1.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
2.
ChemSpider
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ChemSpider is a database of chemicals. ChemSpider is owned by the Royal Society of Chemistry, the database contains information on more than 50 million molecules from over 500 data sources including, Each chemical is given a unique identifier, which forms part of a corresponding URL. This is an approach to develop an online chemistry database. The search can be used to widen or restrict already found results, structure searching on mobile devices can be done using free apps for iOS and for the Android. The ChemSpider database has been used in combination with text mining as the basis of document markup. The result is a system between chemistry documents and information look-up via ChemSpider into over 150 data sources. ChemSpider was acquired by the Royal Society of Chemistry in May,2009, prior to the acquisition by RSC, ChemSpider was controlled by a private corporation, ChemZoo Inc. The system was first launched in March 2007 in a release form. ChemSpider has expanded the generic support of a database to include support of the Wikipedia chemical structure collection via their WiChempedia implementation. A number of services are available online. SyntheticPages is an interactive database of synthetic chemistry procedures operated by the Royal Society of Chemistry. Users submit synthetic procedures which they have conducted themselves for publication on the site and these procedures may be original works, but they are more often based on literature reactions. Citations to the published procedure are made where appropriate. They are checked by an editor before posting. The pages do not undergo formal peer-review like a journal article. The comments are moderated by scientific editors. The intention is to collect practical experience of how to conduct useful chemical synthesis in the lab, while experimental methods published in an ordinary academic journal are listed formally and concisely, the procedures in ChemSpider SyntheticPages are given with more practical detail. Comments by submitters are included as well, other publications with comparable amounts of detail include Organic Syntheses and Inorganic Syntheses
3.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
4.
PubChem
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PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information, a component of the National Library of Medicine, PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be downloaded via FTP. PubChem contains substance descriptions and small molecules with fewer than 1000 atoms and 1000 bonds, more than 80 database vendors contribute to the growing PubChem database. PubChem consists of three dynamically growing primary databases, as of 28 January 2016, Compounds,82.6 million entries, contains pure and characterized chemical compounds. Substances,198 million entries, contains also mixtures, extracts, complexes, bioAssay, bioactivity results from 1.1 million high-throughput screening programs with several million values. PubChem contains its own online molecule editor with SMILES/SMARTS and InChI support that allows the import and export of all common chemical file formats to search for structures and fragments. In the text search form the database fields can be searched by adding the name in square brackets to the search term. A numeric range is represented by two separated by a colon. The search terms and field names are case-insensitive, parentheses and the logical operators AND, OR, and NOT can be used. AND is assumed if no operator is used, example,0,5000,50,10 -5,5 PubChem was released in 2004. The American Chemical Society has raised concerns about the publicly supported PubChem database and they have a strong interest in the issue since the Chemical Abstracts Service generates a large percentage of the societys revenue. To advocate their position against the PubChem database, ACS has actively lobbied the US Congress, soon after PubChems creation, the American Chemical Society lobbied U. S. Congress to restrict the operation of PubChem, which they asserted competes with their Chemical Abstracts Service
5.
International Chemical Identifier
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Initially developed by IUPAC and NIST from 2000 to 2005, the format and algorithms are non-proprietary. The continuing development of the standard has supported since 2010 by the not-for-profit InChI Trust. The current version is 1.04 and was released in September 2011, prior to 1.04, the software was freely available under the open source LGPL license, but it now uses a custom license called IUPAC-InChI Trust License. Not all layers have to be provided, for instance, the layer can be omitted if that type of information is not relevant to the particular application. InChIs can thus be seen as akin to a general and extremely formalized version of IUPAC names and they can express more information than the simpler SMILES notation and differ in that every structure has a unique InChI string, which is important in database applications. Information about the 3-dimensional coordinates of atoms is not represented in InChI, the InChI algorithm converts input structural information into a unique InChI identifier in a three-step process, normalization, canonicalization, and serialization. The InChIKey, sometimes referred to as a hashed InChI, is a fixed length condensed digital representation of the InChI that is not human-understandable. The InChIKey specification was released in September 2007 in order to facilitate web searches for chemical compounds and it should be noted that, unlike the InChI, the InChIKey is not unique, though collisions can be calculated to be very rare, they happen. In January 2009 the final 1.02 version of the InChI software was released and this provided a means to generate so called standard InChI, which does not allow for user selectable options in dealing with the stereochemistry and tautomeric layers of the InChI string. The standard InChIKey is then the hashed version of the standard InChI string, the standard InChI will simplify comparison of InChI strings and keys generated by different groups, and subsequently accessed via diverse sources such as databases and web resources. Every InChI starts with the string InChI= followed by the version number and this is followed by the letter S for standard InChIs. The remaining information is structured as a sequence of layers and sub-layers, the layers and sub-layers are separated by the delimiter / and start with a characteristic prefix letter. The six layers with important sublayers are, Main layer Chemical formula and this is the only sublayer that must occur in every InChI. The atoms in the formula are numbered in sequence, this sublayer describes which atoms are connected by bonds to which other ones. Describes how many hydrogen atoms are connected to each of the other atoms, the condensed,27 character standard InChIKey is a hashed version of the full standard InChI, designed to allow for easy web searches of chemical compounds. Most chemical structures on the Web up to 2007 have been represented as GIF files, the full InChI turned out to be too lengthy for easy searching, and therefore the InChIKey was developed. With all databases currently having below 50 million structures, such duplication appears unlikely at present, a recent study more extensively studies the collision rate finding that the experimental collision rate is in agreement with the theoretical expectations. Example, Morphine has the structure shown on the right, as the InChI cannot be reconstructed from the InChIKey, an InChIKey always needs to be linked to the original InChI to get back to the original structure
6.
