Hydrogen production through chemical looping using NiO/NiAl2O4 as oxygen carrier

A new autothermal route to produce hydrogen from natural gas via chemical looping technology was investigated. Tests were conducted in a micro-fixed bed reactor loaded with 200 mg of NiO/NiAl₂O₄ as oxygen carrier. Methane reacts with a nickel oxide in the absence of molecular oxygen at 800 °C for a period of time as high as 10 min. The NiO is subsequently contacted with a synthetic air stream (21% O₂ in argon) to reconstitute the surface and combust carbon deposited on the surface. Methane conversion nears completion but to minimize combustion of the hydrogen produced, the oxidation state of the carrier was maintained below 30% (where 100% represents a fully oxidized surface). Co-feeding water together with methane resulted in stable hydrogen production. Although the carbon deposition increased with time during the reduction cycle, the production rate of hydrogen remained virtually constant. A new concept is also presented where hydrogen is obtained from methane with inherent CO₂ capture in an energy neutral 3-reactors CFB process. This process combines a methane combustion step where oxygen is provided via an oxygen carrier, a steam methane reforming step catalyzed by the reduced oxygen carrier and an oxidizing step where the O-carrier is reconstituted to its original state.     

Low roughness diamond films produced at temperatures less than 600°C

Recent progress has been made in the production of low-roughness Chemical Vapor Deposition (CVD) diamond films at temperatures less than 600°C. These films are particularly suitable for cutting tool applications. Such progress was achieved by simultaneously promoting the renucleation process and controlling the growth process at low temperatures. In this paper, we show that below 700°C (unlike what is usually observed at temperatures in the range of 750–900°C), secondary nucleation does not occur easily even on (111) faces. This makes the growth of low roughness films difficult. We also report on the role of a thin gold layer deposited on top of a diamond film in favoring smoother film formation. This observation was seen to be due to the ability of the thin gold layer in promoting renucleation. Furthermore, the effect of the percentage of methane introduced in the feed gas was studied.     

Chemical Differences Between the Wood Extracts of Jack Pine (Pinus Banksiana), Black Spruce (Picea Mariana) and Balsam Fir (Abies Balsamea) from Eastern Canada

Abstract

Differences in the chemical composition of the wood of balsam fir (Abies balsamea (L.), jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.)) were determined by GC analysis of their hexane extracts. Certain constituents such as juvabione, (E)-α-atlantone and α-cadinene were shown to be present only in the heartwood of balsam fir. Analysis of the sapwood of the three species also revealed the presence of certain constituents such as juvabione, dehydrojuvabione and (E)- α-atlantone, all found only in balsam fir and an unidentified compound found only in jack pine. The chromatograms of the hexane extracts of both sapwood and heartwood showed characteristic patterns for each of the three species of conifers.     

Work-related versus non-work-related road accidents, developments in the last decade in France

The aim of this research was to analyze the changes that have affected work-related road accidents between 1997 and 2006, using police data. The study focused on drivers aged between 14 and 64 years. The characteristics considered were the age, gender, type of vehicle and occupation of the individuals involved and the location, time and severity of the accident. Two periods were compared, 1997-2000 and 2003-2006. Three types of journey were considered: while at work, commuting (going to and from work), and non-work-related.The percentage of all accidents which were work-related varied little over the decade (10% while at work and 18% while commuting). The accidents that occurred while at work still had the lowest fatality rates (1.4% among women and 3.4% among men in 2003-2006). Men accounted for the majority of the casualties: 90% of fatalities while at work and approximately 80% for the other types of journey. The greatest reduction took place in the number of motorists, and this has led to an increase in the proportion of motorized two-wheelers both while at work and while commuting. In the case of accidents while at work, the professional drivers still had the highest risk, craftsmen and shopkeepers were also at higher risk than manual workers of both genders and male employees. Extending analysis of this type to other European countries would be of major interest both for epidemiological monitoring and the prevention of occupational road accidents.     

Incidence and risk factors of severe traumatic brain injury resulting from road accidents: a population-based study

A population-based study was carried out in 1996-2001 to provide the incidence and to identify the risk factors of severe traumatic brain injury (TBI) resulting from a road accident. The severe TBI was defined as an injury to the brain or the skull, excluding scalp injuries, with an abbreviated injury scale (AIS) severity score greater than 2. The severe TBI of 1238 patients were described. The annual incidence and mortality of severe TBI were, respectively, 13.7 per 100,000 and 5.3 per 100,000. The fatality rate increased from 20% in childhood to 71% over 75-year-old. Compared to restrained car occupants, the odds ratio for having a severe TBI was 18.1 (95% confidence interval, CI=12.8-25.5) for un-helmeted motorcyclists, 9.2 (95% CI=7.5-11.3) for pedestrians, 6.4 (95% CI=4.7-8.8) for un-helmeted cyclists, 3.9 (95% CI=3.1-4.8) for unrestrained car occupants and 2.8 (95% CI=2.2-3.5) for helmeted motorcyclists. Even after adjustment for several severity factors, male gender and age above 55 were both risk factors. Prevention programs aiming at improving the head protection should be promoted. The circumstances of the accident should be taken into account to predict a severe TBI.     

