Influence of the interaction potential on simulated sputtering and reflection data

The TRIM.SP program which is based on the binary collision approximation was changed to handle not only repulsive interaction potentials, but also potentials with an attractive part. Sputtering yields, average depth and reflection coefficients calculated with four different potentials are compared. Three purely repulsive potentials (Meliere, Kr-C and ZBL) are used and an ab initio pair potential, which is especially calculated for silicon bombardment by silicon. The general trends in the calculated results are similar for all potentials applied, but differences between the repulsive potentials and the ab initio potential occur for the reflection coefficients and the sputtering yield at large angles of incidence.

3D Simultaneous Inversion for Seismic Structure and Local Hypocenters in Germany under Consideration of Seismic Anisotropy in the Upper Mantel

The main task of this work has been to investigate the effects of anisotropy onto the propagation of seismic waves along the Upper Mantle below Germany and adjacent areas. Refraction- and reflexion seismic experiments proved the existence of Upper Mantle anisotropy and its influence onto the propagation of Pn-waves. By the 3D tomographic investigations that have been done here for the crust and the upper mantle, considering the influence of anisotropy, a gap for the investigations in Europe has been closed. These investigations have been done with the SSH-Inversionprogram of Prof. Dr. M. Koch, which is able to compute simultaneously the seismic structure and hypocenters. For the investigation, a dataset has been available with recordings between the years 1975 to 2003 with a total of 60249 P- and 54212 S-phase records of 10028 seismic events. At the beginning, a precise analysis of the residuals (RES, the difference between calculated and observed arrivaltime) has been done which confirmed the existence of anisotropy for Pn-phases. The recognized sinusoidal distribution has been compensated by an extension of the SSH-program by an ellipse with a slow and rectangular fast axis with azimuth to correct the Pn-velocities. The azimuth of the fast axis has been fixed by the application of the simultaneous inversion at 25° - 27° with a variation of the velocities at +- 2.5 about an average value at 8 km/s. This new value differs from the old one at 35°, recognized in the initial residual analysis. This depends on the new computed hypocenters together with the structure. The application of the elliptical correction has resulted in a better fit of the vertical layered 1D-Model, compared to the results of preceding seismological experiments and 1D and 2D investigations. The optimal result of the 1D-inversion has been used as initial starting model for the 3D-inversions to compute the three dimensional picture of the seismic structure of the Crust and Upper Mantle. The simultaneous inversion has showed an optimization of the relocalization of the hypocenters and the reconstruction of the seismic structure in comparison to the geology and tectonic, as described by other investigations. The investigations for the seismic structure and the relocalization have been confirmed by several different tests. First, synthetic traveltime data are computed with an anisotropic variation and inverted with and without anisotropic correction. Further, tests with randomly disturbed hypocenters and traveltime data have been proceeded to verify the influence of the initial values onto the relocalization accuracy and onto the seismic structure and to test for a further improvement by the application of the anisotropic correction. Finally, the results of the work have been applied onto the Waldkirch earthquake in 2004 to compare the isotropic and the anisotropic relocalization with the initial optimal one to verify whether there is some improvement.

Use of video mark schemes to facilitate student generated feedback and reflection

Presentation

Sustaining Success Task: Week 3 Introduction to reflection

An introduction to a method of reflection. This task looks at the process of writing a short piece of reflection and provides a framework for that activity

Sustaining Success Task 4: Reflection and Action - basic

A reflection exercise to help you understand the reflection process better

Sustaining Success Week 4 Task: Reflection and Action - elaborate

link to the documents which describe the personal reflection task. One of the tasks you may choose to submit

Self-medication and related terms: a conceptual reflection

Introduction: self-medication has become a growing practice in the world population. This phenomenon has been promoted as a form of self-care, with a positive impact on reducing spending in health systems, however there is concern about the potential negative effects related to inadequate diagnosis and treatment, which can affect health of individuals. This dual perception of the phenomenon is partly related to a variety of terms and concepts used, that make difficult its theoretical and empirical approach. Harmonization of the definitions involved is required in order to make adequate epidemiological comparisons. Objectives: analyze the concept of self medication and related terms from the definitions in the literature of the subject. Conclusions: in the last four decades it has been an evolution of both the wording and the definitions related to self-medication, from a very simple concept that implies the absence of prescription, to more complex ones that encompass very diverse behaviors, even those mediated by an act of prescription but not followed or not completed by the patient. Additionally the conceptual proliferation seen, justify the ordering of the terms related to self-medication. This paper presents a proposal for classification in four groups: a. self-medication, b. self care, c. pharmaceutical preparations and medicines, and d. prescription. This proposal should facilitate the exploration and analysis of the phenomenon and allow future theoretical approaches.

Al – Qaeda and the international politics: a teorical Reflection

Through the study of the relationship between non-state actors and states, is pretended to analyze the role of Al-Qaeda in international politics. It is argued that Al-Qaeda tries or has the ability to promote or accelerate changes in the power  structure, where stands the American hegemony and the pursuit of balance by  various actors, implementing asymmetric strategies as counter-hegemonic responses.

