bluuebunny/crossref_metadata_2025 huggingface dataset:
Epitaxial and quasiepitaxial growth of halide perovskites: New routes to high end optoelectronics
Authors: Wang Lili , King Isaac , Chen Pei , Bates Matthew , Lunt Richard R.
Published: October 2020

Motivated by the exciting properties of metal halide perovskites in photovoltaic applications, there is an evolving need to further explore the limitations of this class of materials in broader fields and high end optoelectronics, which requires better control over the film structure, defect levels, and quality. Epitaxial growth has been ubiquitously deployed in the semiconducting industry. This affords routes to precisely align the atomic arrangement to control the structure and strain and achieve the highest levels of optoelectronic performance. In this review, the recent emergence and progress in the epitaxial growth of metal halide perovskites are introduced within the context of epitaxial and quasiepitaxial approaches, and recent advances are surveyed from growth methods to application integration. The main criteria distinguishing epitaxy and quasiepitaxy, i.e., lattice matching and ordering, can be deployed to direct the selection of proper substrates, growth methods, and precursors for various applications.
Origin of off-stoichiometry and electrical benignity at the grain boundaries in CuInSe2: A first-principles study
Authors: Zhu Guo-Jun , Yang Ji-Hui , Gong Xin-Gao
Published: October 2020

Grain boundaries (GBs) in polycrystalline CuInSe2 are of both fundamental interest and technological significance for photovoltaic applications. However, the atomic composition and the exact roles of the GBs in CuInSe2 are still unclear despite a large off-stoichiometry around the GBs being reported. In this work, based on first-principles calculations and using ∑3(114) GB as an example, we show that the GB acts as a sink of defects, leading to defect segregations and off-stoichiometry. Furthermore, depending on the chemical potential conditions, different point defects dominate the different segregations. Under common experimental conditions with In rich and Cu poor, we find that the most dominant defect at the GBs is the antisite defect InCu. Our studies show that the existence of InCu can eliminate defect states in the bandgap and thus suppress recombination of photo-generated electron–hole pairs, making the GB electrically benign. To enhance the formation of InCu, we propose an optimal region of chemical potential to realize In segregation and Cu depletion at the GB. Our work thus provides useful insights and understandings for further improvement of CISe polycrystalline solar cells.
Domain engineering in LiNbO3 crystals by e-beam and features of spatial distribution of electric field: Experiment and computer simulation
Authors: Kokhanchik L. S. , Emelin E. V. , Sirotkin V. V. , Svintsov A. A.
Published: October 2020

Domain gratings with different periods were formed on −Z surfaces of lithium niobate using direct electron beam writing (DEBW) at an accelerating voltage of 15 kV. Features of the gratings obtained were compared to computer simulation results of spatial distribution of an electric field for various schemes of e-beam charges disposed near the sample surface. The Monte Carlo method was used to calculate the injection charge distribution. The electrical potential distribution in irradiated samples was determined by the numerical solution of the Poisson equation. The electric field created by the injected charges was calculated both near the surface and by the depth of the irradiated samples. Peculiarities of the field distribution have been found, in which the formation of regular domain gratings is broken due to the proximity of the injected charges. Based on computer simulations and the experimental results of DEBW (at 15 kV), the search for irradiation schemes was carried out to reduce the limitations in grating periods by decreasing the accelerating voltage of electrons up to 10 kV.
First-principles study of intrinsic point defects and Xe impurities in uranium monocarbide
Authors: Huang Gui-Yang , Pastore Giovanni , Wirth Brian D.
Published: October 2020

Based on density functional theory (DFT) calculations, we perform an extensive investigation of intrinsic point defects and Xe impurities in uranium monocarbide (UC). The DFT calculations involve both the conventional generalized gradient approximation (GGA) and the GGA+U approach with the Hubbard parametric term (U), using up to 5×5×5 supercells. GGA calculations for the formation energy of intrinsic defects demonstrate the significant effect of using larger supercells than in previous studies. Results confirm that the ⟨111⟩ and ⟨100⟩ dumbbell interstitials are the most stable interstitial configurations for U and C, respectively. The interstitial mechanisms are favored for self-diffusion of both uranium and carbon and diffusion of Xe under equilibrium conditions. Calculations also reveal that the Xe substitutional defect at the C lattice site tends to adopt an off-site configuration, which can be interpreted as a Xe interstitial–C vacancy complex. We also utilize GGA+U to assess the impact of effective U parameter (Ueff) on the results. Moreover, we introduce a method to estimate the carbon chemical potential by fitting the phase diagram composition data and propose a selection Ueff=1.25 eV based on the experimental Xe diffusion activation energy. With this approach, GGA+U calculations reproduce the available experimental data for the formation energy of the carbon Frenkel pair and can explain the stepwise recovery of intrinsic properties and burst Xe release behavior in UC observed in annealing experiments.
Transition waves in multi-stable metamaterials with space-time modulated potentials
Authors: Ramakrishnan Vinod , Frazier Michael J.
Published: October 2020

