bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing interlayer van der Waals strengths of two-dimensional surfaces and defects, through STM tip-induced elastic deformations
Authors: Sarkar N , Bandaru P R , Dynes R C
Published: January 2023

A methodology to test the interlayer bonding strength of two-dimensional (2D) surfaces and associated one (1D)- and two (2D)- dimensional surface defects using scanning tunneling microscope tip-induced deformation, is demonstrated. Surface elastic deformation characteristics of soft 2D monatomic sheets of graphene and graphite in contrast to NbSe2 indicates related association with the underlying local bonding configurations. Surface deformation of 2D graphitic moiré patterns reveal the inter-layer van der Waals strength varying across its domains. These results help in the understanding of the comparable interlayer bonding strength of 1D grain boundary as well as the grains. Anomalous phenomena related to probing 2D materials at small gap distances as a function of strain is discussed.
Operational space and performance limiting events in the first physics campaign of MAST-U
Authors: Berkery J W , Sabbagh S A , Kogan L , Gibson S , Ryan D , Zamkovska V , Butt J , Harrison J , Henderson S
Published: January 2023

The MAST-U fusion plasma research device, an upgrade to the Mega Amp Spherical Tokamak, has recently completed its first campaign of physics operation. MAST-U operated with Ohmic, or one or two neutral beams for heating, at 400–800 kA plasma current, in conventional or ‘SuperX’ divertor configurations. Equilibrium reconstructions provide key plasma physics parameters vs. time for each discharge, and diagrams are produced which show where the prevalence of operation occurs as well as the limits in various operational spaces. When compared to stability limits, the operation of MAST-U so far has generally stayed out of the low q, low density instability region, and below the high density Greenwald limit, high beta global stability limit, and high elongation vertical stability limit. MAST-U still has the potential to reach higher elongation, which could benefit the plasma performance. Despite the majority of operations happening below established stability limits, disruptions do occur in the flat-top phase of MAST-U plasmas. The reasons for these disruptions are highlighted, and possible strategies to avoid them and to extend the operational space of MAST-U in future campaigns are discussed.
Intelligent recognition and location of the edge coherence mode in EAST
Authors: Liu Xiaotao , Liu Ying , Ye Yang , Zhou Jijun , Liao Shengdi , Liu Chen
Published: January 2023

In the study of multiple pedestal coherent modes in EAST, the high-precision intelligent recognition and location of the edge coherent modes (ECM) is a very meaningful work. In this study, a convolutional neural network (CNN) feature extraction model based on the attention mechanism was constructed to classify and localize the ECM in the EAST experiment. The classifier identified ECM on the test dataset with an accuracy of 0.970; the localizer detected the ECM with an average precision (AP) of 0.956. In addition, we found a strong correlation between the stored energy and current in plasma and the excitation of the ECM during EAST discharge; the triangularity may affect the relative amplitude of the ECM.
Universal conductance fluctuations in a Bi1.5Sb0.5Te1.8Se1.2 topological insulator nano-scaled Hall bar structure
Authors: Zimmermann Erik , Kölzer Jonas , Schleenvoigt Michael , Rosenbach Daniel , Mussler Gregor , Schüffelgen Peter , Heider Tristan , Plucinski Lukasz , Schubert Jürgen , Lüth Hans , Grützmacher Detlev , Schäpers Thomas
Published: January 2023

We present low-temperature magnetotransport measurements characterizing the promising quaternary Bi1.5Sb0.5Te1.8Se1.2 topological insulator material. The measurements performed on a nano-Hall bar grown by selective-area molecular beam epitaxy revealed pronounced universal conductance fluctuations. It is shown that these fluctuations originate from phase-coherent loops within the topologically protected surface states. Furthermore, the decay of the fluctuation amplitude with increasing temperatures suggests a quasi one-dimensional transport regime.
Picosecond random Raman lasing in the spectral range of 360–630 nm using powders of potassium, sodium and strontium nitrates
Authors: Yu Pyatyshev A , Skrabatun A V , Vodchits A I , Larkina A V , Khodasevich I A , Orlovich V A
Published: January 2023

Stimulated Raman scattering (SRS) of picosecond laser radiation at 532 and 355 nm in microcrystalline powders of potassium, sodium, and strontium nitrates has been studied. One anti-Stokes and three Stokes components were generated in all samples when pumping at 532 nm. For the first time to our knowledge, random Raman lasing in the used nitrates has been obtained upon their excitation at 355 nm. In this case, the multifrequency Stokes SRS is also observed in all nitrates. We have analyzed all possible loss channels when ultraviolet radiation is used for excitation of SRS. In general, picosecond random SRS generation has been obtained at 19 spectral lines in the spectral range of 360–630 nm. In all cases, the SRS process is due to the internal symmetric mode of the (NO3)− ion with the frequency shifts of 1050 cm−1 (KNO3), 1069 cm−1 (NaNO3), and 1057 cm−1 (Sr(NO3)2).
Application of silicon carbide temperature monitors in 49-2 swimming-pool test reactor
Authors: Ning Guang-Sheng , Zhang Li-Min , Zhong Wei-Hua , Wang Sheng-Hong , Liu Xin-Yu , Wang Ding-Ping , He An-Ping , Liu Jian , Zhang Chang-Yi
Published: January 2023

