Abstract: Certain aspects of the present disclosure provide methods and apparatus for performing electron paramagnetic resonance (EPR) spectroscopy on a fluid from a flowing well, such as fluid from hydrocarbon recovery operations flowing in a downhole tubular, wellhead, or pipeline. One example method generally includes, for a first EPR iteration, performing a first frequency sweep of discrete electromagnetic frequencies on a cavity containing the fluid; determining first parameter values of reflected signals from the first frequency sweep; selecting a first discrete frequency corresponding to one of the first parameter values that is less than a threshold value; activating a first electromagnetic field in the fluid at the first discrete frequency; and while the first electromagnetic field is activated, performing a first DC magnetic field sweep to generate a first EPR spectrum.

Abstract: Described herein are positron emission tomography (PET)-electron paramagnetic resonance imaging (EPRI) systems and methods of use. In one example, a PET-EPRI system includes a PET-EPR insert, a PET scanner including one or more solid-state photodetectors, and a subject module that can house a subject for scanning. The PET-EPR insert includes an EPR resonator that can nest inside the PET scanner. The EPR resonator includes a resonator that can receive the subject module, a shield encircling the resonator and one or more rapid scan coils (RS-coils) positioned around the shield. The shield can prevent electrical coupling between the RS-coils and the resonator while being transparent to annihilation photons and magnetic field scans.

Abstract: A cryogenic apparatus (10) includes an enclosure (12), a first thermo-mechanical cooler (20) and a second thermo-mechanical cooler (22) which project into the enclosure (12), at least the second thermo-mechanical cooler (22) being a two-stage cooler, and each cooler (20, 22) having a fluid inlet and a fluid outlet for each stage, and a helium gas extraction flow duct (40) which extends into the enclosure (12) and which communicates with a vessel (42) to contain liquid helium within the enclosure (12). There is a first heat exchanger (62) within the gas flow duct (40). A first duct (74) carries cold helium gas from a fluid outlet (73) of the first thermo-mechanical cooler (20) and through the first heat exchanger (62) to the fluid inlet (75) of the second stage of the second thermo-mechanical cooler (22).

Abstract: A passive MRI enhancing embodiment includes a plurality of resonators and increases signal-to-noise ratio of radiofrequency signals emitted by a specimen and captured by an MRI machine. The apparatus increases the magnetic field component of radiofrequency energy during signal transmission from the MRI machine to the specimen, and/or reception of signals from the specimen to the MRI machine. Use of the apparatus improves the images generated by the MRI machine, and/or reduces the time necessary for the MRI machine to capture the image. An isolator embodiment has a nonlinear resonator controllably configurable alternately into an isolation configuration and a transmission configuration, and a second resonator.

Abstract: An Electron Paramagnetic resonance (EPR) system and method allows the measurement paramagnetic characteristics of materials in real-time, such as heavy oil, hydrocarbons, asphaltenes, heptane, vanadium, resins, drilling fluid, mud, wax deposits or the like. The EPR systems and methods discussed herein are low cost, small and light weight, making them usable in flow-assurance or logging applications. The EPR sensor is capable of measuring paramagnetic properties of materials from a distance of several inches. In some embodiments, a window will be used to separate the EPR sensor from the materials in a pipeline or wellbore. Since the sensor does need to be in direct contact with the materials, it can operate at a lower temperature or pressure. In other embodiments, the EPR sensor may be placed in the materials.

Abstract: An electron paramagnetic resonance (EPR) apparatus has a main magnet with two pole pieces on either side of an air gap, and at least one EPR probe head adapted for rapid scan (RS) measurements positioned between the pole pieces of a main magnet, and a pair of RS coils. The EPR apparatus further has at least one EPR probe head adapted for continuous wave (CW) signal measurements, positioned between the pole pieces of the main magnet, and a carrier which allows insertion of the RS coils into the air gap between the pole pieces in an operation position and extraction of the RS coils from the air gap to a storage position outside of a CW operating volume. The system allows a quick and secure change of the RS coils, safely and rapidly, by a single user.

Abstract: Improved loop-gap resonators applicable to Electron-Spin Resonance spectroscopy and to quantum computing employ interdigitated capacitor structures to dramatically increase the capacitance of the resonator, along with corresponding decreases in loop size to enable measurements of small-volume samples or individual quantum bits (qubits). The interdigitated-capacitor structures are designed to minimize parasitic inductance.

