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The hydration structure of protons has been studied for decades in bulk water and protonated clusters due to its importance but has remained elusive in planar confined environments. Two-dimensional (2D) transition metal carbides known as MXenes show extreme capacitance in protic electrolytes, which has attracted attention in the energy storage field. We report here that discrete vibrational modes related to protons intercalated in the 2D slits between Ti3C2Tx MXene layers can be detected using operando infrared spectroscopy. The origin of these modes, not observed for protons in bulk water, is attributed to protons with reduced coordination number in confinement based on Density Functional Theory calculations. This study therefore demonstrates a useful tool for the characterization of chemical species under 2D confinement.

Optical reflection spectra of In2S3 thin films 180 730 nm deposited on glass substrates are measured by infrared spectroscopy using the synchrotron radiation of BESSY II storage ring in the spectral range of 30 8000 cm amp; 8722;1. The aim of the study is to find the influence of different substrate and post annealing temperatures on the electron and phonon systems of In2S3 films deposited on glass. Clear features in the reflectance spectra for the studied films have been found mainly in the phonon excitation range 100 400 cm amp; 8722;1. The experimental dielectric functions amp; 949; amp; 969; of In2S3 films are found to be in good agreement with the calculated ones obtained for In2S3 crystals within the density functional theory. The dielectric functions amp; 949; amp; 969; of the films in the range of 100 400 cm amp; 8722;1 depend substantially on the post annealing temperature. This indicates a transition of the film from the amorphous to the crystalline state. The thorough analysis of the frequency dependence of the reflection coefficient R amp; 969; and optical conductivity amp; 963; amp; 969; in the wavenumber range of 30 130 cm amp; 8722;1 allowed us to reveal the distributed electron states in In2S3 films

The firing behavior of illite-based archaeological ceramics and corresponding firing conditions were investigated, in order to identify the pyrotechnology of ceramic production at archaeological sites in the North Caucasus (Russia, Bronze and Iron Age). Direct observations of the pyrometamorphic degree in the objects by scanning electron microscope (SEM), X-ray powder diffraction (XRD), Raman and Fourier-transform infrared spectroscopy (FT-IR) revealed the thermally induced localization of the redox state within a single object and its influence on the structural distortion, dehydroxylation and total collapse of illite in the ceramics. Fundamental approaches to illite dehydroxylation kinetics and numerical simulations of oxygen diffusion and heat transfer revealed that the firing temperature and time and thickness of the sample, reactivity between oxygen and ceramic pastes and porosity evolution played a decisive role in the firing behavior of the ceramics during the firing at the sites.

Freshwater pollution is a huge concern. A study aiming to evaluate physico-chemical characteristics, microbiota, occurrence of two groups of persistent environmental pollutants with similar chemical properties (polycyclic aromatic hydrocarbons- PAHs and microplastics - MPs) in Alqueva's surface water was performed during 2021. Water samples were collected at three spots related to touristic activities (two beaches and one marina) during the Winter, Spring, Summer and Autumn seasons. In addition, the presence of biofilms on plastic and natural materials (stone, wood/ vegetal materials) were assessed and compared. Water quality based on physicochemical parameters was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters by international organizations. However, carcinogenic compounds were detected in two sampling locations, which can pose a problem for aquatic ecosystems. PAHs profiles showed significant differences when comparing the dry seasons with the rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weigh compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during the Winter season. The polymers detected were poly(methyl-2-methylpropenoate), polystyrene, polyethylene terephthalate, polyamide, polypropylene, styrene butadiene, polyvinyl chloride and low /high density polyethylene with the last being the most frequent. Biofilms were more often detected on plastics than on natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity (e.g., bacteria, fungi/yeast and phytoplancton organisms) and richer in extrapolymeric material. Based on morphological analysis a good agreement between microbiota and microorganism present in the biofilms was found. Among microbiota were identified microorganisms previously linked to plastic and PAHs detoxification suggesting the need for further studies to evaluate the viability of using biofilms as part of a green bioremediation strategy to mitigate water pollution. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730872. We thank INSA for finantial support [2020DSA1756, 2020] info:eu-repo/semantics/publishedVersion

We present infrared (IR) nanospectroscopy results obtained on single hundred-nanometer-sized lipid microvesicles. The use of an IR nanospectroscopy platform allowed us to identify heterogeneities of the molecular cargo of the microvesicles that would not be possible by conventional IR spectroscopy.

