In machinery, a rack is a straight or slightly curved bar; with teeth on one of its edges. Adapted to work into the teeth of a wheeled cog (a pinion), for the purpose of converting a circular motion into a rectilinear motion or vice versa. Research Rack And Pinion
Radiation is the emission or transfer of energy by a beam of particles or waves. It includes all electromagnetic waves, beams of elementary particles, ions, etc., and sound waves. In popular usage the the term is particularly applied to the emission of X-rays. However, sunshine is a good example of radiation. Energy from the sun is conveyed as a stream of invisible electromagnetic waves by
radiation, that energy which is absorbed - for example by a person lieing on a beach - is converted into heat, hence it feels warm. Research Radiation
Radio waves consist of magnetic and electrostatic fields at right angles to each other and also at right angles to the direction of travel. Radio communication is carried on by means of this energy that travels from the transmitter to the receiver. These waves move with the velocity of light and represent electrical energy that has escaped into free space. The chief characteristics of a radio wave are the frequency (or wave length) and the intensity. The frequency represents the number of complete cycles of oscillations that the transmitter sends out per second, and so is the frequency of the alternating current producing the wave. The wave length is the distance in space occupied by one complete cycle of oscillation. The wave length Wl in metres and the frequency f in cycles are related by the equation: Wl = 300,000,000 / f where the quantity 300,000,000 is the velocity of light in metres per second. The frequency is ordinarily expressed in kilohertz, abbreviated kHz, or in megahertz, abbreviated Mhz.
A low-frequency wave is seen from the equation to have a long wave length, while a high frequency corresponds to a short wave length. Radio waves differ from other electromagnetic waves, such as light, only in wave length (or frequency). The strength or intensity of a radio wave is measured in terms of the voltage stress produced by the electrostatic field of the wave, and is usually expressed in microvolts stress per meter. The strength in microvolts per metre is also exactly the same voltage that the magnetic flux of the wave induces in a conductor one metre long when sweeping across the conductor with the velocity of light. The minimum field strength required to give satisfactory reception of a radio wave varies with the amount of interference that is present. Under very favourable conditions waves having a strength of less than 1 uv per metre will produce intelligible Signals; Much greater field strengths are generally necessary, however, because of interfering waves generated by man-made and natural sources. Thus in rural areas experience has shown that it normally requires a field strength of the order of 100 uv per metre to give what the listener considers satisfactory service from a broadcast station, whereas in urban locations the man-made interference is so great that field strengths of 500 to 30, 000 uv per metre are ordinarily needed to insure good reception at all times. The strength of the radio wave reaching the receiver from a distant transmitter is affected by a number of factors. Most important of these are the spreading of the wave owing to distance, the absorption of energy by the earth, and the attenuation and refraction of the wave by the action of the ionised regions (ionosphere) of the upper atmosphere.
The effect of the earth and the ionised regions depends very greatly upon the frequency. Thus low-frequency radio waves such as 12 to 100 khz suffer very little attenuation other than that due to spreading, and the received signal strength does not differ greatly from day to night and season to season. In contrast with this, waves of medium wave broadcast frequencies (550 to 1500 khz) have such high attenuation in the daytime that only local stations can be heard, while at night the attenuation is frequently so low that very distant stations produce satisfactory signals.
High-frequency waves, such as those in the range 6 Mhz to 38 Mhz, behave in a still different manner. Here the ground very quickly absorbs the portion of the wave travelling along the earth's surface. Waves of such frequencies may, however, reach a distant point as a result of refraction of energy earthward by the ionised region in the upper atmosphere. Finally, at very high, ultra high and super high frequencies the ground absorbs the portion of the wave travelling along the earth's surface, while the ionised regions are not capable of bending the wave path appreciably. Communication at these frequencies is hence possible only over distances so short that the earth's curvature permits a substantially straight line path between transmitting and receiving points, or between the earth and satellites where the signal follows a straight line straight through the ionised regions of the atmosphere. Research Radio Waves
Radioactivity is the spontaneous disintegration of an atomic nucleus to produce more stable nucleus and accompanied by the emission of charged particles and possibly also gamma rays. Research Radioactivity
A radiometer is an instrument for measuring the mechanical effect of radiant energy. It consists of four crossed arms of very fine glass supported in the centre by a needle-point, and having at the ends thin pith discs blackened on one side. The instrument is placed in a glass vessel exhausted of air and when exposed to light the arms revolve. It was invented by Crookes in 1874 and forms a popular amusement today. Research Radiometer
RAID (Redundant Array of Independent Disks) is a method in computing in which data stored on a hard disk is transparently spread across several disks rather than a single disk.
