bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel tetranuclear PdII and PtII anticancer complexes derived from pyrene thiosemicarbazones
Authors: Oliveira Carolina G. , Romero-Canelón Isolda , Coverdale James P. C. , Maia Pedro Ivo S. , Clarkson Guy J. , Deflon Victor M. , Sadler Peter J.
Published: June 2020

Cyclometallated palladium(ii) and platinum(ii) pyrenyl-derived thiosemicarbazone (H2PrR) complexes of the type [M4(μ-S-PrR-κ3-C,N,S)4] (M = PdII, PtII; R = ethyl, cyclohexyl) have been synthesised in good yields and fully characterised.
The role of the capping agent and nanocrystal size in photoinduced hydrogen evolution using CdTe/CdS quantum dot sensitizers
Authors: Benazzi Elisabetta , Coni Valerio C. , Boni Mattia , Mazzaro Raffaello , Morandi Vittorio , Natali Mirco
Published: June 2020

Light-driven hydrogen evolution using CdTe/CdS quantum dots as sensitizers depends on the nature of the capping agent and nanocrystal size.
Crystal structures and the ferroelectric properties of homochiral metal–organic frameworks constructed from a single chiral ligand
Authors: Xu Xuebin , Liu Meiying , Liu Zhiliang
Published: June 2020

Crystal structures and ferroelectric properties of homochiral metal–organic frameworks constructed from a single chiral ligand.
The big effect of a small change: formation of CuO nanoparticles instead of covalently bound Cu(ii) over functionalized mesoporous silica and its impact on catalytic efficiency
Authors: Das Trisha , Singha Debdas , Nandi Mahasweta
Published: June 2020

Covalently bound copper(ii) and CuO nanoparticles on mesoporous silica have been prepared by changing the addition sequence of reagents; the latter shows better catalytic activity.
Electronic effect of a perfluorinated β-diketiminate ligand on the bonding nature of copper carbonyl complexes
Authors: Huse Kevin , Weinert Hanns , Wölper Christoph , Schulz Stephan
Published: June 2020

A combined experimental and computational study demonstrates the influence of fluorine substituents on the electronic properties of β-diketiminate ligands.
New Li–Mg phosphates with a 3D framework: experimental and ab initio calculations
Authors: Kellerman D. G. , Tyutyunnik A. P. , Medvedeva N. I. , Chufarov A. Yu. , Fortes A. D. , Gibbs A. S. , Tarakina N. V. , Kalinkin M. O. , Zhuravlev N. A. , Leonidova O. N.
Published: June 2020

We discovered a new phase, LiMg6P5O19, in which magnesium can be partially replaced with lithium and scandium in equal amounts.
Ganoderic acid A from Ganoderma lucidum ameliorates lipid metabolism and alters gut microbiota composition in hyperlipidemic mice fed a high-fat diet
Authors: Guo Wei-Ling , Guo Jian-Bin , Liu Bin-Yu , Lu Jin-Qiang , Chen Min , Liu Bin , Bai Wei-Dong , Rao Ping-Fan , Ni Li , Lv Xu-Cong
Published: June 2020

Ganoderic acid A from Ganoderma lucidum has the potential to prevent hyperlipidemia, modulates the composition of gut microbiota in hyperlipidemic mice, and significantly attenuates the liver metabolite profile in hyperlipidemic mice.
Pseudopeptidic macrocycles as cooperative minimalistic synzyme systems for the remarkable activation and conversion of CO2 in the presence of the chloride anion
Authors: Esteve Ferran , Altava Belén , Burguete M. Isabel , Bolte Michael , García-Verdugo Eduardo , Luis Santiago V.
Published: June 2020

A series of pseudopeptidic compounds have been assayed as organocatalyts for the conversion of CO2 into organic carbonates through a cooperative multifunctional mechanism.
Sustainable at both ends: electrochemical CO2 utilization paired with electrochemical treatment of nitrogenous waste
Authors: Medvedeva Xenia V. , Medvedev Jury J. , Tatarchuk Stephen W. , Choueiri Rachelle M. , Klinkova Anna
Published: June 2020

Optimizing CO2 electrolyzer cell voltage requirement: aqueous and organic reductive electrocatalysis paired with electrooxidation of urea and ammonia.
A fluorous biphase drug delivery system triggered by low frequency ultrasound: controlled release from perfluorous discoidal porous silicon particles
Authors: Liu Jing , Li Shuo , Liu Lina , Zhu Zhiling
Published: June 2020

A fluorous biphase drug delivery system (FB-DDS) trigged by low frequency ultrasound (LFUS) was developed for efficient delivery of fluorine containing pharmaceuticals.
Standardizing luminescence nanothermometry for biomedical applications
Authors: Bednarkiewicz Artur , Marciniak Lukasz , Carlos Luís D. , Jaque Daniel
Published: June 2020

Luminescence nanothermometry requires standardization for reliable and quantitative evaluation.
Fluorinated and [18F]fluorinated morphinan based opioid ligands
Authors: Sandulenko Irina V. , Ambartsumyan Asmik A. , Moiseev Sergey K.
Published: June 2020

Fluorinated 4,5α-epoxymorphinans, opioid ligands for drug development and PET imaging of opioid receptors using [18F]tracers, are reviewed.
Novel synthetic strategy towards subphthalocyanine-functionalized acetylenic scaffolds via various dibromo-enynes
Authors: Broløs Line , Kilde Martin Drøhse , Nielsen Mogens Brøndsted
Published: June 2020