Abstract: A system may include a resonant phase sensing system comprising a resistive-inductive-capacitive sensor and a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor, and a compensation circuit. The measurement circuit may be configured to use a phase detector to measure phase information associated with the resistive-inductive-capacitive sensor and based on the phase information, determine a displacement of a metal plate relative to the resistive-inductive-capacitive sensor. The compensation circuit may be configured to detect a change in a physical property associated with the resistive-inductive-capacitive sensor other than the displacement and compensate the phase information to correct for the change in the physical property.

Abstract: A magnetic resonance spectrometer and a control apparatus for the magnetic resonance spectrometer based on an FPGA. The control apparatus includes a control unit and a conversion receiving unit. The control unit includes a clock source. A waveform generation unit and a signal receiving unit inside the control apparatus are synchronized by means of the same clock source. The control apparatus includes two working modes: a continuous wave mode and an impulse wave mode. The control apparatus can output a microwave signal which is modulated by any wave and has higher synchronism and time resolution.

Abstract: Technologies for a long-lived 3D multimode microwave cavity are disclosed. In the illustrative embodiment, a series of overlapping holes are drilled into a monolithic block of aluminum forming a cavity. The dimensions of the cavity formed by the overlapping holes can be made long by drilling a long series of holes in a row and can be made high by drilling holes a certain depth into the cavity. If two dimensions of the cavity are bigger than the diameter of the holes used to create the cavity, then the cavity can support electromagnetic waves that cannot propagate through the holes, leading to a long lifetime in the cavity. A superconducting qubit or other non-linear element can be inserted into the cavity, which can controllably interact with each of several modes of the cavity. In this way, the modes of the cavity can act as components in a quantum memory.

Abstract: An electron paramagnetic resonance (EPR) apparatus, such as an EPR spectrometer or an EPR imager, comprising a main field magnet with two opposed pole pieces defining an airgap between them, a microwave resonator coupled with a microwave guide, a sample holder and a current source adapted to be used as a coil driver, also comprises a rapid scan (RS) coil assembly with two opposed RS coil devices. Each coil device comprises: i) a coil support having a plate like body and comprising recesses designed to accommodate the at least one coil winding and at least one cooling chamber volume which is connected to cooling liquid supply channels; and ii) RF shielding comprising an electrically conducting, non-magnetic, shielding plate which is mounted laterally onto the coil support, between the coil winding(s) and a corresponding pole piece of the main field magnet, and contacts the cooling chamber volume.

Abstract: Disclosed herein are embodiments for a standing equine magnetic resonance imaging device. The device includes two opposing planar power transmit coils facing each other. Each of the planar power transmit coils includes a plurality of radio frequency conducting planar rungs arranged to form concentric circles and a plurality of radio frequency conducting planar spokes extending from an outermost rung and connecting to each of the rung circles. At least one pin diode is positioned across the outermost rung circle. A plurality of tuning capacitors are positioned across the spokes.

Abstract: A device for generating and detecting a magnetization of a sample includes a magnetic field generator configured to generate a static magnetic field of a predetermined direction and strength at a sample location, a transmitter configured to provide an additional magnetic field at the sample location, and a receiver configured to detect a magnetization of the sample. An assembly of at least two LC oscillators, the oscillation frequency of which is a function of a value of an inductive element of the LC oscillators and which are frequency-synchronized via a wiring, and forced by a control voltage to have a same oscillation frequency, is used as the receiver and/or the transmitter. A controller configured to control the assembly is connected, the assembly and the controller are configured to generate a magnetic field capable of deflecting a magnetization of the sample out of equilibrium.

Abstract: An apparatus for measuring a magnetic field strength is provided. The apparatus includes a stage on which a sample to be measured is placed, a cantilever having a tip, an optical system having a light source and a light receiver, and a microwave power source. The tip is a diamond tip having a nitrogen vacancy defect. The optical system is configured such that excitation light from the light source is focused at the diamond tip. The cantilever is configured as a coaxial microwave antenna through which microwaves from the microwave power source are supplied to the diamond tip.

Abstract: A system and method are disclosed for determining a constituent and/or concentration of a solid dissolved in a liquid. In one embodiment, a method is provided to interrogate and identify a liquid in a medical container.

