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We present a comprehensive, combined experimental and theoretical study of the core-level photoelectron and near-edge x-ray absorption fine structure (NEXAFS) spectra of 2-thiouracil, 4-thiouracil, and 2,4-dithiouracil at the oxygen 1s, nitrogen 1s, carbon 1s, and the sulfur 2s and 2p edges. X-ray photoelectron spectra were calculated using equation-of-motion coupled-cluster theory (EOM-CCSD), and NEXAFS spectra were calculated using algebraic diagrammatic construction and EOM-CCSD. For the main peaks at O and N 1s as well as the S 2s edge, we find a single photoline. The S 2p spectra show a spin–orbit splitting of 1.2 eV with an asymmetric vibrational line shape. We also resolve the correlation satellites of these photolines. For the carbon 1s photoelectrons, we observe a splitting on the eV scale, which we can unanimously attribute to specific sites. In the NEXAFS spectra, we see very isolated pre-edge features at the oxygen 1s edge; the nitrogen edge, however, is very complex, in contrast to the XPS findings. The C 1s edge NEXAFS spectrum shows site-specific splitting. The sulfur 2s and 2p spectra are dominated by two strong pre-edge transitions. The S 2p spectra show again the spin–orbit splitting of 1.2 eV. [ABSTRACT FROM AUTHOR]

Liquid silicone rubber (LSR) is characterized by a wide range of advantageous properties and is therefore used in many branches and industries. However, the material is difficult to recycle due to the non‐reversible cross‐linking reaction. A promising approach to recycle the already cross‐linked (post‐industrial) waste is the mechanical recycling of LSR via grinding and addition of the powder as filler in virgin material. This research focused on the processing of such LSR‐powder‐compounds via injection molding and the influence of the powder content on mechanical properties. Compounds of virgin LSR and ambient ground powder were prepared and injection molded. Both the processability and the mechanical properties were analyzed. Compounds of up to 40 wt% powder content could be processed with standard injection molding machine equipment without any noticeable issues. The results show a similar compression set for the virgin as for the recycled compounds. Hardness decreases slightly but constantly. Tensile strength and elongation at break are at similar levels for all powder added compounds and drop only by 16.6% and 12.6% compared with the virgin LSR. The results are promising and should be the basis for further and more detailed investigations to industrialize the mechanical recycling of LSR. Highlights: Processing on standard injection molding machine with standard parameters.Up to 40 wt% recycled silicone powder content.Using recycled silicone particles has no effect on compression set.Tensile strength and elongation at break decrease only by 16.6% and 12.6%. [ABSTRACT FROM AUTHOR]

We report a joint experimental and computational study of the photoelectron spectroscopy and the dissociative photoionization of fulminic acid, HCNO. The molecule is of interest to astrochemistry and astrobiology as a potential precursor of prebiotic molecules. Synchrotron radiation was used as the photon source. Dispersive photoelectron spectra were recorded from 10 to 22 eV, covering four band systems in the HCNO cation, and an ionization energy of 10.83 eV was determined. Transitions into the Renner–Teller distorted X+2Π state of the cation were simulated using wavepacket dynamics based on a vibronic coupling Hamiltonian. Very good agreement between experiment and theory is obtained. While the first excited state of the cation shows only a broad and unstructured spectrum, the next two higher states exhibit a well-resolved vibrational progression. Transitions into the excited electronic states of HCNO+ were not simulated due to the large number of electronic states that contribute to these transitions. Nevertheless, a qualitative assignment is given, based on the character of the orbitals involved in the transitions. The dissociative photoionization was investigated by photoelectron–photoion coincidence spectroscopy. The breakdown diagram shows evidence for isomerization from HCNO+ to HNCO+ on the cationic potential energy surface. Zero Kelvin appearance energies for the daughter ions HCO+ and NCO+ have been derived. [ABSTRACT FROM AUTHOR]

