Abstract: A gas turbine engine for an aircraft includes a fan system having a reverse travelling wave first flap mode, Fan RTW, and including a fan located upstream of the engine core; a fan shaft; and a front engine structure arranged to support the fan shaft and having a front engine structure nodding mode comprising a pair of modes at similar, but not equal, natural frequencies in orthogonal directions; and a gearbox. An LP rotor system including the fan system and a gearbox output shaft arranged to drive the fan shaft has a first reverse whirl rotor dynamic mode, Rotor RW, and a first forward whirl rotor dynamic mode, 1FW. The engine has a maximum take-off speed, MTO. A backward whirl frequency margin of: the ? lowest ? frequency ? of ? either ? mode ? Fan ? RTW ? or ? Rotor ? RW at ? the ? MTO ? speed the ? MTO ? speed may be in the range from 15 to 50%.

Abstract: The present disclosure relates to systems, methods, and computer-readable media for facilitating the transparent insertion of network virtual appliances into a cloud computing system. For example, a transparent network virtual appliance system can dynamically, seamlessly, and quickly add one or more network virtual appliances utilizing a chained gateway load balancer. In particular, the transparent network virtual appliance system can provide additional services to an application virtual network within a cloud computing system without disrupting or modifying the existing architecture of the cloud computing system.

Abstract: A process for preparing a catalyst material, said catalyst material comprising a support material, a first metal and one or more second metals, wherein the first metal and the second metal(s) are alloyed and wherein the first metal is a platinum group metal and the second metal(s) is selected from the group of transition metals and tin provided the second metal(s) is different to the first metal is disclosed. The process comprises depositing a silicon oxide before or after deposition of the second metal(s), alloying the first and second metals and subsequently removing silicon oxide. A catalyst material prepared by this process is also disclosed.

Abstract: A gas turbine engine for an aircraft includes a fan system having a reverse travelling wave first flap mode, Fan RTW, and including a fan located upstream of the engine core; a fan shaft; and a front engine structure arranged to support the fan shaft and having a front engine structure nodding mode comprising a pair of modes at similar, but not equal, natural frequencies in orthogonal directions; and a gearbox. An LP rotor system including the fan system and a gearbox output shaft arranged to drive the fan shaft has a first reverse whirl rotor dynamic mode, Rotor RW, and a first forward whirl rotor dynamic mode, 1FW. The engine has a maximum take-off speed, MTO. A backward whirl frequency margin of: the ? ? lowest ? ? frequency ? ? of ? ? either ? ? mode ? ? Fan ? ? RTW ? ? or ? ? Rotor ? ? RW ? ? at the ? ? MTO ? ? speed the ? ? MTO ? ? speed may be in the range from 15 to 50%.

Abstract: An aircraft gas turbine engine includes a fan system having a reverse traveling wave first flap mode, Fan RTW, and including a fan upstream of the engine core; a fan shaft; and a front engine structure to support the shaft and having a front engine structure nodding mode FSN including two modes at similar, but unequal, natural frequencies in orthogonal directions; and a gearbox. The engine includes a gearbox, and a gearbox output shaft to couple output of the gearbox to the fan shaft. An LP rotor system including the fan system and the gearbox output shaft has a first reverse whirl rotor dynamic mode, Rotor RW.

Abstract: A load balancer capable of instantiating a data plane within the load balancer, deleting the data plane from the load balancer, and/or enacting a change to the data plane. The load balancer instantiates a data plane for an identified tenant. The instantiated data plane is placed in a data path of network data transmitted from one or more sources to a plurality of tenant addresses that each corresponds to a different tenant or group of tenants. The instantiated data plane is also dedicated to the identified tenant such that the data plane isolates first network data destined to a first tenant address that corresponds to the identified tenant from second network data destined to one or more other tenant addresses. The load balancer also deletes the instantiated data plane from the load balancer, or enacts a change to the instantiated data plane.

