The fragmentation of a discipline: how diversity elevates and undermines Ir’s normative potential

International Relations (ir) has transformed from a relatively state-centric discipline that was primarily concerned about international security and the behavior of great powers into a highly diverse intellectual playing field. The present article assesses the implications of this transformation in relation to ir’s norma­tive potential, defined in terms of knowledge production and critical thinking. Although the field’s growing diversity helps addressing the multiple challenges and crises the world is currently facing, it is also evident that the spe­cialized knowledge and jargon that is needed to engage in a specific subfield prevents ir scholars from understanding one another. This development not only undermines the liveliness of the field, but also obstructs our capacity to interact with political actors and engage with the public. Furthermore, inward-looking scholarly communities curtail critical thinking. Although there is no panacea that can reverse this trend, the article claims that cultivating networks of dialogue may assuage its worst effects by facilitating mutual learn­ing and improving our communicative skills.Las relaciones internacionales (RR.II.) se han ido transformando de una disciplina relativa­mente Estado-céntrica, que principalmente se preocupa por la seguridad internacional y el comportamiento de las grandes potencias, en un campo de juego intelectual mucho más diverso. El presente artículo evalúa las impli­caciones de esta transformación en relación con el potencial normativo de las RR.II., el cual es definido en términos de producción de conocimiento y pensamiento crítico. Aunque la creciente diversidad ayuda a abordar los múltiples desafíos y crisis a los que se enfrenta la humanidad, también es evidente que el co­nocimiento y la jerga especializados, que son necesarios para participar en un subcampo particular, impiden que los académicos de las RR.II. se entiendan entre ellos. Este desarrollo no solo socava la vitalidad de nuestro campo de estudio, sino que también obstruye nuestra capacidad de interactuar con actores políticos y relacionarnos con el público. Además, comuni­dades académicas que solo miran hacia adentro minimizan el pensamiento crítico. Aunque no existe una panacea para revertir esta tendencia, el artículo afirma que el cultivo de redes de diálogo puede mitigar sus peores efectos al fa­cilitar el aprendizaje mutuo y mejorar nuestras habilidades comunicativas

Estimation of gloss from rough surface parameters

Gloss is a quantity used in the optical industry to quantify and categorize materials according to how well they scatter light specularly. With the aid of phase perturbation theory, we derive an approximate expression for this quantity for a one-dimensional randomly rough surface. It is demonstrated that gloss depends in an exponential way on two dimensionless quantities that are associated with the surface randomness: the root-mean-square roughness times the perpendicular momentum transfer for the specular direction, and a correlation function dependent factor times a lateral momentum variable associated with the collection angle. Rigorous Monte Carlo simulations are used to access the quality of this approximation, and good agreement is observed over large regions of parameter space.Comment: 5 page

Modelle und Verfahren für die innerbetriebliche Versorgungslogistik von Bergwerken