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The photoinduced relaxation dynamics of nucleobases and their thionated analogs have been investigated extensively over the past decades motivated by their crucial role in organisms and their application in medical and biochemical research and treatment. Most of these studies focused on the spectroscopy of valence electrons and fragmentation. The advent of ultrashort x‐ray laser sources such as free‐electron lasers, however, opens new opportunities for studying the ultrafast molecular relaxation dynamics utilizing the site‐ and element‐selectivity of x‐rays. In this review, we want to summarize ultrafast experiments on thymine and 2‐thiouracil performed at free‐electron lasers. We performed time‐resolved x‐ray absorption spectroscopy at the oxygen K‐edge after UV excitation of thymine. In addition, we investigated the excited state dynamics of 2‐tUra via x‐ray photoelectron spectroscopy at sulfur. For these methods, we show a strong sensitivity to the electronic state or charge distribution, respectively. We also performed time‐resolved Auger–Meitner spectroscopy, which shows spectral shifts associated with internuclear distances close to the probed site. We discuss the complementary aspects of time‐resolved x‐ray spectroscopy techniques compared to optical and UV spectroscopy for the investigation of ultrafast relaxation processes. [ABSTRACT FROM AUTHOR]

Electrostatically confined quantum dots in bilayer graphene have shown potential as building blocks for quantum technologies. To operate the dots, e.g., as qubits, a precise understanding and control of the confined states and their properties is required. Herein, a large‐scale numerical characterization of confined quantum states in bilayer graphene dots is performed over an extensive range of gate‐tunable parameters such as the dot size, depth, shape, and the bilayer graphene gap. The dot states' orbital degeneracy, wave function distribution, and valley g‐factor are established and the parametric dependencies to achieve different regimes are provided. It is found that the dot states are highly susceptible to gate‐dependent confinement and material parameters, enabling efficient tuning of confined states and valley g‐factor modulation by quantum dot design. [ABSTRACT FROM AUTHOR]

We report a study on the fragmentation of core-ionized and core-excited isocyanic acid, HNCO, using Auger-electron/photoion coincidence spectroscopy. Site-selectivity is observed both for normal and resonant Auger electron decay. Oxygen 1s ionization leads to the CO+ + NH+ ion pairs, while nitrogen 1s ionization results in three-body dissociation and an efficient fragmentation of the H–N bond in the dication. Upon 1s → 10a′ resonant excitation, clear differences between O and N sites are discernible as well. In both cases, the correlation between the dissociation channel and the binding energy of the normal Auger electrons indicates that the fragmentation pattern is governed by the excess energy available in the final ionic state. High-level multireference calculations suggest pathways to the formation of the fragment ions NO+ and HCO+, which are observed although the parent compound contains neither N–O nor H–C bonds. This work contributes to the goal to achieve and understand site-selective fragmentation upon ionization and excitation of molecules with soft x-ray radiation. [ABSTRACT FROM AUTHOR]

The processing of liquid silicone rubber (LSR) in the injection molding process to molded parts offers high economic potential due to its great scalability. Unlike the well‐researched and understood injection molding process of thermoplastics, LSR still lacks basic process knowledge. The cavity pressure curve shows a completely different pattern, as the cold LSR expands strongly once placed in the hot mold due to volume dilation. During processing of LSR exothermic and irreversible cross‐linking, occurs. In this work, a method is introduced to display the cross‐linking reaction in the cavity pressure curve. Using a self‐developed testing device and conventional differential scanning calorimetry measurements, a correlation between cross‐linking and the pressure signal can be demonstrated. A typical deflection is evaluated in the pressure curve by differentiating, which is attributed to the cross‐linking. The relationships established are confirmed by pressure measurements in the mold during the processing of LSR in the injection molding process. The knowledge gained contributes to a better understanding of the process, helps to optimize existing processes and save resources. Existing cavity‐pressure‐measuring‐systems are to be supplemented by an evaluation logic and thus, in addition to cycle time optimization, process variations are to be detected, energy consumption optimized and quality ensured and verified. [ABSTRACT FROM AUTHOR]

HCNO is a molecule of considerable astrochemical interest as a precursor to prebiotic molecules. It is synthesized by preparative pyrolysis and is unstable at room temperature. Here, we investigate its spectroscopy in the soft X-ray regime at the C 1s, N 1s and O 1s edges. All 1s ionization energies are reported and X-ray absorption spectra reveal the transitions from the 1s to the π* state. Resonant and normal Auger electron spectra for the decay of the core hole states are recorded in a hemispherical analyzer. An assignment of the experimental spectra is provided with the aid of theoretical counterparts. The latter are using a valence configuration interaction representation of the intermediate and final state energies and wavefunctions, the one-center approximation for transition rates and band shapes according to the moment theory. The computed spectra are in very good agreement with the experimental data and most of the relevant bands are assigned. Additionally, we present a simple approach to estimate relative Auger transition rates on the basis of a minimal basis representation of the molecular orbitals. We demonstrate that this provides a qualitatively good and reliable estimate for several signals in the normal and resonant Auger electron spectra which have significantly different intensities in the decay of the three core holes. [ABSTRACT FROM AUTHOR]

