Engineering Commons^™

Into The Deep: The Role Of Paradigms In Understanding Engineering Education For Sustainable Development, Iacovos Nicolaou, Eddie Conlon, Brian Bowe

Articles

This article presents summary findings of a mixed methods research project exploring the provision of education for sustainable development (SD) in seven Irish engineering degree programmes. Drawing on Sterling’s (2004) iceberg metaphor and Critical Realism it seeks to identify the underlying socio-cultural barriers preventing a holistic integration of SD in engineering education. It argues that the current focus is predominantly on the environmental dimension of SD and that there are a set of reinforcing mechanisms facilitating the provision of disciplinary education aimed at producing technically proficient, employable graduates in which the social dimension of SD is marginalised. This is underwritten …

Reliability-Based Designs Procedure Of Earth Retaining Walls In Geotechnical Engineering, Juan Camilo Viviescas, Juan Pablo Osorio, Julio E. Canon

Articles

The design and construction of foundations, retaining structures and slopes are usually based on deterministic formulations that do not allow the distinction between the natural variability and the inherent dispersion in the geotechnical parameters. Due to the inherent variability of the soil properties, there is a growing trend to implement reliability-based designs in geotechnical engineering to reduce design uncertainties by probabilistic methods. The reliability designs require the definition of the probability density functions of the geotechnical properties, as well as knowledge of the spatial variability of soils. This paper identifies the procedures, type of soil investigations, simulations and the most …

Modelling Tree Contribution In Susceptibility Analysis Of Shallow Llandslides, Roberto José Marín Sánchez, Juan Pablo Osorio

Articles

In this paper an assessment of shallow landslides susceptibility in a tropical and mountainous terrain is made. A method that allows to model slope stability over large areas is used. Tree contribution is quantified by means of three parameters: rainfall interception, root reinforcement and tree surcharge. A rainfall interception model is used to determine the rain available for infiltration and its temporal distribution during the simulation. The hydrological models included in TRIGRS are described, which allows to determine the pore water pressure depending on the initial conditions. This pore water pressure is used in the revised infinite slope stability model, …

K-Bit-Swap: A New Operator For Real-Coded Evolutionary Algorithms, Aram Ter-Sarkisov, Stephen Marsland

Articles

There has been a variety of crossover operators proposed for Real-Coded Genetic Algorithms (RCGAs), which recombine values from the same location in pairs of strings. In this article we present a recombination operator for RC- GAs that selects the locations randomly in both parents, and compare it to mainstream crossover operators in a set of experiments on a range of standard multidimensional optimization problems and a clustering problem. We present two variants of the operator, either selecting both bits uniformly at random in the strings, or sampling the second bit from a normal distribution centered at the selected location in …

Advances In Diamond Nanofabrication For Ultrasensitive Devices, Stefania Castelletto, Lorenzo Rosa, Jonathan Blackledge, Mohammed Zaher Al Abri, Albert Boretti

Articles

This paper reviews some of the major recent advances in single-crystal diamond nanofabrication and its impact in nano- and micromechanical, nanophotonics and optomechanical components. These constituents of integrated devices incorporating specific dopants in the material provide the capacity to enhance the sensitivity in detecting mass and forces as well as magnetic field down to quantum mechanical limits and will lead pioneering innovations in ultrasensitive sensing and precision measurements in the realm of the medical sciences, quantum sciences and related technologies.

Design And Planned Obsolescence. Theories And Approaches For Designing Enabling Technologies, Matteo Zallio, Damon Berry

Articles

We are currently living in a decade where smart objects and Internet of Things (IoT)-based devices are becoming part of daily life in different contexts. This research seeks to investigate and verify, by using a formal literature review methodology, the most visible aspects of technological development, within the Industry 4.0 and IoT scenario, in relation to the theories of the so called “Planned Obsolescence”.

