Large Amplitude Torsions In Nitrotoluene Isomers Studied By Rotational Spectroscopy And Quantum Chemistry Calculations

The monitoring of gas phase mononitrotoluenes is crucial for defence, civil security and environmental interests since they are used as taggant for TNT detection. Rotational spectra of the three isomers of nitrotoluene have been recorded at low and room temperatures using a supersonic jet Fourier Transform microwave (MW) spectrometer and a millimeter-wave frequency multiplier chain, respectively. Supported by quantum chemistry calculations, the spectral analysis of pure rotation lines in the vibrational ground state has allowed to characterise the rotational energy, the hyperfine structure due to the $^{14}$N nucleus and the internal rotation splittings arising from the methyl group. An anisotropic internal rotation of coupled -CH$_3$ and -NO$_2$ torsional motions was identified for the ortho isomer by quantum chemistry calculations and discussed from the results of its MW analysis. The study of the internal rotation splittings in the spectra of three NT isomers allowed to characterise the internal rotation potentials of the methyl group and to compare them with other mono-substituted toluene derivatives in order to study the isomeric influence on the internal rotation barrier. \footnote{Roucou \it{et al.}, CHEMPHYSCHEM, \bf{21}(22), 2523-2538, (2020).}$^,$ \footnote{Roucou \it{et al.}, CHEMPHYSCHEM, \bf{19}, 1056-1067, (2018).

Chirped Pulse Spectrometer Operating at 200 GHz

The combination of electronic sources operating at high frequencies and modern microwave instrumentation has enabled the recent development of chirped-pulse spectrometers for the millimetre and THz bands. This type of instrument can operate at high resolution which is particularly suited to gas phase rotational spectroscopy. The construction of a chirped pulse spectrometer operating at 200 GHz is described in detail while attention is paid to the phase stability and the data accumulation over many cycles. Validation using carbonyl sulphide has allowed the detection limit of the instrument to be established as function of the accumulation. A large number of OCS transitions were identified using a 10 GHz chirped pulse and include the 6 most abundant isotopologues, the weakest line corresponding to the fundamental R(17) transition of 16 O 13 C 33 S with a line strength of 4.3 x 10-26 cm-1 /(molec.cm-2). The linearity of the system response for different degrees of data accumulation and transition line strength was confirmed over 4 orders of magnitudes. A simple analysis of the time domain data was demonstrated to provide the line broadening coefficient without the need for conversion by a Fourier transform. Finally, the pulse duration is discussed and optimal values are given for both Doppler limited and collisional regimes

Terahertz gas phase spectroscopy using a high finesse Fabry-P\'erot cavity

The achievable instrument sensitivity is a critical parameter for the continued development of THz applications. Techniques such as Cavity-Enhanced Techniques and Cavity Ring Down Spectroscopy have not yet been employed at THz frequency due to the difficulties to construct a high finesse Fabry-P\'erot cavity. Here, we describe such a THz resonator based on a low-loss oversized corrugated waveguide with highly reflective photonic mirrors obtaining a finesse above 3000 around 620 GHz. These components enable a Fabry-Perot THz Absorption Spectrometer with an equivalent interaction length of one kilometer giving access to line intensities as low as 10-27cm- 1/(molecule/cm2) with a S/N ratio of 3. In addition, the intracavity optical power have allowed the Lamb-Dip effect to be studied with a low-power emitter, an absolute frequency accuracy better than 5 kHz can be easily obtained providing an additional solution for rotational spectroscopy.Comment: 7 pages, 4 figure

INFRARED CROSS-SECTIONS OF NITRO-DERIVATIVE VAPORS: NEW SPECTROSCOPIC SIGNATURES OF EXPLOSIVE TAGGANTS AND DEGRADATION PRODUCTS

