considered to be nonspecific universal pattern of a pulmonary disease. Scintigrams of mismatched defect (absent perfusion and homogeneous ventilation) were obtained from 20 patients (13.3%), including 6 with lung carcinoma, 3 with pulmonary embolism, 3 with connective tissue disease, 2 with aortitis syndrome and 6 with other diseases. Scintigrams of mismatch with impaired ventilation and normal perfusion were mainly seen in chronic obstructive lung diseases. Of the 10 patients with bronchial asthma, 5 had scintigrams of improved ventilation after intravenous injection of 250 mg aminophilline, but none of patients with emphysema. The combined scintigraphy has made significant contributions to diagnosis and management of patients with pulmonary disease where the chest X-ray is unhelpful.

  4. Recommendations for mechanical ventilation of critically ill children from the Paediatric Mechanical Ventilation Consensus Conference (PEMVECC).

    Science.gov (United States)

    Kneyber, Martin C J; de Luca, Daniele; Calderini, Edoardo; Jarreau, Pierre-Henri; Javouhey, Etienne; Lopez-Herce, Jesus; Hammer, Jürg; Macrae, Duncan; Markhorst, Dick G; Medina, Alberto; Pons-Odena, Marti; Racca, Fabrizio; Wolf, Gerhard; Biban, Paolo; Brierley, Joe; Rimensberger, Peter C

    2017-12-01

    Much of the common practice in paediatric mechanical ventilation is based on personal experiences and what paediatric critical care practitioners have adopted from adult and neonatal experience. This presents a barrier to planning and interpretation of clinical trials on the use of specific and targeted interventions. We aim to establish a European consensus guideline on mechanical ventilation of critically children. The European Society for Paediatric and Neonatal Intensive Care initiated a consensus conference of international European experts in paediatric mechanical ventilation to provide recommendations using the Research and Development/University of California, Los Angeles, appropriateness method. An electronic literature search in PubMed and EMBASE was performed using a combination of medical subject heading terms and text words related to mechanical ventilation and disease-specific terms. The Paediatric Mechanical Ventilation Consensus Conference (PEMVECC) consisted of a panel of 15 experts who developed and voted on 152 recommendations related to the following topics: (1) general recommendations, (2) monitoring, (3) targets of oxygenation and ventilation, (4) supportive measures, (5) weaning and extubation readiness, (6) normal lungs, (7) obstructive diseases, (8) restrictive diseases, (9) mixed diseases, (10) chronically ventilated patients, (11) cardiac patients and (12) lung hypoplasia syndromes. There were 142 (93.4%) recommendations with "strong agreement". The final iteration of the recommendations had none with equipoise or disagreement. These recommendations should help to harmonise the approach to paediatric mechanical ventilation and can be proposed as a standard-of-care applicable in daily clinical practice and clinical research.

  5. Characteristics of rain penetration through a gravity ventilator used for natural ventilation.

    Science.gov (United States)

    Kim, Taehyeung; Lee, Dong Ho; Ahn, Kwangseog; Ha, Hyunchul; Park, Heechang; Piao, Cheng Xu; Li, Xiaoyu; Seo, Jeoungyoon

    2008-01-01

    Gravity ventilators rely simply on air buoyancy to extract air and are widely used to exhaust air contaminants and heat from workplaces using minimal energy. They are designed to maximize the exhaust flow rate, but the rain penetration sometimes causes malfunctioning. In this study, the characteristics of rain penetration through a ventilator were examined as a preliminary study to develop a ventilator with the maximum exhaust capacity while minimizing rain penetration. A model ventilator was built and exposed to artificial rain and wind. The paths, intensities and amounts of penetration through the ventilator were observed and measured in qualitative and quantitative fashions. In the first phase, the pathways and intensities of rain penetration were visually observed. In the second phase, the amounts of rain penetration were quantitatively measured under the different configurations of ventilator components that were installed based on the information obtained in the first-phase experiment. The effects of wind speed, grill direction, rain drainage width, outer wall height, neck height and leaning angle of the outer wall from the vertical position were analyzed. Wind speed significantly affected rain penetration. Under the low crosswind conditions, the rain penetration intensities were under the limit of detection. Under the high crosswind conditions, grill direction and neck height were the most significant factors in reducing rain penetration. The installation of rain drainage was also important in reducing rain penetration. The experimental results suggest that, with proper configurations of its components, a gravity ventilator can be used for natural ventilation without significant rain penetration problems.

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

    NARCIS (Netherlands)

    Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

    2011-01-01

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

  7. Analysis on ventilation pressure of fire area in longitudinal ventilation of underground tunnel

    Science.gov (United States)

    Li, Jiaxin; Li, Yanfeng; Feng, Xiao; Li, Junmei

    2018-03-01

    In order to solve the problem of ventilation pressure loss in the fire area under the fire condition, the wind pressure loss model of the fire area is established based on the thermodynamic equilibrium relation. The semi-empirical calculation formula is obtained by using the model experiment and CFD simulation. The validity of the formula is verified. The results show that the ventilation pressure loss in the fire zone is proportional to the convective heat release rate at the critical velocity, which is inversely proportional to the upstream ventilation velocity and the tunnel cross-sectional area. The proposed formula is consistent with the law of the tunnel fire test fitting formula that results are close, in contrast, the advantage lies in a clear theoretical basis and ventilation velocity values. The resistance of road tunnel ventilation system is calculated accurately and reliably, and then an effective emergency ventilation operation program is developed. It is necessary to consider the fire zone ventilation pressure loss. The proposed ventilation pressure loss formula can be used for design calculation after thorough verification.

  8. 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

  9. Accuracy of tidal volume delivered by home mechanical ventilation during mouthpiece ventilation

    Science.gov (United States)

    Prigent, Helene; Falaize, Line; Leroux, Karl; Santos, Dante; Vaugier, Isabelle; Orlikowski, David; Lofaso, Frederic

    2016-01-01

    The aim of our study was to evaluate efficacy and reliability of currently available ventilators for mouthpiece ventilation (MPV). Five life-support home ventilators were assessed in a bench test using different settings simulating the specificities of MPV, such as intermittent circuit disconnection and presence of continuous leaks. The intermittent disconnection of the circuit caused relevant swings in the delivered tidal volume (VT), showing a VT overshoot during the disconnection periods and a VT decrease when the interface was reconnected to the test lung. The five ventilators showed substantial differences in the number of respiratory cycles necessary to reach a stable VT in the volume-controlled setting, ranging from 1.3 ± 0.6 to 7.3 ± 1.2 cycles. These differences were less accentuated in the volume-assisted setting (MPV-dedicated mode, when available). Our data show large differences in the capacity of the different ventilators to deal with the rapidly changing respiratory load features that characterize MPV, which can be further accentuated according to the used ventilator setting. The dedicated MPV modes allow improvement in the performance of ventilators only in some defined situations. This has practical consequences for the choice of the ventilator to be used for MPV in a specific patient. PMID:27146811

  10. The influence of ventilated façade on sound insulation properties of envelope walls

    Directory of Open Access Journals (Sweden)

    Fišarová Zuzana

    2017-01-01

    Full Text Available Presented article deals with sound insulation properties of timber structures’ envelope walls. Particularly, the influence of heavy board ventilated façade on laboratory airborne sound insulation R and Rw in dB was studied. The installation method and gaps between façade boards can cause building defects originating in overrating the influence of ventilated cladding on envelope wall acoustic parameters. Real constructions were built for the experimental purposes and measurements, one with gaps between boards and one with simply eliminated gaps for mutual comparison. The results obtained were processed to make tables and graphs and to derive recommendations for the design of this type of constructions involving the general installation method of façade boards. Detailed results are depicted in conclusions.

  11. 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

  12. Fires in large scale ventilation systems

    International Nuclear Information System (INIS)

    Gregory, W.S.; Martin, R.A.; White, B.W.; Nichols, B.D.; Smith, P.R.; Leslie, I.H.; Fenton, D.L.; Gunaji, M.V.; Blythe, J.P.

    1991-01-01

    This paper summarizes the experience gained simulating fires in large scale ventilation systems patterned after ventilation systems found in nuclear fuel cycle facilities. The series of experiments discussed included: (1) combustion aerosol loading of 0.61x0.61 m HEPA filters with the combustion products of two organic fuels, polystyrene and polymethylemethacrylate; (2) gas dynamic and heat transport through a large scale ventilation system consisting of a 0.61x0.61 m duct 90 m in length, with dampers, HEPA filters, blowers, etc.; (3) gas dynamic and simultaneous transport of heat and solid particulate (consisting of glass beads with a mean aerodynamic diameter of 10μ) through the large scale ventilation system; and (4) the transport of heat and soot, generated by kerosene pool fires, through the large scale ventilation system. The FIRAC computer code, designed to predict fire-induced transients in nuclear fuel cycle facility ventilation systems, was used to predict the results of experiments (2) through (4). In general, the results of the predictions were satisfactory. The code predictions for the gas dynamics, heat transport, and particulate transport and deposition were within 10% of the experimentally measured values. However, the code was less successful in predicting the amount of soot generation from kerosene pool fires, probably due to the fire module of the code being a one-dimensional zone model. The experiments revealed a complicated three-dimensional combustion pattern within the fire room of the ventilation system. Further refinement of the fire module within FIRAC is needed. (orig.)