High purity SiC crystal was used as a passive monitor to measure neutron irradiation temperature in the 49-2 research reactor. The SiC monitors were irradiated with fast neutrons at elevated temperatures to 3.2 × 1020 n/cm2. The isochronal and isothermal annealing behaviors of the irradiated SiC were investigated by x-ray diffraction and four-point probe techniques. Invisible point defects and defect clusters are found to be the dominating defect types in the neutron-irradiated SiC. The amount of defect recovery in SiC reaches a maximum value after isothermal annealing for 30 min. Based on the annealing temperature dependences of both lattice swelling and material resistivity, the irradiation temperature of the SiC monitors is determined to be ∼410 °C, which is much higher than the thermocouple temperature of 275 °C recorded during neutron irradiation. The possible reasons for the difference are carefully discussed.
Thermal stress damage mechanism in single-crystal germanium caused by 1080 nm laser irradiation
Authors: Sha 沙 Yin-Chuan 银川 , Li 李 Ze-Wen 泽文 , Jia 贾 Zhi-Chao 志超 , Han 韩 Bing 冰 , Ni 倪 Xiao-Wu 晓武
Published: January 2023

The process of thermal stress damage during 1080 nm laser ablation of single-crystal germanium was recorded in real time using a high-speed charge-coupled device. A three-dimensional finite element numerical model based on Fourier’s heat conduction equation, Hooke’s law and the Alexander–Hasson equation was developed to analyze the thermal stress damage mechanism involved. The damage morphology of the ablated samples was observed using an optical microscope. The results show that the cooling process has an important influence on fracture in the laser-irradiated region of single-crystal germanium. Fracture is the result of a combination of thermal stress and reduction in local yield strength.
Detection of healthy and pathological heartbeat dynamics in ECG signals using multivariate recurrence networks with multiple scale factors
Authors: Ma 马 Lu 璐 , Chen 陈 Meihui 梅辉 , He 何 Aijun 爱军 , Cheng 程 Deqiang 德强 , Yang 杨 Xiaodong 小冬
Published: January 2023

The electrocardiogram (ECG) is one of the physiological signals applied in medical clinics to determine health status. The physiological complexity of the cardiac system is related to age, disease, etc. For the investigation of the effects of age and cardiovascular disease on the cardiac system, we then construct multivariate recurrence networks with multiple scale factors from multivariate time series. We propose a new concept of cross-clustering coefficient entropy to construct a weighted network, and calculate the average weighted path length and the graph energy of the weighted network to quantitatively probe the topological properties. The obtained results suggest that these two network measures show distinct changes between different subjects. This is because, with aging or cardiovascular disease, a reduction in the conductivity or structural changes in the myocardium of the heart contributes to a reduction in the complexity of the cardiac system. Consequently, the complexity of the cardiac system is reduced. After that, the support vector machine (SVM) classifier is adopted to evaluate the performance of the proposed approach. Accuracy of 94.1% and 95.58% between healthy and myocardial infarction is achieved on two datasets. Therefore, this method can be adopted for the development of a noninvasive and low-cost clinical prognostic system to identify heart-related diseases and detect hidden state changes in the cardiac system.
Thermodynamic limit of the XXZ central spin model with an arbitrary central magnetic field
Authors: Wen Fa-Kai , Hao Kun
Published: January 2023

The U(1) symmetry of the XXZ central spin model with an arbitrary central magnetic field
B
is broken, since its total spin in the z-direction is not conserved. We obtain the exact solutions of the system by using the off-diagonal Bethe ansatz method. The thermodynamic limit is investigated based on the solutions. We find that the contribution of the inhomogeneous term in the associated T–Q relation to the ground state energy satisfies an N
−1 scaling law, where N is the total number of spins. This result makes it possible to investigate the properties of the system in the thermodynamic limit. By assuming the structural form of the Bethe roots in the thermodynamic limit, we obtain the contribution of the direction of
B
to the ground state energy. It is shown that the contribution of the direction of the central magnetic field is a finite value in the thermodynamic limit. This is the phenomenon caused by the U(1) symmetry breaking of the system.
Hot electron and ion spectra on blow-off plasma free target in GXII-LFEX direct fast ignition experiment
Authors: Ozaki T. , Abe Y. , Arikawa Y. , Sentoku Y. , Kawanaka J. , Tokita S. , Miyanaga N. , Jitsuno T. , Nakata Y. , Tsubakimoto K. , Sunahara A. , Jhozaki T. , Miura E. , Komeda O. , Iwamoto A. , Sakagami H. , Okihara S. , Ishii K. , Hanayama R. , Mori Y. , Kitagawa Y.
Published: January 2023