Abstract: An EPR resonator for a cylindrical TE01n microwave mode, where n=1, 2, 3, or 4, has: a cylindrical body (10) which has an RF absorption of less than 5% at RFs below 1 kHz, a first plunger (11) delimiting the resonating volume within the body in an axial direction at a first end and a second plunger (12) delimiting the resonating volume within the body at a second end, the second plunger having an opening (13) for inserting an EPR sample. The first and second plunger each has a spiral winding of an electrically conductive filament wherein neither the ends nor neighboring turns of the spiral windings have electrically conductive connections prone to forming electrically closed loops. Using spiral winding plungers for cylindrical TE01n microwave modes provides equivalent functionality compared to conventional plungers, but without creating Eddy currents at frequencies lower than the frequency of the TE01n microwave mode.

Abstract: In various embodiments of the invention, inductive coupling can be to a secondary coil rather than a primary coil in order to optimize the topology of the NMR probe. In addition, by coupling to a secondary coil using a detection coil located below the lower insulator the RF homogeneity and signal to noise can be improved together with the NMR probe topology. By effecting inductive coupling to an inductor in a multiple resonance circuit, rather than to the sample inductor parameters associated with the NMR, probe construction can be arranged to increase RF homogeneity and signal to noise, while reducing space utilization constraints. In various embodiments of the invention, the primary mode in a secondary coil can be split into two modes with a resonator with inductive coupling to the secondary coil.

Abstract: Techniques provide for passive Q switching in a bimodal resonator environment, where magnetic resonators are coupled for power transfer. A passive Q switch is responsive to a driving power from one magnetic resonator coupled to another magnetic resonator. After the driving power reaches a threshold, the passive Q switch shunts the receiving magnetic resonator, at least partially, to reduce the Q of that second resonator, which allows faster detection operation of the second resonator in some applications. The technique allows for fast Q switching in a bimodal resonator system, especially one having resonators having magnetic fields that are orthogonal to one another.

Abstract: This disclosure describes an example device that includes a first contact line, a second contact line, a spin-orbital coupling channel, and a magnet. The spin-orbital coupling channel is coupled to, and is positioned between, the first contact line and second contact line. The magnet is coupled to the spin-orbital coupling channel and positioned between the first contact line and the second contact line. A resistance of the magnet and spin-orbital coupling channel is a unidirectional magnetoresistance.

Abstract: Embodiments of the invention are directed toward a crossed-loop electron paramagnetic resonance resonator comprising a first resonator having a first resonator axis; and a second resonator having a second resonator axis. The first resonator axis and the second resonator axis can be substantially perpendicular. Either or both the first resonator and the second resonator can be a ribbon resonator having a plurality of metallic ribbons formed in a loop. Each metallic ribbon can include a central axis. The plurality of metallic ribbons can be arranged parallel relative one to another.

Abstract: A method for calibrating at least one operating parameter of a magnetic resonance apparatus and a corresponding magnetic resonance apparatus and computer program product are provided. The at least one operating parameter includes a constant component and a variable component. The method includes, after a start-up of at least one part of the magnetic resonance apparatus, determining the variable component of the at least one operating parameter. The constant component of the at least one operating parameter is provided. The constant component and the variable component are used to calibrate the at least one operating parameter.

Abstract: An Electron Paramagnetic resonance (EPR) system and method allows the measurement paramagnetic characteristics of materials in real-time, such as heavy oil, hydrocarbons, asphaltenes, heptane, vanadium, resins, drilling fluid, mud, wax deposits or the like. The EPR systems and methods discussed herein are low cost, small and light weight, making them usable in flow-assurance or logging applications. The EPR sensor is capable of measuring paramagnetic properties of materials from a distance of several inches. In some embodiments, a window will be used to separate the EPR sensor from the materials in a pipeline or wellbore. Since the sensor does need to be in direct contact with the materials, it can operate at a lower temperature or pressure. In other embodiments, the EPR sensor may be placed in the materials.

Abstract: An apparatus and method for triaging patients according to radiation exposure operates by measuring electron paramagnetic resonance spectra of teeth. When operating in vivo, radiation induced spectra are obtained from intact teeth placed within a magnetic field and with a resonator having a loop and two capacitors formed in metal layers on a printed circuit substrate and located near teeth. The resonator is magnetically coupled to an RF measuring system. The spectra are used to determine radiation dose of a subject. The characteristics of the method and the apparatus make it feasible to utilize the system to measure radiation dose using previously untrained operators working in the field under emergency conditions.

