Abstract: An organic light emitting device including an anode; a hole transport region on the anode; an emission layer on the hole transport region; an electron transport region on the emission layer; and a cathode on the electron transport region, wherein the hole transport region includes: a first hole transport layer including a first hole transport material represented by the following Formula 1 or a second hole transport material represented by the following Formula 2; and a second hole transport layer on the first hole transport layer, the second hole transport layer including a third hole transport material represented by the following Formula 3 or a fourth hole transport material represented by the following Formula 4:

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. A pair of ribs are positioned within the channel. The ribs may diverge away from one another and may have a first rib located in a toe portion of the channel and a second rib located in the heel portion of the channel.

Abstract: A golf club head has a body defining a ball striking face. The body further has a first leg extending away from the ball striking face and a second leg extending away from the ball striking face wherein a void is defined between the first leg and the second leg. The body further defines a cover that extends over the void. The golf club head may further have support structures and adjustable weight members.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. The channel may have a cross-sectional profile that is asymmetric with a front wall and a rear wall where the front wall is longer than the rear wall. The channel may also have a center thickness that is different than a thickness at the heel and toe sides.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. A pair of ribs are positioned within the channel. The ribs may diverge away from one another and may have a first rib located in a toe portion of the channel and a second rib located in the heel portion of the channel.

Abstract: An organic light emitting device including an anode; a hole transport region on the anode; an emission layer on the hole transport region; an electron transport region on the emission layer; and a cathode on the electron transport region, wherein the hole transport region includes: a first hole transport layer including a first hole transport material represented by the following Formula 1 or a second hole transport material represented by the following Formula 2; and a second hole transport layer on the first hole transport layer, the second hole transport layer including a third hole transport material represented by the following Formula 3 or a fourth hole transport material represented by the following Formula 4:

Abstract: A golf club head has a body defining a ball striking face. The body further has a first leg extending away from the ball striking face and a second leg extending away from the ball striking face wherein a void is defined between the first leg and the second leg. The body further defines a cover that extends over the void. The golf club head may further have support structures and adjustable weight members.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball where the face has multiple thickness regions. The face has a center region, an upper region, a lower region, a toe region, and a heel region. The upper and lower regions have a ramped thickness extending from a center region to an upper and lower edge of the face. The heel and toe regions have a constant face thickness and have a thickness less than the other regions. Additionally, the club head body has a flange where the face is welded to the club head body. The flange has a thickness that is greater than the thickness of the heel and toe regions of the face.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. The channel may have a cross-sectional profile that is asymmetric with a front wall and a rear wall where the front wall is longer than the rear wall. The channel may also have a center thickness that is different than a thickness at the heel and toe sides.

Abstract: An organic light emitting device including an anode; a hole transport region on the anode; an emission layer on the hole transport region; an electron transport region on the emission layer; and a cathode on the electron transport region, wherein the hole transport region includes: a first hole transport layer including a first hole transport material represented by the following Formula 1 or a second hole transport material represented by the following Formula 2; and a second hole transport layer on the first hole transport layer, the second hole transport layer including a third hole transport material represented by the following Formula 3 or a fourth hole transport material represented by the following Formula 4:

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball where the face has multiple thickness regions. The face has a center region, an upper region, a lower region, a toe region, and a heel region. The upper and lower regions have a ramped thickness extending from a center region to an upper and lower edge of the face. The heel and toe regions have a constant face thickness and have a thickness less than the other regions. Additionally, the club head body has a flange where the face is welded to the club head body. The flange has a thickness that is greater than the thickness of the heel and toe regions of the face.

Abstract: A polycyclic compound and an organic electroluminescence device including the same. The polycyclic compound according to an example embodiment is represented by the following Formula 1. wherein in Formula 1, Cy1 is carbonyl-containing five- or six-membered and substituted or unsubstituted cyclic hydrocarbon or substituted or unsubstituted heterocycle, and R1 to R4 are each independently a hydrogen atom or a group represented by the following Formula 2 or 3.

Abstract: An organic electroluminescence device in which a polycyclic compound including an electron donor and an electron acceptor is included in an emission layer is provided. The electron donor contains an acridine derivative or a dibenzo-azasiline derivative, and the electron acceptor contains B as a ring-forming atom, O or S directly bonded to B, and a heterocyclic group in which three or five hexagonal rings are condensed. Accordingly, an organic electroluminescence device having high efficiency may be achieved.

Abstract: A nitrogen-containing compound and an organic electroluminescence device including the same, the nitrogen-containing compound being represented by the following Formula 1:

Abstract: An organic electroluminescence device includes a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode. The emission layer may include a compound including a first phenyl group that is substituted with at least one cyano group and a second phenyl group that is substituted with five substituted or unsubstituted carbazole groups, the second phenyl group being directly bonded to the first phenyl group.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball where the face has multiple thickness regions. The face has a center region, an upper region, a lower region, a toe region, and a heel region. The upper and lower regions have a ramped thickness extending from a center region to an upper and lower edge of the face. The heel and toe regions have a constant face thickness and have a thickness less than the other regions. Additionally, the club head body has a flange where the face is welded to the club head body. The flange has a thickness that is greater than the thickness of the heel and toe regions of the face.

Abstract: A golf club head has a body defining a ball striking face. The body further has a first leg extending away from the ball striking face and a second leg extending away from the ball striking face wherein a void is defined between the first leg and the second leg. The body further defines a cover that extends over the void. The golf club head may further have support structures and adjustable weight members.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. The channel may have a cross-sectional profile that is asymmetric with a front wall and a rear wall where the front wall is longer than the rear wall. The channel may also have a center thickness that is different than a thickness at the heel and toe sides.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball where the face has multiple thickness regions. The face has a center region, an upper region, a lower region, a toe region, and a heel region. The upper and lower regions have a ramped thickness extending from a center region to an upper and lower edge of the face. The heel and toe regions have a constant face thickness and have a thickness less than the other regions. Additionally, the club head body has a flange where the face is welded to the club head body. The flange has a thickness that is greater than the thickness of the heel and toe regions of the face.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball and a channel extending across a portion of the sole. The channel may be recessed from adjacent surfaces of the sole and have a depth of recession from the adjacent surfaces of the sole. The channel may have a cross-sectional profile that is asymmetric with a front wall and a rear wall where the front wall is longer than the rear wall. The channel may also have a center thickness that is different than a thickness at the heel and toe sides.