bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery of two promising isolated neutron star candidates in the SRG/eROSITA All-Sky Survey
Authors: Kurpas J. , Schwope A. D. , Pires A. M. , Haberl F. , Buckley D. A. H.
Published: April 2023

We report the discovery of the isolated neutron star (INS) candidates eRASSU J065715.3+260428 and eRASSU J131716.9−402647 from the Spectrum Roentgen Gamma (SRG) eROSITA All-Sky Survey. Selected for their soft X-ray emission and absence of catalogued counterparts, both objects were recently targeted with the Large Binocular Telescope and the Southern African Large Telescope. The absence of counterparts down to deep optical limits (25 mag, 5σ) and, as a result, large X-ray-to-optical flux ratios in both cases strongly suggest an INS nature. The X-ray spectra of both sources are well described by a simple absorbed blackbody, whereas other thermal and non-thermal models (e.g., a hot-plasma emission spectrum or power law) are disfavoured by the spectral analysis. Within the current observational limits, and as expected for cooling INSs, no significant variation (> 2σ) has been identified over the first two-year time span of the survey. Upcoming dedicated follow-up observations will help us to confirm the candidates’ nature.
Transition disc nature of post-AGB binary systems confirmed by mid-infrared interferometry
Authors: Corporaal A. , Kluska J. , Van Winckel H. , Andrych K. , Cuello N. , Kamath D. , Mérand A.
Published: April 2023

Context. Many properties of circumbinary discs around evolved post-asymptotic giant branch (post-AGB) binary systems are similar to those of protoplanetary discs around young stars. The deficits of near-infrared (near-IR) flux in the spectral energy distributions (SEDs) of these systems hints towards large dust-free cavities that are reminiscent of transition discs as are commonly observed around young stars.

Aims. We aim to assess the size of the inner rim of six post-AGB binary systems with lack in the near-IR like this. We used resolved mid-infrared (mid-IR) high-angular resolution observations of VLTI/MATISSE and VLTI/MIDI. The inner rim of only one such system was previously resolved. We compared these inner rim sizes to five systems with available MATISSE data that were identified to host a disc starting at the dust sublimation radius.

Methods. We used geometric ring models to estimate the inner rim sizes, the relative flux contributions of the star, the ring, and an over-resolved emission, the orientation of the ring, and the spectral dependences of the components.

Results. We find that the inner dust rims of the targets with a lack of near-IR excess in their SEDs are ∼2.5 to 7.5 times larger than the theoretical dust sublimation radii, and inner rim sizes of the systems that do not show this deficit are similar to those of their theoretical dust sublimation radii. The physical radii of the inner rims of these transition discs around post-AGB binaries are 3–25 au, which are larger than the disc sizes inferred for transition discs around young stars with VLTI/MIDI. This is due to the higher stellar luminosities of post-AGB systems compared to young stars, implying larger dust sublimation radii and thus larger physical inner radii of the transition disc.

Conclusions. With mid-IR interferometric data, we directly confirm the transition disc nature of six circumbinary discs around post-AGB binary systems. Future observational and modelling efforts are needed to progress in our understanding of the structure, origin, and evolution of these transition discs.
The History of Air Fluorescence
Authors: Sokolsky Pierre
Published: April 2023

I describe the history of the use of the air-fluorescence technique in UHECR physics.
The depth of the shower maximum of air showers measured with AERA
Authors: Pont Bjarni
Published: April 2023

The Auger Engineering Radio Array (AERA), as part of the Pierre Auger Observatory, is an array of radio antennas probing the nature of ultra-high energy cosmic rays at energies around the transition from Galactic to extra-galactic origin. It measures the MHz radio emission of extensive air showers produced by cosmic rays hitting our atmosphere. The elemental composition of cosmic rays is a crucial piece of information in determining what the sources of cosmic rays are and how cosmic rays are accelerated. This composition can be obtained from the mass-sensitive parameterXmax, the depth of the shower maximum. We reconstructXmaxwith a likelihood analysis, by comparing the measured radio footprint on the ground to an ensemble of footprints from Monte-Carlo CORSIKA/CoREAS air shower simulations. We compare ourXmaxreconstruction with fluorescenceXmaxmeasurements on a per-event basis, a setup unique to the Pierre Auger Observatory, and show the methods to be fully compatible. Furthermore, we extensively validate our reconstruction by identifying and correcting for systematic uncertainties. We determine the resolution of our method as a function of energy and reach a precision better than 15 g cm−2at the highest energies. With a bias-free set of around 600 showers, we find a light to light-mixed composition at energies between 1017.5to 1018.8eV, also in agreement with the Auger fluorescence measurements.
A detailed presentation of the highest-energy cosmic rays recorded at the Pierre Auger Observatory
Authors: Buscemi Mario
Published: April 2023

