Utjecaj materijala i geometrije radnog komada kod savijanja laserom

Seit den siebziger Jahre ist durch die Einführung des Laserstrahls in die Fertigungstechnik eine ganze Reihe neuer Verfahren entstanden. Einige dieser Verfahren sind mittlerweile in die technische Anwendung übergangen wie zu Beispiel Schneiden, Schweißen, Drehen, Fräsen, Bohren und Umformen. Gemeinsames Merkmal der Lasergestützten Formgebungsverfahren ist die digitale Speicherung der Werkstückgeometrie in einem NC-Programm anstelle der analogen Speicherung im Werkzeug und sukzessive Abarbeitung dieses Programm, die zusätzlich Steuermöglichkeiten während des Prozessablaufs ermöglicht. Weiterhin ergibt die Vorgehensweise eine sehr hohe Flexibilität hinsichtlich der Werkstückgeometrie, die im Bereich des Rapid Prototyping genutzt werden. In dieser Arbeit wird Werkstoff - Geometriewerkstückbeeinflussung auf den Laserstrahlbiegen analysiert. Einfluss hat Blechdicke, längen der Biegekante und Biegeschenkel.Od kada je sedamdesetih godina uveden laser u tehnologiju izrade nastali su mnogi novi postupci. Neki od tih postupaka našli su tehničku primjenu u tehnologiji izrade kao na primjer rezanje, zavarivanje, tokarenje, glodanje, bušenje i oblikovanje metala deformiranjem. Karakteristika je postupka izrade potpomognuta laserom digitalno spremanje geometrije radnog dijela u NC - program, provođenje analognog spremanja podataka u (stroj) alat i sukcesivna obrada ovog programa, koji osigurava dodatno mogućnost upravljanja za vrijeme odvijanja procesa. Nadalje, postiže se fleksibilnost s obzirom na geometriju radnog komada, koja se primjenjuje u području brze izrade prototipova. U ovom se radu analizira utjecaj materijala i geometrije radnog komada na savijanja laserom. Utjecaj ima: debljina lima, duljina ruba savijanja i duljina kraka savijanja

The Cooperative Participatory Evaluation of Renewable Technologies on Ecosystem Services (CORPORATES)

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The Mid-Infrared Properties of X-ray Sources

We combine the results of the Spitzer IRAC Shallow Survey and the Chandra XBootes Survey of the 8.5 square degrees Bootes field of the NOAO Deep Wide- Field Survey to produce the largest comparison of mid-IR and X-ray sources to date. The comparison is limited to sources with X-ray fluxes >8x10-15 erg cm-2s-1 in the 0.5-7.0 keV range and mid-IR sources with 3.6 um fluxes brighter than 18.4 mag (12.3 uJy). In this most sensitive IRAC band, 85% of the 3086 X-ray sources have mid-IR counterparts at an 80% confidence level based on a Bayesian matching technique. Only 2.5% of the sample have no IRAC counterpart at all based on visual inspection. Even for a smaller but a significantly deeper Chandra survey in the same field, the IRAC Shallow Survey recovers most of the X-ray sources. A majority (65%) of the Chandra sources detected in all four IRAC bands occupy a well-defined region of IRAC [3.6] - [4.5] vs [5.8] - [8.0] color-color space. These X-ray sources are likely infrared luminous, unobscured type I AGN with little mid-infrared flux contributed by the AGN host galaxy. Of the remaining Chandra sources, most are lower luminosity type I and type II AGN whose mid-IR emission is dominated by the host galaxy, while approximately 5% are either Galactic stars or very local galaxies.Comment: Accepted for publication in Ap

Participatory scenario development for environmental management:A methodological framework illustrated with experience from the UK uplands

