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matrenka [14]
3 years ago
10

A wastewater is to be disinfected using ultraviolet (UV) light. Batch experiments find that the bacterial concentration decays u

nder UV light with first-order kinetics, with a half of the initial bacteria killed after 6.2 minutes of illumination. You need to design a reactor than can kill 99% of bacteria in a stream having a flow rate of 140, 000 gal/d. Assume that regardless of the reactor type it will be possible to have UV illumination conditions identical to those of the batch experiment. a. Based on the batch experiments, what is the first-order rate constant k for bacterial inactivation
Engineering
1 answer:
Ksivusya [100]3 years ago
7 0

Answer:

k = 0.1118 per min

Explanation:

Assume;

Initial number of bacteria = N0

Number of bacteria IN 'T' time = Nt

So,

Nt=N0e^{-kt}\\\\in\ 6.2 min\\\\\\frac{N0}{2}= N0e^{-k(6.2)}\\\\ln\frac{1}{2} = -k[6.2]

k = 0.1118 per min

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Answer: It helps your back posture and shows respect

Explanation:

5 0
3 years ago
Read 2 more answers
A 50000 N plane has wings with a span of 30 m and a chord of 6 m. How much cargo can this plane carry while cruising at 550 km/h
soldi70 [24.7K]

Answer:

The amount of cargo the plane can carry is 8707.89 N

Explanation:

The surface area of the wings facing the air = 30×6×2 × sin(2.5) = 15.7 m²

The speed of the plane 550 km/h = 152.78 m/s

The volume of air cut through per second = 15.7 × 152.78 = 2399.07 m³

The mass of air = Volume × Density = 2399.07 × 0.37 = 887.65 kg

Weight of air = Mass × Acceleration due to gravity = 887.65 × 9.81 = 8707.89 N

Given that the plane is already airborne, the additional cargo the plane can carry is given by the available lift force of the plane.

The amount of cargo the plane can carry = 8707.89 N

8 0
4 years ago
A 20cm-long rod with a diameter of 0.250 cm is loaded with a 5000 N weight. If the diameter of the bar is 0.490 at this load, de
Margaret [11]

If the diameter of the bar is 0.490 at this load, determine I. the engineering stress and strain, and [2] II. the true stress and strain is 1561. 84 MPa.

<h3>What is strain?</h3>

Strain is a unitless degree of ways a great deal an item receives larger or smaller from an implemented load. Normal stress happens while the elongation of an item is in reaction to an everyday pressure (i.e. perpendicular to a surface), and is denoted via way of means of the Greek letter epsilon.

  1. L = 20 cm d x 1 = 0.21 cm
  2. dx 2 = 0.25 cmF=5500 a) σ= F/A1= 5000/(π/4x(0.0025)^2)= 1018.5916 MPa lateral stress= Ad/d1= (0.0021-0.0025)/0.0025 = - 0.1 longitudinal stress (ɛ_l)= -lateral stress/v = -(-0.16)/0.3
  3. (assuming a poisson's ration of 0.3) ε_l=0.16/0.3 = 0.5333
  4. b) σ_true= σ(1+ ɛ_I)= 1018.5916(1+0.5333
  5. = 1561.84 MPa.

Read more about the diameter :

brainly.com/question/358744

#SPJ1

4 0
2 years ago
Which of the following is an example of a hardwood? A maple B spruce C pine D fir
bearhunter [10]

Answer:

A. Maple

Explanation:

Maple is a hardwood.

Hope that helps!

7 0
2 years ago
Batteries typically have ratings stated in ampere-hours, that let you estimate the length of time any particular current level c
DerKrebs [107]

Answer: attached

Explanation:

6 0
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