6051. Computer’s processing speed is measured in term of :
6052. The last time when I saw Mr. John he looked very relaxed. He explained that he had been on holiday the ------ week.
6053. I ............. live there when I was a boy.
6054. Which of the following impellers are used for wide range of viscosities?
6055. Which of the following type(s) of stirrer can be used for microbiological processes?
6056. The range of width for the baffle in the fermenter is __________ times of vessel diameter
6057. The average concentration of oxygen in the boundary layers surrounding the bubbles (Co) in a reactor is normally determined by
6058. Why vortexing is undesirable in the agitation of biological systems?
6059. The rate limiting step in the movement of oxygen from the gas phase in a bubble to the cell is the movement of oxygen molecules through
6060. Penetration theory assumes that turbulent eddies travel from the bulk of the phase to the interface where they remain constant for a constant exposure time (te). The model correlating KL, mass transfer coefficient and DAB, diffusivity can be expressed as
6061. The oxygen uptake requirements of a microbial population is characterized by the following parameters: μm = 0.2 h-1, K0 = 0.2 mg O2.l-1, Y0 = 0.5 mg dry weight/mg O2 and C0,crit=0.8 mg.l-1 The required concentration of cells is 1000 mg.l-1 and the saturation oxygen concentration of the medium is 5.8 mg.l-1. The required KLa must be greater than
6062. Which have the maximum resistance while transferring carbon dioxide from the bulk liquid to an air bubble?
6063. If liquid density and viscosity remains constant, then the Reynolds number in a stirred tank reactor will vary with the
6064. What is the ratio of depth of liquid in vessel to the diameter of tank (H:Dt)?
6065. Radial flow impellers
6066. Transient flow range of mixing speed is obtained for
6067. A typical ceiling fan would be best described as a(n)
6068. What is the ratio of diameter of impeller to the diameter of tank (Da:Dt)?
6069. The reason of using a flat disk in a Turbine is
6070. Which of the following is not considered among the three best-known theories of interphase mass transfer?
6071. Which of the following is most likely to cause an increase in the rate of oxygen transfer into a particular aerated fermentation system?
6072. At 25°C, the saturation concentration of oxygen in water is 1.26 mmol/l and the partial pressure of oxygen is 1 atm. The Henry's law constant will be
6073. Gas hold up, characterizing the hydrodynamics in a fermenter, mainly depends on the
6074. Turbine impeller consists of flat impeller blades with
6075. An aerated bioreactor will increase oxygen transfer rates with the addition of detergents because it
6076. Vortexing in stirred tank reactors can be prevented by
6077. Which of the following would be best described as an axial flow impeller?
6078. Henry's law relates
6079. Power number is ratio of
6080. The volume of liquid (VL) in a cylindrical reactor can be calculated from the liquid height (HL) and tank diameter (Dt) using the following equation
6081. The average fractional gas hold up (H) can be given as (where Zf and Zl are the level of aerated and clear liquid respectively)
6082. Which of the following(s) is/are non-mechanically agitated reactors?
6083. Which of the following best explains the reasons for using axial flow impellers in crystallization and precipitation reactions?
6084. Which of the following will have the highest surface area available for oxygen transfer?
6085. A flooded impeller will lead to poor oxygen transfer rates because
6086. Power consumption by agitation is
6087. Which of the following impellers will provide radial flow?
6088. When liquid is pumped through cooling coil in a stirred tank reactor to cool. Which of the following is not correct?
6089. When the height of an aerated bioreactor is increased, it will increase the oxygen transfer rate by
6090. Which of the following is correct for the off-centre impellers?
6091. The power required by an impeller in a gas sparged system compare to the power required by impeller operating at same speed in a gas free liquid is usually
6092. Which of the following stirrer requires least amount of energy for same yield?
6093. A reactor has a total volume of 50,000 litres. If it has a headspace volume of 10,000 litres, then volume of liquid in the reactor will be
6094. Pure oxygen, if used instead of air will increase oxygen transfer rates because
6095. For aerated mixing vessels in an aqueous solution, the mass transfer coefficient (kL) co-relating power consumption (Pm) and fermenter volume (V) can be expressed as
6096. Higher temperatures affect oxygen transfer rates by
6097. The Intermig impeller is
6098. Main reason for using baffles in stirred tank reactors are
6099. Which of the following is not classified as an axial flow impeller?
6100. The river which originates from Trimbak in Nasik hills?