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Evaluating the influence of functional unit on life cycle assessment (LCA) reliability of concrete

Materials Today: Proceedings 2024年

作者： Glenda Terán-Cuadrado Sami Sbahieh Furqan Tahir Anissa Nurdiawati Mohammed A. Almarshoud Sami G. Al-Ghamdi Chemical Engineering Program Physical Sciences and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia KAUST Climate and Livability Initiative King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Division of Sustainable Development College of Science and Engineering Hamad Bin Khalifa University Doha 34110 Qatar Environmental Science and Engineering Program Biological and Environmental Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Civil and Environmental Engineering Department College of Engineering University of Jeddah (UJ) Jeddah 23890-2871 Saudi Arabia

The linear lifecycle of concrete, from production through usage to disposal, highlights its status as one of the most carbon-, energy-, and resource-intensive processes in the industry. The development of life cycle assessment (LCA) models to quantify concrete’s embodied and buildings’ operational emissions is strongly influenced by the selection of the functional unit (FU) since it dictates the magnitude and significance of the environmental burdens from concrete and buildings' life span. The chosen FU should comprehensively capture the concrete's functionalities and construction parameters. Nonetheless, establishing a FU that encompasses spatial, temporal, and intensity aspects of cement/concrete and its applications remains a significant limitation in the practice of current LCA models. This study analyzed the FU influence on the environmental footprint of concrete samples with specific compressive strengths (material level) via LCA. The LCA was conducted in OneClick LCA using the environmental product declaration (EPD) provided by the software for each ready-mix concrete sample. From the LCA results, the C 30/37 concrete mix (lowest compressive strength) exhibited the lowest carbon footprint for all the environmental indicators when a volume-based FU was considered. In contrast, the results were more favorable for the C 65/70 concrete specimen when the compressive strength (28 curing days) was chosen because less cement is needed to achieve one MPa of strength. This behavior was also observed in the modeling of a column in a building, where the mixture with the highest compressive strength (C 65/70) showed the lowest environmental impact for all the indicators. However, this assessment does not represent the actual building system's footprint. Thus, regionally specific functional units need to be established, considering not just concrete functionalities but also national regulations, stakeholder needs, and local resource availability.

关键词： Buildings Concrete Functional unit Embodied carbon emissions LEED Life cycle assessment (LCA)

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Assessment and Tracking Electric Vehicle Battery Degradation Cost using Blockchain

Assessment and Tracking Electric Vehicle Battery Degradation...

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Innovative Smart Grid Technologies (ISGT)

作者： Shashank Narayana Gowda Basem A. Eraqi Hamidreza Nazaripouya Rajit Gadh Smart Grid Energy Research Center University of California Los Angeles USA Division King Abdullah University of Science and Technology (KAUST) Physical Science and Engineering Thuwal Saudi Arabia School of Electrical and Computer Engineering Oklahoma State University Stillwater USA

ISBN: (数字)9781728188973

ISBN: (纸本)9781728188980

This paper proposes a blockchain-based method for assessment and tracking of electric vehicle battery degradation costs. Vehicle-to-Grid (V2G) technology allows the bidirectional flow of electric power between the electric vehicle (EV) and the electric grid. However, for making optimal charging/discharging decisions, it is essential to precisely evaluate the battery degradation. In the proposed method, the initial degradation cost is estimated based on the present status of the EV battery in terms of range and age. Following this, a degradation cost of the battery is obtained from battery specifications and continuously tracking the variables that affect battery energy capacity, which will determine the economic loss to EV users for participating in V2G programs. A Mixed Integer Linear program to minimize cost includes this degradation cost in its objective function to make the optimal decision for an EV's interaction with the grid. At the end of each 24-hour cycle, the battery degradation cost is updated based on the charging/discharging transactions performed during the cycle and the temperature conditions. These transactions and battery degradation costs are stored in a consortium blockchain that is shared among the relevant actors.