  13. Ventilation practices in subarachnoid hemorrhage: a cohort study exploring the use of lung protective ventilation.

    Science.gov (United States)

    Marhong, Jonathan D; Ferguson, Niall D; Singh, Jeffrey M

    2014-10-01

    Acute respiratory distress syndrome (ARDS) is common following aneurysmal subarachnoid hemorrhage (SAH), but the influence of mechanical ventilator settings on its development is unclear. We sought to determine adherence to lung protective thresholds in ventilated patients with SAH and describe the association between ventilator settings and subsequent development of ARDS. We conducted a retrospective cohort study of consecutive patients receiving mechanical ventilation within 72 h of SAH at a single academic center. Ventilator settings and blood gas data were collected twice daily for the first 7 days of ventilation along with ICU and hospital outcomes. Lung protective ventilation was defined as follows: tidal volume ≤8 mL/kg of predicted body weight, positive end-expiratory pressure (PEEP) ≥5 cm H(2)O, and peak or plateau pressure ≤30 cm H(2)O. The development of ARDS was ascertained retrospectively by PaO(2)/FiO(2) ≤300 with new bilateral lung opacities on chest X-ray within one day of hypoxemia. We identified 62 patients who underwent early mechanical ventilation following SAH. PS and Continuous Positive Airway Pressure were common ventilator modes with a median tidal volume of 7.8 mL/kg [interquartile range 6.8-8.8], median peak pressure of 14 cm H(2)O [IQR 12-17], and median PEEP of 5 cm H(2)O [IQR 5-6]. Adherence to tidal volumes ≤8 mL/kg was seen in 64 % of all observations and peak pressures protective criteria were seen in 58 % of all observations. Thirty-one patients (50 %) were determined to have ARDS. ARDS patients were more frequently ventilated with a peak pressure >30 cm H(2)O (11.3 % of ARDS ventilation days vs. 0 % of non-ARDS ventilation days; p mechanical ventilation frequently breathe spontaneously, generating tidal volumes above usual protective thresholds regardless of meeting ARDS criteria. In patients with SAH, the presence of an additional ARDS risk factor should prompt close screening for the development of ARDS and

  14. Computer program for sizing residential energy recovery ventilator

    International Nuclear Information System (INIS)

    Koontz, M.D.; Lee, S.M.; Spears, J.W.; Kesselring, J.P.

    1991-01-01

    Energy recovery ventilators offer the prospect of tighter control over residential ventilation rates than manual methods, such as opening windows, with a lesser energy penalty. However, the appropriate size of such a ventilator is not readily apparent in most situations. Sizing of energy recovery ventilation software was developed to calculate the size of ventilator necessary to satisfy ASHRAE Standard 62-1989, Ventilation for Acceptable Air Quality, or a user-specified air exchange rate. Inputs to the software include house location, structural characteristics, house operations and energy costs, ventilation characteristics, and HVAC system COP/efficiency. Based on these inputs, the program estimates the existing air exchange rate for the house, the ventilation rate required to meet the ASHRAE standard or user-specified air exchange rate, the size of the ventilator needed to meet the requirement, and the expected changes in indoor air quality and energy consumption. In this paper an illustrative application of the software is provided

  15. Potential risk for bacterial contamination in conventional reused ventilator systems and disposable closed ventilator-suction systems.

    Science.gov (United States)

    Li, Ya-Chi; Lin, Hui-Ling; Liao, Fang-Chun; Wang, Sing-Siang; Chang, Hsiu-Chu; Hsu, Hung-Fu; Chen, Sue-Hsien; Wan, Gwo-Hwa

    2018-01-01

    Few studies have investigated the difference in bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilator systems, and the association between system disconnection and bacterial contamination of ventilator systems. The enrolled intubated and mechanically ventilated patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilator circuit systems to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study. The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable ventilator system. The inspiratory and expiratory limbs of the disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier of the reused ventilator system was significantly higher than that in the disposable ventilator system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia. Both the reused and disposable ventilator systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation to decrease the risks of environmental pollution and human exposure, especially for the disposable ventilator system. ClinicalTrials.gov PRS / NCT03359148.

  16. Electronic structure of point defects in semiconductors

    International Nuclear Information System (INIS)

    Bruneval, Fabien

    2014-01-01

    trace concentration (of the order of one part per million). However, owing to the heavy burden of the quantum-mechanical electronic structure calculations, which grow very rapidly with the number of electrons, the present day simulations do not easily exceed a few hundred atoms nowadays. This induces effective defect concentrations of the order of one percent which are very far from the diluted defects observed in the experiments. The extrapolation of high concentrations to low concentrations is difficult because defects in semiconductors often bear a net electric charge which induces long-range interactions between the spuriously interacting charged defects. The first part of my work presents the techniques available in this area, improvements in the techniques and some understanding of these spurious interactions. The second topic addressed in this memoir focuses on improving the electronic structure of defects in semiconductors and insulators. Defects in these materials introduce discrete electronic levels within the band gap of the pristine bulk material. These electronic levels correspond to the electrons involved in the defect states. Their wave function is more or less localized around the defect region and the filling of the state may also vary with the thermodynamic conditions (Fermi level). These levels inside the band gap govern the modification of the properties of electronic and optical transport. Unfortunately the standard ab initio approaches, in the context of Density Functional Theory (DFT), are unable to get the correct band gaps of semiconductors and insulators. This is why many defect properties cannot be predicted with certainty within these approaches. This second part demonstrates how the introduction of the many-body perturbation theory in the so-called GW approximation solves the problem of band gaps and thus allows one to obtain more reliable defect properties. Of course, the field of ab initio electronic structure for defects is far from being

  17. A Porcine Model for Initial Surge Mechanical Ventilator Assessment and Evaluation of Two Limited Function Ventilators

    Science.gov (United States)

    Dickson, Robert P; Hotchkin, David L; Lamm, Wayne JE; Hinkson, Carl; Pierson, David J; Glenny, Robb W; Rubinson, Lewis

    2013-01-01

    Objective To adapt an animal model of acute lung injury for use as a standard protocol for a screening, initial evaluation of limited function, or “surge,” ventilators for use in mass casualty scenarios. Design Prospective, experimental animal study. Setting University research laboratory. Subjects 12 adult pigs. Interventions 12 spontaneously breathing pigs (6 in each group) were subjected to acute lung injury/acute respiratory distress syndrome (ALI/ARDS) via pulmonary artery infusion of oleic acid. Following development of respiratory failure, animals were mechanically ventilated with a limited function ventilator (Simplified Automatic Ventilator [SAVe] I or II; Automedx) for one hour or until the ventilator could not support the animal. The limited function ventilator was then exchanged for a full function ventilator (Servo 900C; Siemens). Measurements and Main Results Reliable and reproducible levels of ALI/ARDS were induced. The SAVe I was unable to adequately oxygenate 5 animals, with PaO2 (52.0 ± 11.1 torr) compared to the Servo (106.0 ± 25.6 torr; p=0.002). The SAVe II was able to oxygenate and ventilate all 6 animals for one hour with no difference in PaO2 (141.8 ± 169.3 torr) compared to the Servo (158.3 ± 167.7 torr). Conclusions We describe a novel in vivo model of ALI/ARDS that can be used to initially screen limited function ventilators considered for mass respiratory failure stockpiles, and is intended to be combined with additional studies to defintively assess appropriateness for mass respiratory failure. Specifically, during this study we demonstrate that the SAVe I ventilator is unable to provide sufficient gas exchange, while the SAVe II, with several more functions, was able to support the same level of hypoxemic respiratory failure secondary to ALI/ARDS for one hour. PMID:21187747

  18. [A comparison of leak compensation in six acute care ventilators during non-invasive ventilation].

    Science.gov (United States)

    Hu, X S; Wang, Y; Wang, Z T; Yan, P; Zhang, X G; Zhao, S F; Xie, F; Gu, H J; Xie, L X

    2017-02-12

    Objective: To compare the ability of leak compensation in 6 medical ventilators during non-invasive ventilation. Methods: Six medical ventilators were selected, including 3 non-invasive ventilators (V60, Flexo and Stellar150), and 3 invasive ventilators(Avea, Servo I and BellaVist). Using a lung simulator, the ability of leak compensation was evaluated during triggering and cycling in 2 respiratory mechanics conditions (high airway resistance condition and high elastance resistance condition), and each condition was performed under 2 PEEP levels (4, and 8 cmH(2)O, 1 mmHg=0.098 kPa) at 4 air leak level conditions (L0: 2-3 L/min, L1: 8-10 L/min, L2: 22-27 L/min, L3: 35-40 L/min). Results: In the high elastance resistance condition (L2, L3)with different leak levels, the number of auto-triggering and miss-triggering of the non-invasive ventilator Flexo was significantly less than those of the others (L2: 1, 1; L3: 1.67, 1.33, P ventilators ( P ventilators (1, 0.67, 0, P ventilators in both high airway resistance and high elastance resistance conditions with L0 and L1 leak levels and PEEP levels [ARDS, PEEP=4: (109.8±1.8) ms, (112.0±0.6) ms; ARDS, PEEP=8: (103.1±0.7) ms, (109.7±0.7) ms; COPD, PEEP=4: (207.3±1.1) ms, (220.8±1.1) ms; COPD, PEEP=8: (195.6±6.7) ms, (200.0±1.2) ms , P ventilators could be synchronized, among which V60, Stellar150 and Flexo presented a good performance features in specific conditions.

  19. Government and governance strategies in medical tourism

    NARCIS (Netherlands)

    Ormond, M.E.; Mainil, T.

    2015-01-01

    This chapter provides an overview of current government and governance strategies relative to medical tourism development and management around the world. Most studies on medical tourism have privileged national governments as key actors in medical tourism regulation and, in some cases, even

  20. Engineering governance: introducing a governance meta framework.

    NARCIS (Netherlands)

    Brand, N.; Beens, B.; Vuuregge, E.; Batenburg, R.

    2011-01-01

    There is a need for a framework that depicts strategic choices within an organisation with regard to potential governance structures. The governance meta framework provides the necessary structure in the current developments of governance. Performance as well as conformance are embedded in this

  1. 48 CFR 15.407-1 - Defective certified cost or pricing data.

    Science.gov (United States)

    2010-10-01

    ...—Modifications. The clauses give the Government the right to a price adjustment for defects in certified cost or... recognize that the Government's right to a price adjustment is not affected by any of the following... certified, cost or pricing data, the Government has the right, under the clauses at 52.215-10, Price...

