An innovative route for valorising iron and aluminium oxide rich industrial wastes: Recovery of multiple metals.

Several industrial wastes including biomass, fly ashes, red mud, mill scales, water treatment residues, have significant concentrations of metal oxides: Fe2O3, Al2O3, TiO2, SiO2 etc. Several efforts have been made towards recovering metals within these wastes. Rather than recovering one metal at a time, we report a novel approach for simultaneously extracting multiple metals from mixed oxides in a single process step. Using three distinct furnaces/heating regimes, the carbothermic reduction of Fe2O3/Al2O3/SiO2 system was investigated at 1450-1700 °C for up to 2 h over a wide composition range. Complete reduction was achieved for both Fe2O3 and SiO2 in all cases leading to the formation of Fe and Fe-Si alloys. The reduction of alumina at moderate temperatures was the key challenge. No alumina reduction was observed during reductions at 1450 °C. A partial reduction of alumina and the formation of Fe-Al alloys was detected in the Al2O3/Fe2O3/C system at 1550 °C. The formation of Fe-Si-Al alloys was also observed in the Fe2O3/SiO2/Al2O3/C system at 1550 °C. Complete reduction of alumina was observed at 1600-1700 °C, even for up to 50 wt% alumina in the system. Optimal operating conditions and reference standards were established for the simultaneous recovery of multiple metals from waste oxides. While conserving natural resources, this novel route will lower the burden on waste storage facilities with significant contributions to the economic and environmental sustainability of industrial waste management.

[Experience of Treatment of Spontaneous Rupture of Left Ventricular Posterior Wall After Mitral Valve Replacement].

Spontaneous rupture of the left ventricular posterior wall after mitral valve replacement is a severe complication and is associated with high mortality rate. This complication was first described in 1967 by Roberts and Morrow, which describe the results of autopsy of two patients. In leading clinics around the world left ventricular wall ruptures after mitral valve replacement account for up to 20% of causes of hospital mortality. Currently there is no clear-cut strategy of treatment of this complication. In this article we present analysis of both traditional and non-traditional methods of treatment of this complication as well as own small positive and negative experience.

High resolution EPR spectroscopy of C(60)F and C(70)F in solid argon: reassignment of C(70)F regioisomers.

Free radicals C(60)F and C(70)F were generated in solid argon by means of chemical reaction of photogenerated fluorine atoms with isolated fullerene molecules (C(60) or C(70)). High resolution anisotropic electron paramagnetic resonance (EPR) spectra of C(60)F and C(70)F at low temperature have been obtained for the first time. The spectrum of C(60)F is characterized by an axially symmetric hyperfine interaction on (19)F nucleus. The hyperfine coupling constants A(iso)=202.8 MHz (Fermi contact interaction) and A(dip)=51.8 MHz (electron-nuclear magnetic-dipole interaction) have been measured for C(60)F in solid argon. Quantum chemical calculations using hybrid density-functional models (either PBE0 or B3LYP) with high-quality basis sets give a theoretical estimate of the hyperfine coupling constants in good agreement with the measurements. The electron spin density distribution in C(60)F is theoretically characterized using the Hirshfeld atomic partitioning scheme. Unlike C(60), five isomers of C(70)F can in principle be produced by the attachment of a fluorine atom to one of the five distinct carbon atoms of the C(70) molecule (denoted A, B, C, D, and E, from pole to equator). The measured high resolution EPR spectrum of the C(70)+F reaction products is interpreted to show the presence of only three regioisomers of C(70)F. Based on the comparison of the measured hyperfine constants with those estimated by the quantum chemical calculation, an assignment of the spectra to the isomers (A, C, and D) is made, which differs strongly from the previous one [J. R. Morton, K. F. Preston, and F. Negri, Chem. Phys. Lett. 221, 59 (1994)]. The new assignment would allow the conclusion that the low-temperature attachment of F atom to the asymmetric C=C bonds of C(70) molecule, namely, C(A)[Double Bond]C(B) and C(D)=C(E), shows remarkably high selectivity, producing only one of the two isomers in each case, A and D, respectively. Theoretical investigation of the reaction mechanism is made, and it shows that the attachment reaction should have no barrier in the gas phase. The thermodynamic equilibration of the C(70)F isomers is excluded by the high activation energy ( approximately 30 kcal/mol) for the F atom shifts. The explanation of the high selectivity presents a challenge for theoretical modeling.

