THE CHEMICAL WORLD THIS WEEK C&EN REPORTS: American C o n c r e t e I n s t i t u t e , Annual Convention
Electric Current a n d Vacuum Speed Curing of Concrete Further research urged deterioration CIN C I N N ATI.—Gathered in Cincinnati last week for their 48th annual convention, members of the American Concrete Institute took time out from technical discussions to honor one of their n u m b e r with a special "Harvey Whipple L u n c h e o n / ' W h i p p l e retired March 1, after more than 32 years of service as ACI secretarytreasurer; during those years h e played a major role in promoting t h e Institute's o b jectives in correlating a n d disseminating information for the improvement of concrete products and structures. In technical sessions, interest centered upon means of increasing the speed of curing concrete for construction projects, and on increasing its longevity in service. Vacuum processing of newly p l a c e d concrete, a development which has m a d e considerable progress abroad, was described by K. P. Billner of Vacuum Concrete Corp. In this process specially designed v a c u u m mats remove the excess mixing w a t e r from
\m Jaboratery curiosity
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longer in the laboratory
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of s c i e n t i f i c c u r i o s i t y , L i t h i u m h a s achieved t h e status of a new i n d u s t r y t h r o u g h t h e medium of a p p l i e d r e s e a r c h . L i t h i u m ' s commercial significance emb r a c e s field after field. T h e a m a z i n g i n crease in usage of Lithium a n d L i t h i u m c h e m i c a l s h a s been p o s s i b l e l a r g e l y t h r o u g h t h e extensive d e v e l o p m e n t w o r k of Metalloy C o r p o r a t i o n , basic t o this f a s t - g r o w i n g industry. L O O K T O M E T A L L O Y — S u p p l i e r of 7 Forms o f Lithium M e t a l — 1 7 Lithium C o m p o u n d s Supplied experimentally or commercially . . . Metal— Ingot-Cup-Shot-Rod-Wire-Ribbon-Cartridge
COMPOUNDS Aluminate-Amide-Borate- BromideCcirbonafe-Chloride-Cobaltite-Fluoride-Hydride-Hydroxide-ManganifeNitrafo - Nitride - Silicate - Titanote Zirconale-Zirconium Silicate
If It's UTHIUM—ll's METALLOYI W r i t e Dept. A f o r D a t a Sheets
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METALLOY CORP., Division |
causes of
Rand T o w e r • .. Minneapolis 2 , Minnesota'. ;-
concrete
concrete a n d induce early hardening; forms can b e removed early a n d cast members can b e handled several hours earlier tin an is possible with ordinary concreting methods. V a c u u m lifters, used in t h e construction of reservoirs, canal linings, largediameter pipes, and apartment-building components, eliminate t h e necessity for lifting-eyes or bolts in cast slabs or panels. Electric current is utilized in J a p a n to shorten t h e curing period, according to Chuzo Itakura of Hokkaido University. In t h e severe climate of Hokkaido, h e reported, winter construction has b e e n exp e d i t e d b y the use of electrodes placed on the surface of, or e m b e d d e d in, t h e fresh concrete. Cost of curing w a s said to be from 7 to 1 0 % of construction cost for plain concrete, and from 10 to 1 5 % for reinforced concrete. An analysis of causes of concrete deterioration, essential to t h e development of methods for increasing durability, was
C & E N REPORTS:
ONCE
NO
on
recommended by C. B. Porter of t h e Chesapeake & Ohio Railway. A survey of concrete structures in railroad systems, Mr. Porter said, revealed that the primary causes of deterioration are a n excess of mixing water in the concrete, deleterious aggregates which cause pop-outs, excess seepage of water from embankments, a n d volume changes caused b y shrinkage. Mr. Porter outlined a P u r d u e University r e search program sponsored by the American Association of Railroads, for the d e velopment of acceptance standards for waterproof paints and bituminous coatings for concrete structures. T h e role of air entrainment in improving the durability of concrete pavements, said Frank H. Jackson of the National Bureau of Public Roads, is a n important b u t not an all-inclusive one. Air entrainment greatly increases resistance to freezing and thawing, Mr. Jackson said, b u t a s presently applied in practice it is not t h e fïna) answer to salt scaling of pavements—particularly in the northern states where large quantities of r a w salt are used to melt ice quickly. At the business session of t h e meeting, A. T. Goldb^ck, engineering director of t h e N a t i o n a l ^ C r u s h e d Stone Association, was elected ACI president for the coming year. C. H . Scholer of Kansas State College was elected for a two-year term as vice president.
