Covariant Quantum Dynamical Semigroups: Unbounded generators

A survey of the probabilistic approaches to quantum dynamical semigroups with unbounded generators is given. An emphasis is made upon recent advances in the structural theory of covariant Markovian master equations. The relations with the classical Levy-Khinchin formula are elucidated. As an example, a complete characterizations of the Galilean covariant irreversible quantum Markovian evolutions is given in terms of the corresponding quantum master and Langevin equations. Important topics for future investigation are outlined.Comment: 14 pages,Latex, no figures, submitted to the Semigroup Volume, Group 21, Goslar 199

Sky-blue thermally activated delayed fluorescence (TADF) based on Ag(i) complexes: strong solvation-induced emission enhancement

A new Ag(I) complex based on tris(2-pyridyl)phosphine (Py3P), [Ag-2(Py3P)(3)(SCN)(2)], has been synthesized and chemically characterized. Theoretical calculations and photophysical investigations reveal thermally activated delayed fluorescence (TADF) coupled with outstanding solvato- and vapor-luminescent behavior. The parent complex [Ag-2(Py3P)(3)(SCN)(2)] shows sky-blue TADF (lambda(max) = 469 nm) at ambient temperature with a quantum yield of Phi(PL) = 16% and an emission decay time of 2.2 mu s. Upon exposing the complex to CH2Cl2 or CHCl3 vapors, [Ag-2(Py3P)(3)(SCN)(2)]center dot 0.66CH(2)Cl(2) and [Ag-2(Py3P)(3)(SCN)(2)]center dot CHCl3 solvates are formed. This process is accompanied by a strong enhancement of the luminescence intensity. Both solvates also emit sky-blue TADF (lambda(max) = 478-483 nm), but the emission quantum yield reaches Phi(PL) approximate to 70% at an emission decay time of 9-12 mu s, depending on the solvent. According to DFT/TD-DFT computations, the observed TADF originates from a (1)(M + X)LCT excited state. The experimentally determined Delta E(S-1 - T-1) gap for [Ag-2(Py3P)(3)(SCN)(2)]center dot 0.66CH(2)Cl(2) is relatively large and amounts to 1040 cm(-1) (approximate to 129 meV)

Fast combustion waves and chemi-ionization processes in a flame initiated by a powerful local plasma source in a closed reactor

One alternative biofuel to substitute fossil fuels is bioethanol. Microalgae Spirulina sp. contains high carbohydrates, which has 17-25% potential to produce bioethanol. Urea and NaHCO3 can be used as additional nutrients sources of nitrogen and carbon to Spirulina sp. cultivation. Deficiency of nitrogen causing the cell’s enzymes change that shown through decreased lipid and chlorophyll synthesis. While deficiency of carbon can affect the growth rate. In this research, the growth rate of Spirulina sp. is analyzed using Optical Density (OD) method. The growth rate calculation is used to measure the growth of microalgae cells shown in the growth curve. This was a laboratory-scale method using CRD with 4 treatments and 5 replications namely treatment A addition of 0.36 g/500 ml urea without addition of NaHCO3, treatment B addition of 0.043 g/500 ml NaHCO3 without addition of urea, treatment C addition of 0.36 g/500 ml urea and 0.043 g/500 ml NaHCO3, and control without addition of urea or NaHCO3. The results indicated that addition of urea and NaHCO3 didn’t affect to OD and Spirulina sp. growth rate. The highest growth rate was treatment A with 0.00906/day of growth rate followed by treatment C which has 0.00865/day of growth rate. Treatment B and control treatment (K) showed a low growth rate. The maximum OD value obtained in treatment C was 0.674 cells/ml on the 10th day. This research can be used as the reference to larger scale of Spirulina sp. cultivation in the field of bioethanol production