TECHNOLOGY
MASKING ODORS John H. Birden, right, looks on as Kenneth C. Jordan demonstrates the new atomic battery which these two men developed at Mound Laboratory. Using this atomic battery as a source of power, a stand ard voltmeter will give better than a one-half volt read ing. The battery uses the heat from radioactivity to pro duce electricity
Radioactive Heat to Electricity Polonium battery may someday offer instruments and apparatus long life dependability; known output Α Ν atomic battery which uses the " heat from radioactivity to produce electrical energy has been developed by Mound Laboratory. The new bat tery makes use of a thermopile which converts the heat from radioactive decay into electricity, according to J. J. Burbage, director of Mound Lab. This laboratory is operated by Mon santo Chemical for the Atomic Energy Commission. The battery, developed by John H. Birden and Kenneth C. Jordan of Mound Lab, produces electrical energy comparable to ordinary dry cells. Unit is small and total weight is only about 31 grams. Radioactive source of the new battery is polonium. Mound Lab says primary reason for use of polonium is safety. This element is essentially a pure alpha particle emitting material (5.298 m.e.v. energy with a 138 day half-life). Alpha particles are very easy to shield; a sheet of paper some times being sufficient. In the battery, one hundred and fifty curies of polonium are sealed in a small capsule, the surface of which is in con tact with the hot junctions of 40 ther mocouples. T h e capsule is thermally in sulated with a silica aerogel and is po sitioned within a surrounding container. Cold thermocouple junctions are lo cated on the surface of this container. A temperature difference of about 450° F. is maintained between the cap sule and the actual container or be tween the hot and cold junction. Salient features of such a cell, ac cording to Burbage, is that the battery VOLUME
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can b e small and light. Moreover, the operating life is dependent only upon the radioactive material used. Another advantage is that the voltage-current rating can be varied b y proper choice of wire size and the number of ther mocouple junctions. As an example, the Monsanto test unit uses a polonium heater of 4.65 watts and delivers a maximum electrical power of 9.4 milli watts ( 0 . 2 % efficiency). It has am in ternal resistance of 15 ohms, a no-load voltage of 0.75 volts and a current power of 2 5 milliamperes. Moreover, the output is not affected by extreme variations in the temperature of sur roundings as is a flashlight battery. The polonium battery is believed to have capabilities for use in instruments and apparatus where long life depend ability and known output are primary requirements. Also, Mound Lab says, it would be desirable for applications where weight must b e limited and where apparatus is subjected to wide variations in temperature. At the present time, large scale manufacture of the battery is not eco nomical, according to Mound Lab. T h e reason is that alpha-emitting radioiso topes are routinely available only in relatively small quantities and their cost is high. Mound L a b says that unit will prob ably b e called the heat battery. I t is about the fourth battery developed in t h e last eight months. Others are solar battery of Bell L a b and the beta emit ting units of both RCA and Tracerlab. The RCA battery employs stron-
OCTOBER
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1954
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WASTE MATERIALS Among the myriad of weighty problems that must b e faced jointly b y both industry and city management « . . that of malodorous waste materials looms ever higher. In the manu facturing process for many products, including such vital industries as canning and meat supply . . . large quantities of waste material are left, which almost immediately develop extremely objectionable odors. To solve this problem, many modern manufacturers h a v e availed themselves of the serv ices of the industrial perfumer. By developing an inexpensive but highly effective masking odor for such waste products —the problem of their dis posal can b e handled with much less difficulty and the possibility of creating a public nuisance is materially lessened. The D & O Industrial Odorant Labs have had considerable experience in developing such masking odors f o r v a r i o u s waste materials . . . and the services and facilities of this department are available to m a n u f a c t u r e r s with similar problems. Consult D & O .
B01 Our 156th Year of Service
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TECHNOLOGY tium-90 as its radioactive source and is almost exclusively a beta emitter. Moreover, atomic energy is converted directK· to electrical energy. This bat tery is pretty much a high voltage, low current, high internal resistance type compared to Mound's, which is a low voltage, low internal resistance type. If, and when, the RCA battery and the Mound battery are available commercially, the two would probably
be used for different applications be cause of their property differences. Another battery, developed this year by Tracerlab, employs radioactive tri tium, a constituent of the hydrogen bomb as the source of initial power. This battery converts atomic energy di rectly to electricity. It is commercially available but permission of A E C is re quired to purchase it, according t o Tracerlab.
