Theo Gavrielides, Waves of healing: using restorative justice for street group violence

Abstract included in tex

Coexisting periodic attractors in injection locked diode lasers

We present experimental evidence for coexisting periodic attractors in a semiconductor laser subject to external optical injection. The coexisting attractors appear after the semiconductor laser has undergone a Hopf bifurcation from the locked steady state. We consider the single mode rate equations and derive a third order differential equation for the phase of the laser field. We then analyze the bifurcation diagram of the time periodic states in terms of the frequency detuning and the injection rate and show the existence of multiple periodic attractors.Comment: LaTex, 14 pages, 6 postscript figures include

Deconstructing ‘justice’ and reconstructing ‘fairness’ in a convergent European justice system: an Aristotelian approach to the question of representation of justice in Europe

‘Justice’ is spoken of in two ways: the lawful and the fair. The law is a human construct that is devoted to the advantage of all, or to the advantage of the best, or to the advantage of those in power or to the advantage of those representing it – let it be the politician, the media, the TV presenter, the filmmaker. Thus, the law serves the production or the preservation of happiness within politics and business. The law commands us to act according to the mean. A well-written law follows the mean well and a poorly written law does not. On the other hand, fairness is a principle sometimes materialised through the law and the given justice system. Fairness is the ultimate value pursued by both the common law and civil law traditions. However, its distribution through the law and the representation of this delivery varies. Does this mean that a different kind of justice is distributed? Through the teachings of Aristotle, this essay aims to deconstruct the notion of justice, by breaking down its two ingredients, the lawful and the fair, and by analysing the effect of their representation in modern European society. The relativity attached to the notion of justice is not a modern phenomenon, but a philosophical matter that can be analysed and indeed explained through the teachings of Aristotle and its contemporary students. The analysis will be developed in the context of convergent Europe, focusing on the role of the media and courts especially in relation to criminal justice

Analytical theory of external cavity modes of a semiconductor laser with phase conjugate feedback

SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Restorative justice: the perplexing concept. Conceptual fault lines and power battles within the restorative justice movement

Although the fast-growing literature on restorative justice is extensive, and in some regards repetitive, there is still no consensus as to the nature and extent of applicability of the restorative notion. This article claims that the restorative movement is experiencing a tension between normative abolitionist and pragmatic visions of restorative justice. It proceeds to identify six conceptual fault-lines that characterize this tension. These do not only refer to various definitional positions, but also disagreements that negatively affect both the theoretical and practical development of restorative justice. These tensions also encourage a power-interest battle between different stakeholders within the restorative movement including practitioners, theoreticians, researchers and policy makers. To approach these controversies, there needs to be an acknowledgment of the multidimensional nature of the conceptual problem of restorative justice and the impact it has on its application. The article attempts to get to grips with this problem, and provide a common ground for the future development of restorative justice

Volumetry of low-contrast liver lesions with CT: Investigation of estimation uncertainties in a phantom study