A methodological framework is proposed for participatory scenario development on the basis of evidence from the literature, and is tested and refined through the development of scenarios for the future of UK uplands. The paper uses a review of previous work to justify a framework based around the following steps: i) define context and establish whether there is a basis for stakeholder engagement in scenario development; ii) systematically identify and represent relevant stakeholders in the process; iii) define clear objectives for scenario development with stakeholders including spatial and temporal boundaries; iv) select relevant participatory methods for scenario development, during initial scenario construction, evaluation and to support decision-making based on scenarios; and v) integrate local and scientific knowledge throughout the process. The application of this framework in case study research suggests that participatory scenario development has the potential to: i) make scenarios more relevant to stakeholder needs and priorities; ii) extend the range of scenarios developed; iii) develop more detailed and precise scenarios through the integration of local and scientific knowledge; and iv) move beyond scenario development to facilitate adaptation to future change. It is argued that participatory scenario development can empower stakeholders and lead to more consistent and robust scenarios that can help people prepare more effectively for future change

The Chandra XBootes Survey - III: Optical and Near-IR Counterparts

The XBootes Survey is a 5-ks Chandra survey of the Bootes Field of the NOAO Deep Wide-Field Survey (NDWFS). This survey is unique in that it is the largest (9.3 deg^2), contiguous region imaged in X-ray with complementary deep optical and near-IR observations. We present a catalog of the optical counterparts to the 3,213 X-ray point sources detected in the XBootes survey. Using a Bayesian identification scheme, we successfully identified optical counterparts for 98% of the X-ray point sources. The optical colors suggest that the optically detected galaxies are a combination of z<1 massive early-type galaxies and bluer star-forming galaxies whose optical AGN emission is faint or obscured, whereas the majority of the optically detected point sources are likely quasars over a large redshift range. Our large area, X-ray bright, optically deep survey enables us to select a large sub-sample of sources (773) with high X-ray to optical flux ratios (f_x/f_o>10). These objects are likely high redshift and/or dust obscured AGN. These sources have generally harder X-ray spectra than sources with 0.1<f_x/f_o<10. Of the 73 X-ray sources with no optical counterpart in the NDWFS catalog, 47 are truly optically blank down to R~25.5 (the average 50% completeness limit of the NDWFS R-band catalogs). These sources are also likely to be high redshift and/or dust obscured AGN.Comment: 19 pages, 13 figures, ApJ accepted. Catalog can be found at: http://www.noao.edu/noao/noaodeep or ftp://archive.noao.edu/pub/catalogs/xbootes

Work Package Report 6: Shared, plural and cultural values of ecosystems – Summary

