University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Control reconfiguration & Software. The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Lactide Polymerisation with Air‐Stable and Highly Active Zinc Complexes with Guanidine–Pyridine Hybrid Ligands

Abstract: The synthesis of zinc complexes of guanidine-pyridine hybrid ligands [Zn(DMEGpy)Cl 2 ] (Cl), [Zn-(TMGpy)Cl 2 ] (C2), [Zn(DMEGqu)Cl 2 ] (C3), [Zn(TMGqu)Cl 2 ] (C4), [Zn-(DMEGpy)(CH 3 COO) 2 ] (C5), [Zn-(TMGpy)(CH 3 COO) 2 ] (C6), [Zn-(DMEGqu)(CH 3 COO) 2 ] (C7), [Zn-(TMGqu)(CH 3 COO) 2 ] (C8), [Zn-(DMEGqu) 2 (CF 3 SO 3 )] [CF 3 SO 3 ] (C9) and [Zn(TMGqu)2(CF 3 SO 3 )] [CF 3 SO 3 ] (C10) is reported. These zinc complexes were completely characterised and screened regarding their activity in the ring-opening polymerisation of D,L-lactide. They proved to be active initiators in lactide bulk polymerisation, and polylactides with molecular weights (M w ) up to 176000 g mol -1 could be obtained. They combine high activity with robustness towards moisture and air. The influence of reaction temperature and of the anionic component of the zinc salt on the activity of the catalyst, as well as the occurrence of undesired side reactions, was investigated. By correlating these findings with the structural study on the zinc complexes we could deduce a structure-reactivity relationship for the zinc catalysts. This study was accompanied by DFT calculations. The bis-chelate triflate complexes C9 and C10, supported by quinoline-guanidine ligands L3 and L4, exhibit by far the highest reactivity. Systematic comparison of these complexes with their mono-chelate counterparts and their bis-guanidine analogues allows the attributes that promote polymerisation by neutral guanidine ligand systems to be elucidated: accessibility to the zinc centre and Lewis acidity.

Dietary Glycemic Index and Load and the Risk of Type 2 Diabetes: A Systematic Review and Updated Meta-Analyses of Prospective Cohort Studies

Abstract: Published meta-analyses indicate significant but inconsistent incident type-2 diabetes(T2D)-dietary glycemic index (GI) and glycemic load (GL) risk ratios or risk relations (RR). It is nowover a decade ago that a published meta-analysis used a predefined standard to identify validstudies. Considering valid studies only, and using random effects dose-response meta-analysis(DRM) while withdrawing spurious results (p 1.20 with a lower 95% confidence limit>1.10 across typical intakes (approximately 10th to 90th percentiles of population intakes). Thecombined T2D-GI RR was 1.27 (1.15-1.40) (p < 0.001, n = 10 studies) per 10 units GI, while that forthe T2D-GL RR was 1.26 (1.15-1.37) (p < 0.001, n = 15) per 80 g/d GL in a 2000 kcal (8400 kJ) diet.The corresponding global DRM using restricted cubic splines were 1.87 (1.56-2.25) (p < 0.001, n =10) and 1.89 (1.66-2.16) (p < 0.001, n = 15) from 47.6 to 76.1 units GI and 73 to 257 g/d GL in a 2000kcal diet, respectively. In conclusion, among adults initially in good health, diets higher in GI or GLwere robustly associated with incident T2D. Together with mechanistic and other data, thissupports that consideration should be given to these dietary risk factors in nutrition advice.Concerning the public health relevance at the global level, our evidence indicates that GI and GLare substantial food markers predicting the development of T2D worldwide, for persons ofEuropean ancestry and of East Asian ancestry.

Defects in SiO 2 as the possible origin of near interface traps in the SiC ∕ SiO 2 system: A systematic theoretical study

Abstract: A systematic study of the level positions of intrinsic and carbon defects in ${\mathrm{SiO}}_{2}$ is presented, based on density functional calculations with a hybrid functional in an $\ensuremath{\alpha}$-quartz supercell. The results are analyzed from the point of view of the near interface traps (NIT), observed in both $\mathrm{SiC}∕{\mathrm{SiO}}_{2}$ and $\mathrm{Si}∕{\mathrm{SiO}}_{2}$ systems, and assumed to have their origins in the oxide. It is shown that the vacancies and the oxygen interstitial can be excluded as the origin of such NIT, while the silicon interstitial and carbon dimers give rise to gap levels in the energy range inferred from experiments. The properties of these defects are discussed in light of the knowledge about the $\mathrm{SiC}∕{\mathrm{SiO}}_{2}$ interface.

Maximum Hands-Off Control: A Paradigm of Control Effort Minimization

Abstract: In this paper, we propose a paradigm of control, called a maximum hands-off control. A hands-off control is defined as a control that has a short support per unit time. The maximum hands-off control is the minimum support (or sparsest) per unit time among all controls that achieve control objectives. For finite horizon continuous-time control, we show the equivalence between the maximum hands-off control and $L^{1}$ -optimal control under a uniqueness assumption called normality. This result rationalizes the use of $L^{1}$ optimality in computing a maximum hands-off control. The same result is obtained for discrete-time hands-off control. We also propose an $L^{1}/L^{2}$ -optimal control to obtain a smooth hands-off control. Furthermore, we give a self-triggered feedback control algorithm for linear time-invariant systems, which achieves a given sparsity rate and practical stability in the case of plant disturbances. An example is included to illustrate the effectiveness of the proposed control.

Veins: The Open Source Vehicular Network Simulation Framework

Abstract: We describe Veins, an open-source model library for (and a toolbox around) OMNeT++, which supports researchers conducting simulations involving communicating road vehicles—either as the main focus of a study or as a component. Veins already includes a full stack of simulation models for investigating cars and infrastructure communicating via IEEE 802.11 based technologies in simulations of Vehicular Ad Hoc Networks (VANETs) and Intelligent Transportation Systems (ITS). Thanks to its modularity, though, it can equally well be used as the basis for modeling other mobile nodes (like bikes or pedestrians) and communication technologies (from mobile broadband to visible light). Serving as the basis for hundreds of publications and university courses since its beginnings in the year 2006, today Veins is both one of the most mature and established tools in this domain.