M e t r o p o l i t a n M i c r o c h e m i c a l S o c i e t y , Annual
Symposium
Sensitivity Limits W i d e n e d By Microchemists' N e w Tools Microanalysis has become today a practical tool used even by untrained workers N K W YORK.—Development of modern instruments and equipment in microchemistry, fluorometric analysis, infrared absorption, and quantitative ultramicrochemistry, were some of t h e discussions which highlighted t h e seventh annual microchemical symposium of the Metropolitan Microchemical Society h e r e at F o r d h a m University F e b . 29 to M a r c h 1. Development of Microanalysis. Two comparatively recent events which have led t o the development of a better international understanding of all fields of microchemistry, said H e r b e r t K. Alber, director of research at Arthur H. Thomas Co., was the first International Microchemical Congress at Graz, Austria, in 1950, a n d t h e W o r l d Chemical Conclave held in N e w York last September. Alber showed t h a t microanalysis is no longer a difficult art understood b y com-
CHEMICAL
paratively few persons, but on t h e contrary has become today a practical tool used even by untrained workers. T h e experience of the speaker was drawn upon to illustrate t h e development of microanalysis in various fields. Included in his discussion were water baths; stirring b y electromagnetic forces; micro-combustion equipment, with a n d without automatic features; micro-melting point determinations on hot stages; and various other instruments w h i c h enter into t h e daily work of the microanalyst. Fluor o m e t r y . Present techniques in employing inorganic fluorometric analysis were described by Charles E. White, professor of inorganic chemistry at t h e University of Maryland. Demonstrating his talk with all of the equipment a n d fluorescing solutions required, Prof. White proceeded to illustrate t h e methods employed
AND
ENGINEERING
NEWS
for t h e determination of various elements through fiuorometric analysis. I n t h e following determinations water was employed: aluminum with Pontachrome Blue Black R dye and morin; zir conium w i t h flavanol; and beryllium w i t h l-arnino-4 hydroxyanthraquinone. Chloro form extracts w e r e used w i t h 8-hydroxyquinoline complexes of aluminum, gallium, and indium, a n d alcohol was t h e solvent medium in d i e determination of boron with benzoin, a n d lithium with 8-hydroxyquinoline. I n t h e qualitative determina tion of zinc t h e importance of secondary reagents was m a d e apparent. UV Photometry· T h e application of t h e ultraviolet region of t h e spectrum t o photo metric titrations h a s not b e e n reported, Glark E . Bricker, associate professor of chemistry a t Princeton University d e clared. By an inexpensive adaptation of the Beckman D U spectrophotometer, photometric e n d points i n t h e region of 225 to 4 0 0 millimicrons can b e readily o b tained, h e said. Dr. Bricker took u p photo metric titrations in some detail, outiining the advantages a n d disadvantages of t h e method. Ultramicrochemiccl Methods. T h e growing demands o n ultramicrochemical methods b y clinical chemistry, were e m phasized b y Albert E . Sobel, adjunct p r o fessor a t Polytechnic Institute of Brooklyn. It h a s developed to t h e point, h e stated, where a s m a n y as 1 5 to 3 0 quantitative determinations a r e desirable for a single specimen of blood as an aid in t h e diag nosis a n d treatment of a patient. H e w e n t on to discuss t h e general principles of ultramicro methods a n d t h e instrumenta tion utilized. A modification of t h e Gilmont ultramicroburet, which has a sensitivity of a p proximately 10" θ milliliters or 10 3 cubic microns, was described b y Roger Gilmont, technical director of Emil Greiner Co. T h e development was in connection with a spe cial biochemical study which called for the injection of extremely small volumes of fluid into single muscle fibers. D r . Gilmont indicated t h a t the order of sensitivity of this n e w modification begins to approach t h e ultimate limit of the ultramicroburet. T h e instrument is de p e n d e n t upon t h e displacement principle; it was m a d e possible through the combina tion of a plunger of about 0.003 inches di ameter -with a dial micrometer gage, divi sions o n t h e latter being equivalent to 0.001 inch linear traverse. A n essential feature of t h e instrument is t h e m e a n s employed for supporting the delicate wire plunger. T h e method wherein displaced mercury is weighed could n o t b e used for calibration ow ing t o t h e extremely high sensitivity. Calibration w a s m a d e b y reading the diameter of t h e mercury droplet sus p e n d e d from t h e b u r e t tip against a micro scope ocular scale. T h e volume of the droplet was computed and correlated with the corresponding n u m b e r of scale divi sions o f t h e instrument.
