bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodynamic and Systemic Effects of Albumin in Patients with Advanced Liver Disease
Authors: Tufoni Manuel , Baldassarre Maurizio , Zaccherini Giacomo , Antognoli Agnese , Caraceni Paolo
Published: June 2020

Purpose of Review

Albumin administration is recommended to prevent or treat specific complications of decompensated cirrhosis based on its capacity to expand plasma volume. However, the molecule also has many other biological properties that are unrelated to the oncotic activity. The purpose of this review is to examine the hemodynamic and systemic effects of albumin administration in patients with decompensated cirrhosis.

Recent Findings

Besides plasma expansion, albumin appears to act against inflammation, facilitate immunocompetence, and improve cardiac and endothelial function, thus antagonizing critical steps in the pathophysiological cascade underlying decompensated cirrhosis.

Increasing knowledge of the pathophysiological mechanisms of the disease, as well the pleiotropic properties of the molecule, provides the rationale for considering albumin as a multi-target disease-modifying agent in decompensated cirrhosis. Both oncotic and non-oncotic properties likely concur with the clinical benefits of long-term albumin administration recently demonstrated in these patients.
Regulating Blockchain, DLT and Smart Contracts: a technology regulator’s perspective
Authors: Ellul Joshua , Galea Jonathan , Ganado Max , Mccarthy Stephen , Pace Gordon J.
Published: June 2020

Blockchain, Smart Contracts and other forms of Distributed Ledger Technology provide means to ensure that processes are verifiable, transparent, and tamper-proof. Yet the very same enabling features that bring decentralisation also pose challenges to providing protection for the various users and stakeholders. Most jurisdictions which have implemented regulatory frameworks in this area have focused on regulating the financial aspects of cryptocurrency-based operations. However, they have not addressed technology assurance requirements. In this paper we present a world-first technology regulatory framework.
Is Ethnic Retention a Result of Unmet Educational Aspirations? Academic Career and Ethnic Identity of Migrant Minority Youth in England, Germany, the Netherlands, and Sweden
Authors: Nauck Bernhard
Published: June 2020

Data from 3 waves of the Children of Immigrants’ Longitudinal Survey in 4 European countries (CILS4EU) were used to test for effects of academic trajectories on the development of ethnic retention. The large-scale comparative panel data for the transition at the end of lower secondary school provide answers to the following research questions: Is migrant youth with unmet educational aspirations especially vulnerable to ethnic retention? Is ethnic retention after failure of the academic career enhanced or buffered by societal conditions, i.e., does it vary with educational and social welfare systems? Ethnic retention was captured in 4 dimensions: social retention (ethnic friends), cultural retention (ethnic language use), religious retention (ethnic religiosity), and emotional retention (ethnic identification). Fixed-effects regressions with interaction terms tested the effects of academic track and aspirations in combination with reactive ethnicity and are tested separately for each country. As compared to Sweden, migrant minority youth in England and Germany are much more likely to develop ethnic emotions and practice a minority religion. However, in the fixed-effects analysis capturing within-individual changes, youth with increased educational aspirations but unfavorable career development did not differ substantially from the other career patterns, and if so, they showed lower levels of ethnic retention.
Impact of Brexit on Zonal Approval Procedures and Mutual Recognition Procedures in Plant Protection Legislation
Authors: KOOF Alexander
Published: June 2020

On 29 March 2017, the UK made use of Article 50 of the Treaty on European Union (TEU) and thus initiated its withdrawal from the European Union. As a result, the UK left the European Union on 31 January 2020 (23:00 UTC). This paper provides a legal assessment of the impact of the UK’s withdrawal from the European Union (Brexit) on zonal authorisation and mutual recognition procedures regarding the authorisation of plant protection products. Many legal issues are unclear in this respect due to the lack of European and national case law. The German Administrative Court of Braunschweig had to decide in an urgent procedure on the effects of Brexit with regards to the authorisation of a plant protection product in the mutual recognition procedure.
GENERATING MAXIMAL SUBGROUPS OF FINITE ALMOST SIMPLE GROUPS
Authors: LUCCHINI ANDREA , MARION CLAUDE , TRACEY GARETH
Published: June 2020

For a finite group

$G$

, let

$d(G)$

denote the minimal number of elements required to generate

$G$

. In this paper, we prove sharp upper bounds on

$d(H)$

whenever

$H$

is a maximal subgroup of a finite almost simple group. In particular, we show that

$d(H)\leqslant 5$

and that

$d(H)\geqslant 4$

if and only if

$H$

occurs in a known list. This improves a result of Burness, Liebeck and Shalev. The method involves the theory of crowns in finite groups.
Joined Cases A. K. v. Krajowa Rada Sądownictwa (C-585/18) and CP (C-624/18), DO (C-625/18) v. Sąd Najwyższy (C.J.E.U.)
Authors: Grogan Joelle
Published: June 2020

