Carboxylated Polyurethanes Containing Hyperbranched Polyester Soft Segments

hyperbranched polyester soft segments (HB PU) with functional carboxylic groups in order to enable the preparation of stable HB PU dispersions. Carboxylated hyperbranched polyurethanes were synthesized using a hyperbranched polyester based on 2,2-bis(methylol)propionic acid of the fourth pseudo-generation (Boltorn H40) and hexamethylene (HDI) or isophorone diisocyanate (IPDI). The reactivity of hyperbranched polyester with HDI was lower than expected, possibly due to the presence of less reactive hydroxyl groups in the linear repeat units. A gel was formed at mole ratios r_NCO/OH = 1:2 or 1:4. The synthesis of HB PU was performed with partly esterified hyperbranched polyester with lowered hydroxyl functionality. The carboxyl groups were incorporated in the HB PU backbone by reaction of residual hydroxyl groups with cis-1,2-cyclohexanedicarboxylic anhydride. HB PU aqueous dispersions were stable at least for two months, although their films were brittle. The tensile strength and Young's modulus of blends of linear and HB PU decreased with increasing content of HB PU whereas elongation at break remained nearly constant, which was explained in terms of looser chain packing due to more open tree-like hyperbranched structures

Estimating subseasonal variability and trends in global atmosphere using reanalysis data

A new measure of subseasonal variability is introduced that provides a scale-dependent estimation of vertically and meridionally integrated atmospheric variability in terms of the normal modes of linearized primitive equations. Applied to the ERA-Interim data, the new measure shows that subseasonal variability decreases for larger zonal wave numbers. Most of variability is due to balanced (Rossby mode) dynamics but the portion associated with the inertio-gravity (IG) modes increases as the scale reduces. Time series of globally integrated variability anomalies in ERA-Interim show an increase in variability after year 2000. In recent years the anomalies have been about 2% above the 1981–2010 average. The relative increase in variability projecting on the IG modes is larger and more persistent than for the Rossby modes. Although the IG part is a small component of the subseasonal variability, it is an important effect likely reflecting the observed increase in the tropical precipitation variability. ©2018. The Authors

An assessment of scale-dependent variability and bias in global prediction models

The paper presents a method for the scale-dependent validation of the spatio-temporal variability in global weather or climate models and for their bias quantification in relation to dynamics. The method provides a relationship between the bias and simulated spatial and temporal variance by a model in comparison with verifying reanalysis data. For the low resolution (T30L8) subset of ERA-20C data, it was found that 80–90 (depending on season) of the global interannual variance is at planetary scales (zonal wavenumbers k = 0−3), and only about 1 of the variance is at scales with k> 7. The reanalysis is used to validate a T30L8 GCM in two configurations, one with the prescribed sea-surface temperature (SST) and another using a slab ocean model. Although the model with the prescribed SST represents the average properties of surface fields well, the interannual variability is underestimated at all scales. Similar to variability, model bias is strongly scale dependent. Biases found in the experiment with the prescribed SST are largely increased in the experiment using a slab ocean, especially in k= 0 , in scales with missing variability and in seasons with poorly simulated energy distribution. The perfect model scenario (a comparison between the GCM coupled to a slab ocean vs. the same model with prescribed SSTs) shows that the representation of the ocean is not critical for synoptic to subsynoptic variability, but essential for capturing the planetary scales. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Evaluation of contextual embeddings on less-resourced languages

The current dominance of deep neural networks in natural language processing is based on contextual embeddings such as ELMo, BERT, and BERT derivatives. Most existing work focuses on English; in contrast, we present here the first multilingual empirical comparison of two ELMo and several monolingual and multilingual BERT models using 14 tasks in nine languages. In monolingual settings, our analysis shows that monolingual BERT models generally dominate, with a few exceptions such as the dependency parsing task, where they are not competitive with ELMo models trained on large corpora. In cross-lingual settings, BERT models trained on only a few languages mostly do best, closely followed by massively multilingual BERT models