Classical explosives such as RDX or TNT exhibit a very low vapor pressure at room temperature and their detection in air requires very sensitive techniques with levels usually better than 1 ppb. To overcome this difficulty, it is not the explosive itself which is detected, but another compound more volatile present in the explosive. footnote{J. C. Oxley, J. L. Smith, W. Luo, J. Brady, Prop. Explos. Pyrotec. 34 (2009) 539�543} This volatile compound can exist naturally in the explosive due to the manufacturing process. For example, in the case of DiNitroToluene (DNT), the molecule is a degradation product of TNT and is required for its manufacture. Ortho-Mononitrotoluene (2-NT) and para-mononitrotoluene (4-NT) can be also used as detection taggants for explosive detection. In this study, using the exceptional properties of the SOLEIL synchrotron source, and adapted multipass-cells, gas phase Far-IR rovibrational spectra of different isomers of mononitrotoluene and dinitrotoluene have been investigated. Room temperature Far-IR cross-sections of the 3 isomer forms of mononitrotoluene have been determined for the lowest frequency vibrational bands located below 700 wn.footnote{A. Cuisset, S. Gruet, O. Pirali, G. Mouret, Spectrochimica Acta Part A, 132 (2014) 838-845.} Cross sections and their temperature dependences have been also measured in the Mid-IR using conventional FTIR spectroscopy probing the nitro-derivatives vapors in a heated multipass-cell

Le Corbusier: Architecture as a project of the world approach to a philosophy of architecture

La arquitectura moderna como un producto humano, ayudado por la técnica, da respuesta a las necesidades humanas en el proceso de habitar el mundo. El punto central es la revisión de un “proyecto de mundo” que para algunos maquinizó el problema del habitar y para otros apostó por la esencia antropológica que subyace a la necesidad de dar expresión material a un mejor mundo humano habitable. Este trabajo no procurará entonces hacer una “reivindicación” de Le Corbusier, pues a cada momento histórico le corresponden diversas respuestas a través de los productos humanos que dan cuenta de condiciones particulares de las culturas; se trata más bien de hacer una “reinterpretación” del proyecto de mundo que se gestó con el movimiento moderno de la arquitectura y, particularmente, con Le CorbusierThis article is a result of the reflection around the modern architecture as a human product than, supported by technical, gives answers to the human needs in the process of living in the world. The point is the search and reinterpretation of a “world project” that has been considered the “machining” of the world inhabit by some, and, for others, has been understood as a an movement that opted for the anthropological essence behind the need to give material expression to the human inhabit. This paper does not seek to make a “claim” to rescue Le Corbusier, as I am aware that each historical period has different answers by human products that account for conditions in the cultures, which clearly would not make sense to emulate; rather what I tried to make a “reinterpretation” of the proposed world was conceived with the modern movement in architecture and, particularly, with Le Corbusie

0230: Effectiveness of switching Prasugrel's ‘low responders’ to ticagrelor after acute coronary syndrome

AimsThis study aimed to assess the effectiveness and safety of switching from Prasugrel to Ticagrelor patients identified as Prasugrel low-responders one month after ACS.Methods and results540 patients admitted for ACS with coronary stent implantation and discharged on Prasugrel 10mg were screened. Prasugrel response was assessed one month after discharge using Platelet Reactivity Index Vasodilatator Stimulated Phosphoprotein (PRI VASP). High on-Treatment Platelet Reactivity (HTPR) was defined as VASP>50%. Patients with HTPR were enrolled and switched to Ticagrelor 90 mg twice a day. They were re-tested a month later. Primary endpoint was defined as: comparison of degree of platelet inhibition and incidence of HTPR one month after switching to Ticagrelor in patients with HTPR on Prasugrel therapy. The safety endpoint was the incidence of bleedings under Ticagrelor as compared with Prasugrel therapy, using the Bleeding Academic Research Consensus definition.Between March 2010 and November 2013, 19 patients were defined as HTPR on Prasugrel 10 mg one month after ACS, with a mean VASP of 59,3%. Among these patients, 14 were switched to Ticagrelor 180 mg daily and, at one month, we observed a significant decrease in PRI VASP, with a mean value at 19.6% (p<0.001). No patients remained HTPR and 4 patients (28.4%) were identified as Very Low on-Treatment Platelet Reactivity (VLTPR) (VASP<10%). No ischemic events were reported after switching, while 3 patients (21%) suffered from bleeding complications (2 BARC1 and 1 BARC2 bleedings) during Ticagrelor therapy.ConclusionSwitch to Ticagrelor in Prasugrel's “low responders” patients is an effective strategy, leading to an adequate platelet inhibition in a large majority of patients. This biological tailored approach could be useful in preventing ischemic complications, in this specific high risk population, potentially increasing bleeding risk. This hypothesis needs to be confirmed in large clinical studies.Abstract 0230 – Figur