This Letter introduces a strategy for transition wave (soliton) management in multi-stable mechanical metamaterials, enabling on-demand, post-fabrication control of the associated phase transformation kinetics and distribution. Specifically, the wave dynamics are controlled by a small, kinematically prescribed spatiotemporal variation in the elastic potential, constituting a driving force. The stability of the wave profile under slow-propagation conditions and the characteristic spatial localization of the Hamiltonian energy support an analogy with a Newtonian particle traversing a viscous medium under forcing. The theoretical analysis adopts this particle perspective, describing the soliton dynamics through ordinary, rather than partial, differential equations. While myriads of definitions for the potential modulation are possible, a traveling sinusoid assists the development of analytical solutions. Following this prescription, two wave propagation regimes are revealed: in one, the soliton is carried by the modulation with a commensurate velocity; in the other, the soliton is out-paced by the modulation and, thus, travels at reduced velocity. To illustrate the utility of this method, we demonstrate both the tractor and repulsor effects in multi-stable systems away from equilibrium: as a tractor (repulsor), the potential variation attracts (repels) the transition wave front in opposition to the system's energy-minimizing tendency. This method provides greater flexibility to the transformation performance of multi-stable metamaterials and supports the adoption of such systems in applications demanding multi-functionality.
Design strategy for p-type transparent conducting oxides
Authors: Hu L. , Wei R. H. , Tang X. W. , Lu W. J. , Zhu X. B. , Sun Y. P.
Published: October 2020

Transparent conducting oxides (TCOs), combining the mutually exclusive functionalities of high electrical conductivity and high optical transparency, lie at the center of a wide range of technological applications. The current design strategy for n-type TCOs, making wide bandgap oxides conducting through degenerately doping, obtains successful achievements. However, the performances of p-type TCOs lag far behind the n-type counterparts, primarily owing to the localized nature of the O 2p-derived valence band (VB). Modulation of the VB to reduce the localization is a key issue to explore p-type TCOs. This Perspective provides a brief overview of recent progress in the field of design strategy for p-type TCOs. First, the introduction to principle physics of TCOs is presented. Second, the design strategy for n-type TCOs is introduced. Then, the design strategy based on the concept of chemical modulation of the valence band for p-type TCOs is described. Finally, through the introduction of electron correlation in strongly correlated oxides for exploring p-type TCOs, the performance of p-type TCOs can be remarkably improved. The design strategy of electron correlation for p-type TCOs could be regarded as a promising material design approach toward the comparable performance of n-type TCOs.
Analytical approach to phonon calculations in the SCC-DFTB framework
Authors: Bačić Vladimir , Heine Thomas , Kuc Agnieszka
Published: October 2020

Detailed derivation of the analytical, reciprocal-space approach of Hessian calculation within the self-consistent-charge density-functional based tight-binding framework (SCC-DFTB) is presented. This approach provides an accurate and efficient way for obtaining the SCC-DFTB Hessian of periodic systems. Its superiority with respect to the traditional numerical force differentiation method is demonstrated for doped graphene, graphene nanoribbons, boron–nitride nanotubes, bulk zinc-oxide, and other systems.
Studying time-dependent contribution of hot-electron versus lattice-induced thermal-expansion response in ultra-thin Au-nanofilms
Authors: Wang Peng-Jui , Shen Chih-Chiang , Chou Kuan-Yu , Ho Mu-Han , Sheu Jinn-Kong , Sun Chi-Kuang
Published: October 2020

Through the femtosecond-time-resolved study of photoacoustic pulse generation in ultra-thin gold nanofilms, we observed a time delay of 0.5–0.7 ps in the formation of thermal-expansion pulses after photoexcitation. Our observation indicates that lattice anharmonicity dominates over hot electron pressure in the thermal expansion of Au nanofilms under ultrashort-pulsed photoexcitation.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: October 2020

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials that supersede earlier data or suggest new research applications.
Changes in surface soil properties and macroinvertebrate communities with the conversion of secondary forests to oil palm (Elaeis guineensis) plantations
Authors: Yeo Joseph G. , N'Dri Julien K. , Edoukou Ettien F. , Ahui Jean-Luc D. S.
Published: October 2020