RAID provides three potential advantages over using simple disks: enhanced speed, increased storage capacity using a single 'virtual' disk rather than several separate disks and a lessened impact of a disk failure. The actual benefits provided depend upon the implementation employed.
The data is stored using techniques such as RAID Level 0 in which the data is stored across two or more disks which appear as a single disk to the user (a technique known as striping), this method providing faster disk access at the risk of losing all data if any one disk drive in the array fails. RAID level 0 is typically used in desktop and workstation computers where high performance is required for non-critical data; RAID level 1 in which the data is stored across two or more disks each holding a copy of the other disk or disks, known as mirroring. In this case, should one disk fail the data can be retrieved from one of the other copies. RAID level 1 provides faster read access to the disks, but at the expense of requiring additional disk drives and slower write access; and RAID level 5 in which data is stored across two or more disks for performance, and also recovery information is written to another disk so that in the event that one disk fails, the data which was stored on the failed disk can be recreated onto a replacement disk at the expense of slower disk writes. RAID level 5 is typically used in file and application servers. RAID level 10 uses four disk drives to create a combination of striping and mirroring, one pair of disks stripe the data across them, the other two disks mirror the first two to provide a backup copy in case of a disk failure. RAID level 10 is typically used in database servers which require both high performance and reliability.
RAID is implemented either by a hardware system, or by software, such as the Intel Matrix Storage Manager. A hardware RAID system comprises a collection of disk which plug into a hostcomputer through a single cable and appear to the operating system as a single disk drive. A software RAID system employs a program that operates on the hostcomputer to present the disks as a single volume. Software RAID controllers are cheaper than hardware controllers, and with the advent of faster processors became more viable. Research RAID
A ram-jet is a jet engine with no compressor, in which air is drawn in and compressed by the forward motion of the engine. It has no moving parts, and is essentially a shaped duct, consisting of an intake section which acts as a compressor by slowing down the entering air, a combustion chamber where fuel is added and burnt, and a nozzle section in which the stream of hot gas is accelerated to give a high-speed exhaust jet. The jet provides propulsive thrust in a manner similar to that of a rocket. The ram-jet has to be launched at high speed, so has found limited application. Research Ram-Jet
RapidFile is ideal for the user who wants a fast file manager with sophisticated capabilities, including a form-letter generator and a good report writer. Since the product tries to load the entire database into RAM, databases of a few thousand records or less run very quickly. Although it has more sophisticated string and math functions it lacks some of the advanced features of Q&A.
RapidFile allows users to design multiple formats for viewing the same data. The format that is active on the screen is the one that will be used to produce reports. Research RapidFile
Raptor is a firewall that provides real-time securiy for computer networks.