Polystyrene deuteride shell targets with two holes were imploded by the Gekko XII laser and additionally heated by the LFEX laser in a direct fast ignition experiment. In general, when an ultra-intense laser is injected into a blow-off plasma created by the imploding laser, electrons are generated far from the target core and the energies of electrons increase because the electron acceleration distance has been extended. The blow-off plasma moves not only to the vertical direction but to the lateral direction against the target surface. In a shell target with holes, a lower effective electron temperature can be realized by reducing the inflow of the implosion plasma onto the LFEX path, and high coupling efficiency can be expected. The energies of hot electrons and ions absorbed into the target core were calculated from the energy spectra using three electron energy spectrometers and a neutron time-of-flight measurement system, Mandala. The ions have a large contribution of 74% (electron heating of 4.9 J and ion heating of 14.1 J) to target heating in direct fast ignition.
Recycled waste glass usage for construction materials
Authors: Tihomirovs P , Korjakins A
Published: January 2023

Recycling glass waste obtained from different industries is an issue in today’s economy. One of the ways of recycling is to produce lightweight ceramic by applying glass waste, clay, and gasifier as raw materials. The present research has been devoted to the evaluation of the influences of different clays extracted from two Latvian quarries (Lielauce un Samini) on the properties of lightweight ceramics. The main criteria of applicated clay as raw materials for producing lightweight ceramic are the following: saturation of SiO2 should be a maximum of 70% and Al2O3 minimum of 12%. The aim of the present research was to elaborate a composition for producing glass ceramic from glass waste with minimum energy consumption with a gasifier. The most important properties of the final product are thermal conductivity, compression strength, volume density, size, granulometry, and pore distribution. Two parameters of them, compression strength and volume density have been tested and analysed in the present research framework. Burning time is one more important additional parameter, which has been considered evaluating the properties of the final product. The obtained volume density is in the range of 226.75 kg/m3 to 475.78 kg/m3 depending on the composition.
Comparison of thermal conductivity of foamed geopolymers containing phase change materials
Authors: Bąk Agnieszka , Pławecka Kinga , Łach Michał
Published: January 2023

The aim of this work was to investigate the effect of Phase Change Materials on the insulation properties - thermal conductivity coefficient [λ], of fabricated foamed geopolymer panels. Phase Change Materials have been widely reported in the public literature, making them increasingly popular in recent times. PCMs have the ability to accumulate heat, which they can absorb or release due to thermal transformation, which contributes to energy efficiency. This paper presents the results of research on geopolymers based on fly ash with the addition of microencapsulated and macroencapsulated phase change materials (PCMs). Geopolymer composites were prepared by adding 0%, 5%, 10% and 15% PCM and the curing process was carried out at 60°C. Three different phase change materials with melting points of 28°C (MicroCapsPCM28 (Slovenia)) and 25°C and 42°C (PX25 and GR42 (Germany), respectively) were used. All the phase change materials used belong to the paraffin group. The obtained composite sheets were subjected to thermal conductivity tests in 3 temperature ranges (0-20°C; 20-40°C; 30-50°C). The paper also presents the density results of the foamed composites investigated, as well as the visual evaluation and the morphology of the porous structure using scanning electron microscopy. As a result of the study, it was found that foamed geopolymer composites without PCM addition have lambda coefficient values of 0.06 - 0.07 [W/m*K], while with the addition of phase change materials 0.07 - 0.085 [W/m*K]. The obtained test results give the potential to use these materials in construction as insulating materials. The use of these substances in building partitions results in the decrease of daily temperature amplitudes inside the building, as well as in the phase shift of the time of release of stored heat.
The influence of modified biopolymer on mechanical, hygrothermal properties and durability of ecological clay materials
Authors: Trambitski Y , Kizinievič O , Kizinievič V
Published: January 2023

In this study, the effect of modified biopolymer (retrograded corn starch) on the mechanical and hygroscopic properties of clay materials was investigated. Also, described the technology of a modified biopolymer preparation. Clay materials were fabricated using different amounts of modified biopolymer. These studies have shown that the addition of modified polymer has a significant effect on the properties and durability of the clay materials. The incorporation of modified polymers into the clay matrix contributed to an increase in compressive strength by 62% (6.8 to 11 MPa). The surface moisture adsorption increased by 29% (from 141.1 to 179.3 g/m2). Durability of the clay materials also significantly increased. Also, it was found that the modified polymers had a significant influence on the structure of ecological clay materials.
Experimental investigation of heat transfer in bio-based building block with microencapsulated PCM
Authors: Cieślikiewicz Łukasz , Łapka Piotr , Dietrich Fabian , Wendołowicz Mateusz , Brzyski Przemysław
Published: January 2023

