A study was performed to determine maximum hand grip torque that can be exerted when tightening or loosening circular electrical connectors. A static, sustained three-second exertion was used as the strength criterion. Torque was applied to simulated connector rings and was measured by means of a single bridge torsional load cell. Other variables tested included the type of grip employed, orientation of the connector, use of work gloves and chemical defense gloves, height of the connectors, and direction of rotation. Hand grip torque strength was found to be directly related to connector diameter with similar strength patterns exhibited for tightening and loosening. Higher torque was exerted when the connectors were on the subject's right side. The use of gloves resulted in higher torque in most situations. Connector height and direction of rotation had little effect on torque strength.

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We have measured the reflectivity of the interface between the two phases in equilibrium just below the critical consolute temperature of a binary fluid mixture. By comparison with the Fresnel reflectivity calculated for a sharp boundary using measured values of the indices of refraction, we find that the interface is diffuse with an effective thickness -1000 A at 0.38°C below the critical temperature. The temperature dependence of the effective thickness is near that predicted by lattice-gas models for the range of correlations in critical fluids.Recent theoretical discussions of critical phenomena 1 ? 2 in liquid mixtures, fluids, and ferromagnets, based on numerical solutions of the Ising lattice or lattice-gas models, 3 provide satisfying agreement with available experimental data on critical phenomena that was unattainable with the classical models homologous with van der Waals or Bragg-Williams theories. As T-~T C , physical properties can be represented by powers of I T-T c I. For example, the composition miscibility gap AC in a mixture of fluids, and the spontaneous magnetization M of a nonconducting ferromagnet, are supposed to vary as (T c -T)& where the theoretical and experimental values of /3 are ~I 3-5 An "effective" range of correlations A that diverges as (T c -T)""^ is a feature of the theory. But the parameter v is only approximately specified by the theory, and is moreover rather sensitive to experimental errors. Best values seem to be y~0.6 to 0.7. Classical theory yields ^ = 0.50. Our results provide a new measure of quantities related to v and 0.However, we have measured an interface property, not a bulk property of a critical mixture. A thorough thermodynamic treatment of the interface in classical critical fluids has been given by Cahn and Hilliard, 6 " 8 and it has been slightly extended. 9 Landau and Lifshitz 10 point out that the law by which the interface of separation disappears in a critical fluid "has not yet been discovered." However, we conjecture that the effective interface thickness is related to the effective range of correlations.We studied the binary system cyclohexane plus methanol which displays a miscibility gap with a critical temperature of T c = 45.14°C at about 50 at.% cyclohexane. 11 We consistently attained this value of T c only within 0.1 °C after purification. Temperatures were measured with a Beckmann-type thermometer to ±0.01°C and controlled to ±0 o 01°C during measurements taken only after equilibration by vigorous mixing and protracted settling. The indices of refraction of the two phases in equilibrium and n 2 were measured at 5790 A to ±0.000 05 and at other wavelengths to ±0.0002 with a Bausch and Lomb dipping refractometer modified to reduce contamination and permit immersion in a water bath with temperatures regulated to ±0.005°C.The reflectivity of the interface was measured relative to a glass reflectance standard at five wavelengths. The filtered light from a highintensity mercury discharge tube was reflected from the interface in nearly normal inci...

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h a r d s , W a l t e r E. Gilmore, and Lon N. b n e y , I d a h o N a t i o n a l E n g i n e e r i n g L a b o r a t o r y EG&G Idaho, I n c . Idaho F a l l s , I D 83415 AB S TKA CT I n t h i s c a s e s t u d y , human f a c t o r s p e r s o n n e l were r e q u e s t e d t o p h e d documents and r e s e a r c h f i n d i n g s sponsored by t h e United S t a t e s Nuclear R e g u l a t o r y Commission (USNRC) were used. P r e l i m i n a r y t a s k s i n v o l v e d a review o f t h e d r a f t p l a n t p r o c e d u r e s . Then, i n t e r v i e w s w i t h o p e r a t o r s w e r e conducted t o e s t a b l i s h t h e i n i t i a l i n f o r m a t i o n f o r t h e d i s p l a y s . c r i t e r i a t o d e t e r m i n e t h e o p t i m a l p r e s e n t a t i o n formats. s i d e r t h e User Computer I n t e r f a c e (UCL) i n many of t h e s e s y s t e m s c a n have d e v a s t a t i n g r e s u l t s . An i n a d e q u a t e u s e r i n t e r f a c e a t t h e CRT c o n s o l e , s u c h as e x t e n s i v e s c r e e n c l u t t e r , poor l a y o u t and o r g a n i z a t i o n of p l a n t i n f o r m a t i o n , and c o d i n g , c a n c o n t r i b u t e n o t o n l y t o o p e r a t o r e r r o r , b u t r e d u c e t h e o p e r a t o r s a c c e p t a n c e o f t h e equipment. In some i n s t a n c e s , o p e r a t o r s have been known t o simply t u r n o f f CKT-generated d i s p l a y s y s t e m s i n n u c l e a r power p l a n t s , b e c a u s e t h e y d i d n o t p r e s e n t them t h e informa t i o n t h e y needed i n a ready-to-use format. Energy A s s i s t a n t S e c r e t a r y Defense Programs, O f f i c e of Nuclear Material P r o d u c t i o n , u n d e r DOE C o n t r a c t No. UE-AC07-ID01570. a f t e r m a t h o f Tnree M i l e I s l a n d . A s u b s t a n t i a l p o r t i o n of t h e USNRC-funded human f a c t o r s r e s e a r c h i n r e c e n t y e a r s h a s been d e v o t e d t o d e v e l o p i n g U C I g u i d e l i n e s t h a t c a n b e used t o assess t h e u s e a b i l i t y and o p e r a b i l i t y of complex n u c l e a r p r o c e s s c o n t r o l systems (Danchak, 1981; Banks, Gertman, P e t e r s e n . , 1982;Banks, Gilmore, Blackman, and Gertman, 1983;Gilmore, 1985). These g u i d e l i n e s , though n o t r e g u l a t o r y r e q u i r e m e n t s , are c u r r e n t l y b e i n g used by t h e USNRC p e r s o n n e l a s a n a i d f o r c o n d u c t i n g p l a n t a u d i t s . The need t o i n c o r p o r a t e human f a c t o r s e n g i n e e r i n g w i t h p a r t i c u l a r emphasis on t h e c o n t r o l s y s t e m t o b e implemented a t t h e Idaho N a t i o n a l E n g i n e e r i n g L a b o r a t o r y (INEL). e f f o r t d e m o n s t r a t e how a U C I