Abstract: A method for automatically altering an imaging area in microscopic imaging of a biological sample. In the method, a sample outline is differentiated from surrounding tissues by means of endogenous or exogenous markers; an initial sample imaging area is set; optical microscopic imaging is performed on a sample surface layer, wherein the imaging area is larger than an area to be imaged of the sample; an actual sample area is calculated by an outline identification algorithm using an imaging result of the sample surface layer and is set as an imaging area of next layer; optical microscopic imaging is performed on a sample to be imaged of the next layer according to the set imaging area, wherein the imaging area covers the area to be imaged of the sample and no redundant imaging is performed; and the above steps are repeated until a data acquisition task is completed.

Abstract: A system and method are disclosed for interrogating a liquid in a container. The liquid sample, such as drugs in a liquid base, is identified based on a radio frequency and/or ultrasonic measurement.

Abstract: Apparatuses and methods for non-contact sensing of physical or chemical properties of a target sample using a planar microwave resonator are provided. In one aspect, a planar microwave resonator is used in combination with an active feedback loop for increasing the quality factor of the resonator to compensate for an existing signal loss in the sample or environment. In another aspect, an active feedback loop is used in combination with a microwave resonator to compensate for signal loss in a lossy medium. In another aspect, a planar microwave resonator comprising a secondary layer defining a sensing interface may be used to facilitate the sensing by exposing the secondary layer to a substance to be investigated. In another aspect, a planar microwave resonator sensor is provided comprising separate resonator and active feedback loop components that are indirectly connected through an electromagnetically coupling and may be constructed on two separate support structure.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a receiving unit and a determining unit. The receiving unit collectively receives settings of an imaging region on an image of a subject with respect to at least part of imaging protocols in a series of imaging protocols performed in an examination. The determining unit determines the propriety of the setting with respect to each imaging protocol included in the part of the imaging protocols before imaging is started using the part of the imaging protocols.

Abstract: A magnetometer including a detector configured to measure the amplitude of an output signal at an oscillation frequency to deduce a component of a magnetic field to be measured starting from the value of a resonance gradient, including a main excitation source outputting a measurement signal oscillating at a main oscillation frequency and a secondary excitation source outputting a reference signal with known amplitude oscillating at a secondary oscillation frequency, the detector being configured to measure the output signal amplitude at a harmonic of the secondary oscillation frequency and to deduce said resonance gradient. The invention also applies to a network of magnetometers and a method of measuring a magnetic field without slaving and compensation of fluctuations of the resonance gradient.

Abstract: A control device that controls a spectrometer includes: a specimen image display control section that performs a control process that displays a specimen image acquired by the spectrometer on a display section; and an spectrometer control section that performs a control process that causes the spectrometer to start analysis based on designation of an analysis position within the specimen image that has been performed by a pointing device, and performs a control process that causes the spectrometer to stop the analysis based on cancellation of the designation of the analysis position that has been performed by the pointing device.

Abstract: Apparatus and method that includes amplifiers for transceiver antenna elements, and more specifically to power amplifying an RF (radio frequency) signal using a distributed power amplifier having electronic devices (such as field-effect transistors) that are thermally and/or mechanically connected to each one of a plurality of antenna elements (also called coil elements) to form a hybrid coil-amplifier (e.g., for use in a magnetic-resonance (MR) imaging or spectroscopy machine), and that is optionally adjusted from a remote location, optionally including remotely adjusting its gains, electrical resistances, inductances, and/or capacitances (which controls the magnitude, phase, frequency, spatial profile, and temporal profile of the RF signal)—and, in some embodiments, the components are compatible with, and function in, high fields (such as a magnetic field of up to and exceeding one tesla or even ten tesla or more and/or an electric field of many thousands of volts per meter).

Abstract: A system and method for measuring the amount of sugar in a sample including measuring a solution of the sugar using oscillating electromagnetic fields generated in the sample at least two radio frequencies at which the electromagnetic properties of the solution differ. There are detected characteristics of the oscillating electromagnetic fields generated in the sample at each radio frequency that are dependent on the electromagnetic properties of the solution. A measure of the amount of sugar is derived from those characteristics. By combining measurements at different radio frequencies, the effects of changes in the ion concentration can then be removed to give an unambiguous measure for the sugar.

