Technological diffusion between different environmental countries

Using an endogenous Schumpeterian R&D growth model, this paper intends to analyse how international trade of intermediate goods can affect the structure and diffusion of technological knowledge between ecological and dirty countries. Each country is assumed to have different environmental quality levels and different available technological knowledge and to be able of conducting R&D activities (innovative in ecological-country and imitative in dirty-country). We concluded that under international trade, there is a higher probability of successful imitation that improves the Dirty-country ability to benefit from Ecological-country innovations. This induces an efficient allocation of production in the Dirty-country, where marginal cost is lower, and increases the ecological goods production. Furthermore, subsidies, by promoting technological knowledge progress, lead to a permanent increase in the world steady-state growth rate.info:eu-repo/semantics/acceptedVersio

Experimental realization of the Yang-Baxter Equation via NMR interferometry

The Yang-Baxter equation is an important tool in theoretical physics, with many applications in different domains that span from condensed matter to string theory. Recently, the interest on the equation has increased due to its connection to quantum information processing. It has been shown that the Yang-Baxter equation is closely related to quantum entanglement and quantum computation. Therefore, owing to the broad relevance of this equation, besides theoretical studies, it also became significant to pursue its experimental implementation. Here, we show an experimental realization of the Yang-Baxter equation and verify its validity through a Nuclear Magnetic Resonance (NMR) interferometric setup. Our experiment was performed on a liquid state Iodotrifluoroethylene sample which contains molecules with three qubits. We use Controlled-transfer gates that allow us to build a pseudo-pure state from which we are able to apply a quantum information protocol that implements the Yang-Baxter equation.Comment: 10 pages and 6 figure

Produção de plantas medicinais em sistemas agroflorestais: resultados preliminares de pesquisas participativas com agricultores familiares.

bitstream/item/41998/1/CT0070.pd

Entanglement and Bell's inequality violation above room temperature in metal carboxylates

In the present work we show that a special family of materials, the metal carboxylates, may have entangled states up to very high temperatures. From magnetic susceptibility measurements, we have estimated the critical temperature below which entanglement exists in the cooper carboxylate \{Cu$_2$(O$_2$CH)$_4$\}\{Cu(O$_2$CH)$_2$(2-methylpyridine)$_2$\}, and we have found this to be above room temperature ($T_e \sim 630$ K). Furthermore, the results show that the system remains maximally entangled until close to $\sim 100$ K and the Bell's inequality is violated up to nearly room temperature ($\sim 290$ K)

Decay-Time Asymmetries at the B-Factories

Absract (Invited talk at the X DAE High Energy Physics symposium in December 1992, held at Tata Institute of Fundamental Research, Bombay)Comment: 20pages, TIFR/TH/93-1

Experimental Determination of Thermal Entanglement in Spin Clusters using Magnetic Susceptibility Measurements

The present work reports an experimental observation of thermal entanglement in a clusterized spin chain formed in the compound Na$_2$Cu$_5$Si$_4$O$_{14}$. The presence of entanglement was investigated through two measured quantities, an Entanglement Witness and the Entanglement of Formation, both derived from the magnetic susceptibility. It was found that pairwise entanglement exists below $\sim 200$ K. Tripartite entanglement was also observed below $\sim 240$ K. A theoretical study of entanglement evolution as a function of applied field and temperature is also presented.Comment: Submited to Phys. Rev.

Avaliação de características fenotípicas para a determinação do rendimento foliar em espinheira-santa (Maytenus ilicifolia Martius).

A espinheira-santa (Maytenus ilieifolia) é uma espécie medicinal arbórea, nativa das formações de Floresta Ombrófila Mista do sul do Brasil, a qual vem sofrendo grande pressão de exploração nos seus ambientes naturais. Este trabalho teve como objetivo caracterizar o rendimento de indivíduos de diferentes populações naturais de espinheira-santa, por meio de características fenotípicas não destrutivas, a fim de contribuir para o processo de manejo sustentável. Para fins de determinação do rendimento, foram avaliados o número de ramos primários com e sem folhas, a altura, o diâmetro a altura do colo (DAC) e a altura da primeira ramificação, em 60 indivíduos de espinheira-santa de duas populações naturais, com características distintas. Estimou-se coeficientes de corre/ação entre estes parâmetros, bem como equações de regressão entre e o número de ramos primários com folhas (X) e o rendimento (R). As equações R = 0,75205 • X, para populações que ocorrem a pleno sol, e R = 1,53459 • X, para populações que ocorrem no sub-bosque de formações secundárias, são de uso prático e capazes de representar com elevada precisão o rendimento em populações com essas características ambientais

On the nonextensive character of some magnetic systems

During the past few years, nonextensive statistics has been successfully applied to explain many different kinds of systems. Through these studies some interpretations of the entropic parameter q, which has major role in this statistics, in terms of physical quantities have been obtained. The aim of the present work is to yield an overview of the applications of nonextensive statistics to complex problems such as inhomogeneous magnetic systems.Comment: to appear in the Proceedings of the conference CTNEXT07, Complexity, Metastability and Nonextensivity, Catania, Italy, 1-5 July 2007, Eds. S. Abe, H.J. Herrmann, P. Quarati, A. Rapisarda and C. Tsallis (American Institute of Physics, 2007) in pres