Raptor was the first firewall to be recognised s an IPSec-certified VPN server for Windows NT, and was given a perfect score of five out of five by Secure Computing Magazine. However, Raptor is vulnerable to remote attack itself and can be locked up by being sent an unknown IP option in an IPpacket being sent to it. Research Raptor
Raw sienna is a yellow-brown earth colour consisting chiefly of iron oxide and containing smaller amounts of silica, alumina, manganese oxide and calcium carbonate. Raw sienna is found mainly in Italy and Sicily, and gets its name from the Italian town of Sienna. Raw sienna is a somehat transparent, golden yellow pigment. Research Raw Sienna
Rayon is an artificial silk made from cellulose. It was invented around the start of the 20th century, with the first knitwear made from rayon appearing in 1916. Rayon has a high absorbency which allows it to dye well. Research Rayon
Ready, Set, Go! is a powerful desktop publishing program for the Mac with a full-featured built-in word processor. The program uses a flexible grid approach. To create a document, users choose from one of eight standard grids or customize their own. Style sheets to use with any document, automatic chaining of text blocks, and interactive facing pages gives precise control over page composition and enables fast work. Ready, Set, Go! has very strong text-handling capabilities. Its full-featured word processor, similar to MacWrite includes a 100,000 word spelling dictionary a glossary, automatic hyphenation and kerning, and search-and-replace functions. Search-and-replace and make global changes are possible based on font attributes, type styles, and point sizes of up to 255 characters. Ready, Set, Go! can import formatted text files directly from MacWrite, Microsoft Word and other word processing programs. Graphics can be imported in a variety of formats or through the Clipboard. Scaling and sizing is done through a dialog box in
which positions are defined and images sized through measured units. Defining the distance at which text should wrap around an object frame is also possible through the dialog box. The built-in graphic toolbox allows boxes, lines, rules, circles, and ovals to be drawn on a document. Research Ready, Set, Go!
The Realistic DX-100 was a budget priced, low performance American general coverage receiver made between 1981 and 1984 and providing coverage from 550 khz to 30 Mhz in AM, SSB and CW modes. Research Realistic DX-100
A rectifier is a device which converts one or more alternating-current waves into a uniderictional (direct) wave. rectifiers are used in power supplies to convert alternating current (AC) into direct current (DC). Research Rectifier
A red box is an electronic apparatus coupled acoustically to the handset transmitter of a single- slot coin telephone. the device emits signals identical to those tones emitted when coins are deposited. thus, local or toll calls may be placed without the actual deposit of coins. Research Red Box
Red lead is a bright orange-red pigment used in priming paints for both wood and metal. Red lead is prepared by oxidising molten lead until a yellow crust, called massicot, is formed. The massicot is then ground, washed and levigated, and then further roasted until the desired colour is obtained. Red lead is an oxide of lead containing some monoxide of lead which combines readily with an oil or varnish medium when the pigment is mixed, causing the paint to oxidise and as such allowing red lead paint to dry and harden even when not exposed to the air. Research Red Lead
Red oxide is an iron oxide pigment prepared by calcining a yellow iron oxide such as ochre at a high temperature. Red oxide was formerly used as a primer for iron and steel, until it was realised that red oxide does not inhibit rusting, and cheaper grades may stimulate corrosion. Research Red Oxide
In computing, a referrer is the URL of the currently being viewed web page that the browser sends to the web server along with the request for another page when the reader clicks on a hyperlink, or when another file, such as an image, is requested by the page. Research Referrer
Reffy by Acyon is a computer program for the Windows operating-system. Reffy is a referral marketing tool, designed to access multiple web sites passing a user-specified referral string to each one. This process, known variously as viral marketing or referrer spamming, has the objectives of providing links to a specified web site - named in the referral string - through publicly visible web site log files and bringing a specified web site address to the notice of administrators of other web sites - the concept being that vain web site administrators will think that their web site is being linked to by the named referrer, and will visit to try and find their link. The whole process is strongly discouraged by the Internet community and use of Reffy or similar tools frequently results in web sites named in the supplied referral string being blacklisted from search engines and general web sites. Research Reffy
