Pumped heat energy storage with liquid media: Thermodynamic assessment by a transcritical Rankine-like model

[EN]A pumped heat energy storage (PHES) system based on a Rankine cycle for supercritical working fluids, such as carbon dioxide and ammonia, accounting for the irreversible latent and sensible heat transfers between the working fluid and the storage liquid medium, as water or thermal oil, is analyzed. The model also includes several parameters such as pressure losses, heat exchanger efficiencies, and isentropic efficiencies of the compressor, pump, and expansion devices (such as turbines and valves), that take into account the main internal and external losses and heat leak to the environment. The model allows for the calculation of specific energy, the heat pump performance coefficient, heat engine efficiency, and overall round-trip efficiency, as well as the temperatures of the working fluid and reservoirs. A zero-dimensional model is also used to determine the time dependence of heat leak in the tanks. The main results show that this technology could achieve round trip efficiency values in the order of 50–70%. Irreversibilities in compression and expansion appears as the most influential energy losses factor. The time effect of the ambient conditions on the tanks has been analyzed for a wet subtropical climate but it seems that the ambient conditions have no major influence on the performance of the system. In addition, explicit numerical results and temperature–entropy plots are presented for two representative systems as carbon dioxide-water and ammonia-thermal oil to take into account the main values in an operating condition

Secretory carcinoma of the breast containing the ETV6-NTRK3 fusion gene in a male: case report and review of the literature

BACKGROUND: Secretory carcinoma (SC) of the breast is a rare and indolent tumor. Although originally described in children, it is now known to occur in adults of both sexes. Recently, the tumor was associated with the ETV6-NTRK3 gene translocation. CASE PRESENTATION: A 52-year-old male was diagnosed with secretory breast carcinoma and underwent a modified radical mastectomy. At 18 months the tumor recurred at the chest wall and the patient developed lung metastases. He was treated concurrently with radiation and chemotherapy without response. His tumor showed the ETV6-NTRK3 translocation as demonstrated by fluorescent in situ hybridization (FISH). CONCLUSION: SC is a rare slow-growing tumor best treated surgically. There are insufficient data to support the use of adjuvant radiation or chemotherapy. Its association with the ETV6-NTRK3 fusion gene gives some clues for the better understanding of this neoplasm and eventually, the development of specific therapies

Response of a low elevation carbonate lake in the Yucatan Peninsula (Mexico) to climatic and human forcings

The importance of climate change, specifically drought, across the Maya region in the northern Neotropics, remains a topic of lively debate. Part of this discussion hinges on the coherency of response to climatic variability across different archives and proxies. In this paper we present a 6600-year palaeolimnological record from Yaal Chac, a carbonate lake (known locally as a cenote) in the northern lowlands of the Yucatan Peninsula, 2‰), but show no covariation with δ13C. A major transition occurs at ca. 4360 cal yr BP, with a change to generally more organic sediments and increased variability in all proxies. Although direct evidence for anthropogenic activity in the Yaal Chac catchment is limited, it seems feasible that human impact was affecting the system. Comparison with other records from the Northern Maya lowlands and the wider region shows little coherence in the mid Holocene, when Yaal Chac seems to have been quite stable, but possibly responsive to increased climatic seasonality, driving the production of seasonal laminae. In the late Holocene, when the climate was generally more variable, there is more coherence between Yaal Chac and other regional records, including the so called Pan Caribbean Dry Period (3500–2500 cal yr BP) and the droughts of the late Pre-Classic period (1800–1600 cal yr BP). The Yaal Chac record shows no evidence of drought at the time of either the Maya ‘hiatus’ or the Maya ‘collapse’ of the Terminal Classic, but does record drying from the 14th to 19th centuries CE, in keeping with other proxy and historical records. This new record from Yaal Chac highlights the spatial variability of responses to climate forcings and the importance of recognising individual system sensitivity

On the statistics of superlocalized states in self-affine disordered potentials

We investigate the statistics of eigenstates in a weak self-affine disordered potential in one dimension, whose Gaussian fluctuations grow with distance with a positive Hurst exponent $H$. Typical eigenstates are superlocalized on samples much larger than a well-defined crossover length, which diverges in the weak-disorder regime. We present a parallel analytical investigation of the statistics of these superlocalized states in the discrete and the continuum formalisms. For the discrete tight-binding model, the effective localization length decays logarithmically with the sample size, and the logarithm of the transmission is marginally self-averaging. For the continuum Schr\"odinger equation, the superlocalization phenomenon has more drastic effects. The effective localization length decays as a power of the sample length, and the logarithm of the transmission is fully non-self-averaging.Comment: 21 pages, 6 figure

