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Found 6327 publications
Truck platoon analysis for autonomous trucks
Publication Name: SN Applied Sciences
Publication Date: 2023-05-01
Volume: 5
Issue: 5
Page Range: Unknown
Description:
Selection of optimum platoon pattern based on types of trucks inside the platoon, the number of trucks in the platoon, headway distance, interplatoon distance as well as the use of different lateral wander modes for autonomous trucks has been analyzed. The objective of this research is to study the impacts of axle configurations, truck grouping, headway distance and lateral wander options on the performance of truck platoons. Four different headway distances from 2 to 5 m are compared. The first platoon PT-1 only consists of semi trailers, the second platoon PT-2 only consists of rigid body trucks and the third platoon PT-3 consists of equally distributed random traffic mix. Analysis has been conducted using the dload subroutine for projecting zero wander and uniform wander movements for each truck in the platoon on a three layered pavement crossection at vehicle speeds of 90 km/h for a total of 15 years of pavement lifetime consisting of 1.4 million equivalent single axle loads in finite element software ABAQUS. Results show that PT-3 platoon yields the minimum accumulation of damaging strains when compared against other platoon types. A headway distance of 5 m is suggested when using a zero wander mode and 3 m when using a uniform wander mode. In case of zero wander mode, fatigue life of the pavement decreases by 1.2 years and the use of uniform wander mode delays the rutting by 1.6 years, thereby increasing lifetime of the pavement.
Open Access: Yes
New Organizational Environment Types Based on Garvin and Quinn – the Case of Slovakian Small and Medium Enterprises
Publication Name: TEM Journal
Publication Date: 2023-05-01
Volume: 12
Issue: 2
Page Range: 691-699
Description:
The aim of the study was to examine what common characteristics can be observed in companies based on Garvin’s learning organization and the Quinn’s organizational culture. Both of the trends are considered a fundamental factor of modern management. Studying the international scientific literature, it is clear that examining the overlaps between the two approaches is highly incomplete. The issue was approached from the perspective of employees, as they show high willingness to express their opinion. A questionnaire survey was used as a part of our research. 549 responses were included in the analysis, during which we applied a cluster analysis. Based on the results, three different types of organizational environment can be defined: supporting, neutral and distancing.
Open Access: Yes
DOI: 10.18421/TEM122-12
Understanding the Mechanisms of Fe Deficiency in the Rhizosphere to Promote Plant Resilience
Publication Name: Plants
Publication Date: 2023-05-01
Volume: 12
Issue: 10
Page Range: Unknown
Description:
One of the most significant constraints on agricultural productivity is the low availability of iron (Fe) in soil, which is directly related to biological, physical, and chemical activities in the rhizosphere. The rhizosphere has a high iron requirement due to plant absorption and microorganism density. Plant roots and microbes in the rhizosphere play a significant role in promoting plant iron (Fe) uptake, which impacts plant development and physiology by influencing nutritional, biochemical, and soil components. The concentration of iron accessible to these live organisms in most cultivated soil is quite low due to its solubility being limited by stable oxyhydroxide, hydroxide, and oxides. The dissolution and solubility rates of iron are also significantly affected by soil pH, microbial population, organic matter content, redox processes, and particle size of the soil. In Fe-limiting situations, plants and soil microbes have used active strategies such as acidification, chelation, and reduction, which have an important role to play in enhancing soil iron availability to plants. In response to iron deficiency, plant and soil organisms produce organic (carbohydrates, amino acids, organic acids, phytosiderophores, microbial siderophores, and phenolics) and inorganic (protons) chemicals in the rhizosphere to improve the solubility of poorly accessible Fe pools. The investigation of iron-mediated associations among plants and microorganisms influences plant development and health, providing a distinctive prospect to further our understanding of rhizosphere ecology and iron dynamics. This review clarifies current knowledge of the intricate dynamics of iron with the end goal of presenting an overview of the rhizosphere mechanisms that are involved in the uptake of iron by plants and microorganisms.
Open Access: Yes
Two-Dimensional Numerical Analysis for TBM Tunneling-Induced Structure Settlement: A Proposed Modeling Method and Parametric Study
Publication Name: Infrastructures
Publication Date: 2023-05-01
Volume: 8
Issue: 5
Page Range: Unknown
Description:
The construction of tunnels in densely populated urban areas poses a significant challenge in terms of anticipating the settlement that may result from tunnel excavation. This paper presents a new and more realistic modeling method for tunnel excavation using a Tunnel Boring Machine (TBM). This method is compared with other reference modeling methods using a validated model of a subsurface tunnel excavated by a TBM with a slurry shield. A parametric study is conducted to investigate the impact of key parameters, including structure width, foundation depth, eccentricity, load on the structure, overburden depth, and tunnel diameter, on tunnel–soil–structure interaction and the resulting structure settlements. The results reveal that the tunnel diameter, eccentricity, and overburden depth have a significant impact on structure settlements, with values of 22.5%, 17%, and 7.1%, respectively. Finally, the paper proposes an equation for predicting the maximum settlement of a structure, considering the critical parameters. The validity of the equation is evaluated by comparing its results with the outputs from various case studies, including a newly validated model, two real-life case studies, and centrifuge tests. The results indicate a high level of consistency between the calculated and measured settlements.
