Abstract: An episulfide which has an alicyclic, aromatic or heterocyclic skeleton and has two or more moieties represented by the formula ##STR1## wherein X is S or O, and S is in an amount of 50% or more, on the average, of the total of S and O constituting a three-membered ring. A cured material obtained by polymerizing this episulfide compound is a desirable optical material for various uses, particularly as a lens material for spectacles.

Abstract: The present invention relates to a method of determining histamine content as a freshness index of food. An examination liquid is injected in a reaction cell, an amount of dissolved oxygen (DO) is recorded through an oxygen sensor and an amplifier in the recorder. Then, an enzymatic reagent having histamine oxidase activity is injected in the reaction cell, a decrease in the dissolved oxygen is recorded in the recorder, and the histamine concentration is determined on the basis of the decrease by a micro computer.

Abstract: The invention provides an electrophotographic photoreceptor which has a practical high sensitivity to red light or infrared ray, especially semiconductor laser beam and is excellent in storage stability. The photoconductor layer of this photoreceptor comprises comprises an inorganic photoconductor, a binder resin, a sensitizing dye and optionally an acid anhydride, wherein said sensitizing dye is at least one of dye compounds represented by the following formulas [I], [II], [III] and [IV]: ##STR1## In the above formulas, the respective symbols are as defined hereinbefore.

Abstract: The present invention provides a method for image formation which is free from the problems such as uneven development and pepper fog and can give photographic characteristics of extremely high contrast negative tone using a stable developer and which comprises developing a silver halide photographic light-sensitive material in the presence of a compound represented by the following formula (I): ##STR1## wherein R.sub.1 represents an alkyl group of 1-8 carbon atoms or a cycloalkyl group having 4-8 carbon atoms in the ring, R.sub.2, R.sub.3 and R.sub.4 may be identical or different and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a heterocyclic group with a proviso that they cannot be simultaneously hydrogen atoms, R.sub.2 and R.sub.3 may link to each other to form a ring structure, and at least one hydroxy group is present in the substituents R.sub.2, R.sub.3 and R.sub.4.

Abstract: Disclosed is a method for image formation which comprises developing a silver halide photographic photosensitive material in the presence of a compound represented by the following formula [I] or [II]: ##STR1## wherein Ar represents an aryl group, R.sub.1, R.sub.2 and R.sub.3 which may be identical or different each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, with a proviso that they cannot be simultaneously hydrogen atoms, R.sub.1 and R.sub.2 may link to each other to form a ring, and at least one of R.sub.1, R.sub.2 and R.sub.3 has at least one hydroxyl group as a substituent, ##STR2## wherein Ar.sub.1 and Ar.sub.2 each represents a divalent aromatic group, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, R.sub. and R.sub.2 may link to each other to form a ring and R.sub.3 and R.sub.

Abstract: A new method of rapidly analyzing plural substances in the presence of biological catalyzers is disclosed. The method is practiced by way of the steps of injecting both pH buffer solution and specimen into a reaction cell, successively adding a plurality of enzymes to induce up-take reaction of dissolved oxygen, causing the plurality of substances to be subjected to selective oxidation in the stepwise manner, obtaining a stepdown curve of dissolved oxygen by automatically recording the oxidative process by means of a dissolved oxygen sensor, qualitatively determining each of the substances with reference to the kind of added enzymes and the order of their addition and quantitatively determining the same with reference to the extent of decrease in dissolved oxygen. Typically, oxidation of the substances is carried out by way of two or three or further more steps.

Abstract: Disclosed is a silver halide photographic light-sensitive material which has a hydrophilic colloid layer containing at least one of the dyes represented by the following formulas (I) and (II): ##STR1## wherein R.sup.1 and R.sup.2 may be identical or different and each represents an alkyl group; Y.sup.1 and Y.sup.2 may be identical or different and each represents a group of atoms necessary to form a hydrocarbon ring together with the carbon atom at 3-position of indole ring; L represents a methine group; the dye molecule has at least three acid substituents; X.sup..theta. represents an anion; and n is 1 or 2 and is 1 when the dye form an inner salt, ##STR2## wherein R.sub.1 and R.sub.2 may be identical or different and each represents a substituted or unsubstituted alkyl group; Z.sub.1 and Z.sub.2 each represents a group of non-metallic atoms necessary to form a substituted or unsubstituted benzo condensed ring or naphtho condensed ring, with a proviso that R.sub.1, R.sub.2, Z.sub.1 and Z.sub.

