The Importance of TDA Thermal Analysis in an Automated Metallurgical Process

The article presents the results of research and work related to the implementation of the research and development project POIR.01.01.01-00-0120/17 co-financed by the EU, through the NCBR, entitled: Innovative technology using thermal analysis, TDA, of self-feeding manufacturing of high-quality cast iron to produce new generation, enhanced performance casts. In many foundries, thermal derivative analysis (TDA) is used in addition to chemical analysis to evaluate the physical and chemical properties of an alloy while it is still in the melting furnace or ladle and before it is poured into the mold. This fact makes it possible to improve the metallurgical quality of the alloy by introducing alloying additives, carburizers or modifiers into the furnace as part of the pre-modification or primary or secondary modification in the ladle or when pouring into molds. Foundry machinery (modifier dosing systems and spheroidizing station) is very important in these operations. Only the full synergy of modern equipment with modern technology ensures high quality and repeatability of the casting process. The article mainly discusses the obtained parameters of TDA analysis (with the use of the ITACA system) at different stages of melting and how to improve them by using modern and fully automated dosing systems (Itaca OptiDose, ItacaWire and ItacaStream). Special attention was paid to the minimum temperature of the eutectoid. The change of its value after the modification process, its influence on the quality of the melted metal, a very strong correlation with the number of nuclei and the number of graphite precipitations in the casts were shown

Alkaline Earth Metal Zirconate Perovskites MZrO3 (M=Ba2+, Sr2+, Ca2+) Derived from Molecular Precursors and Doped with Eu3+ Ions

The effect of alkaline earth metal alkoxides on the protonation of zirconocene dichloride was investigated. This approach enabled the design of compounds with preset molecular structures for generating highâ purity binary metal oxide perovskites MZrO3 (M=Ba2+, Sr2+, Ca2+). Singleâ source molecular precursors [Ba4Zr2(μ6â O)(μ3,η2â OR)8(OR)2(η2â HOR)2(HOR)2Cl4], [Sr4Zr2(μ6â O)(μ3,η2â OR)8(OR)2(HOR)4Cl4], [Ca4Zr2(μ6â O)(μ3,η2â OR)8(OR)2Cl4], and [Ca6Zr2(μ2,η2â OR)12(μâ Cl)2(η2â HOR)4Cl6]â 8â CH2Cl2 were prepared via elimination of the cyclopentadienyl ring from Cp2ZrCl2 as CpH in the presence of M(OR)2 and alcohol ROH (ROH=CH3OCH2CH2OH) as a source of protons. The resulting complexes were characterized by elemental analysis, IR and NMR spectroscopy, and singleâ crystal Xâ ray diffraction. The compounds were then thermally decomposed to MCl2/MZrO3 mixtures. Leaching of MCl2 from the raw powder with deionized water produced highly pure perovskiteâ like oxide particles of 40â 80â nm in size. Luminescence studies on Eu3+â doped MZrO3 revealed that the perovskites are attractive host lattices for potential applications in display technology.Molecular perovskite precursors: A simple, highâ yield synthetic route for the preparation of singleâ source molecular precursors for preparing alkaline earth metal zirconate perovskites MZrO3 (M=Ba, Sr, and Ca; see figure), which were subsequently doped with Eu3+ ions, is presented. The CaZrO3:Eu3+ phosphor showed the highest luminescent intensity and is a highly promising candidate for applications in trichromatic white LEDs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137272/1/chem201504846-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137272/2/chem201504846_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137272/3/chem201504846.pd

Inside Back Cover: Alkaline Earth Metal Zirconate Perovskites MZrO3 (M=Ba2+, Sr2+, Ca2+) Derived from Molecular Precursors and Doped with Eu3+ Ions (Chem. Eur. J. 14/2016)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137453/1/chem201600400.pd

Unexpected Reactions between Ziegler–Natta Catalyst Components and Structural Characterization of Resulting Intermediates

