S-Cubed Annual Science Conference 2019 - Abstract Booklet by S-Cubed

ANNUAL

SCIENCE

CONFERENCE 2019

Annual Science Conference

Introduction Dear All,

-Cubed) Annual Science insight into the recent research currently being conducted at the University of Malta. This year we aimed to bring together a multi-disciplinary group of scientists, each of which making tremendous advancements in their respective without the guidance of the Dean of the Faculty of Science and Head of the Department of Physics, Prof. Charles V. Sammut, and our kind sponsors. We would also like to thank Esplora for hosting one of our largest events at their Science Centre. The venue acts both as a place where science is taught in new and unique ways to all ages, as well as an opportunity for students to volunteer and get involved in the teaching of science. ce. Regards, Edward Attard Selvagi & James W. Caruana Organisational Committee

Annual Science Conference

Advisory Committee Dean of Faculty of Science & Head of Physics Department: Professor Charles V. Sammut Head of Biology Department: Professor Joseph A. Borg Head of Chemistry Department: Professor Emmanuel Sinagra Head of Geosciences Department: Professor Pauline Galea Head of Mathematics Department: Professor David Buhagiar Head of Statistics & Operations Research Department: Doctor Fiona Sammut

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Organisational Committee President: Yacopo Baldacchino

Vice-President: Edward Attard Selvagi

Secretary General: Samuel Zammit

Financial Officer: Kurt Darmanin

Public Relations Officer: Martina Ciantar

Social Policy Officer: James Caruana

Education Officer: Lara Ann Xiberras

Science Communication: Francesca Camilleri

International Officer: May Hefny

Media Officer: Mariah Zammit

Leisure Officer: Ian Saliba

Leisure Officer: Owen Cuschieri

Internal Secretary: Gianni Ciappara

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Programme 08:30 - 09:30

Registration

09:30 - 09:50

Opening Address from Dean & President

09:50 - 10:10

Geosciences

Chantelle Dimech

10:10 - 10:30

Geosciences

Christa Marie Pisani

10:30 - 10:50

Chemistry

Rebekah Attard Trevisan

10:50 - 11:10

Metamaterials

Matthew Xuereb

11:10 - 11:50

Coffee Break

11:50 - 12:10

Biology

ERA

12:10 - 12:30

Biology

ThaĂs Amaral

12:30 - 12:50

Mathematics

Mary Grace Cassar

12:50 - 13:30

Coffee Break

13:30 - 13:50

Mathematics

Luke Collins

13:50 - 14:10

Physics

Gianbattista-Piero Nicosia

14:10 - 14:30

Physics

Jake Xuereb

Annual Science Conference

Abstracts Department of Geosciences Evaluating crustal attenuation and earthquake source parameters for the Corinth Gulf, Greece Chantelle Dimech 1, Sebastiano 1 , Christos Evangelidis 2, Efthimios Sokos 3 1 Department of Geosciences, University of Malta 2 National Observatory of Athens 3 University of Patras One of the main goals of seismology is to try and predict future ground motion to improve planning and design of infrastructure as well as to provide useful information for civil protection plans. This is especially important if there is no strongmotion data available for the area under study, as is the case with the Gulf of Corinth. In this study, predictive relationships will be used by estimating source and propagation terms to predict the amplitudes of ground motion due to specific earthquake scenarios. For the Corinth Gulf, 297 events were used obtained from 85 3-component stations with a magnitude range between Mw 2.04.5 with a travel path that ranged from a few kilometres to about 200 km. The depths of the events are quite shallow occurring at a maximum of 36km deep. These are called crustal events and are used since the methodology is applied for crustal events.

The Corinth Gulf, located in central Greece, is a highly seismically active area in the Mediterranean. In the past, it has experienced magnitude 6 earthquakes such as the events that occurred in 1983, one of which had a Mw of 6.7 and two events of Mw = 6.4. Strong-motion events can then be simulated once all the information is acquired. This will be done using a stochastic programme known as EXSIM which obtains peak ground acceleration and peak ground velocity to predict ground motion scenarios. The final results obtained can later be used for upgrading seismic hazard maps and for engineering designs as well as implementing tools like ShakemapÂŠ.