Two-dimensional ECD FT-ICR mass spectrometry of peptides and glycopeptides

2D FT-ICR MS allows the correlation between precursor and fragment ions by modulating ion cyclotron radii for fragmentation modes with radius-dependent efficiency in the ICR cell without the need for prior ion isolation. This technique has been successfully applied to ion-molecule reactions, Collision-induced dissociation and infrared multiphoton dissociation. In this study, we used electron capture dissociation for 2D FT-ICR MS for the first time, and we recorded two-dimensional mass spectra of peptides and a mixture of glycopeptides that showed fragments that are characteristic of ECD for each of the precursor ions in the sample. We compare the sequence coverage obtained with 2D ECD FT-ICR MS with the sequence coverage obtained with ECD MS/MS and compare the sensitivities of both techniques. We demonstrate how 2D ECD FT-ICR MS can be implemented to identify peptides and glycopeptides for proteomics analysis.     

Pilot scale preparation of wheat gluten protein fractions: II. Technological properties of the fractions

Fractions differing in prolamin compositions were obtained on a pilot scale when wheat gluten proteins were separated by differential extraction in dilute acetic acid. The soluble fractions were enriched in gliadins and the insoluble ones were richer in glutenins. The effects of the gluten fractions on the technological properties of wheat flours were investigated using an alveographic test and a comparison was made with gluten-added flours. Gliadin-rich fractions increased the extensibility of the dough and reduced its resistance to deformation. On the other hand, glutenin-rich fractions had an opposite effect and increased the dough resistance more than that of equally-concentrated whole gluten. The magnitude of the effects was strongly related to the gliadin and glutenin contents of the fractions. Prediction of technological effects is thus possible using composition analyses based on protein extractibility or size-exclusion chromatography. Finally, the improving effects of the gliadin-rich and of the glutenin-rich fractions were observed at different stages of the breadmaking process.     

Phototransformation of selected human-used macrolides in surface water: Kinetics, model predictions and degradation pathways

The phototransformation of clarithromycin and roxithromycin, two human-used macrolide (MLs) antibiotics was investigated in surface waters. Photolysis kinetic data suggest that degradation in water would occur via the direct photolysis of the Fe(III)-MLs complexes. Hydroxyl radicals, singlet oxygen and other photooxidants generated from nitrate ions and from excited chromophores present in humic acids appeared to have only a very limited impact on the overall degradation of MLs under the adopted UV-vis irradiation conditions. A photolysis model applied to the Fe(III)-clarithromycin complex in river water showed that a half-life of 40 days was predicted under clear-sky irradiation in November, 26 days in February, and 10 in May. Direct photolysis could have a limited impact on the environmental concentrations of MLs in rivers, due to a too short water residence time but might be important in shallow lakes and lagoons. Photoinduced degradation of MLs mainly implied changes in the structure of the aglycone, probably leading to their detoxification because the pseudoerythromycin derivatives have very little antimicrobial activity.     

Individuals taking a French driving licence points recovery course: Their attitudes towards violations

This paper sets out to describe the drivers attending driving licence points recovery courses (PRC), in order to modify the psychologist’s approach during the sessions.The paper describes a questionnaire-based survey of a representative sample of 853 drivers taking a “course designed to raise awareness about the causes and consequences of road traffic accidents”. The data are analyzed in part by applying a multiple correspondence analysis.Among those taking part in PRC, recognizing whether they commit violations or not seems to be independent from the perceived probability of sanctioning and the perceived danger. The group of course-takers is divided into two main clusters (“offenders” and “victims”) which require a completely different approach on the part of the training staff.     

Transformation of the antiepileptic drug oxcarbazepine upon different water disinfection processes

Transformation of the pharmaceutical oxcarbazepine (OXC), a keto analogue of carbamazepine (CBZ) was investigated under different water disinfection processes (ozonation, chlorination and UV irradiation) to compare its persistence, toxicity and degradation pathways with those of CBZ. Analysis by LC-ion trap-MSⁿ allowed for the identification of up to thirteen transformation products (TPs). The major abundant and persistent TPs (10,11-dihydro-10,11-trans-dihydroxy-carbamazepine (DiOH-CBZ), acridine (ACIN) and 1-(2-benzaldehyde)-(1H, 3H)-quinazoline-2,4-dione (BQD)) were identical to those previously reported during water treatment of CBZ. Only one new compound arising from an intramolecular cyclisation reaction was identified during UV irradiation. OXC reacted quickly with hydroxyl radical and relatively rapidly with free chlorine while slow reaction rates were recorded in presence of ozone and upon UV irradiation. An increase of the acute toxicity of UV irradiated solutions, monitored by a Daphnia magna bioassay, was recorded, probably due to the accumulation of ACIN. The formation of ACIN is of concern due to the carcinogenic properties of this chemical. ACIN was also generated during the direct UV photo transformation of DiOH-CBZ and 10-hydroxy-10,11-dihydro-carbamazepine (OH-CBZ), two metabolites of OXC and CBZ widely detected in water resources. Analysis of tap water samples revealed the occurrence at ng/L levels of the major TPs detected under laboratory scale experiments, except ACIN.