In this work, we investigated precursors and procatalysts with well-defined crystal structures and morphologies in Ziegler–Natta systems to improve our understanding of the nature of the active metal sites. Molecular cluster precursors such as [Mg₄Ti₃(μ₆-O)­(μ₃-OH)₃(μ-OEt)₉(OEt)₃(EtOH)₃Cl₃], [Mg₄Ti₃(μ₆-O)­(μ₃-OH)­(μ₃-OEt)₂(μ-OEt)₉(OEt)₃(EtOH)₃Cl₃], and [Mg₆Ti₄(μ₆-O)₂(μ₃-OH)₄(μ-OEt)₁₄(OEt)₄(EtOH)₂Cl₂] were prepared via simple elimination of the cyclopentadienyl ring from Cp₂TiCl₂ as CpH in the presence of magnesium metal and ethanol. Titanocene dichloride acts as both a source of titanium and a magnesium-chlorinating agent. The resulting novel complexes were characterized using single-crystal X-ray diffraction. In these compounds, Ti­(OEt)₄ molecules are grafted onto Mg₄ and Mg₆ ethoxide cubane-like surfaces; this strongly affects the procatalyst morphology, which is transferred to the polymer. Mg₄(OR)₈ units act as carriers for the AlR₃ co-catalyst, resulting in return of alkyl functions to the Ti center

Transformation of Barium–Titanium Chloro–Alkoxide Compound to BaTiO₃ Nanoparticles by BaCl₂ Elimination

In this Article, we present how the molecular precursor of binary oxide material having an excess of alkali earth metal can be transformed to the highly phase pure BaTiO₃ perovskite. Here, we synthesized and compared two barium–titanium complexes with and without chloride ligands to determine the influences of different ligands on the phase purity of binary oxide nanoparticles. We prepared two barium–titanium complexes, i.e., [Ba₄Ti₂(μ₆-O)­(OCH₂CH₂OCH₃)₁₀­(HOCH₂CH₂OCH₃)₂­(HOOCCPh₃)₄] (<b>1</b>) and [Ba₄Ti₂(μ₆-O)­(μ₃,η₂-OCH₂CH₂OCH₃)₈­(μ-OCH₂CH₂OCH₃)₂­(μ-HOCH₂CH₂OCH₃)₄Cl₄] (<b>2</b>). The barium–titanium precursors were characterized using elemental analysis, infrared and nuclear magnetic resonance spectroscopies, and single-crystal X-ray structural analysis, and their thermal decomposition products were compared. The complex <b>1</b> decomposed at 800 °C to give a mixture of BaTiO₃ and Ba₂TiO₄, whereas <b>2</b> gave a BaCl₂/BaTiO₃ mixture. Particles of submicrometer size (30–50 nm) were obtained after leaching of BaCl₂ from the raw powder using deionized water. Preliminary studies of barium titanate doped with Eu³⁺ sintered at 900 °C showed that the dominant luminescence band arose from the strong electric dipole transition, ⁵D₀–⁷F₂

Transformation of Barium–Titanium Chloro–Alkoxide Compound to BaTiO₃ Nanoparticles by BaCl₂ Elimination

In this Article, we present how the molecular precursor of binary oxide material having an excess of alkali earth metal can be transformed to the highly phase pure BaTiO₃ perovskite. Here, we synthesized and compared two barium–titanium complexes with and without chloride ligands to determine the influences of different ligands on the phase purity of binary oxide nanoparticles. We prepared two barium–titanium complexes, i.e., [Ba₄Ti₂(μ₆-O)­(OCH₂CH₂OCH₃)₁₀­(HOCH₂CH₂OCH₃)₂­(HOOCCPh₃)₄] (<b>1</b>) and [Ba₄Ti₂(μ₆-O)­(μ₃,η₂-OCH₂CH₂OCH₃)₈­(μ-OCH₂CH₂OCH₃)₂­(μ-HOCH₂CH₂OCH₃)₄Cl₄] (<b>2</b>). The barium–titanium precursors were characterized using elemental analysis, infrared and nuclear magnetic resonance spectroscopies, and single-crystal X-ray structural analysis, and their thermal decomposition products were compared. The complex <b>1</b> decomposed at 800 °C to give a mixture of BaTiO₃ and Ba₂TiO₄, whereas <b>2</b> gave a BaCl₂/BaTiO₃ mixture. Particles of submicrometer size (30–50 nm) were obtained after leaching of BaCl₂ from the raw powder using deionized water. Preliminary studies of barium titanate doped with Eu³⁺ sintered at 900 °C showed that the dominant luminescence band arose from the strong electric dipole transition, ⁵D₀–⁷F₂