This study covers a defined number of works on Design theories and practices on how to face the issue of built-in obsolescence of devices in the era of the Connected Devices. The majority of the works …

An Evaluation Of The Efficiency Of Compartmented Alginate Fibres Encapsulating Rejuvenator As Asphalt Pavement Healing System, Amir Tabakovic, Luke Schuyffel, Aleksandar Karac, Erik Schlangen

Articles

This paper explores the potential methods for evaluating a healing system for asphalt pavements. The healing system under investigation involves compartmented calcium-alginate fibres encapsulating an asphalt binder healing agent (rejuvenator). This system presents a novel method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are used to distribute the rejuvenator throughout the pavement mixture, thereby overcoming some of the problems associated with alternate asphalt pavement healing methods, i.e., spherical capsules and hollow fibres. The asphalt healing efficiency methods to be evaluated in this paper include: (i) standard test methods for asphalt pavements, such as the Indirect Tensile Strength …

Magnetic Field Sensor Based On A Combination Of A Microfiber Coupler Covered With Magnetic Fluid And A Sagnac Loop, Fangfang Wei, Arun Mallik, Dejun Liu, Qiang Wu, Gang-Ding Peng, Gerald Farrell, Yuliya Semenova

Articles

This paper proposes a novel magnetic field sensor based on a microfiber coupler (MFC) combined with a magnetic fluid (MF) in a Sagnac loop formed from a polarization maintaining fiber (PMF). Thanks to the small (~2.6μm) waist diameter of the MFC, the resulting interference is strongly influenced by the presence of the MF and this leads to the desirable high sensitivity of the structure to the applied magnetic field. The maximum magnetic field sensitivities of −100pm/mT and −488pm/mT have been experimentally demonstrated with the PMF lengths of 75cm and 20cm respectively in the range of magnetic field strengths from 0 …

A Comparative Analysis Of Pretreatment Strategies On The Properties And Hydrolysis Of Brewers’ Spent Grain, Rajeev Ravindran, Swarna Jaiswal, Nissreen Abu-Ghannam, Amit Jaiswal

Articles

In this study, brewer’s spent grain (BSG) was subjected to a range pretreatments to study the effect on reducing sugar yield. Glucose and xylose were found to be the predominant sugars in BSG. Brewers spent grain was high in cellulose (19.21g/100g of BSG) and lignin content (30.84g/100g of BSG). Microwave assisted alkali (MAA) pretreatment was found to be the most effective pretreatment for BSG, where the pretreatment was conducted at 400W for 60s. A maximum reducing yield was observed with high biomass loading (1g/10ml), cellulase (158.76 μl/10ml), hemicellulase (153.3 μl/10ml), pH (5.4) and an incubation time (120h). Upon enzymatic hydrolysis, …

Effects Of Vegetation On Slope Stability: A Review, Roberto José Marín Sánchez, Juan Pablo Osorio

Articles

Slope stability is usually affected by factors that reduce soil strength and increase driving forces acting on the slope material, sometimes generating mass movements. Among these factors, vegetation has an important role related to hydrological (e.g. evapotranspiration and infiltration) and mechanical (e.g. tree surcharge and root reinforcement provided by trees) mechanisms. In this review, vegetation influences associated to slope stability are identified, describing the mechanisms involved in the occurrence of mass movements. Finally, the way these factors affect slope stability is explained according to soil properties, climatic conditions and environmental characteristics.

Two-Step Sequential Pretreatment For The Enhanced Enzymatic Hydrolysis Of Coffee Spent Waste, Rajeev Ravindran, Swarna Jaiswal, Nissreen Abu-Ghannam, Amit Jaiswal

Articles

In the present study, eight different pretreatments of varying nature (physical, chemical and physico-chemical) followed by a sequential, combinatorial pretreatment strategy was applied to spent coffee waste to attain maximum sugar yield. Pretreated samples were analysed for total reducing sugar, individual sugars and generation of inhibitory compounds such as furfural and hydroxymethyl furfural (HMF) which can hinder microbial growth and enzyme activity. Native spent coffee waste was high in hemicellulose content. Galactose was found to be the predominant sugar in spent coffee waste. Results showed that sequential pretreatment yielded 350.12mg of reducing sugar/g of substrate, which was 1.7-fold higher than …

Irish Bim Study 2017, Barry Mcauley, Alan Hore, Roger West

Articles

The Construction IT Alliance (CitA) recently published its Global BIM Study as part of its BIM Innovation Capability Programme (BICP). The study sought to identify how BIM was being currently addressed in 27 countries across the globe. The study sought to identify the presence of three key ingredients in these countries:

1. Regulatory requirement for BIM

2. Champions driving BIM

3. Noteworthy publications

The report identified a number of recurring themes that would help to shape Ireland’s BIM programme. The report concluded that Ireland should adopt a programme of partnership between industry and the Irish Government in order to affect …

Effect Of Sky Conditions On Light Transmission Through A Suspended Particle Device Switchable Glazing, Aritra Ghosh, Brian Norton, Aidan Duffy