Axial alkynylation of boron subphthalocyanine with dibromo-substituted enynes and enediynes is presented and the convenient use of these compounds for subsequent metal-catalyzed coupling reactions.
Pyrazoles: ‘one-pot’ synthesis from arenes and carboxylic acids
Authors: Kim Jung Keun , Gong Ming , Shokova Elvira A. , Tafeenko Viktor A. , Kovaleva Olga V. , Wu Yangjie , Kovalev Vladimir V.
Published: June 2020

A rapid and efficient method for ‘one-pot’ synthesis of pyrazoles from (hetero)arenes and carboxylic acids via successive formation of ketones and β-diketones followed by heterocyclization with hydrazine has been developed.
Facile preparation of polycarbonates from bio-based eugenol and 2-methoxy-4-vinylphenol
Authors: Huang Mengqian , Bai De , Chen Qin , Zhao Changbo , Ren Tianhua , Huang Caijuan , North Michael , Xie Haibo
Published: June 2020

Polymerization of α,ω-diene functionalized carbonate monomers prepared from bio-based eugenol and 2-methoxy-4-vinylphenol through thiol–ene click and ADMET polymerizations produced polycarbonates with moderate molecular weight satisfactory thermal properties.
In situ synthesis of Cl-doped Bi2O2CO3 and its enhancement of photocatalytic activity by inducing generation of oxygen vacancies
Authors: Li Jie-hao , Ren Jie , Liu Ying , Mu Hui-ying , Liu Rui-hong , Zhao Jun , Chen Lan-ju , Li Fa-tang
Published: June 2020

Cl-Doped Bi2O2CO3 is prepared using ionic liquids as dopants and the oxygen-vacancy-induced photocatalytic mechanism is revealed.
Pleurocorols A and B: rearranged steroids from the fruiting bodies of Pleurotus cornucopiae
Authors: Kikuchi Takashi , Mori Maki , In Yasuko , Zhang Jie , Yamada Takeshi , Hirano Tomoya
Published: June 2020

Pleurocorols A and B, unprecedented steroids with an 11(9 → 8)abeo-ergostane and a 5(6 → 7), 11(9 → 7)diabeo-ergostane skeleton, respectively, were isolated from Pleurotus cornucopiae.
Engineering a protease-based and site-specific PEGylation-based strategy for the controlled release of exenatide
Authors: Zhang Aihong , Lin Yin , Nong Shirly , Zhao Wei , Dong Mei
Published: June 2020

Using the commercially available antidiabetic drug exenatide (exendin-4) as a model peptide, we designed a novel exenatide derivative, termed LEX-1, comprising a 12-mer albumin-binding peptide, a protease-sensitive linker and a native exenatide.
Symmetry of three-center, four-electron bonds
Authors: Reiersølmoen Ann Christin , Battaglia Stefano , Øien-Ødegaard Sigurd , Gupta Arvind Kumar , Fiksdahl Anne , Lindh Roland , Erdélyi Máté
Published: June 2020

The factors determining the symmetry and the fundamental nature of the three-center, four-electron bonds are assessed.
Designing a highly stable coordination-driven metallacycle for imaging-guided photodynamic cancer theranostics
Authors: He Lizhen , Cai Li-Xuan , Li Meng-Hua , Zhang Guang-Lu , Zhou Li-Peng , Chen Tianfeng , Lin Mei-Jin , Sun Qing-Fu
Published: June 2020

A highly-luminescent metallacycle with chemical stability and singlet oxygen production ability were obtained by a spontaneous deprotonation self-assembly process, which exhibits application potential in imaging-guided photodynamic cancer therapy.
Recent advances in low oxidation state aluminium chemistry
Authors: Hobson Katie , Carmalt Claire J. , Bakewell Clare
Published: June 2020

Documenting the synthesis and isolation of novel low oxidation state aluminium (Al) compounds, which until recently has seen relatively slow progress over the 30 years since such species were first isolated.
Organic linkage controls the photophysical properties of covalent photosensitizer–polyoxometalate hydrogen evolution dyads
Authors: Luo Yusen , Maloul Salam , Endres Patrick , Schönweiz Stefanie , Ritchie Chris , Wächtler Maria , Winter Andreas , Schubert Ulrich S. , Streb Carsten , Dietzek Benjamin
Published: June 2020

Understanding the complex photophysics of covalent photosensitizer–catalyst (PS–CAT) dyads is the basis for advanced structure and reactivity design.
Carbonated water droplets on a dusty hydrophobic surface
Authors: Abubakar Abba Abdulhamid , Yilbas Bekir Sami , Al-Qahtani Hussain , Hassan Ghassan , Yakubu Mubarak , Hatab Saeed B.
Published: June 2020

Dust mitigation from surfaces remains essential, particularly for the efficient operation of energy harnessing devices.
Ternary molybdenum sulfoselenide based hybrid nanotubes boost potassium-ion diffusion kinetics for high energy/power hybrid capacitors
Authors: Gao Jingyu , Wang Gongrui , Liu Yi , Li Jie , Peng Bo , Jiao Shuhong , Zeng Suyuan , Zhang Genqiang
Published: June 2020

MoS2−xSex/carbon hybrid nanotubes with expanded interplanar spacing could deliver a reversible capacity of 237.0 mA h g−1 after 300 cycles at 0.5 A g−1 for PIBs, and an energy density of 44.1 W h kh−1 at a power density of 15 414 W kg−1 in a K+ hybrid capacitor.
Confined cavity on a mass-producible wrinkle film promotes selective CO2 reduction
Authors: Cho Kyeong Min , Jung Woo-Bin , Kim Donggyu , Kim Ju Ye , Kim Yesol , Yun Geun-Tae , Ryu Seunghwa , Al-Saggaf Ahmed , Gereige Issam , Jung Hee-Tae
Published: June 2020