Simplified molecular-input line-entry system
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The simplified molecular-input line-entry system is a specification in form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules, the original SMILES specification was initiated in the 1980s. It has since modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a standard called OpenSMILES was developed by the Blue Obelisk open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, in July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol, algorithms have been developed to generate the same SMILES string for a given molecule, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES
7.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
8.
Density
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The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume, ρ = m V, where ρ is the density, m is the mass, and V is the volume. In some cases, density is defined as its weight per unit volume. For a pure substance the density has the numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity, osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser. Thus a relative density less than one means that the floats in water. The density of a material varies with temperature and pressure and this variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object, increasing the temperature of a substance decreases its density by increasing its volume. In most materials, heating the bottom of a results in convection of the heat from the bottom to the top. This causes it to rise relative to more dense unheated material, the reciprocal of the density of a substance is occasionally called its specific volume, a term sometimes used in thermodynamics. Density is a property in that increasing the amount of a substance does not increase its density. Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass, upon this discovery, he leapt from his bath and ran naked through the streets shouting, Eureka. As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment, the story first appeared in written form in Vitruvius books of architecture, two centuries after it supposedly took place. Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time, from the equation for density, mass density has units of mass divided by volume. As there are units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per metre and the cgs unit of gram per cubic centimetre are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. In industry, other larger or smaller units of mass and or volume are often more practical, see below for a list of some of the most common units of density
9.
Melting point
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The melting point of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid phase exist in equilibrium, the melting point of a substance depends on pressure and is usually specified at standard pressure. When considered as the temperature of the change from liquid to solid. Because of the ability of some substances to supercool, the point is not considered as a characteristic property of a substance. For most substances, melting and freezing points are approximately equal, for example, the melting point and freezing point of mercury is 234.32 kelvins. However, certain substances possess differing solid-liquid transition temperatures, for example, agar melts at 85 °C and solidifies from 31 °C to 40 °C, such direction dependence is known as hysteresis. The melting point of ice at 1 atmosphere of pressure is close to 0 °C. In the presence of nucleating substances the freezing point of water is the same as the melting point, the chemical element with the highest melting point is tungsten, at 3687 K, this property makes tungsten excellent for use as filaments in light bulbs. Many laboratory techniques exist for the determination of melting points, a Kofler bench is a metal strip with a temperature gradient. Any substance can be placed on a section of the strip revealing its thermal behaviour at the temperature at that point, differential scanning calorimetry gives information on melting point together with its enthalpy of fusion. A basic melting point apparatus for the analysis of crystalline solids consists of an oil bath with a transparent window, the several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bath is heated and with the aid of the melting of the individual crystals at a certain temperature can be observed. In large/small devices, the sample is placed in a heating block, the measurement can also be made continuously with an operating process. For instance, oil refineries measure the point of diesel fuel online, meaning that the sample is taken from the process. This allows for more frequent measurements as the sample does not have to be manually collected, for refractory materials the extremely high melting point may be determined by heating the material in a black body furnace and measuring the black-body temperature with an optical pyrometer. For the highest melting materials, this may require extrapolation by several hundred degrees, the spectral radiance from an incandescent body is known to be a function of its temperature. An optical pyrometer matches the radiance of a body under study to the radiance of a source that has been previously calibrated as a function of temperature, in this way, the measurement of the absolute magnitude of the intensity of radiation is unnecessary. However, known temperatures must be used to determine the calibration of the pyrometer, for temperatures above the calibration range of the source, an extrapolation technique must be employed
10.
TNT equivalent
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TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The ton of TNT is a unit of energy defined by convention to be 4.184 gigajoules. The convention intends to compare the destructiveness of an event with that of conventional explosives, the kiloton is a unit of energy equal to 4.184 terajoules. The megaton is a unit of equal to 4.184 petajoules. The kiloton and megaton of TNT have traditionally used to describe the energy output. The TNT equivalent appears in various nuclear weapon control treaties, and has used to characterize the energy released in such other highly destructive events as an asteroid impact. A gram of TNT releases 2673–6702 J upon explosion, the energy liberated by one gram of TNT was arbitrarily defined as a matter of convention to be 4184 J, which is exactly one kilocalorie. The measured, pure heat output of a gram of TNT is only 2724 J, alternative TNT equivalency can be calculated as a function of when in the detonation the value is measured and which property is being compared. A kiloton of TNT can be visualized as a cube of TNT8.46 metres on a side, the RE factor is the relative mass of TNT to which an explosive is equivalent, the greater the RE, the more powerful the explosive. This enables engineers to determine the proper masses of different explosives when applying blasting formulas developed specifically for TNT. For example, if a timber-cutting formula calls for a charge of 1 kg of TNT, then based on octanitrocubanes RE factor of 2.38, using PETN, engineers would need 1. 0/1.66 kg to obtain the same effects as 1 kg of TNT. With ANFO or ammonium nitrate, they would require 1. 0/0.74 kg or 1. 0/0.42 kg, *, TBX or EBX, in a small, confined space, may have over twice the power of destruction. The total power of aluminized mixtures strictly depends on the condition of explosions, guide for the Use of the International System of Units. National Institute of Standards and Technology, nuclear Weapons FAQ Part 1.3 Rhodes, Richard. The Making of the Atomic Bomb, cooper, Paul W. Explosives Engineering, New York, Wiley-VCH, ISBN 0-471-18636-8 HQ Department of the Army, Field Manual 5-25, Explosives and Demolitions, Washington, D. C. Pentagon Publishing, pp. 83–84, ISBN 0-9759009-5-1 Explosives - Compositions, Alexandria, VA, thermobaric Explosives, Advanced Energetic Materials,2004. THE NATIONAL ACADEMIES PRESS, nap. edu, retrieved September 2004
11.
