(n.) Any large piece of timber or iron long in proportion to its thickness, and prepared for use.
(n.) One of the principal horizontal timbers of a building or ship.
(n.) The width of a vessel; as, one vessel is said to have more beam than another.
(n.) The bar of a balance, from the ends of which the scales are suspended.
(n.) The principal stem or horn of a stag or other deer, which bears the antlers, or branches.
(n.) The pole of a carriage.
(n.) A cylinder of wood, making part of a loom, on which weavers wind the warp before weaving; also, the cylinder on which the cloth is rolled, as it is woven; one being called the fore beam, the other the back beam.
(n.) The straight part or shank of an anchor.
(n.) The main part of a plow, to which the handles and colter are secured, and to the end of which are attached the oxen or horses that draw it.
(n.) A heavy iron lever having an oscillating motion on a central axis, one end of which is connected with the piston rod from which it receives motion, and the other with the crank of the wheel shaft; -- called also working beam or walking beam.
(n.) A ray or collection of parallel rays emitted from the sun or other luminous body; as, a beam of light, or of heat.
(n.) Fig.: A ray; a gleam; as, a beam of comfort.
(n.) One of the long feathers in the wing of a hawk; -- called also beam feather.
(v. t.) To send forth; to emit; -- followed ordinarily by forth; as, to beam forth light.
(v. i.) To emit beams of light.
Example Sentences:
(1) An argon laser beam was used to irradiate the round window in 17 guinea pigs.
(2) Streaming is shown to occur in water in the focused beams produced by a number of medical pulse-echo devices.
(3) 11 patients with a postoperative classification of stage D had additional external beam radiation to the pelvic and paraaortic lymph nodes with shielding of the implanted prostatic region.
(4) The data collection scheme for the scanner uses multiple rotations of a linearly shifted, asymmetric fan beam permitting user-defined variable resolution.
(5) The scatter measurement was made using a standard imaging geometry with both beam stops and an additional x-ray detector placed behind the standard imaging detector.
(6) In an effort to decrease the treatment time for this technique, the flattening filter has been removed from an AECL Therac-6 linear accelerator and the characteristics of the resulting beam have been measured.
(7) 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.
(8) The special advantage of the UV-beam is that it allow to inactivate selectively of the particular elements of nuclear apparatus of living ciliates is to observe consequences of operation on distant descendants of irradiated cell.
(9) Three-five days after endoscopic laser destruction long-distance open-field gamma-beam therapy was administered to 10 patients and polychemotherapy to 9 of these.
(10) Guidelines for external beam treatment have been set forth in the ASTRO Newsletter.
(11) 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.
(12) Nevertheless some technical variations are required, to maintain the typical homogeneity of photon beams.
(13) The RBEs of fast neutron, thermal neutron beams, and neutron capture therapy relative to 60Co gamma-ray were calculated as 2.78, 4.18, and 6.15 at 0.1 surviving fraction, respectively.
(14) Some patients received postoperative external beam irradiation (2000 cGy whole pelvis and an additional 3000 cGy to the parametria, with a midline stepwedge) when deep myometrial invasion was present.
(15) Between 1981 and 1985, 20 patients with malignancy-associated ureteral obstruction (MAUO) were given external beam irradiation with a palliative intent.
(16) Finally, the question of oncogenic effects raised with 193 nm laser beams does not seem to apply to the 308 nm wavelength.
(17) Hence the laser beam acts as a fixation target and measuring beam.
(18) Electron beam therapy is usually employed for the treatment of tumours located at or near the surface of the body, because the electron beam gives a high dose near the surface, but falls off rapidly with increasing depth beyond the level of the 80% depth dose.
(19) By embedding the biopsy in the acrylic resin LR White, unsupported sections of which are stable in the electron beam, light and electron microscopy and immunocytochemistry become feasible on sections from the same block.
(20) Real 60Co beams contain lower energy components; in addition, Awall is defined differently by different authors.
Collimator
Definition:
(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).