cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A critical review on the process of contaminant removal in Fe0-H2O systems.
Creators: name: Noubactep, C.
Publisher: name: FID GEO
Year: 2008

description: A central aspect of the contaminant removal by elemental iron materials (Fe0 or Fe0 materials) is that reduction reactions are mediated by the iron surface (direct reduction). This premise was introduced by the pioneers of the reactive wall technology and is widely accepted by the scientific community. In the meantime enough evidence has been provided to suggest that contaminant reduction through primary corrosion products (secondary reductants) does indeed occur (indirect reduction). It was shown for decades that iron corrosion in the pH range of natural waters (4-9) inevitably yields an obstructive oxide film of corrosion products at the metal surface (oxide film). Therefore, contaminant adsorption on to corrosion products and contaminant co-precipitation with corrosion products inevitably occurs. For adsorbed and coprecipitated contaminants to be directly reduced the oxide film should be electronic conductive. This study argues through a literature review a series of points which ultimately lead to the conclusion that, if any quantitative contaminant reduction occurs in the presence of Fe0 materials, it takes place within the matrix of corrosion products and is not necessarily a direct reduction. It is concluded that Fe0 materials act both as source of corrosion products for contaminant adsorption/coprecipitation and as a generator of FeII and H2 (H) for possible catalytic contaminant reduction.
Lambda and Phi Production in Heavy Ion Collisions
Creators: name: Mischke, A.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Recent NA49 results on $Λ$ and $ϕ$ production in central Pb-Pb collisions at beam energies from 40 to 158 A$\cdot$GeV are presented.
description: 3 pages, 4 figures, International School of Subnuclear Physics (Erice, 2003)
Zastosowanie metody E-H do określenia zasięgu geograficznego rynku masła
THE APPLICATION OF E-H METHOD TO DETERMINE THE GEOGRAPHIC SCOPE OF THE BUTTER MARKET
Creators: name: Roman, Monika
name: Roman, Monika
Publisher: name: Unknown
Year: 2017
Subjects: subject: Agribusiness
subject: metoda Elzinga-Hogarty
subject: LIFO test
subject: LOFI test
subject: rynek masła
subject: delimitacja rynku

description: The aim of the paper was to define geographic scope of the butter market using Elzinga-Hogarty test. For practical use of this method author made three assumptions: 1) for butter products was classified according to the customs nomenclature code 040510; 2) starting point of the analysis was Poland market; 3) LOFI i LIFO tests were established at the level of 90%. The article uses secondary data on butter: production, import, export and population of countries collected by FAO for 2013, as well as data on the consumption of butter from CDIC reports on global consumption of dairy products. Results of the research allow the author to define butter market as a semi-global market which consists of Poland area and 8 other countries in the Europe. Such market has production of 1.66 billion kg, consumption of 1.64 billion kg and small import at the level of 0,13 billion kg as well as small exports at the level of 0.17 billion kg.
Oxygen enhanced atomic chain formation
Creators: name: Thijssen, W. H. A.
name: Marjenburgh, D.
name: Bremmer, R. H.
name: van Ruitenbeek, J. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report experimental evidence for atomic chain formation during stretching of atomic-sized contacts for gold and silver, that is strongly enhanced due to oxygen incorporation. While gold has been known for its tendency to form atomic chains, for silver this is only observed in the presence of oxygen. With oxygen the silver chains are as long as those for gold, but the conductance drops with chain length to about 0.1 conductance quantum. A relation is suggested with previous work on surface reconstructions for silver (110) surfaces after chemisorption of oxygen.
description: 4 pages, 4 figures
title: Μία συνομιλία μεταξύ τοπίου και κατασκευής.
Επανεξετάζοντας στοιχεία ανώνυμης αρχιτεκτονικής: το παράδειγμα του ημινομαδικού συστήματος κτηνοτροφίας στην ευρύτερη περιοχή του Παρνασσού.

title: A dialogue between landscape and human structure.  Reviewing anonymous architectural elements: the example of semi-nomadic husbandry system in the broader area of mount Parnassus
Creators: name: Σεφερλη-Φραντζη Κονδυλια
Publisher: name: Technical University of Crete
Year: 2021

