Monte Carlo simulation of electron and proton irradiation of carbon nanotube and graphene transistors

Carbon-based nanotechnology electronics can provide high performance, low-power and low-weight solutions, which are very suitable for innovative aerospace applications. However, its application in the space environment where there is a radiation hazard, requires an assessment of the response of such electronic products to the background irradiance. To explore the potential of carbon-based nanotechnology, Monte Carlo simulations of radiation interacting with a gate-all-around carbon nanotube (GAACNFET) and a top-gated graphene FET are presented. Geant4 is used to calculate the energy deposited into the dielectric layers and the displacement damage in the nanosemiconductors under proton and electron irradiation. Both an unshielded and two cases with 250 μm thick NiFe and Pb shielding are tested at a fluence of 1015 m-2. The energy range of the particles considered is 10-2 – 102 MeV for the unshielded and 1 – 103 MeV for the shielded case. The results indicate that the graphene transistor is more susceptible to displacement damage than the CNT-based syste

Enhancing public safety and security of critical national infrastructure utilizing the Nigerian Satellite Augmentation System (NSAS)

After the First World War, radio time signals offered alternative technology for determination of the Greenwich time and thus longitude at sea. The first manifestation of new technology capable of usurping the super accurate mechanical chronometers occurred in 1904, when the United States Navy began to experiment with the transmission of radio-time signals as an aid to the determination of longitude (Davies, 1978; Lawal & Chatwin, 2011). The challenge in precision continued with precision in Navigation systems, which depends on electromagnetic waves travelling at 300,000,000 m/s, which means that one microsecond error in a vessel’s time will result in 300metres of navigational error. The Global Positioning System (GPS) originated from the Navigation System with Timing and Ranging known as NAVSTAR, which was initiated by the Joint Program Office (JPO) of the U.S. Department of Defence (DoD) in 1973.The first GPS satellite was sent into orbit in 1978. Initial Operational Capability (IOC) was reached in July 1993 with 24 satellites, while Full Operational Capability (FOC) was declared on July, 17th, 1995. Improvement in accuracy for general transportation, especially in aviation, ushered in augmentation systems. The quest for performance focused on the ability to accurately transmit and keep time signals stable up to the picosecond level and even more in receivers and clock reference signals for space systems, especially in navigation satellites using high performance oscillators ranging from ultra-stable quartz crystals with ovenized control to high performance atomic circuits (Lawal & Chatwin, 2011). The Satellite-Based Augmentation System (SBAS) arose from the need to provide continuity, availability, integrity and accuracy of global positioning signals to eliminate errors and compensate for discrepancies associated with GPS signals and other navigation systems. The NigComSat-1R Navigation (L-band) payload is a Space Based Augmentation System meant to provide a Navigation Overlay Service (NOS) similar to the European Geostationary Navigation Overlay Service (EGNOS). This paper describes the huge untapped potential that the hybrid satellite offers in the area of public safety, security of critical national infrastructure, aviation, maritime, defense, effectiveness of Location Based Services for Emergency and Crisis management amongst other applications; it thus fills a great gap in the augmentation systems for Africa

Investment guidance for the Chinese medical device market

The medical device market is one of the most attractive and profitable areas in the global economy. Since China opened its doors to the world it has attracted increasing amounts of foreign investment. The Chinese medical device market is currently one of the most promising and fastest growing markets, which is the second largest market in the world with 200 billion yuan (RMB) total sales in 2013. This paper illustrates the geographical distribution of the Chinese medical device industry, combined with the location quotient (LQ) assessment, to reveal the medical device industry’s professional level and degree of concentration in each province, providing guidance for investors who are interested in medical device investment in China. The LQ and market share (MS) matrix reveals that the best investment regions in China are: Bohai Economic Rim, Yangtze River Delta and Pearl River Delta Economic Zones

A comparison of two regularization methods based on the Sussex EIM MK4 system

A comparison of two regularization methods: the general regularization method and the Sheffield method using the voltage ratio rather than the difference

