Despite the overwhelming demand for nanoscale technologies, little research exists on the effects of these materials on marine environments, with concern growing for their ecotoxicological impacts on aquatic species.��

Researchers have previously looked at the impacts of individual nanoparticles on aquatic species.

Prof. Sheehan, Dean of the College of Arts and Sciences, published the results in, with authors Ilaria Marisa, Maria Gabriella Marin and Valerio Matozza, University of Padova; Davide Asnicar and Marco Parolini, University of Milan; Nicola Brianese, Institute for Energetics and Interphases, Italy; and Maria Fedorova and Ralf Hoffman, Universitat Leipzig.����

“Organisms are exposed to complex mixtures of contaminants in their environments, not just individual substances,” Prof. Sheehan explained. “The challenge for ecotoxicological studies is to understand the potential combined effects induced by exposure to these mixtures. For aquatic species, there has been plenty of attention given to mixtures of pharmaceutical compounds, such as those in personal-care products, and the pollutants found in herbicides and pesticides, but little is known about the impact of manufactured nanomaterials in marine environments.”

Metal and metal-oxide nanoparticles are useful in a wide variety of commercial applications and consumer products, with manufacturers taking advantage of their unique electrical, optical and catalytic properties. Nanoparticles are extremely small fragments of matter with a diameter less than 100 nanometers, roughly one thousand times smaller than a single strand of human hair. Their unique properties stem from their small size, but these properties may also pose problems for marine coastal areas, which are a sink for chemical and physical contaminants, including nanoparticles.

“Laboratory toxicity studies on freshwater and marine species have shown the potential adverse effects of nanoparticles in the environment, but since information on their concentrations in marine areas is still lacking, we can only use predicted environmental concentrations as a reference,”��Prof. Sheehan said. “Animals in these environments can easily come into contact with nanoparticles through their diet, and they can accumulate in the body, leading to oxidative stress, damage to DNA, protein and organelles, and even changes in gene expression.”

This includes bivalve organisms such as clams, oysters, and mussels, which filter large quantities of water to capture and ingest food particles. They play a critical role in cycling nutrients between the sediments and the water with a profound influence on water quality.

Because they are an important contributor to an aquatic environment, determining the impacts of nanoparticles on this group of animals is important for a full understanding of how manufactured nanoparticles might affect marine and coastal environments. Additionally, if nanoparticles are accumulating in bivalve tissues, they may be transferred to other animals that eat them, including humans.

“Although nanoparticles are present in aquatic environments in small quantities, so far, their mixture could cause different effects compared to each single nanoparticle,” Prof. Sheehan said. “A mixture of nanoparticle pollutants could interact in many different ways to induce biological responses at different levels of biological organization. There is also the potential ‘Trojan horse’ effect, which implies the facilitated uptake of toxic molecules adsorbed onto nanoparticles into the cells. Investigations on the combined toxic effects of multiple chemicals in organisms are much more challenging than those regarding single compounds, meaning information is lacking. Plus, the number of possible combinations of pollutants is extremely large and we don’t know which combinations would be the most ecotoxicologically relevant.”

The research team investigated two metal oxide nanoparticles — zinc oxide and titanium dioxide — and a carbon nanoparticle (FC60) to assess their effects both independently and in mixture. These nanoparticles are the most produced and most commonly used in products worldwide, and while many studies have been conducted to understand their impacts individually, this was the first to study their effects as a mixture. The team collected specimens of the marine clam Ruditapes philippinarum to test the effects of the nanoparticle mixture over seven days.

They used a multi-biomarker approach to better understand the effects of the nanoparticle mixture, and in all tissues analyzed, oxidative stress was the main mechanism influenced by nanoparticle toxicity. The research team found that during the early days of the investigation, the clam gills and digestive gland were able to cope with the presence of nanoparticles, limiting any damage, but after seven days, the mixture caused significant damage to the lipids and DNA in the digestive gland.

“Our findings indicated that the nanoparticle mixture had detrimental effects on the haemolymph, gills and digestive gland of clams, with the digestive gland most affected,” Prof. Sheehan said. “We also found that while concentrations differed, the nanoparticles did accumulate in the clams. Overall, the complexity of assessing the effects of contaminant mixtures was clear, and many environmental drivers and physiological constraints in various species need consideration in future studies.”

Jade Sterling
Science Writer
17 June 2022

The post Nanoparticles in the Marine Environment appeared first on Khalifa University.

