Digital Commons Network^™

Advances In Precision Microfabrication Through Digital Light Processing: System Development, Material And Applications, Xinhui Wang, Jinghang Liu, Yang Zhang, Per Magnus Kristiansen, Aminul Islam, Michael Gilchrist, Nan Zhang

Articles

Digital Light Processing (DLP) is an advanced additive manufacturing technology which has garnered substantial recognition and has been extensively applications in various fields. This review focuses on the precision microfabrication process of DLP, providing an overview of the DLP 3D printing system, including the digital light engine, project lenses, motorised stage and resin vat for micro-structure fabrication. Additionally, this review paper comprehensively analyses commercially available DLP printers, covering resolution, cost and a detailed discussion on the importance of photopolymer resins, emphasising the monomer, photo-initiator, photoabsorber, etc. Based on the photopolymerisation theory, the DLP high-precision printing process is analysed, which is …

Novel Block Grid Analysis (Bga) Based Algorithm For Use In Determining Coefficients Of Similarities Between Uv Fluorescent Spectra, Kevin Mellon, Noel Carey

Articles

No abstract provided.

A Feed Direction Cutting Force Prediction Model And Analysis For Ceramic Matrix Composites C/Sic Based On Rotary Ultrasonic Profile Milling, M. Amin, M. F. Rathore, A. Ahmed, W. Saleem, Q. Li, A. Israr

Articles

Ceramic matrix composites have immense applications in the aerospace, aircraft, and automobile industries. Belonging to this class, carbon-fiber reinforced ceramic matrix composites (C/SiC) are used for critical applications due to their superior properties. However, these materials have also stringent properties of heterogeneity, anisotropy, and varying thermal properties that affect machining quality and process efficiency. So, developing a cutting force prediction model and analyzing machining parameters is an essential need for the accurate machining of such materials. In this study, a mechanistic-based feed direction cutting force prediction model for rotary ultrasonic profile milling of C/SiC composites is developed and validated experimentally. …

Development And Evaluation Of A Multifrequency Ultrafast Doppler Spectral Analysis (Mfudsa) Algorithm For Wall Shear Stress Measurement: A Simulation And In Vitro Study, Andrew Malone, Sean Cournane, Izabela Naydenova, James F. Meaney, Andrew J. Fagan, Jacinta Browne

Articles

Cardiovascular pathology is the leading cause of death and disability in the Western world, and current diagnostic testing usually evaluates the anatomy of the vessel to determine if the vessel contains blockages and plaques. However, there is a growing school of thought that other measures, such as wall shear stress, provide more useful information for earlier diagnosis and prediction of atherosclerotic related disease compared to pulsed-wave Doppler ultrasound, magnetic resonance angiography, or computed tomography angiography. A novel algorithm for quantifying wall shear stress (WSS) in atherosclerotic plaque using diagnostic ultrasound imaging, called Multifrequency ultrafast Doppler spectral analysis (MFUDSA), is presented. …

Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

An analog holographic wavefront sensor (AHWFS), for measurement of low and high order (defocus and spherical aberration) aberration modes has been developed as volume phase holograms in a photopolymer recording medium. This is the first time that high order aberrations such as spherical aberration can be sensed using a volume hologram in a photosensitive medium. Both defocus and spherical aberration were recorded in a multi-mode version of this AHWFS. Refractive elements were used to generate a maximum and minimum phase delay of each aberration which were multiplexed as a set of volume phase holograms in an acrylamide based-photopolymer layer. The …

Improving The Angular Visibility Of Photopolymer-Based Reflection Holograms For Sensing Applications, Tatsiana Mikulchyk, Kevin Murphy, John Walsh, Suzanne Martin, Dervil Cody, Izabela Naydenova

Articles

Volume reflection hologram-based sensors are designed to visibly change colour in response to a target stressor or analyte. However, reflection holograms fabricated in thick photopolymer films are highly angularly selective, making these sensors challenging to view and interpret by non-experts. Here, the use of speckle holography to improve the visibility of reflection holograms is presented. A novel recording approach combining speckle recording techniques with Denisyuk reflection recording geometry is described. The recorded speckle reflection grating operates as a series of multiplexed reflection gratings with a range of spatial frequencies, capable of reflecting light at a wider range of angles. A …

