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Contrary to the idea that ‘Brexit means Brexit’, the article demonstrates that, in spite of leaving the Area of Freedom, Security and Justice, the UK is not automatically seeking to distance itself from the EU’s activities and approaches to these policy fields. Using the concepts of disengagement, continued engagement and re-engagement and drawing from historical institutionalism, the article further clarifies that present and future trajectories of UK positions in respect of the EU action are conditioned by a path dependence created by the evolution of UK opt-ins and opt-outs in this field, by the politicisation of the Brexit negotiations in the context of the UK–EU relations and by domestic UK politics. We explore this argument across three policy areas: (1) police and judicial cooperation, (2) immigration, borders and asylum, and (3) cybersecurity.

What is the impact of the UK’s withdrawal from the EU on British policies, polity and politics and their future trajectories? This question has been overlooked so far, as many observers have focused on the identity, cultural, and political reasons behind the Brexit vote or scrutinized closely the process of withdrawal. The de-Europeanization literature has tried to capture the new dynamics behind the impact of Brexit on the domestic scene by understanding it as a will to dismantle policies and politics previously Europeanized. On the contrary, we argue here that Brexit is not necessarily the end of UK’s engagement with the EU. This editorial and this special issue provide a more nuanced explanation and support the idea that Brexit is not putting an end to the EU’s influence over British public policies. In fact, we identify several pathways to the EU–UK relationship which can be conceptualized along a continuum from de-Europeanization to re-engagement scenarios. Building on the literature that has suggested the trajectories of disengagement and de-Europeanization, this editorial more specifically contributes to the debate by coining the concept of continued engagement and re-engagement and highlighting the need to analyse British politics, policies, and polity in relation to the EU through a variety of pathways.

This article develops a timely new model for EU foreign policy by advancing the call for a ‘decentring agenda’, focused on the challenge of inclusive ‘reconstruction’. It does so by first staking out an ontological space at the intersection of empirical multiplexity and normative pluriversality. Within this space, it proposes an ethically informed methodological tool: the contrapuntal negotiation of dissonant perspectives on common governance challenges. It then suggests ways to reconstruct analytical and policy-making processes and outcomes on the basis of mutuality and local empowerment. Using three scales of ‘contrapuntality’ (micro, meso and macro) to read key empirical sites at the intersection of the EU's internal and external policies (migration, religious and neighbourhood governance), it argues that by decentring in these and further arenas, the EU can seek to become a more reflexive global actor in sync with the ethical and practical demands of our multiplex world.

Forest certification has become a strategic instrument for businesses, particularly for accessing sensitive envi-ronmental markets and within sustainability commitments. This trend is also visible in Spain, where PEFC (Program for the Endorsement of Forest Certification) certification has increased by 91% in the past five years. However, there is a weak understanding of the certification impacts at the level of companies, especially when it comes to economic impacts. This study applies a longitudinal methodology to measure financial performance before and after obtaining PEFC-certification in Spain by analysing treatment and selection effects. The results show significant differences in economic profitability and turnover between certified and non-certified com-panies prior to certification. However, these differences are not significant in subsequent periods. Therefore, we could not confirm a treatment effect between forest certification and improved financial performance. Instead, we find a positive selection effect: companies with better financial performance have a greater propensity for certification, as has been previously detected for standards such as ISO 9001/14001. Compared to previous studies that predominantly assess economic impacts qualitatively, we use economic-financial data to avoid possible distortion emerging from perceptions and opinions. The main contribution of this study lies in the quantitative assessment of the impacts of forest certification on economic profitability and turnover. The authors want to express their gratitude to the SAREN Research Group (IT1619–22, Basque Government).

To what extent can a decentred approach improve our understanding of migration governance? In the field of public policy, it ‘highlights the diverse and contingent meanings that inform the actions ...

Laser based directed energy deposition (DED) is a competitive method for repairing and remanufacturing metallic parts used in numerous industries including aerospace and biomedical. However, the numerous dynamic phenomena associated with the DED process often result in defects such as entrapped-gas pores, lack of fusion, and undesirable anisotropic properties. The entrapped-gas pore, being one of the most common issues, not only influences melt-pool dynamics but also reduces the fabrication quality and mechanical properties of parts fabricated by the DED process. To reduce and further understand this issue, the real-time observation of the pore formation process needs to be studied first. To directly observe the phenomena in the melt pool, high-speed techniques are needed because rapid solidification leads to rapid pore formation and movement. In-situ high-speed X-ray has been proven to be an effective method in investigating the melt pool dynamics and pore formation mechanisms in the laser powder bed fusion process, in which the fabrication process is quite different from that in DED. Here, the high-speed X-ray method is extended to study the formation of entrapped-gas pores. The real-time formation and quantitative analysis of pores under each set of processing parameters (particle velocity, laser power, and spot welding dwelling time of stationary laser) in the DED process are investigated. We found that the DED with a higher particle velocity (3.19 m/s) produced a smaller average pore size of 27.8 µm and a lower pore area fraction of 0.52%. The DED under lower laser power (156 W) generated a smaller average pore size of 20.3 µm and a lower pore area fraction of 1.94%. The shorter dwelling time (10 ms) benefited the decrease of both average pore size and pore area fraction.

