Atom cooling using the dipole force of a single retroreflected laser beam

We present a mechanism for cooling atoms by a laser beam reflected from a single mirror. The cooling relies on the dipole force and thus in principle applies to arbitrary refractive particles including atoms, molecules, or dielectric spheres. Friction and equilibrium temperatures are derived by an analytic perturbative approach. Finally, semiclassical Monte-Carlo simulations are performed to validate the analytic results.

Enhancing solar cells with localized plasmons in nanovoids

Localized plasmon resonances of spherical nanovoid arrays strongly enhance solar cell performance by a factor of 3.5 in external quantum efficiency at plasmonic resonances, and a four-fold enhancement in overall power conversion efficiency. Large area substrates of silver nanovoids are electrochemically templated through self-assembled colloidal spheres and organic solar cells fabricated on top. Our design represents a new class of plasmonic photovoltaic enhancement: that of localized plasmon-enhanced absorption within nanovoid structures. Angularly-resolved spectra demonstrate strong localized Mie plasmon modes within the nanovoids. Theoretical modelling shows varied spatial dependence of light intensity within the void region suggesting a first possible route towards Third Generation plasmonic photovoltaics. (C) 2011 Optical Society of America

The Terror that Underpins the “Peace”: The Political Economy of Colombia's Paramilitary Demobilization Process

Studies on terrorism have traditionally focused on non-state actors who direct violence against liberal states. These studies also tend to focus on political motivations and, therefore, have neglected the economic functions of terrorism. This article challenges the divorce of the political and economic spheres by highlighting how states can use terrorism to realise interconnected political and economic goals. To demonstrate this, we take the case of the paramilitary demobilisation process in Colombia and show how it relates to the US-Colombian free trade agreement. We argue that the demobilisation process fulfils a dual role. First, the process aims to improve the image of the Colombian government required to pass the controversial free trade agreement through US Congress to protect large amounts of US investment in the country. Second, the demobilisation process serves to mask clear continuities in paramilitary terror that serve mutually supportive political and economic functions for US investment in Colombia.

Family, state, class and solidarity: re-conceptualising intergenerational solidarity through the grounded theory approach

The relationship between class and intergenerational solidarities in the public and private spheres calls for further conceptual and theoretical development. This article discusses the findings from the first wave of a qualitative longitudinal study entitled Changing Generations, conducted in Ireland in 2011–2012, comprising 100 in-depth interviews with men and women across the age and socioeconomic spectrums. Constructivist grounded theory analysis of the data gives rise to the following postulates: (1) intergenerational solidarity at the family level is strongly contoured by socioeconomic status (SES); (2) intergenerational solidarity evolves as family generations observe each others’ practices and adjust their expectations accordingly; (3) intergenerational solidarity within families is also shaped by the public sphere (the welfare state) that generates varying expectations and levels of solidarity regarding State supports for different age groups, again largely dependent on SES; (4) the liberal welfare state context, especially at a time of economic crisis, enhances the significance of intergenerational solidarity within families. We conclude by calling for research that is attuned to age/generation, gender and class, and how these operate across the family and societal levels.

Mechanical properties of polyamide 6 reinforced microfibrilar composites

The mechanical behavior of microfibrilar composites (MFC), consisting of a matrix of high-density polyethylene (HDPE) and reinforcement of polyamide 6 (PA6) fibrils, with and without compatibilization, was studied. The composites were produced by conventional processing techniques with various shape and arrangement of the PA6 reinforcing entities: long, unidirectional, or crossed bundles of fibrils (UDP and CPC, respectively), middle-length, randomly oriented bristles (MRB), or non-oriented micrometric PA6 spheres (NOM). The tensile, flexural, and impact properties of the MFC materials (UDP, CPC, and MRB) were determined as a function of the PA6 reinforcement shape, alignment and content, and compared with those of NOM, the non-fibrous composite. It was concluded that the in-situ MFC materials based on HDPE/PA6 blends display improvements in the mechanical behavior when compared with the neat HDPE matrix, e.g., up to 33% for the Young modulus, up to 119% for the ultimate tensile strength, and up to 80% for the flexural stiffness. Copyright © 2011 Society of Plastics Engineers.

Beyond Individualism: Social Work and Social Identity

Individualism continues to have a notable impact on social work. The personalisation of services and the individualisation of care are just two examples of this societal trend. While helping service users to articulate their aspirations for a better future, individualism, if taken too far, undermines the social aspects of life. In response to this concern, this paper argues that social work must appreciate the interplay between the individual and the collective spheres, and its impact on identity formation, in order to enhance human well-being. To give substance to this argument, Jenkins's model of social identity is appropriated and augmented to take account of four interlinked, yet distinct, orders of experience, namely the individual, interactional, institutional and societal orders. This reworked conceptualisation is then considered in terms of its implications for social work practice.