Copyright of Public Health Forum is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: A variety of empirical studies have shown the negative effects of unemployment on health. A research gap exists regarding salutogenic factors and successful coping strategies to master involuntary job loss and unemployment with the least damage to health. Hence, this study aims at generating a deeper understanding of coping with unemployment and maintaining health. Design and methods: We conducted problem-centered guideline interviews with 21 unemployed people. For the analysis of the interviews, we followed the qualitative content analysis. Results: The study identified that five themes were particularly relevant in coping with unemployment: i) the financial situation, ii) social support and psychosocial strains due family obligations, iii) health problems, iv) time structure, and v) coping strategies. The respondents expressed their financial situation as a major strain in unemployment. They emphasized the importance of social support by their families, but reported also stressful psychosocial demands due to their family members. Further, our respondents mentioned their health problems as a barrier to reintegration into the labour market. In connection with social role demands, a rudimentary time structure was reported by the participants. The common reported coping strategy in unemployment is seeking social support. Conclusions: In summary, our results show - besides health problems and a deteriorated financial situation in unemployment - the great importance of social support and time structure for maintaining mental health in unemployment. Consequently, health promotion approaches for the unemployed should especially target social support and time structure. [ABSTRACT FROM AUTHOR]

The ultrafast photo‐induced ring opening of the oxirane derivative trans‐stilbene oxide has been studied through the use of ultrafast UV/UV pump‐probe spectroscopy by using photo‐ion detection. Single‐ and multiphoton probe paths and final states were identified through comparisons between UV power studies and synchrotron‐based vacuum ultraviolet (VUV) single‐photon ionization studies. Three major time‐dependent features of the parent ion (sub‐450 fs decay, (1.5±0.2) ps, and >100 ps) were observed. These decays are discussed in conjunction with the primary ring‐opening mechanism of stilbene oxide, which occurs through C−C dissociation in the oxirane ring. The appearance of fragments relating to the masses of dehydrogenated diphenylmethane (167 amu) and dehydrogenated methylbenzene (90 amu) were also investigated. The appearance of the 167 amu fragment could suggest an alternative ultrafast ring‐opening pathway via the dissociation of one of the C−O bonds within the oxirane ring. [ABSTRACT FROM AUTHOR]

Processing of liquid silicone rubber (LSR) in the injection molding process has a high economic potential. Since there are some fundamental differences compared to classical thermoplastic injection molding, up to now there is a lack of well‐founded knowledge of the process which allows an estimation of the cycle time. Because, in addition to reverse temperature control, LSR processing also involves an irreversible temperature‐ and time‐dependent chemical reaction. In this paper, the complex cross‐linking reaction is first modelled phenomenologically using dynamic differential scanning calorimetry (DSC) measurements and the well‐fitting Kamal‐Sourour model. Afterwards, a temperature and cross‐linking simulation is set up, which reliably simulates the time‐ and travel‐dependent temperature profile and degree of cross‐linking in the mold. Therefore, the released exothermic cross‐linking heat is also taken into account. The simulated temperature values are verified with measurements in the cavity during the injection molding process. The measured values correspond very well with the simulated values at different mold temperatures. It is shown that the influence of the cross‐linking heat on the overall temperature profile in the LSR component during the injection molding process is relatively low. Nevertheless, the model is necessary to determine the degree of cross‐linking ‐ it can be used to calculate the cycle time at which the component of a certain cross‐section can be ejected at a known tool temperature and is fully cross‐linked. With this knowledge, existing processes can be optimized in terms of mold temperature and curing time, but also new components can be calculated economically. [ABSTRACT FROM AUTHOR]