Integrated landscape management (ILM) has received increased interest to reconcile multiple conflicting demands on a landscape scale. ILM aims at addressing major interconnected global challenges, such as poverty, food security, deforestation, and climate change. A principal element of ILM is the consideration of multiple scales, harmonizing local-level needs and ambitions with those that derive from outside the landscape. ILM initiatives are most often initiated by local actors focusing on local priorities, thereby insufficiently realizing that the landscape is embedded in a wider macroeconomic and societal context. We contextualize a landscape initiative located in the high forest zone of southern Ghana, focusing on global socioeconomic and political developments that are expected to have an influence on the region. We built two “sustainability” scenarios for the period between 2015 and 2030, reflecting the demands and ambitions of local stakeholders (bottom-up) and of global environmental policy (top-down) for the region. We find that global climate and cocoa production priorities could induce synergies between food production, biodiversity conservation, and climate change mitigation at the scale of the case study region but could come at the cost of mixed forest systems that play an important role in livelihoods on the landscape scale. Land change scenarios can play a critical role in assessing and visualizing such interactions and provide a platform for discussion and negotiation on how to integrate different objectives in the design of landscape initiatives.

In laser-based directed energy deposition (DED) additive manufacturing, interactions among the laser beam, particle flow, and melt pool influence the properties of the solidified final part. Two separate DED systems, one with high powder flow rates to represent industrial-scale DED processing and the other with low powder flow rates for individual particle tracking, were synchronized with the high-speed imaging setup at the Advanced Photon Source in Argonne National Laboratory. In-situ x-ray imaging of the DED process using both systems highlighted the influence of powder flow rates. Increased powder flow rates resulted in less laser absorption into the melt pool, leading to a transition from a keyhole mode to a melt pool without a keyhole but with surface fluctuations due to powder flow. Increased velocities of particles during powder flow resulted in a decrease in particle melting times and a greater propensity for porosity formation. Overall, better understanding of the interactions that occur during various scales of the DED process will enable flexibility, control, and new materials development in DED-based additive manufacturing.

Laser powder bed fusion is a metal additive manufacturing technique that has received significant scientific and industrial attention over the past decades. However, the quality and reproducibility of parts manufactured by this technique is still a problem. Overcoming this issue requires an understanding of multiple complex physical phenomena which occur simultaneously during the process. This work illustrates a powerful new technique which synchronizes high-speed x-ray imaging with high-speed infrared imaging to study laser powder bed fusion processes in real time. Using this technique, we demonstrate the simultaneous observation of multiple phenomena including three-dimensional melt pool visualization, vapor plume dynamics, spatter formation, thermal history, and point cooling rates. The paired observation of these dynamic phenomena is critical to understanding the fundamentals of laser powder bed fusion, and the overall impact of process parameters on print quality.

Despite a growing number of national-scale ecosystem service (ES) assessments, few studies consider the impacts of ES use and consumption beyond national or regional boundaries. Interregional ES flows ecosystem services imported from and exported to other countries are rarely analyzed and their importance for global sustainability is little known. Here, we provide a first multi-ES quantification of a nation's use of ES from abroad. We focus on ES flows that benefit the population in Germany but are supplied outside German territory. We employ a conceptual framework recently developed to systematically quantify interregional ES flows. We address four types of interregional ES flows with: (i) biophysical flows of traded goods: cocoa import for consumption; (ii) flows mediated by migratory species: migration of birds providing pest control; (iii) passive biophysical flows: flood control along transboundary watersheds; and (iv) information flows: China's giant panda loan to the Berlin Zoo. We determined that: (i) Ivory Coast and Ghana alone supply around 53% of Germany's cocoa while major negative consequences for biodiversity occurred in Cameroon and Ecuador; (ii) Africa´s humid and sub-humid climate zones are important habitats for the majority of migratory bird species that provide natural pest control services in agricultural areas in Germany; (iii) Upstream watersheds outside the country add an additional 64% flood regulation services nationally, while Germany exports 40% of flood regulation services in neighboring, downstream countries; (iv) Information flows transported by the pandas were mainly related to political aspects and - contrary to our expectations - considerably less on biological and natural aspects. We discuss the implications of these results for international resource management policy and governance. (c) 2020 The Authors Thomas Kastner was supported by the Vienna Science and Technology Fund (WWTF), project no. ESR17-014. Laura Lopez-Hoffman acknowledges the support of the National Science Foundation (NSF) awards DEB-1118975 and DEB-1518359. Support for Liu's time was provided by US National Science Foundation and Michigan AgBioResearch. Javier Martínez-López acknowledges the support of the Spanish Government through María de Maeztu excellence accreditation 2018-2021 (Ref. MDM-2017-0714). Sarah Wolff was supported by the European Research Council grant GLOLAND (grant no. 311819)

