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Found 6319 publications

A Review on the Differences Between Particle Emission, Filtration and Regeneration of Particulate Filters of Diesel and Gasoline Engines

Ibolya Zsoldos Péter Nagy

Publication Name: Lecture Notes in Mechanical Engineering

Publication Date: 2021-01-01

Volume: 22

Issue: Unknown

Page Range: 158-173

Description:

The exhaust aftertreatment systems of diesel passenger cars have been equipped with diesel particulate filters since 2009 when the EURO 5 standard was introduced. This device is a trap for particulates, which originate from internal combustion engines in soot form. These particles must be filtered because they are able to enter the bloodstream through the human respiratory system and can cause an adverse effect on health. Investigations conducted after the 2016 diesel scandal concluded that gasoline engines with direct injection systems commonly in use today, also produce a high number of particles, therefore they must be equipped with gasoline particulate filters. The current EURO 6d TEMP regulation introduced in September 2017 specifies that the NEDC-regulation has to be replaced gradually with the WLTP investigation and the RDE realistic vehicle tests, thus making the real results of the measurements impossible to avoid. Also the particulate emission per one hundred kilometers will be observable in case of direct injection gasoline engines. This paper presents the formation of soot particles during the combustion processes of diesel and gasoline engines, the deposition of particles in particulate filters and explores and analyses the differences between the regeneration processes due to the deposition of particles.

Open Access: Yes

DOI: 10.1007/978-981-15-9529-5_14

Retrofit Synthesis of Industrial Heat Exchanger Networks with Different Types of Heat Exchangers

Olga Arsenyeva Ákos Orosz Ferenc Friedler

Publication Name: Chemical Engineering Transactions

Publication Date: 2021-01-01

Volume: 88

Issue: Unknown

Page Range: 613-618

Description:

Heat Exchanger Network (HEN) synthesis is a powerful tool for the development of more efficient processes with high utilization of mass and energy resources. The implementation of compact heat exchangers with enhanced heat transfer into the industrial flowsheets can provide more efficient and economically feasible solutions. Plate Heat Exchanger (PHE) is one of established types of enhanced HEs. To estimate possible benefits of that kind of heat transfer enhancement, a mathematical model of PHE, which accounts for different plate types and corresponding corrugations geometry, is used. The integration of this model with the P-graph-based HEN synthesis approach allowed to create the method, which considers different types of heat exchangers. This approach enables to integrate not only conventional shell-and-tube heat exchangers, but also PHEs, which overall heat transfer coefficient is in average 2-3 times higher, during the optimization process of a new or existing HEN. The capabilities of the proposed method are presented via a case study for oil preheat train, where an existing network is retrofitted; first with shell-and-tube heat exchangers only, then with the consideration of both shell-and-tube and plate heat exchangers.

Open Access: Yes

DOI: 10.3303/CET2188102

Potentials and challenges of augmented reality smart glasses in logistics and supply chain management: a systematic literature review

Horst Treiblmaier John G. Keogh Abderahman Rejeb G. Keong Leong

Publication Name: International Journal of Production Research

Publication Date: 2021-01-01

Volume: 59

Issue: 12

Page Range: 3747-3776

Description:

This study investigates the potentials and challenges of applying augmented reality (AR) smart glasses in logistics and supply chain management (SCM). A systematic literature review on AR smart glasses was conducted to provide a comprehensive synthesis of what has been published in the literature to capture the dynamics surrounding this technology and identify areas deserving of further academic attention. To summarise the latest developments in this field, eighty-two (82) publications were selected and thoroughly analysed. In terms of research findings, four main clusters of potential benefits were identified: visualisation, interaction, user convenience, and navigation. In contrast, the challenges posed by smart glasses in the logistics field were clustered around technical, organisational, and ergonomic considerations. The accumulation of knowledge and actionable insights in this study will benefit both academics and practitioners interested in this emerging wearable technology segment. As the first attempt to explore the importance of smart glasses in logistics and SCM activities, this study offers significant contributions to the literature by codifying extant knowledge on AR smart glasses and setting forth an agenda for future research.

Open Access: Yes

DOI: 10.1080/00207543.2021.1876942

Mathematics and computational intelligence synergies for emerging challenges

Eloísa Ramírez-Poussa Juan Moreno-García Ĺaszĺo T. Ḱoczy Jesús Medina-Moreno

Publication Name: International Journal of Computational Intelligence Systems

Publication Date: 2021-01-01

Volume: 14

Issue: 1

Page Range: 818-820

Description:

No description provided

Open Access: Yes

DOI: 10.2991/ijcis.d.210121.001

Hawkes processes: some key ideas, links to neuroscience and system identification

Dániel Fabó György Perczel Loránd Erőss Zsuzsanna Vágó László Gerencsér

Publication Name: Communications in Information and Systems

Publication Date: 2021-01-01

Volume: 21

Issue: 3

Page Range: 385-413

Description:

The primary objective of the present paper is to provide a brief survey of basic ideas and some key results of the theory of Hawkes processes that may serve as an interface for multidisciplinary research between mathematics and neurosciences, with hints to epidemiology. The class of Hawkes processes is considered as an appropriate model to describe the pattern of neuronal firing, see [56] [38]. As such, it is a prime candidate for detecting changes in brain activity, and consequently to predict epileptic seizures. Most of the advanced results will be presented via simple examples. In addition, we elaborate on links between the theory of Hawkes processes and linear stochastic systems, in particular system identification. A few new results in this context will be also presented with the outline of their proofs.

