Distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect

Conventional detection scheme for self-mixing sensors uses an integrated photodiode within the laser package to monitor the self mixing signal. This arrangement can be simplified by directly obtaining the self-mixing signals across the laser diode itself and omitting the photodiode. This work reports on a Vertical-Cavity Surface-Emitting Laser (VCSEL) based selfmixing sensor using the laser junction voltage to obtain the selfmixing signal. We show that the same information can be obtained with only minor changes to the extraction circuitry leading to potential cost saving with reductions in component costs and complexity and significant increase in bandwidth favoring high speed modulation. Experiments using both photo current and voltage detection were carried out and the results obtained show good agreement with the theory.

'Nothing good ever came out of Japan': Race-mixing and the limits of diaspora

This paper argues that postcolonial notions of diaspora are premised on immigrant subjectivities and standpoints which do not fully apprehend the mixed-race / bi-racial experience and the local effect of cultural hybridity in Western settings. The paper was prompted by a recent conversation with Dee, the daughter of a Japanese warbride. As a child Dee recalled being told by her friend's mother that 'nothing good ever came out of Japan'. The significance of constant interpolations into 'Asianness' by statements such as these; by the 'where do you come from?' question and by more blatant discriminations are inadequately addressed by traditional and postcolonial notions of diaspora. 'Roots' and 'routes' imagery feature prominently in discussions of diaspora and hybridity which aim to decolonise culture and identity in deconstructive moves that highlight their flexible, multiple, contractedness. While it has been argued that even these conceptualisations are problematic because they privilege orders of explanation, theory and standpoint that are forced back into line with traditional notions of discrete 'races', cultures, ethnicities and identities, cultural studies and postcolonial theorists do not appear to find this contradiction overly troubling. Lodged in bodies that do not easily conflate to neat either/or cultures, politics and genetics, race-mixing also defies and yet return us to culture and biology. However, I argue that their refractions though the same tired old orders of racial, ethnic, cultural and national differentiation prevent us from disregarding the discursive effects of racism and racialisation.

Spectroscopic analysis of terrestrial analogues for the interpretation of surface composition of rocky bodies in the solar system. Effects of mineral mixing and particle size. Applications to moon, mars and implications for mercury.

Among the Solar System’s bodies, Moon, Mercury and Mars are at present, or have been in the recent years, object of space missions aimed, among other topics, also at improving our knowledge about surface composition. Between the techniques to detect planet’s mineralogical composition, both from remote and close range platforms, visible and near-infrared reflectance (VNIR) spectroscopy is a powerful tool, because crystal field absorption bands are related to particular transitional metals in well-defined crystal structures, e.g., Fe2+ in M1 and M2 sites of olivine or pyroxene (Burns, 1993). Thanks to the improvements in the spectrometers onboard the recent missions, a more detailed interpretation of the planetary surfaces can now be delineated. However, quantitative interpretation of planetary surface mineralogy could not always be a simple task. In fact, several factors such as the mineral chemistry, the presence of different minerals that absorb in a narrow spectral range, the regolith with a variable particle size range, the space weathering, the atmosphere composition etc., act in unpredictable ways on the reflectance spectra on a planetary surface (Serventi et al., 2014). One method for the interpretation of reflectance spectra of unknown materials involves the study of a number of spectra acquired in the laboratory under different conditions, such as different mineral abundances or different particle sizes, in order to derive empirical trends. This is the methodology that has been followed in this PhD thesis: the single factors previously listed have been analyzed, creating, in the laboratory, a set of terrestrial analogues with well-defined composition and size. The aim of this work is to provide new tools and criteria to improve the knowledge of the composition of planetary surfaces. In particular, mixtures composed with different content and chemistry of plagioclase and mafic minerals have been spectroscopically analyzed at different particle sizes and with different mineral relative percentages. The reflectance spectra of each mixture have been analyzed both qualitatively (using the software ORIGIN®) and quantitatively applying the Modified Gaussian Model (MGM, Sunshine et al., 1990) algorithm. In particular, the spectral parameter variations of each absorption band have been evaluated versus the volumetric FeO% content in the PL phase and versus the PL modal abundance. This delineated calibration curves of composition vs. spectral parameters and allow implementation of spectral libraries. Furthermore, the trends derived from terrestrial analogues here analyzed and from analogues in the literature have been applied for the interpretation of hyperspectral images of both plagioclase-rich (Moon) and plagioclase-poor (Mars) bodies.

