Operator, organizational, direct and general suport, and depot maintenance manual : pump, centrifugal, gasoline engine driven, 50 GPM, 100-foot head, flammable liquid, bulk transfer (Barnes model-QM-2-28002) FSN 4320-913-7131.

Includes index.

Operator and organizational maintenance manual : pump, centrifugal, fresh water; gasoline driven, 2 wheel mounted; 4 in 500 GPM, 30 ft head, (Carver model K400S) FSN 4320-810-7311 (less engine).

Includes index.g

Organizational, direct support, and general support maintenance repair parts and special tools list for pump unit, centrifugal, flood and transfer, diesel-engine-driven, 1250 gpm at 180 fth, NSN 4320-01-194-5601.

"18 July 1988."

Organizational, direct and general support, and depot maintenance repair parts and special tools list : pump, centrifugal, GED, skid mounted, 6 in., 1120 gpm (Carver model K906MP), FSN 4320-929-0681.

"October 1968."

Operator and organizational maintenance manual : pump, centrifugal, fresh water; gasoline driven, 2 wheel mounted; 4 in 500 gpm, 30 ft head, (Carver model K400S) FSN 4320-810-7311 (less engine).

"March 1961."

Operator, organizational, field, and depot maintenance manual : pump, centrifugal, fresh water, gasoline driven, base mounted, 4 in, 200 gpm, 300 ft head (Carver model 4WHIS), serial number range 37715RF through 37814RF, FSN 4320-810-7310 ....

"September 1961."

Organizational maintenance repair parts and special tools lists for test sets AN/GGM-15(V)1 (NSN 6625-00-464-1702), AN/GGM-15(V)2 (NSN 6625-00-442-6131), and generator, signal ... analyzer, signal distortion ... oscilloscope ... dolly, test equipment V-434/GGM-15(V) (NSN 6625-00-435-7775).

Includes index.

Organizational, DS, GS, and depot maintenance manual : distortion analyzer, Hewlett-Packard models 333A and 334A.

"May 1967."

Intermodulation distortion in carrier frequency systems.

Thesis (doctoral)--

A novel phantom and method for comprehensive 3-dimensional measurement and correction of geometric distortion in magnetic resonance imaging

A phantom that can be used for mapping geometric distortion in magnetic resonance imaging (MRI) is described. This phantom provides an array of densely distributed control points in three-dimensional (3D) space. These points form the basis of a comprehensive measurement method to correct for geometric distortion in MR images arising principally from gradient field non-linearity and magnet field inhomogeneity. The phantom was designed based on the concept that a point in space can be defined using three orthogonal planes. This novel design approach allows for as many control points as desired. Employing this novel design, a highly accurate method has been developed that enables the positions of the control points to be measured to sub-voxel accuracy. The phantom described in this paper was constructed to fit into a body coil of a MRI scanner, (external dimensions of the phantom were: 310 mm x 310 mm x 310 mm), and it contained 10,830 control points. With this phantom, the mean errors in the measured coordinates of the control points were on the order of 0.1 mm or less, which were less than one tenth of the voxel's dimensions of the phantom image. The calculated three-dimensional distortion map, i.e., the differences between the image positions and true positions of the control points, can then be used to compensate for geometric distortion for a full image restoration. It is anticipated that this novel method will have an impact on the applicability of MRI in both clinical and research settings. especially in areas where geometric accuracy is highly required, such as in MR neuro-imaging. (C) 2004 Elsevier Inc. All rights reserved.

A proposed scheme for comprehensive characterization of the measured geometric distortion in magnetic resonance imaging using a three-dimensional phantom

Recently, a 3-dimensional phantom that can provide a comprehensive, accurate and complete measurement of the geometric distortion in MRI has been developed. In this paper, a scheme for characterizing the measured geometric distortion using the 3-D phantom is described. In the proposed scheme, a number of quantitative measures are developed and used to characterize the geometric distortion. These measures encompass the overall and spatial aspects of the geometric distortion. Two specific types of volume of interest, rectangular parallelepipeds (including cubes) and spheres are considered in the proposed scheme. As an illustration, characterization of the geometric distortion in a Siemens 1.5T Sonata MRI system using the proposed scheme is presented. As shown, the proposed scheme provides a comprehensive assessment of the geometric distortion. The scheme can be potentially used as a standard procedure for the assessment of geometric distortion in MRI. (C) 2004 American Association of Physicists in Medicine.