[The intra-aortic antibacterial therapy of wounded patients with gunshot meningoencephalitis]. / Vnutriaortal'naia antibakterial'naia terapiia ranenykh s ognestrel'nym meningoéntsefalitom.

The original decision of permanent introduction of antibacterial means to tissues of brain at gunshot meningoencephalitis is offered. For antibacterial therapy the intra-aortal catheter with diameter of 2,5 mm (through a.femoralis) was introduced. After washing the catheter by solution of crystalloid with heparin the various combinations of preparations in 5% solution of glucose were introduced: cephalosporin--8 g/day; hentamicin and brumacilin--240 mg/day accordingly, amicacin--1500 mg/day. Speed of introduction--20-50 mg/h, total volume--500 ml. The catheter was in aorta not more than 10 days, maximum--14 days. A described technique was applied in Burdenko Main Military Clinical Hospital on 34 wounded in head. At computer tomography of brain of all wounded intracranially the splinters and bullets were revealed, clinically--meningoencephalitis. Foreign bodies have been extracted after cupping of clinical and laboratory signs of meningoencephalitis. The authors consider, that the technique is effective not only at wounds of brain, but also at suppurative meningoencephalitis of other etiology.

[Changes in the central and peripheral hemodynamics of patients with acute peritonitis in the immediate postoperative period]. / Izmeneniia tsentral'noi i perifericheskoi gemodinamiki u bol'nykh s ostrym peritonitom v blizhaishem predoperatsionnom periode.

The article examines hemodynamic indices in patients with acute peritonitis in proximate preoperative period, taking into account etiology of the disease, a period passed from the appearance of illness and up to the performance of operation, and the scope of infusion-transfusion therapy. An algorithm of preoperative volemic preparation was worked out which made it possible to normalize hemodynamic homeostasis in patients and assure the performance of operation in more favourable physiologic conditions.

[Early diagnosis of acute renal insufficiency in patients with peritonitis]. / Ranniaia diagnostika ostroi pochechnoi nedostatochnosti u bol'nykh peritonitom.

Changes in osmolarity, blood and urine levels of medium-size molecules (MSM), osmolarity and MSM index, free water clearance (FWC) and alterations in traditional clinical and biochemical parameters typical of acute renal failure (creatinine, urea nitrogen, K+, Na+, diuresis) have been compared in 27 patients with peritonitis complicated in 17 cases by acute renal failure (ARF). In patients with developing ARF disturbances in osmotic condition, osmotic clearance, FWC, MSM level precede an increase in creatinine and urea nitrogen level and diuresis decrease. Dynamic studies of FWC and MSM blood and urine levels allow of early ARF diagnosis in patients with peritonitis. Progressive growth of plasma osmolarity and FWC with a parallel decrease in MSM index below 1 is a criterion indicative of functional renal failure turning into organic one.

[Renin activity and functional status of the adrenal cortex in surgical intervention during ketamine anesthesia]. / Aktivnost' renina i funktsional'noe sostoianie kory nadpochechnikov pri operativnykh vmeshatel'stvakh v usloviiakh ketaminovoi anestezii.

The renin activity and gluco- and mineralocorticoid adrenalocortical function were studied in 22 patients operated mainly on abdominal organs under the conditions of ketamine anesthesia. As noted, the ketamine injection followed with hypertension and tachicardia does not give rise to the renin activity and to the 11-OKS and aldosterone blood levels, as well. An evident trend to the increase of the concentration of the adrenocortical hormones, together with the occurrence of hypokemia and progressive hyperglycemia have been traced throughout the anesthesia and operation.