Abstract: A vertical take-off and landing aircraft includes a propulsion mechanism that generates lift and thrust, a main frame that supports seating and a landing undercarriage, a sub-frame which supports the propulsion mechanism and is arranged so as to be swingable back and forth relative to the main frame, a motive power supply unit supported by the main frame and supplying motive power to the propulsion mechanism, a control stick connected to the sub-frame, and a main wing arranged on the propulsion mechanism, wherein the main wing is formed to be retracted to a position not interfering with an air flow of the propulsion mechanism in a normal time and to be movable to a position where lift is generated when thrust is lost. Gliding is made possible even if thrust is lost while increasing in size of a fuselage is avoided.

Abstract: There is provided a vertical take-off and landing aircraft including: a propulsion mechanism for generating lift and thrust; a power supply unit (e.g. an engine as a power source) for supplying power to the propulsion mechanism; a main frame for supporting the engine, a seat, and a landing undercarriage; a sub-frame for supporting the propulsion mechanism; a frame coupling unit for rotatably coupling the main frame and the sub-frame; and a control stick connected to the sub-frame, so that an occupant sitting on a seat operates a control stick thereby to move the sub-frame relative to the main frame so as to change the orientation of the propulsion mechanism.

Abstract: A vertical take-off and landing aircraft including a propulsion mechanism that generates lift and thrust, a main frame that supports seating and a landing undercarriage, a subframe which supports the propulsion mechanism and which is arranged so as to be swingable back and forth relative to the main frame, motive power supply means supported by the main frame and supplying motive power to the propulsion mechanism, and a control stick connected to the subframe in which the propulsion mechanism includes a pair of ducted fans arranged on a left side and a right side, respectively, of the main frame, swing shafts arranged in the ducted fans, and extending in a horizontal direction, and control vanes connected to the swing shafts, and swinging the control vane enables the subframe to move relative to the main frame. Maneuverability can be improved with addition of control mechanisms restrained.

Abstract: A vertical take-off and landing aircraft includes a propulsion mechanism having a fan for generating lift and thrust, an engine for supplying motive power to the propulsion mechanism, a frame coupling the propulsion mechanism and the engine, seating connected to and suspended from the frame so as to be swingable back and forth relative to the frame, a control stick connected to the frame, and a landing undercarriage connected to the seating, wherein the propulsion mechanism is connected to the frame such that the drive shaft of the fan is directed vertically during landing, and the frame is moved relative to the seating by manipulating the control stick, to change the orientation of the propulsion mechanism. The thrust can be controlled with simple configuration, and take-off and landing can be performed safely even in a small space surrounded by obstacles.

Abstract: A vertical take-off and landing aircraft includes a propulsion mechanism that generates lift and thrust, a main frame that supports seating and a landing undercarriage, a sub-frame which supports the propulsion mechanism and is arranged so as to be swingable back and forth relative to the main frame, a motive power supply unit supported by the main frame and supplying motive power to the propulsion mechanism, a control stick connected to the sub-frame, and a main wing arranged on the propulsion mechanism, wherein the main wing is formed to be retracted to a position not interfering with an air flow of the propulsion mechanism in a normal time and to be movable to a position where lift is generated when thrust is lost. Gliding is made possible even if thrust is lost while increasing in size of a fuselage is avoided.

Abstract: A vertical take-off and landing aircraft including a propulsion mechanism that generates lift and thrust, a main frame that supports seating and a landing undercarriage, a subframe which supports the propulsion mechanism and which is arranged so as to be swingable back and forth relative to the main frame, motive power supply means supported by the main frame and supplying motive power to the propulsion mechanism, and a control stick connected to the subframe in which the propulsion mechanism includes a pair of ducted fans arranged on a left side and a right side, respectively, of the main frame, swing shafts arranged in the ducted, fans, and extending in a horizontal direction, and control vanes connected to the swing shafts, and swinging the control vane enables the subframe to move relative to the main frame. Maneuverability can be improved with addition of control mechanisms restrained.

Abstract: There is provided a vertical take-off and landing aircraft including: a propulsion mechanism for generating lift and thrust; a power supply unit (e.g. an engine as a power source) for supplying power to the propulsion mechanism; a main frame for supporting the engine, a seat, and a landing undercarriage; a sub-frame for supporting the propulsion mechanism; a frame coupling unit for rotatably coupling the main frame and the sub-frame; and a control stick connected to the sub-frame, so that an occupant sitting on a seat operates a control stick thereby to move the sub-frame relative to the main frame so as to change the orientation of the propulsion mechanism.