Probe–Integrated Electrochemical Sensing Platform For Measuring Trace Levels Of Parathion Pesticides Residues In Water Using Au- Nanoparticles Anchored Nafion Nano Composite Modified Glassy Carbon Electrode, H. Alwael, S.H. Al-Sedran, Mohamed Oubaha, N.A.A. Asiri, A.S. Bashammakh, A.S. Alharthy, N.A. Albassami, T.N. Abduljabbar, G.I. Mohamed, H.M. Nassef, E.A. Bahaidarah, B.G. Alhogbi, M.S. El-Shahawi

Articles

Nanomaterial represents a principal driver to the adoption of electrochemical sensors for pesticides residues in water. Thus, the current strategy reports facile and highly sensitive electrochemical probe for monitoring parathion residues in water. The probe was based upon the use of Au nanoparticles (AuNPs) functionalized Nafion nanocomposites modified glassy carbon electrode (Au NPs/Nafion/GCE). The surface morphology, effective surface area and electrocatalytic performance of the Au NPs/Nafion/GCE were recorded and assigned using a scanning electron microscopy (SEM), cyclic voltammetry (CV) and electronic spectra. A straightforward protocol based upon combination of Au NPs/Nafion/GCE and square wave- adsorptive cathodic stripping voltammetry at pH …

Review-Electrode Kinetics And Electrolyte Stability In Vanadium Flow Batteries, Andrea Bourke, Daniela Oboroceanu, Nathan Quill, Catherine Lenihan, Maria Alhajji Safi Maria Alhajji Safi, Mallory A. Miller, Robert F. Savinell, Jesse S. Wainright, Varsha Sasikumarsp, Maria Rybalchenko, Pupak Amini, Niall Dalton, Robert P. Lynch, D. Noel Buckley

Articles

Two aspects of vanadium flow batteries are reviewed: electrochemical kinetics on carbon electrodes and positive electrolyte stability. There is poor agreement between reported values of kinetic parameters; however, most authors report that kinetic rates are faster for VIV/VV than for VII/VIII. Cycling the electrode potential increases the rates of both reactions initially due to roughening but when no further roughening is observed, the VII/VIII and VIV/VV reactions are affected oppositely by the pretreatment potential. Anodic pretreatment activates the electrode for the VII/VIII reaction, and deactivates it for VIV/VV. Three states of the carbon surface are suggested: reduced and oxidized states …

Effects Of Flexibility In Coarse-Grained Models For Bovine Serum Albumin And Immunoglobulin G, Frank Hirschmann, Hender Lopez, Felix Roosen-Runge, Tilo Seydel, Frank Schreiber, Martin Oettel

Articles

We construct a coarse-grained, structure-based, low-resolution, 6-bead flexible model of bovine serum albumin (BSA, PDB: 4F5S), which is a popular example of a globular protein in biophysical research. The model is obtained via direct Boltzmann inversion using all-atom simulations of a single molecule, and its particular form is selected from a large pool of 6-bead coarse-grained models using two suitable metrics that quantify the agreement in the distribution of collective coordinates between all-atom and coarse-grained Brownian dynamics simulations of solutions in the dilute limit. For immunoglobulin G (IgG), a similar structure-based 12-bead model has been introduced in the literature [Chaudhri …

Review Of Recent Advances In Photosensitive Polymer Materials And Requirements For Transmission Diffractive Optical Elements For Led Light Sources, Michael Murray, Izabela Naydenova, Suzanne Martin

Articles

Scattered light from outdoor LED sources is a major contributor to blue-spectrum light pollution which negatively impacts ecology and public health. Volume holographic diffractive optical elements (DOEs), made with low-cost photosensitive polymers, are proposed as a technological solution that can minimise this scattering. This review examines requirements needed for efficient operation of transmission-format DOEs with LEDs and implications for material choices. For such DOEs to have a single diffraction order and high efficiency there is a corresponding range of acceptable Δn. A survey of materials also found that many current materials satisfy the Δn requirements for single-element DOEs. It is …

