#Question id: 14234
#Section 5: Bioprocess Engineering and Process Biotechnology
Nutrient medium is to be heated from 10⁰C to 28⁰C is a single-pass countercurrent shell-and-tube heat exchanger before being pumped into a fed-batch fermenter. Medium passes through the tubes of the exchanger; the shell-side fluid is water which enters with flow rate 3 x 10^4 kg h^- 1 and temperature 60⁰C pre-heated medium is required at a rate of 50 m^3 h^-1. The density, viscosity and heat capacity of the medium are the same as water; the thermal conductivity of the medium is 0.54 Wm^- 1 ⁰C ^- 1. It is proposed to use 30 steel tubes with inner diameter 5 cm; the tubes will be arranged in line. The pipe wall is 5-mm thick; the thermal conductivity of the metal is 50 Wm^- 1 ⁰C ^- 1. The maximum linear shell-side fluid velocity is estimated as 0.15 m s^-1. Calculate the log-mean temperature difference _________
#Question id: 221
#Section 2: General Biology
Which statement is false about 5,6,7,8-tetrahydrobiopterin?
#Question id: 199
#Section 2: General Biology
The ʺ+ʺ sign in NAD+ indicates that
#Question id: 1133
#Section 3: Genetics, Cellular and Molecular Biology
What tertiary structure characterizes all cytokines?
#Question id: 3023
#Section 2: General Biology
During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?