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PTR Rifle, PTR-91
PTR can refer to: * Particle transfer roller, for cleaning motion picture film * Peak-to-trough ratio, a parameter in pharmacokinetics * Petir LRT station (LRT station abbreviation), Singapore * PetroChina (NYSE: PTR) * Photothermal Ratio, light/temperature ratio for a plant * Physical transmission right in the electricity market * Physikalisch-Technische Reichsanstalt, later Physikalisch-Technische Bundesanstalt, a German research institute * Pitrilysin, an enzyme * Planar ternary ring in algebra * Pool Test Reactor, Canada * Proton-transfer-reaction mass spectrometry, used in chemical analysis * PTR rifle, made by PTR Industries, Inc., US * List of DNS record types#PTR, A type of DNS record in computer networking * Pointer_(computer_programming), Pointer in computer programming (e.g. the PTR keyword in x86 assembly language) * Palanivel Thiagarajan, an Indian politician * Puerto Rico, ITU country code * Public Test Realm, a server in ''Overwatch'' where updates are tested by develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Transfer Roller
The particle transfer roller, often abbreviated to PTR, is a device for cleaning film stock, motion picture film. It consists of a cylindrical roller coated with ethyl carbamate, urethane, over which the surface of the film passes. History The particle transfer roller was developed by Eastman Kodak and launched in 1989. It was intended to replace the organic solvents that were the main method of film cleaning before that point. Although their effectiveness is not usually considered sufficient for film laboratory, lab operations, where ultrasonic film cleaner, ultrasonic cleaning with a solvent solution remains the standard, the PTR sold widely for use in projection booths and transfer houses. Use At least two PTRs are needed in the film path – one for the base side and one for the emulsion side – though four are frequently used. A set of PTRs is frequently placed in the film paths of movie projector, projectors, telecine machines, Motion picture film scanner, scanners and Optica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pool Test Reactor
Pool Test Reactor (PTR) was a 10 kWt ordinary (light) water moderated pool-type reactor fueled with highly enriched uranium built at Chalk River in 1957. It used 93% enriched uranium-aluminum plate-type fuel. The reactor, was used for burnup measurement of fissile samples from NRX. The reactor was designed and built by Canadair. History On November 29, 1957 the reactor attained first criticality and shortly took over the function of ZEEP for measuring reactivity effects of materials, particularly after irradiation Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, most often gamma radiation, for a variety of purposes. Irradiators may be used for sterilizing medical and p .... It was shut down and defueled in 1990. External links Atomic Energy of Canada Limited {{authority control Atomic Energy of Canada Limited Nuclear research reactors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puerto Rico
; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territory of the United States under the designation of Commonwealth (U.S. insular area), commonwealth. Located about southeast of Miami, Miami, Florida between the Dominican Republic in the Greater Antilles and the United States Virgin Islands, U.S. Virgin Islands in the Lesser Antilles, it consists of the eponymous main island and numerous smaller islands, including Vieques, Puerto Rico, Vieques, Culebra, Puerto Rico, Culebra, and Isla de Mona, Mona. With approximately 3.2 million Puerto Ricans, residents, it is divided into Municipalities of Puerto Rico, 78 municipalities, of which the most populous is the Capital city, capital municipality of San Juan, Puerto Rico, San Juan, followed by those within the San Juan–Bayamón–Caguas metro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palanivel Thiagarajan
Dr. Palanivel Thiagarajan (PTR) (born 7 March 1966) is an Indian politician and the current Minister of Information Technology and Digital Services of Tamil Nadu. He was elected to the Tamil Nadu Legislative Assembly election in 2016 and 2021 from Madurai Central. Early life He is the son of the late P. T. R. Palanivel Rajan, who was also a well-known politician in Tamil Nadu. His grandfather, P. T. Rajan, was the Chief Minister of Madras Presidency from 4 April 1936, to 24 August 1936. Following his schooling at The Lawrence School, Lovedale, and Vikaasa School, Madurai, Thiagarajan, he graduated with a degree in chemical engineering from the National Institute of Technology, Tiruchirappalli (formerly, Regional Engineering College, Tiruchirappalli). He obtained a master's degree in operations research and a Ph.D. in human factors engineering/engineering psychology at University at Buffalo. He then completed his MBA in financial management at MIT Sloan School of Managemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer (computer Programming)
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as ''dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables, linked lists, and tree structures). In particular, it is often much cheaper in time and space to copy and deref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of DNS Record Types
This list of DNS record types is an overview of resource records (RRs) permissible in zone files of the Domain Name System The Domain Name System (DNS) is a hierarchical and distributed name service that provides a naming system for computers, services, and other resources on the Internet or other Internet Protocol (IP) networks. It associates various information ... (DNS). It also contains pseudo-RRs. Resource records Other types and pseudo-RRs Other types of records simply provide some types of information (for example, an HINFO record gives a description of the type of computer/OS a host uses), or others return data used in experimental features. The "type" field is also used in the protocol for various operations. Obsolete record types Progress has rendered some of the originally defined record-types obsolete. Of the records listed at IANA, some have limited use, for various reasons. Some are marked obsolete in the list, some are for very obscure services, some ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTR Rifle
