Document jmavOwbL9052QY0MXZ8yeaRYR

Unfortunately, a knowledge of surface temperature is in itself not sufficient to predict die relative safe* ty or hazard of human contact with a heated surface. It is well known, for example, that a metal surface is more likely to cause bums through its heat flow than a plastic surface, though both are of the same elevated temperature. Therefore there has been a need for a definitive instrument to mea sure and indicate the temperature, that would be experienced by sc one in contact with a heated face. Louis A. Marzetta, an electronics engineer with the National Bu sau of Standards has recently develc ?ed such a device, called a "therme he* siometerwhich consists of a c lindrical measuring probe similar o a human finger. The probe is con nected to an electronic unit that gives a digital reading of the co tact temperature in degrees C. The end of the probe, design d to be pressed against the heatec test surface, is made of silicone ru her; this material is resilient, as is h man tissue; and its thermal prop rties also are close to those of huma i tis sue. A heated wire, wound arour i an inner core tube keeps the prol s as sembly at 33 C--the temperatv e of a finger, and a resistance then 10meter transducer inside the core tube acts as the heat sensor. Obviously, damage to tissue rom a heated surface is a functior not only of the surface temperature but abo the length of time the tiss e is in contact with the surface. To duplicate this time factor, the i lermesthesiometer contains an ad istable circuit that allows meas re inents for contact periods of I, 2, 4, or 8 seconds. The measuring time is started automatically upon thermal contact, and `'frozen" at the interval end. Although no instrument maker, as yet, manufactures the thermesthesiometer, NBS officials report, a mar ket potential exists for it. This mar ket should develop quickly if the unit is used by the Consumer Prod uct fhf.n III.... rnnn m n huir Sr safety criteria and regulation. Q keeping a sharp lookout on vinyl chloride South Nohwaix, Conn.--Six months ago the New Year entered with a host of problems--most of which were expected. But one parti cular problem not only was unex pected, but was deadly also. In January, offidab at B.F. Good rich Chemical Co.'s Louisville, Ky. plant reported that four workers had died of an extremely rare liver cancer, angiosarcoma. All had been involved in the plant's main activity: converting vinyl chloride monomer to polyvinyl chloride--the industrial chemical widely used in plastic pipes, floor tiles, phonograph re cords, and countless other products. Then, in February, the company lost two more workers, again from angiosarcoma, bringing the total to six. Previously, the nationwide occurance was thought to be less than 30 cases a year. Thus, such regulatory agencies as the National Institute of Occupa tional Safety & Health (NIOSH) and the Occupational Safety A Health Administration (OSHA) quickly rushed into the picture. po/ntin our a hevAway to jmmove burn safety finger-like temperature instrument puts blame on faulty design# as did the employes' unions, and many of the 23 U.S. VCM/PVC manufacturers, who employ some 6,500 persons at 37 plants. Much of the resulting debate cen tered around the limits set for safety. The previous level bad been 500 ppm vinyl chloride in the atmos phere. Union offidab urged an im mediate 95% emergency reduction to 50 ppm. Several firms, however, argued that more time should be taken to investigate the problem and that controb should be set by ordi nary (and sometimes lengthy) rulemaking procedures. Nonetheless, under strong union pressure, NIOSH urged the Labor Dept to quickly issue rules requir ing a "closed system" for VCM manufacture and processing, envi ronment monitoring around VCM/ PVC plants, as well as periodic em ploye medical tests. These proposals, however, included no mention of safe exposure limits. Terre Haute, Ind.--A tank car con taining the controversial chemical vinyl chloride overturned here last March 17, allowing vapors to es cape through a 15 x 31-cm open ing. The tank car, owned by the Pennsylvania Central Railroad, was lined with lead wool and "Neo prene," and It was thought that none of the liquid escaped. Nevertheless, residents were evacuated over a 15-block area as a "precautionary" measure, reports the Smlthsonafn Institution Center for Short-Lived Phenomena (Cam bridge, Mass.). The residents were allowed to return to their homes the following day. To their credit, B. F. Goodrich voluntarily limited their safe level to less than 50 ppm, as did several other manufacturers. (As of this writing, laboratory mice and rats have developed angiosarcoma from breathing VCM vapors in varying amounts from 200 to 2,500 ppm, but not yet at 50 ppm. Dr. Cesare Maltoni of the Instituto Di Oncologia, Bologna, Italy, is concentrating now on that 50-ppm level in MCAsponsored tests.) Not all firms were as concerned as B. F. Goodrich and others, who voluntarily limited exposure leveb. In a March 1974 survey of five VCM and two PVC plants in the New Orleans-Baton Rouge, La., area, OSHA judged control measures to be "inadequate," and that actual exposure to the chemicals was gen erally unknown. Finally, in mid-April, OSHA pub lished in die Federal Register an emergency temporary ceiling of 50 47IHDUSTflUl. MSCAnCH--^AJNf 1174 RSV 0006570 Whenyou need clean vacuum and high reliability Airco Temescal's new Model 514 Turbomolecular Pump, with its 6-inch ASA flange, fits right on the vacuum chamber. It weighs less than 60 pounds and operates smoothly and quietly at 24,000 RPM. There is no horizontal- or vertical-axis pump of this size, domestic or imported, that can compare for particle accelerator, vacuum deposition or sputtering appli cations. Model 514 is a fitting counterpart to the Model 614 S.N.E.C.M.A. turbomolecular pump intro duced by Airco Temescal in 1971. Check these facts: 500 L/S (air) pumping speed. Ultra-clean. No measurable hydrocarbon backstreaming. 