The paper presents the investigation of heat transfer in hemp shives and magnesia binder composite with microencapsulated phase change material (PCM) to increase the building material’s thermal mass. The investigated sample was prepared as a three-layer block of dimensions 600×400×480 mm. The external layers of the block had a density of approximately 400-450 kg/m3 and a thickness of 50-60 mm, while the inner layer had a density of approximately 200-250 kg/m3 and a thickness of 290 mm. The study was performed with a block placed between two specially designed climatic chambers. Conditions in chambers were fully stabilized. Additionally, 50 mm wide channels with fans in both chambers were added close to the sample surfaces to force uniform airflow along both sample surfaces. For parameters control in the chambers, dedicated software was developed. Inside the sample nine temperature sensors were placed. During measurements, the temperature of 30°C and relative humidity of 40% was maintained in one chamber, while in the second one, after stabilization in temperature of 20°C and relative humidity of 50%, the temperature was decreased to 15°C without humidity control. During measurement insulating properties of PCM in dynamic conditions were analyzed.
Experimental verification of conditions within the cups in the cup method of water vapor permeability measurement
Authors: Pietrak K , Krakowiak M , Łapka P
Published: January 2023

Vapor transmission coefficients of building materials can be determined using the cup method, known from ASTM and ISO standards. The measurement principle is simple, but the method is known to be problematic. In this paper, problems concerning the discrepancy between assumed and real values of relative humidity inside the cups are investigated. This concerns especially dry cups, in which desiccants are expected to produce relative humidity close to 0%. Interestingly, there are studies which suggest a much greater value should be used. To verify these claims, experiments were conducted for cups filled with calcium chloride (CaCl2), and saturated aqueous solution of potassium nitride (KNO3), covered with hemp-lime concrete samples. The study confirms earlier reports of a discrepancy between actual and assumed values of relative humidity inside the cups and shows that they might introduce significant error in the measurement of water vapor transmission coefficients.
Environment Risk Management of Warehouse and Production Hall Investment Projects
Authors: Kalisa Ing. Eric , Korytárová Jana
Published: January 2023

Planning, implementation and operation of buildings and related outdoor areas in accordance with the principle of sustainable construction represent a current topic.

Important elements of sustainability include the environmental impact assessment of construction works which may include CO2 emissions. Warehouses and manufacturing facilities are significant environmental polluters and emitters of CO2. Management of industrial companies seeks to manage this environmental risk and find ways of its reduction within the framework of sustainable development.

The article deals with environmental risk management in general, its identification, assessment methods and development of the countermeasures to reduce or eliminate them. Continuous monitoring and control of the functioning of the measures represent an important component of their management. An analysis of a research sample of warehouse and manufacturing facility projects located in industrial zones shows that if companies fail to continuously reduce emissions, they may face secondary risks which may be related to the company’s social impact, sales or reputation of the company and may affect, for example, their share prices.

The output of the research presented in this article is a list of initiatives on reducing environmental risks (especially CO2) of warehouses and manufacturing facilities, determination of the costs associated with them and assessment of the socioeconomic impacts (benefits to society). The research serves as one of the steps towards determining the overall socio-economic effectiveness of these measures.
Experimental analysis of timber-concrete composite behaviour with synthetic fibres
Authors: Buka-Vaivade K , Serdjuks D , Zvirina D , Pakrastins L
Published: January 2023

With the growing importance of the principles of sustainable construction, the use of load-bearing timber-concrete composite structures is becoming increasingly popular. Timber-concrete composite offers wider possibilities for the use of timber in construction, especially for large-span structures. The most significant benefit from combining these materials can be obtained by providing a rigid connection between the timber and concrete layers, which can be obtained by the adhesive timber-to-concrete connection produced by the proposed stone chips method. A sustainable solution involves the abandonment of steel longitudinal reinforcement. The use of such a solution in practice is often associated with fears of a fragile collapse. Therefore, the issue of how to increase the safety factor of the proposed material is topical now. The experimental investigation is made to determine the effect of synthetic fibre use on timber-concrete composite behaviour by testing a series of timber-concrete composite specimens with and without fibres in the concrete layer. The obtained results show that adding 0.5 % of synthetic macro fibres allows to abandon the use of longitudinal steel reinforcement and prevents the formation of large cracks in concrete and the disintegration of the concrete layer in case of collapse.
Effective thermal conductivity of composites with anisotropic particles of various shapes embedded in an isotropic matrix
Authors: Pietrak K , Furmański P , Łapka P
Published: January 2023

The paper demonstrates a method to calculate effective thermal conductivity in a two-phase medium with an isotropic host phase and embedded anisotropic particles. The presented scheme enables easy incorporation of various regular shapes of filler particles if the principal values of their Eshelby tensor are supplied. Basic shapes, such as spheroids, may approximate a wide range of fillers used to enhance thermal conduction, such as polymers filled with highly conductive metal and ceramic powders, graphite and graphene flakes, and nanotubes. Different spatial orientations and sizes of particles may be supplied to the model in the form of probability distributions. The method is well suited to numerical implementation, and the resulting computations are less demanding than popular mesh-based methods, i.e., Finite Volume and Finite Element Methods. It does not include interfacial thermal resistance between particles and matrix, but the addition of this component is planned in future papers.
Complex coating system for improving corrosion resistance of AZ31 magnesium alloy
Authors: Drunka R , Iesalniece P , Steins I , Grase L , Eiduks T V , Savkovs K , Blumbergs I
Published: January 2023

