Engineering Commons^™

Direct Femtosecond Laser Inscription Of High-Order Bragg Gratings In Fluoroaluminate Glass Fiber, Lin She, Niannian Xu, Pengfei Wang, Jiquan Zhang, Mo Liu, Nian Lv, Ruoning Wang, Zhenrui Li, Shijie Jia, Shunbin Wang, Gerald Farrell, Weimin Sun

Articles

This letter reports the fabrication of fiber Bragg gratings (FBGs) within in-house fabricated fluoroaluminate (AlF3) glass fibers using femtosecond (fs) laser inscription at 800 nm. The grating strength of the FBGs was investigated for different pulse energies and different orders, and a 3rd-order FBG with Bragg wavelength at 1557 nm was found to have the highest reflectivity of 99.5%. In addition, the reflectivity of the mid-IR grating peaks for different orders was also studied, and a 2nd-order FBG with a reflectivity of 98.8% was obtained at 2864 nm. Finally, the temperature characteristics of a mid-IR FBG were studied between 30 …

Recent Advances In Luminescence And Lasing Research In Zbya Glass, Changjun Xu, Jiquan Zhang, Mo Liu, Haiyan Zhao, Fengzi Ling, Shijie Jia, Gerald Farrell, Shunbin Wang, Pengfei Wang

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In the last few decades, fluoride glasses have attracted a growing interest due to their unique advantages compared to multi-component oxide glasses. Among them, the most studied and widely used were fluorozirconate glasses, represented by ZrF4–BaF2–LaF3–AlF3–NaF (ZBLAN) glasses. However, compared with ZBLAN glasses, a kind of fluorozirconate glass with the components ZrF4–BaF2–YF3–AlF3 (ZBYA) has higher thermal and chemical stability. In this paper, we first introduce the advantages of ZBYA glasses compared to ZBLAN glasses. Then we review and discuss recent advances in research on luminescence and lasing in ZBYA glass and fiber. These studies suggest that ZBYA glass has strong …

All-Optical Modulator Based On A Microfibre Coil Resonator Functionalized With Mxene, Pengfei Wang, Shi Li, Fengzi Ling, Gerald Farrell, Elfed Lewis, Yu Yin

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A novel all-optical modulator based on a microfibre coil resonator (MCR) functionalized using MXene is reported. The MCR was manufactured by winding a tapered fibre on a polycarbonate (PC) resin cylinder with low refractive index to support the microfibre, which also forms a fluidic channel coil. The MXene dispersion was injected into the channel to allow the deposition of an MXene layer using a photodeposition process. The transmission spectra were tuned using a tunable laser with a centre wavelength of 1550 nm and the light-matter interaction resulting from the photo-thermal effect and MXene absorption provide the all-optical modulation in this …

A Micron-Range Displacement Sensor Based On Thermo-Optically Tuned Whispering Gallery Modes In A Microcapillary Resonator, Zhe Wang, Arun Kumar Mallik, Fangfang Wei, Zhuochen Wang, Anuradha Rout, Qiang Wu, Yuliya Semenova

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A novel micron-range displacement sensor based on a whispering-gallery mode (WGM) microcapillary resonator filled with a ne matic liquid crystal (LC) and a magnetic nanoparticle- coated fiber half-taper is proposed and experimentally demonstrated. In the proposed device, the tip of a fiber half-taper coated with a thin layer of magnetic nanoparticles (MNPs) moves inside the LC-filled microcapillary resonator along its axis. The input end of the fiber half-taper is connected to a pump laser source and due to the thermo-optic effect within the MNPs, the fiber tip acts as point heat source increasing the temperature of the LC material in …

Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal

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Active packaging improves a packaging system’s effectiveness by actively integrating additional components into the packaging material or the headspace around the packaging. Consumer demand and awareness have grown enough to replace chemical agents with natural active agents. Essential oils (EOs) are extensively distributed throughout nature but at low levels and sometimes with poor recovery yields, which poses an issue with their application in food. Due to the instability of EOs when added directly into a food product, they require encapsulation before being added to a packaging matrix such as liposomes, solid-lipid nanoparticles, nano-emulsions, cyclodextrins, and nanostructured lipid nano-carriers. This article …

In-Flow Dynamics Of An Area-Difference-Energy Spring-Particle Red Blood Cell Model On Non-Uniform Grids, Brendan Walsh, Fergal Boyle

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In this paper the area-difference-energy spring-particle (ADE-SP) red blood cell (RBC) structural model developed by Chen and Boyle is coupled with a lattice Boltzmann flux solver to simulate RBC dynamics. The novel ADE-SP model accounts for bending resistance due to the membrane area difference of RBCs while the lattice Boltzmann flux solver offers reduced computational runtimes through GPU parallelisation and enabling the employment of non-uniform meshes. This coupled model is used to simulate RBC dynamics and predictions are compared with existing experimental measurements. The simulations successfully predict tumbling, tank-treading, swinging and intermittent behaviour of an RBC in shear flow, and …

Opportunities And Barriers Faced By Early-Career Civil Engineers Enacting Global Responsibility, Shannon Chance, Inês Direito, John Mitchell

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The term ‘global responsibility’ projects a holistic sense of ethics, sustainability, and obligation. To achieve the long-term viability of human life on Earth, civil engineering must be conducted in increasingly responsible ways, and civil engineers must value and enact global responsibility in their work. Interviews conducted with nine civil engineers in London provide insight regarding engineers’ familiarity with the term, how they learned about it, what opportunities and barriers they face, and what might be done by professional and educational institutions to help them practice more responsibly. Results indicate: the term itself is novel but underlying concepts are not; continuing …

A Knowledge-Based Model For Context-Aware Smart Service Systems, Thang Le Dinh, Thanh Thoa Pham Thi, Cuong Pham-Nguyen, Le Nguyen Hoai Nam

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The advancement of the Internet of Things, big data, and mobile computing leads to the need for smart services that enable the context awareness and the adaptability to their changing contexts. Today, designing a smart service system is a complex task due to the lack of an adequate model support in awareness and pervasive environment. In this paper, we present the concept of a context-aware smart service system and propose a knowledge model for context-aware smart service systems. The proposed model organizes the domain and context-aware knowledge into knowledge components based on the three levels of services: Services, Service system, …

Transferring Studies Across Embodiments: A Case Study In Confusion Detection, Na Li, Robert J. Ross

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Human-robot studies are expensive to conduct and difficult to control, and as such researchers sometimes turn to human-avatar interaction in the hope of faster and cheaper data collection that can be transferred to the robot domain. In terms of our work, we are particularly interested in the challenge of detecting and modelling user confusion in interaction, and as part of this research programme, we conducted situated dialogue studies to investigate users' reactions in confusing scenarios that we give in both physical and virtual environments. In this paper, we present a combined review of these studies and the results that we …

Advancing Competency In Managing Risk And Knowledge: Steps Toward Operationalisation Of The Risk-Knowledge Infinity Cycle (Rki Cycle) Part 3: Uncovering Knowledge For Qrm Through Knowledge Mapping At Node 1, Martin Lipa, Valerie Mulholland, Anne Greene

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To date, literature on the Risk-Knowledge Infinity Cycle (RKI Cycle) has mainly been theoretical. This paper series intent is to focus on the operationalisation of the RKI Cycle by describing a series of steps – the “How to” – for RKI Cycle deployment, to help move the RKI Cycle from theory to practice. The third paper in this series focuses on ensuring the best available knowledge flows into QRM through a case study demonstrating knowledge mapping to support effective quality risk assessment during commissioning and qualification activities.