  2. Characterizing the chaotic nature of ocean ventilation

    Science.gov (United States)

    MacGilchrist, Graeme A.; Marshall, David P.; Johnson, Helen L.; Lique, Camille; Thomas, Matthew

    2017-09-01

    Ventilation of the upper ocean plays an important role in climate variability on interannual to decadal timescales by influencing the exchange of heat and carbon dioxide between the atmosphere and ocean. The turbulent nature of ocean circulation, manifest in a vigorous mesoscale eddy field, means that pathways of ventilation, once thought to be quasi-laminar, are in fact highly chaotic. We characterize the chaotic nature of ventilation pathways according to a nondimensional "filamentation number," which estimates the reduction in filament width of a ventilated fluid parcel due to mesoscale strain. In the subtropical North Atlantic of an eddy-permitting ocean model, the filamentation number is large everywhere across three upper ocean density surfaces—implying highly chaotic ventilation pathways—and increases with depth. By mapping surface ocean properties onto these density surfaces, we directly resolve the highly filamented structure and confirm that the filamentation number captures its spatial variability. These results have implications for the spreading of atmospherically-derived tracers into the ocean interior.

  3. Protective mechanical ventilation, why use it?

    Science.gov (United States)

    Seiberlich, Emerson; Santana, Jonas Alves; Chaves, Renata de Andrade; Seiberlich, Raquel Carvalho

    2011-01-01

    Mechanical ventilation (MV) strategies have been modified over the last decades with a tendency for increasingly lower tidal volumes (VT). However, in patients without acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) the use of high VTs is still very common. Retrospective studies suggest that this practice can be related to mechanical ventilation-associated ALI. The objective of this review is to search for evidence to guide protective MV in patients with healthy lungs and to suggest strategies to properly ventilate lungs with ALI/ARDS. A review based on the main articles that focus on the use of strategies of mechanical ventilation was performed. Consistent studies to determine which would be the best way to ventilate a patient with healthy lungs are lacking. Expert recommendations and current evidence presented in this article indicate that the use of a VT lower than 10 mL.kg(-1), associated with positive end-expiratory pressure (PEEP) ≥ 5 cmH(2)O without exceeding a pressure plateau of 15 to 20 cmH(2)O could minimize alveolar stretching at the end of inspiration and avoid possible inflammation or alveolar collapse. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  4. Design Feature 7: Continuous Preclosure Ventilation

    International Nuclear Information System (INIS)

    A.T. Watkins

    1999-01-01

    This design feature (DF) is intended to evaluate the effects of continuous ventilation in the emplacement drifts during preclosure and how the effects, if any, compare to the Viability Assessment (VA) reference design for postclosure long term performance. This DF will be evaluated against a set of criteria provided by the License Application Design Selection (LADS) group. The VA reference design included a continuous ventilation airflow quantity of 0.1 m 3 /s in the emplacement drifts in the design of the repository subsurface facilities. The effects of this continuous ventilation during the preclosure was considered to have a negligible effect on postclosure performance and therefore is not included during postclosure in the assessment of the long term performance. This DF discusses the effects of continuous ventilation on the emplacement drift environment and surrounding rock conditions during preclosure for three increased airflow quantities. The three cases of continuous ventilation systems are: System A, 1.0 m 3 /s (Section 8), System B, 5.0 m 3 /s (Section 9), and System C, 10.0 m 3 /s (Section 10) in each emplacement drift split. An emplacement drift split is half total length of emplacement drift going from the east or west main to the exhaust main. The difference in each system is the quantity of airflow in the emplacement drifts

  5. Low resource ventilation unit; Ressourcebesparende ventilationsenhed

    Energy Technology Data Exchange (ETDEWEB)

    Drivsholm, C.

    2012-03-15

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

  6. Optimized mine ventilation on demand (OMVOD)

    International Nuclear Information System (INIS)

    Anderson, M.

    2009-01-01

    This paper provided an overview of the Optimized Mine Ventilation on Demand (OMVOD) system that is being installed at Xstrata Nickel Rim South Project and at Vale Inco's Totten Mine in Sudbury. The OMVOD system is designed to dynamically monitor and control air quality and quantity in real time and dilute and remove hazardous substances including diesel particulate matter (DPM), carbon monoxide (CO) and nitrous oxide (NO 2 ). It is also designed to control the thermal environment and provide ventilation for humans as well as mobile equipment engine combustion according to regulatory standards. The paper highlighted the OMVOD system optimization of energy, air quality measurement and control and production management of the mines through real time dynamic automation. Topics of discussion included real-time tracking and monitoring of diesel equipment; real-time tracking of underground miners; real-time evaluation of mine ventilation networks; and real-time control and optimization of ventilation equipment. ABB and Simsmart Technologies have joined forces to provide underground mining customers with a ventilation optimization solution. Simsmart's OMVOD provides proven real time/dynamic automation technology to significantly reduce energy costs, provide health and safety benefits as well as major capital cost savings while realizing an increase in production.

  7. Ventilation system for 99Mo production apparatus

    International Nuclear Information System (INIS)

    Izumo, Mishiroku; Okane, Shougo; Sorita, Takami; Aoyama, Saburou

    1978-04-01

    In production of 20 Ci 99 Mo from 235 U fission, about 120 Ci of radioiodine ( 131 I, 132 I, and 133 I) is involved. To remove airborne radioiodine from the exhaust air from production apparatus and minimize radioiodine release to the atmosphere, the ventilation system is equipped with 2 units of Model-FD charcoal filter (KI 3 -Impregnated charcoal 2 inch thick of Barnebey-Cheney Co.). From September 1976 to December 1977, 21 runs of 99 Mo production involving airborne radioiodine were carried out. The ventilation system was operated continuously for the whole 15 months period; variation in removal efficiency of airborne radioiodine from the exhaust air stream was observed. In the runs valuable experiences were gained in operation and maintenance of the ventilation system including activated charcoal filter and health-physics management of such facility. Following are the results: (1) Airborne radioiodine from 99 Mo production apparatus is reduced to 10 -3 % of the original quantity. (2) When the ventilation system is operated at a maximum air flow rate through the filter, the average efficiency during 15 months is over 98%. (3) Airborne radioiodine released from 99 Mo production apparatus to the ventilation system is less than 5% particulate iodine and alkyl iodines and more than 95% inorganic iodine. (4) Airborne radioiodine released from the stack is less than 28 μCi/run, which is below the limit in regulations on Radioisotope Production Laboratory. (auth.)

  8. Underground ventilation remote monitoring and control system

    International Nuclear Information System (INIS)

    Strever, M.T.; Wallace, K.G. Jr.; McDaniel, K.H.

    1995-01-01

    This paper presents the design and installation of an underground ventilation remote monitoring and control system at the Waste Isolation Pilot Plant. This facility is designed to demonstrate safe underground disposal of U.S. defense generated transuranic nuclear waste. To improve the operability of the ventilation system, an underground remote monitoring and control system was designed and installed. The system consists of 15 air velocity sensors and 8 differential pressure sensors strategically located throughout the underground facility providing real-time data regarding the status of the ventilation system. In addition, a control system was installed on the main underground air regulators. The regulator control system gives indication of the regulator position and can be controlled either locally or remotely. The sensor output is displayed locally and at a central surface location through the site-wide Central Monitoring System (CMS). The CMS operator can review all sensor data and can remotely operate the main underground regulators. Furthermore, the Virtual Address Extension (VAX) network allows the ventilation engineer to retrieve real-time ventilation data on his personal computer located in his workstation. This paper describes the types of sensors selected, the installation of the instrumentation, and the initial operation of the remote monitoring system

  9. Computational fluid dynamics in ventilation: Practical approach

    Science.gov (United States)

    Fontaine, J. R.

    The potential of computation fluid dynamics (CFD) for conceiving ventilation systems is shown through the simulation of five practical cases. The following examples are considered: capture of pollutants on a surface treating tank equipped with a unilateral suction slot in the presence of a disturbing air draft opposed to suction; dispersion of solid aerosols inside fume cupboards; performances comparison of two general ventilation systems in a silkscreen printing workshop; ventilation of a large open painting area; and oil fog removal inside a mechanical engineering workshop. Whereas the two first problems are analyzed through two dimensional numerical simulations, the three other cases require three dimensional modeling. For the surface treating tank case, numerical results are compared to laboratory experiment data. All simulations are carried out using EOL, a CFD software specially devised to deal with air quality problems in industrial ventilated premises. It contains many analysis tools to interpret the results in terms familiar to the industrial hygienist. Much experimental work has been engaged to validate the predictions of EOL for ventilation flows.

  10. Tunnel Ventilation Control Using Reinforcement Learning Methodology

    Science.gov (United States)

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

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

  11. Repairing Nanoparticle Surface Defects.

    Science.gov (United States)

    Marino, Emanuele; Kodger, Thomas E; Crisp, Ryan W; Timmerman, Dolf; MacArthur, Katherine E; Heggen, Marc; Schall, Peter

    2017-10-23

    Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We utilized atomically thin semiconductor nanoplatelets as a convenient platform for studying, both microscopically and spectroscopically, the development of defects during ligand exchange with the conductive ligands Na 4 SnS 4 and (NH 4 ) 4 Sn 2 S 6 . These defects can be repaired via mild chemical or thermal routes, through the addition of L-type ligands or wet annealing, respectively. This results in a higher-quality, conductive, colloidally stable nanomaterial that may be used as the active film in optoelectronic devices. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  12. Defect identification using positrons

    International Nuclear Information System (INIS)

    Beling, C.D.; Fung, S.

    2001-01-01

    The current use of the lifetime and Doppler broadening techniques in defect identification is demonstrated with two studies, the first being the identification of carbon vacancy in n-6H SiC through lifetime spectroscopy, and the second the production of de-hydrogenated voids in α-Si:H through light soaking. Some less conventional ideas are presented for more specific defect identification, namely (i) the amalgamation of lifetime and Doppler techniques with conventional deep level transient spectroscopy in what may be called ''positron-deep level transient spectroscopy'', and (ii) the extraction of more spatial information on vacancy defects by means of what may be called ''Fourier transform Doppler broadening of annihilation radiation spectroscopy'' (orig.)

