Electronically compensated current transformer modelling

The behaviour of electronically compensated current transformers is examined with reference to a model valid for frequencies ranging from industrial to ultra-acoustic both in steady-state and in transient conditions. The influence of the hysteresis and saturation effects is evidenced. A comparison with other proposed current transducers is also given. A quantitative treatment of the errors is given and a good agreement between simulation results and experimental data is obtained.     

Spin-rotation invariance and the structure of correlation functions in magnetic systems

We analyze, in the framework of the functional approach to statistical mechanics, general properties of correlation functions in ordered magnetic systems. The aim of this paper is to investigate what consequences can be derived from the requirement of invariance of the theory under local infinitesimal spin rotation. The extension of the method that we introduce, to include anisotropic Hamiltonians, is discussed, and the case of the anisotropy described by an internal field is worked out. Our main results are a set of generalized Ward identities, a microscopic definition of the stiffness constant as a static limit of a local response function, and an exact asymptotic expression for the correlation functions of interest, for zero temperature and small wave length and frequency. Modifications to the hydrodynamic expression for correlation functions in the case where anisotropy is present are also discussed.     

Structure-composition relationships of the Traditional Balsamic Vinegar close to jamming transition

The Traditional Balsamic Vinegar of Modena (TBVM), an Italian valuable specialty produced from cooked grape must becomes viscous through a long-ageing process. TBVM may undergo jamming transition which causes its depreciation. A liquid and jammed TBVM were investigated for their microstructure and elemental composition by coupling two non-destructive techniques, i.e. Environmental Scanning Electronic Microscopy (ESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The same samples were also analyzed for their molecular size distribution by Size Exclusion Chromatography (SEC) and their shear viscosity with a stress-controlled rheometer. TBVM in the jammed state behaved as a pseudoplastic fluid due to the presence of nitrogen-free polymers with a molecular size dispersion lower than a liquid TBVM, the latest showed the Newtonian flow behavior. TBVM solid particles detected close to jamming transition showed a C/O ratio of 2.5 (liquid TBVM) and 3.7 (jammed TBVM), thus much higher than the main TBVM constituents (glucose, fructose and acetic acid). The Fe and Mg content was higher and pH was lower in the jammed TBVM. It was hypothesized that jamming transition in TBVM was the result of the unbalance between two time-dependent phenomena, i.e. the increase of the bulk viscosity and the structure relaxation of nitrogen-free polymers.     

Primary structure of water buffalo alpha-lactalbumin variants A and B

A novel electrophoretic alpha-lactalbumin (alpha-la) variant was detected in the Italian water buffalo breed. The isoelectric point of the variant, labelled A, was lower than the most frequent variant B. It presented an allelic frequency of 0.5% compared with the 97.1% of the BB allele. From Liquid Chromatography-Electrospray Ionization/Mass spectrometry, the molecular mass of the two alpha-la A and B variants were measured as 14,235.1+/-0.8 and 14,236.1+/-0.9 Da, respectively. The two proteins were sequenced and differentiated from one another by a single amino acid substitution, Asn45(B)-->Asp45(A). As this amino acid substitution altered the N-glycosylation sequence consensus Asn45-X-Ser46 it may be deduced that the protein glycosylation level of the alpha-la A would decrease.     

Analysis of furan in coffee of different provenance by head-space solid phase microextraction gas chromatography–mass spectrometry: effect of brewing procedures

A simple, sensitive and accurate method for the analysis of furan in roasted coffee has been used based on headspace–solid-phase micro-extraction (HS–SPME) coupled to gas chromatography–mass spectrometry (GC–MS). The extraction was performed using 75-µm carboxen/polydimethylsiloxane fiber. Ionic strength, extraction time and temperature, and desorption time were assessed as the most important parameters affecting the HS–SPME procedure and d ₄-furan was used as the internal standard. The linearity range was in the range 0.0075–0.486 ng g^?1; the LOD and LOQ calculated using the signal-to-noise ratio approach were 0.002 and 0.006 ng g^?1, respectively. The inter- and intra-day precision was 8 and 10%, respectively. The concentration of furan found in batches of roasted coffee powder different producing countries ranged from 57.3 to 587.3 ng g^?1. The mean reduction in furan levels observed when brewing coffee by either infusion, using a moka pot or an expresso machine was 57, 67.5 and 63.3%, respectively.     

