The present work deals with thermodynamic analysis of cascade refrigeration system using ozone friendly refrigerants pair R507A and R23. R507A is azeotropic mixture composed of HFC refrigerants R125/R143a (50%/50% wt.). R23 is a single component HFC refrigerant used as replacement to CFC refrigerant R13 in low temperature applications. These refrigerants have zero ozone depletion potential and ...

A detailed kinetic study of the endo-selective epoxide-opening cascade reaction of a diepoxy alcohol in neutral water was undertaken using (1)H NMR spectroscopy. The observation of monoepoxide intermediates resulting from initial endo and exo cyclization indicated that the cascade proceeds via a stepwise mechanism rather than through a concerted one. Independent synthesis and cyclization of the...

Policies for promoting sustainable development of dam projects in the world have always been an argument due to negative impacts on ecosystems. How improve efficiency identifying and main indicators environmental impact assessment (EIA) process post (PEIA) is a common topic. Since rapid construction past decades, most China turned operation period. In order identify provide scientific bases dec...

We study fermion mass matrices of the cascade form which naturally lead to the tri-bimaximal generation mixing in the lepton sector. The cascade neutrino matrix predicts a parameter-independent relation among the observables; the neutrino mixing angles and mass squared differences. The relation makes interesting predictions that the atmospheric neutrino mixing angle is close to maximal and the ...

Multi-enzyme cascade reactions are frequently found in living organisms, in particular when an intermediate should be eliminated. Recently, enzyme-mimic nanomaterials (nanozymes) received much attention for various applications, because they are usually more stable and cost-effective than enzymes. However, enzyme-nanozyme cascade reations have not been yet extensively exploited. Therefore, in t...

The main nonradiative capture mechanisms, cascade and multiphonon emission, have been numerically simulated by the Monte Carlo method. To do so, both mechanisms were included in the frame of a previous numerical procedure to which the nonacoustic-phonon contribution was also added. Different centers were studied. Capture by shallow donors (P, As, and Sb) in n-type silicon were interpreted consi...

Electrostatic comb-drive actuators have been developed and employed for many applications. However, side stability (side pull-in) limits the actuator stroke constraining its applications. Hence, extending the stable traveling range is an important issue for designing electrostatic comb-drive actuators. This study presents a novel cascade electrostatic comb-drive actuator. Instead of shifting th...