Karboksilirani poliuretani s visoko razgranatim poliesterskim mekanim segmentima

hyperbranched polyester soft segments (HB PU) with functional carboxylic groups in order to enable the preparation of stable HB PU dispersions. Carboxylated hyperbranched polyurethanes were synthesized using a hyperbranched polyester based on 2,2-bis(methylol)propionic acid of the fourth pseudo-generation (BoltornŽ H40) and hexamethylene (HDI) or isophorone diisocyanate (IPDI). The reactivity of hyperbranched polyester with HDI was lower than expected, possibly due to the presence of less reactive hydroxyl groups in the linear repeat units. A gel was formed at mole ratios rNCO/OH = 1:2 or 1:4. The synthesis of HB PU was performed with partly esterified hyperbranched polyester with lowered hydroxyl functionality. The carboxyl groups were incorporated in the HB PU backbone by reaction of residual hydroxyl groups with cis-1,2-cyclohexanedicarboxylic anhydride. HB PU aqueous dispersions were stable at least for two months, although their films were brittle. The tensile strength and Young\u27s modulus of blends of linear and HB PU decreased with increasing content of HB PU whereas elongation at break remained nearly constant, which was explained in terms of looser chain packing due to more open tree-like hyperbranched structures.Rad prikazuje sintezu i karakterizaciju poliuretana s mekanim segmentima od visoko razgranatoga poliestera (HB PU) s funkcionalnim karboksilnim skupinama s namjenom pripreme stabilnih disperzija HB PU. Za sintezu karboksiliranih HB PU upotrijebili smo visoko razgranati poliester na osnovi 2,2-bis(metilol)propionske kiseline četvrte pseudo-generacije (Boltorn H40) i heksametilen-diizocijanat (HDI) ili izoforon-diizocijanat (IPDI). Reaktivnost visoko razgranatog poliestra s HDI-om bila je niža od očekivane, vjerojatno zbog postojećih manje reaktivnih hidroksilnih skupina u linearnim jedinicama. Reakcijske smjese gelirale su kod množinskog omjera rNCO/OH = 1:2 i 1:4. HB PU sintetizirali smo iz djelimično preostaloga visoko razgranatoga poliestera s nižom -OH funkcionalnosti. Karboksilne skupine smo u lanac HB PU uveli s esterifikacijom neizreagiranih hidroksilnih skupina s anhidridom cis-1,2-cikloheksandikarboksilne kiseline. Vodene disperzije HB PU bile su stabilne najmanje dva mjeseca, filmovi su bili krhki. Ispitivanja na vučnu čvrstoću i na Youngov modul elastičnosti su pokazali da su se iznosi kod smjesa linearnoga i HB PU s povećavajućim udjelom HB PU se smanjivali, dok je naprezanje na rastezanje do loma ostalo nepromijenjeno, što smo objasnili s manje gustim slaganjem lanaca zbog više otvorenih drvenastih visoko razgranatih struktura

Doses in the Vicinity of Mobile X-ray Equipment in a Children’s Intensive Care Unit

Most of the patients in the intensive care unit for children are newborns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment including mobile shields is routinely used for diagnosis of the respiratory tract, heart and endovascular cateterisation. The aim of this work was to determine the radiation exposure to the children in the vicinity of the exposed patient in the same or next room. Three measurement runs were carried out with thermoluminescence dosimetry system. The results show that the homogeneity of the irradiation field is adequate, the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is very low, practically in the range of the lowest detectable dose. The entrance dose on the breast of the patient was found to be 0.07 mSv. Therefore, there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment

Doses in the Vicinity of Mobile X-ray Equipment in a Children’s Intensive Care Unit

Most of the patients in the intensive care unit for children are newborns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment including mobile shields is routinely used for diagnosis of the respiratory tract, heart and endovascular cateterisation. The aim of this work was to determine the radiation exposure to the children in the vicinity of the exposed patient in the same or next room. Three measurement runs were carried out with thermoluminescence dosimetry system. The results show that the homogeneity of the irradiation field is adequate, the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is very low, practically in the range of the lowest detectable dose. The entrance dose on the breast of the patient was found to be 0.07 mSv. Therefore, there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment

Interdisciplinary design of a fish ramp using migration routes analysis

The study presents several steps of a fish ramp geometry optimization performed with a 3D numerical model DualSPHysics, which is based on the smoothed particle hydrodynamics (SPH) method. The optimization process led to the design of a bottom ramp that is capable of providing suitable conditions for the migration of target fish species (Salmo truta, Phoxinus phoxinus, Cottus gobio, and Eudontomyzon vladykovi). Migration routes were determined as complex 3D volumes of fluid according to the simulated velocity field in various steady flow conditions. Including three categories of potential migration zones (rest, effort, and limit zones), migration routes were quantified in high detail in terms of the size and position of each zone, and in terms of the distance from a given fluid part to the nearest rest zone. The interdisciplinary approach of this study also led to the development of new tools for the DualSPHysics model, specifically suited to improve functionality in eco-hydraulics research. Fishway Ramp River restoration Smoothed particle hydrodynamics DualSPHysicspublishedVersio

Atmospheric energy spectra in global kilometre-scale models

Eleven 40-day long integrations of five different global models with horizontal resolutions of less than 9 km are compared in terms of their global energy spectra. The method of normal-mode function decomposition is used to distinguish between balanced (Rossby wave; RW) and unbalanced (inertia-gravity wave; IGW) circulation. The simulations produce the expected canonical shape of the spectra, but their spectral slopes at mesoscales, and the zonal scale at which RW and IGW spectra intersect differ significantly. The partitioning of total wave energies into RWs an IGWs is most sensitive to the turbulence closure scheme and this partitioning is what determines the spectral crossing scale in the simulations, which differs by a factor of up to two. It implies that care must be taken when using simple spatial filtering to compare gravity wave phenomena in storm-resolving simulations, even when the model horizontal resolutions are similar. In contrast to the energy partitioning between the RWs and IGWs, changes in turbulence closure schemes do not seem to strongly affect spectral slopes, which only exhibit major differences at mesoscales. Despite their minor contribution to the global (horizontal kinetic plus potential available) energy, small scales are important for driving the global mean circulation. Our results support the conclusions of previous studies that the strength of convection is a relevant factor for explaining discrepancies in the energies at small scales. The models studied here produce the major large-scale features of tropical precipitation patterns. However, particularly at large horizontal wavenumbers, the spectra of upper tropospheric vertical velocity, which is a good indicator for the strength of deep convection, differ by factors of three or more in energy. High vertical kinetic energies at small scales are mostly found in those models that do not use any convective parameterisation

Structural and time-resolved mechanistic investigations of protein hydrolysis by the acidic proline-specific endoprotease from Aspergillus niger

Proline-specific endoproteases have been successfully used in, for example, the in-situ degradation of gluten, the hydrolysis of bitter peptides, the reduction of haze during beer production, and the generation of peptides for mass spectroscopy and proteomics applications. Here we present the crystal structure of the extracellular proline-specific endoprotease from Aspergillus niger (AnPEP), a member of the S28 peptidase family with rarely observed true proline-specific endoprotease activity. Family S28 proteases have a conventional Ser-Asp-His catalytic triad, but their oxyanion-stabilizing hole shows a glutamic acid, an amino acid not previously observed in this role. Since these enzymes have an acidic pH optimum, the presence of a glutamic acid in the oxyanion hole may confine their activity to an acidic pH. Yet, considering the presence of the conventional catalytic triad, it is remarkable that the Aspergillus niger enzyme remains active down to pH 1.5. The determination of the primary cleavage site of cytochrome c along with molecular dynamics-assisted docking studies indicate that the active site pocket of AnPEP can accommodate a reverse turn of approximately 12 amino acids with proline at the S1 specificity pocket. Comparison with the structures of two S28-proline-specific exopeptidases reveals not only a more spacious active site cavity but also the absence of any putative binding sites for amino- and carboxyl-terminal residues as observed in the exopeptidases, explaining AnPEP's observed endoprotease activity. This article is protected by copyright. All rights reserved.</p