Clarifying the acquis humanitaire: a transnational legal perspective on the internalization of humanitarian norms

Although the international obligations and institutional frameworks for disaster response are not yet settled, as evidenced by the International Law Commission’s work on the protection of persons in the event of disasters and the on-going promotion of disaster laws by the Red Cross Movement; the diverse source and nature of such initiatives suggests that the international community is engaged in a process of norm creation, elaboration and interpretation reflecting a desire for legal clarity in humanitarian operations. Situated within the framework of transnational law, this paper argues that an acquis humanitaire, based on the principle of humanity, encapsulates the evolving body of law and practice specifically relating to the protection of persons in times of humanitarian crisis in both armed conflicts and natural or human-made disasters. Reflecting the non-traditional, non-statist, dynamic and normative basis of transnational legal process, as elaborated by Harold Koh, the constant flow of ideas and principles between the national, regional and international spheres provides an analytical framework for the on-going transnational dialogues on the social, political and legal internalization of humanitarian norms. Drawing on the internalization of humanitarian norms within the United Kingdom, this paper concludes that as the international community examines the codification of a universal legal framework for the protection of persons in the event of disasters it is necessary to understand the transnational process of interpretation and internalization of humanitarian norms, and how this may vary across different regions and countries.

Polymeric materials based on silk proteins

Silks are protein-based fibers made by arthropods for a variety of task-specific applications. In this article, we review the key features of silk proteins. This article initially focuses on the structure and function of silk proteins produced naturally by silkworms and spiders, followed by the biological and technical processing of silk proteins into a variety of morphologies (including capsules, fibers, films, foams, gels and spheres). Finally, we highlight the potential applications of silk-based materials. 

Reducing Child Protection Error in Social Work: Towards an Holistic-Rational Perspective

Social work in the United Kingdom remains embroiled in concerns about child protection error. The serious injury or death of vulnerable children continues to evince much consternation in the public and private spheres. Governmental responses to these concerns invariably draw on technocratic solutions involving more procedures, case management systems, information technology and bureaucratic regulation. Such solutions flow from an implicit use of instrumental rationality based on a ‘means-end’ logic. While bringing an important perspective to the problem of child protection error, instrumental rationality has been overused limiting discretion and other modes of rational inquiry. This paper argues that the social work profession should apply an enlarged form of rationality comprising not only the instrumental-rational mode but also the critical-rational, affective-rational and communicative-rational forms. It is suggested that this combined, conceptual arsenal of rational inquiry leads to a gestalt which has been termed the holistic-rational perspective. It is also argued that embracing a more rounded perspective such as this might offer greater opportunities for reducing child protection error.

The importance of oral health for the systemic well being of an ageing population

The proportion of adults over the age of 60 years is expanding rapidly across European Union countries, including the Republic of Ireland. As the older population has grown faster than the total population, the proportion of older persons relative to the rest of the population has increased considerably (Figure 1). This trend mirrors the arrival of the “baby boomer� generation into early old age and will have wide ranging effects on social, political and economic spheres as well as presenting significant challenges for healthcare delivery and public healthcare policy.

A Constitution of Social Governance for the European Union

This chapter considers the EU’s socio-economic constitution under the lens of humaneness. It argues that the EU’s unique socio-economic constitution demands equilibrium of socio-economic integration instead of widening the gap between economic integration at EU levels and social integration at national levels. While the EU lacks the legislative competences to achieve this equilibrium, the constitutional principle still prevails. Indeed, the EU competences reflect its own values as well as the socio-economic constitutions of its constituent Member States. These frequently do not allow for total state-governance of social spheres such as working life, education, care or other social services. Instead, societal actors are given scope to (co-)govern these spheres at national levels. Accordingly, the apparent tension between the EU’s socio-economic values and principles and its limited competences in the social policy field can be resolved through a dynamic interpretation of the EU Treaties towards a “constitution of social governance”. This interpretation reads the Treaties as authorising governance by societal actors. The chapter connects the idea of humanness to the ideals of social governance at EU level and proposes two options for practical application of the concept. These are rules for trans-national labour markets based on European collective labour agreements and a European higher education sector developed by agreements between universities.

