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Desulfurization of molten iron by molten slag is an electrochemical reaction. Previous investigations confirmed that applying electricity could enhance the desulfurization of molten iron, but a quantitative relation between the electricity and the desulfurization was not fully elucidated. The present study attempted to correlate the extent of the electrochemical desulfurization with the applied electricity via a series of high-temperature desulfurization experiments and thermodynamic analyses. A molten iron containing C and S was allowed to react with CaO– $$\hbox {Al}_{{2}}\hbox {O}_{{3}}$$ – $$\hbox {MgO}_{\text {sat.}}$$ slag at 1673 K (1400 $$^\circ $$ C), with and without the electricity of constant current. S distribution coefficients ( $$L_{\text {S}}$$ = (pct S)/[pct S]) were obtained after the normal and the electrochemical equilibria, respectively. The obtained results were interpreted by employing the Nernst equation in order to extract the potential difference ( $$\varDelta \phi _{\text {S}}$$ ) for the electrochemical desulfurization. It was found that applying electric current (I) increased the $$L_{\text {S}}$$ after the electrochemical desulfurization, which resulted in the increase of $$\varDelta \phi _{\text {S}}$$ . A resistance, $$R_{\text {DeS}} = \varDelta \phi _{\text {S}}$$ /I, or a specific resistivity, $$\rho _{\text {DeS}} = \varDelta \phi _{\text {S}}$$ /(I/A), where A is the cathodic area, for the electrochemical desulfurization was defined, which can be used to characterize the susceptibility to the electrochemical desulfurization. It was found that $$R_{\text {DeS}}$$ was independent of the I within the range of this investigation, decreased as (pct CaO)/(pct $$\hbox {Al}_{{2}}\hbox {O}_{{3}}$$ ) increased and was proportional to the resistance of the slag ( $$R_{\text {slag}}$$ ). A favorable condition for the electrochemical desulfurization is not the same as that for the normal desulfurization condition. The $$\varDelta \phi _{\text {S}}$$ , which is an indicator of the extent of electrochemical desulfurization, was independently predicted by employing a thermodynamic model for the oxysulfide slag. The model prediction was in a good agreement with the experimental data. The model was used to predict necessary current level for a desired electrochemical desulfurization.

Sulfur dissolves in molten oxide slag as a sulfide (S $$^{2-}$$ ) under many high-temperature metallurgical processing environments. O $$^{2-}$$ and S $$^{2-}$$ exchange reaction in the molten oxide has been well known. Traditionally, a sulfide capacity ( $$C_{\text{S}}$$ ) was used to characterize the S-holding ability of molten slags under given sulfurizing potential ( $$p_{{\text{S}}_2}/p_{{\text{O}}_2}$$ )—dilute dissolution behavior of sulfide in the molten slags. A number of sulfide capacity models have been reported. Those were reviewed with an emphasis on their core idea regarding the formulation of $$C_{\text{S}}$$ models. It was pointed out that two issues should be explicitly taken into account in the modeling of sulfide dissolution in molten oxide: “oxygen distribution” in the slag (free, non-bridging, and bridging oxygens) and “sulfide stability.” These two issues are the core facts that control the sulfide dissolution in the molten oxide. The $$C_{\text{S}}$$ models taking into account these issues resulted in improved results for the sulfide capacity calculation. In addition to this, some additional issues which were often neglected were raised: (1) sulfide dissolution in acidic slag, (2) sulfide dissolution at high S content, and (3) sulfide dissolution in multi-component slag where more than one basic oxide exist. These issues were interpreted by “cooperative phenomena” using the Modified Quasichemical Model (MQM) in the quadruplet approximation. This approach treats the $$C_{\text{S}}$$ as the real S content under a given sulfurizing potential by formulating the Gibbs energy of the “oxysulfide” solution. The model explicitly distinguishes two distinct sublattices for cations and anions. A Second-Nearest-Neighbor (SNN) Short-Range Ordering (SRO) between two different cations over O anion was considered, which accounts for the distribution of free, bridging, and non-bridging oxygens in the slag. A First-Nearest-Neighbor (FNN) SRO between cation and anion (O and S) was taken into account, which represents the chemical stability of sulfide of different cations. By simultaneously taking into account the FNN- and SNN-SRO using the quadruplets, a configurational entropy of the mixing in the solution was described. Therefore, the approach takes into account the actual sulfide dissolution mechanism in the molten oxide more realistically, thereby resulting in superior prediction ability for the sulfide capacity calculation. In addition, the application of the MQM was extended in a highly concentrated region of sulfide, thereby describing molten “oxysulfide.” Recent experimental works on oxysulfide phase diagrams and the model calculations are discussed to show the wider model applicability. Sulfide dissolution in slags with more than one basic oxide component results in the sulfur association with the various cations. A quantitative description of the different cation-sulfur associations is described in terms of the FNN SRO. By considering the FNN SRO, it is possible to find which cation is more associated with sulfur than other cations. The application of the model is also useful not only in understanding the dissolution behavior of sulfide in slags but also in designing slag/flux in various metallurgical processes.