Joined Cases C-585/18, C-624/18, and C-625/18 concerning the independence of the Disciplinary Chamber of the Sąd Najwyższy (Polish Supreme Court) is the latest in a series of European Union (EU) Member States requesting the Court of Justice of the EU (CJEU) to rule on the independence of their judicial systems. While the organization of justice systems within Member States is a competence of Member States (and thus not for the EU to determine or decide), the CJEU has held that Member States are nevertheless required to comply with obligations under EU law to ensure effective judicial protection and, as a necessary corollary, judicial independence. The significance of the current case lies in the formulation by the CJEU of a “European” standard of judicial independence, and its finding that national judges may set aside the jurisdiction of courts found not to be independent against that standard and to disapply any national measure (in accordance with the principle of the primacy of EU law over national law) that gives jurisdiction to a non-independent court.
Early Judeo-Arabic Birth Narratives in the Polemical Story “Life of Jesus” (Toledot Yeshu)
Authors: Goldstein Miriam
Published: June 2020

This is a first-time presentation of the initial section of the Toledot Yeshu (TY) narrative describing the birth and early life of Jesus in Judeo-Arabic, a text with important implications for current research on TY. First, the origin of the birth narrative has been debated in recent scholarship on the Hebrew versions of TY. The existence of this lengthy Judeo-Arabic birth narrative, preserved in two manuscripts belonging to the Russian National Library, as well as the identification of other, earlier Judeo-Arabic manuscript fragments that include the TY birth narrative, demonstrates that the birth narrative formed part of TY significantly earlier than has been previously suggested. Second, the narrative preserved in the Russian manuscripts also demonstrates the relevance of the Judeo-Arabic versions of TY for the understanding of the development of this protean work. Examination of their textual tradition reveals interesting connections with particular Hebrew versions of TY from Europe and can shed light on the question of how the work moved between East and West. Finally, this Judeo-Arabic version of TY is significant in its demonstration of a clever adaptation to its linguistic and cultural surroundings. It incorporates a lengthy introduction—the only one currently known in all of the TY literature—which is a literary tour de force employing contemporaneous Arabic style together with a well-known rabbinic dictum, thereby situating Toledot Yeshu simultaneously in its Islamicate milieu and in Jewish textual and even ritual tradition. The discussion concludes with a transcription and translation of the birth narrative as preserved in these two Russian manuscripts.
Design, construction and utilization of a university plasma laboratory
Authors: Gekelman W. , Pribyl P. , Lucky Z. , Tang S. W. , Han J. , Qian Y.
Published: June 2020

We present the elements required to construct two devices used in an undergraduate plasma physics laboratory. The materials and construction costs of the sources, the vacuum systems and probe drives and electrical circuits are presented in detail in the text and the first appendix. We also provide the software for probe motion and data acquisition as well as the electrical schematics for key components. Experiments which have been performed are listed and two (resonance cones and whistler waves) are described in greater detail. The machines are flexible and original research is possible.
Reflect, Revisit, Reimagine: Ethnography of Language Policy and Planning
Authors: Hornberger Nancy H.
Published: June 2020

Tracing applied linguists’ interests in language policy and planning (LPP) as reflected in the pages of theAnnual Review of Applied Linguisticssince its founding in 1980, I focus on the emergence of, and current boom in, ethnographic LPP research. I draw on the ethnographic concept of ideological and implementational LPP spaces as scalar, layered policies and practices influencing each other, mutually reinforcing, wedging, and transforming ideology through implementation and vice versa. Doing so highlights how the perennial policy-practice gap is given nuance through exploration of the intertwining dynamics of top-down/bottom-up language planning activities and processes, monoglossic/heteroglossic language ideologies and practices, potential equality/actual inequality of languages, and critical/transformative research paradigms in LPP.
An approximate version of Jackson’s conjecture
Authors: Liebenau Anita , Pehova Yanitsa
Published: June 2020

A diregular bipartite tournament is a balanced complete bipartite graph whose edges are oriented so that every vertex has the same in- and out-degree. In 1981 Jackson showed that a diregular bipartite tournament contains a Hamilton cycle, and conjectured that in fact its edge set can be partitioned into Hamilton cycles. We prove an approximate version of this conjecture: for everyε > 0 there existsn0such that every diregular bipartite tournament on 2n≥n0vertices contains a collection of (1/2–ε)ncycles of length at least (2–ε)n. Increasing the degree by a small proportion allows us to prove the existence of many Hamilton cycles: for everyc > 1/2 andε > 0 there existsn0such that everycn-regular bipartite digraph on 2n≥n0vertices contains (1−ε)cnedge-disjoint Hamilton cycles.
Immunosuppressant associated torsades de pointes after acute heart rejection in an 8-year-old boy
Authors: Hsin-Ming Liu , Wei-Chieh Tseng , Shuenn-Nan Chiu
Published: June 2020

Torsades de pointes is a kind of life-threatening ventricular tachyarrhythmia. We report a case of torsades de pointes in an 8-year-old boy with acute rejection after orthotopic heart transplantation. The causes of torsades de pointes could be either congenital or acquired. In this case, various causes including acute rejection-related repolarisation heterogeneity, dose-dependent acquired long QT resulting from treatment with immunosuppressants, and AKAP9 (A-kinase anchoring protein 9) genetic variants are the possible mechanisms.
Supervised learning for the detection of negation and of its scope in French and Brazilian Portuguese biomedical corpora
Authors: Dalloux Clément , Claveau Vincent , Grabar Natalia , Oliveira Lucas Emanuel Silva , Moro Claudia Maria Cabral , Gumiel Yohan Bonescki , Carvalho Deborah Ribeiro
Published: June 2020

