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Publications - 6383

Graphene-based molecular dynamics nanolithography of fullerenes, nanotubes and other carbon structures

Ibolya Zsoldos István László

Publication Name: Epl

Publication Date: 2012-09-01

Volume: 99

Issue: 6

Page Range: Unknown

Description:

The mass production of fullerenes and nanotubes faces the problem of their selective production. Here we present special kind of graphene patterns which can be used as initial structures for fullerenes, nanotubes and other carbon nanostructures. We proved in quantum chemical molecular dynamics calculations that these structures transform in a self-organizing way into the desired structures. Our results can initiate new experimental researches for improving the existing carbon nanostructure productions and to develop a new, structure-selective nanolithography of fullerenes, nanotubes and other carbon structures. We present such kind of graphene patterns which generate the self-organizing processes. In our molecular dynamics simulation we obtained the C 60 and C 70 fullerene, the (5,5) armchair nanotube and (9,0) zigzag nanotube. We present also a graphene pattern for self-organizing Y junction production. © Copyright EPLA, 2012.

Open Access: Yes

DOI: 10.1209/0295-5075/99/63001

Development of Safety Performance Functions for Two-Lane Rural First-Class Main Roads in Hungary

Attila Borsos Gyula Orosz John N. Ivan

Publication Name: Traffic Safety Volume 4

Publication Date: 2016-01-01

Volume: 4

Issue: Unknown

Page Range: 87-100

Description:

This chapter describes a modeling effort to define accident prediction models for first-class main roads outside built-up areas in Hungary using variables that are available and believed to exert an influence on safety performance. Models are proposed using the Generalized Linear Modeling (GLM) approach assuming a negative binomial error structure. The chapter also overviews design characteristics and accident statistics of two-lane rural first-class main roads. Five variables are used to predict accident frequencies, Annual Average Daily Traffic (AADT), posted speed, curve, roadway width and shoulder width. Traffic volume is used as an exposure to accidents and the length of the homogenous sections. Safety Performance Functions (SPFs) have been widely used in the traffic safety field for analyzing how the safety performance of road facilities is related to various road characteristics. The chapter reviews literature to demonstrate problems associated with conventional regression techniques used for accident prediction.

Open Access: Yes

DOI: 10.1002/9781119307853.ch6

Parallel implementation of a combustion chamber simulation with MPI-OpenMP hybrid techniques

László Környei

Publication Name: Mipro 2012 35th International Convention on Information and Communication Technology Electronics and Microelectronics Proceedings

Publication Date: 2012-08-22

Volume: Unknown

Issue: Unknown

Page Range: 356-361

Description:

The parallelization techniques utilized in a study of gas flow in a combustion chamber are described and discussed in this paper. Models of compressible fluid dynamics are solved with the finite volume method, and an additional algorithm, called "snapper" that handles piston and valve movement. In order to achieve an acceptable scaling on a CPU cluster with 240 cores, a two-stage parallelization with MPI in conjecture with OpenMP is implemented. For some types of physical investigations, the actual spatial region of interest is somehow changing, deforming, or moving in time in a predefined fashion. Handling gas dynamics with piston motion, even with the simplest models requires precaution. Apart from numerical and physical corrections, there are challenges, where multiple types of unstructured, and specially generated deforming grids are handled in a computer system with distributed memory. In the present work the results of the first implementations and benchmarks are presented, which prove to be well scaling for this modest-sized cluster. © 2012 MIPRO.

Open Access: Yes

DOI: DOI not available

Soil moisture distribution mapping in topsoil and its effect on maize yield

Viliam Nagy G. Milics Zoltán Varga A. J. Kovács Attila Pörneczi Gábor Baranyai A. Nyéki Lubomír Lichner M. Neményi Tamás Németh

Publication Name: Biologia Poland

Publication Date: 2017-08-28

Volume: 72

Issue: 8

Page Range: 847-853

Description:

Soil moisture content directly influences yield. Mapping within field soil moisture content differences provides information for agricultural management practices. In this study we aimed to find a cost-effective method for mapping within field soil moisture content differences. Spatial coverage of the field sampling or TDR method is still not dense enough for site-specific soil management. Soil moisture content can be calculated by measuring the apparent soil electrical conductivity (ECa) using the Veris Soil EC-3100 on-the-go soil mapping tool. ECa is temperature dependent; therefore values collected in different circumstances were standardized to 25°C temperature (EC25). Constants for Archie's adjusted law were calculated separately, using soil temperature data. According to our results, volumetric moisture content can be mapped by applying ECa measurements in our particular field with high spatial accuracy. Even though within-field differences occure in the raw ECa map standardization to EC25 is recommended. Soil moisture map was also compared to yield map showing correlation (R2 = 0.5947) between the two datasets.

Open Access: Yes

DOI: 10.1515/biolog-2017-0100

Comparison of the English and German Concepts of Contract

Judit Beck

Publication Name: Journal on European History of Law

Publication Date: 2025-01-01

Volume: 16

Issue: 2

Page Range: 87-93

Description:

This paper focuses on the English and German concepts of contract. Among other things, our aim is to examine the relationship between the concept of contract and imperial imperialism. In the course of the study, we examine the development and evolution of contract concepts, as well as some similarities and differences between English and German contract law. Among our aims is to show that there is a link between the development of the field of contract law and imperialism. In the course of the study, we will primarily apply the historical and comparative legal methodologies.