关键词： Degradation Vehicle-to-grid Blockchain Predictive models Batteries Power systems Vehicle dynamics

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Finite-time joint estimation of the arterial blood flow and the arterial Windkessel parameters using modulating functions ⁎

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IFAC-PapersOnLine 2020年第2期53卷 16286-16292页

作者： Mohamed A. Bahloul Taous-Meriem Laleg Kirati Computer Electrical and Mathematical Science and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) 23955-6900 Thuwal Kingdom of Saudi Arabia

Studying the arterial hemodynamic response plays a crucial role in the understanding and the treatment of cardiovascular diseases. Due to the difficulty of measuring the arterial blood flow, its estimation through a particular arterial vessel, using non-invasive arterial pressure waveform measurements, has always been an important topic in physiology. For instance, knowing the blood flow in a specific site of the arterial network helps in the detection of arterial stenosis. It may also help in the diagnosis of heart valve’s diseases. In this paper, an algorithm based on modulating functions is proposed to estimate the arterial blood flow as well as to calibrate the conventional Windkessel model using arterial blood pressure signals measured in a particular site of the arterial system. The algorithm is presented and illustrated through several numerical tests.

关键词： Finite-time estimation modulating functions Windkessel model blood flow

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Linear and Circular Dichroism in Graphene-Based Reflectors for Polarization Control

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Physical Review Applied 2020年第2期13卷 024046-024046页

作者： M. Amin O. Siddiqui M. Farhat College of Engineering Taibah University Madinah 41411 Saudi Arabia Division of Computer Electrical and Mathematical Science and Engineering King Abdullah University of Science and Technology Thuwal 23955-6900 Saudi Arabia

We present an ultrathin graphene metascreen that possesses dispersive optical activity in the early terahertz spectrum. The metascreen design consists of periodically etched L-shaped voids on a graphene substrate backed by a conductive plane. The specific unit-cell design is based on chirality and leads to highly asymmetric radiations from the plasmon-polariton surface currents, leading to linear and circular dichroism. Hence the incident linearly or circularly polarized electric fields are effectively absorbed by the metasurface in different proportions. Consequently, the metasurface assumes half- and quarter-wave-plate behaviors in different parts of the reflected optical spectrum. In particular, we show via full-wave simulations that the dichroic metascreen supports perfect linear-to-circular polarization conversion (circular dichroism) in two adjacent terahertz frequency bands. In two other terahertz bands, it rotates the incoming linearly polarized wave vector by 90∘ (linear dichroism). Moreover, since graphene has a variable refractive-index dependence on its chemical potential, the dispersion characteristics can be shifted to neighboring frequencies within the early terahertz spectrum. We further demonstrate an angularly stable response for incident angles varying between 0∘ and 45∘. The tunable linear and circular dichroism characteristics are well suited for applications in sensing, imaging, and spectroscopy at terahertz frequencies.

关键词： Metamaterials Photonics Plasmonics Polarization of light Surface plasmon polariton Graphene Multilayer thin films Chiral symmetry

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Lattice Transformation from 2-D to Quasi 1-D and Phonon Properties of Exfoliated ZrS2 and ZrSe2

arXiv

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arXiv 2022年

作者： Alsulami, Awsaf Alharbi, Majed Alsaffar, Fadhel Alolaiyan, Olaiyan Aljalham, Ghadeer Albawardi, Shahad Alsaggaf, Sarah Alamri, Faisal Tabbakh, Thamer A. Amer, Moh R. Center of Excellence for Green Nanotechnologies Joint Centers of Excellence Program King Abdulaziz City for Science and Technology Riyadh Saudi Arabia Department of Mechanical and Aerospace Engineering University of California Los Angeles Los AngelesCA90095 United States National Center for Nanotechnology Materials Science Institute King Abdulaziz City for Science and Technology Riyadh Saudi Arabia Department of Electrical and Computer Engineering University of California Los Angeles Los AngelesCA90095 United States