Articles

A suspended particle device (SPD) switchable glazing changes its state from opaque to transparent in the presence of a power supply. SPD glazing's near normal transmission varies with incident angle and clearness index. Due to a lower diffuse component, higher glazing transmission ensues at higher clearness indices. Transmittance values for different azimuthal incident angle for a SPD glazing for its “transparent” and “opaque” states have been determined. In Dublin, below 0.5 clearness index, isotropic diffuse transmittance was prevailed while transmission of direct insolation was dominant above 0.5 clearness index. For south facing vertical plane SPD glazing transmittance in its transparent …

Stakeholder Outcomes In A Wind Turbine Investment; Is The Irish Energy Policy Effective In Reducing Ghg Emissions By Promoting Small-Scale Embedded Turbines In Sme's?, Tony Kealy

Articles

As a member state of the European Union (EU), Ireland has adopted an energy policy which includes promoting wind powered electricity generators as an economically viable, GHG-reducing, alternative to environmentally damaging fossil-fuel driven electrical generators. This longitudinal, inductive in-depth study investigates the outcomes for the government and other stakeholders involved in a wind turbine project investment by a Small-to-Medium-Enterprise (SME) based in rural Ireland. A case study research methodology is used to acquire and analyse quantitative numerical data from multiple sources including electrical power and energy meters, historical electricity bills and company sustainability reports. The study found that the installation …

Detection Of Trends In The 7-Day Sustained Low-Flow Time Series Of Irish Rivers, Ahmed Nasr, Michael Bruen

Articles

A combination of statistical hypothesis testing methods (Mann-Whitney, Mann-Kendall and Spearman’s rho) and visual exploratory analysis were used to investigate trends in Irish 7-day sustained low-flow (7SLF) series possibly driven by changes in summer rainfall patterns. River flow data from 33 gauging stations covering most major Irish rivers were analysed, after excluding catchments where low flows are influenced by significant human interventions. A statistically significant increasing trend in the 7SLF series was identified by all three tests at eight gauging stations; in contrast, a statistically significant decreasing trend was identified by all three tests at four stations. The stations with …

Mid-Infrared Self-Similar Compression Of Picosecond Pulse In An Inversely Tapered Silicon Ridge Waveguide, Jin-Hui Yuan, Jian Chen, Feng Li, Chao Mei, Zhe Kang, Xianting Zhang, Yin Xu, Binbin Yan, Xinzhu Sang, Qiang Wu, Xian Zhou, Kangping Zhong, Kuiru Wang, Chongxiu Yu, Gerald Farrell

Articles

On chip high quality and high degree pulse compression is desirable in the realization of integrated ultrashort pulse sources, which are important for nonlinear photonics and spectroscopy. In this paper, we design a simple inversely tapered silicon ridge waveguide with exponentially decreasing dispersion profile along the propagation direction, and numerically investigate self-similar pulse compression of the fundamental soliton within the mid-infrared spectral region. When higher-order dispersion (HOD), higher-order nonlinearity (HON), losses (α), and variation of the Kerr nonlinear coefficient γ(z) are considered in the extended nonlinear Schrödinger equation, a 1 ps input pulse at the wavelength of 2490 nm is …

The Effect Of The Local Field And Dipole-Dipole Interactions On The Absorption Spectra Of Noble Metals And The Plasmon Resonance Of Their Nanoparticles, I.I. Shaganov, T.S. Perova, Kevin Berwick

Articles

An analysis of the effect of free and bound electrons on the optical properties of noble metals and their nanoparticles is performed, based on the Drude-Lorentz model. It is shown that the shifts in the absorption bands of plasmons localized in spherical nanoparticles with respect to the zero frequency of free electrons in a bulk metal can be estimated using the theory of resonant dipole-dipole interactions. The calculation includes account for differences between the effective and average electromagnetic fields. It is established that the difference in oscillator strength for free electrons in the bulk metal, obtained using the Drude-Lorentz model, …

Bismuth-Doped Glass Microsphere Lasers, Zaijn Fang, Sile Nic Chormaic, Shanyu Wang, Xin Wang, Jibo Yu, Yuxuan Jiang, Jianrong Qiu, Pengfei Wang

Articles

In this work, a hybrid structure consisting of a multicomponent germanate glass microsphere containing bismuth as a gain medium is proposed and presented. The bismuth-doped germanate glass microspheres were fabricated from a glass fiber tip with no precipitation of the bismuth metal. Coupling with a fiber taper, the bismuth-doped microsphere single-mode laser was observed to lase at around 1305.8 nm using 808 nm excitation. The low threshold of absorbed pump power at 215 μWmakes this microlaser appealing for various applications, including tunable lasers for a range of purposes in telecommunication, biomedical, and optical information processing.

