Construction of Co0.85Se@nickel nanopores array hybrid electrode for high-performance asymmetric supercapacitors. - In: Chemical engineering science. - Amsterdam [u.a.] : Elsevier Science, Bd. 247 (2022), S. 1-9
Nanostructured current collectors have larger specific surface area and short ion/electron transport path, which are highly desirable for supercapacitors applications. Herein, Co0.85SeNiNPs (Co0.85Se@NiNP) hybrid electrodes are proposed and fabricated, in which NiNP is served as nanostructured current collectors. NiNP has a vertical pore structure and a large specific surface area, which could effectively promote the ion/electron transport efficiency and reduce internal electrical resistance. Compared with Ni foam and Ni foil as current collectors, NiNP enables Co0.85Se@NiNP electrodes show significantly improved specific capacity, rate performance and cycle stability. Finally, an asymmetric supercapacitor device was assembled with Co0.85Se@NiNP hybrid electrode as the binder-free positive electrode and activated carbon (AC) coated on nickel foam as negative electrode. The Co0.85Se@NiNP//AC asymmetric supercapacitors can work in a wide potential window of 0 - 1.6 V with an ultrahigh specific capacity of 182.3 F g^-1 at 1 A g^-1. Most importantly, Co0.85Se@NiNP//AC has a high energy density of 64.81 Wh kg^-1 at 800 W kg^-1 and an outstanding cycle stability of up to 12000 cycles, indicating that Co0.85Se@NiNP electrode has great application potential in supercapacitors.
On convexity and quasiconvexity of extremal value functions in set optimization. - In: Applied set-valued analysis and optimization. - Edmonton : Biemdas Academic Publishers, ISSN 2562-7783, Bd. 3 (2021), 3, S. 293-308
We study different classes of convex and quasiconvex set-valued maps defined by means of the l-less relation and the u-less relation. The aim of this paper is to formulate necessary and especially sufficient conditions for the convexity/quasiconvexity of extremal value functions.
Ordered nanostructures arrays fabricated by anodic aluminum oxide (AAO) template-directed methods for energy conversion. - In: Nanotechnology. - Bristol : IOP Publ., ISSN 1361-6528, Bd. 32 (2021), 50, S. 1-27
Clean and efficient energy conversion systems can overcome the depletion of the fossil fuel and meet the increasing demand of the energy. Ordered nanostructures arrays convert energy more efficiently than their disordered counterparts, by virtue of their structural merits. Among various fabrication methods of these ordered nanostructures arrays, anodic aluminum oxide (AAO) template-directed fabrication have drawn increasing attention due to its low cost, high throughput, flexibility and high structural controllability. This article reviews the application of ordered nanostructures arrays fabricated by AAO template-directed methods in mechanical energy, solar energy, electrical energy and chemical energy conversions in four sections. In each section, the corresponding advantages of these ordered nanostructures arrays in the energy conversion system are analysed, and the limitation of the to-date research is evaluated. Finally, the future directions of the ordered nanostructures arrays fabricated by AAO template-directed methods (the promising method to explore new growth mechanisms of AAO, green fabrication based on reusable AAO templates, new potential energy conversion application) are discussed.
On a class of integral systems. - In: Complex analysis and operator theory. - Cham (ZG) : Springer International Publishing AG, ISSN 1661-8262, Bd. 15 (2021), 6, S. 1-39
We study spectral problems for two-dimensional integral system with two given non-decreasing functions R, W on an interval [0, b) which is a generalization of the Krein string. Associated to this system are the maximal linear relation Tmax and the minimal linear relation Tmin in the space L2(dW) which are connected by Tmax=T*min. It is shown that the limit point condition at b for this system is equivalent to the strong limit point condition for the linear relation Tmax. In the limit circle case the Evans-Everitt condition is proved to hold on a subspace T*N of Tmax characterized by the Neumann boundary condition at b. The notion of the principal Titchmarsh-Weyl coefficient of this integral system is introduced. Boundary triple for the linear relation Tmax in the limit point case (and for T*N in the limit circle case) is constructed and it is shown that the corresponding Weyl function coincides with the principal Titchmarsh-Weyl coefficient of the integral system. The notion of the dual integral system is introduced by reversing the order of R and W and the formula relating the principal Titchmarsh-Weyl coefficients of the direct and the dual integral systems is proved. For every integral system with the principal Titchmarsh-Weyl coefficients q a canonical system is constructed so that its Titchmarsh-Weyl coefficient Q is the unwrapping transform of q: Q(z)=zq(z2).