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Abstracts Department of Geosciences Oil spill modelling and forecasting in Maltese waters Christa Marie Pisani through the Mediterranean; 20% of which are oil tankers. For a country like Malta, these pose an imminent threat, an oil spill waiting to happen. It is, thus, of crucial importance to know when an oil spill happens, where it is going, and in what shape and form it will get there. All of this can be done through observation and forecasting. Synthetic Aperture Radar (SAR) satellite technology allows us to detect, observe, and follow a spill soon after this happens. With the help of numerical models, we are also able to better see how a spill will evolve and how it will move. In this work, use of the MEDSLIK Lagrangian model is made to model the movement of spills around the Maltese islands. The considered spill parameters are based on typical scenarios that can happen in this region. Forecasted atmospheric and hydrodynamic data is obtained from different sources including the ROSARIO model that is run by the Physical Oceanography Research group of the University of Malta, and other models obtained through the COPERNICUS Marine

Core Service. Validation is carried out by comparing the resulting trajectories with the paths followed by actual satellite tracked drifters that were deployed in the Malta Channel. The main objective for any authority when an oil spill occurs is to minimise the impact both on the coast and the seabed. Such modelling tools will help ease mitigation procedures and as well as makes the best use of the equipment that is available. Keywords: oil spills; numerical modelling; satellite data; Maltese shores; oil on coast.

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Abstracts Department of Chemistry Solid State Chemistry in Interstellar Ice Processes Rebekah Attard Trevisan Interstellar ices present in the interstellar medium (ISM) are of importance, particularly in solid state processes.1 In a mostly gaseous medium, the ice which accumulates on dust grains in the ISM provides a solid catalytic surface. These interstellar ices are constantly being bombarded by cosmic and UV radiation, which triggers the process of photolysis and formation of radicals.2 These can then be involved in various chemical reactions, such as in the formation of complex organic molecules and hydrogenation reactions in the bulk of the ice.3 Interstellar ices can have different compositions, with the main constituent being amorphous solid water (ASW), which can form structures of different porosities. The porosity of the ASW affects the surface area available for reaction, providing a larger effective surface for reaction.1 Various solid-state astrochemical processes occur on the surface and in the bulk of interstellar ices, however three main mechanisms occur on their surfaces: Langmuir-Hinshelwood (LH), Eley-Rideal (ER) and hot-atom mechanisms. The main

difference between the mechanisms is that, in the ER and hot-atom mechanisms, the high energy of the incoming species helps overcome the activation barrier of the reaction, whereas in the LH mechanism, the reactants are in thermal equilibrium with the ice surface.3 The formation of comets and other celestial bodies, as well as the growth of molecules in the ISM often depends on the chemistry that occurs on the surfaces of interstellar ices.4 The evaporation of interstellar ices also has the potential to alter the gas-phase chemistry of the region where they are present.

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References

(1) Guss, K.M. Physics and Chemistry of Interstellar Ice. Ph.D. Leiden University, 2013. (2) Puletti, F. Laboratory spectroscopic studies of interstellar ice analogues. Ph.D, University College London, 2014. (3) Linnartz, H.; Ioppolo, S.; Fedoseev, G. International Reviews in Physical Chemistry, 2015, 34, 205-237. (4) Kemsley, J. Space-Dust Science | April 19, 2010 Issue - Vol. 88 Issue 16 | Chemical & Engineering News https://cen.acs.org/articles/88/i16/SpaceDust-Science.html (accessed Feb 19, 2019).

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Abstracts Metamaterials Unit Natural Materials and Man-made Constructs Matthew A. Xuereb 1,2, Keith M. Azzopardi 3, Ruben Gatt 2, Daphne Attard 2 and Joseph N. Grima 1,2 1 Department of Chemistry, Faculty of Science, University of Malta, Msida MSD 2080, Malta 2 Metamaterials Unit, Faculty of Science, University of Malta, Msida MSD 2080, Malta 3 Thought 3D LTD., 2150, KBIC, Kordin Industrial Estate, Paola, PLA 3000 An Auxetic material or structure is one (NPR), i.e. expands transversely when uniaxially compressed or contracts transversely when uniaxially stretched (vij) ranges from -1.0 to +0.5 for isotropic systems and is defined as the negative of the transverse strain (ď Ľj) divided by the axial LOAD LOAD strain (ď Ľi), the latter being the strain induced in the direction of the loading force.

e ei

vij =CONVENTIONAL - j

LOAD

CONVENTIONAL

LOAD

AUXETIC

Figure 1: Uniaxial loading behaviour of a conventional material vs an auxetic material

