Abstract: The present invention discloses methods to create higher quality group III-nitride wafers that then generate improvements in the crystalline properties of ingots produced by ammonothermal growth from an initial defective seed. By obtaining future seeds from carefully chosen regions of an ingot produced on a bowed seed crystal, future ingot crystalline properties can be improved. Specifically the future seeds are optimized if chosen from an area of relieved stress on a cracked ingot or from a carefully chosen N-polar compressed area. When the seeds are sliced out, miscut of 3-10° helps to improve structural quality of successive growth. Additionally a method is proposed to improve crystal quality by using the ammonothermal method to produce a series of ingots, each using a specifically oriented seed from the previous ingot. When employed, these methods enhance the quality of Group III nitride wafers and thus improve the efficiency of any subsequent device.

Abstract: A work vehicle is articulated with a front frame and a rear frame linked to the front frame. The work vehicle includes a hydraulic actuator, a control valve, an operation member and a force imparting component. The hydraulic actuator is configured to be hydraulically driven to change a steering angle of the front frame with respect to the rear frame. The control valve is configured to control flow of fluid supplied to the hydraulic actuator. The operation member is linked to the control valve and configured to be operated by an operator. The force imparting component is configured to impart an assist force or a counterforce to an operation of the operation member.

Abstract: An articulated work vehicle with linked front and rear frames includes a joystick lever, a hydraulic actuator, a control valve, a force imparting component, a joystick displacement sensor, a steering angle sensor, and a controller. The joystick lever is operated to allow a target steering angle to be set. The hydraulic actuator is driven hydraulically to change an actual steering angle. The control valve controls flow of fluid supplied to the hydraulic actuator to eliminate deviation between the target and actual steering angles. The force imparting component imparts an assist force or a counterforce to the operation of the joystick lever. The controller controls the force imparting component so that a counterforce is imparted to the operation of the joystick lever when the joystick lever has been operated in an opposite direction from a rotation direction of the front frame based on detections of the sensors.

Abstract: An articulated work vehicle with linked front and rear frames includes a joystick lever, a force imparting component, and a controller. The joystick lever can be moved to an inside or an outside with respect to an operator's seat by being operated by an operator, to change a steering angle of the front frame with respect to the rear frame. The force imparting component is configured to impart an assist force or a counterforce to an operation of the joystick lever by the operator. The controller controls the force imparting component so that an operating force required to move the joystick lever to the outside is different from an operating force required to move the joystick lever to the inside.

Abstract: An articulated work vehicle with linked front and rear frames includes a hydraulic actuator, a joystick lever operated by an operator, a control valve, a force imparting component, and a controller. The hydraulic actuator is driven hydraulically to change a steering angle of the front frame with respect to the rear frame. The control valve is linked to the joystick lever, to control flow of fluid supplied to the hydraulic actuator according to an operation amount of the joystick lever, and to restrict the operation amount of the joystick lever to a predetermined range. The force imparting component imparts an assist force or a counterforce to the operation of the joystick lever by the operator. The controller controls the force imparting component so as to decrease the assist force or increase the counterforce before the operation of the joystick lever is restricted by the control valve.

Abstract: Provided is a magneto-optical material which does not absorb fiber laser light in a wavelength range of 0.9-1.1 ?m and does not cause a thermal lens, while having a larger Verdet constant than TGG crystals, and which is suitable for constituting a magneto-optical device such as an optical isolator. This magneto-optical material is formed of a single crystal of a rare earth oxysulfide that is represented by formula (1) or a transparent ceramic which contains, as a main component, a rare earth oxysulfide that is represented by formula (1), and this magneto-optical material has a Verdet constant of 0.14 min/(Oe·cm) or more at the wavelength of 1,064 nm. (TbxR1-x)2O2S??(1) (In the formula, x is 0.3 or more but less than 1; and R represents at least one rare earth element that is selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium.

Abstract: An articulated work vehicle with linked front and rear frames includes a joystick lever, a force imparting component, a speed sensor, and a controller. The joystick lever is configured to change a steering angle of the front frame with respect to the rear frame by operation by an operator. The force imparting component is configured to impart an assist force or a counterforce to operation of the joystick lever by the operator. The speed sensor is configured to sense speed of the work vehicle. The controller is configured to control the force imparting component so as to impart the assist force or the counterforce according to the speed sensed by the speed sensor.

