(n.) A telescope arranged and used to determine errors of collimation, both vertical and horizontal.
(n.) A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used.
Example Sentences:
(1) The dual-probe system incorporates a central collimated probe for monitoring activity in the LV surrounded by an annular detector collimated in such a manner as to provide simultaneous real-time monitoring of the LV background activity.
(2) The second area of improved SPECT technology is camera collimation and related imaging techniques.
(3) Comparative clinical studies on temporomandibular joints (TMJ) between the LEGP and fan beam collimators also confirm the superior image quality obtained with the fan beam collimator.
(4) In work to determine whether X-radiation could be used to induce tumors of the colon in outbred Holtzman rats, a technique was devised so that only the descending colon could be irradiated with a collimated X-ray beam and tumorigenic exposures in the kilo-Roentgen range were delivered.
(5) In the RAO view with the collimator flat against the chest there was better resolution of the cardiac apex.
(6) As an initial feasibility study of computer-controlled radiation therapy, its application to produce wedge-shaped dose distributions by moving the collimator jaws has been evaluated.
(7) Analysis of the penumbra width of cross dose distributions, as a function of field sizes, allowed us to postulate that the dmax shift could be due to the phantom scattered photons, which in turn were generated by the collimator scattered photons.
(8) Larger detectors with converging collimation result in much higher photon input rates to the scintillation crystal in routine clinical studies than has occurred in the past.
(9) Neutron spectra at various locations in a phantom, irradiated by collimated beams of 14 MeV neutrons and neutrons from 252 Cf and Po-Be sources, were calculated using the Monte Carlo technique.
(10) Without scatter, the resolution was 4.7 mm (full width at half-maximum); in a scatter medium, the resolution was 5.3-10.0 mm with high resolution collimation and 7.7-18.8 mm with general purpose collimation, depending on filtering.
(11) Quantitative measurement of the scatter dose in polystyrene solid phantoms with a Farmer type chamber and effects of shielding blocks under the collimators were studied.
(12) Spatial resolution with parallel-hole or converging collimators was much less satisfactory with Ta-178 because of septal penetration by high-energy photons.
(13) Moving the collimator during imaging will reduce septal aberrations but will not increase resolution.
(14) The nonuniform response inherent in the use of the pinhole collimator has a significant effect, but with computer processing this is readily eliminated.
(15) The exchange of collimator pairs results in significant output differences but has a negligible effect on the depth-dose curves.
(16) This was consistent with the design of the line focus and the beam collimators used in this system.
(17) One-centimeter collimation contiguous scans through the chest were obtained in all patients.
(18) A further increase in photon utization is gained for small-organ imaging with converging collimators, which produce images with superior resolution and sensitivity to that obtained with equivalent parallel-hole collimators.
(19) Normal quantitative circumferential profile limits were established for a 30 degrees bilateral rotating slant-hole (RSH) collimator tomographic system.
(20) Central axis percentage depth doses and off-axis ratios measured with such a collimator show variations with the source-to-surface distance (SSD).
Divergence
Definition:
(n.) Alt. of Divergency
Example Sentences:
(1) A neodymium YAG (Nd:YAG) laser was evaluated in a dog ulcer model used in the same manner as is recommended for bleeding patients (power 55 W, divergence angle 4 degrees, with CO2 gas-jet assistance).
(2) The primary afferent fibers diverge in the brainstem into a short ascending and a long descending tract.
(3) Sires of the cows had been divergently selected on yearling weight (YW) and total maternal (MAT) EPD to form four groups: high YW, high MAT EPD; high YW, low MAT EPD; low YW, high MAT EPD; and low YW, low MAT EPD.
(4) The region is distinctive in that the sequence is absent from the homologous domain of the erythroid alpha chain and diverges from the normal internal repeat structure observed throughout other spectrins.
(5) Eye movements of convergence and divergence were recorded by a limbus tracker.
(6) The process of vectorial repeat addition continued in two platyrrhine sublineages after their divergence from each other.
(7) In this paper, we have characterized new and divergent EF-C binding sites in several viral regulatory regions.
(8) We propose that BGP I diverged from NCA by acquiring an immunoglobulin-like domain substantially different from the domains found in NCA or CEA and also a new cytoplasmic domain.
(9) We present a comparison of the Canadian and American data on expenditures, identifying the sectors in which the experience of the two nations diverges most, and describing the processes of control.
(10) Cognate sites in genomes that diverged approximately 100 million years ago can be detected by PCR assays based on primer pairs from unique sequences.
(11) The sequences in the 5'-flanking region of the alpha- and beta-MYHC-encoding genes diverge extensively from one another, suggesting that expression of the alpha- and beta-MYHC genes is independently regulated.
(12) This article examines the history of Dr. Crozat and his appliance, discusses the development and divergence in its use, and demonstrates this divergence with a few selected, documented case reports.
(13) Species of the genera Saccharomyces, Schizosaccharomyces, Debaryomyces and Schwanniomyces were compared from their extent of divergence in three regions from small (18S) and large (25S) subunit ribosomal RNAs comprising a total of 900 nucleotides.
(14) In order to obtain probes for the analysis of RPE development from its earliest divergence from the neural retina to late stages of differentiation, we have developed a panel of monoclonal antibodies which recognize antigens specific to the RPE.
(15) The 18S data provide the principal signal that supports the more basal divergences, but the data do not unambiguously address relationships among taxa in the clade that includes most colonial flagellates and Chlamydomonas taxa representative of the Euchlamydomonas group (sensu Ettl).
(16) The developed apparatus included ultrasonic generators operating at a frequency of 0.5-3 MHz, piezoceramic radiators of various design providing the heating of an object with convergent, divergent and plane ultrasonic waves, thermoprobes in the form of single or multiple thermocouples with the bends from 5 points at a 5 mm distance from one another, temperature meters and various auxiliaries.
(17) The C. elegans core histone genes are organized as divergently transcribed pairs of H3-H4 and H2A-H2B and contain 5' conserved sequence elements in the shared spacer regions.
(18) The sequence data of the 3' terminus of the alpha-3 genomic clone suggests that it encodes for a divergent alpha-tubulin, and it most probably corresponds to the testis-specific gene.
(19) We have systematically analyzed the promoter-regulatory elements of the human and bovine alpha-subunit genes to elucidate the molecular mechanisms underlying their divergent patterns of tissue-specific expression.
(20) These results support a hypothesis which proposes that ancestral SIN virus diverged into two distinct groups.