Complex coating for corrosion protection was developed on magnesium alloy AZ31 using plasma electrolytic oxidation (PEO), spray pyrolysis (SP) and two-part paint. PEO coatings were obtained using electrolyte with phosphate modifier. The oxide layer formed via PEO was sealed using pyrolyzed TiO2 and finally coated with spray primer-paint system to further protect the surface. The specimens were tested for corrosion using immersion gravimetric method in 3% NaCl solution for 1 week and mass loss was recorded. Morphology of the PEO and SP coatings were studied using SEM and chemical analysis of SP coating by EDS. It was found that 30 minutes of spray time in SP process caused surface cracks in the coating. Paint was applied in varying numbers of primer and paint layers and 2 layers each produced the best results in terms of corrosion resistance.
Optimal Sensor Placement in Composite Circular Cylindrical Shells for Structural Health Monitoring
Authors: Rucevskis Sandris , Kovalovs Andrejs , Chate Andris
Published: January 2023

This work presents an approach for optimal placement of strain sensors in composite circular cylindrical shells. The approach uses numerical strain values in longitudinal and transverse directions extracted from the top surface of the thin-walled composite cylindrical shell. Numerical model of composite cylindrical shell was modelled using the FE commercial solver ANSYS. The modal analysis was performed to determine the first 12 natural frequencies and corresponding mode shapes. Number of sensors and their locations were obtained taking into account physical constraints of strain sensors and optimization strategies. Finally, the optimal sensor placements were obtained. Maximal number of sensors in each direction equals 30.
Thermal Oxidation of Tungsten Coatings for Detection by Infrared Spectrometry Method
Authors: Goldmane Annija Elizabete , Avotina Liga , Vanags Edgars , Trimdale-Deksne Aija , Zaslavskis Aleksandrs , Kizane Gunta , Dekhtyar Yuri
Published: January 2023

Physical vapor deposition (PVD) of metallic thin films is used extensively in the fabrication of semiconductor technology devices - use as of lately for them have grown. Tungsten (W) is a low resistivity, refractory metal, that is often deposited by PVD methods for use as a gate contact to semiconductor devices and due to the low work function and high thermal stability, W can be used for the fabrication of field emitters in microelectronics [1-3]. In order to monitor quality of the synthesized thin films by magnetron sputtering method, it is necessary to develop methodology suitable for the analysis of these thin films. Infrared spectrometry is a sensitive method for the analysis of chemical bonds, but W thin films contain weakly polar and non-polar W-W bonds, that cannot be directly detected by infrared spectrometry, therefore oxidation of W is selected as thermal oxidation method for detecting oxidized products for thin films of thickness 150 nm, for instance, W-O bonds. After oxidation, it was observed, that the oxidation of W thin films takes place already at a 600 °C in the air atmosphere. The Fourier transform infrared spectrometry (FTIR) spectra of modified coatings showed formation of additional new signals in the region of 700-900 cm−1 attributed to W-O, O-W-O, W=O bonds - formation of W-oxygen bonds on Si-SiO2 substrate was achieved. For coating homogeneity and production quality formation, additionally synthesized control samples are recommended for FTIR analysis.
Al-Ti-Mg composite target for PVD protective coatings for magnesium made by powder metallurgy technique
Authors: Zemcenkovs Vjaceslavs , Lisnanskis Marks , Pole Eleonora
Published: January 2023

Target metal plates for PVD application made from ternary metal composites of Al, Ti* and Mg were produced by compacting metal powders. Al content was fixed at 70 wt. % and the other two were changed to study the effect of composition on the properties of the plates. Ti* powder, in the form of Ti6Al4V alloy, and pure Mg powder were varied in ratios of 2, 1 and 0.5 by weight. The compositions can be written as Al-70 wt.% Ti*-X wt.% and Mg-Y wt.% (X=20, 15,10, and Y=10, 15, 20). The powders were wet milled and compacted under uniaxial compressive load to form the plates. The strength of the plates was measured by performing 3-point bending tests and load till failure was reported. Effect of cold compaction load, mixing time of the powders and Ti* powder content on the microstructural and mechanical properties was studied.
Cu-Al-Ag composite target for PVD protective coatings for magnesium made by powder metallurgy technique
Authors: Zemcenkovs Vjaceslavs , Lisnanskis Marks , Pole Eleonora
Published: January 2023

A new composite metal target for physical vapor deposition (PVD) coating on Mg alloys was produced using powder metallurgy (PM) technique. The ternary Cu-Al-Ag composite metal targets were produced in three different compositions with Cu content fixed at 80 wt. % and varying Al/Ag ratios of 1, 1.5 and 7, respectively, resulting in composition Cu-80 wt. % Al-X wt.% and Ag-Y wt.% (X=10.0, 15.0,17.5, and Y=10.0, 5.0, 2.5). Target plates in the chosen composition were synthesized using powder compaction method. Effect of powder mixing time and compaction load on the density and strength of green parts was studied. The effect of powder mixing time, compaction force and silver addition on microstructural and mechanical properties of PVD targets investigated.
Impact of amino acids as performance-controlling additives on the hydration of reactive MgO
Authors: Liang Shuang , Zhou Xiangming , Hou Pengkun
Published: January 2023