Durability Of Switching Behaviour After Outdoor Exposure For A Suspended Particle Device Switchable Glazing, Aritra Ghosh, Brian Norton

Articles

Adaptive suspended particle device (SPD) switchable glazing is promising for low energy building application. SPD glazing allows light passes through it in the presence of applied voltage and block light in the absence of power supply. In this work SPD glazing performance after 3 years of outdoor exposure was evaluated. It was found that contrast ratio of SPD glazing before and after exposures changed from 1:11 to 1:10. SPD glazing surface temperature for any transparency level varies between 13 and 40 °C under indoor and outdoor thermal exposure. SPD glazing's surface temperature variation occurs due to the incident radiation level, …

Effect Of Atmospheric Transmittance On Performance Of Adaptive Spd-Vacuum Switchable Glazing, Aritra Ghosh, Brian Norton, Aidan Duffy

Articles

Combined suspended particle device (SPD)-vacuum glazing is a potential adaptive glazing for low energy building application. Glazing transmission is an essential parameter to determine indoor comfort level of building due to glazing. In this work, above 0.5 clearness index, a strong correlation between glazing transmission and clearness index (Atmospheric transmission) has been evaluated for south facing vertical plane glazing. Below 0.5 clearness index, isotropic diffuse transmittance was dominant and one single value of glazing transmission was found which is suitable for building energy calculation throughout the year. Below 0.5 clearness index, for south facing vertical plane SPD-vacuum glazing transmission was …

Solar Dryers For Tropical Food Preservation: Thermophysics Of Crops, Systems And Components, Vivek Tomar, G. N. Tiwari, Brian Norton

Articles

Drying reduces the moisture content of harvested crops thus slowing decay processes to enable longerterm storage. Solar dryers contain the crop being dried, to enhance solar energy collection incurring lower crop losses than are associated with open-sun drying and recurrent costs than are inherent to uses of fossil-fuels for drying. The influences of key environmental, operational and design parameters for solar dryers are discussed including: (i) psychrometry of drying processes and ambient conditions, (ii) how initial crop properties are converted to final desired product attributes, (iii) feasibility of using powered components such as fans and (iv) air-heating solar collector selection.

Thermal Inactivation Analysis Of Water-Related Pathogens In Domestic Hot Water Systems, Liam Mccarton, Sean O'Hogain

Articles

This study aims to investigate whether hot water systems supplied with harvested rainwater present an increased risk to health over hot water systems supplied with potable mains water. It reviews previous studies investigating the health effects of utilising rainwater within domestic systems. The main risk to public health of mains-supplied hot water systems is the operation, maintenance, age, location and temperature of the system. Rainwater-harvesting systems contain an inherent water treatment train consisting of flocculation, settlement, sorption and bioreaction, and stored rainwater quality improves as metal and chemical contaminants settle to form sludge. Laboratory experiments were conducted using a variety …

Magnetic Field Sensor Based On A Combination Of A Microfiber Coupler Covered With Magnetic Fluid And A Sagnac Loop, Fangfang Wei, Arun Mallik, Dejun Liu, Qiang Wu, Gang-Ding Peng, Gerald Farrell, Yuliya Semenova

Articles

This paper proposes a novel magnetic field sensor based on a microfiber coupler (MFC) combined with a magnetic fluid (MF) in a Sagnac loop formed from a polarization maintaining fiber (PMF). Thanks to the small (~2.6 μm) waist diameter of the MFC, the resulting interference is strongly influenced by the presence of the MF and this leads to the desirable high sensitivity of the structure to the applied magnetic field. The maximum magnetic field sensitivities of −100 pm/mT and −488 pm/mT have been experimentally demonstrated with the PMF lengths of 75 cm and 20 cm respectively in the range of …

A Chalcogenide Multimode Interferometric Temperature Sensor Operating At A Wavelength Of 2 Μm, Lin She, Pengfei Wang, Weimin Sun, Xianfan Wang, Wenlei Yang, Gilberto Brambilla, Gerald Farrell