Occupational safety and health
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These terms of course also refer to the goals of this field, so their use in the sense of this article was originally an abbreviation of occupational safety and health program/department etc. The goals of occupational safety and health programs include to foster a safe, OSH may also protect co-workers, family members, employers, customers, and many others who might be affected by the workplace environment. In the United States, the occupational health and safety is referred to as occupational health and occupational and non-occupational safety. In common-law jurisdictions, employers have a common law duty to take care of the safety of their employees. As defined by the World Health Organization occupational health deals with all aspects of health, Health has been defined as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Occupational health is a field of healthcare concerned with enabling an individual to undertake their occupation. Health has been defined as It contrasts, for example, with the promotion of health and safety at work, since 1950, the International Labour Organization and the World Health Organization have shared a common definition of occupational health. It was adopted by the Joint ILO/WHO Committee on Occupational Health at its first session in 1950, the concept of working culture is intended in this context to mean a reflection of the essential value systems adopted by the undertaking concerned. Such a culture is reflected in practice in the systems, personnel policy, principles for participation, training policies. Professionals advise on a range of occupational health matters. The research and regulation of safety and health are a relatively recent phenomenon. As labor movements arose in response to concerns in the wake of the industrial revolution. The initial remit of the Inspectorate was to police restrictions on the hours in the textile industry of children. The commission sparked public outrage resulted in the Mines Act of 1842. Otto von Bismarck inaugurated the first social insurance legislation in 1883, similar acts followed in other countries, partly in response to labor unrest. Although work provides many economic and other benefits, an array of workplace hazards also present risks to the health. Personal protective equipment can protect against many of these hazards. Physical hazards affect many people in the workplace, Falls are also a common cause of occupational injuries and fatalities, especially in construction, extraction, transportation, healthcare, and building cleaning and maintenance
12.
GHS hazard pictograms
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Hazard pictograms form part of the international Globally Harmonized System of Classification and Labelling of Chemicals. Two sets of pictograms are included within the GHS, one for the labelling of containers and for workplace hazard warnings, either one or the other is chosen, depending on the target audience, but the two are not used together. The two sets of use the same symbols for the same hazards, although certain symbols are not required for transport pictograms. Transport pictograms come in variety of colors and may contain additional information such as a subcategory number. It has still to be implemented by the European Union in 2009, the following pictograms are included in the Worldwide Model Using but have not been incorporated into the GHS, ICZ and Catwallsh Hazcom Labelling because of the nature of the hazards. Globally Harmonized System of Classification and Labelling of Chemicals, New York and Geneva, United Nations,2007, ISBN 978-92-1-116957-7, ST/SG/AC. 10/30/Rev. Model Regulations, New York and Geneva, United Nations,2007, ISBN 978-92-1-139120-6, manual of Tests and Criteria, New York and Geneva, United Nations,2002, ISBN 92-1-139087-7, ST/SG/AC. 10/11/Rev.4 GHS pictogram gallery from the United Nations Economic Commission for Europe
13.
Explosive material
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An explosive charge is a measured quantity of explosive material, which may be composed of a single ingredient or a combination of two or more. Materials that detonate are said to be high explosives and materials that deflagrate are said to be low explosives, Explosives may also be categorized by their sensitivity. Sensitive materials that can be initiated by a small amount of heat or pressure are primary explosives. A wide variety of chemicals can explode, a number are manufactured specifically for the purpose of being used as explosives. The remainder are too dangerous, sensitive, toxic, expensive, unstable, in contrast, some materials are merely combustible or flammable if they burn without exploding. The distinction, however, is not razor-sharp, though early thermal weapons, such as Greek fire, have existed since ancient times, the first widely used explosive in warfare and mining was black powder, invented in 9th century China. This material was sensitive to water, and it produced copious amounts of dark smoke, the first useful explosive stronger than black powder was nitroglycerin, developed in 1847. Since nitroglycerin is a liquid and highly unstable, it was replaced by nitrocellulose, TNT in 1863, smokeless powder, dynamite in 1867, World War I saw the adoption of TNT trinitrotoluene in artillery shells. World War II saw a use of new explosives. In turn, these have largely replaced by more powerful explosives such as C-4. However, C-4 and PETN react with metal and catch fire easily, yet unlike TNT, C-4 and PETN are waterproof, the largest commercial application of explosives is mining. In Materials Science and Engineering, explosives are used in cladding, a thin plate of some material is placed atop a thick layer of a different material, both layers typically of metal. Atop the thin layer is placed an explosive, at one end of the layer of explosive, the explosion is initiated. The two metallic layers are forced together at high speed and with great force, the explosion spreads from the initiation site throughout the explosive. Ideally, this produces a metallurgical bond between the two layers and it is possible that some fraction of the surface material from either layer eventually gets ejected when the end of material is reached. Hence, the mass of the now welded bilayer, may be less than the sum of the masses of the two initial layers, there are applications where a shock wave, and electrostatics, can result in high velocity projectiles. Thus, explosives are substances that contain an amount of energy stored in chemical bonds. Consequently, most commercial explosives are compounds containing -NO2, -ONO2 and -NHNO2 groups that
14.