We present a highly flexible and portable instrument to perform pump-probe spectroscopy with an optical and an X-ray pulse in the gas phase. The so-called URSA-PQ (German for 'Ultraschnelle Röntgenspektroskopie zur Abfrage der Photoenergiekonversion an Quantensystemen', Engl. 'ultrafast X-ray spectroscopy for probing photoenergy conversion in quantum systems') instrument is equipped with a magnetic bottle electron spectrometer (MBES) and tools to characterize the spatial and temporal overlap of optical and X-ray laser pulses. Its adherence to the CAMP instrument dimensions allows for a wide range of sample sources as well as other spectrometers to be included in the setup. We present the main design and technical features of the instrument. The MBES performance was evaluated using Kr M4,5NN Auger lines using backfilled Kr gas, with an energy resolution ΔE/E ≅ 1/40 in the integrating operative mode. The time resolution of the setup at FLASH 2 FL 24 has been characterized with the help of an experiment on 2-thiouracil that is inserted via the instruments' capillary oven. We find a time resolution of 190 fs using the molecular 2p photoline shift and attribute this to different origins in the UV-pump—the X-ray probe setup. [ABSTRACT FROM AUTHOR]

One‐second wind data on the West Florida Shelf were used to examine turbulent scales from large eddies to small eddies in the atmospheric surface layer within a frequency band from 0.02 to 0.3 Hz (periods from ~1 min to ~3 s). Data were collected at two at‐sea locations spanning 6.5 months. Three events in three wind ranges were examined in exploring the one‐dimensional turbulent power spectra: >14 m/s, wind range I; those between 10 and 14 m/s, wind range II; and those between 5 and 10 m/s, wind range III. Events consisted of ensembles of abutting 30‐min subsets spanning 5.5 to 23 hr. The mean vector wind time scale of T0 = 30 min was found to be reasonable for the West Florida Shelf region. The first wind range provided the best results, more or less in line with a Kolmogorov −5/3 power law whose mean vector wind speed over 21 subsets (10.5 hr) was nearly 15 m/s. The one‐dimensional turbulent power spectra provided an estimate of the dissipation rate (ε) from which other turbulent quantities could be computed: u*, τ, and Cd (the frictional velocity, the surface stress, and the drag coefficient, respectively). The salient point here is that these quantities were larger than those from previous observational studies. Where the power law was not operant intrinsic turbulent spatial scales ranged from 1 to 0.1 m and provide evidence of anisotropy for frequencies greater than 0.1 Hz. Plain Language Summary: Wind data sampled at 1 Hz were collected at two at‐sea locations on the West Florida Shelf where data common to both moorings span roughly 6.5 months. We showed that a mean vector wind time scale of T0 = 30 min is reasonable for the West Florida Shelf domain. Three wind ranges were examined from which the one‐dimensional turbulent power spectra allowed estimates of turbulent parameters crucial in developing momentum flux algorithms used in numerical models of both the atmosphere and the ocean. Turbulence parameters were found to be larger than expected suggesting that improving flux algorithms should be a high priority. Key Points: Using 1‐s wind observations from the West Florida Shelf, turbulence parameters were examined and compared with Kolmogorov similarity theoryThree events were examined consisting of ensembles of abutting 30‐min subsets spanning from 5.5 to 23 hrTurbulence parameters were larger than expected; evidence of anisotropy and deviations from similarity suggest improvements are needed in momentum flux algorithms presently operant in numerical models [ABSTRACT FROM AUTHOR]

In this paper, we report X-ray absorption and core-level electron spectra of the nucleobase derivative 2-thiouracil at the sulfur L1- and L2,3-edges. We used soft X-rays from the free-electron laser FLASH2 for the excitation of isolated molecules and dispersed the outgoing electrons with a magnetic bottle spectrometer. We identified photoelectrons from the 2p core orbital, accompanied by an electron correlation satellite, as well as resonant and non-resonant Coster–Kronig and Auger–Meitner emission at the L1- and L2,3-edges, respectively. We used the electron yield to construct X-ray absorption spectra at the two edges. The experimental data obtained are put in the context of the literature currently available on sulfur core-level and 2-thiouracil spectroscopy. [ABSTRACT FROM AUTHOR]

Current observations are compared from upward- and downward-looking acoustic Doppler current profilers (ADCPs) deployed on the West Florida Shelf (WFS). Despite regional differences, statistical analyses show good agreement between all sets of observations throughout the water column except in the upper few meters where all downward-looking ADCPs exhibit small, but significant, reduction in rms speed values. Evidence suggests that this reduction is mooring related. It is possible that the presence of near-surface bubbles caused by wave activity could bias the near-surface observations. Otherwise, either the upward- or downward-looking mooring systems produce equivalent observations with differences due to spatial variations. [ABSTRACT FROM AUTHOR]