Abstract: An exposure control method and apparatus for a camera having a two-area divided brightness measurement system. A central light value is determined based on a central area brightness of a photographic scene, and a peripheral light value is determined based on a peripheral area brightness of the scene. After determining by comparison between the central and peripheral light values whether the scene is back-lighted or front-lighted, a correction coefficient specific to back-lighted scenes or that specific to front-lighted scenes is read from a memory. An exposure value suitable for a main subject is calculated according to the following equation:Es=log.sub.2 {1-(1-.alpha.).sub.2.sup.LVb-LVa }-log.sub.2 .alpha.+LVawherein Es represents the exposure value and .alpha. represents the correction coefficient.

Abstract: An exposure control method and apparatus for a camera having a two-area divided brightness measurement system. A central light value is determined based on a central area brightness of a photographic scene, and a peripheral light value is determined based on a peripheral area brightness of the scene. After determining by comparison between the central and peripheral light values whether the scene is back-lighted or front-lighted, a correction coefficient specific to back-lighted scenes or that specific to front-lighted scenes is read from a memory. An exposure value suitable for a main subject is calculated according to the following equation:Es=log.sub.2 {1-(1-.alpha.)2.sup.LVb-LVa }-log.sub.2 .alpha.+LVAwherein Es represents the exposure value and .alpha. represents the correction coefficient.

Abstract: A position sensor for detecting a position by comparing a detected level with a threshold level. This operation is performed without being affected by the characteristics intrinsic to the used sensor means or by power supply variations. Furthermore, the operation is not varied even if the sensor means ages. The sensor means is caused to shift from a first operating state to an unoperated state and then to a second operating state according to operation of an object whose position should be detected. The level of the output from the sensor means is compared with a threshold level. Thus, the timing at which the sensor means shifts from the unoperated state to the second operating state is detected. The output level detected when the sensor means is in the first state is stored in a capacitor and divided by resistors to obtain the threshold level.

Abstract: A spray dryer which has a tank for receiving batches of differing materials to be spray dried. The tank is rotatable about a horizontal axis. The tank has an open top and a cover which is hinged on an axis perpendicular to the tank axis. The cover carries atomizer which has a shaft extending through the cover into the tank when the cover is closed. A spray disk is attached to the atomizer shaft.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) and (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having units (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(HN--X--NH--Z.sub.1).sub.l -- (II)--(HN--X--NH--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--(O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) an (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having units (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(HN--X--NH--Z.sub.1).sub.l -- (II)--HN--X--NH--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) and (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having unit (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(NN--X--NH--Z.sub.1).sub.l -- (II)--(NN--X--Nh--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: A method of producing a polydiacetylene thin film comprises spreading on a water surface a diacetylene compound having one or more conjugated diacetylene groups, subjecting the diacetylene compound to incomplete polymerization by irradiation with ultraviolet rays to an extent incapable of causing complete polymerization, transferring the spread film to a substrate to form a monolayer or built-up film thereon, and irradiating the transferred film with ultraviolet rays or an electron beam to complete the polymerization thereof.

Abstract: A hair treatment composition comprising 0.1% by weight or more of 3,4,4'-trichlorocarbanilide and 0.03% by weight or more of vitamine E acetate in an aqueous medium.This hair treatment composition can effectively prevent dandruff in the hair without causing adverse side effects to the skin or scalp.

Abstract: A work table in a glass forming unit in apparatus for producing hollow glass articles has an orifice plate which is loosely fitted in a recess of the work table. Therefore, the orifice plate can be removed or mounted on the work table instantly while the orifice plate is firmly secured to the work table during the operation of the work table because the orifice plate expands by the heat of the handled molten glass to be friction-fitted in the recess. The orifice plate is formed of material having a coefficient of thermal expansion equal to, or relatively larger than, that of the work table.