LIVIVO - Search results -

Search results

Result 1 - 10 of total 26

Search options

Article ; Online: A data-based reduced-order model for dynamic simulation and control of district-heating networks

Jiang, Mengting / Speetjens, Michel / Rindt, Camilo / Smeulders, David

Applied Energy. 2023 June, v. 340 p.121038-

2023

Abstract: This study concerns the development of a data-based compact model for the prediction of the fluid temperature evolution in district heating (DH) pipeline networks. This so-called “reduced-order model” (ROM) is obtained from reduction of the conservation ... ...

Abstract	This study concerns the development of a data-based compact model for the prediction of the fluid temperature evolution in district heating (DH) pipeline networks. This so-called “reduced-order model” (ROM) is obtained from reduction of the conservation law for energy for each pipe segment to a semi-analytical input–output relation between the pipe outlet temperature and the pipe inlet and ground temperatures that can be identified from training data. The ROM basically is valid for generic pipe configurations involving 3D unsteady heat transfer and 3D steady flow as long as heat-transfer mechanisms are linearly dependent on the temperature field. Moreover, the training data can be generated by physics-based computational “full-order” models (FOMs) yet also by (calibration) experiments or field measurements. Performance tests using computational training data for a single-pipe configuration demonstrate that the ROM (i) can be successfully identified and (ii) can accurately describe the response of the outlet temperature to arbitrary input profiles for inlet and ground temperatures. Application of the ROM to two case studies, i.e. fast simulation of a small DH network and design of a controller for user-defined temperature regulation of a DH system, demonstrate its predictive ability and efficiency also for realistic systems. Dedicated cost analyses further reveal that the ROM may significantly reduce the computational costs compared to FOMs by (up to) orders of magnitude for higher-dimensional pipe configurations. These findings advance the proposed ROM as a robust and efficient simulation tool for practical DH systems with a far greater predictive ability than existing compact models.
Keywords	calibration ; energy ; heat transfer ; models ; prediction ; steady flow ; temperature ; District heating network ; Reduced-order model ; Input–output relation ; Linear time-invariant system
Language	English
Dates of publication	2023-06
Publishing place	Elsevier Ltd
Document type	Article ; Online
Note	Use and reproduction
ZDB-ID	2000772-3
ISSN	0306-2619
ISSN	0306-2619
DOI	10.1016/j.apenergy.2023.121038
Database	NAL-Catalogue (AGRICOLA)

Full text online

Accessible to users with ZB MED library card

Order via subito

This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

Details ▾
- Full text online
- Order with fees

Article: Reinforcing Mechanisms of Coir Fibers in Light-Weight Aggregate Concrete.

Zhang, Xiaoxiao / Pel, Leo / Gauvin, Florent / Smeulders, David

Materials (Basel, Switzerland)

2021 Volume 14, Issue 3

Abstract: Due to the requirement for developing more sustainable constructions, natural fibers from agricultural wastes, such as coir fibers, have been increasingly used as an alternative in concrete composites. However, the influence of coir fibers on the ... ...

Abstract	Due to the requirement for developing more sustainable constructions, natural fibers from agricultural wastes, such as coir fibers, have been increasingly used as an alternative in concrete composites. However, the influence of coir fibers on the hydration and shrinkage of cement-based materials is not clear. In addition, limited information about the reinforcing mechanisms of coir fibers in concrete can be found. The goal of this research is to investigate the effects of coir fibers on the hydration reaction, microstructure, shrinkages, and mechanical properties of cement-based light-weight aggregate concrete (LWAC). Treatments on coir fibers, namely Ca(OH)
Language	English
Publishing date	2021-02-02
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	2487261-1
ISSN	1996-1944
ISSN	1996-1944
DOI	10.3390/ma14030699
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Book ; Online: Enhanced Hydrogen Storage in Gold-doped Carbon Nanotubes

Rezaie, Shima / Smeulders, David M. J. / Luna-Triguero, Azahara

A first-principles study

2022

Abstract: Sorbent materials are a promising alternative to advance hydrogen storage technologies. The general disadvantage is the relatively weak solid-gas interaction and adsorption energy, providing low gravimetric and volumetric capacities and extreme ... ...

