Abstract: A voltage controller is operable to generate control signals for controlling an intermediate bus voltage (VIB) in an intermediate bus architecture power system, the intermediate bus voltage comprising a voltage output from a first stage DC-to-DC power converter to at least one second stage DC-to-DC power converter via the intermediate voltage bus in the intermediate bus architecture power system. The voltage controller comprises a receiver operable to receive values of the current input to the first stage DC-to-DC power converter, or the current and voltage output by the first stage DC-to-DC power converter. The voltage controller further comprises an efficiency measuring unit operable to determine a measure of an efficiency of the intermediate bus architecture power system in accordance with the received values.

Abstract: The present invention generally relates to a process for the preparation of aqueous solutions of hyperpolarized molecules ready for use in in-vivo MR diagnostic imaging, the use thereof as MRI contrast agent in investigation methods for producing diagnostic MR images of a human or non-human animal body organ, region or tissue.

Abstract: To reduce power loss in an intermediate bus architecture power system, embodiments of the present invention provide an intermediate bus converter which converts an input voltage to an intermediate bus voltage using a converting unit; receives a signal indicative of an output of a converting unit; determines an intermediate bus voltage to reduce power loss in dependence upon the signal indicative of an output of the converting unit; generates a control signal to control the converting unit to convert the input voltage to the determined intermediate bus voltage; and generates an intermediate bus voltage in dependence upon the control signal.

Abstract: A switching delay controller (150) for controlling a switching delay between the switching of a first and a second switching element (Q1 to Q4) in a switched mode power supply (300), the switched mode power supply comprising a feedback signal generator (140) operable to generate a feedback signal indicative of a difference between an output (Vout) of the switched mode power supply and a reference (Vref) for the output, and a drive circuit (120) for switching the first and second switching elements so as to convert an input voltage (Vin) to the switched mode power supply (300) into an output voltage (Vout) thereof based on the feedback signal.

Abstract: A switched mode power supply (SMPS) comprising a feedback unit, voltage feed forward (VFF) compensation signal generator and a transient detector. A VFF compensation signal is only applied to the output of the feedback unit when a transient is detected by the transient detector on the input voltage of the SMPS, thereby saving power and computation time.

Abstract: A voltage controller (700) operable to generate control signals for controlling an intermediate bus voltage (VIB) in an intermediate bus architecture power system (100), the intermediate bus voltage comprising a voltage output from a first stage DC/DC power converter (200) to at least one second stage DC/DC power converter (500-1 to 500-K). The voltage controller (700) comprises a receiver operable to receive at least one of voltage and current values input to the first stage DC/DC power converter (200). The voltage controller (700) further comprises a efficiency measuring unit operable to determine a measure of the efficiency of the intermediate bus architecture power system in accordance with the received values, and a control signal generator operable to generate control signals in dependence upon the determined efficiency measure to cause the first stage DC/DC converter (200) to set the intermediate bus voltage (VIB).

Abstract: A method of determining a measure of a total capacitance of one or more capacitive elements connected to an output of a switched mode power supply is described. The method includes generating a voltage control signal to cause an output voltage control signal age controller to sweep a voltage at the output of the switched mode power supply from an initial voltage value to a final voltage value. Sample values of a current at the output measured by a current sampler during the sweep of the output voltage are received, and an integrated current value representing a measure of the total capacitance using the received sample values is calculated.

Abstract: A method of determining a current in a switched mode power supply. The method comprises: storing values representing at least one pre-calculated matrix A; receiving measured current values; and using the stored values representing the matrix A and the received current values to calculate a respective initial value for each of the coefficients of the line and for each measured current value: calculating an estimated current using the equation of the line and the calculated initial values of the coefficients; determining a difference between the measured current value and the estimated current value to generate a difference value, and comparing the difference value against a threshold and, if the difference value is greater than the threshold, calculating updated values of the coefficients using stored values representing matrix A and difference value.

Abstract: To calculate a control signal for the duty cycle of a switched mode power supply (SMPS), a voltage feed forward compensator is integrated into a feedback unit. A control unit has an adder with a first input to receive a signal dependent upon an output voltage.