Open Access: Yes

DOI: 10.4310/cis.2021.v21.n3.a4

Numerical Simulation of Coupled Electromagnetic and Thermal Problems in Permanent Magnet Synchronous Machines

Lotfi Abdelhakim Daniel Marcsa V. Chabannes C. Prudhomme Zoltán Horváth

Publication Name: Lecture Notes in Computational Science and Engineering

Publication Date: 2021-01-01

Volume: 139

Issue: Unknown

Page Range: 693-701

Description:

The main objective of our task is to develop mathematical models, numerical techniques to analyse the thermal effects in electric machines, to implement the developed algorithm in multiprocessor or multi-core environments and to apply them to industrial use cases. In this study, we take into account coupled character of the electromagnetic and thermal features of the physical process. Both thermal and electromagnetic processes are considered transient, solved by means of the FEM method on independent meshes and the time-discretization is realized using time operator splitting. Two examples are presented to assess the accuracy of the developed coupled solvers and the numerical results are compared with the experimental ones, which are obtained from a prototype machine.

Open Access: Yes

DOI: 10.1007/978-3-030-55874-1_68

DAIRY WASTEWATER UTILIZATION BY COMBINATION OF OXIDATION PRE-TREATMENT AND ULTRAFILTRATION

Zsuzsanna László Sándor Beszédes E. Lakatos Mihály Zakar Gábor Keszthelyi-Szabó

Publication Name: Environmental Engineering and Management Journal

Publication Date: 2021-01-01

Volume: 20

Issue: 12

Page Range: 1711-1719

Description:

In this work the effects of oxidation pre-treatments (ozonation and Fenton reaction) on membrane filtration of dairy wastewater were investigated, together with the further utilization possibilities of residual wastes. The oxidation pre-treatments enhanced the membrane filtration efficiency, from which the short-term ozone treatment was found to be the most effective method both in terms of increasing the flux and the pollutant removal efficiency. After ozone pre-treatment the phosphate and ammonium content of the wastewater migrated to the permeate, while after Fenton pre-treatment the phosphate content remained in the concentrate, and the ammonium content in the permeate decreased. The concentrate was utilized as biogas resource and it was found that both pretreatments increased the biogas production and its methane content as well. Based on our results it can be concluded that ozone pretreatment combined with membrane separation have improved the efficiency of dairy wastewater treatment and may suit the requirements of circular economy.

Open Access: Yes

DOI: DOI not available

Welding distortion generated uncertainties in the vibrational behavior of a ladder-like structure

Dániel Feszty Marcell Treszkai David Sipos

Publication Name: Proceedings of Inter Noise 2021 2021 International Congress and Exposition of Noise Control Engineering

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Recent developments in acoustic simulation methods allowed engineers to assess the vibroacoustic behavior of various type of structures within a virtual environment, thus allowing the replacement of prototype-based development with simulations. However, there are some factors, that cannot be considered in simulations in advance. In the present study, the effect of the distortions generated due to welding on a ladder-like structure equipped with flat plates was investigated. The measured acceleration frequency response functions were compared to finite element simulation results. The measured responses differed significantly from the simulation, even in the low frequency ranges, where the global modes were not expected to be altered or vanished. Investigation of the simulated results revealed that the additional modes were related to the vibration of the plates, which were assumed to be flat, instead of considering the warping caused by the welding process. After measuring the approximate deformation of the plates, an updated simulation model was made, introducing an approximate curvature in them. The results obtained with the updated simulation model performed much better in the low frequency range as well as in the third octave-averaged frequency bands up 1200 Hz. The sensitivity of the warping was also systematically evaluated.

Open Access: Yes

DOI: 10.3397/IN-2021-2844

Co-composting with herbal wastes: Potential effects of essential oil residues on microbial pathogens during composting

E. Lakatos Babett Greff Jenő Szigeti László Varga

Publication Name: Critical Reviews in Environmental Science and Technology

Publication Date: 2021-01-01

Volume: 51

Issue: 5

Page Range: 457-511

Description:

Because of the increasing use of herbal essential oils (EO) in pharmacology, medicine, and food processing, global EO production grows at a rapid rate, generating large amounts of plant residues worldwide. The use of herbal residues for co-composting with various wastes offers a novel option for eco-friendly and cost effective waste management. However, the biologically active compounds remaining in the herb residues may affect microbial activity in the composting biomass, thereby influencing final compost quality. In this review, we summarize and evaluate current literature on the occurrence and survival of pathogens in composts, the beneficial effects of using herbal residues as bulking agents, and the potential antipathogenic effects of six herb species belonging to the Lamiaceae family as follows: lemon balm (Melissa officinalis L.), oregano (Origanum vulgare L.), lavender (Lavandula angustifolia Mill.), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and sage (Salvia officinalis L.).

Open Access: Yes

DOI: 10.1080/10643389.2020.1732780