Abstract: An optical fiber comprises a core 1 extending in a longitudinal direction and a cladding 3 of silica aerogel preferably having a hydrophobic property to provide a high optical transmission efficiency. The silica aerogel of the cladding is prepared by polymerizing a hydrolyzed alkoxysilane before a supercritical drying treatment and is subjected to a hydrophobic treatment before or during the supercritical drying.

Abstract: An interface between an ATM network and a local network includes a cell disassembler for disassembling ATM cells from the ATM network and transmitting a disassembled signal to the local network. A cell assembler assembles a signal from the local network into ATM cells and transmitting the ATM cells to the ATM network. A cell loss detector is provided for detecting a loss of a cell in a series of ATM cells from the ATM network. A signaling cell detector detects a call setup ATM cell from the ATM network. A coincidence gate produces an output when there is a coincidence between the detection of the cell loss and the detection of the call setup ATM cell. When the coincidence is detected, a busy tone is supplied to the cell assembler, where it is assembled into ATM cells and transmitted to the ATM network.

Abstract: In an environment using the automatic log-on function in a parallel computer system in which one application program runs on a plurality of processors, the concentration of sessions to the application program on a particular processor for which the activation has been completed when the parallel computer system is later activated is prevented and hence the distribution of load is attained. When terminals have been activated or powered on, the session establishment by the automatic log-on function is not executed even if the activation of an application program on one of the processors of the parallel computer system has been completed but the activation status of the application programs on other processors are checked or the execution of the automatic log-on function is suspended for a predetermined time period to control the execution start time of the automatic log-on function.

Abstract: A hydrophobic aerogel having excellent transparency is formed by the following process of the present invention. That is, a first gel having a SiO.sub.2 skeleton structure is prepared by hydrolysis and condensation of an alkoxysilane compound in the presence of a solvent. The solvent contained in the first gel is replaced at least partially with a medium to form a second gel. The second gel is reacted with a hydrophobic agent having hydrophobic groups as well as functional groups reactive with silanol groups under a supercritical condition of the medium to form a hydrophobic gel. The medium contained in the hydrophobic aerogel is removed by a supercritical drying method, so that the hydrophobic aerogel having improved transparency and an extremely fine porous structure is obtained.

Abstract: This invention relates to a method for manufacturing an inorganic porous layered member which can maintain a sufficient distance between layers to show a high degree of heat insulating properties. In the manufacturing method for the inorganic porous layered member according to the present invention, an inorganic layered compound 12 having swelling charecteristics is swelled, and an inorganic pillar and an organic pillar are intercalated to form inorganic compound 16 between layers 14 of the inorganic layered compound 12. Fine gaps are thus formed in a wide range by the intercalation of the inorganic compound 16 between the layers 14 to maintain a sufficient distance between the layers 14, and the inorganic porous layered member 10 having high heat insulating properties is thus produced.

Abstract: A porous clay composite having fine metal particles deposited substantially only on surfaces of inorganic particles which are intercalated between layers of an expandable clay is obtained. After the expandable clay is expanded with a solvent into an expanded clay, the inorganic particles are intercalated between the layers of the expanded clay. The inorganic particles have photo-semiconducting property, that is, a plurality of carriers such as electrons and holes are released from the inorganic particles by irradiation of a light such as ultraviolet light. A solution including metal ions is mixed with the inorganic particles intercalated clay to form a mixed solution thereof. Subsequently, the light is irradiated to the mixed solution to deposit the fine metal particles substantially only on the inorganic particles which are intercalated between the layers of the expanded clay, so that the porous clay composite is formed in the mixed solution.

Abstract: A disc apparatus includes a surface having a slot used for inserting therethrough a disc and a guide mounted to the surface so as to be rotatable up to a position substantially perpendicular to the surface, the guide having a face on the substantial same level as that of an edge of the slot, the face having dimensions enough to cover the slot. A plurality of grooves or a brush extending longitudinally with respect to the slot may be provided on the guide. A projection is projected in a direction substantially perpendicular to both one edge of the slot and the surface of the apparatus. The projection serves to make the positioning when inserting the disc easy. A magnetic substance and a magnet are respectively mounted to positions of the guide and the surface of the apparatus corresponding to each other. The magnetic substance and the magnet serve to bring the guide into contact with the apparatus and thus are effective for preventing the dust from entering into the apparatus.

Abstract: A method of preparing an inorganic porous member causes a layered inorganic compound in swelled state with a solvent contained therein to be dried in a super critical state, so as to have holes held between respective layers of the inorganic compound, whereby the layered compound can be excellently maintained with less agglomeration caused upon removal of the solvent and the hole volume in the entire inorganic porous member can be remarkably increased.

Abstract: A method for manufacturing a fine porous member provides that vacant space within the porous member is sufficiently finely small such that the thermal conductivity of the member is lower than that of stationary air. In the method, a fine particle powder together with an ultrafine particle powder preliminarily subjected to a surface treatment for prevention of cohesiveness and employed at least as a part of the fine particle powder, are molded into the fine porous member, whereby the vacant space between the respective particles are made finely small to a remarkable extent and the porous member is provided as highly adapted to be used as a heat insulator.

Abstract: In order to increase the heat exchange capacity and efficiency of a cooling fin for an automotive radiator, air conditioner heat exchanger, or the like, a plurality of small triangular or similar shaped projections which produce a texture similar to that of a vegetable grater, are arranged to project into the flow of a fluid medium which passes over the fin in a manner to split a part of the flow into spiralling flow patterns which curl along the surface of fin downstream of the projections and transfer heat from said surface to the fluid medium or vice versa.