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Flügge Droplets
A respiratory droplet is a small aqueous droplet produced by exhalation, consisting of saliva or mucus and other matter derived from respiratory tract surfaces. Respiratory droplets are produced naturally as a result of breathing, speaking, sneezing, coughing, or vomiting, so they are always present in our breath, but speaking and coughing increase their number. Droplet sizes range from < 1 μm to 1000 μm, and in typical breath there are around 100 droplets per litre of breath. So for a breathing rate of 10 litres per minute this means roughly 1000 droplets per minute, the vast majority of which are a few micrometres across or smaller. As these droplets are suspended in air, they are all by definition aerosols. However, large droplets (larger than about 100 μm, but depending on conditions) rapidly fall to the ground or another surface and so are only briefly suspended, while droplets much smaller than 100 μm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sneeze
A sneeze (also known as sternutation) is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth and nose in an explosive, spasmodic involuntary action. This action allows for mucus to escape through the nasal cavity and saliva to escape from the oral cavity. Sneezing is possibly linked to sudden exposure to bright light (known as photic sneeze reflex), sudden change (drop) in temperature, breeze of cold air, a particularly full stomach, exposure to allergens, or viral infection. Because sneezes can spread disease through infectious aerosol droplets, it is recommended to cover one's mouth and nose with the forearm, the inside of the elbow, a tissue or a handkerchief while sneezing. In addition to covering the mouth, looking down is also recommended to change the direction of the droplets spread and avoid high concentration in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intubation
Intubation (sometimes entubation) is a medical procedure involving the insertion of a tube into the body. Most commonly, intubation refers to tracheal intubation, a procedure during which an endotracheal tube is inserted into the trachea to support patient ventilation. Other examples of intubation include balloon tamponade using a Sengstaken–Blakemore tube (a tube into the gastrointestinal tract), urinary catheterization, and nasogastric intubation using a feeding tube. Types of Intubation and Their Indications Tracheal Intubation Tracheal intubation is a procedure involving the placement of an endotracheal tube into a patient’s windpipe, also known as the trachea. This procedure may be done to treat either emergent or non-emergent conditions. Examples of emergent conditions include airway compromise, respiratory failure, allergic reactions, and trauma. An example of a non-emergent condition where tracheal intubation is performed includes surgery, during which an indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computational Fluid Dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid dynamics, fluid flows. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid (liquids and gases) with surfaces defined by Boundary value problem#Boundary value conditions, boundary conditions. With high-speed supercomputers, better solutions can be achieved, and are often required to solve the largest and most complex problems. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulence, turbulent flows. Initial validation of such software is typically performed using experimental apparatus such as wind tunnels. In addition, previously performed Closed-form solution, analytical or Empirical research, empirical analysis of a particular problem can be used for compa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory System
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it lives and its evolutionary history. In terrestrial animal, land animals, the respiratory surface is internalized as linings of the lungs. Gas exchange in the lungs occurs in millions of small air sacs; in mammals and reptiles, these are called pulmonary alveolus, alveoli, and in birds, they are known as Bird anatomy#Respiratory system, atria. These microscopic air sacs have a very rich blood supply, thus bringing the air into close contact with the blood. These air sacs communicate with the external environment via a system of airways, or hollow tubes, of which the largest is the trachea, which branches in the middle of the chest into the two main bronchus, bronchi. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wells Curve
The Wells curve (or Wells evaporation falling curve of droplets) is a diagram, developed by William F. Wells, W. F. Wells in 1934, which describes what is expected to happen to small respiratory droplets, droplets once they have been exhaled into air. Coughing, sneezing, and other violent exhalations produce high numbers of respiratory droplets derived from saliva and/or respiratory mucus, with sizes ranging from about 1 μm to 2 mm. Wells' insight was that such droplets would have two distinct fates, depending on their sizes. The interplay of gravity and evaporation means that droplets larger than a humidity-determined threshold size would fall to the ground due to gravity, while droplets smaller than this size would quickly evaporate, leaving a dry residue that drifts in the air. Since droplets from an infected person may contain infectious bacteria or viruses, these processes influence transmission of respiratory diseases. A traditional hard size cutoff of 5 Micrometre, μm b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup has a higher viscosity than water. Viscosity is defined scientifically as a force multiplied by a time divided by an area. Thus its SI units are newton-seconds per metre squared, or pascal-seconds. Viscosity quantifies the internal friction, frictional force between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's center line than near its walls. Experiments show that some stress (physics), stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions ( anions), which results in a compound with no net electric charge (electrically neutral). The constituent ions are held together by electrostatic forces termed ionic bonds. The component ions in a salt can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as sodium (Na+) and chloride (Cl−) in sodium chloride, or polyatomic, such as ammonium () and carbonate () ions in ammonium carbonate. Salts containing basic ions hydroxide (OH−) or oxide (O2−) are classified as bases, such as sodium hydroxide and potassium oxide. Individual ions within a salt usually have multiple near neighbours, so they are not considered to be part of molecules, but instead part of a continuous three-dimensional network. Salts usually form crystalline structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greywater
Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater from toilets. Sources of greywater include sinks, showers, baths, washing machines or dishwashers. As greywater contains fewer pathogens than blackwater, it is generally safer to handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, and other non- potable uses. Greywater may still have some pathogen content from laundering soiled clothing or cleaning the anal area in the shower or bath. The application of greywater reuse in urban water systems provides substantial benefits for both the water supply subsystem, by reducing the demand for fresh clean water, and the wastewater subsystems by reducing the amount of conveyed and treated wastewater. Treated greywater has many uses, such as toilet fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tap Water
Tap water (also known as running water, piped water or municipal water) is water supplied through a Tap (valve), tap, a water dispenser valve. In many countries, tap water usually has the quality of drinking water. Tap water is commonly used for drinking, cooking, and washing. Indoor tap water is distributed through indoor plumbing, which has been around since History of plumbing, antiquity but was available to very few people until the second half of the 19th century when it began to spread in popularity in what are now developed country, developed countries. Tap water became common in many regions during the 20th century, and is now lacking mainly among people in poverty, especially in developing country, developing countries. Governmental agencies commonly regulate Drinking water quality standards, tap water quality. Calling a water supply "tap water" distinguishes it from the other main types of fresh water which may be available; these include water from Rainwater harvesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toilet Plume
A toilet plume is the invisible to the naked eye, cloud-like dispersal of potentially infectious sewage particles as a result of flushing a toilet. Flush particles rapidly rise out of the bowl and several feet into the air after flushing. These particles go on to spread onto surfaces like floors and counters; or objects like hand towels, bathmats or toothbrushes. Day to day use of a toilet by healthy individuals is considered to be of a lower health risk. However, if an individual is sick with something and currently shedding out large quantities of an infectious virulent pathogen (virus or bacteria) in their urine, feces or vomitus, this dynamic completely changes. Aerosolization of the toilet bowl contents allows these particles to free-float haphazardly, to either be inhaled or land on surfaces. There is evidence that specific pathogens such as norovirus or SARS coronavirus can be spread by toilet aerosols. It has been hypothesized that dispersal of pathogens may be reduced by clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Health Organization
The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Geneva, Switzerland, and has 6 regional offices and 150 field offices worldwide. Only sovereign states are eligible to join, and it is the largest intergovernmental health organization at the international level. The WHO's purpose is to achieve the highest possible level of health for all the world's people, defining health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." The main functions of the World Health Organization include promoting the control of epidemic and endemic diseases; providing and improving the teaching and training in public health, the medical treatment of disease, and related matters; and promoting the establishment of international standards for biologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