Reflection 1 and Reflection 1 Plus were designed by Hewlett-Packard 3000 experts to turn the IBMPC, XT, AT, or PS/2 into a fully functional HP 3000 workstation by emulating the HP 2392, 2622A, or 2624B (which activates advanced forms processing). They also emulate the DEC VT102 terminal. Both Reflection packages support speeds to 38.4K bps via direct connect. Screen features similar to those of the HP 262x as well as complete block-mode capability for V-3000 are supported. 132- column display is available through horizontal scrolling. Both Reflection packages include a proprietary built-in application programming interface (API), allowing programmers to extend the terminal emulation capabilities of the package by writing DOS applications to existing host programs. Manual terminal emulation commands, such as typing on a PC keyboard, or issuing host commands, can be simulated through API commands. In addition, both packages support Codepage 863, and print to disk capabilities. Reflection supports a type-ahead key buffer so
you do not have to wait for your HP 3000 print spoolings. It includes a complete system for transferring files between the PC and the HP 3000, VAX under VMS, and most UNIX and HPUX systems. Hostresident error checking programs are included as is support for XMODEM, with cyclic redundancy check (CRC), and KERMIT protocols. Reflection 1 Plus included all functions of Reflection 1, and added a function which lets you back up and restore PC files to a file on a VAX running VMS or UNIX. The host file transfer program maintained an internal structure in the backup file to keep track of all the PC files it contains. If something disastrous occurs and you needed to restore one or more files, you could tell Reflection 1 Plus to restore files in all subdirectories as well as the files in the specified directory. By using the command language program to invoke the backup procedure ensures timely, accurate, and automated file backups. Reflection 1 Plus supports LANS such as DEC's LAT, Novell, 3Com, Ungermann-Bass, and LANs that use interrupt 14. Both programs
support multitasking or background mode operation, so you can run DOS applications in the foreground, and hotkey back to your host session. Research Reflection 1
Reflection 2 is a software program designed to turn an IBMPC, XT, AT, or PS/2 into the functional equivalent of DEC's VT52, 102, 220, and 320 terminals. The program shares some benefits offered by other Reflection products, such as background multitasking, and on-screen 132-column display (with supported adapters).
Reflection 2 Plus includes all functions of Reflection 2, and adds a function which lets you back up and restore PC files to a file on a VAX running VMS or UNIX. The host file transfer program maintains an internal structure in the backup file to keep track of all the PC files it contains. If something disastrous occurs and you need to restore one or more files you can tell Reflection 2 Plus to restore files in all subdirectories as well as the files in the specified directory. By using the command language program to invoke the backup procedure; timely, accurate, and automated backups of files can be ensured. Reflection 2 Plus supports LANs, such as DEC's LAT, Novell, 3Com, IBM's PC Network, Ungermann-Bass, and LANs that use interrupt 14. Both Reflection packages include a proprietary built-in application programming interface (API), allowing programmers to extend the terminal emulation capabilities of the package by writing DOS applications to existing host programs. Manual terminal emulation commands, such as typing on a PC keyboard,
or issuing host commands, can be simulated through API commands. In addition, both packages support Codepage 863, DEC SIXEL graphics, and print to disk capabilities. Research Reflection 2
Reflection 4 emulates DEC's VT330/340 ReGIS (Remote Graphics Instruction Set) colour graphics terminals and DEC's VT241 terminal including the Tektronix 4014, and VT52, 100, 220, and 320. Digital's ALL-IN-1, DECgraph, Datatrieve, and Access Technology's 20/20 can make special use of the VT340's capabilities. Features such as 16 colours from a palette of 64, polygon fill, shading with selected patterns, rubber band cursors, rotated and italicised character sets, pixelvector positioning, and mouse support are all included. Reflection 4 includes all emulation and communication features in Reflection 2. It adds emulation of all ReGIS commands on an IBMPC, XT, AT, or PS/2 with an EGA or VGA card and provides a scaled image showing the complete ReGIS screen (800 x 480 pixels) on the physical display (640 x 350 with an EGAmonitor). ReGIS graphs can be captured and saved to PC disk and changed and redisplayed without a host connections and character set storage can be configured. Reflection 4 Plus includes all of the functions
of Reflection 4 and adds a function which lets you back up and restore PC files to a file on a VAX running VMS or UNIX. Research Reflection 4
Reflection 7 is a terminal emulation program for the IBMPC, XT, AT, or PS/2 that enables them to become the functional equivalents of the Hewlett-Packard 2623A monochrome graphics terminal or the HP 2627A colour graphics terminal, as well as providing Tektronix 4010 and DEC VT102 emulations. HP 2627A colour graphics emulation can display graphs in up to eight colours and requires an EGA or VGA display adapter with 256K of video RAM and an EGA or VGA colour display. The HP 2623A monochrome graphics emulation runs with most standard graphics adapters. Colour graphics emulation features include the ability to create graphics text in eight sizes, either upright or slanted. Text can be displayed in any of four directions, and can be left, right, or centre justified. Plotters can be attached through a serial port to support either eavesdrop or pass-through mode.