To elucidate the reoxidation mechanism of Al-killed ultra-low C steel by FetO-containing slag, the kinetics of a reaction 2Al + 3(FetO) = (Al2O3) + 3Fe between the steel and CaO–Al2O3–FetO–MgOsat. slag was investigated mostly at 1823 K. Al contents (total and soluble), and total O content in steel samples were measured during the reactions under various initial compositions of slag ((pct CaO) $$_0$$ /(pct Al2O3) $$_0$$ , (Fe $$_t$$ O) $$_0$$ ), and the reaction temperature. The experimental results were analyzed using the reaction rate model developed in the present study, which is based on probable rate controlling step and employing CALPHAD thermodynamics using FactSage thermochemical software and databases. When the (pct Fe $$_t$$ O) $$_0$$ was higher than 10, the rate model could explain the measured data with an assumption that the rate was solely controlled by mass transport of Al in the steel. However, mixed transport control theory should be used to interpret the reaction rate when the (pct Fe $$_t$$ O) $$_0$$ was lower than 10. Decreasing (pct Fe $$_t$$ O) during the reoxidation reaction changes the reaction mechanism in terms of the mode of rate-controlling step. The mass transport coefficient of Al in the steel (k Al M was $$5\times 10^{-4}$$ m s $$^{-1}$$ at 1823 K (1550 °C), which is in favorable agreement with those in the literature. The mass transport coefficients of Al $$_2$$ O $$_3$$ was formulated to depend on the viscosity of the slag. In the mixed transport control regime, the apparent mass transport coefficient gradually decreased due to the slow mass transport of Al $$_2$$ O $$_3$$ as a resistance to the overall mass transport. This was also additionally supported by evaluating the activation energy of the apparent mass transport coefficient, which turned out to increase as the reoxidation reaction proceeds. Therefore, it can be concluded that the reaction mechanism gradually changes during the reoxidation reaction. (pct CaO) $$_0$$ /(pct Al $$_2$$ O $$_3$$ ) $$_0$$ ratio affects the reoxidation rate only when (Fe $$_t$$ O) $$_0$$ was low.

In this study, a novel chemical–mechanical planarization (CMP) slurry that can perform self-stop polishing was designed. The essential aspects for self-stop polishing are precise design of a nonionic polymer type, molecular weight, and molecular concentration of a self-stopping chemical agent. A good example is polyvinylpyrrolidone (PVP) with a molecular weight of 1300 k and molecular concentration of 0.3 wt%. In this chemical design, the adsorption of a polymer hindrance layer on the surface film topography during CMP can become sufficient under self-stop conditions such as a specific polishing time (e.g., 4 min). The self-stop polishing mechanism is associated with the presence of a relative local pressure difference on the surface film topography. The proper adsorption of the polymer hindrance layer on the surface topography can achieve a uniform relative local pressure distribution globally, and the film polishing rate can achieve adequate planarization of the surface film topography.