LOAD

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The counter-intuitive behaviour of auxetic materials results in a number of advantageous properties over materials, some of which are; increased shear strength and toughness, improved indentation resistance and exceptional particularly suitable for smart filtration systems, medical devices and sports safety equipment, amongst other protective gear [1-4]. Despite their unquestionable applications, auxetic systems are still not widely commercially available due to economically unfeasible manufacturing methods, which makes this one of the many hurdles that current and future researchers in this field of study must overcome. Even though man-made auxetic materials are commercially limited, one must appreciate that nature produces such systems itself, for example; cow teat skin natural crystalline materials silicates and zeolites [7-14].

such

1. Allen, T.; Duncan, O.; Foster, L.; Senior, T.; Zampieri, D.; Edeh, V.; Alderson, A. Auxetic Foam for SnowSport Safety Devices. Snow Sport. Trauma Saf. Proc. Int. Soc. Ski. Safety. Adv. Exp. Med. Biol. 2016, 21, 1 22. 3. 2. Allen, T.; Hewage, T.; Newton-Mann, C.; Wang, W.; Duncan, O.; Alderson, A. Fabrication of Auxetic Foam Sheets for Sports Applications. Phys. Status Solidi Basic Res. 2017, 254 (12), 1 6. 4. 3. Allen, T.; Martinello, N.; Zampieri, D.; Hewage, T.; Senior, T.; Foster, L.;

Alderson, A. Auxetic Foams for Sport Safety Applications. Procedia Eng. 2015, 112 (0), 104 109. 5. 4. Foster, L.; Peketi, P.; Allen, T.; Senior, T.; Duncan, O.; Alderson, A. Application of Auxetic Foam in Sports Helmets. Appl. Sci. 2018, 8 (3), 354. 5. Lees C.; Vincent J.V.; Hillerton J. E. Poisson's ratio in skin Bio-medical materials and engineering, 1991, 1, 19-23. 6. Gatt, R.; Vella Wood, M.; Gatt, A.; Zarb, F.; Formosa, C.; Azzopardi, K.; Casha, A.; Agius, T.; SchembriWismayer, P.; Attard, L. et al. Tendons: An Unexpected Mechanical Response. Acta Biomaterialia 2015, 24, 201-208. 7. Grima, J. N.; Gatt, R.; Zammit, V.; Williams, J. J.; Evans, K. E.; Alderson, A.; Walton, R. I. Natrolite: A Zeolite . Appl. Phys. 2007, 101 (8). 8. Sanchez-Valle, C.; Sinogeikin, S. V.; Lethbridge, Z. A. D.; Walton, R. I.; Smith, C. W.; Evans, K. E.; Bass, J. D. Brillouin Scattering Study on the Single-Crystal Elastic Properties of Natrolite and Analcime Zeolites. J. Appl. Phys. 2005, 98 (5) 9. Siddorn, M.; Coudert, F.-X.; Evans, K. E.; Marmier, A. A Systematic Ratio Materials and the Prediction of Complete Auxeticity in Pure Silica Zeolite JST. Phys. Chem. Chem. Phys. 2015, 17 (27), 17927 17933. 10. Grima, J. N.; Zammit, V.; Gatt, R.; Attard, D.; Caruana, C.; Chircop

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Bray, T. G. On the Role of Rotating Tetrahedra for Generating Auxetic 11. Grima, J. N.; Gatt, R.; Alderson, A.; Evans, K. E. On the Origin of Auxetic Behaviour in the Silicate ÎąCristobalite. J. Mater. Chem. 2005, 15 (37). 12. Yeganeh-Haeri, A.; Weidner, D. J.; Parise, J. B. Elasticity of ACristobalite: A Silicon Dioxide with a 1992, 257 (5070), 650 652. 13. Azzopardi, K. M.; Brincat, J. P.; Grima, J. N.; Gatt, R. Anomalous Elastic Properties in Stishovite. RSC Adv. 2015, 5 (12), 8974 8980.

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Abstracts Department of Biology Is climate change influencing a marine benthic foraminiferan to spread in the Mediterranean Sea? ThaĂs Amaral This project investigates the influence of elevated seawater temperatures on aspects of the ecology of Amphistegina spp. in temperate central Mediterranean waters as a case study, based on populations from Malta. The research work makes use of the thermal effluent from the Delimara Power Station that is discharged in the semi-enclosed inlet of il-Hofra zZghira, and which results in elevated temperatures close to the outfall and a gradient of decreasing temperature away from the discharge point within the inlet. The status of Amphistegina spp. at il-Hofra z-Zghira will be compared with that at selected reference locations not receiving thermal inputs, in order to assess the influence of elevated temperature on the foraminifera. Aspects that will be taken into consideration shall include the morphology of the test, population size structure, and population density. The impacts of Amphistegina spp. on sediment characteristics and on native foraminiferal assemblages, and whether these impacts are enhanced under an elevated temperature regime, will also be assessed. The results will be interpreted within the

context of the implications of elevated sea temperature, as a component of climate change, for biological invasions by thermophilic biota such as Amphistegina spp.