Photocatalytic degradation of eleven microcystin analogues and nodularin by TiO2 coated glass microspheres

Microcystins and nodularin are toxic cyanobacterial secondary metabolites produced by cyanobacteria that pose a threat to human health in drinking water. Conventional water treatment methods often fail to remove these toxins. Advanced oxidation processes such as TiO2 photocatalysis have been shown to effectively degrade these compounds. A particular issue that has limited the widespread application of TiO2 photocatalysis for water treatment has been the separation of the nanoparticulate power from the treated water. A novel catalyst format, TiO2 coated hollow glass spheres (Photospheres���), is far more easily separated from treated water due to its buoyancy. This paper reports the photocatalytic degradation of eleven microcystin variants and nodularin in water using Photospheres���. It was found that the Photospheres��� successfully decomposed all compounds in 5 minutes or less. This was found to be comparable to the rate of degradation observed using a Degussa P25 material, which has been previously reported to be the most efficient TiO2 for photocatalytic degradation of microcystins in water. Furthermore, it was observed that the degree of initial catalyst adsorption of the cyanotoxins depended on the amino acid in the variable positions of the microcystin molecule. The fastest degradation (2 minutes) was observed for the hydrophobic variants (microcystin-LY, -LW, -LF). Suitability of UV-LEDs as an alternative low energy light source was also evaluated.

John Punch, Scotist Holy War, and the Irish Catholic Revolutionary Tradition in the Seventeenth Century

During the 1640s, the Irish Franciscan theologian John Punch taught his theology students in Rome that war against Protestants was made just by their religion alone. Jesuits like Luis de Molina identified the holy war tradition in which Punch stood as a Scotist one, and insisted that the Scotists had confused the natural and supernatural spheres. Among Irishmen, Punch was unusual. The main Irish Catholic revolutionary tradition employed Jesuit and Thomist theory. They argued that the Stuarts had lost the right to rule Ireland for natural reasons, not supernatural ones; because the Stuarts were tyrants, not because they were Protestants.

A Constitution of Social Governance for the European Union

his chapter considers the EU’s socio-economic constitution under the lens of humaneness. It argues that the EU’s unique socio-economic constitution demands equilibrium of socio-economic integration instead of widening the gap between economic integration at EU levels and social integration at national levels. While the EU lacks the legislative competences to achieve this equilibrium, the constitutional principle still prevails. Indeed, the EU competences reflect its own values as well as the socio-economic constitutions of its constituent Member States. These frequently do not allow for total state-governance of social spheres such as working life, education, care or other social services. Instead, societal actors are given scope to (co-)govern these spheres at national levels. Accordingly, the apparent tension between the EU’s socio-economic values and principles and its limited competences in the social policy field can be resolved through a dynamic interpretation of the EU Treaties towards a “constitution of social governance”. This interpretation reads the Treaties as authorising governance by societal actors. The chapter connects the idea of humanness to the ideals of social governance at EU level and proposes two options for practical application of the concept. These are rules for trans-national labour markets based on European collective labour agreements and a European higher education sector developed by agreements between universities.