Articles

This paper investigated the fabrication of a singlemode-multimode-singlemode fiber structure based on a chalcogenide (As2S3 and AsxS1−x) multimode fiber sandwiched between two standard silica singlemode fibers using a commercial fiber fusion splicer. The temperature dependence of this hybrid fiber structure was investigated and a first proof of concept showed that the hybrid SMS fiber structure has an average experimental temperature sensitivity of circa 84.38 pm/°C over a temperature range of 20 °C∼100°C at the wavelength range around 2 μm. The measured results show a general agreement with numerical simulations based on a guided-mode propagation analysis method. Our result provides a …

A Curvature Sensor Based On Twisted Single-Mode-Multimode-Single-Mode Hybrid Optical Fiber Structure, Ke Tian, Yifan Xin, Wenlei Yang, Tao Geng, Jing Ren, Ya-Xian Fan, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

An optical fiber curvature sensor based on a twisted multimode fiber (MMF) sandwiched between two single-mode fibers (SMF) is proposed and investigated theoretically and experimentally. The measured transmission spectrum exhibits good agreement with theoretical predictions. Compared with a traditional single-mode-multimode-single-mode fiber structure sensor, the proposed configuration offers a higher average curvature sensitivity of -2.42 nm/m -1 over a curvature measurement range of 0-1.7390 m -1 and -7.09 dB/m -1 at an operating wavelength of 1537 nm. The temperature sensitivity of this sensor has been determined as 0.01 nm/°C over a wavelength range of 1535-1550 nm and circa 0.007 dB/°C at …

Investigation Of The Self-Imaging Position Of A Singlemode-Multimode-Singlemode Optical Fiber Structure, Xianfan Wang, Elfed Lewis, Pengfei Wang

Articles

In this paper, a theoretical and experimental investigation of the multimode interference induced self-imaging phenomenon in a singlemode-multimode-singlemode (SMS) fiber structure is described. The simulated transmission spectra based on guided modal propagation analysis and beam propagation method are presented and compared with experimental obtained results. The temperature dependence of the self-imaging position of the SMS fiber structure is also investigated. These investigations provide excellent opportunities for multiple future applications including telecommunications and sensing.

Formative Assessment In Mathematics For Engineering Students, Eabhnat Ni Fhloinn, Michael Carr

Articles

this paper, we present a range of formative assessment types for engineering mathematics, including in-class exercises, homework, mock examination questions, table quizzes, presentations, critical analyses of statistical papers, peer-to-peer teaching, online assessments and electronic voting systems. We provide practical tips for the implementation of such assessments, with a particular focus on time or resource constraints and large class sizes, as well as effective methods of feedback. In addition, we consider the benefits of such formative assessments for students and staff.

Characteristics Of Different Systems For The Solar Drying Of Crops, Brian Norton

Articles

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for

dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder,

seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and

contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of

complex interactions particular between the intensity and duration of solar energy, the prevailing ambient

relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the

design and …

Interior Colour Rendering Of Daylight Transmitted Through A Suspended Particle Device Switchable Glazing, Aritra Ghosh, Brian Norton

Articles

The colour rendering index (CRI) and correlated colour temperature (CCT) of daylight change upon transmission through a variable transmittance suspended particle device (SPD) switchable glazing.

The luminous transmittance of SPD glazing was found to vary from 0.02 to 0.55 in opaque and transparent state respectively. Below 0.14 transmittance, the CRI for a particular SPD glazing was less than 80.

No strong correlation was found between CCT and CRI. The CRI of SPD glazing in a transparent state was similar to double panes glazing for SPD glazing transmittance greater than 0.24.

A Packaged Whispering Gallery Mode Strain Sensor Based On A Polymer Wire Cylindrical Micro Resonator, Vishnu Kavungal, Gerald Farrell, Qiang Wu, Arun Mallik, Yuliya Semenova

Articles

We propose a whispering gallery mode (WGM) strain sensor formed by a polymer-wire cylindrical micro resonator for strain measurement applications. WGMs are generated by evanescently coupling light into the polymer-wire resonator from a silica fiber taper fabricated by the micro heater brushing technique. Accurate and repeatable measurements of a strains up to one free spectral range (FSR) shift of the WGMs (corresponding to 0.33 % of the polymer-wire elongation, 3250 μɛ) are demonstrated experimentally with the proposed sensor. Practical packaging method for the proposed strain sensor on a glass microscope slide has also been realized making the sensor portable and …