364 results about "Decay time" patented technology

A chemical-sensing apparatus is formed from the combination of a chemical preconcentrator which sorbs and concentrates particular volatile organic chemicals (VOCs) and one or more chemiresistors that sense the VOCs after the preconcentrator has been triggered to release them in concentrated form. Use of the preconcentrator and chemiresistor(s) in combination allows the VOCs to be detected at lower concentration than would be possible using the chemiresistor(s) alone and further allows measurements to be made in a variety of fluids, including liquids (e.g. groundwater). Additionally, the apparatus provides a new mode of operation for sensing VOCs based on the measurement of decay time constants, and a method for background correction to improve measurement precision.

A method and apparatus for discriminating the types of radiation interacting with an integrated radiation detector having of a pulse-mode operating photosensor which is optically coupled to a gamma-ray scintillator sensor and a neutron scintillator sensor and uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse processing provides for, among other things, faithful representation of the true energy spectrum of the gamma radiation field and allows for radioisotope identification by searching for the presence of characteristic energy lines in the gamma energy spectrum. The pulse shape discrimination method ensures that the high sensitivity and resolution of the isotope identification function is not affected during operation in mixed neutron-gamma fields.

A process for measuring the absorption spectrum of a target analyte using a cavity ring down spectrometer, comprising the steps of: i) tuning the spectrometer laser so that the light transmitted from the laser into the spectrometer optical cavity is varied over a wavelength interval which encompasses both the absorption wavelength of a spectral feature of the target analyte and a plurality of the free spectral ranges of the optical cavity; ii) triggering a plurality of ringdown events; iii) for each ringdown event, recording the decay time constant and the trigger time at which the light into the cavity is shut off; iv) organizing the decay time constants, light wavelengths and trigger times as a function of trigger time; v) ordering said light wavelengths by increasing value and placing groups of wavelengths into individual bins; vi) computing the average wavelength of each bin group; vii) grouping the decay time constants and trigger times into bins that parallel said wavelength bins, with the decay time constants in each of said parallel bin being arranged by increasing trigger time; viii) computing the average decay time for each decay time bin and using this decay time average, together with the average wavelength from the parallel wavelength bin, to compute the optical loss for the target analyte at said average wavelength.

Hafnium oxide HfO₂ scintillator compositions are doped with titanium oxide and at least an oxide of a metal selected from the group consisting of Be, Mg, and Li. The scintillator compositions can include sintering aid material such as scandium and/or tin and a rare earth metal and/or boron for improved transparency. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power. The scintillators can be used as detector elements in X-ray CT systems.

The invention relates to an on-line monitoring method of low-frequency oscillation of a power system. In the on-line monitoring method, parallel filtration calculation is carried out at an oscillation frequency by creatively utilizing time-frequency atom compound band-pass filter function to obtain oscillation mode number, practical oscillation frequency distribution and real-time amplitude information. On the basis of the redundancy of adjacent real-time amplitude information, various oscillation mode amplitudes and decay time constants can be obtained by utilizing least square optimization estimation; based on the obtained oscillation frequency distribution, amplitude and decay time constant, a low-frequency oscillation signal model can be built, wherein only an initial phase and direct-current component amplitude of each mode are unknown; and optimization estimation is carried out on the model by utilizing a particle swarm optimization algorithm to obtain the initial phase and the direct-current component amplitude. The method has good noise robustness, can be used for accurately distinguishing compound oscillation models, is favorable for the strong non-linear mode analysis ofthe power system and is convenient for on-line monitoring and application.

The invention provides a computer implemented method to automate the calibration of the drive voltage waveform of a solenoid operated valve. An initial estimate of valve electromagnetic parameters and valve closure point is derived and the drive voltage waveform is created based in part on circuit constraints and the parameters and valve closure point. The drive voltage waveform is applied to the valve coil and the coil current feedback is obtained and used to update the initial estimate. This process is repeated until the coil current feedback meets predetermined criteria. The electromagnetic parameters include the L/R ratio of the valve during the pull-in time and decay time, the valve back emf during the pull-hold time, and the average resistance during hold when current is steady. The closure point is used to anchor the drive voltage waveform and is adjusted at a slower rate than the other parameters.

Scintillator compositions having a garnet crystal structure useful for the detection of high-energy radiation, such as X, beta, and gamma radiation, contain (1) at least one of terbium and lutetium; (2) at least one rare earth metal; and (3) at least one of Al, Ga, and In. Terbium or lutetium may be partially substituted with Y, La, Gd, and Yb. In particular, the scintillator composition contains both terbium and lutetium. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power.

The invention relates to a high-energy ray laminated type crystal module detector which belongs to the technical field of radiation detection imaging. The invention is characterized in that the detector is formed by alternately arraying at least more than two strip type crystal units with different luminescence decay time along the width direction, wherein the alternate arraying method comprises alternating in one direction and alternating in two directions; the laminated type crystal module is coupled with different glimmer detector arrays by utilizing optical cement, and a decoding circuit is added to obtain the high-energy ray detector; high-energy rays are emitted to the crystal module to generate twinkling light; after the twinkling light is converted and amplified through the glimmer detector, an electric pulse signal is obtained and processed to obtain the acting information of energy, time, coordinates, and the like of the high-energy rays; through the screening of the decoding circuit to the pulse signal, a crystal unit material having main action with the high-energy rays is obtained; and the coordinate information is corrected through judging the material. The method can reduce the mistake positioning of the glimmer detector arrays to the position of high-energy ray deposition so as to improve the spatial resolution of the detector.

