during the last years the total cost of lng technology has decreased significantly due to improvements of the liquefaction process. however, many liquefaction plants that are still in operation use a three-cascade refrigeration system. in this paper, an advanced exergetic analysis is applied to better understand the operation of a three-cascade refrigeration system for liquefaction of natural g...

proton exchange membrane fuel cells (pemfcs) with a dead-ended anode and cathode can obtain high hydrogen and oxygen utilization by a comparatively simple system. nevertheless, the accumulation of the water in the anode and cathode channels might cause a local fuel starvation degrading the performance and durability of pemfcs. in this study, a brand new design for a polymer electrolyte membrane...

man-made reservoirs constructed on running waters, where a decrease in flow velocity and anincrease in flocculent settling occurs, create perfect conditions for the deposition of allohtonic matter andadsorbed pollutants, such as toxic polychlorinated dibenzo-p-dioxins (pcdds) and polychlorinateddibenzofurans (pcdfs). the results obtained from the research on a cascade of five small reservoirs l...

Leftward flow generated by motile cilia is known to underlie left-right asymmetry in vertebrate embryos. A new study now links intraciliary calcium oscillations to cilia motility and the downstream nodal signaling cascade that drives left-sided development.

This paper describes the analysis of raw wood flows in Slovakia. Material flow analysis was used to reveal and quantify relations between the resources and the primary uses of wood. In particular, two approaches to wood flow modelling were utilised wood balance and wood resource balance. Wood balance was introduced to illustrate a global view of the resources and primary uses of roundwood in Sl...

The properties of rotating turbulence driven by precession are studied using direct numerical simulations and analysis the underlying dynamical processes in Fourier space. study is carried out local coordinate frame, where gives rise to a background shear flow, which becomes linearly unstable breaks down into turbulence. We observe that this precession-driven general characterized coexisting tw...

Determination of the vertebrate left-right body axis during embryogenesis results in asymmetric development and placement of most inner organs. Although the asymmetric Nodal cascade is conserved in all vertebrates, the mechanism of symmetry breakage has remained controversial. In mammalian and fish embryos, a cilia-driven leftward flow of extracellular fluid is required for initiation of the No...

The three-dimensional numerical simulation method is coupled with erosion and particle rebound models based on the results of high-temperature tests to systematically study gas-solid two-phase flow characteristics a flue gas turbine for first time. aerodynamic loss gas-steam mixtures mechanism in cascade under design non-design conditions are investigated. indicate that mixing cooling steam gas...