Beam radiation

The anaerobic reaction of sulfur dioxide with aqueous ammonia produces a solution of ammonium sulfite [10192-30-0]. This reaction proceeds efficientiy, even with a gas stream containing as Httie as 1 wt % sulfur dioxide. The sulfur dioxide can be regenerated at a high concentration by acidulation or by stream stripping of the ammonium sulfite solution, or the sulfite can be made to precipitate and the ammonia recovered by addition of lime (243). The process can also be modified to produce ammonium sulfate for use as fertili2er (244) (see Fertilizers). In a variant of this process, the use of electron-beam radiation cataly2es the oxidation of sulfur dioxide in the presence of ammonia to form ammonium sulfate (245). 

Campbell, F.J. and Brenner, W., Curing high performance structural adhesives by electron-beam radiation. Nav. Eng. J., June, p. 160 (1982). 

Janke, C.J., Dorsey, G.F., Havens, S.J. and Lopata, V.J., Toughened epoxy resins eured by eleetron beam radiation. 28th International SAMPE Technical Conference, S71, 1996. Janke, C.J., Electron beam curable cationic epoxy resin systems and composites. 1st Annual Electron Beam Curing of Composites Workshop, September 18-19, Oak Ridge, TN, Ref. ID, 1996. 

T he total or global solar radiation has a direct part (beam radiation) and a diffuse part (Fig. 11.31). In the simulation, solar radiation input values must be converted to radiation values for each surface of the building. For nonhorizontal surfaces, the diffuse radiation is composed of (a) the contribution from the diffuse sky and (b) reflections from the ground. The diffuse sky radiation is not uniform. It is composed of three parts, referred to as isotropic, circumsolar, and horizontal brightening. Several diffuse sky models are available. Depending on the model used, discrepancies for the boundary conditions may occur with the same basic set of solar radiation data, thus leading to differences in the simulation results. 

Parameters/Units Used in Electron Beam Radiation-Induced... 

Local therapy of early-stage breast cancer consists of modified radical mastectomy or lumpectomy plus external-beam radiation therapy. The surgical approach to the ipsilateral axilla may consist of a full level I/II axillary lymph node dissection or a lymph node mapping procedure with sentinel lymph node biopsy. 

In most instances, external-beam radiation therapy used in conjunction with breast-conserving procedures involves 4 to 6 weeks of radiation therapy directed to the breast tissue to eradicate residual disease. Complications associated with radiation therapy to the breast are minor and include reddening and erythema of the breast tissue and subsequent shrinkage of total breast mass beyond that predicted on the basis of breast tissue removal. Some clinical situations also require postmastectomy radiation therapy as well (see section on locally advanced breast cancer). 

Ic E, Kottapalli B, Maxim J and Pillai SD. 2007. Electron beam radiation of dried and nuts to reduce yeast and mold bioburden. J Food Prot 70(4) 981-985. 

Radiation therapy The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body in the area near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monodonal antibody, that circulates throughout the body. Also called radiotherapy, [nih]... 

To conduct such an experiment using electron beam radiation is more tedious, since the absorption cross section of organic materials to electrons is... 

Figure 5. Inverse number average molecular weight vs dose of PMMA exposed to electron beam radiation.

Exposure of resist materials to electron beam radiation results in dose deposition throughout the thickness of the film for films of nominal l- m... 

PBS (Figure 30) is an alternating copolymer of sulfur dioxide and 1-butene. It undergoes efficient main chain scission upon exposure to electron beam radiation to produce, as major scission products, sulfur dioxide and the olefin monomer. Exposure results first in scission of the main chain carbon-sulfur bond, followed by depolymerization of the radical (and cationic) fragments to an extent that is temperature dependent and results in evolution of the volatile monomers species. The mechanism of the radiochemical degradation of polyolefin sulfones has been the subject of detailed studies by O Donnell et. al. (.41). 

Figure 41. A plot of sensitivity to Mo (5.4k) x-ray radiation and 20 kV electron beam radiation for several resists. EPB is epoxidized polybutadiene, P(GMA-EA) is a copolymer of glycidyl methacrylate and ethyl acrylate (COP), PGMA is poly (glycidyl methacrylate), PBS is poly (butene-1 -sulfone), FBM-1 is poly (2,2,3,3-tetrafluoropropyl methacrylate), P(MMA-MA) is a copolymer of methyl methacrylate and methacrylic acid, PMMA is poly (methyl methacrylate). (Reproduced with permission from Ref. 56J...

The first example of resist relief image formation in the absence of a wet developing step was reported by Bowden and co-workers in 1974 60). These workers reported that exposure of certain poly (olefin sulfones) to electron beam radiation resulted in spontaneous relief image formation. If the films were cast thin enough and the substrates were heated, it was possible to produce clean images in the resist films by exposure alone, thereby avoiding a wet development step. 

Films of polyphthalaldehyde, sensitized by cationic photoinitiators, have been imaged at 2-5-mJ/cm in the deep ultraviolet (DUV) (see Section 3.10), at 1 pC/cm (20 kV) electron beam radiation and at an unspecified dose of Al-A x-ray radiation. The ultimate utility of this "self-developing" resist system will depend upon its efficacy as an etch barrier. It seems clear that such materials would not serve as adequate etch masks for... 

Langer CJ, Paulus R, Ruffer J, Movsas B, Murray K, Rhodes H, Curran WJ. Pro Am Soc Clin Oncol. Phase IIRTOG Trial of Weekly Paclitaxel (TAX) and Conventional External Beam Radiation Therapy for Supratentorial Glioblastoma Mutiforme (abstract 534) 1999. 18. 

S af ar AM, Altamiro PS, Recht A, et al. Phase I trial of gemcitabine, cisplatin and external beam radiation therapy for pancreatic cancer. Proc Am Soc Clin Oncol 1999 18 227a. 

Langer CJ, Ruffer J, Rhodes H, et al. Phase II Radiation Therapy Oncology Group trial of weekly paclitaxel and conventional external beam radiation therapy for supratentorial glioblastoma multiforme. Int J Radiat Oncol Biol Phys 2001 51 113-119. 

Gaspar LE, Winter K, Kocha WI, Coia LR, Herskovic A, Graham M. A phase I/II study of external beam radiation, brachytherapy, and concurrent chemotherapy for patients with localized carcinoma of the esophagus (Radiation Therapy Oncology Group Study 9207) final report. Cancer 2000 88(5) 988-995. 

Androgen deprivation therapy (ADT) is being used increasingly as neo-adjuvant and adjuvant therapy. Neo-adjuvant ADT for 4-6 months before external beam radiation can enhance survival and reduce the prostate volume to be irradiated. Similar benefits have not been seen prior to radical prostatectomy. The benefits of neo-adjuvant therapy are most evident for high risk localized prostate cancer. Adjuvant ADT for up to 2 years following external beam radiation increases disease-free survival and overall survival for locally advanced (T3) tumors. 

Kudoh, H. Katsumura, Y. In Ion-Beam Radiation Chemistry in Radiation Chemistry Present Status and Future Trends , Jonah, C.D. Rao, B.S.M., Eds. Elsevier London, 2002 37 pp. Elliot, A.J. Chenier, M.P. Ouellette, D.C. Koslowsky, V.T. J. Phys. Chem. 1996, 100, 9014. McCracken, D.R. Tsang, K.T. Laughton, P.J. Aspects of the Physics and Chemistry of Water Radiolysis by Fast Neutrons and Fast Electrons in Nuclear Reactors . AECL Publication 11895, Atomic Energy of Canada Limited Chalk River, Ontario, 1998. 

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