Annual Science Conference

Abstracts Department of Mathematics Functional Electrical Stimulation: Optimal Design of Electrodes Mary Grace Cassar Supervisors: Prof. Cristiana Sebu and Prof. Kenneth P. Camilleri This research is concerned with the development of a new approach to noninvasive functional electrical stimulation (FES) for electrical nerve and muscle stimulation, specifically the design of optimal skin surface electrodes to suit specific medical applications. This study addresses two important issues, in which to date limited progress has been made. Firstly, the optimising of the electrode geometry and its physical characteristics. FES depends on the activating function, which is the second derivative of the extracellular electric potential along the nerve fibre [1]. The aim is to maximise the activation function, to achieve a more localised yet deeper stimulation at a desired depth to activate the nerve. Secondly, the optimising of the signal coding used to activate nerves or muscles. The aim is to limit the effects due to high peaks in current density especially at the edges of conventional electrodes. Ultimately to minimise fatigue, rashes, burns and tissue damage which lead to

patients discomfort and intolerance to therapy [1]. The theoretical development and the mathematical models implemented using Matlab for two different electrode geometries are presented [2,3]. The mathematical models take into account the contact impedance between the electrodes and the skin, and it was developed for the conduction of current between the electrodes in a uniform, isotropic, semitissue layer. A weakly singular Fredholm integral equation of the second kind was solved to calculate the electric fields produced by the electrodes.

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Here are presented the models and results obtained from the investigation into how different combinations of sizes and position of the electrodes can optimize and maximize the activation function at a desired depth while also monitoring the current density. Ultimately, the design of the electrodes can be tailored to the fibres. References [1] Rattay F. Electrical Nerve Stimulation: Theory, Experiments and Applications. Springer-Verlag Wien, GmbH. 1990. [2] Paulson, Kevin S., Michael K. Pidcock, and Chris N. McLeod. A probe for organ impedance measurement. IEEE transactions on biomedical engineering 51.10 (2004): 1838-1844. [3] C. Sebu, B. Andrews, S. Chandak and M. K. Pidcock, Optimal electrode design for extracellular fibre stimulation: theoretical developments, to be submitted to IEEE Transactions on Biomedical Engineering.

Annual Science Conference

Abstracts Department of Mathematics Walks and Canonical Double Coverings of Comain Graphs Luke Collins A graph is a network of objects called vertices in which some pairs of vertices are related: such pairs are called edges. Pictorially, the vertices are represented by dots, and edges are represented by lines joining those dots. A graph with n vertices can be represented algebraically using an nĂ&#x2014;n matrix, where the ith row and jth column contains a 1 if vertex i is connected to vertex j, and a 0 if they are not connected. This is called the adjacency matrix. the original graph, but in the second copy. Below are two examples.

A walk in a graph is a sequence of vertices v1, v2 vk where each consecutive pair vi, vj is an edge in the graph. In the example above, v1, v2, v4, v2, v6 is a walk, but v7, v5, v3 is not, because v5 is not connected to v3. The canonical double cover of a graph G, denoted by CDC(G), is another graph obtained from G, first by making two copies of all the vertices, and then joining each vertex in the first copy to its neighbours in

An eigenvalue of a matrix A is said to be main if at least one of its corresponding eigenvectors is not orthogonal to the , 1). The eigenvalues of a graph G are those of its adjacency matrix A,

Annual Science Conference

and similarly, the main eigenvalues of a graph G are those of its adjacency matrix A. In this talk, we discuss various properties equivalent statement relationship between two graphs having the same number of walks from any starting vertex, two graphs having the same CDC, and two graphs having the same main eigenvalues, eigenvectors and eigenspaces. We see which of these properties infer each other, and which do not.

which results appear in a Google search. In this context, vertices represent different webpages, and two webpages are connected if one links to the other. A walk in such a graph corresponds to starting from one webpage, and clicking links to travel to others. If a large number of walks end in a particular webpage, then that more than others. Graphs also have various applications in chemistry, where vertices represent atoms and edges represent bonds. This representation is useful in computer processing of molecular structures.