Khalifa University proudly took home 3rd place at the latest American Association of Petroleum Geologists (AAPG) Imperial Barrel Award Program-Middle East Region. The program is an annual competition for geoscience graduate students from universities around the world. Winners are awarded scholarship funds for their schools.����

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The KU Team was composed of Earth Sciences graduate students Abdulquadri O. Dauda, Abdulwaris Ramoni Ajagunjeun, Ahmed Khaled Eleslambouly, Andreas Fernandez Moncada, and Omar Aldhanhani under the guidance of their team advisor Dr. Mohammad Alsuwaidi, Assistant Professor of Earth Sciences.

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Dr. Alsuwaidi explained, “The team went through a rigorous two-month program where they analyzed a large dataset and assessed whether to invest in a particular petroleum play or not. They examined data in geology, geophysics, petrophysics, and petroleum volumetric estimations, which usually requires teamwork from experts such as geologists, petrophysicists, geophysicists, and petroleum engineers.”

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The team was able to identify 13 different leads within the area that covered aspects such as environmental risks, reserves estimation, etc. They then delivered the results of their analysis to a panel of industry experts. Winners were selected based on their presentation’s technical quality, clarity, and originality.

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“In oil companies, projects like these are conducted for at least a year, but the students were able to complete the analysis and assessment in two months. Participants of these competitions usually make excellent hydrocarbon explorationists,” Dr. Alsuwaidi added.

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Team captain Ahmed K. Eleslambouly said, “It has been a great experience for me and the team as we accomplished work that usually takes a year or more within a very narrow time schedule. I am very proud that we were able to tackle most of the problems and come up with creative ideas and multiple leads within the study area.”

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“The competition was challenging, time consuming, and required much critical thinking. Although it was tough, the outcome for me and my time was worth it and amazing in terms of learning new technical and academic skills, gaining valuable industry knowledge, and getting familiar with the workflow of petroleum and geoscience projects for well-known companies in the oil and gas industry,” Omar Aldhanhani added.

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“It was hard to balance time working on the competition, our own research, semester projects and other school requirements but working with a team of enthusiastic colleagues and the constant encouragement of our faculty advisor, Dr. Mohammed Alsuwaidi, made the experience more pleasant and worthwhile. Our appreciation goes to the Earth Science Department, faculty, and Khalifa University for their support all through the preparation until the delivery of our presentation,” commented Abdulquadri Alabere.

Ara Maj Cruz
Creative Writer
18 May 2022

The post Khalifa University Takes 3rd Place Win at the AAPG Imperial Barrel Award Program appeared first on Khalifa University.

Editor’s Note: This article was updated on 24 November 2021

Two student teams from Khalifa University competed against more than 495 universities in the�� , investing non-fiat US$1 million in trade currency to buy and sell stocks and other commodities over the course of the 7-week competition.��

We are so proud of our KU students for participating in this challenge, which is based on a real-world investment environment using the popular Bloomberg Terminal platform.��Through their dedication and strong team cooperative spirit, and by leveraging the skills they’ve acquired from either business or math courses at KU, our teams performed extremely well and gained a strong understanding of real-world trading.

The team with Faculty Advisor Dr. Ricardo H. Archbold, Assistant Professor of Humanities and Social Sciences, includes the following members:

• Team Captain: Zehara Ali, BSc in��Biomedical Engineering
• Cidrik Mulugheta, BSc in Chemical Engineering
• Hamad Alblooshi, BSc in Mechanical Engineering
• Khalid Adam, BSc in Chemical Engineering
• Tiemar Semere, BSc in Computer Engineering

The second team with Faculty Advisor Dr. Giorgio Consigli, Associate Professor of Mathematics, and supporting advisor Dr. Jorge Zubelli, Professor of Mathematics, includes the following members:

• Team Captain: Bruno Nunes Costa, PhD student
• Omar Forrest, PhD student
• Iman Chaabi, BSc in Mathematics
• Haya Mayoof, BSc in Mathematics
• Mohammed El Amin Azz, BSc in Mathematics

At the end of the competition, Team Captain Zehara placed 50th, while Team Captain Bruno placed 77th, out of 496 total competing universities. While in the Middle East/Africa Regional competition, Team Captain Zehara placed 6th and Team Captain Bruno placed 8th. This is particularly impressive considering that most of the team members do not have a strong knowledge of finance or trading.