description: “Ενώ γύρω μας όλα αλλάζουν, τα αρχέτυπα παραμένουν αναλλοίωτα μέσα στον χρόνο, ως προς τα υλικά, τον τρόπο κατασκευής και την φόρμα, για να εξυπηρετούν άμεσες ανάγκες”1. “Τα μαντριά, παρότι χώροι μελλοθανάτων, φαίνεται να αποτελούν δοχεία ζωής προσαρμοσμένα με μοναδικό τρόπο στο τοπίο, με καλό προσανατολισμό και αερισμό, φυσικά υλικά και μια απλότητα στη δομή τους”2.
Η παρούσα διπλωματική εργασία έχει ως αφετηρία την κατανόηση της σημαντικότητας αυτών των κατασκευών στην πάροδο του χρόνου, ως ενεργά στοιχεία ανώνυμης αρχιτεκτονικής. Κύρια εργαλεία καθίστανται, η χαρτογράφηση, η έρευνα πεδίου και οι βιβλιογραφικές αναφορές. Μέσα απο την κατανόηση των παραμέτρων όσον αφορά στην τοποθεσία, στην κατασκευή και στη λειτουργία τους, προκύπτουν οι σχεδιαστικές αρχές, ευέλικτες στην εποχικότητα της λειτουργίας, καθώς η, ανάλογα με την εποχή μετακίνηση των κοπαδιών, είναι αναγκαία. Σκοπός της διπλωματικής εργασίας είναι να προτείνει τις συνθήκες συνέχειας και επαναπροσδιορισμού του τύπου αυτής της δραστηριότητας.   Προτείνεται ένα σύγχρονο μοντέλο ημινομαδικού συστήματος κτηνοτροφίας, διασφαλίζοντας καλύτερες συνθήκες διαβίωσης των ζώων και του κτηνοτρόφου, διατηρώντας μια σχέση ενσωμάτωσης της κατασκευής στο τοπίο, σε αντιδιαστολή με τις μεγάλες μονάδες μαζικής κτηνοτροφικής παραγωγής. Σε επιλεγμένες τοποθεσίες του Παρνασσού χωροθετείται ένα σύστημα μαντριών, μία χειμερινή και μία θερινή, με κοινές σχεδιαστικές αρχές και προσαρμογή στις εκάστοτε γεωμορφολογικές και κλιματικές συνθήκες.
Strategia kształtowania przewagi konkurencyjnej na rynku produkcji trawników rolowanych oraz mat wegetacyjnych. studium przypadku
STRATEGY OF CREATING A COMPETITIVE ADVANTAGE ON THE MARKET OF ROLL-ON LAWN PRODUCTION AND VEGATATION MATS. CASE STUDY
Creators: name: Rutkiewicz, Krzysztof
name: Woźniak, Monika
name: Rutkiewicz, Krzysztof
name: Woźniak, Monika
Publisher: name: Unknown
Year: 2017
Subjects: subject: Agribusiness
subject: przewaga konkurencyjna
subject: konkurencyjność
subject: trawniki rolowane
subject: maty wegetacyjne

description: The aim of the study was to evaluate the strategy of creating a competitive advantage of a company operating in the Polish sector of rolling lawns and vegetation mats. Authors described the sources of the company competitiveness, including key suppliers, customers and competitors. Research included the internal determinants and tools leading to the stabilisation of the company strategic position. Theoretical information was taken from books, journals and promotional brochures. To evaluate the economic and financial situation of the company there was used a report from the National Court Register. The analysis also was based on deduction, descriptive and critical-cognitive methods. An explicit non-participating observation and a direct interview were implemented. Competition on the rolling lawns’ market is settled. A dispersed localization of companies in Poland means that they are not a threat to each other. A significant barrier is the cost of entry into the sector, related to the purchase of a land and high capital expenditures correlated with a long cycle of a vegetative season. The competitive advantage of the researched company relies on: 1) the convenient location of its office in an expansive region of arable land, conducive to reducing the transport costs of raw materials and final products, 2) distinguishing quality of products, a lack of price competition and generating higher sales revenues, 3) a reputation of the trade mark, which encourages customers to invest in green roofs, 4) a professional execution of orders and consulting. Staff development in terms of skills and knowledge sparks an increased productivity. Economic and financial results of the company confirm the effectiveness of management. The owner is constantly looking for technical innovation and takes care of a good image of the company, taking part in trade exhibitions.
Semistability vs. nefness for (Higgs) vector bundles
Creators: name: Bruzzo, U.
name: Ruiperez, D. Hernandez
Publisher: name: arXiv
Year: 2003
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14D20; 14F05; 14H60

description: According to Miyaoka, a vector bundle E on a smooth projective curve is semistable if and only if a certain numerical class in the projectivized bundle PE is nef. We establish a similar criterion for the semistability of Higgs bundles: namely, such a bundle is semistable if and only if for every integer s between 0 and the rank of E, a suitable numerical class in the scheme parametrizing the rank s locally-free Higgs quotients of E is nef. We also extend this result to higher-dimensional complex projective varieties by showing that the nefness of the above mentioned classes is equivalent to the semistability of the Higgs bundle E together with the vanishing of the discriminant of E.
description: Comments: 20 pages, Latex2e, no figures. v2 includes a generalization to complex projective manifolds of any dimension. To appear in Diff. Geom. Appl
title: Optimization of Gold Nanoparticles for Radiotherapy
Creators: name: Grellet, Sophie
Publisher: name: The Open University
Year: 2020