The conversion of natural forest to oil palm (Elaeis guineensis Jacq.) plantation is perceived as a threat to biodiversity conservation. The aims of this investigation were to assess variation in soil physico-chemical parameters and macroinvertebrate structures following the conversion of secondary forests to oil palm plantations, and to understand what to expect with the aging of the plantations. We hypothesised that soil properties would be improved with respect to biodiversity conservation with the aging of the oil palm plantations. Sampling was carried out in secondary forests, and in 13-, 20- and 39-year-old oil palm plantations at the La Mé Station, Côte d’Ivoire. Three sampling areas were established in each land-use type and age class, for a total of 12 sampling areas. Over a 50-m transect, litter-dwelling macroinvertebrates were sampled by using pitfall traps, and topsoil (0–10 cm) macroinvertebrates by using monoliths (50 cm by 50 cm by 10 cm), following the modified ‘Tropical soil biology and fertility’ method. Soil physical and chemical parameters were characterised. The results showed that the conversion of secondary forests to oil palm plantations was characterised by changes in soil macroinvertebrate density (–30%), taxonomic richness (–37%) and functional groups (–17%), as well as soil bulk density (+14%) and water content (+16%), after ~39 years of conversion. Soil organic carbon, total nitrogen and organic matter increased with the aging of plantations, and reached conditions similar to those of secondary forests. The human interference imposed on macroinvertebrate communities during site preparation and planting was not compensated by the reduction in the soil-degradation index over time. The results have implications for implementation of conservation agriculture and the related management practices.
Clinicians’ narratives in the era of evidence-based practice
Authors: Lazzaro-Salazar Mariana
Published: October 2020

In evidence-based practices, narratives are the vehicle through which medical knowledge is shared and clinical
judgment is grounded. This paper explores narratives as a sanctioned social practice that help a group of clinicians in a
healthcare institution in New Zealand build and negotiate expertise and accountability, as they discuss clinical cases. To this
end, the paper investigates narratives in six staff meetings, which were video and audio recorded. The paper presents a discursive
analysis of the functions of narratives in this context to show how narratives are interactional achievements that are pivotal to
clinical decision-making and to building and contesting professional stances. Finally, the paper reflects on the value of
narratives as shared resources that are sometimes revisited and reframed over time and that help construct a common thread of
history that becomes part of the cultural capital of the organization and positions clinicians as core members of their
community.
Doing narrative analysis from a narratives-as-practices perspective
Authors: De Fina Anna
Published: October 2020

In this paper I lay out some of the main theoretical methodological principles that underlie a
narratives-as-practices approach and discuss three foci that emerge from current research and pave the way for future
investigations. In particular, I focus on mobility, connectivity, time/space anchoring and chronotopicity as both characteristics
of narrative and research areas which allow for an integration of the focus of interactional approaches on emergence with a
consideration of the historical and social embedding of narratives into practices. I review recent research that has contributed
to this trend in narrative studies and discuss some of the limitations of current work and areas that need further investigation.
I advocate for an expansion of research on a wider variety of practices, attention to the characteristics of narrative genres, and
in general a stronger critical engagement with ways in which narratives participate in social processes involving power and
inequality.
Online methods in research on input processing and processing instruction
Authors: Keating Gregory D.
Published: October 2020

Evidence for the input processing (IP) model (VanPatten, 1996, 2004, 2007, 2015a, 2020) and the benefits of processing instruction (PI) comes largely from offline tasks, despite the fact that both are concerned with online sentence comprehension. This chapter aims to stimulate more online research in these areas. I first provide a brief summary of techniques that measure real-time sentence comprehension and then offer suggestions for how they can be used in research on the IP model and PI. Lastly, I review recent online studies of the effects of PI on second language (L2) learners’ real-time sentence comprehension. I end by proposing two new hypotheses regarding the potential that PI has to benefit L2 learners’ online processing of input.
Implementation of Screening, Brief Intervention, and Referral to Treatment (SBIRT) by Nurses on Acute Care Units: A Qualitative Descriptive Study
Authors: Thoele Kelli , Draucker Claire Burke , Newhouse Robin
Published: October 2020

Background

Screening, Brief Intervention, and Referral to Treatment (SBIRT) is an evidence-based intervention for patients with substance use disorders, but this intervention is under-utilized. Little is known about the implementation of SBIRT in acute care facilities. The purpose of this study is to describe implementation of SBIRT by nurses in acute care hospitals.

Methods

A qualitative descriptive design was used for this study. Registered nurses who agreed to participate in the study completed a 1:1 interview using a semi-structured interview guide. Interviews were audio recorded and transcribed and then data were analyzed using qualitative content analysis.

Results

When implementing SBIRT in an acute care setting, participants identified several factors that affect implementation. Some nurses felt that it is “one more thing to do” but other nurses feel that it was a “good, simple” screening tool that does not take long to do and can “plant the seeds of change” for patients. Additionally, participants mentioned barriers and facilitators related to the patients’ responses to SBIRT and organizational factors.