The Little Review on Leptogenesis

This is a brief review on the scenario of baryogenesis through leptogenesis. Leptogenesis is an appealing scenario that may relate the observed baryon asymmetry in the Universe to the low-energy neutrino data. In this review talk, particular emphasis is put on recent developments on the field, such as the flavourdynamics of leptogenesis and resonant leptogenesis near the electroweak phase transition. It is illustrated how these recent developments enable the modelling of phenomenologically predictive scenarios that can directly be tested at the LHC and indirectly in low-energy experiments of lepton-number and lepton-flavour violation.Comment: 15 pages, based on a plenary presentation given at the DISCRETE'08 Symposium, 11-16 December 2008, Valencia, Spai

Status of the UCNτ experiment

The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics beyond the standard model. Measurements of neutron lifetime and β-decay correlation coefficients with precisions of 0.02% and 0.1%, respectively, would allow for stringent constraints on new physics. The UCNτ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime, τ_n = 877.7s (0.7s)_(stat) (+0.4/−0.2s)_(sys). We discuss the recent result from UCNτ, the status of ongoing data collection and analysis, and the path toward a 0.25 s measurement of the neutron lifetime with UCNτ

Leptogenesis from Soft Supersymmetry Breaking (Soft Leptogenesis)

Soft leptogenesis is a scenario in which the cosmic baryon asymmetry is produced from a lepton asymmetry generated in the decays of heavy sneutrinos (the partners of the singlet neutrinos of the seesaw) and where the relevant sources of CP violation are the complex phases of soft supersymmetry-breaking terms. We explain the motivations for soft leptogenesis, and review its basic ingredients: the different CP-violating contributions, the crucial role played by thermal corrections, and the enhancement of the efficiency from lepton flavour effects. We also discuss the high temperature regime $T > 10^7$ GeV in which the cosmic baryon asymmetry originates from an initial asymmetry of an anomalous $R$-charge, and soft leptogenesis reembodies in $R$-genesis.Comment: References updated. Some minor corrections to match the published versio

On Quantum Effects in Soft Leptogenesis

It has been recently shown that quantum Boltzman equations may be relevant for leptogenesis. Quantum effects, which lead to a time-dependent CP asymmetry, have been shown to be particularly important for resonant leptogenesis when the asymmetry is generated by the decay of two nearly degenerate states. In this work we investigate the impact of the use of quantum Boltzman equations in the framework ``soft leptogenesis'' in which supersymmetry soft-breaking terms give a small mass splitting between the CP-even and CP-odd right-handed sneutrino states of a single generation and provide the CP-violating phase to generate the lepton asymmetry.Comment: 15 pages, 4 figures. Replacement to match published versio

Caracterización de la macrofauna edáfica en diferentes sistemas agroforestales, en el Municipio de San Ramón, Departamento de Matagalpa, Nicaragua

El presente estudio de focalizo en caracterizar la macrofauna edáfica en tres diferentes sistemas agroforestales: CMIEA: Café, musáceas, Inga, Erithryna y árboles, CIE: Café, Inga, Erithryna y árboles y CA: Café y árboles en época seca y época lluviosa. Cada sistema tenía 900m2, presentaban aproximadamente 6 especies arbóreas por sistema. Se tomaron 32 monolitos por época, y este se dividió en cuatros estratos (hojarasca, 0 a 10cm, 10 a 20cm y 20 a 30cm) con el método recomendado por el Tropical Soil Biology and Fertility Programme. La macrofauna se conservó en alcohol al 70%, exceptuando las lombrices que fueron preservadas con formalina al 4% y se trasladaron al Laboratorio de Entomología del Departamento de Agroecología de la UNAN-León para su respectiva edificación. Los resultados demuestran que los valores mayores de la abundancia se presentaron en la época lluviosa (391 individuos) y en la época seca (324 individuos). La mayor abundancia se encontró en el sistema CMIEA (162 individuos) en la época lluviosa y mínima en el sistema CA (91 individuos) en la época seca. El índice de diversidad de Shannon fue más alto en el sistema CA (2.73) en la época seca y mínimo en el sistema CIE (1.44). Los arreglos de los sistemas agroforestales no influyen en la abundancia de la macrofauna, sin embargo, favorece la presencia de especie de Philoscidae y lombrices de suelos orden Haplotaxid