Global Short-Term Mortality Risk And Burden Associated With Tropical Cyclones From 1980 To 2019: A Multi-Country Time-Series Study, Wenzhong Huang, Shansan Li, Thomas Vogt, Rongbin Xu, Shilu Tong, Tomas Molina, Pierre Masselot, Antonio Gasparrini, Ben Armstrong, Mathilde Pascal, Dominic Roye, Chris Fook Sheng Ng, Ana Maria Vicedo-Cabrera, Joel Schwartz, Eric Lavigne, Haidong Kan, Patrick J. Goodman, Ariana Zeka, Masahiro Hashizume, Magali Hurtado Dias, Cesar De La Cruz Valencia, Xerxes Seposo, Baltazar Nunes, Joana Madureira, Ho Kim, Whanhee Lee, Aurelio Tobias, Carmen Iniguez, Yue Leon Guo, Shih-Chun Pan, Antonella Zanobetti, Tran Ngoc Dang, Do Van Dung, Tobias Geiger, Christian Otto, Amanda Johnson, Simon Hales, Pei Yu, Zhengyu Yang, Elizabeth A. Ritchie, Yuming Guo

Articles

The global spatiotemporal pattern of mortality risk and burden attributable to tropical cyclones is unclear. We aimed to evaluate the global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019.

Embedded Ai For Wheat Yellow Rust Infection Type Classification, Uferah Shafi, Rafia Mumtaz, Muhammad Deedahwar Mazhar Qureshi, Zahid Mahmood, Sikander Khan Tanveer, Ihsan Ul Haq, Syed Mohammad Hassan Zaidi

Articles

Wheat is the most important and dominating crop in Pakistan in terms of production and acreage, which is grown on 37% of the cultivated area, accounting for 70% of the total production. However, wheat yield is highly affected by stripe rust, which is considered the most devastating fungal disease, causing 5.5 million tonnes of loss per year globally. In order to minimize this loss, the accurate and timely detection of rust disease is crucial instead of manual inspection. Towards this end, we propose a system to detect wheat rust disease and classify its infection types into four classes, including healthy, …

Adaptive Fuzzy Supplementary Controller For Ssr Damping In A Series-Compensated Dfig-Based Wind Farm, Mohamed Abdeen, Sayed Hosny Ahmed El-Banna, Sara Elgohary, Hend Mostafa, Nora Ghaly, Nourhan Adel, Zeinab Elkhwas, Mohamed Alahmady, Hossam Zawbaa, Salah Kamel

Articles

Although using a series compensation technique in a long transmission line effectively increases the transmittable power; it may cause a sub-synchronous resonance (SSR) phenomenon. Gate-controlled series capacitor (GCSC) is an effective method for SSR damping by controlling the turn-off angle. In the previous studies, a constant supplementary damping controller (SDC) was used for controlling the turn-off angle, which can mitigate the SSR phenomenon. However, these methods can not capture the maximum transmittable power at different operating points. In this paper, a fuzzy logic controller (FLC) is proposed to compute the gain of SDC based on the wind speed and the …

Design And Implementation Of A New Adaptive Mppt Controller For Solar Pv Systems, Saibal Manna, Deepak Kumar Singh, Ashok Kumar Akella, Hossam Kotb, Kareem M. Aboras, Hossam Zawbaa, Salah Kamel

Articles

This research provides an adaptive control design in a photovoltaic system (PV) for maximum power point tracking (MPPT). In the PV system, MPPT strategies are used to deliver the maximum available power to the load under solar radiation and atmospheric temperature changes. This article presents a new adaptive control framework to enhance the performance of MPPT, which will minimize the complexity in system control and efficiently manage uncertainties and disruptions in the environment and PV system. Here, the MPPT algorithm is decoupled with model reference adaptive control (MRAC) techniques, and the system gains MPPT with overall system stability. The simulation …