Conclusions

This study identified several barriers and facilitators to SBIRT implementation related to the nurses, patients, and organization. By understanding the factors that influence implementation, healthcare providers can develop strategies to support effective implementation of SBIRT.
Patient Acceptance of Naloxone Resulting from Targeted Intervention from Community Pharmacists to Prevent Opioid Misuse and Accidental Overdose
Authors: Skoy Elizabeth , Werremeyer Amy , Steig Jayme , Eukel Heidi , Frenzel Oliver , Strand Mark
Published: October 2020

Background

Community pharmacists are in a unique position to prevent opioid-related deaths through the provision of naloxone. However, for those identified as candidates for take-home naloxone, the acceptance rate remains low. Value would be gained from knowing what patient demographics and pharmacist actions are associated with increased patient acceptance of naloxone.

Methods

Through a state-wide program, community pharmacists screened all patients receiving an opioid prescription for risk of opioid misuse and/or accidental overdose. Pharmacists prescribed and/or dispensed take-home naloxone to patients at elevated risk. Naloxone acceptance rates were stratified based on risk factors for misuse and overdose to determine which patients are most likely to accept naloxone. Patient acceptance of naloxone and risks were captured electronically.

Results

Pharmacist-initiated naloxone recommendations based on risk screening resulted in a 5.81% take-home naloxone acceptance rate. Individuals that were taking multiple opioid medications were most likely to accept the naloxone (20.45%). Concurrent disease states or medications (COPD, concurrent anxiety/depression medication, concurrent sleep aid) were associated with a statistically significant increase in the rate of naloxone acceptance. Acceptance of take-home naloxone increased as a patient risk for opioid misuse and/or accidental overdose increased.

Conclusion

Patient acceptance of naloxone at the community pharmacy level was notably higher compared to national naloxone dispensing rates when pharmacists implemented a patient screening and systematic risk-based approach to identify candidates in need of take-home naloxone.
Mobilizing diaspora during crisis: Ukrainian diaspora in Canada and the intergenerational sweet spot
Authors: Carment David , Nikolko Milana , MacIsaac Sam
Published: October 2020

Canada’s Ukrainian diaspora occupy an enviable, if not rare, ‘intergenerational sweet spot’. This sweet spot endows them with a high degree of positionality within Canada, enabling both long and short-term support for Ukraine since the crisis began in 2014. In examining Ukrainian diaspora positionality in the Canadian context, we find there are varied strategies that help offset hardship at the community and household level while addressing the long-term fragility of the country. While new migrants and temporary workers are actively remitting back home, older generation diaspora members compensate for smaller remittance volumes by lobbying and by influencing the state apparatus through various forms of political and social activism. This has the effect of shifting the costs borne by individuals to the host state and is consistent with our insights on principal-agent relations between states and diaspora. Although Ukraine’s macroeconomic performance will remain fragile for the foreseeable future, we identify four complementary forms of diaspora engagement in times of crisis, namely the mobilization of aid, political activism and volunteering, remittances and other financial flows, and delegating responsibilities to host-country institutions.
The Hawking energy on the past lightcone in cosmology
Authors: Stock Dennis
Published: October 2020

This work studies the Hawking energy in a cosmological context. The past lightcone of a point in spacetime is the natural geometric structure closely linked to cosmological observations. By slicing the past lightcone into a one-parameter family of spacelike two-surfaces, the evolution of the Hawking energy down the lightcone is studied. Strong gravitational fields may generate lightcone self-intersections and wave front singularities. We show that in the presence of swallow-tail type singularities, the Hawking energy and its variation along the null generators of the lightcone remains well-defined and subsequently discuss its positivity and monotonicity.
The Moka pot: thoughts and experiments
Authors: Binder P-M , Scheidle Clara B
Published: October 2020

Watching over a coffee maker in operation, and designing a simple experiment using it, invokes familiar and unfamiliar physical phenomena and techniques involving calorimetry and heat transfer.
Moisture’s significant impact on twisted polymer actuation
Authors: Higueras-Ruiz Diego R , Feigenbaum Heidi P , Shafer Michael W
Published: October 2020

