Federal Rural University of Rio de Janeiro

www.ufrrj.br
Rio de Janeiro, Brazil

The Federal Rural University of Rio de Janeiro is a centenary Brazilian university located in the city of Seropédica in the State of Rio de Janeiro in Brazil. It possesses the largest campus among Latin American universities, and is known for being the first university to have agriculture related courses in Brazil.Founded in October 20, 1910, by then president of the republic Nilo Peçanha, the College of Agriculture and Veterinary Medicine laid the foundations of agricultural education in Brazil.The ESAMV, however, only began operating in 1913 and ended in 1934. In its place emerged three distinct institutions: the National School of Agriculture , National School of Veterinary Medicine and the National School of Chemistry . These institutions have been crucial to overcoming the fragmentary and differentiated from existing agricultural and veterinary education throughout the nineteenth century and to create an academic reference space. In January 1944, the Rural University is established as an organ of the National Centre for Agronomic Research and Teaching and incorporates the ENA and the Environment.The creation of ESAMV thus represents the origin of the Rural University, today the Federal Rural University of Rio de Janeiro.This university has a college for high school course with technical integrated, like agriculture, hosting and environment called CTUR. It's located inside the campus of the university. Wikipedia.

SEARCH FILTERS
Time filter
Source Type

de Oliveira I.G.,Federal Rural University of Rio de Janeiro
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2017

In this work we discuss the H-T phase diagram for mesoscopic squared superconducting samples at the Bogomolnyi limit, where the Ginzburg-Landau constant κ=1/2. We calculate Hp(T), the vortex penetration field, and Hu(T) the upper critical field. Through the study of the temperature dependence on the Hp, it is possible to distinguish the region where the magnetic field penetrates into the sample, like a type-I or a type-II superconductor. It permits to determine the threshold temperature T(star operator)(L,H) where the phase transition from type-I to type-II occurs for some different sizes L of the mesoscopic superconducting samples. The calculation of the upper critical field Hu(T), for these samples, shows that, these two curves, Hp(T) and Hu(T), overlap at the threshold temperature mentioned above. The magnetization of the system was calculated for all sizes studied in this work, and for temperatures above and below T(star operator)(L,H). This study confirms the existence of the threshold temperature, T(star operator)(L,H), where type-I and type-II interchange in mesoscopic superconductors at the Bogomolnyi limit. © 2017 Elsevier B.V.


Menezes G.,Federal Rural University of Rio de Janeiro | Svaiter N.F.,Brazilian Center for Research in Physics (CBPF)
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2016

We study radiative processes of uniformly accelerated entangled atoms, interacting with an electromagnetic field prepared in the Minkowski vacuum state. We discuss the structure of the rate of variation of the atomic energy for two atoms traveling in different hyperbolic world lines. We identify the contributions of vacuum fluctuations and radiation reaction to the generation of entanglement as well as to the decay of entangled states. Our results resemble the situation in which two inertial atoms are coupled individually to two spatially separated cavities at different temperatures. In addition, for equal accelerations we obtain that one of the maximally entangled antisymmetric Bell state is a decoherence-free state. © 2016 American Physical Society.


Menezes G.,Federal Rural University of Rio de Janeiro
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

We consider radiative processes of a quantum system composed by two identical two-level atoms in a black-hole background. We assume that these identical two-level atoms are placed at fixed radial distances outside a Schwarzschild black hole and interacting with a quantum electromagnetic field prepared in one of the usual vacuum states, namely, the Boulware, Unruh, or Hartle-Hawking vacuum states. We study the structure of the rate of variation of the atomic energy. The intention is to identify in a quantitative way the contributions of vacuum fluctuations and the radiation reaction to the entanglement generation between the atoms as well as the degradation of entangled states in the presence of an event horizon. We find that for a finite observation time the atoms can become entangled for the case of the field in the Boulware vacuum state, even if they are initially prepared in a separable state. In addition, the rate of variation of atomic energy is not well behaved at the event horizon due to the behavior of the proper accelerations of the atoms. We show that the thermal nature of the Hartle-Hawking and Unruh vacuum state allows the atoms to get entangled even if they were initially prepared in the separable ground state. © 2016 American Physical Society.