A catalog that contains details of the highest-energy cosmic rays, recorded by the Pierre Auger Collaboration between 1 January 2004 and 31 December 2020, is presented. Data from 100 air showers, generated by particles having energies in the range 78 EeV to 166 EeV, are described, together with nine other very energetic events used in the energy calibration. The catalog has been created to demonstrate the quality of the data that underlie measurements reported by the Collaboration, and to make the details of these events available for scrutiny. After a brief description of the techniques used for data acquisition and reconstruction, the contents of the catalog will be described. Some events within the catalog will be discussed in detail.
Single source scenario describing the very end of the cosmic ray energy spectrum
Authors: Bakalová Alena , Vícha Jakub , Trávníček Petr
Published: April 2023

The energy spectrum of cosmic rays is steeply falling with a suppression of the flux at the highest energies caused by energy losses during propagation or by reaching the maximum energy of cosmic accelerators. The energy spectrum at the highest energies is currently measured with high precision by two experiments, Telescope Array in the Northern hemisphere and the Pierre Auger Observatory in the Southern hemisphere. In this work, we study the possibility of explaining the shape of the energy spectrum above 1019.5 eV measured by the Pierre Auger Observatory with a single source. Using CRPropa 3 numerical simulations of cosmic ray propagation in the Universe we show possible features of such a single source that would be able to create a shape of the energy spectrum compatible with the measurement including limitations on the source distance, spectral index and mass composition.
Flux predictions in the transition region incorporating the effects from propagation of cosmic rays in the Galactic magnetic field
Authors: Kääpä Alex , Kampert Karl-Heinz , Becker Tjus Julia
Published: April 2023

Galactic cosmic rays (GCRs) and (anisotropically injected) extragalactic cosmic rays (EGCRs) are both affected by the Galactic magentic field (GMF) on their voyage to Earth at energies pertaining to the transition from GCRs to EGCRs, such that their flux, composition and arrival directions are modified. GCRs increasingly leak from the Galaxy with rising energy, leading to a flux suppression. The flux modification imposed on EGCRs is more complex, but may exhibit (subtle) spectral breaks depending on the direction and nature of the injected anisotropy.

Using a full Monte Carlo approach with CRPropa and making realistic and minimal assumptions about the injected GCR and EGCR fluxes, we derive a prediction of the total all-particle flux in the transition region. We find that it cannot account for the flux measured by various cosmic ray experiments in this energy range. This calls for the need of an additional component to the flux in the transition region.
Examination of Xmax anisotropy for the next generation Ultra-high energy cosmic rays observations
Authors: Saito Ryosuke , Tomida Takayuki , Ikeda Daisuke
Published: April 2023

The estimation of mass composition ultra-high energy cosmic rays is essential to understand their origin and generation mechanism. Recent experiments are expected to discover anisotropy of mass composition in ultra-high energy cosmic rays. Anisotropy of mass composition using Xmax is currently being performed, but the problem is that the statistics of cosmic rays with measured Xmax is very small. For the next generation experiments, it is important to know how much statistics can be accumulated to find Xmax anisotropy. Therefore, in this analysis, we examine Xmax anisotropic search in ultra-high energy cosmic rays by simulating a cosmic ray air showers under various conditions such as energy spectrum and mass composition.
The transition from Galactic to extragalactic cosmic rays: The high–energy end of the Galactic spectrum
Authors: Cristofari Pierre
Published: April 2023

Understanding the transition from Galactic to extragalactic cosmic rays (CRs) is essential to make sense of the Local cosmic ray spectrum. Several models have been proposed to account for this transition in the 0.1 - 10 × 1018 eV range. For instance: ankle models, where the change from a steep Galactic component to a hard extragalactic spectrum occurs in the 4 − 10 × 1018 eV region, dip models, where the interactions of CR protons with the CMB producing electron-positron pairs shape the ankle, or mixed composition models, in which extragalactic CRs are composed of nuclei of various types.

In all these scenarios, the low-energy part of the transition involves the high-energy part of the Galactic component. Therefore, any information on the Galactic component, such as maximum energy, chemical composition, and spectrum after propagation, is crucial to understanding the Galactic-extragalactic transition. We briefly review the high-energy part of the CR spectrum expected from the best potential sources of Galactic CRs.
A Study of Modified Characteristics of Hadronic Interactions
Authors: Blazek Jiri , Ebr Jan , Vicha Jakub , Pierog Tanguy , Travnicek Petr
Published: April 2023

We have implemented ad-hoc modifications to the CORSIKA Monte-Carlo generator which allow us to simultaneously adjust the multiplicity, elasticity and cross-section of hadronic interactions with respect to the predictions of the Sibyll 2.3d interaction model, in order to assess whether a reasonable combination of changes (that is not excluded by current experimental data) could alleviate the observed tension between the model predictions and observed features of extensive air showers induced by ultra-high energy cosmic rays (UHECR). Previously, we have studied the effects of such changes on proton-initiated showers. Because a multitude of experimental data suggest that the primary composition of the UHECR is mixed, we have expanded the modification procedure to include nuclear projectiles in a consistent way based on the superposition model, in a similar manner as was used in the previous studies carried out using one-dimensional simulation methods. As we are using a fully three-dimensional approach, we can quantify the effects of the changes on both longitudinal and lateral features of the showers. With the inclusion of nuclear projectiles, we can study the impact of the changes on observable quantities for realistic primary beams as well as on the determination of the primary composition from data under the assumption of the modified hadronic interactions.
Search for upward-going showers with the Pierre Auger Observatory
Authors: Novotný Vladimír
Published: April 2023