The PTR rifle is a family of modern, American-manufactured, semi-automatic rifles based on the Heckler & Koch G3 battle rifle. These rifles are produced by PTR Industries, Inc. of Aynor, South Carolina for the law enforcement and civilian markets in the United States. The abbreviation PTR stands for "Precision Target Rifle." History The weapon is based on the Heckler & Koch G3 and HK91 design, which itself is a variant of the Spanish-made CETME rifle. The United States Federal Assault Weapons Ban enacted in 1994, by President Bill Clinton, prohibited certain cosmetic features of the HK91, which meant that the HK91 and its variants could no longer be manufactured and sold to the US civilian market in their original configuration. Furthermore, German-made HK91s were specifically prohibited from importation under an import ban enacted by President George H. W. Bush in 1989. Subsequently, Heckler & Koch ceased manufacture of the semi-automatic G3-variant, the HK91. The PTR-91 was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton-transfer-reaction Mass Spectrometry
Proton-transfer-reaction mass spectrometry (PTR-MS) is an analytical chemistry technique that uses gas phase hydronium ion, hydronium reagent ions which are produced in an ion source. PTR-MS is used for online monitoring of Volatile organic compound, volatile organic compounds (VOCs) in ambient air and was developed in 1995 by scientists at the Institut für Ionenphysik at the University of Innsbruck, Leopold-Franzens University in Innsbruck, Austria. A PTR-MS instrument consists of an ion source that is directly connected to a drift tube (in contrast to Selected ion flow tube mass spectrometry, SIFT-MS no mass filter is interconnected) and an analyzing system (quadrupole mass analyzer or time-of-flight mass spectrometer). Commercially available PTR-MS instruments have a Response time (technology), response time of about 100 ms and reach a detection limit in the single digit Parts-per notation, pptv or even Parts-per notation, ppqv region. Established fields of application are envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planar Ternary Ring
In mathematics, an algebraic structure (R,T) consisting of a non-empty set R and a ternary mapping T \colon R^3 \to R \, may be called a ternary system. A planar ternary ring (PTR) or ternary field is special type of ternary system used by Marshall Hall (mathematician), Marshall Hall to construct projective planes by means of coordinates. A planar ternary ring is not a Ring (mathematics), ring in the traditional sense, but any Field (mathematics), field gives a planar ternary ring where the operation T is defined by T(a,b,c) = ab + c. Thus, we can think of a planar ternary ring as a generalization of a field where the ternary operation takes the place of both addition and multiplication. There is wide variation in the terminology. Planar ternary rings or ternary fields as defined here have been called by other names in the literature, and the term "planar ternary ring" can mean a variant of the system defined here. The term "ternary ring" often means a planar ternary ring, but i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak-to-trough Ratio
Peak-to-trough ratio (PTR), also known as peak-to-trough variation or peak-to-trough fluctuation, is a parameter in pharmacokinetics which is defined as the ratio of Cmax (peak) concentration and Cmin (trough) concentration over a dosing interval for a given drug. A drug with an elimination half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma. ... of 24 hours taken once per day will have a peak-to-trough ratio of approximately 2. Peak-to-trough ratio depends on half-life and dosing interval, with longer half-lives and shorter dosing intervals giving smaller ratios. References Pharmacokinetic metrics {{Pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitrilysin
Pitrilysin (, ''Escherichia coli protease III'', ''protease Pi'', ''proteinase Pi'', ''PTR'', ''Escherichia coli metalloproteinase Pi'') is an enzyme. This enzyme catalyses the following chemical reaction: : Preferential cleavage of -Tyr16- Leu- and -Phe25- Tyr-bonds of oxidized insulin B chain. Also acts on other substrates of less than 7 kDa such as glucagon This enzyme is present in bacteria ''Escherichia coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly fo ...''. References External links * {{Portal bar, Biology, border=no EC 3.4.24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physikalisch-Technische Reichsanstalt
The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of the Federal Republic of Germany, with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under federal government control, without legal capacity, under the auspices of the Federal Ministry for Economic Affairs and Climate Action. Tasks Together with NIST in the USA and the NPL in Great Britain, PTB ranks among the leading metrology institutes in the world. As the National Metrology Institute of Germany, PTB is Germany's highest and only authority in terms of correct and reliable measurements. The Units and Time Act Bundesgesetzblatt (Federal Law Gazette), volume 2008, part I, No. 28, p. 1185 ff., 11 July 2008] assigns all tasks which are related with the realization and dissemination of the units to PTB. All legally relevant aspects regarding the units as well as PTB’s responsibilities have been combined in this Act. Previo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