Carbon Nanotube Coated Fibrous Tubes For Highly Stretchable Strain Sensors Having High Linearity, Chenchen Li, Bangze Zhou, Yanfen Zhou, Jianwei Ma, Fenglei Zhou, Shaojuan Chen, Stephen Jerrams, Liang Jiang

Articles

Strain sensors are currently limited by an inability to operate over large deformations or to exhibit linear responses to strain. Producing strain sensors meeting these criteria remains a particularly difficult challenge. In this work, the fabrication of a highly flexible strain sensor based on electrospun thermoplastic polyurethane (TPU) fibrous tubes comprising wavy and oriented fibers coated with carboxylated multiwall carbon nanotubes (CNTs) is described. By combining spraying and ultrasonic-assisted deposition, the number of CNTs deposited on the electrospun TPU fibrous tube could reach 12 wt%, which can potentially lead to the formation of an excellent conductive network with high conductivity …

Os-Walk-Eu: An Open-Source Tool To Assess Health-Promoting Residential Walkability Of European City Structures, Stefan Fina, Christian Gerten, Brian Pondi, Lorraine D'Arcy, Niamh O' Reilly, David Sousa Vale, Mauro Pereira, Samuele Zilio

Articles

Introduction This paper introduces OS-WALK-EU, a new open-source walkability assessment tool developed specifically for urban neighbourhoods and using open-source spatial data. A free and open-source tool, OS-WALK-EU is accessible to the general public. It uses open data available worldwide and free online services to compute accessibility, while at the same time allowing users to integrate local datasets if available. Based on a review of existing measurement concepts, the paper adopts dimensions of walkability that were tested in European city environments and explains their conceptualization for software development. We invite the research community to collaboratively test, adopt and use the tool …

Dominant Frequency Component Tracking Of Noisy Time-Varying Signals Using The Linear Predictive Coding Pole Processing Method, Jin Xu, Mark Davis, Ruairí De Fréin

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The linear predictive coding pole processing (LPCPP) method proposed in our previous work overcomes the shortcomings of the LPC method, especially its sensitivity to noise and the filter order. The LPCPP method is a parameterised method that involves processing the LPC poles to produce a series of reduced-order filter transfer functions to estimate the dominant frequency components of a signal. This paper analyses the ability of the LPCPP method to track the frequency changes of noisy, time-varying signals in real-time. Linear chirped frequency modulation signals are used in a series of experiments to simulate signals with different rates of frequency …

Formation Of Gold Nanoparticle Self-Assembling Films In Various Polymer Matrices For Sers Substrates, Ksenia A. Maleeva, Ilia E. Kaliya, Anton P. Tkach, Anton A. Babaev, Michail Baranov, Kevin Berwick, Tatiana S. Perova, Alexander V. Baranov, Kirill V. Bogdanov

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Surface-enhanced Raman spectroscopy (SERS) is regarded as a versatile tool for studying the composition and structure of matter. This work has studied the preparation of a SERS substrate based on a self-assembling plasmonic nanoparticle film (SPF) in a polymer matrix. Several synthesis parameters for the SPF are investigated, including the size of the particles making up the film and the concentration and type of the self-assembling agent. The result of testing systems with different characteristics is discussed using a model substance (pseudo isocyaniniodide). These models can be useful in the study of biology and chemistry. Research results contain the optimal …

Development And Characterisation Of A Whole Hybrid Sol-Gel Optofluidic Platform For Biosensing Applications, Emma Mchugh, Graceson Antony, Arun Kumar Mallik, Alicja Kaworek, Declan Mccormack, Brendan Duffy, Mohamed Oubaha

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This work outlines, for the first time, the fabrication of a whole hybrid sol-gel optofluidic platform by integrating a microfluidic biosensor platform with optical waveguides employing a standard photolithography process. To demonstrate the suitability of this new hybrid sol-gel optofluidic platform, optical and bio-sensing proof-of-concepts are proposed. A photoreactive hybrid sol-gel material composed of a photopolymerisable organically modified silicon alkoxide and a transition metal complex was prepared and used as the fabrication material for the entire optofluidic platform, including the optical waveguides, the sensing areas, and the microfluidic device. The most suitable sol-gel materials chosen for the fabrication of the …