Open Access: Yes
Screening of Domestic Cats from North-Eastern Hungary for Hepatozoon felis and Cytauxzoon europaeus That Cause Infections in Local Wildcat Populations
Publication Name: Pathogens
Publication Date: 2023-05-01
Volume: 12
Issue: 5
Page Range: Unknown
Description:
Among vector-borne protozoa Hepatozoon felis and Cytauxzoon europaeus are considered emerging species in felids in Europe. To investigate the presence of these two protozoa 127 domestic cats and 4 wildcats were screened by PCRs targeting the 18S rRNA gene of Hepatozoon spp. and piroplasms, as well as the cytb gene of Cytauxzoon spp. The samples were collected inside and outside a region of Hungary, where both protozoan groups are endemic in wildcats. Among domestic cats, one proved to be infected with H. felis. Furthermore, spleen samples of four wildcats were also examined, among which three tested positive for H. felis, and one had co-infection with C. europaeus. Importantly, H. felis from the co-infected wildcat belonged to genogroup II, similarly to H. felis from the positive domestic cat. Based on phylogenetic evidence, this genogroup probably represents a separate species from genogroup I of H. felis, which was hitherto reported from Mediterranean countries in Europe. The two other wildcats also harbored H. felis from genogroup I. Neither Hepatozoon nor Cytauxzoon infections were detected outside the recently discovered endemic region. In conclusion, this study demonstrates for the first time in Europe that H. felis from genogroup II may emerge in free-roaming domestic cats in regions where this protozoan parasite is endemic in wildcats.
Open Access: Yes
Elicitation of Content Layout Preferences in Virtual 3D Spaces Based on a Free Layout Creation Task
Publication Name: Electronics Switzerland
Publication Date: 2023-05-01
Volume: 12
Issue: 9
Page Range: Unknown
Description:
Three-dimensional virtual reality (VR) environments, whether operating on desktop platforms or immersive screens, have been recognized for enabling novel and extremely engaging methods of interacting with digital content across various fields of application. Studies conducted over the past several years have also consistently suggested that utilizing 3D in contrast to 2D interfaces can lead to enhancements in multiple performance dimensions. These enhancements encompass better understanding and retention of information, increased capacity for inventive and efficient collaboration, and the ability to execute workflows that integrate numerous information sources more quickly. At the same time, how digital content such as documents, audio–visual content and web browsers are integrated into 3D spaces is often decided by the creators of the spaces based on either aesthetic considerations, or on a case-by-case basis depending on the workflow. In this paper, we present the results of an experiment we conducted to better understand how users prefer to arrange digital content in their 3D environments, depending on the subject matter, the format of the content (e.g., text-based, image, or audio–visual) and the 3D objects within the space. The results of the experiment presented in the paper can help inform future 3D VR design methodologies and may also provide support for automated content arrangement solutions.
Open Access: Yes
Evaluation of the Szapáry Long-Span Box Girder Bridge Using Static and Dynamic Load Tests
Publication Name: Infrastructures
Publication Date: 2023-05-01
Volume: 8
Issue: 5
Page Range: Unknown
Description:
This paper presents the results of a recent field test carried out before the opening phases of the Szapáry motorway bridge across the Tisza River in central Hungary. The evaluation test was based on static and dynamic load tests that provided information on deflection, stresses, and dynamic mode shapes along the bridge. The structure has two large continuous independent steel box girders that cover spans across the floodplain and river. Various configurations of truck loading applied up to 6400 kN of loading on the deck. During the static tests, string potentiometers recorded deflections at mid-span. Additionally, strain gauges enabled strain/stress measurements at the mid-point of the longest span and directly above one support. Dynamic loadings showed variation in deflection response due to vehicle speed, and ambient vibration testing led to determining vibration modes and frequencies. A three-dimensional finite-element model produced similar deflections, stresses, and modal behavior. Measured and modeled deflections and stresses indicated that the bridge performed within design margins. The testing and analysis results will be part of a future program assessing conditioned-based maintenance.
Open Access: Yes
Adaptation of Life Form Categorisation of Ellenberg and Mueller-Dombois to the Hungarian Flora
Publication Name: Acta Botanica Hungarica
Publication Date: 2023-04-25
Volume: 65
Issue: 1-2
Page Range: 1-34
Description:
The categorisation of plant species according to their life form has a long history in plant ecology. The most popular system worldwide and also in Hungary is Raunkiaer's categorisation according to the position of buds (meristems) surviving the adverse season. The original system contains only seven categories, resulting in high diversity within each category. Therefore, different refinements are suggested. This paper aims to apply an internationally accepted refinement of Raunkiaer's categorisation, the Ellenberg and Mueller-Dombois system, to the Hungarian flora.
Open Access: Yes
Evaluation of the Unsaturated Shear Strength Parameters of Compacted, Heaving Soil Using Geotechnical Properties
Publication Name: E3s Web of Conferences
Publication Date: 2023-04-24
Volume: 382
Issue: Unknown
Page Range: Unknown
Description:
The shear strength is a fundamental property of soil material under structural loads. The determination of shear strength properties of unsaturated soils is challenging and time-consuming. Geotechnical predictive models can be utilized to assess the unsaturated shear strength of heaving soil. This study attempts to propose predictive models to evaluate the unsaturated shear strength parameters of compacted heaving soil. These parameters include the angle of internal friction associated with the net normal stress (φ), angle indicating the rate of increase in shear strength with respect to a change in matric suction (φb), and effective cohesion (c'). The geotechnical properties of soils were assessed through laboratory tests such as particle size distribution, consistency limits, specific gravity, modified Proctor compaction test, swelling test, suction test, and advanced triaxial testing. Multivariate analysis was conducted using NCSS 12 software to design the models. The validation of models includes the determination coefficient, probability value, comparing experimental values with predicted values, and comparing the developed models with other model found in recent literature. The models engineered in this study can estimate the unsaturated shear strength parameters of compacted heaving soil with acceptable precision.
Open Access: Yes