Abstract: A gas turbine engine, in particular an aircraft engine, includes: a turbine connected via an input shaft device to a gearbox device having a sun gear, a planet carrier having a plurality of planet gears attached thereto, and a ring gear, the sun gear is connected to the input shaft device, the planet carrier or the ring gear is connected to a propulsive fan via an output shaft device of the gearbox device, with a rear carrier bearing device radially between the planet carrier and a static structure on the input side of the gearbox device or a front carrier bearing device radially between the planet carrier and a static structure on the output side of the gearbox device.

Abstract: A process for preparing a catalyst material, said catalyst material comprising a support material, a first metal and one or more second metals, wherein the first metal and the second metal(s) are alloyed and wherein the first metal is a platinum group metal and the second metal(s) is selected from the group of transition metals and tin provided the second metal(s) is different to the first metal is disclosed. The process comprises depositing a silicon oxide before or after deposition of the second metal(s), alloying the first and second metals and subsequently removing silicon oxide. A catalyst material prepared by this process is also disclosed.

Abstract: A process for preparing a catalyst material, said catalyst material comprising a support material, a first metal and one or more second metals, wherein the first metal and the second metal(s) are alloyed and wherein the first metal is a platinum group metal and the second metal(s) is selected from the group of transition metals and tin provided the second metal(s) is different to the first metal is disclosed. The process comprises depositing a silicon oxide before or after deposition of the second metal(s), alloying the first and second metals and subsequently removing silicon oxide. A catalyst material prepared by this process is also disclosed.

Abstract: A load balancer capable of instantiating a data plane within the load balancer, deleting the data plane from the load balancer, and/or enacting a change to the data plane. The load balancer instantiates a data plane for an identified tenant. The instantiated data plane is placed in a data path of network data transmitted from one or more sources to a plurality of tenant addresses that each corresponds to a different tenant or group of tenants. The instantiated data plane is also dedicated to the identified tenant such that the data plane isolates first network data destined to a first tenant address that corresponds to the identified tenant from second network data destined to one or more other tenant addresses. The load balancer also deletes the instantiated data plane from the load balancer, or enacts a change to the instantiated data plane.

Abstract: A load balancer capable of adjusting how network data is distributed to a tenant or group of tenants by manipulating the data plane. The load balancer is placed directly in the flow path of network data that is destined for a tenant or group of tenants having a tenant address. The load balancer includes a control plane and one or more data planes. Each data plane may contain one or more network traffic multiplexors. Further, each data plane may be dedicated to a tenant or group of tenants. Data planes may be added or deleted from the load balancer; additionally, multiplexors may be added or deleted from a data plane. Accordingly, network data directed towards one tenant is less likely to affect the performance of load balancing performed for another tenant.

Abstract: A system performed by a computing device for validating routing tables of routing devices is provided. The routing tables map destination addresses to a next hops of the routing device. The system accesses one or more contracts that specify the desired behavior of a routing table of a routing device by specifying destination addresses and permissible next hops. For each routing device, the system generates a violation predicate for each contract that is applicable to the routing device. When a violation predicate is evaluated for a target destination address and a target next hop of the routing device, the violation predicate indicates whether the routing table violates the contract. The system then solves the violation predicates for all possible combinations of a target destination address and target next hops to determine whether any routing table violates the desired behavior of its routing device as specified by a contract.

Abstract: A process for preparing a catalyst material, said catalyst material comprising a support material, a first metal and one or more second metals, wherein the first metal and the second metal(s) are alloyed and wherein the first metal is a platinum group metal and the second metal(s) is selected from the group of transition metals and tin provided the second metal(s) is different to the first metal is disclosed. The process comprises depositing a silicon oxide before or after deposition of the second metal(s), alloying the first and second metals and subsequently removing silicon oxide. A catalyst material prepared by this process is also disclosed.

