Ductility refers to the ability of a material to sustain significant plastic deformation before fracture. Plastic deformation is the permanent distortion of a material under applied stress, as opposed to elastic deformation, which is reversible upon removing the stress. Ductility is a critical mechanical performance indicator, particularly in applications that require materials to bend, stretch, or deform in other ways without breaking. The extent of ductility can be quantitatively assessed using the percent elongation at break, given by the equation:
Lock picking is the practice of unlocking a lock by manipulating the components of the lock device without the original key.
A blade is the sharp, cutting portion of a tool, weapon, or machine, specifically designed to puncture, chop, slice, or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are intended to cut. This includes early examples made from flaked stones like flint or obsidian, evolving through the ages into metal forms like copper, bronze, and iron, and culminating in modern versions made from steel or ceramics. Serving as one of humanity's oldest tools, blades continue to have wide-ranging applications, including in combat, cooking, and various other everyday and specialized tasks.
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.
Prince Rupert's drops are toughened glass beads created by dripping molten glass into cold water, which causes it to solidify into a tadpole-shaped droplet with a long, thin tail. These droplets are characterized internally by very high residual stresses, which give rise to counter-intuitive properties, such as the ability to withstand a blow from a hammer or a bullet on the bulbous end without breaking, while exhibiting explosive disintegration if the tail end is even slightly damaged. In nature, similar structures are produced under certain conditions in volcanic lava, and are known as Pele's tears.
Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. The exact temperature determines the amount of hardness removed, and depends on both the specific composition of the alloy and on the desired properties in the finished product. For instance, very hard tools are often tempered at low temperatures, while springs are tempered at much higher temperatures.
Shot peening is a cold working process used to produce a compressive residual stress layer and modify the mechanical properties of metals and composites. It entails striking a surface with shot with force sufficient to create plastic deformation.
A window film, sometimes called tint, is a thin laminate film that can be installed on the interior or exterior of glass surfaces in automobiles and boats, and as well as on the interior or exterior of glass in homes and buildings. It is usually made from polyethylene terephthalate (PET), a thermoplastic polymer resin of the polyester family, due to its clarity, tensile strength, dimensional stability, and ability to accept a variety of surface-applied or embedded treatments.
In materials science and solid mechanics, residual stresses are stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening imparts deep beneficial compressive residual stresses into metal components such as turbine engine fan blades, and it is used in toughened glass to allow for large, thin, crack- and scratch-resistant glass displays on smartphones. However, unintended residual stress in a designed structure may cause it to fail prematurely.
Home security includes both the security hardware placed on a property and individuals' personal security practices. Security hardware includes doors, locks, alarm systems, lighting, motion detectors, and security camera systems. Personal security involves practices like ensuring doors are locked, alarms are activated, owning a Dog, windows are closed, and extra keys are not hidden outside.
In materials science, hardness is a measure of the resistance to localized plastic deformation, such as an indentation or a scratch (linear), induced mechanically either by pressing or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter.
Safety glass is glass with additional safety features that make it less likely to break, or less likely to pose a threat when broken. Common designs include toughened glass, laminated glass, and wire mesh glass. Toughened glass was invented in 1874 by Francois Barthelemy Alfred Royer de la Bastie. Wire mesh glass was invented in 1892 by Frank Shuman. Laminated glass was invented in 1903 by the French chemist Édouard Bénédictus (1878–1930).
Architectural glass is glass that is used as a building material. It is most typically used as transparent glazing material in the building envelope, including windows in the external walls. Glass is also used for internal partitions and as an architectural feature. When used in buildings, glass is often of a safety type, which include reinforced, toughened and laminated glasses.
Tempered or toughened glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempering puts the outer surfaces into compression and the interior into tension. Such stresses cause the glass, when broken, to shatter into small granular chunks instead of splintering into large jagged shards as ordinary annealed glass does. These smaller, granular chunks are less likely to cause deep penetration when forced into the surface of an object compared to larger, jagged shards because the reduction in both the mass and the maximum dimension of a glass fragment corresponds with a reduction in both the momentum and the penetration depth of the glass fragment.
Taylor v. United States, 495 U.S. 575 (1990), was a U.S. Supreme Court decision that filled in an important gap in the federal criminal law of sentencing. The federal criminal code does not contain a definition of many crimes, including burglary, the crime at issue in this case. Yet sentencing enhancements applicable to federal crimes allow for the enhancement of a defendant's sentence if he has been convicted of prior felonies. The Court addressed in this case how "burglary" should be defined for purposes of such sentencing enhancements when the federal criminal code contained no definition of "burglary." The approach the Court adopted in this case has guided the lower federal courts in interpreting other provisions of the criminal code that also refer to generic crimes not otherwise defined in federal law.
Safety and security window films are polyester or PET films that are applied to glass and glazing in order to hold them together if the glass is shattered. The main difference between film and laminated glass is that these shatter safe films can be applied to the glass or glazing after manufacture or installation. I.e., these films are retrofit products. These films are used widely all over the world; they can be found on trains, buses, cars, and buildings.
A Bologna bottle, also known as a Bologna phial or philosophical vial, is a glass bottle which has great external strength, often used in physics demonstrations and magic tricks. The exterior is generally strong enough that one could pound a nail into a block of wood using the bottle as a hammer; however, even a small scratch on the interior would cause it to crumble.
Stephen Wayne Anderson was an American contract killer and serial killer who was executed at California's San Quentin State Prison by lethal injection in 2002 for the murder of Elizabeth Lyman. He was either known to have killed or admitted to the killings of at least eight other people, including a fellow inmate and at least seven contract killings.
Solid is one of the four fundamental states of matter along with liquid, gas, and plasma. The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural rigidity and resistance to a force applied to the surface. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire available volume like a gas. The atoms in a solid are bound to each other, either in a regular geometric lattice, or irregularly. Solids cannot be compressed with little pressure whereas gases can be compressed with little pressure because the molecules in a gas are loosely packed.
On February 24, 1986, the body of Sherri Rasmussen was found in the apartment she shared with her husband, John Ruetten, in Van Nuys, California, United States. She had been beaten and shot three times in a struggle. The Los Angeles Police Department (LAPD) initially considered the case a botched burglary and were unable to identify a suspect. Rasmussen's father believed that LAPD officer Stephanie Ilene Lazarus, who was formerly in a relationship with Ruetten, was a prime suspect.