Reflection 7 supports all the features of Reflection 1. Reflection 7 Plus supports LANs such as DEC' s LAT, Novell, 3Com, Ungermann-Bass, and LANs that support interrupt 14.
Reflection 7 Plus adds a function which lets you back up and restore PC files to a file on a VAX running VMS or UNIX. Both Reflection packages include a proprietary built-in application programming interface (API), allowing programmers to extend the terminal emulation capabilities of the package by writing DOS applications to existing host programs. Manual terminal emulation commands, such as typing on a PC keyboard, or issuing host commands, can be simulated through API commands. In addition, both packages support Codepage 863, and print to disk capabilities. Research Reflection 7
Where as most database products are designed to facilitate the storage and retrieval of data, Reflex was designed for analysing data. It helps to see relationships and trends and is particularly appropriate for analysing survey results. Because Reflex allows the user to create graphs and crosstabs, it was recommended for the executive who must make decisions based on the information stored in the database. Research Reflex
RegSeeker is a free for personal use utility tool for the Windows operating system that includes a powerful registry cleaner. RegSeaker can display various information from the Windows registery including startup entries, several histories and installed applications. With RegSeeker you can search for any item inside your registry, export/delete the results, and open them in the registry.
RegSeeker also includes facility for optimizing the operating system, finding duplicated files, and bad shortcuts. Research RegSeeker
Relativity is a theory concerning the nature of space and time propounded by Einstein. The theory consists of two parts. The special theory states that the speed of light is the same for all observers, whatever their speed. That is that light from an object travels at the same velocity whether the object is moving or stationary. The general theory of relativity relates to gravity. Matter in space is said to cause space to curve so as to set up a gravitational field and gravitation becomes a property of space. Research Relativity
Relay Gold by Microcom is a versatile terminal emulation software package which allows PCs connection to mainframes, information services, or other PCs. It offers a single, universal solution to a variety of connectivity needs through support for asynchronous dial-up, networks such as TYMNET and TELENET, satellite connections, 3270 emulation boards, or through protocol converters via a single user interface. It offers advanced technology for automatic communications and multitasking. Its implementation of the ACT data compression algorithm, licensed from Adaptive Computer Technologies, makes file transfer throughput up to four times faster than the effective speed of your modem, offering up to 9600 bps with a 2400 bpsmodem. You can connect to a mainframe for 3270 emulation over normal phone lines without additional boards or cables.
