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Found 6515 publications

Combined Effect of Nano Ferrite and Nano Silica on Properties of Cement Mortar

Rasha R. Rawdhan Azhar J. Bohan Ghaed K. Salman Muhanad Al-Jubouri

Publication Name: International Journal of Integrated Engineering

Publication Date: 2024-01-01

Volume: 16

Issue: 1

Page Range: 350-360

Description:

This study investigates the effects of adding nano-ferrite (N.F.) and nano-silica (N.S.) on the mechanical and biological properties of mortar. By assessing four water-to-cement ratios (1–4%), the ideal nanoparticle doses were determined. Results indicated that both N.F. and N.S. significantly increased the mortar’s strength at ratios between 1% and 4%, while combinations of N.F. and N.S. improved strength up to 3% and 4% substitution, respectively. The mechanisms of strength enhancement were attributed to nanoparticles acting as fillers and hydration accelerators, which densify the mortar microstructure and promote the production of calcium silicate hydrate (C-S-H) gels. In terms of biological properties, the study examined the antibacterial effects of nano-silica and nano-ferrite. Nano-silica demonstrated greater antibacterial potency against all bacterial strains assessed. Both materials exhibited a stronger antibacterial impact on Gram-positive bacteria (Staphylococcus aureus) compared to Gram-negative bacteria (Escherichia coli), due to differences in cell wall structures. The study emphasizes the importance of optimal nanoparticle dosages and identifies limitations that warrant further research, such as durability and potential downsides at higher concentrations. Despite these challenges, the findings underscore the potential of nanoparticles to enhance mortar performance and suggest promising applications in construction and the development of antibacterial materials. Future research should focus on overcoming these constraints and exploring the practical applications of nanoparticle-enhanced mortar in real-world scenarios.

Open Access: Yes

DOI: 10.30880/IJIE.2024.16.01.030

Monitoring of embankment construction processes

E. Koch

Publication Name: Pollack Periodica

Publication Date: 2007-04-01

Volume: 2

Issue: 1

Page Range: 89-100

Description:

Nowadays more and more engineering structures are constructed on soft soils of low strength. High compressibility, low permeability and liability to secondary compression of these soils can result in long-term settlements and a menace with critical situations when the construction deadlines are tough. To cope with these problems several technologies have recently been developed in the embankment construction practice. Staged construction, over-filling, vertical drainage, stone columns, dynamic compaction - all of them often combined successfully with geosynthetics - are preferred to the previously predominant technology of soil replacement. Nevertheless, common design methods often do not balance properly the structural modeling, computation, economical and construction aspects. This is why a correct design may become a subject of reconsideration and modification in specific circumstances. There remains a room for innovative approaches, when conventional solutions are used. Two examples seem to prove that construction combined with monitoring may tum out to be good compromises. © 2007 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.2.2007.1.8

Evaluating the Reliability of Hinge Definitions in Pushover Analyses: A Comparative Study of SAP2000, AxisVM

Orsolya K. Kegyes-B. Kevin Karanja Kuria

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 291-297

Description:

This study evaluates the performance of SAP2000, and AxisVM in conducting pushover analyses, with a focus on the manual (user) definition of plastic hinges versus the automatic definitions provided by the software. Three structures, namely a single column subjected to a point load, a 2D reinforced concrete (RC) frame model, and a 3D RC model, are considered. It explores the performance of the three models in different conditions, including, application of the different software, the use of user defined (manual) hinges, and automatically generated hinges to assess their response to various analytical excitations. The need for engineers to focus on understanding the application of defining the hinge properties according to existing guidelines, including FEMA-356, ASCE 41-13/17, and Eurocodes, is highly emphasized, in addition to the existing methods as found in the literature. This is achieved by considering and comparing the capacity curves generated by the software. The results vary in some instances, especially when comparing results from user-defined and automatic hinges. It is also found that when used with precision, the results are almost similar, it is also important to use software that allows ultimate precision for better results.

Open Access: Yes

DOI: 10.3233/ATDE240558

Progress on joint experiments on small tokamaks

E. Sukhov G. M. Vorobjev A. Singh V. Weinzettl B. Kuteev G. Mank G. Kirnev A. Malaquias I. Ďuran I. El Chama Neto B. Tál N. Kirneva A. Melnikov P. Khorshid M. Hron P. Peleman J. Sentkerestiova A. Fonseca C. R. Gutierrez Tapia J. Zajac M. Berta A. Talebitaher M. Sokolov V. Vershkov E. Del Bosco A. W. Kraemer-Flecken J. G. Ferreira J. Brotankova J. Stockel A. M. Marques Fonseca M. Gryaznevich G. Van Oost E. Dufkova R. Dejarnac V. Soldatov V. Budaev Y. Kuznetsov L. Ruchko H. Hegazy A. Ovsyannikov H. Hegazy G. Ramos L. I. Krupnik S. Zoletnik

Publication Name: 34th Eps Conference on Plasma Physics 2007 Eps 2007 Europhysics Conference Abstracts

Publication Date: 2007-12-01

Volume: 31

Issue: 1

Page Range: 435-438

Description:

No description provided

Open Access: Yes

DOI: DOI not available

In trust we thrive: What drives the sharing economy?