Ecosystem services (ES) assessments commonly focus on a specific biophysical region or nation and take its geographic borders as the system boundary. Most geographical regions are, however, not closed systems but are open and telecoupled with other regions, such that the use of ES in one location is dependent on ecosystem processes and ecological management in other locations. Interregional ES flows often affect national economies and may trigger issues of national security and global equity. To date, however, methodologies for assessing interregional flows of ES have been published in dispersed literature. This paper provides a three-step guidance for how to assess four different types of interregional ES flows (traded goods, passive biophysical flows, species migration and dispersal as well as information flows). This guidance is intended to complement national and regional ecosystem assessments. The three steps are to (i) define the goal and scope of interregional ES flow assessments, (ii) quantify the interregional ES flows using a tiered approach and (iii) interpret results in terms of uncertainties, consequences and governance options. We compile different indicators for assessing interregional ES flows and evaluate their suitability for national and regional ES assessments. Finally, to assess the implications of interregional ES flows for environmental sustainability and human well-being, we relate our flow indicators to the Sustainable Development Goals. This guidance towards systematic assessment of interregional ES flows provides a first step to measure and quantify externalised environmental costs and can contribute to the development of indicators to address interregional imbalances in trade, foreign policy and beyond.

To design microstructure and microhardness in the additive manufacturing (AM) of nickel (Ni)-based superalloys, the present work develops a novel data-driven approach that combines physics-based models, experimental measurements, and a data-mining method. The simulation is based on a computational thermal-fluid dynamics (CtFD) model, which can obtain thermal behavior, solidification parameters such as cooling rate, and the dilution of solidified clad. Based on the computed thermal information, dendrite arm spacing and microhardness are estimated using well-tested mechanistic models. Experimental microstructure and microhardness are determined and compared with the simulated values for validation. To visualize process–structure–properties (PSPs) linkages, the simulation and experimental datasets are input to a data-mining model—a self-organizing map (SOM). The design windows of the process parameters under multiple objectives can be obtained from the visualized maps. The proposed approaches can be utilized in AM and other data-intensive processes. Data-driven linkages between process, structure, and properties have the potential to benefit online process monitoring control in order to derive an ideal microstructure and mechanical properties. Keywords: Additive manufacturing, Data science, Multiphysics modeling, Self-organizing map, Microstructure, Microhardness, Ni-based superalloy

In additive manufacturing (AM) processes, materials are selectively added in layer-wise fashion to build three-dimensional objects. This approach provides several advantages over conventional manuf...

The main argument is that improving migrants’ rights and conceptual linkages between SSG/R and migration is best achieved, by decentring our gaze, namely going beyond the ‘national’ and ‘state-centric’ view that characterizes traditionally SSG/R and to consider the agency of both migrants and SSR actors. First from a migrants’ perspective, it is key for SSR actors to go beyond traditional legal classifications and to consider the diversity of personal situations that involve refugees, stranded migrants and asylum seekers, which might endorse different roles at different times of their journeys and lives. Second, the transnational nature of migration calls for a transnationalization of SSG/R too. For too long the concept has mostly been applied within the national setting of SSR institutions and actors. Migration calls for a clear decentring that involves a transnational dimension and more work among transnational actors and policymakers to facilitate a norm transfer from the domestic to the interstate and international level. As such, the ‘transnational’ nature of migration and its governance needs to be ‘domesticated’ within the national context in order to change the mindset of SSG/R actors and institutions. More importantly, the paper argues that poor SSG/R at home produces refugees and incentivizes migrants to leave their countries after being victims of violence by law enforcement and security services. During migrants’ complex and fragmented journeys, good security sector governance is fundamental to address key challenges faced by these vulnerable groups. I also argue that a better understanding of migrants’ and refugees’ security needs is beneficial and central to the good governance of the security sector. After reviewing the key terms of migration and its drivers in section 2, section 3 reviews how SSG is part of the implementation of the GCM. SSR actors play a role in shaping migratory routes and refugees’ incentives to leave, in explaining migrants’ and refugees’ resilience, in protecting migrants and refugees, and in providing security. Although it cautions against artificial classifications and the term of ‘transit migration’, section 4 reviews what the core challenges are in the countries of origin, transit and destination. Section 5 provides a detailed overview of the linkages between migration and each security actor: the military, police forces, intelligence services, border guards, interior ministries, private actors, criminal justice, parliaments, independent oversight bodies and civil society. Section 6 formulates some recommendations.