Menezes G.,Federal Rural University of Rio de Janeiro
Physical Review D | Year: 2017

We consider radiative processes of an atom in a rotating black-hole background. We assume the atom, represented by a hypothetical two-level system, is coupled via a monopole interaction with a massless quantum scalar field prepared in each one of the usual physical vacuum states of interest. We constrain ourselves to two different states of motion for the atom, namely a static situation in which the atom is placed at a fixed radial distance, and also the case in which it has a stationary motion but with zero angular momentum. We study the structure of the rate of variation of the atomic energy. The intention is to clarify in a quantitative way the effect of the distinguished contributions of vacuum fluctuations and radiation reaction on spontaneous excitation and on spontaneous emission of atoms. In particular, we are interested in the comprehension of the combined action of the different physical processes underlying the Hawking effect in the scenario of rotating black holes as well as the Unruh-Starobinskii effect. We demonstrate that, in the case of static atoms, spontaneous excitation is also connected with the Unruh-Starobinskii effect, but only in the case of the quantum field prepared in the Frolov-Thorne vacuum state. In addition, we show that, in the zero angular momentum observer's perspective, the Boulware vacuum state contains an outward flux of particles as a consequence of the black-hole superradiance. The possible relevance of the findings in the present work is discussed. © 2017 American Physical Society.


Barreiro E.J.,Federal University of Rio de Janeiro | Kummerle A.E.,Federal University of Rio de Janeiro | Kummerle A.E.,Federal Rural University of Rio de Janeiro | Fraga C.A.M.,Federal University of Rio de Janeiro
Chemical Reviews | Year: 2011

The importance of the simple methyl group as a very useful structural modification in the rational design of bioactive compounds and drugs is examined. The methyl effect alters both biological phases of a drug, represented by its pharmacodynamic and pharmacokinetc profile, due to the modifications introduced in the stereoeletronic properties. Cimetidine contains an imidazolyl nucleus and a methyl group at C-5, thus favoring the tautomeric form necessary for H 2 receptor selectivity. The thioether in the side chain of cimetidine ensured adequate hydrophobic properties and led to increased selective antagonist activity. The activation mechanism of proton pump inhibitors (PPI) is directly related to the nitrogen nucleophilicity of the pyridine moiety, which depends on the electronic effect of substituents on the pKa of the pyridine ring. When electron-donating substituent, such as methyl groups are attached to the pyridine ring then its pKa increases, thus increasing its protonation rate at any given pH.


Abreu E.M.C.,Federal Rural University of Rio de Janeiro | Abreu E.M.C.,Federal University of Juiz de fora | Neto J.A.,Federal University of Juiz de fora
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

Verlinde's ideas considered gravity as an emergent force originated from entropic concepts. This hypothesis generated a huge number of papers through the last recent years concerning classical and quantum approaches about the issue. In a recent paper Kobakhidze, using ultra-cold neutrons experiment, claimed that Verlinde's entropic gravity is not correct. In this Letter, by considering the Tsallis nonadditivity entropy concerning the holographic screen, where we assumed that the bits are entangled states, we showed that it is possible to confirm Verlinde's formalism. © 2013 Elsevier B.V.


Alves W.A.,Federal Rural University of Rio de Janeiro
Vibrational Spectroscopy | Year: 2010

Spectral changes in the v1 region of pyridine (py) and pyrimidine (pd) at 991 cm-1 have been observed by means of a temperature dependent Raman study of the equimolar mixtures of formamide (FA)/py and FA/pd. The thermodynamic functions of the respective H-bonded complexes are determined and discussed as a function of the physical and chemical properties of the corresponding azabenzenes. The equilibrium constant values for the 1:1 FA:py complex are much greater than those obtained for the 2:1 FA:pd complex. This result clearly shows that py is a stronger base than pd, although their dipole moment (μ) values are almost identical. This last parameter seems to play an important role with respect to the band shifts (Δv) as well as to the formation enthalpies (ΔH°) of these complexes. The values of -43.6 J mol-1 K-1 for 1:1 FA:py and -75 J mol-1 K -1 for 2:1 FA:pd indicate that the whole hydrogen bonding process is entropically unfavorable. The high molecular association extent in these systems is likely the explanation to the significantly smaller band shifts in magnitude as compared to ternary systems. © 2010 Elsevier B.V. All rights reserved.


