Ventilation Research Papers - Academia.edu (original) (raw)

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- by James Duffin
- •
- Carbon Dioxide, Modeling, Sex Hormones, Mathematical Modeling

One limitation of the coronavirus disease 2019 (COVID-19) pandemic response has been the lack of widely available, practical tools to measure factors, such as ventilation and airflow, that can impact transmission risk. The Centers for Disease Control and Prevention (CDC) has recommended that steps be taken to improve ventilation in healthcare facilities, schools, businesses, and households. 1 However, limited guidance has been provided on how to evaluate the adequacy of ventilation. To be useful in real-world settings, tools to assess ventilation must be inexpensive, safe, and easy to use. An ideal tool would provide rapid and easy-to-interpret results that could be used to identify areas with inadequate ventilation and to assess the impact of interventions. One promising candidate as a practical tool to assess ventilation is carbon dioxide monitoring using inexpensive handheld devices that measure carbon dioxide concentrations. The concentration of carbon dioxide in outdoor air is ∼400 parts per million (ppm) versus ∼40,000 ppm in exhaled breath. 2 Thus, carbon dioxide levels rise in occupied spaces that are inadequately ventilated. 2 According to the CDC, carbon dioxide readings >800 ppm in buildings are an indicator of suboptimal ventilation requiring intervention. 1 Carbon dioxide monitoring has been used to assess ventilation and to identify measures to reduce risk in settings such as schools, university buildings, dental offices, motor vehicles, and hospitals. 3-7 The most important limitation of carbon dioxide monitoring is that it does not account for filtering of air. For example, carbon dioxide levels rise above 800 ppm in the cabin of airplanes both in flight and during boarding and deplaning, but the risk for viral transmission may remain low because the air conditioning system provides rapid recirculation of air through high-efficiency particulate air (HEPA) filters. 5 Other potential tools to assess ventilation include handheld particle counters and devices that measure total volatile organic compounds. 8,9 In an assessment of ventilation in public spaces,

- by Curtis Donskey
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- Carbon Dioxide, Ventilation, Airflow, Covid-19
- by Noam Weisbrod
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- Earth Sciences, Arid environments, Biological Sciences, Environmental Sciences
- by Lionel Raffin
- •
- Surgery, Thorax, Ventilation, Clinical Sciences
- by Ahmet Alver
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- Surgery, Nonparametric Statistics, Treatment, Peroxidase
- by Clive Beggs
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- Microbiology, Medical Microbiology, Environmental Monitoring, Clostridium difficile
- by Nicole von Steinbüchel
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- Psychology, Pain, Palliative Care, Sexuality
- by Lance Wallace
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- Indoor Air Quality, Housing, Environmental Monitoring, Environmental Sciences
- by Petter Steen
- •
- Emergency Medical Services, Cardiac arrest, Prospective studies, Humans
- by Fiona Wood
- •
- British medical history, Masks, Humans, Resuscitation
- by Laure Itard
- •
- Architecture, Energy, Sensitivity Analysis, Comparative Study
- by Albert Heber
- •
- Engineering, Air Quality, Research Design, Environmental Monitoring
- by Andrei Dragomirescu
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- Engineering, Civil Engineering, Stability, Numerical Simulation
- by J. Hirunlabh
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- Mechanical Engineering, Renewable Energy, Air Conditioning, Ventilation
- by Anthony Lau
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- Engineering, Technology, Ventilation, Prediction Model
- by Charlie Huizenga and +1
- •
- Engineering, Architecture, Biometeorology, Workplace

Radiographers process X-ray films using developer and fixer solutions that contain chemicals known to cause or exacerbate asthma. In a study in British Columbia, Canada, radiographers' personal exposures to glutaraldehyde (a constituent of the developer chemistry), acetic acid (a constituent of the fixer chemistry), and sulfur dioxide (a byproduct of sulfites, present in both developer and fixer solutions) were measured. Average full-shift exposures to glutaraldehyde, acetic acid, and sulfur dioxide were 0.0009 mg/m3, 0.09 mg/m3, and 0.08 mg/m3, respectively, all more than one order of magnitude lower than current occupational exposure limits. Local exhaust ventilation of the processing machines and use of silver recovery units lowered exposures, whereas the number of films processed per machine and the time spent near the machines increased exposures. Personnel in clinic facilities had higher exposures than those in hospitals. Private clinics were less likely to have local exha...

- by Michael Brauer and +1
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- Photochemistry, Environmental Monitoring, Humans, Ventilation
- by Guttorm Brattebø and +1
- •
- Environmental Monitoring, Adolescent, Norway, Humans
- by Jarek Kurnitski
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- Engineering, Energy Efficiency in Buildings, Simulation, Seasonality
- by Clive Beggs
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- Nursing, Aerosols, Humans, Infection Control
- by Marcos De Paula and +1
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- Air Quality, Ls-Dyna, Ventilation
- by Sébastien Gilot
- •
- Ventilation, SITU

The “Green Building” is an interdisciplinary theme, where the green building concept includes a multitude of elements, components and procedures which diverge to several subtopics that intertwined to form the green building concept. Generally, the green building is considered to be an environmental component, as the green building materials are manufactured from local eco-sources, i.e. environmentally friendly materials, which are then used to make an eco-construction subject to an eco-design that provides a healthy habitat built on the cultural and architectural heritage in construction while ensuring conservation of natural resources. This ensures disassembling the building components and materials, after a determined building lifetime, to environmentally friendly materials that can be either re-used or recycled. During their lifecycle, the green buildings minimize the use of resources (energy and water); reduce the harmful impact on the ecology, and provide better indoor environm...

