Search results for "complex"

ELSA Project: Toward a complex network approach to ATM delays analysis

2011

The paper presents the preliminary results delivered by the WPE project ELSA. After some introductory notes about the project aims and structure, the paper shows how tools borrowed by the Complex Network Theory can be used to study the issue of delays in the air traffic system.

Statistical Characterization and Agent-Based Modelling of the Air Transportation Socio-technical Complex System

2017

Analysis of the Structure and Dynamics of European Flight Networks

2022

We analyze structure and dynamics of flight networks of 50 airlines active in the European airspace in 2017. Our analysis shows that the concentration of the degree of nodes of different flight networks of airlines is markedly heterogeneous among airlines reflecting heterogeneity of the airline business models. We obtain an unsupervised classification of airlines by performing a hierarchical clustering that uses a correlation coefficient computed between the average occurrence profiles of 4-motifs of airline networks as similarity measure. The hierarchical tree is highly informative with respect to properties of the different airlines (for example, the number of main hubs, airline participa…

The impact of partners’ financial condition on alliance contract design: evidence from biotech-pharma alliances

2014

Superallowed α Decay to Doubly Magic 100Sn

2018

We report the first observation of the 108Xe→104Te→100Sn α-decay chain. The α emitters, 108Xe [Eα=4.4(2)  MeV, T1/2=58+106−23  μs] and 104Te [Eα=4.9(2)  MeV, T1/2<18  ns], decaying into doubly magic 100Sn were produced using a fusion-evaporation reaction 54Fe(58Ni,4n)108Xe, and identified with a recoil mass separator and an implantation-decay correlation technique. This is the first time α radioactivity has been observed to a heavy self-conjugate nucleus. A previous benchmark for study of this fundamental decay mode has been the decay of 212Po into doubly magic 208Pb. Enhanced proton-neutron interactions in the N=Z parent nuclei may result in superallowed α decays with reduced α-decay wi…

La modélisation complexe en géographie

2013

Oxidovanadium(v) complexes with l-proline-based amino acid phenolates

2019

L-proline was used to prepare chiral, tridentate amino acid phenol proligands H2L1—4. These proligands react with vanadium precursors VO(acac)2, VOSO4 ∙ 5 H2O and VO(OPr)3 in methanol to form the corresponding oxidoalkoxidovanadium(V) complexes 1—4. The complexes crystallize from methanol, and are octahedrally coordinated with a general formula [VO(L1—4)(OMe)(MeOH)]. In solution, however, they adopt several different conformations or isomeric structures depending on the solvent. peerReviewed

Aerobic composting and anaerobic digestion of pulp and paper mill sludges

1997

The feasibility of aerobic vessel composting and anaerobic digestion for the treatment of pulp and paper mill sludges were studied. The composting studies made use of primary and secondary sludge from a de-inking and paper mill. In six parallely aerated 500 1 vessels with various carbon : nitrogen (C:N) -ratios, the most optimal performance was obtained with C:N -ratios of c. 22–35, while higher and lower ratios delayed the temperature increase. With the optimal ratios, the thermophilic stage was reached within 36 h, and the stage lasted for about seven days. In the scale-up study (18 m3 compost vessel), the thermophilic stage was reached within 24 h. An effective dehydratation of the mass …

Learning complex analysis in different branches – Project Spotlight-Y for future teachers

2018

International audience; At the University of Bremen in teaching complex analysis, we split the last part of the lecture into two branches according to profession: While future mathematicians deepen their understanding in a branch for them, future teachers take a branch of the lecture where they prepare a task with dynamical geometry software for pupils which is based on phenomena of complex analysis. Here, we describe the design of the course, some general aims and first results obtained from the branch for future teachers.

Coordination Chemistry of a Bis(Tetrazine) Tweezer: A Case of Host-Guest Behavior with Silver Salts

2021

The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows the formation of constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is reinforced by π-stacking of the electron-poor nitrogen-containing heteroaromatic moieties. The resulting tetra-aromatic structure can be used as a weak coordinating ligand with cationic silver. This coordination generates a set of bis(tetrazine)-silver(I) coordination complexes tolerating a large variety of counter anions of various geometries, namely, PF6−, BF4−, SbF6−, ClO4−, NTf2−, and OTf−. These compounds were characterized…