Answer:
The entity relationship (ER) data model has existed for over 35 years. It is well suited to data modelling for use with databases because it is fairly abstract and is easy to discuss and explain. ER models are readily translated to relations. ER models, also called an ER schema, are represented by ER diagrams.
Answer:
The rate of cell metabolism is limited by mass transfer since the value of maximum cell concentration obtained (38 g/l) is lower than 50 g l-1, the value planed.
Explanation:
Data
<u>kLa</u> = 0.17/s
<u>Solubility of oxygen</u> = 8 × 10^-3 kg / m^3
<u>The maximum specific oxygen uptake rate </u>= 4 mmol O2 / g h.
<u>Concentration of oxygen</u> = 0.5 × 10^-3 kg/ m^3
<u>**The maximum cell density</u> = 50 g/l
___________________
The calculated maximum cell concentration:
xmax= kLa · CAL*/ qo
CAL* is the solubility of oxygen in the broth and qo is the specific oxygen uptake rate
Replacing the data given
xmax= ( 0.17/s ) · (8 × 10^-3 kg / m^3) / 4 mmol O2 / g h
4 mmol O2 / g h to kg O2/ g s
= 3.56 x 10^-3 kg O2/ g s
So then,
xmax= ( 0.17/s ) · (8 × 10^-3 kg / m^3) / 3.56 x 10^-3 o kg O2/ g s
xmax= 3. 8 x 10^4 g/ m^3 = 38 g/l
_____________________
Answer: Ice melt is generally applied in advance of snow and ice or applied on top of the already formed ice and snow. Ice melt or deicer lowers the freezing point of water, preventing the buildup of ice or breaking up pre-formed ice into liquid slush. This layer absorbs some of the heat from the air and has a slight insulating effect on the remaining ice. When you melt an ice cube in a cup of water, it's exposed to both air and water. The part of the ice cube in the water melts faster than the ice in the air, but as the ice cube melts, it sinks further down. When ice or any other solid melts, its potential energy increases. Indeed, this is the only increase in energy, since the thermal kinetic energy, or temperature, does not increase while melting. At each phase change of water, whether ice to liquid water or liquid water to water vapor, the potential energy decreases.As glaciers melt, they add nutrients to the ocean and fertilize the local ecosystem. In Greenland and Antarctica, the ocean is short on iron, so melting glaciers make up for the lack of iron. Photosynthesizing phytoplankton are the base of the food web in the ocean and require lots of light and nutrients to grow.A
Explanation:
Byeeeeeee Remember to stan BTS , Wear Your Mask, And Drink Water
Answer:
See explanation
Explanation:
Given:
Initial pressure,
p
1
=
15
psia
Initial temperature,
T
1
=
80
∘
F
Final temperature,
T
2
=
200
∘
F
Find the gas constant and specific heat for carbon dioxide from the Properties Table of Ideal Gases.
R
=
0.04513
Btu/lbm.R
C
v
=
0.158
Btu/lbm.R
Find the work done during the isobaric process.
w
1
−
2
=
p
(
v
2
−
v
1
)
=
R
(
T
2
−
T
1
)
=
0.04513
(
200
−
80
)
w
1
−
2
=
5.4156
Btu/lbm
Find the change in internal energy during process.
Δ
u
1
−
2
=
C
v
(
T
2
−
T
1
)
=
0.158
(
200
−
80
)
=
18.96
Btu/lbm
Find the heat transfer during the process using the first law of thermodynamics.
q
1
−
2
=
w
1
−
2
+
Δ
u
1
−
2
=
5.4156
+
18.96
q
1
−
2
=
24.38
Btu/lbm