- by Mohamed Samer
- •
- Air Quality, Design, Cultural Heritage, Renewable Energy

The objective of this study was to study the performances of six 200-L polyethylene bins, each with different design for passive aeration to organic wastes composting. Food scraps and dry leaves (1.6 kg) were added to each bin once a day until the bin was full. Temperatures at the middle portion were measured daily. The compost from each bin was taken once a week for 120 days for analysis of C, N, volatile solids, and a germination index once a week for 120 days. After 120 days, the compost sample from each bin was taken to determine the mass reduction, size distribution, CEC, N, P and K values. The results showed that the temperatures inside the bins were in the ranges of 24 °C–57 °C. The composts in all bins were found to be stable at around 56–91 days. The wastes decayed fastest in bins with lateral and vertical systems of natural ventilation. It took about two months to stabilize the organic wastes, with a 59–62% decrease of mass. The C/N ratio, CEC, N, P, and K values of the final composts were 14.8–16.0, 66–68 cmol/kg, and 1.26–1.50% N, 0.52–0.56% P2O5 and 1.66–1.92% K2O, respectively.

- by Somjai Karnchanawong
- •
- Engineering, Design, Conception, Environmental Sciences
- by Philippa L Howden-Chapman
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- Human Geography, Housing, Risk assessment, Environmental Pollution
- by Jane Pillow
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- Mechanical Engineering, Biomedical Engineering, Biomechanics, Humans
- by Peter Luh
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- Mechanical Engineering, Atmospheric Modeling, Heat Transfer, Numerical Analysis

Mixing and displacement ventilation are common systems in commercial buildings, while mixing ventilation is used in residential buildings. Displacement ventilation provides fresh air to the occupied zone in a more efficient way than mixing ventilation but it is important to know how well it works with a floor system for heating or cooling. Can, for example, a floor heating system warm up the supply air too fast and destroy the displacement effect? Will floor cooling, combined with displacement ventilation, result in too high a vertical temperature difference and too low a temperature at feet level? The required amount of ventilation depends on the ventilation effectiveness. In standards, the recommended values for ventilation effectiveness depend on the position of the supply and exhaust device and on the difference between supply and room air temperature. Among others, for warm air heating the ventilation effectiveness is always less than 1 and can be as low as 0.4. This would then...

- by Angela Simone
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- Architecture, Building, Ventilation
- by Naoual Bekkioui
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- Mechanical Engineering, Renewable Energy, Modeling, Climate
- by Alan Chan
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- Occupational Health, Indoor Air Quality, Hong Kong, Air flow

This 1992 paper reports on work in progress in 'Design for Energy Efficiency,' one of fifteen task areas of the U.S. Department of Energy sponsored Energy Efficient Industrialized Housing research program. In this task, design studies establish visions of energy efficient housing systems and technologies for the year 2030 from which shorter term research activities can be defined. One study for a 'Multifamily Concrete Panel House in a Hot-Arid Climate,' a primarily passive solar design, responds to trends anticipating demand for small, minimum cost multi-family houses in sun-belt suburbs, diversifying household composition, declining wood resources, advancing concrete technology, increasing site density, and competition for cooling energy. Task background and progress is presented with an emphasis on passive solar systems and goals.

- by IOSR Journals
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- Public Health, Low Birth Weight, Neonatal, Ventilation
- by Ashok Gadgil
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- Engineering, Earth Sciences, Computer Simulation, Computation Fluid Dynamics
- by Chunrong Jia
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- Organic Chemistry, Kinetics, Housing, Environmental Monitoring
- by F Musau
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- Architecture, Energy efficiency, Simulation, Building
- by stephen wanless
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- Nursing, Critical Care, Humans, Critical Care Nursing
- by Thomas Guerrero
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- Algorithms, Computed Tomography, Optical Flow, Humans
- by Ronald Hershow
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- Hospital Infection, Filtration, Chicago, Aspergillus
- by Gabriel Bekö and +1
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- Architecture, Indoor Air Quality, Carbon Dioxide, Concentration

ABSTRACT
Both primary and secondary ventilation is important in underground mining. Secondary
ventilation refers to the provision of ventilation to development ends, stopes and services facilities,
which constitute secondary circuits tapped off the primary circuit or main through flow of air.
An unbalanced primary and secondary combination can cause re-circulation, which is inefficient
and potentially hazardous. These inefficiencies extend into operational and other considerations,
such as power.
Most cost justification analysis covers capital and physical consumables. These analyses are
often not comprehensive or holistic. This case study is an example of ‘how to holistically justify’ a
secondary ventilation circuit and optimise it to meet all stakeholder needs.
This paper particularly addresses the following:
•• how to account for all stakeholders in a secondary ventilation cost justification
•• the secondary ventilation components
•• the cost justification outcomes and how to measure them
•• some of the sensitivities
•• the stakeholders
•• how to present the justification to meet the stakeholder needs
•• secondary ventilation cost justification.