At present, small angle X ray scattering SAXS studies of perfluorinated sulfonic acid ionomers PFSAs are unable to fully determine the true shape of their building blocks, as recent SAXS modelling predicts disk and rod like nanoionic domains as being equally possible. This scenario requires evidence based findings to unravel the real shape of PFSA building blocks. Herein, a SAXS pattern signature for a lamellar nanophase separation of the ionic domains of Nafion is presented, backed by mid and far infrared spectroscopy MIR and FIR and wide angle X ray scattering WAXS data of Nafion in different ionic forms, a broad range of ionic phase contents EW amp; 8764; 859 42 amp; 8198;252 g eq amp; 8722;1 and temperatures. The study indicates that the lamellar arrangement of the ionic domains is the most representative morphology that accounts for the physical properties of this ionomer. The lamellar SAXS reflections of Nafion are enhanced in electric and magnetic field aligned membranes, as confirmed by atomic force microscopy AFM . Electric and magnetic field assisted casting of Nafion allowed producing nanostructured and anisotropic films with the lamellas stacked perpendicularly to the field vector, which is the direction of interest for several applications. Such nanostructured Nafion membranes are bestowed with advanced optical and proton transport properties, making them promising materials for solar and fuel cells

Current submillisecond time resolved broad band infrared spectrosco py, one of the most frequently used techniques for studying structure amp; 8722;functionrelationships in life sciences, is typically limited to fast cycling reactions that can berepeated thousands of times with high frequency. Notably, a majority of chemical andbiological processes do not comply with this requirement. For example, the activationof vertebrate rhodopsin, a prototype of many protein receptors in biological organismsthat mediate basic functions of life, including vision, smell, and taste, is irreversible.Here we present a dispersive single shot Fe amp; 769;ry spectrometer setup that extends suchspectroscopy to irreversible and slow cycling systems by exploiting the uniqueproperties of brilliant synchrotron infrared light combined with an advanced focalplane detector array embedded in a dispersive optical concept. We demonstrate oursingle shot method on microbial actinorhodopsin with a slow photocycle and onvertebrate rhodopsin with irreversible activation

Mit diesem Kapitel soll die Diskussion um Fake News im vorliegenden Buch um eine Ausfuhrung daruber erganzt werden, ob bzw. unter welchen Randbedingungen es moglich ist, automatisiert Fake News zu erkennen oder wenigstens entsprechende Beitrage mit einer Warnung zu markieren. Ein wichtiges Ziel dieser Darstellung ist es, die Ausfuhrungen, insbesondere die informationstheoretischen Aspekte, moglichst allgemein verstandlich zu halten. Die Erlauterungen erfolgen dabei mit Bezug auf ein Tool, welches – thematisch eingeschrankt – eine solche Markierung leistet.

Unter einem Team von Unbemannten Systemen verstehen wir eine kleinere Anzahl von Systemen, die uber unterschiedliche Fahigkeiten verfugen und bei der Erfullung eines Auftrags kooperieren. Der Einsatz eines solchen Teams verspricht Flexibilitat bei der erfolgreichen Bearbeitung unterschiedlicher Auftrage. Teams von Unbemannten Systemen konnen allerdings nur dann effizient agieren, wenn sie in einem hohen Mas autonom sind. Idealerweise sollte ein einzelner Nutzer mit dem Team interagieren und sich dabei auf das „Was ist zu tun?“ beschranken. An dieser Stelle kommt „Semantik“ ins Spiel: Das Team muss uber genugend „Intelligenz“ verfugen, um Auftrage zu „verstehen“, sie in Teilauftrage zu zerlegen und kooperativ zu bearbeiten.

Etalon effects in THz transmittance spectra, either taken in time- domain or frequency-domain, often hamper or even hinder the interpretation of film properties. In this paper we discuss the transferability and applicability of spectroscopic methods typically employed in the near and mid infrared spectral range to eliminate the fringes in the transmittance spectra in the THz spectral range.

A specially developed experimental set up has been integrated into a commercially available FT IR Spectrometer to study the curing of Epoxy Systems. MIR and FIR spectra measured during the curing process at different temperatures of an epoxy system will be presented in dependency of the curing time. The experiments and the selected set up are discussed to demonstrate its potential for future monitoring and ageing control applications during a manufacturing process of polymer composites.