Abstract: A debugging device for a body coil of a magnetic resonance imaging (MRI) system includes a pair of output ports connected to a pair of input ports of the body coil. The debugging device also includes a pair of input ports connected to a pair of output ports of the MRI system. The debugging device includes a pair of extension circuits, separately connected between the pair of input ports and the pair of output ports; and a first adjustment capacitor for reducing or eliminating coupling between the pair of input ports. The first adjustment capacitor is bridged between the pair of input ports, and the capacitance of the first adjustment capacitor is variable.

Abstract: A magnetic field focusing assembly includes a magnetic field generating device configured to generate a magnetic field, and a split ring resonator assembly configured to be magnetically coupled to the magnetic field generating device and configured to focus the magnetic field produced by the magnetic field generating device.

Abstract: A device based on a spin Hall effect and spin-transfer torque (STT) effect is provided to include a magnetic tunneling junction (MTJ) element including a free magnetic layer structured to have a magnetization direction that can be changed by spin-transfer torque; an electrically conducting magnetic layer structure exhibiting a spin Hall effect (SHE) and, in response to an applied in-plane charge current, generating a spin-polarized current of a magnetic moment oriented in a predetermined direction having both an in-plane magnetic moment component parallel to a surface of the electrically conducting magnetic layer structure and a perpendicular magnetic moment component perpendicular to the surface of the electrically conducting magnetic layer structure. The magnetization direction of the free magnetic layer is capable of being switched by the spin-polarized current via a spin-transfer torque (STT) effect. This device can be configured in a 3-terminal configuration.

Abstract: Methods and systems are provided for tools having non-resonant circuits for analyzing a formation and/or a sample. For example, nuclear magnetic resonance and resistivity tools can make use of a non-resonant excitation coil and/or a detection coil. These coils can achieve desired frequencies by the use of switches, thereby removing the requirement of tuning circuits that are typical in conventional tools.

Abstract: The sensor for sensing at least a physical property of an environment generally has a microwave resonator having a top conductive layer, a bottom conductive layer and a substrate layer therebetween, the substrate layer being made of a first dielectric material, a fence electrically connecting the top conductive layer to the bottom conductive layer across the substrate layer, and enclosing at least one resonance cavity, at least one microwave signal port across the fence, at least one sensing portion of a second dielectric material functionalized to the physical property of the environment, extending in the at least one resonance cavity and being exposed to the environment across at least one of the top conductive layer and the bottom conductive layer, the microwave resonator having at least one resonance frequency being dependent of the exposure of the second dielectric material with the environment to affect a microwave signal resonating therein.

Abstract: An electron spin resonance spectrometer includes a bridge to transmit an excitation frequency and to receive a signal frequency; a probe electrically connected to the bridge and comprising: a first conductor in electrical communication with the bridge to transmit the signal frequency to the bridge; a shorting member electrically connected to the first conductor to transmit the excitation frequency to a sample, to produce the signal frequency, and to transmit the signal frequency to the first conductor; and a second conductor electrically connected to the shorting member; and a magnet disposed proximate to the probe.

Abstract: An apparatus and method for improved S/N measurements useful for electron paramagnetic resonance imaging in situ and in vivo, using high-isolation transmit/receive surface coils and temporally spaced pulses of RF energy (e.g., in some embodiments, a RF pi pulse) having an amplitude sufficient to rotate the magnetization by 180 degrees followed after varied delays, by a second RF pulse having an amplitude half that of the initial pulse to rotate the magnetization by, e.g., 90 degrees (a pi/2 pulse), to the plane orthogonal to the static field where it evolves for a short time. Then a third RF pi pulse sufficient to rotate the magnetization by, e.g., 180 degrees, forms an echo (in some embodiments, the second and third pulses are from the same signal as the first pulse but are phase shifted by 0, 90, 180, or 270 degrees to reduce signal artifact), to image human body.

Abstract: A microwave resonator device (1), being configured in particular for electron spin resonance measurements, comprises a resonator being resonant with first and second microwave field modes and including first and second resonance sections (7, 8) arranged along a longitudinal axis (2) of the resonator, and a coupling unit being arranged between the first and second resonance sections, wherein the coupling unit includes a conducting plate (16) being arranged on the longitudinal axis (2) and covering a central portion of a cross-sectional area of the resonator, the conducting plate (16) is adapted to adjust a first mode frequency of the first microwave field mode, and the conducting plate (16) is arranged at a field minimum of the second microwave field mode. Furthermore, a method of conducting an electron spin resonance measurement with a sample to be investigated is described.

