Playing with Solid State Benzene

molecular structure

Computational chemistry is a powerful interdisciplinary field where traditional chemistry experiments are replaced by computer simulations. They make use of the underlying physics to calculate chemical or material properties. The field is evolving as fast as the increase in computational power. The great shift towards computational experiments in the field is not surprising since they may reduce research costs by up to 90% — a welcome statistic during this financial crisis.

Keith M. Azzopardi (supervised by Dr Daphne Attard) used two distinct computational techniques to uncover the structure of a carcinogenic chemical called solid state benzene. He also looked into its mechanical properties, especially its auxetic capability, materials that become thicker when stretched. By studying benzene, Azzopardi is testing the approach to see if it can work. Many natural products incorporate the benzene ring, even though they are not toxic.

The crystalline structures of solid state benzene were reproduced using computer modelling. The first technique used the ab initio method, that uses the actual physical equations of each atom involved. This approach is intense for both the computer and the researcher. It showed that four of the seven phases of benzene could be auxetic.

The second less intensive technique is known as molecular mechanics. To simplify matters it assumes that atoms are made of balls and the bonds in between sticks. It makes the process much faster but may be unreliable on its own due to some major assumptions. For modelling benzene, molecular mechanics was insufficient.

Taken together, the results show that molecular mechanics could be a useful, quick starting point, which needs further improvement through the ab intio method.

 

This research was performed as part of a Masters of Science in Metamaterials at the Faculty of Science. It is partially funded by the Strategic Educational Pathways Scholarship (Malta). This Scholarship is part-financed by the European Union – European Social Fund (ESF) under Operational Programme II –Cohesion Policy 2007-2013, “Empowering People for More Jobs and a Better Quality Of Life”. It was carried out using computational facilities (ALBERT, the University’s supercomputer) procured through the European Regional Development Fund, Project ERDF-080 ‘A Supercomputing Laboratory for the University of Malta’.

Xemxija and Earthquakes

On February 22, 2011, a magnitude 6.3 earthquake struck the city of Christchurch, New Zealand, killing 181 people and causing widespread destruction. Curiously, this damage was not evenly distributed, even for areas right next to each other. This phenomenon is called the site effect and depends on the underlying geology.

Malta, unlike New Zealand, is not typically associated with earthquakes. The islands lack a seismic building code and many structures could be damaged with moderate shaking. Malta’s past records list several earthquakes that have damaged buildings and even caused some to collapse. Apart from not being reinforced, buildings have been built on less stable ground, which increases risk.

 

Setting up the Micromed Tromino, the instrument used to perform recordings of ambient noise measurements
Setting up the Micromed Tromino, the instrument used to perform recordings of ambient noise measurements

Sharon Pace (supervised by Dr Pauline Galea) investigated this effect in one test area — Xemxija, in the north of Malta. She studied how sites in Xemxija would respond to the energy from an earthquake by using a portable seismograph to record ambient noise (caused by sea waves, vehicular traffic, and other anthropogenic sources) at over 100 points across the village (pictured). The ground’s surface can be considered a vibrating platform, which can be shaken both by ambient noise as well as stronger waves from earthquakes. The ground may “resonate” at particular frequencies, or not at all, depending on the kind of rock or soil layers making up the top 30 to 50 metres. Analysis of ambient noise shows if such resonance phenomena exist, how they are related to the local geology, and how this would translate into actual earthquake shaking.

 

Resonant peak frequency distribution patterns around the Xemxija area
Resonant peak frequency distribution patterns around the Xemxija area

At Xemxija, the study confirmed that the presence of clay (whether at the surface or buried) does amplify the grounds motion at certain frequencies.  The results match previous studies in other areas, but this research went further by constructing geological models that can determine the ground’s underlying structure .

Taken together, the survey shows areas in Xemxija that might need extra support to survive future earthquakes and prevent deaths. Xemxija is not the only area with soft clay geology, the urbanised area of Mellieħa and historic citadel Mdina are built on top of similar structures. Considering the importance of these areas means that more studies are needed to better understand the structure of Maltese buildings and how they would respond to earthquakes.

 

This research was performed as part of a Masters of Science in Physics at the Faculty of Science. It was partially funded by the Strategic Educational Pathways Scholarship (Malta). This scholarship is part-financed by the European Union — European Social Fund (ESF) under Operational Programme II — Cohesion Policy 2007 – 2013, “Empowering People for More Jobs and a Better Quality of Life”.

Scientific beauty of diamonds

Laptops and mobiles are smaller, thinner, and more powerful than ever. The drawback is heat, since computing power comes hand in hand with temperature. Macs have been known to melt down, catch fire and fry eggs — PCs can be even more entertaining. David Grech (supervised by Prof. Emmanuel Sinagra and Dr Ing. Stephen Abela) has now produced diamond–metal matrix composites that can remove waste heat efficiently.

Diamonds are not only beautiful but have some remarkable properties. They are very hard, can withstand extreme conditions, and even transfer heat energy faster than any metals. This ability makes diamonds ideal as heat sinks and spreaders.