Key findings: Finding 1: Shared values resulting from deliberative, group-based valuation are different from individual values. Case study evidence suggests that they are more informed, considered, confident and reflective of participants’ deeper-held, transcendental values. Deliberated, group-based monetary values may be a better reflection of real welfare impacts than non-deliberated individual values, if derived through a carefully designed and managed process. Although more research is needed to expand the currently small evidence base on deliberative monetary methods, group deliberation has the potential to significantly enhance elicitation of values. Finding 2: The ethical, moral and justice dimensions of many environmental issues necessitate approaches that allow for the elicitation of shared and plural values. Key ethical concerns include: 1) providing a space and opportunity for people to identify values that they may find difficult to articulate (e.g. spiritual, identity); 2) recognising that some values cannot be traded without discussion and negotiation (e.g. the legal or felt rights of local people, intrinsic values of other species); and 3) understanding that it is often difficult to isolate valuation from decision-making processes because people feel there are strong ethical or moral issues at stake that need to be debated (e.g. the justice of the process, fairness in the distribution of benefits or disbenefits, responsibility, and issues of sustainability and future generations). Finding 3: Catalyst and/or conflict points can play a key role in the emergence and articulation of values at a societal or community level that have not previously been outwardly or explicitly articulated. Catalyst and conflict points can be symbolic and are often linked to wider contested issues and meanings about who is involved in decision-making, whose voice counts and who receives the benefits or disbenefits of environmental change. These catalyst points can potentially be connected to feelings of powerlessness that give rise to concern and protest. By recognising transcendental societal and communal values (the deeper-held and overarching values held by society and communities), it becomes possible to make these values explicit and incorporate them in decision-making to better anticipate and manage conflicts. Finding 4: There is a diversity of ways in which shared, plural, cultural and social values are used, but they are rarely conceptualised. The UK NEAFO provides a clear theoretical framework that distinguishes and categorises different dimensions and types of shared values. The proposed range of value types was both identifiable and distinguishable within case study results. This suggests that the framework provides a useful basis for operationalizing shared values for decision-making. Finding 5: Shared and social values in the sense of value to society is conceptualised very differently by conventional economics and other disciplines. Neoclassical economists have generally undertaken valuation by equating social value with the aggregate of individual values. They consider values as fundamentally commensurable. In contrast, literature from other disciplines consistently considers values as plural, not just in the sense that multiple things have value, but also that there are multiple dimensions to value that cannot necessarily be captured in a single metric. Within mainstream economics, the difficulties associated with commensurability and aggregating values have long been recognised, but have also been neglected. An interesting area for future debate between economic and non-economic views on values may be the normative nature of value-aggregation. Finding 6: A mixed method approach is required to elicit the multiple dimensions of shared values and to translate deeper-held, transcendental values into contextual values and preferences. Monetary valuation is limited to quantifying values. Other methods are needed to understand their meaning or content, and the communal, societal and transcendental values that underpin them. Psychometric, non-analytical and interpretive methods (e.g. storytelling) can reveal those shared values. They can be combined with deliberative-analytical methods (e.g. deliberative monetary valuation and multi-criteria analysis) to provide a comprehensive valuation that can quantify values, understand their individual and shared meanings and significance, and better include ethical dimensions. Finding 7: Deliberative and social learning processes help people to understand the values held by others; they can lead to increased sharing of values and/or to greater acceptance of the decisions emerging from such processes. Deliberation clearly affects what values participants express compared to non-deliberated processes. There is also a growing body of theoretical and empirical research suggesting that deliberation has the potential to affect how people understand and shape the values of others. Although rarely considered in the economic literature, the concept of social learning helps to explain some of the processes involved in deliberation. The extent to which deliberation or social learning helps participants express and shape values will depend upon the frequency and depth of interactions and the timescale over which interactions occur. Only a shift in cultural values (e.g. less emphasis on material wealth), reflected in other societal institutions (e.g. changes in the indicators used to measure national progress) is likely to achieve sustainable outcomes in the long-term. Finding 8: Media analysis is a promising avenue for characterising different types of shared values at a large scale, as well as assessing the conflicts between the communal values of different sectors of society. There has been a marked increase in public interest in environmental issues over the last decade, which is reflected in their increased media coverage. Media content and discourse analysis is able to distinguish and characterise the plurality of cultural, societal and transcendental values and their interrelationships, and can offer a picture of the self- and other-regarding values that underpin environmental issues and conflicts. Social media can provide a further forum for understanding societal and communal values surrounding environmental issues. Finding 9: Aesthetic and spiritual values of ecosystems have a strong non-instrumental component. While they benefit human well-being, they should not simply be classified as just ‘services’ or ‘benefits’. Many spiritual discourses about nature resist talk of consequentialist benefits and economic analysis. These discourses counter assertions of the disenchantment of the world, which is associated with an instrumental environmental ethic and the commodification of nature. Allowing the possibility of enchantment can be a richer way of understanding our experience of nature and alerts us to the limitations of using economic models for valuation and informing decisions about these profound cultural ecosystem ‘services’. Faith communities have experience of using these non-utilitarian values in their own decision-making and provide models that could be adapted for use in environmental decision-making. Finding 10: Subjective well-being measures provide a useful means of assessing ‘intangible’ cultural ecosystem services and their benefits. Different user groups associate common elements of subjective well-being with environmental settings, providing opportunities for development of standardised measures. In the UK NEAFO, key facets of well-being associated with places in nature across different user groups included: engagement with nature (incorporating elements of connectedness, getting to know nature and the beauty of nature, and taking care of a place); therapeutic benefits (including physical and mental aspects of health); place identity (including a sense of place and belonging); spiritual value (in the sense of feeling connected or responsible to something larger than oneself); social bonding with others; and transformative and memorable experiences. Further empirical work with different user groups and environmental settings would allow for the continued development of a standardised tool for large-scale non-monetary assessment of cultural ecosystem services