What are graphs used for? Graphs are abstract representations of structures in which items are connected. Social networking sites, such as Facebook,

example, make use of graph theoretic results. Graphs are also fundamental to the PageRank algorithm, which determines the order in

In general, the results of graph theory may be applied to scenarios where objects are sometimes connected, and sometimes not. They have been applied in computer science, chemistry, physics, biology, sociology, and other mathematical disciplines such as group theory , topology and knot theory.

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Abstracts Department of Physics Stabilitiy of the ALICE-HMPID detector in the LHC Run 1 and 2 and PIF performance in p-Pb collisions at â&#x2C6;&#x161;đ?&#x2018;şđ?&#x2018;ľđ?&#x2018;ľ = 8.02 TeVGianbattista-Piero Nicosia The stability and the performance of the High Momentum Particle Identification Detector (HMPID), present in the A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC) at CERN, were studied. The stability was investigated by analysing data obtained in 2018 and thus improving the statistics already analysed for Run 2, making the detector stability study up to date. The Particle Identification (PID) performance of the detector was studied for p-Pb collisions at â&#x2C6;&#x161;đ?&#x2018;şđ?&#x2018;ľđ?&#x2018;ľ = 8.02 TeV, which data were collected in 2016. Finally, the evaluation of the pions, kaons and protons pT spectra for p-Pb collisions at â&#x2C6;&#x161;đ?&#x2018;şđ?&#x2018;ľđ?&#x2018;ľ = 8.02 TeV were obtained.

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Abstracts Department of Physics Can stitching up Spacetime differently give us different Quantum Mechanics? Jake Xuereb Relativity he takes what he learned from Special Relativity and applies it to accelerating frames, creating a theory of Gravitation. This theory has been immensely successful in predicting how our universe should look like but is not airtight. Both experimental evidence and the lack of a renormalisable quantum field theory of gravity give credence to the fact that gravity is still not understood. To face this challenge we are looking at gravity from a new angle, or twist one should say! This twist comes in the form of trying to understand gravity through spacetime torsion rather than spacetime curvature. The question of whether changing the way we stitch spacetime together changes how quantum phenomena work now arises. As tools to examine this, we make use of the gravitational phenomenon of blackholes and the quantum mechanical phenomenon of entanglement. References The Geometrical Trinity of Gravity - BeltrĂĄn JimĂŠnez, Jose et al. arXiv:1903.06830 [hepth]

f(T) teleparallel gravity and cosmology Cai, Yi-Fu et al. Rept.Prog.Phys. 79 (2016) no.10, 106901 arXiv:1511.07586 [gr-qc] Stationary Black Holes: Uniqueness and Beyond - Chrusciel, Piotr T. et al. Living Rev.Rel. 15 (2012) 7 arXiv:1205.6112 [grqc] Torsion gravity: A Reappraisal - Arcos, H.I. et al. Int.J.Mod.Phys. D13 (2004) 2193-2240 gr-qc/0501017

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Sponsors What should be done to improve the environment in the future? This pertinent question is very much in the interests of the Environment and Resources Authority (ERA). In fact, the Authority is in the process of developing a National Strategy for the Environment (NSE). This National Strategy aims towards a better and sustainable quality of life and provides clear and long-term direction. The main piece of legislation that tackles the environment in Malta is the Environment Protection Act1. The new National Strategy will support existing policy, providing the strategic roadmap that addresses the aims of this Act, and horizontally integrates environmental stewardship in all national policy. The National Strategy will, in turn, lead to plans, policies and programmes that improve the environment in a long-term scenario. This long-sighted approach aims to look at what is necessary beyond the usual five to ten year cycles that are normally considered when the environment is discussed. The main consideration is what state the environment should be in the future.

Chapter 549 of the Laws of Malta.

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Any goal calls for a starting point. For this reason, details and action plans that need to be undertaken will be presented in ten-year phases, with intermittent reviews. This will enable the effective updating of the National Strategy. Each ten-year period will be accompanied by an action plan, consisting of timeframes, budgets and delegated responsibilities for each measure. Sets of metrics will be developed to assess progress, and progress will be reported regularly. The Strategy will be reviewed in line with results of these reports, to make sure that actions continue to target the right improvements. The first step in line with this Strategy is the preparation of a vision, which will focus around the premise that a healthy environment is both our duty as citizens and also our right. Furthermore, the vision will emphasize our moral and legal obligations to contribute towards a sustainable future. ERA is keen to work on and implement national environmental targets that address the main environmental challenges Malta is facing. Moreover, it looks forward towards integrating and synergising the efforts of all policies and stakeholders who directly or indirectly influence the state of our environment.

For further information kindly, contact ERA on nse@era.org.mt

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