  13. Xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans: correlation of xenon and CT density values with pulmonary function test results

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Yang, Dong Hyun; Seo, Joon Beom; Chae, Eun Jin; Lee, Jeongjin; Hong, Soo-Jong; Yu, Jinho; Kim, Byoung-Ju; Krauss, Bernhard

    2010-01-01

    Xenon ventilation CT using dual-source and dual-energy technique is a recently introduced, promising functional lung imaging method. To expand its clinical applications evidence of additional diagnostic value of xenon ventilation CT over conventional chest CT is required. To evaluate the usefulness of xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans (BO). Seventeen children (age 7-18 years; 11 boys) with BO underwent xenon ventilation CT using dual-source and dual-energy technique. Xenon and CT density values were measured in normal and hyperlucent lung regions on CT and were compared between the two regions. Volumes of hyperlucent regions and ventilation defects were calculated with thresholds determined by visual and histogram-based analysis. Indexed volumes of hyperlucent lung regions and ventilation defects were correlated with pulmonary function test results. Effective doses of xenon CT were calculated. Xenon (14.6 ± 6.4 HU vs 26.1 ± 6.5 HU; P 25-75 , (γ = -0.68-0.88, P ≤ 0.002). Volume percentages of xenon ventilation defects (35.0 ± 16.4%)] were not significantly different from those of hyperlucent lung regions (38.2 ± 18.6%). However, mismatches between the volume percentages were variable up to 21.4-33.3%. Mean effective dose of xenon CT was 1.9 ± 0.5 mSv. In addition to high-resolution anatomic information, xenon ventilation CT using dual-source and dual-energy technique demonstrates impaired regional ventilation and its heterogeneity accurately in children with BO without additional radiation exposure. (orig.)

  14. 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...... to have high ventilation effectiveness. Furthermore, personalized ventilation may reduce the risk of cross-infection, and in some cases, it can also reduce the source of infection. Personalized ventilation can especially be used in hospital wards, aircraft cabins and, in general, where people are in fixed...

  15. Quantum computing with defects

    Science.gov (United States)

    Varley, Joel

    2011-03-01

    The development of a quantum computer is contingent upon the identification and design of systems for use as qubits, the basic units of quantum information. One of the most promising candidates consists of a defect in diamond known as the nitrogen-vacancy (NV-1) center, since it is an individually-addressable quantum system that can be initialized, manipulated, and measured with high fidelity at room temperature. While the success of the NV-1 stems from its nature as a localized ``deep-center'' point defect, no systematic effort has been made to identify other defects that might behave in a similar way. We provide guidelines for identifying other defect centers with similar properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate systems. To elucidate these points, we compare electronic structure calculations of the NV-1 center in diamond with those of several deep centers in 4H silicon carbide (SiC). Using hybrid functionals, we report formation energies, configuration-coordinate diagrams, and defect-level diagrams to compare and contrast the properties of these defects. We find that the NC VSi - 1 center in SiC, a structural analog of the NV-1 center in diamond, may be a suitable center with very different optical transition energies. We also discuss how the proposed criteria can be translated into guidelines to discover NV analogs in other tetrahedrally coordinated materials. This work was performed in collaboration with J. R. Weber, W. F. Koehl, B. B. Buckley, A. Janotti, C. G. Van de Walle, and D. D. Awschalom. This work was supported by ARO, AFOSR, and NSF.

  16. Defects in semiconductors

    International Nuclear Information System (INIS)

    Pimentel, C.A.F.

    1983-01-01

    Some problems openned in the study of defects in semiconductors are presented. In particular, a review is made of the more important problems in Si monocrystals of basic and technological interest: microdefects and the presence of oxigen and carbon. The techniques usually utilized in the semiconductor material characterization are emphatized according its potentialities. Some applications of x-ray techniques in the epitaxial shell characterization in heterostructures, importants in electronic optics, are shown. The increase in the efficiency of these defect analysis methods in semiconductor materials with the use of synchrotron x-ray sources is shown. (L.C.) [pt

  17. Randomized, controlled trial comparing synchronized intermittent mandatory ventilation and synchronized intermittent mandatory ventilation plus pressure support in preterm infants.

    Science.gov (United States)

    Reyes, Zenaida C; Claure, Nelson; Tauscher, Markus K; D'Ugard, Carmen; Vanbuskirk, Silvia; Bancalari, Eduardo

    2006-10-01

    Prolonged mechanical ventilation is associated with lung injury in preterm infants. In these infants, weaning from synchronized intermittent mandatory ventilation may be delayed by their inability to cope with increased respiratory loads. The addition of pressure support to synchronized intermittent mandatory ventilation can offset these loads and may facilitate weaning. The purpose of this work was to compare synchronized intermittent mandatory ventilation and synchronized intermittent mandatory ventilation plus pressure support in weaning from mechanical ventilation and the duration of supplemental oxygen dependency in preterm infants with respiratory failure. Preterm infants weighing 500 to 1000 g at birth who required mechanical ventilation during the first postnatal week were randomly assigned to synchronized intermittent mandatory ventilation or synchronized intermittent mandatory ventilation plus pressure support. In both groups, weaning followed a set protocol during the first 28 days. Outcomes were assessed during the first 28 days and until discharge or death. There were 107 infants enrolled (53 synchronized intermittent mandatory ventilation plus pressure support and 54 synchronized intermittent mandatory ventilation). Demographic and perinatal data, mortality, and morbidity did not differ between groups. During the first 28 days, infants in the synchronized intermittent mandatory ventilation plus pressure support group reached minimal ventilator settings and were extubated earlier than infants in the synchronized intermittent mandatory ventilation group. Total duration of mechanical ventilation, duration of oxygen dependency, and oxygen need at 36 weeks' postmenstrual age alone or combined with death did not differ between groups. However, infants in synchronized intermittent mandatory ventilation plus pressure support within the 700- to 1000-g birth weight strata had a shorter oxygen dependency. The results of this study suggest that the addition of

  18. Federalism and multilevel governance

    NARCIS (Netherlands)

    van der Wusten, H.; Agnew, J.; Mamadouh, V.; Secor, A.J.; Sharp, J.

    2015-01-01

    Federalism and multilevel governance both emphasize polycentricity in governing arrangements. With their different intellectual pedigrees, these concepts are discussed in two separate sections. Fragments are now increasingly mixed up in hybrid forms of governance that also encompass originally

  19. Developing digital forensic governance

    CSIR Research Space (South Africa)

    Grobler, M

    2010-03-01

    Full Text Available This paper presents a Digital Forensic (DF) governance framework and its mapping on the SANS ISO/IEC 38500:2009 Corporate governance of information technology structure. DF governance assists organisations in guiding the management team...

  20. Voluntary Environmental Governance Arrangements

    NARCIS (Netherlands)

    van der Heijden, J.

    2012-01-01

    Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently

  1. Ventilation safety of facilities comprising nuclear reactors

    International Nuclear Information System (INIS)

    Guirlet, J.

    1982-01-01

    The reliability of the ventilation is one of the most important aspects in the prevention of the nuisances that a nuclear installation can provide, since the ventilation is located at the last barrier. A certain number of essential points have been recalled here. But it is necessary to bear in mind other requirements such as the limitation in the number of crossovers, the answers to be found should the system fail, the need to show that ventilation systems do not in themselves bring other nuisances such as noise, irradiation or contamination hazards, likelyhood of recycling the contamination, vibrations, fire. Finally, it is absolutely essential, right from the project stage, that the design ensures that very good accessibility, very easy dismantling and handling, as well as all the facilities needed to make sure of the initial and periodic tests, are guaranteed [fr

  2. Flow measurement in mechanical ventilation: a review.

    Science.gov (United States)

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

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. Phrenic pacing compared with mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Morten Packert; Laub, Michael; Biering-Sørensen, Fin

    2017-01-01

    mechanical ventilator dependent tetraplegics met the inclusion criteria. Data were retrieved from medical records and a structured follow-up interview with seven individuals from each group. RESULTS: No significant differences were found when comparing age at injury, time since injury, length...... of hospitalization, incidence of pneumonia, number of pneumonia hospitalizations, number of tracheal suctions, speech quality and activities of daily living or quality of life. On the Short Form Health Survey (SF36) mental health summary the median for both users of phrenic nerve pacing and users of mechanical...... ventilation was one s.d. above the mean of a standard population. CONCLUSIONS: Nine people have had a phrenic nerve pacer implanted. They do not significantly differ from a group of home mechanical ventilator dependent tetraplegics on a number of performance measures, but both groups seem to have better...

  4. Optimized ventilation-on-demand (VOD)

    Energy Technology Data Exchange (ETDEWEB)

    Masse, M. [Simsmart Technologies Inc., Brossard, PQ (Canada); Cervinka, A. [Newtrax Technologies Inc., Montreal, PQ (Canada)

    2008-07-01

    This presentation described how the combination of 2 innovative technologies can help optimize mine ventilation. Newtrax Technologies has developed a self-contained battery-powered wireless electronic system designed to operate in harsh industrial environments, including underground mines. Simsmart Technologies has created an advanced process and control simulation based design tool used in industrial applications, including mine ventilation systems. This presentation described the system components and how they work. These included the wireless mesh network designed for dynamic diesel machinery tracking and operating status monitoring; the real-time ventilation model and fan speed optimizer; the OPC server for information interchange; the OPC linkage to existing control infrastructure; a human machine interface that provide data archiving capability; live MS-Excel to interrogate the simulation, controls and optimizer; and, the battery-powered network mesh that provides SCADA functionality to route optimized setpoints. Details of the user interface were also provided. 1 tab., 20 figs.

  5. Indirect Calorimetry in Mechanically Ventilated Patients

    DEFF Research Database (Denmark)

    Allingstrup, Matilde Jo; Kondrup, Jens; Perner, Anders

    2017-01-01

    Background and Aims: The 2 currently available indirect calorimeters, CCM Express Indirect Calorimeter (MedGraphics, St Paul, MN) and Quark RMR ICU Indirect Calorimeter (COSMED, Rome, Italy), have not been validated against a gold standard in mechanically ventilated patients. Our aim was to do so...... using a gold-standard, modified Tissot bell-spirometer method in mechanically ventilated patients who were hemodynamically, respiratory, and metabolically stable. Methods: We studied 30 patients undergoing general anesthesia and major gynecological surgery. We measured oxygen consumption ((Formula...... of 77 (167) with limits of agreement −249 to 404 kcal/d. Conclusions: The QUARK RMR ICU Indirect Calorimeter compared better with the gold standard for values of (Formula presented.) O2 and REE than did the CCM Express Indirect Calorimeter in mechanically ventilated patients who were circulatory...