Geometric distortion in clinical MRI systems - Part II: correction using a 3D phantom

In this paper, we present the correction of the geometric distortion measured in the clinical magnetic resonance imaging (MRI) systems reported in the preceding paper (Part 1) using a 3D method based on the phantom-mapped geometric distortion data. This method allows the correction to be made on phantom images acquired without or with the vendor correction applied. With the vendor's 2D correction applied, the method corrects for both the residual geometric distortion still present in the plane in which the correction method was applied (the axial plane) and the uncorrected geometric distortion along the axis non-nal to the plane. The evaluation of the effectiveness of the correction using this new method was carried out through analyzing the residual geometric distortion in the corrected phantom images. The results show that the new method can restore the distorted images in 3D nearly to perfection. For all the MRI systems investigated, the mean absolute deviations in the positions of the control points (along x-, y- and z-axes) measured on the corrected phantom images were all less than 0.2 mm. The maximum absolute deviations were all below similar to0.8 mm. As expected, the correction of the phantom images acquired with the vendor's correction applied in the axial plane performed equally well. Both the geometric distortion still present in the axial plane after applying the vendor's correction and the uncorrected distortion along the z-axis have all been restored. (C) 2004 Elsevier Inc. All rights reserved.

Geometric distortion in clinical MRI systems - Part I: evaluation using a 3D phantom

Recently, a 3D phantom that can provide a comprehensive and accurate measurement of the geometric distortion in MRI has been developed. Using this phantom, a full assessment of the geometric distortion in a number of clinical MRI systems (GE and Siemens) has been carried out and detailed results are presented in this paper. As expected, the main source of geometric distortion in modern superconducting MRI systems arises from the gradient field nonlinearity. Significantly large distortions with maximum absolute geometric errors ranged between 10 and 25 mm within a volume of 240 x 240 x 240 mm(3) were observed when imaging with the new generation of gradient systems that employs shorter coils. By comparison, the geometric distortion was much less in the older-generation gradient systems. With the vendor's correction method, the geometric distortion measured was significantly reduced but only within the plane in which these 2D correction methods were applied. Distortion along the axis normal to the plane was, as expected, virtually unchanged. Two-dimensional correction methods are a convenient approach and in principle they are the only methods that can be applied to correct geometric distortion in a single slice or in multiple noncontiguous slices. However, these methods only provide an incomplete solution to the problem and their value can be significantly reduced if the distortion along the normal of the correction plane is not small. (C) 2004 Elsevier Inc. All rights reserved.

The effects of body position on distortion-product Otoacoustic emission testing

Otoacoustic emissions are frequently acquired from patients in a variety of body positions aside from the standard, seated orientation. Yet little knowledge is available regarding whether these deviations will produce nonpathological changes to the clinical results obtained. The present study aimed to describe the effects of body position on the distortion-product otoacoustic emissions of 60 normal-hearing adults. With particular attention given to common clinical practice, the Otodynamics ILO292, and the measurement parameters of amplitude, signal-to-noise ratio, and noise were utilized. Significant position-related effects and interactions were revealed for all parameters. Specifically, stronger emissions in the mid frequencies and higher noise levels at the extreme low and high frequencies were produced by testing subjects while lying on their side compared with the seated position. Further analysis of body position effects on emissions is warranted, in order to determine the need for clinical application of position-dependent normative data.

Segregation distortion for seed testa color in mungbean (Vigna radiata L. Wilcek)

Genetic segregation experiments with plant species are commonly used for understanding the inheritance of traits. A basic assumption in these experiments is that each gamete developed from megasporogenesis has an equal chance of fusing with a gamete developed from microsporogenesis, and every zygote formed has an equal chance of survival. If gametic and/or zygotic selection occurs whereby certain gametes or zygotic combinations have a reduced chance of survival, progeny distributions are skewed and are said to exhibit segregation distortion. In this study, inheritance data are presented for the trait seed testa color segregating in large populations (more than 200 individuals) derived from closely related mungbean (Vigna radiata L. Wilcek) taxa. Segregation ratios suggested complex inheritance, including dominant and recessive epistasis. However, this genetic model was rejected in favor of a single-gene model based on evidence of segregation distortion provided by molecular marker data. The segregation distortion occurred after each generation of self-pollination from F-1 thru F-7 resulting in F-7 phenotypic frequencies of 151:56 instead of the expected 103.5:103.5. This study highlights the value of molecular markers for understanding the inheritance of a simply inherited trait influenced by segregation distortion.