Selective reduction of CO2 to carbon monoxide is achieved by Au wrinkle film which can be made in simple and mass-producible process.
Electrochemical transformation reaction of Cu–MnO in aqueous rechargeable zinc-ion batteries for high performance and long cycle life
Authors: Fenta Fekadu Wubatu , Olbasa Bizualem Wakuma , Tsai Meng-Che , Weret Misganaw Adigo , Zegeye Tilahun Awoke , Huang Chen-Jui , Huang Wei-Hsiang , Zeleke Tamene Simachew , Sahalie Niguse Aweke , Pao Chih-Wen , Wu She-huang , Su Wei-Nien , Dai Hongjie , Hwang Bing Joe
Published: June 2020

Rechargeable aqueous zinc-ion batteries (ZIBs) are emerging as an alternative to lithium-ion batteries in large-scale energy storage applications due to their safety and environmental friendliness.
Coexistence of humic acid enhances the reductive removal of diatrizoate via depassivating zero-valent iron under aerobic conditions
Authors: He Chuan-Shu , Ding Rong-Rong , Zhou Guan-Nan , He Di , Fan Peng , Guan Xiao-Hong , Mu Yang
Published: June 2020

The coexistence of humic acid (HA) could accelerate the ZVI-mediated reductive removal of organic contaminants via ZVI surface depassivation under aerobic conditions.
Alkali metal insertion into hard carbon – the full picture
Authors: Euchner Holger , Vinayan Bhaghavathi P. , Reddy M. Anji , Fichtner Maximilian , Groß Axel
Published: June 2020

In operando Raman scattering during Li insertion into hard carbon, including the D-band (left) and the explanation for its disappearance (right).
Zeolites for theranostic applications
Authors: Khodadadi Yazdi Mohsen , Zarrintaj Payam , Hosseiniamoli Hadi , Mashhadzadeh Amin Hamed , Saeb Mohammad Reza , Ramsey Joshua D. , Ganjali Mohammad Reza , Mozafari Masoud
Published: June 2020

Theranostic platforms bring about a revolution in disease management. During recent years, theranostic nanoparticles have been utilized for imaging and therapy simultaneously. Among different classes of biomaterials, zeolites have proven to be highly efficient for theranostic applications.
pH-Responsive nanocomposite fibres allowing MRI monitoring of drug release
Authors: Zhang Ziwei , Wells Connor J. R. , King Aaron M. , Bear Joseph C. , Davies Gemma-Louise , Williams Gareth R.
Published: June 2020

pH-responsive nanofibres containing iron oxide nanoparticles (NPs) and a model drug demonstrate on-demand dissolution, triggering release of both drug and NPs and allowing magnetic resonance imaging-guided therapeutic delivery.
Mechanical, adhesive and self-healing ionic liquid hydrogels for electrolytes and flexible strain sensors
Authors: Gao Zijian , Kong Lingshu , Jin Rining , Liu Xin , Hu Wei , Gao Guanghui
Published: June 2020

The prepared ionic liquid hydrogel was employed as flexible sensor and electrolyte with great mechanical, self-healing, adhesive and conductive properties.
High harmonic generation in graphene–boron nitride heterostructures
Authors: Chen Zi-Yu , Qin Rui
Published: June 2020

High harmonic generation and enhancement by tuning the interlayer separation in two-dimensional van der Waals heterostructures are investigated.
A self-assembled fiber Mach–Zehnder interferometer based on liquid crystals
Authors: Li Yong , Chen Yuzhi , Yi Duo , Du Yu , Luo Wei , Hong Xueming , Li Xuejin , Geng Youfu , Luo Dan
Published: June 2020

In this work, we fabricated a self-assembled fiber Mach–Zehnder interferometer (MZI) based on liquid crystals (LCs), which offers a new method for LC/fiber sensing.
Unusual phase-pure zinc blende and highly-crystalline As-rich InAs1−xSbx nanowires for high-mobility transistors
Authors: Yip SenPo , Li Dapan , Li Fangzhou , Wang Wei , Kang Xiaolin , Meng You , Zhang Heng , Lai Zhengxun , Wang Fei , Ho Johnny C.
Published: June 2020

Unusual phase-pure zinc blende and highly-crystalline As-rich InAs1−xSbx nanowires with x < 0.2 are successfully achieved for the fabrication of high-mobility transistors.
Mass spectrometry-based methods for structural biology on a proteome-wide scale
Authors: Jones Lisa M.
Published: June 2020

Mass spectrometry (MS) has long been used to study proteins mainly via sequence identification and quantitation of expression abundance. In recent years, MS has emerged as a tool for structural biology. Intact protein structural analysis has been enabled by the development of methods such as native MS, top-down proteomics, and ion mobility MS. Other MS-based structural methods include affinity purification MS, chemical cross-linking, and protein footprinting. These methods have enabled the study of protein–protein and protein–ligand interactions and regions of conformational change. The coupling of MS with liquid chromatography has permitted the analysis of complex samples. This bottom-up proteomics workflow enables the study of protein structure in the native cellular environment and provides structural information across the proteome. It has been demonstrated that the crowded environment of the cell affects protein binding interactions and affinities. Performing studies in this complex environment is essential for understanding the functional roles of proteins. MS-based structural methods permit analysis of samples such as cell lysates, intact cells, and tissue to provide a more physiological view of protein structure. This mini-review discusses the various MS-based methods that can be used for proteome-wide structural studies and highlights some of their application.
Pathogenic role of human C-reactive protein in diabetic retinopathy
Authors: Qiu Fangfang , Ma Xiang , Shin Young-Hwa , Chen Jianglei , Chen Qian , Zhou Kelu , Wu Wenjing , Liang Wentao , Wu Yalin , Song Qing , Ma Jian-Xing
Published: June 2020

Purpose: Elevated blood levels of C-reactive protein (CRP) are associated with both type 1 and type 2 diabetes and diabetic complications, such as diabetic retinopathy (DR). However, its pathogenic role in DR remains unknown. The present study aims to investigate the potential role of CRP in DR pathogenesis and explore its underlying mechanism.

