Mathematical control of complex systems

Copyright © 2013 ZidongWang et al.This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Nanoscale Quantum Calorimetry with Electronic Temperature Fluctuations

Motivated by the recent development of fast and ultra-sensitive thermometry in nanoscale systems, we investigate quantum calorimetric detection of individual heat pulses in the sub-meV energy range. We propose a hybrid superconducting injector-calorimeter set-up, with the energy of injected pulses carried by tunneling electrons. Treating all heat transfer events microscopically, we analyse the statistics of the calorimeter temperature fluctuations and derive conditions for an accurate measurement of the heat pulse energies. Our results pave the way for novel, fundamental quantum thermodynamics experiments, including calorimetric detection of single microwave photons.Comment: 6 pages, 3 figures plus supplemental material, 8 pages, 1 figur

On the hydrodynamics and heat convection of an impinging external flow upon a cylinder with transpiration and embedded in a porous medium

This paper extends the existing studies of heat convection by an external flow impinging upon a flat porous insert to that on a circular cylinder inside a porous medium. The surface of the cylinder is subject to constant temperature and can include uniform or non-uniform transpiration. These cylindrical configurations are introduced in the analyses of stagnation point flows in porous media for the first time. The equations governing steady transport of momentum and thermal energy in porous media are reduced to simpler nonlinear differential equations and subsequently solved numerically. This reveals the dimensionless velocity and temperature fields of the stagnation-point flow, as well as the Nusselt number and shear stress on the surface of the cylinder. The results show that transpiration on the surface of the cylinder and Reynolds number of the external flow dominate the fluid dynamics and heat transfer problems. In particular, non-uniform transpiration is shown to significantly affect the thermal and hydrodynamic responses of the system in the circumferential direction. However, the permeability and porosity of the porous medium are found to have relatively smaller influences

Frankincense improves memory retrieval in rats treated with Lipopolysaccharide

Introduction: Frankincense has been shown to possess anti-inf lammatory activity. In this studythe effect of pretreatment with the hydro-alcoholic extract of frankincense on memory retrievalwas assessed in lipopolysaccharide (LPS) treated rats.Methods: Forty-two adult male Wistar rats were distributed into 7 groups of 6 each. One groupreceived LPS (1 mg/kg; i.p) pre-test. The control group received saline (1 ml/kg; i.p). 2 groups ofanimals received frankincense (50 mg/kg; P.O) or DMSO 5 (1 ml/kg; P.O) and 30 minutes laterLPS (1 mg/kg; i.p). Two other groups of animals received frankincense (50 mg/kg; P.O) or DMSO5 (1 ml/kg; P.O) and 30 minutes later saline (1 ml/kg; i.p). Another group of rats received LPS(1 mg/kg; i.p) and 30 minutes later Ibuprofen (100 mg/kg; P.O). In all the experimental groups,memory retrieval was assessed 4 hours following the last injection, using a passive avoidancetask (PAT). Hippocampal TNF-&alpha; levels were measured by ELISA as an index of LPS-inducedneuroinf lammation.Results: LPS impaired memory retrieval by decreasing step-through latency (STL), significantly.LPS also increased levels of TNF-&alpha; in the hippocampus as compared to the control group.Administration of frankincense (50 mg/kg; P.O) before LPS (1 mg/kg; i.p) improved memoryretrieval as compared to the control group. Frankincense reduced hippocampal TNF-&alpha; level in theLPS treated rats, significantly, compared to the control group.Conclusion: The results indicate that the hydro-alcoholic extract of frankincense has the potentialto improve memory retrieval in LPS treated rats, possibly via an anti-neuroinf lammatory activity.</p

Mathematical control of complex systems 2013

Mathematical control of complex systems have already become an ideal research area for control engineers, mathematicians, computer scientists, and biologists to understand, manage, analyze, and interpret functional information/dynamical behaviours from real-world complex dynamical systems, such as communication systems, process control, environmental systems, intelligent manufacturing systems, transportation systems, and structural systems. This special issue aims to bring together the latest/innovative knowledge and advances in mathematics for handling complex systems. Topics include, but are not limited to the following: control systems theory (behavioural systems, networked control systems, delay systems, distributed systems, infinite-dimensional systems, and positive systems); networked control (channel capacity constraints, control over communication networks, distributed filtering and control, information theory and control, and sensor networks); and stochastic systems (nonlinear filtering, nonparametric methods, particle filtering, partial identification, stochastic control, stochastic realization, system identification)

Polarization control of single photon quantum orbital angular momentum states

The orbital angular momentum of photons, being defined in an infinitely dimensional discrete Hilbert space, offers a promising resource for high-dimensional quantum information protocols in quantum optics. The biggest obstacle to its wider use is presently represented by the limited set of tools available for its control and manipulation. Here, we introduce and test experimentally a series of simple optical schemes for the coherent transfer of quantum information from the polarization to the orbital angular momentum of single photons and vice versa. All our schemes exploit a newly developed optical device, the so-called "q-plate", which enables the manipulation of the photon orbital angular momentum driven by the polarization degree of freedom. By stacking several q-plates in a suitable sequence, one can also access to higher-order angular momentum subspaces. In particular, we demonstrate the control of the orbital angular momentum $m$ degree of freedom within the subspaces of $|m|=2 \hbar$ and $|m|=4\hbar$ per photon. Our experiments prove that these schemes are reliable, efficient and have a high fidelity.Comment: 9 pages, 8 figure