- by Allison Golsby
- •
- Engineering, Ventilation, Natural ventilation, Mine Ventilation
- by ΗΜΕΡΟΛΟΓΙΟ ΕΙΔΙΚΗΣ and +1
- •
- Housing, Environmental Monitoring, Health Policy, Multidisciplinary
- by Petr Pospisil
- •
- Safety, Ventilation, Tunnel Engineering
- by Ingrid Bergh and +1
- •
- Health Sciences, Nursing, Medical Sciences, Surgery
- by Prof Dr Mohsen Aboulnaga
- •
- Mechanical Engineering, Design, Renewable Energy, Energy Conservation
- by Martin Keszler
- •
- Humans, Ventilation, Volume, Clinical Sciences

Las funciones principales de la respiración son proporcionar oxígeno a los tejidos y retirar el dióxido de carbono. Los cuatro componentes principales de la respiración son: 1) ventilación pulmonar, que se refiere al flujo de entrada y salida de aire entre la atmósfera y los alvéolos pulmonares; 2) difusión de oxígeno (O2) y de dióxido de carbono (CO2) entre los alvéolos y la sangre; 3) transporte de oxígeno y de dióxido de carbono en la sangre y los líquidos corporales hacia las células de los tejidos y viceversa, 4) regulación de la ventilación y otras facetas de la respiración. Mecánica de la ventilación pulmonar Músculos que causan la expansión y contracción pulmonar Los pulmones se pueden expandir y contraer de dos maneras: 1) mediante el movimiento hacia abajo y hacia arriba del diafragma para alargar o acortar la cavidad torácica, y 2) mediante la elevación y el descenso de las costillas para aumentar y reducir el diámetro anteroposterior de la cavidad torácica. La respiración tranquila normal se consigue por el movimiento del diafragma. Durante la inspiración (proceso activo) la contracción del diafragma tira hacia abajo de las superficies inferiores de los pulmones. Después, durante la espiración (pasivo) el diafragma simplemente se relaja, y el retroceso elástico de los pulmones, de la pared torácica y de las estructuras abdominales comprime los pulmones y expulsa el aire. En la respiración forzada las fuerzas elásticas no son suficientemente potentes para producir la espiración rápida necesaria, de modo que se consigue una fuerza adicional principalmente mediante la contracción de los músculos abdominales. El segundo método para expandir los pulmones es elevar la caja torácica. Al elevarla se expanden los pulmones porque, en la posición de reposo natural, las costillas están inclinadas hacia abajo, lo que permite que el esternón se desplace hacia abajo y hacia atrás hacia la columna vertebral. Cuando la caja costal se eleva, las costillas se desplazan hacia adelante, alejándose de la CV y haciendo que el diámetro anteroposterior del tórax sea mayor durante la inspiración máxima que durante la espiración. Por tanto, todos los músculos que elevan la caja torácica se clasifican como músculos inspiratorios y los músculos que hacen descender la caja torácica se clasifican como músculos espiratorios. Los músculos más importantes que elevan la caja torácica son los intercostales externos, otros que contribuyen son: los músculos esternocleidomastoideos (elevan el esternón); serratos anteriores (elevan muchas costillas), y escalenos (elevan las dos primeras costillas). Los intercostales externos están alargados hacia adelante y hacia abajo. Cuando se contraen tiran de las costillas superiores hacia adelante en relación con las costillas inferiores y actúan como una palanca sobre las costillas para levantarlas hacia arriba, produciendo de manera la inspiración. Los músculos espiradores (los que tiran hacia abajo las costillas) son los rectos del abdomen (empujan hacia abajo las costillas inferiores y al mismo tiempo tmb comprimen el contenido abdominal hacia arriba contra el diafragma) y los intercostales internos. Los intercostales internos, ejercen una función totalmente opuesta a los externos ya que actúan como músculos respiratorios porque se angulan entre las costillas en dirección opuesta y producen una palanca contraria. Energía necesaria para la respiración Durante la respiración tranquila normal para la ventilación pulmonar solo es necesario el 3-5% de la energía total que consume el cuerpo. Sin embargo, durante el ejercicio intenso la cantidad de energía necesaria puede aumentar hasta 50 veces. Se puede dividir en tres partes: 1) el trabajo necesario para expandir los pulmones contra las fuerzas elásticas del pulmón y del tórax (trabajo de distensibilidad o elástico) 2) el trabajo necesario para superar la viscosidad de las estructuras del pulmón y de la pared torácica (trabajo de resistencia tisular) 3) el trabajo necesario para superar la resistencia de las vías aéreas al movimiento de entrada de aire hacia los pulmones (trabajo de resistencia de las vías aéreas.)

- by Ines Pirola
- •
- Ventilation, Sistema respiratorio
- by Dick Heederik and +1
- •
- Construction Materials, Environmental Monitoring, Construction Industry, Humans