Nanocomposites for SERS : synthesis, optical and analytical studies

Esta tese descreve diversas estratégias preparativas assim como estudos de caracterização de nanocompósitos e outras nanoestruturas, para a análise em espectroscopia de Raman com intensificação por superfície (SERS). Em particular foi estudada a incorporação de nanopartículas (NPs) metálicas de Ag e Au em matrizes poliméricas visando avaliar o potencial destes materiais como novos substratos para SERS na deteção de moléculas. O primeiro capítulo consiste numa revisão bibliográfica, onde é destacado o desenvolvimento de novos substratos para SERS utilizando nomeadamente nanopartículas de Ag, Au e Cu. Numa primeira fase, esta secção apresenta uma breve descrição sobre as propriedades plasmónicas dos metais utilizados e alguns conceitos básicos de espectroscopia de difusão de Raman. Posteriormente, descreve-se em mais detalhe o efeito de SERS, revendo-se sobretudo a química de materiais descrita em trabalhos recentes tendo em conta a sua utilização como novas plataformas para análise química por SERS. O capítulo 2 descreve a síntese e caracterização de nanocompósitos de poli(acrilato de butilo) obtidos através de polimerização in situ por miniemulsão na presença de nanopartículas de Ag. Os nanocompósitos Ag/PtBA foram investigados como novos substratos de SERS visando o desenvolvimento de novas plataformas versáteis para deteção molecular. Estudos como o efeito da temperatura, pH e pressão foram investigados, visando a compreensão do efeito da matriz polimérica na difusão/adsorção do analito (ácido tiossalicílico) na superfície metálica. No capítulo 3, os nanocompósitos de Ag/PtBA descritos anteriormente foram investigados detalhadamente como substratos para bio-deteção em SERS, usando a adenina como analito modelo. Os nanocompósitos foram submetidos a vários tratamentos pré-analíticos para a bio-deteção da adenina. Foram realizadas experiências nos sistemas Ag/PtBA de modo a obter informação sobre o efeito do pH na deteção deste analito em soluções aquosas diluídas. Os nanocompósitos poliméricos obtidos apresentam a vantagem de poderem ser processados utilizando tecnologia disponível. Pelo que o estudo das suas propriedades térmicas é especialmente relevante. Assim, a influência da incorporação de NPs inorgânicas na temperatura de transição vítrea (Tg) do polímero PtBA foi investigada por meio de calorimetria diferencial de varrimento (DSC) e os resultados são apresentados no capítulo 4. Estes estudos descrevem efeitos na Tg do PtBA quando analisado em nanocompósitos obtidos por diferentes métodos (métodos ex situ e in situ), contendo nanopartículas metálicas com diferentes distribuições de tamanho e presentes em quantidade variável na matriz polimérica. Estes estudos possibilitaram relacionar a influência das NPs metálicas na mobilidade das cadeias poliméricas com as propriedades térmicas observadas. O capítulo 5 descreve a preparação e caracterização de materiais compósitos de base polimérica (PtBA) e NPs de Au com morfologia de bastonetes (NRs). Estes materiais foram investigados como substratos para SERS tendo originado um bom sinal de SERS na análise de 2-2’-ditiodipiridina. Investigouse igualmente o efeito da variação da morfologia das NPs metálicas (esferas e bastonetes), a razão de aspecto (R.A.) dos bastonetes e o tipo de matriz polimérica (PtBA e PnBA) no sinal de SERS. No capítulo 6 é descrita a utilização da técnica de SERS como método alternativo para a monitorização de alterações morfológicas de coloides de NRs de Au. Os NRs de Au foram recolhidos em diferentes fases de oxidação promovida pela presença de K2S2O8 e a sua sensibilidade como substratos de SERS foi avaliada utilizando o anião dietilditiocarbamato (DTC) como analito modelo. Os estudos foram realizados utilizando as linhas de excitação a 1064 nm e 633 nm. Este estudo demonstrou que a sensibilidade dos NRs de Au como substratos de SERS diminui à medida que a sua R.A. diminui devido à competitividade do CTAB (estabilizante) e o DTC pela superfície dos NRs. É de salientar que este processo é acompanhado por um diferente comportamento em termos de adsorção dos dois tautómeros do DTC à superfície do metal. O capítulo 7 introduz um novo tipo de compósitos para SERS, utilizando matrizes biopoliméricas. Assim, descreve-se a preparação e caracterização de nanocompósitos de carragenano e NPs de Ag. Nesta secção é avaliada a utilização destes materiais como novos substratos para a análise em SERS, utilizando a 2-2’-ditiodipiridina como molécula modelo. Descrevem-se estudos pioneiros que procuram relacionar a dependência do sinal de SERS com a força do gel. Para tal, realizou-se um estudo sistemático aos nanobiocompósitos usados como substratos de SERS em diferentes condições analíticas e investigaram-se as suas propriedades reológicas. No capitulo 8 é descrita a investigação de nanocompósitos de Ag/Gelatina como substratos para SERS, utilizando o anião dietilditiocarbamato como analito modelo. Realizaram-se várias experiências para correlacionar a variação da força do gel com o aumento do sinal de SERS bem como a diferente adsorção dos dois tautómeros do DTC à superfície do metal. Ao longo desta dissertação são apresentados metodologias distintas para a preparação e obtenção de nanocompósitos com base em polímeros (sintéticos ou naturais) e NPs metálicas (Ag e Au). Esta investigação não só permitiu a síntese e estudo de novos substratos para SERS mas também a compreensão do efeito matriz/NPs metálicas no sinal de SERS e na formação de “hot spots”. Este trabalho contribui para o enriquecimento na área da Nanociência e Nanotecnologia demonstrando a eficácia e reprodutibilidade de nanocompósitos com base em polímeros como novos substratos para SERS. Embora as propriedades óticas apresentadas por estes materiais serem aqui direcionadas para a deteção molecular pela técnica de SERS, estes materiais podem ser investigados em outras área tecnológicas.