Wilkinson J.,Federal Rural University of Rio de Janeiro
Environment and Planning A | Year: 2011

The explosive growth of food commodity markets in the wake of massive, sustained demand from the 'emerging economies' might seem to mark a rupture with the niche quality markets which many authors have identified as the dominant tendencies in agrofood since the 1980s and a return to the mass markets of yesteryear. In this paper it is argued, however, that the distinguishing characteristics of special quality markets, and particularly the role of new social movements in their construction, are now being extended to the marketing of basic food commodities. Rather than a return to the commodity economy, therefore, we are witnessing a struggle to incorporate the values associated with fair trade, organics, and sustainability as benchmarks for global commodity trade in food, feed, fuels, and forestry products. I illustrate these tendencies through a discussion of the fair trade and responsible soy movements, representing the niche quality and the resurgent commodity markets, respectively, illustrating not only their similar dynamics but also their continuity in terms of leading actors and networks. Brazil provides a privileged vantage point for analysing this interface between global commodity markets and social movements. The strategic role of networks, in which civil society organisations and social movements are key both for the definition and the subsequent functioning of these markets points to the considerable weakening and possible demise of the traditional commodity economy. I draw attention, however, to the North-South and particularly European roots of these tendencies whose survival power is threatened as the axis for trade and investment shifts increasingly South-South with China as its principal driving force. © 2011 Pion Ltd and its Licensors.


Terra B.D.F.,Federal Rural University of Rio de Janeiro | Araujo F.G.,Federal Rural University of Rio de Janeiro
Ecological Indicators | Year: 2011

Large river-reservoir systems are some of the most difficult aquatic ecosystems to assess because: (1) they typically lack minimally disturbed reference sites; (2) the reservoirs are not natural systems to begin with; and (3) reservoirs with high exchange rates are transitional systems between rivers and lakes. These features are further complicated in Brazil where fish species taxonomy is incomplete (let alone fully described ecologically), where waters naturally have high organic and thermal loadings, and where dams and reservoirs provide most of the nation's electricity and water supplies. As a first step towards generating a biological tool for assessing the effects of reservoirs on rivers, we developed a preliminary River-Reservoir Fish Assemblage Index (RRFAI) in a transitional river-reservoir system in southeastern Brazil. To do so, we gill-netted fish monthly between October 2006 and September 2007 (excluding May and July 2007) immediately upriver of the reservoir, in the upper reservoir, in the lower reservoir, and immediately downriver of the reservoir. In developing our RRFAI we sought fish assemblage metrics to represent ecological characteristics including richness, habitat, trophic, tolerance, and resilience guilds. Despite clear differences in fish assemblage composition between river and reservoir sites, we found 9 metrics common to both systems that were nonredundant and had low sampling variability (number of native species, number of characiform species, number of siluriform species, % omnivorous individuals, % invertivorous individuals, % non-native carnivorous individuals, % intolerant individuals, % tolerant individuals, number of tolerant species). Fish assemblage condition was significantly and consistently lower in the lower reservoir. There was no significant difference between the dry and wet season in RRFAI scores, suggesting that a single season sample should usually suffice. Further research is needed along distinct disturbance gradients in multiple river-reservoir systems in Brazil to confirm the sensitivity of our preliminary RRFAI for assessing the physical and chemical habitat disturbances common to such systems. © 2010 Elsevier Ltd. All rights reserved.


This study had as its objective to evaluate the effects of different tillage and crop systems on the growth and productivity of sugarcane plants. The experiment was conducted in Linhares, ES. It is one of the oldest assays in the country investigating the effects of unburned and burned sugarcane. Installed in a Yellow Latosol with sandy/medium texture, the treatments consisted of plots (conventional and minimum tillage) and subplots (raw and burned sugarcane). Plant growth, contribution of organic matter and quantification of sugarcane yield were evaluated. The diameter was larger for minimum tillage, and tillering was greater for conventional tillage. The height and tillering were superior in the cut without burning. For stems productivity, the treatments did not present significant differences. The leaves were larger in minimum tillage and tips in unburned cane. The minimum tillage propitiates the increase in diameter initially and largest productivity of leaves in the crop. Tillering is favored by conventional tillage. The unburned cane did not present negative influence of straw in the regrowth. After 16 years of sugarcane cultivation with and without straw burning, it resulted in larger productivity of pointers increasing the productivity of the stems in unburned cane.

Loading Federal Rural University of Rio de Janeiro collaborators
Loading Federal Rural University of Rio de Janeiro collaborators