Mass Balance Modeling for Electric Arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey

  In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace (LF). This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 9593%. These efficiencies are calculated for all input elements as 845% for C, 3031% for Si, 4636% for Mn, 3064% for P, 4196% for S, and 6979% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system.     

A study on compatibility of experimental effective atomic numbers with those predicted by ZXCOM

In this study, effective atomic numbers(Zeff) of materials determined at different experimental conditions by measuring the elastic-to-inelastic γ-ray scattering ratios are compared to ZXCOM predictions. It also presents the experimental data obtained via the transmission technique The agreement and disagreement between ZXCOM and experimental values are investigated. The theoretical basics of determining Zeffby scattering mode are outlined. The study shows that choosing appropriate experimental conditions can provide a good compatibility between the experimental results and theoretical ZXCOM calculations     

TDPAC study of the Hf-doped LaNi5-hydrogen system

The dependence of the electric field gradients (EFGs) in the Hf-doped LaNi₅-hydrogen system, as a function of hydrogen composition ratio (X), has been investigated in the range 0≤X≤5.7 using the Time Differential Perturbed Angular Correlation (TDPAC) technique. The TDPAC spectrum of LaNi₅ was fitted with a single EFG, while two EFGs were needed to fit the LaNi₅H_x spectra. The first EFG was similar to the one found in metallic LaNi₅ and the second one was interpreted as related to those probe atoms located in the basal plane next to hydrogen interstitial sites located in the same plane. The relative fraction of the probe atoms experiencing these EFGs is dependent on the relative occupation of hydrogen in these sites.     

In situ detection of tandem DNA repeat length

A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats known lengths. Single-stranded loops structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase.     

High pressure study of β-UH3 crystallographic and electronic structure

The crystallographic and electronic structure of β-UH₃ were studied as a function of pressure by combining X-ray diffraction results with the full potential linearized augmented plane wave (LAPW) calculations. No phase transition was observed up to a pressure of 29 GPa, with a total volume contraction of V/V₀=0.87, and a bulk modulus value of B₀=33±5 GPa. The calculated value of the electric field gradient main component at the uranium 6(c) site was found to be linear dependent in the pressure induced volume reduction. This linear dependence is attributed to the increase in the positive p–p contribution to the efg as a function of volume, while the negative s–d, d–d and the lattice contributions to the efg are almost pressure independent.     

粉末冶金Al-1．1Sc和Al-2SC合金晶体结构的实验和第一性原理研究

采用气体雾化合金颗粒制备Al-1．1％Sc和Al-2％Sc合金。采用x射线衍射分析合金样品以确定样品的晶格参数。利用这些晶格参数,分别通过WIEN2K和EMTO程序对该合金的力学性能进行理论计算。将实验得到的合金的弹性模量和理论计算结果进行比较。讨论了计算得到的A13Sc相和AI—Sc合金的力学性能以确定Al-Sc合金中最佳的Sc含量。结果表明,最高的Sc含量约为1．0％,更多的Sc不能提高合金的力学性能。