Abstract: A sample preparation method for characterization of nanoparticles embedded in the supports of heterogeneous catalysts, with improved particle dispersion, is introduced. The supported catalyst is first ground or milled into fine powder. Then, the powder is mixed into an organic solvent, and an etchant is added to the solvent to digest the supports and release metallic nanoparticles. The resulting solution is then placed in an ultrasonic bath where ultrasonic waves are generated and applied to the solution. The ultrasonic waves suppress agglomeration of the particles and also break up those particle clusters resulting from agglomeration during the prior steps. Subsequently, a sample is extracted from the solution and prepared for analysis.

Abstract: The catalytic efficiency of supported catalysts containing metal nanoparticles is strongly related to the chemical softness at the surfaces of such nanoparticles. Supported catalysts containing platinum nanoparticles having average surface softness values (expressed in scaled units ranging from 0 to 1) between 0.07198 and 0.09247 exhibit high catalytic efficiency. The catalytic efficiency of such platinum nanoparticles for CO oxidation, expressed as the turn-over frequency (TOF), was observed to be on or above 0.03062 s?1. The supported catalysts containing platinum nanoparticles with tighter average surface softness ranges exhibit even higher catalytic efficiencies. The TOF for CO oxidation of platinum nanoparticles having average surface softness values between 0.08031 and 0.08679 was observed to be on or above 0.06554 s?1.

Abstract: The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.

Abstract: Phasor measurement units (108) provide phasor data from various locations (102) in an electrical power system. The phasor data is referenced to a common timing signal. Non-phasor measurement data is also obtained at various locations in the power system. A phasor assisted state estimator (120) uses the phasor data and the non-phasor data to determine the power system state.

Abstract: The catalytic efficiency of supported catalysts containing metal nanoparticles is strongly related to the chemical softness at the surfaces of such nanoparticles. The chemical softness of a nanoparticle is obtained using results from Density Functional Theory modeling, an extended version of Embedded Atom Method modeling, and continuum modeling based on size and shape of the nanoparticle. A metal nanoparticle of a certain size and shape is first modeled using the extended EAM and EAM parameters that have been validated with results from DFT modeling, to obtain atomic energy densities at each atom location. The chemical softness value at each atom location is then calculated from the atomic energy densities and various parameters that are derived based on results from DFT modeling. The surface chemical softness value is derived from the local chemical softness values based on the geometry and atomistic structure of the metal nanoparticle.

Abstract: The present disclosure relates to monitoring of electromechanical oscillations in electric power systems, and their identification by an adaptive algorithm based on a repeatedly measured and evaluated signal. In order for an estimation of parameters of a model of the power system to reasonably converge, proper initialization of the recursive calculation is required, including the definition of tuning parameters constraining the model and the calculation. Initialization for a second signal to be exploited can then be simplified by copying the set of tuning parameters tuned previously for a different signal. A conditioning gain multiplying the second signal establishes compatibility between the different signals, and a signal pre-filter in turn discards contributions beyond a frequency band comprising typical electromagnetic oscillations.

Abstract: At least one key of a keypad of an electronic device, such as a wireless terminal, includes a polymer light emitting device, also referred to as a polymer LED, thereon. A polymer LED may be on the inner and/or outer surface of the face of the key and may be unpatterned and/or patterned to form a symbol.

Abstract: The present disclosure is concerned with the combined voltage or power flow control and damping of electromechanical oscillations in an electric power system by Flexible AC Transmission System (FACTS) devices or High Voltage DC (HVDC) transmission devices. To this end, information about a state or operating point of the power system is generated from suitable second system signals (y2) and a control parameter (cp) of a FACTS controller is derived therefrom. The control parameter and a first system signal (y1) are used in the calculation of a control command (u) defining the settings of the FACTS device. Following a change in the state of the power system such as a change in the topology of a transmission network, poorly damped or even unstable oscillations are avoided by appropriate re-tuning of the control parameter of the damping or stabilizing equipment.

Abstract: Phasor measurement units (108) provide phasor data from various locations (102) in an electrical power system. The phasor data is referenced to a common timing signal. Non-phasor measurement data is also obtained at various locations in the power system. A phasor assisted state estimator (120) uses the phasor data and the non-phasor data to determine the power system state.

Abstract: At least one key of a keypad of an electronic device, such as a wireless terminal, includes a polymer light emitting device, also referred to as a polymer LED, thereon. A polymer LED may be on the inner and/or outer surface of the face of the key and may be unpatterned and/or patterned to form a symbol.

Abstract: The invention relates to a powder metallurgical combination comprising an iron-based powder A essentially consisting of core particles of iron pre-alloyed with molybdenum and having 6-15%, preferably 8-12% by weight of copper diffusion alloyed to the core particles, an iron-based powder B essentially consisting of particles of iron pre-alloyed with molybdenum and having 4.5-8%, preferably 5-7% by weight of nickel diffusion alloyed to the core particles, and an iron-based powder C essentially consisting of particles of iron pre-alloyed with molybdenum. The invention also relates to the powders A and B per se. Further the invention relates to a method for preparing an iron-based sintered component comprising 0.3-2% by weight of molybdenum, 0.2-2%. Preferably 0.4-0.08% by weight of copper and 0.1-4% by weight of nickel and to a method to obtain a sintered component having a predetermined strength and a predetermined dimensional change during sintering.