RDX
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RDX is the organic compound with the formula 3. It is a white solid used as an explosive. Chemically, it is classified as nitramide, a more powerful explosive than TNT, it was used widely in World War II. It is often used in mixtures with other explosives and plasticizers or phlegmatizers, RDX is stable in storage and is considered one of the most powerful and brisant of the military high explosives. RDX is also known, but less commonly, as cyclonite, hexogen, T4, in the 1930s, the Royal Arsenal, Woolwich, started investigating cyclonite to use against German U-boats that were being built with thicker hulls. The goal was a more powerful than TNT. For security reasons, Britain termed cyclonite as Research Department Explosive, the term RDX appeared in the United States in 1946. The first public reference in the United Kingdom to the name RDX, RDX was widely used during World War II, often in explosive mixtures with TNT such as Torpex, Composition B, Cyclotols, and H6. RDX was used in one of the first plastic explosives, the bouncing bomb depth charges used in the Dambusters Raid each contained 6,600 pounds of Torpex. RDX is believed to have used in many bomb plots including terrorist plots. RDX forms the base for a number of military explosives, Composition A, Granular explosive consisting of RDX. C-4 consists of RDX, a plasticizer, a binder, which is usually polyisobutylene, Composition CH-6,97. 5% RDX,1. 5% calcium stearate,0. 5% polyisobutylene, and 0. 5% graphite. DBX, Castable mixture consisting of 21% RDX, 21% ammonium nitrate, 40% TNT, developed during World War II, it was to be used in underwater munitions as a substitute for Torpex employing only half the amount of then-strategic RDX. As the supply of RDX became more adequate, the mixture was shelved, Cyclotol, Castable mixture of RDX with TNT designated by the amount of RDX/TNT, such as Cyclotol 70/30. HBX, Castable mixtures of RDX, TNT, powdered aluminium, h-6, Castable mixture of RDX, TNT, powdered aluminum, and paraffin wax. PBX, RDX is also used as a component of many polymer-bonded explosives. RDX-based PBXs typically consist of RDX and a polymer/co-polymer binder, semtex, Plastic demolition explosives containing RDX and PETN as major energetic components. Torpex, 42% RDX, 40% TNT, and 18% powdered aluminium, the mixture was designed during World War II and used mainly in underwater ordnance
15.
Hexanitrohexaazaisowurtzitane
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Hexanitrohexaazaisowurtzitane /ˈhɛksɑːˈnaɪtroʊˈhɛksɑːˌæzɑːˌaɪsoʊˈvʊərtsɪteɪn/, also called HNIW and CL-20, is a nitroamine explosive with the formula C6H6N12O12. The structure of CL-20 was first proposed in 1979 by Dalian Institute of Chemical Physics, in 1980s, CL-20 was developed by the China Lake facility, primarily to be used in propellants. It has a better ratio than conventional HMX or RDX. It releases 20% more energy than traditional HMX-based propellants, and is superior to conventional high-energy propellants. Industrial production of CL-20 was achieved in China in 2011, CL-20 has not yet been fielded in any production weapons system, but is undergoing testing for stability, production capabilities, and other weapons characteristics. First, benzylamine is condensed with glyoxal under acidic and dehydrating conditions to yield the first intermediate compound, four benzyl groups selectively undergo hydrogenolysis using palladium on carbon and hydrogen. The amino groups are then acetylated during the same step using acetic anhydride as the solvent, finally, compound 4 is reacted with nitronium tetrafluoroborate and nitrosonium tetrafluoroborate, resulting in HNIW. In August 2012, Onas Bolton et al. published results showing that a cocrystal of 2 parts CL-20 and 1 part HMX had similar safety properties to HMX, but with a greater firing power closer to CL-20. 2,4, 6-Tris-1,3, 5-triazine 4, 4’-Dinitro-3, 3’-diazenofuroxan Heptanitrocubane HHTDD Octanitrocubane Iceane RE factor Bolton, Onas, improved Stability and Smart-Material Functionality Realized in an Energetic Cocrystal. Lowe, Derek Things I wont work with, Hexanitrohexaazaisowurtzitane
16.
Octanitrocubane
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Octanitrocubane is a high explosive that, like TNT, is shock-insensitive. The octanitrocubane molecule has the chemical structure as cubane except that each of the eight hydrogen atoms is replaced by a nitro group. It is however not as powerful as once thought, as the high density theoretical crystal structure has not been achieved, for this reason heptanitrocubane, the slightly less nitrated form, is believed to have marginally better performance despite having a worse oxygen balance. Octanitrocubane is thought to have 20–25% greater performance than HMX and this increase in power is due to its highly expansive breakdown into CO2 and N2, as well as to the presence of strained chemical bonds in the molecule which have stored potential energy. In addition, octanitrocubane produces no water vapor making it less visible, octanitrocubane has a detonation velocity of 10,100 m/s, making it the fastest known explosive. Small amounts have been synthesized in the laboratory, but not enough for testing as an explosive. The R. E. factor of octanitrocubane is 2.38, although octanitrocubane is predicted to be one of the most effective explosives, the difficulty of its synthesis inhibits practical use. Philip Eatons synthesis was difficult and lengthy, and required cubane as a starting point, as a result, octanitrocubane is more valuable, gram for gram, than gold. A proposed path to synthesis is the cyclotetramerization of the as yet undiscovered, hexanitrohexaazaisowurtzitane 4, 4′-Dinitro-3, 3′-diazenofuroxan RE factor American Chemical Society lauds difficult synthesis of new compound, March 20,2001
17.