Automatic detection of negated content is often a prerequisite in information extraction systems in various domains. In the biomedical domain especially, this task is important because negation plays an important role. In this work, two main contributions are proposed. First, we work with languages which have been poorly addressed up to now: Brazilian Portuguese and French. Thus, we developed new corpora for these two languages which have been manually annotated for marking up the negation cues and their scope. Second, we propose automatic methods based on supervised machine learning approaches for the automatic detection of negation marks and of their scopes. The methods show to be robust in both languages (Brazilian Portuguese and French) and in cross-domain (general and biomedical languages) contexts. The approach is also validated on English data from the state of the art: it yields very good results and outperforms other existing approaches. Besides, the application is accessible and usable online. We assume that, through these issues (new annotated corpora, application accessible online, and cross-domain robustness), the reproducibility of the results and the robustness of the NLP applications will be augmented.
Uncertainty Estimation in Regional Models of Long‐Term GIA Uplift and Sea Level Change: An Overview
Authors: Simon K. M. , Riva R. E. M.
Published: June 2020

This work provides a comparison of four approaches that can be used to describe uncertainty in models of the long‐term glacial isostatic adjustment (GIA) process. The four methods range from pessimistic to optimistic representations of GIA uncertainty. Each estimation method is applied to selected one dimensional GIA model predictions and compared with vertical land motion data from Global Positioning System (GPS) measurements across Fennoscandia and North America. The methods are evaluated relative to two main properties: (1) their expected ability to separate non‐GIA from GIA signals and (2) their estimated statistical appropriateness given a specific GIA model and data set. For the first point, non‐GIA signals are considered isolated from the long‐term (millennial time scale) GIA signal at sites where measurement and model uncertainties do not overlap. Across methods, the frequency and accuracy with which non‐GIA signals are separated from GIA signals in GPS data display both consistent similarities and disparities. For the second point, we compare model predictions with rates of vertical land motion and relative sea level change that have been cleaned of non‐GIA signals to determine the most appropriate value of model uncertainty and relate the findings to the four approaches. Best fit inferences suggest that within deglaciation centers, GIA model uncertainty is up to ~2 mm/yr (vertical land motion). Likewise, away from the former ice sheet centers, GIA uncertainty for relative sea level change is inferred to be ~0.3–0.5 mm/yr along the U.S. East Coast and ~0.6–0.8 mm/yr in the North Sea.
Adaptive Localization for Satellite Radiance Observations in an Ensemble Kalman Filter
Authors: Lei Lili , Whitaker Jeffrey S. , Anderson Jeffrey L. , Tan Zhemin
Published: June 2020

Localization is essential to effectively assimilate satellite radiances in ensemble Kalman filters. However, the vertical location and separation from a model grid point variable for a radiance observation are not well defined, which results in complexities when localizing the impact of radiance observations. An adaptive method is proposed to estimate an effective vertical localization independently for each assimilated channel of every satellite platform. It uses sample correlations between ensemble priors of observations and state variables from a cycling data assimilation to estimate the localization function that minimizes the sampling error. The estimated localization functions are approximated by three localization parameters: the localization width, maximum value, and vertical location of the radiance observations. Adaptively estimated localization parameters are used in assimilation experiments with the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) model and the National Oceanic and Atmospheric Administration (NOAA) operational ensemble Kalman filter (EnKF). Results show that using the adaptive localization width and vertical location for radiance observations is more beneficial than also including the maximum localization value. The experiment using the adaptively estimated localization width and vertical location performs better than the default Gaspari and Cohn (GC) experiment, and produces similar errors to the optimal GC experiment. The adaptive localization parameters can be computed during the assimilation procedure, so the computational cost needed to tune the optimal GC localization width is saved.
The Electromagnetic Emissions and Plasma Modulations at Middle Latitudes Related to SURA‐CSES Experiments in 2018
Authors: Zhang Xuemin , Frolov Vladimir , Shen Xuhui , Wang Yalu , Zhou Chen , Lu Hengxin , Huang Jianping , Ryabov Alexander , Zhai Dulin
Published: June 2020