The gems are inflexible making them difficult to mould into the complex shapes demanded by the microelectronics industry. By linking diamonds with other materials, new architectures can be constructed. Grech squashed synthetic diamond and silver powders together at the metal’s melting point. The resulting composite material expanded very slowly when heated. The material could dissipate heat effectively, and was cheaper and simpler to produce than current methods — a step closer to use on microchips.

Grech’s current research is focused on obtaining novel types of interfaces between the diamond powders and the metal matrix. The new materials can improve the performance of heat sinks. New production techniques could help make these materials. By depositing a very thin layer of nickel (200 nanometres thick) on diamond powders using a chemical reaction, the gems would form chemical bonds with the layer while the metal matrix would form metallic bonds. The material would transfer heat quickly and expand very slowly on heating. A heat sink made out of this material would give us a cooler microprocessor and powerful electronics that does not spontaneously catch fire — good news for tech lovers.

nanoShots

 

This research was performed as part of a Bachelor of Science (Hons) at the Faculty of Science. It is funded by the Malta Council for Science and Technology through the National Research and Innovation Programme (R&I 2010-25 Project DIACOM) and IMA Engineering Services Ltd. 

Labs in solution

Imagine the smallest thing you possibly can. The eye of a needle? A human hair? A particle of dust? Think smaller, something you cannot even see, something on a molecular scale. Now imagine that molecule has the potential of a whole laboratory. This dream is now becoming a reality.

In recent years, the field of molecular sensors has grown into one of the most ground-breaking areas in Chemistry. Molecular sensors are compounds that can detect a substance, or unique mixture of substances, and provide an easily detectable output. Usually this is a change in the absorption of ultraviolet or visible light, or in the emission of Fluorescence. In other words: colours!

John Gabarretta (supervised by Dr David Magri) created a simple example of these fluorescent molecular sensors. The molecule was based on the Fluorophore-Spacer-Receptor model, where the ‘output’ part of the molecule (the fluorophore — a structure which shines light) is separated from the ‘input’ part (the receptor — a structure which is sensitive to a particular substance, such as acidity or a metal ion) by an intermediate spacer, whose main function is to link these two components together. The model means that a molecule can detect a chemical and respond by shining light or not. The process gives information about the chemicals in a solution.

The molecule’s structure, based on the Fluorophore-Spacer-Receptor model (shown as a scheme), allowed for a bright blue fluorescence when exposed to Ultraviolet light
The molecule’s structure, based on the Fluorophore-Spacer-Receptor model (shown as a scheme), allowed for a bright blue fluorescence when exposed to Ultraviolet light

 

The molecule was made by a two-step synthetic route (which took several attempts and resulted in several different colours), and its behaviour was tested by dipping into an acid. In water the molecule was switched ‘off’, but quickly turned ‘on’ in an acidic solution by giving a bright blue light when exposed to ultraviolet light (UV) — a pretty satisfying sight!

Molecular sensors have some very advanced applications — the pioneer A. P. de Silva said that there is room for a “small space odyssey with luminescent molecules”. This odyssey includes some that detect substances such as sugars.

While very advanced systems are approaching chemical computers, since they have multiple inputs and use Boolean Logic, the so-called ‘Moleculator’ or ‘gaming tic-tac-toe’ systems. The future is bright (if you pardon the pun) and with more complex structures more possibilities will appear; the molecular laboratory may become a reality detecting diseases or toxins in no time at all.

 

This research was performed as part of a Bachelor of Science (Honours) at the Faculty of Science.

Insects in Malta

Insects are vital. Insects also cover the planet, with local research showing that there might be over 6,000 species — a wonderful world awaits. Find out about the incredible world of insects in Malta!

Continue reading

Keeping heart attacks on hold

Heart attacks and strokes kill millions every year. Most are caused by blockages to blood vessels. Vessels can be pried open by heart stents, tubular devices that are inserted and inflated to prevent vessels from collapsing or blocking. Stents incur many problems ranging from flaring at the edges to fracturing to unexpected shrinking. All lead to complications, further surgery, and even death.

Luke Mizzi (supervised by Prof. Joseph N. Grima, Dr Daphne Attard, and Dr Ruben Gatt) has studied existing stent designs to identify their weaknesses and is currently studying novel designs that overcome these problems. He used computer simulations to replicate the stresses current stents experience in the human body. These stents performed well in response to inflation and bending. However, shortening still occurs and they do not expand uniformly leading to flaring at the edges.

Mizzi found which current designs fared well but no design had all the features needed by heart stents. Crowns with a zigzagging structure allow for high expandability while S-shaped connections between crowns allow for high flexibility.

Mizzi who forms part of the Metamaterials Unit is designing new stent geometries that build on these features incorporating them all and improving stent performance. The next step for these researchers are designs that support part of the throat or oesophagus to continue saving lives.