Acetic anhydride
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Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of an acid and is widely used as a reagent in organic synthesis. It is a liquid that smells strongly of acetic acid. Acetic anhydride, like most acid anhydrides, is a molecule with a nonplanar structure. The pi system linkage through the central oxygen offers very weak resonance stabilization compared to the repulsion between the two carbonyl oxygens. The energy barriers to rotation between each of the optimal aplanar conformations are quite low. Like most acid anhydrides, the carbon of acetic anhydride has electrophilic character. Acetic anhydride was first synthesized in 1852 by the French chemist Charles Frédéric Gerhardt by heating potassium acetate with benzoyl chloride, carbonylation of the methyl iodide in turn affords acetyl iodide, which reacts with acetate salts or acetic acid to give the product. Rhodium chloride in the presence of iodide is employed as catalysts. Because acetic anhydride is not stable in water, the conversion is conducted under anhydrous conditions, to a decreasing extent, acetic anhydride is also prepared by the reaction of ketene with acetic acid at 45–55 °C and low pressure. Due to its low cost, acetic anhydride is purchased, not prepared, acetic anhydride is a versatile reagent for acetylations, the introduction of acetyl groups to organic substrates. In these conversions, acetic anhydride is viewed as a source of CH3CO+, alcohols and amines are readily acetylated. For example, the reaction of acetic anhydride with ethanol yields ethyl acetate, in specialized applications, Lewis acidic scandium salts have also proven effective catalysts. Aromatic rings are acetylated by acetic anhydride, usually acid catalysts are used to accelerate the reaction. It is also used for the preparation of mixed anhydrides such as that with nitric acid, aldehydes react with acetic anhydride in the presence of an acidic catalyst to give geminal diacetates. 6% by weight. Aqueous solutions have limited stability because, like most acid anhydrides, in this case, acetic acid is formed, 2O + H2O →2 CH3CO2H As indicated by its organic chemistry, Ac2O is mainly used for acetylations leading to commercially significant materials. Similarly it is used in the production of aspirin, which is prepared by the acetylation of salicylic acid and it is also used as a wood preservative via autoclave impregnation to make a longer-lasting timber. S. DEA List II precursor, and restricted in other countries
18.
Paraformaldehyde
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Paraformaldehyde is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units. Paraformaldehyde commonly has an odor of formaldehyde due to decomposition. Paraformaldehyde forms slowly in aqueous formaldehyde solutions as a white precipitate, formalin actually contains very little monomeric formaldehyde, most of it forms short chains of polyformaldehyde. A small amount of methanol is added as a stabilizer to limit the extent of polymerization. Paraformaldehyde can be depolymerized to formaldehyde gas by dry heating and to form a solution by water in the presence of a base or heat. The very pure formaldehyde solutions obtained in this way are used as a fixative for microscopy, the resulting formaldehyde gas from dry heating paraformaldehyde is flammable. Once paraformaldehyde is depolymerized, the resulting formaldehyde may be used as a fumigant, disinfectant, fungicide, longer chain-length polyoxymethylenes are used as a thermoplastic and are known as polyoxymethylene plastic. It was used in the past in the discredited Sargenti method of root canal treatment, paraformaldehyde is not a fixative, it must be depolymerized to formaldehyde in solution. In cell culture, a typical formaldehyde fixing procedure would involve using a 4% formaldehyde solution in phosphate buffered saline on ice for 10 minutes, as a formaldehyde releasing agent, paraformaldehyde is a potential carcinogen. Its acute oral lethal dose in rats is 592 mg/kg. Polyoxymethylene plastic 1,3, 5-Trioxane, the trimer of formaldehyde Polymer
19.
Ammonium nitrate
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Ammonium nitrate is a chemical compound, the nitrate salt of the ammonium cation. It has the chemical formula NH4NO3, simplified to N2H4O3 and it is a white crystal solid and is highly soluble in water. It is predominantly used in agriculture as a high-nitrogen fertilizer and its other major use is as a component of explosive mixtures used in mining, quarrying, and civil construction. It is the constituent of ANFO, a popular industrial explosive which accounts for 80% of explosives used in North America. Many countries are phasing out its use in consumer applications due to concerns over its potential for misuse, ammonium nitrate was mined there in the past, but virtually 100% of the chemical now used is synthetic. This reaction is violent owing to its exothermic nature. After the solution is formed, typically at about 83% concentration, the AN melt is then made into prills or small beads in a spray tower, or into granules by spraying and tumbling in a rotating drum. The prills or granules may be dried, cooled. These prills or granules are the typical AN products in commerce, the ammonia required for this process is obtained by the Haber process from nitrogen and hydrogen. Ammonia produced by the Haber process is oxidized to nitric acid by the Ostwald process, transformations of the crystal states due to changing conditions affect the physical properties of ammonium nitrate. Ammonium nitrate is an important fertilizer with the NPK rating 34-0-0 and it is less concentrated than urea, giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrates advantage over urea is that it is more stable, during warm weather it is best to apply urea soon before rain is expected or to cover it with soil to minimize nitrogen loss. ANFO is a mixture of 94% ammonium nitrate and 6% fuel oil used as a bulk industrial explosive. Ammonium nitrate-based explosives were used in the Oklahoma City Bombing in 1995 and 2011 Delhi bombings, the 2013 Hyderabad blasts, due to these bans, Potassium chlorate — the stuff that makes matches catch fire — has surpassed fertilizer as the explosive of choice for insurgents. Ammonium nitrate is used in instant cold packs, as its dissolution in water is highly endothermic. Health and safety data are shown on the safety data available from suppliers. Heating or any ignition source may cause violent combustion or explosion, ammonium nitrate reacts with combustible and reducing materials as it is a strong oxidant. Although it is used for fertilizer, it can be used for explosives
20.
