Controlled oxide removal for the preparation of damage-free InAs(110) surfaces

Controlled oxide removal from InAs(110) surfaces using atomic hydrogen (H*) has been achieved by monitoring the contaminant vibrational modes with high resolution electron energy loss spectroscopy (HREELS). The contributing oxide vibrational modes of the partially H* cleaned surface have been identified. Following hydrocarbon desorption during preliminary annealing at 360 °C, exposure to atomic hydrogen at 400 °C initially removes the arsenic oxides and indium suboxides; complete indium oxide removal requires significantly higher hydrogen doses. After a total molecular hydrogen dose of 120 kL, a clean, ordered surface, exhibiting a sharp (1×1) pattern, was confirmed by low energy electron diffraction and x-ray photoelectron spectroscopy. Energy dependent HREELS studies of the near-surface electronic structure indicate that no residual electronic damage or dopant passivation results from the cleaning process

Electron dynamics in InNxSb1–x

Electron transport properties in InNxSb1–x are investigated for a range of alloy compositions. The band structure of InNxSb1–x is modeled using a modified k·p Hamiltonian. This enables the semiconductor statistics for a given x value to be calculated from the dispersion relation of the E– subband. These calculations reveal that for alloy compositions in the range 0.001<=x<=0.02 there is only a small variation of the carrier concentration at a given plasma frequency. A similar trend is observed for the effective mass at the Fermi level. Measurements of the plasma frequency and plasmon lifetime for InNxSb1–x alloys enable the carrier concentration and the effective mass at the Fermi level to be determined and a lower limit for the electron mobility to be estimated

Student opinions on their development of non-technical skills in IT education

It is recognized that non-technical or soft skills are a vital part of the IT curriculum and hence are considered to be core curriculum components, particularly in the USA and Australia and is also an important worldwide issue. An extensive analysis within an Australian university context found a mismatch between employer expectations and the university-based instruction in these skills. However, it was noted that this unpreparedness in soft skills may be because students may not have appreciated the importance of these skills – a result confirmed by this study, which used a questionnaire delivered to project students undertaking a range of IT based courses. Internships are not common in Australia and hence to address this problem guest speakers from industry are now regularly invited to give presentations to project students. Furthermore it was also found that those students who had workplace experience more fully appreciated the role of workplace soft skills than those who did not have such experience. This study clearly indicates the importance of a team based project unit for teaching soft skills. A further implication is that students need to be made aware of the importance of soft skills in the workplace as a part of their studies

Origin of the n-type conductivity of InN: the role of positively charged dislocations

As-grown InN is known to exhibit high unintentional n-type conductivity. Hall measurements from a range of high-quality single-crystalline epitaxially grown InN films reveal a dramatic reduction in the electron density (from low 1019 to low 1017 cm–3) with increasing film thickness (from 50 to 12 000 nm). The combination of background donors from impurities and the extreme electron accumulation at InN surfaces is shown to be insufficient to reproduce the measured film thickness dependence of the free-electron density. When positively charged nitrogen vacancies (VN+) along dislocations are also included, agreement is obtained between the calculated and experimental thickness dependence of the free-electron concentration

Network Security Devices and Protocols Using State Model Diagrams

Network security is concerned with protecting sensitive information, limiting unauthorised access, and reinforcing network performance. An important factor in network security is encryption. Internet Security Protocol (IPSec) is the de facto open standard for encryption and replaces the older Cisco Encryption Technology (CET). Both encryption protocols are typically implemented and managed using the text based Command Line Interface (CLI). A graphical user interface (GUI) is available; however, it is not routinely used. Regardless of whether the CLI or GUI is used, both encryption suites are complex to implement and manage. State Model Diagrams (SMDs) were developed and successfully used as the pedagogical foundation of internetworking technologies. SMDs integrate pertinent output from devices and protocol finite state information. SMDs are modular and hierarchical models thereby providing top down deconstruction as a cascaded structure. In terms of ease of use, hyperlinks may be used to navigate between different state tables and diagrams. Moreover, as hierarchical model characteristics allow technical detail to be presented and integrated to assist in managing devices. In this paper, SMDs were used to evaluate CET and IPSec via experiments in order to determine their potential value as network management tool

Economic Sustainability of Remote Access Networking Classrooms

Within the higher education domain, there is a prevalent belief that e-learning, virtual classroom and tele-education are essential requirements for the long-term effectiveness and success of educational institutions. Many information technologies have been adopted to assist studying and learning remotely and are hence potentially beneficial to students, teachers and educational providers. For educational providers, the benefits are that there are no physical or geographical limits to the number of students that can be enrolled in a course of study. However, within the field of network technology, students must actually use network devices during their studies. This is important not only because it significantly enhances student learning, but also within this field, employers expect students to have practical ‗hands-on‘ experience. Software simulators are available but they cannot provide students with the necessary practical experience of connecting together the physical devices. Despite the requirements to provide a ‗hands-on\u27 approach it effectively eliminates remote on-line students. Edith Cowan University (ECU) invested over AUD$350,000 in dedicated network teaching laboratories, which are considered to be of a \u27world-class\u27 standard. An access server has been used to provide remote students with access to this equipment. Significantly it is also possible to view the actual network devices by means of a webcam. Whilst remote access to equipment has been possible students only interact via a computer screen. This work allows students to interact by means of Webcam (visual) and Voice over Internet Protocol (VoIP) (audio). Work to date has consisted of establishing the appropriate infrastructure and testing the communication links. Further trials are planned for semester 2, 2008. Traditional remote access can only operate via Command Line Interface (CLI), this can be difficult for many students to practice and gain experience in computer network and internetworking. In effect on-line students will be able to conduct their workshops on a remotely located \u27world class\u27 network laboratory. For students, the on-line curriculum is available twenty four hours a day; there is typically on-line support, and software is now available allowing access to recorded lectures

Core-level photoemission spectroscopy of nitrogen bonding in GaNxAs1–x alloys

The nitrogen bonding configurations in GaNxAs1–x alloys grown by molecular beam epitaxy with 0.07=0.03, the nitrogen is found to exist in a single bonding configuration – the Ga–N bond; no interstitial nitrogen complexes are present. The amount of nitrogen in the alloys is estimated from the XPS using the N 1s photoelectron and Ga LMM Auger lines and is found to be in agreement with the composition determined by x-ray diffraction

Hydrogen gas and its role in cell signalling

This is the author accepted manuscript. The final version is available from CAB International via the DOI in this record. Hydrogen gas (H2) was once thought to be inert in biological systems but it has now become apparent that exposure of a wide range of organisms, including animals and plants, to H2or hydrogen-rich water has beneficial effects. It is involved in plant development, and alleviation of stress and illness, such as reperfusion injury. Here, an overview of how H2interacts with organisms is given

Submission to the Senate Select Committee on Administration of Sport Grants Should there be a $100 million federal community sport grants program at all?

It is questionable whether national funds designed to be allocated in small amounts paid directly to local community organisations have a part to play in a federal system. Apart from the clear temptation for pork-barrelling, they make no sense in terms of efficiency and rational policy, particularly when, as is the case with sport and recreation, there is already a system in place to assess local community needs