production of selected secondary metabolites in transformed ...

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CONCLUSION M 12000 10000 8000 6000 4000 2000 0 0 20 40 60 80 100 Conve rs ion [%] 1.3 1.25 1.2 1.15 1.1 1.05 1 D M(theor.) Fig. 7: Molecular weight plot for polymerization 2 ATRP has been employed to produce polystyrene macromolecules containing polyhedral oligomeric silsesquioxanes (POSS). Polymerizations initiated with POSS prove slower growth of polymers than polymerizations initiated with low-molecular initiators, and also lower initiation efficiency, which causes the molecular weight to be much higher than expected. Further work is underway to optimize the conditions of the polymerizations with respect to the efficiency of initiation, polydispersity of polymer and polymerization rate. REFERENCE [1] Agaskar P.A., Inorg. Chem., 30 (1991), p. 2707-2708 [2] Zhang C., Laine R.M., J. Organomet. Chem., 521 (1996), p. 199-201 [3] Lichtenhan J.D. et al., Mat. Res. Soc.Symp. Proc., 435 (1996), p. 3-11 [4] Wang J.S., Matyjaszewski K., J. Am. Chem. Soc., 117 (1995), p. 5614-5615 [5] Pyun J. et al., J. Am. Chem. Soc. 123 (2001), p. 9445-9446 [6] Matyjaszewski K. et al., ACS Symp. Ser. 729 (2000), p. 270-283 [7] Brown D.A., Price G.J., Polymer 42 (2001), p. 4767-4771 [8] Miller P.J., Matyjaszewski K., Macromolecules 32 (1999), p. 8760-8767 Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006 Sekce DSP 2006, strana 232 M D
MEASUREMENT OF THERMOPHYSICAL PROPERTIES OF PMMA BY PULSE TRANSIENT METHOD Ing. Pavla Štefková Supervisor: Prof. Ing. Oldřich Zmeškal, CSc. Institute of Physical and Applied Chemistry, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00 Brno, Czech Republic, email: stefkova@fch.vutbr.cz INTRODUCTION Polymethyl methacrylate (PMMA) is the synthetic polymer of methyl methacrylate. This thermoplastic and transparent plastic was developed in 1928 in various laboratories and was brought to market in 1933 by the German Company Rohm and Haas. This material is used as the standard reference material for thermal conductivity measurements in metrology. Chemical analysis and materials testing are becoming ever more important as science, trade and society are getting more complex worldwide. The number and significance of decisions based on the results of chemical analysis and materials’ testing is ever increasing in all spheres of life. For this purpose results of analysis and testing have to be reliable and comparable as well as acceptable worldwide. The use of certified reference materials is an efficient and proper tool to achieve these goals [1]. Measurement of the thermophysical properties of PMMA shows that some effects influencing the measurement process have to be known when one want to use it as laboratory reference or standard reference material (SRM). This material should be used for validation of apparatuses upon well-known experimental conditions, to obtain reliable data [2]. The pulse transient method allows investigating the thermal diffusivity, specific heat and thermal conductivity within single measurement. The principle of this method and the arrangement of the measured sample are shown in Figure 1. The heat pulse is generated by the passing of the electrical current through the plane electrical resistor made of metallic foil. A sensor measures the time development of the temperature field (temperature response) in a point of the tested body. Then the temperature is characterized by a function [3] ⎟ 2 Q S ⎛ h ⎞ ΔT = ⋅ exp ⎜ ⎜− . (1) ( E− D) / 2 cp ρ ( 4π at ) ⎝ 4a t ⎠ The thermophysical parameters are calculated from the characteristic parameters of the temperature response (time and the maximum of temperature response to the heat pulse). The thermal diffusivity is given by 2 h a = 2tmax f a the specific heat by 2 h = 2( E − D) tmax , (2) Q cp = ⋅ ρ ΔTmaxh and thermal conductivity by f c = 2π exp( 1) Q E− D ρ ΔTmaxh ( E −D ) / 2 ⎛ E − D ⎞ ⋅ ⎜ 2 exp( 1) ⎟ ⎝ π ⎠ (3) Q λ = cp ρ a = E− D−2 2( E − D) ΔTmaxt maxh ( E −D ) / 2 ⎛ E − D ⎞ ⎜ 2 exp( 1) ⎟ . ⎝ π ⎠ (4) Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006 Sekce DSP 2006, strana 233
Page 1 and 2: PRODUCTION OF SELECTED SECONDARY ME
Page 3 and 4: containing ampicillin, IPTG and x-g
Page 5 and 6: THE SIMPLE METHOD FOR THE RECOGNITI
Page 7 and 8: Figure 1 Negative-ion mode MALDI-TO
Page 9 and 10: Table 1 Evaluation of negative-ion
Page 11 and 12: Fig. 1: Scheme of the hydride gener
Page 13 and 14: [4] H. Matusiewicz, M. Kopras, J. A
Page 15 and 16: - are hypotriglyceridemic; - exhibi
Page 17 and 18: HYDROPHOBIZED SODIUM HYALURONATE IN
Page 19 and 20: spectrophotometer (AMINCO-Bowman, S
Page 21 and 22: Hyaluronate derivatives showed with
Page 23 and 24: copolymers were additionally functi
Page 25 and 26: Each micelle has a hydrophobic core
Page 27 and 28: STUDY OF THE COPPER(II) IONS NON-ST
Page 29 and 30: CuSO4, Cu(ClO4)2 and Cu2P2O7 of the
Page 31 and 32: total flux [mol.m -2 ] 0.7 0.65 0.6
Page 33 and 34: number of free radicals is very low
Page 35: Differences can be caused by severa
Page 39 and 40: The typical time responses of tempe
Page 41 and 42: Figure 4 illustrates the typical de
Page 43 and 44: sodium sulphate and filtered to a 5
Page 45 and 46: Compare all tested evening primrose
Page 47 and 48: IMPROVED FLUORIMETRIC DETERMINATION
Page 49 and 50: Al F i 80 70 60 50 40 30 20 10 0 0
Page 51 and 52: F i 60 50 40 30 20 10 Data UCL LCL
Page 53 and 54: PHYSICAL-CHEMICAL ASPECTS OF PAINT
Page 55 and 56: Finally, the solubility parameter o
Page 57 and 58: Study of the influence of different
Page 59 and 60: Fig.1: Chemical structures of pI ma
Page 61 and 62: Identification of pI markers - Firs

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