Recent reports on thermal and thermoelectric properties of emerging 2-Dimensional (2D) materials have shown promising results. Yet, most of these emerging materials are underrepresented or lack a consistent and thorough investigation. Among these materials are Zirconium based chalcogenides such as Zirconium Disulfide (ZrS2) and Zirconium Dieselenide (ZrSe2). Here, we investigate the thermal properties of these Zirconium based materials using confocal Raman spectroscopy. We observed 2 different and distinctive Raman signatures for exfoliated ZrX2 (where X = S or Se). These Raman modes generally depend on the shape of the exfoliated nanosheets, regardless of the incident laser polarization. These 2 shapes are divided into 2D- ZrX2 and quasi 1D- ZrX2. For 2D- ZrX2, Raman modes are in alignment with those reported in literature. However, for quasi 1D-ZrX2, we show that Raman modes are identical to exfoliated ZrX3 nanosheets, indicating a major lattice transformation from 2D to quasi-1D. We also measure thermal properties of each resonant Raman mode for each ZrX2 shape. Based on our measurements, most Raman modes exhibit a linear downshift dependence with temperature. However, for ZrS2, we see an upshift (blueshift) with temperature for A1g mode, which is attributed to non-harmonic effects caused by dipolar coupling with IR-active modes. Moreover, the observed temperature dependence coefficient for some phonon modes of quasi 1D-ZrX2 differ dramatically, which can be caused by the quasi 1D lattice. Finally, we measure phonon dynamics under optical heating for each of 2D-ZrX2 and quasi 1D-ZrX2 and show phonon confinement in quasi 1D-ZrX2 nanosheets. We extract the thermal conductivity and the interfacial thermal conductance for each of 2D-ZrX2 and quasi 1D-ZrX2 nanosheets. Our calculations indicate lower interfacial thermal conductance for quasi 1D-ZrX2 compared to 2D-ZrX2, which can be attributed to the phonon confinement in 1D. Based on our model, we show low thermal con

关键词： Thermal conductivity

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Janus monolayers of magnetic transition metal dichalcogenides as an all-in-one platform for spin-orbit torque

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Physical Review B 2021年第10期104卷 104415-104415页

作者： Idris Smaili Slimane Laref Jose H. Garcia Udo Schwingenschlögl Stephan Roche Aurélien Manchon King Abdullah University of Science and Technology (KAUST) Computer Electrical and Mathematical Science and Engineering Division (CEMSE) Thuwal 23955-6900 Saudi Arabia King Abdullah University of Science and Technology (KAUST) Physical Science and Engineering Division (PSE) Thuwal 23955-6900 Saudi Arabia Catalan Institute of Nanoscience and Nanotechnology (ICN2) CSIC and BIST Campus UAB Bellaterra 08193 Barcelona Spain ICREA–Institució Catalana de Recerca i Estudis Avançats 08010 Barcelona Spain Aix-Marseille Université CNRS CINaM Marseille France

We theoretically predict that vanadium-based Janus dichalcogenide monolayers constitute an ideal platform for spin-orbit torque memories. Using first-principles calculations, we demonstrate that magnetic exchange and magnetic anisotropy energies are higher for heavier chalcogen atoms, while the broken inversion symmetry in the Janus form leads to the emergence of Rashba-like spin-orbit coupling. The spin-orbit torque efficiency is evaluated using optimized quantum transport methodology and found to be comparable to heavy nonmagnetic metals. The coexistence of magnetism and spin-orbit coupling in such materials with tunable Fermi-level opens new possibilities for monitoring magnetization dynamics in the perspective of nonvolatile magnetic random access memories.

关键词： Magnetization dynamics Spin transfer torque Spin-orbit coupling 2-dimensional systems

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IMPATT Efficiency Extraction Using On-Chip Antenna Radiation

IMPATT Efficiency Extraction Using On-Chip Antenna Radiation

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International Review of Progress in Applied Computational Electromagnetics (ACES)

作者： Talal Al-Attar Computer Electrical and Mathematical Science & Engineering Division King Abdullah University of Science and Technology Thuwal Saudi Arabia

ISBN: (数字)9781733509602

ISBN: (纸本)9781728162850

IMPATT diodes were designed and integrated with microstrip patch antenna on-chip in standard CMOS technology to extract the efficiency beyond avalanche frequency. By comparing the on-chip simulations and measurements of an IMPATT diode integrated in a CPW to an integrated one with a microstrip patch antenna at the same biasing conditions, the results demonstrated an efficiency ranging from ~ 0.01% to 0.016% without and with the added surface roughness losses, respectively. Such variation is strongly associated with the uncertainty provided by the increase of conduction losses ranging between 40%~80% beyond the avalanche frequency.

关键词： Antenna measurements Rough surfaces Surface roughness Patch antennas System-on-chip Microstrip antennas Microstrip

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Coat-and-print patterning of silver nanowires for flexible and transparent electronics

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npj Flexible Electronics 2019年第1期3卷 149-155页

作者： Weiwei Li Azat Meredov Atif Shamim IMPACT Lab ComputerElectrical and Mathematical Sciences and Engineering(CEMSE)DivisionKing Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia.

