RBE

Ceiling beams will not affect jet attachment to the ceiling if they are located further than 1.6x from the air supply outlet.If a beam is located closer than 1,6x rbe impingement of the jet on this beam will change the jet direction. 

In the selection of control equipment, the most important waste-gas characteristics are volumetric flow rate, concentration and composition of organic compounds in the waste-gas, waste-gas temperature and humidity, and rbe content of particulate matter, chlorinated hydrocarbons, and toxic pollutants. Other factors influencing the equipment selection are the required removal efficiency, recovery requirements, investment and operating costs, ease of installation, and considerations of operation and maintenance. The selection of a suitable control method is based on the fundamental selection criteria presented as well as the special characteristics of the project. 

FIGURE 13. Relative binding energy, RBE, along the symmetric bond stretching in S02. PP calculations without 3d orbitals. 

Relative Biological Effectiveness (RBE)—The RBE is a factor used to compare the biological effectiveness of absorbed radiation doses (i.e., rad) due to different types of ionizing radiation. More specifically, it is the experimentally determined ratio of an absorbed dose of a radiation in question to the absorbed dose of a reference radiation (typically 60Co gamma rays or 200 keV x rays) required to produce an identical biological effect in a particular experimental organism or tissue (see Quality Factor). 

RBE is used to denote the experimentally determined ratio of the absorbed dose from one radiation type to the absorbed dose of a reference radiation required to produce an identical biologic effect under the same conditions. Gamma rays from cobalt-60 and 200-250 keV x-rays have been used as reference standards. The term RBE has been widely used in experimental radiobiology, and the term quality factor used in calculations of dose equivalents for radiation safety purposes (ICRP 1977 NCRP 1971 UNSCEAR 1982). RBE applies only to a specific biological end point, in a specific exposure, under specific conditions to a specific species. There are no generally accepted values of RBE. 

Take images using a confocal microscope. We use a Leica DM RBE TCS SP1 microscope (Leica, Wetzlar, Germany) and process images in Adobe Photoshop... 

Vulpis (1973) added pure natural boron as H3B03, which contains about 19% B-10, to the blood culture. It was then irradiated with thermal neutrons from a reactor. The reaction of B-10(n,a)Li-7 within the culture served as alpha source. The dose range was 35 to 195 mGy according to her dose estimation which was complicated by subtracting the dose due to the reactor radiation alone. The dicentric chromosomes appeared to follow a linear response up to about 0.18 Gy and then leveled off to a plateau due to a "saturation effect. The relative biological efficiency (RBE) with respect to X-rays with the doses up to 5f1 Gy was found to be 23. v... 

This was added to lymphocyte-rich blood plasmas and then removed after about 2 hours exposure. They found dose varying RBEs of 119 to 45 for doses of 8.5 to 70 mGy. Their dose estimation, however, was critizised by Fisher and Harty (1982) according to microdosimetric considerations. Therefore also the over tenfold discrepancy of their RBEs for alpha particles to the other studies was attributed to erraneous dose estimations. 

Purrott et al. (1980) used a method similar to DuFrain et al.. see above. They added Pu-239 and Am-241 nitrate solutions to agitated whole blood samples. A linear dose relationship was observed over the dose range of 0.13 to 1.6 Gy and the RBE compared to Co-60 gamma rays was 4 8. 

Edwards et al. (1980) used a Cm-242 source to irradiate externally a thin film of blood. The energy of 4 9 MeV of the alpha particles were almost entirely absorbed by the blood. The dicentrics yield was linear from 0.11 to 4 2 Gy. From this resulted a RBE of 17.9 with respect to Co-60 gamma rays. It was, however, only 6.0 at the initial slope. To explain this RBE, which was low compared to that expected from neutron experiments, a model is presented taking into account cell killing and mitotic delay. 

No calculation of the RBE of the alpha rays at this very low dose range can be made, as no in vitro study was carried out with x- or gamma rays at such low dose levels. The lowest dose of x-rays with which a chromosome aberration study has been carried out was 4 mGy (Pohl-Riiling et al.t 1983) A very rough estimation of the RBE at doses between 2 and 4 mGy yield a value between 2 and 3 ... 

The dose to bone included a relative damage factor, n, in addition to the quality factor, QF (then termed RBE). The n factor represented the relative effectiveness of the dose from the radionuclide as compared with the dose equivalent from 226Ra. The assumptions used by both NCRP and ICRP in making this comparison of bone seeking radio-... 

Relative biological effectiveness (RBE) The biological effectiveness of any type of ionizing radiation in producing a specific damage (i.e., leukemia, anemia, carcinogenicity). See Radiation dose. 

Roentgen equivalent man (rem) The amount of ionizing radiation of any type that produces the same damage to humans as 1 roentgen of radiation. One rem = 1 roentgen equivalent physical (rep)/relative biological effectiveness (RBE). In the latest nomenclature, 100 rem = 1 Sievert (Sv). 

The results from similar clonogenic survival studies with an [ At]-IgG monoclonal antibody to human leukemia cells 158) have given a mean Dq of 12 At atoms cell the RBE has been determined as approximately 4, when compared to the y-radiations from cobalt-60 13). A range of RBE values (2.8-S.2) for At a-particles compared with other low-LET (y,/ ) radiations has been obtained for a variety of tissues under different in vitro and in vivo experimental conditions 12, 13, 29, 61, 64). 

Muller WA, Luz A, Schaffer EH, et al. 1983. The role of time-factor and RBE for the induction of osteosarcomas by incorporated short-lived bone-seekers. Health Phys44(Suppl 1) 203-212. 

These values are general and approximate. RBE and QF values vary widely with... 

Note that the RBE is a decreasing function of Z)h- If Ph = Pi, and taking Eq. (35) into account, one obtains the simplified expression ... 

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