The dissolution behavior of Sn in CaO– $$\hbox {CaF}_2$$ flux was investigated. A chemical equilibration technique was employed which allows pure liquid Sn dissolves into the molten flux under various oxygen partial pressure and the flux composition. At an equilibrium, (% Sn) in the flux increased by increasing (% CaO) and $$p_{\text{O}_2}$$ . It was found that Sn dissolves into the molten flux as ( $$\hbox {SnO}_3$$ ) $$^{4-}$$ in the condition of the present study. Distribution of Sn between CaO saturated flux and C saturated liquid Fe was measured under a pure CO atmosphere. Sn distribution ratio ( $$L_{\text{Sn}} = (\%\,\text{Sn})_{\text{flux}}/[\%\,\text{Sn}]_{\text{iron}}$$ ) was as low as $$\sim 10^{-4}$$ , which was consistent with a thermodynamic prediction. Sn distribution was favored at a lower temperature. Thermodynamic modeling was carried out for the Sn dissolution in the flux. A noticeable negative deviation between CaO and SnO was identified.

Evaporation kinetics of tramp elements (M = As and Sn) in liquid iron were investigated by high-temperature gas–liquid reaction experiments and a phenomenological kinetic model. Residual content of As or Sn in the liquid iron ([pct M]) during the evaporation was measured in the temperature range of 1680 °C to 1760 °C. [pct As] and [pct Sn] decreased faster as the reaction temperature and [pct C]0 increased. Assuming first-order reaction kinetics, the apparent rate constants (kM) were obtained at each reaction temperature and [pct C]0. [pct M] in a liquid iron during the top-blown oxygen steelmaking process was simulated, with an emphasis on enlarging the reaction surface area by forming a large number of liquid iron droplets. The surface area and the droplet generation rate were obtained based on the oxygen-blowing condition. The whole surface area increased up to ∼163 times the initial liquid iron (bath) surface area, due to the generation of the droplets. Using the kM obtained in the present study, the evaporation of M during the top-blown oxygen steelmaking process for 200 tonnes of liquid iron was simulated. For a condition of [pct M]0 = 0.005 (M = As and Sn), As and Sn could be removed from the liquid iron, which was seen to be much improved by the consideration of the droplet generation. However, additional actions are required to improve the evaporation rate, as the evaporation rate in the BOF process was not fast enough to be practically considered.

A series of steel-flux reaction experiments was conducted to elucidate the reaction mechanism between high Mn-high Al steel and CaO- $${\text{SiO}}_2$$ -type molten mold flux of low MgO content $$(({\text{pct MgO}})_0 = 0$$ to 1.8) at 1723 K ( $$1450\,^\circ \text {C}$$ ). Composition evolutions in the liquid steel and the molten flux during the reaction and microstructure change in the flux near the steel-flux interface were investigated by employing different experimental techniques. $$4{\underline{{\text{Al}}}} + 3({\text{SiO}}_2) = 3{\underline{\text{Si}}} + 2({{\text{Al}}_2} {{\text{O}}_3}$$ ) was confirmed as a major reaction in the system. It was found that rate of $${{\text{Al}}_2} {{\text{O}}_3}$$ accumulation in the flux was retarded as the initial Al content in the steel ( $$[{\text{pct Al}}]_0$$ ) increased from 1 to 5 or 11, approximately. Moreover, keeping the initial content of MgO in the flux ( $$({\text{pct MgO}})_0$$ ) < 1.8) resulted in a slower reaction rate than that with the normal MgO content ( $$({\text{pct MgO}})_0 = \sim 2.5$$ ) reported previously, even at high Al content ( $$[{\text{pct Al}}]_0 = 4.6 {\text{to}} 5.8$$ ). From the microstructure analysis in the flux, the $${{\text{Al}}_2} {{\text{O}}_3}$$ -rich zone and calcium aluminate layer were observed near the interface. A rapid increase of $${{\text{Al}}_2} {{\text{O}}_3}$$ in the flux near the interface was found at the early stage of the reaction. As the reaction proceeded, however, the concentration gradients in the flux did not show noticeable changes. This suggests that mass transport in the flux was hindered by accumulation of the reaction products near the interface. The formation mechanism of the calcium aluminate layer was discussed by considering the measured flux compositions and phase diagram analysis calculated using the CALPHAD technique. Several kinetic analyses indicated that mass transport in the flux significantly affects the overall reaction rate in the high Mn-high Al steel and CaO- $${\text{SiO}}_2$$ -type molten mold flux system with high Al $$([{\text{pct Al}}]_0 \ge 5$$ ) and low MgO content $$(({\text{pct MgO}})_0 \le 1.8$$ ). The formation of a calcium aluminate layer in the low-MgO flux was beneficial to retarding the reaction rate.