Motivated by the ANITA report of pulses compatible with upward-going extensive air showers, we present a recent search for such showers using the Pierre Auger Observatory. The dataset, registered using the fluorescence detector of the Observatory, is scanned to identify showers ascending from the ground. Consistent with the exit angles reported from the first and third ANITA flights, we focus on shower geometries that are incompatible with Standard Model interactions of neutrinos in the Earth. We present the effective area of the Observatory to generic upward-going showers as a function of shower energy and altitude. This can be used to constrain predictions based on physics beyond Standard Model and the upgoing-shower interpretation of the ANITA results. To demonstrate the method, we calculate limits to the production rate of tau leptons near the ground emerging under a range of exit angles.
Current status of the TAx4 surface detectors
Authors: Kido Eiji
Published: April 2023

Telescope Array (TA) is the largest ultrahigh-energy cosmic-ray (UHECR) observatory in the northern hemisphere. It explores the origin of UHECRs using a surface detector (SD) array, covering approximately 700 km2, and a fluorescence detector (FD) stations viewing the skies above the array. TA has found evidence for a cluster of cosmic rays with energies greater than 57 EeV known as a HotSpot. Recently, TA has obtained additional evidence for an excess of cosmic rays with energies above 1019.4eV and also found implications of spectrum anisotropy. An expanded SD array and FD stations called TAx4 experiment was designed to increase the data collection rate at the highest energies to confirm the anisotropies with more data. We have constructed and deployed more than half of the SDs for the TAx4 experiment and began stable data taking operations. We present TAx4 SD’s current status.
The Effect on Using Cells versus Spores of Bacillus Sphaericus on the Healing Performance of Self-Healing Mortar
Authors: Risdanareni Puput , Wang Jianyun , De Belie Nele
Published: April 2023

Bacteria-based self-healing concrete has become an effective approach to mitigate microcracks in the concrete structure. However, there are still doubts about when to use vegetative cells or spores of Bacillus sphaericus as a healing agent. Thus, this research aims to give recommendations regarding this choice. Spores and cells were encapsulated into expanded clay aggregate to protect them from the harsh environment of fresh mortar. The viability of cells and spores after encapsulation was investigated. The 28- and 90-day mortar compressive strength was analysed. The healing performance of the resulting mortar samples that were cracked at the age of 28 and 90 days has also been observed. The results show that both cells and spores were still active after encapsulation. The yeast extract added to mortar containing spores decreased the compressive strength of the mortar compared to the reference sample. From the healing performance result, it seems that the spores are more suitable for mitigating microcracks in aged mortar, while cells are more suitable for mitigating early-age cracks in the mortar.
Analysis of non-axenic biomasses for self-healing concrete
Authors: Tezer Mustafa Mert , De Belie Nele , Boon Nico , Verstraete Willy
Published: April 2023

As an alternative to the usage of axenic bacteria to achieve microbially induced calcium carbonate precipitation (MICP), this study evaluates the usage of two non-axenic biomasses as self-healing agents. A fungi-based consortium (Yeast) and heterotrophic nitrifiers (HTN) were harvested from the incubation of agricultural side streams. The characteristics of the two biomasses were identified through flow cytometry, total suspended solids and volatile suspended solids tests. The incorporation of the biomasses into concrete was evaluated in terms of compressive strength, flow and healing ability. Self-healing ability was analyzed through microscope imaging on prismatic (60x60x220 mm) samples. Cracks were induced with a three-point bending test where the widths were controlled with an LVDT sensor. A curing period of 56 days was applied to the samples and visual inspection was conducted at the start and end of the healing period with an optical microscope. Results compare and discuss the differing effects of active and autoclaved biomasses on the concrete properties and crack closure.
Bond behaviour evaluation between steel reinforcement and self-healing concrete containing non-axenic biomasses
Authors: Hermawan Harry , Tezer Mustafa Mert , Verstraete Willy , de Belie Nele , Serna Pedro , Gruyaert Elke
Published: April 2023