Distributed Intermittent Fault Diagnosis In Wireless Sensor Network Using Likelihood Ratio Test, Bhabani Sankar Gouda, Meenakshi Panda, Trilochan Panigrahi, Sudhakar Das, Bhargav Appasani, Omprakash Acharya, Hossam Zawbaa, Salah Kamel

Articles

In current days, sensor nodes are deployed in hostile environments for various military and commercial applications. Sensor nodes are becoming faulty and having adverse effects in the network if they are not diagnosed and inform the fault status to other nodes. Fault diagnosis is difficult when the nodes behave faulty some times and provide good data at other times. The intermittent disturbances may be random or kind of spikes either in regular or irregular intervals. In literature, the fault diagnosis algorithms are based on statistical methods using repeated testing or machine learning. To avoid more complex and time consuming repeated …

Intelligent Beam Steering For Wireless Communication Using Programmable Metasurfaces, Nouman Ashraf, Taqwa Saeed, Hamidreza Taghvaee, Sergi Abadal, Vasos Vasos, Christos Liaskos Christos Liaskos, Andreas Pitsillides, Marios Lestas Marios Lestas

Articles

Future generations of wireless communications are envisioned to provide several Gbps data rates per user for billions of users simultaneously [1]. The proliferation of billions of Internet of Things (IoT) devices in various industries has pushed wireless networks to their limits in terms of the required capacity to effectively communicate the vast amounts of data that are generated [2]. Moreover, the increasing number of IoT devices is changing mobile communication services from interpersonal communication to smart interconnection among billions of devices. 6G is expected to fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all …

Metaheuristic Optimization Techniques Used In Controlling Of An Active Magnetic Bearing System For High-Speed Machining Application, Suraj Suraj, Pabitra Kumar Biswas Pabitra Kumar Biswas, Sukanta Debnath, Anumoy Ghosh, Thanikanti Sudhakar Babu, Hossam Zawbaa, Salah Kemal

Articles

Smart control tactics, wider stability region, rapid reaction time, and high-speed performance are essential requirements for any controller to provide a smooth, vibrationless, and efficient performance of an in-house fabricated active magnetic bearing (AMB) system. In this manuscript, three pre-eminent population-based metaheuristic optimization techniques: Genetic algorithm (GA), Particle swarm optimization (PSO), and Cuckoo search algorithm (CSA) are implemented one by one, to calculate optimized gain parameters of PID controller for the proposed closed-loop active magnetic bearing (AMB) system. Performance indices or, objective functions on which these optimization techniques are executed are integral absolute error (IAE), integral square error (ISE), integral …

Performance Improvement Of Hybrid System Based Dfig-Wind/Pv/Batteries Connected To Dc And Ac Grid By Applying Intelligent Control, Younes Sahri, Salah Tamalouzt, Sofia Lalouni Belaid, Mohit Bajaj, Sherif S.M. Ghoneim, Hossam Zawbaa, Salah Kamel

Articles

One of the main causes of CO2 emissions is the production of electrical energy. Therefore, many researchers goal’s is to develop renewable power systems. This paper proposes a new intelligent control development of hybrid PV–Wind-Batteries. Neuro-Fuzzy Direct Power Control (NF-DPC) is invested in order to enhance system performance and generated currents quality. An improved MPPT algorithm based on Fuzzy Controller (FC) is invested for PV power optimization. In addition, a new Modified Fuzzy Direct Power Control (MF-DPC) is developed and applied to the grid side converter to control the active and reactive power by monitoring the involved active power flow …

Analysis And Design Of Secure Sampled-Data Control Subject To Denial-Of-Service Attacks, Hira Sana, Ghulam Mustafa, Owais Khan, Nouman Ashraf, Abdul Qayyum Khan, Muhammad Abid, Haroom Ur Rashid Khan

Articles

This study addresses the issue of secure control design for cyber-physical systems (CPS) against denial of service (DoS) attacks. We take into account a continuous-time linear system with a convex quadratic performance measure and a sampled linear state feedback control. DoS attacks impose constraints on the CPS, where packets may be jammed between the sensor and controller by a malicious entity, potentially resulting in system instability and performance degradation. We assume that the attacker can perform DoS attacks with a limited time and frequency due to energy restrictions. We devise an efficient procedure using the linear matrix inequality approach to …

