Treatment of transient phenomena in analysis of slag-metal-gas reaction kinetics

Equations commonly used in describing reaction kinetics are examined and the problem of applying such equations to transient processes is discussed. Three examples of transient phenomena are examined in detail. It is shown that for carbon injection into slag, the reaction can be described by employing data for carbon oxidation in CO/CO2 by assuming reaction conditions approximately halfway between those in equilibrium with the slag and those in equilibrium with carbon. It is demonstrated that, when the time averaged interfacial area is employed, the rate of reaction between slag and iron-aluminum alloys can be described by a single first order rate equation, accommodating a 300% change in interfacial area. Creation of surface area in oxygen steelmaking is discussed and a method to determine the size distribution of droplets that are generated is proposed. It is concluded that changes in conditions during reaction complicate the analysis of kinetics. However, it should be possible to develop quantitative kinetic models to describe real processes

Medicinal plants grown in soil amended with struvite recovered from anaerobically pretreated poultry manure wastewater

ABSTRACT 3--P = 1:1:1, pH = 9.0) was tested as a slow release fertilizer on the growth of four medicinal plants including garden rocket (Eruca sativa), dill (Anethum graveolens), fennel (Foeniculum vulgare) and parsley (Petroselinum crispum) in a series of labscale greenhouse experiment. Pot trial tests indicated that rates of increase in fresh weights, dry weights and fresh heights of plants grown in soil fertilized with the recovered struvite were determined as 405%, 488%, and 51% for garden rocket; 154%, 191%, and 44% for dill; 152%, 379%, and 27% for fennel; 141%, 208%, and 22% for parsley, respectively, compared to the control pot. Results of a static bioassay test proved that the use of plants cultivated in MAP pots as the feeding material did not cause any acute toxicity symptoms or mortality in guppy fish (Lebistes reticulatus), and all survived and exhibited normal visual responses at the end of 170-h exposure. Findings of this study confirmed that the recovered struvite from UASB effluent provided a valuable slow release fertilizer for the agricultural use, resulting an edible multi-nutrient animal feed

TEM characterization and high-resolution modelling of second-phase particles of V and Ti containing TWIP steel under uniaxial hot-tensile condition

Composition and crystallographic nature of precipitates in microalloyed advanced high-strength steels (AHSS) greatly influence their microstructure and mechanical behavior. Second-phase precipitation in a high-Mn twinning-induced plasticity (TWIP) steel single microalloyed with V and Ti under uniaxial hot-tensile condition is experimentally and theoretically studied using high-resolution this purpose, carbon extraction replica technique, image treatment, and computer simulation are used to determine the crystallographic features of particles and compared with experimental measurements. Results show particle morphologies depending on crystallographic orientation, namely, hexagonal-type for TWIP-V steel and rectangular-type for TWIP-Ti steel. Measurements on particle size range from 10 to 190 nm in both steels. HRTEM digital image processing allows correcting the obtained Fast Fourier Transform (FFT) diffraction patterns, where interplanar distance measurements indicate the presence of VC and TiC compounds. In the case of the modeled particles, it is possible to identify the NaCltype crystal structure, which are correctly relate with experimental morphologies. Finally, theoretical simulations based on the multislice approach of the dynamical theory of electron diffraction allow modeling HRTEM images. Thus, results indicate that current characterization and simulation procedure are helpful in recognizing crystallographic nature of precipitates formed in the studied TWIP steels.Peer ReviewedPostprint (author's final draft

Reaction Between Nitrogen and Spinel in Chromium

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66029/1/j.1151-2916.1968.tb15671.x.pd

Different regression equations relate age to the incidence of Lauren types 1 and 2 stomach cancer in the SEER database: these equations are unaffected by sex or race

BACKGROUND: Although impacts upon gastric cancer incidence of race, age, sex, and Lauren type have been individually explored, neither their importance when evaluated together nor the presence or absence of interactions among them have not been fully described. METHODS: This study, derived from SEER (Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute) data, analyzed the incidences of gastric cancer between the years 1992–2001. There were 7882 patients who had developed gastric cancer. The total denominator population was 145,155, 669 persons (68,395,787 for 1992–1996, 78,759,882 for 1997–2001). Patients with multiple tumors were evaluated as per the default of the SEER*Stat program. 160 age-, five year period (1992–1996 vs 1997–2001)-, sex-, race (Asian vs non-Asian)-, Lauren type- specific incidences were derived to form the stratified sample evaluated by linear regression. (160 groups = 2 five year periods × 2 race groups × 2 sexes × 2 Lauren types × 10 age groups.) Linear regression was used to analyze the importance of each of these explanatory variables and to see if there were interactions among the explanatory variables. RESULTS: Race, sex, age group, and Lauren type were found to be important explanatory variables, as were interactions between Lauren type and each of the other important explanatory variables. In the final model, the contribution of each explanatory variable was highly statistically significant (t > 5, d.f. 151, P < 0.00001). The regression equation for Lauren type 1 had different coefficients for the explanatory variables Race, Sex, and Age, than did the regression equation for Lauren type 2. CONCLUSION: The change of the incidence of stomach cancer with respect to age for Lauren type 1 stomach cancer differs from that for Lauren type 2 stomach cancers. The relationships between age and Lauren type do not differ across gender or race. The results support the notion that Lauren type 1 and Lauren type 2 gastric cancers have different etiologies and different patterns of progression from pre-cancer to cancer. The results should be validated by evaluation of other databases