Eine Vielzahl der Rohstoffe, die in unserer Zeit industriell verarbeitet werden, wird im Bergbau gewonnen. Die vorliegende Arbeit hat den Abbau von Kalisalz unter Tage vor Augen. Der Abbau von Salz in großen Mengen erfordert den Einsatz von Maschinen. Für deren Instandhaltung sowie die Versorgung mit Betriebsstoffen stehen unter Tage Werkstätten und Lager zur Verfügung. Zur Gewährleistung eines reibungslosen Abbaus sind zahlreiche Transporttätigkeiten erforderlich. Zu transportieren sind beispielsweise Maschinenöle, Baumaterialien, Ersatzteile, defekte Maschinenteile und Abfälle. Die möglichen Strecken zur Nutzung für Transporte sind durch das Grubengebäude vorgegeben. Das Grubengebäude wächst mit fortschreitendem Abbau der Lagerstätte, wobei im Wesentlichen die räumliche Ausdehnung der Lagerstätte die resultierende Gestalt des Grubengebäudes bestimmt. Das Streckennetz eines Grubengebäudes, das die verfügbaren Fahrwege für Fahrzeuge definiert, weist in der Regel wenig Redundanzen auf. Gründe dafür sind zum einen der Aufwand der Auffahrung von Strecken und zum anderen der Aufwand für die kontinuierliche Sicherung aller zugänglichen Bereiche des Grubengebäudes. Im Rahmen der vorliegenden Arbeit werden Bäume und die neu eingeführte Struktur des Brückengraphen, als eine verallgemeinerte Baumstruktur, zur Darstellung des Streckennetzes eines Bergwerks verwendet. Als Problemstellungen werden die kapazitierte Tourenplanung auf Bäumen und Brückengraphen, der Ein- und Mehr-Fahrzeug-Fall des Gabelstaplerproblems auf Bäumen und schließlich die Planungsaufgabe einer Transportabteilung, die Abrollcontainer zur Durchführung von Transportaufträgen nutzt, untersucht. Für die kapazitierte Tourenplanung wird auf die Besonderheit der Problemstellung mit einer Baumstruktur eingegangen. Auf den Erkenntnissen basierend werden zwei mathematische Modelle für Brückengraphen als Streckennetz der Problemstellung vorgestellt. Zusätzlich wird ein zweistufiges Verfahren zur Näherung einer guten Lösung beschrieben. Die Anforderungen an das Gabelstaplerproblem auf Bäumen im Ein- und Mehr-Fahrzeugfall (MV)-TSCP werden beschrieben und auf dieser Grundlage mathematische Modelle formuliert. Weiter werden Möglichkeiten zur Komprimierung der Instanzen beschrieben. Während manche Instanzen des TSCP mit linearem Aufwand gelöst werden können, ist bei Vorliegen von Kurzzyklen aus Aufträgen im Allgemeinen die Lösung eines Steinerbaumproblems erforderlich. Die betrachtete Planungsaufgabe einer Transportabteilung unterstellt fünf Basistypen von Aufträgen und ermöglicht durch deren Verknüpfung die Abbildung zahlreicher weiterer Transporttätigkeiten. Die Berücksichtigung heterogener Mitarbeiter und Fahrzeuge sowie von Kompatibilitäten zwischen Fahrzeugen, Mitarbeitern, Material- und Containertypen ermöglicht die Abbildung realer Situationen. Die Transporttätigkeiten werden als Aufträge verwaltet. Innerhalb der Planungsperiode können nicht alle Aufträge durchgeführt werden, sodass eine Auswahl zu treffen ist. Ein gemischt-ganzzahliges, lineares Modell wird für die Problemstellung formuliert. Im Anschluss wird eine Möglichkeit zur Integration einer Pausenregelung in das Modell erläutert und ein Vorgehen zur Einbeziehung einer Priorisierung bei der Bestimmung von Nutzenwerten vorgestellt. Ein deterministisches, heuristisches Lösungsverfahren wird beschrieben. Anschließend werden eine Verfahrensvariante und die Möglichkeiten zur Erweiterung der Verfahrensvarianten zu Multi-Start-Verfahren vorgestellt. Die vorgestellten Modelle und Verfahren werden in Testläufen gegenübergestellt. Dafür kommt für mathematische Modelle kommerzielle Optimierungssoftware zum Einsatz. Die Resultate der Testläufe werden in der Arbeit beschrieben. Bezüglich der als Planungsaufgabe einer Transportabteilung untersuchten Problemstellung liefern alle Varianten des heuristischen Verfahrens gegenüber der kommerziellen Optimierungssoftware bessere Lösungen.Many of today's industrially processed raw materials are extracted in mines. Mining raw materials in large quantities requires machinery. Underground workshops and warehouses are available for their maintenance and the supply of operating materials. To ensure that mining runs smoothly, numerous transport activities are required. For example, machine oils, construction materials, spare parts, defective machine parts and waste need to be transported. The possible routes for transport are determined by the mine system. The mine system grows as the deposit is mined, with the spatial extent of the deposit largely determining the resulting shape of the mine system. The road network of a mine system, which defines the available routes for vehicles, usually has few redundancies. The reasons for this are, on the one hand, the cost of excavating the routes and, on the other hand, the effort required to continuously secure all accessible areas of the mine system. In the context of the present work, trees and the newly introduced structure of the bridge graph as a generalised tree structure are used to represent the road network of a mine. As problems, the capacitated routing problem on trees and bridge graphs, the single and multi-vehicle case of the stacker crane problem on trees and, finally, the planning task of a transport department using roll-off containers for the execution of transport jobs are investigated. For the capacitated routing problem, the specificity of the problem with a tree structure is addressed. Based on the findings, two mathematical models for the problem with bridge graphs as the network are presented. In addition, a two-step procedure for approximating a good solution is described. The requirements for the stacker crane problem on trees in the single and multi-vehicle (MV)TSCP cases are described. On this basis, mathematical models are formulated. In addition, ways of compressing the instances of the problem are described. While some instances of the TSCP can be solved with linear effort, the presence of short cycles between jobs generally requires the solution of a steiner tree problem. The considered planning task of a transport department assumes five basic types of jobs and allows the mapping of numerous other transport activities by linking them. The consideration of heterogeneous employees and vehicles as well as compatibilities between vehicles, employees, material and container types enables the mapping of real situations. Transport activities are managed as jobs. Not all jobs can be executed within the planning period, so jobs must be selected. A mixed integer linear model is formulated for the problem. A way of incorporating a break rule into the model is then explained, and a procedure for incorporating prioritisation into the determination of utility values is presented. A deterministic heuristic solution procedure is described. A variant of the procedure is then presented, together with the possibility of extending the procedure to multi-start procedures. The models and methods presented are tested and compared. For this purpose, commercial optimisation software for mathematical models is used. The results of the test runs are described in the paper. With regard to the investigated problem as a planning task of a transport department, all variants of the heuristic procedure provide better solutions than the commercial optimisation software