Although steel reinforcements are used to withstand tensile forces in concrete, cracks are an unavoidable phenomenon. The presence of cracks, in fact, increases the risk for lowering the service life and durability of concrete structures. A critical issue occurs when due to splitting forces, cracks appear in concrete along the tensioned rebars which damage the bonding between the steel and concrete matrix. As a mitigation plan, the cracks should be healed at short notice and the bonding has to be recovered by the potential use of healing agents. This paper aims to investigate the bond behaviour of steel reinforcement in self-healing concrete. Two biomasses were employed as healing agents namely HTN (bacteria-based) and YEAST (fungi-based). The fresh and hardened properties of the normal and self-healing concretes were initially evaluated. The bond properties were investigated by performing pull-out tests on three different states of concrete: uncracked, cracked, and healed. Results revealed that the additions of biomasses did not induce negative effects on the compressive strength of hardened concrete. Moreover, the average bond strength of uncracked concretes containing HTN and YEAST improved by 20% and 8%, respectively, as compared with normal concrete. The introduction of a crack caused a significant reduction in bond strength regardless of the addition of healing agents. Nevertheless, it was found that the bond strength was slightly recovered after healing under water immersion.
Self-healing performance of cement mortar mixed with pulverized clinker and inorganic admixture
Authors: Suh Jung-Il , Van Mullem Tim , De Brabandere Laurena , Lee Kwang-Myong , Cho Young-Keun , De Belie Nele
Published: April 2023

This study evaluated the mechanical properties and self-healing performance of cement mortar containing pulverized clinker, calcium sulfoaluminate (CSA), and Na2SO4. Mechanical properties of cement mortar were investigated by measuring compressive strength, and sealing efficiency were evaluated by a hydrostatic permeability test and a nitrogen gas diffusion test. Moreover, the healing products adhering to the cracks were visually observed with an optical microscope and a scanning electron microscope (SEM). As a result, incorporating pulverized clinker with mineral admixtures increased the 3- and 28-day strength by approximately 20%. There was a difference in the sealing efficiency depending on the evaluation method. The sealing efficiency of the gas diffusion test was underestimated due to the difference in characteristics according to the type of medium passing through the crack. Nevertheless, when the inorganic additive was mixed with cement mortar, CaCO3 precipitated as the healing product within 0.3 mm cracks and improved self-healing performance.
The effect of graphene nanoplatelet addition on the mechanical, durability and self-healing properties of engineered cementitious composites
Authors: Göçügenci Aysu , Keskin Süleyman Bahadır
Published: April 2023

Nanomaterial usage is an effective method to enhance the mechanical and durability properties of cementitious materials. Graphene Nanoplatelets (GNPs) are cost-efficient graphene-based nanomaterials that can exhibit graphene-like features. Although GNPs have been found to improve mechanical and durability properties, their effect on the self-healing behavior of cementitious materials, particularly Engineered Cementitious Composites (ECC), has not been examined in the literature studies. Therefore, this study aims to investigate the effects of GNP addition on mechanical, durability and self-healing behavior of ECC. During the study, the mechanical, durability, and self-healing characteristics of ECC with and without GNP were observed by using various mechanical and non-destructive test methods. Compression test, four-point bending test, resonance frequency test, ultrasonic pulse velocity test, sorptivity test, electrical impedance test and microscopic inspection were conducted. According to the test results, 0.05% GNP addition increased the compressive strength of ECC specimens. With the effect of GNP, first cracking strength, ultimate flexural strength and deformation values increased both for virgin and preloaded ECC specimens. The preloaded specimens with GNP performed similarly to virgin specimens under bending. The cracks of preloaded GNP specimens were either closed completely or extensively compared to control specimens. The crack numbers of GNP specimens after failure were also greater than that of control specimens. Accordingly, the flexural and self-healing behavior of the specimens improved with GNP addition. The effect of improvement by GNP addition was also evident in nondestructive tests. A considerable increment occurred in electrical resistance with GNP addition.
Monitoring of self-healing cementitious materials through contactless ultrasound
Authors: Lefever Gerlinde , Charkieh Ahmad Shawki , Van Hemelrijck Danny , Snoeck Didier , Aggelis Dimitrios G.
Published: April 2023

Self-healing cementitious composites provide an alternative to labour-intensive and costly manual repairs. While a cementitious blend possesses an inherent ability to repair its own damage through autogenous healing, an enhancement of the self-healing capacity can be obtained through the inclusion of superabsorbent polymers (SAPs). The implementation of such innovative materials within the construction industry requires proper evaluation methods to ensure a safe environment for the user. Over the past few years, contact ultrasonic measurements have proven their potential in assessing the self-healing progress. The sensitivity of ultrasonic waves to the elastic properties of the material under study allows for a direct link with the regained mechanical performance. Additionally, its non-destructive nature enables in-situ evaluations. However, the coupling of the sensors leads to a certain variability in the obtained results, as the application of the sensors is not identical between measurements. In an effort to increase the reliability of the results, contactless ultrasound can be applied, which is investigated in the present research.
Fundamental research on non-destructive testing of reinforced concrete structures using sub-terahertz reflected waves
Authors: Kobayashi Chihiro , Nishiwaki Tomoya , Hara Shoumi , Tanabe Tadao , Oohashi Takahiro , Hamasaki Hitoshi , Hikishima Shuya , Tanaka Akio , Arita Koji
Published: April 2023