Since reactive magnesia (MgO) is produced at a lower temperature than CaO and is capable of sequestering significant quantities of CO2, it is considered to be a technically superior and more sustainable alternative to Portland cement. To obtain maximum carbonation and associated high strength, a variety of additives are investigated for MgO. Using amino acids as an additive is a new concept to control the polymorphism of carbonates. As the hydration of magnesia plays an important role in magnesia carbonation, this study investigates the impact of amino acids (i.e. L-arginine (L-Arg) and L-aspartic (L-Asp)) on the hydration of magnesia. Subsequent tests, including X-ray diffraction (XRD), pH tests, inductively coupled plasma optical emission spectrometry (ICP-OES), thermogravimetry (TG) - differential thermogravimetry (DTG), and scanning electron microscopy-Energy-dispersive X-ray spectroscopy (SEM-EDX) were conducted after the measurement of their strength development. The results revealed that magnesia hydrated with/without amino acids only formed brucite (Mg(OH)2) as the hydration product. A lower hydration degree was observed in the hydrated composites with the presence of amino acids, regardless of the type of amino acids. Specifically, the use of L-Asp not only delayed the hydration of MgO but also reduced the amount of brucite. The increasing amorphousness of brucite with increasing L-Asp concentration was also observed, compared to the control batch. Additionally, Mg2+ concentration was increased with the addition of L-Asp, allowing the blends to absorb more CO2 with a higher concentration of Mg2+.
Methods for measuring plastic shrinkage and related cracking of 3D-printed concrete
Authors: Markin Slava , Mechtcherine Viktor
Published: January 2023

Developments in the application of the 3D concrete printing (3DCP) technology in the construction industry over the past few years are providing a chance to increase productivity and cost efficiency. However, before reaching an industrial stage of the 3DCP technology several hurdles should be overcome. One of the major challenges is to guarantee high durability and long-life cycle of the printed elements. Since 3D-printed elements are subjected to very early and fast evaporation of the pore water, accelerated capillary pressure build-up may lead to severe plastic shrinkage and, consequently, a high cracking propensity of the 3D-printed elements. Durability and robustness would be severely impaired. Experimental quantification of the plastic shrinkage and related cracking is essential to identify appropriate mitigation strategies. The article at hand presents innovative approaches for quantification of the plastic shrinkage and related cracking of the printable cementitious compositions by means of contactless 3D digital image correlation technique. Various experimental setups were presented and their effectiveness for measurement of the plastic shrinkage and plastic shrinkage cracking were analysed.
Two approaches for analysis of the dynamic pile bearing capacity via pile driving formulas
Authors: Kovzels J , Paeglitis A.
Published: January 2023

Piling is considered the most cost-efficient solution in deep foundation structures, and it involves many modern-day solutions in every field, such as modern-day materials and construction equipment. However, analysis of pile bearing capacity that includes evaluating of soil conditions and its mechanical properties is relatively new compared to piling itself. Pile bearing capacity depends on two factors – the strength of the structural element itself and the resistance of the soil around the pile. This resistance must be enough to avoid excessive displacements, rotations and other movements that make the superstructure unstable. The structural strength of the pile itself could be determined, though soil resistance is affected by many factors. One of the pile bearing capacity establishment methods is pile driving formulas – equations that establish pile bearing capacity considering set per blow and hammer impact energy. However, given establishment approach is considered unreliable and out of date, although this approach has several advantages – fast execution and minimum additional equipment required. Paper deals with two approaches for analysing the dynamic pile bearing capacity via pile driving formulas and correlation establishment between dynamic load test and static load test. In paper correlation between both dynamic pile bearing capacity approaches and static load test is established.
Development of a static plate test finite element calculation model
Authors: Virsis Endijs , Paeglitis Ainars , Zarins Atis
Published: January 2023

In the last few years as the budget for the road sector has been decreasing in Latvia, the number of road pavement structure reinforcement projects has been increasing. In order to ensure the long-term viability of the road it is necessary to assess the load-bearing capacity of the existing road structure and the subgrade. During the geotechnical research, the load-bearing capacity of the existing base layers is assessed using static plate test. However, the accuracy of the results is strongly influenced by the thickness of the existing asphalt layer and the size of the dismantled asphalt area. In order to determine the load-bearing capacity of the existing road base in the deeper layers, the engineer performs a subjective experience-based interpretation that is not based on mathematical calculations. With the development of geotechnical survey equipment and engineers’ understanding of the bearing capacity of the subgrade, it is also possible to use other field research methods, such as probing and interpretation of their data. Various software’s for soil calculations have been developed worldwide. With the help of software’s, it is possible to evaluate the properties of soil layers, predict deformations and develop reinforcement solutions, however, the obtained results do not reflect the basic bearing capacity, which is expressed in MPa units. It is planned to develop a Finite Element Method simulation of static plate test based on the values of the soil layer parameters obtained from the interpretations of the probe data and to compare the results with the static plate test performed on site. The aim of the study is to determine whether the load-bearing capacity of the existing base can be accurately determined by finite element calculations - a simulation of a static plate test based on the physical-mechanical properties of the soil determined during the geotechnical survey.
Traffic safety analysis for different road junctions in the Latvian national road network in the period from 2017-2019
Authors: Amare V , Smirnovs J
Published: January 2023