The students used the same type of terminals and data information that is available to real investment banks and financial exchanges.�� They gained the knowledge of how to access financial information and determine the economic trends that affect stocks and other commodities and exchanges across the world.��Profits and losses were determined by the real-world performance of these financial instruments.�� The teams had to indicate the strategy they used to determine the trades.

Participating students became certified on the Bloomberg Terminal, which gives them a competitive advantage in the job market post-graduation.

Erica Solomon
Publication Senior Specialist
9 November 2021

The post KU Students Compete in Bloomberg Trading Challenge appeared first on Khalifa University.

Four New Doctorate Programs by College of Arts and Sciences, as well as Additional Master’s and Bachelor’s Programs Added for 2021-2022 Academic Year ��

Khalifa University’s College of Arts and Sciences (CoAS) is now offering four new PhD programs, raising the total number of doctorate fields to 15, for the academic year 2021-2022, and further widening human capital development in strategic areas of the UAE and the region.��

The launch of the new Master’s and PhD programs represents Khalifa University’s commitment to contribute human capital to the Abu Dhabi Economic Vision 2030, which aims to build a sustainable and diversified, high value-added economy, as well as to achieve effective transformation of the Emirate’s economic base and bring about global integration. These programs will prepare the students for the job market of the future, equipping them with the knowledge of new technological advancements and innovations, and developing them into experts in these fields.��

The four new PhD programs in Chemistry, Physics, Math, and Earth Sciences are offered through the College of Arts and Sciences. The PhD offering in the College of Engineering includes Aerospace, Biomedical, Chemical, Electrical, Computer, Engineering Systems, Materials, Mechanical, Nuclear, Petroleum and Robotics. With this, Khalifa University now offers PhDs in 15 fields, one MD, 17 Master’s and 16 Bachelor’s programs. In line with the Abu Dhabi Economic Vision 2030, these programs are designed to develop highly skilled science and engineering professionals capable of transferring state-of-the-art technologies to priority sectors of industry, business and government.��

Students must complete a dissertation that involves creative, research-oriented work within the field of Chemistry, Physics, Math, or Earth Sciences. In addition to defending the thesis, the outcome of research should demonstrate the synthesis of information into knowledge in a form that may be used by others.��

Dr. Arif Sultan Al Hammadi, Executive Vice-President, Khalifa University, said: “The new doctorate and Master’s programs further expand our academic and research offerings, designed to create consummate professionals in all areas that are strategic to the UAE’s economy. We continuously evaluate the human capital needs of the UAE and the region to design our academic and research programs so that future engineers, scientists and healthcare experts will be fully equipped to face diverse challenges. We believe the new academic programs will attract more students to Khalifa University’s state-of-the-art research and academic facilities where they will be able to develop themselves into career professionals.”��

From Fall 2021, Khalifa University is offering new bachelor’s programs in Cell and Molecular Biology, and Earth and Planetary Sciences, as well as new Master’s in Aerospace Engineering.��

In addition to offering more academic programs, Khalifa University has consistently expanded its research domain to cover more strategic industries such as space systems and technologies, aerospace, robotics, machine intelligence, nuclear engineering, clean energy, sustainability, nanotechnologies, cyber security, biotechnology, advanced manufacturing and supply chain logistics.��

Over the years, Khalifa University has consistently remained as a top-ranked academic institution in the UAE and is ranked among the Top 200 institutions globally, especially in research and innovation. In the most recent Nature Index 2021 rankings, Khalifa University is placed top in the UAE and second among Arab institutions in terms of research output, with a total of 22 research papers, and ‘share’ of 6.53 that is nearly three times higher than the second-ranked university. Khalifa University is also top-ranked in the UAE and among the top 10 out of 125 Arab institutions in the 2021 Times Higher Education (THE) Arab Universities Ranking.

Clarence Michael
English Editor Specialist
13 September 2021

The post Khalifa University’s PhD Programs in 15 Fields to Further Expand Human Capital Development in Strategic Areas for UAE and Region appeared first on Khalifa University.

Research into how Emirati English speakers use language to refuse a request to take a photograph shows it’s not as simple as saying ‘no’.��

It’s never nice to have a request denied. But everyone needs to refuse a request every now and again, and there are various reasons why a person may say no. However, cultural diversity between speakers may mean that while one participant would be unaffected by a simple and direct ‘no’, another may need more from the refuser to save face in a potentially unpleasant situation.