An integrated radiation detector having a pulse-mode operating photosensor optically coupled to a gamma sensing element and a neutron sensing element is disclosed. The detector includes pulse shape and processing electronics package that uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse shape and processing electronics package determines a maximum gamma energy from the spectrum associated with gamma rays detected by the gamma sensing element to adaptively select a gamma threshold for the neutron sensing element. A light pulse attributed to the neutron sensing element is a valid neutron event when the amplitude of the light pulse is above the gamma threshold.

Apparatus and method for detecting connectivity in a channel in an endoscope undergoing reprocessing using an automatic reprocessor, the apparatus including a source of pressurized fluid which may be a gas alone or gas and liquid and a back pressure detector connected to the channel or channels of interest in the endoscope, the method including providing a source of pressurized fluid, directing the pressurized fluid to a channel in an endoscope, monitoring the time for the back pressure in the pressurized fluid to decay to a predetermined level; and determining whether the channel is connected and open or disconnected by comparing the decay time of the actual back pressure to one or more predetermined values corresponding to the specific channel or channels and model of endoscope undergoing reprocessing.

A method and system for estimating native hydrocarbons from oil-based drilling muds with the aid of NMR data. Adaptive echo stacking may be used to balance between precision and sensitivity to changes in the fluid composition. Apparent T₂ decay time and effective diffusion constants derived from the NMR data may be transformed into an indication of native hydrocarbon type, using known diffusion constants, fuzzy logic, and neural networks.

A site is maintained that allows consumers to suggest, comment on and/or vote on ideas about a product or service. Some site embodiments can enable sponsoring organizations (customers) to maintain their own sites for displaying articles and allowing multiple viewers to vote on these articles. Site information for multiple tenants may be maintained in a common multi-tenant system. Votes may indicate a variety of different types of criteria, such as the importance, correctness, and/or user preference for the articles or other Qualitative Management Criteria (QMC) for determining the merit of an idea or an article. The votes may be tallied into an overall Total Qualitative Management Criterion (TQMC) for the idea or article. Newer votes may be adjusted according to an increasing function of time to enable the relative weightings of the older votes to diminish over time without having to compute a decaying time function to determine weightings for each vote.

A method for calculating a primary time constant of a power grid. It comprises the steps of: establishing an electromechanical transient model of the power grid using the widely used power system analysis software package (PSASP) according to the actual power grid parameters and network topology; establishing an electromagnetic transient model under PASAP using the actual power grid parameters for a site which requires the calculation of the primary time constant of the power grid, and setting a ground short circuit fault at the site; obtaining a transient short circuit current of the short circuit point of the power grid using a hybrid simulation method of the electromechanical and electromagnetic transient models; filtering out a periodic component in the transient short circuit current to obtain a non-periodic component attenuated with time, and finding the attenuation time constant of the non-periodic component which is the primary time constant of the power grid.

A disclosed method for implementing time decay in the analysis of streaming data objects is based on the age, referred to herein as the forward age, of a data object measured from a landmark time in the past to a time associated with the occurrence of the data object, e.g., an object's timestamp. A forward time decay function is parameterized on the forward age. Because a data object's forward age does not depend on the current time, a value of the forward time decay function is determined just once for each data object. A scaling factor or weight associated with a data object may be weighted according to its decay function value. Forward time decay functions are beneficial in determining decayed aggregates, including decayed counts, sums, and averages, decayed minimums and maximums, and for drawing decay-influenced samples.

A system for tagging articles. A glass is fabricated from (1) a combination of oxides and (2) one or more rare earth elements. The glass is divided into particles or fragments, which are attached to the article. When the particles are excited by specific radiation, they emit a characteristic signature, in terms of a collection of frequencies, each frequency having a characteristic amplitude and decay time. However, the particles cannot be counterfeited, or reverse-engineered, because, at present, no systematic data is available which correlates a particle's characteristic signature with the composition and processing of the particle itself. Thus, at best, a trial-and-error approach must be taken in attempts at counterfeiting, which is considered impossible.

A method for automatically reconfiguring a webpage is provided. The web page may include a plurality of sections, and each section may include at least one aspect related to a particular topic, such as customer support and an option for casting a vote for a topic posted. A vote may be received vote for at least one of the plurality of sections. A Total Qualitative Management Criterion (TQMC) may be determined for each section of the website. An increasing function of time may be applied to newer votes to enable relative weightings of older votes to diminish over time without requiring computing a decaying time function to determine weightings for each vote. The webpage may be reconfigured based on ranking the sections according to the TQMC for each section.

Efficiently controlled converter system embodiments are provided to operate in different operational modes. In a first operational PWM mode, first and second transistors are switched with a feedback-controlled duty cycle to thereby realize an inductor current that maintains a system output voltage. In a second operational PFM mode, after the output voltage decays to a lower threshold over a decay time, the control and synchronous transistors are driven a sufficient number of times to raise the output voltage to an upper threshold. The systems are controlled to efficiently transition between the first and second operational modes. For example, a converter system preferably transitions to the second PFM operational mode when current peaks of the inductor current drop below a predetermined current threshold and the system preferably transitions to the first PWM operational mode when the output voltage drops to a predetermined reference voltage.