TexRad-Feedback plc - cancer management imaging software

At the University of Sussex Professor Chris Chatwin, Dr Rupert Young & Dr Balaji Ganeshan were awarded an Achieving Impact Award by Vice Chancellor Professor Michael Farthing and Deputy Vice Chancellor Professor Michael Davies for their cancer management Imaging Software.The TexRAD Cancer management technology is being used as a research tool in seven of the G8 Countries; FDA and CE approvals for clinical use are imminent

Global panopticon

Contemporary panopticon infrastructure and technologies are deployed to secure citizens using video surveillance, biometrics, labelling technologies, satellites and the global fibre network. This is an expanding business sector

Rapid prototyping and time compression

Rapid Prototyping - manufacture by layering processes: Stereolithography Selective Layer Sintering (SLS) Laminated Object Manufacture (LOM) Solid Ground Curing Small batch programmable rapid manufacture with lasers Micro-Engineering – Prototyping and Manufacture Additive - fabrication Subtractive – machinin

A service oriented approach for guidelines-based clinical decision support using BPMN

Evidence-based medical practice requires that clinical guidelines need to be documented in such a way that they represent a clinical workflow in its most accessible form. In order to optimize clinical processes to improve clinical outcomes, we propose a Service Oriented Architecture (SOA) based approach for implementing clinical guidelines that can be accessed from an Electronic Health Record (EHR) application with a Web Services enabled communication mechanism with the Enterprise Service Bus. We have used Business Process Modelling Notation (BPMN) for modelling and presenting the clinical pathway in the form of a workflow. The aim of this study is to produce spontaneous alerts in the healthcare workflow in the diagnosis of Chronic Obstructive Pulmonary Disease (COPD). The use of BPMN as a tool to automate clinical guidelines has not been previously employed for providing Clinical Decision Support (CDS)

A Global Space Policy that would revive Space Exploration

Almost every nation today relies on space-based technology for communications, weather forecasting, satellite navigation and resource management, either through ndigenous programs or through programs run by its allies. As such, it is safe to say that every country is a space-faring nation. However,when it comes to space science and technology, attention must be directed towards countries that possess the ability to launch payloads. Russia, Japan, China, ESA, India, Israel, Iran and the United States form an exclusive club of nations that not only possess launch capability but also dominate research and development in space sciences. With the exception of the ESA, whose space policy is dictated by its member states and primarily serves the EU, all other countries have national space programs governed by a dedicated space policy. However, all states including the EU have the following objectives in common: 1. Development and exploitation of space applications to serve the state’s public policy objectives, 2. Ensuring that the state’s national security and defense needs are met with regards to space, 3. Securing unrestricted access to critical technologies allowing states to pursue independent applications, and 4. To further international collaboration between likeminded nations through improved coordination of international activities and by setting in place a better mechanism for sharing of resources. Whilst the above nations agree in principal to the UN Outer Space Treaty, and they all consider space as a vital resource for ensuring national security. As such, any application or development of critical technologies is used primarily to bolster a state’s national defense capability. Current national space programs run by these countries cover various commercial, civilian and military aspects. This cross discipline research and development has led to an extremely integrated industrial base, where drawing a line between civilian and military programs is often impossible. This hazy line has often hindered technology transfer even in commercial applications as companies grapple with stringent export control regulations. With respect to the United States, whilst ITAR has ensured that critical technology is not transferred without the states consent, many in Washington agree that the regulation fails to meet its objectives and must be overhauled. It has also hindered US companies wanting to sell their products outside the United States, prompting other nations to develop indigenous technologies and market them as ITARfree. Although it is safe to assume that research and development with regards to space will be dominated by the United States and its partners in Europe for the foreseeable future, the recent recession has caused financial strains on both sides of the Atlantic causing drastic changes with regards to space budgets and the future outlook for both NASA and ESA. This paper briefly discusses why emerging nations might consider investing in a national space program, and factors that would determine its success. It also focuses on how the establishment of a global space program could prove to be an innovative and cost-effective way of ensuring a robust space industry that serves the social and political objectives of member nations whilst promoting a global technological base that fosters innovation, growth and sustainable development