description: Radiotherapy is currently used in around 50% of cancer treatments. Although highly effective it is also damaging to surrounding healthy tissues and needs to be improved by better targeting of cancer cells. Improved radiotherapy outcomes can be achieved by using nanoparticles, especially those with high atomic number (Z), that interact with ionising radiation to generate secondary electrons and reactive species that increase cellular damage. One of the most promising elements to use is gold, in the form of gold nanoparticles (AuNPs) because of its biocompatibility and amenability to surface modification. For example, surface modification of AuNPs with simple sugars can improve their solubility and cellular uptake. Furthermore, positively charged AuNPs are thought to have an improved cellular uptake because of their interactions with negatively charged cell membranes. This thesis is focussed on two research areas: (1) the development of dual action chemo-radiosensitising AuNPs and (2) the development of oligonucleotide-AuNPs for radiosensitisation. (1) It is shown that sugar-PEGamine coated AuNPs demonstrate selective uptake and toxicity toward skin cancer cells with an IC50 of 1 μg/ml [Au], without damaging normal skin cells at this concentration. Oxidative stress and caspase-dependent apoptosis both play a key role in the toxicity of these AuNPs. Moreover, AuNPs coated with sugar and PEGamine show a strong radiosensitisation effect in combination with kilovoltage X-rays and a smaller effect with megavoltage X-rays. (2) Oligonucleotide-phosphine-coated AuNPs are shown to demonstrate a limited uptake in the cellular cytoplasm compared to the previous AuNPs but increase AuNPs uptake into the cell nucleus. The limited uptake into the cells, as well as the DNA triplex forming oligonucleotides (TFOs) attached to the AuNPs, is still responsible for a radiosensitisation effect, although smaller than with sugar:PEGamine AuNPs. In the future, the uptake of the oligonucleotides AuNPs may possibly be improved by varying their size (from 3.5 to 2 nm) and/or adding a spacer between the NP and the TFO.
title: State policy, liberalisation and the development of the Indian software industry
Creators: name: Heeks, Richard Brendan
Publisher: name: The Open University
Year: 1991

description: This thesis investigates the relationship between industrial development and industrial policy in a developing country. The chosen industry - software - is of recent origin and of growing importance in many developing countries, for which it can present one of the best entry points into the information technology production complex. Yet this industry and, particularly, the role of state policy in its development have been relatively neglected within the literature. The key policy issue of recent years has been policy liberalisation, and the thesis takes as its central theme the role that policy liberalisation plays in software industry development. A specific case study is made of the Indian software industry and Indian software policy because these have been long-standing, and because they combine high growth with liberalisation. The conclusion reached is that certain policy liberalisations may have a role to play in software industry development but that liberalisation cannot be seen as a 'panacea' for such development. The impacts of some liberalisations run counter to some long-term development objectives while state intervention is seen to have played a positive and necessary role in assisting software industry growth. At the same time, certain liberalisations are found to be either politically or financially unfeasible. Software policy makers face a major decision on whether to orient their industry towards the domestic or export markets. It is argued that the Indian industry has shown an export bias which should be reduced by greater orientation to the domestic market. Other developing countries may need to focus even more on domestic-oriented production rather than exports. Policy is not the only determinant of software industry development because technology, market entry barriers, input supply constraints, and producer-consumer relations also play a part. Nevertheless, policy has a very important role to play and should be applied in a non-dogmatic way that is responsive to the specific and changing circumstances of individual nations and industries.
Juraphyllites Muller 1939
Creators: name: Fauré, Philippe
name: Sekatni, Nejla
name: Arfaoui, Mohamed Sabri
name: Alouani, Rabah
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Ammonoidea
Juraphyllitidae
Juraphyllites

description: Genre Juraphyllites Müller, 1939
 ESPÈCE TYPE. — Phylloceras diopsis Gemmellaro, 1884 par désignation originale.
description: Published as part of Fauré, Philippe, Sekatni, Nejla, Arfaoui, Mohamed Sabri & Alouani, Rabah, 2021, Le Jurassique du Jebel Ressas (Tunisie). Identification du Sinémurien supérieur dans la Formation Zaghouan. Précisions stratigraphiques et paléobiogéographiques sur le Sinémurien de Tunisie, pp. 95-119 in Geodiversitas 43 (4) on page 104, DOI: 10.5252/geodiversitas2021v43a4, http://zenodo.org/record/4555560
A Bethe--Salpeter Description of Light Mesons
Creators: name: Weigel, H.
name: Alkofer, R.
name: Watson, P.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a covariant approach to describe the low--lying scalar, pseudoscalar, vector and axialvector mesons as quark--antiquark bound states.This approach is based on an effective interaction modeling of the non--perturbative structure of the gluon propagator that enters the quark Schwinger--Dyson and meson Bethe--Salpeter equations. We extract the meson masses and compute the pion and kaon decay constants. We obtain a quantitatively correct description for pions, kaons and vector mesons while the calculated spectra of scalar and axialvector mesons suggest that their structure is more complex than being quark--antiquark bound states.
description: Talk presented by HW at the international Scalar Meson Workshop, Utica, NY, May 2003; 12 pages, uses aip style files
Exhumation and uplift of the Sierras Pampeanas: preliminary implications from K–Ar fault gouge dating and low-T thermochronology in the Sierra de Comechingones (Argentina)
Creators: name: Löbens, Stefan
name: Bense, Frithjof
name: Wemmer, Klaus
name: Dunkl, István
name: Costa, Carlos
name: Layer, Paul
name: Siegesmund, Siegfried
Publisher: name: Springer-Verlag
Year: 2011