This paper presents the concept, a system-overview, and the evaluation of EnArgus, the central information system for energy research funding in Germany. Initiated by the German Federal Ministry for Economic Affairs and Energy (BMWi), EnArgus establishes a one-stop information system about all recent and ongoing energy research funding projects in Germany. Participants ranging from laypersons to experts were surveyed in three workshops to evaluate both the public and expert interfaces of the EnArgus system in comparison to peer systems. The results showed that the EnArgus system was predominantly evaluated positively by the various participants. It contributes to making the energy sector more transparent and offers clear advantages for professional use compared to similar systems. The system’s semantic processing enables more precise hits and better coverage by including semantically related terms in search results; its intelligence makes it fail-safe, rendering it suitable for areas where poor results can have dire consequences. Reporting on an actual real-world system, the paper also provides a roadmap-view of how electronic filing of administrative project data can be semantically enhanced and opened-up to provide the basis for new ways into the data that are key for future breakthrough AI interfaces.

Etalon features in infrared spectra of stratified samples, their influence on the interpretation, and methods to circumvent their presence in infrared spectra have been in discussion for decades. This paper focuses on the application of a method originally developed to remove interference fringes in the mid-infrared spectra for far-infrared Fourier transform spectroscopy on thin polymer films. We show that the total transmittance reflectance technique, commonly used for mid-infrared, also works successfully in the far-infrared spectral range where other approaches fail. Experimental spectra obtained by such technique are supported by model calculations and reveal the possibility and limits to obtain almost undisturbed far-infrared spectra which are suitable to determine low-energy vibrations of ionomer salts under certain sample conditions.

Conformational changes of the light-sensitive membrane receptor and proton pump bacteriorhodopsin is investigated by tip-enhanced mid-infrared nanospectroscopy on individual cell membrane patches, with a dramatic increase of sensitivity (in terms of number of probed molecules) compared with standard mid-infrared spectroscopy.

We discuss the concept of an IR spectrograph suitable for linear array detection. The dispersive element of the spectrograph is based on an arrangement of commercially available low-cost prisms. The dispersion is such that the whole spectral bandwidth of interest is distributed along the linear array of detector pixels in such a way to achieve an optimum for the spectral resolution. The concept is exemplarily shown for the design of a spectrograph working in the range between 5000 and 2500 wavenumbers spread onto a linear 128-pixel array detector.

The temperature induced dehydration process of the 3M Brand perfluoroimide acid (PFIA), an advanced proton exchange membrane for fuel cells, was studied by in situ infrared spectroscopy to understand proton transport processes under conditions of low hydration levels. A comprehensive assignment of the vibrational bands of PFIA in the mid infrared region is provided. Investigation of the kinetics in conjunction with 2D correlation spectroscopy methods revealed the sequential process of the hydration and dehydration in a conclusive model. The results indicate that at a lower water content the sulfonate group of the PFIA side chain is preferentially ionised and involved in a hydrogen bonding structure with the sulfonyl imide acid group, until a sufficient amount of water is present to ionise the second ionic site. Comparison to the well-understood NAFION™ membrane revealed that under low humidity conditions a higher amount of water is retained in PFIA in a state most similar to liquid water. The results contribute to a better understanding of water retention capability and thus proton conductivity under high- temperature and low-humidity conditions.

Two polyethylene types with ultra-high (UHMW-PE) and high molecular weight (HMW-PE) used as neutron radiation shielding materials in casks for radioactive waste were irradiated with doses up to 600 kGy using a 60Co gamma source. Subsequently, thermal aging at 125°C was applied for up to one year. Degradation effects in the materials were characterized using colorimetry, UV-Vis spectroscopy, IR spectroscopy, and DSC. Both materials exhibited a yellowing upon irradiation. The discoloration of UHMW-PE disappeared again after thermal aging. Therefore, the yellowing is assumed to originate from annealable color centers in the form of free radicals that are trapped in the crystalline regions of the polymer and recombine at elevated temperatures. For the antioxidant-containing HMW-PE, yellowing was observed after both irradiation and thermal aging. The color change was correlated mainly to decomposition products of the antioxidant in addition to trapped radicals as in UHMW-PE. Additionally, black spots appeared after thermal aging of HMW-PE.