Abstract: A vertical take-off and landing aircraft includes a propulsion mechanism having a fan for generating lift and thrust, an engine for supplying motive power to the propulsion mechanism, a frame coupling the propulsion mechanism and the engine, seating connected to and suspended from the frame so as to be swingable back and forth relative to the frame, a control stick connected to the frame, and a landing undercarriage connected to the seating, wherein the propulsion mechanism is connected to the frame such that the drive shaft of the fan is directed vertically during landing, and the frame is moved relative to the seating by manipulating the control stick, to change the orientation of the propulsion mechanism. The thrust can be controlled with simple configuration, and take-off and landing can be performed safely even in a small space surrounded by obstacles.

Abstract: Object of the present invention is to provide a preparation for oral cavity that is appropriately usable as a prophylactic agent for dental caries, a therapeutic agent for dental caries at early stage, a prophylactic and/or therapeutic agent for dentinal hypersensitivity, a preparation for the lining of a dentin cavity surface, or the like, which has a superior effect of sealing the dentinal tubules, is capable of improving the acid resistance of the teeth and re-calcifying the teeth, ensures a short-time treatment with an easy operation, and has a high safety and good aesthetic properties.

Abstract: Object of the present invention is to provide a preparation for oral cavity that is appropriately usable as a prophylactic agent for dental caries, a therapeutic agent for dental caries at early stage, a prophylactic and/or therapeutic agent for dentinal hypersensitivity, a preparation for the lining of a dentin cavity surface, or the like, which has a superior effect of sealing the dentinal tubules, is capable of improving the acid resistance of the teeth and re-calcifying the teeth, ensures a short-time treatment with an easy operation, and has a high safety and good aesthetic properties.

Abstract: Disclosed is a dental-caries detecting solution prepared by dissolving a dye capable of staining a carious region of a tooth to provide enhanced visibility of the carious region, in a water-miscible organic solvent, which is capable of distinctively staining only a first decalcified layer, or an outer layer of a softened dentine, to be removed, absolutely without staining a second layer, or an inner layer of the softened dentine, which should not be removed. In the dental-caries detecting solution, the water-miscible organic solvent contains a compound having a carbon number of 11 or more and including one or more hydroxyl groups. The water-miscible organic solvent is adjusted such that the dental-caries detecting solution has a viscosity of 300 to 1500 Cp.

Abstract: A two-part dental restoration composition composed of a powder and a liquid which are to be combined and evenly mixed prior to usage. The powder is composed of a fluoride containing and releasing glass having an average particulate size under one micron, an aromatic sulfinic acid or its salt and a tertiary amine. The liquid is composed of water-soluble methacryloxyalkyl phosphate, dimethacrylates, diluent monomers and a photoinitiator.

Abstract: A light-curable orthodontic bracket adhesive composition is provided for bonding an orthodontic bracket to the surface of a human tooth. The composition contains a particulate filler material, an acrylate-based resin, and a photoinitiator composition effective to catalyze polymerization upon irradiation. A method of using the composition is also provided.

Abstract: A dental material having X-ray contrastability which is excellent in strength, aesthetic appearance, workability, marginal blocking and the like and possesses high value in use can be provided by using a methacrylate having an aromatic hydrocarbon substituted by bromine in the molecule as polymerizable monomer and, as occasion demands, combining a filler and/or hardener suitably selected with this compound.

Abstract: Phosphate derivatives represented by the formula ##STR1## wherein R represents a group containing at least one reactive double bond and A represents a group which may optionally contain reactive double bonds are disclosed. The phosphate derivatives of the present invention have at least two reactive double bonds, and polymers prepared from these phosphate derivatives in the presence or absence of other polymerizable monomers are useful as fillers for human hard tissues such as bones and teeth.

Abstract: A cyclic pyrophosphate derivative having the formula ##STR1## wherein A represents a direct bond between the two phenyl rings or a divalent moiety selected from the group consisting of lower alkylene, aryl substituted lower alkylene, cycloalkylidene, sulfonyl and oxy;R.sup.1 represents alkyl, acryloyloxy lower alkyl or methacryloyloxy lower alkyl in which the lower alkyl can be substituted with halogen; andR.sup.2 represents independently hydrogen, halogen, lower alkyl or lower alkoxy;a method of preparing the same, a dental filling material comprising the same and a method of filling dental cavities are disclosed.

Abstract: Compositions capable of evaluating dental caries activity by making use of color reaction, which are composed of an aqueous solution containing coloring agents and water-soluble substances that are to produce an osmotic pressure higher than the physiological one on the cell membrane of cariogenic bacteria but free from any buffer action by themselves. Upon introducing dental plaque of a dental caries patient into this solution and thus measuring activity of the sordes by means of color reaction, it is possible to evaluate readily the status praesens of dental caries and its activity without any cultivation of cariogenic bacteria being required.