PROCESS GAS MIXTURES I For calibrating a process gas c h r o m a - 1 Itography unit, or performing s é p a r a - 1 I t i o n studies on a gas stream in your I I plant. These mixtures can be m a d e to I I match your system in almost all cases. I
STANDARDIZATION. This new integrated computing system jointly developed by Beckman and Scientific Data Systems comes in eight standard models
More Hybrid Computers Become Available
IMatheson is the world's leading supplier of I [high purity gas mixtures. Custom and stockI • mixtures of 95 gases available from mixing! • laboratories in 5 plants. Write for catalog. I
MATHESOIN East Rutherford. N.J. Forest Park. Ga. Joliet. III.. La Porte. Teias. Newark. Calif
Matheson of Canada, Whitby, Ont. •or more —from Matheson
Although more highly developed, they have yet to penetrate chemical application appreciably Hybrid computers, once makeshift combinations of existing analog and digital machines with a custom-engineered hookup, are now coming into their own as a separate branch of computer hardware. The number of such systems available and their sophistication have grown rapidly, with several new entries just introduced at the Spring Joint Computer Conference in Washington, D.C. Following what has become general practice for hybrids, the systems have been developed jointly and are often marketed jointly by an analog company and a digital company. Thus, Beckman (analog) and Scientific Data Systems (digital) have teamed to bring out what they prefer to call an integrated computing system. Packard Bell (digital) and Computer Products, Inc. (analog), have expanded their HYCOMP system to include the former's PB440 with the latter's Mark III. Applied Dynamics (analog) has its 64PBC combined with the PDP-5 from Digital Equipment Corp. (digital). Adage, Inc., is offering the Ambi-
log 200, designed entirely by itself. Visitors to the conference show also had a chance to see the HYDAC 2400, introduced last year by Electronic Associates (analog) and Computer Controls Co. (digital). Applications Expanded. Historically, the hybrid concept came into being seven or eight years ago to meet aerospace industry needs that couldn't be filled adequately by either analog or digital machines. Potential applications have expanded well beyond the aerospace industry and include many in the chemical field in the simulation and design area. However, penetration of the hardware into the chemical industry market has been slight so far, mainly because of cost. Current hybrid systems start at about $100,000, or slightly below, for a basic configuration, and head upward with additional capability. A typical system adequate for a range of chemical needs might run several hundred thousand dollars. However, it should be only a matter of time until hybrids become a recognized computing tool in the chemical
Specify SPECTROQUAUTY
CARBON DISULFIDE U.V. Cut-off 380 m M Evap. Residue Moisture Fluorescence
.0003% max. .05% max. .5 ppb as quinine base max. Used extensively as a solvent for bitumens, fats, gums, rubber, oils, waxes, resins, phosphorus, sulfur and many other substances; transmission characteristics in the NIR and IR make it one of the best solvents known for these regions of the spectrum; water solubility 0.29% @ 20° C; miscible with ethanol, ether, methanol, carbon tetrachloride, chloroform, benzene and oils; dipole moment 0.0D. Comparative tests prove MC&B Spectroquality Solvents are the highest quality most complete line of solvents for spectrophotometry and fluorometry. Write for wall chart showing UV, IR, and NIR transmittance of 40 Spectroquality solvents.
tVKJJB DMthn of Th« Mathvon Co., Inc. Norwood (Cincinnati) O., Boat Rutherford, Ν. Υ.
MAY 4, 1 9 6 4 C&EN
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A MILLION MIXTURES*
Biological Atmospheres For providing a controlled environment while performing culture studies. Matheson is the world's leading supplier of high purity gas mixtures. Custom and stock mixtures of 95 gases available from mixing laboratories in 5 plants. Write for catalog.
East Rutherford, N. J. Fortst Park. Ga.. Jolirt, III., La Porte, Texas, Newark. Calif.
Matheson of Canada, Whitby, Ont. •or more—from Matheson
Specify
spec tra-...
quality p-DIOXANE U.V. Cut-off 215 π\μ Evap. residue Moisture Fluorescence
.0005% max. .05% max. 0.5 ppb as quinine base max. A cyclic ether which, unlike simple alpha tic ethers, is miscible in all proportions with water. It is also completely miscible with most organic solvents. Thus, it uniquely combines the solvent properties of water, alcohol and ethers. An excellent solvent for both mineral and vegetable oils, fats, greases, cellulose acetate and cellulose ethers. On heating it is a good solvent for paraffin and many waxes. The ability to dissolve both water and paraffin makes it an excellent solvent in histological techniques.
