Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material, adsorbing residual contaminants from the liquid fraction are adsorbed onto decomtaminated solids to produce decontaminated liquids and contaminated solids.

Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises leaching a mixture of solids, water and contaminant in a three step process with solvents to obtain contaminated solvent and water and a mixture of decontaminated solids and solvent. The contaminant is stripped from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants.

Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material adsorbing residual contaminants from the liquid fraction are adsorbed onto decontaminated solids to produce decontaminated liquids and contaminated solids.

Abstract: A method and apparatus is provided for characterizing magnetic coating compositions that contain magnetic particles dispersed in a solvent resin matrix. The coating composition, as it passes through a tube, is subjected to an alternating magnetic field and perpendicular thereto a constant magnetic field of appropriate field strength and duration. Via a measuring coil surrounding the tube the induced signal in the composition is monitored and the degree of dispersion, is measured by measuring the magnetic susceptibility of the coating material. By applying a constant magnetic field the degree of dispersion cna be changed at least for a certain time. The method and apparatus of the present invention can be incorporated into a coating apparatus to monitor and improve the magnetic characteristics of the coating material being applied to a substrate.

Abstract: Method for measuring the properties of a slider/disk interface in a magnetic disk storage apparatus by measuring a triboelectric current flowing between disk and slider. Rotational speed is adjusted between 100 and 500 rpm so as to obtain a frictional contact between disk and slider. The shape of the tribo current curve obtained during the measuring time interval is analyzed. An early maximum of the tribo current amplitude and a subsequent continual decay indicates a good slider/disk interface and a long lifetime.

Abstract: The magnetic disk contains on a disk substrate a magnetic layer comprising a binder, magnetic particles and abrasion-resistant particles, the abrasion-resistant particles being enveloped with a layer intensifying the bond between binder and abrasion-resistant particles. The enveloping layer either has a large specific surface and consists e.g. of SiO.sub.2 /Al.sub.2 O.sub.3 produced by processing the particles with an alkali metal silicate solution and an aluminum sulphate solution, or it is chemically bonded to the binder by enveloping the particles with poly(tetrafluroethylene) and coupling the latter, via an amino bridge to the binder, e.g. an epoxide resin.The magnetic disk according to the invention minimizes the abrasion of the magnetic layer as well as the damaging of the magnetic layer and of the magnetic head by knocked-out abrasion-resistant particles.

Abstract: For characterizing coating compositions with magnetic particles the coating composition is subjected to an alternating magnetic field of variable frequency. The field induced by the coating composition after energization is recorded, and thus the susceptibility of the coating composition is measured. Depending on the variable frequency, conclusions can be made regarding the degree of dispersion, particle density, and viscosity of the coating composition. The variable frequency is between 1 and 100 cps, and the field intensity of the energizing field should be lower than 10 Oerstedt. The coating composition is fluid or stagnant in a pipe *1, 11 which is surrounded by field coil and measuring coil.

Abstract: Multi-layer magnetic thin film disks comprising a synthetic resin layer on an aluminum-containing substrate and an overlying metallic magnetic layer, are liable to have pin holes in the synthetic resin layer caused by galvanic corrosion of the aluminum in the substrate. The pin holes are passivated by aluminum oxide produced therein by anodically oxidizing the aluminum of the substrate in an electrolytic bath, the electric voltage of which is well below the normal passivation voltage for aluminum.