Relay Gold supports up to 15 simultaneous communications sessions on a PC and lets users send and receive files in background without leaving their foreground application. For example, you can be simultaneously connected to two different computers through a modem and a 3270 emulation board. The script language lets you automate applications such as login, complex data collection, and file transfer between Relay Gold and other applications products. Using IF.THEN..ELSE logic, nesting, and looping,
Relay Gold can handle any contingency and can perform transfer operations unattended. A learn mode captures your keystrokes and creates scripts automatically Pop-up windows make the script language easy to use. Relay Communications also has host component software available which will allow your PC to do 3270 terminal emulation asynchronously, without an emulation adapter. The two programs,
Relay Gold on the PC and Relay (VM, TSO, or 3270) on the host, work together to create a shell on the PC which handles the EBCDIC to ASCII data translation and converts file attributes. This can be a real savings for large users who want neither the expense of emulation adapters or cluster controllers. With the host component installed, users are also guaranteed error-free file transfer between PC and the host. In this environment Relay Gold provides 3278 models 2, 3, 4, and 5 as well as 3279 models 2 and 3 terminal emulations. In addition, Relay Gold supports graphics terminals such as the IBM 3279 models S2G and S3G (fully supporting the IBM 3279 Program Symbol Set), and DEC VT240 (fully supporting ReGIS and SIXEL graphics). Relay Gold provides DFT support for both SNA and non-SNA single- and multisession applications. Research Relay Gold
Remote 2 is a remote-control communications program that lets you control one PC from either a PC or a dumb terminal as if you were at its keyboard. Useful for remote support or diagnostics, Remote 2 supports both remote and local printing and a variety of terminal emulations, including 3270 through an IRMA card. A chat window lets users send messages back and forth while performing support or file transfer functions. Because it does not use a serialization scheme, Remote 2 needs only a single copy of the package to operate. The package includes both the host and support modules necessary to remotely control one PC from another or a dumb terminal. Even though the program was designed around, and works best with, its own host and support modules, it can be used with nearly any communication program, including Crosstalk XVI and Crosstalk Mk 4, to call and operate the hostmodule. Remote 2 has password security protection and callback security and supports modem speeds up to 38,400 bps. The program gives a choice of three
operational modes: manual, where the host accepts a call at the user's request, keeping the keyboards live for troubles hooting and co-computing; restart, where
Remote 2 responds to a call, then reboots and waits for the next call; and always read. where
Remote 2 lets you call in and monitor the program of an ongoing application, make changes, and continue after hanging up. Research Remote 2
Resin is an adhesive and inflammable substance, a compound of carbon, hydrogen and oxygen which is insoluble in water. They are secreted by some plants and animals, and are also produced by the oxidation of carbon compounds such as the terpenes. Research Resin
A retort is a vessel used in the extraction of volatile products by heating. It differs from a still in being employed at a higher temperature, and for actions in which, as a rule, chemical changes occur. In general a retort consists of a chamber to contain the materials to be heated, fitted at the top with a pipe to lead off vapour, and very often a door or hopper for filling. Research Retort
In audio engineering, reverb is an effect used to simulate acoustic space, and consists of both early reflections, and echoes that are so closely spaced that they are perceived as a single decaying sound. Research Reverb
Ricin is a naturally occuring toxicalbumin that can be extracted from the oil expressed from the seeds of the castor oil plant (Ricinus). Ricin exhibits its toxicity by causing the red blood cells in the affected animal to coagulate Research Ricin
RM/COBOL is an implementation of a CSA-certified COBOL that is based on the ANSI 74 standards. It executes on more than 35 operating systems, including PCDOS, MSDOS, TRS-DOS, RM/COS, OASIS, and Unix. The program is used often for accounting applications. RM/COBOL is available on the MC68000, Z80, 6809, Z8000, 8086, 9900, PDPll, LSI-11, and the IBM 30xx, 43xx, and 370 mainframes. A major advantage of RM/COBOL is its ability to develop an application on the mainframe for use on the PC or vice versa. Software developed in RM/COBOL on one system can execute on any
RM/COBOL system. RM/ COBOL supports all standard COBOL file-access methods at the highest ANSI 74 level. Research RM/COBOL
