Enzymatic removal of selected aromatic contaminants from wastewater by a fungal peroxidase from Coprinus macrorhizus in batch reactors

The use of enzymes such as horseradish peroxidase (HRP) for degrading or removing toxic organics from synthetic wastewater has been demonstrated previously. Potential alternatives to HRP are other peroxidases, various ligninases, haloperoxidases and laccases. Results of this study indicate that a fungal peroxidase from Coprinus macrorhizus (CMP) has the capability to catalyze the same reactions as HRP. Similarly, in batch reactors the trend and removal efficiency of aromatic compounds by CMP from synthetic wastewater depend on the nature of the compound.     

Influence of initial texture on the microstructural instabilities during compression of commercial α-Titanium at 25 °C to 400 °C

Cylindrical specimens of textured commercial pure α-titanium plate, cut with the cylinder axis along the rolling direction for one set of experiments and in the long transverse direction for the other set, were compressed at strain rates in the range of 0.001 to 100 s~’ and temperatures in the range of 25 °C to 400 °C. At strain rates ≥ 1 s⁻¹ ’, both sets of specimens exhibited adiabatic shear bands, but the intensity of shear bands was found to be higher in the rolling direction specimens than in the long transverse direction specimens. At strain rates ⪯0.1s ⁻¹ the material deformed in a microstructurally inhomogeneous fashion. For the rolling direction specimens, cracking was observed at 100 °C and at strain rates ⪯0.1 s⁻¹. This is attributed to dynamic strain aging. Such cracking was not observed in the long transverse specimens. The differences in the intensity of adiabatic shear bands and that of dynamic strain aging between the two sets of test specimens are attributed to the strong crystallographic texture present in these plates.     

Synthesis and Irreversibility of Oxygen Weight Loss in 80 K YBa2Cu4O8 Superconductor

Synthesis of YBa₂Cu₄O₈ superconductor usually requires oxygen pressure greater than 20 MPa and very long heating schedules at high temperatures. Here we report synthesis of YBa₂Cu₄O₈ superconductor by the standard solid-state reaction between the precursors BaCu₂O₃ and Y₂O₃ in the presence of alkali nitrate. NaNO₃, under ambient O₂ pressure. The resulting sample showed zero resistance at 78 K. The presence of 124 was confirmed by high-resolution X-ray diffraction studies. Irreversibility of oxygen weight loss was studied by thermogravimetric analysis and differential thermal analysis.     

Space bounded computations: review and new separation results

In this paper we review the key results about space bounded complexity classes, discuss the central open problems and outline the prominent proof techniques. We show that, for a slightly modified Turing machine model, low level deterministic and nondeterministic space bounded complexity classes are different. Furthermore, for this computation model, we show that Savitch's theorem and the Immerman-Szelepcsényi theorem do not hold in the range lg lg n to lg n. We also present other changes in the computation model which bring out and clarify the importance of space constructibility. We conclude by enumerating open problems which arise out of the discussion.     

Compressibility and sound velocity measurements on N2 up to 1 GPa

A gas expansion technique has been used to determine the pVT properties of N₂ up to 1 GPa at 298.15 K, with an accuracy of 0.08% in density, 1 mK in temperature, and 0.05%+0.2 MPa in pressure. The sound velocity has been measured by a phase-comparison pulse-echo technique between 123 and 298 K at intervals of 25 K and at pressures up to 1 GPa, with an accuracy of better than 0.02% in sound velocity, 10 mK in temperature, and 0.05%+0.2 MPa in pressure. An equation of state is presented that correlates the density data over the wide pressure range of 36–1000 MPa with maximum deviations between the calculated and the experimental densities of less than 0.05%.     

Transient analysis of closed loop solar water heating system

This paper presents a simplified transient analysis of a forced-circulation solar water heating system with a heat exchanger in the collector loop. Besides two modes of hot water withdrawal viz constant flow and constant collection temperature; the paper also studies the effectiveness of the flow through the heat exchanger and its length. The system performance has been further studied by considering different timings of starting hot water withdrawal. Calculations have been made for a typical cold day (26 January 1980) in New Delhi.