Estoque de carbono e nutrientes na Serapilheira e solos de fragmentos florestais da Mata Atlântica do Estado Rio de Janeiro.

Esse trabalho objetiva contribuir para o entendimento da quantificação dos estoques de carbono da serapilheira em sistemas florestais do domínio da Mata Atlântica de duas regiões morfoclimáticas distintas do Estado do Rio de Janeiro. Trata-se de duas Microbacias Hidrográficas (MBH), respectivamente Santa Maria, em São José de Ubá, município situado na região Noroeste fluminense e Caixa d?água, situada no município de Trajano de Moraes, na região Serrana do Estado do Rio de Janeiro. Essas MBHs foram selecionadas no âmbito do Projeto RIO-RURAL, desenvolvidas pela Secretaria de Desenvolvimento Sustentável (SDS) da Secretaria de Agricultura e Pecuária do Estado do Rio de Janeiro (SEAPEC).bitstream/item/110806/1/ComTec-67-Estoque-Carbono.pd

A Derivation of a Variable Vertical Mesh Spacing for Les Models: Application To a CBL

A derivation of a variable vertical mesh spacing for LESmodels: application to a CB

GEOMETRIC EVALUATION USING CONSTRUCTAL DESIGN OF A COASTAL OVERTOPPING DEVICE WITH DOUBLE RAMP CONSIDERING A REGULAR WAVE AND TIDAL VARIATION

Concern for the environment and new ways of electricity generation, have led to studies of renewable energy sources, among these the Wave Energy Converters (WECs) are an option, however there are still many challenges to define how best to realize the conversion of the energy of the waves into electricity. In this work, a numerical study was carried out with the purpose of maximizing the available power (Pd) of a two-ramp overtopping device, considering the area fraction of ramps (ϕ1 and ϕ2) equal to 0.0006 and the ratio between height and length of the ramps (H1/L1 = H2/L2) equal to 0.3. The distance between the ramps (Lg) was varied in three values: 1.0; 1.5 and 2.0 m, besides three values for the free surface of water (h): 9.8; 10.0 and 10.2 m; simulating a tidal effect. The Constructal Design and Exhaustive Search methods were used, respectively, in the geometric evaluation (determination of a search field) and optimization. For the wave generation, the Second Order Stokes Theory was used, with wave period (T) of 7.5 s and wave height (H) 1.0 m. The results showed that there was no accumulation of water in the upper ramp of the device, in addition, with the increase of Lg there was an increase of Pd in h = 10.0 and 10.2 m, and Pd kept practically constant in h = 9, 8 m. And, as expected, with increasing of h, there was an increase in Pd

CONSTRUCTAL DESIGN APPLIED TO A FINNED CHANNEL UNDER FORCED CONVECTION FLOWS WITH DIFFERENT IMPOSED PRESSURE DROPS

This paper aims to numerically study the heat transfer in a two dimensional finned channel under laminar, incompressible and forced convective flow with adiabatic walls. The main purpose is to maximize the convection heat transfer by changing the fin’s dimensions by means of Constructal Design. Numerical computations are performed for different Bejan numbers ranging from 0.182 up to 18.2. For all simulations the Prandlt number is kept constant, Pr = 0.71. The fluid motion throughout the channel is caused by imposition of pressure difference between inlet/outlet surfaces. Concerning heat transfer, it is caused by the difference of temperature between the inlet stream of fluid and the heated fins placed at the channel surfaces. The first fin is positioned in the lower surface of the channel while the second one is placed in the upper one. The problem is submitted to three constraints, the channel area (H × L), area of two fins and occupancy areas for the fins. It is considered here that both fins have the same fraction area (ratio between the fins and occupancy areas) f = 0.2. The problem is submitted to three degrees of freedom: H/L (ratio between height and length of channel), H3/L3 and H4/L4 which represent the ratio between the height and length of the first and second fin, respectively. Here, the second fin remains unchanged, being its dimensions H4/L4 = 2.0, whereas the first one is free to modify its dimensions, H3/L3. The channel dimensions are also constant. The solutions are sought using the conservation equations of mass, momentum and energy being these ones discretized through the Finite Volume Method (FVM). Results showed the importance of Constructal Design application for thermal improvement of the problem. Thermal efficiency differences of 5 times where achieved when comparing the best and worst cases. Other important observation is concerned with the effect of ratio H3/L3 over heat transfer ratio (q) which varied significantly from a case where a pressure drop is imposed in the channel to other case where the driven force is caused by imposition of velocity field at the channel inlet

Simulações Les de uma Camada Limite Convectiva Empregando um Espaçamento de Grade Vertical Variável

Simulações LES de uma camada limite convectivaempregando um espaçamento de grade vertical variáv