Fermi acceleration and suppression of Fermi acceleration in a time-dependent Lorentz Gas

We study some dynamical properties of a Lorentz gas. We have considered both the static and time dependent boundary. For the static case we have shown that the system has a chaotic component characterized with a positive Lyapunov Exponent. For the time-dependent perturbation we describe the model using a four-dimensional nonlinear map. The behaviour of the average velocity is considered in two situations (i) non-dissipative and (ii) dissipative. Our results show that the unlimited energy growth is observed for the non-dissipative case. However, when dissipation, via damping coefficients, is introduced the senary changes and the unlimited engergy growth is suppressed. The behaviour of the average velocity is described using scaling approach

Lepton Flavor Violating Photoleptonic Effect

We study lepton flavor violating analogs of the photoelectric effect, with a final $\mu$ or $\tau$ instead of an electron: $\gamma e\to \mu$ and $\gamma e\to \tau$. On the basis of the general parametrization of the matrix element of the electromagnetic current we estimate the upper limits for the cross sections and event rates of these processes, imposed by the current experimental bounds on $\mu\to e \gamma$ and $\tau\to e \gamma$ decays.Comment: 6 pages, 1 figure, RevTeX

Book Reviews

Williston: the Law governing Sales of Goods at Common Law and Under the Uniform Sales Act ; Russell: Cases on the Measure of Damages; Scott: The Courts of the State of New York. Their History, Development and Jurisdiction; Macomber: The Fixed Law of Patents, As Established by the Supreme Court of the United States and the Nine Circuit Courts of Appeals; Scott: The Evolution of Law. A historical review based upon the author\u27s Commentaries on the Evolution of Law

AN UPDATE ON THE BREEDING BIOLOGY AND BIOMETRY OF HAUXWELL’S THRUSH (TURDUS HAUXWELLI) FROM LOWLAND SOUTHWESTERN BRAZILIAN AMAZON

The Neotropical region is home to a large number of species of the genus Turdus. While the breeding biology of this genus is well known in general, data are scant for some Amazonian species, including Hauxwell’s Thrush (Turdus hauxwelli). Here, we present new data on the breeding and biometry of T. hauxwelli based on field observations and captures in a fragment of terra firme forest in southwestern Amazonia, Brazil. We monitored six active nests between 2012 and 2014, and collected data on the incubation and nestling phases on five nests. The nests were built at a mean height of 1.9 m (range: 0.53–3.2 m) above the ground. We estimated incubation time as 13–14 days. We monitored the development of 11 nestlings in four nests. The mean weight of the newly-hatched nestlings was 6.56 g (range: 4.3–9.0 g [SD = 2.27]). The constant (K) of the growth rate in the nestlings was 0.43 (range: 0.31–0.51; SE=0.03), with an asymptote of 51.1 g (range: 45.04 - 62.32; SE= 0.31). The daily survival rate of the nests during the incubation phase was 97%. However, the survival rate during the nestling phase was only 12%. Mayfield’s success was 70% during the incubation phase and 21% during the development of the nestlings, whereas apparent success was 75% in the incubation phase and 27% in the nestling phase. We banded and measured 64 adult individuals, 13 juveniles, and four nestlings in 2005 and between 2009 and 2017. Minimum longevity, calculated from the recapture of banded individuals, was 6 years, 3 months and 11 days (or 2298 days after banding). Our results indicate that T. hauxwelli has a breeding season restricted to a few months of the rainy season (November–March), which overlaps with molt

Systematic evaluation of software product line architectures

The architecture of a software product line is one of its most important artifacts as it represents an abstraction of the products that can be generated. It is crucial to evaluate the quality attributes of a product line architecture in order to: increase the productivity of the product line process and the quality of the products; provide a means to understand the potential behavior of the products and, consequently, decrease their time to market; and, improve the handling of the product line variability. The evaluation of product line architecture can serve as a basis to analyze the managerial and economical values of a product line for software managers and architects. Most of the current research on the evaluation of product line architecture does not take into account metrics directly obtained from UML models and their variabilities; the metrics used instead are difficult to be applied in general and to be used for quantitative analysis. This paper presents a Systematic Evaluation Method for UML-based Software Product Line Architecture, the SystEM-PLA. SystEM-PLA differs from current research as it provides stakeholders with a means to: (i) estimate and analyze potential products; (ii) use predefined basic UML-based metrics to compose quality attribute metrics; (iii) perform feasibility and trade-off analysis of a product line architecture with respect to its quality attributes; and, (iv) make the evaluation of product line architecture more flexible. An example using the SEI’s Arcade Game Maker (AGM) product line is presented as a proof of concept, illustrating SystEM-PLA activities. Metrics for complexity and extensibility quality attributes are defined and used to perform a trade-off analysis