*7&e (fyemtccU New Distributor Improves Dust Testing E m p l o y m e n t of a new type d u s t distributor h a s e n a b l e d c h e m i c a l t e c h n o l o g i s t s of the W h i t e m a r s h R e s e a r c h L a b o r a t o r i e s of the P e n n s y l v a n i a S a l t M a n u f a c t u r i n g Co. t o modify the conventional laboratory duster, so a s to p r o v i d e c o n t r o l o f nearly all variables in tests. A d v a n t a g e s o f t h e n e w d i s t r i b u t o r which is t u r n e d of c l e a r p l a s t i c are t h a t t h e e n t i r e dust s a m p l e is s h o t o u t , a n d t h e d u s t s a m p l e is c o m p l e t e l y b r o k e n u p , t h u s e l i m i n a t i n g agglomeration. E x a c t n e s s a n d reproducibility o f e x p e r i m e n t a l c o n d i t i o n s a r e provided by an a i r - m e a s u r i n g d e v i c e which, c o n t r o l s t h e press u r e ' a n d a m o u n t o f air u s e d . T h e d u s t e r is u s e d i n d e t e r m i n i n g type o f d e p o s i t , d r i f t i n g r a t e o f s e t t l e , a b i l i t y o f dusts t o s t i c k t o p l a n t s , a n d s e l e c t i o n of proper size particles for i n s e c t i c i d a l p r o p e r t i e s . I t is n o w b e i n g u s e d to test v e h i c l e s for Iiexachlorocycloh e x a n e a n d o t h e r n e w i n s e c t i c i d e s a n d fungicide d u s t s a n d already h a s b e e n u s e d effectively i n d e v e l o p i n g several D D T a n d c r y o l i t e d u s t base i n s e c t i c i d e s .
Complete view of fluster showing /oircr, dust distributor, and placement of plant to be dusted. Under the table is the air tank and solettoid control
Dust sample holder (md distributor. Top ti^be which extends down into air chamber is jfor dust sample. Air is forced in « t the bottom tube and is kept from back pressure by a b»al\ check valve. Tlvree small pipes extending from near &he top of the air chamber to the bottom of Z.he sample tube carry ^the generating air bZasl
lielttw. Air pressure tank at the right and pressure control mechanism, '"fired** by solenoid valve at the left, makes close contrtf! and reproducibility possible
Disassembled view of dust distributor showing arrangement of air pressure tubes. The three shorter tubes,, not visible in the photo above, carry s i r earn.s of air that completely break up the sample as it is blown past them 506
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Sample A shows more even distribution and poivdering of sample shot from distribu tor than sample Β which was made without using distributor. Right. Cloud of dust showing how completely it htis been broken up by the dust distributor
Quartz oscillator plates, approximately 40 mm. in diameter and 3 mm. thick, i^re used in cavitatioti, coagulation, and emulsificalion processes. De veloped by North American Phillips Co., Inc., they carry α chemically applied silver coating on each side, they have a frequency of 1 megacycle and are λ capable of carrying a power load of approximately 2 /·ι kw.
These plastic parts of white polystyrene rank among the largest and longest castings ever produced 1 on a single in jection chamber machine. They are 31 /s inches long, have a projected area of 120 sq. inches? and were pro duced in a 70-secorul cycle on a Z6-ounce plastics in jection molding machine built by the Hydraulic Press Manufacturing Co., of Mt. Cilead, Ohio
After évacua tion to a high vacuum, through the mercury diffusion appfiratus shown, this inner bulb of an experimental mercury vapor lamp has been filled tvith argon gas and mercury and is being sealed off by Normcin C. Beese tit the Wes linghouse Hesearch Laboratories in Bloomjield, IV. J. The bulb will be used in determining the efficiency of high intensity mercury vapor lamps V O L U M E
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