Materials and methods: Human CRP transgenic (hCRP-Tg) rats were employed for streptozotocin (STZ)-induced diabetic and oxygen-induced retinopathy (OIR) models. The retina function was monitored by electroretinography (ERG) and retinal thickness was measured by optical coherence tomography (OCT). TUNEL and cell death ELISA were performed to measure the apoptosis. Oxidative stress was detected by the measurement of reactive oxygen species (ROS) in cells and 3-Nitrotyrosine staining in tissue sections.

Results: In non-diabetic condition, hCRP-Tg with elevated hCRP levels in the retinas demonstrated declined ERG responses and decreased retinal thickness. In STZ-induced diabetic condition, overexpression of hCRP deteriorated retinal neurodegeneration as shown by ERG and apoptosis assays. hCRP also exacerbated retinal leukostasis and acellular capillary formation induced by diabetes. In the OIR model, overexpression of hCRP exacerbated retinal neovascularization (NV). In retinal cell lines, hCRP treatment induced cell death and over-production of ROS. Furthermore, hCRP-induced overexpression of pro-inflammatory, pro-oxidative, and pro-angiogenic factors was associated with up-regulation of CD32 and the NF-κB signaling in the retinas.

Conclusions: Elevated hCRP levels play a pathogenic role in DR. Targeting the hCRP-CD32-NF-κB pathway may represent a novel therapeutic strategy for DR.
IOTA: a 1.7‐TOP/J inference processor for binary convolutional neural networks with 4.7 K LUTs in a tiny FPGA
Authors: Kim T. , Shin J. , Choi K.
Published: June 2020

This Letter presents an efficient inference processor for binary convolutional neural networks in an FPGA that has tight limitation of the available hardware resources. The proposed processor, named inference processor in a tiny FPGA (IOTA), incorporates the dual block‐processing cores, which process each constituent block of a network cooperatively skipping redundant operations. Implemented in Intel®MAX®10, IOTA achieves the energy efficiency of 1.7 TOP/J with the resource usage of just 4.7 K lookup table (LUT) and 384Kbit BRAMs, where a single binary operation has been counted by 1 OP. A fully‐integrated inference system has been developed to demonstrate the functionality of IOTA. It can infer the classes of 172.85 images per joule for the CIFAR‐10 classification task.
The abundance of S- and Si-bearing molecules in O-rich circumstellar envelopes of AGB stars
Authors: Massalkhi S. , Agúndez M. , Cernicharo J. , Velilla-Prieto L.
Published: June 2020

Aims.We aim to determine the abundances of SiO, CS, SiS, SO, and SO2in a large sample of oxygen-rich asymptotic giant branch (AGB) envelopes covering a wide range of mass loss rates to investigate the potential role that these molecules could play in the formation of dust in these environments.

Methods.We surveyed a sample of 30 oxygen-rich AGB stars in theλ2 mm band using the IRAM 30m telescope. We performed excitation and radiative transfer calculations based on the large velocity gradient method to model the observed lines of the molecules and to derive their fractional abundances in the observed envelopes.

Results.We detected SiO in all 30 targeted envelopes, as well as CS, SiS, SO, and SO2in 18, 13, 26, and 19 sources, respectively. Remarkably, SiS is not detected in any envelope with a mass loss rate below 10−6M⊙yr−1, whereas it is detected in all envelopes with mass loss rates above that threshold. From a comparison with a previous, similar study on C-rich sources, it becomes evident that the fractional abundances of CS and SiS show a marked differentiation between C-rich and O-rich sources, being two orders of magnitude and one order of magnitude more abundant in C-rich sources, respectively, while the fractional abundance of SiO turns out to be insensitive to the C/O ratio. The abundance of SiO in O-rich envelopes behaves similarly to C-rich sources, that is, the denser the envelope the lower its abundance. A similar trend, albeit less clear than for SiO, is observed for SO in O-rich sources.

Conclusions.The marked dependence of CS and SiS abundances on the C/O ratio indicates that these two molecules form more efficiently in C- than O-rich envelopes. The decline in the abundance of SiO with increasing envelope density and the tentative one for SO indicate that SiO and possibly SO act as gas-phase precursors of dust in circumstellar envelopes around O-rich AGB stars.
Formation pathways of complex organic molecules: OH• projectile colliding with methanol ice mantle (CH3OH)10
Authors: Inostroza-Pino Natalia , Mardones Diego , Ge Jixing J. X. , MacLeod-Carey Desmond
Published: June 2020