A total of 17 SURA‐China Seismo‐Electromagnetic Satellite (CSES) experiments in 2018 have been summarized and analyzed in multiple parameters detected in the topside ionosphere at altitude of 507 km from CSES. Most of them were fulfilled with underdense heating condition, and no any artificial density duct had been detected onboard CSES, but some plasma perturbations were actually observed in lower and topside ionosphere. Among them, different modulated waves were also transmitted by [power on, power off] and amplitude modulation modes on the pumping high‐frequency (HF) wave from SURA, and some were illustrated in HF electric field from CSES in local nighttime, one being verified at fmod in single component of very low frequency (VLF) electric field in local daytime. In addition, X mode‐emitted HF waves excited a filamentary structure on the existing VLF transmitters in local daytime, being different with those in O‐mode HF waves to enhance the VLF transmitter signals and widen their frequency band in local nighttime. These phenomena and their coupling process were discussed finally on the interaction of radio waves with plasma parameters in ionosphere.
Bullet‐Shaped Magnetite Biomineralization Within a Magnetotactic Deltaproteobacterium: Implications for Magnetofossil Identification
Authors: Li Jinhua , Menguy Nicolas , Roberts Andrew P. , Gu Lin , Leroy Eric , Bourgon Julie , Yang Xin’an , Zhao Xiang , Liu Peiyu , Changela Hitesh G. , Pan Yongxin
Published: June 2020

Magnetite produced by magnetotactic bacteria (MTB) provides stable paleomagnetic signals because it occurs as natural single‐domain magnetic nanocrystals. MTB can also provide useful paleoenvironmental information because their crystal morphologies are associated with particular bacterial groups and the environments in which they live. However, identification of the fossil remains of MTB (i.e., magnetofossils) from ancient sediments or rocks is challenging because of their generally small sizes and because the growth, morphology, and chain assembly of magnetite within MTB are not well understood. Nanoscale characterization is, therefore, needed to understand magnetite biomineralization and to develop magnetofossils as biogeochemical proxies for paleoenvironmental reconstructions. Using advanced transmission electron microscopy, we investigated magnetite growth and chain arrangements within magnetotactic Deltaproteobacteria strain WYHR‐1, which reveals how the magnetite grows to form elongated, bullet‐shaped nanocrystals. Three crystal growth stages are recognized: (i) initial isotropic growth to produce nearly round ~20 nm particles, (ii) subsequent anisotropic growth along the [001] crystallographic direction to ~75 nm lengths and ~30–40 nm widths, and (iii) unidirectional growth along the [001] direction to ~180 nm lengths, with some growing to ~280 nm. Crystal growth and habit differ from that of magnetite produced by other known MTB strains, which indicates species‐specific biomineralization. These findings suggest that magnetite biomineralization might be much more diverse among MTB than previously thought. When characterized adequately at species level, magnetofossil crystallography, and apomorphic features are, therefore, likely to become useful proxies for ancient MTB taxonomic groups or species and for interpreting the environments in which they lived.
Transcriptional regulation of MdmiR285N microRNA in apple (Malus x domestica) and the heterologous plant system Arabidopsis thaliana
Authors: Pompili Valerio , Piazza Stefano , Li Mingai , Varotto Claudio , Malnoy Mickael
Published: June 2020

Malus x domestica microRNA MdmiR285N is a potential key regulator of plant immunity, as it has been predicted to target 35 RNA transcripts coding for different disease resistance proteins involved in plant defense to pathogens. In this study, the promoter region of MdmiR285N was isolated from the apple genome and analyzed in silico to detect potential regulatory regions controlling its transcription. A complex network of putative regulatory elements involved in plant growth and development, and in response to different hormones and stress conditions, was identified. Activity of the β-Glucoronidase (GUS) reporter gene driven by the promoter of MdmiR285N was examined in transgenic apple, demonstrating that MdmiR285N was expressed during the vegetative growth phase. Similarly, in transgenic Arabidopsis thaliana, spatial and temporal patterns of GUS expression revealed that MdmiR285N was differentially regulated during seed germination, vegetative phase change, and reproductive development. To elucidate the role of MdmiR285N in plant immunity, MdmiR285N expression in wild-type apple plants and GUS activity in transgenic apple and Arabidopsis thaliana plants were monitored in response to Erwinia amylovora and Pseudomonas syringae pv. Tomato DC3000. A significant decrease of MdmiR285N levels and GUS expression was observed during host-pathogen infections. Overall, these data suggest that MdmiR285N is involved in the biotic stress response, plant growth, and reproductive development.
A highly sensitive uric acid electrochemical biosensor based on a nano-cube cuprous oxide/ferrocene/uricase modified glassy carbon electrode
Authors: Yan Qinghua , Zhi Na , Yang Li , Xu Guangri , Feng Qigao , Zhang Qiqing , Sun Shujuan
Published: June 2020

A uric acid (UA) electrochemical biosensor was constructed using ferrocene (Fc) decorated cuprous oxide (Cu2O) enhanced electro-active characteristics and covalently immobilized with uricase (UOx) on glassy carbon electrode (GCE). The electrochemical characteristics of the fabricated electrode was analysed by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry (DPV). DPV studies revealed rapid response of fabricated electrode UOx/Fc/Cu2O/GCE towards UA in a wide concentration range of 0.1–1,000 μM with a sensitivity of 1.900 μA mM−1 cm−2and very low detection limit of 0.0596 μM. A very low magnitude Michaelis–Menten constant (Km) value was evaluated as 34.7351 μM which indicated the chemical attraction of the enzyme towards the UA was much higher. The developed biosensor was successfully applied to detect UA in human urine samples. Moreover, reproducibility and stability studies demonstrated the fabricated UOx/Fc/Cu2O/GCE biosensor had high reproducibility with a RSD of 2.8% and good reusability with a RSD of 3.2%. Specificity studies results showed the fabricated biosensor had strong anti-interference ability. The improved sensor performance was attributed to the synergistic electronic properties of Cu2O and Fc that provided enhances delectrocatalytic activity and electron transfer. The present biosensor can be extended for use in clinical settings.
Co-evaporation as an optimal technique towards compact methylammonium bismuth iodide layers
Authors: Momblona Cristina , Kanda Hiroyuki , Sutanto Albertus Adrian , Mensi Mounir , Roldán-Carmona Cristina , Nazeeruddin Mohammad Khaja
Published: June 2020