Traffic organization must be safe, but according to traffic accident data, the highest number is at intersections. Different intersections are evaluated based on various criteria - road throughput, conflict points, number and severity of road traffic accidents. There are many different types of intersections in the road network, each of them is suitable for certain road parameters in the road network. In the main road network of the State of Latvia for the period 2017-2019, data was collected and places where road traffic accidents often occur were evaluated. Where one of the most important tasks was to find a rational way to improve safety without losing the importance of the road. The aim of this work is to analyze the impact of different intersections on the road network, as well as to provide recommendations for a safe consistent road network based on actual data.
Elephant trunks use an adaptable prehensile grip
Authors: Schulz Andrew K , Reidenberg Joy S , Ning Wu Jia , Ying Tang Cheuk , Seleb Benjamin , Mancebo Josh , Elgart Nathan , Hu David L
Published: January 2023

Elephants have long been observed to grip objects with their trunk, but little is known about how they adjust their strategy for different weights. In this study, we challenge a female African elephant at Zoo Atlanta to lift 20–60 kg barbell weights with only its trunk. We measure the trunk’s shape and wrinkle geometry from a frozen elephant trunk at the Smithsonian. We observe several strategies employed to accommodate heavier weights, including accelerating less, orienting the trunk vertically, and wrapping the barbell with a greater trunk length. Mathematical models show that increasing barbell weights are associated with constant trunk tensile force and an increasing barbell-wrapping surface area due to the trunk’s wrinkles. Our findings may inspire the design of more adaptable soft robotic grippers that can improve grip using surface morphology such as wrinkles.
Quantifying global carbon dioxide removal deployment
Authors: Powis Carter M , Smith Stephen M , Minx Jan C , Gasser Thomas
Published: January 2023

Despite the importance of carbon dioxide removal (CDR) in most climate change mitigation scenarios that limit warming to well below 2 °C, the study of CDR is still a nascent field with basic questions to be resolved. Crucially, it is not known how much CDR is currently deployed at a global scale, nor how that compares to mitigation scenario estimates. Here, we address this problem by developing an estimate of global current CDR activity. We draw on national greenhouse gas inventory data combined with CDR registries and commercial databases to estimate that global anthropogenic activity presently generates ∼1985 MtCO2yr−1 of atmospheric removals. Almost all of these—1983 MtCO2yr−1—are removals from land-use, land-use change and forestry. Non-land-management CDR projects such as bioenergy with carbon capture and storage, direct air capture with carbon capture and storage and biochar remove only about 2 MtCO2yr−1. We compare this estimate with Shared Socioeconomic Pathways projections of CDR deployed in ‘well-below 2°C’ mitigation pathways. In so doing we demonstrate current CDR deployment would need to grow exponentially to keep the world aligned with most ‘well-below 2°C’ scenarios, which see CDR deployment growing between 75% and 100% per year between 2020 and 2030, adding ∼300–2500 MtCO2 in total CDR capacity. To conclude we discuss uncertainties related to our estimates, and suggest priorities for the future collection and management of CDR data, particularly related to the role of the land sink in generating CDR.
Quantifying the fragility of coral reefs to hurricane impacts: a case study of the Florida Keys and Puerto Rico
Authors: Madden I A , Mariwala A , Lindhart M , Narayan S , Arkema K K , Beck M W , Baker J W , Suckale J
Published: January 2023

Ecosystems like coral reefs mitigate rising coastal flood risks, but investments into their conservation remain low relative to the investments into engineered risk-mitigation structures. One reason is that quantifying the risk-reduction benefits of coral reefs requires an estimate of their fragility to severe stresses. Engineered structures typically have associated fragility functions which predict the probability of exceeding a damage state with the increasing loading intensity imposed by a stressor, like a hurricane. Here, we propose a preliminary framework for capturing the fragility of coral reefs towards hurricanes in an analogous way to that of an engineered structure. We base our framework on Disturbance Response Monitoring data collected in the Florida Keys and Puerto Rico following hurricanes Irma and Maria. We first establish a qualitatively consistent correlation between hurricane impacts and coral mortality rates using two surveys of coral health. We focus specifically on stony coral mortality as a metric for reef damage, simplifying the effect of coral morphology into a single quantitative index at the site scale. To quantify the loading intensity of a hurricane, we propose a Hurricane Wind Exposure Time that captures spatial variations in the exposure of different coral reef sites to hurricane force winds. We ultimately derive a simple empirical fragility function for the Florida Keys and Puerto Rico to support side-by-side comparisons of the cost-effectiveness of a coral reef and engineered solutions to flood risk reduction in these regions.
Factors of the information and network economy sustainable development in Ukraine
Authors: Liakhovych O , Zaluzhnyi A , Prytula M , Skakovska S , Osadcha O
Published: January 2023