Abstract	Sorbent materials are a promising alternative to advance hydrogen storage technologies. The general disadvantage is the relatively weak solid-gas interaction and adsorption energy, providing low gravimetric and volumetric capacities and extreme operational conditions. Here we propose Au-doped carbon nanotubes (CNTs) as an efficient alternative for reversible hydrogen capture at high temperatures. This work investigates the properties of several modified CNTs using density functional theory. We analyze the binding and formation energies of the uniformed Au-doped CNTs and assess their adsorption capability. The hydrogen storage mechanisms of the nanostructures are studied in depth using partial density of states and charge transfer analysis showing that the increase of diameter has a positive effect on the outcome. Our findings show that the modified structures are able to capture from six to nine hydrogen molecules per gold atom, achieving volumetric capacities ranging from 154 to 330 g/l, surpassing the DOE target. In addition, the calculated desorption temperatures indicate high performance of Au-doped CNTs, obtaining hydrogen capture-release working conditions above 200 K.
Keywords	Condensed Matter - Materials Science
Subject code	541
Publishing date	2022-11-24
Publishing country	us
Document type	Book ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Book ; Online: A reduced-order model for dynamic simulation of district heating networks

Jiang, Mengting / Speetjens, Michel / Rindt, Camilo / Smeulders, David

2022

Abstract: This study concerns the development of a data-based compact model for the prediction of the fluid temperature evolution in district heating (DH) pipeline networks. This so-called "reduced-order model" (ROM) is obtained from reduction of the conservation ... ...

Abstract	This study concerns the development of a data-based compact model for the prediction of the fluid temperature evolution in district heating (DH) pipeline networks. This so-called "reduced-order model" (ROM) is obtained from reduction of the conservation law for energy for each pipe segment to a semi-analytical input-output relation between the pipe outlet temperature and the pipe inlet and ground temperatures that can be identified from training data. The ROM basically is valid for generic pipe configurations involving 3D unsteady heat transfer and 3D steady flow as long as heat-transfer mechanisms are linearly dependent on the temperature field. Moreover, the training data can be generated by physics-based computational "full-order" models (FOMs) yet also by (calibration) experiments or field measurements. Performance tests using computational training data for a single 1D pipe configuration demonstrate that the ROM (i) can be successfully identified and (ii) can accurately describe the response of the outlet temperature to arbitrary input profiles for inlet and ground temperatures. Application of the ROM to two case studies, i.e. fast simulation of a small DH network and design of a controller for user-defined temperature regulation of a DH system, demonstrate its predictive ability and efficiency also for realistic systems. Dedicated cost analyses further reveal that the ROM may significantly reduce the computational costs compared to FOMs by (up to) orders of magnitude for higher-dimensional pipe configurations. These findings advance the proposed ROM as a robust and efficient simulation tool for practical DH systems with a far greater predictive ability than existing compact models. Comment: 30 pages, 19 figures
Keywords	Mathematics - Numerical Analysis
Subject code	621
Publishing date	2022-11-25
Publishing country	us
Document type	Book ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Evaluation of environmental and economic hotspots and value creation in multi-product lignocellulosic biorefinery

Obydenkova, Svetlana V. / Kouris, Panos D. / Smeulders, David M.J. / Boot, Michael D. / van der Meer, Yvonne

Biomass and Bioenergy. 2022 Apr., v. 159 p.106394-

2022

Abstract: This paper presents systematic analysis of value creation chains and their economic and environmental hotspots within a multi-product biorefinery with the primary goal to promote sustainable biorefining. Lignocellulosic biorefinery producing ethanol, ... ...

