Abstract: A laser oscillation mechanism of a laser beam irradiation unit has a first mode to break growing debris, a second mode to suppress generation of molten debris, and a third mode to break the growing debris and suppress generation of the molten debris. The laser oscillation mechanism includes a selecting part that selects any of the first mode, the second mode, and the third mode. The laser oscillation mechanism sets a repetition frequency with a first group being one unit in the first mode, and sets a repetition frequency with a second group being one unit in the second mode, and sets a repetition frequency with a third group being one unit in the third mode.

Abstract: A laser processing apparatus includes a laser oscillating mechanism for emitting pulsed laser beams. The laser oscillating mechanism includes a group setting section for establishing the number of pulsed laser beams to be applied to a workpiece until a time after which melted debris produced by the pulsed laser beams applied to the workpiece is solidified, and assigns the pulsed laser beams to a group, under conditions that, within a period of time which is shorter than a period of time in which the melted debris is produced, and within a period of time after which a plasma generated by the pulsed laser beam becomes extinct, a next pulsed laser beam is applied to the workpiece to sustain the plasma uninterruptedly to break growing debris, and a time interval setting section for establishing a time interval between the group and another group adjacent thereto.

Abstract: A laser beam irradiating unit of a laser processing apparatus includes a laser oscillating mechanism. The laser oscillating mechanism includes a group setting unit configured to, on a condition that a pulsed laser beam is applied at shorter time intervals than a length of time that molten debris is generated, set the number of pulsed laser beams to be applied until a time that the molten debris is solidified and set the number of pulsed laser beams as one group. A time interval setting unit is configured to set a time until heat generated by application of the pulsed laser beams of the one group is cooled, which serves as a time interval between the one group and an adjacent group, and set time intervals of the pulsed laser beams constituting the one group. The laser oscillating mechanism sets a repetition frequency with the one group as one unit.

Abstract: A laser processing apparatus includes a chuck table that holds a workpiece, a laser beam irradiation unit that irradiates the workpiece with a laser beam, and a feed mechanism that moves the chuck table and the laser beam irradiation unit relative to each other to execute processing feed. The laser beam irradiation unit includes a laser oscillation mechanism that emits a pulsed laser beam and a beam condenser that condenses the pulsed laser beam emitted by the laser oscillation mechanism and irradiates the workpiece with the pulsed laser beam. The laser oscillation mechanism has a group setting part that sets multiple pulsed laser beams into one group and a time interval setting part that sets a time interval of the pulsed laser beams that configure the one group, and sets the repetition frequency in such a manner as to regard the one group as one unit.

Abstract: A gelling material is composed of water-absorbent resin 12 wrapped in a bag composed of two laminated water-soluble sheets 1.1, the water-absorbent resin being prepared so as to enable the bag to be disintegrated by an inner pressure generated when an expanded volume of the water-absorbent resin by absorbing water through the bag exceeds a maximum volume capacity. When the gelling material is added to the aqueous fluid, the water-absorbent resin 12 is spread in the aqueous fluid at a stroke, and is diffused uniformly. Thus, the water-absorbent resin 12 is brought fully in contact with the aqueous fluid. Since this enables the aqueous fluid to be gelled in a short period of time, the aqueous fluid can be processed speedily. Even the aqueous fluids, which are difficult to be handled by the conventional gelling material, can be gelled conveniently in a short period of time, and the resulting gell can be easily handled, thereby enabling an easy disposal of the aqueous fluids, i.e., the gell.

Abstract: A gelling material is composed of water-absorbent resin 12 wrapped in a bag composed of two laminated water-soluble sheets 1.cndot.1, the water-absorbent resin being prepared so as to enable the bag to be disintegrated by an inner pressure generated when an expanded volume of the water-absorbent resin by absorbing water through the bag exceeds a maximum volume capacity. When the gelling material is added to the aqueous fluid, the water-absorbent resin 12 is spread in the aqueous fluid at a stroke, and is diffused uniformly. Thus, the water-absorbent resin 12 is brought fully in contact with the aqueous fluid.Since this enables the aqueous fluid to be gelled in a short period of time, the aqueous fluid can be processed speedily. Even the aqueous fluids, which are difficult to be handled by the conventional gelling material, can be gelled conveniently in a short period of time, and the resulting gell can be easily handled, thereby enabling an easy disposal of the aqueous fluids, i.e., the gell.

Abstract: A process for the production of alkylene glycols, which comprises causing a corresponding alkylene carbonate to react with water in the presence of a catalyst of at least one member selected from the group consisting of molybdenum and tungsten.

Abstract: A process for the production of alkylene glycols, which comprises causing a corresponding alkylene oxide to react with water in the presence of a catalyst of at least one member selected from the group consisting of molybdenum and tungsten.