DamA dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations.
Dental implantA dental implant (also known as an endosseous implant or fixture) is a prosthesis that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, or facial prosthesis or to act as an orthodontic anchor. The basis for modern dental implants is a biological process called osseointegration, in which materials such as titanium or zirconia form an intimate bond to the bone. The implant fixture is first placed so that it is likely to osseointegrate, then a dental prosthetic is added.
PressurePressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi, symbol lbf/in2) is the traditional unit of pressure in the imperial and US customary systems.
Bridge (dentistry)A bridge is a fixed dental restoration (a fixed dental prosthesis) used to replace one or more missing teeth by joining an artificial tooth definitively to adjacent teeth or dental implants. Fixed bridge: A dental prosthesis that is definitively attached to natural teeth and replaces missing teeth. Abutment: The tooth that supports and retains a dental prosthesis. Pontic: The artificial tooth that replaces a missing natural tooth. Retainer: The component attached to the abutment for retention of the prosthesis.
St. Francis DamThe St. Francis Dam was a concrete gravity dam located in San Francisquito Canyon in northern Los Angeles County, California that was built between 1924 and 1926 to serve the city of Los Angeles's growing water needs. It failed catastrophically in 1928 due to a defective soil foundation and design flaws, unleashing a flood that claimed the lives of at least 431 people.
Abutment (dentistry)In dentistry, an abutment is a connecting element. This is used in the context of a fixed bridge (the "abutment teeth" referring to the teeth supporting the bridge), partial removable dentures (the "abutment teeth" referring to the teeth supporting the partial) and in implants (used to attach a crown, bridge, or removable denture to the dental implant fixture). The implant fixture is the screw-like component that is osseointegrated. Dental bridge abutments are made such that the path of insertion of the teeth involved is nearly parallel with each other.
Slope stability analysisSlope stability analysis is a static or dynamic, analytical or empirical method to evaluate the stability of slopes of soil- and rock-fill dams, embankments, excavated slopes, and natural slopes in soil and rock. It is performed to assess the safe design of a human-made or natural slopes (e.g. embankments, road cuts, open-pit mining, excavations, landfills etc.) and the equilibrium conditions. Slope stability is the resistance of inclined surface to failure by sliding or collapsing.
Embankment damAn embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface and a dense, impervious core. This makes the dam impervious to surface or seepage erosion. Such a dam is composed of fragmented independent material particles. The friction and interaction of particles binds the particles together into a stable mass rather than by the use of a cementing substance.
Dam failureA dam failure or dam burst is a catastrophic type of structural failure characterized by the sudden, rapid, and uncontrolled release of impounded water or the likelihood of such an uncontrolled release. Between the years 2000 and 2009 more than 200 notable dam failures happened worldwide. A dam is a barrier across flowing water that obstructs, that directs or slows down the flow, often creating a reservoir, lake or impoundments.
Removable partial dentureA removable partial denture (RPD) is a denture for a partially edentulous patient who desires to have replacement teeth for functional or aesthetic reasons and who cannot have a bridge (a fixed partial denture) for any reason, such as a lack of required teeth to serve as support for a bridge (i.e. distal abutments) or financial limitations. This type of prosthesis is referred to as a removable partial denture because patients can remove and reinsert it when required without professional help.
