Abstract: Provided are a mutant cis-prenyltransferase (CPT) family protein and a method for producing a polyisoprenoid, which enable the production of a high molecular weight polyisoprenoid. Included is a mutant cis-prenyltransferase (CPT) family protein obtained by mutating the amino acid sequence of a C-terminal region of a cis-prenyltransferase (CPT) family protein not found on rubber particles to be identical or similar to the amino acid sequence of a C-terminal region of a cis-prenyltransferase (CPT) family protein found on rubber particles.

Abstract: Provided are a mutant cis-prenyltransferase (CPT) family protein and a method for producing a polyisoprenoid, which enable the production of a high molecular weight polyisoprenoid. Included is a mutant cis-prenyltransferase (CET) family protein obtained by mutating the amino acid sequence of a N-terminal region of a cis-prenyltransferase (CPT) family protein not found on rubber particles to be identical or similar to the amino acid sequence of a N-terminal region of a cis-prenyltransferase (CPT) family protein found on rubber particles, and mutating the amino acid sequence of a C-terminal region of the cis-prenyltransferase (CPT) family protein not found on rubber particles to be identical or similar to the amino acid sequence of a C-terminal region of a cis-prenyltransferase (CPT) family protein found on rubber particles.

Abstract: A golf club head having a hollow portion therein, the head includes a face portion, and a main body including a crown portion and a sole portion each extending backwardly from the face portion. The main body is provided with at least one slit that penetrates the main body and extends in a head-front-back direction. The at least one slit includes a pair of slit inner walls extending in the head-front-back direction and at least one joint connecting the pair of slit inner walls to each other.

Abstract: A tread portion 2 of a tire 1 includes a plurality of shoulder blocks 11 and a plurality of middle blocks 12. An inner edge 11B in the tire axial direction of a tread surface of each shoulder block 11 protrudes on an outer side in a tire radial direction with respect to a virtual profile 18. A side surface S on the inner side in the tire axial direction of each shoulder block 11 includes one first side surface S1 extending from the inner edge 11B toward a groove bottom, and at least one second side surface S2 extending from a bottom side end of the first side surface S1 toward the groove bottom, and the second side surface S2 is a surface inclined toward the inner side in the tire axial direction relative to the first side surface S1.

Abstract: A golf club head includes a weight object and a weight object receiving portion that is provided on an outer surface of the head and in which at least a part of the weight object is housed. The weight object or the weight object receiving portion includes a shape change mechanism that enables the weight object or the weight object receiving portion to change a shape of itself. The weight object receiving portion includes: a rotational force applying part that applies a rotational force on the weight object as a reaction generated when the weight object is pressed by the shape change; and a rotation prevention part that is located at a position abutting against the weight object when the rotational force is applied and that stops the weight object from being rotated by the rotational force and prevents rotation of the weight object.

Abstract: Provided is an evaluation method that can easily evaluate the percentage of voids in a rubber material. The present disclosure relates to an evaluation method including evaluating the percentage of voids in a rubber material with a strain applied thereto based on the ?void calculated from the following Equation (1) using the transmittance and thickness of the rubber material with no strain applied thereto and the transmittance and thickness of the rubber material with the strain applied thereto.

Abstract: A tread portion of a tire includes at least one land portion. The land portion includes an outer region disposed inwardly of a tread surface in a tire radial direction, an inner region disposed on an inner side in the tire radial direction, and at least one sipe. The sipe includes one outer sipe element extending in the outer region in a tire axial direction, and a plurality of inner sipe elements extending in the inner region. The inner sipe elements include a component extending in a tire circumferential direction, and is connected to the outer sipe element.

Abstract: A tire 1 includes a pair of crown circumferential grooves 30, a pair of shoulder circumferential grooves 31, a crown land portion 40, and a pair of middle land portions 41 and 42, the crown land portion 40 includes a main crown shallow groove 100 and at least two sub-crown shallow grooves 101 and 102 each extending so as to communicate with the crown circumferential groove 30 and the main crown shallow groove 100, the pair of middle land portions 41 and 42 include V-shaped slots 201 and 202, respectively, and the sub-crown shallow grooves 101 and 102 and the slots 201 and 202 are located so as to be substantially point-symmetrical about a midpoint between positions at which the adjacent sub-crown shallow grooves 101 and 102 communicate with the main crown shallow groove 100.

Abstract: A tyre includes a tread portion including first and second land portions. The first middle land portion is provided with first middle lateral grooves traversing the first middle land portion completely. The second middle land portion is provided with second middle lateral grooves traversing the second middle land portion completely. Each of the first middle lateral grooves and the second middle lateral grooves is a curved groove which includes a first convex portion located on a first side with respect to a groove-reference-straight-line that connects both ends of a groove centerline of the curved groove and a second convex portion located on a second side with respect to the groove-reference-straight-line, and a circumferential length of the groove-reference-straight-line of each first middle lateral groove is smaller than a circumferential length of the groove-reference-straight-line of each second middle lateral groove.