Research on the ways Emirati English speakers refuse requests may be lacking, but Khalifa University’s Dr. Tanju Deveci, Associate Professor, and Dr. Jessica Midraj, Assistant Professor, both in the Department of English, are looking to change that with their latest investigation into how Emiratis say ‘no’ when responding to requests for photographs.

While the reasons for refusing may relate to social forces and cultural norms, the language used and the way Emiratis phrase their refusals is not as clearly researched. Dr. Deveci and Dr. Midraj asked 94 students how they would respond to a request for a photograph by strangers and published their research in the.

“Awareness of socio-cultural rules is essential for effective communication with people from different cultures,” explained the authors. “Not only does this awareness include social norms, but it also includes ways in which language should be used to achieve communication aims. Communicating with people from the same cultural background as us is usually easier than communicating with people from foreign cultures.”

While English is the most popular language used to communicate between people of different cultures and countries, it is not generally the meanings of words that cause difficulties. After all,

“Given the advances in technology and increased opportunities for international travel, we interact with people from foreign cultures more frequently than ever,” said the authors. “Differences between cultural norms still causes challenges. Our competence in a language largely depends on our knowledge of how that language is socially appropriate.”

Sociolinguistics covers the effects of any and all aspects of society on the way language is used. This includes cultural norms, expectations and context, and considers how social attitudes determine what is considered appropriate language use in a particular setting. For example, determining whether slang is appropriate in a conversation is a daily application of sociolinguistics.��

“Using language in socio-linguistically appropriate ways is particularly important in countries where English is predominantly used by people from different linguistic backgrounds for daily activities,” explained the authors. “One such country is the United Arab Emirates, with 88.52 percent of its residents being expatriates from various countries, not to mention the increasing number of tourists. Tourism adds to the existing diversity of cultures within the region, increasing the opportunity for people of different cultures to interact. However, this also brings language and culture-related challenges for the tourists, expatriates and Emiratis, requiring all parties to have intercultural communication competence skills alongside language skills.”

Intercultural communication competence (ICC) is the ability to communicate effectively and appropriately with people of other cultures and can be thought of as cultural awareness. Lack of awareness of cultural tendencies can create communication breakdowns. One such example is the refusal speech act, where one refuses a request made by someone else.

In linguistics, a speech act both presents information but performs an action as well. In their study with 94 Emirati English-speakers enrolled in university, the authors used the following example, where a tourist couple asks:

“Your national clothes look very interesting, and you look so nice in them! Would you mind if we have a photo taken with you?”

In the study, Emiratis’ use of the English language for the refusal speech act was investigated.

“The refusal speech act likely causes distress to the speaker,” explained the authors. “Likewise, a lack of awareness of an Emirati’s communication tendencies and preferred ways of language use may result in the non-Emiratis feeling uneasy and awkward.”

The participants in the study indicated that they would feel fairly comfortable talking to a tourist couple they have never met before but differences in gender appeared when responding to the request for a photograph.

Male participants indicated that they would feel more comfortable than the female participants accepting a request to take a photo. The results showed that 58.5 percent would accept the request, while 32 percent would reject the request and 9.5 percent would offer an alternative suggestion, essentially rejecting the initial request.

The influence of gender on speech acts of refusal varies depending on a multitude of sociocultural factors. Men may use more direct refusals, simply saying ‘no’, where women are more likely to employ ‘negative willingness’, saying things such as ‘Okay but only with my face covered’.

A considerably higher number of female participants indicated they would either reject the request or offer an alternative, with 31 percent of the refusal speech acts including a statement of regret, rather than a direct ‘no’. The female participants were also more likely to give a reason for their reluctance to be photographed, with five reasons related to tradition or culture. Additionally, only female participants used intensifiers in their refusals: ‘so’, ‘very’ or ‘really’ such as ‘I am really ���ǰ�����’.

“It’s important to note that well over one-third of the participants stated they would either reject the request or suggest a condition, with female participants refusing more than male participants,” explained the authors. “Alternatives raised by the female participants included covering their faces or allowing the photo with the female tourist only. It is also important to note the avoidance by all participants of the negation word ‘no’ and their tendency to apologize to the requester.”

Refusals exist in all languages, but their performance differs across cultures. The authors suggest that in the UAE, using certain linguistic features to make the hearer feel at ease is common when refusing a request. Prompted by the urge to keep a tourist ‘interested and attached to the place visited’, a speaker is more likely to use positive politeness strategies, with men more likely to use a statement of regret, and women more likely to provide an excuse or a reason. This supports previous research that gender responses may be influenced by situational and sociocultural factors, however the lack of literature on Emirati language use prevents any stronger conclusions.