It was recently shown that inexpensive drawn polymer monofilaments, such as nylon fishing line, can be used to create thermally driven actuators. These actuators are called twisted polymer actuators (TPAs). TPAs can produce linear actuation when they are both twisted and coiled. In this configuration, these actuators are called twisted coiled polymer actuators (TCPAs). These same drawn polymers can be used to create torsional actuation when the precursor monofilament is twisted but still remains straight, known as straight twisted polymer actuators (STPAs), which is also thought to be the elemental unit of TCPAs. The torsional thermal actuation of STPAs is primarily a result of the anisotropic thermal properties of the virgin material (axial thermal contraction and radial thermal expansion), which manifests as linear actuation in the coiled configuration (TCPA). This paper presents two moisture related matters: moisture content impact on the thermal actuation of TPAs and the capability of TPAs to actuate as a function of moisture absorption at room temperature. For the former, we first present moisture dependencies of the axial thermal contraction and axial modulus of the precursor (straight, untwisted) monofilament. This study is conducted because closed-form and finite element models often use the physical properties of the precursor monofilament as inputs to predict the thermal actuation of TPAs. The results show that, both, axial thermal contraction and axial modulus, are strongly dependent on moisture content. Second, we present the experimental thermal actuation for STPAs and TCPAs at different moisture content percentages. We present torsional actuation responses for three different pitch angles STPAs (36, 25, and 15°) at two percentages added moisture by weight (0% and 4%). Similarly, we study the linear thermal actuation of TCPAs under an isotonic tensile load at the above moisture percentages. The results show an increase in actuation for those samples at 4% moisture content of approximately 100% for STPAs at 75 °C and a 50% for TCPAs samples at 100 °C. Finally, we report for the first time, that TPAs can be hygroscopically actuated. Here, we present torsional actuation responses under free torsion conditions for a 36° pitch angle STPA as well as axial contraction of a TCPA under an isotonic tensile load as a function of moisture absorption and show that moisture absorption can cause a similar actuation responses as seen when a thermal load is applied. Like the thermal actuation, we expect this hygroscopic actuation of TPAs is produced by a combination between the swelling that occurs on the precursor monofilament during moisture absorption and its anisotropic nature.
Water balance of the turn-of-the-century drought in the Southwestern United States
Authors: McCabe Gregory J , Wolock David M
Published: October 2020

Analysis of the water balance of the southwestern United States (SWUS) during 1900 through 2018 was used to evaluate the magnitude of the turn-of-the-century (TOC) drought in the SWUS. Results indicate that the warm season (April through September) soil moisture and runoff during the TOC drought were among the lowest values of the 1900 through 2018 period. Additionally, increases in temperature were identified as a significant driver of low soil moisture and runoff conditions during the warm season. In contrast, during the cool seasons (October through March) and the water year (October 1 through September 30) during the TOC drought, soil moisture and runoff did not indicate extremely dry conditions even though temperatures were the highest of the 1900 through 2018 period.
Mining the gap in long-term residential water and electricity conservation
Authors: Bolorinos Jose , Rajagopal Ram , Ajami Newsha K
Published: October 2020

Climate change and economic development provide a strong rationale for urban water and electricity conservation. Although behavioral and technological factors link short-term conservation of both resources, their long-term residential consumption trends have diverged across industrialized nations: from 1990 to 2010, per capita water use decreased, while per capita electricity use increased. This long-term ‘conservation gap’ has not generally been examined but it presents an opportunity to better understand what drives persistent residential conservation. Here, we analyze 2002–2012 water and electricity consumption from 38 000 California residences to characterize the conservation gap and its socio-economic determinants. Aggregate per-residence consumption figures show a 19% decline in water use—concentrated in the 2007–2009 drought—and an 8% increase in electricity use—coinciding with early 2000s economic growth. We find no meaningful socio-economic variation in micro-scale consumption trends across the study area but the ‘gap’ tendency is greater in residences with low customer-turnover, suggesting that widespread factors—including the proliferation of consumer electronics and small appliances—drove electricity use increases. Long-term water conservation was also widespread, suggesting that droughts provide immediate, locally-driven conservation imperatives that have been successfully leveraged for long-term water savings.Similar episodes were not generally available to electricity policy makers during the study period, but extreme climate events could drive energy efficiency campaigns in the future.
Integrable generalisations of Dirac magnetic monopole
Authors: Veselov A P , Ye Y
Published: October 2020

We classify certain integrable (both classical and quantum) generalisations of Dirac magnetic monopole on topological sphere S
2 with constant magnetic field, completing the previous local results by Ferapontov, Sayles and Veselov. We show that there are two integrable families of such generalisations with integrals, which are quadratic in momenta. The first family corresponds to the classical Clebsch systems, which can be interpreted as Dirac magnetic monopole in harmonic electric field. The second family is new and can be written in terms of elliptic functions on sphere S
2 with very special metrics.
Adaptive glass system: idea development and design
Authors: Bizonova S
Published: October 2020

The aim of the paper is to create a concept of a glass system independently reacting to the parameters of the environment in which is located. Autonomous insulation unit is responded to changes of environmental parameters, capable of evaluating mode efficiency with and without the use of selective layers. Parameter specification of individual modes, description of operation is needed. As a result, a construction scheme of the glass system is proposed.
Stress analysis of asphalt mixture in the indirect tensile strength test
Authors: Bokomlaško J , Mandula J
Published: October 2020

