Direct Connection of Supercapacitor-Battery Hybrid Storage System to the Grid-tied Photovoltaic System

IEEE Penetration rate of grid-connected photovoltaic (PV) generation to the existing utility grid is rapidly increasing over the years. Since the power generated from PV systems fluctuate according to the weather condition, e.g., cloud passing, this can significantly disturb the stability of a weak utility grid. The integration of energy storage devices and its ramp-rate control technique are required to reduce the impact of PV systems output fluctuations and augment the stability of the utility grid. In this paper, ramp-rate control is applied to the direct connection of energy storage devices in PV generation system configuration. The direct connection of supercapacitors string and battery combination scheme is proposed to reduce the number of power converters so that the efficiency of the system is increased. In this work, the PV system output is controlled by directly control the energy storage system (ESS) to limit the changing rate of PV output to desired ramp-rate value. Hence, reducing the battery charge/discharge cycles and extending the expected lifetime of the ESS. The performance of the proposed direct connection scheme of ESS and its ramp-rate control strategy is verified using a 1-kW PV system prototype

Neutrinoless double-beta decay with three or four neutrino mixing

Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses. Considering the four-neutrino schemes that can accommodate also the results of the LSND experiment, it is shown that only one of them is compatible with the results of neutrinoless double-beta decay experiments and with the measurement of the abundances of primordial elements produced in Big-Bang Nucleosynthesis. It is shown that in this scheme, under the assumptions that massive neutrinos are Majorana particles and there are no cancellations among the contributions of the different neutrino masses, the results of the LSND experiment imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay.Comment: 18 pages including 2 figures, RevTe

The great depression in Argentina, Brazil and Uruguay: revisiting vulnerabilities and policies

In this thesis Marcelo Gerona and Silvana Sosa undertake an analysis of the Great Depression (1928-1934) in a sample of three highly interconnected South American countries: Argentina, Brazil and Uruguay (ABU). The problem tackled in this work is the relative vulnerabilities of ABU, which contributed to the strong impact of the Great Depression, as well as the nature of the policy responses to the economic emergency. In this context, the hypothesis is that ABU were highly vulnerable to the Great Depression, and among them the smallest country, Uruguay, was the most vulnerable of all. This research is original not only for having assessed jointly these three scarcely analysed countries from a historical-comparative perspective during this uneasy period of time, but also because of the introduction of a new eclectic conception of ‘complex vulnerability’ that involves many paradigms and points of view. Furthermore, the historic research along with a comparative reference to the Financial Crisis of 2008 helps the reader to understand the role of the semi-periphery, in an effort that is appealing for both historians and policymakers worldwide.Political Culture and National Identit

The Interplay Between the "Low" and "High" Energy CP-Violation in Leptogenesis

We analyse within the "flavoured" leptogenesis scenario of baryon asymmetry generation, the interplay of the "low energy" CP-violation, originating from the PMNS neutrino mixing matrix $U$, and the "high energy" CP-violation which can be present in the matrix of neutrino Yukawa couplings, $\lambda$, and can manifest itself only in "high" energy scale processes. The type I see-saw model with three heavy right-handed Majorana neutrinos having hierarchical spectrum is considered. The "orthogonal" parametrisation of the matrix of neutrino Yukawa couplings, which involves a complex orthogonal matrix $R$, is employed. In this approach the matrix $R$ is the source of "high energy" CP-violation. Results for normal hierarchical (NH) and inverted hierarchical (IH) light neutrino mass spectrum are derived in the case of decoupling of the heaviest RH Majorana neutrino. It is shown that taking into account the contribution to $Y_B$ due to the CP-violating phases in the neutrino mixing matrix $U$ can change drastically the predictions for $Y_B$, obtained assuming only "high energy" CP-violation from the $R$-matrix is operative in leptogenesis. In the case of IH spectrum, in particular, there exist significant regions in the corresponding parameter space where the purely "high energy" contribution in $Y_B$ plays a subdominant role in the production of baryon asymmetry compatible with the observations.Comment: Results unchanged; comments and references added; version to be puplished in Eur.Phys.J.