In the face of accelerating forest degradation and deforestation, forest certification emerged in the early 1990s as a voluntary and market-based mechanism to promote environmentally appropriate, socially beneficial, and economically viable management of the world’s forests. A key goal of forest certification is to reduce forest degradation and deforestation while enhancing forest enterprises’ economic viability. However, whether forest certification contributes to meeting such goals is unclear. We conducted a systematic literature review on such impacts, reviewing empirical studies published between 1993 and 2021 regarding the impact of forest certification on forest degradation, deforestation, and economic viability. Drawing on 98 empirical studies, we analyzed these impacts and provide an overview of the studies’ findings in terms of geographical distribution, indicators considered, and the certification schemes assessed. We found that the impact of forest certification on deforestation has been specifically understudied (n = 11) compared to forest degradation (n = 42) and economic viability (n = 45). On deforestation, studies have focused on Africa (45%) and South America (36%); on forest degradation, studies have focused on Europe (40%) and Asia (20%); on economic viability, studies have focused on Asia (33%), Europe (33%) and South America (20%). We found positive-neutral (54%; 46%) impacts on deforestation, positive-neutral-mixed (70%; 21%; 9%) impacts on forest degradation and positive-negative-mixed (50%; 33%; 17%) impacts on economic viability. We did not find clear evidence that impact is linked to a specific region or certification scheme. However, scarce evidence on the impacts of the Programme for the Endorsement of Forest Certification (PEFC), the application of various methods, and site-specific indicators in the individual studies challenge such comparison and hamper the generalization of findings. This systematic review provides an overview of the state-of-the-art research on the effectiveness and economic viability of forest certification, evaluates and discusses the current evidence base, and concludes with future research lines.

This special issue expands on the existing literature on the international dimension of democratization by focusing on democracy projection, defined as the projection of (democratic) norms in the every-day practice of interactions, beyond any donor-recipient relationship, between states and foreign civil society actors on issue areas where both have interests to defend. The SI examines the issue areas of trade, anti-corruption, applied research, gender and LGBTI, focusing on EU practices in its everyday dealings with civil society in the Southern Mediterranean. The authors conclude, based on comparative case studies relying on extensive interviews, direct observations and content analysis, that democracy projection varies according to four main factors: EU’s perceived interest, its ideational commitment to norms of dialogue and inclusion, the degree of institutional inertia and discourses/structures of meanings dominating in some policy areas which preclude EU engagement on substance., peer-reviewed

Exploring the challenges of Covid-19 for the European Union (EU) during March-August 2020, this article argues that contrary to prior crises the EU has demonstrated a certain degree of adaptability...

Das Booklet ist Ergebnis eines Masterseminars zur stadtebaulichen Denkmalpflege an der Otto-Friedrich-Universitat Bamberg. Es basiert auf den ertragreichen Recherchen und Arbeiten von 16 StudentInnen im Masterstudiengang Denkmalpflege / Heritage Conservation. Hierin werden Stadtkarten als historische Quellen vorgestellt. Exemplarisch zeigen die Studierendenarbeiten, wie diese Dokumente digital uberlagert und damit im Kontext neu interpretiert werden konnen und welche Erkenntnisse man dadurch einerseits uber die Karten und ihre Entstehung und andererseits uber die Stadtentwicklung bei Kriegsende und im Wiederaufbau gewinnen kann.

Powder-blown laser additive manufacturing adds flexibility, in terms of locally varying powder materials, to the ability of building components with complex geometry. Although the process is promising, porosity is common in a built component, hence decreasing fatigue life and mechanical strength. The understanding of the physical phenomena during the interaction of a laser beam and powder-blown deposition is limited and requires in-situ monitoring to capture the influences of process parameters on powder flow, absorptivity of laser energy into the substrate, melt pool dynamics and porosity formation. This study introduces a piezo-driven powder deposition system that allows for imaging of individual powder particles that flow into a scanning melt pool. Here, in-situ high-speed X-ray imaging of the powder-blown additive manufacturing process of Ti-6Al-4V powder particles is the first of its kind and reveals how laser-matter interaction influences powder flow and porosity formation.