description: The Sierras Pampeanas in central and north-western Argentina constitute a distinct morphotectonic feature between 27°S and 33°S. The last stage of uplift and deformation in this area are interpreted to be closely related to the Andean flat-slab subduction of the Nazca plate beneath the South American plate. K–Ar fault gouge dating and low-temperature thermochronology along two transects within the Sierra de Comechingones reveal a minimum age for the onset of brittle deformation about 340 Ma, very low exhumation rates since Late Paleozoic time, as well as a total exhumation of about 2.3 km since the Late Cretaceous. New Ar–Ar ages (7.54–1.91 Ma) of volcanic rocks from the San Luis volcanic belt support the eastward propagation of the flat-slab magmatic front, confirming the onset of flat-slab related deformation in this region at 11.2 Ma. Although low-temperature thermochronology does not clearly constrain the signal of the Andean uplift, it is understood that the current structural relief related to the Comechingones range has been achieved after the exhumation of both fault walls (circa 80–70 Ma).
Family ties to Buddhist monks and nuns in medieval China : a biographical and hagiographical study of the Southern Xiao family branch
Creators: name: Phan, Cam Van Thi
Publisher: name: University of British Columbia
Year: 2011

description: The roles of kinship and family ties have recently become recognized as a vital yet unexplored area in the study of medieval Buddhism. This is especially critical in restructuring the relationship between political and religious spheres, which for the Sinologist have always been intricately linked to one another. Although there are studies noting the prominence of family connection in the study of monks and nuns, past studies have focused mainly on the manipulation and modification of religion by political figures for solely secular purposes. Not many studies have turned the tables to analyze the significance of a monk or nun's family background and its intimate influence throughout his or her religious life; nor have they considered how a layman or laywoman's spiritual devotion greatly shapes his or her social life and political career. It is my aim to extend such research and explore on a larger scale the intricate relationship between monastic and lay family members, in this case Xiao Yu, his daughters, sons and relatives, ten in all, from the Southern Xiao family branch during the late Sui to early Tang period. This research serves to prove that the life of a monk or nun, while determined by that individual's vocation and endeavor, is to a degree also conditioned by his or her family background, kinship ties and secular acquaintance. This research, based upon hagiography, epigraphy and relevant materials from canonical and secular sources substantiates the belief that comprehensive study of the monastic order should involve analysis of factors beyond the spiritual sphere.
title: Carbon deposition on transition metal- and uranium-oxides
Creators: name: Hallam, Keith Richard
Publisher: name: The Open University
Year: 1991

description: Advanced gas cooled nuclear reactors (AGRs) contain a range of alloys, selected for their physical and chemical performance in the conditions present. Carbon deposition on boiler and fuel pin heat transfer surfaces affects a reactor's efficiency and may necessitate downrating to maintain safety margins. This is believed to arise from decomposition of some of the coolant gas constituents. Deposition minimisation, while maintaining the structural integrity of the reactor, is technologically and economically important. This study has looked at deposition on a range of transition metal spinels, manganese oxides, uranium oxides and single crystal magnetite samples with a view to furthering knowledge of catalytic reactions that may occur within an AGR. In particular, the effect of mixed valency on deposition rates was studied. The spinels were successfully prepared by solid state reactions between the relevant oxides, oxalates and I or carbonates. A range of elemental and chemical analytical techniques were used to characterise the samples both before and after exposure under controlled gas and radiological conditions. Deposition was induced, to varying extents, on all the samples exposed. No filamentary deposits were observed. The spinels gave quantities of deposition in the order: Manganese spinels gave increasing deposition with increasing manganese content at 650°C, but decreasing deposition at 550°C. Iron-cobalt spinels showed no consistent increase or decrease in carbon deposition with changing composition. Nickel rich spinels were unstable in the reaction gas mixture and generated metallic nickel during exposure. At both temperatures, this gave levels of carbon deposition which increased with increasing nickel content of the original oxide. NiF~04 exposed at 550°C fragmented as it catalysed carbon formation. Manganese oxides converted to MnO during exposure, MnO proving also to be a most effective catalyst. Mn304' an Mn2+ I Mn3+ compound where the manganese ions do not form an electron exchanging octahedrally coordinated pair, did not yield large quantities of deposit. The uranium oxides examined converted to the interacting mixed valence U409' which gave copious carbon deposition. The U4+ I U6+ non interacting mixed valence Ot-U30 S gave the least deposition. Magnetite slices gave laminar carbon deposits, but no filamentary growth. Structured deposit was seen in two cases, including on one face oriented approximately parallel to the [111] plane, the plane previously expected to catalyse deposition most effectively.
title: Interpretations of a constructivist philosophy in mathematics teaching
Creators: name: Jaworski, Barbara
Publisher: name: The Open University
Year: 1991