Abstract: A load balancer capable of adjusting how network data is distributed to a tenant or group of tenants by manipulating the data plane. The load balancer is placed directly in the flow path of network data that is destined for a tenant or group of tenants having a tenant address. The load balancer includes a control plane and one or more data planes. Each data plane may contain one or more network traffic multiplexors. Further, each data plane may be dedicated to a tenant or group of tenants. Data planes may be added or deleted from the load balancer; additionally, multiplexors may be added or deleted from a data plane. Accordingly, network data directed towards one tenant is less likely to affect the performance of load balancing performed for another tenant.

Abstract: A system performed by a computing device for validating routing tables of routing devices is provided. The routing tables map destination addresses to a next hops of the routing device. The system accesses one or more contracts that specify the desired behavior of a routing table of a routing device by specifying destination addresses and permissible next hops. For each routing device, the system generates a violation predicate for each contract that is applicable to the routing device. When a violation predicate is evaluated for a target destination address and a target next hop of the routing device, the violation predicate indicates whether the routing table violates the contract. The system then solves the violation predicates for all possible combinations of a target destination address and target next hops to determine whether any routing table violates the desired behavior of its routing device as specified by a contract.

Abstract: A system performed by a computing device for validating routing tables of routing devices is provided. The routing tables map destination addresses to a next hops of the routing device. The system accesses one or more contracts that specify the desired behavior of a routing table of a routing device by specifying destination addresses and permissible next hops. For each routing device, the system generates a violation predicate for each contract that is applicable to the routing device. When a violation predicate is evaluated for a target destination address and a target next hop of the routing device, the violation predicate indicates whether the routing table violates the contract. The system then solves the violation predicates for all possible combinations of a target destination address and target next hops to determine whether any routing table violates the desired behavior of its routing device as specified by a contract.

Abstract: A load balancer capable of adjusting how network data is distributed to a tenant or group of tenants by manipulating the data plane. The load balancer is placed directly in the flow path of network data that is destined for a tenant or group of tenants having a tenant address. The load balancer includes a control plane and one or more data planes. Each data plane may contain one or more network traffic multiplexors. Further, each data plane may be dedicated to a tenant or group of tenants. Data planes may be added or deleted from the load balancer; additionally, multiplexors may be added or deleted from a data plane. Accordingly, network data directed towards one tenant is less likely to affect the performance of load balancing performed for another tenant.

Abstract: A system performed by a computing device for validating routing tables of routing devices is provided. The routing tables map destination addresses to a next hops of the routing device. The system accesses one or more contracts that specify the desired behavior of a routing table of a routing device by specifying destination addresses and permissible next hops. For each routing device, the system generates a violation predicate for each contract that is applicable to the routing device. When a violation predicate is evaluated for a target destination address and a target next hop of the routing device, the violation predicate indicates whether the routing table violates the contract. The system then solves the violation predicates for all possible combinations of a target destination address and target next hops to determine whether any routing table violates the desired behavior of its routing device as specified by a contract.

Abstract: A load balancer capable of adjusting how network data is distributed to a tenant or group of tenants by manipulating the data plane. The load balancer is placed directly in the flow path of network data that is destined for a tenant or group of tenants having a tenant address. The load balancer includes a control plane and one or more data planes. Each data plane may contain one or more network traffic multiplexors. Further, each data plane may be dedicated to a tenant or group of tenants. Data planes may be added or deleted from the load balancer; additionally, multiplexors may be added or deleted from a data plane. Accordingly, network data directed towards one tenant is less likely to affect the performance of load balancing performed for another tenant.

Abstract: A de-alloyed catalyst of formula PtXY, wherein X is selected from the group consisting of Ni, Co and Cr; and Y is selected from the group consisting of Zn, Al, Sn, Be, Pb, Ga, V, In, Y, Sr and Ti; characterised in that the total atomic composition relative to Pt of X and Y at the surface of the de-alloyed catalyst as determined from X-ray photoelectron spectroscopy is between 20 and 99% lower than the total atomic composition relative to Pt of X and Y in the bulk of the de-alloyed catalyst is disclosed.