While the sample size for this study was small, the results show certain trends in language use by young Emiratis with a set of cultural values. More general research into the refusal speech act used by the Emirati population could consider different types of situations, age groups and social distance between speakers, which could provide more insight into the specific uses within the culture and across cultures.

“The refusal speech act can be a nervous event that every human will experience,” said the authors. “Saying no can be more formidable during exchanges with people from distinct cultures from our own. The fact that we are able to and required to interact with people from other cultures means we have to develop an understanding of the nuances of communication and appropriate responses so that everyone in the interaction can be comfortable.”

The study participants were students registered in the authors’ Introduction to Applied Linguistics classes. In involving the students in the research, the authors aimed to help them understand the course contents better, while also contributing to a greater understanding of Emirati utilization of the refusal speech act.

Jade Sterling
Science Writer
17 August 2021

The post “Can We Take a Picture with You?”: The Refusal Speech Act Between Emiratis and Tourists appeared first on Khalifa University.

Dr. Ash Rossiter, Assistant Professor in the Institute of International and Civil Security (IICS) and the Department of Humanities and Social Sciences, has published a third book in 2020, titled .����

Published by Routledge and featuring contributions from leading security studies scholars from across the globe, the edited volume looks at technological impact of advances in robotics and autonomous systems across a range of contemporary security issues and settings.

Robotics, Autonomous Systems, and International Security marks Dr. Rossiter’s third book for 2020. It follows his single-authored monograph Security in the Gulf: Local Militaries before British Withdrawal, published by Cambridge University Press, and Conflict and Cooperation in the Indo-Pacific, a co-edited volume published by Routledge and written with KU and IICS colleague Dr. Brendon J. Cannon.

The publication of three books in a single year is a rare feat, which, according to Dr. Rossiter, was “only made possible by the research and publication culture fostered by the KU leadership and the seemingly inexhaustible encouragement within the College of Arts and Sciences.”

Alongside authoring or editing these books, Ash has published over a dozen peer-reviewed journal articles or book chapters. “Rightly, publishing high-quality articles in top journals has been – and remains – my core research output aim,” says Dr. Rossiter. “However,” he adds, “books are often signature publications in the social sciences and are highly valued.”

With the publication of these three books, Dr. Rossiter’s attention now turns to his two new book projects under contract: one on intelligence history with Georgetown University Press, and co-authored with KU and IICS’s Dr. Athol Yates, the other titled Warfare in the Robotics Age with the highly regarded American independent press Lynne Rienner.

Staff Report
2 January 2021

The post Book on Robotics and Security Marks Khalifa University Faculty’s Third Book in a Single Year appeared first on Khalifa University.

The terahertz range offers opportunities for detecting all sorts of things but using this range has proved difficult until now

Read Arabic story here:

Terahertz radiation – a band of the electromagnetic spectrum between microwaves and the infrared range – is useful for detecting toxic gases, explosives, and even diseases. But scientists have only been able to generate terahertz radiation at temperatures below 200 kelvins (-73 degrees Celsius) or lower, making it difficult to make use of this unique band in real-world applications, resulting in what’s known as the ‘terahertz gap.’

Now, researchers from Khalifa University are making progress towards a new way of generating terahertz radiation at room temperature by capitalizing on the unique electronic characteristics of a semiconducting superlattice material.

“This research has great potential in the UAE because the terahertz range of frequencies can be used to detect dangerous gases in the environment, explosives, and a number of gases in exhaled human and animal breath,” explained Dr. Mauro Pereira, Professor and Chair of the Khalifa University Department of Physics. “It could also be used to screen diseases in an early stage without invasive testing, and could therefore become a powerful tool in diagnosis for respiratory, gastrointestinal, and hepatic diseases.”

Dr. Pereira is lead author on a paper that was recently published in describing the new technique to generate terahertz radiation. He was joined by Dr. Vladimir Anfertev and Dr. Vladimir Vaks, both from the Institute for Physics of Microstructures, Nizhny Novgorod, Russia, and Dr. Yuliia Shevchenko from the Czech Academy of Sciences Institute of Physics.

To reach the terahertz radiation frequency at room temperature, the researchers created a special kind of material, known as a semiconductor superlattice. Semiconductor superlattices are made by layering atomically thin sheets of different materials (such as silicon and graphene) on top of each other. The layering gives the material an important electronic property called “nonlinearity.”