Rosetta observes sublimating surface icesComets are “dirty snowballs” made of ice and dust, but they are dark because the ice sublimates away, leaving some of the dust behind on the surface. The Rosetta spacecraft has provided a close-up view of the comet 67P/Churyumov-Gerasimenko as it passes through its closest point to the Sun (see the Perspective by Dello Russo). Filacchioneet al.detected the spectral signature of solid CO2(dry ice) in small patches on the surface of the nucleus as they emerged from local winter. By modeling how the CO2sublimates, they constrain the composition of comets and how ices generate the gaseous coma and tail. Fornasieret al.studied images of the comet and discovered bright patches on the surface where ice was exposed, which disappeared as the ice sublimated. They also saw frost emerging from receding shadows. The surface of the comet was noticeably less red just after local dawn, indicating that icy material is removed by sunlight during the local day.Science, this issue p.1563, p.1566; see also p.1536

The stability of the high-pressure CaCO3 calcite (cc)-related polymorphs was studied in experiments that were performed in conventional diamond anvil cells (DAC) at room temperature as a function of pressure up to 30 GPa as well as in internally heated diamond anvil cells (DAC-HT) at pressures and temperatures up to 20 GPa and 800 K. To probe structural changes, we used Raman and FTIR spectroscopy. For the latter, we applied conventional and synchrotron mid-infrared as well as synchrotron far-infrared radiation. Within the cc-III stability field (2.2–15 GPa at room temperature, e.g., Catalli and Williams in Phys Chem Miner 32(5–6):412–417, 2005), we observed in the Raman spectra consistently three different spectral patterns: Two patterns at pressures below and above 3.3 GPa were already described in Pippinger et al. (Phys Chem Miner 42(1):29–43, 2015) and assigned to the phase transition of cc-IIIb to cc-III at 3.3 GPa. In addition, we observed a clear change between 5 and 6 GPa that is independent of the starting material and the pressure path and time path of the experiments. This apparent change in the spectral pattern is only visible in the low-frequency range of the Raman spectra—not in the infrared spectra. Complementary electronic structure calculations confirm the existence of three distinct stability regions of cc-III-type phases at pressures up to about 15 GPa. By combining experimental and simulation data, we interpret the transition at 5–6 GPa as a re-appearance of the cc-IIIb phase. In all types of experiments, we confirmed the transition from cc-IIIb to cc-VI at about 15 GPa at room temperature. We found that temperature stabilizes cc-VI to lower pressure. The reaction cc-IIIb to cc-VI has a negative slope of −7.0 × 10−3 GPa K−1. Finally, we discuss the possibility of the dense cc-VI phase being more stable than aragonite at certain pressure and temperature conditions relevant to the Earth’s mantle.

The far-infrared (IR) optical constants of a set of hazardous and flammable liquids have been obtained by means of spectroscopic ellipsometry in attenuated total reflection configuration over a broad spectral range. Such liquids recently became of considerable concern for transportation security measures worldwide. Their optical identification at check-in gates can only become possible if the characteristic spectra are already known. The refractive indices and the extinction coefficients reported here contribute to a spectroscopic data base in the far-IR and terahertz (THz) spectral regions and may support modeling the performance of THz screening systems on liquids for airports and other security sensitive areas. Examples of several container material/liquid systems are discussed. From the measured optical constants typical THz waveforms are calculated and discussed.

The channelrhodopsin-ChR2 is a light-sensitive transmembrane protein that acts as a selective ion channel between the intra- and the extra-cellular environments. In the last decade, ChR2 has proven to be essential for optogenetics, because, if expressed in mammalian neural cells, it enables the control of neuronal activity in response to visible light. Mid-infrared difference spectroscopy can probe the functional conformational changes of light-sensitive proteins, however intrinsic limitations of standard IR spectroscopy in terms of diffraction, and therefore number of probed proteins, require that the mid-IR experiments be performed on huge numbers of lipid membrane patches with overexpressed proteins. In this work, we apply for the first time IR difference nanospectroscopy, based on the use of mid-IR lasers and an atomic force microscope (AFM), to single membrane patches containing ChR2, obtaining relevant spectroscopy results for optogenetic applications and, more generally, for future experimental studies of light-sensitive proteins at the nanoscale.

We report on a polarizing interferometer-ellipsometer arrangement that overcomes the need for additional measurements with a retarder for the unambiguous determination of the ellipsometric parameters in the far infrared spectral range. It consists of a Martin–Puplett interferometer and a wire-grid polarizer as an analyzer. The application of such interferometer-ellipsometer is experimentally demonstrated on a polyethylene sample deriving the refractive index and the thickness in the spectral range between 15 and 35 c m − 1 . Based on these results, a similar solution without a retarder for the mid-infrared spectral region is additionally proposed.