 

This research was performed as part of Doctoral Studies at the Faculty of Science at the University of Malta. It is funded by the Malta Council for Science and Technology through its R&I programme. This project is in collaboration between the University of Malta, HM RD Ltd, part of the HalMann Vella Group of Companies, and Tek-Moulds Precision Engineering Limited.

Make light talk to light

Dr André Xuereb

Technology has made the world a very small place. Using light has transformed communication systems and a web of optical fibres span beneath our streets. This technology is no panacea since light cannot talk to another light beam: currently, ‘translators’ are needed. We want to push forward research into technologies that remove this requirement, addressing both commercial considerations and the underlying mechanisms. Our research is using exotic effects of quantum mechanics to help cut out the middleman and make light talk to light. This would increase speed, make security unbreakable, and improve energy efficiency. Malta’s communication technology would be revolutionised.

The Nanomolecular World

In life we are more capable of observing what we easily see. New technologies make it much easier to peek into the nano world to see molecules and atoms. By looking at the very small systems we can understand much larger ones.

Dr Reuben Cauchi (supervised by Prof. Joseph N. Grima, Dept. of Chemistry and Metamaterials Unit) has studied the structural chemistry of particular inorganic crystals (zeolites) through various molecular modelling techniques to learn how nano features result in unusual properties. By using structural chemistry techniques, Cauchi also studied the mechanisms that influenced these unusual properties under different conditions of pressure and temperature. They resulted in some extremely useful properties.

Dr Cauchi observed multiple unusual properties in a single zeolite crystal. Such complex combinations gave birth to the idea that other systems apart from zeolites can have more than one property at the same time. Studying zeolites allowed
the team Cauchi is part of to develop smart systems. These systems can be controlled by changes to stimuli indirectly related to each other, which effect the response to other stimuli.

Zeolites are naturally found crystals and beautiful systems to learn from. Studying such structures may help us think of new ideas and ways for technology improvement. For example, some of Cauchi’s findings are now being used by the Metamaterials Unit to develop smart honeycomb-like systems which can improve heart stent designs or make superior skin grafts.

 

This research was performed as part of Doctoral Studies at the Faculty of Science at the University of Malta and with the help of Gdansk University of Technology. It is partially funded by the Strategic Educational Pathways Scholarship (Malta). The scholarship is part-financed by the European Union — European Social Fund (ESF) under Operational Programme II — Cohesion Policy 2007–2013, “Empowering People for More Jobs and a Better Quality of Life”. The Metamaterials Unit also acknowledges the funds received from the Malta Council for Science and Technology through their R&I scheme.

The future is bright, The future is research

Mario Cachia

Today’s world is unforgiving; we cannot slack. Be it students in academic pursuits, or executives in professional ones, the need to create new things and innovate is essential to keep up with ever-changing times. The RIDT believes that University and its students are the cradle of all needed change. Our aim is to continue promoting and stimulating research within our Campus community. We believe that our students carry this important message best.

For this reason, the RIDT has embarked on campaigns and initiatives to gather more interest and feedback from University students and alumni. The RIDT participated in the annual KSU Freshers’ Week. Here we met and greeted thousands of students just starting out their degrees. At the same time, we launched our Facebook page to regularly update and engage with students. We succeeded in attracting nearly 1,000 followers in less than two months from launch. We felt that this was not enough, and in order to further engage our online audience, we enticed them to become closer to University research. With this in mind, we launched a fresh online competition, the UoM Research Challenge, where participants had to answer questions about research happening at University. The competition was sponsored by GO, who donated an iPad Mini for the fastest person to complete the challenge. We have plenty of fresh, innovative concepts lined up for the New Year.

Throughout December, the RIDT is collaborating with KSU and l-Istrina to promote research within the University and the local community. We want to reach out to raise awareness that research is a tool that can make everyone’s lives better. Many people throughout the world suffer from various socio-economic problems, ranging from deadly diseases and famine to poverty and unemployment. Through research, we can truly make a difference to all of these people, and we want to start here, from home.  By fostering a sense of awareness and belonging within our students and alumni, we can look forward to a bright future. In this future, we would be proud of a University making a difference in Malta and the rest of the world.

RIDT is the University’s Research Trust aimed towards fostering awareness and fundraising for high-calibre local research. For more information, visit
www.ridt.eu or find RIDT on Facebook www.facebook.com/RIDTMalta

Christopher Curmi, winner of the UoM Research Challenge, awarded an iPad Mini by the RIDT CEO Wilfred Kenely. Photo by Edward Duca

Author: Mario Cachia, RIDT Campaign Officer

 

Is Time Travel possible?

Theory says yes; practicality says no. Thanks to Einstein time travel is possible. The easiest way is travelling very close to the speed of light. Achieve 99.5% close to light speed means that in 5 years you travel 50 years. Goodbye friends and family you left behind. The harder way is creating a wormhole, a device that can bend space and time, looping it on itself to go into the future or past. The energy required would rival the energy of the stars. Sorry Sci-Fi fans.