In this article, we simulated the collisions of an OH• projectile impacting on a methanol cluster formed by ten units of methanol to mimic an ice mantle (CH3OH)10. The chemical processes occurring after the impact were studied through Born-Oppenheimer (ab-initio) molecular dynamics. We focus on collisions with initial kinetic impact energy of 10–22 eV, where the richest chemistry happens. We report the formation mechanisms of stable complex organic molecules (COMs) such as methoxymethanol CH3OCH2OH, formic acid HCOOH, formyl radical HCO, formaldehyde H2CO and its elusive HCOH isomer. We show that CH2(OH)2, •CH2OH or +CH2OH are key intermediates to generate H2CO and other COMs. We compare the outcomes using OH• with those using OH− projectiles. These processes are likely relevant to the production of COMs in astrophysical environments. We discuss its formation mechanism and the astrophysical implications of these chemical pathways in star-forming regions.
The dependence of episodic accretion on eccentricity during the formation of binary stars
Authors: Kuruwita Rajika L. , Federrath Christoph , Haugbølle Troels
Published: June 2020

Context. Episodic accretion has been observed in short-period binaries, where bursts of accretion occur at periastron. The binary trigger hypothesis has also been suggested as a driver for accretion during protostellar stages.

Aims. Our goal is to investigate how the strength of episodic accretion bursts depends on eccentricity.

Methods. We investigate the binary trigger hypothesis in longer-period (> 20 yr) binaries by carrying out three-dimensional magnetohydrodynamical simulations of the formation of low-mass binary stars down to final separations of ∼10 AU, including the effects of gas turbulence and magnetic fields. We ran two simulations with an initial turbulent gas core of one solar mass each and two different initial turbulent Mach numbers, ℳ = σv/cs = 0.1 and ℳ = 0.2, for 6500 yr after protostar formation.

Results. We observe bursts of accretion at periastron during the early stages when the eccentricity of the binary system is still high. We find that this correlation between bursts of accretion and passing periastron breaks down at later stages because of the gradual circularisation of the orbits. For eccentricities greater than e = 0.2, we observe episodic accretion triggered near periastron. However, we do not find any strong correlation between the strength of episodic accretion and eccentricity. The strength of accretion is defined as the ratio of the burst accretion rate to the quiescent accretion rate. We determine that accretion events are likely triggered by torques between the rotation of the circumstellar disc and the approaching binary stars. We compare our results with observational data of episodic accretion in short-period binaries and find good agreement between our simulations and the observations.

Conclusions. We conclude that episodic accretion is a universal mechanism operating in eccentric young binary-star systems, independent of separation, and it should be observable in long-period binaries as well as in short-period binaries. Nevertheless, the strength depends on the torques and hence the separation at periastron.
Massive disc galaxies too dominated by dark matter in cosmological hydrodynamical simulations
Authors: Marasco A. , Posti L. , Oman K. , Famaey B. , Cresci G. , Fraternali F.
Published: June 2020

We investigated the disc-halo connection in massive (M⋆ >  5 × 1010 M⊙) disc galaxies from the cosmological hydrodynamical simulations EAGLE and IllustrisTNG, and compared this connection with that inferred from the study of H I rotation curves in nearby massive spirals from the Spitzer Photometry and Accurate Rotation Curves dataset. We find that discrepancies between the simulated and observed discs arise both on global and local scales. Globally, the simulated discs inhabit halos that are a factor ∼4 (in EAGLE) and ∼2 (in IllustrisTNG) more massive than those derived from the rotation curve analysis of the observed dataset. We also used synthetic rotation curves of the simulated discs to demonstrate that the recovery of the halo masses from rotation curves are not systematically biased. We find that the simulations predict systems dominated by dark matter with stellar-to-total enclosed mass ratios that are a factor of 1.5−2 smaller than real galaxies at all radii. This is an alternative manifestation of the ‘failed feedback problem,’ since it indicates that simulated halos hosting massive discs have been too inefficient at converting their baryons into stars, possibly owing to an overly efficient stellar and/or AGN feedback implementation.
Prospects for radio detection of stellar plasma beams
Authors: Vedantham H. K.
Published: June 2020

Violent solar eruptions are often accompanied by relativistic beams of charged particles. In the solar context they are referred to as solar particle events and are known to generate a characteristic swept-frequency radio burst. Due to their ionising potential, these beams influence atmospheric chemistry and habitability. Radio observations provide a crucial discriminant between stellar flares that do and do not generate particle beams. Here I use solar empirical data and semi-quantitative theoretical estimates to gauge the feasibility of detecting the associated radio bursts. My principal conclusion is that a dedicated search for swept frequency radio bursts on second timescales in existing low-frequency (ν ≲ 102 MHz) datasets, while technically challenging, will likely provide the evidence high-energy particles beams in Sun-like stars.
Evaluation of the risk of decay of wooden beams embedded in internally insulated walls by long-term measurements
Authors: De Mets Timo , Tilmans Antoine
Published: June 2020

Internal insulation of existing walls is crucial to increase the energy efficiency of the building stock. However, this technique influences the drying potential of the wall and could consequently increase the decay risk of wooden beams embedded in the existing wall. We performed a long-term field study on different test walls with wooden beams. This paper discusses 2.5 years of measurements by analysing the moisture contents at the beam ends for the different test walls. The use of vapour open insulation materials has only a slightly favourable impact. On the other hand, measures to lower the moisture content of the wall have a significant effect, either by locally interrupting the insulation at the beam junction or by applying a water repellent treatment. Controlling the rain load on the wall seems to be a key point towards a moisture-safe application of internal insulation with embedded wooden beams.
The Impact of Climate Change on Material Degradation Criteria in Heritage over Iran: Regional Climate Model Evaluation
Authors: Hedayatnia Hamed , Steeman Marijke , Van Den Bossche Nathan
Published: June 2020

Understanding how climate change accelerates or slows down the process of material deterioration is the first step towards assessing adaptive approaches for the preservation of historical heritage. Analysis of the climate change effects on the degradation risk assessment parameters like salt crystallization cycles is of crucial importance when considering mitigating actions. Due to the vulnerability of cultural heritage in Iran to climate change, the impact of this phenomenon on basic parameters plus variables more critical to building damage like salt crystallization index needs to be analyzed. Regional climate modelling projections can be used to asses the impact of climate change effects on heritage. The output of two different regional climate models, the ALARO-0 model (Ghent University-RMI, Belgium) and the REMO model (HZG-GERICS, Germany), is analyzed to find out which model is more adapted to the region. So the focus of this research is mainly on the evaluation to determine the reliability of both models over the region. For model validation, a comparison between model data and observations was performed in 4 different climate zones for 30 years to find out how reliable these models are in the field of building pathology.
Pressure difference in buildings with good air-tightness: control measurements after IAQ renovations
Authors: Laine Katariina
Published: June 2020

Improving air tightness of structures prevents uncontrolled air leaks and it can be used to solve IAQ problems in buildings, usually in combination with other renovation methods. When improving air tightness, the airflow rates of mechanical ventilation usually need to be readjusted to correspond to the changed airtightness of the envelope. In optimal situation the supply- and exhaust air volumes are balanced and the pressure differential is close to zero Pascal. The article presents several buildings (n=7, built 1986-2005, renovated 2012-2019), where air tightness has been improved and the mechanical ventilation/pressure ratio has been adjusted as a part of other IAQ renovations. The pressure difference measurements (duration 7...14 days) have been done three times after renovation: right after the renovation, after 2 years and after 5 years. In addition, the long-term functionality of the air tightness renovation has been tested at the age of 5 years both with visual survey and with a tracer-gas leak test. After 5 years, the structures had remained airtight and the sealing materials were found to be durable. Pressure ratio needed some fine adjustment in 30 % of the renovated areas, where monitoring was made right after the renovation. At the age of 5 years the pressure ratio range was acceptable (-5...+5 Pa) and stable in approximately 85 % of the renovated areas. In these airtight buildings, the major effect to the pressure difference was caused by the mechanical ventilation system. Pressure difference adjustment and stability was possible to reach in all studied buildings with careful maintenance.
Influence of Building Envelope Type on the Minimum Mechanical Ventilation Rate to Achieve a Positive Indoor Air Pressure
Authors: Shi Yuchen , Li Xiaofeng , Sadatiseyedmahalleh Seyedehelham
Published: June 2020

In order to limit the infiltration of outdoor air pollutants, a positive indoor air pressure should be maintained. This study aims to investigate the minimum mechanical ventilation rate to achieve a positive indoor air pressure for large space buildings with different kinds of envelopes. The types of building envelope include envelope with multilayer windows (which generally appears in shopping malls and open-plan office buildings), envelope with entrances on the first floor and multilayer windows, and envelope with openings at bottom and top levels (which generally appears in industrial plants). It is concluded that the minimum ratio between mechanical ventilation and initial infiltration rates to achieve a positive indoor air pressure depends on the window width-height ratio, the vertical spacing between windows, and the number of window layers. More regulations are summarized and analysed to guide the ventilation design.
A prospective Study on the Evolution of Airtightness in 41 low energy Dwellings
Authors: Verbeke Stijn , Audenaert Amaryllis
Published: June 2020

Airtightness of the building envelope is an important parameter affecting the performance of (low energy) buildings. In case the airtightness is effectively measured, this is typically only done once as part of the commissioning of the construction work. Several factors could affect the evolution of the airtightness of the envelope after the building is constructed. In this work, follow-up airtightness tests have been carried out to investigate the evolution of the performance in the interval of 0.5 up to 12 years compared to the original pressurisation test. The results on 41 low-energy dwellings indicate that the airtightness is indeed not a fixed value over time. Of the 41 buildings, 29 display an increased air permeability resulting in an increase of up to 200% in relative terms or up to 1.36 ACH50 (air changes per hour at 50 Pa pressure difference [h-1]). Conversely, four of the buildings in the dataset show a significant improvement of the airtightness; resulting in a decrease of air leakage of up to -1.19 ACH50. Analysis of the data shows that on average the air permeability at 50 Pa pressure difference increased by 38%, but with great variation depending multiple factors such as initial airtightness value and construction type. This corresponds to an average increase of the specific air permeability of the building envelope of 0.15 m³/(h·m²). Most of the buildings under analysis are low energy buildings or passive houses which were very airtight at time of construction. Despite the observed evolution in air permeability, many buildings under investigation can still be considered sufficiently airtight a few years after initial construction.
Effect of moisture buffering on surface temperature variation: study of different indoor cladding materials
Authors: Legros Clémence , Piot Amandine , Woloszyn Monika , Pailha Mickael
Published: June 2020

The building materials used indoors constantly interact with the environment in which the occupants live. Recent studies have shown that natural materials, such as wood, can improve human well-being. In addition, the building materials facing the indoor air are able to adsorb and desorb water vapour from their surface and exchange it with the surrounding air. This mass exchange comes along with heat exchange, modifying their surface temperature, and thus the indoor environment. Therefore, in this article, we are investigating whether moisture buffering has an impact on comfort. For this purpose, room-scale numerical simulations have been carried out with WUFI Plus, comparing two types of interior cladding materials: painted plasterboards and a raw spruce panelling. The results show a slightly lower surface temperature and air temperature during the summer period when using spruce. A higher hygroscopicity of the spruce than the gypsum can explain this difference in behaviour between the two studied materials. Thus, spruce exchanges more latent heat with the surrounding air. However, only this thermal difference cannot explain the difference in comfort perception between the gypsum and the wood.
Sensitivity of the hygrothermal behaviour of homogeneous masonry constructions: from Sobol indices to decision trees
Authors: Calle Klaas , Van Den Bossche Nathan
Published: June 2020