We have conducted high pressure far-infrared absorbance and Raman spectroscopic investigations on a natural iron-free dolomite sample up to 40 GPa. Comparison between the present observations and literature results unraveled the effect of hydrostatic conditions on the high pressure dolomite polymorph adopted close to 40 GPa, i.e. the triclinic Dol-IIIc modification. In particular, non-hydrostatic conditions impose structural disorder at these pressures, whereas hydrostatic conditions allow the detection of an ordered Dol-IIIc vibrational response. Hence, hydrostatic conditions appear to be a key ingredient for modeling carbon subduction at lower mantle conditions. Our complementary first-principles calculations verified the far-infrared vibrational response of the ambient- and high pressure dolomite phases.

The late eighteenth century Eidsvoll manor house in Norway was modernised in the first two decades of the nineteenth century. The house and its interiors were colour examined during an architectural paint research. Two colour schemes from the early nineteenth century were found; a light greyish lead white and a green copper-based oil paint. The green colour scheme had discoloured severely. In this paper we discuss the results of synchrotron based infrared spectroscopy experiments on the green paint, which consisted of a verdigris pigment used in oil with lead white and chalk. The analytical results are compared with contemporary recipes found in painters’ handbooks around 1800 and seems to be darker than any recipe provided.

We have conducted a comprehensive investigation of the optical and vibrational properties of the binary semiconductor SnSe as a function of temperature and pressure by means of experimental and ab initio probes. Our high-temperature investigations at ambient pressure have successfully reproduced the progressive enhancement of the free carrier concentration upon approaching the Pnma → Bbmm transition, whereas the pressure-induced Pnma → Bbmm transformation at ambient temperature, accompanied by an electronic semiconductor → semi-metal transition, has been identified for bulk SnSe close to 10 GPa. Modeling of the Raman-active vibrations revealed that three-phonon anharmonic processes dominate the temperature-induced mode frequency evolution. In addition, SnSe was found to exhibit a pressure-induced enhancement of the Born effective charge. Such behavior is quite unique and cannot be rationalized within the proposed effective charge trends of binary materials under pressure.

Coherent synchrotron radiation from an electron storage ring is observed in the THz spectral range when the bunch length is shortened down to the sub-mm-range. With increasing stored current, the bunch becomes longitudinally unstable and modulates the THz emission in the time domain. These micro-instabilities are investigated at the electron storage ring BESSY II by means of cross-correlation of the THz fields from successive bunches. The investigations allow deriving the longitudinal length scale of the micro bunch fluctuations and show that it grows faster than the current-dependent bunch length. Our findings will help to set the limits for the possible time resolution for pump-probe experiments achieved with coherent THz synchrotron radiation from a storage ring.

THz and mid IR spectroscopy of high-molecular PE (HMW) and ultra high-molecular PE (UHMW) reveals modifications of the molecular structure. Characteristic absorption bands are changed if the two materials are exposed by γ_Co60radiation up to 600 kGy and subsequently stored at an annealing temperature of 398 K until for 729 days. UHMW-PE and HMW-PE behave differently during the ageing process because of their molecular weight and inherent structure distinctions. The spectroscopic data offer characteristic absorption bands, which have been used to describe the complete ageing process in more detail. For instance, the integral absorption in the B 1u THz-region can be used to describe quantitatively the reduction of crystallinity. The formation of trans vinylene unsaturation and the decay of vinyl during ageing can be observed in detail in the mid IR range.

We apply mid-infrared absorption microspectroscopy to investigate the light-induced conformational changes of bacteriorhodopsin embedded in native purple membranes deposited on gold substrates. The difference spectra (visible light ON-visible light OFF) obtained on thin films of bacteriorhodopsin display main spectral features connected to the light-induced proton pump process, representing a promising preliminary step towards the investigation of light-sensitive proteins by means of mid-IR tip-enhanced nanospectroscopy.