We present a general diagrammatic approach to the construction of efficient algorithms for computing the Fourier transform of a function on a finite group. By extending work which connects Bratteli diagrams to the construction of Fast Fourier Transform algorithms %\cite{sovi}, we make explicit use of the path algebra connection to the construction of Gel'fand-Tsetlin bases and work in the setting of quivers. We relate this framework to the construction of a {\em configuration space} derived from a Bratteli diagram. In this setting the complexity of an algorithm for computing a Fourier transform reduces to the calculation of the dimension of the associated configuration space. Our methods give improved upper bounds for computing the Fourier transform for the general linear groups over finite fields, the classical Weyl groups, and homogeneous spaces of finite groups, while also recovering the best known algorithms for the symmetric group and compact Lie groups., Comment: 53 pages, 5 appendices, 34 figures

We consider Metropolis-based systematic scan algorithms for generating Birman-Murakami-Wenzl (BMW) monoid basis elements of the BMW algebra. As the BMW monoid consists of tangle diagrams, these scanning strategies can be rephrased as random walks on links and tangles. We translate these walks into left multiplication operators in the corresponding BMW algebra. Taking this algebraic perspective enables the use of tools from representation theory to analyze the walks; in particular, we develop a norm arising from a trace function on the BMW algebra to analyze the time to stationarity of the walks., 24 pages, 9 figures

Conserving and managing global natural capital requires an understanding of the complexity of flows ofecosystem services across geographic boundaries. Failing to understand and to incorporate these flowsinto national and international ecosystem assessments leads to incomplete and potentially skewed conclusions,impairing society’s ability to identify sustainable management and policy choices. In this paper,we synthesise existing knowledge and develop a conceptual framework for analysing interregionalecosystem service flows. We synthesise the types of such flows, the characteristics of sending and receivingsocio-ecological systems, and the impacts of ecosystem service flows on interregional sustainability.Using four cases (trade of certified coffee, migration of northern pintails, flood protection in the Danubewatershed, and information on giant pandas), we test the conceptual framework and show how anenhanced understanding of interregional telecouplings in socio-ecological systems can inform ecosystemservice-based decision making and governance with respect to sustainability goals.&nbsp

This paper presents our latest work on comprehensive modeling of process-structure-property relationships for additive manufacturing (AM) materials, including using data-mining techniques to close the cycle of design-predict-optimize. To illustrate the process-structure relationship, the multi-scale multi-physics process modeling starts from the micro-scale to establish a mechanistic heat source model, to the meso-scale models of individual powder particle evolution, and finally to the macro-scale model to simulate the fabrication process of a complex product. To link structure and properties, a high-efficiency mechanistic model, self-consistent clustering analyses, is developed to capture a variety of material response. The model incorporates factors such as voids, phase composition, inclusions, and grain structures, which are the differentiating features of AM metals. Furthermore, we propose data-mining as an effective solution for novel rapid design and optimization, which is motivated by the numerous influencing factors in the AM process. We believe this paper will provide a roadmap to advance AM fundamental understanding and guide the monitoring and advanced diagnostics of AM processing.

MoNbTiV high-entropy alloy was in situ alloyed with laser power-blown directed energy deposition additive manufacturing from a mixture of four elemental powders of Mo, Nb, Ti, and V. This study provides a fundamental understanding of the alloying process through in situ high-speed synchrotron X-ray imaging and infrared imaging. High-speed X-ray imaging was used to investigate the in situ alloying process through direct observation. The particle delivery velocities of four different elemental powders under the same processing conditions were studied to reveal the performance of the powders during the in situ alloying process. We found that the Ti and Nb powders showed the greatest and smallest averaged particle-delivery velocities among these four powders, respectively, and the particle delivery velocity would be affected by the particle characteristics, particle size, and density of powders. The velocities of the resulting melt pool flow were measured to show the melt flow dynamics in such a process. The residence time of each elemental powder was also obtained, and Mo powders showed the largest residence time followed by Nb, V, and Ti powders. The porosity induced by unmelted particles and entrapped gas occurred in the alloying process. The Mo powders resulted in the most unmelted particles, and the entrapped gas porosity was mainly induced by the keyhole fluctuation. With the assistance of an infrared camera, we reported the emissivity of the melt pool, the change of thermal properties, and melt pool morphology during alloying.

