Power Generation with Renewable Energy and Advanced Supercritical CO2 Thermodynamic Power Cycles: A Review

Supercritical CO2 (S-CO2) thermodynamic power cycles have been considerably investigated in the applications of fossil fuel and nuclear power generation systems, considering their superior characteristics such as compactness, sustainability, cost-effectiveness, environmentally friendly working fluid, and high thermal efficiency. They can be potentially integrated and applied with various renewable energy systems for low-carbon power generation such that extensive studies in these areas have also been conducted substantially. However, there is a shortage of reviews that specifically concentrate on the integrations of S-CO2 with renewable energy encompassing biomass, solar, geothermal, and waste heat. It is thus necessary to provide an update and overview of the development of S-CO2 renewable energy systems and identify technology and integration opportunities for different types of renewable resources. Correspondingly, this paper not only summarizes the advantages of CO2 working fluid, design layouts of S-CO2 cycles, and classifications of renewable energies to be integrated but also reviews the recent research activities and studies carried out worldwide on advanced S-CO2 power cycles with renewable energy. Moreover, the performance and development of various systems are well grouped and discussed

Functional Integral Approach to the Single Impurity Anderson Model

Recently, a functional integral representation was proposed by Weller (Weller, W.: phys.~stat.~sol.~(b) {\bf 162}, 251 (1990)), in which the fermionic fields strictly satisfy the constraint of no double occupancy at each lattice site. This is achieved by introducing spin dependent Bose fields. The functional integral method is applied to the single impurity Anderson model both in the Kondo and mixed-valence regime. The f-electron Green's function and susceptibility are calculated using an Ising-like representation for the Bose fields. We discuss the difficulty to extract a spectral function from the knowledge of the imaginary time Green's function. The results are compared with NCA calculations.Comment: 11 pages, LaTeX, figures upon request, preprint No. 93/10/

TWITTER IN THE MARKETING

We report on a compact and highly efficient diode-end-pumped TEM00 Nd:YVO4 slab laser with an output power of 103 W and beam quality M2 1.5. The optical-to-optical efficiency was 41.5%. In electro-optically Q-switched operation. 83 W of average power at a pulse-repetition rate of 50 kHz with a pulse length of 11.3 ns was obtained. At a pulse-repetition rate of 10 kHz, 5.6 mJ of pulse energy, and 870 kW of peak power were measured

A partition approach for underwater explosion based on smoothed particle method

As a Lagrangian particle method, smoothed particle hydrodynamics (SPH) has been applied into the problems of fluid-structure interaction (FSI) more and more. However, the transient fluid-structure interactions characterized by severe reactions and wide spreads are very expensive to be carried out with three-dimensional SPH method due to the approach of solid modeling, especially when the structure is subjected to the shock loads from mid-field or far-field, which is almost impossible to achieve. Therefore, based on the previous research, the coupled SPH-BEM method is put forward and applied to underwater explosion in this paper. The structure is modeled and solved with SPH method while the fluid boundary only required is coped with a boundary element method (BEM), the second-order doubly asymptotic approximations (DAA2). The FSI method will reduce the elements of structures and fluid greatly so as to solve the problems of fluid-structure interactions feasibly and efficiently. The mid-plane of a plate only discretized into a layer of particles is taken as the study object in the SPH shell element and the related physical quantities is integrated in the thickness direction to capture the dynamic response of structures; the fluid boundary only discretized into a piece of boundary elements is employed in the BEM method to solve fluid dynamics based on the retarded potential equation; treatments of the coupled fluid-structure interface are made to satisfy the compatibility conditions and the messages related to motions and loads are well delivered. Finally, two standard examples are carried out to test the above algorithm

A wireless ECG plaster for real-time cardiac health monitoring in body sensor networks

10.1109/BioCAS.2011.61077632011 IEEE Biomedical Circuits and Systems Conference, BioCAS 2011205-20

Degradation of Inorganic Nitrogen in Beiyun River of Beijing, China

AbstractNitrogen pollution characteristics of Beiyun River and the migration of inorganic nitrogen in sediment-water were studied using laboratory experiment. Extract NH4-N was the dominant pollutants in Beiyun River that caused the severe harm to aquatic system. NH4-N exchange in sediment-water system was observable at different sites. The calculating of NH4-N degradation coefficients showed there was little difference of NH4-N degradation rate at three sites of Beiyun River. Nitrification process was mainly occurred in 12 days and NH4-N can rapidly in the degradation without input

LQ control without Ricatti equations: deterministic systems

We study a deterministic linear-quadratic (LQ) control problem over an infinite horizon, and develop a general apprach to the problem based on semi-definite programming (SDP)and related duality analysis. This approach allows the control cost matrix R to be non-negative (semi-definite), a case that is beyond the scope of the classical approach based on Riccati equations. We show that the complementary duality condition of the SDP is necessary and sufficient for the existence of an optimal LQ control. Moreover, when the complementary duality does hold, an optimal state feedback control is constructed explicitly in terms of the solution to the semidefinite program. On the other hand, when the complementary duality fails, the LQ problem has no attainable optimal solution, and we develop an E-approximation scheme that achieves asymptotic optimality

Using a novel petroselinic acid embedded cellulose acetate membrane to mimic plant partitioning and in vivo uptake of polycyclic aromatic hydrocarbons

A new type of composite membrane is introduced to mimic plant uptake of hydrophobic organic contaminants (HOCs). Petroselinic acid (cis-6-octadecenoic acid),the major component of plant lipids, was embedded in the matrix of cellulose acetate polymer to form the petroselinic acid embedded cellulose acetate membrane (PECAM). Accumulation of the polycyclic aromatic hydrocarbons (PAHs) naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), and benz(a)pyrene (Bap) by PECAM was compared with their uptake by plants. The accumulation of Nap, Phe, Pyr, and Bap by PECAM reached equilibrium in 24,48,144, and 192 h, respectively. The petroselinic acid-water partition coefficients (log K(pw), 3.37, 4.90, 5.24, and 6.28 for Nap, Phe, Pyr, and Bap, respectively) were positively correlated with the hydrophobicity of the compounds (R(2) = 0.995) and were almost the same as the lipid-normalized root partition coefficients (log K(lip)) for the corresponding compounds. Their relationship can be expressed as log K(pw) = 0.98 log K(lip). The normalized plant uptake coefficients (log K(u)) obtained by in vivo experiments with a range of plant species (2.92, 4.43, 5.06, and 6.13 on average for Nap, Phe, Pyr, and Bap, respectively) were slightly lower than those of the log K(pw) values for the corresponding compounds, presumably due to their acropetal translocation and biodegradation inside plants. This work suggests that PECAMs can well mimic plant partitioning and in vivo uptake of PAHs and may have good potential as a nonliving accumulator to mimic plant uptake of PAHs and perhaps other HOCs

Numerical simulation of primary atomization with large eddy simulation method

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.As the awareness of the environmental protection and energy conservation, a more restricted rule is proposed on engine performance, e.g. high power output, fuel economy and low pollution. It is very important to understand the spray atomization mechanism and the factors which have effects on the characteristics spray and its regulation. The combination of LES (Large eddy simulation) and the VOF method by using open source CFD software OpenFoam in Linux system is used to imitate umbrella morphology on the oil spray and fracture mechanism in the primary atomization stage. The radial and axial velocity, pressure and droplet distribution are obtained by present method and some meaningful results are concluded. Finally, the influence of the air dynamics on the fuel primary breakup and the effects of grid sizes for LES are analyzed.cf201