Whale-associated barnacles are intriguing in terms of their planktonic food sources, mating habits, and mechanisms of host attachment. We present observations of the whale-associated barnacles Coronula diadema (Linnaeus, 1767) and Conchoderma auritum (Linnaeus, 1767) obtained from dead humpback whales (Megaptera novaeangliae (Borowski, 1781)) collected in Korea. Shell bases of Coronula diadema are inflected and sharp-edged with hollow coring tubes at the periphery. The coring tubes are filled with whale skin, supporting the model that shell accretion into the whale skin is achieved by basal constriction to achieve strong attachment. Conchoderma auritum attaches to the shell surfaces of Coronula and has a pair of tubular ear-shaped structures on the capitulum. Both species have short and thick-segmented cirri that allow feeding in strong currents. The distal ends of the cirri in both species are often equipped with sharp, large claw-like setae, which are likely used to capture large zooplankton for food. Coronula diadema and Conchoderma auritum are simultaneous hermaphrodites. Coronula diadema can mate up to nine surrounding individuals. Conchoderma auritum lives in clumps and mating group size can up to 26 individuals.

During the solidification of steel, phosphorus strongly segregates in the interdendritic liquid phase. In the continuous casting process, even low levels of P may have a detrimental effect on the final product quality. However, phosphorus is partly added up to 0.10 wt pct to improve the mechanical properties of advanced steel grades nowadays, e.g., High-Strength Interstitial-Free (HSIF). To provide new experimental data for the development of thermodynamic databases and solidification models for P alloyed steel grades, phase equilibria in the Fe-P and Fe-C-P key systems were studied up to 1550 °C using differential scanning calorimetry (DSC) and high temperature laser scanning confocal microscopy (HT-LSCM). Special focus was placed on solid/liquid equilibrium temperatures in the Fe-rich part of the binary Fe-P system between 0.025 and 9 wt pct P. In the ternary system, three isoplethal sections with 0.10 mass pct. P, 0.20 mass pct. C and constant mass percent ratio P/C of 2 were investigated. In the latter section, HT-LSCM observations were linked with DSC signals to optically identify present phase stabilities. Particularly at [pct P] < 1, significant differences between performed measurements and calculated phase equilibrium temperatures using thermodynamic assessments from the literature were identified. In all ternary sections, the experiments indicate less influence of P on the hypo-peritectic range compared to the thermodynamic calculations.

Polynomial representation of partial excess Gibbs energy (i.e., activity coefficient) in multicomponent dilute solution has been widely used after Wagner. Although Wagner’s Interaction Parameter Formalism has been known to be only strictly valid at infinite dilute concentration, it has been used often, even at finite concentration, due to its mathematical simplicity. Nevertheless, several attempts have been made to correct the formalism to be thermodynamically consistent at finite concentration. Among those, Unified Interaction Parameter Formalism proposed by Pelton and Bale, which may be considered as an extension of Darken’s quadratic formalism, has obtained much attention. However, there have been much confusion and debate about the way of the correction. Recently, a thermodynamic analysis was reported that there are infinite numbers of ways to correct Wagner’s formalism to be thermodynamically consistent, which may prevent one from using the Unified Interaction Parameter Formalism with confidence. In the present article, the correction to the Wagner’s formalism is discussed by revisiting Darken’s condition of the thermodynamic consistency. It is shown that the correction to the Wagner’s formalism can be made uniquely. It is pointed out that to ensure the thermodynamic consistency among the activity coefficients of all components, Gibbs–Duhem relation and Maxwell relation among all components including solvent–solute, must be obeyed. Derived expressions for activity coefficients of all components by path-independent integration are also shown to be the same as those obtained by differentiating a corresponding integral excess partial Gibbs energy.