Nuclear weapon
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A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from small amounts of matter. The first test of a bomb released the same amount of energy as approximately 20,000 tons of TNT. The first thermonuclear bomb test released the same amount of energy as approximately 10 million tons of TNT, a thermonuclear weapon weighing little more than 2,400 pounds can produce an explosive force comparable to the detonation of more than 1.2 million tons of TNT. A nuclear device no larger than traditional bombs can devastate a city by blast, fire. Nuclear weapons are considered weapons of destruction, and their use. Nuclear weapons have been used twice in nuclear warfare, both times by the United States against Japan near the end of World War II, the bombings resulted in the deaths of approximately 200,000 civilians and military personnel from acute injuries sustained from the explosions. The ethics of the bombings and their role in Japans surrender remain the subject of scholarly, since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated on over two thousand occasions for the purposes of testing and demonstration. Only a few nations possess such weapons or are suspected of seeking them, israel is also believed to possess nuclear weapons, though in a policy of deliberate ambiguity, it does not acknowledge having them. Germany, Italy, Turkey, Belgium and the Netherlands are nuclear weapons sharing states, south Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons. Modernisation of weapons continues to occur, all existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is exclusively from fission reactions are commonly referred to as bombs or atom bombs. This has long noted as something of a misnomer, as their energy comes from the nucleus of the atom. The latter approach is considered more sophisticated than the former and only the approach can be used if the fissile material is plutonium. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons of TNT, all fission reactions necessarily generate fission products, the radioactive remains of the atomic nuclei split by the fission reactions. Many fission products are highly radioactive or moderately radioactive. Fission products are the radioactive component of nuclear fallout
21.
Rocket
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A rocket is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed entirely from propellant carried within the rocket before use, Rocket engines work by action and reaction and push rockets forward simply by expelling their exhaust in the opposite direction at high speed, and can therefore work in the vacuum of space. In fact, rockets work more efficiently in space than in an atmosphere, multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, auxiliary engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin. Rockets for military and recreational uses date back to at least 13th century China, significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Earths moon. Rockets are now used for fireworks, weaponry, ejection seats, launch vehicles for satellites, human spaceflight. Chemical rockets are the most common type of high power rocket, chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks, the first gunpowder-powered rockets were developed in Song China, by the 13th century. The Chinese rocket technology was adopted by the Mongols and the invention was spread via the Mongol invasions to the Near East, medieval and early modern rockets were used militarily as incendiary weapons in sieges. An early Chinese text to mention the use of rockets was the Huolongjing, between 1270 and 1280, Hasan al-Rammah wrote al-furusiyyah wa al-manasib al-harbiyya, which included 107 gunpowder recipes,22 of which are for rockets. In Europe, Konrad Kyeser described rockets in his military treatise Bellifortis around 1405. The name Rocket comes from the Italian rocchetta, meaning bobbin or little spindle, the Italian term was adopted into German in the mid 16th century by Leonhard Fronsperger and Conrad Haas, and by the early 17th century into English. Artis Magnae Artilleriae pars prima, an important early work on rocket artillery. The first iron-cased rockets were developed in the late 18th century in the Kingdom of Mysore, in 1814, Francis Scott Key wrote the line rockets red glare while held captive on a British ship that was laying siege to Fort McHenry. The first mathematical treatment of the dynamics of rocket propulsion is due to William Moore, in 1815, Alexander Dmitrievich Zasyadko constructed rocket-launching platforms, which allowed rockets to be fired in salvos, and gun-laying devices. William Hale in 1844 greatly increased the accuracy of rocket artillery, the Congreve rocket was further improved by Edward Mounier Boxer in 1865. Konstantin Tsiolkovsky first speculated on the possibility of manned spaceflight with rocket technology, robert Goddard in 1920 published proposed improvements to rocket technology in A Method of Reaching Extreme Altitudes
22.
TNT
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Trinitrotoluene, or more specifically 2,4, 6-trinitrotoluene, is a chemical compound with the formula C6H23CH3. This yellow-colored solid is used as a reagent in chemical synthesis. The explosive yield of TNT is considered to be the measure of bombs. In chemistry, TNT is used to charge transfer salts. TNT was first prepared in 1863 by German chemist Julius Wilbrand and its potential as an explosive was not appreciated for several years, mainly because it was so difficult to detonate and because it was less powerful than alternatives. Its explosive properties were first discovered by another German chemist, Carl Häussermann, the German armed forces adopted it as a filling for artillery shells in 1902. The British started replacing lyddite with TNT in 1907, TNT is still widely used by the United States military, as well as construction companies around the world. The majority of TNT currently used by the US military is manufactured by Radford Army Ammunition Plant near Radford, in industry, TNT is produced in a three-step process. First, toluene is nitrated with a mixture of sulfuric and nitric acid to produce mononitrotoluene, the MNT is separated and then renitrated to dinitrotoluene. In the final step, the DNT is nitrated to trinitrotoluene using a mixture of nitric acid. Nitric acid is consumed by the process, but the diluted sulfuric acid can be reconcentrated and reused. The rinse water from sulphitation is known as red water and is a significant pollutant, control of nitrogen oxides in feed nitric acid is very important because free nitrogen dioxide can result in oxidation of the methyl group of toluene. This reaction is exothermic and carries with it the risk of a runaway reaction leading to an explosion. In the laboratory,2,4, 6-trinitrotoluene is produced by a two-step process, a nitrating mixture of concentrated nitric and sulfuric acids is used to nitrate toluene to a mixture of mono- and di-nitrotoluene isomers, with careful cooling to maintain temperature. The nitrated toluenes are then separated, washed with dilute sodium bicarbonate to remove oxides of nitrogen, towards the end of the nitration, the mixture is heated on a steam bath. The trinitrotoluene is separated, washed with a solution of sodium sulfite. TNT is one of the most commonly used explosives for military, industrial, TNT has been used in conjunction with hydraulic fracturing, a process used to recover oil and gas from shale formations. The technique involves displacing and detonating nitroglycerin in hydraulically induced fractures followed by wellbore shots using pelletized TNT, TNT is valued partly because of its insensitivity to shock and friction, with reduced risk of accidental detonation compared to more sensitive explosives such as nitroglycerin
23.