14 stages for maximum compression ratio of all gases. Low ultimate of 2 x 10-9 torr. Vertical axis, 7%-inch I.D. inlet port. Direct replace ment for 6-inch diffusion pumps. Small size...only 11% inches high. No baffles or LN2 traps required No belts, refrigeration, gears or rotating shaft seals. The Model 514 Turbomolecular pump has the relia bility that only a superiorvertical-axis pump can offer. Don't put up with contaminated chambers any longer. Write or call for details today. AlRCtTTemescal mA Division of Airco, Inc. 2BS0 Seventh Street Berkeley. Ca. 94710 Telephone: (-115) 34t-5720 RSV 0006571 ppm affecting all companies mairing the monomer or polymerizing it And the permanent standard, it has been rumored, may be set as low as 1 ppm. To measure the actual concentra tion, NIOSH has reportedly urged OSHA to require usage of a gas chromatograph coupled with a sam ple-collecting tube. Industry spokes men, however, have criticized that method as being expensive and not providing real-time analysis. There are other techniques, it should be noted, that may be better suited for VCM monitoring. One of these is infrared spectroscopy. Officials at Wilks Scientific Co. Close WATCH ON VINT1 CHlOKfDf infrared gas analyzer detects at 1 ppm here discussed with Industrial Re search how typical low-level VCM monitoring can be handled with IR techniques. Says Terry F. Sinclair, "Vinyl chloride concentrations less than 100 ppm can be analyzed easily using our `MIRAN I' Portable Gas Analyzer. This is a single-beam spectrometer equipped with a unique variable-pathlength gas cell. The vinyl chloride absorption bands at 6.15, 9.8, 10.9, and 13.9 j>m are considered in quantitative analysis, and minimum detectable concentra tions are usually found to be less than 1 ppm." The choice of bands depends upon other chemicals present, as some 20 different chemicals are com monly found in VCM use or proces sing. Thus, if the environment con tains ethylene, Freon-11, perchloroethylene, and vinylidine chloride, in addition to vinyl chloride, the 13.9 Mm band will be found free from interference. Says Sinclair, "A major strength of the IR method is that, should there be interference from extran eous chemicals (such as Freon-113, which interferes slightly at 13.9 Mm), it would still be safe to do the analysis. Concentrations m excess of the ceiling limit will always give ab sorbances above the limit value, and once the contaminant is known, it is relatively easy to subtract its spec trum." Infrared gas spectroscopy is suit able, for area (atmosphere) surveys, leak detection, and general VCM compliance testing. In addition there are systems available to monitor 6, 12, 24, or more remote points, such as the MIRAN II, which can handle samples from distances approaching 60 meters (200 ft). Life on Mai lay be ui lerground MSMuKDO ^tation, Antahtica-- A r^entdiscovery that 10,000-year old frazfti bacteria can be thawed out jsftnrevived may have important impucatimis in the search for life on Mars. This concision is based on re search performed by a U.S.-Japan- New Zealand drilling team studying the frozen continents geologic his tory. The team members, being con cerned about the fragile antaitic en vironment, routinely Vnade checks that no microorganisms from the drilling team ended up irathe rocks. Biologists in the project took samples of deep rode cores drilled \p, and added them to nutirient solutions de signed to encourage bacteria gr\wth. A solution prepared with rl drilled from a 120-meter depth hire showed obvious signs of bacteria life. Frank Morelli of the Jet pulsion Laboratory (Pasadena, Cal.] and the Darwin Research Instit of Dana Point, Cal, initially pected that the bacteria represented the type of contamination th/R pro ject scientists were trying Jp avoid. However, checks made Ai micro organisms around the AuiUing site and laboratory showedrthe cultured bacteria from the cores were not from these sources. Morelli then ran four extra checks on the cores, each time producing the same unidentified bacteria. Then, deeper cores from the same site produced slightly different bacteria strains--also unidentified-- and cores collected by Morelli's colleague, Roy Cameron, from >ther site 96-km away produced cultured bacteria colonies that act ual^ reproduced. two scientists were thus forcedkto conclude that the bacteria were native to the cores, which are datra geologically as being be tween V),000 awK'' 1,000,000 years old. y*lainl^^ne microorgan isms had sutviuro in a freeze-dried form in theVfocks all these years, and hadbeen revived by warmth^nd tHe nutrient solution. lg the rketors that kept the baepfea alive foXthousands of years Iger than any creatures previously lentified, suggests^ Cameron, were their small size andViigh concentra tion, and the low smperature of the ice-pocked antarok rocks. Cameron and MoreJL point out that their discovery hn important implications in the searenuor life on other planets, especially Mars, which in some ways resembles Aitartica. If the Viking mission, designed to land instruments on the reAplanet