Background In arthroscopic shoulder surgery, a mechanical fluid-irrigation system is used to wash out blood from the joint. If used at high pressure, it can cause side effects such as fluid extravasation, leading to airway obstruction after surgery. Desflurane is prone to increasing sympathetic nerve activity and plasma catecholamine release more than another inhalation anesthetics. The objective of this study was to determine whether desflurane could increase in the irrigation pump pressure than sevoflurane in shoulder arthroscopy. Methods Patients were randomized into a sevoflurane group (group S) and a desflurane group (group D). Each included 20 patients. For group S, sevoflurane 1.2 MAC and intravenous remifentanil were administered for anesthesia maintenance. Group D received desflurane 1.2 MAC and intravenous remifentanil. Starting at 20 mmHg of pump pressure, the surgeon estimated the visibility of the surgical field (grade I-IV). After that, the pressure was freely adjusted by the surgeon to obtain clear vision with the arthroscope during the surgery. Results The maximum pressure of the mechanical water pump was higher in group D than group S (54.0 ± 6.8 mmHg vs. 48.9 ± 5.7 mmHg, P = 0.017), but the difference was not statistically significant at a significance level of 0.01. The arthroscopic visibility at the surgical site did not differ significantly between the two groups (P = 0.284). Conclusions When desflurane is used in arthroscopic shoulder surgery, it does not require more pressure from the irrigating-fluid pump to secure a clear vision of the surgical site, compared to sevoflurane.

One of the industrial wastes, red mud, was assessed as an additive to lime, as a new desulfurization flux for the hot metal in the steelmaking process. Since typical red mud contains some amount of iron oxide, a preliminarily reduced red mud was mainly investigated. Pre-reduction of the red mud and execution of mechanical stirring to the hot metal were effective to enhance desulfurization efficiency (extent and rate of the reaction). However, adding more than 20 pct of red mud in the lime/red mud (pre-reduced) flux did not increase the desulfurization rate. In order to assess the desulfurization efficiency in a more quantitative manner, a "DeS Index" was defined as: [Formula: see text] . This takes into account the extent, rate, and cost of the desulfurization simultaneously. With this index, it was found that the presently developed red mud (pre-reduced)/lime mixtures showed almost similar desulfurization efficiency compared with those of commercially used desulfurization fluxes. It was even better than a typical lime/fluorspar mixed flux, which is now prohibited from being used in many companies due to its environmentally harmful character. It is emphasized that the desulfurization efficiency should be assessed under the mechanical stirring in order to be used in the KR type desulfurization process.

The usage of low-grade ferrous scrap has increased over decades to decrease CO2 emissions and to produce steel products at a low cost. A serious problem in melting post-consumer scrap material is the accumulation of tramp elements, e.g., Cu and Sn, in the liquid steel. These tramp elements are difficult to remove during conventional steelmaking processes. Sn is considered as one of the most harmful tramp elements because, together with Cu, it sometimes induces the liquid metal embrittlement in high-temperature ferrous processing, e.g., continuous casting and hot rolling. Furthermore, the chemical interaction between Fe and Sn plays an important role in the Sn smelting process. The raw material used in the Sn smelting process is SnO2 (cassiterite), in which Fe3O4 is a gangue in the Sn ore. In the process, the reduction of Fe3O4 is unavoidable, which results in forming a Fe-Sn alloy (hardhead). The recirculation of the hardhead decreases the furnace capacity and increases the energy consumption in the smelting. The need to efficiently recover Sn from secondary resources is therefore inevitable. The CALculation of PHAse Diagrams (CALPHAD) approach helps to predict the equilibrium state of the multicomponent system. Previously reported studies of the Fe-Sn system show inconsistencies in the calculations and the experimental results. Mainly the miscibility gap in the liquid phase was under debate, as experimental data of the phase boundary are scattered. Experimental study and re-optimization of model parameters were carried out with emphasis on the correct shape of the miscibility gap. Three different experimental techniques were employed: differential scanning calorimetry, electromagnetic levitation, and contact angle measurement. The present thermodynamic model has higher accuracy in predicting the solubility of Sn in the body-centered cubic (bcc), compared to previous assessments. This is achieved by re-evaluating the Gibbs energies of the FeSn and FeSn2 compounds and the peritectic reaction related to Fe5Sn3. Also, the inconsistencies related to the miscibility gap around XSn = 0.31-0.81 were resolved. The database developed in the present study can contribute to the development of a large CALPHAD database containing tramp elements.