Abstract: Disclosed is a method for determining the degree of freshness of such raw, frozen and processed perishable foodstuffs as meat, poultry and fish and an instrument therefor. The degree of freshness can be easily determined by the method of the present invention in shorter periods of time than by the conventional methods.The method of this invention comprises determining the amount of certain decomposition products of adenosine triphosphate such as hypoxanthine, inosine and inosinic acid by measuring the consumption of dissolved oxygen while each compound is subjected to action by certain enzymes, i.e., hypoxanthine by xanthine oxidase, inosine by nucleoside phosphorylase and inosinic acid by alkaline phosphatase, nucleoside phosphorylase and xanthine oxidase.

Abstract: The present invention provides a method for photographic processing of a silver halide photographic light-sensitive material with high sensitivity and with less fog. This method comprises imagewise exposing a silver halide photographic light-sensitive material and then developing the exposed light-sensitive material in the presence of at least one compound selected from the group consisting of the compounds represented by the following formulas (I)-(IV): ##STR1## wherein Z represents a group of atoms necessary to form a condensed aromatic ring which may have a substituent in addition to ##STR2## R represents a hydrogen atom or a monovalent organic group, R.sub.1 represents a hydrogen atom or a substituted or unsubstituted alkyl group and X represents an oxygen atom, a sulfur atom, a selenium atom or >N--R.sub.2 wherein R.sub.

Abstract: Disclosed is a method for producing images which comprises imagewise exposing a silver halide photographic light-sensitive material and then developing the exposed light-sensitive material in the presence of a compound represented by the following general formula [I], [II] or [III]: ##STR1## wherein Ar represents an aryl group, R represents a hydrogen atom, an alkyl group, an alkenyl group, an unsaturated hetero ring group or an aryl group and R.sub.1 and R.sub.2 each represent a hydrogen atom or a group represented by the general formula (i): ##STR2## wherein R.sub.0 represents an alkyl group, an alkenyl group, an aryl group, an alkoxy group or an aryloxy group and n is an integer of 1 or 2. ##STR3## wherein Ar, R.sub.1 and R.sub.2 are as defined in the general formula [I] and R.sub.3 and R.sub.4 each represent a hydrogen atom, an alkyl group, an aryl group, an unsaturated hetero ring group or a substituted amino group and R.sub.3 and R.sub.

Abstract: A new method of rapidly analyzing plural substances in the presence of biological catalyzers is disclosed. The method is practiced by way of the steps of injecting both pH buffer solution and specimen into a reaction cell, successively adding a plurality of enzymes to induce uptake reaction of dissolved oxygen, causing the plurality of substances to be subjected to selective oxidation in the stepwise manner, obtaining a stepdown curve of dissolved oxygen by automatically recording the oxidative process by means of a dissolved oxygen sensor, qualitatively determining each of the substances with reference to the kind of added enzymes and the order of their addition and quantitatively determining the same with reference to the extent of decrease in dissolved oxygen. Typically, oxidation of the substances is carried out by way of two or three or further more steps.