in 1976, fails to detect life mi the surface, Cameron notes, scientists may well speculate that "the surface permafrost of that planet may kolc the key to ancient--and living--bfa deep within it" materials' depositing a heap, superhard ating Los Angeles A new material has been discowred that is second in hardness only to diamond--and it can be Vroduced relatively easily and cheaply. Tciw superhard material is made of titanium carbide, formed in thin lajrers through vapor deposition. De- ribed as "easily the most startling 'material development in recent years," the new titanium carbide material promises to have a wide range of uses in cutting, grinding, id wear-resistant applications. Dr. Rointan F. Bunshah, inventor orathe material and a UCLA engi neering professor, believes that titaniim carbide can be produced at one-hundredth to one-thousandth the cost of various commercial grades oXsynthetic diamonds. In the forming process, titanium metal atomV are vaporized by an electric beam\n a vacuum chamber. A hydrocarboi^as is then injected into the chamber and the reaction forms titanium caahide. The newly-formeW vapor is then condensed and deponed at desired rates and degrees of hardness. De- Clrcla 147 on inquiry curd or dlHor-qu (Ira#): #00/821-0580 INDUSTRIAL RESEARCH--JUNE H74 A9 RSV 0006572 CAMBRIDGE SCIENCE PARK ENGLAND Landscaped Low density Light industrial development For advanced technology in leading scientific area A SCHEME BY TRINITY COLLEGE (The College of Newton Maxwell Rayleigh JJ Thomson Rutherford Bragg and many distinguished living scientists) Letting agents: B1DWELLS chartered surveyors Trumpington Road Cambridge CB2 2LD-England Telephone*. Trumpington (022 021)3391 diCMircoler-data (fnraian)q:uSirOyOc/6a2r1d-OoSSr Q 50 INDUSTRIAL RESEARCH--JUNE 174 pending on need, it can be deposited as a powder or a coating, and the deposition rate can be varied from 1,000 to 250,000 A per minute. In future research. Dr. Bunshah reports he will be seeking ways to tailor-make titanium carbide coatings for specific applications by varying the compound's composition and mi* crostructure. O new process synthesizes ferrichrome Toxyo--A method to artificially mass produce ferrichrome, chemically identified as C27H42Ol3N,Fe, has been developed here at the Sagami Chemical Research Center. The private institute said the syn thesizing method could be widely applied to such areas as the fermen tation industries, pharmaceuticals, petroleum protein feeds, and so on. With only the few milligrams of ferrichrome previously extractable from a 20-liter solution of iron bac teria, production costs had been pro hibitive. But now the institute says the synthetic costs are no more than IS of that of natural ferrichrome. Formation of the chemical is ac complished by first creating a hexapeptide in a straight molecular chain of two known kinds of amino acids, then turning the chain into a circle and adding iron trichloride. O body armor jacket: true long-life material Los Angeles--If someone stepped up to within a few inches of you with a .38 caliber revolver pointed at your chest and pulled the trigger, you'd be a goner. Not, however, if you were wearing a new bulletproof vest being studied for the Justice Dept, by Aerospace Corp, As an agency official recently told a re porter, the new body armor gives promise of being the "ultimate jacket." The new protective material is not made of steel or some other heavy, burdensome substance, but a lightweight synthetic fiber called "Kevlar." Kevlar, developed by Du Pont, was worked on for five years before it was released for commer cial studies under the Kevlar trade mark. Major interest by industry has been the material's potential for tire cord. Goodyear, for example, is us ing it under the trade name MExten.M The grade used for Exten is Kev lar 49. The fiber, which has a fila ment diameter of 0.001 cm, has a tensile strength of 3,620 n/m: (oio,000 psi), elongation to break of 2.75%, and density of 1.45 g/cm3. The body armor material primarily differs from the tire cord grade in having an elongation to break per centage greater than for Kevlar 49. Studies of the body armor are be ing sponsored not only by the Jus tice Dept.'s National Institute of Law Enforcement and Criminal Justice, but by the Army. Experi ments at Aerospace are being per formed under contracts to both agencies. Much of the effort is aimed at establishing scientific baselines for the new systems. Questions hopefully to be an swered by ballistics tests and scan ning electron microscope examina tion of fiber breakage include dis covering the energy dissipation properties involved, the interaction between the deformed armor and underlying body tissue, and the ef fects on both of these by variations in the material system. From data collected from studies like that at Aerospace, government agencies hope to gain feedback into improving basic armor design. This might include changes in the weav ing process to minimize the size of cavities formed after projectile im pact and the proper arrangement of garment layers. For instance, con siderations include whether a large number of thin layers or fewer num bers of thick layers should be used and whether these layers should be loose or closely tied together. As Justice Dept, officials pointed out, the low density of Kevlar can permit making high-strength jackets weighing only 1.5 times normal ones. Possible uses range from socks to snap-in coat liners. ''What are you going to call this new thing you've invented, Aweat?" RSV 0006573