Abstract: The invention relates to a device for generation of microwaves comprising a coaxial virtual cathode oscillator (1) with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (8) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming an anode (3) and connected to a transmission device (8) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of a centre conductor (5) arranged to coincide with the centre axle (19) for the cathode's (2) outer cylindrical tube and in electrical connection with the tube a device for generation of microwaves is obtained having improved energy efficiency and better broadband performance.

Abstract: The invention relates to a device for generation of microwaves comprising a coaxial virtual cathode oscillator (1) with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (8) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming an anode (3) and connected to a transmission device (8) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of a centre conductor (5) arranged to coincide with the centre axle (19) for the cathode's (2) outer cylindrical tube and in electrical connection with the tube a device for generation of microwaves is obtained having improved energy efficiency and better broadband performance.

Abstract: A method for diagnosing system health with system event logs is provided. The method includes receiving a plurality of event logs and health indicator states from a system; transducing the plurality of event logs into numeric-based metrics of the system; and deriving, based on the transduced numeric-based metrics, at least one model of the system that correlates the plurality of event logs to the corresponding health indicator states.

Abstract: The invention relates to a method of 13C-MR detection using an imaging medium comprising hyperpolarised 13C acetate and to an imaging medium comprising hyperpolarised 13C-acetate.

Abstract: The invention relates to a device for generation of microwaves comprising a virtual cathode oscillator (1) in a coaxial embodiment with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (14) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming a anode (3) and connected to a waveguide (13) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of electrically conductive structures (5 and 6) a device for generation of microwaves is achieved that demonstrates higher efficiency and higher peak output.

Abstract: The invention relates to a device for generation of microwaves comprising a virtual cathode oscillator (1) in a coaxial embodiment with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (14) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming a anode (3) and connected to a waveguide (13) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of electrically conductive structures (5 and 6) a device for generation of microwaves is achieved that demonstrates higher efficiency and higher peak output.

Abstract: The invention relates to a device for the generation of microwaves, comprising a virtual cathode oscillator (1) in coaxial construction having an outer substantially cylindrical tube constituting a cathode (2) and connected to a transmission conductor (14) for feeding the cathode (2) with voltage pulses, as well as an inner substantially cylindrical tube, at least partially transparent for electrons, constituting an anode (3) and connected to a wave guide (13) for the discharge of microwave radiation generated by the formation of a virtual cathode (4) inside a region enclosed by the anode. The device comprises an electrically conductive structure in the form of a reflector (19) disposed adjacent to the anode (3). The cathode (2) comprises a substantially rotationally symmetric, electrically conductive body (15) having a cavity (16).

Abstract: The invention relates to hyperpolarised 13C-?-ketoisocaproate, its use as imaging agent, an imaging medium comprising hyperpolarised 13C-?-ketoisocaproate and methods of 13C-MR detection wherein such an imaging medium is used. Further, the invention relates to methods of producing hyperpolarised 13C-?-ketoisocaproate.

Abstract: The invention relates to hyperpolarised 13C-alanine, its use as imaging agent, an imaging medium comprising hyperpolarised 13C-alanine and methods of 13C-MR detection wherein such an imaging medium is used. Further, the invention relates to methods of producing hyperpolarised 13C-alanine.

Abstract: A wireless receiver for receiving a signal with a characteristic pattern includes a predictor for predicting the presence of a non-zero value of the characteristic pattern. A tracker tracks a noise component in the received signal between predicted non-zero values. The resulting noise component is subtracted from the received signal to output a processed signal, which is then decoded by a pattern discriminator and demodulator. The wireless receiver is less sensitive to noise and interference.

Abstract: The invention relates to a dynamic nuclear polarisation (DNP) method for producing hyperpolarised amino acids and amino sulphonic acids and compositions for use in the method. As a sample, an ammonium salt of an amino acid, an ammonium salt of an aminosulphonic acid, a carboxylate salt of an amino acid, a sulphonate salt of an aminosulphonic acid or mixtures thereof is used.