Touching Language!

This paper argues for using academic Arabic more actively in Arabic Studies in Germany. Based on an ongoing discussion at the Centre for Near and Middle Eastern Studies at the Philipps-Universität Marburg about the pros and cons of dealing more closely with academic knowledge production from the MENA region, this paper sheds light on the potentials of academic Arabic for non-native students and scholars. In the framework of postcolonial studies, it discusses linguistic, epistemic and ethic benefits of using academic Arabic in teaching and researching more actively and maps recent German initiatives to foster academic Arabic. As a conclusion, it calls for a close affective contact with Arabic: Daring to touch language and getting touched by language

Fiber-optical switch controlled by a single atom

We demonstrate highly efficient switching of optical signals between two optical fibers controlled by a single atom. The key element of our experiment is a whispering-gallery mode bottle microresonator, which is coupled to a single atom and interfaced by two tapered fiber couplers. Even in the presence of the coupling fibers, the atom--resonator system reaches the strong coupling regime of cavity quantum electrodynamics (CQED), leading to a vacuum Rabi splitting in the excitation spectrum. We systematically investigate the switching efficiency of our system, i.e., the probability that the CQED fiber-optical switch redirects the light into the desired output. We obtain a large redirection efficiency reaching a raw fidelity of more than 60% without post-selection.Comment: 5 pages, 4 figure

Dilations and rigid factorisations on noncommutative L^p-spaces

We study some factorisation and dilation properties of completely positive maps on noncommutative L^p-spaces. We show that Akcoglu's dilation theorem for positive contractions on classical (=commutative) L^p-spaces has no reasonable analog in the noncommutative setting. Our study relies on non symmetric analogs of Pisier's operator space valued noncommutative L^p-spaces that we investigate in the first part of the paper.Comment: To be published in Journal of Functional Analysi

Die Entblößung der Wörter

Aḥmad Fāris al-Shidyāq (1805/1806–1887) is regarded as one of the most important Arab intellectuals of the nineteenth century. In 1855, in Paris, he published his masterpiece, al-Sāq ʿalā al-sāq fī mā huwa al-Fāriyāq (Leg Over Leg, or, The Turtle in the Tree, Concerning The Fāriyāq What Manner of Creature Might He Be), a landmark in modern Arabic literature, which confronts the reader with numerous word lists. From the perspective of Literary and Cultural Studies, this book approaches al-Shidyāq’s lists as a fundamental social and cultural critique of his time. It develops a set of analytical tools to describe the epistemic and aesthetic dimensions of ‘exposing words’, and to make sense of the plentiful, but often neglected, word lists found throughout Arabic literature and lexicography. This include, for instance, the poetics of enumerative rhymed prose and lists of synonyms that played a distinctive role in the premodern and early modern Arabic tradition, while they remain largely neglected by literary and cultural studies. In dialogue with theories of, for instance, Assmann, Barthes and Cixous, the book discusses al-Shidyāq’s word lists as a fundamental social and cultural critique of the nineteenth century. In this regard, the enumeration of arcane Arabic words often negotiate the contemporary discourses of gender, pleasure and language and read them ‚against the grain‘. In the framework of the “return to philology“ (Edward Said), this book treats al-Shidyāq’s approach to language as a radical social and cultural criticism of the nineteenth century, which sheds new light on the Nahḍa, the Arab renewal movement on the eve of modernity. In regard to the Nahḍa Studies, this study also provides a substantial insight in the middle period of al-Shidyaq’s works written and published in London and Paris between 1848 and 1857. Drawing on fresh sources, it traces al-Shidyaq position within networks of Arab and European scholars and authors, and it unearhtes, for the first time, the historic Arabic and European reception of al-Sāq. The extensive supplement provides a selection of Arabic, French, English, and German paratexts from the nineteenth century that are important for understanding al-Shidyāq’s life and work

Minimizing Aliasing in Multiple Frequency Harmonic Balance Computations

The harmonic balance method has emerged as an efficient and accurate approach for computing periodic, as well as almost periodic, solutions to nonlinear ordinary differential equations. The accuracy of the harmonic balance method can however be negatively impacted by aliasing. Aliasing occurs because Fourier coefficients of nonlinear terms in the governing equations are approximated by a discrete Fourier transform (DFT). Understanding how aliasing occurs when the DFT is applied is therefore essential in improving the accuracy of the harmonic balance method. In this work, a new operator that describe the fold-back, i.e. aliasing, of unresolved frequencies onto the resolved ones is developed. The norm of this operator is then used as a metric for investigating how the time sampling should be performed to minimize aliasing. It is found that a time sampling which minimizes the condition number of the DFT matrix is the best choice in this regard, both for single and multiple frequency problems. These findings are also verified for the Duffing oscillator. Finally, a strategy for oversampling multiple frequency harmonic balance computations is developed and tested

Immobilized Ru‐Pincer Complexes for Continuous Gas‐Phase Low‐Temperature Methanol Reforming‐Improving the Activity by a Second Ru‐Complex and Variation of Hydroxide Additives

Ru-pincer complexes were immobilized as supported liquid phase (SLP) materials to allow the methanol reforming reaction as continuous gas phase process. Under reaction conditions, the liquid phase forms from the hydroxide coating. Several hydroxides were screened and CsOH showed highest activity compared to the standard KOH coating. The well-known Ru-pincer complex carbonylchlorohydrido [bis(2-di-i-propylphosphinoethyl)amine]ruthenium(II) is limited in catalyzing the final step of the methanol reforming. Addition of a second complex, having a methylated backbone in the pincer-ligand, could overcome these limitations. Significant enhancement of the overall catalytic activity was observed

Organic potatoes, reduced tillage and mulch in temperate climates

The experiments with mulching were done in a systems approach comparing potatoes as they are typically produced in Germany with ploughing to a system of non-inversion tillage combined with mulch. As the plots are integrated in two long-term experiments comparing ploughed versus minimum tillage it was not possible to integrate a mulched ploughed treatment or a non-mulched non-inversion tillage due to restrictions in plot size. We tested the effects of mulching in a ploughed system in 2015. There was no late blight but good erosion control (Pict.5) and yields were increased through mulching. Compost effects on the system were so far not clearly visible. It will most likely take several more years of regular applications to start seeing changes in system performance. Overall, mulching will change the potato system and it will depend very much on the local soil and climatic conditions if and when mulching will be positive (Table 1). On the one hand, mulching is labor intensive and requires the availability of materials to use. Besides freshly cut materials silage is an alternative option some farmers are using in vegetables in Germany. This reduces the dependence on the growing conditions for the mulch early in the season and likely also increases the fertilization effect. Farms that have no animals often mulch grass-clover. This will suppress N-fixation by the clover due to the nutrients in the mulch and thus reduce the usefulness of the grass-clover for nutrient accumulation. In addition it may result in leaching and thus loss of nutrients and even potentially harm the environment. Using the first and most rich harvest as mulch in the potatoes or alternatively making silage for later use is easier than composting such materials. Once the mulch is applied, no more mechanical weed control is done saving labor and energy. More importantly, it will also reduce the mechanical damage done to the potato foliage that makes them more susceptible to infections and it allows for profuse growth of fine roots into the applied mulch materials. Mulching also reduced Colorado potato beetles in both years to some extent but these data need confirmation. Also, the residual effects on the subsequent crop after the potatoes due to the increased input of organic amendments still need to be studied. Ecologically speaking mulching has many advantages. These advantages are especially important in water restricted areas. If and how mulching is feasible and economical depends on the specific conditions and organization of a farm, however