Terahertz and sub-terahertz waves are unexplored waves range between infrared waves and microwaves. This range features with unique characteristics of both light straightness and electromagnetic wave transmission. Terahertz and sub-terahertz waves are attractively new diagnose method of inner objects because they are safer compared to normal non-destructive inspection methods involving high energy, such as X-rays. Hereby, a novel non-destructive inspection method for concrete and reinforced concrete structures is proposed using sub-terahertz reflection imaging. In Japan, where earthquakes and other natural disasters frequently occur, this technique is expected to be used to remotely inspect the deterioration of damaged RC structures that are difficult to access to. The results of this study confirm that various types of condition changes in concrete can be found by using this sub-terahertz imaging method. The presence of cracks/voids in concrete and under the finishing layers was successfully detected based on differences in reflectance. Moreover, the presence of metals inside/behind the concrete specimens was able to be identified. It was also confirmed that the decline rate of the mechanical properties of concrete could be evaluated according to the decrease in reflectance due to the existence of fine cracks.
Self-sensing Sustainable Cementitious Mixtures Incorporating Carbon Fibres
Authors: Almotlaq Thamer , Saafi Mohamed
Published: April 2023

This paper focuses on sustainable cementitious composites in terms of their conductivity, hydration and self-sensing properties, which are key features for smart city infrastructures. Smart cities have massive infrastructures that are interconnected, transmitting data and information for health-monitoring and performance optimization. In this regard, having them made of sustainable building materials (concrete) that are also sufficiently conductive, will be a suitable solution for structures’ performance. The studied sustainable cementitious mixtures are made by sea components (sea water and sea sand), which are abundant resources. The primary goal of this study is to improve the mixes’ electrical conductivity and sensitivity. To achieve this goal, milled carbon fibres (MCFs) and chopped carbon fibres (CCFs) in 6 different proportions were added to the cementitious mixes. The experimental study is divided into impedance spectroscopy to study the conductivity and hydration development, and self-sensing properties, conducted on various mix designs. The results show that incorporating sea components improve the electrical conductivity of the mixes by 40-50%. Further improvements were achieved by adding MCF as it shows a remarkable reduction by 60% compared to the plain ss-sw (sea sand and sea water) samples. Adding CCF improved the conductivity even further and resulted in sample’s resistivity as low as 53 Ωcm after 1 year of curing time.
LCA based recommendations for the selection of eco-concretes using blast furnace slag and fly ash
Authors: Maury-Ramírez Aníbal , Rojas Manzano Manuel Alejandro , De Belie Nele
Published: April 2023

The development of circular economy models for the construction sector brings important challenges and opportunities to research and particularly to make knowledge transfer, for example through public policies. Santiago de Cali, third major city of Colombia (South America), is developing a circular economy model policy, which is mainly based on waste valorisation. Among others, the model includes a family of eco-concrete products that replaces Portland cement by blast furnace slag and fly ash coming from local industries. Therefore, the aim of this research is to develop scientific based recommendations to stakeholders for the selection of different concrete products (i.e. beams, columns, slabs) using blast furnace slag and fly ash (eco-concretes). Considering that life cycle assessment (LCA) is the most employed tool for consolidating, comparing, and assessing sustainability impacts [1], the LCA of these concrete products for the design of a sustainable residential house was performed. The LCA software Building for Environmental and Economic Sustainability (BEES) developed by the National Institute of Standards and Technology (NIST) was selected for the study. Results include a discussion on the environmental impacts. Furthermore, a methodology for the selection of sustainable building materials is presented.
Large-Scale Laboratory Trials of Self-Healing Technologies
Authors: Rengaraju Sripriya , Vlachakis Christos , Afroughsabet Vahid , Al-Tabbaa Abir
Published: April 2023

Prolonging the life of the reinforced concrete structure is the most promising solution to reduce the carbon emissions from concrete. To achieve that, the structure should be protected from crack formation, which acts as an easy pathway for deleterious agents. Self-healing technologies are intended to provide long-term resilience against cracking due to various deterioration processes. Technologies that performed well in small, laboratory-scale studies are taken to the next level to assess their performance on a larger scale and monitored using various NDT equipment. A 1m long beam with a cross-section (140×120 mm) was cast with two rebars – one with a cover depth of 50 mm from the top and another with a cover depth of 20 mm from the bottom. The mix design consists of CEM IIIA (50 OPC: 50 Slag) cement and 30% lightweight aggregate as a replacement for coarse aggregate. At 28 days of curing, the concrete beams are subjected to accelerated corrosion (by applying a voltage to the bottom rebar) to induce internal cracking. Once internal cracking is induced, the beams are subjected to another 28 days under water for healing. The performance of the beams is monitored via ultrasonic pulse velocity and half-cell potential before and after voltage application. This paper shows the preliminary results and the self-healing efficiency and corrosion resistance of these beams are continuously being monitored under severe chloride conditions to predict the long-term performance.
Effect of SAPs and polypropylene fibres on the freeze-thaw resistance of low carbon roller compacted concrete pavement
Authors: Afroughsabet Vahid , Al-Tabbaa Abir
Published: April 2023

