In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...

In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...

Again, this can be viewed as a change of variables; on the left-hand side, there are n diagonal free parameters wjj and n(n−1) 2 off-diagonal free parameters wjk, j < k in the matrix W (the remaining offdiagonal parameters are fixed, as W is symmetric); on the right-hand side, there are n free parameters in the matrix Λ and (n − 1) + (n − 2) + . . . + 1 + 0 = n(n−1) 2 free parameters in the mat...

Rising wildfire suppression expetizditures on public land in the United States have led to increased scrutiny of wildfifne managemefzt practices. One area that has received particular attention is the Forest Service's increasing reliance on contract fire crews. Because a contract crew rate includes several costs that are not included in the wage costs of a Forest Service crew, it is difsicult t...

The present article deals with the analysis of thermal-bending stresses in a heated thin annular sector plate with simply supported boundary condition under transient temperature distribution using Berger’s approximate methods. The sectional heat supply is on the top face of the plate whereas the bottom face is kept at zero temperature. In this study, the solution of heat conduction is obtained...

in this paper, we give a characterization of strongly jordan zero-product preserving maps on normed algebras as a generalization of  jordan zero-product preserving maps. in this direction, we give some illustrative examples to show that the notions of strongly zero-product preserving maps and strongly jordan zero-product preserving maps are completely different. also, we prove that the direct p...

let $r$ be an associative ring with identity and $z^*(r)$ be its set of non-zero zero divisors.  the zero-divisor graph of $r$, denoted by $gamma(r)$, is the graph whose vertices are the non-zero  zero-divisors of  $r$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$.  in this paper, we bring some results about undirected zero-divisor graph of a monoid ring ov...