Abstract: Provided, as a transparent magneto-optical material which does not absorb fiber laser light within a wavelength range of 0.9-1.1 ?m and is thus suitable for constituting a magneto-optical device such as an optical isolator wherein the formation of a thermal lens is suppressed, is a magneto-optical material which is composed of a transparent ceramic that contains a complex oxide represented by formula (1) as a main component, or which is composed of a single crystal of a complex oxide represented by formula (1). Tb2xR2(2-x)O8-x??(1) (In the formula, 0.800<x<1.00, and R represents at least one element selected from the group consisting of silicon, germanium, titanium, tantalum tin, hafinum and zirconium (excluding the cases where R represents only silicon, germanium or tantalum).

Abstract: The present invention discloses a production method for group III nitride ingots or pieces such as wafers. To solve the coloration problem in the wafers grown by the ammonothermal method, the present invention composed of the following steps; growth of group III nitride ingots by the ammonothermal method, slicing of the ingots into wafers, annealing of the wafers in a manner that avoids dissociation or decomposition of the wafers. This annealing process is effective to improve transparency of the wafers and/or otherwise remove contaminants from wafers.

Abstract: The present invention discloses methods to create higher quality group III-nitride wafers that then generate improvements in the crystalline properties of ingots produced by ammonothermal growth from an initial defective seed. By obtaining future seeds from carefully chosen regions of an ingot produced on a bowed seed crystal, future ingot crystalline properties can be improved. Specifically, the future seeds are optimized if chosen from an area of relieved stress on a cracked ingot or from a carefully chosen N-polar compressed area. When the seeds are sliced out, miscut of 3-10° helps to improve structural quality of successive growth. Additionally a method is proposed to improve crystal quality by using the ammonothermal method to produce a series of ingots, each using a specifically oriented seed from the previous ingot. When employed, these methods enhance the quality of Group III nitride wafers and thus improve the efficiency of any subsequent device.

Abstract: The present invention discloses a method of removing contaminant from group III nitride single-crystal wafers. The method involves annealing a wafer to concentrate a contaminant in a region of the crystal near the surface of the crystal and removing some of the crystal near the surface that contains at least a portion of the region containing concentrated contaminant. The resultant thinner wafer therefore has less contaminant in it.

Abstract: Provided is a light transmitting metal oxide sintered body manufacturing method for obtaining a light transmitting sintered body, the main component of which is metal oxide, by carrying out hot isostatic pressing at a HIP heat processing temperature (T) set in a temperature range of 1000-2000° C. The light transmitting metal oxide sintered body manufacturing method, by which light transmitting properties can be improved, is characterized by the following: in the temperature elevating step of the hot isostatic pressing, a temperature range (S) from room temperature to the HIP heat processing temperature (T) is divided into a plurality of stages; for each divided stage the temperature elevation rate is controlled; and the temperature elevation rate of a final stage (14) that includes at least the HIP heat processing temperature (T) is 10° C./h to 180° C./h.

Abstract: Provided is a magneto-optical material which does not absorb fiber laser light in a wavelength range of 0.9-1.1 ?m and does not cause a thermal lens, while having a larger Verdet constant than TGG crystals, and which is suitable for constituting a magneto-optical device such as an optical isolator. This magneto-optical material is formed of a single crystal of a rare earth oxysulfide that is represented by formula (1) or a transparent ceramic which contains, as a main component, a rare earth oxysulfide that is represented by formula (1), and this magneto-optical material has a Verdet constant of 0.14 min/(Oe·cm) or more at the wavelength of 1,064 nm. (TbxR1-x)2O2S??(1) (In the formula, x is 0.3 or more but less than 1; and R represents at least one rare earth element that is selected from the group consisting of yttrium, lutetium, gadolinium, holmium, scandium, ytterbium, europium and dysprosium.

Abstract: This invention provides a transparent magnetooptical material that is suitable for use in a magnetooptical device such as an optical isolator. Said magnetooptical material comprises either a transparent ceramic consisting primarily of a complex oxide that can be represented by formula (1) or a single crystal of such a complex oxide. Said magnetooptical material does not absorb fiber-laser light in the 0.9-1.1 ?m wavelength range, does not cause heat lensing, and has a higher Verdet constant than TGG crystals, with a Verdet constant of at least 0.14 min/(Oe·cm) at a wavelength of 1,064 nm. Tb2R2O7??(1) (In formula (1), R represents one or more elements selected from among the group consisting of silicon, germanium, titanium, tantalum, tin, hafnium, and zirconium (but not silicon only, germanium only, or tantalum only).