  6. Personal Exposure in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter Vilhelm

    1996-01-01

    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......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...... contaminant sources, this entrainment improves the indoor air quality. Measurements of exposure due to a passive contaminant source show a significant dependence on the flow field as well as on the contaminant source location. Poor system performance is found in the case of a passive contaminant released...

  7. A stability analysis of ventilated boiling channels

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.; Podowski, M.Z.; Lahey, R.T. Jr.

    1986-01-01

    A mathematical model has been developed for the linear stability analysis of a system of ventilated parallel boiling channels. This model accounts for subcooled boiling, an arbitrary heat flux distribution, distributed and local hydraulic losses, heated wall dynamics, slip flow, turbulent mixing and arbitrary flow paths for transverse ventilation. The digital computer program MAZDA-NF was written for numerical evaluation of the mathematical model. Comparison of MAZDA-NF results with those obtained form both a closed form analytical solution and experiment, showed good agreement. A parametric study revealed that such phenomena as subcooled boiling, the transverse coupling between channels (due to cross-flow and mixing) and power skewing can have a significant impact on predicted stability margins. An analysis of an advanced BWR fuel, of the ASEA-ATOM SVEA design, has indicated that transverse ventilation may considerably improve channel stability. (orig.)

  8. Cellular phone interference with the operation of mechanical ventilators.

    Science.gov (United States)

    Shaw, Cheryl I; Kacmarek, Robert M; Hampton, Rickey L; Riggi, Vincent; El Masry, Ashraf; Cooper, Jeffrey B; Hurford, William E

    2004-04-01

    To determine whether a cellular phone would interfere with the operation of mechanical ventilators. Laboratory study. University medical center. Fourteen mechanical ventilators. We evaluated change in operation and malfunction of the mechanical ventilators. The cellular phone (Nokia 6120i) was computer controlled, operating at 828.750 MHz analog modulation. It was operated at 16, 40, 100, 250, and 600 mW, 30 cm from the floor and 30, 15, and ventilator. Six of the 14 ventilators tested malfunctioned when a cellular phone at maximum power output was placed ventilating when the cellular phone at maximum power output was placed ventilator. One ventilator doubled the ventilatory rate and another increased the displayed tidal volume from 350 to 1033 mL. In one of the infant ventilators, displayed tidal volume increased from 21 to 100 mL. In another ventilator, the high respiratory rate alarm sounded but the rate had not changed. In a controlled laboratory setting, cellular phones placed in close proximity to some commercially available intensive care ventilators can cause malfunctions, including irrecoverable cessation of ventilation. This is most likely to occur if the cellular phone is or =3 feet from all medical devices. The current electromagnetic compatibility standards for mechanical ventilators are inadequate to prevent malfunction. Manufacturers should ensure that their products are not affected by wireless technology even when placed immediately next to the device.

  9. E-Government Dimension

    OpenAIRE

    Rosiyadi, Didi; Suryana, Nana; Cahyana, Ade; Nuryani, Nuryani

    2007-01-01

    Makalah ini mengemukakan E-Government Dimension yang merupakan salah satu hasil TahapanPengumpulan Data, dimana tahapan ini adalah bagian dari penelitian kompetitif di Lembaga Ilmu PengetahuanIndonesia 2007 yang sekarang sedang dilakukan. Data E-Government Dimension ini didapatkan dari berbagaisumber yang meliputi E-Government beberapa Negara di dunia, E-Government yang dibangun oleh beberapapenyedia aplikasi E-Government. E-Government Dimension terdiri dari tiga dimensi yaitu DemocraticDimen...

  10. Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

    Science.gov (United States)

    Dellaca', Raffaele L; Veneroni, Chiara; Farre', Ramon

    2017-06-01

    This review addresses how the combination of physiology, medicine and engineering principles contributed to the development and advancement of mechanical ventilation, emphasising the most urgent needs for improvement and the most promising directions of future development. Several aspects of mechanical ventilation are introduced, highlighting on one side the importance of interdisciplinary research for further development and, on the other, the importance of training physicians sufficiently on the technological aspects of modern devices to exploit properly the great complexity and potentials of this treatment. To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice.To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients.To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment.To better understand and classify ventilation modes.To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms.

  11. SUPRAGLOTTIC JET VENTILATION VERSUS CONVENTIONAL ENDOTRACHEAL VENTILATION IN MINOR LARYNGEAL SURGERIES

    Directory of Open Access Journals (Sweden)

    Illendual Upendranath

    2016-08-01

    Full Text Available Any attempt at intubation will cause many cardiovascular responses and the major concern during this time is to attenuate the same. Similar response is seen during procedures on Larynx in microlaryngeal surgery which produces an intense cardiovascular stimulation during suspension laryngoscopy and intubation. AIM OF STUDY Supraglottic jet ventilation versus conventional endotracheal ventilation in minor laryngeal surgeries. To evaluate the haemodynamic response in supraglottic jet ventilation and conventional intubation in minor laryngeal surgeries. METHODS Patients were randomised to 2 Groups: 30 patients in each group; Group A - in whom supraglottic jet ventilation was planned and Group B - in whom endotracheal intubation was planned. RESULT The haemodynamic response in terms of increase in MAP and HR is significantly more with endotracheal intubation than with supraglottic jet ventilation. CONCLUSION Our study showed that supraglottic jet ventilation showed a better haemodynamic stability when compared to conventional endotracheal intubation in patients undergoing minor laryngeal surgeries. Statistical scores were also in favour of the patients treated with supraglottic jet ventilation based on the p values.

  12. Factors Predicting Ventilator Dependence in Patients with Ventilator-Associated Pneumonia

    Directory of Open Access Journals (Sweden)

    Chia-Cheng Tseng

    2012-01-01

    Full Text Available Objectives. To determine risk factors associated with ventilator dependence in patients with ventilator-associated pneumonia (VAP. Study Design. A retrospective study was conducted at Chang Gung Memorial Hospital, Kaohsiung, from January 1, 2007 to January 31, 2008. Methods. This study evaluated 163 adult patients (aged ≥18 years. Eligibility was evaluated according to the criterion for VAP, Sequential Organ Failure Assessment (SOFA score, Acute Physiological Assessment and Chronic Health Evaluation II (APACHE II score. Oxygenation index, underlying comorbidities, septic shock status, previous tracheostomy status, and factors related to pneumonia were collected for analysis. Results. Of the 163 VAP patients in the study, 90 patients survived, yielding a mortality rate of 44.8%. Among the 90 surviving patients, only 36 (40% had been weaned off ventilators at the time of discharge. Multivariate logistic regression analysis was used to identify underlying factors such as congestive cardiac failure (P=0.009, initial high oxygenation index value (P=0.04, increased SOFA scores (P=0.01, and increased APACHE II scores (P=0.02 as independent predictors of ventilator dependence. Results from the Kaplan-Meier method indicate that initial therapy with antibiotics could increase the ventilator weaning rate (log Rank test, P<0.001. Conclusions. Preexisting cardiopulmonary function, high APACHE II and SOFA scores, and high oxygenation index were the strongest predictors of ventilator dependence. Initial empiric antibiotic treatment can improve ventilator weaning rates at the time of discharge.

  13. Nunavut housing ventilation research 2003-2005

    Energy Technology Data Exchange (ETDEWEB)

    Fugler, D.

    2005-11-15

    Inuit children in Alaska and Nunavut have high rates of severe lower respiratory tract infections, with hospitalization rates of 300 per year for each 1000 infants. The aim of this research report was to summarize the findings of a pilot project measuring the indoor air quality (IAQ) in 20 Cape Dorset houses as well as a study measuring the ventilation rates of 100 house from 4 communities in Nunavut. The 20 house pilot study included a respiratory questionnaire; a detailed home inspection and data collection; a blower door airtightness test; 7 day measurements of nitrogen dioxide (NO{sub 2}), nicotine, carbon dioxide (CO{sub 2}), relative humidity and temperature; a natural air change rate testing using Brookhaven tracer gas technology; and settled floor dust and bed dust collection followed by biological analysis. The 100 house study recorded 3 to 5 days of house temperatures, relative humidity and CO{sub 2}. The Brookhaven tracer gas technique was used to establish house air change rate. A questionnaire was used to assess ventilation devices. A medical questionnaire was administered and an evaluation of hospitalization data was carried out. Results indicated that a large number of Nunavut houses were not adequately ventilated. In the 20 house study, a third of the houses showed air change rates that would be considered low by any ventilation standards, and that were very low when considering the high occupancy of the houses. In the hundred house study, almost all houses indicated a mean CO{sub 2} level over 1000 ppm, and peaks exceeded 2000 ppm in approximately half the houses. The concentrations were far higher than those seen in southern Canadian homes. It was concluded that the development and promotion of energy-efficient ventilation devices could help to resolve ventilation deficiencies in Nunavut. 2 figs.

  14. Thermoregulation and ventilation of termite mounds

    Science.gov (United States)

    Korb, Judith

    2003-05-01

    Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO2 concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed.

  15. Ventilation-perfusion distribution in normal subjects.

    Science.gov (United States)

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

    2012-09-01

    Functional values of LogSD of the ventilation distribution (σ(V)) have been reported previously, but functional values of LogSD of the perfusion distribution (σ(q)) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σ(V), σ(q), and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations of the gases at end-expiration during the first 10 breaths were measured with the subjects at rest and at increasing levels of exercise. The regional distribution of ventilation and perfusion was described by a bivariate log-normal distribution with parameters σ(V), σ(q), and ρ, and these parameters were evaluated by matching the values of expired gas concentrations calculated for this distribution to the measured values. Values of cardiac output and LogSD ventilation/perfusion (Va/Q) were obtained. At rest, σ(q) is high (1.08 ± 0.12). With the onset of ventilation, σ(q) decreases to 0.85 ± 0.09 but remains higher than σ(V) (0.43 ± 0.09) at all exercise levels. Rho increases to 0.87 ± 0.07, and the value of LogSD Va/Q for light and moderate exercise is primarily the result of the difference between the magnitudes of σ(q) and σ(V). With known values for the parameters, the bivariate distribution describes the comprehensive distribution of ventilation and perfusion that underlies the distribution of the Va/Q ratio.

