Random access

Because the preferred y carboxyl is more sterically accessible, random carbodiimide activation of folic acid usually yields a 70 30 ratio of y carboxyl a carboxyl-derivatized protein. 

There are two types of memory in most contputers random access memory (RAM) and read-only memory (ROM). The term random access is somewhiil misleading, because ROM may also be accessed randomly. Riindom access means that all locations in the memory are equally accessible and can be reached at about the same speed. Thus, read-write memory is a more... 

Nonvolatile vs volatile Nonerasable vs erasable Speed of access Access time Memory cycle time Transfer rate Capacity Word size Number of words Method of access Random Sequential Direct Associative Organization... 

A typical transputer architecture. The transputer (sometimes referred to as a computer on a chip) has four input/output links (0, 1, 2, 3) to other transputers, a channel for inputting/requesting data (event link), some built-in random-access memory, an interface to the main operating system (clock, boot, etc.), and an external memory interface. Internal communication is via a bus. 

The memory units within the computer — known as random access memory (RAM) — must be capable of change as needed to run software programs. 

Ranceite Rancidity Rancimat system Random access memory Random copolymer Random copolymers... 

Main memories almost exclusively consist of semiconductors on a siUcon basis in complementary metal oxide semiconductor technology (CMOS). The most important types are the pure read only memory (ROM) and the write/read memory (RAM = random access memory), which is available as S-RAM (static RAM) or as D-RAM (dynamic RAM). 

Clinical analyzers can also be classified according to their degree of flexibiUty. Most of the modern systems are random access analyzers, for which the tests on various specimens are performed in any order programmed by the operator. Some analyzers operate in batch or profile mode, ie, they perform the same test or group of tests on every sample until the system is reset for another test or group of tests. 

The stmcture of activated carbon is best described as a twisted network of defective carbon layer planes, cross-linked by aHphatic bridging groups (6). X-ray diffraction patterns of activated carbon reveal that it is nongraphitic, remaining amorphous because the randomly cross-linked network inhibits reordering of the stmcture even when heated to 3000°C (7). This property of activated carbon contributes to its most unique feature, namely, the highly developed and accessible internal pore stmcture. The surface area, dimensions, and distribution of the pores depend on the precursor and on the conditions of carbonization and activation. Pore sizes are classified (8) by the International Union of Pure and AppHed Chemistry (lUPAC) as micropores (pore width <2 nm), mesopores (pore width 2—50 nm), and macropores (pore width >50 nm) (see Adsorption). 

An alternative method, proposed by Andersen [23], shows that the coupling to the heat bath is represented by stochastic impulsive forces that act occasionally on randomly selected particles. Between stochastic collisions, the system evolves at constant energy according to the normal Newtonian laws of motion. The stochastic collisions ensure that all accessible constant-energy shells are visited according to their Boltzmann weight and therefore yield a canonical ensemble. 

A copy (5V4 inch floppy disk) of a menu-driven computer program to calculate Gibbs free energy of formation and change in Gibbs free energy for reactions (including random access data file of compound coefficients) is available for a nominal fee. For details, contact C. L. Yaws, Dept, of Chem. Eng. Lamar University, P.O. Box 10053, Beaumont, Texas 77710, USA. 

Today, dynamic random-access memories (DRAMs) are transistor/capacitor-based semiconductor devices, with access times measured in nanoseconds and very low costs. Core memories were made of magnetic rings not less than a millimetre in diameter, so that a megabyte of memory would have occupied square metres, while a corresponding DRAM would occupy a few square millimetres. Another version of a DRAM is the read-only memory (ROM), essential for the operation of any computer, and unalterable from the day it is manufactured. We see that developments in magnetic memories involved dramatic reductions in cost and... 

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