Starch Atoms in 3-D Members of Starch Round Table put together world's largest molecular model, a part of starch amylopectin >-pHE world's largest molecular model ••• was put together by delegates to the 15th session of the Starch Round Table, a conference of the Corn Indus tries Research Foundation. Model's chief architect was George V. Caesar of Huron Milling. T h e giant molecule is a segment of starch amylopectin, consisting of 1775 scaled atoms models on loan from Fisher Scientific. T h e starch scientists used over 400 paraffin carbon atoms, over 600 ether oxygen atoms, and over 700 hydrogen atoms. Molecular weight of the molecule is 13,608; degree of polymerization is 84. Number of branches is (1,6):4; c/c branched is 4.8. Average chain length is 2 1 glucose residues. Starch chemists say that capturing the molecule in three dimensions in stead of the traditional two-dimensional
blackboard diagram revealed that: ro tation around the 1,6 branching point is freer than around 1,4 because of the protruding primary alcohol group; an anomalous 1,3 linkage is seen to be at least sterically possible; intra hydrogenbonding is marked, especially at posi tions 2 and 3 of adjacent ring hydroxyls; the role of the primary alcohol groups is predominant because of steric free dom; an α-Schardinger dextrin of 6 glucose residues was constructed, hav ing the appearance of a truncated cone around 12 A. in diameter X 8 A. in height, four of the primary hydroxyls being hydrogen-bonded in pairs and the other two to ring oxygens. T h e plan of the amylopectin seg ment, put together at the starch con ference, was outlined b y C . F . Cori, Nobel prize winner. T h e "atoms in 3-D" used by starch
Over-all length of the starch amylo pectin segment is about 140 centi meters; over - all width is about 60 centimeters. Reduc ing end of the giant molecule is the end in the foreground. The other terminals are nonreducing. George V. Caesar, Huron Milling, pic tured here, was the model's chief architect. He pio neered the use of scaled atom-models to show the molecu lar geometry of starch 4184
chemists a r e "based on electron diffrac tion studies o f physical chemistry and on quantum mathematics. A centimeter on t h e meter stick equals one Angstrom unit on t h e invisible molecule. These s a m e atom models were instru mental in t h e first synthesis of the 10 and 12-carbcm-ring compounds that led to today's artificial· perfume musks, compounds too involved to b e visual ized in a n y other way. Moreover, these atom molecules did yeoman service in the studies of E d w a r d C. Kendall tiiat l e d to the synthesis of "compound Έ " o r cortisone. Certain inexplicable facts about the cortical hormones could b e accounted for only if o n e postulated that an atom of oxy gen linked carbons N o . 3 a n d No. 9 in t h e ultracomplex molecule. W h e n the molecule was sketched in the con ventional two-dimensional form, the two carbon atoms in question—each situated o n a n entirely different carbon ring—seemed, in the words of one bio chemist, "mules apart." W h e n , how ever, the atom balls were assembled into a three-dimensional model, it was discovered that the two carbons were almost side l)y side and that a n oxygen atom could fît in quite easily. Two D o w Chemical researchers recently discovered through t h e use of atom models that rotenone, D D T , and methoxychlor all have striking similarity t h a t helps account for their striking parallel action a s insecticides. Probably most typical of how atom molecules a r e used in the nation's laboratories is the example of Firestone Rubber C o . , where scaled atom models a i e used i n early stages of work on such all pmrpose synthetic rubbers as GR-S a n d o n a variety of plastics. It seems that the size and shape of t h e atom groups on the rubber molecule determine the rubberiness and twist. Before expensive experiments on a new r u b b e r compound get under way, Firestone researchers t r y to make it with atom models. If t h e wooden model s h o w s that in the present molecule atom groups are so arranged t h a t t h e desired groups cannot b e added, researchers can switch to more favorable molecules as their base. • New cell-purpose g r e a s e has been developed by Esso Research Center. Esso says that the grease, known as Esso Multipurpose Grease H , will do various jo"bs in automotive equipment normally requiring several individual greases. Tins feature, it was said, keeps dirt and water out of bearings and also gives t h e grease a n adhesive quality t h a t m a k e s it cling to parts to b e lubricated e v e n when they are i n motion.
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