Open Access: Yes

DOI: DOI not available

Resource savings, recycling and utilization, and energy transition: Introduction

Aviral Tiwari Xin Zhao Umer Shahzad

Publication Name: Geoscience Frontiers

Publication Date: 2024-05-01

Volume: 15

Issue: 3

Page Range: Unknown

Description:

No description provided

Open Access: Yes

DOI: 10.1016/j.gsf.2024.101797

Using Multivariate Statistical Analysis for Examining the Relationship between Food Waste Generation and Socio-economic Factors

A. Zseni András Horváth Gergely Zoltán Macher Dóra Sipos Judit Pécsinger

Publication Name: Journal of Sustainable Development of Energy Water and Environment Systems

Publication Date: 2025-09-01

Volume: 13

Issue: 3

Page Range: 1-16

Description:

Food waste contributes to social inequalities and sustainability issues by worsening resource overuse and environmental harm. The United Nations Sustainable Development Goal 17 highlights the importance of reducing food waste to address hunger and promote a sustainable, economically viable global food system. This paper examines the geographic differences in food waste levels among European Union member nations and analyses the associations between food waste and diverse environmental, geographic, social and economic indicators, including Sustainable Development Goals and other sustainability metrics. Using dimensionality reduction methods, nontrivial multivariate connections between food waste and these parameters were identified, allowing for the characterisation of countries based on a few significant factors. Principal Component Analysis (PCA), applied to food waste data across European Union countries, uncovered three distinct groups: (1) those with elevated food waste in primary production, manufacturing and distribution stages; (2) those with lower waste in these domains yet elevated waste in restaurants and households; and (3) those with all of their food waste components smaller than or equal to the average. The multivariate linear correlation between the PCA factors and socio-economic parameters is nonsignificant, but a few (nonlinear) regularities could be identified: five of the six countries of the first group above are characterised by the population settled mainly on flatland and an above-average supply of meat or fish. Another pattern observed is that former Eastern Bloc countries belong to the third group. The research findings offer valuable insights that can inform the efforts of environmental experts, professionals and policymakers working in the circular economy and waste management domains. This knowledge can facilitate the development of more effective strategies aimed at mitigating food waste and promoting sustainability.

Open Access: Yes

DOI: 10.13044/j.sdewes.d13.0579

Developing a machine learning-based rapid visual screening method for seismic assessment of existing buildings on a case study data from the 2015 Gorkha, Nepal earthquake

Orsolya Kegyes-Brassai Nurullah Bektaş

Publication Name: Bulletin of Earthquake Engineering

Publication Date: 2025-09-01

Volume: 23

Issue: 12

Page Range: 4981-5019

Description:

Each existing building is required to be assessed before an impending severe earthquake utilizing Rapid Visual Screening (RVS) methods for its seismic safety since many buildings were constructed before seismic standards, without taking into account current regulations, and because they have a limited lifetime and safety based on how they were designed and maintained. Building damage brought on by earthquakes puts lives in danger and causes significant financial losses. Therefore, the fragility of each building needs to be determined and appropriate precautions need to be taken. RVS methods are used when assessing a large building stock since further in-depth vulnerability assessment methods are computationally expensive and costly to examine even one structure in a large building stock. RVS methods could be implemented in existing buildings in order to determine the damage potential that may occur during an impending earthquake and take necessary measures for decreasing the potential hazard. However, the reliability of conventional RVS methods is limited for accurately assessing large building stock. In this study, building inspection data acquired after the 2015 Gorkha, Nepal earthquake is used to train nine different machine learning algorithms (Decision Tree Classifier, Logistic Regression, Light Gradient Boosting Machine Classifier, eXtreme Gradient Boosting Classifier, Gradient Boosting Classifier, Random Forest Classifier, Support Vector Machines, K-Neighbors Classifier, and Cat Boost Classifier), which ultimately led to the development of a reliable RVS method. The post-earthquake building screening data was used to train, validate, and ultimately test the developed model. By incorporating advanced feature engineering techniques, highly sophisticated parameters were introduced into the developed RVS method. These parameters, including the distance to the earthquake source, fundamental structural period, and spectral acceleration, were integrated to enhance the assessment capabilities. This integration enabled the assessment of existing buildings in diverse seismically vulnerable areas. This study demonstrated a strong correlation between determining building damage states using the established RVS method and those observed after the earthquake. When comparing the developed method with the limited accuracy of conventional RVS methods reported in the literature, a test accuracy of 73% was achieved, surpassing conventional RVS methods by over 40% in accurately classifying building damage states. This emphasizes the importance of detailed data collection after an earthquake for the effective development of RVS methods.

Open Access: Yes

DOI: 10.1007/s10518-024-01924-x

Automated elasto-plastic design of truss structures based on residual plastic deformations using a geometrical nonlinear optimization framework

Majid Movahedi Rad Péter Grubits

Publication Name: Computers and Structures

Publication Date: 2025-09-01

Volume: 316

Issue: Unknown

Page Range: Unknown

Description:

This paper introduces a novel automated framework for the optimal design of steel truss structures, incorporating plastic deformations through the complementary strain energy of residual forces while minimizing weight. The presented methodology is equally applicable to purely elastic scenarios, ensuring zero plastic deformations and further reducing material usage. To achieve this, a nonlinear finite element (FE) program was developed, capable of accounting for large deformations and initial geometric imperfections. A genetic algorithm (GA) was integrated to iteratively optimize the objective function, enabling a fully automated design process. The efficiency and versatility of the framework were validated through four numerical examples. The first two comprise benchmark cases: a 9-bar planar truss and a 25-bar space truss. The remaining two examples were selected to be more representative of practical applications, involving a prestressed arched truss and a double-layer space truss. Analyses of various configurations were performed to demonstrate the robustness of the approach. Using the proposed methodology, significant improvements in plastic performance and material efficiency were achieved, underscoring its potential, adaptability, and effectiveness in advancing truss design techniques.

Open Access: Yes

DOI: 10.1016/j.compstruc.2025.107855