Abstract	This paper presents systematic analysis of value creation chains and their economic and environmental hotspots within a multi-product biorefinery with the primary goal to promote sustainable biorefining. Lignocellulosic biorefinery producing ethanol, crude lignin oil (CLO) and electricity was analysed. The methodology involves transformation of technological model into an input-output one with the use of matrix notation for the analysis of economic and environmental attributes along value chains. The results show that the accumulation of biomass through energy supply grows by a factor of 1.2 for ethanol and electricity, and by 1.4 for CLO value chains, of which solid recovery, lignin solvolysis and biomass pretreatment are responsible for the most significant growth indicating the necessity for energy optimization of those steps. The analysis reveals a superfluous role of infrastructure in pretreatment and lignin drying processes. Of infrastructural costs related to the equipment required for the pretreatment step, wastewater treatment (WWT) facility is responsible for 58%, and of the costs of lignin drying, the combined heat and power plant is responsible for 56%. WWT determines 75% of infrastructural GHG emissions attributable to pretreatment, and 57% of those related to lignin drying. This points at an advantage of a biorefinery concept involving the removal of lignin fraction before the valorization of carbohydrates. Another hotspot, the lignin solvolysis technology, shows environmental and economic advantages of its further optimization in terms of production costs and GHG emissions. The proposed method is helpful for analyzing economic and environmental hotspots in new biorefinery concepts and integration pathways.
Keywords	bioenergy ; biomass ; biorefining ; electricity ; energy ; equipment ; ethanol ; heat ; lignin ; lignocellulose ; models ; oils ; power plants ; solvolysis ; wastewater treatment ; Multi-product biorefinery ; Hotspot ; Value chain analysis ; Life cycle assessment ; Techno-economic analysis
Language	English
Dates of publication	2022-04
Publishing place	Elsevier Ltd
Document type	Article ; Online
Note	Use and reproduction
ZDB-ID	1090121-8
ISSN	0961-9534
ISSN	0961-9534
DOI	10.1016/j.biombioe.2022.106394
Database	NAL-Catalogue (AGRICOLA)

Full text online

Accessible to users with ZB MED library card

In stock of ZB MED Bonn / Germany

Z 5470: Show issues

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Details ▾

Article: The Influence of Gas-Wall and Gas-Gas Interactions on the Accommodation Coefficients for Rarefied Gases: A Molecular Dynamics Study.

Mohammad Nejad, Shahin / Nedea, Silvia / Frijns, Arjan / Smeulders, David

Micromachines

2020 Volume 11, Issue 3

Abstract: Molecular dynamics (MD) simulations are conducted to determine energy and momentum accommodation coefficients at the interface between rarefied gas and solid walls. The MD simulation setup consists of two parallel walls, and of inert gas confined between ...

Abstract	Molecular dynamics (MD) simulations are conducted to determine energy and momentum accommodation coefficients at the interface between rarefied gas and solid walls. The MD simulation setup consists of two parallel walls, and of inert gas confined between them. Different mixing rules, as well as existing ab-initio computations combined with interatomic Lennard-Jones potentials were employed in MD simulations to investigate the corresponding effects of gas-surface interaction strength on accommodation coefficients for Argon and Helium gases on a gold surface. Comparing the obtained MD results for accommodation coefficients with empirical and numerical values in the literature revealed that the interaction potential based on ab-initio calculations is the most reliable one for computing accommodation coefficients. Finally, it is shown that gas-gas interactions in the two parallel walls approach led to an enhancement in computed accommodation coefficients compared to the molecular beam approach. The values for the two parallel walls approach are also closer to the experimental values.
Language	English
Publishing date	2020-03-19
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	2620864-7
ISSN	2072-666X
ISSN	2072-666X
DOI	10.3390/mi11030319
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article ; Online: Energy quay walls

Haasnoot Jacco / Vardon Philip J. / Pantev Ivaylo / Bersan Silvia / Bloemers Bob / Smeulders David

E3S Web of Conferences, Vol 205, p

2020 Volume 06002

Abstract: In the Netherlands and other countries around the world there are extensive canals and rivers with banks supported by walls. Especially in the historic inner cities of the Netherlands, quay walls currently need to be replaced. During construction, ... ...