The most studied perovskite-based solar cells reported up to date contain the toxic lead in its composition. Photovoltaic research and development towards non-toxic, lead-free perovskite solar cells are critical to finding alternatives to reduce human health concerns associated with them. Bismuth-based perovskite variants, especially in the form of methylammonium bismuth iodide (MBI), is a good candidate for the non-toxic light absorber. However, the reported perovskite variant MBI thin films prepared by the solution process so far suffers from poor morphology and surface coverage. In this work, we investigate for the first time the optoelectronic, crystallographic and morphological properties of MBI thin films prepared via thermal co-evaporation of MAI and BiI3. We find by modifying the precursor ratio that the layer with pure MBI composition lead to uniform, compact and homogeneous layers, broadening the options of deposition techniques for lead-free based perovskite solar cells.
Scattering symmetry-breaking induced spin photocurrent from out-of-plane spin texture in a 3D topological insulator
Authors: Huang Y. Q. , Buyanova I. A. , Chen W. M.
Published: June 2020

We theoretically study helicity-dependent photocurrent in a three-dimensional topological insulator Bi2Te3 under elastic scattering of different symmetries. By exploring spin-selective optical transitions and symmetry-breaking scattering, we are able to address the out-of-plane spin texture of the topological helical surface states and to generate directional, spin-polarization tunable photocurrent that is otherwise forbidden for the original C3v symmetry of the surface. This can be achieved regardless of the Fermi level, even under the condition when the topological states are inaccessible in dark. This work paves the way to robustly explore the out-of-plane spin texture for harvesting opto-spintronic functionalities of topological insulators.
Ascorbate maintains a low plasma oxygen level
Authors: Injarabian Louise , Scherlinger Marc , Devin Anne , Ransac Stéphane , Lykkesfeldt Jens , Marteyn Benoit S.
Published: June 2020

In human blood, oxygen is mainly transported by red blood cells. Accordingly, the dissolved oxygen level in plasma is expected to be limited, although it has not been quantified yet. Here, by developing dedicated methods and tools, we determined that human plasma pO2 = 8.4 mmHg (1.1% O2). Oxygen solubility in plasma was believed to be similar to water. Here we reveal that plasma has an additional ascorbate-dependent oxygen-reduction activity. Plasma experimental oxygenation oxidizes ascorbate (49.5 μM in fresh plasma vs < 2 μM in oxidized plasma) and abolishes this capacity, which is restored by ascorbate supplementation. We confirmed these results in vivo, showing that the plasma pO2 is significantly higher in ascorbate-deficient guinea pigs (Ascorbateplasma < 2 μM), compared to control (Ascorbateplasma > 15 μM). Plasma low oxygen level preserves the integrity of oxidation-sensitive components such as ubiquinol. Circulating leucocytes are well adapted to these conditions, since the abundance of their mitochondrial network is limited. These results shed a new light on the importance of oxygen exposure on leucocyte biological study, in regards with the reducing conditions they encounter in vivo; but also, on the manipulation of blood products to improve their integrity and potentially improve transfusions’ efficacy.
Synthesis of hyaluronic acid oligosaccharides with a GlcNAc–GlcA repeating pattern and their binding affinity with CD44
Authors: Yeh Che-Jui , Zulueta Medel Manuel L. , Li Yaw-Kuen , Hung Shang-Cheng
Published: June 2020

A practical route for the synthesis of hyaluronic acid oligosaccharides was developed, and a tetrasaccharide (GlcNAc–GlcA)2 was identified as the minimum length that binds to human CD44 (KD = 3.5 μM) using isothermal titration calorimetry.
Live-cell imaging of lipid droplets using solvatochromic coumarin derivatives
Authors: Jana Palash , Siva Aravintha , Soppina Virupakshi , Kanvah Sriram
Published: June 2020

Lipid droplets (LDs), the lipid-rich intracellular organelles were selectively detected using simple coumarin containing fluorophores.
Effect of grain size distribution and size-dependent grain heating on molecular abundances in starless and pre-stellar cores
Authors: Sipilä O. , Zhao B. , Caselli P.
Published: June 2020