We have used grazing-angle infrared spectroscopy to detect the Berreman effect (BE) in the quasi-two-dimensional electron system (q-2DES) which forms spontaneously at the interface between SrTiO 3 (STO) and a thin film of LaAlO 3 (LAO). From the BE, which allows one to study longitudinal optical excitations in ultrathin films like the q-2DES, we have extracted at different temperatures its thickness, the charge density and mobility of the carriers under crystalline LAO (sample A), and the charge density under amorphous LAO (sample B). The latter quantity turns out to be higher than in sample A, but a comparison with Hall measurements shows that under amorphous LAO the charges are partly localized at low T with a low activation energy (about 190 K in units of kB) and are thermally activated according to a model for large polarons. The thickness of the q-2DES extracted from our spectra turns out to be 4±1 nm for crystalline LAO and 7±2 nm for amorphous LAO.

We combined the focused ion beam sample preparation technique with polarized synchrotron-based FTIR (Fourier transform infrared) spectroscopy, laser-Raman spectroscopy, electron microprobe analysis (EMPA), and transmission electron microscope (TEM) analysis to identify and quantify structurally bound OH, F, Cl, and CO3 groups in fluorapatite from the Northwest Africa 2975 (NWA 2975) shergottite. In this study, the first FTIR spectra of the OH-stretching region from a Martian apatite are presented that show characteristic OH-bands of a F-rich, hydroxyl-bearing apatite. Depending on the method of apatite-formula calculation and whether charge balance is assumed or not, the FTIR-based quantification of the incorporated OH, expressed as wt% H2O, is in variably good agreement with the H2O concentration calculated from electron microprobe data. EMP analyses yielded between 0.35 and 0.54 wt% H2O, and IR data yielded an average H2O content of 0.31 ± 0.03 wt%, consistent with the lower range determined from EMP analyses. The TEM observations implied that the volatiles budget of fluorapatite is magmatic. The water content and the relative volatile ratios calculated for the NWA 2975 magma are similar to those established for other enriched or intermediate shergottites. It is difficult to define the source of enrichment: either Martian wet mantle or crustal assimilation. Comparing the environment of parental magma generation for NWA 2975 with the terrestrial mantle in terms of water content, it displays a composition intermediate between enriched and depleted MORB.

Semantic applications today provide benefits to numerous organisations in business sectors such as health care, finance, industry, and the public sector. These applications use the semantics of a domain in order to improve usability, correctness, and completeness. Developing semantic applications requires methodological skills, e.g., ontology engineering, quality assurance for ontologies, and licence management. Various technologies are available for implementing semantic applications, e.g., data integration, semantic search, machine learning, and complex event processing. This chapter gives an overview of methodologies, technologies, and corporate use of semantic applications.

This chapter is about natural language texts generated automatically. We will discuss the motivation as to why these texts are needed and discuss which domains will profit from such texts. During recent years NLG technology has matured. Millions of news articles are generated daily. However, there is potential for higher quality and more elaborated styles. For this purpose, new techniques have to be developed. These techniques need to be semantically driven. As examples, we will discuss (a) the use and the retrieval of background information by following paths in knowledge graphs, (b) how to calculate and exploit information structure, and (c) how to hyper-personalise automatically generated news.

Very recently an ultralow thermal conductivity and a surpassing high thermoelectric figure of merit were reported in SnSe which makes this material very attractive for electrical energy harvesting. In this paper we follow the evolution of the low-energy phonons with doping, temperature and pressure and compare the experimental results with ab initio calculations to help understanding better the low thermal conductivity in SnSe and may help developing highly efficient thermoelectric materials.

A Mid-Infrared spectrometer specifically suitable for non-cyclic or slow cycling processes was developed for microsecond time-resolved measurements. The spectrometer overcomes the limit of conventional time-resolved Fourier-transform techniques such as step-scan FTIR which require cyclic systems where the reaction cascade is to be triggered thousands of times and in quick succession. In our approach, a combination of a fast linear detector array with highly brilliant synchrotron radiation source and a dispersive spectrometer core allows investigations of irreversible reaction cascades with high signal-to-noise ratio. We discuss first measurements to estimate the performance achieved so far.

The far infrared refractive indices and the extinction coefficients of liquids can be obtained by means of spectroscopic ellipsometry in attenuated total reflection configuration. Such optical constants will contribute to a spectroscopic data base in the far infrared and terahertz spectral regions. The experimental implementation and the calibration procedure of the method are described in detail. The temperature dependency of the optical constants for water over a broad spectral range is exemplarily presented.

