Abstract: An apparatus for obtaining resistivity images of a borehole includes an array of measure electrodes separated from a pad or the body of the instrument by a focusing electrode. The focusing electrode is maintained at a slightly higher potential than the measure electrodes. The apparatus is primarily intended for use with conducting fluids but may also be used with non-conducting fluids. A modulated electrical current with a carrier frequency of 1 MHz is injected into the formation. When used with a non-conducting fluid, capacitive coupling between the electrode and the conductive formation is provided by the dielectric of fluid. When used with a conducting borehole fluid, an additional capacitor may be incorporated into the circuit. The current in the measure electrode is indicative of the conductivity of the formation.

Abstract: An apparatus for obtaining resistivity images of a borehole includes an array of measure electrodes separated from a pad or the body of the instrument by a guard electrode. The guard electrode is maintained at a slightly lower potential than the pad and the measure electrode is at an intermediate potential thereto. With this arrangement, the current from the guard electrode defocuses the measure current from the measure electrode as it enters the formation, and at greater distances, the current from the measure electrode is refocused by the effect of the current from the pad. This defocusing and refocusing defines a region of investigation away from the borehole wall that is relatively insensitive to borehole rugosity. Circumferential and vertical overlap may be obtained either by the arrangement of the measure electrodes, or by relying on the broadening of the measure beam as it enters the formation.

Abstract: An apparatus for obtaining resistivity images of a borehole includes an array of measure electrodes separated from a pad or the body of the instrument by a guard electrode. The guard electrode is maintained at a slightly lower potential than the pad and the measure electrode is at an intermediate potential thereto. With this arrangement, the current from the guard electrode defocuses the measure current from the measure electrode as it enters the formation, and at greater distances, the current from the measure electrode is refocused by the effect of the current from the pad. This defocusing and refocusing defines a region of investigation away from the borehole wall that is relatively insensitive to borehole rugosity. Circumferential and vertical overlap may be obtained either by the arrangement of the measure electrodes, or by relying on the broadening of the measure beam as it enters the formation.

Abstract: A process for the preparation of Type V hydroxygallium phthalocyanine which comprises the in situ formation of an alkoxy-bridged gallium phthalocyanine dimer, hydrolyzing said alkoxy-bridged gallium phthalocyanine dimer to hydroxygallium phthalocyanine, and subsequently converting the hydroxygallium phthalocyanine product obtained to Type V hydroxygallium phthalocyanine.

Abstract: A process for the preparation of alkoxy-bridged metallophthalocyanine dimers by the reaction of a trivalent metal compound with ortho-phthalodinitrile or 1,3-diiminoisoindoline in the presence of a diol.

Abstract: Alkoxy-bridged metallophthalocyanine dimers of the formula C.sub.32 H.sub.16 N.sub.8 MOROMN.sub.8 H.sub.16 C.sub.32, or of the formula ##STR1## wherein M is a metal, and R is an alkyl or an alkyl ether.

Abstract: Photoconductive imaging members comprised of an alkoxy-bridged metallophthalocyanine dimer as a charge generator material, wherein said dimer is of the formula C.sub.32 H.sub.16 N.sub.8 MOROMN.sub.8 H.sub.16 C.sub.

Abstract: Disclosed is an improved layered photoresponsive imaging member comprised of a supporting substrate; an imidazole perinone comprised of components with a mixture of cis and trans isomers of Formulas III, IV, and V, including trans indanthrene Brilliant Orange, cis indanthrene Bordeaux Red; bis(4,5-dimethyl)benzimidazole perinone and bis 2,3 naphthimidazole perinone, and an aryl amine hole transport layer comprised of molecules of the following formula: ##STR1## dispersed in a resinous binder and wherein X is selected from the group consisting of halogen and alkyl.

Abstract: An improved layered photoresponsive imaging member comprised of a supporting substrate; a photogenerator layer comprised of cis and trans naphthalene imidazole perylene component of the following formula; ##STR1## and an aryl amine hole transport layer dispersed in a resinous binder.

Abstract: Disclosed are unsymmetrical squaraine compounds of the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of alkyl, aryl, heterocyclic, benzyl, and halobenzyl; and X.sub.1, X.sub.2 and X.sub.3 are independently selected from the group consisting of hydrogen, alkyl, halogen, carboxy, and hydroxy; and photoresponsive imaging members having incorporated therein the aforementioned squaraine compounds.

Abstract: Disclosed are unsymmetrical squaraine compounds of the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of alkyl, aryl heterocyclic, benzyl, and halobenzyl; and X.sub.1, X.sub.2 and X.sub.3 are independently selected from the group consisting of hydrogen, alkyl, halogen, carboxy, and hydroxy; and photoresponsive imaging members having incorporated therein the aforementioned squaraine compounds.

Abstract: An improved process for the preparation of mixed squaraine compositions which comprises reacting squaric acid, an aromatic amine, and a fluoroaniline, in the presence of an aliphatic alcohol, and an optional azeotropic substance.

Abstract: An improved process for the preparation of mixed squaraine compositions which comprises reacting squaric acid, an aromatic amine, and a fluoroaniline, in the presence of an aliphatic alcohol, and an optional azeotropic substance.

Abstract: Photoresponsive devices, including layered photoresponsive devices comprised of a photoconductive layer of squaraine compositions of the following formula: ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected from the group consisting of alkyl substitutents and aryl substituents.

Abstract: Disclosed is an improved process for the preparation of squaraine compositions which comprises reacting squaric acid, an aromatic amine, and a composition selected from the group consisting of phenols and phenol squaraines, in the presence of an aliphatic alcohol, and an optional azeotropic substance.

Abstract: Squaraine compositions of the following formula ##STR1## wherein Ar is selected from the moieties specified in the specification are useful for incorporation into layered photoresponsive devices.

Abstract: An improved photoresponsive device comprised in the order stated of (1) a supporting substrate, (2) a photoconductive layer comprised of squaraine compositions of the following formula: ##STR1## wherein Ar is selected from the moieties specified resulting in the following -squaraines:I. bis-9-(8-hydroxyjulolidinyl)squaraine ##STR2## II. bis-9-(8,10-dihydroxyjulolidinyl)squaraine ##STR3## III. bis(4-dimethylamino-2-methylthiophenyl)squaraine ##STR4## and IV. bis(2,6-dihydroxy-4-dimethylaminophenyl)squaraine ##STR5## and (3) a diamine hole transport layer.