Nowadays asphalt mixture is the most used material in the construction and reconstruction of roads. It is used for its advantages, such as availability of materials, flexibility and no need for dilatation. However, the asphalt mixture has one disadvantage, namely temperature sensitivity. At different temperatures it exhibits different physical-mechanical properties. For a better understanding of the physical-mechanical properties of the asphalt mixture, we can use complex rheological models. Complex rheological models can describe the viscoelastic behaviour of the asphalt mixture with a high prediction. Laboratory tests are required to determine input values for complex rheological models. The article is focused on the analysis of asphalt mixture in the indirect tensile strength test and compare with numerical solution.
The treatment and properties of construction waste for subsequent use in cement composites
Authors: Charvát J , Vaclavik V , Dvorsky T , Svoboda J , Macalova K , Gola L
Published: October 2020

The paper presents the results of construction waste treatment for possible replacement of natural aggregates in cement composites. The individual processes of construction waste treatment for the purpose of obtaining the required fractions 0/4 mm, 4/8 mm and 8/16 mm are described. It deals with the so-called recycled aggregate, which will subsequently be used in cement composites as a substitute for natural aggregate. The properties of individual fractions of recycled aggregate are presented, both in terms of composition, density, water absorption and granulometric, mineralogical and elemental composition.
Construction of modular green roof panel
Authors: Hejl M
Published: October 2020

This article is dedicated to make people familiar with process of creating new construction of modular green roof panel. Article also shows creative process of prefabricated panel and all versions of its construction from the first attempts to final ecological modular panel for green roof. Article also describes problems of every version of modular panel which was created, and solutions which were made for final versions of green roof modular panel. Article also shows a final modular panel with its construction and possibility of its use on the roofs. In the article you can also read about tests which will be done in the future for verification of right construction of green roof panels and its behaviour in the real outside conditions.
Coupled heat and moisture transport in building material – water absorption coefficient and capillary water content
Authors: Jaroš P , Vertal’ M
Published: October 2020

At present, restoration of historic buildings is a difficult process. The most common problem of historic buildings is increased moisture, because waterproofing is missing and thanks that water can be transported in porous material by capillary forces. There is several simulation software available, which can include many factors such as water transport from the ground, sun radiation, impact of driven rain. Also it includes thermal conductivity, specific heat capacity and water vapor diffusion factor, which are depended on content of water. For correct assessment of hygrothermal behaviour of these buildings and find suitable retrofit strategies, hygric and thermal properties are needed. When we want to use simulation software for assessment of hygrothermal behaviour of historic structures, we need to know heat and water transmission parameters of sandstones. In this paper are presented two water transmission parameters and that water absorption coefficient and capillary water content. For the test measurement of these parameters was used clay brick. The water absorption and capillary water content are obtained by experiment of one-dimensional transport water. The results are compared with values of clay brick, which are presented in German material database.
Innovation in construction: trends and obstructions of adoption and implementation
Authors: Klosova D , Kozlovská M
Published: October 2020

Innovation initiatives are crucial for any industry because their future growth depends on it. Innovative technologies that can have a great impact on the construction industry, such as building information modelling, automation and robotics, augmented reality, virtual reality, simulation, internet of things were reviewed in this article. In spite of that, innovation implementation in the construction sector has generally lagged behind other industry sectors affecting the productivity as well. The governments are aiming to improve this through increasing the level of investments into manufacturing and innovative research in this area. This article reviews the process of adopting innovative technologies and the reasons why there are obstacles to their implementation. It is expected that integration between machines and humans will enhance human capabilities, allowing them to concentrate on more creative and value added, socially important activities in the future. There is also need of changing thinking in order to transfer the results of these technological studies into production in the construction industry.
Fungicidal properties of cement composites based on waste sludge water from concrete plant
Authors: Klus L , Dvorsky T , Svoboda J , Charvat J , Macalova K , Chlebkova L , Václavík V
Published: October 2020

The present article deals with the fungicidal properties of cement composites based on Waste Sludge Water (WSW) from a concrete plant (CP). The article compares the ability of standard cement composites and cement composites based on WSW to withstand microscopic fungi Aspergillus niger, Trichoderma nereus and Penicillium glabrum. The results of the tests show that the use of WSW as a substitute for pure mixing water in the preparation of cement composites does not have a significant positive or negative effect on the fungicidal properties of the prepared composites.
A batch study of Ni(II) sorption on natural Slovak zeolite
Authors: Kovacova Z , Pla C
Published: October 2020

The adsorption mechanism of nickel on natural Slovak zeolite, a regional low-cost material, was studied in a batch system. The effect of various initial concentrations of metal ions in the adsorption process was tested. The highest adsorption efficiency (almost 70%) was reached at a concentration of 50 mg/L. The lowest efficiency was determined at a concentration of 350 mg/L (approx. 19%). Sorption data have been interpreted in terms of Langmuir and Freundlich isotherms. The Freundlich model with regression coefficient 0.83 better fitted for the batch experiments. The change of pH in equilibrium showed to ion-exchange reaction. The conductivity increases in all cases. Due to relatively low efficiency in higher concentration of aquatic solutions, further research and modification of zeolite is needed.
3D printers as part of Construction 4.0 with a focus on transport constructions
Authors: Krupík P
Published: October 2020