Nipuna: A Novel Optimizer Activation Function For Deep Neural Networks, Golla Madhu, Sandeep Kautish, Khalid Abdulaziz Alnowibet, Hossam Zawbaa, Ali Wagdy Mohamed

Articles

In recent years, various deep neural networks with different learning paradigms have been widely employed in various applications, including medical diagnosis, image analysis, self-driving vehicles and others. The activation functions employed in deep neural networks have a huge impact on the training model and the reliability of the model. The Rectified Linear Unit (ReLU) has recently emerged as the most popular and extensively utilized activation function. ReLU has some flaws, such as the fact that it is only active when the units are positive during back-propagation and zero otherwise. This causes neurons to die (dying ReLU) and a shift in …

Collective Relaxation Processes In Nonchiral Nematics, Neelam Yadav, Yuri Panarin, Wanhe Jiang, Georg H. Mehl, Jagdish Vij

Articles

Nematic–nematic transitions in a highly polar nematic compound are studied, in thick cells in which the molecules are aligned parallel to the substrates but perpendicular to the applied electric field, using dielectric spectroscopy in the frequency range 1 Hz to 10 MHz over a wide temperature range. The studied compound displays three nematic phases under cooling from the isotropic phase: ubiquitous nematic N; high polarizability NX; and ferroelectric nematic NF. Two collective processes were observed. The dielectric strength and relaxation frequency of one of the processes P2 showed a dependence on the thickness of the cell. The process P1 is …

Understanding Professional Skills In Engineering Education: A Phenomenographic Study Of Faculty Conceptions, Una Beagon, Brian Bowe

Articles

Abstract Background Globalization and socially complex problems will greatly affect the way engineers work in the future. Therefore, efforts to transform engineering education must focus on professional skills and engagement of faculty as key change agents.

Purpose/Hypotheses For engineering programs to address the needs of society, graduates must have the skills to tackle future challenges. Transformation will only be successful if faculty fully engage in all curriculum design aspects; however, little is known about how faculty view professional skills. This understanding is critical if we wish to support and encourage their participation in the transformation effort. This novel study reveals …

Investigation Of Oleic Acid As A Dispersant For Hydroxyapatite Powders For Use In Ceramic Filled Photo-Curable Resins For Stereolithography, Brendan Kennedy, Eamonn De Barra, Stuart Hampshire, Maura Kelleher

Articles

Stereolithography allows production of porous hydroxyapatite scaffolds for bone regeneration but is limited by the challenging rheology of ceramic filled resins. Oleic acid, a natural fatty acid, was applied in concentrations of 0.0–0.3 wt% to improve the rheological properties of HAp resins for the fabrication of solid cylinders and scaffolds by digital light processing (DLP) printing in a wiperless system. Bonding by chemisorption was confirmed by FTIR analysis. The powders were then incorporated into a photo-curable resin of 1–6 hexanediol diacrylate at 18–30 vol%. The shear viscosity and sedimentation rates of photocurable resins containing HAp powder decreased with increasing concentration …

Pro-Environmental Diversification Of Pasture-Based Dairy And Beef Production In Ireland, The United Kingdom And New Zealand: A Scoping Review Of Impacts And Challenges, Maria Markiewicz-Keszycka, Aileen Carter, Donal O'Brien, Maeve Henchion, Simon Mooney, Paul Hynds

Articles

Grass-fed dairy and beef products are valued by consumers for their unique nutrient profile, enhanced animal welfare and lower environmental footprint compared to conventional produce derived from animals reared indoors on higher volumes of concentrate feeds (O'Callaghan et al., Reference O'Callaghan, Vázquez-Fresno, Serra-Cayuela, Dong, Mandal, Hennessy, McAuliffe, Dillon, Wishart, Stanton and Ross2018; Moscovici Joubran et al., Reference Moscovici Joubran, Pierce, Garvey, Shalloo and O'Callaghan2021). For the current study, pasture-based production of dairy and beef is defined as a system within which cattle graze freely outdoors on green pasture for ≥6 months per year, using grazed grass as the primary feed …

