A numerical investigation of laminar mixed convection heat transfer in a SHALLOW two sided lid driven rectangular ENCLOSURE of aspect ratio 5, (AR=5) is executed. The natural convection effect is sustained by subjecting the bottom wall to a higher temperature than its top counterpart. In addition, the two horizontal walls of the ENCLOSURE are moving in different directions and the two vertical walls of the ENCLOSURE are kept insulate. Discretization of the governing equations is achieved through a finite volume scheme. Fluid flow and heat transfer characteristics are examined in the domain of the Richardson number and Grashof number as 10-3£Ri=Gr / Re2£103 and Gr=10 4 while the bottom side of ENCLOSURE is moving in two different horizontal directions. The working fluid is assigned a Prandtl number of 0.7, 10 and 100 throughout this investigation. Temporal variations of streamlines, isotherms, and Nusselt number are presented in this investigation for various pertinent dimensionless groups.

There are two main methods in fire modeling: zone models and field models. The conservation of mass and energy in ENCLOSURE is the theoretical base of zone models. The models deal with heat release rate, fire plume, mass flow, smoke movement and gas temperature in fires. Theoretical principles of compartment fire zone modeling are presented and the behavior of fire in ENCLOSUREs is discussed. The conservation laws are presented in control volume form and applied to the behavior of fire in ENCLOSUREs. The governing equations are derived and presented. Some zone models and their field of application in fire modeling are also given.

The problem of steady, laminar and incompressible natural convection flow in an octagonalENCLOSURE was studied. In this investigation, two horizontal walls were maintained at a constant hightemperature, two vertical walls were kept at a constant low temperature and all inclined walls wereconsidered adiabatic. The ENCLOSURE was assumed to be filled with a Bousinessq fluid. The studyincludes computations for different Prandtl numbers Pr such as 0.71, 7, 20 and 50 whereas the Rayleighnumber Ra was varied from 103 to 106. The pressure-velocity form of Navier-Stokes equations andenergy equation was used to represent the mass, momentum and energy conservations of the fluidmedium in the ENCLOSURE. The governing equations and boundary conditions were converted todimentionless form and solved numerically by penalty finite element method with discretization bytriangular mesh elements. Flow and heat transfer characteristics were presented in terms of streamlines, isotherms and average Nusselt number Nu. Results showed that the effect of Ra on the convection heattransfer phenomenon inside the ENCLOSURE was significant for all values of Pr studied (0.71-50). It wasalso found that, Pr influence natural convection inside the ENCLOSURE at high Ra (Ra > 104).

In this paper, shielding effectiveness (SE) of a perforated ENCLOSURE with imperfectly conducting walls is evaluated. To this end, first, an accurate numerical technique based on method of Moments (MoM) is presented. In this method, lossy metallic walls of the ENCLOSURE are replaced by equivalent electric surface current sources. Then, the impedance boundary condition on the imperfectly conducting surfaces is applied and an electric field integral equation is extracted. At the end, the integral equation is solved numerically by Galerkin method. In addition to the mentioned numerical method, an extremely fast analytical technique based on transmission line model (TLM) is proposed which is able to predict the SE with high level of accuracy over a large frequency bandwidth just in a few seconds. For validation of both methods, other commercial softwares (FEKO and CST) are employed and several ENCLOSUREs with different conductivities are studied. Lossy MoM method shows accurate results for conductivities down to 10S/m, while efficient TLM method proves its accuracy for conductivities down to 250S/m.

Study of difference of vegetation species diversity under the circumstances of ENCLOSURE and grazing are important for improving the management of rangeland habitats. This study by the aim of investigating the effects of livestock grazing on the change of species richness and diversity on the grazed rangelands and comparison of that with ENCLOSURE area were selected. For measuring the vegetation characteristics, suitable sampling plot size was determined using minimal area method. For this purpose, homogeneous units were selected inside and outside of the ENCLOSURE and eighty 1m2 plots using systematic-randomized method along of 8 transects with 50m long on the foothill were established and list of existing species, density, canopy cover, litter, stone and gravels and bare soil were measured. For evaluation of numerical diversity indices Ecological Methodology6.2 software was used and diversity and evenness numerical indices were calculated. Data analysis was conducted in the SPSS18 software environment and means comparison were performed using Duncun's method in the probability level of 5. Results show that on the study area 96 plant species belonging to 26 family and 68 genera are exist. Results of statistical analysis for species frequency on both study sites show that in the ENCLOSURE all of the numerical indices from richness, evenness and species diversity perspective were more than grazed areas. Moreover, results of mean comparison show that canopy cover, density and litters inside of the ENCLOSURE in comparison with outside of the ENCLOSURE are 16.71%, 4.21% and 7.69%, respectively increased and the amount of stone and gravels and bare soil in comparison with outside of the ENCLOSURE are 9.93% and 14.13%, respectively decreased. Thus, it can be concluded that practicing suitable management with reducing livestock from rangeland can be caused ecosystem sustainability and in conclusion increasing diversity, richness and evenness on these areas.

There are numbers of models for prediction of hydrodynamic parameters at nearshore according to different assumptions. However, the capability and comprehensiveness of the models in different conditions are still questionable. In this article, the results of numerical model based on Non-Linear SHALLOW Water (NSW) equations were compared to the results of MIKE21 BW 1DH which are based on Boussinesq equations in order to investigate the level of the accuracy of NSW in different beach slopes and bed particle sizes, under various incident wave conditions. The results of two numerical models in terms of water depth are also compared with field data. No clear advantage of Boussinesq model on NSW model is evident in prediction of water depth in the surf and swash zone. This will encourage application of NSW equation (due to relative simplicity) for prediction of sediment transport and beach profile evolution in the surf and swash zone.

Due to space limitation along with the necessity to the increase of the substations, gas insulated substations (GISs) have been favorable option owing to their minimum required space for installation. One of the main challenge in this substation is very fast transient overvoltage (VFTO) giving rise to the operation of disconnector. These waves travel through various components. Interestingly, along with waves, a wave is inducted on the ducts called transient ENCLOSURE voltage (TEV) or transient ground potential rise (TGPR). This paper has been devoted to investigate these waves through modeling GIS and presenting some analytical approach. Subsequently, the impact of GIS design, CVT, arrester, and ground strap have been discussed through simulations in EMTP-RV. Finally, the impact of high frequency ground behavior has been discussed to show the importance of the design of grounding system in GISs from high frequency point of view.

Selecting the suitable shape and area of plot is very effective in sampling efficiency in vegetation studies and causes the least variance and time of sampling. to this purpose, for reduction of sampling time and increase of work speed comparing the plot size in estimating the quantitative characteristics of species (containing canopy cover percentage and density of species) in either ENCLOSURE and non ENCLOSURE area. For do this research, first established 1m2 plots and daubenmire (25×60 cm) plots randomly in the case study in two ENCLOSURE and non ENCLOSURE area and registered canopy cover percentage and density of species in each plot. Analysed and compared statistically data get of the plots with different size in inside and outside of ENCLOSURE. results get showed that vegetation type, plants distribution and measuring variable type have intensive effect on plot size and shape, according as optimum plot size differ for estimating the quantitative characteristics of species in two ENCLOSURE and non ENCLOSURE area. Therefore seem it is better using 1m2 plots and daubenmire plots for estimating the canopy cover and density in non ENCLOSURE and ENCLOSURE area respectively.