description: This thesis is a research biography which reports a study of mathematics teaching. It involves research into the classroom teaching of mathematics of six teachers, and into their associated beliefs and motivations. The teachers were selected because they gave evidence of employing an investigative approach to mathematics teaching, according to the researcher's perspective. A research aim was to characterise such an approach through the practice of these teachers. An investigative approach was seen to be embedded in a radical constructivist philosophy of knowledge and learning. Observations and analysis were undertaken from a constructivist perspective and interpretations made were related to this perspective. Research methodology was ethnographic in form, using techniques of participant-observation and informal interviewing for data collection, and triangulation and respondent validation for verification of analysis. Analysis was qualitative, leading to emergent theory requiring reconciliation with a constructivist theoretical base. Rigour was sought by research being undertaken from a researcher-as-instrwnent position, with the production of a reflexive account in which interpretations were accounted for in terms of their context and the perceptions of the various participants including those of the researcher. Research showed that those teachers who could be seen to operate from a constructivist philosophy regularly made high level cognitive demands which resulted in the incidence of high level mathematical processes and thinldng skills in their pupils. Levels of interpretation within the study led to the identification of investigative teaching both as a style of mathematics teaching and as a form of reflective practice in the teaching of mathematics. These forms were synthesised as a constructivist pedagogy and as an epistemology for practice which may be seen to forge links between the theory of mathematics teaching and its practice. The research is seen to have implications for the teaching of mathematics, and for the development of mathematics teaching itself through professional development of mathematics teachers.
The turbulent dynamo as an instability in a noisy medium
Creators: name: Leprovost, Nicolas
name: Dubrulle, Bérengère
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study an example of instability in presence of a multiplicative noise, namely the spontaneous generation of a magnetic field in a turbulent medium. This so-called turbulent dynamo problem remains challenging, experimentally and theoretically. In this field, the prevailing theory is the Mean-Field Dynamo (Krause and Rädler, 1980) where the dynamo effect is monitored by the mean magnetic field (other possible choices would be the energy, flux,...). In recent years, it has been shown on stochastic oscillators that this type of approach could be misleading. In this paper, we develop a stochastic description of the turbulent dynamo effect which permits us to define unambiguously a threshold for the dynamo effect, namely by globally analyzing the probability density function of the magnetic field instead of a given moment.
description: 6 pages
Josephson current via an isolated Majorana zero mode
Creators: name: Liu, Chun-Xiao
name: van Heck, Bernard
name: Wimmer, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the equilibrium dc Josephson current in a junction between an $s$-wave and a topological superconductor. Cooper pairs from the $s$-wave superconducting lead can transfer to the topological side either via an unpaired Majorana zero mode localized near the junction, or via the above-gap continuum states. We find that the Majorana contribution to the supercurrent can be switched on when time-reversal symmetry in the conventional lead is broken, e.g., by an externally applied magnetic field inducing a Zeeman splitting. Moreover, if the magnetic field has a component in the direction of the effective spin-orbit field, there will be a Majorana-induced anomalous supercurrent at zero phase difference. This behavior may serve as a signature characteristic of Majorana zero modes, and is accessible to devices with only superconducting contacts.
description: 10 pages, 4 figures
Constrained deformation of a confined solid: a strain induced crystal-smectic transition
Creators: name: Chaudhuri, Debasish
name: Sengupta, Surajit
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We report results of computer simulations of two-dimensional hard disks confined within a quasi one-dimensional ``hard-wall'' channel, a few atomic radii wide. Starting from a commensurate triangular solid a rescaling of the system size parallel to the channel length introduces a rectangular distortion of the solid which, beyond a critical limit, phase separates into alternating bands of solid and smectic phases. The resulting solid- smectic interfaces are broad and incorporate misfit dislocations. The stress-strain curve shows large plastic deformation accompanying the crystal-smectic transition which is reversible. The smectic phase eventually melts into a modulated liquid with a divergent Lindemann parameter.
description: 4 pages 2 b+w and 2 color eps files
Fermion dynamical symmetry and strongly-correlated electrons: a comprehensive model of high-temperature superconductivity
Creators: name: Guidry, Mike
name: Sun, Yang
name: Wu, Lian-Ao
name: Wu, Cheng-Li
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We review application of the SU(4) model of strongly-correlated electrons to cuprate and iron-based superconductors. A minimal self-consistent generalization of BCS theory to incorporate antiferromagnetism on an equal footing with pairing and strong Coulomb repulsion is found to account systematically for the major features of high-temperature superconductivity, with microscopic details of the parent compounds entering only parametrically. This provides a systematic procedure to separate essential from peripheral, suggesting that many features exhibited by the high-$T\tsub c$ data set are of interest in their own right but are not central to the superconducting mechanism. More generally, we propose that the surprisingly broad range of conventional and unconventional superconducting and superfluid behavior observed across many fields of physics results from the systematic appearance of similar algebraic structures for the emergent effective Hamiltonians, even though the microscopic Hamiltonians of the corresponding parent states may differ radically from each other.
description: 62 pages, 56 figures, accepted for publication Frontiers of Physics
Das Interglazial von Fahrenkrug in Holstein
Creators: name: Averdieck, F.-R.
Publisher: name: Geozon Science Media
Year: 1962

description: Die Neuuntersuchung des Interglazialvorkommens von Fahrenkrug bei Segeberg (Holstein) ergab ein saale/weichselinterglaziales Alter (Zone e bis i). Die Angabe von Rotbuche, Fagus silvatica L., muß auf eine Fehlbestimmung zurückgeführt werden. Da bisher Rotbuchenfunde älteren Datums durch Nachuntersuchungen nicht bestätigt werden konnten, muß mit dem Fehlen von Fagus mindestens für das Jungpleistozän Nord- und Mitteleuropas gerechnet werden. Ausnahmen, die vermutlich in ein Würm-Interstadial zu stellen sind, sind aus dem Alpengebiet bekannt. Möglicherweise hängen hiermit fernverwehte Buchenpollen in einigen Fundplätzen des Brørup-Interstadials zusammen.
description: research
Fernwirkungen der litorinen Ostseetransgression auf tiefliegende Becken und Flußtäler
Creators: name: Richter, G.
Publisher: name: Geozon Science Media
Year: 1968

