Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: method development and first intercomparison results

In situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called trace gas extractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, µmole mole−1) methane is 0.1 and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. Based on repeated measurements of compressed air during a 2-week intercomparison campaign, the repeatability of the TREX–QCLAS was determined to be 0.19 and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to isotope-ratio mass spectrometry (IRMS) based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers. Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX–QCLAS data and bag/flask sampling–IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. This also displays the potential to improve the interlaboratory compatibility based on the analysis of a reference air sample with accurately determined isotopic composition.

Descrittione del Regno di Napoli nella quale s'ha piena contezza, cosi' del sito d'esso, de'nomi delle prouintie antiche ... come de'monti, de'mari ... Et vi si fa mentione de i re, con la loro vita, & effigie, che l'han dominato ... le loro arme ... e con un preambolo de i re di Gierusalem, oue si dichiara perche i re di Napoli habbiano quel titolo : Con la tauola copiosissima, & altre cose notabili, che nella prima impressione non erano

Contiene con portada propia: Della descritione del Regno di Napoli ... Libro secondo. In Napoli : Nella Stamperia dello Stigliola à Porta Reale, 1597

Rerum memorabilium iam inde ab anno Domini M.D. ad annum fere LX in Rep. Christiana gestarum libri quinque : ex plerisque... historiographis, praecipue autem D. Fontano... & Ioanne Sleidano collecti /

CCBE S. XVI

Disquisitiones dogmaticae de controversiis in theologia morali insignibus ... / authore D. Eusebio Amort ...

Mode of access: Internet.

Traduction nouvelle de odes d'Anacreon sur l'original grec /

Poesíes de M.D.L.F., en p. 1-81 de la segunda secuencia con portadilla, pag. y sign. propias.

R.D. Eusebii Amort ... Theologia eclectica moralis et scholastica : sub auspiciis SS. D.N. Benedicti XIV ...

Mode of access: Internet.

R.D. Eusebii Amort ... Theologia eclectica moralis et scholastica : sub auspiciis SS. D.N. Benedicti XIV ...

Mode of access: Internet.

R.D. Eusebii Amort ... Theologia eclectica moralis et scholastica : sub auspiciis SS. D.N. Benedicti XIV ...

Mode of access: Internet.

Régénération des colonies, ou moyens de restituer graduellement aux hommes leur état politique, et d'assurer la prospérité des nations ; et moyens pour rétablir promptement l'ordre dans les colonies françaises /

Goldsmiths'-Kress no. 15174.0-1, suppl.

R.D. Eusebii Amort ... Theologia eclectica moralis et scholastica : sub auspiciis SS. D.N. Benedicti XIV ...

Mode of access: Internet.

Sistema enzimático y procedimiento para la preparación de d-aminoacidos o derivados de los mismos

La presente invención se refiere a un procedimiento para la preparación de D-aminoácidos o derivados de D-aminoácidos, a partir de mezclas racémicas de D,L-hidantoinas caracterizado por estar constituido por las enzimas hidantoín racemasa, D-hidantoinasa y D-carbomilasa; y a un sistema enzimático de utilidad en dicho procedimiento que cataliza la conversión estereoselectiva de D-5-hidantoina hasta D-aminoácido y la racemización entre los enantiómeros de la misma.

Sistema de coexpresión enzimática para la producción de D-aminoácidos

La presente invención se refiere a un vector de coexpresión para la preparación de D-aminoácidos o derivados de D-aminoácidos, a partir de la mezcla racémica de la D,L-5-hidantoína correspondiente y a un sistema enzimático que da lugar a una ruta metabólica nueva de utilidad en dicho procedimiento, que cataliza la conversión estereoselectiva de D,L-5-hidantoína hasta D-aminoácido y la racemización entre los enantiómeros de la misma.

Description de la mise en place des techniques p?dagogiques de type collaboratif pour l?am?lioration de la comp?tence communicative orale en fran?ais, chez les ?l?ves de terminale d?un lyc?e priv? [recurso electr?nico]

R?SUM?: Ce m?moire a comme but la description de la mise en place de deux unit?s didactiques pour l?am?lioration de la comp?tence communicative orale en fran?ais d?un groupe d??l?ves de terminale d?un lyc?e de Cali. Ce travail s?inscrit dans la recherche action qui nous a permis de mener un processus de diagnostic, d?impl?mentation et d??valuation. Les techniques utilis?es ont ?t? les enqu?tes, entretiens aux ?l?ves et au professeur titulaire, observations de classes et enregistrements audio et vid?o. L?analyse de la phase d?impl?mentation s?est faite ? partir de trois grandes cat?gories qui rassemblent le sens de l?approche collaborative et la comp?tence communicative orale. Les r?sultats montrent que les ?l?ves ont am?lior? leur expression orale en fran?ais notamment l?enrichissement de vocabulaire et la fluidit?, ? travers des contenus proches de leur r?alit?. Nous montrons les b?n?fices de l?approche collaborative tels que le travail de groupe, le changement de r?les de l?enseignant et des ?l?ves et la possibilit? de co-?valuation du processus dans un cours de fran?ais langue ?trang?re.

Comparative analysis of triple band S-C-L erbium-doped fibre and semiconductor optical amplifier for CWDM applications

The authors present a comparative analysis between a triple-band S-C-L erbium-doped fibre amplifier and a commercial semiconductor optical amplifier in a CWDM application scenario. Both technologies were characterised for gain and noise figures from 1480 to 1610 nm (S, C and L bands) and their systemic performances were evaluated in terms of bit error rate measurements for a wide range of optical power levels.