The Diderot meteorite: The second chassignite

The Diderot meteorite is a dunite discovered in Sahara. The martian origin is unambiguous and Diderot shares strong petrographical similarities with Chassigny

Utilization of stochastically located customer owned battery energy storage systems for violation management on UK LV residential feeders with varying renewables penetrations

As the installed capacity of residential rooftop PV systems increases in the UK, the likelihood that LV networks will experience periods of unacceptably high voltage or line utilization increases also. Whilst the use of battery energy storage systems (BESSs) for violation management has been explored in previous work, the robustness and cost effectiveness of utilizing existing customer owned BESSs for such purposes has not been extensively examined on UK LV networks. In this paper, we use mixed-integer quadratically constrained programming (MIQCP) formulations to determine optimal BESS takeover for violation control at various PV and ASHP ownership fractions, whilst implementing Monte-Carlo methods to explore the multiple possible technology ownership patterns that may occur at each penetration level. We compare the cost of feasible BESS takeover solutions to the cost of the reconductoring works that would be required to mitigate the same violations, where novel mixed integer linear programming (MILP) formulations are used to determine the optimum reconductoring strategies. We perform the analysis on two models of real urban feeders located in the north west of England, and find that whilst BESS control may sometimes compete economically with reconductoring, BESS takeover control cannot consistently and adequately mitigate violations at the majority of PV and ASHP ownership fractions when BESSs are available at fewer than 100% of PV array owners residences

Battery energy storage for management of LV network operational violations : a multi-feeder analysis

With increasing penetration of rooftop PV systems on UK LV networks, it is becoming more likely that specific LV networks will experience unacceptable line congestion and voltage rises. In this study, we use Mixed Integer Quadratically Constrained Program (MIQCP) formulations to examine the possibility of eliminating these violations via aggregation and control of behind-the-meter (BTM) battery energy storage systems (BESSs), therefore delaying traditional reinforcement. By applying the formulations to 29 UK LV feeders, we examine the trends between the violation control capability of each method and a set of feeder topology metrics, to determine whether the suitability of networks to violation management strategies may be predicted from easy to obtain metrics, rather than extensive power flow modelling. It is found that instances in which BESSs may be reliably used to manage violations exist but are infrequent

Convergence of the critical attractor of dissipative maps: Log-periodic oscillations, fractality and nonextensivity

For a family of logistic-like maps, we investigate the rate of convergence to the critical attractor when an ensemble of initial conditions is uniformly spread over the entire phase space. We found that the phase space volume occupied by the ensemble W(t) depicts a power-law decay with log-periodic oscillations reflecting the multifractal character of the critical attractor. We explore the parametric dependence of the power-law exponent and the amplitude of the log-periodic oscillations with the attractor's fractal dimension governed by the inflexion of the map near its extremal point. Further, we investigate the temporal evolution of W(t) for the circle map whose critical attractor is dense. In this case, we found W(t) to exhibit a rich pattern with a slow logarithmic decay of the lower bounds. These results are discussed in the context of nonextensive Tsallis entropies.Comment: 8 pages and 8 fig

The Effects of Atmospheric Dispersion on High-Resolution Solar Spectroscopy

We investigate the effects of atmospheric dispersion on observations of the Sun at the ever-higher spatial resolutions afforded by increased apertures and improved techniques. The problems induced by atmospheric refraction are particularly significant for solar physics because the Sun is often best observed at low elevations, and the effect of the image displacement is not merely a loss of efficiency, but the mixing of information originating from different points on the solar surface. We calculate the magnitude of the atmospheric dispersion for the Sun during the year and examine the problems produced by this dispersion in both spectrographic and filter observations. We describe an observing technique for scanning spectrograph observations that minimizes the effects of the atmospheric dispersion while maintaining a regular scanning geometry. Such an approach could be useful for the new class of high-resolution solar spectrographs, such as SPINOR, POLIS, TRIPPEL, and ViSP

Local and macroscopic tunneling spectroscopy of Y(1-x)CaxBa2Cu3O(7-d) films: evidence for a doping dependent is or idxy component in the order parameter

Tunneling spectroscopy of epitaxial (110) Y1-xCaxBa2Cu3O7-d films reveals a doping dependent transition from pure d(x2-y2) to d(x2-y2)+is or d(x2-y2)+idxy order parameter. The subdominant (is or idxy) component manifests itself in a splitting of the zero bias conductance peak and the appearance of subgap structures. The splitting is seen in the overdoped samples, increases systematically with doping, and is found to be an inherent property of the overdoped films. It was observed in both local tunnel junctions, using scanning tunneling microscopy (STM), and in macroscopic planar junctions, for films prepared by either RF sputtering or laser ablation. The STM measurements exhibit fairly uniform splitting size in [110] oriented areas on the order of 10 nm2 but vary from area to area, indicating some doping inhomogeneity. U and V-shaped gaps were also observed, with good correspondence to the local faceting, a manifestation of the dominant d-wave order parameter

Gas-liquid transition in the model of particles interacting at high energy

An application of the ideas of the inertial confinement fusion process in the case of particles interacting at high energy is investigated. A possibility of the gas-liquid transition in the gas is considered using different approaches. In particular, a shock wave description of interactions between particles is studied and a self-similar solution of Euler's equation is discussed. Additionally, Boltzmann equation is solved for self-consistent field (Vlasov's equation) in linear approximation for the case of a gas under external pressure and the corresponding change of Knudsen number of the system is calculated.Comment: 24 pages, 2 figur

Thermostatistics of deformed bosons and fermions

Based on the q-deformed oscillator algebra, we study the behavior of the mean occupation number and its analogies with intermediate statistics and we obtain an expression in terms of an infinite continued fraction, thus clarifying successive approximations. In this framework, we study the thermostatistics of q-deformed bosons and fermions and show that thermodynamics can be built on the formalism of q-calculus. The entire structure of thermodynamics is preserved if ordinary derivatives are replaced by the use of an appropriate Jackson derivative and q-integral. Moreover, we derive the most important thermodynamic functions and we study the q-boson and q-fermion ideal gas in the thermodynamic limit.Comment: 14 pages, 2 figure

Presidential Popularity and Reputation

This paper reports on the results of an empirical study of relationships between the popularity of US presidents and economic variables. Traditionally, these relationships are based on the hypothesis that voters hold the incumbent President responsible for the economic situation. We derive an alternative specification of popularity, based on the hypothesis that political parties perform better on different issues. Empirical evidence turns out to be strongly in favour of our hypothesis. Our findings have important implications for studies on government behaviour in which it is assumed that one of the objectives of administrations is to maximise votes