PÊNDULO ANCORADO EM MINI-IMPLANTES: AVALIAÇÃO DENTÁRIA E ESQUELÉTICA

O aparelho Pêndulo é eficaz na correção das más oclusões de Classe II, com comprometimento dentoalveolar superior. No entanto, a perda de ancoragem caracterizada pela mesialização dos pré-molares superiores, e pela vestibularização e protrusão dos incisivos superiores, constitui um grave efeito colateral deste dispositivo. O objetivo deste estudo foi avaliar as possíveis alterações dentárias e esquelética, sagitais e verticais, decorrentes do uso do Pêndulo modificado, ancorado em mini-implantes. Dez indivíduos foram tratados neste estudo, sendo que telerradiografias em norma lateral foram realizadas no início do tratamento, e imediatamente após a remoção do Pêndulo. Em cada indivíduo foram instalados dois mini-implantes no palato, que receberam carga imediata por meio da ativação do Pêndulo modificado, apoiado nestes dispositivos de ancoragem temporária. Nenhum dos dentes avaliados apresentou alterações verticais estatisticamente significantes; o mesmo ocorreu para as alterações esqueléticas verticais e sagitais, e para o trespasse vertical e horizontal. Com relação às alterações estatisticamente significantes, o primeiro molar superior moveu-se para distal aproximadamente 5,6mm em 6,2 meses, e com inclinação distal média de 7,100. Os segundos pré-molares superiores distalizaram em média 2,7mm e inclinaram 5,550; já os segundos molares superiores moveram-se em média 4,6mm para distal com uma inclinação de 13,700; valores estes também considerados estatisticamente significantes. O sistema de distalização de molares superiores, composto pelo Pêndulo modificado ancorado em mini-implantes, mostrou-se eficaz na correção da má oclusão de Classe II, sem produzir os efeitos de perda de ancoragem. (AU)

PÊNDULO ANCORADO EM MINI-IMPLANTES - ANÁLISE EM MODELOS DIGITAIS

A distalização dos molares superiores é uma opção de tratamento da má oclusão de Classe II, quando o envolvimento é principalmente dentoalveolar. Dispositivos intrabucais como o aparelho Pêndulo, dispensam a colaboração do paciente quanto ao uso, porém promovem efeitos muitas vezes indesejáveis como a vestibularização dos dentes anteriores que participam na ancoragem e a inclinação dos molares distalizados. Após o surgimento dos Dispositivos de Ancoragem Temporária (DATs), como o mini-implante pode-se alcançar a ancoragem de forma previsível e eficiente. Com isto, por meio de um estudo prospectivo, foram avaliadas as alterações dentárias, promovidas pela distalização de molares superiores com um aparelho Pêndulo modificado, apoiado em dois mini-implantes instalados no palato de 10 indivíduos, sendo 2 do sexo feminino e 8 do masculino, com média de idade de 14,3 anos. A amostra foi composta por 20 modelos digitalizados em 3D, obtidos de em duas fases: no início do tratamento (T1) e após distalização com sobrecorreção de 1 mm (T2), permitindo quantificar as alterações dentárias sagitais, transversais e possíveis movimentos de rotação, angulação e movimentos verticais. Os resultados obtidos mostraram que no sentido sagital, houve uma efetiva distalização com significância estatística, para os segundos molares superiores; primeiros molares superiores em média de 4,34 mm e 3,91mm para o lado direito e esquerdo, respectivamente, e para os segundos pré-molares do lado direito e esquerdo de 2,06 mm e 1,95 mm, respectivamente. Porém, para os dentes anteriores, foi constatada a perda de ancoragem. No sentido transversal, o maior aumento ocorreu na região dos dentes posteriores. Os movimentos de rotação, angulação e vertical dos primeiros molares superiores, indicam que houve rotação mesiovestibular e inclinação distal das coroas destes dentes de ambos os lados; as medidas verticais, demonstram que houve movimento significativo apenas para o primeiro molar direito, com inclinação distal pela intrusão da cúspide distal. Este dispositivo mostrou-se eficaz na correção da Classe II em um tempo médio de 6,2 meses.(AU)

Mixing the grant cocktail:towards an understanding of the outcomes of financial support to small firms

One of the key policy objectives of government at national and regional level, is to overcome the constraints preventing local industry achieving greater competitiveness in the international market-place. This paper examines the impact of grant assistance to Northern Ireland small firms delivered over the period 1994 ^ 97 by the former Local Enterprise Development Unit through its Growth Business Support Programme (GBSP). Previous work by the authors showed that there was some tentative evidence to suggest a link between employment growth and grant aid provided to very small firms (fewer than 10 employees) assisted under the GBSP. The central objective of the empirical work reported in this paper is to extend the previous analysis by understanding the extent to which the value of financial assistance influences growth (employment, turnover, and productivity measures) and if differential impacts arise depending on the nature and timing (lag structures) of the grant assistance.

Understanding mobile phone usage while driving:mini-bus and taxi drivers' experiences in Istanbul

In emerging markets, the amount of mobile communication and the number of occasions mobile phones are used are increasing. More and more settings appropriate or not for mobile phone usage are being exposed. Although prohibited by many governments, there is evidence that use of new mobile devices while driving are somehow becoming current everyday practice, hence legitimatizing usage for many users. Dominant dangerous behavior in the absence of enforced legal framework is being deployed and has become routine for many m-users. This chapter adopts a qualitative case study approach (20 cases) to examine the public transport drivers' motives, logic and legitimacy processes. The question which these issues raise in the light of advancing m-technologies is: How do, in the context of emerging market, undesired emerging routines enactment get to be reflected upon and voluntarily disregarded to maximize the benefits of m-technologies while minimizing their drawbacks? Findings point out at multiple motives for usage including external social pressure through the ubiquitous 24/7 usage of mtechnology, lack of alternative communication protocol, real time need for action and from an internal perspectives boredoms, lack of danger awareness, blurring of the boundaries between personal and business life and lack of job fulfillment are uncovered as key factors. As secondary dynamic factors such as education, drivers work' histories, impunity, lack of strong consumer opposition appear central in shaping the development of the routines. © 2011, IGI Global.