  16. 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.

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

    Science.gov (United States)

    Hess, Dean R

    2012-06-01

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

  18. 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...

  19. Preoperational test report, recirculation ventilation systems

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

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

  20. 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.

  1. Air change. Ventilation requirements of closed rooms

    Energy Technology Data Exchange (ETDEWEB)

    Cords, W

    1988-04-01

    Closed rooms have to be ventilated in order to compensate influences changing the composition and quality of air. Details are given on the conditions and factors determining the required change of air as well as the design of ventilation systems. Reference is made to the respiratory consumption of oxygen, the increase of hazardous carbon dioxide contents causing headaches and indispositions, water vapor exhalations, body heat, odors, cold air coming in from outside, bodily heat losses, carbon dioxide limiting values, air speeds, and air pressures inside rooms. The humidity and temperatures of frequented rooms should keep within the maximum values. (HWJ).

  2. Ventilation of nuclear rooms and operators' protection

    International Nuclear Information System (INIS)

    Vavasseur, C.

    1985-01-01

    Ventilation systems are designed to guarantee air replacement in rooms so as to evacuate gases, odors and aerosols liable to be produced therein. This air is conditioned, filtered, heated, and the relative humidity checked. At the outlet, a filtration system adapted to the type of effluent prevents the external dispersion of toxic substances. Ventilation is defined by the air change time. A comfort rule recommends reducing the velocities reaching the person present in less than 0.2 m/sec. This reduction is achieved by adjusting the natural property of the jets, induction, by means of diffusers placed at the vents

  3. Ventilation influence upon indoor air radon level

    International Nuclear Information System (INIS)

    Tian Deyuan

    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 in-draft > exhaust plus in-draft

  4. Improving comfort and health with personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    The thermal environment and air quality in buildings affects occupants¿ health, comfort and performance. The heating, ventilating and air-conditioning (HVAC) of buildings today is designed to provide a uniform room environment. However, large individual differences exist between occupants in regard...... 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...

  5. 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......Emission of volatile organic compounds (VOCs) from materials is traditionally determined from tests carried out in small-scale test chambers. However, a difference in scale may lead to a difference in the measured emission rate in a small-scale test chamber and the actual emission rate in a full...

  6. 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...

  7. Defect detection module

    International Nuclear Information System (INIS)

    Ernwein, R.; Westermann, G.

    1986-01-01

    The ''defect detector'' module is aimed at exceptional event or state recording. Foreseen for voltage presence monitoring on high supply voltage module of drift chambers, its characteristics can also show up the vanishing of supply voltage and take in account transitory fast signals [fr

  8. Quantum computing with defects.

    Science.gov (United States)

    Weber, J R; Koehl, W F; Varley, J B; Janotti, A; Buckley, B B; Van de Walle, C G; Awschalom, D D

    2010-05-11

    Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of a quantum computer. Among the possibilities in the solid state, a defect in diamond known as the nitrogen-vacancy (NV(-1)) center stands out for its robustness--its quantum state can be initialized, manipulated, and measured with high fidelity at room temperature. Here we describe how to systematically identify other deep center defects with similar quantum-mechanical properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate defect systems. To illustrate these points in detail, we compare electronic structure calculations of the NV(-1) center in diamond with those of several deep centers in 4H silicon carbide (SiC). We then discuss the proposed criteria for similar defects in other tetrahedrally coordinated semiconductors.

  9. TNKVNT: A model of the Tank 48 purge/ventilation exhaust system. Revision 1

    International Nuclear Information System (INIS)

    Shadday, M.A. Jr.

    1996-04-01

    The waste tank purge ventilation system for Tank 48 is designed to prevent dangerous concentrations of hydrogen or benzene from accumulating in the gas space of the tank. Fans pull the gas/water vapor mixture from the tank gas space and pass it sequentially through a demister, a condenser, a reheater, and HEPA filters before discharging to the environment. Proper operation of the HEPA filters requires that the gas mixture passing through them has a low relative humidity. The ventilation system has been modified by increasing the capacity of the fans and changing the condenser from a two-pass heat exchanger to a single-pass heat exchanger. It is important to understand the impact of these modifications on the operation of the system. A hydraulic model of the ventilation exhaust system has been developed. This model predicts the properties of the air throughout the system and the flowrate through the system, as functions of the tank gas space and environmental conditions. This document serves as a Software Design Report, a Software Coding report, and a User's Manual. All of the information required for understanding and using this code is herein contained: the governing equations are fully developed, the numerical algorithms are described in detail, and an extensively commented code listing is included. This updated version of the code models the entire purge ventilation system, and is therefore more general in its potential applications

  10. Continuous use of an adaptive lung ventilation controller in critically ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... Adaptive lung ventilation (ALV) refers to closed-loop mechanical ventilation designed to work ... optimise the controller performance, the volume controller .... PawEE), vital capacity IYC), an index of airway resistance relative to ...

  11. Dimensionless study on dynamics of pressure controlled mechanical ventilation system

    International Nuclear Information System (INIS)

    Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing

    2015-01-01

    Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

  12. Ventilation systems in houses. Special issue; Woonhuisventilatie. Special

    Energy Technology Data Exchange (ETDEWEB)

    Op ' t Veld, P.; Van der Aa, A. [Cauberg-Huygen Raadgevend Ingenieurs, Rotterdam (Netherlands); Verschoor, M.J.E. [Afdeling Koudetechniek en Warmtepompen, TNO Milieu, Energie en Procesinnovatie TNO-MEP, Apeldoorn (Netherlands); Van Gulik, L.H. [Itho, Scheidam (Netherlands); Van der Mark, K.; Overman, P. [AGPO, Breda (Netherlands); Roemer, J.C.; Schuitema, R. [ECN Duurzame Energie in de Gebouwde Omgeving DEGO, Petten (Netherlands); Weterings, M. [GGD voor Rotterdam e.o., Rotterdam (Netherlands); Rosenmai, T.; Rasmussen, S. [Copenhagen Business School, Copenhagen (Denmark); Vollebregt, R. [Bureau Kent, Utrecht (Netherlands); Smeets, L.J.M. [Nederlandse onderneming voor energie en milieu Novem, Utrecht (Netherlands)

    2001-06-01

    In 10 articles attention is paid to several aspects with respect to ventilation of houses. This issue includes an overview of suppliers of high-efficiency heat recovering balanced ventilation systems.

  13. Dimensionless study on dynamics of pressure controlled mechanical ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing [Beihang University, Beijing (Korea, Republic of)

    2015-02-15

    Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

  14. A comparison of leak compensation in acute care ventilators during noninvasive and invasive ventilation: a lung model study.

    Science.gov (United States)

    Oto, Jun; Chenelle, Christopher T; Marchese, Andrew D; Kacmarek, Robert M

    2013-12-01

    Although leak compensation has been widely introduced to acute care ventilators to improve patient-ventilator synchronization in the presence of system leaks, there are no data on these ventilators' ability to prevent triggering and cycling asynchrony. The goal of this study was to evaluate the ability of leak compensation in acute care ventilators during invasive and noninvasive ventilation (NIV). Using a lung simulator, the impact of system leaks was compared on 7 ICU ventilators and 1 dedicated NIV ventilator during triggering and cycling at 2 respiratory mechanics (COPD and ARDS models) settings, various modes of ventilation (NIV mode [pressure support ventilation], and invasive mode [pressure support and continuous mandatory ventilation]), and 2 PEEP levels (5 and 10 cm H(2)O). Leak levels used were up to 35-36 L/min in NIV mode and 26-27 L/min in invasive mode. Although all of the ventilators were able to synchronize with the simulator at baseline, only 4 of the 8 ventilators synchronized to all leaks in NIV mode, and 2 of the 8 ventilators in invasive mode. The number of breaths to synchronization was higher during increasing than during decreasing leak. In the COPD model, miss-triggering occurred more frequently and required a longer time to stabilize tidal volume than in the ARDS model. The PB840 required fewer breaths to synchronize in both invasive and noninvasive modes, compared with the other ventilators (P ventilators. The PB840 and the V60 were the only ventilators to acclimate to all leaks, but there were differences in performance between these 2 ventilators. It is not clear if these differences have clinical importance.

  15. WE-AB-202-05: Validation of Lung Stress Maps for CT-Ventilation Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cazoulat, G; Jolly, S; Matuszak, M; Balter, J; Brock, K [University of Michigan, Ann Arbor, MI (United States); Kipritidis, J; Keall, P [University of Sydney, Sydney NSW (Australia); Siva, S; Hofman, M [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne VIC (Australia)

    2016-06-15

    Purpose: To date, lung CT-ventilation imaging has been based on quantification of local breathing-induced changes in Hounsfield Units (HU) or volume. This work investigates the use of a stress map resulting from a biomechanical deformable image registration (DIR) algorithm as a metric of the ventilation function. Method: Eight lung cancer patients presenting different kinds of ventilation defects were retrospectively analyzed. Additionally, to the 4DCT acquired for radiotherapy planning, five of them had PET and three had SPECT imaging following inhalation of Ga-68 and Tc-99m, respectively. For each patient, the inhale phase of the 4DCT was registered to the exhale phase using Morfeus, a biomechanical DIR algorithm based on the determination of boundary conditions on the lung surfaces and vessel tree. To take into account the heterogeneity of the tissue stiffness in the stress map estimation, each tetrahedral element of the finite-element model was assigned a Young’s modulus ranging from 60kPa to 12MPa, as a function of the HU in the inhale CT. The node displacements and element stresses resulting from the numerical simulation were used to generate three CT-ventilation maps based on: (i) volume changes (Jacobian determinant), (ii) changes in HU, (iii) the maximum principal stress. The voxel-wise correlation between each CT-ventilation map and the PET or SPECT V image was computed in a lung mask. Results: For patients with PET, the mean (min-max) Spearman correlation coefficients r were: 0.33 (0.19–0.45), 0.36 (0.16–0.51) and 0.42 (0.21–0.59) considering the Jacobian, changes in HU and maximum principal stress, respectively. For patients with SPECT V, the mean r were: 0.12 (−0.12–0.43), 0.29 (0.22–0.45) and 0.33 (0.25–0.39). Conclusion: The maximum principal stress maps showed a stronger correlation with the ventilation images than the previously proposed Jacobian or change in HU maps. This metric thus appears promising for CT-ventilation imaging

  16. Design guidelines for natural ventilation systems in tertiary sector buildings

    OpenAIRE

    Van Moeseke, Geoffrey; Bruyère, Isabelle; De Herde, André; CISBAT 2005: Renewables in a changing climate

    2005-01-01

    Parameters determining efficiency of natural ventilation systems are numerous. The most important are architecture and system design. This article get onto both but focuses on system design. Through dynamic simulations it shows that natural ventilation management has a large impact on energy saving but most of all on thermal comfort. Natural ventilation techniques are also weighted against hybrid solutions and high efficiency mechanical cooling solutions. Natural ventilation techniques show t...