Building Professional Capacity Aiming to Improve the Educational Position of Migrant Children : a reflection on the Sirius network activities

Resumen basado en el de la publicaci??n

Evolving definition of sociomuseology : proposal for reflection

Sociomuseology expresses a considerable amount of the effort made to suit museological facilities to the conditions of contemporary society. The process of opening up the museum, as well as its organic relation with the social context that infuses it with life, has resulted in the need to structure and clarify the relations, notions and concepts that may define this process. Sociomuseology is thus a scientific field of teaching, research and performance which emphasizes the articulation of museology, in particular, with the areas of knowledge covered by Human Sciences, Development Studies, Services Science, and Urban and Rural Planning. The multidisciplinary approach of Sociomuseology aims to strengthen the acknowledgement of museology as a resource for the sustainable development of Humanity, based on equal opportunities as well as social and economic inclusion. Sociomuseology bases its social intervention on mankind’s cultural and natural heritage, both tangible and intangible. What characterizes Sociomuseology is not so much the nature of its premises and its goals, as is the case with other areas of knowledge, but the interdisciplinary focus which makes it draw on perfectly consolidated areas of knowledge and relate them with Museology itself.

Ovenbird (Seiurus aurocapilla) Territory Placement Near Seismic Lines is Influenced by Forest Regeneration and Conspecific Density

The boreal forest of western Canada is being dissected by seismic lines used for oil and gas exploration. The vast amount of edge being created is leading to concerns that core habitat will be reduced for forest interior species for extended periods of time. The Ovenbird (Seiurus aurocapilla) is a boreal songbird known to be sensitive to newly created seismic lines because it does not include newly cut lines within its territory. We examined multiple hypotheses to explain potential mechanisms causing this behavior by mapping Ovenbird territories near lines with varying states of vegetation regeneration. The best model to explain line exclusion behavior included the number of neighboring conspecifics, the amount of bare ground, leaf-litter depth, and canopy closure. Ovenbirds exclude recently cut seismic lines from their territories because of lack of protective cover (lower tree and shrub cover) and because of reduced food resources due to large areas of bare ground. Food reduction and perceived predation risk effects seem to be mitigated once leaf litter (depth and extent of cover) and woody vegetation cover are restored to forest interior levels. However, as conspecific density increases, lines are more likely to be used as landmarks to demarcate territorial boundaries, even when woody vegetation cover and leaf litter are restored. This behavior can reduce territory density near seismic lines by changing the spatial distribution of territories. Landmark effects are longer lasting than the effects from reduced food or perceived predation risk because canopy height and tree density take >40 years to recover to forest interior levels. Mitigation of seismic line impacts on Ovenbirds should focus on restoring forest cover as quickly as possible after line cutting.

A comparison of cross-hole electrical and seismic data in fractured rock

Cross-hole anisotropic electrical and seismic tomograms of fractured metamorphic rock have been obtained at a test site where extensive hydrological data were available. A strong correlation between electrical resistivity anisotropy and seismic compressional-wave velocity anisotropy has been observed. Analysis of core samples from the site reveal that the shale-rich rocks have fabric-related average velocity anisotropy of between 10% and 30%. The cross-hole seismic data are consistent with these values, indicating that observed anisotropy might be principally due to the inherent rock fabric rather than to the aligned sets of open fractures. One region with velocity anisotropy greater than 30% has been modelled as aligned open fractures within an anisotropic rock matrix and this model is consistent with available fracture density and hydraulic transmissivity data from the boreholes and the cross-hole resistivity tomography data. However, in general the study highlights the uncertainties that can arise, due to the relative influence of rock fabric and fluid-filled fractures, when using geophysical techniques for hydrological investigations.

A fuzzy multi-criteria decision approach for enhanced auto-tracking of seismic events

The main activity carried out by the geophysicist when interpreting seismic data, in terms of both importance and time spent is tracking (or picking) seismic events. in practice, this activity turns out to be rather challenging, particularly when the targeted event is interrupted by discontinuities such as geological faults or exhibits lateral changes in seismic character. In recent years, several automated schemes, known as auto-trackers, have been developed to assist the interpreter in this tedious and time-consuming task. The automatic tracking tool available in modem interpretation software packages often employs artificial neural networks (ANN's) to identify seismic picks belonging to target events through a pattern recognition process. The ability of ANNs to track horizons across discontinuities largely depends on how reliably data patterns characterise these horizons. While seismic attributes are commonly used to characterise amplitude peaks forming a seismic horizon, some researchers in the field claim that inherent seismic information is lost in the attribute extraction process and advocate instead the use of raw data (amplitude samples). This paper investigates the performance of ANNs using either characterisation methods, and demonstrates how the complementarity of both seismic attributes and raw data can be exploited in conjunction with other geological information in a fuzzy inference system (FIS) to achieve an enhanced auto-tracking performance.