Passage Tombs And Wind Turbines—A Contested Relationship?, Frank Prendergast, Muiris O'Sullivan Prof

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Geospatial and archaeoastronomical analysis of the proposed location of large-scale wind turbines showed a significant negative visual impact on two National Monuments (Knockroe and Kilkieran) and on a hilltop passage tomb at Baunfree. These places straddle county boundaries and their constituent monuments are components of a rare and internationally important prehistoric landscape. Tipperary County Council gave considerable weight to the findings described in this paper in making their decision to refuse planning permission.

Quantum Mechanics And Control Using Fractional Calculus: A Study Of The Shutter Problem For Fractional Quantum Fields, Jonathan Blackledge

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The ‘diffraction in space’ and the ‘diffraction in time’ phenomena are considered in regard to a continuously open, and a closed shutter that is opened at an instant in time, respectively. The purpose of this is to provide a background to the principal theme of this article, which is to extend the ‘quantum shutter problem’ for the case when the wave function is determined by the fundamental solution to a partial differential equation with a fractional derivative of space or of time. This involves the development of Green’s function solutions for the space- and time-fractional Schrödinger equation and the time-fractional …

Measurement Of Orientation And Distance Change Using Circularly Polarized Uwb Signals, Janusz Przewocki, Max Ammann, Adam Narbudowicz

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The article proposes methodology to use circularly polarized (CP) ultra-wideband (UWB) signals for simultaneous measurement of orientation and distance changes between transmitter and receiver. The proposed technique uses the rotational Doppler effect on CP pulsed communication. The amplitude of a CP signal is immune to polarization misalignment in the presence of rotation; however, the phase is subjected to a frequency-invariant shift proportional to the rotation angle. This significantly distorts the pulse shape in the time domain and can be used for the measurement of the rotated angle. By combining the technique with the well-known localization capability of UWB systems, one …

Determining Realistic U-Values To Substitute Default U-Values In Epc Database To Make More Representative; A Case-Study In Ireland., Kumar Raushan, Ciara Ahern, Brian Norton

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Energy Performance Certificates (EPCs) are the foremost source of information on the energy performance of the EU’s building stock. Inherent in all EPC methodologies are trade-offs between reproducibility, accuracy, assessor expertise and costs. During an assessment, where accurate building data acquisition would be excessively invasive or costly, nationally specified default values are used.

Default values are necessarily pessimistic to; avoid a better-than-merited rating, enable homeowners to know the advantage of energetic refurbishment, encourage homeowners to record upgrades informing EPCs, and propel assessors to seek-out information to provide an accurate rating.

This work reviews default U-value use across Europe and the …

Preparing Engineering Students For The Challenges Of The Sdgs: What Competences Are Required?, Una Beagon, Klara Kövesi, Brad Tabas, Bente Nørgaard, Riitta Lehtinen, Brian Bowe, Christiane Gillet, Claus Monrad Spliid

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Despite the emerging discussions about the growing role of engineers in achieving the Sustainable Development Goals (SDGs), there is a lack of agreement on which competences should be prioritised to prepare engineering students to resolve future sustainability challenges. This study examined and compared the views of key stakeholders of engineering education (Academics, Employers and Students) using twelve focus groups in Denmark, Finland, France and Ireland. The findings were mapped against competences identified in previous studies to highlight gaps and opportunities for development. The results confirm the strong emphasis on normative, strategic and systems thinking competences in engineering. However, the outcomes …

Home Energy Management System Considering Effective Demand Response Strategies And Uncertainties, Marcos Tostado-Véliz, Paul Arévalo, Salah Kamel, Hossam Zawbaa, Francisco Jurado

