Nan Zhao-Dong

Establishment of experimental model of bacterial growth under inhibitory conditions

The thermal curves ofB. subtilis andP. atruginosa were determined by using a 2277 Thermal Activity Monitor (Sweden). Under inhibitory conditions, an experimental model of bacterial growth was established. The growth rate constant (μ), deceleration rate constant (β) and optimum temperature (T) of bacterial growth were calculated.ZusammenfassungMittels eines 2277 Thermal Activity Monitor (Schweden) wurden die thermischen Kurven vonB. subtilis undP. atruginosa ermittelt. Unter Inhibitionsbedingungen wurde ein experimentelles Modell bakterielen Wachstums festgestellt. Die Wachstumsgeschwindigkeitskonstante μ, Verlangsamungskonstante α und optimale Temperature (T) für das bakterielle Wachstum wurden bestimmt.

Study on the thermokinetic properties of bacterial growth

The power-time curves of bacterial growth at different temperatures were determined by using the 2277 Thermal Activity Monitor (Sweden). From these curves, the growth rate constant (μ) and activation energy (Ea) were calculated. According to the transition state theory of reaction dynamics, the activation entropy (ΔS≠), activation Gibbs free energy (ΔG≠) and equilibrium constant (K≠) of the activation state could be calculated. These results permitted thermodynamic analysis of the bacterial growth metabolism.

Study of a Biological Oscillation System by a Microcalorimetric Method

The power–time curves of a biological oscillation system were determined for different temperatures, acidities and carbon sources, by using a 2277 thermal activity monitor. The apparent activation energy and order of the oscillation reaction were calculated from the induction period (tin) and the first oscillation period (tp). The regularity of the biological oscillation system is discussed.

Thermodynamic investigation of the azeotrope of water and ethanol

The molar heat capacities of the azeotrope in the binary system of water and ethanol were measured by an adiabatic calorimeter in the temperature range from 78 K to 320 K. The functions of the heat capacity with respect to the thermodynamic temperature were established. The glass transition occurred at 98. 496 K. The phase transitions took place in the temperature ranges from 123.08 K to 156.96 K and 269.03 K to 273.20 K corresponding to the solid-solid phase transition of ethanol, solid-liquid phase transition of ethanol, and solid-liquid phase transition of water, respectively. The thermodynamic functions and the excess thermodynamic functions of the azeotrope relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to the temperature.

A study of the optimum fungistatic action of a synthetic medicine using a microcalorimetric method

Abstract In this paper, we have determined bacterial growth thermograms using a thermal activity monitor. We have also determined bacterial growth thermograms of inhibitor and have studied the fungistatic action of a synthetic medicine (W2). We have calculated the rate constant at different concentrations and with the optimum allowable concentration of the synthetic medicine W2.

Determination of power-time curves of bacterial growth

Bacterial growth power-time curves were determined with a 2277 Thermal Activity Monitor. Bacterial multiplication curves were measured at different temperatures and an experimental model was established. Both growth rate constants and lowest growth temperatures were calculated.

Thermodynamic Investigation of the High Efficient Working Fluid Used for a Heat Pipe

The heat capacities of the high efficient working fluid used for a heat pipe( C-p) were measured by a low temperature adiabatic calorimeter over the range from 78 to 320 K. No thermal anomaly was observed in the range from 78 to 245 K and 274 to 320 K. The functions of C-p vs T were established based on the measured heat capacity data by least-square fitting method to be C-p/(J . K-1 . g(-1)) = 0. 5369 T + 0. 07279 in the range of 78. 41 similar to 245. 19 K. The freezing point, freezing enthalpy and freezing entropy of it were determined to be 271. 21 K, 353. 6 J . g(-1) and 1. 304 J . K-1 . g(-1), respectively. The heat capacities of it are near a constant to be C-p/ (J . K-1 . g(-1)) = 3. 403 +/- 0. 020 in the range 274 K less than or equal to T less than or equal to 320 K. According to the relationship of thermodynamic functions, the thermodynamic function values of the working fluid were calculated in the temperature range of 280 similar to 320 K with 5 K intervals.

Low Temperature Heat Capacities and Thermodynamic Functions of Potassium Dichromate

The molar heat capacities ( C-p,C-m) of crystalline potassium dichromate (K2Cr2O7) were measured with a precision automated adiabatic calorimeter over the temperature range from 100 K to 390 K. No phase transition or other thermal anomaly was observed in this temperature region. However, it was found that the relationship of C-p,C-m with respect to temperature T is different in different temperature regions. The polynomial functions of C-p,C-m vs. T were established in different temperature regions based on the heat capacity measurements by means of the least-fitting square method. These functions are as following: for 100 K less than or equal to T less than or equal to 275 K, C-p,C-m = 0. 005 T-2 - 1.0320 T + 125. 22 (J . K-1 . mol (-1)); for 275 K less than or equal to T less than or equal to 350 K, C-p.m = 209. 37 J . K-1 . mol - 1; for 350 K less than or equal to T less than or equal to 390 K, C-p,C-m = 0. 0266T(2) - 18. 823T + 3542. 3 J . K-1 . mol (-1). According to the relationship of C-p,C-m vs. T and thermodynamic equations, the values of thermodynamic function of potassium dichromate were calculated in the temperature range of 298. 15 similar to 400. 15 K with 5 K intervals.

Extraction of Cr(III) with HEH[EHP] in Benzene or Cyclohexane, Using a Perfusion/titration Microcalorimetric Method

The extraction of Cr3+ with HEH[EHP] in benzene or cyclohexane was studied by using a perfusion/titration micro-calorimetric method. The heat produced in the reaction processes was determined via the power-time curve and the reaction heat at 298 K was identified. The extraction equilibrium constants and thermodynamic functions at different temperatures were calculated by using all of the reaction heats and extraction equilibrium constants.