Evaporation boundary conditions for the linear R13 equations based on the onsager theory

Due to the failure of the continuum hypothesis for higher Knudsen numbers, rarefied gases and microflows of gases are particularly difficult to model. Macroscopic transport equations compete with particle methods, such as the Direct Simulation Monte Carlo method (DSMC), to find accurate solutions in the rarefied gas regime. Due to growing interest in micro flow applications, such as micro fuel cells, it is important to model and understand evaporation in this flow regime. Here, evaporation boundary conditions for the R13 equations, which are macroscopic transport equations with applicability in the rarefied gas regime, are derived. The new equations utilize Onsager relations, linear relations between thermodynamic fluxes and forces, with constant coefficients, that need to be determined. For this, the boundary conditions are fitted to DSMC data and compared to other R13 boundary conditions from kinetic theory and Navier–Stokes–Fourier (NSF) solutions for two one-dimensional steady-state problems. Overall, the suggested fittings of the new phenomenological boundary conditions show better agreement with DSMC than the alternative kinetic theory evaporation boundary conditions for R13. Furthermore, the new evaporation boundary conditions for R13 are implemented in a code for the numerical solution of complex, two-dimensional geometries and compared to NSF solutions. Different flow patterns between R13 and NSF for higher Knudsen numbers are observed

Personal Transparency in Perspective: The Impact of Social Networking Sites on the Recruitment Process

The “transparency trend” is hot for the summer of 2011. At least that is what they said in the fashion capitals of Milan, Paris, and London. In the new summer collections, sheer seethrough dresses reveal the beauties of the human body and leave little to the imagination. Architects too are attracted by the intriguing properties of transparent materials to create a new perception of space and boundaries, which challenges some traditional understandings of private living and daily work life. Whereas in the past, it was a Puritan statement to live without curtains at the windows, to show you had nothing to hide, today, the transparent way of life is often used to enable the owner to display their wealth and luxury. Institutions have increasingly followed this transparency trend in fashion and architecture by using glass for their buildings. Transparency is not only a fashion trend, but also a political challenge. Fashion and politics meet in the huge glass buildings of the European Union in Brussels and Strasbourg, which reflect the Union’s strategy to improve its democratic legitimacy; one of the main aims of the Lisbon Treaty (2009). In terms of adaption to this see-through trend, institutions are not only voluntarily moving towards greater transparency, they are being ambushed by those who believe that information is a public good, which should not be guarded by a few. By revealing “suppressed and censored injustices” (WikiLeaks, n.d.), WikiLeaks practices what some call “guerrilla transparency” (The Economist, 2010). When people think of transparency, the recent commotion caused by WikiLeaks’ publication of thousands of documents on nationally and internationally sensitive issues is at the forefront of their minds. This event has triggered a worldwide debate on the balance between state security and citizens’ right to know

