This work aims to produce a high manganese steel with more refined austenite grains and better wear resistance without sacrificing the toughness and tensile properties by Mn alloying and Ti ladle treatment in comparision to ASTM A128 Gr. E1 steel (1.0C-13Mn) that is mostly used in the mining industry. The 1.0C-17Mn-xTi alloys (x=0, 0.05 and 0.1, in wt.%) were prepared. A relationship was established between the microstructures and mechanical properties of the as-cast and solution annealed alloys. Increasing Ti content increases the stable Ti(CN) phase on and beside the grain boundaries and decreases up to 37% the austenite grain size of the as-cast alloy with 0.10wt.% Ti. Correspondingly, after solution annealed, optimized titanium content (0.05wt.%) results in significant improvements in wear resistance, hardness, elongation, yield and tensile strengths by 44%, 31%, 30%, 8% and 12%, respectively, except 9% decrease in impact toughness compared to ASTM A 128 Gr. E1 steel without modification. These results show that 1.0C-17Mn-0.05Ti alloy can be used for parts exposed to high load wear and applied in conditions where relatively high tensile properties with sufficent ductility is needed.
Drug-related renal damage is manifold in its origin, clinical picture and prognosis. The disorder can manifest itself as a purely functional phenomenon with tubular elimination of amino acids, enzymes, protein, glucose and electrolytes, or it is due to reversible hemodynamic changes; on the other hand, it may be accompanied by cell necrosis and inflammation. Hemodynamic, toxic, immunologic, or mechanically obstructive mechanisms or a combination of these play a pathogenetic role. It is important to know the renal parameters before and monitor them during treatment with nephrotoxic drugs; to avoid concomitant administration of two or more nephrotoxic drugs; and to make the diagnosis as well as terminate exposure rapidly. 相似文献
Novel bioengineering copolymers were synthesized by radical copolymerization of N-isopropylacrylamide (NIPA) and 3,4-2H-dihydropyran (DHP) with 2,2′-azobisisobutyronitrile as an initiator in acetone solution at 70 °C under nitrogen atmosphere. Structure, tacticity and compositons of the copolymers prepared in a wide range of monomer feed were confirmed by FTIR, 1H{13C} NMR-DEPT and elemental analyses. The monomer reactivity ratios (r1 and r2) were detected using known two methods: r1 (NIPA)?=?1.25 and r2?=?0.035 (DHP), and r1 (NIPA) ?=?0.97 and r2?=?0.022 (DHP) by Kelen-Tüdös and Jaacks methods, respectively. It was demonstrated that the studied monomer pair has a tendency to form H-bonding beween amide/ether groups through ?NH...O< complexation which played an important role in the stereoselective chain growth, and significant decrease of allyl degradative chain transfer reactions. This phenomenon is also confirmed by the observed relatively high molecular weights of copolymers (Mv). The synthesized water-soluble stimuli-responsive poly(NIPA-co-DHP)s exhibit thermal stability, higher glass-transition temperature, polyelectrolyte, pH- and temperature-sensitive behavior and can be attributed to the class of bioengineering functional copolymers useful for various bio- and gene-engineering, and drug delivery applications. 相似文献
Effective atomic numbers for (PbO and Na2B4O710H2O) and (UO2(NO3)2, and Na2B4O710H2O) mixtures against changing contents of PbO, Na2B4O710H2O, and UO2(NO3)2 were measured in the X-ray energy range from 25.0 to 58.0 keV. The gamma rays emitted by a 241Am annular source have been sent on the absorbers which emits their characteristic X-rays to be used in transmission arrangement. The X-rays were counted by a Si(Li) detector with a resolution of 146 eV at 5.90 keV. The changing compositions of the compounds were assigned to be 0, 0.167, 0.333, 0.500, 0.666, 0.833 and total masses of the mixtures were adjusted to be identical. Also, the total effective atomic numbers of each mixture were estimated by using the mixture rule. The measured values were compared with estimated values for the mixtures. 相似文献