Octol
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Octol is a melt-castable, high explosive mixture consisting of HMX and TNT in different weight proportions. The applications of Octol are generally military, e. g. shaped charges and warheads used in guided missiles, Octol is somewhat more expensive than RDX-based explosives, such as Composition B and Cyclotol. The advantage of Octol is that it reduces the size. These are important considerations where smart weapons such as guided missiles are concerned, a light warhead means a superior power to weight ratio. This in turn results in a higher velocity missile with a longer range, as a result, the target has less opportunity to recognise and evade the attack. Octol is also referred to as Oktol, particularly in Eastern Europe, RE factor Reference to Octol used as a booster
24.
Warhead
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The term warhead refers to the explosive or toxic material that is delivered by a missile, rocket, or torpedo. Types of warheads include, Explosive, An explosive charge is used to disintegrate the target, conventional, Chemicals such as gunpowder and high explosives store significant energy within their molecular bonds. This energy can be released quickly by a trigger, such as an electric spark, thermobaric weapons enhance the blast effect by utilizing the surrounding atmosphere in their explosive reactions. Blast, A strong shock wave is provided by the detonation of the explosive, fragmentation, Metal fragments are projected at high velocity to cause damage or injury. Continuous rod, Metal bars welded on their ends form a cylinder of interconnected rods. The rapidly expanding ring produces a planar cutting effect that is devastating against military aircraft, shaped charge, The effect of the explosive charge is focused onto a specially shaped metal liner to project a hypervelocity jet of metal, to perforate heavy armour. Nuclear, A runaway nuclear fission or nuclear fusion reaction causes immense energy release, chemical, A toxic chemical, such as poison gas or nerve gas, is dispersed, which is designed to injure or kill human beings. Biological, An infectious agent, such as spores, is dispersed. Often, a biological or chemical warhead will use a charge for rapid dispersal. Type of detonators include Guidance system List of aircraft weapons List of missiles Nuclear weapon yield Missile The Nuclear Weapon Archive, the B61 Bomb - Intermediate yield strategic and tactical thermonuclear bomb. Atomic Audit - The Costs and Consequences of U. S, ogden Air Logistics Center at Hill AFB, Utah. NNSA Achieves Significant Milestone for B61 Bomb, Nuclear Weapons, The Secret History, pp. 162–164
25.
Shaped charge
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A shaped charge is an explosive charge shaped to focus the effect of the explosives energy. Various types are used to cut and form metal, initiate nuclear weapons, penetrate armor, the Munroe or Neumann effect is the focusing of blast energy by a hollow or void cut on a surface of an explosive. The earliest mention of hollow charges occurred in 1792, the first true hollow charge effect was achieved in 1883, by Max von Foerster, chief of the nitrocellulose factory of Wolff & Co. in Walsrode, Germany. By 1886, Gustav Bloem of Düsseldorf, Germany had obtained U. S, patent 342,423 for hemispherical cavity metal detonators to concentrate the effect of the explosion in an axial direction. The Munroe effect is named after Charles E. Munroe, who discovered it in 1888. As a civilian chemist working at the U. S. Conversely, if letters were raised in relief above the surface of the explosive, in 1894, Munroe constructed the first crude shaped charge, Among the experiments made. Was one upon a safe twenty-nine inches cube, with four inches. Hen a hollow charge of nine pounds and a half in weight and untamped was detonated on it. The hollow cartridge was made by tying the sticks of dynamite around a tin can, part of that 1900 article was reprinted in the February 1945 issue of Popular Science, describing how shaped-charge warheads worked. It was this article that at last revealed to the public how the fabled Bazooka actually worked against armored vehicles during WWII. In 1910, Egon Neumann of Germany discovered that a block of TNT, the military usefulness of Munroes and Neumanns work was unappreciated for a long time. Between the world wars, academics in several countries – Myron Yakovlevich Sukharevskii in the Soviet Union, payment and Donald Whitley Woodhead in Britain, and Robert Williams Wood in the U. S. – recognized that projectiles could form during explosions. However, it was not until 1932 that Franz Rudolf Thomanek, when the Austrian government showed no interest in pursuing the idea, Thomanek moved to Berlins Technische Hochschule, where he continued his studies under the ballistics expert Carl Julius Cranz. There in 1935, he and Hellmuth von Huttern developed a prototype anti-tank round, although the weapons performance proved disappointing, Thomanek continued his developmental work, collaborating with Hubert Schardin at the Waffeninstitut der Luftwaffe in Braunschweig. By 1937, Shardin believed that hollow-charge effects were due to the interactions of shock waves and it was during the testing of this idea that, on February 4,1938, Thomanek conceived the shaped-charge explosive. During World War II, shaped-charge munitions were developed by Germany, Britain, the Soviet Union, the development of shaped charges revolutionized anti-tank warfare. Tanks faced a serious vulnerability from a weapon that could be carried by an infantryman or aircraft, one of the earliest uses of shaped charges was by German glider-borne troops against the Belgian Fort Eben-Emael. These demolition charges – developed by Dr. Wuelfken of the German Ordnance Office – were unlined explosive charges and didnt produce a metal jet like the modern HEAT warheads
26.
