INDUSTRIAL A N D ENGINEERING CHEMISTRY
November, 1923
obtain the stress per unit width of fabric measured perpendicularly to the threads of
1131
Therefore,, the ratio of load to stress relief
and correcting for the thread , concentration due to fabric distortion, we get the real fabric stress
= 7 r
PROOF OF EQUATION 30 THAT PROOF OF LOAD RELATION To FABRIC STRESS RELIEF-Fig. 23 represents djagrammaticallf the cross section of an inflated carcass, having a diameter D and an i d a t i o n pressure P. PD According to Equation 1, the transverse fabric stress = 2’ Fig. 21 represents the same carcass deflected under the load L per unit of carcass length. - P-H The new fabric stress (79) - 2 PD PH So that the stress relief due to flexure = 7 2 (80)
-
$(D-H)
(81)
Now, because the carcass retains the same transverse perimeter 2 W = rD-7rH (82) = 7r(D-H) or W = But W =
So t h a t L
=
7r
5
R.5
K
= E-Fig.
25 represents a
sector of unstressed carcass subtended by the angle 8. Rl = radius to center of outer ply Rz = radius to center of inner ply Ra = imaginary value of radius R1, if the tire were simply inflated until the stress per ply were equal to that sustained by the outer ply under critical curvature conditions. (This has already been explained in the text. See Equation 27.) Now let Fig. 26 represent the same sector of carcass flexed to critical curvature. The subtended angle a: i s greater than the angle 8. Since the stress on the outer ply is the same in both Figs. 25 and 26, then the outer ply lengths are the same, so that R.@ = R5ff (85) Similarly, the inner ply lengths are the same, so that Rz8 = Raa (86) Therefore, combining Equations 85 and 86
(D-H)
L
p
(83)
% (D-H)
and simplifying
The World’s Dairy Congress N Iaternational Congress on dairying, held in this country A Oceober 2 to 10, was attended by 1800 delegates, including over 200 from 43 foreign countries. At the opening sessions in Washington, October 2 and 3 , the delegates were welcomed by Secretary Hughes and addresses were made by Secretaries Wallace and Hoover. Additional sessions were devoted to papers on international trade and the development of the dairy industry. On October 4 the Congress adjourned to Philadelphia, where a demonstration was given of the methods used by the National Dairy Council in educating the public to the nutritive value of milk. From Philadelphia special trains took the delegates to Syracuse, where the IVational Dairy Exposition was held. October 5,6,8,9, and 10 were given over to technical papers on topics related to the dairy industry. About, 245 papers were presented a t the 27 sessions into which the Congress was divided. Abstracts of the papers in English, French, German, and Spanish were available a t registration, and full papers and proceedings will be published by the Government. Three of the sessions were devoted to the nutritional side of the milk question, and included papers by McCollum, Mendel, Blackham, Sherman; Block, and Pirquet. R. M. Allen and Chas. A. Glabau discussed the question of the use of milk and milk powders in the baking industry, both from the standpoint of the increase in nutritive value and the effect of the addition of milk solids on the size and quality of the loaf. In the section on equipment two papers discussed the use of various metals in the handling of milk and the manufacture of milk products. In the session devoted to the transportation of milk considerable attcmtion was given to the use of steel tanks for both automobile and railroad shipments. A collection of papers on milk secretion and the nutrition of dairy cows included contributions by Porcher, Isaachsen, Koestler, Forbes, and Meigs. H. M.
.
Evans discussed the occurrence and distribution of a new dietary factor essential to reproduction. Additional papers of interest to chemists appeared in various sessions of the Congress. These included a paper by I,. L. Van Slyke on “The Chemistry of Casein;” by I,. S. Palmer on the “Chemistry of Milk a n d , Milk Products from a Colloidal Standpoint;” by Alan Leighton and P. N. Peter on “Factors Influencing the Crystallization of Lactose;” by A. Miyawaki on “The Keeping Quality of Sweetened Condensed Milk;” by H. H. Somer on “The Heat of Coagulation of Milk;” by A. Leighton and E. F. Deysher on “Factors Influencing the Heat Coagulation of Milk and the Thickening of Condensed Milk;” by G. C. Supplee on “The Keeping Quality of Dry Milk;” by G. E. Holm and G. R. Greenbank on “The Keeping Quality of Butterfat with Special Reference to Milk Powder;” and by H. Jephcott and N. Ratcliffe on “Fat in Commercial Casein.” The splendid program was largely due to the work of I,. A. Rogers, of the Dairy Division, U. S. Department of Agriculture. Syracuse University a t a special convocation conferred the degree of doctor of science on C. J. Hastings, of Canada; C. Orla-Jensen, of Denmark; Masayoshi Sato, of Japan; Haakon Isaachsen, of Norway; Gerald Leighton, of Scotland; Robert Burri, of Switzerland; Robert Stenhouse Williams, of England; Charles Borcher, of France; and Sir Arnold Theiler, of South Africa. The degree of doctor of laws was conferred on Cesares Longobardi, of Italy, and H. E. Van Norman, president of the Congress. A number of excursions were arranged for the delegates, both before and following the Congress, to farms, dairy manufacturing establishments, and educational institutions. These included an automobile trip ending a t Ithaca for the dedication of the new dairy building of Cornel1 University and a long trip to the Pacific Coast.
