A Dynamic Multimedia User-Weight Classification Scheme for IEEE_802.11 WLANs

In this paper we expose a dynamic traffic-classification scheme to support multimedia applications such as voice and broadband video transmissions over IEEE 802.11 Wireless Local Area Networks (WLANs). Obviously, over a Wi-Fi link and to better serve these applications - which normally have strict bounded transmission delay or minimum link rate requirement - a service differentiation technique can be applied to the media traffic transmitted by the same mobile node using the well-known 802.11e Enhanced Distributed Channel Access (EDCA) protocol. However, the given EDCA mode does not offer user differentiation, which can be viewed as a deficiency in multi-access wireless networks. Accordingly, we propose a new inter-node priority access scheme for IEEE 802.11e networks which is compatible with the EDCA scheme. The proposed scheme joins a dynamic user-weight to each mobile station depending on its outgoing data, and therefore deploys inter-node priority for the channel access to complement the existing EDCA inter-frame priority. This provides efficient quality of service control across multiple users within the same coverage area of an access point. We provide performance evaluations to compare the proposed access model with the basic EDCA 802.11 MAC protocol mode to elucidate the quality improvement achieved for multimedia communication over 802.11 WLANs.Comment: 15 pages, 8 figures, 3 tables, International Journal of Computer Networks & Communications (IJCNC

Technology-enabled Learning (TEL): YouTube as a Ubiquitous Learning Aid.

The use of social networks such as Facebook, Twitter, and YouTube in the society has become ubiquitous. The advent of communication technologies alongside other unification trends and notions such as media convergence and digital content allow the users of the social network to integrate these networks in their everyday life. There have been several attempts in the literature to investigate and explain the use of social networks such as Facebook and WhatsApp by university students in the Arab region. However, little research has been done on how university students utilise online audiovisual materials in their academic activities in the UAE. This research aims to elucidate the use of YouTube as a learning aid for university students in the UAE. We adopt the technology acceptance model (TAM) as the theoretical framework for this investigation. A quantitative methodology is employed to answer the research question. Primary data consisting of 221 correspondents were analysed, covering patterns of using YouTube as an academic audiovisual learning aid. Statistical techniques including descriptive, correlations, regression tests were used to analyse the data. The study concluded that students use YouTube as a learning tool for their academic studies and enriching their general knowledge; and there is a positive relationship between the use of YouTube videos in academic settings and the students’ overall performance. This study can shed light for teachers, curriculum designers, government entities, and other stakeholders on how to best utilise and integrate the online technology — YouTube — as a learning aid

Mass Mentality, Culture Industry, Fascism

Some fashionable leftist movements and populist intellectuals habitually blame the sources of information for public ignorance about the miserable state of the world. It could be argued, however, that the masses are ignorant because they prefer ignorance. A mass individual is politically apathetic and intellectually lazy. As a result, even when huge amounts of information are available, which is the case in this epoch, the masses insist on choosing ignorance. It is true that there is not enough information about what has happened in a place such as Darfur, but the masses choose not to access even the amount of information that is available. The great majority of people in China, Iran, and America, despite the fact that they have varying amounts of access to various types of "knowledge," still tend to be misinformed. It seems that a mass individual is curious only about what directly affects his/her own personal life. I will explore the connection between mass mentality and the culture industry in order to capture the essential role of the former in the latter. I will also argue that a mass individual is the source of fascism although fascism as a phenomenon needs a mass culture in which to flourish

CASE STUDY ON GIS DEFECTS AND NEW POSSIBILITIES FOR PREVENTIVE MAINTENANCES

The paper reports on the practical aspects of diagnosis of gas insulated systems (GIS). The defects frequency in a GIS probably reflects the care taken during assembling, com-missioning and in-service. A preventive maintenance system for gas insulated system (GIS) is suggested. This new system serves for diagnosing defects and injecting different types of gases into the section where corona discharges (CD) or particle discharges (PD) are occurring. Automatic injection of SF6 gas and/or a special gas mixture improves the dielectric strength and so prevents faults in service. Criteria for source discrimination, localisation and evaluation for the developed system are discussed

The geochemistry of thermal aureoles at Cashel, Co. Galway and Comrie, Perthshire