We present a new gas-grain chemical model to constrain the effect of grain size distribution on molecular abundances in physical conditions corresponding to starless and pre-stellar cores. We simultaneously introduce grain-size dependence for desorption efficiency induced by cosmic rays (CRs) and for grain equilibrium temperatures. The latter were calculated with a radiative transfer code via custom dust models built for the present work. We explicitly tracked of ice abundances on a set of grain populations. We find that the size-dependent CR desorption efficiency affects ice abundances in a highly nontrivial way that depends on the molecule. Species that originate in the gas phase, such as CO, follow a simple pattern in which the ice abundance is highest on the smallest grains and these are the most abundant in the distribution. Some molecules, such as HCN, are instead concentrated on large grains throughout the time evolution; others, such as N2, are initially concentrated on large grains, but at late times on small grains because of grain-size-dependent competition between desorption and hydrogenation. Most of the water ice is on small grains at high medium density (n(H2) ≳ 106 cm−3), where the water ice fraction, with respect to the total water ice reservoir, can be as low as ~10−3 on large (>0.1 μm) grains. Allowing the grain equilibrium temperature to vary with grain size induces strong variations in relative ice abundances in low-density conditions in which the interstellar radiation field and in particular its ultraviolet component are not attenuated. Our study implies consequences not only for the initial formation of ices preceding the starless core stage, but also for the relative ice abundances on the grain populations going into the protostellar stage. In particular, if the smallest grains can lose their mantles owing to grain-grain collisions as the core is collapsing, the ice composition in the beginning of the protostellar stage could be very different than in the pre-collapse phase because the ice composition depends strongly on the grain size.
The sustained post-outburst brightness of Nova Per 2018, the evolved companion, and the long orbital period
Authors: Munari U. , Moretti S. , Maitan A.
Published: June 2020

Nova Per 2018 (= V392 Per) halted the decline from maximum when it was 2 mag brighter than quiescence and since 2019 has been stable at such a plateau. The ejecta have already fully diluted into the interstellar space. We obtained BVRIgrizY photometry and optical spectroscopy of V392 Per during the plateau phase and compared it with equivalent data gathered prior to the nova outburst. We find the companion star (CS) to be a G9 IV/III and the orbital period to be 3.4118 days, making V392 Per the longest known period for a classical nova. The location of V392 Per on the theoretical isochrones is intermediate between that of classical novae and novae erupting within symbiotic binaries, in a sense bridging the gap. The reddening is derived to be EB − V = 0.72 and the fitting to isochrones returns a 3.6 Gyr age for the system and 1.35 M⊙, 5.3 R⊙, and 15 L⊙ for the companion. The huge Ne overabundance in the ejecta and the very fast decline from nova maximum both point to a massive white dwarf (WD) (MWD ≥ 1.1−1.2 M⊙). The system is viewed close to pole-on conditions and the current plateau phase is caused by irradiation of the CS by the WD still burning at the surface.
Towards the evaluation of a thermal compartmentation renovation concept through in-situ measurements
Authors: Rovers Twan , Struck Christian , van ‘t Ende Jeroen
Published: June 2020

Facing the energy transition, Dutch social housing corporations are expected to fulfil a pioneering role in realising fossil fuel free and CO2 neutral dwellings and neighbourhoods. However, given the high current costs of retrofitting dwellings to net zero energy, housing corporations are searching diligently for alternative, more affordable, renovation strategies. A Thermal Compartmentation renovation concept has been developed, in which retrofitting efforts are concentrated on the living spaces in dwellings. By means of co-heating tests, the quality of the thermal shell of three retrofitted case objects has been evaluated. It is found that both the airtightness and the heat loss coefficient (HLC) improved significantly as a result of the renovation. As would be expected, the realised ‘warm compartments’ show a better thermal performance than the entire dwellings. Although the measurements and subsequent analyses have confirmed the impact of the renovation measures on the buildings’ thermal performance, additional research targeting the inhabited dwellings is necessary to draw up final conclusions on the potential of the Thermal Compartmentation renovation concept.
Hygro-thermal performance of wooden beam ends: experimental investigations of uninsulated and internally insulated brick wall
Authors: Kopecký Pavel , Staněk Kamil , Tywoniak Jan
Published: June 2020

Wooden floors were traditionally used in brick apartment houses built at the turn of 20th century in many European cities. Thermal renovation of such houses often involves thermal insulation at interior side of external walls. Internal insulation makes microclimate in the vicinity of wooden beam ends colder and more humid. The real-scale experiment involving a part of wooden floor connected to a 30 cm thick masonry wall was monitored for two consecutive years. Measured data were used to compare microclimate in sealed and open joist pockets. Joist pockets were either placed in the masonry wall with plaster on both sides or placed in the same masonry wall insulated on the interior side (vapour open thermal insulation system). The measured results indicate that the sealing tape alone is not sufficient to keep the relative humidity in joist pockets below 85 % in cold climate and under high internal moisture load. The paper concludes that reasonable trade-off between thermal efficiency, thermal comfort and moisture safety is difficult to reach for masonry with internal insulation and wooden floors. Sealing provisions complemented by tempering of joist pockets are considered as two key technical measures for reliable hygro-thermal performance of wooden beam ends in full-brick masonry with interior thermal insulation in cold temperate climate.
Overheating risk of a typical Norwegian residential building retrofitted to higher energy standards under future climate conditions
Authors: Tian Zhiyong , Hrynyszyn Bozena Dorota
Published: June 2020

