Abstract: Methods are disclosed for characterizing samples containing a plurality of molecular species through the use of multi-dimensional spectra obtained by processing of measurements resulting from pulse sequences combining NMR spectroscopy and NMR relaxation techniques.

Abstract: Methods are disclosed for characterizing samples containing a plurality of molecular species through the use of multi-dimensional spectra obtained by processing of measurements resulting from pulse sequences combining NMR spectroscopy and NMR relaxation techniques.

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: 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: A low-cost single-sided NMR sensor to produce depth profiles with microscopic spatial resolution is presented. The open geometry of the NMR sensor provides a non-invasive and non-destructive testing method to characterize the depth structure of objects of arbitrary size. The permanent magnet geometry generates one plane of constant magnetic field intensity parallel to the scanner surface. By combining the highly uniform static gradient with selective RF excitation, a thin flat sensitive slice can be defined. By moving the relative position between the slice and the object, one-dimensional profiles of the near surface of large samples are produced with high spatial resolution.

Abstract: In a unilateral NMR probe for the analysis of a material comprising at least one magnet for generating a constant time-invariant polarization field B0 in the material to be analyzed and current conductors forming a radio frequency oscillation circuit for generating a pulsed radio frequency magnetic excitation field B1 which is superimposed on the polarization field N0 in the material, the circuit conductors are so designed as to provide several adjacent excitation fields B0 with alternatingly oppositely oriented magnetic fields, whereby the current conductors generating each one of the excitation fields have a distance from each other which causes a certain penetration depth in the material to be analyzed and echoes received therefrom provide measurement values which are characteristic for the material being analyzed.

Abstract: Stochastic pulsing using random or pseudo-random sequences is used for determination of nuclear spin properties of earth formations. This reduces the power requirements. Processing of the received signals may include linear or nonlinear cross-correlation with the excitation pulse sequence. Inversion of the results of the processing gives the desired nuclear spin property.

Abstract: In a method for generating measurement signals in time constant inhomogeneous magnetic fields, which are produced by a NMR-MOUSE apparatus in the surrounding medium, a static magnetic polarization field B0 and a pulsed magnetic polarization field B1 are generated, whereby echo signals S are generated which are measured, and an additional pulsed or oscillating magnetic field Bz is provided, which affects the echo signals S so as to generate contrasts for the measuring locations of the echo signals.

Abstract: An apparatus for and a method of single-sided MRI with a palm-sized probe. The probe includes a planar permanent magnet having a gap between the north and south poles of the magnet. Positioned in the gap are an RF coil and a pair of gradient coils. The gradient coils are located on either side of the RF coil. The probe further includes an RF tuning circuit and a gradient input. In use, the pair of gradient coils produce a controlled magnetic field gradient over the field of view thereby improving image resolution.