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Nowadays, load serving entities require more active participation from consumers. In this context, demand response programs and home energy management systems play a crucial role in achieving multiple goals such as peak clipping. However, the adoption of demand response initiatives typically has a negative impact on the monetary expenditures of the users. This way, a demand response program should be as effective as possible to make the different goals more easily achievable without compromising the financial requirements of the users. This paper develops a home energy management system that incorporates three novel effective demand response strategies. The effectiveness of the …

Improvement Of Active Distribution Systems With High Penetration Capacities Of Shunt Reactive Compensators And Distributed Generators Using Bald Eagle Search, Ahmad Eid, Salah Kamel, Dr Hossam Zawbaa, Mostafa Dardeer

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This work proposes an intelligent allocation of distributed generation (DG) units and shunt reactive compensators (SRC) with high penetration capacities into distribution systems for power loss mitigation using the Bald Eagle Search (BES) optimization algorithm. The intelligent allocation causes a reduction in voltage variations and enhances the voltage stability of the systems. The SRC units include shunt capacitors (SC), Static Var Compensators (SVC), and Distribution Static Compensators (DSTATCOM), which are determined according to their capacities. The optimization study includes the 33-bus and the 118-bus distribution systems as medium to large systems. Performance parameters, including the reactive power loss, Total Voltage …

Performance Of An Adaptive Aggregation Mechanism In A Noisy Wlan Downlink Mu-Mimo Channel, Lemlem Kassa, Mark Davis, Jianhua Deng, Jingye Cai

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This paper investigates an adaptive frame aggregation technique in the medium access control (MAC) layer for the Wireless Local Area Network (WALN) downlink Multi-User–Multiple-In Multiple-Out (MU-MIMO) channel. In tackling the challenges of heterogeneous traffic demand among spatial streams, we proposed a new adaptive aggregation algorithm which has a superior performance over the baseline First-in–First-Out (FIFO) scheme in terms of system throughput performance and channel utilization. However, this earlier work does not consider the effects of wireless channel error. In addressing the limitations of this work, this study contributes an enhanced version of the earlier model considering the effect of channel …

Rss-Based Indoor Localization System With Single Base Station, Samir Salem Al-Bawri, Mohammad Tariqul Islam, Mandeep Jit Singh, Mohd Faizal Jamlos, Adam Narbudowicz, Max Ammann, Dominique M.M.P. Schreurs

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The paper proposes an Indoor Localization System (ILS) which uses only one fixed Base Station (BS) with simple non-reconfigurable antennas. The proposed algorithm measures Received Signal Strength (RSS) and maps it to the location in the room by estimating signal strength of a direct line of sight (LOS) signal and signal of the first order reflection from the wall. The algorithm is evaluated through both simulations and empirical measurements in a furnished open space office, sampling 21 different locations in the room. It is demonstrated the system can identify user’s real-time location with a maximum estimation error below 0.7 m …

Information Modelling For Urban Building Energy Simulation—A Taxonomic Review, Avichal Malhotra, Julian Bischof, Alexandru Nichersu, Karl-Heinz Häfele, Johannes Exenberger, Divyanshu Sood, James Allan, Jérôme Frisch, Christoph Van Treeck, James O'Donnell, Gerald Schweiger

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Climate change, increasing emissions and rising global temperatures have gradually affected the way we think about the future of our planet. Urban areas possess significant potential for reducing the energy consumption of the overall energy system. In recent years, there is an increasing number of research initiatives related to Urban Building Energy Modelling (UBEM) that focus on simulation processes and validation techniques. Although input data are crucial for the modelling process as well as for the validity of the results, the availability of input data and associated data formats were not analysed in detail. This paper closes the identified knowledge …

Designing A Robust Decentralized Energy Transactions Framework For Active Prosumers In Peer-To-Peer Local Electricity Markets, Mehdi Mehdinejad, Heidar Ali Shayanfar, Behnam Mohammadi-Ivatloo, Hamed Nafisi