Purpose: To evaluate the performance of lesion volumetry in hepatic CT as a function of various imaging acquisition parameters. Methods: An anthropomorphic abdominal phantom with removable liver inserts was designed for this study. Two liver inserts, each containing 19 synthetic lesions with varying diameter (6–40 mm), shape, contrast (10–65 HU), and both homogenous and mixed-density were designed to have background and lesion CT values corresponding to arterial and portal-venous phase imaging, respectively. The two phantoms were scanned using two commercial CT scanners (GE 750 HD and Siemens Biograph mCT) across a set of imaging protocols (four slice thicknesses, three effective mAs, two convolution kernels, two pitches). Two repeated scans were collected for each imaging protocol. All scans were analyzed using a matched-filter estimator for volume estimation, resulting in 6080 volume measurements across all of the synthetic lesions in the two liver phantoms. A subset of portal venous phase scans was also analyzed using a semi-automatic segmentation algorithm, resulting in about 900 additional volume measurements. Lesions associated with large measurement error (quantified by root mean square error) for most imaging protocols were considered not measurable by the volume estimation tools and excluded for the statistical analyses. Imaging protocols were grouped into distinct imaging conditions based on ANOVA analysis of factors for repeatability testing. Statistical analyses, including overall linearity analysis, grouped bias analysis with standard deviation evaluation, and repeatability analysis, were performed to assess the accuracy and precision of the liver lesion volume biomarker. Results: Lesions with lower contrast and size ≤10 mm were associated with higher measurement error and were excluded from further analysis. Lesion size, contrast, imaging slice thickness, dose, and scanner were found to be factors substantially influencing volume estimation. Twenty-four distinct repeatable imaging conditions were determined as protocols for each scanner with a fixed slice thickness and dose. For the matched-filter estimation approach, strong linearity was observed for all imaging data for lesions ≥20 mm. For the Siemens scanner with 50 mAs effective dose at 0.6 mm slice thickness, grouped bias was about −10%. For all other repeatable imaging conditions with both scanners, grouped biases were low (−3%–3%). There was a trend of increasing standard deviation with decreasing dose. For each fixed dose, the standard deviations were similar among the three larger slice thicknesses (1.25, 2.5, 5 mm for GE, 1.5, 3, 5 mm for Siemens). Repeatability coefficients ranged from about 8% to 75% and showed similar trend to grouped standard deviation. For the segmentation approach, the results led to similar conclusions for both lesion characteristic factors and imaging factors but with increasing magnitude in all the error metrics assessed. Conclusions: Results showed that liver lesion volumetry was strongly dependent on lesion size, contrast, acquisition dose, and their interactions. The overall performances were similar for images reconstructed with larger slice thicknesses, clinically used pitches, kernels, and doses. Conditions that yielded repeatable measurements were identified and they agreed with the Quantitative Imaging Biomarker Alliance’s (QIBA) profile requirements in general. The authors’ findings also suggest potential refinements to these guidelines for the tumor volume biomarker, especially for soft-tissue lesions

Routledge International Handbook of Restorative Justice

This up-to-date resource on restorative justice theory and practice is the literature’s most comprehensive and authoritative review of original research in new and contested areas. Bringing together contributors from across a range of jurisdictions, disciplines and legal traditions, this edited collection provides a concise, but critical review of existing theory and practice in restorative justice. Authors identify key developments, theoretical arguments and new empirical evidence, evaluating their merits and demerits, before turning the reader’s attention to further concerns informing and improving the future of restorative justice. Divided into four parts, the Handbook includes papers written by leading scholars on new theory, empirical evidence of implementation, critiques and the future of restorative justice. This companion is essential reading for scholars of restorative justice, criminology, social theory, psychology, law, human rights and criminal justice, as well as researchers, policymakers, practitioners and campaigners from around the world

Modélisation du poly-époxy DGEBA-EDA et de sa réactivité vis-à-vis du cuivre : approche expérimentale et numérique