description: An drei Seebecken im Flußgebiet der Peene (Mittelmecklenburg), dereh Boden heute unter dem Meeresspiegel liegt, wird die holozäne Entwicklung verfolgt. Nach einer spätpleistozänen Staubeckenphase erfüllten präboreale Seen die gesamten Beckenniederungen einschließlich der heutigen Verlandungsflächen. Im Boreal und Alt-Atlantikum verlandeten die Seen bis etwa auf ihr heutiges Ausmaß. Vom Jung-Atlantikum an geraten die Seen in den Rückstaubereich der Litorina-Transgression. In drei Überflutungsphasen, deren älteste dem hochlitorinen Transgressionsstoß entspricht, erobern die Seen Teile der Verlandungsflächen zurück. Zwischengeschaltete Verlandungsphasen sind besonders im Subboreal stark ausgeprägt. Der gesamte Spiegelanstieg beträgt seit dem Boreal 3,5 - 4 m. Die Seespiegel liegen zu Beginn der ersten Überflutungsphase (Jung-Atlantikum — frühes Subboreal) ca. 3 m, zu Beginn der zweiten (spätes Subboreal — frühes Subatlantikum) ca. 2 m und zu Beginn der dritten (Subatlantikum) ca. 1 m unter dem Spiegelstand des vorigen Jahrhunderts. Der Brackwassereinbruch bleibt auf die Unterläufe der Flüsse beschränkt. Die geschilderten Fernwirkungen der Litorina-Transgression reichen im Peenegebiet bis zu 90 – 120 km landeinwärts und bis zu + 5 - 6 m NN. Sie greifen in den noch uneinheitlichen, aus Schmelzwasserrinnen hervorgegangenen Entwässerungssystemen des Jungmoränengebietes anscheinend weiter landeinwärts als an den Nordseeflüssen, wo die Transgression in Flußtäler mit ausgeglichenem Gefälleprofil eindrang.
description: research
Co-Digestion of Rice Straw with Cow Manure in an Innovative Temperature Phased Anaerobic Digestion Technology: Performance Evaluation and Trace Elements
Creators: name: Muhayodin, Furqan
name: Fritze, Albrecht
name: Larsen, Oliver Christopher
name: Spahr, Marcel
name: Rotter, Vera Susanne
Publisher: name: Technische Universität Berlin
Year: 2021
Subjects: subject: 620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: rice straw
subject: cow manure
subject: anaerobic digestion
subject: trace elements
subject: temperature
subject: methane
subject: nutrients
subject: renewable energy

description: Rice straw is an agricultural residue produced in abundant quantities. Open burning and plowing back the straw to the fields are common practices for its disposal. In-situ incorporation and burning cause emissions of greenhouse gas and particulate matter. Additionally, the energy potential of rice straw is lost. Anaerobic digestion is a technology that can be potentially used to utilize the surplus rice straw, provide renewable energy, circulate nutrients available in the digestate, and reduce greenhouse gas emissions from rice paddies. An innovative temperature phased anaerobic digestion technology was developed and carried out in a continuous circulating mode of mesophilic and hyperthermophilic conditions in a loop digester (F1). The performance of the newly developed digester was compared with the reference digester (F2) working at mesophilic conditions. Co-digestion of rice straw was carried out with cow manure to optimize the carbon to nitrogen ratio and to provide the essential trace elements required by microorganisms in the biochemistry of methane formation. F1 produced a higher specific methane yield (189 ± 37 L/kg volatile solids) from rice straw compared to F2 (148 ± 36 L/kg volatile solids). Anaerobic digestion efficiency was about 90 ± 20% in F1 and 70 ± 20% in F2. Mass fractions of Fe, Ni, Co, Mo, Cu, and Zn were analyzed over time. The mass fractions of Co, Mo, Cu, and Zn were stable in both digesters. While mass fractions of Fe and Ni were reduced at the end of the digestion period. However, no direct relationship between specific methane yield and reduced mass fraction of Fe and Ni was found. Co-digestion of rice straw with cow manure seems to be a good approach to provide trace elements except for Se.
Die pollenstratigraphische Gliederung des Pleistozäns in Nordwestdeutschland: 1. Die Pollenstratigraphie im älteren Pleistozän
Creators: name: Rein, Ulrich
Publisher: name: Geozon Science Media
Year: 1955