Transformation of Barium–Titanium Chloro–Alkoxide Compound to BaTiO₃ Nanoparticles by BaCl₂ Elimination

In this Article, we present how the molecular precursor of binary oxide material having an excess of alkali earth metal can be transformed to the highly phase pure BaTiO₃ perovskite. Here, we synthesized and compared two barium–titanium complexes with and without chloride ligands to determine the influences of different ligands on the phase purity of binary oxide nanoparticles. We prepared two barium–titanium complexes, i.e., [Ba₄Ti₂(μ₆-O)­(OCH₂CH₂OCH₃)₁₀­(HOCH₂CH₂OCH₃)₂­(HOOCCPh₃)₄] (<b>1</b>) and [Ba₄Ti₂(μ₆-O)­(μ₃,η₂-OCH₂CH₂OCH₃)₈­(μ-OCH₂CH₂OCH₃)₂­(μ-HOCH₂CH₂OCH₃)₄Cl₄] (<b>2</b>). The barium–titanium precursors were characterized using elemental analysis, infrared and nuclear magnetic resonance spectroscopies, and single-crystal X-ray structural analysis, and their thermal decomposition products were compared. The complex <b>1</b> decomposed at 800 °C to give a mixture of BaTiO₃ and Ba₂TiO₄, whereas <b>2</b> gave a BaCl₂/BaTiO₃ mixture. Particles of submicrometer size (30–50 nm) were obtained after leaching of BaCl₂ from the raw powder using deionized water. Preliminary studies of barium titanate doped with Eu³⁺ sintered at 900 °C showed that the dominant luminescence band arose from the strong electric dipole transition, ⁵D₀–⁷F₂

Measurement of electrons from semileptonic heavy-flavour hadron decays at midrapidity in pp and Pb–Pb collisions at √sNN = 5.02 TeV

The differential invariant yield as a function of transverse momentum (pT) of electrons from semileptonic heavy-flavour hadron decays was measured at midrapidity in central (0–10%), semi-central (30–50%) and peripheral (60–80%) lead–lead (Pb–Pb) collisions at √sNN = 5.02 TeV in the pT intervals 0.5–26 GeV/c (0–10% and 30–50%) and 0.5–10 GeV/c (60–80%). The production cross section in proton–proton (pp) collisions at √s = 5.02 TeV was measured as well in 0.5 < pT < 10 GeV/c and it lies close to the upper band of perturbative QCD calculation uncertainties up to pT = 5 GeV/c and close to the mean value for larger pT. The modification of the electron yield with respect to what is expected for an incoherent superposition of nucleon–nucleon collisions is evaluated by measuring the nuclear modification factor RAA. The measurement of the RAA in different centrality classes allows in-medium energy loss of charm and beauty quarks to be investigated. The RAA shows a suppression with respect to unity at intermediate pT, which increases while moving towards more central collisions. Moreover, the measured RAA is sensitive to the modification of the parton distribution functions (PDF) in nuclei, like nuclear shadowing, which causes a suppression of the heavy-quark production at low pT in heavy-ion collisions at LHC

HΛ3 and H‾Λ‾3 lifetime measurement in Pb–Pb collisions at √sNN=5.02 TeV via two-body decay

An improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb–Pb collisions at √sNN = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the dN/d(ct) spectrum. The measured value, τ = 242+34 −38 (stat.) ± 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle