bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of climate change on the energy performance and thermal comfort of high-rise residential buildings in cold climates
Authors: Mutasim Baba Fuad , Ge Hua
Published: September 2019

Buildings now produce more than a third of global greenhouse gases, making them more than any other sector contributing to climate change. This paper investigates the effect of climate change on the energy performance and thermal comfort of a high-rise residential building with different energy characteristic levels, i.e. bylaw to meet current National Energy Code of Canada for Buildings (NECB), and passive house (PH) under two climate zones in British Columbia, Canada. SRES A2, RCP-4.5 and RCP-8.5 emission scenarios are used to generate future horizon weather data for 2020, 2050, and 2080. The simulation results show that for both bylaw and PH cases, the heating energy consumption would be reduced while cooling energy consumption would be increased. As a result, for the bylaw case, the total energy consumption would be decreased for two climate zones, while for PH case, the total energy consumption would be increased for zone 4 and decreased for zone 7. In addition, the number of hours with overheating risks would be increased under future climates, e.g. doubled in 2080, compared to the historical weather data. Therefore, efforts should be made in building design to take into account the impact of climate change to ensure buildings built today would perform as intended under changing climate.
Identification of biofilm composition covering lime-based materials
Authors: Kobetičová Klára , Nábělková Jana , Kočí Václav
Published: September 2019

This paper aims at identification of biofilms composition taken from lime and lime-cement plasters. The samples of plasters were exposed to natural weathering for more than three years to weather conditions of Prague as a representative of Central European continental climate. After biofilms sampling, they were cultivated using specific nutrient solutions and analysed using various types of microscopes. It was found, that the plasters were covered mostly by green algae (Hematococcus pluvialis, Klebsormidium sp., Trebouxiophyceae, Chlorophyceae and Chlorellaceae), cyanobacteria (Nostoc, Anabaena, Leptolyngbya, Phormidium, Plectonema, Synechococcales and Oscillatoriale), moulds (Aspergillus niger, Alternaria) and moss (Ceratodon purpureus). Possible influence of these organisms on hygrothermal behaviour of the base materials is subsequently discussed.
Can artificial neuron networks be used for control of HVAC in environmental quality management systems?
Authors: Romanska-Zapala Anna , Bomberg Mark
Published: September 2019

The concept of environmental quality management has been described in papers [1 - 4] that looked at the next generation of low energy buildings from the point of view of the occupant. Optimizing energy use is difficult for a few reasons: presence of dramatic changes in the manner we design and operate buildings, change in the role of an architect who must be a leader of interacting team, often quality management is biased towards the design more than on performance of the finished product and finally the need for integrated monitoring and modeling in the occupancy stage.

Effectively, we are integrating heating/cooling and ventilation with the structure at the same time as we verify the appropriateness of the new methods to evaluate performance of these systems. In this process we require double controls, one by the occupant and the other by the computerized (smart) control system. The traditional approaches to modify human behavior generally failed because occupants were not given enough control over their environment. Thus, a major part of the trend to a low-carbon, climate resilient future will be focused on methodology to include path from a complex field testing of building performance to simplified testing that combined with simple monitoring and data from utilities would allow assessment of the energy and carbon emission in a district of a city.

Our experience shows that preliminary design must be optimized during the period of service for all more complex buildings such as large residential, office or commercial buildings. In this context the artificial neural network approach appears to have significant advantages. Yet, traditionally ANN requires large data set to establish functional relations during the learning stage and therefore the first question is how precise can the control of temperature be when the heat exchanger is subjected to different climatic conditions.
Application of ANN for analysing a neighbourhood of single-family houses constituting an Energy Cluster
Authors: Zygmunt Marcin , Gawin Dariusz
Published: September 2019

In this article a simple computer tool that can predict energy demand of residential buildings area in Poland by means of artificial neural network is developed and its application is demonstrated. Authors focused on energy demand analyses for single-family houses, representative for the Polish household sector. Advanced computer simulations were performed by means of the Energy Plus software, with hourly calculation step. Then, the obtained results and simulation parameters were used as input data for artificial neural network analysis. As a result, authors developed a simple, user friendly computer tool that can predict, with relatively good accuracy in comparison to the Energy Plus results, energy demand for residential buildings located in Poland. The software might be used for local (a single building) or regional (whole areas, neighbourhoods) analyses of single-family houses in Polish household sector. Additionally, for the analysed area, Renewable Energy potential can be checked – the developed software allows for analyses of solar energy application in the building/neighbour-hood design. Some examples of the energy analyses performed by means of the developed software have been presented.
Air change rate in ventilated attics – reality and input for simulations
Authors: Møller Eva B. , Morelli Martin , Hansen Thor
Published: September 2019

To remove moisture by ventilating constructions is a well-known strategy, used successfully in numerous facades and roofs. However, simulating ventilation is often difficult as convection in this case is in another dimension than what is usually in focus in 1D hygrothermal simulations. There are strategies for simulating ventilation in 1D programs assuming a fixed air change rate (ACH). Unfortunately, ACH in roofs highly depend on wind direction and speed, hence a constant rate is a gross simplification. The article describes a comparative study between simulations with a 1D hygrothermal simulation program (WUFI) and simulations with BSim, a program in which the indoor climate can be simulated in different zones, in this case the ventilated attic. Focus is the effect of ACH in the attic on temperature and relative humidity. Finally, measurements of ACH in attics of ten single-family houses are presented. These measurements show that average ACH measured over more than two weeks differ very much from house to house although the ventilation openings in all houses seemed to be in accordance with current guidelines. Even measurements of the same attic differ considerably from time to time. The paper discusses what implications this should have on simulations.
User-dependent hygrothermal assessment and material parameter optimization for a wood-based construction under climate conditions of South Korea
Authors: Seo Jiwon , Vogdt Frank U.
Published: September 2019

Hygrothermal simulation programs are widely used nowadays, but reliable results can only be achieved with the knowledge of input parameter values. This study shows how the difficulties, obtaining accurate material properties and specifying boundary conditions, affect the hygrothermal performance of the construction. A wood-based construction is investigated under climate conditions of South Korea. Sensitive material parameters and boundary conditions, which significantly influence the relative humidity in the construction, are identified by means of the method of Morris. The most influential material parameters are varied for specific boundary conditions using Latin Hypercube sampling, resulting in a wide range of relative humidity values (~51 % until ~99 %) on OSB surface. Low relative humidity values on OSB are obtained with a Pareto-optimal material parameter set.
Modelling the disaggregated demand for electricity at the level of residential buildings with the use of artificial neural networks (deep learning approach)
Authors: Jasiński Tomasz
Published: September 2019

The paper addresses the issue of modelling the demand for electricity at the level of residential buildings with the use of artificial intelligence tools, namely artificial neural networks (ANN). The real data for six buildings acquired by measurement meters installed in them was used in the research. Their original frequency of 1 Hz has been resampled to a frequency of 1/600 Hz which corresponds to a period of 10 minutes. Out-of-sample forecasts verified the ability of ANN to disaggregate electricity usage for its specific applications. Four categories were distinguished, which were electricity consumption by: (i) fridge, (ii) washing machine, (iii) personal computer and (iv) freezer. Both standard ANNs with multilayer perceptron architecture and newer types of networks based on deep learning approach were used. The simulations included a total of over 10,000 ANNs differing, e.g. architecture, input variables, activation functions, their parameters, and training algorithms. The research confirmed the possibility of using ANN in modelling the disaggregation of electricity consumption and indicated the way of building a highly optimized model.
Thermal mass and thermal comfort in offices – experimental studies of a concrete floor
Authors: Grynning Steinar , Nocente Alessandro , Gullbrekken Lars , Skjeggerud Kjell
Published: September 2019

Previous studies demonstrated that the use of thermal mass in buildings can contribute to reduce the energy demand and improve the thermal comfort. The thermal mass effect strongly depends on the properties of the materials facing the internal environment. High thermal capacity and conductivity are vital to achieve the desired effects. Concrete have both and it is a common building material. However, scientifically sound experimental studies that quantify the effects in a controlled environment are scarce. The aim is to study the effects of thermal mass on indoor environment and comfort in a quantifiable way in an extensive experimental campaign where comparative measurements were carried out in The ZEB TestCell Laboratory in Trondheim, Norway. The facility consists of two identical real-weather exposed rooms the size of a single person office. One of the rooms was constructed with a 70 mm thick concrete flooring, the other with an 18 mm wood-flooring. Free-floating temperature propagations were measured in different natural ventilation scenarios. The results showed that peak temperatures were notably reduced in the test room with the concrete flooring. During the warmest periods, a temperature peak reduction of more than 10% was found compared to the wooden-floored room.
Generative reverse-modelling approach to hygrothermal material characterization
Authors: Klõšeiko Paul , Freudenberg Peggy
Published: September 2019

Reliable hygrothermal modelling depends on the quality of material characterization, especially so when higher moisture contents are concerned. Previous research has shown that adding additional material tests (e.g. capillary condensation redistribution (CCR) test) to the experimental dataset brings improvements to the modelling accuracy, but also adds to the workload of characterization process. This paper discusses a generative optimization workflow to increase the speed of the characterization and quality of the result. The proposed workflow incorporates optimization tool GenOpt and hygrothermal modelling software IBK Delphin to search for best fit of the water vapour and liquid conductivity curves of interior insulation materials based on modelling the CCR, drying and wet cup tests. Finally, models using material data from the proposed workflow and from the software database are compared to measurement results from two studies on interior thermal insulation. The results suggest that the generative optimization shows promise on the grounds of reducing tedious work analysing material tests. Also, a wider experimental dataset is shown to be useful when characterizing the vapour and liquid conductivity functions in over-hygroscopic region.
Properties of magnesium oxide boards used as sheathing in exterior walls
Authors: Wøhler Nielsen Stefanie , Rode Carsten , Bunch-Nielsen Tommy , Kielsgaard Hansen Kurt , Kunther Wolfgang , Grelk Bent
Published: September 2019

Sheathing boards based on magnesium oxide (MgO) became very popular in the Danish market around the year 2010. However, it was realized a few years later that they condensed humidity from ambient air. The leakage from the boards led to severe problems with corrosion of metallic components and moisture uptake and degradation of wooden members. The boards have been banned from use in the Danish market since 2015, while damage cases valuing around 370 million EUR still need to be reconciled [1]. The binder in MgO board is formed by a chemical reaction between MgO and MgCl2. However, MgSO4 is a possible alternative to MgCl2, and such boards may have smaller moisture uptake, to reduce this issue. This paper gives an account of recent activities to compare properties of MgO boards, based on chlorides or sulphates. The investigations comprise: (1) Analysis of elemental composition and crystalline components, (2) Examination in optical microscope and scanning electron microscope, (3) Determination of moisture retention and water vapour permeability, (4) Analysis of chemical composition of leaked salt water from boards, and (5) Visual observation of decomposition and determination of dry mass change after exposure to high humidity.
Transition from n50 to actual air exchange dependent on climatic conditions
Authors: Kisilewicz Tomasz , Nowak-Dzieszko Katarzyna , Rojewska-Warchał Małgorzata
Published: September 2019

The knowledge of the air flow and air exchange in the building is critical both on the design and operation stage of the building. Infiltration of air interferes with the mechanical ventilation and determines the proper functioning of the natural ventilation system, still commonly used in the standard buildings. The building airtightness can be described by n50 parameter, however it does not specify the real air exchange in natural conditions. According to the simple procedure of the standard EN ISO 13789, factor n50 may be easily converted to the monthly averaged air change rate. However, it is difficult to accept the same value of air change rate in any month of a year, as it is often done in the certification procedures. More precise, climate dependent conversion procedures have been elaborated in USA, but they were developed for the specific local building technology and local climate conditions. This paper presents the results of the preliminary measurements conducted in a single family house in Poland, built in a heavy-weight technology. The real air exchange rate was measured in various climatic conditions by means of gas tracing method, with CO2 as the tracer gas, in order to prove a relationship between the enhanced procedure and the external conditions. Acceptable agreement between the results of the measurement and model calculations was obtained. Based on the preliminary results, the authors determined the more realistic influence of the enhanced algorithm on the ventilation energy demand. The use of the simplified model resulted in case of the analyzed object in 15% overestimation of the ventilation thermal losses.
Mechanical properties of concrete for radioactive waste repositories
Authors: Koňáková Dana , Vejmelková Eva , Pommer Vojtěch , Scheinherrová Lenka , Konvalinka Petr , Černý Robert
Published: September 2019

Concrete casing for radioactive repositories have to meet many strict requirements. One of the most important is a radiation protection and a radionuclide inhabitation. Bentonite, with a great sorption capacity, seems to be a suitable material for this purpose. Therefore, the main aim of this study was to assess an impact of the bentonite utilization as a component in concrete mixtures. For this reason, basic physical properties and mechanical parameters of concretes containing different amount of bentonite were determined. Bentonite applications led to the open porosity growth, while the matrix densities were not influenced. Regarding the mechanical parameters, the compressive strengths as well as the flexural strengths were significantly deteriorated by the bentonite application. Despite the presented negative effect, the obtained results seems to prove a possible applicability of a lower percentage of bentonite in concrete structures not as a cement replacement, but just as a component.
Transport of gadolinium in a cement composite
Authors: Medved’ Igor , Kalvoda Ladislav , Vejmelková Eva , Vratislav Stanislav , Černý Robert
Published: September 2019

Development of cement based composites suitable for radionuclide immobilization is of great interest for secure containment of nuclear waste. This requires, in particular, detailed knowledge of how radionuclides are transported in such composites. In this paper we investigate the transport of gadolinium in a dry cement composite. Experimental data are obtained in a non-destructive way by neutron imaging. Their theoretical interpretation is based on a diffusion-advection model in which sorption is included.
Altitudinal variations in wing morphology of Aedes albopictus (Diptera, Culicidae) in Albania, the region where it was first recorded in Europe
Authors: Prudhomme Jorian , Velo Enkelejda , Bino Silvia , Kadriaj Perparim , Mersini Kujtim , Gunay Filiz , Alten Bulent
Published: September 2019

The rapid spread and settlement of Aedes albopictus mosquitoes across at least 28 countries in Europe, as well as several countries in Asia Minor, the Middle East and Africa, has made it one of the most invasive species of all time. Even though the biology of Ae. albopictus in its native tropical environment has been documented for a long time, the biology and ecology of this species in newly colonized temperate environments remain poorly known despite its important role as a vector for about twenty arboviruses. In this context, the main goals of this work were to investigate Ae. albopictus phenotypic variations at a local scale in Albania, the country where Ae. albopictus was first recorded in Europe, and to determine if its phenotypes could be affected by altitude. Analysis of Ae. albopictus wing phenotypes was performed using a geometric morphometric approach. We observed shape and size variations among altitudinal populations of Ae. albopictus. Differences of wing phenotypes were highlighted between altitude groups for male and female mosquitoes. The phenotypic variations observed in Ae. albopictus between altitudinal groups indicated these populations are exposed to environmental and ecological pressures. These results suggest the presence of phenotypic plasticity in this species.
„Bei mir wird alles immer besser!“
Authors: Pott Claudia
Published: September 2019

„Da stimmt etwas nicht“, dachte sich Gerhard Schweizer, als er am 8. August 2012
abends mit seiner linken Hand die Tasten der PC-Tastatur nicht mehr richtig
traf. Er suchte den Grund dafür in seiner großen Müdigkeit, denn tagsüber hatte
er Brennholz gespalten. Also begab er sich recht bald ins Bett. Als er nach ca.
vier Stunden die Toilette aufsuchen wollte, fiel er der Länge nach hin und
stellte fest, dass er weder Bein noch Arm bewegen konnte. Seine Lebensgefährtin
verständigte sofort den Notarzt, der ihn umgehend ins Krankenhaus brachte. Es
folgten drei Tage auf der Stroke Unit sowie eine Woche auf der neurologischen
Station. Dort musste er aus dem Bett gehoben werden, und auch auf die Toilette
konnte er nicht selbstständig gehen. Nach der Woche ging es nach Lenggries in
die stationäre Reha. Die erste Zeit verbrachte er weiterhin im Rollstuhl und
bekam Sonderkost wegen der Schluckprobleme. Nach sieben Wochen verließ er die
Rehaklinik gehend – die Strecke von der Station zum Auto auf dem Parkplatz
schaffte er „gerade so“. Nach wenigen Wochen zu Hause besuchte er für weitere
drei Monate eine ambulante neurologische interdisziplinäre Reha-Einrichtung.
Während dieser Zeit konnte er viele Verbesserungen erreichen, z. B. wieder Auto
fahren. Nur die linke Hand blieb trotz Fortschritten (s)ein Sorgenkind, und das
geliebte Hobby Segeln musste er aufgeben. Dafür suchte er sich eine neue
Freizeitaktivität, um sportlich aktiv zu sein, und entdeckte seine Leidenschaft
für lange Fahrradtouren.
Oxytocin Compared to Buccal Misoprostol for Induction of Labor after Term Prelabor Rupture of Membranes
Authors: Freret Taylor S. , Chacón Kelly M. , Bryant Allison S. , Kaimal Anjali J. , Clapp Mark A.
Published: September 2019

Objective This study was aimed to determine if admission-to-delivery times vary between term nulliparous women with prelabor rupture of membranes (PROM) who initially receive oxytocin compared with buccal misoprostol for labor induction.

Study Design This is a retrospective cohort of 130 term, nulliparous women with PROM and cervical dilation of ≤2 cm who underwent induction of labor with intravenous oxytocin or buccal misoprostol. The primary outcome was time from admission to delivery. Linear regressions with log transformation were used to estimate the effect of induction agent on time to delivery.

Results Women receiving oxytocin had faster admission-to-delivery times than women receiving misoprostol (16.9 vs. 19.9 hours, p = 0.013). There were no significant differences in secondary outcomes between the groups. In the adjusted model, women who received misoprostol had a 22% longer time from admission to delivery (95% CI 5.0–42.0%) compared with women receiving oxytocin.

Conclusion In term nulliparous patients with PROM, intravenous oxytocin is associated with faster admission-to-delivery times than buccal misoprostol.
Measurements of radial profile of hydrogen and deuterium density in isotope mixture plasmas using bulk charge exchange spectroscopy
Authors: Ida K. , Yoshinuma M. , Yamasaki K. , Kobayashi T. , Fujiwara Y. , Chen J. , Murakami I. , Satake S. , Yamamoto Y. , Murakami S. , Kobayashi M.
Published: September 2019

A bulk charge exchange spectroscopy system has been applied to measure the radial profiles of the hydrogen (H) and deuterium (D) density ratio in the isotope mixture plasma in a large helical device. Charge exchange lines of Hα and Dα are fitted by 4 Gaussian of H and D cold components and H and D hot components with 5 parameters by combining the measurement of plasma toroidal rotation velocity with carbon charge exchange spectroscopy. The radial profiles of the relative density of hydrogen and deuterium ions are derived from H and D hot components measured and the beam density calculated from beam attenuation calculation. A proof-of-principle experiment is performed by the H pellet and the D pellet injections into the H-D mixture plasma.
Enhanced magnetic modulation in NiO-based memory device through ionic liquid pre-treatment
Authors: Kang Xin , Gao Yingjie , Liu Lifu , Chen Wei , Zhao Xu
Published: September 2019

The electrical manipulation of magnetism is of particular importance owing to its potential applications in low-power memory devices and spintronics. In this study, we demonstrate enhanced magnetic modulation and an increased exchange bias field (HEB) in NiO films pretreated with ionic liquid (IL), which we refer to as IL-NiO films. The saturation magnetization of the IL-NiO film in the low-resistance state (LRS) is more than 2.5 times than that in the high-resistance state; this value is more than 80% higher than that of the NiO film without IL pretreatment (As-NiO). In addition, the HEB value of the IL-NiO film is more than 140% higher than that of the As-NiO film. Further analysis indicates that oxygen vacancies and metallic Ni0 are introduced into the NiO film during the IL pretreatment process, which results in the formation of thicker ferromagnetic Ni conductive filaments (CFs) after the set process. These thicker Ni CFs enhance the magnetism of the IL-NiO film and increase the coupling area between the ferromagnetic Ni and antiferromagnetic NiO in the LRS, thus leading to a larger magnetic modulation and higher HEB in the IL-NiO film. We believe that our findings can significantly contribute to further advancements in memory devices and allied applications.
Magnetically aggregated biosensors for sensitive detection of biomarkers at low concentrations
Authors: Burg Shmuel , Cohen Meir , Margulis Michael , Roth Shira , Danielli Amos
Published: September 2019

Detection of biomarkers at low concentrations is essential for early diagnosis of numerous diseases. In many sensitive assays, the target molecules are tagged using fluorescently labeled probes and captured using magnetic beads. Magnetic beads facilitate washing and separation steps, are well suited for automation, and improve the assay sensitivity. Current devices rely on quantifying the target molecules by detecting the fluorescence signal from individual beads. Thus, to detect low concentrations of target molecules, these devices require sophisticated optical detectors, making them bulky and expensive. Here, we propose a compact fluorescence-based system that simply uses a small permanent magnet with a conic tip to aggregate the magnetic beads, forming a cluster of fluorescently labeled probes whose fluorescence signal is much greater than that of a single bead. Using the magnetically aggregated biosensors to detect human Interleukin-8, we demonstrated a limit of detection of 0.1 ng/l and a 4-log dynamic range performance, which is on par with the most sensitive devices but is achieved without their bulk and cost.
Electronic synapses with near-linear weight update using MoS2/graphene memristors
Authors: Krishnaprasad Adithi , Choudhary Nitin , Das Sonali , Dev Durjoy , Kalita Hirokjyoti , Chung Hee-Suk , Aina Olaleye , Jung Yeonwoong , Roy Tania
Published: September 2019

Emulating the human brain's circuitry composed of neurons and synapses is an emerging area of research in mitigating the “von Neumann bottleneck” in present computer architectures. The building block of these neuromorphic systems—the synapse—is commonly realized with oxide-based or phase change material-based devices, whose operation is limited by high programming currents and high reset currents. In this work, we have realized nonvolatile resistive switching MoS2/graphene devices that exhibit multiple conductance states at low operating currents. The MoS2/graphene devices exhibit essential synaptic behaviors, such as short and long-term potentiation, long-term depression, and the spike timing dependent plasticity learning rule. Most importantly, they exhibit a near-linear synaptic weight update, without any abrupt reset process, allowing their use in unsupervised learning applications. These electronic synapses are built with chemical vapor deposited MoS2 and graphene, demonstrating potential for large-scale realizations of machine learning hardware.
Prediction of improved magnetization and stability in Fe16N2 through alloying
Authors: Szymanski N. J. , Adhikari V. , Willard M. A. , Sarin P. , Gall D. , Khare S. V.
Published: September 2019

We study the structural, energetic, electronic, and magnetic properties of Fe16 − xMxN2 alloys, where M represents 3d transition metals Ti, V, Cr, Mn, Co, and Ni, using special quasirandom structures and density functional theory calculations. We describe stabilization of Fe16N2 resulting from the enhanced occupation of bonding states relative to the corresponding antibonding states as observed from crystal orbital Hamiltonian population analysis. The hybrid HSE06 functional is employed to calculate a magnetic moment of 2.844 μB/Fe, agreeing with recent experimental work and suggesting the importance of electronic exchange effects. Upon alloying, magnetization is found to decrease with all transition metals excluding Mn, for which exceptionally strong ferromagnetic coupling is achieved via nitrogen-mediated exchange interactions. We identify a 1.41% magnetization increase at low Mn concentrations coupled with a decrease in formation energy, making Fe16 − xMnxN2 a suitable candidate for permanent magnet applications. Novel end-member systems of the form M16N2 are also investigated, with results implying stability and potential synthesizability of all compounds except Ti16N2 owing to weak metallic bonding among Ti atoms.
Finger-like solutions in striation model of ionospheric plasma
Authors: Goncharov V. P.
Published: September 2019

A conformal mapping approach is used to study the interfacial instability in the striation model of ionospheric plasma. The distinctive feature of such instability is the emergence of fingering structures at the interface between two plasmas when the drift velocity is directed from a less dense plasma toward a denser one. The instability increment depends only on the normal component of the drift velocity, which should be continuous in crossing the interface. The tangential component of the drift velocity has no effect, and in crossing the interface, it either is absent or undergoes a jump by varying inversely with plasma densities. The fingerlike structures grow, while their tips propagate in opposite directions by reaching a steady speed at t → ∞.
Building a Maxey–Riley framework for surface ocean inertial particle dynamics
Authors: Beron-Vera F. J. , Olascoaga M. J. , Miron P.
Published: September 2019

A framework for the study of surface ocean inertial particle motion is built from the Maxey–Riley set. A new set is obtained by vertically averaging each term of the original set, adapted to account for Earth’s rotation effects, across the extent of a sufficiently small spherical particle that floats at an assumed unperturbed air–sea interface with unsteady nonuniform winds and ocean currents above and below, respectively. The inertial particle velocity is shown to exponentially decay in time to a velocity that lies close to an average of seawater and air velocities, weighted by a function of the seawater-to-particle density ratio. Such a weighted average velocity turns out to fortuitously be of the type commonly discussed in the search-and-rescue literature, which alone cannot explain the observed role of anticyclonic mesoscale eddies as traps for marine debris or the formation of great garbage patches in the subtropical gyres, phenomena dominated by finite-size effects. A heuristic extension of the theory is proposed to describe the motion of nonspherical particles by means of a simple shape factor correction, and recommendations are made for incorporating wave-induced Stokes drift and allowing for inhomogeneities of the carrying fluid density. The new Maxey–Riley set outperforms an ocean adaptation that ignored wind drag effects and the first reported adaption that attempted to incorporate them.
Simultaneous reconstruction of temperature and velocity fields using nonlinear acoustic tomography
Authors: Yu Tao , Cai Weiwei
Published: September 2019

Acoustic tomography developed and investigated before can only recover either the temperature or the velocity field from the time-of-flight measurements along a single direction of sonic rays. However, the sonic propagation time is a nonlinear function of temperature and velocity; thus, in principle, the measurements allow us to reconstruct both simultaneously. In order to achieve this, we propose a modality of acoustic tomography based on the recently proposed concept of nonlinear tomography, which can take full advantage of the aforementioned nonlinear dependences. Proof-of-concept numerical demonstrations are presented using representative two-dimensional temperature and flow velocity phantoms. The obtained simulative results confirmed the feasibility of nonlinear acoustic tomography in recovering the distributions of temperature and velocity fields.
Hydrodynamic interaction facilitates the unsteady transport of two neighboring vesicles
Authors: Lee Julian , Seyler Sean L. , Pressé Steve
Published: September 2019

We obtain a numerical solution of the equation for the synchronous unsteady motion of two spherical vesicles in incompressible viscous fluid in the presence of both Stokes drag and hydrodynamics memory. We find that for a given amount of work performed, the final distance traveled by each vesicle is increased by the presence of the other vesicle moving in the same direction. The result suggests that the unsteady transport of the vesicles by molecular motors in vivo may be facilitated due to an effective hydrodynamic interaction between the neighboring vesicles.
Direct observation of domain kinetics in rhombohedral PMN-28PT single crystals during polarization reversal
Authors: Ushakov A. D. , Esin A. A. , Akhmatkhanov A. R. , Hu Q. , Liu X. , Zhao Y. , Andreev A. A. , Wei X. , Shur V. Ya.
Published: September 2019

Relaxor-based ferroelectric crystals of lead magnesium niobate-lead titanate (PMN-PT) are attracting great attention due to their prominent piezoelectric properties. Moreover, an enhancement of the integral properties requires the deep understanding of domain kinetics and domain structure evolution for application of the domain engineering techniques in relaxor-PT materials. Here, we demonstrate the results of studying the domain structure evolution by direct optical imaging during polarization reversal in [111]-oriented rhombohedral PMN-PT single crystals. Three domain types involved in the switching process have been revealed. The following consequent stages of the domain structure evolution have been separated: (I) nucleation and growth of a↑-domains and 2a-CDW and (II) nucleation and growth of c↓-domains. The undesirable effect of the partial backswitching during the electric field decrease was attributed to the clamped switching conditions.
Active control of vortex-induced vibration of a circular cylinder using machine learning
Authors: Ren Feng , Wang Chenglei , Tang Hui
Published: September 2019

We demonstrate the use of high-fidelity computational fluid dynamics simulations in machine-learning based active flow control. More specifically, for the first time, we adopt the genetic programming (GP) to select explicit control laws, in a data-driven and unsupervised manner, for the suppression of vortex-induced vibration (VIV) of a circular cylinder in a low-Reynolds-number flow (Re = 100), using blowing/suction at fixed locations. A cost function that balances both VIV suppression and energy consumption for the control is carefully chosen according to the knowledge obtained from pure blowing/suction open-loop controls. By implementing reasonable constraints to VIV amplitude and actuation strength during the GP evolution, the GP-selected best ten control laws all point to suction-type actuation. The best control law suggests that the suction strength should be nonzero when the cylinder is at its equilibrium position and should increase nonlinearly with the cylinder’s transverse displacement. Applying this control law suppresses 94.2% of the VIV amplitude and achieves 21.4% better overall performance than the best open-loop controls. Furthermore, it is found that the GP-selected control law is robust, being effective in flows ranging from Re = 100 to 400. On the contrary, although the P-control can achieve similar performance as the GP-selected control at Re = 100, it deteriorates in higher Reynolds number flows. Although for demonstration purpose the chosen control problem is relatively simple, the training experience and insights obtained from this study can shed some light on future GP-based control of more complicated problems.
Modeling of chirping toroidal Alfvén eigenmodes in NSTX
Authors: White R. B. , Duarte V. N. , Gorelenkov N. N. , Fredrickson E. D. , Podestà M. , Berk H. L.
Published: September 2019

Modulation of mode amplitude and frequency of TAE modes, observed experimentally and referred to as chirping, is investigated using a guiding center code and a δf formalism. Chirping is observed as the development in time of Fourier sidebands that move above and below the nominal mode frequency. Subsequent doubling of the sidebands is also sometimes observed. Equilibria with conventional positive magnetic shear are used, as well as NSTX reversed shear cases. The onset of chirping can be triggered by a sudden increase in mode damping, as can occur by the mode contacting the continuum.
Size effect of one-dimensional nanostructures on bubble nucleation in water splitting
Authors: Chen Juanwen , Guo Liejin
Published: September 2019

One-dimensional (1D) nanostructures have wide applications in photocatalysts for water splitting. Their surfaces may impact the gas bubble nucleation rate, thus influencing the efficiency of gas evolution. However, the effects of the 1D nanostructured surfaces on the bubble nucleation have not been studied to date. Herein, these effects are theoretically analyzed, based on the changes of free energy for a bubble nucleus forming inside/outside a nanotube. The results show that compared to flat surfaces, the inner tube wall favors the bubble nucleation, while the outer wall has an opposite effect. These differences become increasingly significant with tube radius Rt reducing when Rt < 10r* (r*-bubble equilibrium radius). The size effect is further verified experimentally for bubble nucleation on TiO2 nanotube arrays. The sensitivity of bubble nucleation to nanostructure dimensions should be considered in designing high-efficient photocatalysts.
Boiling enhancement on surfaces with smart wettability transition
Authors: Zhang Lei , Wang Tao , Kim Soelha , Tan Sicong , Jiang Yuyan
Published: September 2019

Surfaces integrated with controllable wetting behaviors are playing an increasingly important role in a diverse range of applications. But their application in heat transfer is seldom studied. In this work, the excellent performance of the smart-wettability-control surface in boiling heat transfer was investigated experimentally. The experimental results demonstrated that the smart-wettability-control surface integrated perfectly the advantages of hydrophobic (better heat transfer coefficient) and hydrophilic surfaces (higher critical heat flux). We attribute this enhancement to the smart control of nucleation sites and three-phase contact line movement, which could be supported by the visualization image. This enhancement strategy can be used to improve the capacity of heat transfer devices.
Biharmonic versus bimodal AFM: Numerical and experimental study on soft matter
Authors: Eslami Babak , Damircheli Mehrnoosh
Published: September 2019

Bimodal atomic force microscopy (AFM) provides both topographical and material composition of a material with a single-pass experiment. Based on the rectangular beam theory, the cantilever's second to first eigenmode frequency is 6.27. Due to the fact that they are not multiple integers, there are irregular taps over the surface during an experiment. This can cause nonlinear vibrations in the cantilever in addition to the fact that the probe does not interact with each pixel similarly. Therefore, exciting the cantilever with higher harmonics instead of the eigenmodes in multifrequency AFM mechanisms and its advantages are discussed. Based on this theoretical discussion, this study provides the guideline to select the correct harmonic. It is found that the ratio of second to first eigenmode frequency heavily depends on the geometry of the cantilever. Additionally, it is found that cantilevers with lower eigenmode frequency ratios, excited with the first eigenmode frequency and higher harmonic, can provide higher phase contrasts. Numerical studies are done on a polystyrene (PS) and gold (Au) sample system. Based on this study, first one needs to minimize f2/f1. Second, the second excitation frequency should be the closest n-th harmonic to f2/f1 (i.e., one needs to minimize |n−f2f1|). Experimentally, a bimodal AFM scheme with an external function generator is used to image PS and low-density polyethylene polymer blend. The highest 2nd eigenmode phase contrast is observed with a cantilever that has a lower f2/f1 and is excited with its first eigenmode frequency and 6th harmonic (i.e., the nearest harmonic to the second eigenmode).
Facile synthesis of tin monosulfide nanosheets via physical vapour deposition and their near-infrared photoresponse
Authors: Yuan Shuo , Liu Gangzha , Tian He , Fan Chao , Wang Mengjun , Li Erping
Published: September 2019

Two-dimensional layered materials (TDLMs), such as tin sulfide (SnS2), have attracted significant attention due to their vast potential applications in the fields of electronics, optoelectronics, energy conversion, and storage. Tin monosulfide (SnS) is an intrinsic p-type semiconductor in the family of TDLMs. Further explorations of SnS requires the development of efficient synthesis techniques. Here, we report SnS nanosheets grown via a physical vapour deposition (PVD) approach. The morphology was characterized using Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). These SnS nanosheets exhibit a square shape with a smooth surface having an average lateral size of 7 μm and a thickness of 12 nm. No impurities were observed in the SnS nanosheets. Furthermore, photodetectors based on such SnS nanosheets were fabricated. The results show that the as-grown SnS has an excellent photo-response performance for an 850-nm laser with a high responsivity of 1604 AW-1, an external quantum efficiency of 2.34 × 105% and a detectivity of 3.42 × 1011 jones, which are larger than those values reported for previous SnS-based photodetectors. Moreover, the rise and fall times are 7.6 and 29.9 ms, respectively. Our work provides a strategy to obtain high-purity and ultrathin SnS while indicating that SnS has a great potential in applications for near-infrared photodetectors.
Room-temperature angular-dependent topological Hall effect in chiral antiferromagnetic Weyl semimetal Mn3Sn
Authors: Yan J. , Luo X. , Lv H. Y. , Sun Y. , Tong P. , Lu W. J. , Zhu X. B. , Song W. H. , Sun Y. P.
Published: September 2019

Chiral antiferromagnetic (AFM) Weyl semimetal Mn3Sn shows a large anomalous Hall effect (AHE) around room temperature, due to the Berry curvature generated by Weyl nodes in electronic dispersions. Here, we study the temperature- and angular-dependent Hall effect and magnetic measurement in single-crystalline Mn3Sn. There are some intriguing phenomena: first, a large hysteretic-type AHE has been observed only above 270 K, while the coercivity is around 300 Oe and independent of temperature. Second, the temperature- and angular-dependent topological Hall effect is obtained, which may stem from the real space topological spin texture. Third, the coercivity extracted from the angular-dependent AHE is well fitted with the Stoner-Wohlfarth model, which reflects the evolution of domain walls and magnetic anisotropy. Thus, it shows that not only the topological structure in momentum space but also the real space topological spin texture plays an important role in anomalous transport properties of Mn3Sn. Our work pushes forward to the realization of room temperature AFM spintronics and paves the way toward the possible devices based on the unconventional Hall effect.
Testable theory suggests information has mass and could account for universe’s dark matter
Authors: Gasparini Allison
Published: September 2019

A new paper formulates and suggests laboratory experiments to confirm mass-energy-information equivalence.
Notes on the cultural value, biology and conservation status of the Data Deficient Tagula butcherbird (Cracticus louisiadensis Tristram, 1889)
Authors: Goulding W. , Moss P. , McAlpine C. A.
Published: September 2019

The Tagula butcherbird (Cracticus louisiadensis) is an endemic island species of butcherbird that has remained virtually unknown for over 130 years. The lack of information on the species has resulted in it being assigned to the Data Deficient category by BirdLife International and the IUCN, leaving its conservation status open to continuing speculation. This is an ongoing concern given the rapid environmental changes occurring in the region. Here, we describe the first observations of the habitat use, life history and ecology of the species. We also present information collected across the island distribution of the species, including density and population estimates. We found the Tagula butcherbird to be culturally important and relatively common in suitable habitats across four islands of the Louisiade Archipelago (Papua New Guinea). However, the species was absent from highly disturbed areas. We estimated this species’ extent of occurrence to be ~1200km2 and area of occupancy to be less than 800km2. Population densities were estimated via pre-dawn assessments of singing birds and line transects. Density estimates were found to be between 0.14 and 0.53 individuals per hectare, with the highest density observed on Sabara Island. These densities were combined with remote sensing data to estimate the amount of available habitat and the species’ population size, which was estimated to be between ~11500 and 23000 individuals. The species’ dependence on forest habitat with a relatively intact canopy, combined with the likely continuing destruction of habitat on Junet and Panawina Islands, remains a conservation concern.
Acting upon background of understanding rather than role
Authors: Albl-Mikasa Michaela
Published: September 2019

Research into dialogue interpreting has thus far focused on its interactional dimension. Only recently have cognitive approaches been introduced. This article uses the situated cognition and functional pragmatics paradigms to explain how a broad and holistic understanding of the (healthcare) set-up in which dialogue interpreting assignments take place enables interpreters to develop an awareness of the purpose-orientation of medical professionals’ (inter)action plan. This understanding forms part of an inferential mental backdrop that allows interpreters to go from bottom-up drifting to gaining top-down control over their task. On the basis of a corpus of 19 interpreter-mediated doctor-patient encounters, the article suggests that it is acting upon an integral background of understanding as inferential basis (rather than role) that empowers dialogue interpreters to perform successfully.
Asymmetrical language proficiency in dialogue
interpreters
Authors: Tiselius Elisabet , Englund Dimitrova Birgitta
Published: September 2019

Language proficiency of dialogue interpreters, who typically
work in the public service sector, is an under-researched area. Unlike as in the case of conference interpreters, there is no generally accepted definition of
proficiency levels of working languages for dialogue interpreters. This article
discusses language proficiency in dialogue interpreting. It presents a
methodological problem, namely, how to define and determine a given
interpreter’s stronger and weaker working languages. We discuss different methods
for determining the individual interpreter’s stronger and weaker working
languages, such as self-assessment, demographic, socio-linguistic questionnaire
and test score (Dialang). We conclude that there is a need for more research in
this area.
Environmental constraints on growth, development and physiology of citrus.
Authors: Albrigo L. G. , Stelinski L. L. , Timmer L. W.
Published: September 2019

This chapter emphasizes the role of climatic factors in worldwide citrus production. The effect of climate on citrus growth and development, fruit yields, economic returns and fruit quality are discussed.