A material that is nonlinear behaves in a peculiar way. When it is radiated with light (or any form of energy), the atomic crystals in the material will vibrate not only at its natural frequency, but also at its “harmonic frequencies.” The harmonic frequencies are the waveforms of the natural frequency multiplied by two, three, four, five and so on until the frequency becomes so faint that it is no longer observable.��������

A nonlinear material with a natural frequency of 10 gigahertz, could have harmonic frequencies of 20 gigahertz, 30 gigahertz, 40 gigahertz and so on.�� As the harmonic frequency increases, however, the vibrations become more faint.

“Nonlinear physics is playing a major role in bridging what was once called the ‘terahertz gap’ and its multitude of applications,” explained Dr. Pereira.

“We take a source at a frequency that is easy to generate and use that to create higher frequencies in harmonic generation. We take a source operating at around 120 Gigahertz and multiply it all the way to 720 Gigahertz and beyond, using semiconductor superlattices and controlling the nonlinearities of the material. We use similar superlattices to detect the high frequencies at room temperature in an efficient way.”

The ability to leverage semiconductor superlattices and their corresponding harmonics can get scientists closer towards creating efficient devices that can generate radiation at terahertz frequencies from gigahertz inputs.

��“Semiconductor superlattice multipliers were only expected to deliver odd harmonics, but we have shown that they can also generate even harmonics. By actually controlling the even harmonics and increasing their output by several orders of magnitude with applied voltages, we open the possibility of exploiting a wide range of frequencies,” explained Dr. Pereira.

“The superlattices are already being used by our Russian colleagues for breath analysis and we are designing new samples and devices based on them here at Khalifa University.”��

Jade Sterling
Science Writer

Erica Solomon
Senior Publication Specialist

10 December 2020

The post Khalifa University Researcher Bridges the Terahertz Gap to Create Powerful Sensing and Imaging Capabilities appeared first on Khalifa University.

The new ‘nano-memory’ cell is designed as a type of non-volatile memory that can complete ‘read-write’ operations with a significantly smaller footprint and simple design using a single gold nanoparticle

To meet the growing demand for faster, smaller and more powerful electronics, a team of researchers from Khalifa University has developed a new type of ultra-small memory cell that could provide greater memory storage and improved processing speed on extremely small computer chips.��

The new ‘nano-memory’ cell is tiny – only one gold nanoparticle thick, or about one-one thousandth the size of a human hair – and is sandwiched between very thin layers of aluminum oxide. It has a unique and simple structure that allows data to be ‘written’ onto it and ‘read’ from it by charging and discharging a single nanoparticle. Its simple design makes it easy to fabricate, and in turn, easily scalable and commercially viable.��

Lead author Dr. Moh’d Rezeq, Associate Professor of Physics, along with Dr. Irfan Saadat, Professor of Electrical Engineering and Computer Science, Dr.�� Ammar Nayfeh, Associate Professor of Electrical Engineering and Computer Science, and Postdoctoral Fellows Dr. Ayman Rezk and Dr. Yawar Abbas,�� describe the new memory cell in a paper published in June 2020 in the journal Applied Physics Letters.��

Computer Memory and MOSFETs

Computers represent information in binary code, which is written as sequences of 0s and 1s, known as a binary digit, or ‘bit.’ The files and programs on our computers comprise millions of these bits, which are stored in the computer’s memory, and then executed by the computer’s central processing unit.��

There are two types of memory systems in a computer: Non-volatile memory (NVM), which is memory that can retrieve stored information even when the power to a computer has been turned off, and volatile memory, which is memory that processes information only when the computer is running.��

NVM systems like flash memory use floating gate metal-oxide semiconductor field effect transistors to store each bit in a specific memory cell as an electric charge.��

Metal-oxide semiconductor field effect transistors, or MOSFETs, are the building blocks of modern day computers. The billions of transistors found in all electronics today to switch and amplify electric signals are designed as MOSFETs.��

Floating gate MOSFETs are designed in a way that allow the charge, which would normally pass through in a typical MOSFET, to be trapped in the ‘floating gate’ part of the system. This trapped charge represents a stored bit.

Dr. Rezeq and his team from KU have proposed a new, simpler memory cell structure to replace the floating gate MOSFET architecture.