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Division of Thê Mêihtton Co., Inc. Norwood (Cincinnati) O., East Rutherford, Ν J.
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industry. The applications are there, waiting for economics to coincide with need. Broadly, hybrids are useful for simulating highly complex physical systems. More specifically, they can find use in such applications as proc ess control system simulation, steadystate tubular reactor calculations, and heat transfer boundary value prob lems. Standardization. The Beckman/SDS system takes a big step in the di rection of standardization and flexibil ity. The California companies—the former of Richmond and the latter of Santa Monica—are offering their in tegrated system in a series of eight standard models made up from one of two Beckman analog computers and any of four SDS digital computers. The interface module is standard. The two Beckman analogs are the Models 2220 and 2230, basically simi lar systems except for control console and computing capacity. The SDS digitals are the Models 910, 920, 930, and 9300. Speed and capability in crease with increasing model number. Both the analog and digital subsys tems are all-solid state, as is the inter face. A software package of programed routines is provided by Beckman and SDS for the hybrid, and the compa nies plan to continue to develop and maintain the software. Among the programs currently available are prob lem definition and analysis, program generation, problem run, problem check-out, hardware maintenance and diagnostics, and display and docu mentation. Languages for problem generation include Meta-Symbol, a macro-assembly program which ac cepts and processes machine-oriented statements, and Real-Time Fortran, a form of the standard Fortran II ori ented toward time-dependent prob lems. The latter incorporates fixedpoint arithmetic procedures. A feature of the Ambilog 200 of Adage, Inc., of Cambridge, Mass., is that it combines analog and digital operation in the computing elements, rather than as independent subsys tems. Main operating section of the system is what is termed the ambilogical section. It includes a group of subsystems involved with analog in put and output, analog-to-digital and digital-to-analog conversion, and hy brid arithmetic. The system control integrates the ambilogical section with a sequential digital core memory and various digital input-output devices.
Rapid Gain Is Prospect For Bridge-Repair Epoxies The use of modified epoxy resins to surface bridge decks and expressway ramps is beginning to gain momen tum. Only slightly more than 2 mil lion lb. of these resins were used last year to coat bridge and expressway traffic lanes. However, the outlook is for rapid gains now that construction crews are becoming proficient in their use. The leading candidate for highway surfacing at present is coal tar-modi fied epoxy resins. Pittsburgh Chemi cal owns the basic compositïbn-ofmatter patent (U.S. 2,765,288) covering coal tar epoxies. The company recently licensed Ciba Products Co., of Fair Lawn, N.J., under its patent estate for the material. Shell Chemical, another licensee of Pitt Chem, has been offering a coal tar-epoxy bridge and highway system under the Guardkote trademark. Other chemical firms are aiming at entering a market for epoxy modifiers in highway surfacing. Neville Chemical, Pittsburgh, Pa., says it has developed a new series of hydrocarbon resins for modifying epoxies. The compounds aren't diluents; it's likely that they react with the epoxy. The company gives no further details, but does admit that it has been testing a number of modified epoxy highway materials for two years. Sales of unmodified epoxy resins soared 2 5 % last year to 88.8 million lb. from 1962's total of 71.1 million lb. Production for the same periods was 94.0 and 78.2 million lb., respectively, according to the U.S. Department of Commerce's Tariff Commission. While highway surfacing accounted for only about 1 million lb. of unmodified epoxies last year, total highway uses may take as much as 10% of sales, according to Jones-Dabney Co., of Louisville, Ky. Uses for epoxies in the burgeoning highway construction market include bonding new concrete to old, filling and sealing cracks, patching, skid-proofing, and bonding traffic buttons and signs to concrete. High-Wear Surfaces. The potential for modified epoxy systems in bridge and expressway surfacing is large. These systems promise to aid highway engineers in combating the problems that plague these high-wear surfaces. The surfaces are subject to numerous freeze and thaw cycles during the Continued on page 59