Selection And Characterization Of Bacteriocinogenic Lactic Acid Bacteria From The Intestine Of Gilthead Seabream (Sparus Aurata) And Whiting Fish (Merlangius Merlangus): Promising Strains For Aquaculture Probiotic And Food Bio-Preservation, Sarah Cheriet, Sana Lenglitz, Amel Romdhani, Paul Hynds, Mohamed Salah Abbassi, Taofik Ghrairi

Articles

This study sought to evaluate the probiotic properties and the food preservation ability of lactic acid bacteria isolates collected from the intestines of wild marine fishes (gilthead seabream (Sparus aurata) (n = 60) and whiting fish (Merlangius merlangus) (n = 40)) from the Mediterranean sea in the area of Mostaganem city, Algeria. Forty-two isolates were identified as: Enterococcus durans (n = 19), Enterococcus faecium (n = 15), Enterococcus faecalis (n = 4), Lactococcus lactis subp. lactis (n = 3), and Lactobacillus plantarum (n = 1). All isolates showed inhibition to at least one indicator strain, especially against Listeria monocytogenes, Staphylococcus …

Wind Energy Harvesting And Conversion Systems: A Technical Review, Sinhara M. H. D. Perera, Ghanim Putrus, Michael Conlon, Mahinsasa Narayana, Keith Sunderland

Articles

Wind energy harvesting for electricity generation has a significant role in overcoming the challenges involved with climate change and the energy resource implications involved with population growth and political unrest. Indeed, there has been significant growth in wind energy capacity worldwide with turbine capacity growing significantly over the last two decades. This confidence is echoed in the wind power market and global wind energy statistics. However, wind energy capture and utilisation has always been challenging. Appreciation of the wind as a resource makes for difficulties in modelling and the sensitivities of how the wind resource maps to energy production results …

Fostering Spatial Ability Development In And For Authentic Stem Learning, Caiwei Zhu, Chloe Oi-Ying Leung, Eleni Lagoudaki, Mariana Velho, Natalia Segura-Caballero, Dietsje Jolles, Gavin Duffy, Gunter Maresch, Marianna Pagkratidou, Remke Klapwijk

Articles

Empirical interdisciplinary research has explored the role of spatial ability in STEM learning and achievement. While most of this research indicates that fostering spatial thinking in educational contexts has the potential to positively impact students’ enrollment and performance in STEM subjects, there is less agreement on the best approach to do so. This article provides an overview of various types of effective spatial interventions and practices in formal or informal educational contexts, including targeted training of STEM-relevant spatial skills, spatialized curricula embedded in schools, integrated STEM practices addressing students’ use of spatial skills, and spatial activities in informal STEM education. …

An Experimental-Numerical Study Of Heat Transfer Enhancement In A Minichannel Using Asymmetric Pulsating Flows, Parth S. Kumavat, Sajad Alimohammad, Seamus M. O'Sullivan

Articles

The development of current and next-generation high-performance electronic devices has led to miniaturization in more densely packed spaces. The increasing power levels have resulted in ever-increasing heat flux densities which necessitates the evolution of new liquid-based heat exchange technologies. Implementation of single-phase cooling systems using pulsating flow is viewed as a potential solution to the problems involving high energy density electronics. This work involves a combined experimental and numerical analysis of pulsating flows in a rectangular mini channel undergoing asymmetric sinusoidal flow pulsation formats. The mini channel design includes a heated bottom section approximated as a constant heat flux boundary …

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

Articles

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

Myopia Outcome Study Of Atropine In Children: Two-Year Result Of Daily 0.01% Atropine In A European Population, James Loughman, Emmanuel Kobia-Acquah, Gareth Lingham, John Butler, Ekaterina Loskutova, David A. Mackey, Samantha S.Y. Lee, Daniel I. Flintcroft

Articles

The Myopia Outcome Study of Atropine in Children (MOSAIC) is an investigator-led, double-masked, randomized controlled trial investigating the efficacy and safety of 0.01% atropine eye drops for managing myopia progression in a predominantly White, European population.