Diffusion of the hydroxide-ion in liquid CaO-Al2O3-slags by application of Fourier-Transform-lnfrared-Spectroscopy

Water vapour is soluted in liquid CaO-Al₂O₃-slags as OH^?-ion. To determine the diffusion coefficient a capillary technique is used. Roughly 5 cm long platinum capillaries filled with liquid slag are equilibrated at 1500 and 1600 °C and bar different times and then are quenched in liquid D₂O. By dividing these capillaries into roughly 3 mm long segments enough sample substance is won to obtain FT-IR spectra of the OH-band. From measurement of the integral extinction of the OH-band and OH^?-concentration profile through the capillary is obtained. FT-IR-spectroscopy is very suitable for this capillary technique because it needs only very little sample substance.     

Fast radix-p discrete cosine transform

A new fast radix-p-algorithm (p 2) for the discrete cosine transform (DCT) and its inverse is presented. It is based on the divide-and-conquer method and on the arithmetic with Chebyshev polynomials. The algorithm can be applied for the efficient calculation of DCT's of arbitrary transform lengths and for the implementation of other discrete Vandermonde transforms withO(N logN) arithmetical operations.     

Effect of nitrogen and nickel on the stability of an Fe-12Cr-23Mn austenitic steel

The effect of nitrogen and nickel on the austenite stability and the structural changes as a result of cold work of an Fe-12Cr-23Mn alloy steel has been examined by transmission electron microscopy and X-ray analysis. Prestrain was performed either at room temperature or at 200° C. Final strain was carried out at liquid nitrogen temperature. The volume fraction of strain-induced martensite decreased by 40% and 12% due to the addition of 2.43% Ni and 0.11% N, respectively, despite whether prestrain was performed or not. The mechanisms are discussed in terms of the phase, stacking faults, dislocation cells and dislocation tangles induced by prestrain and final strain.     

Stability and work hardening of an Fe-12Cr-23Mn austenitic steel

The effect of pre-strain on the strain-induced martensitic transformation of an Fe-12Cr-23Mn austenitic steel has been investigated through transmission electron microscopy and X-ray analysis. Pre-strain was performed either at room temperature or at 200° C. Final strain was carried out at liquid-nitrogen temperature. The phase was shown to form on {1 1 1} planes of the austenite matrix predominantly by overlapping of stacking faults. The martensite transformation sequence was . Nucleation of the phase mainly occurred at intersections of bands. Austenite stability was shown to increase by pre-strain at 25° C or 200° C. Pre-strain at 200° C has a greater effect on austenite stability than does pre-strain at 25° C. The mechanism was discussed in terms of martensite transformation rate and various substructures introduced during straining. Work hardening was shown to depend on the degree of pre-strain and final strain. The correlation between work hardening and substructures introduced during straining was examined.     

Out-of-Field Hippocampus from Partial-Body Irradiated Mice Displays Changes in Multi-Omics Profile and Defects in Neurogenesis

The brain undergoes ionizing radiation exposure in many clinical situations, particularly during radiotherapy for brain tumors. The critical role of the hippocampus in the pathogenesis of radiation-induced neurocognitive dysfunction is well recognized. The goal of this study is to test the potential contribution of non-targeted effects in the detrimental response of the hippocampus to irradiation and to elucidate the mechanisms involved. C57Bl/6 mice were whole body (WBI) or partial body (PBI) irradiated with 0.1 or 2.0 Gy of X-rays or sham irradiated. PBI consisted of the exposure of the lower third of the mouse body, whilst the upper two thirds were shielded. Hippocampi were collected 15 days or 6 months post-irradiation and a multi-omics approach was adopted to assess the molecular changes in non-coding RNAs, proteins and metabolic levels, as well as histological changes in the rate of hippocampal neurogenesis. Notably, at 2.0 Gy the pattern of early molecular and histopathological changes induced in the hippocampus at 15 days following PBI were similar in quality and quantity to the effects induced by WBI, thus providing a proof of principle of the existence of out-of-target radiation response in the hippocampus of conventional mice. We detected major alterations in DAG/IP3 and TGF-β signaling pathways as well as in the expression of proteins involved in the regulation of long-term neuronal synaptic plasticity and synapse organization, coupled with defects in neural stem cells self-renewal in the hippocampal dentate gyrus. However, compared to the persistence of the WBI effects, most of the PBI effects were only transient and tended to decrease at 6 months post-irradiation, indicating important mechanistic difference. On the contrary, at low dose we identified a progressive accumulation of molecular defects that tended to manifest at later post-irradiation times. These data, indicating that both targeted and non-targeted radiation effects might contribute to the pathogenesis of hippocampal radiation-damage, have general implications for human health.     

Wet hydrogen peroxide catalytic oxidation (WHPCO) of organic waste in agro-food and industrial streams

This review discusses the use of iron- or copper-based solid catalysts in the wet oxidation using H₂O₂ as oxidant of organic molecules present in agro-food and industrial waste aqueous streams. After an introduction on the advantages and limits of using wet hydrogen peroxide catalytic oxidation (WHPCO) as opposite to wet air catalytic oxidation (WACO), the contribution shortly analyses recent results in the field in order to evidence new trends and open issues. More specific examples discussed regard the performances of Fe/zeolite and Fe-containing pillared clays in the oxidation of selected molecules (p-coumaric acid, propionic acid) of relevance for the treatment of organic waste from agro-food production (with reference especially to olive oil milling wastewater). The application of WHPCO in the treatment of complex effluents from electronic industry is also shortly discussed.     

Homogeneous versus heterogeneous catalytic reactions to eliminate organics from waste water using H2O2

Homogeneous (Cu²⁺ ions) and heterogeneous (Cu²⁺-pillared clay) Fenton-like catalysts have been compared in the conversion of p-coumaric acid. The performances of the two classes of catalysts are similar for an analogous amount of copper, but there are some relevant differences in terms of (i) the presence of an induction time, (ii) the turnover frequency, (iii) the efficiency in the use of H₂O₂, (iv) the initial attack of p-coumaric acid (hydroxylation on the aromatic ring or oxidative attack on the double bond of the lateral chain), and (v) the effect of dissolved oxygen on the removal of total organic carbon (TOC). These differences were interpreted in terms of reaction network of generation of radical oxygen species and of organics conversion. The possible formation of a surface peroxo adduct coordinated to a copper binulcear site was also evidenced for the solid heterogeneous catalyst.     

On the correspondence between abstract dialectical frameworks and nonmonotonic conditional logics

Annals of Mathematics and Artificial Intelligence - The exact relationship between formal argumentation and nonmonotonic logics is a research topic that keeps on eluding researchers despite recent...