Gauri Shankar Gupta Kinga Szabó

Publication Name: Corvinus Journal of Sociology and Social Policy

Publication Date: 2020-01-01

Volume: 11

Issue: 2

Page Range: 49-68

Description:

The rapid growth of the sharing economy in the last two decades may signal a paradigm shift in global capitalism and societal values. Digital platforms have brought together strangers with under-utilized capacities and assets with those who need them but who are not looking for ownership. The radius of trust, which was initially confined to family, friends and local communities, now encompasses strangers who speak no common language and who may live oceans apart. Trust, driven by Digital Identity (DI) and Trust and Reputation Information (TRI), has enabled what was considered improbable or even impossible some years ago. The further expansion and deepening of trust, based on new technologies combined with the international legal framework, has the potential to rewrite the apparatus of modern capitalism and societal values. Civil society and governments need to engage on this issue to guide them in a direction that is most beneficial to society. However, the current extraordinary situation due to the Coronavirus pandemic, coupled with the foreseeable tendency to complete digital control, is likely to have far-reaching impact on the future development of the sharing economy.

Open Access: Yes

DOI: 10.14267/CJSSP.2020.2.3

Design and Implementation of a Modular Smart Home System Using ESP32 and Apple HomeKit Integration

Stefan Koprda Zoltan Balogh Gyorgy Molnar

Publication Name: Sisy 2025 IEEE 23rd International Symposium on Intelligent Systems and Informatics Proceedings

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 125-130

Description:

This paper presents a modular smart home system integrating ESP32 microcontrollers with Apple HomeKit ecosystem to address scalability and data retention challenges in residential IoT deployments. The proposed solution employs the HomeSpan library for HomeKit-Compatible accessories, enabling secure local communication while maintaining compatibility with Apple's Home application. The key scientific contribution lies in the hybrid architecture combining real-time HomeKit control with a dedicated REST API server featuring SSL encryption and API-key authentication for historical data collection. The system addresses Apple Home app's limitation of lacking data retention capabilities through automated 5-minute data transmission intervals to a secure MariaDB database. Performance evaluation demonstrates stable operation across multiple sensor types (DHT22, PIR motion sensors) and actuators with modular deployment flexibility. Comparative analysis shows improved data persistence and analytics capabilities over standard HomeKit implementations while maintaining the security benefits of local communication protocols. The implementation achieves practical IoT deployment suitable for residential environments with enhanced comfort, safety, and energy efficiency monitoring capabilities.

Open Access: Yes

DOI: 10.1109/SISY67000.2025.11205419

Investigation of swings caused by sudden wind loads during operation of an aerial ladder

Péter Horváth Flóra Hajdu Rajmund Kuti

Publication Name: Fme Transactions

Publication Date: 2020-01-01

Volume: 48

Issue: 2

Page Range: 351-356

Description:

In Hungary, as in other countries around the world, intervention firefighting units often use a mechanically operated aerial ladder for highaltitude rescue tasks. The safe operation of the equipment is only possible under strict safety regulations and requires a high level of expertise from the operating staff. During each intervention, extraordinary events such as sudden wind gusts can occur, which can cause extreme overload of the structural members of aerial ladders and have adverse effects on the equipment that can lead to malfunctions and-even worse-to accidents. Therefore it is important to study the consequences of external influences on aerial ladders during operation. The examination was performed on a widely used Magirus M32-L aerial ladder. The reason for choosing this type of aerial ladder is because it has a wide operating range, therefore test results can be a good starting point for other similar equipment as well. In this paper the development of our beam model and the performed finite element simulations are presented. The aim of the research is to develop a model based on geometrical measurement data that is suitable for studying the effects of wind gusts on the ladder structure. With our research, we aim to contribute to the safe operation of aerial ladders and to prevent possible accidents.

Open Access: Yes

DOI: 10.5937/FME2002351H

Simulation of 3-dimensional cell population growth processes in polyhedral cellular systems

Ibolya Zsoldos Tamás Réti

Publication Name: Materials Science Forum

Publication Date: 2007-01-01

Volume: 537-538

Issue: Unknown

Page Range: 579-590

Description:

In order to simulate the polyhedral grain nucleation in alloys, 3-D cell population growth processes are studied in space-filling periodic cellular systems. We discussed two different methods by which space-filling polyhedral cellular systems can be constructed by topological transformations performed on "stable" 3-D cellular systems. It has been demonstrated that an infinite sequence of stable periodic space-filling polyhedral systems can be generated by means of a simple recursion procedure based on a vertex based tetrahedron insertion. On the basis of computed results it is conjectured that in a 3-D periodic, topologically stable cellular system the minimum value of the average face number 〈f〉 of polyhedral cells is larger than eight (i.e. 〈f〉 > 8). The outlined algorithms (which are based on cell decomposition and/or cell nucleation) provide a new perspective to simulate grain population growth processes in materials with polyhedral microstructure.

Open Access: Yes

DOI: 10.4028/0-87849-426-x.579

Improve the Accuracy of Neural Networks using Capsule Layers

Claudiu Pozna Janos Hollosi

Publication Name: 18th IEEE International Symposium on Computational Intelligence and Informatics Cinti 2018 Proceedings

Publication Date: 2018-11-01

Volume: Unknown

Issue: Unknown

Page Range: 15-18

Description:

Neural networks are a powerful and widely used tools for various classification and segmentation tasks. Nowadays, in the field of computer vision the convolutional neural networks (CNNs) are the most popular solution for many problems. The CNNs performance is looks like exceptionally great when the test images are very close to the training dataset. However if the input images are transformed, such as rotating or tilting, the efficiency of the neural network may be greatly reduced. A new kind of neural network, is called capsule network, is trying to solve this problem. In this paper we examines the efficiency of the capsule network, by trying to increase the accuracy of different networks with capsule layers.

Open Access: Yes

DOI: 10.1109/CINTI.2018.8928194