Grâce à la métallisation de leur surface, des pièces en polymères peuvent substituer certains composants métalliques dans les industries de l'aérospatiale et du transport. Les polymères ont des masses volumiques plus faibles que les métaux et une réactivité chimique limitée, ce qui en fait des candidats idéaux pour les applications spatiales. En combinant techniques expérimentales et simulations numériques, nous avons étudié les mécanismes fondamentaux de la métallisation de surface d'un polymère poly-époxy (DGEBA / EDA). L'objectif de notre étude était de développer un modèle non empirique prenant en compte les mécanismes régissant la nucléation et la croissance des films minces métalliques. Notre groupe a une longue expérience des dépôts chimiques en phase vapeur, CVD. Mais cette technique n'a pas été choisie pour la métallisation de nos surfaces de polymères car les températures requises dans le réacteur étaient trop élevées. Comme alternative, nous avons effectué une évaporation sous ultravide de Cu à température ambiante, conduisant à une diffusion des atomes en phase gazeuse sans énergie cinétique. Les processus d'adsorption et de diffusion sont donc plus proches des conditions thermodynamiques associées aux calculs. Un protocole expérimental a été mis en place afin de créer une surface polymère chimiquement homogène présentant une faible rugosité. Le polymère obtenu a été caractérisé (i) par spectroscopie infrarouge à transformée de Fourier, pour déterminer le taux de polymérisation (supérieur à 90%), (ii) par calorimétrie différentielle à balayage pour obtenir la température de transition vitreuse (Tg) ( 118,1 °C), (iii) par microscopie à force atomique (AFM) pour estimer la rugosité de la surface (Ra ˜ 1 nm), et (iv) par spectroscopie de photoélectrons X (XPS) pour caractériser les liaisons chimiques de surface. La surface de polymère a ensuite été métallisée. Grâce à des analyses AFM, l'épaisseur du film mince a été estimée à 6 nm. Nous avons ensuite utilisé l'XPS pour caractériser les liaisons interfaciales Cu / Poly-époxy. Nous avons déduit de l'interprétation des spectres XPS que le Cu est adsorbé préférentiellement sur un atome d'oxygène spécifique du polymère. Pour identifier clairement ces sites d'adsorption de Cu, nous avons ensuite simulé les spectres XPS du polymère non revêtu, par des calculs quantiques, en utilisant un modèle moléculaire (dimère : 1 molécule de DGEBA liée à 1 molécule d'EDA). Les méthodes Hartree-Fock (HF) et de la théorie de la fonctionnelle de la densité (DFT) nous ont permis de simuler des spectres XPS pour la surface nue, en prenant en compte les effets d'état final et initial. Grâce à ces résultats, nous avons pu décomposer le spectre expérimental en 8 contributions, ce qui conduit à des résultats beaucoup plus précis que les résultats habituels obtenus par l'utilisation exclusive des expériences et de la littérature. Nous avons ensuite effectué des simulations de dynamique moléculaire classique (MD) pour passer d'un modèle moléculaire (dimère) à un modèle de polymère amorphe. Nous avons utilisé le champ de force Amber généralisé (GAFF) et nous avons développé un code de réticulation des molécules de monomères. Le système initial était un mélange stœchiométrique de molécules DGEBA et EDA qui a été équilibré à 700K. Lorsque l'équilibre a été atteint, certaines propriétés structurales (par exemple, la distribution des liaisons) ont été extraites des simulations NPT. À partir de ce mélange liquide de monomères, notre code de réticulation a identifié et relié les atomes réactifs (à une distance interatomique prédéfinie < 3 Å). Après chaque étape de polymérisation, le système a été rééquilibré à 700K (simulations NPT). Après plusieurs cycles de réticulation/simulation de dynamique moléculaire, nous avons pu atteindre un taux de polymérisation de 93% et la fonction de distribution radiale (RDF), la masse volumique (1.115 à 300K) et la température de transition vitreuse Tg (115,5 °C) ont été calculées. La Tg est en accord avec la valeur expérimentale de 118,1 °C, validant notre approche numérique pour développer un modèle pour les polymères poly-époxy.Metallization of polymer surfaces can lead to the substitution of metallic components. Polymers have lower densities and limited chemical reactivity, making them ideal candidates for the space applications. Through experiments and calculations, we studied the fundamental mechanisms of surface metallization of a poly-epoxy polymer (DGEBA/EDA). The objective of our study was to develop a non-empirical model that could take into account the mechanisms governing the nucleation and growth of thin metal films. Our group has a long experience in chemical vapor deposition, CVD, and metallization of polymer composites. But we did not applied CVD at first because of the high temperatures required in the reactor. We alternatively used ultrahigh vacuum evaporation of Cu at ambient temperature. Therefore, we make sure that atoms diffuse in the gas phase without kinetic energy. Adsorption and diffusion processes are thus closer to thermodynamic conditions that prevails in calculations. An experimental protocol was refined in order to create a chemically homogeneous polymer surface with a low roughness (Ra<1nm). The bulk and the surface of the pristine polymer were characterized (i) by Fourier Transform Infrared Spectroscopy, to determine the polymerization rate (above 90%), (ii) by differential scanning calorimetry in order to obtain the glass transition temperature (Tg) (118.1 °C), (iii) by atomic force microscopy (AFM) to calculate surface roughness (Ra ˜ 1 nm), and (iv) by X-ray photoelectron spectroscopy (XPS) to characterize surface chemical bonding. The surface was then metallized. Through AFM, the thickness of the thin film was estimated at 6 nm. We then used XPS to characterize the Cu/Poly-epoxy interfacial bonding. We deduced that Cu adsorbed preferentially on a specific oxygen atom of the polymer. To clearly identify this Cu adsorption site, we further simulated the XPS spectra of our clean or metallized polymer by quantum calculations, using a dimer model (1 molecule of DGEBA connected to 1 molecule of EDA). In the Hartree-Fock (HF) and Density Functional Theory (DFT) framework, we first simulated the XPS spectra for the pristine surface taking into account initial and final state effects. Thanks to these results, we were able to analyze the experimental spectrum with 8 contributions, leading to much more accurate results than the usual results obtained by the exclusive use of experiments and literature. We then performed classical Molecular Dynamics (MD) simulations to move from a dimer model to an amorphous polymer model. We used the general Amber force field (GAFF) and we developed a code to mimic the reticulation of monomers molecules. We started from a stoichiometric mixture of DGEBA and EDA molecules. When equilibration was reached, structural properties at 700K (e.g. distribution of bonds) were extracted from the results of the NPT simulations. From this melt of monomers, the homemade reticulation code identified and connected reactive atoms (at a pre-defined inter-atomic distance < 3Å). After each step of polymerization, the system was equilibrated at 700K (NPT simulations). After multiple reticulation/MD cycles we could achieve a polymerization rate of 93% and the Radial Distribution Function (RDF), the density and the glass transition temperature Tg were calculated. The value of the computed density was 1.115 at 300K and the calculated Tg (115.5 °C) was in good agreement with the experimental Tg of 118.1 °C, validating our numerical approach to develop a model for poly-epoxies

