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The continuously increasing interest in the use of Second Generation High Temperature Superconductor (2G-HTS) over wide range of temperatures (4.2–77 K) and intermediate to very high fields (∼3 to >30 T) entails a major problem of lack of techniques capable of inspecting critical current (Ic) performance at the target fields and temperatures (B, T) over long lengths. The complete lack of correlation between critical current performance at (77 K, 0T) and the target (B,T) calls for alternative techniques capable of reliable performance characterization over long lengths in a time and cost effective manner. In this study, we explore the possibility of using Raman spectroscopy features to provide insight into Jc(B,T) performance of RECBO films. We present results on correlation between features of Raman spectra of tetragonal REBCO films and their in-field Jc(B,T) performance. In particular, we identify a secondary peak in the vicinity of Cu2 peak as a feature that correlates with Jc(B,T) at intermediate fields (0–4 T) and temperatures (30–77 K). The feature appears as a shoulder or asymmetry of Cu2 peak but is fitted as a separate Voigt profiled peak. The intensity of this peak, normalized to the intensity of the Cu2 peak, has a strong negative correlation with Jc(B,T), with Pearson correlation coefficient −0.88 to −0.97.

Novel adsorbent materials were prepared from sodium alginate and polyvinyl alcohol (AL-PVA) in 5 different ratios to evaluate their adsorption capacities for Pb (II), Cu (II) and Zn (II) in a multicomponent solution of 10 mg/L of each metal, then they were tested with wastewater from a glass industry to remove these heavy metals. The adsorption tests with the materials of different AL-PVA ratios showed that the most efficient material was the one with the ratio 50/50, this composite was characterized by SEM and FTIR spectra before and after the adsorption process; the zero-point charge, swelling kinetics and acid resistance tests were determined. The experimental multicomponent adsorption kinetics data fitted best the pseudo-first-order model according to the R2values and the similarity between the experimental adsorption capacity and the calculated one, the adsorption isotherm data of Pb (II) fitted best to the linear model and those of Cu (II) and Zn (II) to the Langmuir model. The adsorbent material shows a high potential for the removal of Pb (II), Cu (II) and Zn (II).

In this work, we evaluate the use of scanning Raman spectroscopy for characterizing long lengths of REBCO coated conductor tapes, as it can provide detailed insight into structure, composition, and local variations arising from defects or strain. We generate 2D maps of Raman wavelength and intensity features over extended 1 meter length of conductor and correlate them to the information collected by reel-to-reel (R2R) 2D X-Ray Diffraction (2D-XRD) and R2R Scanning Hall Probe Microscopy (SHPM). The three methods are compared in terms of depth of information, detectability of variation in features of interest and the potential for evaluating critical current performance over a range of fields and temperatures.

The structure of heat-treated sol–gel-made SiO2 samples containing copper or iron in various amounts was studied using Raman spectroscopy and x-ray diffraction. The treatments were in air in the temperature range 200–800 °C. Copper and iron concentrations were in the range 7–55 wt%. It was found that in the samples containing copper, the metal is mainly dissolved in the SiO2 network when the thermal treatment is at low temperatures. For higher annealing temperatures, first a copper silicate is formed and then most of the copper forms cupric oxide particles at temperatures of about 800 °C. In samples containing iron, the formation of particles with nanometric size of the γ-Fe2O3 (maghemite) phase is observed after annealing at 500 °C. At 800 °C the maghemite phase is transformed into the stable hematite (α-Fe2O3) phase. Copyright © 1999 John Wiley & Sons, Ltd.

It is the aim of this paper to describe the most important techniques that are being used in Mexico City to retrofit buildings damaged during the 1985 earthquake. The information is presented by means of four case studies. These cases offer practical design examples of the typical solutions adopted and illustrate the various aspects of the repair and strengthening process such as damage assessment, emergency measures for temporary protection, the retrofitting technique employed in each case and considerations and decisions made in the analysis and design.

Coatings on glass substrates with a weight composition of 60 CuO:40 SiO2 were prepared using the sol–gel method. To accomplish this, copper was incorporated in the starting solution prior to the film formation. Then thermal treatments in air on the freshly made coatings produced samples with the above-mentioned composition. Thermal annealings of the oxidized coatings under a CO–CO2 atmosphere produce, first, the reduction of the copper oxide particles to form metallic copper particles and, second, the deposition of ultrathin graphite layers on the copper particles located near the surface of the coating. The strong graphite Raman signal observed in these samples is interpreted as being due to the surface enhancement of the graphite lines produced by the metallic copper particles. A simple approach is used to calculate the enhancement in the Raman lines and this agrees well with the enhancement measured experimentally. © 1998 John Wiley & Sons, Ltd.