Abstract: An RFID antenna assembly configured to be energized with a carrier signal is disclosed. The RFID antenna assembly includes an inductive component including a loop antenna assembly, at least one capacitive component coupled to the inductive component, and an eddy current trap positioned a predetermined distance from the loop antenna assembly.

Abstract: A cavity enhanced absorption spectrometer (CEAS) and method for controlling the same. The CEAS includes a coherent electro-magnetic radiation source, an electro-magnetic modulator that creates a sideband with an adjustable frequency that is offset from the radiation source frequency by imparting an adjustable frequency modulation to the radiation. The CEAS also includes a RF source that drives the electro-magnetic modulator and a cavity enhanced absorption resonator (CEAR) that receives the sideband. A detector measures the proximity of the frequency of the sideband relative to the resonant frequency of the CEAR and generates a proximity detector signal, which is converted by a controller to a control signal that controls at least one of the RF source and the resonant frequency of the CEAR such that the frequency of the sideband and the resonant frequency of the CEAR are adjusted to maintain a predetermined proximity therebetween.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: An improved system for interfacing with a subject material is provided where an interface material having target atoms with a known nuclear quadrupole resonance frequency is purposely associated with a subject material. An excitation signal is used to cause a nuclear quadrupole resonance of the target atoms and a receiving devices receives a received signal comprising a probe signal energy. A signal sampling device samples the received signal to produce detection data that is used for at least one of detecting the subject material, locating the subject material, tracking the subject material, or conveying information.

Abstract: A method for performing magnetic resonance measurements on a sample includes applying a first predetermined number of pulse trains for excitation, each pulse train having a constant amplitude and including a second predetermined number of pulses spaced by a predetermined time interval. The pulse trains are modulated by a bent function. After each pulse, data is sampled. Preferably a square number of pulses is generated being constant in power, and the Walsh transform of the sequence of their phases is constant in power, so that the power of the excitation in time and frequency domain is constant. The method can reduce power requirements and may permit undercutting specific absorption rate (SAR) limits due to the small excitation power necessary to create time signals with reasonable signal to noise ratio.

Abstract: System and methods for detecting substances such as explosives via the nuclear quadrupole resonance effect. We observe that the nuclear quadrupole resonances of explosives located within a cavity portal involve continuous Rabi transitions which are nonlinear processes since stimulated emission occurs. In other words, where there are no resonances caused by the presence of an explosive, high average power and low average power measurements should be identical. However, when resonances are stimulated by the system, the difference between these two conditions can be compared to determine a correction to measurements made when a person located in the cavity has explosive material on their person, without the need for separate empty portal or elaborate calibration procedures.

Abstract: A system for performing Walsh reconstruction of time dependent fields with a quantum probe that includes a diamond structure that includes nitrogen-vacancy (NV) centers for sensing magnetic and electric fields. An arbitrary waveform generator and microwave waveguides manipulate the quantum spins in the diamond structure using a plurality of coherent control sequences to measure the arbitrary profile of time-varying magnetic fields. A laser that optically addresses the quantum spins in the diamond structure for initialization and readout.

Abstract: An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

Abstract: Methods of marking paper products and marked paper products are provided. Some methods include irradiating the paper product to alter the functionalization of the paper.

Abstract: A double solenoid coil operates in accordance with input first and second signals to generate an electromagnetic field and to provide the generated electromagnetic field as a sample. Then, a signal corresponding to the generated electromagnetic field is received, amplified, and output by a double lock-in amplifier. Free radicals generated by the sample in accordance with the electromagnetic field are measured based on the signal output from the double lock-in amplifier.

Abstract: The present invention provides an apparatus and a corresponding method useful for electron paramagnetic resonance imaging, in situ and in vivo, using high-isolation transmit/receive (TX/RX) coils, which, in some embodiments, provide microenvironmental images that are representative of particular internal structures in the human body and spatially resolved images of tissue/cell protein signals responding to conditions (such as hypoxia) that show the temporal sequence of certain biological processes, and, in some embodiments, that distinguish malignant tissue from healthy tissue. In some embodiments, the TX/RX coils are in a surface, volume or surface-volume configuration.