The article is devoted to determining the role of the information sector of the economy in the new conditions of ensuring the sustainable development of the economic system. The article determines that the largest influence on the GDP per capita of Ukraine is exerted by the indicator of realized Internet services. This proves the fact that today the consumption of information and communication services plays a leading role in the economic growth of the country. And therefore, there is an opportunity not only to influence the growth of GDP by creating conditions of a technical and informational and communication nature, but also to determine the prerequisites for the growth of national income based on the study of consumer needs and their transformations in the conditions of digitalization. In accordance with the concept of sustainable development, the indicator of the usefulness of information needs is not their volume and the desire of economic subjects to use them, but the characteristics of reliability, completeness, accuracy, novelty, efficiency. Along with this, it was noted that the comprehensiveness and unrestrained consumption leads to social irresponsibility, massification, negative effects on the ecological situation of the environment, the undermining of sustainable mechanisms of the existence of civilization as a whole, which requires the justification of alternative approaches of “frugal” and “restrained” consumption. The implementation of prosumerism approaches is defined as an alternative way to building an information and network economy of sustainable development.
Oxygen productivity of urban forests of Kyiv city as a constituent of its sustainable development
Authors: Vasylyshyn R , Lakyda I , Melnyk O , Lakyda M , Soshenskyi O , Pinchuk A
Published: January 2023

The oxygen-producing function of urban forests is an integral factor in creating favourable living conditions for the population in an urbanized environment. Managerial decisions aimed at the development of environmental potential in urban forests shall be based on sustainable development goals and ensure the balanced use of their ecosystem functions. As a result of the research, quantitative values of the oxygen productivity of urban forests in Kyiv have been computed. Also, we have analysed the influence of the main biometric characteristics of stands on the intensity of their oxygen production capacity. The informational basis for evaluating the oxygen productivity of urban forests consists of research data that reflects the silvicultural characteristics of more than 14,000 forested plots featuring different species composition, age, and site index class, growing in different types of conditions. As a methodological basis, we have applied the semi-empirical method, which involves assessing the net primary production of ecosystems. The proposed quantitative values of oxygen productivity in Kyiv’s urban forests serve as an information component in forming a sustainable development strategy for the preservation and extended restoration of forest ecosystems in the region.
Methodological aspects of determining the economic efficiency of environmental management
Authors: Kovshun N , Kostrychenko V , Solodkyy V , Savytska O , Kushnir N , Malanchuk L
Published: January 2023

Methodical approaches to calculating the economic efficiency of natural resources use are considered. The characteristics of water services regulation in Ukraine are given. Economic indicators of regional development in the Vistula River basin are investigated. The dynamic analysis of revenues for special water use and expenditures for water resources in the Vistula River basin is carried out. Revenues to the state and local budgets were investigated in terms of rent payments, environmental tax, rent and special use of fish and other aquatic bioresources. To calculate the economic efficiency, the state expenditures under the budget program “Operation of the state water management complex and water resources management” in the Vistula River basin area were used. The obtained indicator was improved by taking into account the environmental component. Expenditures in the context of capital and current investments from the state and local budgets for environmental programs in the field of water resources protection were analyzed. The indicator of reduced costs for water resources in 2020 is formed. It is proposed to assess economic efficiency through the indicator of the level of coverage of the reduced costs of water resources.
Products brand marketing strategy based on environmental friendliness agricultural innovation: China-Ukraine’s case
Authors: Prokopenko K , Liang R , Bliumska-Danko K , Artyukhov A , Dluhopolskyi O
Published: January 2023

This research focuses on the influence of modern agricultural innovation on brand strategy, analysing the trends and characteristics of modern agricultural innovation in Ukraine and China, describe differences between countries. The situation in agriculture show – the same background of enterprises can have different results with profit or loss. Therefore, important to establish a commitment of customers to build an agricultural products brand marketing strategy and, as result, increase the profitability of the enterprise. Analyses the development trend of modern agricultural innovation, the characteristics of modern agricultural innovation, and the status of agricultural product brand marketing using literary analysis and case analysis methods, explains the impact of modern agricultural innovation on agricultural product brand marketing, and proposes agricultural product brand marketing strategies for building a good reputation for the brand. A model of the dependence of the purchase intention of consumers of agricultural products on the environmental friendliness of the brand is proposed, which is based on the analysis of the direct effect of public awareness of the environmental friendliness of the brand on the intention of consumers to purchase the products of an agricultural enterprise and the mediating effect of trust in the brand on the intention of the consumer to purchase the products of an agricultural enterprise.