Cell membranes are intrinsically heterogeneous, as the local protein and lipid distribution is critical to physiological processes. Even in template systems embedding a single protein type, like purple membranes, there can be a different local response to external stimuli or environmental factors, resulting in heterogeneous conformational changes. Despite the dramatic advances of microspectroscopy techniques, the identification of the conformation heterogeneity is still a challenging task. Tip-enhanced infrared nanospectroscopy is here used to identify conformational changes connected to the hydration state of the transmembrane proteins contained in a 50 nm diameter cell membrane area, without the need for fluorescent labels. In dried purple membrane monolayers, areas with fully hydrated proteins are found among large numbers of molecules with randomly distributed hydration states. Infrared nanospectroscopy results are compared to the spectra obtained with diffraction-limited infrared techniques based on the use of synchrotron radiation, in which the diffraction limit still prevents the observation of nanoscale heterogeneity.

The terahertz/far-infrared spectra ( −1 ) of perfluorinated sulfonic acid (Nafion NR211 polymer) and perfluoroimide acid (PFIA polymer) and their alkali (M + ) salts have been analyzed and the results are presented. Pronounced features in the spectra of these ionomers that correlate systematically with the corresponding cation mass are reported and from their spectral position the force constants are derived. The average vibrational force constants for Nafion/M + and PFIA/M + are found to be 54 ± 7 and 39 ± 4 N/m, respectively. Such terahertz/far-infrared signatures probe the detailed structure of the Nafion/M + and PFIA/M + ionic clusters and, in turn, provide benchmarks for elucidating the ionomer “water channels” or water molecules located in the ionomer–water interface upon hydration. Qualitative trends in the vibrational energies of Nafion and PFIA can be explained by consideration of electronic and/or structural (ionic domain-size) effects.

A complete study of the decayed gilded decorations of the stalactite vaults in the Hall of the Kings in the Alhambra complex (Granada, Spain) has been carried out for the first time. Preliminary investigations were carried out in situ using a portable Raman spectrometer and enabled the identification of tin (II) oxide in the black areas nearby the golden flakes. This suggested the presence of an altered tin foil. Then, a comprehensive characterization of these decorations was achieved through the use of complementary nondestructive techniques working on microsamples. Two main metallic structures were identified by means of scanning electron microscopy coupled to energy dispersive X-ray spectroscopy: (1) a thin (1–2 µm) gold leaf (probably original), and (2) redecorations with a laminated structure formed by a gold leaf placed over a thicker (10–15 µm) tin foil. Synchrotron Fourier-transform infrared microspectroscopy revealed the use of proteinaceous glue to fix the gold leaf directly on the plasterwork, whereas in the case of the laminated structures, either glue or a natural resin was found. Raman microspectroscopy provided insight into the main decay processes affecting the gildings: the detachment of the metals due to the alteration of the organic materials employed as adhesives (forming calcium oxalates) and the oxidation of the tin foil. In addition, two technologies of false gilding have been encountered. One was based on a tin foil tinted to look like gold by means of a varnish (composed of a drying oil and a natural resin), and the second was made up with a tin–copper alloy (bronze) that appears severely degraded to copper oxalate and tin (II) oxide, as revealed by Raman microspectroscopy. Copyright © 2014 John Wiley & Sons, Ltd.

A combined high-pressure mid-infrared absorption and Raman spectroscopy study on a natural CaMg0.98Fe0.02(CO3)2 dolomite sample was performed both at ambient and high temperatures. A pressure–temperature phase diagram was constructed for all the reported dolomite ambient- and high-pressure polymorphs. In addition, a local distortion of the ambient-pressure dolomite structure was identified close to 11 GPa, just before the transition toward the first known high-pressure phase. All the Clausius–Clapeyron slopes are found to be positive with similar magnitudes. Complementary first-principles calculations suggest a metastable nature of the high-pressure dolomite polymorphs. Finally, theoretical spectroscopy is used to interpret and discuss the observed changes in the measured vibrational spectra.