Hayabusa 2
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Hayabusa2 is an asteroid sample return mission operated by the Japanese space agency, JAXA. It follows on from Hayabusa and addresses weak points learned from that mission, initially, launch was planned for 30 November 2014, but was delayed to 3 December 201404,22 UTC. The target is asteroid 162173 Ryugu, Hayabusa 2 is expected to arrive at the target in July 2018, survey the asteroid for a year and a half, depart in December 2019, and return to Earth in December 2020. The spacecraft features ion engines, upgraded guidance and navigation technology, antennas, operations at the asteroid will be similar to those of the previous Hayabusa, but with an explosive device to dig the asteroid surface for fresh sample material. Hayabusa2 was approved by the Space Activities Commission, a board governing funding for the Japanese space program, in July 2009, at the 27th ISTS conference in Japan, Makoto Yoshikawa of JAXA presented a proposal entitled Hayabusa Follow-on Asteroid Sample Return Missions. In August 2010, JAXA obtained approval from the Japanese government to begin development of Hayabusa 2, the estimated cost of the project is 16.4 billion yen. NEC Corp. the builder of the Hayabusa probe, began the design of the 590 kg spacecraft, its Ka-band communications system. The German Aerospace Center built a small lander called MASCOT for the mission in a cooperation with the French space agency CNES. The MASCOT carries an infrared spectrometer, a magnetometer, a radiometer and a camera, the Small Carry-on Impactor is a small drop-off explosively formed penetrator, consisting of a 2.5 kilogram copper projectile and a 4.5 kilogram shaped charge. It will be dropped off Hayabusa2, the low gravity leaves the spacecraft enough time to maneuver to the side of the asteroid. A second instrument will then be deployed, the deployable camera and this camera will observe the explosion of the Small Carry-on Impactor instrument. The copper penetrator will strike the asteroid with a velocity of 2 km/s, the crater formed by the impact will be the site of further observations by the spacecraft. The shaped charge will consist of 4.5 kg of plasticized HMX with a 2.5 kg copper liner, development of New Sampling Devices for Solar System Small Body Sample Return Program in the Hayabusa Era
27.
Asteroid
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Asteroids are minor planets, especially those of the inner Solar System. The larger ones have also been called planetoids and these terms have historically been applied to any astronomical object orbiting the Sun that did not show the disc of a planet and was not observed to have the characteristics of an active comet. As minor planets in the outer Solar System were discovered and found to have volatile-based surfaces that resemble those of comets, in this article, the term asteroid refers to the minor planets of the inner Solar System including those co-orbital with Jupiter. There are millions of asteroids, many thought to be the remnants of planetesimals. The large majority of known asteroids orbit in the belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter. However, other orbital families exist with significant populations, including the near-Earth objects, individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups, C-type, M-type, and S-type. These were named after and are identified with carbon-rich, metallic. The size of asteroids varies greatly, some reaching as much as 1000 km across, asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition, while asteroids are composed of mineral and rock, comets are composed of dust. In addition, asteroids formed closer to the sun, preventing the development of the aforementioned cometary ice, the difference between asteroids and meteoroids is mainly one of size, meteoroids have a diameter of less than one meter, whereas asteroids have a diameter of greater than one meter. Finally, meteoroids can be composed of either cometary or asteroidal materials, only one asteroid,4 Vesta, which has a relatively reflective surface, is normally visible to the naked eye, and this only in very dark skies when it is favorably positioned. Rarely, small asteroids passing close to Earth may be visible to the eye for a short time. As of March 2016, the Minor Planet Center had data on more than 1.3 million objects in the inner and outer Solar System, the United Nations declared June 30 as International Asteroid Day to educate the public about asteroids. The date of International Asteroid Day commemorates the anniversary of the Tunguska asteroid impact over Siberia, the first asteroid to be discovered, Ceres, was found in 1801 by Giuseppe Piazzi, and was originally considered to be a new planet. In the early half of the nineteenth century, the terms asteroid. Asteroid discovery methods have improved over the past two centuries. This task required that hand-drawn sky charts be prepared for all stars in the band down to an agreed-upon limit of faintness. On subsequent nights, the sky would be charted again and any moving object would, hopefully, the expected motion of the missing planet was about 30 seconds of arc per hour, readily discernible by observers
28.
Solar wind
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The solar wind is a stream of charged particles released from the upper atmosphere of the Sun. This plasma consists of electrons, protons and alpha particles with thermal energies between 1.5 and 10 keV. Embedded within the plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and its particles can escape the Suns gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field. At a distance of more than a few radii from the sun. The flow of the wind is no longer supersonic at the termination shock. The Voyager 2 spacecraft crossed the shock more than five times between 30 August and 10 December 2007, Voyager 2 crossed the shock about a billion kilometers closer to the Sun than the 13.5 billion kilometer distance where Voyager 1 came upon the termination shock. The spacecraft moved outward through the shock into the heliosheath. Other related phenomena include the aurora, the tails of comets that always point away from the Sun. The existence of flowing outward from the Sun to the Earth was first suggested by British astronomer Richard C. In 1859, Carrington and Richard Hodgson independently made the first observation of what would later be called a solar flare, george FitzGerald later suggested that matter was being regularly accelerated away from the Sun and was reaching the Earth after several days. In 1910 British astrophysicist Arthur Eddington essentially suggested the existence of the wind, without naming it. The idea never caught on even though Eddington had also made a similar suggestion at a Royal Institution address the previous year. In the latter case, he postulated that the material consisted of electrons while in his study of Comet Morehouse he supposed them to be ions. The first person to suggest that the material consisted of both ions and electrons was Kristian Birkeland. His geomagnetic surveys showed that activity was nearly uninterrupted. In 1916, Birkeland proposed that, From a physical point of view it is most probable that solar rays are neither exclusively negative nor positive rays, in other words, the solar wind consists of both negative electrons and positive ions. Three years later in 1919, Frederick Lindemann also suggested that particles of both polarities, protons as well as electrons, come from the Sun
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