A meshfree method for a PDE-constrained optimization problem. - In: SIAM journal on numerical analysis. - Philadelphia, Pa. : SIAM, ISSN 1095-7170, Bd. 59 (2021), 4, S. 1896-1917
We describe a new approximation method for solving a PDE-constrained optimization problem numerically. Our method is based on the adjoint formulation of the optimization problem, leading to a system of weakly coupled, elliptic PDEs. These equations are then solved using kernel-based collocation. We derive an error analysis and give numerical examples.
Cost-effective sensor for flow monitoring in biologic microreactors. - In: IEEE sensors journal. - New York, NY : IEEE, ISSN 1558-1748, Bd. 21 (2021), 19, S. 21314-21321
A pre-registered short-term forecasting study of COVID-19 in Germany and Poland during the second wave. - In: Nature Communications. - [London] : Nature Publishing Group UK, ISSN 2041-1723, Bd. 12 (2021), S. 1-16
Disease modelling has had considerable policy impact during the ongoing COVID-19 pandemic, and it is increasingly acknowledged that combining multiple models can improve the reliability of outputs. Here we report insights from ten weeks of collaborative short-term forecasting of COVID-19 in Germany and Poland (12 October-19 December 2020). The study period covers the onset of the second wave in both countries, with tightening non-pharmaceutical interventions (NPIs) and subsequently a decay (Poland) or plateau and renewed increase (Germany) in reported cases. Thirteen independent teams provided probabilistic real-time forecasts of COVID-19 cases and deaths. These were reported for lead times of one to four weeks, with evaluation focused on one- and two-week horizons, which are less affected by changing NPIs. Heterogeneity between forecasts was considerable both in terms of point predictions and forecast spread. Ensemble forecasts showed good relative performance, in particular in terms of coverage, but did not clearly dominate single-model predictions. The study was preregistered and will be followed up in future phases of the pandemic.
Antitumor efficiency of the natural alkaloid berberine complexed with C60 fullerene in Lewis lung carcinoma in vitro and in vivo. - In: Cancer nanotechnology : basic, translational and clinical research.. - Wien [u.a.] : Springer, ISSN 1868-6966, Bd. 12 (2021), S. 1-18
Berberine (Ber) is a herbal alkaloid with pharmacological activity in general and a high anticancer potency in particular. However, due to its low bioavailability, the difficulty in reaching a target and choosing the right dose, there is a need to improve approaches of Ber use in anticancer therapy. In this study, Ber, noncovalently bound to a carbon nanostructure C60 fullerene (C60) at various molar ratios of the components, was explored against Lewis lung carcinoma (LLC).
Neurochirurgische Planung mittels automatisierter Bilderkennung und optimaler Pfadplanung :
Neurosurgery planning based on automated image recognition and optimal path design. - In: Automatisierungstechnik : AT.. - Berlin : De Gruyter, ISSN 2196-677X, Bd. 69 (2021), 8, S. 708-721
Stereotactic neurosurgery requires a careful planning of cannulae paths to spare eloquent areas of the brain that, if damaged, will result in loss of essential neurological function such as sensory processing, linguistic ability, vision, or motor function. We present an approach based on modelling, simulation, and optimization to set up a computational assistant tool. Thereby, we focus on the modeling of the brain topology, where we construct ellipsoidal approximations of voxel clouds based on processed MRI data. The outcome is integrated in a path-planning problem either via constraints or by penalization terms in the objective function. The surgical planning problem with obstacle avoidance is solved for different types of stereotactic cannulae using numerical simulations. We illustrate our method with a case study using real MRI data.
C60 fullerene against SARS-CoV-2 coronavirus: an in silico insight. - In: Scientific reports. - [London] : Macmillan Publishers Limited, part of Springer Nature, ISSN 2045-2322, Bd. 11 (2021), S. 1-12
- Im Titel ist "60" tiefgestellt
Based on WHO reports the new SARS-CoV-2 coronavirus is currently widespread all over the world. So far > 162 million cases have been confirmed, including > 3 million deaths. Because of the pandemic still spreading across the globe the accomplishment of computational methods to find new potential mechanisms of virus inhibitions is necessary. According to the fact that C60 fullerene (a sphere-shaped molecule consisting of carbon) has shown inhibitory activity against various protein targets, here the analysis of the potential binding mechanism between SARS-CoV-2 proteins 3CLpro and RdRp with C60 fullerene was done; it has resulted in one and two possible binding mechanisms, respectively. In the case of 3CLpro, C60 fullerene interacts in the catalytic binding pocket. And for RdRp in the first model C60 fullerene blocks RNA synthesis pore and in the second one it prevents binding with Nsp8 co-factor (without this complex formation, RdRp can't perform its initial functions). Then the molecular dynamics simulation confirmed the stability of created complexes. The obtained results might be a basis for other computational studies of 3CLPro and RdRp potential inhibition ways as well as the potential usage of C60 fullerene in the fight against COVID-19 disease.