Sökning: "cascade"

Visar resultat 6 - 10 av 484 avhandlingar innehållade ordet cascade.

1. 6. Amine Transaminases in Multi-Step One-Pot Reactions

   Författare :Mattias Anderson; Per Berglund; Frank Hollmann; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biocatalysis; enzyme; amine transaminase; ω-transaminase; amination; primary amine; chiral amine; chemoenzymatic; green chemistry; synthesis; cascade; Bioteknologi; Biotechnology;

   Sammanfattning : Amine transaminases are enzymes that catalyze the mild and selective formation of primary amines, which are useful building blocks for biologically active compounds and natural products. In order to make the production of these kinds of compounds more efficient from both a practical and an environmental point of view, amine transaminases were incorporated into multi-step one-pot reactions. LÄS MER

3. 7. Modeling of Unsteady Flow Effects in Throughflow Calculations

   Författare :Magnus Stridh; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rotor-stator interaction; mixing-plane; linear Navier-Stokes; cascade; turbomachinery; transport equation; Linear harmonic; compressor; throughflow; turbine; Deterministic stress terms;

   Sammanfattning : In this work an evaluation of a deterministic stress transport model and a linearized Navier-Stokes harmonic approach for including unsteady effects in the steady mixing-plane computations of a multistage transonic compressor has been performed. The results of these two models are compared with those of time-average time-accurate solutions. LÄS MER

4. 8. Modeling Unsteady flow Effects in 3D Throughflow Calculations

   Författare :Magnus Stridh; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughflow; turbomachinery; mixing-plane; rotor-stator interaction; cascade; Deterministic stress terms; Linear harmonic; compressor; preconditioned GMRES; Unsteady; linear Navier-Stokes; turbine;

   Sammanfattning : The flow field in a transonic multistage compressor is compressible, three-dimensional and highly unsteady and can be predicted in principle by the exact time-accurate Navier-Stokes equations. The high Reynolds number encountered in multistage turbomachinery together with the wall-bounded nature of the flow environment however prevent the use of DNS to solve the exact N-S equations. LÄS MER

5. 9. Lineshape in Quantum Cascade Lasers - Temperature, Screening and Broadening

   Författare :Rikard Nelander; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Cascade Lasers; quantum wells; spectral lineshape; Non-Equilibrium Green s Functions; screening; temperature dependence;

   Sammanfattning : This dissertation deals with the optical properties of Quantum Cascade Lasers (QCLs). Studies are performed using transport calculations employing the theory of Non-Equilibrium Green's Functions, and screening is studied within the Random Phase Approximation. Focus is put on the temperature dependent effects in THz QCLs. LÄS MER

7. 10. Modeling Quantum Cascade Lasers : The Challenge of Infra-Red Devices

   Författare :Martin Franckie; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Cascade Lasers; Non-equilibrium Green s functions; Modeling; semiconductor heterostructures; Quantum Cascade Lasers; Non-equilibrium Green s functions; THz radiation; infrared radiation; semiconductor heterostructures; Modeling Simulation Technology; Fysicumarkivet A:2016:Franckié;

   Sammanfattning : We live in a time of rapid scientific and technological advancement. People liv- ing 100 years ago could never dream of inventions like those having completely changed our way of life, and our perception of the world; computers, mobile phones, the Internet, space travel, unraveling the mysteries of the early universe and distant galaxies, and our insight into the microscopic world of quantum phe- nomena. LÄS MER