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Experimental Investigation and Applicability of Multi-Stage Simulations in the Case of a Thick-Walled Injection-Moulded Composite

Ferenc Ronkay Tamás Morauszki Gabor Dogossy

Publication Name: Applied Sciences Switzerland

Publication Date: 2022-09-01

Volume: 12

Issue: 17

Page Range: Unknown

Description:

The structure and mechanical properties of an injection-moulded short glass fibre (GF)-reinforced polymer composite were analysed through simulation methods. Fibre orientation, which evolves during the production of a thick-walled automotive part, was determined with an injection moulding simulation. Next, using the material model for the injected product, the force that resulted from the given deformation was determined with finite element software. To validate the simulation results, the examined products were manufactured with 30% reinforced GF, and then measurements were carried out. The validation of the fibre orientation tensor was achieved with optical microscope images, while the validation of the finite element, which analysed the flexural tests, was carried out through a comparison of flexural rigidity. The aim of the project was to verify the reliability of multi-stage finite element software. According to the results, in the case of a thick-walled GF-reinforced product, it was demonstrated that the integration of a different finite element software could be used reliably.

Open Access: Yes

DOI: 10.3390/app12178415

Response to Artificial intelligence-based colorectal polyp histology prediction using narrow-band image-magnifying colonoscopy: a stepping stone for clinical practice

Istvan Racz András Horváth Zoltán Horváth

Publication Name: Clinical Endoscopy

Publication Date: 2022-09-01

Volume: 55

Issue: 5

Page Range: 701-702

Description:

No description provided

Open Access: Yes

DOI: 10.5946/ce.2022.123.1

Laser powder bed fusion and casting for an advanced hybrid prototype mold

Martin Zobač Imre Fekete J. G. Kovacs Béla Zink István Hatos Dániel Török Tatyana Ageyeva Róbert Boros H. Hargitai

Publication Name: Journal of Manufacturing Processes

Publication Date: 2022-09-01

Volume: 81

Issue: Unknown

Page Range: 748-758

Description:

One of the factors limiting the throughput of injection molding is cooling time, which is the most significant part of the total cycle time. The cooling efficiency of molds can be considerably improved with additive manufacturing techniques. A 3D printed injection mold with conformal cooling channels reduces cooling time by 30–40 %. However, the cooling efficiency of these molds can be further improved with a multi-material approach and the use of materials with excellent thermal and mechanical properties. In this study, we propose a hybrid mold insert made of steel and copper, produced with the combination of Laser Powder Bed Fusion (L-PBF) and casting. The steel shell that contains conformal cooling channels was printed by L-PBF. Then this shell was cast with copper. We found that the hybrid mold insert we developed has lower residual cooling time and heat extraction is more uniform than the conventional printed steel insert. The developed hybrid mold insert enables a reduction of residual cooling time by 15 %.

Open Access: Yes

DOI: 10.1016/j.jmapro.2022.07.034

General formulation of resilience for designing process networks

Ákos Orosz Jean Pimentel Ferenc Friedler Andres Argoti

Publication Name: Computers and Chemical Engineering

Publication Date: 2022-09-01

Volume: 165

Issue: Unknown

Page Range: Unknown

Description:

Herein, the formula proposed for quantifying the resilience of engineering systems, including processing systems, is general in several aspects. The structure of a system can be highly complex where the numbers of loops, raw materials, and products are not limited. The mathematical models of the operating units can be either linear or nonlinear for simulating the effect of the failures. The damage caused by an unexpected event can result in various levels of operation for the operating units. The proposed formula is also general in the sense that all possible combinations of failures are considered. The problem formulation, the related structure representation, the enumeration and evaluation of possible failures are based on the P-graph framework and its algorithms. The proposed formula for resilience is applicable to any complex engineering system whose behavior is primarily determined by its structure, including supply chains, information systems, municipal infrastructures, and electrical transmission networks.

Open Access: Yes

DOI: 10.1016/j.compchemeng.2022.107932

Predicting Modified Fournier Index by Using Artificial Neural Network in Central Europe

Tamás Ratonyi Endre Harsányi A. Széles Bashar Bashir Safwan Mohammed Muhammad Farhan Ul Moazzam Firas Alsilibe István Takács Abdullah Alsalman A. Nyéki

Publication Name: International Journal of Environmental Research and Public Health

Publication Date: 2022-09-01

Volume: 19

Issue: 17

Page Range: Unknown

Description:

The Modified Fournier Index (MFI) is one of the indices that can assess the erosivity of rainfall. However, the implementation of the artificial neural network (ANN) for the prediction of the MFI is still rare. In this research, climate data (monthly and yearly precipitation (pi, Ptotal) (mm), daily maximum precipitation (Pd-max) (mm), monthly mean temperature (Tavg) (°C), daily maximum mean temperature (Td-max) (°C), and daily minimum mean temperature (Td-min) (°C)) were collected from three stations in Hungary (Budapest, Debrecen, and Pécs) between 1901 and 2020. The MFI was calculated, and then, the performance of two ANNs (multilayer perceptron (MLP) and radial basis function (RBF)) in predicting the MFI was evaluated under four scenarios. The average MFI values were between 66.30 ± 15.40 (low erosivity) in Debrecen and 75.39 ± 15.39 (low erosivity) in Pecs. The prediction of the MFI by using MLP was good (NSEBudapest(SC3) = 0.71, NSEPécs(SC2) = 0.69). Additionally, the performance of RBF was accurate (NSEDebrecen(SC4) = 0.68, NSEPécs(SC3) = 0.73). However, the correlation coefficient between the observed MFI and the predicted one ranged between 0.83 (Budapest (SC2-MLP)) and 0.86 (Pécs (SC3-RBF)). Interestingly, the statistical analyses promoted SC2 (Pd-max + pi + Ptotal) and SC4 (Ptotal + Tavg + Td-max + Td-min) as the best scenarios for predicting MFI by using the ANN–MLP and ANN–RBF, respectively. However, the sensitivity analysis highlighted that Ptotal, pi, and Td-min had the highest relative importance in the prediction process. The output of this research promoted the ANN (MLP and RBF) as an effective tool for predicting rainfall erosivity in Central Europe.