Heat waves had attacked Norway in 2018 and 2019. Residents in Norway experienced a very uncomfortable indoor environment in the summer of 2018 and 2019. Few publications on the overheating risk of a typical Norwegian residential building under future climate change conditions were found. The typical Norwegian residential building retrofitted according to the minimum Norwegian energy requirements in the Norwegian Building Act of 2010 (Pbl2010/TEK17) and the international EnerPHit Standard was modelled in this study. Overheating risk of the typical residential building was simulated by Energy Plus engine via Ladybug and Honeybee plugins based on the Grasshopper. Overheating hours of the studied rooms under present-day, the 2050s and the 2080s weather conditions were shown. Too good airtightness does increase the overheating risk of the building when retrofitted to higher energy standards. It was found in this study that better insulation does reduce the overheating hours of the bedrooms slightly. This may be caused by low g-value of the windows based on recommendation according to the EnerPHit Standard. Overheating should be paid more attention in term of the expected future climate conditions. These results can provide some references to the buildings retrofitted to high-performance buildings.
The influence of unmeasured occupancy disturbances on the performance of black-box thermal building models
Authors: Rævdal Lund Christensen Louise , Hauge Broholt Thea , Dahl Knudsen Michael , Elbæk Hedegaard Rasmus , Petersen Steffen
Published: June 2020

Previous studies have identified a significant potential in using economic model predictive control for space heating. This type of control requires a thermodynamic model of the controlled building that maps certain controllable inputs (heat power) and measured disturbances (ambient temperature and solar irradiation) to the controlled output variable (room temperature). Occupancy related disturbances, such as people heat gains and venting through windows, are often completely ignored or assumed to be fully known (measured) in these studies. However, this assumption is usually not fulfilled in practice and the current simulation study investigated the consequences thereof. The results indicate that the predictive performance (root mean square errors) of a black-box state-space model is not significantly affected by ignoring people heat gains. On the other hand, the predictive performance was significantly improved by including window opening status as a model input. The performance of black-box models for MPC of space heating could therefore benefit from having inputs from sensors that tracks window opening.
Use of a radiator for user-centric cooling – Measurement and Simulation
Authors: Winkler Matthias , Pazold Matthias , Zegowitz Andreas , Giglmeier Sabine , Antretter Florian
Published: June 2020

With further increasing temperatures during warm summers, cooling of buildings is becoming more popular even in moderate middle or northern European climate zones. Techniques that allow fast conditioning of rooms with intermittent usage, like conference rooms or certain types of residential rooms, promise high potentials for energy savings. Combining heat pumps, that can be used both in cooling and heating modes, with floor and wall heating systems can be a suitable technology. In many cases houses have a conventional heating system with radiators and the question arise if the oil or gas based heating system can be replaced by a heat pump. Mixed systems combining e.g.gas and a heatpump are also possible. For summertime cooling, the same system that is already installed for heating can be used and the radiators allow comparatively fast reaction times in theory. However, the system comes with potential shortcomings: Cooled surfaces increase the risk of condensation and mold growth significantly while higher surface temperatures decrease cooling power of the system. Also, the system’s reaction times have to be tested in realistic conditions. For a first prove of the system’s applicability a study with combined measurements and hygrothermal building simulations was performed. In a test chamber measurements of a system were conducted under controlled conditions. A simulation model in the hygrothermal whole building software WUFI® Plus was developed and validated with the measurements. The research shows that the simulation model is able to represent the effects on indoor climate as well as condensation reliably.
Thermal mass and the effects on heating and cooling demands – an experimental study of an exposed concrete floor
Authors: Nocente Alessandro , Grynning Steinar
Published: June 2020

The increase of thermal mass in buildings is discussed as a useful measure for reducing the energy demand for heating and cooling while contributing to improve the internal comfort. Several studies confirmed its positive effect, but few conducted a solid comparative measurement campaign and rarely in comparative conditions. The present work reports the results of an extensive comparative campaign in a test cell facility, where the internal conditions are measured in two identical rooms. One of the rooms was equipped with a large concrete mass while the other was constructed with a thin wooden floor. Measurements were conducted for circa a month, divided in four phases. The internal temperature of the two rooms was kept within typical boundaries of actual office rooms by a water-based cooling and heating systems. The energy demand of both heating and cooling was measured. Occupancy was simulated by a mannequin and by the lighting, both active only in office hours. The results demonstrated a positive impact of the thermal mass on the energy use. Since the test rooms are highly insulated, the energy use associated to cooling was dominant. During the experimental campaign, a reduction of up to 44% of the energy demand due to cooling was registered.
Investigating overheating by measurement and simulation in classrooms
Authors: Pazold Matthias , Winkler Matthias , Antretter Florian
Published: June 2020

