The Underground Injection Control Branch of the Office of Drinking Water, US Environmental Protection Agency requested evaluation of a document submitted by Disposal Systems, Incorporated (DSI), in which health based limits (HBLS) were established for 442 hazardous compounds listed in 40 CFR 261, Appendix VII[I and 40 CFR 264, Appendix IX. The contractor was asked to review the document, evaluate the proposed methods for assigning HBLS, and determine whether - the relationship established between HBLs and concentration reduction factors is valid. He was also asked to determine the suitability of the use of ``reference molecules`` as a substitute for those compounds for which no data allows specification of HBLs and evaluate whether DSI`s approach could be used to modify and upgrade UIC Guidance No. 7 1. Finally, the feasibility of computer model simulations was to be considered if complex and varied mixes of compounds were to be injected.

Research was concentrated on two-phase Ti-TiCr{sub 2} alloys, two- phase Fe-ZrFe{sub 2} alloys, and two-phase ternary Ni-Cu-Mg alloys containing MgNi{sub 2} and MgCu{sub 2} phases. Work demonstrated that a variety of room-temperature deformation processes are possible in Laves phases. A strain-induced phase transformation from C36{r_arrow}C15 structures is one mechanism for plastic deformation in ZrFe{sub 2}. The C15 structure in TiCr{sub 2} deforms by slip and twinning. The microstructure after indentation of specimens containing C36 phases ZrFe{sub 2} and MgNi{sub 2} indicates that a variety of slip systems operate in this form. 8 figs.

Research was concentrated on two-phase Ti-TiCr[sub 2] alloys, two- phase Fe-ZrFe[sub 2] alloys, and two-phase ternary Ni-Cu-Mg alloys containing MgNi[sub 2] and MgCu[sub 2] phases. Work demonstrated that a variety of room-temperature deformation processes are possible in Laves phases. A strain-induced phase transformation from C36[r arrow]C15 structures is one mechanism for plastic deformation in ZrFe[sub 2]. The C15 structure in TiCr[sub 2] deforms by slip and twinning. The microstructure after indentation of specimens containing C36 phases ZrFe[sub 2] and MgNi[sub 2] indicates that a variety of slip systems operate in this form. 8 figs.

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