Additive manufacturing (AM) possesses appealing potential for manipulating material compositions, structures and properties in end-use products with arbitrary shapes without the need for specialized tooling. Since the physical process is difficult to experimentally measure, numerical modeling is a powerful tool to understand the underlying physical mechanisms. This paper presents our latest work in this regard based on comprehensive material modeling of process---structure---property relationships for AM materials. The numerous influencing factors that emerge from the AM process motivate the need for novel rapid design and optimization approaches. For this, we propose data-mining as an effective solution. Such methods--used in the process---structure, structure---properties and the design phase that connects them--would allow for a design loop for AM processing and materials. We hope this article will provide a road map to enable AM fundamental understanding for the monitoring and advanced diagnostics of AM processing.

The thermal history generated by the additive manufacturing process influences the resulting material properties. Although trends exist between solidification rate and microstructure, solidification rate is not enough to predict final microstructure and thus mechanical properties. The purpose of this study is to relate the combined effects of solidification time and cooling time of the built material to its final ultimate tensile strength. Cooling time was defined as the time from when the location of interest last passes through 1,200 °C to when it reaches 400 °C. Nine locations on a laser deposited IN718 thin wall were studied in detail to understand the effect of cooling rate on tensile strength. Tensile samples were machined at these locations. The thermal histories of the locations of interest were compared with build geometry and the ultimate tensile strength of that location. An inverse proportional relationship was seen between the distance of the location of interest from the substrate and the cooling time. A trend was also seen linking increased surface temperature and increased solidification time. Weighted Cooling And Solidification Time (WCAST) was defined as the sum of weighted normalized solidification time and the normalized cooling time. Ultimate tensile strength was seen to decrease as WCAST increased. Optical microscopy images of the build microstructure confirm that longer cooling and solidification times lead to coarser microstructures, which may cause the lower tensile strengths measured.

Since the Arab uprisings, religious engagement is central to EU relations with the Southern Mediterranean. Given that the EU is a liberal-secular power, this article investigates why and how the EU...

Additive manufacturing of components made of nickel-based and high strength materials that endure extreme environments, such as Inconel 718, is gaining traction in aerospace and automotive industries. However, one of the remaining challenges of laser deposited alloys is the volume change of the clad during a build, leading to warping, compromised dimensional integrity of the final part, and an increase in surface roughness. In addition, there has been no work in the prediction and control for volume change of localized areas within a laser deposited component. The dimensional integrity of a completed laser deposited structure is dependent on the uniformity of each individual clad track, with high variability in thermal history and clad height. The approach in this paper is the use of an in-situ infrared camera to capture the thermal history and determine the unique solidification rate of each localized point of each clad. Clad height measurements various points of the clads relative to the tool path were used to establish a relationship between process parameters, solidification rate and the volume change of the clad that verify analytical thermal models in the literature. Expanding these relationships to more complex build geometries, different laser deposited materials and a wider variety of processing conditions will allow for a better understanding, and therefore control, of the laser deposition process for more ubiquity of additive manufacturing in industry.

We present a general diagrammatic approach to the construction of efficient algorithms for computing a Fourier transform on a semisimple algebra. This extends previous work wherein we derive best estimates for the computation of a Fourier transform for a large class of finite groups. We continue to find efficiencies by exploiting a connection between Bratteli diagrams and the derived path algebra and construction of Gel'fand-Tsetlin bases. Particular results include highly efficient algorithms for the Brauer, Temperley-Lieb algebras, and Birman-Murakami-Wenzl algebras., 22 pages, 13 figures, 2 appendices. arXiv admin note: text overlap with arXiv:1512.02445

Additive manufacturing (AM) of titanium alloys is a rapidly growing field due to an increase in design flexibility of parts. However, AM parts are highly anisotropic in material microstructure and mechanical behavior due to the change of the local processing conditions in the build-up process. This study follows a link chain model to investigate the relationships between process parameters, cooling rate, porosity and mechanical behavior. The aim of this work is to present a framework that is inspired by the three-link chain model. The framework combines theoretical, computational and experimental approaches. We demonstrate this by using an in-house thermal simulator to link predicted cooling rates with micrographs describing experimental shape descriptors to develop a relationship between solidification cooling rate and porosity geometry. Finally, representative volume elements from predicted porosity maps allow for a prediction of mechanical properties at localized areas. The capability of being able to predict mechanical behavior of titanium alloys is demonstrated for the directed energy deposition process.