The KU Nano-Memory Cell Design

In a typical floating gate MOSFET, a stack of gates is arranged on a base, known as a substrate, that is made up of n- and p-type silicon semiconductors. The gates are insulated from the substrate by metal oxide insulating layers, also known as dielectrics. Source and drain terminals are connected directly to the substrate so that electrons can flow through a channel underneath the floating gate (see Figure A). The electrons don’t flow until a voltage is applied to the gate.��

This structure, however, imposes some limitations on device performance and scaling, and also introduces some fabrication complexity.

In Dr. Rezeq’s work the design is simpler. A single gold nanoparticle is placed on a silicon substrate that has been covered with a thin layer of aluminium oxide. Then, another thin layer of aluminium oxide is placed around the entire nanoparticle. In this design, the gold nanoparticle itself is the cell in which the charge is stored.��

Their design does not involve the use of conventional source and drain terminals, and the substrate is only an n-type silicon semiconductor. Instead of source and drain terminals, they attach one electrode above the gold nanoparticle (see Figure B). In their proof-of-concept prototype, they used a nano-probe as the electrode.��

After injecting an electrical charge (i.e. electrons) into the nanoparticle through the nano-probe, the researchers observed that a few electrons successfully tunnelled their way into the nanoparticle and became trapped in the nanoparticle itself. Thus, the team observed what would be called in a working computer as the ‘writing’ process.

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To complete the ‘reading’ process, which is the process that takes place when the computer’s central processing unit executes and ‘reads’ from the memory cell, another voltage is applied through the electrode, allowing the CPU to read the current signal. If there is a charge in the nano-particle (which represents the ‘on’ state, or a 1 in binary code) the current signal will be less than the case when the nano-particle is discharged (which represents the ‘off’ state, or a 0 in binary code).

Dr. Rezeq credits the success of the nano-memory cell to the right size of the gold nanoparticle and the right thickness of the aluminum oxide layers.��

“The selection of the nanoparticle size and the highly insulating – or high-K – aluminum oxide thickness is critical to optimize the tunnelling current and increase the charge retention time,” he said.��

Metal oxides that are very good at insulating, including aluminium dioxide, are known as ‘high-k’ dielectrics. In floating gate MOSFETs, these insulating layers play a key role in ensuring the flow of electrons between the source and drain terminals does not affect the charge in the floating gate. In Dr. Rezeq’s nano-memory cell, the dielectric ensures that the charge stays trapped in the gold nanoparticle, and does not leak out. The dielectric has to be thin enough to let the charge in via the electron tunnelling process, but thick enough to keep it there when there is no voltage bias applied. Furthermore, their design allows erasing and writing memory data regularly.��

“The nanoparticle itself here is used as a storage site of electrons but also regulates the current. Since the size of the nanoparticle can be controlled down to a few nanometers, this can result in a significant improvement in the capacity of the memory storage devices,” explained Dr. Rezeq. “Such devices are particularly interesting for their endurance, small operating voltage, and faster write/read cycles. These improvements are related to unique characteristics from the nanoparticles, particularly when combined with very thin high-k dielectrics.”

It is well accepted that nanotechnology will play a vital role in the ability to increase computing device performance across a broad range of applications and this work demonstrates where the future lies.��

Dr. Rezeq plans to continue working on his nano-memory cell proof-of-concept and bring it into the next phase of development.��

Jade Sterling, Science Writer and Erica Solomon, Publication Senior Specialist
30 September 2020

The post Khalifa University Designs Ultra-Small Memory Cell that Could Boost Storage Density in Computers appeared first on Khalifa University.

Khalifa University Assistant Professor Shares Lessons on Locusts

The size and weight of a paper clip, a single locust hardly appears capable of the devastation and destruction associated with it. But a single locust isn’t the problem—swarms are.

In a paper published in the Emirates Natural History Group journal,, Dr. Athol Yates, Assistant Professor at the Khalifa University Institute for International and Civil Security, described the little-known, large-scale anti-locust campaign in the Arabian Peninsula, which was a combined military and civilian effort.��

لا يمكن للجرادة وحدها ذات الحجم والوزن الصغيرين الذان لا يتعديان حجم ووزن الدبوس الورقي أن تحدث أضراراً إلا إذا كان الجراد في أسراب. وفي هذا الصدد، وضح الدكتور أثول ياتيس، الأستاذ المساعد في الأمن المدني والدولي في جامعة خليفة، في ورقته البحثية التي نُشرت في قسم (تريبولوس) من…

— جامعة خليفة للعلوم والتكنولوجيا (@KhalifaUni)

“The desert locust is one of the most damaging pests to agriculture due to its ability to form huge swarms which devour everything in their paths,” explained Dr. Yates. “They have often caused devastation in the Arabian region, like in 1958 when they destroyed about 85 percent of crops in the then Trucial States.”