The Mid-IR and X-ray Selected QSO Luminosity Function

We present the J-band luminosity function of 1838 mid-infrared and X-ray selected AGNs in the redshift range 0<z<5.85. These luminosity functions are constructed by combining the deep multi-wavelength broad-band observations from the UV to the mid-IR of the NDWFS Bootes field with the X-ray observations of the XBootes survey and the spectroscopic observations of the same field by AGES. Our sample is primarily composed of IRAC-selected AGNs, targeted using modifications of the Stern et al.(2005) criteria, complemented by MIPS 24 microns and X-ray selected AGNs to alleviate the biases of IRAC mid-IR selection against z~4.5 quasars and AGNs faint with respect to their hosts. This sample provides an accurate link between low and high redshift AGN luminosity functions and does not suffer from the usual incompleteness of optical samples at z~3. We find that the space density of the brightest quasars strongly decreases from z=3 to z=0, while the space density of faint quasars is at least flat, and possibly increasing, over the same redshift range. At z>3 we observe a decrease in the space density of quasars of all brightnesses. We model the luminosity function by a double power-law and find that its evolution cannot be described by either pure luminosity or pure density evolution, but must be a combination of both. Our best-fit model has bright and faint power-law indices consistent with the low redshift measurements based on the 2QZ and 2SLAQ surveys and it generally agrees with the number of bright quasars predicted by other LFs at all redshifts. If we construct the QSO luminosity function using only the IRAC-selected AGNs, we find that the biases inherent to this selection method significantly modify the behavior of phi*(z) only for z<1 and have no significant impact upon the characteristic magnitude M*_J(z).Comment: Corrected minor typo in equations (4) and (6). Accepted for publication in The Astrophysical Journal. 56 pages + 6 tables + 16 figure

Ultracool Field Brown Dwarf Candidates Selected at 4.5 microns

We have identified a sample of cool field brown dwarf candidates using IRAC data from the Spitzer Deep, Wide-Field Survey (SDWFS). The candidates were selected from 400,000 SDWFS sources with [4.5] <= 18.5 mag and required to have [3.6]-[4.5] >= 1.5 and [4.5] - [8.0] <= 2.0 on the Vega system. The first color requirement selects objects redder than all but a handful of presently known brown dwarfs with spectral classes later than T7, while the second eliminates 14 probable reddened AGN. Optical detection of 4 of the remaining 18 sources implies they are likely also AGN, leaving 14 brown dwarf candidates. For two of the brightest candidates (SDWFS J143524.44+335334.6 and SDWFS J143222.82+323746.5), the spectral energy distributions including near-infrared detections suggest a spectral class of ~ T8. The proper motion is < 0.25 "/yr, consistent with expectations for a luminosity inferred distance of >70 pc. The reddest brown dwarf candidate (SDWFS J143356.62+351849.2) has [3.6] - [4.5]=2.24 and H - [4.5] > 5.7, redder than any published brown dwarf in these colors, and may be the first example of the elusive Y-dwarf spectral class. Models from Burrows et al. (2003) predict larger numbers of cool brown dwarfs should be found for a Chabrier (2003) mass function. Suppressing the model [4.5] flux by a factor of two, as indicated by previous work, brings the Burrows models and observations into reasonable agreement. The recently launched Wide-field Infrared Survey Explorer (WISE) will probe a volume ~40x larger and should find hundreds of brown dwarfs cooler than T7.Comment: 13 pages, 6 figures, accepted for publication in the June 2010 issue of The Astronomical Journa