Understanding the spatial-temporal variability in ecosystem services (ES) demand can help anticipate externalities of land use change. This study presents new operational approaches to quantify and map demand for three non-commodity ES on a global scale: animal pollination, wild medicinal plants and outdoor recreation. We show how the demand for these ES differs between beneficiaries and world regions. While the demand for animal pollination is accounted for via the consumption preferences for pollinator-dependent crop products, the demand for wild medicinal plants is quantified by the direct reliance on wild medicinal plants for basic healthcare needs. The demand for outdoor recreation is represented by the possibility and interest to participate in related activities. For animal pollination and outdoor recreation, demand is highest in industrial countries; demand for wild medicinal plants is highest in least developed countries, given their direct reliance on this ES for healthcare. Spatial demand-supply mismatches can cause trade-offs between ES in distant provisioning areas and can lead to unintended impacts on human well-being. The study reveals that quantifying and mapping spatial patterns of ES demand on a global scale requires clear conceptualization and operationalization of specific ES to select the most appropriate methods and arrive at meaningful results.

Background: Recent research has shown an increased risk of accidents and injuries in ADHD patients, which could potentially be reduced by stimulant treatment. Therefore, the first aim of our study was to evaluate the prevalence of adult ADHD in a trauma surgery population. The second aim was to investigate accident mechanisms and circumstances which could be specific to ADHD patients, in comparison to the general population. Methods: We screened 905 accident victims for ADHD using the ASRS 18-item self-report questionnaire. The basic demographic data and circumstances of the accidents were also assessed. Results: Prevalence of adult ADHD was found to be 6.18% in our trauma surgery patient sample. ADHD accident victims reported significantly higher rates of distraction, stress and overconfidence in comparison to non-ADHD accident victims. Overconfidence and being in thoughts as causal mechanisms for the accidents remained significantly higher in ADHD patients after correction for multiple comparison. ADHD patients additionally reported a history of multiple accidents. Conclusion: The majority of ADHD patients in our sample had not previously been diagnosed and were therefore not receiving treatment. The results subsequently suggest that general ADHD screening in trauma surgery patients may be useful in preventing further accidents in ADHD patients. Furthermore, psychoeducation regarding specific causal accident mechanisms could be implemented in ADHD therapy to decrease accident incidence rate.

Directed energy deposition (DED) additive manufacturing (AM) is receiving growing attention in many applications, such as repair, remanufacturing, and fabrication of functionally graded structures. However, the laser-matter interactions and melt pool dynamics in laser DED with powder flow are still unclear, particularly in how pores form and flow inside the melt pool during the process. Understanding the porosity formation mechanisms is critical in the qualification, certification, and overall properties of a DED AM part. Porosity is a common phenomenon and can significantly hinder the quality of DED fabricated parts, as the pores can act as sites of crack nucleation and propagation. Here, we reveal four types of pore formation mechanisms through in-situ and operando high-speed high-resolution X-ray imaging in the DED AM process. Our results confirm that porosity within the feedstock powder induces pores in the process. We also observed pore formation mechanisms unique to the laser-based, powder-blown DED process as a result of powder delivery, keyhole dynamics, melt pool dynamics, and shield gas. High-speed X-ray images provide direct evidence for pore formation mechanisms and show that the pores related to the interaction between the delivered powder and melt pool are the largest in size in laser-based powder-blown DED AM. These results will guide porosity mitigation, elimination, and control in DED AM.

Directed energy deposited (DED) Ti–6Al–4V components and prototypes are quickly growing in prevalence in aerospace and biomedical industries for their increased strength and fast processing time. However, one of the remaining challenges in DED processes, particularly laser engineered net shaping (LENS), is the characterization of the inherent anisotropy in material properties. Anisotropy in microstructure, porosity and mechanical behavior arises due to unique material thermal histories during processing. Understanding anisotropy in additive manufacturing can lead to refined process parameters, characterization methods, material and thermal modeling as well as improved mechanical properties. This paper investigates the anisotropic mechanical properties, specifically ultimate tensile strength, of LENS-processed Ti–6Al–4V and how these properties depend on geometry and direction of build processing. Mechanical properties were found to be most desirable when the tensile orientation is orthogonal to the build direction and parallel to the scan direction as well as closer to the center of a fully dense component. This study investigates microstructure through X-ray diffraction, fractography and porosity shape and connectivity analysis. Models that predict mechanical behavior based on processing details are in development. There is potential to achieve desirable mechanical properties through melt pool and thermal controls for high-strength and energy efficient materials by predicting mechanical properties from process parameters.

Additive manufacturing has the potential to revolutionize the production of metallic components as it yields near net shape parts with complex geometries and minimizes waste. At the present day, additively manufactured components face qualification and certification challenges due to the difficulty in controlling defects. This has driven a significant research effort aimed at better understanding and improving processing controls – yielding a plethora of in-situ measurements aimed at correlating defects with material quality metrics of interest. In this work, we develop machine-learning methods to learn correlations between thermal history and subsurface porosity for a variety of print conditions in laser powder bed fusion. Un-normalized surface temperatures (in the form of black-body radiances) are obtained using high-speed infrared imaging and porosity formation is observed in the sample cross-section through synchrotron x-ray imaging. To demonstrate the predictive power of these features, we present four statistical machine-learning models that correlate temperature histories to subsurface porosity formation in laser fused Ti-6Al-4V powder.

Background: Recent research has shown an increased risk of accidents and injuries in ADHD patients, which could potentially be reduced by stimulant treatment. Therefore, the first aim of our study was to evaluate the prevalence of adult ADHD in a trauma surgery population. The second aim was to investigate accident mechanisms and circumstances which could be specific to ADHD patients, in comparison to the general population. Methods: We screened 905 accident victims for ADHD using the ASRS 18-item self-report questionnaire. The basic demographic data and circumstances of the accidents were also assessed. Results: Prevalence of adult ADHD was found to be 6.18% in our trauma surgery patient sample. ADHD accident victims reported significantly higher rates of distraction, stress and overconfidence in comparison to non-ADHD accident victims. Overconfidence and being in thoughts as causal mechanisms for the accidents remained significantly higher in ADHD patients after correction for multiple comparison. ADHD patients additionally reported a history of multiple accidents. Conclusion: The majority of ADHD patients in our sample had not previously been diagnosed and were therefore not receiving treatment. The results subsequently suggest that general ADHD screening in trauma surgery patients may be useful in preventing further accidents in ADHD patients. Furthermore, psychoeducation regarding specific causal accident mechanisms could be implemented in ADHD therapy to decrease accident incidence rate.

We develop an approach to finding upper bounds for the number of arithmetic operations necessary for doing harmonic analysis on permutation modules of finite groups. The approach takes advantage of the intrinsic orbital structure of permutation modules, and it uses the multiplicities of irreducible submodules within individual orbital spaces to express the resulting computational bounds. We conclude by showing that these bounds are surprisingly small when dealing with certain permutation modules arising from the action of the symmetric group on tabloids., Comment: 19 pages

Land restoration has received increased attention recently as a tool to counteract negative externalities of unsustainable land management on human well-being. This is reflected in targets of the Sustainable Development Goals (SDGs), the Convention on Biological Diversity (CBD), the United Nations Framework of the Convention on Climate Change (UNFCCC) and the United Nations Convention to Combat Desertification (UNCCD). However, the implications of these targets for land use, especially considering their potential conflict with growing food production demands, are largely unexplored. We study the potential and aggregated consequences of meeting these targets on land cover and land system change. We do so by analyzing targets originating from these global commitments towards land restoration and protection and implement them in a global land system change model. We compare this Restoration and Protection scenario with simulation results of two plausible pathways of socio-economic development in the absence of these targets, following the Shared Socio-Economic Pathway (SSP) storylines. We find that meeting global land restoration and protection targets would increase global tree cover by 4 million km², increasing forest carbon stocks by 50 Gt and protecting 28% of the terrestrial area with the highest value of both biodiversity and carbon storage. Gains in tree cover and natural land systems would cause a contraction of crop, pasture- and bare land. This results in further cropland intensification and the expansion of land systems that are combining land use demands in mosaics of forest and agriculture. Without these targets, land system architecture tends to become more specialized, while many carbon and biodiversity hotspots, such as in the Americas, India, and Indonesia would be lost. Grassland-agriculture mosaics were threatened by land use change under all scenarios, requiring greater consideration in research and environmental policy. Our results emphasize the need for targeted land management in line with the analyzed policy targets if global restoration and protection targets are to be achieved.

Maintaining mostly a national and EU-level focus, the transnational dimension has been overlooked in the policy instrumentation literature. Seeking to fill this gap, this article researches the factors that shape the choice and evolution of policy instruments in transnational administrations, namely above and beyond the state. In an empirical analysis of budget support, it finds that the preference of the European Commission for this development aid instrument is dependent upon transnational agency and EU domestic habitat. This is evidenced in three steps. First, conflicting global objectives and institutional strategies of re-legitimization provided transnational administrative agency with power and leverage to promote managerial norms over developmental ones. Second, transnational knowledge networks have provided the European Commission venues of socialization to maintain its monopoly over the instrument. Third, the de-politicized transnational logic of budget support as a managerial tool is correlated to an increased politicization by some EU member states.