Plagues of locusts occur periodically, with most lasting for several years. The United Arab Emirates is not only in the path of locust swarms but is also a breeding site for the locusts.

“While scientific efforts started in the early 1900s to combat locust plagues, a lack of knowledge about the insect made it difficult,” explained Dr. Yates. “During the 1930s, great efforts were made to collect reliable information across the region, which allowed both the seasonal breeding areas and the paths of migrating swarms to be identified.”

There were multiple problems in how locust swarms were tackled prior to the campaigns led by the British military. As locust swarms occur in cycles of multiple years separated by an absence, countries only took action when they appeared, meaning responses were too late because little action was taken between these cycles to prevent reoccurrence. Since locusts cross international borders, countering them also requires coordinated action across countries. However, most responses were isolated. On top of this, chemical poison was only introduced in the early 1940s, with methods to counter locusts before this only partially effective and often improvised.

“In 1942, the first effective chemical poison was used to control locust populations,” explained Dr. Yates. “Sodium arsenate was mixed with wheat bran and laid in the path of the juvenile insects. Those that ate this preparation died, meaning they perished before becoming airborne and preventing further breeding.”

During this time, the Trucial States were a British protected state, with the British promising to protect the Trucial Coast from external aggression, in exchange for the Rulers allowing Britain to act with foreign powers on their behalf.

World War II started in 1939, with the Middle East a significant theater of operations in the early years because it allowed access to Africa, the oil of the Gulf and launching of operations against the Axis powers (Germany, Italy, and Japan) in the Mediterranean. In 1941, locust swarms were reported in the Arabian Peninsula, marking the start of seven years of locust plagues, threatening the stability of the region.

“The locust threat presented the British with unpalatable choices between allowing the local population to starve or importing and distributing large amounts of food,” explained Dr. Yates. “The latter would have had significant military consequences as it would divert ships and manpower essential for military operations in the region, while the former would lead to civil disturbances that would also affect military operations and undermine British prestige. In military terms, combatting locusts was ‘regarded as second only in importance to operations against the enemy.’”

In 1943, Britain formed the Middle East Anti-Locust Unit (MEALU) and tasked it with destroying locust swarms at the source. Its success hinged on coordination and input from other countries and large-scale logistics assistance from the British military. Such an undertaking was only feasible as a combined effort, with intense research and international conferences needed to develop the plan for the largest-ever coordinated operation against locusts in the Middle East.

“Until the very early 1940s, anti-locust measures concentrated on protecting crops. This defensive strategy meant waiting until the locusts arrived near the crops and then attempting to destroy them,” explained Dr. Yates. “In contrast, the MEALU approach involved sending scouting parties out into the desert, and when locusts were located, sending workers to destroy them. This required considerable planning and coordination so that the work was continuous, efficient, and effective.”

After 1944, the locust menace had been significantly reduced, but the threat remained as the war raged on. Combatting locusts remained a high priority but the military equipment and personnel were required in other arenas and could no longer participate in the anti-locust campaigns in the Middle East. Attention shifted in the immediate years after the war to more national-based efforts with less cross-country coordination. There was particular reluctance for the British to be in charge of the anti-locust campaign across the region.

“Wilfred Thesiger, an English explorer and travel writer, applied to work on locust research as he had a desire to explore the region. He was tasked with gathering information on the environmental conditions of southern Arabia to see if they were right for the development of desert locust swarms. Thesiger’s first journey began in October 1945 in Salalah, Oman. He explored the south-eastern edge of the Empty Quarter and the region around the intersection of modern-day Oman, Yemen and Saudi Arabia, recording information on locust breeding, seasonal rainfall and vegetation.”

During the 1950s and 1960s, Britain and Pakistan in particular supported anti-locust activities in the Trucial States. Now, pest control teams in the UAE are spearheaded by the Ministry of Climate Change and Environment.

“The British military’s support for the anti-locust campaign during the Second World War rarely rates a footnote in the histories of the Middle East,” said Dr. Yates. “This is unfortunate, for it overlooks important contributions made by the military in those years, not only to the health and livelihoods of the people of the Middle East, but also to winning World War II.”

Jade Sterling
Science Writer
30 August 2020

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