Most concrete currently used in pavement is based on Portland cement (PC), being responsible for 8-10% of total CO2 emission. Moreover, external pavements are subjected to exposure classes XF4 and XD3 which are related to corrosion and freeze-thaw. Freeze-thaw resistance is an important durability property of concrete, especially for concrete pavements that are subjected to the de-icing salts. This study was designed to explore the freeze-thaw resistance and mass scaling resistance of low carbon Roller Compacted Concrete (RCC) in the presence of water and de-icing salts. Four different RCC mixes were used with a water/binder ratio of 0.45. PC was replaced with 80% ground granulated blast-furnace slag (GGBS) in all mixes to develop low carbon concrete and move towards a more sustainable cementitious composite. To assess the effectiveness of smart engineered additives, superabsorbent polymers (SAPs) were used at 0.3% by weight of total binder, and Polypropylene (PP) fibre with 12-mm length at fibre volume fractions of 0.3% for the mitigation of freeze-thaw damage. The compressive strength, freeze-thaw resistance, and mass scaling resistance of concrete specimens were evaluated. The results indicate that both additives improved the compressive strength and freeze-thaw resistance of concrete with and without de-icing salts. The inclusion of PP fibre was more effective compared to the addition of SAPs to mitigate the extent of internal structural damage and mass scaling of self-healing concrete mixes with respect to the reference concrete after 56 freeze-thaw cycles.
Limits and possibilities of thermodynamic modelling of autogenous self-healing of concrete
Authors: Lahmann Daniel , Kessler Sylvia
Published: April 2023

Autogenous self-healing of water retaining concrete structures is included in Eurocode 1992-3 as a possibility to heal cracks up to a width of 200 μm without additional repair. In this self-healing scenario water flow through a crack should result in a progressive closure of the fracture, mainly due to CaCO3 precipitation, when certain hydraulic gradients are met, the pH of the water is > 5.5 and the concentration of CO2 in the water remains < 40 mg*L-1. The material composition is not further restricted by the regulation. However, despite standardization, the healing effect seems to be random in practice, which requires further research, while experiments aimed at quantifying autogenous self-healing are expensive and time-consuming. Thermodynamic models could support in estimating the effect of different environments such as groundwater or seawater exposure on autogenous self-healing. Moreover, adjusting the water chemistry according to the conditions of different construction sites and changing the material design could easily be considered. In this study thermodynamic models of a hydrated CEM I 52.5 R paste that is exposed to either simulated groundwater or seawater are discussed concerning the influence on autogenous self-healing and compared to experimental and literature data.
Effect of microstructure heterogeneity shapes on constitutive behaviour of encapsulated self-healing cementitious materials
Authors: Sayadi Sina , Ricketts Evan , Schlangen Erik , Cleall Peter , Mihai Iulia , Jefferson Anthony
Published: April 2023

Self-healing cementitious materials with microcapsules are complex multiscale and multiphase materials. The random microstructure of these materials governs their mechanical and transport behaviour. The actual microstructure can be represented accurately with a discrete lattice model, but computational restrictions mean that the size of domain that can be considered with this approach is limited. By contrast, a smeared approach, based on a micromechanical formulation, provides an approximate representation of the material microstructure with low computational costs. The aim of this paper is to compare simulations of a microcapsule-based self-healing cementitious system with discrete-lattice and smeared-micromechanical models, and to assess the relative strengths and weaknesses of these models for simulating distributed fracture and healing in this type of self-healing material. A novel random field generation technique is used to represent the microstructure of a cementitious mortar specimen. The meshes and elements are created by the triangulation method and used to determine the input required for the lattice model. The paper also describes the enhancement of the TUDelft lattice model to include self-healing behaviour. The extended micromechanical model considers both microcracking and healing. The findings from the study provide insight into the relative merits of these two modelling approaches.
Investment Environment has Changed, Natural Selection Makes Investors Pay More Attention to Liquidity
Authors: Song Xiangfan
Published: April 2023

With the rise of global protectionism, de-globalization, Sino-U.S. Trade conflict, the instability of policies will increase the probability of tail events. In this paper, we mentioned the natural selection in the financial industry. In the past, the investment environment has been stable for a long time, it would cause some investors have not ability to respond to the crisis. Change some investment habits, and deal with the hold up and Bank run caused by the tail events with increased probability by retaining more cash flow. This method can enable us to effectively respond to market fluctuations caused by unstable policies and improve the success rate.
The Enlightenment of Eu Experience to the Integration of Yangtze River Delta
Authors: Cheng Huimin , Cao Wei , Li Jingwen
Published: April 2023