Product-Group Unification in Type IIB String Thoery

The product-group unification is a model of unified theories, in which masslessness of the two Higgs doublets and absence of dimension-five proton decay are guaranteed by a symmetry. It is based on SU(5) x U(N) (N=2,3) gauge group. It is known that various features of the model are explained naturally, when it is embedded in a brane world. This article describes an idea of how to accommodate all the particles of the model in Type IIB brane world. The GUT-breaking sector is realized by a D3--D7 system, and chiral quarks and leptons arise from intersection of D7-branes. The D-brane configuration can be a geometric realization of the non-parallel family structure of quarks and leptons, an idea proposed to explain the large mixing angles observed in the neutrino oscillation. The tri-linear interaction of the next-to-minimal supersymmetric standard model is obtained naturally in some cases.Comment: 33 pages, 5 figure

Effect of olive oil in dairy cow diets on the fatty acid profile and sensory characteristics of cheese

The effect of dietary unrefined olive oil (OO) residues and hydrogenated vegetable oil (HVO) on the fatty acid profiles of milk and cheese and the sensory characteristics of cheeses was determined. For 9 weeks, animals were fed a control diet with no added lipid (n = 5 cows), or fat-supplemented diets containing OO or HVO (in both cases n = 5 cows; 30 g kg-1 dry matter). Compared with control and HVO, OO increased C18:1 cis-9, and C18:3 cis-9, cis-12, cis-15 fatty acids in milk; and also increased C18:1 trans-10, C18:1 trans-11, C18:1 cis-9, C18:2 cis-9, trans-11 and C18:3 cis-9, cis-12, cis-15 fatty acids in cheeses. OO reduced the number of holes, overall odour and acidity of cheeses, whereas HVO increased the cow milk odour, bitterness and acidity of cheeses. Overall, OO can improve the cheese fatty acid profile, but with adverse effects on sensory attributes

Effects of pH and ionic strength on the protease activity of gastric extracts from the Coho salmon Oncorhynchus kisutch

The activity of fish acid proteases is strongly dependent on the pH, and many basic and applied works had focused on researching the pH-profile of digestive proteases using different buffered media. Nevertheless, enzymatic activity is also known to be affected by the ionic strength (IS) of the medium. The present work is aimed at researching the combined effects of pH (2.5, 3.0, 3.5, 3.75 and 4.0) and IS (50, 100 and 200 mM) on the protease activity of gastric extracts of juvenile Coho salmon Oncorhynchus kisutch. It is concluded that the activity of Coho salmon gastric proteases is maximal at pH 2.5-3.0, drops towards pH 4.0 irrespective of ionic strength, and they showed a lower activity at IS 50 mM in comparison to IS 100 or 200 mM. The present results point out to the convenience of considering the effect of ionic strength when measuring the activity of fish gastric proteases

Efeitos das deficiências de alguns micronutrientes em dois cultivares (Santa Rosa e UFV-1) de soja (Glycine max (L.) Merill)

Two soybean varieties were grown in nutrient solution either in the presence on in the absence of B, Cu and Zn. Symptoms of deficiency were observed. Dry matter production and yield data were recorded. Leaf analyses were made in the end of the pod filling period (except in the case of the minus B treatment in which plants failed to produce grains). Main conclusions were the following: (1) lack of B in the substrate affected dry matter production more than the deficiencies of Cu and Zn; (2) Cu deficiency reduced growth and yield formation more than the lack of Zn; (3) symtoms of deficiency are in agreement with those already described; (4) variety UFV-1 seems more sensitive to the deficiency of micronutrients than Santa Rosa; (5) leaf levels of B and Zn indicative of adequate nutritional status seem to be different for the two varieties.Os cultivares de soja Santa Rosa e UFV-1 foram cultivados em solução nutritiva deficiente em B, Cu ou Zn. As plantas carentes em B não completaram o ciclo, enquanto as demais o fizeram. A carência de Cu afetou a produção de matéria seca e a de vagens mais que a falta de Zn. Quantitativamente, as deficiências induzidas afetaram a variedade UFV - 1 mais que a Santa Rosa

Astrophysical Axion Bounds

Axion emission by hot and dense plasmas is a new energy-loss channel for stars. Observational consequences include a modification of the solar sound-speed profile, an increase of the solar neutrino flux, a reduction of the helium-burning lifetime of globular-cluster stars, accelerated white-dwarf cooling, and a reduction of the supernova SN 1987A neutrino burst duration. We review and update these arguments and summarize the resulting axion constraints.Comment: Contribution to Axion volume of Lecture Notes in Physics, 20 pages, 3 figure