Effects of the 1993 flood on the determination of flood magnitude and frequency in Iowa /

Mode of access: Internet.

Magnitude and frequency of the floods of January 1997 in northern and central California, preliminary determinations /

Mode of access: Internet.

Intermodulation distortion in carrier frequency systems.

Thesis (doctoral)--

Techniques for estimating magnitude and frequency of floods on streams in Indiana /

Mode of access: Internet.

Flood-frequency estimates for five gaged basins in Wichita, Kansas /

Bibliography: p. 22-23.

Extent and frequency of inundation of flood plain in vicinity of Bound Brook in Somerset and Middlesex Counties, New Jersey,

Open-file report [no. 3]

Extent and frequency of inundation of Millstone River flood plain in Somerset County, New Jersey,

Open-file report [no. 4]

Flood record compilation and frequency plot.

Cover title.: Electronic computer program for flood record compilation and frequency plot (BPR program HY-5) Developed by: U. S. Dept. of Commerce, Bureau of Public Roads.

Structure and metal binding studies of the second copper binding domain of the Menkes ATPase

Biological utilisation of copper requires that the metal, in its ionic forms, be meticulously transported, inserted into enzymes and regulatory proteins, and excess be excreted. To understand the trafficking process, it is crucial that the structures of the proteins involved in the varied processes be resolved. To investigate copper binding to a family of structurally related copper-binding proteins, we have characterised the second Menkes N-terminal domain (MNKr2). The structure, determined using H-1 and N-15 heteronuclear NMR, of the reduced form of MNKr2 has revealed two alpha-helices lying over a single beta-sheet and shows that the binding site, a Cys(X)(2)Cys pair, is located on an exposed loop. H-1-N-15 HSQC experiments demonstrate that binding of Cu(I) causes changes that are localised to conserved residues adjacent to the metal binding site. Residues in this area are important to the delivery of copper by the structurally related Cu(I) chaperones. Complementary site-directed mutagenesis of the adjacent residues has been used to probe the structural roles of conserved residues. (C) 2003 Published by Elsevier Inc.

A distributed equivalent magnetic current based FDTD method for the calculation of E-fields induced by gradient coils

This paper evaluates a new, low-frequency finite-difference time-domain method applied to the problem of induced E-fields/eddy currents in the human body resulting from the pulsed magnetic field gradients in MRI. In this algorithm, a distributed equivalent magnetic current is proposed as the electromagnetic source and is obtained by quasistatic calculation of the empty coil's vector potential or measurements therein. This technique circumvents the discretization of complicated gradient coil geometries into a mesh of Yee cells, and thereby enables any type of gradient coil modelling or other complex low frequency sources. The proposed method has been verified against an example with an analytical solution. Results are presented showing the spatial distribution of gradient-induced electric fields in a multi-layered spherical phantom model and a complete body model. (C) 2004 Elsevier Inc. All rights reserved.

Laser frequency locking by direct measurement of detuning

We present a new method of laser frequency locking in which the feedback signal is directly proportional to the detuning from an atomic transition, even at detunings many times the natural linewidth of the transition. Our method is a form of sub-Doppler polarization spectroscopy, based on measuring two Stokes parameters (I-2 and I-3) of light transmitted through a vapor cell. It extends the linear capture range of the lock loop by as much as an order of magnitude and provides frequency discrimination equivalent to or better than those of other commonly used locking techniques. (C) 2004 Optical Society of America

Determination of domain sizes in blends of poly(ethylene) and poly(styrene) formed in the presence of supercritical carbon dioxide

Well-mixed blends of poly(ethylene) and poly(styrene) have been synthesized using supercritical carbon dioxide as a solvent. The morphology of the blends has been conclusively characterized using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), Raman microprobe microscopy, and C-13 solid-state cross-polarization magic angle spinning NMR (C-13 CPMAS NMR). DSC measurements demonstrate that poly(styrene) in the blends resides solely in the amorphous regions of the poly(ethylene) matrix; however, corroborative evidence from the SAXS experiments shows that poly(styrene) resides within the interlamellar spaces. The existence of nanometer-sized domains of poly(styrene) was shown within a blend of poly(styrene) and poly(ethylene) when formed in supercritical carbon dioxide using Raman microprobe microscopy and C-13 CPMAS NMR spectroscopy coupled with a spin diffusion model. This contrasts with blends formed at ambient pressure in the absence of solvent, in which domains of poly(styrene) in the micrometer size range are formed. This apparent improved miscibility of the two components was attributed to better penetration of the monomer prior to polymerization and increased swelling of the polymer substrate by the supercritical carbon dioxide solvent.

Determination of thermal and optical parameters of melanins by photopyroelectric spectroscopy

Photopyroelectric spectroscopy (PPE) was used to study the thermal and optical properties of melanins. The photopyroelectric intensity signal and its phase were independently measured as a function of wavelength and chopping frequency for a given wavelength in the saturation part of the PPE spectrum. Equations for both the intensity and the phase of the PPE signal were used to fit the experimental results. From these fits we obtained for the first time, with great accuracy, the thermal diffusivity coefficient, the thermal conductivity, and the specific heat of the samples, as well as a value for the condensed phase optical gap, which we found to be 1.70 eV. (c) 2005 American Institute of Physics.

DHPLC analysis of patients with nevoid basal cell carcinoma syndrome reveals novel PTCH missense mutations in the serol-sensing domain

Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is an autosomal dominant disorder characterised by multiple basal cell carcinomas, palmar and plantar pitting, odontogenic keratocysts of the jaws and bilamellar calcification of the falx. Mutations in the PTCH gene are responsible for NBCCS but most studies have found mutations in less than half of the cases tested. We used denaturing high performance liquid chromatography (DHPLC) to screen for PTCH mutations in 28 NBCCS cases, most of whom had been previously evaluated by single stranded conformation polymorphism analysis but found to be negative. Protein truncating (n = 10) and missense or indel (n = 4) mutations were found in 14/28 (50%) cases and one additional case carried an unclassified variant, c.2777G>C. Thirteen of the variants were novel. The mutation frequency was similar in inherited and de novo cases. Three of the missense and indel mutations were in the sterol-sensing domain, and one was in the sixth transmembrane domain.

An inverse methodology for high-frequency RF coil design for MRI with de-emphasized B-1 fields

An inverse methodology for the design of biologically loaded radio-frequency (RF) coils for magnetic resonance imaging applications is described. Free space time-harmonic electromagnetic Green's functions and de-emphasized B-1 target fields are used to calculate the current density on the coil cylinder. In theory, with the B-1 field de-emphasized in the middle of the RF transverse plane, the calculated current distribution can generate an internal magnetic field that can reduce the central overemphasis effect caused by field/tissue interactions at high frequencies. The current distribution of a head coil operating at 4 T (170 MHz) is calculated using an inverse methodology with de-emphasized B-1. target fields. An in-house finite-difference time-domain routine is employed to evaluate B-1 field and signal intensity inside a homogenous cylindrical phantom and then a complete human head model. A comparison with a conventional RF birdcage coil is carried out and demonstrates that this method can help in decreasing the normal bright region caused by field/tissue interactions in head images at 170 MHz and higher field strengths.