On Graph Refutation for Relational Inclusions

We introduce a graphical refutation calculus for relational inclusions: it reduces establishing a relational inclusion to establishing that a graph constructed from it has empty extension. This sound and complete calculus is conceptually simpler and easier to use than the usual ones.Comment: In Proceedings LSFA 2011, arXiv:1203.542

Production and nutritional composition of two annual ryegrass cultivars (Diploid and Tetraploid)

The feed cost represents the major cost in milk production. Direct grazing and forage produced on the dairy farm could allow the farmer to a better feed production cost control. Ryegrass have been extensively used for grazing and forage production. This study evaluates the production and nutritional composition of two ryegrass cultivars diploid and tetraploid alone or in a binary mixture (50:50). The results showed that the binary mixture is a good option because of its higher production of DM/ha, higher ME and NFC and lower content of NDF, ADF and ADL.info:eu-repo/semantics/publishedVersio

Further progress in ion back-flow reduction with patterned gaseous hole-multipliers

A new idea on electrostatic deviation and capture of back-drifting avalanche-ions in cascaded gaseous hole-multipliers is presented. It involves a flipped reversed-bias Micro-Hole & Strip Plate (F-R-MHSP) element, the strips of which are facing the drift region of the multiplier. The ions, originating from successive multiplication stages, are efficiently deviated and captured by such electrode. Experimental results are provided comparing the ion-blocking capability of the F-R-MHSP to that of the reversed-bias Micro-Hole & Strip Plate (R-MHSP) and the Gas Electron Multiplier (GEM). Best ion-blocking results in cascaded hole-multipliers were reached with a detector having the F-R-MHSP as the first multiplication element. A three-element F-R-MHSP/GEM/MHSP cascaded multiplier operated in atmospheric-pressure Ar/CH4 (95/5), at total gain of ~10^{5}, yielded ion back-flow fractions of 3*10^{-4} and 1.5*10^{-4}, at drift fields of 0.5 and 0.2 kV/cm, respectively. We describe the F-R-MHSP concept and the relevance of the obtained ion back-flow fractions to various applications; further ideas are also discussed.Comment: 17 pages, 11 figures, published in JINS

Organizational Characteristics and Performance of Export Promotion Agencies: Portugal and Ireland compared

Export Promotion Agencies (EPAs) have been in operation in developed countries since the beginning of the 20th century to improve the competitiveness of firms by increasing knowledge and competences applied to export market development.Export Promotion Agencies; Organizational Performance; Portugal; Ireland

Efficient ion blocking in gaseous detectors and its application to gas-avalanche photomultipliers sensitive in the visible-light range

A novel concept for ion blocking in gas-avalanche detectors was developed, comprising cascaded micro-hole electron multipliers with patterned electrodes for ion defocusing. This leads to ion blocking at the 10^{-4} level, in DC mode, in operation conditions adequate for TPCs and for gaseous photomultipliers. The concept was validated in a cascaded visible-sensitive gas avalanche photomultiplier operating at atmospheric pressure of Ar/CH_{4} (95/5) with a bi-alkali photocathode. While in previous works high gain, in excess of 10^{5}, was reached only in a pulse-gated cascaded-GEM gaseous photomultiplier, the present device yielded, for the first time, similar gain in DC mode. We describe shortly the physical processes involved in the charge transport within gaseous photomultipliers and the ion blocking method. We present results of ion backflow fraction and of electron multiplication in cascaded patterned-electrode gaseous photomultiplier with K-Cs-Sb, Na-K-Sb and Cs-Sb visible-sensitive photocathodes, operated in DC mode.Comment: Proceeding paper to 10-th International Conference On Instrumentation For Colliding Beam Physics, Budker Institute of Nuclear Physics, Novosibirsk, Russia, February 28 - March 5, 2008, Submitted to NIMA, 5 pages, 7 figure

On Graphical Calculi for Modal Logics

We present a graphical approach to classical and intuitionistic modal logics, which provides uniform formalisms for expressing, analysing and comparing their semantics. This approach uses the flexibility of graphical calculi to express directly and intuitively the semantics for modal logics. We illustrate the benefits of these ideas by applying them to some familiar cases of classical and intuitionistic multi-modal logics.Cálculos Gráficos para lógicas modais Apresentamos uma abordagem gráfica para as lógicas modais clássica e intuicionista, capaz de fornecer formalismos uniformes para expressar, analisar e comparar suas respectivas semânticas. Tal abordagem utiliza a flexibilidade dos cálculos gráficos para expressar, direta e intuitivamente, a semântica das lógicas modais. Ilustramos os benefícios dessas ideias aplicando-as a alguns casos conhecidos de lógicas multimodais clássica e intuicionista.---Artigo em inglês

On The Evolution of TFP in Latin America (revised)

Due to several policy distortions, including import-substitution industrialization, widespread government intervention and both domestic and international competitive barriers, there has been a general presumption that Latin America has been much less productive than the leading economies in the last decades. In this paper we show, however, that until the late seventies Latin American countries had high productivity levels relative to the United States. It is only after the late seventies that we observe a fast decrease of relative TFP in Latin America. We also show that the inclusion of human capital in the production function makes a crucial di¤erence in the TFP calculations for Latin America.

The Evolution of International Output Differences (1960-2000): From Factors to Productivity

This article presents a group of exercises of level and growth decomposition of output per worker using cross-country data from 1960 to 2000. It is shown that at least until 1975 factors of production (capital and education) were the main source of output dispersion across economies and that productivity variance was considerably smaller than in later years. Only after this date did the prominence of productivity start to show up in the data, as the majority of the literature has found. The growth decomposition exercises showed that the reversal of relative importance of productivity vis-a-vis factors is explained by the very good (bad) performance of productivity of fast- (slow-) growing economies. Although growth in the period, is on average, is mostly due to factor accumulation, its variance is explained by productivity.Cross-Country Income Inequality, Development, Total Factor Productivity, Aggregate Production Function, Growth Decomposition