Detailed investigations of the Cashel-Lough Wheelaun and Comrie thermal aureoles show that similar intensive mineralogical changes have taken place in both aureoles irrespective of the intrusive and country rock types and the regional metamorphism experienced by the country rocks. The chemistry in the two aureoles also generally shows similar trends although original sedimentary variations across the Aberfoyle slates severely affected the behaviour of most elements. In the Cashel thermal aureole, it is shown that the elements which are commonly enriched in acidic rocks viz : Si, K, Na, P, U, Rb, Ba, Th and to some extent Zr were removed from the envelope hornfelses, those commonly enriched in mafic rocks viz: Mg, Fe, Cr, Ni, and Co were enriched whereas those elements which are intermediate in character viz: Al, Ti, Ca, and Sr were both enriched and removed. Eu was removed much less significantly compared to the other REE thus giving increasing positive Eu anomalies as the degree of hornfelsing and partial melting rise. In the Comrie thermal aureole, the sedimentary variations mention ed above strongly affected the variation of elements during hornfelsing and partial melting of the Aberfoyle Slates, although the available evidence suggests similar trends to the Cashel thermal aureole. Mineralogical, chemical and Sr isotope evidence show that the Cashel trondhjemite migmatite leucosomes were produced at degrees of partial melting of between 15 and 30% and their chemical compositions compare reasonably well with the melts derived from the metasediments as calculated using the strongly compatible elements Cr, Ni and Co. This conclusively indicates they were derived from the metasediments and so does the Cashel microgranite sill. The Comrie leucosomes are dominantly late stage magmatic injections although the melts, which were probably near eutectic in composition in part, derive from the partially melted metasediments. The elements as deduced from the Cashel, and probably also the Comrie and Cortlandt, New York aureoles, were fractionated into the melts in the following order :Si>K>Na>Ca>Mn>AI>Fe>Mg and Rb>Ba>Sr>Ga>Cr, Ni, Co. This calculated order of fractionation of elements, which is the opposite to magmatic crystallization, provides a unique picture on the mode of interaction of mantle derived magmas with the earth's crust and therefore gives clear explanation on how S-type granites and other crustally contaminated rock types are produced, especially as the melts derived from both the Cashel and Comrie hornfelses are S-type melts as defined by Chappell and White (1974)

Earth-abundant nanostructured catalysts for solar fuel production at room temperature

Improving the performance of solar energy harvesting martials is a challenge facing the renewable energy industry. Over the past few decades, metal oxides have been extensively explored as photoelectrodes for solar-driven production of fuel due to their exceptional stability, semiconducting properties, abundance, and low cost. However, most metal oxides have absorption activity that is limited to the ultraviolet spectral region because of their wide band gap (\u3e 3.0 eV). This is inconvenient because the ultraviolet spectral region contains only 3-5% of all incident solar energy. The current semiconductor technologies resort to either (i) doping as a means of narrowing the band-gap and enhancing light absorption, or (ii) decoration with metals to enhance charge separation. In the first part of the thesis, the synthesis of highly ordered titanium oxynitride nanotube arrays sensitized with Ag nanoparticles (Ag/TiON) was studied for the first time. Ag/TiON proved to be an attractive class of materials for visible-light-driven water splitting. The nanostructure topology of TiO2, TiON and Ag/TiON was investigated using FESEM and TEM. The X-ray photoelectron spectroscopy (XPS) and the energy dispersive X-ray spectroscopy (EDS) analyses confirm the formation of the oxynitride structure. Upon their use to split water photoelectrochemically under AM 1.5 G illumination (100 mW/cm2, 0.1 M KOH), the titanium oxynitride nanotube array films showed significant increase in the photocurrent (6 mA/cm2) compared to the TiO2 nanotubes counterpart (0.15 mA/cm2). Moreover, decorating the TiON nanotubes with Ag nanoparticles (13 ±2 nm in size) resulted in exceptionally high photocurrent reaching 14 mA/cm2 at 1.2 VNHE. This enhancement in the photocurrent is related to the synergistic effects of Ag decoration, nitrogen doping, and the unique structural properties of the fabricated nanotube arrays. In the second part of the thesis, the effect of Ni alloying with Cu on the electrochemical reduction of CO2 was studied. The GAXRD analysis confirmed the formation of mixed Cu-Ni catalysts. Linear sweep scans showed the Cu70Ni30 to have the lowest overpotential (-0.5VNHE) and highest cathodic current (-1.8mA/cm2). Chronoamperometry measurements, at -0.5 VNHE in CO2-saturated 0.1M KOH, confirmed similar pattern when no limiting current was observed for the electrochemical reduction of CO2. This volcano effect of exceptionally high current and low overpotential was unique for 30% Ni and was attributed to CO2 adsorption and superior charge transfer kinetics

Language and social power

Unequal social relations and domination by individuals and groupings in a society can be created and maintained by violence. But this generally is inadequate for the legitimation of that situation or for the acquiescence of those less privileged; the maintenance of the inequality is affected by language, by devaluing the subjugated's language and by using language to create the impression of the legitimacy of the unequal relations. This study aims to explore some aspects of how language and specifically speech acts are structured to create unequal social relations and link this to discourse practices that maintain this inequality. Language is, however, not an inflexible medium; as it can be used to shape the subjugated's consciousness to regard the inequality as normal, it can also form and reflect a resistance consciousness. Language and power mesh in many ways. Chapter one will deal generally with issues of language and power relations in society. This dissertation hopes to focus on how ideology and power are present in and structured into utterances. Chapter two will show that the speech act theory can be extended to include ideological force or intent as part of a speech act. This intent is structured in the details of the utterance; and that will be the area of chapter three, which reviews the "critical linguistics" thinking around discourse analysis of manipulative intent; and the last chapter will focus on how language can be a means of resisting social domination and creating true consensus