Abstract: A pneumatic tyre includes a tread portion provided with circumferential grooves to form circumferential land portions, a belt layer, and a band layer disposed outwardly in the tyre radial direction of the belt layer. The band layer includes a first layer covering an entire width of the belt layer, and second layers disposed outwardly in the tyre radial direction of the first layer and arranged separately in a tyre axially direction from one another. Each second layer is located radially inwardly of a respective one of the circumferential land portions. In each circumferential land portion, the second layer has at least one axial edge that is away at a distance (A) of equal to or more than 3.0 mm in the tyre axial direction from a groove bottom of one of the circumferential grooves nearest to the at least one axial edge.

Abstract: A tire includes a tread portion including a first tread edge, a second tread edge, a crown land portion arranged between the first tread edge and the second tread edge, and a first crown circumferential groove extending continuously in a tire circumferential direction adjacent to the crown land portion on a first tread edge side. The first crown circumferential groove includes a groove bottom having a plurality of protrusions projecting in a tire radial direction. The crown land portion is not provided with drainage grooves that have an opening width exceeding 2.0 mm at a ground contact surface of the crown land portion and a depth exceeding 2.0 mm of an area where a distance between two opposite groove walls thereof exceeds 2.0 mm. The crown land portion is provided with a plurality of sipes.

Abstract: Provided is a method of quantification of free sulfur that can accurately measure the free sulfur content of a rubber composition. The present disclosure relates to a method of quantification of free sulfur in a rubber composition, the method including extracting the free sulfur in the rubber composition with toluene.

Abstract: A tire includes a first middle land portion provided with middle lateral grooves that traverses the first middle land portion completely in the tire axial direction, and first middle sipes that extends from a first longitudinal edge of the first middle land portion and has terminal ends in the first middle land portion. Each middle lateral groove includes a first groove portion extending from the first longitudinal edge, a second groove portion extending from a second longitudinal edge, and a circumferential groove portion being in communication with the first and second groove portions. The circumferential groove portion includes a first circumferential groove edge on a first longitudinal edge side and a second circumferential groove edge on a second longitudinal edge side. The terminal ends of the first middle sipes are located on the second longitudinal edge side to the first circumferential groove edges of the circumferential groove portions.

Abstract: A motorcycle tire set includes a front-wheel tire and a rear-wheel tire. Each of the front and rear-wheel tires includes a carcass, a band layer arranged radially outwardly of the carcass in the tread portion, and a tread rubber arranged radially outwardly of the band layer. The carcass includes a carcass ply including carcass cords. The band layer includes a jointless band ply in which a band cord is circumferentially wound spirally at an angle equal to or less than 5 degrees. The tread rubber includes a crown rubber portion. An angle ?1 of the carcass cords of the front-wheel tire is 65 degrees or more with respect to the tire circumferential direction. A rubber hardness of the crown rubber portion of the rear-wheel tire is greater than a rubber hardness of the crown rubber portion of the front-wheel tire.

Abstract: A tire includes a tread portion including at least one circumferential groove extending continuously in a tire circumferential direction. The at least one circumferential groove includes a groove bottom having a plurality of protrusions projecting in a tire radial direction. Each of the plurality of protrusions has a longitudinally elongated shape with a width in a tire axial direction and a length in the tire circumferential direction that is greater than the width. Each of the plurality of protrusions includes a tapered portion whose width decreases in the tire circumferential direction.

Abstract: A tire includes a first middle land portion having circumferentially extending first and second longitudinal edges. The first middle land portion is provided with middle lateral grooves. At least one of the middle lateral grooves includes a first groove portion extending in the tire axial direction from the first longitudinal edge, and a second groove portion extending in the tire axial direction from the second longitudinal edge. The first groove portion and the second groove portion are offset in the tire circumferential direction to form a pair of circumferential groove edges between a pair of groove edges of the first groove portion and a pair of groove edges of the second groove portion. A maximum groove depth of the first groove portion is different from a maximum groove depth of the second groove portion.

Abstract: A tread portion includes a crown land portion including first and second longitudinal edges extending in the tire circumferential direction. The crown land portion is provided with first, second and third crown sipes. The first, second and third crown sipes open at the ground contact surface via respective chamfer portions. The first and third crown sipes extend from the first longitudinal edge and have closed ends in the ground contact surface. The second crown sipes extend from the second longitudinal edge and have closed ends in the ground contact surface. Each first crown sipe has a constant opening width in a longitudinal direction of the sipe. Each second crown sipe has a constant opening width in a longitudinal direction of the sipe. Each third crown sipe has an opening width which decreases continuously from the first longitudinal edge toward the closed end thereof.

Abstract: A golf club head includes: a head body that includes a cavity; a weight that is detachably attached to the cavity; and a cover that is openably and closably attached to the head body and that covers at least a part of the cavity when the cover is in a closed state. The weight is attached to the cavity in a state where the weight is slidingly movable in the cavity. In the closed state, the cover applies a pressing force to the weight. The weight may be fixed to the cavity by a static frictional force increased by the pressing force. The cavity may form a slide groove.

Abstract: Provided is a tire including a tread portion. The tread portion can include three circumferential grooves and four land portions. The circumferential grooves can include two shoulder circumferential grooves and one crown circumferential groove. The land portions can include two shoulder land portions and two middle land portions. The two middle land portions can each include a circumferential sipe, a plurality of first middle lateral grooves, and a plurality of second middle lateral grooves. The two shoulder land portions can each include a plurality of shoulder lateral grooves extending from a tread end and terminating in the shoulder land portion.