Digital and technological innovations that have grown rapidly in recent years have been referred to as the 4th Industrial Revolution or Industry 4.0. The paper comprehensively deals with the description of the 3D printers as part of Construction 4.0 with a focus on transport construction. The aim of the article is description of this issue comprehensively and with the help of SWOT analysis identify weaknesses, strengths, opportunities and threats with focus on the transport constructions. The content is complemented by an assessment of the current situation, indicating the possibility of use in practice.
Evaluation of microwave drying effects on historical brickwork and modern building materials
Authors: Kvapilová V
Published: October 2020

One of the most common reasons for any construction work requirements is an increased humidity of the building. Increased humidity does not affect only buildings with basement, but also buildings without it, which were not properly hydro-isolated or the hydro isolation was damaged due to aging or to adverse environmental effects. Such situations are solved with designing suitable remediation measures, which necessarily includes drying of damp masonry as well. This almost always includes historical buildings, where protection against groundwater was never planned. Such buildings are usually very sensitive to any physical intervention into construction itself and destructive methods of revitalization are very often completely out of the question, therefore it is necessary to develop methods, which can be used particularly for historical buildings. This article focuses on evaluating effects of microwave drying historical brickwork as well as modern building materials. First, the method of microwave drying is described in general, then we cover the experiment, which was performed at the Faculty of Civil Engineering at Brno University of Technology. The experiment was applied on two pillars made of historical brickwork. Those samples were being thoroughly analysed during the drying process and final outcomes were compared to already existing experiments on modern materials. The goal of this work is to find out, if the method of microwave drying is more suitable for described conditions and also to set such process of drying, which would provide the highest effectivity.
Comparison of Mechanical and Adhesive Joints for Structural Glass – A review
Authors: Lavko M , Kvočák V
Published: October 2020

The presented paper compares types of connections mostly used for glass structures. Two groups are recognised and it is mechanical connections and adhesive joints. Bolted connections are mostly used as it is relatively simply to design and to provide, but to be able to create such a connections holes needs to be drilled in glass panes, which leads to discontinuities in geometry, weakening the glass panes and to creation of local stress peaks in the area where the bolt is inserted. On the other hand, adhesive joints don’t lead to peak stresses as the stress is redistributed along larger area. Huge variety of accessible adhesives enable the joints to be used in almost each conditions. Main disadvantage of adhesives the change in behaviour over time, manly decrease in strength. Also, mechanical properties are influenced by UV radiation, humidity, temperature, etc. The most common adhesives used for structural glass and their performance is shown and discussed in the paper.
Surface runoff as a potential source of pollution
Authors: Marko I , Csicsaiová R , Rozsa G , Stanko Š
Published: October 2020

Due to the accelerated development of urbanized areas, the increase of paved and impermeable surfaces, permanent changes in the environment of the city occur. The spatial structure of the city is changing. There are creating significant artificial landscape elements that are not able to absorb rainwater. As a consequence of this unnatural phenomenon in the city was identified a new area pollution source - surface runoff. The formation of surface runoff is affected by several factors. For us, it is important the character of the pollutants in the surface runoff. The paper aims to point out the impact of surface runoff from urbanized areas on the environment. Compare quality parameters of rainwater runoff from different types of paved areas (different types of roof, roadway, car parking). To get acquainted with the legislation covering the area permitted criteria for the content of undesirable substances and the method of their removal.
Adsorption of specific chloroacetanilides on granular activated carbon
Authors: Marton M , Ilavský J , Barloková D
Published: October 2020

Pesticides, as one of the main monitored micropollutants these days, are monitored and determined even in the drinking water, because of their toxic effect on the living organisms. Presence of these pesticides in the drinking water is undesirable and, therefore, they need to be removed. Chloroacetanilides belong to the group of herbicides, which are commonly used in agriculture. Their complex structure prevents common biological degradation, so more complex processes are needed. One of the most efficient process for their removal is adsorption on activated carbon. In this article adsorption of certain chloroacetanilides from water for two different types of granular activated carbon is presented. Matrix used for dilution of pesticides was drinking water and the efficiency of the removal of pesticides ranged from 5 to 60 % for the specific sorption materials and pesticides. This research has shown that adsorption material Filtrasorb 400 is far more efficient than Norit 1240.
Trend analysis of drought indices in the eastern Slovakia
Authors: Nagy P , Purcz P , Galas S , Portela M M , Hlavatá Helena , Simonová Dorota
Published: October 2020