Abstract	In the Netherlands and other countries around the world there are extensive canals and rivers with banks supported by walls. Especially in the historic inner cities of the Netherlands, quay walls currently need to be replaced. During construction, temporary valuable underground space is created that can be used to accommodate energy installations for the benefit of the surrounding buildings. The quay wall itself can also be a thermal active structure relying on a combination of aquatic and geothermal energy. Two different designs for quay walls incorporating thermal energy infrastructure have been designed: (i) based around a sheet pile; and (ii) based around a concrete pile with a ‘L’ wall on top. An evaluation of the energy, mechanics, finances and CO2 saving is presented for a case study in this paper. It is seen that for the case studies elaborated, both walls can supply sufficient thermal energy for the houses along the canals improved by good use of surface water, reduce CO2 emissions by more than 1 tonne per meter length and can be financially positive. The influence on the mechanical performance of the energy quay wall (settlements, bearing capacity and bending) has been evaluated and found to be reassuringly small.
Keywords	Environmental sciences ; GE1-350
Subject code	690
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	EDP Sciences
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Modeling rarefied gas-solid surface interactions for Couette flow with different wall temperatures using an unsupervised machine learning technique.

Mohammad Nejad, Shahin / Iype, Eldhose / Nedea, Silvia / Frijns, Arjan / Smeulders, David

Physical review. E

2021 Volume 104, Issue 1-2, Page(s) 15309

Abstract: In rarefied gas flows, discontinuity phenomena such as velocity slip and temperature jump commonly appear in the gas layer adjacent to a solid boundary. Due to the physical complexity of the interactions at the gas-solid interface, particularly in the ... ...

Abstract	In rarefied gas flows, discontinuity phenomena such as velocity slip and temperature jump commonly appear in the gas layer adjacent to a solid boundary. Due to the physical complexity of the interactions at the gas-solid interface, particularly in the case of systems with local nonequilibrium state, boundary models with limited number of parameters cannot completely describe the reflection of gas molecules at the boundary. In this work, the Gaussian mixture (GM) model, which is an unsupervised machine learning technique, is employed to construct a statistical gas-solid surface scattering model based on the collisional data obtained from molecular dynamics (MD) simulations. The GM model is applied to study Couette flow for different inert gases (Ar and He) confined between two parallel infinite gold walls at different temperatures. A direct comparison between the results obtained from the GM model and the Cercignani-Lampis-Lord (CLL) scattering kernel against the MD collisional data in terms of the distribution of the predicted postcollisional velocities, and accommodation coefficients has shown that the results from the GM model are an excellent match with the MD results outperforming the CLL scattering kernel. As an example, for He gas, while the predicted energy accommodation coefficient by the CLL model is more than two times higher than the MD predictions, the value computed by the GM model is in excellent agreement with the MD results. This superior performance of the GM model confirms its high potential to derive a generalized boundary condition in systems encountered with highly nonequilibrium and complex gas flow conditions.
Language	English
Publishing date	2021-08-13
Publishing country	United States
Document type	Journal Article
ZDB-ID	2844562-4
ISSN	2470-0053 ; 2470-0045
ISSN (online)	2470-0053
ISSN	2470-0045
DOI	10.1103/PhysRevE.104.015309
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article: Exploring the Electronic Structure of New Doped Salt Hydrates, Mg₁–ₓCaₓCl₂·nH₂O, for Thermochemical Energy Storage

Heijmans, Koen / Tranca, Ionut C / Gaastra-Nedea, Silvia V / Smeulders, David M. J

Journal of physical chemistry. 2020 Oct. 29, v. 124, no. 45

2020

Abstract: Chloride-based salt hydrates, MgCl₂·nH₂O and CaCl₂·nH₂O (n = 0,1,2,4,6), are promising materials for thermochemical heat storage systems due to their high sorption energy capacity. However, both salts have their own shortcoming characteristics within the ...