A rocket is a cylindrical case which can be projected as a result of the reaction of gases discharged from its rear when its combustible contents are ignited. Research Rocket
Rogue is a Dungeons-and-Dragons-like game using character graphics, written under BSDUNIX and subsequently ported to other UNIX systems and MS-DOS. The original BSD `curses(3)' screen-handling package was hacked together by Ken Arnold to support `rogue(6)' and has since become one of UNIX's most important and heavily used application libraries. Nethack, Omega, Larn, and an entire subgenre of computerdungeongames all took off from the inspiration provided by `rogue(6)'. Research Rogue
Rosaniline is a base compound of many aniline dyes. It is a basic compound prepared by oxidising a mixture of aniline and toluidine by nitro-benzene in the presence of ferrous chloride. Rosaniline itself is a colourless solid, but if converted into a salt by the addition of an acid, it loses water and becomes coloured. Research Rosaniline
Rosolic acid, methyl-aurine, is a derivative of triphenyl-methane, corresponding to rosaniline, but with the amido groups of that compound replaced by hydroxyl groups. It is used as an indicator in acidimetry and sometimes as a dye. Research Rosolic Acid
Rottenstone is a mild abrasive in the form of a very finely powdered soft yellowstone used in the hand polishing of varnished work. Linseed oil is generally used as a lubricant for the rottenstone. Research Rottenstone
Rouge or colcothar, is ferric oxide obtained by calcining iron sulphate. It is a fine, deep-red powder used as a polishing agent for glass and metals. Research Rouge
Rubber is a gummy substance exuded by a wide variety of trees and plants, especially the trees Hevea brasiliensis, and several other species of Hevea which grow in the East Indies, particularly the Malaypeninsula, and other parts of the world. Rubber is also obtained from the large tree Castilla elastica, found in Mexico. So-called dandelion rubber is derived from the roots of various species of dandelion plant Taraxacuin, chiefly Kok sagyz, etc., grown in Turkestan.
Rubber trees are tapped and the latex, a milk-like juice, containing about 30-40% rubber, is coagulated by exposing it to heat and wood smoke, or by mechanical means, so as to separate the
rubber from the water, mineral salts, sugars, resins, and protein matters. The rubber obtained in this way is known as 'crude'. Latex is also extensively used in industry for making foam rubber products, footwear, dolls, etc.
Untreated crude rubber is naturally soft and lacks the requisite strength for making into manufactured articles. To improve its strength and usefulness it is vulcanised or heated with sulphur, the proportion of sulphur used determining the hardness and elasticity of the rubber. Fillers such as carbon black or channel black are also vital constituents of rubber, particularly tyre rubber. About 75% of the rubber produced goes into the manufacture of tyres, the remainder being utilised for cable sheathing, wire covering, footwear, flooring, proofing of clothing, togs, upholstery material, hose, etc. Latest developments include bullet-proof tyres, non-tear rubber for fuel tanks, flame-proof hose, suits for frogmen. Research Rubber
Rubidium is a metallic element, symbol Rb. It is one of the alkali metals in group 1 of the periodic table. It was discovered spectroscopically in 1860 by the German chemistRobert Bunsen and the German physicist Gustav Kirchhoff, who named the element after the red lines in its spectrum. Metallic rubidium is silver-white and very soft. After caesium, it is the most active of the alkali metals. It tarnishes immediately upon exposure to air and ignites spontaneously to form rubidium oxide. It reacts violently with water. In general chemical behaviour, rubidium resembles the alkali metals, sodium and potassium. It is a widely distributed element, ranking 23d in order of abundance of the elements in the crust of the earth. It is not found in large deposits but occurs in small amounts in certain mineral waters and in many minerals usually associated with other alkali metals. It is also found in small quantities in tea, coffee, tobacco, and other plants, and trace quantities of the element may be required by living organisms.
Rubidium is used in making certain catalysts and in photoelectric cells. The rate of radioactive decay of the isotope rubidium-87 can be used in geologic age determination. Research Rubidium
Rust is the product of the corrosion of iron or steel, due largely to electrolytic action. Rust consists mainly of hydrated ferric oxide with some basic ferrous or ferric carbonates also present. Research Rust
Ruthenium is a metal element of the platinum group of elements, occurring in the Urals and Americas. It is a hard, brittle, grey metal that forms ruthenious and ruthenic salts, of a reddish brown colour, of which ruthenious chloride gives a characteristic fine black precipitate with water.
Ruthenium has the symbolRu. Research Ruthenium
Abbreviations
SciTech
Research Rabbet
