Books SUB MICRON PARTICLE SIZE A N A L Y S I S DOWN TO 0.01 MICRON IT'S SIMPLE WITH A JOYCE-LOEBL DISC CENTRIFUGE 3 Benefit from the wealth of experience established in our application's laboratory in analysing a w i d e spectrum of particulate materials. The results are summarised in a free booklet 'APPLICATION REPORTS' covering the f o l l o w i n g major end-user groups: * Polymer Emulsions * Inks and Pigments * Titanium Dioxide
* Magnetic Iron Oxide * Carbon Black * A n d many others
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Vickers Instruments Inc.
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JOYCE LOEBL
Wobum v"* Massachusetts 0 1 8 0 1 ^ U.S.A.*'" >^
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Valco Zero Dead Volume Chromatography Fittings Wide variety of metals and d e s i g n · Valco's sophisticated machining techniques make possible manufacturing of special fitting designs in virtually all materials. No "swaging" or "biting" Valco fittings do not swage or bite into the tube. There is no reliance on crimping or necking at the bore. Operating pressures exceed 10,000 psi Valco fittings are designed for close tolerance heavy wall tube and can operate at pressures in excess of 10,000 psi, however, their unique design also makes them ideal for vacuum applications. Competitive prices Call Valco for your chromatography fitting needs — you'll be pleased with the prices, selection and delivery.
VALCO instruments co P O Box 19032 Houston. Tx 77024 713-688-9345 rWX: 910-881-5500 Telex 79-0033
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ANALYTICAL CHEMISTRY,
V O L . 5 0 , NO.
1 1 , SEPTEMBER
1978
sumptions are made about the reader's background. It is in effect, a primer to volume I. "Volume 0, The Beginner's Book" has only six chapters and is highly illustrated. Complementing the diagrams and illustrations, the textual material makes abrupt changes to boldface type for a phrase, sentence, or group of sentences to highlight an important thought. The first chapter describes the parts of a microcomputer system beginning with chips, then cards, and finally system. A discussion of the most common peripherals follows, including keyboards, printers, video display units (VDU), and floppy disk drives. A good discussion of diskette systems is given, leading into random access, physical and logical records, and records vs. files. Chapter 2 introduces Joe Bitburger, a character the novice will have no trouble identifying with. A scenario develops in which Joe purchases a microcomputer kit and quickly learns further hardware must be added to make the system functional. Concepts covered in chapter 2 include machine language programming and debugging from an operations point of view. At this point, Joe Bitburger disappears, and the author lapses into a less colorful style of prose which is technically very sound. Chapter 3 does an excellent job of describing the I/O functions desired, options possible, and the logical to physical translation. Included in this chapter is a fine overview of device drivers. With the first three chapters behind the reader, chapter 4 gets down to some fundamental concepts that, although dry, must be covered. Topics included are numbering systems, binary arithmetic, number conversions, ASCII character coding, Boolean operations, flags, and logical operators. Chapter 5 begins with programming languages. Comparisons are made between assemblers, compilers, and interpreters. This is followed by the standard modular description of a computer system on a functional basis. The informational paths within a system are shown as the logical steps of a single instruction (ADD) are carried out. This smoothly leads into the idea of an instruction set, program and data storage, and the program event sequence. Chapter 6 is the last, attempting to tie all the elements together to a coherent conclusion. Relatively difficult concepts for the novice are covered here such as double words, busses, timing diagrams, and the tight interaction between the ALU, control unit,