Abstract	Chloride-based salt hydrates, MgCl₂·nH₂O and CaCl₂·nH₂O (n = 0,1,2,4,6), are promising materials for thermochemical heat storage systems due to their high sorption energy capacity. However, both salts have their own shortcoming characteristics within the operational temperature of the thermochemical heat storage applications. While the higher hydrates of CaCl₂·nH₂O (n = 4,6) have a low melting point, the lower hydrates of MgCl₂·nH₂O (n = 0,1,2) can form the highly toxic and corrosive HCl gas. Both shortcomings cap the individual use of these salts to a restricted range of the available hydrates. A combination of these two salts showed to have the potential to overcome these shortcomings. The present study focuses on finding stable configurations of potential superior salt hydrate combinations using the evolutionary algorithm USPEX as well as manual mutations of known pristine structures. The newly found structures are less stable than the pure salts, but stable enough to be combined. Extensive electronic density-derived tools, like the Density Derived Electronic and Chemical (DDEC6) bond orders and net atomic charges, as well as Bader topological analysis, are used to predict the HCl gas formation based on the chemical environment in the new metastable structures. We find that doping MgCl₂·nH₂O with calcium considerably reduces HCl formation compared to its pure form, caused by a combination of the stronger Ca–Cl interaction than Mg–Cl and a less polar H₂O molecule in a calcium environment than in a magnesium environment. This provides the possibility to shift the p, T-equilibrium curve of HCl outside the thermal storage operational window.
Keywords	algorithms ; calcium ; energy ; heat ; magnesium ; sorption ; temperature ; topology ; toxicity
Language	English
Dates of publication	2020-1029
Size	p. 24580-24591.
Publishing place	American Chemical Society
Document type	Article
Note	NAL-AP-2-clean
ISSN	1932-7455
DOI	10.1021/acs.jpcc.0c05799
Database	NAL-Catalogue (AGRICOLA)

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Seismoelectric interface electromagnetic wave characteristics for the finite offset Vertical Seismoelectric Profiling configuration: Theoretical modeling and experiment verification.

Liu, Yukai / Smeulders, David / Su, Yuanda / Tang, Xiaoming

The Journal of the Acoustical Society of America

2018 Volume 143, Issue 1, Page(s) EL13

Abstract: The seismoelectric interface electromagnetic characteristics have been studied for the finite offset Vertical Seismoelectric Profiling (VSEP) configuration. The approach consists of theoretical modeling and laboratory verification. The results show that ... ...

Abstract	The seismoelectric interface electromagnetic characteristics have been studied for the finite offset Vertical Seismoelectric Profiling (VSEP) configuration. The approach consists of theoretical modeling and laboratory verification. The results show that the wave variation characteristics along the finite offset measurement line are markedly different from those along the zero-offset line. More interestingly, the wave characteristics for both configurations can be satisfactorily explained by the electric dipole model for the seismoelectric interface wave radiation. Besides, the experiment confirms the modeling result based on the seismoelectric coupling theory and validates the VSEP technique as an effective method for subsurface interface delineation.
Language	English
Publishing date	2018-02-01
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	219231-7
ISSN	1520-8524 ; 0001-4966
ISSN (online)	1520-8524
ISSN	0001-4966
DOI	10.1121/1.5020261
Database	MEDical Literature Analysis and Retrieval System OnLINE

In stock of ZB MED Cologne/Königswinter

Zs.B 591: Show issues

Location:
Je nach Verfügbarkeit (siehe Angabe bei Bestand)
bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
ab Jg. 2022: Lesesaal (EG)

Order via subito

Details ▾
- See ZB MED holdings
- Order with fees

To top

Full text online

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

In stock of ZB MED Bonn / Germany

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

In stock of ZB MED Cologne/Königswinter

Order via subito