Extreme weather changes have been increasing in the recent times also in the eastern Slovakia. Extremely dry periods alternate with above-average precipitation. In the paper the drought indices were evaluated: Standardized Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI). Using the non-parametric statistical Mann-Kendall test. The evaluated period was 1960 – 2015 at selected river and climatological stations in the eastern Slovakia. The results showed that no clean significant trends occurred in all evaluated indices and stations.
Computer modeling of flow on the object of the sewer network
Authors: Šutúš M , Hrudka J , Rózsa G , Škultétyová I
Published: October 2020

This work deals with the creation of a hydrodynamic model of the combined sewerage overflow chamber in Banská Bystrica. As an object on the sewer network, we chose a combined sewerage overflow chamber, because its correct functionality directly affects the quality of the environment in the recipient. Simulations were calculated in the program Ansys Workbench 19.2 – Fluid Flow (Fluent). The basis of the work was the creation of a 3D graphic model. The 3D model serves as a base for flow modeling. The core of the work are simulations in the combined sewerage overflow chamber that should correspond to real flow. The goal of our work is to compare the influence of inflow velocity and flow rakes on hydrodynamic flow.
The design of the technical flood protection measures on Svitava River, Czech Republic
Authors: Uhmannova H , Ondrejka Harbulakova V , Cetkovska L
Published: October 2020

The paper present the design of the technical flood protection measures on Svitava River in Březová above Svitava town. The current state of the study area was evaluated and determined based on related documents available for public as well as on the personal survey of the landscape. Technical solution as proposal of adjustment of the Svitava River (by composite trapezoid), extracting sediments and designing, stabilization of the bank and construction of the protective floodwall is shown in the paper. The riverbed slopes were fortified with a stone riprap with a sieve of grass mixture.
The treehouses
Authors: Vacenovská V
Published: October 2020

The goal of this research is to evaluate and find new solution in the area of wooden constructions placed in the treetops, which are interesting mainly due to their independence and amazing view among the treetops, and enable the utilization of the land below the treehouse itself. Treehouses can be constructed as a detached object without having to interfere with the trunk, or anchored into the trunk using special anchoring elements, where compact root system of surrounding trees is essential for healthy grow of the tree. Wood is also a specific natural material, which offers a possibility to create architecturally interesting and modern construction. This article is focused on evaluation of anchoring suitability of these constructions in treetops, evaluation of using these houses for recreational purposes as well as permanent living, effect of climate conditions on suitably chosen wood type and construction of these objects.
Building materials for 3D print
Authors: Wawrek I
Published: October 2020

The paper maps the current level of knowledge in 3D printing of construction objects. It introduces different approaches to creating wall structures of two world companies dealing with the problem of 3D print. It confronts their solution with the normative requirements for the territory of the Slovak Republic valid after 2021. It also presents proposals for possible improvement of the thermal-technical properties of the perimeter wall, modification of the design of the internal structure and properties of the printed material towards the normative requirements.
Associations of Maternal Androgen-Related Conditions With Risk of Autism Spectrum Disorder in Progeny and Mediation by Cardiovascular, Metabolic, and Fertility Factors
Authors: Rotem Ran S , Nguyen Vy T , Chodick Gabriel , Davidovitch Michael , Shalev Varda , Hauser Russ , Coull Brent A , Bellavia Andrea , Weisskopf Marc G
Published: October 2020

Fetal exposure to elevated androgens is thought to contribute to autism spectrum disorder (ASD) risk. However, data rely heavily on in utero androgens measurements, which also reflect fetal secretions. Thus, in utero hyperandrogenemia might indicate adverse autism-related neurogenesis that has already occurred affecting fetal androgen homeostasis, rather than being a cause of the disorder. Associations between maternal androgen-related conditions and ASD could more directly implicate androgens’ etiological role. We examined the association between maternal hyperandrogenemia-related conditions, focusing primarily on polycystic ovarian syndrome (PCOS), and progeny ASD, in an Israeli cohort of 437,222 children born in 1999–2013. Odds ratios and 95% confidence intervals were estimated using generalized estimating equations. Multiple mediation analyses using natural effect models were conducted to evaluate combined mediation of the PCOS effect by androgen-related cardiovascular, metabolic, and fertility factors. Results indicated that children of mothers with PCOS had higher ASD odds compared with children of mothers without PCOS (odds ratio = 1.42, 95% confidence interval: 1.24,1.64), and this effect was only partly mediated by the factors considered. Elevated odds were also observed for other hyperandrogenemia-related conditions. Findings provide support for direct involvement of maternal hyperandrogenemia in ASD etiology. Alternatively, findings might reflect shared genetic and/or environmental factors independently affecting maternal androgen homeostasis and fetal neurodevelopment.