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In this paper, a fully decentralized local energy market based on peer-to-peer(P2P) trading is proposed for small-scale prosumers. In the proposed market, the prosumers are classified as buyers and sellers and can bilaterally engage in energy trading (P2P) with each other. The buyer prosumers are equipped with electrical storage and can participate in a demand response (DR) program while protecting their privacy. In addition to bilateral negotiating with the local sellers, these players can compensate for their energy deficiency from the upstream market as the retail market at hours without local generation. In this paper, the retail market price is …

Heat Transfer And Friction Factor Correlations Development For Double Pass Solar Air Heater Artificially Roughened With Perforated Multi-V Ribs, Varun Pratap Singh, Siddharth Jain, Ashish Karn, Gaurav Dwivedi, Ashwani Kumar, Sachin Mishra, Naveen Kumar Sharma, Hossam Zawbaa, Salah Kamel

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Thermo-hydraulic performance of a Double Pass Parallel Flow Solar Air Heater (DPPFSAH) roughened with perforated multi-V ribs has been studied experimentally in a prior study and the effect of variation in open area ratio and change in relative roughness width has been analysed and reported. The current work builds upon the aforementioned earlier study by discussing in detail the methodology and various steps involved in the development of a correlation for variable parameters with Nusselt number and friction factor for DPPFSAH. The outcomes show that perforations in the multi-V ribs lead to a considerable rise in the Nusselt number, a …

Electrooptic, Pyroelectric And Dielectric Spectroscopic Studies Of Nematic And Twist Bend Nematic Phases Of Achiral Hockey-Shaped Bent-Core Liquid Crystal, Sithara P. Sreenilayam, Neelam Yadav, Yuri Panarin, G. Shanker, J.K. Vij

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Experimental and theoretical investigations of the twist-bend nematic (NTB) phase in liquid crystals have recently received significant attention for reasons of unusual and interesting characteristics of the NTB. Though NTB was predicted to exist for rigid bent-core LCs by Ivan Dozov in 2001, nevertheless it has unambiguously been proven to exist only in a few bent-core systems so far. Here the characteristics of both the nematic (N) and NTB phases are investigated for a hockey shaped achiral rigid bent-core LC, called BCI, in planar and homeotropic aligned cells, using polarizing optical microscopy, electro-optics, pyroelectricity and wide band dielectric spectroscopy. Spontaneous …

Optimal Design Of Photovoltaic, Biomass, Fuel Cell, Hydrogen Tank Units And Electrolyzer Hybrid System For A Remote Area In Egypt, Abd El-Sattar Abd El-Sattar, Salah Kamel, Hamdy M. Sultan, Hossam Zawbaa, Francisco Jurado

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In this paper, a new isolated hybrid system is simulated and analyzed to obtain the optimal sizing and meet the electricity demand with cost improvement for servicing a small remote area with a peak load of 420 kW. The major configuration of this hybrid system is Photovoltaic (PV) modules, Biomass gasifier (BG), Electrolyzer units, Hydrogen Tank units (HT), and Fuel Cell (FC) system. A recent optimization algorithm, namely Mayfly Optimization Algorithm (MOA) is utilized to ensure that all load demand is met at the lowest energy cost (EC) and minimize the greenhouse gas (GHG) emissions of the proposed system. The …

Human Mental Workload: A Survey And A Novel Inclusive Definition, Luca Longo, Christopher D. Wickens, Gabriella Hancock, P.A. Hancock

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Human mental workload is arguably the most invoked multidimensional construct in Human Factors and Ergonomics, getting momentum also in Neuroscience and Neuroergonomics. Uncertainties exist in its characterization, motivating the design and development of computational models, thus recently and actively receiving support from the discipline of Computer Science. However, its role in human performance prediction is assured. This work is aimed at providing a synthesis of the current state of the art in human mental workload assessment through considerations, definitions, measurement techniques as well as applications, Findings suggest that, despite an increasing number of associated research works, a single, reliable and …