The theoretical assignments of spectral peaks of liquid phase ortho -, meta -, and para -xylene recorded with far-infrared (FIR) and THz spectroscopy in the spectral range between 550 and 50 cm −1 is done with density functional theory (DFT) calculations. As THz spectroscopic techniques drastically evolved in recent years, the critical focus of this paper lies on the applicability of theoretical concepts, used as computational standard in near- and mid-IR spectra, to the FIR-THz region. An evaluation of the choice of functionals, basis sets, and appropriate scaling factors as well as the tractability of the liquid phase in a polarizable continuum model is performed. Alongside a new analysis procedure based on spectral Hard Modeling has been developed. DFT line spectra are fitted to experimental FIR spectra where a quantitative track record allows for meaningful comparisons. With all these tools we are able to reproduce experimental spectra in an optically appealing way and we can explain trends for each spectrum as well as across the row of the isomers.

One of the most effective uses of social media in crisis situation is for the distribution by emergency services, government agencies, and others of reliable information about the nature of the crisis. The panic and confusion that often occurs in the early stages of a crisis can be minimized through such messaging. The value of this role of social media in such cases cannot be underestimated.

The workload of a single operator of a multi robot systems increases with the number of robots in use. Supervisory control is a general idea to solve this issue. In this paper we present an experiment in which we compare single robot control and group robot control. Using single robot control the user must task each robot separately. Using group robot control, he can task the whole group and a planning component generates a plan and observes the execution. We compare performance, errors and workload of the user under single robot control and group robot control conditions.

By use of resonantly-enhanced mechanical photoexpansion technique we have performed mid-infrared vibrational spectroscopy and imaging on the nanoscale of individual purple membranes deposited on ultraflat gold substrate. The observed Amide I and Amide II bands of proteins are in good agreement with the far-field infrared transmission spectra previously collected on large numbers of membranes. A comparison between the near-field signal of single purple membranes and that of two overlapping membranes is presented. The results are discussed by adopting simple thermal and electromagnetic considerations.

The low-temperature softening of the TO1 phonon of SrTiO3 (STO), which determines its incipient ferroelectricity, is known to be partially hindered either in the bulk under strong electric fields, or in thin STO films. Here we show, by terahertz (THz) reflectivity measurements, that a similar effect is produced in bulk STO and at zero static field by ultrathin metallic films on its surface, like a 10-nm-thick film of SrRuO3 (SRO), or the two-dimensional electron system (2DES) present at the interface with LaAlO3. In SRO/STO, the observed hardening is well explained by the depolarizing action of the SRO free electrons which follow adiabatically the ion motion. In LAO/STO, a weaker TO1 hardening could be detected by patterning the 2DES in the form of microstripes and using a polarized THz field parallel (E-) or orthogonal (E-) to the stripes. At 10 K, when TO1 is excited together with the free electrons by E-, its absorbance is harder by about 7 cm-1 than that measured when TO1 is coupled to the plasmon-polariton confined within the stripes, being excited by E-.

Third-generation storage rings are modern facilities working with high currents and designed to host powerful radiation sources, like undulators and wigglers, and to deliver high-brilliance beams to users. Many experiments at high spatial resolution, such as spectromicroscopy at the nanometre scale and with high temporal resolution to investigate kinetics down to the picosecond regime, are now possible. The next frontier is certainly the combination of different methods in a unique set-up with the ultimate available spatial and temporal resolutions. In the last decade much synchrotron-based research has exploited the advantage of complementary information provided by time-resolved X-ray techniques and optical methods in the UV/Vis and IR domains. New time-resolved and concurrent approaches are necessary to characterize complex systems where physical-chemical phenomena occur under the same experimental conditions, for example to detect kinetic intermediates via complementary but independent observations. In this contribution we present scientific cases from original works and literature reviews to support the proposed IR/X-ray simultaneous approach, with both probes exploiting synchrotron radiation sources. In addition, simple experimental layouts that may take advantage of the high brilliance and the wide spectral distribution of the synchrotron radiation emission will be given for specific researches or applications to investigate dynamic processes and non-equilibrium phenomena occurring in many condensed matter and biological systems, of great interest for both fundamental research and technological applications.

Hazardous liquids, liquid explosives and flammable liquids are characterized by means of terahertz time domain spectroscopy (THz-TDS) in analogy to existing non-destructive testing (NDT) strategies. Various polar liquids (alcohols, acetone, hydrogen peroxide, nitro methane) and non-polar aircraft and automobile fuels as well as organic solvents are characterized in the practically relevant, non-contact and non-destructive reflection geometry in the time domain. Absorption coefficients and indices of refraction of a representative set of these liquids are investigated in the spectral range between 0.1 THz and 1.1 THz in transmission configuration by two different set-ups either suitable for strongly or weakly absorbing liquids.