In this study, the chemical decomposition of a polyimide-film (i.e., a PI-film)-surface into a soft-film-surface containing negatively charged pyromellitic dianhydride (PMDA) and neutral 4,4′-oxydianiline (ODA) was successfully performed. The chemical decomposition was conducted by designing the slurry containing 350 nm colloidal silica abrasive and small molecules with amine functional groups (i.e., ethylenediamine: EDA) for chemical–mechanical planarization (CMP). This chemical decomposition was performed through two types of hydrolysis reactions, that is, a hydrolysis reaction between OH− ions or R-NH3+ (i.e., EDA with a positively charged amine groups) and oxygen atoms covalently bonded with pyromellitimide on the PI-film-surface. In particular, the degree of slurry adsorption of the PI-film-surface was determined by the EDA concentration in the slurry because of the presence of R-NH3+, that is, a higher EDA concentration resulted in a higher degree of slurry adsorption. In addition, during CMP, the chemical decomposition degree of the PI-film-surface was principally determined by the EDA concentration; that is, the degree of chemical composition was increased noticeably and linearly with the EDA concentration. Thus, the polishing-rate of the PI-film-surface increased notably with the EDA concentration in the CMP slurry.

The origin of the solubility minimum of oxide ( $$ {M}_x\text{O}_y$$ ) in liquid Fe-M-O alloy was investigated, and the minimum was predicted based on thermodynamic calculations. Due to the characteristic property of activities of M and O in the liquid, a maximum exists in the product between the two activities if the affinity of M to O is significantly high, as most deoxidizing elements are. A critical activity product is defined, which is an indicator of the solubility minimum of the $$ {M}_x\text{O}_y$$ in the liquid Fe-M-O alloy according to the following relationship: $${{\text{max}}}(a_M^x \times a_{\underline{{{\text{O}}}}}^y) = {K_{M_x{{\text{O}}}_y}\times a_{M_x{{\text{O}}}_y}}$$ , where the $$a_{M_x{{\text{O}}}_y}$$ is unity if the alloy is in equilibrium with the pure $$M_x{{\text{O}}}_y$$ . The origin of the solubility minimum was explained using the change of the activity product by composition. Available CALPHAD assessments for several binary Fe-M liquid alloys and Wagner’s solvation shell model were combined to calculate the activity product in the Fe-M-O alloy, which can be used to predict the solubility minimum of $$ {M}_x\text{O}_y$$ . A favorable agreement was obtained when $$M = {\text{Al}}$$ , B, Cr, Mn, Nb, Si, Ta, Ti, V, and Zr. The Gibbs energy of dissolution of O in pure liquid M ( $$\Delta g^\circ _{\underline{{{\text{O}}}}(M)}$$ ) and the Gibbs energy of the formation of $$ {M}_x\text{O}_y$$ per mole of atoms ( $$\Delta g^\circ _{M_x{{\text{O}}}_y}/(x+y)$$ ) play important roles in determining the solubility minimum, as long as an interaction between Fe and M is less significant than the interaction between metal (Fe and M) and O. Predictions of the solubility minima of CaO and MgO were not satisfactory, requiring further improvement of the present analysis.

The interfacial reaction between high-Mn–high-Al steel and CaO-SiO2-type mold flux was investigated, with particular emphasis on the reduction of additive oxide components by Al. Typical additive oxide components (B2O3, Na2O) could be reduced by Al, thereby losing their initial role in the flux. It is proposed to consider the chemical stability of the additive components in the flux in addition to the physico-chemical properties of the flux when developing the mold flux chemistry.

The complete mitochondrial genome of gilbert’s irish lord (Hemilepidotus gilberti), a fish belonging to family Cottidae, was sequenced for the first time. This complete mitochondrial genome was 16,907 nucleotides in length, consisting of 38 mitochondrial genes (13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region). The order of these genes was similar to that of other teleosts. The overall A, C, G, and T nucleotide contents in mitogenome were 26.8%, 30.4%, 17.0%, and 25.8%, respectively. The A + T content (52.6%) was higher than the G + C content (47.4%). NJ phylogenetic analysis was performed for 10 related species within the family of Cottidae along with, two fish species belonging to another family (Sebastidae).