(207)Pb Spin-Lattice Relaxation in Solid PbMoO(4) and PbCl(2)

We have measured the (207)Pb nuclear spin-lattice relaxation rate R as a function of temperature T at two nuclear magnetic resonance frequencies omega(0) in the ionic solids lead molybdate (PbMoO(4)) and lead chloride (PbCl(2)). R is unexpectedly large, proportional to T(2), and independent of omega(0). Taken together with previous work in lead nitrate [Pb(NO(3))(2)], these results show that the relaxation does not depend on the nature or rotational motion of the counterion, particularly since the counterion in lead chloride is a single chlorine atom. The theory that explains the observed relaxation rate is reviewed. A second-order Raman process dominates the observed relaxation process. It involves the modulation of the spin-rotation interaction by the lattice vibrations

First Responders to Hyperosmotic Stress in Murine Astrocytes: Connexin 43 Gap Junctions Are Subject to an Immediate Ultrastructural Reorganization

In a short-term model of hyperosmotic stress, primary murine astrocytes were stimulated with a hyperosmolar sucrose solution for five minutes. Astrocytic gap junctions, which are mainly composed of Connexin (Cx) 43, displayed immediate ultrastructural changes, demonstrated by freeze– fracture replica immunogold labeling: their area, perimeter, and distance of intramembrane particles increased, whereas particle numbers per area decreased. Ultrastructural changes were, however, not accompanied by changes in Cx43 mRNA expression. In contrast, transcription of the gap junction regulator zonula occludens (ZO) protein 1 significantly increased, whereas its protein expression was unaffected. Phosphorylation of Serine (S) 368 of the Cx43 C–terminus has previously been associated with gap junction disassembly and reduction in gap junction communication. Hyperosmolar sucrose treatment led to enhanced phosphorylation of Cx43S368 and was accompanied by inhibition of gap junctional intercellular communication, demonstrated by a scrape loading-dye transfer assay. Taken together, Cx43 gap junctions are fast reacting elements in response to hyperosmolar challenges and can therefore be considered as one of the first responders to hyperosmolarity. In this process, phosphorylation of Cx43S368 was associated with disassembly of gap junctions and inhibition of their function. Thus, modulation of the gap junction assembly might represent a target in the treatment of brain edema or trauma

Spin-Lattice Relaxation of Heavy Spin-1/2 Nuclei in Diamagnetic Solids: A Raman Process Mediated By Spin-Rotation Interaction

We present a theory for the nuclear spin-lattice relaxation of heavy spin-1/2 nuclei in solids, which explains within an order of magnitude the unexpectedly effective lead and thallium nuclear spin-lattice relaxation rates observed in the ionic solids lead molybdate, lead chloride, lead nitrate, thallium nitrate, thallium nitrite, and thallium perchlorate. The observed rates are proportional to the square of the temperature and are independent of magnetic field. This rules out all known mechanisms usually employed to model nuclear spin relaxation in lighter spin-1/2 nuclei. The relaxation is caused by a Raman process involving the interactions between nuclear spins and lattice vibrations via a fluctuating spin-rotation magnetic field. The model places an emphasis on the time dependence of the angular velocity of pairs of adjacent atoms rather than on their angular momentum. Thus the spin-rotation interaction is characterized not in the traditional manner by a spin-rotation constant but by a related physical parameter, the magnetorotation constant, which relates the local magnetic field generated by spin rotation to an angular velocity. Our semiclassical relaxation model involves a frequency-mode description of the spectral density that can directly be related to the mean-square amplitudes and mode densities of lattice vibrations in the Debye model