Historic masonry constructions are difficult to mimic in hygrothermal models. Next to the usual uncertainties on the input of hygrothermal models as the outdoor/indoor climate also the properties of the wall themselves are often highly uncertain due to the natural origin of the aggregates and the various, manual production processes used through time. Therefore, this paper presents a probabilistic analysis that indicates the sensitivity of several damage criteria which are often encountered in practice such as mould growth at the interior surface, frost damage, and potential decay of wooden beam heads. The analysis is based on 1D simulations, including realistic variations on climate parameters as wall properties. With Kriging based surrogate modelling the output of the probabilistic simulations is translated into sensitivity indices, Total Sobol indices. These indices summarize the dependency of the damage criteria for each of the input parameters including multi order effects. The Total Sobol indices indicate a generally high dependency of each of the damage criteria on the rain intensity, the trend of the moisture retention/liquid conductivity curve and the absorption coefficient. Based on the probabilistic output binary flowcharts are generated to indicate for which combinations of input parameters high risks are to be expected. These binary flowcharts can be adopted by e.g. engineering firms to define whether, a more detailed assessment is required, and which input are necessary. This indicates when basic in situ assessments of the hygrothermal properties of the facade can suffice.
Hydrothermal performance of the external wooded frame wall structure reinforced with ballistic panels
Authors: Borodinecs Anatolijs , Prozuments Aleksejs , Zemitis Jurgis , Zajecs Deniss , Bebre Guna
Published: June 2020

In recent years construction of bullet resistant walls has become very common not only for military buildings but also for public and residential buildings. The existing wall structure in those buildings is reinforced by ballistic panels. However, in the cold climate regions external application or installation of the ballistic panels can cause interstitial water vapor condensation. Also, an incorrect application of such panel on the internal surface can lead to an insufficient drying of the structure during the summertime. This paper presents an analysis of thermodynamic properties of ballistic panels. For this purpose, laminated and non-laminated ballistic panels were examined. Thermal conductivity features such as water vapor permeability were evaluated in laboratory conditions. Based on gathered results the DELPHIN simulation software and THERM calculation tools were used to analyze the thermal resistance of wooded frame wall reinforced with ballistic panels. The obtained results were validated under controlled environment. Temperature and moisture measurements were performed inside the tested wooded frame structures reinforced by ballistic panels under different internal and external air parameter fluctuations.
Hygrothermal conditions in ventilated attics with different air change rates and ceiling constructions
Authors: Morelli Martin , Møller Eva , Hansen Thor
Published: June 2020

A recently Danish study reported that no vapour barrier is needed in ceilings, if the attic is well ventilated and the ceiling towards the dwelling is airtight. Based on that study, new investigations were initiated with focus on the hygrothermal behaviour in ventilated attics with different air change rates. A test house with three sets of four different ceiling constructions – all airtight – was used in this study. The ventilation rate was reduced in two of the sets with approx. 35 % and 50 %, respectively. Air change rates were measured with tracer gas. Furthermore, temperature and relative humidity was measured every hour. Measurements in similar ceilings with mineral wool or cellulose-based insulation material show that hygroscopic properties of the insulation have very limited effect on relative humidity. Furthermore, only at low ventilation rate the effect of a vapour barrier could be measured with minor impact. Based on the short-measured period the calculations of the risk of mould growth showed no risk. The results indicate that even when the ventilation is reduced by 50 %, the ventilated attic still performs well if the ceiling is highly airtight. However, the importance of vapour barriers becomes more important at lower air change rates.
Experimental investigation and hygrothermal modelling of freeze-thaw process of saturated fired clay materials including supercooling phenomenon
Authors: Fukui Kazuma , Iba Chiemi , Taniguchi Madoka , Takahashi Kouichi , Ogura Daisuke
Published: June 2020

To investigate the supercooling phenomenon in fired clay materials, low-temperature differential scanning calorimetry (DSC) and a one-dimensional freeze-thaw (FT) experiment were performed on saturated specimens. The rate of increase in ice saturation during freezing was calculated from the DSC result. Rapid ice growth over a relatively narrow temperature range (within about 0.2 K) was observed at a cooling rate of 0.25 K/min. In the FT experiment, the temperature distribution of a specimen was measured with inserted thermocouples. According to the results of the FT experiment, a rapid temperature increase was observed at sub-zero temperatures accompanied by freezing of the supercooled water. When the supercooled water began to freeze, the released latent heat was found to strongly prevent the specimen temperature from dropping even during the cooling period. Finally, a hygrothermal model of freezing and thawing including a non-equilibrium supercooling process was developed. The freezing rate of the supercooled water was modelled based on the DSC result. The validity of the model was verified by comparing the results of the FT experiment and calculations. The model was found to be able to replicate the rapid temperature rise during the cooling period of the FT experiment.
Stochastic Finite Element Method for Modelling Heat Transfer in the Building Envelope
Authors: Grymin Witold , Koniorczyk Marcin
Published: June 2020

