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Shock Xpress
Shock may refer to: Common uses Healthcare * Acute stress reaction, also known as psychological or mental shock ** Shell shock, soldiers' reaction to battle trauma * Circulatory shock, a 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, a result of severe allergic reaction *** Neurogenic shock, due to a high spinal cord injury disrupting the sympathetic nervous system ** Hypovolemic shock, resulting from an insufficient blood volume *** Hemorrhagic shock, from a large volume lost to bleeding **Obstructive shock, resulting from mechanical obstruction of blood flow * Cold shock response of organisms to sudden cold, especially cold water * Electric shock ** Defibrillation, electric shock to restore heart rhythm ** Electroconvulsive therapy o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acute Stress Reaction
Acute stress reaction (ASR), also known as psychological shock, mental shock, or simply shock, as well as acute stress disorder (ASD), is a psychological response to a terrifying, Psychological trauma, traumatic, or surprising experience. The reactions may include but are not limited to intrusive thoughts, or Dissociation (psychology), dissociation, and reactivity symptoms such as Avoidance coping, avoidance or hyperarousal. It may be exhibited for days or weeks after the traumatic event. If the condition is not correctly addressed, it may develop into post-traumatic stress disorder (PTSD). Diagnosis The International Classification of Diseases (ICD) treats this condition differently from the Diagnostic and Statistical Manual of Mental Disorders (DSM). According to the ICD-11, acute stress reaction refers to the symptoms experienced a few hours to a few days after exposure to a traumatic event. In contrast, DSM-5 defines acute stress disorder by symptoms experienced 48 hours t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetic Hypoglycemia
Diabetic hypoglycemia is a low blood glucose level occurring in a person with diabetes mellitus. It is one of the most common types of hypoglycemia seen in emergency departments and hospitals. According to the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP), and based on a sample examined between 2004 and 2005, an estimated 55,819 cases (8.0% of total admissions) involved insulin, and severe hypoglycemia is likely the single most common event. In general, hypoglycemia occurs when a treatment to lower the elevated blood glucose of diabetes inaccurately matches the body's physiological need, and therefore causes the glucose to fall to a below-normal level. Signs and symptoms Diabetic hypoglycemia can be mild, recognized easily by the patient, and reversed with a small amount of carbohydrates eaten or drunk, or it may be severe enough to cause unconsciousness requiring intravenous dextrose or an injection of glucagon. Severe hypoglycemic unconsciousne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (economics)
In economics, a shock is an unexpected or unpredictable event that affects an economy, either positively or negatively. Technically, it is an unpredictable change in exogenous factors—that is, factors unexplained by an economic model—which may influence endogenous economic variables. The response of economic variables, such as GDP and employment, at the time of the shock and at subsequent times, is measured by an impulse response function. Types of shocks A technology shock is the kind resulting from a technological development that affects productivity. If the shock is due to constrained supply, it is termed a supply shock and usually results in price increases for a particular product. Supply shocks can be produced when accidents or disasters occur. The 2008 Western Australian gas crisis resulting from a pipeline explosion at Varanus Island is one example. A demand shock is a sudden change of the pattern of private expenditure, especially of consumption spendin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Shock
Thermal shock is a phenomenon characterized by a rapid change in temperature that results in a transient mechanical load on an object. The load is caused by the differential expansion of different parts of the object due to the temperature change. This differential expansion can be understood in terms of strain, rather than stress. When the strain exceeds the tensile strength of the material, it can cause cracks to form, and eventually lead to structural failure. Methods to prevent thermal shock include: * Minimizing the thermal gradient by changing the temperature gradually * Increasing the thermal conductivity of the material * Reducing the coefficient of thermal expansion of the material * Increasing the strength of the material * Introducing compressive stress in the material, such as in tempered glass * Decreasing the Young's modulus of the material * Increasing the toughness of the material through crack tip blunting or crack deflection, utilizing the process of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shocks And Discontinuities (magnetohydrodynamics)
