The behavior of metal droplets in a slag-metal-gas emulsion through impinging gas blowing was investigated experimentally using a cast iron-slag-nitrogen gas system at high temperatures. A mathematical model of the emulsification process for determining the generation rate, size distribution, and residence time of metal droplets has been developed and successfully validated using experimental data. From the present work, it was found that the generation rate and size distribution of metal droplets is strongly influenced by the ratio of the inertial force of blown gas to the surface tension and buoyancy forces of the liquid metal. A new dimensionless number, i.e. blowing number, which represents the ratio of inertial to surface tension and buoyancy forces and also the departure of the system from its stable condition defined by the Kelvin-Helmholtz criterion, is proposed. A functional relationship of generation rate and size distribution of metal droplets with the blowing number is proposed.KEY WORDS: droplet generation; droplet size distribution; residence time; impinging gas blowing; slagmetal emulsion; steelmaking.

In basic oxygen steelmaking, the major portion of the refining is realized through reactions between metal droplets and slag. The residence time of metal droplets in the slag crucially influences the productivity. A model for the prediction of trajectory and residence time of metal droplets in slags has been developed based on mechanics and chemical kinetics principles. When there is no decarburization, analysis of the ballistic motion of metal droplets in the slag predicts very short residence times (Ͻ1 second). This result demonstrates that when decarburization is very weak, the metal droplets spend a very short time in the slag. This could explain in part the poor kinetic behavior in the end stage of the blow. During active decarburization metal droplets normally become bloated, resulting in a decreased apparent density. Accounting for this, the ballistic model predicts residence times ranging from 10 to 200 seconds, which are much more in keeping with practical experience and previous laboratory studies. Excellent agreement between the model and laboratory measurements, combined with reasonable predictions of industrial residence times, shows that this model can be used to provide a much improved understanding of theoretical aspects of oxygen steelmaking.

In ladle metallurgical operations, it is common practice to use an inert gas for stirring. The stirring is used to achieve homogenization and to pursue chemical and physical changes. The raised region where the gas discharges from the bath during argon stirring is usually called a spout.Where the spout is uncovered by slag, the region is called the spout eye.1) The spout region is significance in industrial practice, since it is an important site for slag-metal reactions and the site of undesirable reactions between metal and air. However, there has been relatively little study to elucidate the phenomena.Recently, Yonezawa and Schwerdtfeger 1,2) reported a comprehensive investigation of the spout region. They studied the phenomena with the objectives to determine the dimensions of the spout and the spout eye. Data were obtained from cold model experiments, by using mercury and silicon oil for simulating metal and slag, respectively, and plant measurements on a 350 t ladle. A video camera was employed to measure the spout formation and spout eye area. For measuring the height of the spout, electroresistivity probes were used for the cold model and the dissolved tube length technique for the plant measurements. The results indicated that spout eye formation and spout eye size are highly dynamic, as a consequence of the discontinuous gas discharge at the nozzle and of the subsequent disintegration into bubbles.Despite their success in measuring spout eyes, both in the cold model experiments and plant trials, they failed to develop an adequate functional correlation between eye area, A es , and operational variables. By employing dimensional analysis technique,

Drug-induced liver injury (DILI) is the most common adverse drug reaction in the treatment of tuberculosis (TB). Several studies showed that patients with TB and the slow-acetylator phenotype caused by NAT2 variants are highly susceptible to DILI caused by anti-TB drugs, hereafter designated AT-DILI. However, the role of NAT2 variants in AT-DILI has never been assessed for an Indonesian population. We recruited 50 patients with TB and AT-DILI and 191 patients with TB but without AT-DILI; we then used direct DNA sequencing to assess single-nucleotide polymorphisms in the coding region of NAT2. NAT2*6A was significantly associated with susceptibility to AT-DILI (P=7.7 × 10(-4), odds ratio (OR)=4.75 (1.8-12.55)). Moreover, patients with TB and the NAT2-associated slow-acetylator phenotype showed higher risk of AT-DILI than patients with the rapid- or intermediate-acetylator phenotypes (P=1.7 × 10(-4), OR=3.45 (1.79-6.67)). In conclusion, this study confirms the significance of the association between slow-acetylator NAT2 variants and susceptibility to AT-DILI in an Indonesian population.

Quantification of metal droplets ejected due to impinging gas jet on the surface of liquid metal is an important parameter for the understanding and for the modelling of the refining kinetics of reactions in slag-metal emulsion zone. In the present work a numerical study has been carried out to critically examine the applicability of droplet generation rate correlation previously proposed by Subagyo et al. on the basis of dimensionless blowing number (NB). The blowing number was re-evaluated at the impingement point of jet with taking into account for the temperature effect of change in density and velocity of the gas jet. The result obtained from the work shows that the modified blowing number NB,T at the furnace temperature of 1873K (1600 °C) is found to be approximately double in magnitude compared to NB calculated by Subagyo and co-workers. When NB,T has been employed to the Subagyo's empirical correlation for droplet generation, a wide mismatch is observed between the experimental data obtained from cold model and hot model experiments. The reason for this large deviation has been investigated in the current study and a theoretical approach to estimate the droplet generation rate has been proposed. The suitability of the proposed model has been tested by numerically calculating the amount of metals in slag. The study shows that the weight of metals in emulsion falls in the range of 0 to 21 wt pct of hot metal weight when droplet generation rate has been calculated at ambient furnace temperature of 1873K (1600 °C).

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This paper discusses good criteria for a supply chain performance measurement model and their level of importance. The criteria were obtained from results of previous research findings and recommendations from several researchers. The criteria are divided into two categories, namely efficient and effective. To examine which criteria can be used to assess a supply chain performance measurement model, a survey was conducted by distributing questionnaires to supply chain actors from different industry fields (both manufacturing and services) in Indonesia using random sampling techniques. Data analysis using pairwise comparisons with an analytical Hierarchy Process model showed that efficient criteria were more important than effective criteria. Efficient criteria consisted of three sub-criteria: the amount of data is not too much and low cost and output is presented in a simple form. Effective criteria consisted of the criteria in the order of importance as follows: clarity, validity, comprehensiveness, responsiveness and dynamics. Further research is needed for developing a model that meets these criteria

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