The integrated development of the Yangtze River Delta is an important national strategy of China. The new round of scientific and technological revolution and industrial transformation in the world has brought new opportunities and challenges to the Yangtze River Delta. At present, there are still problems such as unbalanced development and industrial homogenization in the Yangtze River Delta. As an international organization with a supranational nature, the EU has a relatively mature governance system in the process of promoting integration, which is of great significance to the development of the integration of the Yangtze River Delta. In view of the current development dilemma of the Yangtze River Delta, Based on the experience of EU integration, this paper puts forward some suggestions on administrative governance: strengthening the implementation of integrated layout through regional planning and multi-party participation, realizing the adjustment of industrial structure and building an ecological metropolitan area.
The Change of the Scale of China’s Shadow Banking and the Effects of Financial Deleveraging
Authors: Liu Jialin
Published: April 2023

This paper aims to discuss the effectiveness of financial deleveraging by observing and studying the changes in the scale of shadow banking in China. China’s shadow banking can be divived into two parts: intra-bank shadow banking and extra-bank shadow banking, whose scale can be calculated by the indirect method based on the balance sheet and the direct method respectively. Through data statistics and calculations, it is concluded that the scale of shadow banking in China has slowed down since 2017 and started to decline gradually in 2018. In other words, financial deleveraging is effective.
Research on the Influencing Factors of Capital Asset Income ---- Is Based on the Fama-French Three-Factor Model
Authors: Xinwen Zhang
Published: April 2023

Capital asset pricing is very important to the development of listed companies. It is not only related to the performance of micro enterprises, but also related to the stability and development of macro financial markets. Therefore, the in-depth study of the law and influencing factors of listed companies’ return on capital assets is a theoretical problem worthy of in-depth exploration, but also has significant practical significance. In this paper, 160 stocks from 2012 to 2021 are selected for empirical analysis, and it is concluded that stocks of small-scale companies can realize good risk hedging as a hedge tool, and the trend of large-scale high-yield stocks conforms to the traditional capital asset pricing theory.
Estimating the Price Elasticity of Natural Gas and Electricity in Pacific Northwest
Authors: Xue Zhao
Published: April 2023

This paper estimates the price elasticity of electricity and natural gas in the Pacific Northwest. Electricity and natural gas are substitutes; and demands of different classes of consumers for the energy are price-inelasticity. The results are when the price of retail electricity and natural gas changes, consumers would choose the cheaper one to make up for the increased cost of another energy price. Consumers’ demand for energy is mainly stable, they won’t affect a lot by the change in energy prices.
Empirical Analysis of The Impact of Industrial Convergence on The Regional Economy of The Yangtze River Delta
Authors: Zhou Ziqi
Published: April 2023

Regional integration is an important measure to promote the development of China’s regional economy. Analyzing regional economies through statistical methods and studying the causes of regional economic differences can provide effective analysis and scientific advice on the economic development problems of each region, which is conducive to a more accurate understanding of China’s regional economic development and the promotion of the healthy development of each region. Based on a statistical perspective, this paper analyses industrial convergence in the context of regional integration in the Yangtze River Delta region and clarifies the current situation of industrial convergence in the Yangtze River Delta region. Then, using data from four provinces and cities in Anhui, Shanghai, Jiangsu and Zhejiang for three consecutive decades from 1992 to 2021, a fixed-effects panel data regression model is established.t
Impact of China’s Economic Policy Uncertainty on Inflation Rate
Authors: Wang Yizhi
Published: April 2023

Although a decrease in the rate of Chinese inflation happens, it will still be higher than it was before the global financial crisis. The international economy will continue to deteriorate in 2022 due to geopolitical tensions and the slowdown in global economic development and will experience a small recession in 2023. Studies show that the EPU (economic policy uncertainty) index strongly explains large changes in equity markets like the S&P 500 and has an inverse relationship with real macroeconomic variables like employment and economic growth. The rate of inflation might be impacted. Research on the relationship between the index of economic policy uncertainty and the inflation rate is scant. In an effort to assist government agencies in making decisions, this study, which is based on a VAR model, examines the relationship between the index of economic policy uncertainty and the rate of inflation. We find that economic policy uncertainty has a small impact on the inflation rate, but the inflation rate can increase the economic policy uncertainty index.
Social Interaction, Financial Literacy, and Household Financial Fragility
Authors: Dan Shi , Sheng-nan Yu
Published: April 2023

With the rapid development of digitalization, social interaction is becoming more and more frequent and complex, and the problem of household financial fragility is becoming more and more prominent, which brings challenges to macro financial stability. In order to explore the relationship between social interaction and household financial vulnerability, Based on the data of China Family Panel Studies(CFPS) 2018, this paper constructs an index system of social interaction, financial literacy and household financial fragility, discusses the influence mechanism of social interaction on household financial fragility, and clarifies the mechanism of social interaction affecting household financial fragility through financial literacy. The results show that social interaction significantly alleviates household financial fragility; social interaction alleviates household financial fragility by improving financial literacy ; this impact mainly exists in subgroups with higher financial literacy, urban and Internet-using households. Therefore, household financial fragility can be alleviated by improving social interaction conditions and narrowing the financial literacy gap.
Analysis of Communication Strategy of Xi’an Urban Tourism Industry in the Background of New Media -- Based on the Perspective of Integrated Marketing
Authors: Xue Haoyuan
Published: April 2023