Abstract: Present invention discloses a high-pressure vessel of large size formed with a limited size of e.g. Ni—Cr based precipitation hardenable superalloy. Vessel may have multiple zones. For instance, the high-pressure vessel may be divided into at least three regions with flow-restricting devices and the crystallization region is set higher temperature than other regions. This structure helps to reliably seal both ends of the high-pressure vessel, at the same time, may help to greatly reduce unfavorable precipitation of group III nitride at the bottom of the vessel. Invention also discloses novel procedures to grow crystals with improved purity, transparency and structural quality. Alkali metal-containing mineralizers are charged with minimum exposure to oxygen and moisture until the high-pressure vessel is filled with ammonia. Several methods to reduce oxygen contamination during the process steps are presented.

Abstract: Present invention discloses a high-pressure vessel of large size formed with a limited size of e.g. Ni—Cr based precipitation hardenable superalloy. Vessel may have multiple zones. For instance, the high-pressure vessel may be divided into at least three regions with flow-restricting devices and the crystallization region is set higher temperature than other regions. This structure helps to reliably seal both ends of the high-pressure vessel, at the same time, may help to greatly reduce unfavorable precipitation of group III nitride at the bottom of the vessel. Invention also discloses novel procedures to grow crystals with improved purity, transparency and structural quality. Alkali metal-containing mineralizers are charged with minimum exposure to oxygen and moisture until the high-pressure vessel is filled with ammonia. Several methods to reduce oxygen contamination during the process steps are presented.

Abstract: Provided is a light transmitting metal oxide sintered body manufacturing method for obtaining a light transmitting sintered body, the main component of which is metal oxide, by carrying out hot isostatic pressing at a HIP heat processing temperature (T) set in a temperature range of 1000-2000° C. The light transmitting metal oxide sintered body manufacturing method, by which light transmitting properties can be improved, is characterized by the following: in the temperature elevating step of the hot isostatic pressing, a temperature range (S) from room temperature to the HIP heat processing temperature (T) is divided into a plurality of stages; for each divided stage the temperature elevation rate is controlled; and the temperature elevation rate of a final stage (14) that includes at least the HIP heat processing temperature (T) is 10° C./h to 180° C./h.

Abstract: Provided is a method of manufacturing a transparent sesquioxide sintered body by which a transparent M2O3 type sesquioxide sintered body can be manufactured. A powder including particles of an oxide of at least one rare earth element selected from Y, Sc or lanthanide elements and Zr oxide particles is prepared as a raw material powder, wherein in the particle size distribution of the rare earth element oxide particles, or in the particle size distribution of secondary particles in the case where the rare earth element oxide particles are agglomerated to form the secondary particles, the particle diameter D2.5 value at which the cumulative particle amount from the minimum particle size side is 2.5% based on the total particle amount is in the range from 180 nm to 2000 nm, inclusive. The raw material powder is press molded into a predetermined shape, followed by sintering.

Abstract: A work vehicle includes a pair of booms, a link mechanism and a control unit. The booms are attached to a front part of a vehicle body in an upwardly and downwardly rotatable state. The link mechanism couples a working unit to tips of the booms. The link mechanism is configured to keep the working unit in a posture generally parallel to the ground without rotating the working unit with respect to the ground while the booms are elevated from a position where the working unit is disposed on the ground when the working unit is a fork. The control unit is configured to execute a tilt angle adjusting control for the working unit in accordance with variation in an angle of the booms while the booms are elevated when a tilt angle of the working unit is greater than or equal to a predetermined threshold.

Abstract: The present invention discloses methods to produce large quantities of polycrystalline GaN for use in the ammonothermal growth of group III-nitride material. High production rates of GaN can be produced in a hydride vapor phase growth system. One drawback to enhanced polycrystalline growth is the increased incorporation of impurities, such as oxygen. A new reactor design using non-oxide material that reduces impurity concentrations is disclosed. Purification of remaining source material after an ammonothermal growth is also disclosed. The methods described produce sufficient quantities of polycrystalline GaN source material for the ammonothermal growth of group III-nitride material.