Michael D. Rowe

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Nuclear quadrupole resonance (NQR) offers an unequivocal method of detecting and identifying land mines. Unfortunately, the practical use of NQR is restricted by the low signal-to-noise ratio (SNR), and the means to improve the SNR are vital to enable a rapid, reliable, and convenient system. In this paper, an approximate maximum-likelihood detector (AML)(More)
The problem of estimating the spectral content of exponentially decaying signals from a set of irregularly sampled data is of considerable interest in several applications, for example in various forms of radio frequency spectroscopy. In this paper, we propose a new nonparametric iterative adaptive approach that provides a solution to this estimation(More)
Nuclear quadrupole resonance (NQR) is a solid-state radio frequency (RF) spectroscopic technique, allowing the detection of compounds containing quadrupolar nuclei, a requirement fulfilled by many high explosives and narcotics. The practical use of NQR is restricted by the inherently low signal-to-noise ratio (SNR) of the observed signals, a problem that is(More)
The explosive pentaerythritol tetranitrate (PETN) C(CH(2)-O-NO(2))(4) has been studied by (1)H NMR and (14)N NQR. The (14)N NQR frequency and spin-lattice relaxation time T(1Q) for the nu(+) line have been measured at temperatures from 255 to 325K. The (1)H NMR spin-lattice relaxation time T(1) has been measured at frequencies from 1.8kHz to 40MHz and at(More)
Nuclear quadrupole resonance is a radio frequency (rf) spectroscopic technique, closely related to NMR, which can be used to detect signals from solids containing nuclei with spin quantum number >1/2. It is nondestructive, highly specific and noninvasive, requires no static magnetic field, and as such is currently used in the detection of explosives and(More)
We report the detection and analysis of a suspected counterfeit sample of the antimalarial medicine Metakelfin through developing nitrogen-14 nuclear quadrupole resonance ((14)N NQR) spectroscopy at a quantitative level. The sensitivity of quadrupolar parameters to the solid-state chemical environment of the molecule enables development of a technique(More)
Pulsed (35)Cl nuclear quadrupole resonance (NQR) experiments have been performed on 250-mg tablets of the antidiabetic medicine Diabinese to establish the conditions needed for noninvasive quantitative analysis of the medicine in standard bottles. One important condition is the generation of a uniform radio-frequency (RF) field over the sample, which has(More)
Nuclear quadrupole resonance (NQR) is a radio frequency (RF) spectroscopic technique, allowing the detection of many high explosives and narcotics. In practice, NQR is restricted by the low signal-to-noise ratio of the observed signals, a problem further exacerbated by the presence of strong RF interference (RFI). The current literature focuses on the use(More)
The explosive hexahydro-1,3,5-trinitro-s-triazine (CH2-N-NO2)3, commonly known as RDX, has been studied by 14N NQR and 1H NMR. NQR frequencies and relaxation times for the three ν+ and ν- lines of the ring 14N nuclei have been measured over the temperature range 230-330 K. The 1H NMR T1 dispersion has been measured for magnetic fields corresponding to the(More)