Abstract: A method and system are disclosed for managing congestion in an electrical transmission network. The electrical transmission network includes Power Flow Control Devices (PFDs) that adjust the transmission capability of the electrical transmission network. The method includes determination of a reference generation schedule followed by setting up of an objective function based on the reference generation schedule, a power flow in the electrical transmission network, bids for regulation, an actual generation schedule, and set points of PFDs. An optimisation problem is solved to minimize the objective function for a set of decision variables and the set of decision variables is applied in order to minimize congestion cost in the electrical transmission network.

Abstract: The present invention is concerned with a method for real-time emergency control of power transmission networks, based on a modification of the model predictive control (MPC) approach. Following the detection of a contingency at time tc only one nominal trajectory xnom is approximated, together with its corresponding trajectory sensitivities for evaluating the effect of various key parameters or potential control actions. An optimum input control is finally identified via the solution of a cost function including e.g. a punishment for excessive load shedding. The process is started only if the nominal trajectory does not remain within acceptable trajectory limits.

Abstract: The invention concerns an improved segregation-resistant and dust-resistant metallurgical composition for making compacted parts, comprising at least about 80 percent by weight of an iron or iron-based powder; at least one alloying powder; and (c) about 0.05 to about 2 percent by weight of a binding/lubricating combination of polyethylene wax and ethylene bis-stearamide, the polyethylene wax having a weight average molecular weight below about 1000 and a melting point below that of ethylene bis-stearamide, and being present in amount between 10 and 90% by weight of the binding/lubricating combination.

Abstract: A telescopic fork leg incorporates mutually displaceable inner and outer tube parts and a damping arrangement for damping the relative movements of the tube parts. The damping arrangement comprises tubular and coaxially disposed units. A piston belonging to a first outer tube part operates in a chamber within the interior of the tubular units in a medium present in the chamber, which medium, at a piston speed above a chosen value, is transferred between the top and bottom sides of the piston via passage(s) disposed in, on or by the piston and adjustable damping-influencing members.

Abstract: A method for determining an equivalent impedance of a transmission section of an electrical network, includes representing the transmission section as having at least two interfaces with other sections of the network. For each interface, a voltage phasor and a current phasor flowing through the interface are determined from simultaneously made measurements at the interfaces. From the phasors, the equivalent impedance is calculated. The required simultaneousness of the phasor measurements is achieved by means of Phasor Measurement Units (PMUs) that are synchronized via the Global Positioning System (GPS).

Abstract: A relationship between a temperature Tl of a power line or power transmission conductor 10, an electrical quantity of the power line such as a current l or power flow P through the power line, as well as meteorological quantities or ambient conditions of the power line such as wind speed W, wind direction, humidity, solar radiation S and ambient temperature Ta, is established in the form of a thermal model of the power line. Values of the aforementioned quantities or variables are continuously measured, and the collected values of the quantities are evaluated in order to update model parameters of the thermal model during operation of the power line. In an exemplary embodiment, an average temperature representative of the entire line is determined via two phasor measurement units (PMU) 11, 11? providing synchronized phasor values from two ends of the power line. An ohmic resistance of the power line can be computed from the phasor values, from which in turn the average line temperature can be derived.

Abstract: The detection of electromechanical oscillations in power systems and the estimation of their frequency and damping parameters are based on a linear time-varying model. The parameters of the linear model are on-line adapted by means of Kalman filtering techniques to optimally approximate the measured signal representing the behavior of the power system based on a quadratic criterion. The estimated model parameters are then the basis for the calculation of parameters of the oscillations. Adaptive algorithms are based on a recursive calculation of the estimated parameter vector for each time-step based on the new value of the measured signal and the old values of the estimated parameters.

Abstract: In a method, computer program and system for determining an operational limit of a power transmission line, time-stamped current phasor information and voltage phasor information for a first end and a second end of the line are determined, an ohmic resistance of the line is computed from the phasor information, and an average line temperature is computed from the ohmic resistance. This allows to determine the average line temperature without dedicated temperature sensors. The average line temperature represents the actual average temperature and is largely independent of assumptions regarding line parameters.

Abstract: In a method, computer program and system for determining an operational limit of a power transmission line, time-stamped current phasor information and voltage phasor information for a first end and a second end of the line are determined, an ohmic resistance of the line is computed from the phasor information, and an average line temperature is computed from the ohmic resistance. This allows to determine the average line temperature without dedicated temperature sensors. The average line temperature represents the actual average temperature and is largely independent of assumptions regarding line parameters.