description: Durch die pollenanalytischen Untersuchungen von oberpliozänen und altinterglazialen Ablagerungen in den letzten Jahren ergibt sich nunmehr eine pollenstratigraphische Gliederung des älteren Pleistozäns in NW-Deutschland. Wie in einer Tafel dargestellt wird, tritt eine schrittweise Verarmung der Baumflora vom Oberpliozän bis zum mittleren Pleistozän auf. Während in der oberpliozänen Reuver-Stufe und in den gleichalten Braunkohlen im Kaolinsand von Sylt u. a. noch die für das jüngere Tertiär typischen Baumpollen von Sciadopitys, Sequoia und Nyssa reichlich vorhanden sind, dürften sie unter der Einwirkung der ersten Kaltzeit (ältester Diluvialschotter) aus Mitteleuropa verschwunden sein. Im ältesten Interglazial von Tegelen (Praetiglian und Tiglian) sind sie schon nicht mehr vorhanden. Damit ist die Plio-Pleistozängrenze pollenanalytisch zu erfassen. Einige andere in Tegelenschichten noch vorhandene tertiäre Relikte (Carya, Juglans, Pterocarya) sind im nächsten Interglazial (Günz-Mindel), d. h. in den Vorkommen vom Cromer-Forest-Bed und bei Bilshausen, praktisch verschwunden. Durch eine spezifische Vegetationsentwicklung mit einer Buchenphase im Höhepunkt der EMW-Zeit und anschließenden sehr hohen Carpinus-Werten sind die Ablagerungen dieser Warmzeit von der nächstjüngeren zwischen der Mindel- und Riß-Eiszeit zu unterscheiden. Wenn auch die Horizonte von Neede und der Krefelder Schichten nur den oberen Teil eines vollständigen Mindel-Riß-Interglazials darstellen sollten, so ist doch diese Warmzeit mit durchweg hohen Werten der Tanne neben reichlich Kiefer, Fichte und Erle bis nach Polen hinein charakterisiert. Hieraus ergibt sich auch die Unterscheidung von der Pollenführung jüngerer Interglaziale. Obwohl die Gliederung des älteren Pleistozäns auf pollenanalytischer Grundlage in großen Zügen feststehen dürfte, sind doch noch sehr viele Einzelprobleme zu klären. Die Identifizierung einer pollenführenden interglazialen Schicht ist z. Z. nur dann möglich, wenn innerhalb des Profils mehrere Vegetationsphasen erfaßt werden können.
description: research
High-energy elementary amplitudes from quenched and full QCD
Creators: name: Martini, A. F.
name: Menon, M. J.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Making use of the Stochastic Vacuum Model and the gluon gauge-invariant two-point correlation function, determined by numerical simulation on the lattice in both quenched approximation and full QCD, we calculate the elementary (quark-quark) scattering amplitudes in the momentum transfer space and at asymptotic energies. Our main conclusions are the following: (1) the amplitudes decrease monotonically as the momentum transfer increases; (2) the decreasing is faster when going from quenched approximation to full QCD (with decreasing quark masses) and this effect is associated with the increase of the correlation lengths; (3) dynamical fermions generate two components in the amplitude at small momentum transfer and the transition between them occurs at momentum transfer near 1 GeV$^2$. We also obtain analytical parametrizations for the elementary amplitudes, that are suitable for phenomenological uses, and discuss the effects of extrapolations from the physical regions investigated in the lattice.
description: 6 pages, 4 figures, aps-revtex4, to be published in Physics Letters B
Adaptive Online Learning for the Autoregressive Integrated Moving Average Models
Creators: name: Shao, Weijia
name: Radke, Lukas Friedemann
name: Sivrikaya, Fikret
name: Albayrak, Sahin
Publisher: name: Technische Universität Berlin
Year: 2021
Subjects: subject: 000 Informatik, Informationswissenschaft, allgemeine Werke
subject: ARIMA model
subject: time series analysis
subject: online optimization
subject: online model selection

description: This paper addresses the problem of predicting time series data using the autoregressive integrated moving average (ARIMA) model in an online manner. Existing algorithms require model selection, which is time consuming and unsuitable for the setting of online learning. Using adaptive online learning techniques, we develop algorithms for fitting ARIMA models without hyperparameters. The regret analysis and experiments on both synthetic and real-world datasets show that the performance of the proposed algorithms can be guaranteed in both theory and practice.
Hansie: Hybrid and Consensus Regression Test Prioritization
Creators: name: Shouvick Mondal
name: Rupesh Nasre
Publisher: name: Zenodo
Year: 2021

