We consider spectral optimization problems of the form min { λ1(Ω;D) : Ω ⊂ D, |Ω| = 1 } , where D is a given subset of the Euclidean space R. Here λ1(Ω;D) is the first eigenvalue of the Laplace operator −∆ with Dirichlet conditions on ∂Ω ∩D and Neumann or Robin conditions on ∂Ω ∩ ∂D. The equivalent variational formulation λ1(Ω;D) = min {∫

Objective: To present a geometric ruler to determine predictive values of binary diagnostic test results from prevalence, sensitivity and specificity without calculation. Methods: On logarithmic scale the relationships between pre-/post-test odds and the likelihood ratio as well as sensitivity, speci ficity and the likelihood ratio appear as simple linear (additive) equations. Results: Each of ...

the performance of a γ-al 2 o 3 /n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). compared with pure          n-decane, the obtained results in this research show that by using γ-al 2 o 3 /n-decane nanofluid ...

egg drop syndrome (eds) is caused by a hemagglutinating adenovirus which has become a major cause of lost egg production and sever economic losses in breeder and layer chicken flocks throughout the world. a pcr assay was optimized for detection of eds virus in inoculated allantoic fluids (afs) of duck and chicken emberyonated eggs. two strains of eds viruses were propagated in allantoic cavity ...

to prepare hemagglutination inhibition (hi) antigen the egg drop syndrome virus (edsv) was propagated in 10-day-old embryonated duck eggs. the virus antigen was inactivated with two methods including heating (65°c) and adding 0.5% formaldehyde by considering low destroying effect on hemagglutination (ha) and hi titers. the edsv hi titers of 310 sera and 100 yolks obtained from 23 chicken farms ...

the thermo-hydraulic behavior of the air flow over a two dimensional ribbed channel wasnumerically investigated in various rib-width ratio configurations (b/h=0.5-1.75) atdifferent reynolds numbers, ranging from 6000 to 18000. the capability of differentturbulence models, including standard k-ε, rng k-ε, standard k-ω, and sst k-ω, inpredicting the heat transfer rate was compared with the experi...

drop plate technique has a priority and preference compared with the spread plate procedure, because of less time, quantity of media, effort requirement, little incubator space, and less labor intensive. the objective of this research was to compare the accuracy and fidelity of drop plate method vs. spread plate method by parametric and nonparametric statistical tests. for bacterial enumeration...