Abstract: Disclosed are novel antifoggant precursors having the general formula (I) or (II) which are sufficiently stable in a wealkyl acidic medium, are markedly effective in restraining over-development fog and besides cause little loss of sensitivity: ##STR1## (wherein Y represents oxygen atom or ##STR2## X represents OR.sub.3 when Y is oxygen atom and R.sub.3 when Y is ##STR3## where R.sub.1 and R.sub.2 each represents hydrogen atom, alkyl group aryl group and R.sub.3 represents hydrogen atom, alkyl group or phenyl group; R.sub.4 -R.sub.6 each represent hydrogen atom, halogen atom, alkyl group, carboxyl group, alkoxycarbonyl group or phenyl group, R.sub.4 and R.sub.5 may form together a benzene ring; R.sub.7 represents hydrogen atom, alkyl group or phenyl group; and A represents a heterocyclic group of the mercapto antifoggant.) ##STR4## (wherein X, Y, R.sub.4 -R.sub.5 and A are the same as defined for the general formula (I) and R.sub.4 and R.sub.5 or R.sub.5 and R.sub.6 may form together a benzene ring.).

Abstract: A rotor having N and S poles is rotatively supported through bearings from the lower end of an electrode to be immersed in a water sample in which dissolved oxygen is measured. A rotor driving means is disposed adjacent to the rotor, the means generally comprising a magnet which is so constructed that the N and S poles thereof alternately approach the rotor. The rotor follows the rotation of the rotor driving means to rotate in and stir the water sample.

Abstract: A rapid, accurate and simple method is disclosed for determining an index of freshness of fish and mollusks. The index of freshness is expressed as the ratio of the combined molar concentration of inosine and hypoxanthine to the total molar concentration of the decomposition products of adenosine triphosphate. Each concentration is determined electrochemically from the amount of hydrogen peroxide produced when a sample extract from fish or mollusks is subjected to the action of certain enzymes. The emzymes used for inosine and hypoxanthine concentration are nucleoside phosphorylase and xanthine oxidase and for the concentration of the decomposition products of adenosine triphosphate are alkaline phosphatase, adenylic acid kinase, AMP deaminase and adenosine deaminase in a crude extract obtained from calf intestine, nucleoside phosphorylase and xanthine oxidase. Sodium azide may be added to the sample extract to inhibit errors in measurement caused by the presence of catalase.

Abstract: Apparatus for determining a concentration of hydrogen peroxide in an aqueous solution featuring (A) a sampling system, (B) a reaction system, (C) an oxygen concentration determining system, (D) an automatic calibration system and (E) a sequence circuit system. One cycle of determination consists of three operating stages. In the first stage, a zero point adjustment and a span adjustment are established to properly calibrate the sensitivity of an oxygen detector, air saturated water or a fresh sample being used as the standard. In the second stage, a sample is introduced and hydrogen peroxide in the sample is decomposed with a hydrogen peroxide decomposing agent. The concentration of oxygen dissolved in the sample is then determined by means of the oxygen detector. In the third stage, the reaction vessel is washed with fresh water or a fresh sample after the discharging of the used sample. Determinations are repeated at a predetermined time interval under the control of the sequence circuit system.

Abstract: There is disclosed a silver halide photosensitive material which contains in at least one of silver halide emulsion layers and colloid layers at least on antifoggant precursor compound represented by the general formula: ##STR1## wherein A, Z, R.sub.1 and R.sub.2 are the same as defined previously. This photosensitive material is stabilized against overdevelopment fogging.

Abstract: There is disclosed a silver halide photographic photosensitive material which contains in at least one of silver halide emulsion layers and colloid layers permeable to water through to or out from said emulsion layer at least one compound represented by the following general formula (I): ##STR1## wherein A, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same as defined previously. This photosensitive material has stability against over-development fogging.

Abstract: Compounds represented by the following general formula are used as hardeners for gelatin, in particular gelatin layers of photographic light sensitive materials ##STR1## (wherein R and X are the same as defined in the specification).

Abstract: A silver halide photosensitive material is stabilized against overdevelopment fogging by containing at least one antifoggant thioether represented by the following general formula I in silver halide emulsion layer and/or layer contiguous to said emulsion layer; ##STR1## wherein A represents the heterocyclic group of a mercapto antifoggant; R.sub.1 and R.sub.2, which may jointly form a benzene ring, represent each a halogen atom or an alkyl, aryl or aryloxy group.

Abstract: The compounds represented by the general formula (I) or (II) as defined in the specification are novel and useful developing agent precursors in silver halide photographic light sensitive materials.