Improving the energy efficiency of the buildings is one of the most effective and fastest ways of reduction of the carbon dioxide emission. However, in the assessment of the energy demand of the buildings, numerous factors are uncertain, i.e. layer thickness, material parameters, climatic conditions, etc. In the present study, mathematical model was developed for analyzing temperature distribution and heat flux in the wall with thermal conductivity of insulation as a random parameter. The results obtained employing a stochastic perturbation technique were compared against the results of the Monte Carlo simulation. Stochastic perturbation technique has been implemented using the tenth order Taylor series expansion. The direct differential method was used to determine the values of Taylor’s coefficient. The obtained results indicate good accordance of the stochastic perturbation technique with the Monte Carlo method. Afterwards, the expected value of the heat flux and its variance were studied for the reference year for a city in the Central Europe. Two cases of the external wall were investigated, in which the thermal insulation was localized either on the internal or the external side of the wall. Performed analyses serve as a good method for assessing the reliability of results obtained using standard, deterministic approach.
The influence of polyisocyanurate (PIR) facing on the heat transfer through the corners of insulated building partitions
Authors: Makaveckas Tomas , Bliūdžius Raimondas
Published: June 2020

Prefabricated products made of polyisocyanurate (PIR) thermal insulation material covered with cardboard, plastic, aluminium or composite facings are used for thermal insulation of building envelopes. The facing of these products is selected according to their conditions of use, and the effect of the facing on the declared thermal properties of the product depend only on water vapor diffuse properties of the facing. However, at the corners of the building where these products are joined, facings can be in the direction of the heat flux movement and significantly increase heat transfer through the longitudinal thermal bridge formed in the corner of the building. After analysing the solutions for installation of PIR thermal insulation products on the walls and roof corners of buildings, calculations of the heat transfer coefficients of the linear thermal bridges were made, and the influence of various facings and different structural solutions on the heat transfer coefficient value of the thermal bridge was determined. Aluminium foil facing have the greatest influence, but other facings must also be considered. The structural solutions with the greatest increase in the heat transfer due to the effect of the facing were selected, and the influence to the thermal and air tightness properties of the structural solution when facing is removed were analysed, the stability of thermal properties of the thermal insulation material were analysed as well. Proposals for joining PIR thermal insulation products with heat-conductive facings in the corners of buildings were prepared.
Acceptable air velocities using demand-controlled ventilation for individual cooling
Authors: Thunshelle Kari , Nordby Henrik S. , Rikoll Solberg Håkon , Holøs Sverre , Schild Peter G.
Published: June 2020

One of the main challenges in highly insulated buildings is the increasing share of energy demand for cooling. New solutions for low energy cooling are needed. Individual cooling by demand-controlled ventilation and use of ceiling mounted nozzles for cooling by higher air velocities could be an alternative. A laboratory study was designed to investigate thermal comfort and thermal sensation for elevated indoor room temperatures relevant to Norwegian summer climate; 24℃, 26℃ and 28℃ with a relative humidity set point of 40 %. Air flow was set to give air velocities of 0.25 m/s, 0.50 m/s and 0.75 m/s. 21 test persons were exposed to different air velocities in a cross-over study. Questionnaires on thermal comfort and thermal sensation were answered repeatedly. Jets from ceiling mounted supply air nozzles was shown to improve thermal comfort at 24 °C, 26 °C and 28 °C. In general, most test persons preferred low air velocity (0.25 m/s) at 24 °C, while high (0.5 m/s) or extra high (0.75 m/s) air velocities were preferred at 26 °C. At 28 °C, extra high or even higher air velocities were preferred.
Impact of high residential density on the building technology, HVAC systems, and indoor environment in Swedish apartments
Authors: Abdul Hamid Akram , von Platten Jenny , Mjörnell Kristina , Johansson Dennis , Bagge Hans
Published: June 2020

During the last few years, there has been an increased number of overcrowded apartments, due to increased migration but also housing shortage in general, particularly in the suburbs to major cities. The question is how the indoor environment in these apartments is affected by the high number of persons and how the problems related to high residential density can be overcome. This paper aims to specify the problem by investigating and analysing the technical parameters influenced by residential density in Swedish apartments built between 1965-1974. To map the situation, 11 interviews with employees at housing companies were conducted. Based on extreme conditions described in the interviews, simulations of the indoor climate and moisture risks at some vulnerable parts of constructions were made. Simulations were focused on moisture loads and CO2 concentrations as functions of residential density and ventilation rate. Finally, measures to combat problems associated to overcrowding are suggested. The aim is that the results should be used by authorities to formulate incentives and/or recommendations for housing companies to take actions to ensure a good indoor environment for all, irrespective of residential density conditions.
Identification and improvement of critical joints in CLT construction without weather protection
Authors: Kalbe Kristo , Kukk Villu , Kalamees Targo
Published: June 2020

Wetting of timber structures during erection can have a harmful effect on their durability and could lead to adverse health effects. The probability of dampness related problems is very high when timber is exposed to free water. However, it is not always possible to implement full weather protection and thus there is a need for cost optimal solutions to increase the moisture safety of precipitation-exposed timber construction. In this study we observed the construction works and monitored the timber moisture content (MC) of a cross-laminated timber (CLT) building and proposed a set of activities and designed connection details that could help to avoid moisture ingress during the installation of CLT panels. Our findings showed that the most sensitive area to wetting is the end-grain on the CLT panel and the MC remained within critical limits in structures where drying was prohibited. Therefore, the most vulnerable section of the CLT structure is the foundation connection. We suggest using liquid-applied membrane coating on the cut edges of CLT panels to protect the end grain and to cover the horizontal CLT panels with self-adhesive membranes and vertical CLT panels with temporary clear weather protection foils.