Open Access: Yes

DOI: 10.3390/ijerph191710653

Integrating innovative digital technologies into use assessment of parks and protected areas in North America

Farhad Moghimehfar Garrett Stone Monir Shahzeidi Jesse Miller

Publication Name: Handbook of Innovation for Sustainable Tourism

Publication Date: 2022-08-16

Volume: Unknown

Issue: Unknown

Page Range: 347-360

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Wear behaviour of ceramic particle reinforced atmospheric plasma spray coatings on the cylinder running surface of internal combustion engines

Ibolya Zsoldos Alexander Dudás András Lajos Nagy Gabor Laki Barna Hanula Dirk Bartel

Publication Name: Wear

Publication Date: 2022-08-15

Volume: 502-503

Issue: Unknown

Page Range: Unknown

Description:

Atmospheric plasma spray coatings can provide a solution for corrosion and wear resistant cylinder coating surfaces in hybrid powertrains. This article presents experimental results from a model study of metal matrix composite coating samples of chromium steel with varied ceramic content, in order to characterize the effect of hard particles and porous coating structure on friction and wear. Experiments were conducted on a high-frequency reciprocating rig with coated cast-iron cylinder segments and hard chromium coated piston ring segments. Samples were investigated under continuous and scarce lubrication conditions. A ceramic content of 35 wt% was found to be ideal in terms of friction and wear. Coatings with a higher ceramic content exhibited severe abrasive wear, whereas a ceramic content under 35 wt% allowed for increased adhesion between the ring and cylinder surfaces. A detailed investigation of focused ion beam milled sections of the coated cylinder wall segments revealed a stabilizing effect of the ceramic particles, which reduces the delamination of the coating structure.

Open Access: Yes

DOI: 10.1016/j.wear.2022.204373

Burnout syndrome among healthcare professionals of neonatal intensive care units

Mihály Dió Ibolya Lipienné Krémer Ágnes Harmath Zsuzsanna Soósné Kiss

Publication Name: Orvosi Hetilap

Publication Date: 2022-08-07

Volume: 163

Issue: 32

Page Range: 1268-1274

Description:

Introduction: Burnout syndrome among healthcare workers is a well-known problem. Its occurrence and the roots have been addressed in several studies. The daily work of the specialist employees in the neonatal intensive care units is extremely stressful physically and mentally. Objective: The study assessed the frequency and intensity of burnout phenomenon among healthcare professionals working in neonatal intensive care units and examined the relations between institutional levels, occupation, and work experience. Method: Data were collected in 2019 using the Maslach Burnout Inventory (MBI) questionnaire compiled by Maslach and Jackson. Results: In the field of examined dimensions of burnout syndrome, the most characteristic was emotional exhaustion, which has occurred with a frequency of nearly 30% and with typically high intensity among professionals working in neonatal intensive care units (N = 278). In addition, one-fifth were characterized by a high frequency and intensity of depersonalization. At the same time, nearly a third of them experienced a decrease in personal effectiveness. Work¬place and time spent in healthcare did not show a significant connection with the incidence of burnout syndrome, however, burnout syndrome occurred with a higher frequency and intensity among those working in level III. neo¬natal intensive care unit. Conclusion: This is the first comprehensive burnout survey among premature and new born intensive care units in Hungary. Knowing the consequences of burnout syndrome, it is important to prevent and recognize symptoms as early as possible.

Open Access: Yes

DOI: 10.1556/650.2022.32539

Design and implementation of a software tester for benchmarking stateful NATxy gateways: Theory and practice of extending siitperf for stateful tests

Gábor Lencse

Publication Name: Computer Communications

Publication Date: 2022-08-01

Volume: 192

Issue: Unknown

Page Range: 75-88

Description:

Our siitperf is the world's first RFC 8219 compliant free software SIIT (Stateless IP/ICMP Translation, also called stateless NAT64) benchmarking tool. It was written in C++ using DPDK (Intel Data Plane Development Kit). Our current effort aims to design and implement a test program for stateful NATxy gateways, including both stateful NAT64 and stateful NAT44 (also called NAPT: Network Address and Port Translation). Due to the object-oriented design of siitperf, it is feasible to extend it for stateful tests, while keeping its original design and features. In this paper, we introduce the problem of benchmarking stateful NATxy gateways and propose various solutions. We disclose the design and the most important implementation decisions of the stateful extension of siitperf. We prove the viability of our design and implementation by a functional NAT64 test and performing the maximum connection establishment rate, throughput, and frame loss rate measurements of the Jool stateful NAT64 implementation. We also carry out an initial performance estimation of the stateful extension of siitperf. Our tester is distributed as free software under the GPLv3 license for the benefit of the research, benchmarking and networking communities.

Open Access: Yes

DOI: 10.1016/j.comcom.2022.05.028