Fining white wine with plant proteins: effects of fining on proanthocyanidins and aroma components

Plant-derived insoluble proteins (wheat gluten, and isolates from pea, lentil, and soybean) were used as fining agents in model white wine (made from Catalanesca grapes) after cold stabilization. Plant proteins were effective in giving a fast and remarkable decrease in turbidity. GC/MS and HPLC/MS approaches indicated that individual proteins had a different impact on the levels of compounds relevant to wine stability. Protein stability of wine was not affected by fining with plant proteins. Lentil proteins and gluten gave the best removal of monomeric and dimeric flavonol. Both caused a decrease in the total content of fermentative aroma compounds, such as ethyl esters, acetate esters, and alcohols. Lentil proteins had the highest impact on the aroma components, giving a marked decrease in aroma components. Gluten may thus be regarded as giving the best balance between fining efficacy and retention of aroma compounds. Also, gluten in the treated wines remained well below the suggested threshold for gluten-free foods. This study provides a methodological frame for thorough characterization of the impact of specific interventions on key wine components.     

Treatment of vulvovaginal candidiasis in pregnancy. A comparative study

A carefully controlled comparative study showed miconazole nitrate 2% vaginal cream (Monistat) to be a highly effective agent in the treatment of vaginal candidiasis in pregnant subjects. Miconazole nitrate was significantly more effective than nystatin (Mycostatin) in the treatment of vaginal candidiasis in all three trimesters of pregnancy, and also more effective regardless of whether the candidal infection was primary or recurrent. Observations relating to the safety of this therapy during pregnancy were made and discussed.     

Exposure to fine and ultrafine particles from secondhand smoke in public places before and after the smoking ban, Italy 2005

Background

A smoking ban in all indoor public places was enforced in Italy on 10 January 2005.

Methods

We compared indoor air quality before and after the smoking ban by monitoring the indoor concentrations of fine (<2.5 μm diameter, PM_2.5) and ultrafine particulate matter (<0.1 μm diameter, UFP). PM_2.5 and ultrafine particles were measured in 40 public places (14 bars, six fast food restaurants, eight restaurants, six game rooms, six pubs) in Rome, before and after the introduction of the law banning smoking (after 3 and 12 months). Measurements were taken using real time particle monitors (DustTRAK Mod. 8520 TSI; Ultra‐fine Particles Counter‐TRAK Model 8525 TSI). The PM_2.5 data were scaled using a correction equation derived from a comparison with the reference method (gravimetric measurement). The study was completed by measuring urinary cotinine, and pre‐law and post‐law enforcement among non‐smoking employees at these establishments

Results

In the post‐law period, PM_2.5 decreased significantly from a mean concentration of 119.3 μg/m³ to 38.2 μg/m³ after 3 months (p<0.005), and then to 43.3 μg/m³ a year later (p<0.01). The UFP concentrations also decreased significantly from 76 956 particles/cm³ to 38 079 particles/cm³ (p<0.0001) and then to 51 692 particles/cm³ (p<0.01). Similarly, the concentration of urinary cotinine among non‐smoking workers decreased from 17.8 ng/ml to 5.5 ng/ml (p<0.0001) and then to 3.7 ng/ml (p<0.0001).

Conclusion

The application of the smoking ban led to a considerable reduction in the exposure to indoor fine and ultrafine particles in hospitality venues, confirmed by a contemporaneous reduction of urinary cotinine.     

Assessing the Potential Content of Ethyl Carbamate in White,Red, and Rosé Wines as a Key Factor for Pursuing Urea Degradation by Purified Acid Urease

The ethyl carbamate (EC) content of a wine after a given temperature‐time storage was theoretically predicted from the potential concentration of ethyl carbamate (PEC), as determined via an accelerated EC formation test. Such information was used to decide whether an enzymatic treatment was needed to reduce the wine urea level before bottling/aging. To this end, 6 white, red, and rosé wines, manufactured in Italy as such or enriched with urea, were tested for their PEC content either before or after enzymatic treatment using a purified acid urease preparation derived from Lactobacillus fermentum. The treatment was severely affected by the total phenolic content (TP) of the wine, the estimated pseudo‐first‐order kinetic rate constant for NH₃ formation reducing by a factor of approximately 2000 as the TP increased from 0 to 1.64 g L^‐1. Such a sensitivity to TP was by far greater than that pertaining to a killed cell‐based enzyme preparation used previously. Urea hydrolysis was successful at reducing EC concentration in wines with low levels of TP and other EC precursors.