Abstract: A propionic acid thiol ester derivative having the formula: ##STR1## wherein R.sub.1 is a cyano group, a trifluoromethyl group, a halogen atom or a nitro group,R.sub.2 is a hydrogen atom, a halogen atom or a cyano group,R.sub.3 is a thiazolin-2-yl group or a benzothiazol-2-yl group, andA is a methine group or a nitrogen atom.

Abstract: 1,2,4-oxadiazole derivatives having selective herbicidal action in controlling broad leaf weeds and cyperaceous weeds without causing phytotoxicity to geraminous crop plants having the formula: ##STR1## wherein A is a methine group or a nitrogen atom; R.sub.1 is a chlorine atom or a methyl group; when A is a methine group, R.sub.2 is a hydrogen atom if R.sub.1 is a methyl group, and a hydrogen atom or a methyl group if R.sub.1 is a chlorine atom, and when A is a nitrogen atom, R.sub.2 is a hydrogen atom; R.sub.3 is a hydrogen atom, an alkyl group having from 1 to 11 carbon atoms, a benzyl group unsubstituted or substituted by chlorine or methoxy; a phenoxymethyl group unsubstituted or substituted by chlorine or methyl, or a lower alkoxyalkyl group.

Abstract: A hydroxyacetic acid amide derivative having the formula: ##STR1## wherein each of R and R.sub.1 which may be the same or different, is an alkyl, alkenyl, alkynyl or alkoxyalkyl group having from 1 to 4 carbon atoms, provided that R and R.sub.1 are not simultaneously alkyl groups.

Abstract: A propionic acid thiol ester derivative having the formula: ##STR1## wherein R.sub.1 is a cyano group, a trifluoromethyl group, a halogen atom or a nitro group, R.sub.2 is a hydrogen atom, a halogen atom or a cyano group, R.sub.3 is a thiazolin-2-yl group or a benzothiazol-2-yl group, and A is a methine group or a nitrogen atom.

Abstract: Novel compounds in the form of 2-[4-(4-cyanophenoxy)-phenoxy]-propionic or acetic acid amide derivatives and selective herbicides containing the same as an active ingredient.

Abstract: Propionic acid derivatives represented by the formula (I) ##STR1## wherein X indicates an oxygen atom or a sulfur atom, Y indicates a hydrogen atom or a halogen atom, R.sub.1 and R.sub.2 are the same or different group, indicating an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, lower alkoxy group, lower alkoxyalkyl group, phenyl group, respectively, or R.sub.1 and R.sub.2 may form a heterocyclic group together with a nitrogen atom bonding to said R.sub.1 and R.sub.2, and herbicidal compositions employing them.

Abstract: An arm extends out over the surface on which the ellipse is to be drawn, from a support in the form of a base plate with a handle that can be grasped to hold the support in a desired position. A piece of string is slackly fixed at two space sites along its length to two selected places spaced along the length of the arm of the support. A string-follower is provided in the form of a shaft having an arm radially and rotatably projecting from its lower end. At a site displaced from the shaft, a perforation is provided down through this arm. A drawing instrument is mounted to the string-follower so that its drawing tip underlies the lower opening of the perforation. The string extends down through the perforation to limit to limit the envelope of excursion of the string-follower in drawing an ellipse.

Abstract: This specification discloses a dark current correcting device in a spectrophotometer utilizing, as the photoelectric converting element, an image sensor capable of electrical scanning such as a photo-diode array to improve the scanning speed and the reliability, thus eliminating the error component by the dark current from the photoelectric conversion signal obtained from each photoelectric converting element of the image sensor and enabling obtainment of a true photoelectric conversion signal.

Abstract: This specification discloses a spectrophotometer utilizing, as the photoelectrical converting element, an image sensor capable of electrical scanning such as a photo-diode array, thus adjusting the integration time thereof, namely, the scanning time of the image sensor and enhancing the S/N (signal-to-noise ratio).

Abstract: A spectrophotometer has an image sensor capable of electrically scanning, such as a photo-diode array, as a photoelectrical converting element. A photoelectrical conversion signal is obtained corresponding to an arbitrarily selected wavelength from the signal time-sequentially produced from a one-dimensional image sensor by means of such a simple structure.

Abstract: This specification discloses a refractometer of the type in which a sample is introduced onto a prism by a pump device, whereafter the sample is illuminated so that the critical angle of the total reflection determined by the refractive indices of the sample and the prism is measured. The refractometer comprises a substantially rectangular parallelopiped frame member, a cylinder provided within the frame member and having a piston slidably disposed at the upper end thereof, an observation lens barrel disposed laterally within the frame member and in juxtaposed relationship with the cylinder, prism holding means, and reflector means for directing a light beam emergent from the prism to the observation lens barrel.