Xi’an is among the ancient Chinese cities with rich culture and geographical sites. Technological development promises Xi’an a significant breakthrough in communicating the unique traits of a fact that boosts revenues from urban tourism. Most research on marketing strategy focuses on the impacts of an advertisement on brand reputation but does not narrow it down to a specific marketing strategy. The research reports the finding of meta-analysis and case studies whose focus is to determine how the network media and new media have contributed to Xi’an’s tourism by spreading a positive image of the city. The research proposed that integrated marketing on new media presents business entities as a platform for developing the required brand awareness. The findings of this research indicated that Integrated marketing on new media is the future of marketing since it incorporates various media forms in one platform. Even though new media bears some setbacks on the tourism docket, the benefits associated with integrated marketing promotion in the new media have boosted Xi’an’s tourism industry, as evident in the upsurge of tourists from 2018 to date.
Research on the Influence of Cultural Capital on Human Sports Practice
Authors: Cuijuan Lin , Hai Yang
Published: April 2023

The concept of cultural capital originated from Pierre Bourdieu’s theoretical hypothesis that explains the different academic achievements of children from different social classes. Different from the research paradigms of Karl Marx and Maximilian Weber who conducted social stratification research by analyzing people’s possession of tangible social resources, Bourdieu proposed that cultural capital is also of great significance in social stratification, and social classes use cultural capital to establish stratification and demonstrate the cultural taste and habitus of different classes. In the field of sports practice, families and schools are important fields for the generation and accumulation of cultural capital. When influencing people’s sports behaviors, cultural capital has the characteristics of concealment, stratification, symbolism, and inheritance. Sports culture capital has an important influence on people’s cultural taste and habitus in sports, specifically, on people’s participation, selection, and consumption of sports.
Discussion on the Influence Mechanism of Employee Stock Ownership Plan on Company Earnings Management
Authors: Zhang Jide , Lyu Yaoyao
Published: April 2023

Based on the samples of A-share non-financial listed companies in Shanghai and Shenzhen from 2013 to 2019, this paper studies the impact of the implementation of employee stock ownership plan on earnings management, and finds that employee stock ownership is significantly positively correlated with the company’s accrual earnings management level. Further research shows that employee stock ownership has a significantly higher effect on upward earnings management than downward earnings management. The above research results show that the management has the motivation to ‘please’ employees. In order to make more cash out when the employee stock ownership is lifted, the management conducts positive earnings management to push up the stock price, thus damaging the interests of shareholders.
A Survey Report on the Characteristics of Cognitive Ability of English Prefabricated Chunks for Higher Vocational College Students
Authors: An Weiyu , Ya Dong
Published: April 2023

This paper uses a questionnaire to find out that the cognitive ability of higher vocational college students in English prefabricated chunks is weak, and there are many problems such as insufficient knowledge reserve of prefabricated chunks and weak awareness of their use. The aim is to develop students’ learning habits of memorizing, understanding, applying and transferring English language with prefabricated chunks as the smallest unit.
A Brief discussion on the standardized management of material master data in Enterprise Resource Planning system for engineering enterprises
Authors: Wei Cuicui , Yu Yang , Xu Changzhao , Mao Lixiang , Meng Fanzhao
Published: April 2023

Taking the Enterprise Resource Planning system of a loader enterprise as an example, this paper expounds on the principle of master material data coding, the existing problems in the standardization process of master material data and the measures taken.
Analysis on the Market influencing factors of Laos attracting Chinese Enterprises to start a Business in Laos
Authors: Philakone Chindavong
Published: April 2023

With the gradual deepening of the initiative of the Belt and Road Initiative, the scale of China’s investment in Laos has also expanded. The domestic investment environment in Laos continues to improve, and international cooperation is deepening. Both products and technologies have flooded into the Lao domestic market, which has had a huge impact and impact on the development of Laos’ local economy. At the same time, Chinese companies choosing to invest and start businesses in the domestic market of Laos can expand the income sources of Chinese companies, increase the international reputation of Chinese companies, and promote social development. With the continuous strengthening of China-Laos cooperation in various fields, Laos has also taken some measures to attract Chinese companies to invest and start businesses in Laos, and China-Laos cooperation has reached a new level. However, due to the lack of economic growth in Laos and the lack of a comprehensive industrial sector, there are many problems in the investment environment. If Laos fails to take effective measures, it is likely to harm Chinese companies investing in Laos. Therefore, Chinese companies pay great attention to the industries of large regional and regional companies in Laos, which are closely related to the climate and market conditions in Laos.