Feasibility of recovering metals from associated slags
The associated mineral ore accompanying Valuable Metal Compounds (VMC) have been usually treated in a smelting furnace ,such as Blast Furnace, Reverberatory, Blowing Furnace, hence the VMC were mostly concentrated into the molten associated slags and separated from liquid metals. So the associated slags become an important man-made resources (Table I), in which the VMC exist dispersively in various mineral phases with fine grain size1–4. Due to complex mineralogy and very fine mineral dissemination of the associated slags, it is difficult to recovery the VMC from the slags by metallurgical or mineral process conventionally . Based on several case studies in laboratory and practices in pilot plant on the associated slags , there occur a feasibility to recovery the VMC from the slags by a new process-Selective Precipitation Technique (SPT) on which three continuous steps are involved (in Figure 1).
Thermodynamic Properties of the MgO-BO1.5-SiO2 System at 1723 K
To determine the thermodynamic properties of the MgO-BO1.5 binary system, the following reaction was used: MOn(in slag)+nC(gr.)=M(in liquid copper)+nCO (g) where MOn represents MgO or BO1.5. The activity coefficients of boron and magnesium in liquid copper were first determined by equilibrating pure liquid B2O3 or pure solid MgO with liquid copper under controlled CO partial pressure in a graphite crucible at 1723K: ln γB=0.82+2.81xB, ln γMg=-1.22 (xB≤0.106, xMg≤0.0013) The themodynamic properties of MgO and BO1.5 in MgO-BO1.5 binary slag at 1723K were determined as a function of composition by equilibrating the MgO-BO1.5 slag with liquid copper under CO atmosphere. In addition, the interaction parameter (eMgB) in the Cu-B-Mg alloy was determined to be -100 at 1723K.
Exposure to violence in incarcerated youth from the city of São Paulo.
OBJECTIVE
This study aimed to determine the extent of exposure to community violence among delinquent Brazilian youth in the 12-month period prior to their incarceration and to identify factors associated with this exposure.


METHOD
With an oversampling of girls, a cross-section of youth under 18 years of age from juvenile detention units in the city of São Paulo, Brazil completed a structured interview. Key items related to exposure to violence (witnessed and experienced) were drawn from the Social and Health Assessment questionnaire to cover the 12-month period prior to incarceration.


RESULTS
Participants (n = 325, 89% boys) reported high rates of exposure to violence with largely similar levels for boys and girls. Being threatened with physical harm, being beaten or mugged and/or shot at were the most common forms of violence experienced. After controlling for demographic and family variables, the fact of having peers involved in risk behavior, easy access to guns and previous involvement with the justice system were associated with witnessed violence; whereas having slept on the street was the only variable associated with experienced violence.


CONCLUSION
This group of youth was exposed to high levels of violence and other adverse experiences. Future research should examine the effectiveness of strategies aimed at reducing the exposure to violence of high-risk youth.