Hierarchical 1-3D titania Hyper-Branched Nanorods (HBNs) thin films for photocatalytic CO2 utilisation applications

Despite our efforts, the concentration of CO2 in the atmosphere is constantly rising at an alarming rate. It is of paramount importance to develop technologies that will expedite the reduction of the rate that CO2 is released into the atmosphere. CO2 utilisation technologies consider CO2 as a valuable carbon building block in a circular carbon economy approach, where the released CO2 is captured, and utilised to produce valuable chemicals. One of these technologies is the photocatalytic utilisation of CO2 for the production of solar fuels and value added chemicals, which has the added advantage of utilising light with mild reaction conditions. However, photocatalysis is limited to the absorbed light energy and CO2 is a very stable molecule which requires a large amount of energy for its conversion. Therefore, designing highly efficient materials as photocatalysts becomes a very important task. The current thesis is concerned with the growth of titania 1-3D hierarchical hyperbranched nanorods (HBNs) on fluorine-doped tin oxide (FTO) conductive glass as thin films to be used as photocatalysts for CO2 reduction reactions. This thesis is focused on investigating the capabilities and photocatalytic behaviour of the titania HBNs material. The HBNs were found to have improved light harvesting when compared to Degussa P25 TiO2 (48.2 to 28.6 μmol m 2 s -1 ), attributed to their 1-3D morphology. P25 is a blend of mainly anatase and traces of rutile phase TiO2, commonly used as a benchmark for photocatalytic applications. P25 was supported on FTO glass and its performance was compared with that of FTO supported HBNs. This thesis is presented as a collection of published bodies of work, where the HBNs are characterised, modified and tested in photocatalytic reactions. In more detail, two reactions are presented, firstly the CO2 photoreduction to produce solar fuels such as CH4 and CO. The HBNs were found to have superior conversion rates (up to 8.7 μmol gcat -1 h -1 ) compared to P25 (6.9 μmol gcat -1 h -1 ) but, more importantly, offer the ability to shift the selectivity of the reaction product from CO to CH4, utilising a facile phase altering treatment. Additionally, the HBNs were loaded with CuO and RuO2 and their performance was investigated and compared. CuO has shown the ability to improve the optical properties of the material, while RuO2 exhibited improved charge separation and suppressed the recombination rate, which led to further improvement in the photocatalytic performance. The second reaction is the CO2 cycloaddition to epoxides, for the photogeneration of cyclic carbonates, which are primarily used as electrolytes in Li-ion batteries amongst others. In the current thesis it is demonstrated that a photocatalytic approach is possible for this reaction. Additionally, RuO2-HBNs are shown to be the best performing photocatalyst in terms of conversion. The main appeal of the photocatalytic approach is the significantly milder reaction conditions (below 55 °C and 200 kPa) when compared to the conditions currently being used in the industry (100-200 °C and 5- 10 MPa).Heriot-Watt University fundin