  17. 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.......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....

  18. Comparison of two modes of ventilation after fast-track cardiac surgery: Adaptive support ventilation versus synchronized intermittent mandatory ventilation

    International Nuclear Information System (INIS)

    Aghadavoudi, O.

    2012-01-01

    Objective: There is substantial debate regarding the appropriate protocol for ventilatory management in fast-track cardiac anesthesia (FTCA). This study was carried out to assess and compare the risks and benefits of respiratory weaning based on adaptive support ventilation (ASV) and synchronized intermittent mandatory ventilation (SIMV) after uncomplicated cardiac surgery. Methodology: In a randomized clinical trial, after receiving approval of the Department Research Committee and informed consent from study subjects, 100 patients undergoing elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) were enrolled during a 4-month period at a university-based hospital. After surgery and admission to the intensive care unit (ICU), patients were randomized to ASV and SIMV groups. Arterial blood gas (ABG) and hemodynamic variables, respiratory and ventilator characteristics including lung compliance, rapid shallow breathing index (RSBI), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (P peak), mean airway pressure (p mean), Pao2/FIo2, duration of mechanical ventilation and tracheal intubation, and length of ICU stay were recorded and compared between the two groups. The data were analyzed in 82 patients after considering the exclusion criteria. Results: There were no differences between ASV and SIMV groups in demographics and preoperative characteristics. The duration of tracheal intubation and the length of ICU stay were similar in both groups. There were no statistically and clinically relevant differences between the two groups in ABG, hemodynamic changes, and respiratory and ventilator characteristics during ICU stay. Conclusion: Although ASV may facilitate postoperative respiratory management in FTCA, both ASV and SIMV provide similarly safe and practicable respiratory weaning in the cardiac ICU. The evaluation of potential advantages in patient outcomes and resource utilization of respiratory weaning based on ASV

  19. PRACTICE OF GOOD GOVERNANCE AND CORPORATE GOVERNANCE

    Directory of Open Access Journals (Sweden)

    Bălăceanu Cristina

    2010-12-01

    Full Text Available Corporate governance reforms are occurring in countries around the globe and potentially impacting the population of the entire planet. In developing countries, such reforms occur in a larger context that is primarily defined by previous attempts at promoting “development” and recent processes of economic globalization. In this context, corporate governance reforms (in combination with the liberalising reforms associated with economic globalization, in effect represent a new development strategy for third world countries. The most basic questions that arise with respect to this situation are what the prospects for this new development model are and whether alternatives should be considered. Keywords: governance, corporate governance, economic globalization, development.

  20. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Science.gov (United States)

    2010-10-01

    ... section is satisfied, a vessel having only a natural ventilation system must satisfy the following: V/A≥1... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). 169.315... SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.315 Ventilation (other than machinery...

  1. 9 CFR 354.226 - Lighting and ventilation.

    Science.gov (United States)

    2010-01-01

    ... Facilities § 354.226 Lighting and ventilation. There shall be ample light, either natural or artificial or both, of good quality and well distributed, and sufficient ventilation for all rooms and compartments... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Lighting and ventilation. 354.226...

  2. 33 CFR 183.630 - Standards for natural ventilation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Standards for natural ventilation... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of § 183.620, “natural ventilation” means an airflow in a compartment in a...

  3. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Science.gov (United States)

    2010-10-01

    ... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments containing pumps, compressors, pipes, control spaces, etc. connected with the cargo handling facilities... the ventilation system associated with the compartment. Inlets to exhaust ducts shall be provided and...

  4. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

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

  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. 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

  7. 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

  8. Analysis on present radon ventilation situation of Chinese uranium mines

    International Nuclear Information System (INIS)

    Li Xianjie; Hu Penghua

    2010-01-01

    Mine Ventilation is the most important way in lowering radon of uranium mines. At present, radon and radon daughter concentration of underground air is 3∼5 times higher than any other air concentration of foreign uranium mines, as the same input for Protective Ventilation between Chinese uranium mines with compaction methodology and international advanced uranium mines. In this passage, through the analysis of Ventilation Radon Reduction status in Chinese uranium mines and the comparison of advantages and shortcomings between variety of ventilation and radon reduction, it illuminated the reasons of higher radon and radon daughter concentration in Chinese uranium mines and put forward some problems in three aspects, which are Ventilation Radon Reduction Theory, Ventilation Radon Reduction Measures and Ventilation Management. And to above problems, this passage put forward some proposals and measures about some aspects, such as strengthen examination and verification and monitoring practical situation, making clear ventilation plan, in according to mining sequence strictly, training Ventilation technician forcefully, enhance Ventilation System management, development of Ventilation Radon Reduction technology research in uranium mines and carrying out ventilation equipments as soon as possible in further and so on. (authors)

  9. 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 ...

  10. Ventilation measurements as an adjunct to radon measurements in buildings

    International Nuclear Information System (INIS)

    Knutson, E.O.; Franklin, H.

    1977-01-01

    The concentration of radon in a building is a function of the radon sources within the building and of the building's ventilation characteristics. To complement its radon measurement program, HASL is currently assessing apparatus and procedures for measuring building ventilation. Results are reported from ventilation measurements made in the laboratory and in a residential building

  11. Effect of repository underground ventilation on emplacement drift temperature control

    International Nuclear Information System (INIS)

    Yang, H.; Sun, Y.; McKenzie, D.G.; Bhattacharyya, K.K.

    1996-01-01

    The repository advanced conceptual design (ACD) is being conducted by the Civilian Radioactive Waste Management System, Management ampersand Operating Contractor. Underground ventilation analyses during ACD have resulted in preliminary ventilation concepts and design methodologies. This paper discusses one of the recent evaluations -- effects of ventilation on emplacement drift temperature management

  12. Ventilator induced lung injury (VILI) in acute respiratory distress ...

    African Journals Online (AJOL)

    The lung protective ventilation strategy- Low tidal volume ventilation has shown some reduction in mortality in patients with ARDS but mortality is still high in patient with severe ARDS secondary to Pneumocystis jiroveci pneumonia (PJP) despite of lung protective ventilation strategy. In patients with Severe ARDS due to PJP ...

  13. 21 CFR 868.5935 - External negative pressure ventilator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External negative pressure ventilator. 868.5935 Section 868.5935 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is a...

  14. 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 to...

  15. 46 CFR 171.118 - Automatic ventilators and side ports.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Automatic ventilators and side ports. 171.118 Section 171.118 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY... Bulkhead or Weather Deck § 171.118 Automatic ventilators and side ports. (a) An automatic ventilator must...

  16. 21 CFR 868.5925 - Powered emergency ventilator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered emergency ventilator. 868.5925 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5925 Powered emergency ventilator. (a) Identification. A powered emergency ventilator is a demand valve or inhalator intended to provide emergency...

  17. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a...

  18. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a...

  19. Use of noninvasive and invasive mechanical ventilation in cardiogenic shock

    DEFF Research Database (Denmark)

    Hongisto, Mari; Lassus, Johan; Tarvasmaki, Tuukka

    2017-01-01

    BACKGROUND: Despite scarce data, invasive mechanical ventilation (MV) is widely recommended over non-invasive ventilation (NIV) for ventilatory support in cardiogenic shock (CS). We assessed the real-life use of different ventilation strategies in CS and their influence on outcome focusing on the...

  20. Natural ventilation for reducing airborne infection in hospitals

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Hua [School of Energy and Environment, Southeast University, Nanjing (China); Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong (China); Li, Yuguo; Ching, W.H.; Sun, H.Q. [Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong (China); Seto, W.H.; Ching, Patricia [Department of Microbiology, Queen Mary Hospital, Hong Kong (China)

    2010-03-15

    High ventilation rate is shown to be effective for reducing cross-infection risk of airborne diseases in hospitals and isolation rooms. Natural ventilation can deliver much higher ventilation rate than mechanical ventilation in an energy-efficient manner. This paper reports a field measurement of naturally ventilated hospital wards in Hong Kong and presents a possibility of using natural ventilation for infection control in hospital wards. Our measurements showed that natural ventilation could achieve high ventilation rates especially when both the windows and the doors were open in a ward. The highest ventilation rate recorded in our study was 69.0 ACH. The airflow pattern and the airflow direction were found to be unstable in some measurements with large openings. Mechanical fans were installed in a ward window to create a negative pressure difference. Measurements showed that the negative pressure difference was negligible with large openings but the overall airflow was controlled in the expected direction. When all the openings were closed and the exhaust fans were turned on, a reasonable negative pressure was created although the air temperature was uncontrolled. The high ventilation rate provided by natural ventilation can reduce cross-infection of airborne diseases, and thus it is recommended for consideration of use in appropriate hospital wards for infection control. Our results also demonstrated a possibility of converting an existing ward using natural ventilation to a temporary isolation room through installing mechanical exhaust fans. (author)

  1. 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

    vertical air temperature differences and air velocities for different hybrid systems are less than 3 C and 0.2 m/s when supply air temperature is 19 C, air change rate is 4.2 h-1, and heated surface temperature of floor/ceiling heating system is 25 C. Ventilation effectiveness of mixing ventilation system...... 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...