Silver nanowires(Ag NWs)possess excellent optoelectronic properties,which have led to many technology-focused applications of transparent and flexible *** of these applications require patterning of Ag NWs into desired shapes,for which maskbased and printing-based techniques have been developed and widely ***,there are still several limitations associated to these *** limitations,such as complicated patterning procedures,limited patterning area,and compromised optical transparency,hamper the efficient fabrication of high-performance Ag NW ***,we propose a coat-and-print approach for effectively patterning Ag *** printed a polymer-based ink on the spin-coated Ag NW *** ink acts as a protective layer to help remove excess Ag NWs from the substrate and then dissolves itself into an organic *** this way,we can take advantage of both coating-based techniques(lead to Ag NWs with high transparency)and printing-based techniques(efficiently pattern diverse shapes).The resultant Ag NW patterns exhibit comparable conductivity(sheet resistance:7.1 to 30 Ohm/sq)and transparency(transmittance:84 to 95%atλ=550 nm)to those made by conventional coating *** addition,the patterned Ag NWs exhibit robust mechanical stability and reliability,surviving extensive bending and peeling *** to higher conductivity,efficient patterning ability and inherent transparency,this material system and application method is highly suitable for transparent and flexible *** a proof of concept,this research demonstrates a wide-band antenna,operating in the mm-wave range that includes the 5G communication *** proposed antenna exhibits a wide bandwidth of 26 GHz(from 17.9 GHz to 44 GHz),robust return loss under 1000 cyclic bending(bending radius of 3.5 mm),and decent transparency over the entire visible wavelength(86.8%transmittance atλ=550 nm).This work’s promising results indicate that this method can be adapted for r

关键词： nanowires transparent transparency

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Simultaneous solar power harnessing and water treatment for water-energy sustainability

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Materials science and engineering: R: Reports 2025年 166卷

作者： Abdul Ghaffar Muhammad Bilal Asif Javeed Mahmood Cafer T. Yavuz Oxide & Organic Nanomaterials for Energy & Environment (ONE) Laboratory Chemistry Program Physical Science & Engineering (PSE) King Abdullah University of Science and Technology (KAUST) Thuwal 23955 Saudi Arabia

Solar evaporation is a promising technique for simultaneous water treatment and energy generation because it is environmentally friendly and has low maintenance costs. Several options are available to harness low-grade waste energy and mass flow, as well as salinity and temperature gradients, for interfacial solar evaporation. This review provides a comprehensive summary of the materials and devices used for simultaneous water treatment and energy harvesting, along with how they influence the chemistry of the water-energy nexus. Key approaches to improve energy conversion efficiency, minimize energy losses, and low-grade residual heat applications have been explored, including piezoelectric, pyroelectric, salinity gradient, triboelectric, and thermo-electrochemical methods. The physics and engineering of solar-thermal approaches, modes of operation, and materials, as well as hybrid desalination and energy generation with different solar-thermal materials, solar-steam devices, and systems are also assessed. Finally, future research challenges and opportunities are outlined in the context of commercialization.

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Control of Smart Buildings and Utility-Scale Batteries Enabling 24/7 Carbon-Free Energy*

Control of Smart Buildings and Utility-Scale Batteries Enabl...

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European Control Conference (ECC)

作者： Faran A. Qureshi Jeff S. Shamma Robotics Intelligent Systems and Control (RISC) Laboratory Computer Electrical and Mathematical Sciences and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia University of Illinois at Urbana-Champaign USA

Wind power is a clean and sustainable source of electricity, but its intermittent nature creates challenges for its grid integration. Utility-scale batteries are a popular and effective solution to make wind power dispatchable, however, batteries are expensive and increase the overall cost of operation. In this paper, we propose utilizing the flexibility in the consumption of smart buildings to reduce the size of the utility-scale batteries needed for the dispatchability of wind energy. A method based on stochastic optimization is proposed to compute the dispatch plan required to participate in the day-ahead energy market. A stochastic model predictive controller is proposed for the control of the buildings and batteries to track the dispatch plan in real-time. Simulations are carried out with realistic building models and real weather, wind power production, and forecast data. Results demonstrate that utilizing the flexibility of building thermodynamics can significantly reduce the size (and usage) of the required battery for making the wind power production dispatchable.

关键词： Smart buildings Computational modeling Stochastic processes Production Wind power generation Predictive models Data models

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