description: Traditionally, given a test-suite and the underlying system-under-test, existing test-case prioritization heuristics report a permutation of the original test-suite that is seemingly best according to their criteria. However, we observe that a single heuristic does not perform optimally in all possible scenarios, given the diverse nature of software and its changes. Hence, multiple individual heuristics exhibit effectiveness differently. Interestingly, together, the heuristics bear the potential of improving the overall regression test selection across scenarios. In this paper, we pose the test-case prioritization as a rank aggregation problem from social choice theory. Our solution approach, named Hansie, is two-flavored: one involving priority-aware hybridization, and the other involving priority-blind computation of a consensus ordering from individual prioritizations. To speed-up test-execution, Hansie executes the aggregated test-case orderings in a parallel multi-processed manner leveraging regular windows in the absence of ties, and irregular windows in the presence of ties. We show the benefit of test-execution after prioritization and introduce a cost-cognizant metric (EPL) for quantifying overall timeline latency due to load-imbalance arising from uniform or non-uniform parallelization windows. We evaluate Hansie on 20 open-source subjects totaling 287,530 lines of source code, 69,305 test-cases, and with parallelization support of up to 40 logical CPUs.
Robust and optimal predictive control of the COVID-19 outbreak
Creators: name: Köhler, Johannes
name: Schwenkel, Lukas
name: Koch, Anne
name: Berberich, Julian
name: Pauli, Patricia
name: Allgöwer, Frank
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Biological sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We investigate adaptive strategies to robustly and optimally control the COVID-19 pandemic via social distancing measures based on the example of Germany. Our goal is to minimize the number of fatalities over the course of two years without inducing excessive social costs. We consider a tailored model of the German COVID-19 outbreak with different parameter sets to design and validate our approach. Our analysis reveals that an open-loop optimal control policy can significantly decrease the number of fatalities when compared to simpler policies under the assumption of exact model knowledge. In a more realistic scenario with uncertain data and model mismatch, a feedback strategy that updates the policy weekly using model predictive control (MPC) leads to a reliable performance, even when applied to a validation model with deviant parameters. On top of that, we propose a robust MPC-based feedback policy using interval arithmetic that adapts the social distancing measures cautiously and safely, thus leading to a minimum number of fatalities even if measurements are inaccurate and the infection rates cannot be precisely specified by social distancing. Our theoretical findings support various recent studies by showing that 1) adaptive feedback strategies are required to reliably contain the COVID-19 outbreak, 2) well-designed policies can significantly reduce the number of fatalities compared to simpler ones while keeping the amount of social distancing measures on the same level, and 3) imposing stronger social distancing measures early on is more effective and cheaper in the long run than opening up too soon and restoring stricter measures at a later time.
description: This is the accepted version of the paper in Annual Reviews in Control, 2020
title: Platinum-group element mineralisation in the Shetland ophiolite complex
Creators: name: Lord, Richard Alastair
Publisher: name: The Open University
Year: 1992

description: The Shetland ophiolite complex exhibits the lower part of the definitive Penrose sequence, but chromitites from the Cliff locality contain levels of Pt and Pd which are unusual in ophiolites. Aspects of this mineralisation suggest both magmatic and hydrothermal concentration processes, although neither individually explain the observed paragenesis. This study examines the distribution of PGE within a representative fresh vertical section of the ophiolite stratigraphy, to assess the relative roles of such processes in the concentration and fractionation of PGE. In the field area around Balta Sound, tectonised mantle harzburgites are overlain by a layered ultramafic cumulate sequence. Accessory Ni-Cu sulphides occur throughout these cumulates. Two stratigraphically controlled zones of chromite enrichment have been identified which mark the bases of cyclic repetitions. Such chromite enrichments lack progressive changes in mineral chemistry so repetitions within the cumulate sequence are attributed to influxes of primitive magma during open system fractionation. The distribution of PGE and other chalcophiles show primary lithological associations, indicating a magmatic origin. Os-Ir-Ru concentrations occur in cbromitites, whereas Pt-PdRh concentrations occur in sulphide-bearing dunites, chromite-rich dunites, or basal pyroxenites. Stratigraphically controlled zones of PGE-enriched sulphide-bearing cumulate dunites occur close to the base of each cyclic repetition and are continuous over a strikelength of 2 km. The fractionation between PGE and other cha1cophiles is consistent with magmatic processes. The distribution and fractionation of PGE can be explained by an open system model. Negative slope patterns are produced by the precipitation of PGM from PGE saturated magmas during chromite crystallisation. This initial process buffers the PGE concentrations in each primitive magma pulse. On entering the axial chamber and mixing with the evolving resident magma, sulphide saturation occurs and the remaining PGE are partitioned into immiscible sulphide liquids. Multiple inputs result in repeated PGE enriched zones. This model explains why successive stratigraphic PGE-enriched horizons have similar positive slope patterns but progressively fractionated host silicate and sulphide compositions.
Particle-Resolved Computational Fluid Dynamics as the Basis for Thermal Process Intensification of Fixed-Bed Reactors on Multiple Scales
Creators: name: Jurtz, Nico
name: Srivastava, Urvashi
name: Moghaddam, Alireza Attari
name: Kraume, Matthias
Publisher: name: Technische Universität Berlin
Year: 2021
Subjects: subject: 620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: fixed-bed reactor
subject: wall structures
subject: complex particle shapes
subject: process intensification
subject: heat transfer

description: Process intensification of catalytic fixed-bed reactors is of vital interest and can be conducted on different length scales, ranging from the molecular scale to the pellet scale to the plant scale. Particle-resolved computational fluid dynamics (CFD) is used to characterize different reactor designs regarding optimized heat transport characteristics on the pellet scale. Packings of cylinders, Raschig rings, four-hole cylinders, and spheres were investigated regarding their impact on bed morphology, fluid dynamics, and heat transport, whereby for the latter particle shape, the influence of macroscopic wall structures on the radial heat transport was also studied. Key performance indicators such as the global heat transfer coefficient and the specific pressure drop were evaluated to compare the thermal performance of the different designs. For plant-scale intensification, effective transport parameters that are needed for simplified pseudo-homogeneous two-dimensional plug flow models were determined from the CFD results, and the accuracy of the simplified modeling approach was judged.