  2. Public management and governance

    National Research Council Canada - National Science Library

    Bovaird, A. G; Löffler, Elke

    2009-01-01

    ... how the process of governing needs to be fundamentally altered if a government is to retain public trust and make better use of society's resources. Key themes covered include: ■ ■ ■ ■ the challenges and pressures which governments experience in an international context; the changing functions of modern government in the global economy; the 'mixed ec...

  3. Numerical simulation and comparison of two ventilation methods for a restaurant - displacement vs mixed flow ventilation

    Science.gov (United States)

    Chitaru, George; Berville, Charles; Dogeanu, Angel

    2018-02-01

    This paper presents a comparison between a displacement ventilation method and a mixed flow ventilation method using computational fluid dynamics (CFD) approach. The paper analyses different aspects of the two systems, like the draft effect in certain areas, the air temperatureand velocity distribution in the occupied zone. The results highlighted that the displacement ventilation system presents an advantage for the current scenario, due to the increased buoyancy driven flows caused by the interior heat sources. For the displacement ventilation case the draft effect was less prone to appear in the occupied zone but the high heat emissions from the interior sources have increased the temperature gradient in the occupied zone. Both systems have been studied in similar conditions, concentrating only on the flow patterns for each case.

  4. 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

    conditions, varying the nominal air change rate from 4.5h-1 down to 1.5h-1. Contaminant removal and mean-age-of-air measurements were performed to characterize the ventilation effectiveness and air velocity; air and operative temperature profiles were measured, together with thermal manikin equivalent...... temperatures, to evaluate the thermal environment. The combined system was able to achieve good ventilation effectiveness close to a heat source, so that in the occupant's breathing zone the ventilation effectiveness was significantly better than for ideal mixing, even at a nominal air change rate as low as 1......% 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....

  5. Biphasic cuirass ventilation is better than bag-valve mask ventilation for resuscitation following organophosphate poisoning

    Directory of Open Access Journals (Sweden)

    Ilan Gur

    2015-01-01

    Conclusions: The noninvasive, easy-to-operate Biphasic Cuirass Ventilation device was effective in reducing OP-induced mortality and might be advantageous in an organophosphate mass casualty event. This finding should be validated in further investigations.

  6. 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....... The guidebook introduces rules for good quality prediction work, and it is the purpose of the guidebook to improve the technical level of CFD work in ventilation.......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...... 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. The guidebook is also written for people working with CFD who have to be more aware of how this numerical method is applied in the area of ventilation...

  7. 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...

  8. 46 CFR 116.610 - Ventilation ducts.

    Science.gov (United States)

    2010-10-01

    ... incidental to its installation, must be made of noncombustible material. (c) Combustibles and other foreign materials are not allowed within ventilation ducts. However, metal piping and electrical wiring installed in... the wiring does not interfere with the operation of fire dampers. Electrical wiring and piping may not...

  9. 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...

  10. 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 fr...

  11. Lung-protective perioperative mechanical ventilation

    NARCIS (Netherlands)

    Hemmes, S.N.T.

    2015-01-01

    Intraoperative ventilation has the potential to cause lung injury and possibly increase risk of pulmonary complications after surgery. Use of large tidal volumes could cause overdistension of lung tissue, which can be aggravated by too high levels of positive end-expiratory pressure (PEEP). Too low

  12. Management of mechanical ventilation during laparoscopic surgery.

    Science.gov (United States)

    Valenza, Franco; Chevallard, Giorgio; Fossali, Tommaso; Salice, Valentina; Pizzocri, Marta; Gattinoni, Luciano

    2010-06-01

    Laparoscopy is widely used in the surgical treatment of a number of diseases. Its advantages are generally believed to lie on its minimal invasiveness, better cosmetic outcome and shorter length of hospital stay based on surgical expertise and state-of-the-art equipment. Thousands of laparoscopic surgical procedures performed safely prove that mechanical ventilation during anaesthesia for laparoscopy is well tolerated by a vast majority of patients. However, the effects of pneumoperitoneum are particularly relevant to patients with underlying lung disease as well as to the increasing number of patients with higher-than-normal body mass index. Moreover, many surgical procedures are significantly longer in duration when performed with laparoscopic techniques. Taken together, these factors impose special care for the management of mechanical ventilation during laparoscopic surgery. The purpose of the review is to summarise the consequences of pneumoperitoneum on the standard monitoring of mechanical ventilation during anaesthesia and to discuss the rationale of using a protective ventilation strategy during laparoscopic surgery. The consequences of chest wall derangement occurring during pneumoperitoneum on airway pressure and central venous pressure, together with the role of end-tidal-CO2 monitoring are emphasised. Ventilatory and non-ventilatory strategies to protect the lung are discussed.

  13. Nuclear waste repository ventilation system studies

    International Nuclear Information System (INIS)

    Smith, P.R.; Hensel, E.C.; Leslie, I.H.; Schultheis, T.M.; Walls, J.R.; Gregory, W.S.

    1993-01-01

    Ventilation studies of the Waste Isolation Pilot Plant described in this article were performed by personnel from New Mexico State University in collaboration with Sandia National Laboratories, Los Alamos National Laboratory, and Westinghouse Corporation. The following research tasks were performed: 1) High-efficiency particulate air filters of the type used at the Waste Isolation Pilot Plant were loaded with salt aerosol from the site, 2) Filter resistance as a function of salt mass and flow rate was established for later use in computer simulations, 3) Filter efficiency was measured during the loading tests to establish a relation between efficiency and salt loading, 4) The structural strength of the salt-loaded high-efficiency filters was investigated by subjecting the filters to pressure transients of the types expected from fires, explosions and tornados, 5) Computer codes, obtained from Los Alamos National Laboratory, were used to model the ventilation systems and study their response to accident-induced pressure transients and heat fluxes, 6) Partial verification of the computer simulations was obtained by comparing normal operation of the ventilation systems to predicted normal operation, 7) A feasibility study using model-based control of the ventilation systems was initiated and will be completed during the second year of the project. (author) 12 figs., 16 refs

  14. Simulation of forced-ventilation fires

    International Nuclear Information System (INIS)

    Krause, F.R.; Gregory, W.S.

    1982-01-01

    Fire hazard descriptions and compartment fire models are assessed as input to airflow network analysis methods that simulate the exposure of ventilation system components to fire products. The assessment considered the availability of hazard descriptions and models for predicting simultaneous heat and mass release at special compartment openings that are characterized by a one-dimensional and controllable volumetric flux

  15. Project Design Concept - Primary Ventilation System

    International Nuclear Information System (INIS)

    MCGREW, D.L.

    2000-01-01

    Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment reports. Based on the deficiencies identified in the tank farm system assessment reports, and additional requirements analysis performed in support of the River Protection Project (RPP), an approved scope for the TFRSO effort was developed and documented in the Upgrade Scope Summary Report (USSR), WHC-SD-W314-RPT-003, Rev. 4. The USSR establishes the need for the upgrades and identifies the specific equipment to be addressed by this project. This Project Design Concept (PDC) is in support of the Phase 2 upgrades and provides an overall description of the operations concept for the W-314 Primary Ventilation Systems. Actual specifications, test requirements, and procedures are not included in this PDC. The PDC is a ''living'' document, which will be updated throughout the design development process to provide a progressively more detailed description of the W-314 Primary Ventilation Systems design. The Phase 2 upgrades to the Primary Ventilation Systems shall ensure that the applicable current requirements are met for: Regulatory Compliance; Safety; Mission Requirements; Reliability; and Operational Requirements

  16. Heating, ventilating, and air-conditioning applications

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This book covers: Comfort air conditioning and heating of residences: Space HVAC systems; Industrial and special air conditioning and ventilation for nuclear facilities, and for mines; Energy sources, such as Geothermal energy, solar utilization, and energy resources; Building operation and maintenance; energy management, and Thermal storage

  17. Aerosol delivery in intubated, mechanically ventilated patients

    International Nuclear Information System (INIS)

    MacIntyre, N.R.; Silver, R.M.; Miller, C.W.; Schuler, F.; Coleman, R.E.

    1985-01-01

    To study the effects of respiratory failure and mechanical ventilation on aerosol delivery to the lungs, nuclear scans were performed after aerosolization of 5 to 9 mCi of Tc-99m diethylenetriamine pentaacetic acid in seven stable, intubated, and mechanically ventilated patients. The radioactivity reaching the lungs was 2.9 +/- .7% (mean +/- SD) of the administered dose, an amount significantly less than that in three healthy nonintubated subjects and also less than what would be expected in nonintubated subjects from other published reports. A subsequent study was performed in 15 additional mechanically ventilated patients who were receiving aerosolized bronchodilators through their endotracheal tube. In these patients, heart rate and lung mechanical function values before and after treatment were not significantly different. It is concluded from these studies that aerosol delivery in mechanically ventilated patients is significantly reduced and that this is probably due to a combination of suboptimal breathing pattern, intrinsic airway disease, and the endotracheal tube functioning as both a site for aerosol deposition through impaction as well as a barrier to gastrointestinal absorption

  18. 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

  19. Achieving Natural and Hybrid Ventilation in Practice

    DEFF Research Database (Denmark)

    Liddament, Martin; Axley, James; Heiselberg, Per

    2006-01-01

    Case studies provide essential evidence about the performance of buildings. They also illustrate the methods by which a technology can be implemented as well as highlighting problems. Various case study buildings (both new and retrofit) that incorporate mixed mode, natural ventilation and low ene...

  20. Including Children Dependent on Ventilators in School.

    Science.gov (United States)

    Levine, Jack M.

    1996-01-01

    Guidelines for including ventilator-dependent children in school are offered, based on experience with six such students at a New York State school. Guidelines stress adherence to the medical management plan, the school-family partnership, roles of the social worker and psychologist, orientation, transportation, classroom issues, and steps toward…