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Shock
Shock may refer to: Common uses Collective noun *Shock, a historic commercial term for a group of 60, see English numerals#Special names * Stook, or shock of grain, stacked sheaves Healthcare * Shock (circulatory), circulatory medical emergency ** Cardiogenic shock, resulting from dysfunction of the heart ** Distributive shock, resulting from an abnormal distribution of blood flow *** Septic shock, a result of severe infection *** Toxic shock syndrome, a specific type of severe infection *** Anaphylactic shock ** Hemorrhagic shock, from a large volume of blood loss ** Neurogenic shock, due to a high spinal cord injury disrupting the sympathetic nervous system * Cold shock response of organisms to sudden cold, especially cold water * Electric shock ** Defibrillation, electric shock to restore heart rhythm ** Electroconvulsive therapy or shock treatment, psychiatric treatment * Hydrostatic shock, from ballistic impact * Insulin shock or diabetic hypoglycemia, from too much in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (mechanics)
A mechanical or physical shock is a sudden acceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation. Shock describes matter subject to extreme rates of force with respect to time. Shock is a vector that has units of an acceleration (rate of change of velocity). The unit ''g'' (or g) represents multiples of the acceleration of gravity and is conventionally used. A shock pulse can be characterised by its peak acceleration, the duration, and the shape of the shock pulse (half sine, triangular, trapezoidal, etc.). The shock response spectrum is a method for further evaluating a mechanical shock. Shock measurement Shock measurement is of interest in several fields such as *Propagation of heel shock through a runner's body *Measure the magnitude of a shock need to cause damage to an item: fragility. *Measure shock attenuation through athletic flooring *Measuring the effectiveness of a shock absorber *Measuring th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (circulatory)
Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen. Shock is divided into four main types based on the underlying cause: low volume, cardiogenic, obstructive, and distributive shock. Low volume shock, also known as hypovolemic shock, may be from bleeding, diarrhea, or vomiting. Cardiogenic shock may be due to a heart attack or cardiac contusion. Obstructive shock may be due to cardiac tamponade or a tension pneumothorax. Distributive shock may be due to sepsis, anaphylaxis, injury to the upper spinal cord, or certain overdoses. The diagnosis is generally based on a combination of symptoms, physical examination, and laboratory tests. A decreased pulse pressure (systolic blood pressure m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxic Shock Syndrome
Toxic shock syndrome (TSS) is a condition caused by bacterial toxins. Symptoms may include fever, rash, skin peeling, and low blood pressure. There may also be symptoms related to the specific underlying infection such as mastitis, osteomyelitis, necrotising fasciitis, or pneumonia. TSS is typically caused by bacteria of the ''Streptococcus pyogenes'' or ''Staphylococcus aureus'' type, though others may also be involved. Streptococcal toxic shock syndrome is sometimes referred to as toxic-shock-like syndrome (TSLS). The underlying mechanism involves the production of superantigens during an invasive streptococcus infection or a localized staphylococcus infection. Risk factors for the staphylococcal type include the use of very absorbent tampons, skin lesions in young children characterized by fever, low blood pressure, rash, vomiting and/or diarrhea, and multiorgan failure. Diagnosis is typically based on symptoms. Treatment includes intravenous fluids, antibiotics, incision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Mount
A shock mount or isolation mount is a mechanical fastener that connects two parts elastically. They are used for shock and vibration isolation. Isolation mounts allow a piece of equipment to be securely mounted to a foundation and/or frame and, at the same time, allow it to float independently from the substrate. Uses Shock mounts can be found in a wide variety of applications. Shock mounts can be used to isolate the foundation or substrate from the dynamics of the mounted equipment. This is vital on submarines where silence is critical to mission success. Yachts also use shock mounts to dampen the noise (mainly the one transmitted throughout the structure) and increase the comfort. This is usually done through elastic supports and transmission couplings. Another common example of this are the motor and transmission mounts that are used in virtually every automobile manufactured today. Without isolation mounts, the interior noise and comfort level in today's vehicles would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Absorber
A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most shock absorbers are a form of dashpot (a damper which resists motion via viscous friction). Description Pneumatic and hydraulic shock absorbers are used in conjunction with cushions and springs. An automobile shock absorber contains spring-loaded check valves and orifices to control the flow of oil through an internal piston (see below). One design consideration, when designing or choosing a shock absorber, is where that energy will go. In most shock absorbers, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid heats up, while in air cylinders, the hot air is usually exhausted to the atmosphere. In other types of shock absorbers, such as electromagnetic types, the dissipated energy can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemorrhagic Shock
Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It could be the result of severe dehydration through a variety of mechanisms or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure. In treating hypovolemic shock, it is important to determine the cause of the underlying hypovolemia, which may be the result of bleeding or other fluid losses. To minimize ischemic damage to tissues, treatment involves quickly replacing lost blood or fluids, with consideration of both rate and the type of fluids used. Tachycardia, a fast heart rate, is typically the first abnormal vital sign. When resulting from blood loss, trauma is the most common root cause, but severe blood loss can also happen in various body systems without clear traumatic injury. The body in hypovolemic shock prioritizes getting oxygen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oblique Shock
An oblique shock wave is a shock wave that, unlike a normal shock, is inclined with respect to the incident upstream flow direction. It will occur when a supersonic flow encounters a corner that effectively turns the flow into itself and compresses. The upstream streamlines are uniformly deflected after the shock wave. The most common way to produce an oblique shock wave is to place a wedge into supersonic, compressible flow. Similar to a normal shock wave, the oblique shock wave consists of a very thin region across which nearly discontinuous changes in the thermodynamic properties of a gas occur. While the upstream and downstream flow directions are unchanged across a normal shock, they are different for flow across an oblique shock wave. It is always possible to convert an oblique shock into a normal shock by a Galilean transformation. Wave theory For a given Mach number, M1, and corner angle, θ, the oblique shock angle, β, and the downstream Mach number, M2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell Shock
Shell shock is a term coined in World War I by the British psychologist Charles Samuel Myers to describe the type of post-traumatic stress disorder (PTSD) many soldiers were afflicted with during the war (before PTSD was termed). It is a reaction to the intensity of the bombardment and fighting that produced a helplessness appearing variously as panic and being scared, flight, or an inability to reason, sleep, walk or talk. During the war, the concept of shell shock was ill-defined. Cases of "shell shock" could be interpreted as either a physical or psychological injury, or as a lack of moral fibre. The term ''shell shock'' is still used by the United States’ Department of Veterans Affairs to describe certain parts of PTSD, but mostly it has entered into memory, and it is often identified as the signature injury of the war. In World War II and thereafter, diagnosis of "shell shock" was replaced by that of combat stress reaction, a similar but not identical response to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiogenic Shock
Cardiogenic shock (CS) is a medical emergency resulting from inadequate blood flow due to the dysfunction of the ventricles of the heart.Textbooks of Internal MedicinHarrison's Principles of Internal Medicine 16th Edition, The McGraw-Hill CompaniesCecil Textbook of Medicine by Lee Goldman, Dennis Ausiello, 22nd Edition (2003), W. B. Saunders CompanyThe Oxford Textbook of Medicine Edited by David A. Warrell, Timothy M. Cox and John D. Firth with Edward J. Benz, Fourth Edition (2003), Oxford University Press, Shock: An Overview PDF by Michael L. Cheatham, MD, Ernest F.J. Block, MD, Howard G. Smith, MD, John T. Promes, MD, Surgical Critical Care Service, Department of Surgical Education, |
Anaphylactic Shock
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the following: an itchy rash, throat closing due to swelling which can obstruct or stop breathing; severe tongue swelling which can also interfere with or stop breathing; shortness of breath, vomiting, lightheadedness, loss of consciousness, low blood pressure, and medical shock. These symptoms typically start in minutes to hours and then increase very rapidly to life-threatening levels. Urgent medical treatment is required to prevent serious harm or death, even if the patient has used an epipen or has taken other medications in response, and even if symptoms appear to be improving. Common causes include allergies to insect bites and stings, allergies to foods – including nuts, milk, fish, shellfish, eggs and some fresh fruits or dried fruits; a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Shock
Electrical injury is a physiological reaction caused by electric current passing through the body. The injury depends on the density of the current, tissue resistance and duration of contact. Very small currents may be imperceptible or produce a light tingling sensation. A shock caused by low and otherwise harmless current could startle an individual and cause injury due to jerking away or falling. Stronger currents may cause some degree of discomfort or pain, while more intense currents may induce involuntary muscle contractions, preventing the person from breaking free of the source of electricity. Still larger currents result in tissue damage and may trigger ventricular fibrillation or cardiac arrest. Consequences of injury from electricity may include amputations, bone fractures and orthopedic and musculoskeletal injuries. If death results from an electric shock the cause of death is generally referred to as electrocution. Electric injury occurs upon contact of a body part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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