In magnetohydrodynamics (MHD), shocks and discontinuities are transition layers where properties of a plasma change from one equilibrium state to another. The relation between the plasma properties on both sides of a shock or a discontinuity can be obtained from the conservative form of the MHD equations, assuming conservation of mass, momentum, energy and of \nabla \cdot \mathbf . Rankine–Hugoniot jump conditions for MHD The jump conditions across a time-independent MHD shock or discontinuity are referred as the Rankine–Hugoniot equations for MHD. In the frame moving with the shock/discontinuity, those jump conditions can be written: \begin \rho_1 v_ = \rho_2 v_, \\ .2ex B_ = B_, \\ .2ex \rho_1 v_^2 + p_1 + \frac B_^2 = \rho_2 v_^2+ p_2 + \frac B_^2, \\ .2ex \rho_1 v_ \mathbf_ - \frac \mathbf_ B_ = \rho_2 v_ \mathbf_ - \frac \mathbf_ B_, \\ .2ex \displaystyle \left(\frac\frac + \frac\right) \rho_1 v_ + \frac \left - \right= \left(\frac\frac + \frac\right) \rho_2 v_ + \fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Chlorination
Shock chlorination is a process used in many swimming pools, water wells, springs, and other water sources to reduce the bacterial and algal residue in the water. Shock chlorination is performed by mixing a large amount of sodium hypochlorite, which can be in the form of a powder or a liquid such as chlorine bleach, into the water. The common advice is that the amount added must raise the level of chlorine to 10X the level (in parts per million) of chloramines present in the pool water; this is "shocking". A lesser ratio is termed superchlorinating. Water that is being shock chlorinated should not be swum in or drunk until the sodium hypochlorite count in the water goes down to three ppm or less which is generally more than 6 hours. Commercial sodium hypochlorite should not be mixed with commercial calcium hypochlorite, as there is a risk of explosion. Although a verb for superchlorination, "shock" is often misunderstood (through marketing and sales language) to be a unique typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bow Shock
In astrophysics, bow shocks are shock waves in regions where the conditions of density and pressure change dramatically due to blowing stellar wind. Bow shock occurs when the magnetosphere of an astrophysical object interacts with the nearby flowing ambient plasma such as the solar wind. For Earth and other magnetized planets, it is the boundary at which the speed of the stellar wind abruptly drops as a result of its approach to the magnetopause. For stars, this boundary is typically the edge of the astrosphere, where the stellar wind meets the interstellar medium. Description The defining criterion of a shock wave is that the bulk velocity of the plasma drops from " supersonic" to "subsonic", where the speed of sound cs is defined by c_s^2 = \gamma p/ \rho where \gamma is the ratio of specific heats, p is the pressure, and \rho is the density of the plasma. A common complication in astrophysics is the presence of a magnetic field. For instance, the charged particl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (fluid Dynamics)
Shock is an abrupt discontinuity in the flow field and it occurs in flows when the local flow speed exceeds the local sound speed.Courant, Richard, and K.O. Friedrichs. Supersonic Flow and Shock Waves'. Springer Science & Business Media, 1999. 2-3. More specifically, it is a flow whose Mach number exceeds 1. Explanation of phenomena Shock is formed due to coalescence of various small pressure pulses. Sound waves are pressure waves and it is at the speed of the sound wave the disturbances are ''communicated'' in the medium. When an object is moving in a flow field the object sends out disturbances which propagate at the speed of sound and ''adjusts'' the remaining flow field accordingly. However, if the object itself happens to travel at speed greater than sound, then the disturbances created by the object would not have traveled and ''communicated'' to the rest of the flow field and this results in an abrupt change of property, which is termed as ''shock'' in gas dynamics term ... [...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 direction of incoming air. It occurs 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, can be calcu ... [...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 speed, 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 Wave interference, constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distan ... [...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 to provide shock (mechanics), shock and vibration isolation. Isolation mounts allow equipment to be securely mounted to a foundation and/or frame and, at the same time, allow it to float independently from it. Uses Shock mounts are found in a wide variety of applications. They 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 mechanical noise (mainly transmitted throughout the structure) and increase comfort. This is usually done through elastic supports and transmission couplings. Other common examples are the motor and transmission mounts used in virtually every automobile manufactured today. Without isolation mounts, interior noise and comfort levels would be significantly different. Such shock and vibration-isolation mounts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Absorber
A shock absorber or damper is a mechanical or hydraulics, hydraulic device designed to absorb and Damping ratio, damp shock (mechanics), shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically thermal energy, 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 Pneumatic cylinder, air cylinders, the hot air is usually exhausted to the atmosphere. In other types of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