New two-story wood-construction classrooms where added to an existing heavy-weight construction school building in the year 2006. The glass façade of some classrooms is south oriented. The building design meets the local thermal protection requirement of 2006, but the indoor temperature rises above thermal comfort conditions in the classrooms. As usual in Germany, no active cooling device is and shall be used. Measurements during holidays with close to none internal loads in addition to measurements during regular school occupancy documented the overheating. The measurement results were used to verify a baseline hygrothermal building simulation model that represents the status quo. Various passive measures with regards to construction, design and operation to improve the thermal comfort were assessed. Among them are ventilation strategies and solar protection foil on the glass façade. Furthermore, the already installed temporary sunscreen devices and mechanical night ventilation system coupled to mechanically openable skylights above the classroom doors and within the gravel covered flat roof were investigated with different operating strategies. This paper presents the required steps to improve the simulation model with the measured data in an iterative process. Measures to improve building performance, achieve thermal comfort, and protect overheating are identified.
A new tool for the drying time and the moisture risk estimation in concrete floors
Authors: Sekki Pauli , Marttila Pasi , Merikallio Tarja
Published: June 2020

Moisture management in building site has improved significantly in recent years. However, problems with concrete floors are repeatedly found. One possible reason for the failure may be that the time required for adequate drying of the concrete has not been properly considered when scheduling the building process and because the pressure to complete the building, the floor covering has been installed too early. In building industry, there is a clear need for better understanding of the adequate drying times of concrete structures, as well as tools to make sufficient drying estimates. The new tool BY2020 provides a new approach to drying and moisture risk estimations. The simulation tool is a FEM-based model that allows change in geometry with time so that the material layers are automatically added into the model, based on the determined schedule. The boundary conditions are also changing with time based on the schedule. In addition, the water vapor resistance of the flooring material can be modelled to evaluate the long-term moisture behavior of the floor structure. Preliminary results are encouraging and the feedback on the new approach has been positive. Validation process is ongoing and target completion time for the tool is late 2020.
Thermal comfort: standard compliant modelling of natural ventilation in adaptive time step solvers
Authors: Andreas Nicolai , Heiko Fechner
Published: June 2020

Natural ventilation can help maintain thermal comfort during summer periods. In simulation models for thermal comfort analysis, occupant behaviour related to natural ventilation is often included through definition of ventilation rule sets. For example, windows are opened when room temperature exceeds a given limit while outside temperatures remain below a threshold. Such rules are included in building codes, such as DIN 4108-2 [1]. However, these rules are defined with respect to fixed step time integration methods, often using hourly step sizes. Straight-forward implementation of such rules in error controlled adaptive time step integration solvers (including drivers for Modelica models) fails. The article discusses strategies and model variants that work with such modern solvers and discusses new model parameters such as the delay time or dead-band size. The impact of these parameter choices is illustrated with sensitivity studies using the thermal room model THERAKLES [3-5].
Early-stage concentrations of formaldehydes and TVOCs in a new low-energy building
Authors: Sasic Kalagasidis Angela , Domhagen Fredrik , Langer Sarka
Published: June 2020

This paper deals with temporary discomfort caused by characteristic odours from new objects and materials in office buildings. Earlier investigations have shown that increased ventilation rates in residential buildings decrease the indoor concentrations of non-occupant-related indoor air pollutants such as aldehydes and total volatile organic compounds (TVOCs). To study how this basic principle for the control of indoor air pollutants complies with a demand-controlled ventilation, which is an important energy efficiency measure in modern office buildings, the authors have designed and conducted a serial of field tests. Concentrations of aldehydes and TVOCs have been measured in two newly built and identical meeting rooms under different ventilation strategies. By overruling the existing demand control ventilation and increasing gradually but differently the air change rates in the rooms over a course of five weeks, the concentration of formaldehyde and TVOCs decreased for about 75 % from the initial values of ca. 45 μg/m3 and ca. 400 μg/m3 respectively. Impact of door openings on instantaneous indoor air quality has been studied in parallel by combining CO2 measurements and numerical simulations. Good agreement was found between the simulated and measured CO2 concentrations and thereby the door opening model was verified.
Hygrothermal performance of timber frame walls with brick veneer cladding: a parameter analysis
Authors: Vanpachtenbeke Michiel , Van den Bulcke Jan , Van Acker Joris , Roels Staf
Published: June 2020

To meet the increasingly stringent energy efficiency requirements, the market share of timber frame houses is steadily growing across Europe. Timber frame walls in Belgium are typically combined with a brick veneer cladding, which has a high buffer capacity for wind driven rain and a relative low cavity ventilation rate. Consequently, moisture levels inside the cavity may become high, which might lead to an inward vapour flow and an elevated moisture content in the inner part of the wall. In combination with a moisture sensitive timber frame inner wall, this could result in an increased risk of fungal growth. Therefore, the aim of the current paper is to study the hygrothermal performance of timber frame walls with brick veneer cladding in a moderate sea climate. To do so, a field study on two typical timber frame walls with brick veneer cladding is conducted. The field study specifically focuses on the contradictory criterion for the vapour diffusion resistance of the wind barrier for summer and winter conditions. The data of the in-situ measuring campaign indicates that the differences between set-ups with wind barriers with different vapour diffusion resistance is rather limited. In addition, a parameter analysis is conducted using a numerical model. The parameter analysis indicates an increased mould growth risk due to the brick veneer cladding and the importance of providing hygroscopic moisture buffer capacity inside the wall.