VOLUME
3 0,
Laboratory
Equipment
NEWS
OF THE MONTH
DYNA-CATH High-speed magnetic mercury cathode Removes metals rapidly and completely, with clean mercury surface and minimum r e - s o l u t i o n of de posited metals. For 115V, 50-60 cy/AC. Write for Dyna-Cath Bulletin 250. 12431T $460.00 1 2 4 3 3 T * Anode, Platinum (2 required) 1 2 4 3 4 T * Cathode Connector (2 required) * (.Price subject to current platinum mat.)
b ·• ο INSTRUMENT BRUSH Cleans by radio-activity (Static Master) Cleans bal ances, microscopes, film and optical apparatus. Removes dust by destroying static sur face attraction. Utilizes harm less radio-active Polo nium. Guaranteed for 1 yr. Width I". 692 IT $4.95
W A T E R - T A P FILTER Works w i t h o u t refills Produces crystal clear taste ful water free from chlo rine, rust, sediment, odors. Fits standard water tap. Cleans by reverse flushing. Has long life. Special adapter fits standard hose connection. $9.95 1 3 3 6 6 T - •Filter 1 3368T—Hoie adapter set $ 1.50
POLISHER L o w speed precision finishing (Buehler) Prepares better specimens for metallography. Selective speeds. 1502 50 RPM. Complete with 8" balanced bronze wheel and band to hold polish ing cloth. Sturdy cast flanged bowl with drain, cover, removable hand rest and splash ring. Ball bearing motor. For 115V, 60 cy/AC. 17886 $275.00
N O . 11 > » M A R C H
Complete Buehler line of cutters, presses, grinde>s, sur/acers, polishers and abrasives.
FAST REPAIR SERVICE
Send your microscopes a n d Beckman instruments t o WILL a t Rochester for repairs. O u r trained technicians give you fast, expert repair service a t lowest cost. Five convenient office-warehouses a r e r e a d y to serve you. Contact the one nearest you.
17, 1 9 5 2
FURNACE For high temperature combustion (Leco) Operates at 2600 F continuously and to 3000 F intermittently. Two tube. Thick 6V2" insulation, heavy cast aluminum case permit comfortable work at high tempera tures. For 110V, 50-60 cy/AC. 14576T $745.00
MICROSCOPE Wide field — low cost (Bausch & Lomb) Greenough type, verti cal eyepiece, stereo scopic binocular prism. Complete with 1 set 10 X paired Huygenian eyepieces; 2 sets, 1.0 X and 2.0 paired objec tives. Total magnifica tion, 10 and 20 diam eters. Immediate deliv ery. 1 8446 $260.00 We handle a complete line of laboratory optical equipment.
DEMINERAUZER For mineral-free w a t e r (Barnstcad Bantam) Demineralizes water at 5 to 8 GPH in continuous flow from any water supply, without heat. New direct-reading dial tells quality of water produced. Renewable cartridge eliminates regener ating, backwashing, rinsing. For 115V, 50-60 cy/AC. I 1 8 7 1 — without cartridge... $ 8 3 . 0 0 I I 872—cartridges only. Each—$12.00/ Carton of 6 $ 5 7 . 6 0
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