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3 years ago

Why is it important to use PPE in doing the task of upgrading a computer server?

1 answer:

3 0

PPE is equipment that will protect workers against health or safety risks on the job. Explanation: The purpose is to reduce employee exposure to hazards when engineering and administrative controls are not feasible or effective to reduce these risks to acceptable levels.

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Question 1 : Replacement [42 Pts] Consider the following page reference string:

MakcuM [25]

Answer:

Optimal

Time 123456789101112

RS. ecbeagdcegda

F0. eeeeeeeee e e a

F1 c c c c c c c c c c c

F2 b b b g g g g g g g

F3 a a d d d d d d

Page fault? * * * * * * *

Total page fault:7

2. LRU

Time 1 2 3 4 5 6 7 8 9 10 11 12

RS e c b e a g d c e g d a

F0 e e e e e e e c c c c a

F1 c c c c g g g g g g g

F2 b b b b d d d d d d

F3 a a a a e e e e

Page fault? Y Y Y N Y Y Y Y Y N N Y Total page fault:9

3. LRU approximation algorithm: Second chance

Time 1 2 3 4 5 6 7 8 9 10 11 12

RS e c b e a g d c e g d a

F0 0,e 0,e 0,e 1,e 1,e 0,e 0,e 0,e 1,e 1,e 1,e 0,e

F1 0,c 0,c 0,c 0,c 0,g 0,g 0,g 0,g 1,g 1,g 0,g

F20,b0,b0,b0,b0,d0,d0,d0,d1,d0,dF30,a0,a0,a0,c0,c0,c0,c0,a

Page fault? YYYNYYYYNNNY

Total page fault: 8

4 0

3 years ago

Read 2 more answers

Can you use isentropic efficiency for a non-adiabatic compressor?

vodomira [7]

Mark brainliest please!

Isothermal work will be less than the adiabatic work for any given compression ratio and set of suction conditions. The ratio of isothermal work to the actual work is the isothermal efficiency. Isothermal paths are not typically used in most industrial compressor calculations.

Compressors

Compressors are used to move gases and vapors in situations where large pressure differences are necessary.

Types of Compressor

Compressors are classified by the way they work: dynamic (centrifugal and axial) or reciprocating. Dynamic compressors use a set of rotating blades to add velocity and pressure to fluid. They operate at high speeds and are driven by steam or gas turbines or electric motors. They tend to be smaller and lighter for a given service than reciprocating machines, and hence have lower costs.

Reciprocating compressors use pistons to push gas to a higher pressure. They are common in natural gas gathering and transmission systems, but are less common in process applications. Reciprocating compressors may be used when very large pressure differences must be achieved; however, since they produce a pulsating flow, they may need to have a receiver vessel to dampen the pulses.

The compression ratio, pout over pin, is a key parameter in understanding compressors and blowers. When the compression ratio is below 4 or so, a blower is usually adequate. Higher ratios require a compressor, or multiple compressor stages, be used.

When the pressure of a gas is increased in an adiabatic system, the temperature of the fluid must rise. Since the temperature change is accompanied by a change in the specific volume, the work necessary to compress a unit of fluid also changes. Consequently, many compressors must be accompanied by cooling to reduce the consequences of the adiabatic temperature rise. The coolant may flow through a jacket which surrounds the housing with liquid coolant. When multiple stage compressors are used, intercooler heat exchangers are often used between the stages.

Dynamic Compressors

Gas enters a centrifugal or axial compressor through a suction nozzle and is directed into the first-stage impeller by a set of guide vanes. The blades push the gas forward and into a diffuser section where the gas velocity is slowed and the kinetic energy transferred from the blades is converted to pressure. In a multistage compressor, the gas encounters another set of guide vanes and the compression step is repeated. If necessary, the gas may pass through a cooling loop between stages.

Compressor Work

To evaluate the work requirements of a compressor, start with the mechanical energy balance. In most compressors, kinetic and potential energy changes are small, so velocity and static head terms may be neglected. As with pumps, friction can be lumped into the work term by using an efficiency. Unlike pumps, the fluid cannot be treated as incompressible, so a differential equation is required:

Compressor Work
Evaluation of the integral requires that the compression path be known - - is it adiabatic, isothermal, or polytropic?
uncooled units -- adiabatic, isentropic compression
complete cooling during compression -- isothermal compression
large compressors or incomplete cooling -- polytropic compression
Before calculating a compressor cycle, gas properties (heat capacity ratio, compressibility, molecular weight, etc.) must be determined for the fluid to be compressed. For mixtures, use an appropriate weighted mean value for the specific heats and molecular weight.

Adiabatic, Isentropic Compression

If there is no heat transfer to or from the gas being compressed, the porocess is adiabatic and isentropic. From thermodynamics and the study of compressible flow, you are supposed to recall that an ideal gas compression path depends on:

Adiabatic Path
This can be rearranged to solve for density in terms of one known pressure and substituted into the work equation, which then can be integrated.
Adiabatic Work
The ratio of the isentropic work to the actual work is called the adiabatic efficiency (or isentropic efficiency). The outlet temperature may be calculated from
Adiabatic Temperature Change
Power is found by multiplying the work by the mass flow rate and adjusting for the units and efficiency.
Isothermal Compression

If heat is removed from the gas during compression, an isothermal compression cycle may be achieved. In this case, the work may be calculated from:

http://facstaff.cbu.edu/rprice/lectures/compress.html

4 0

3 years ago

Christopher has designed a fluid power system that repeatedly gets clogs. Which of the following objects should he choose to add

MA_775_DIABLO [31]

Answer:

Valve

Explanation:

Its right

3 0

3 years ago

If gear X turns clockwise at constant speed of 20 rpm. How does gear y turns?

Zepler [3.9K]

Answer:

Gear Y would turn Counter-Clockwise do to the opposite force created from gear X.

Hope this helped! Have a great day!

3 0

3 years ago

A spherical gas container made of steel has a(n) 17-ft outer diameter and a wall thickness of 0.375 in. Knowing that the interna

Arte-miy333 [17]

Answer:

Maximum Normal Stress σ = 8.16 Ksi

Maximum Shearing Stress τ = 4.08 Ksi

Explanation:

Outer diameter of spherical container D = 17 ft

Convert feet to inches D = 17 x 12 in = 204 inches

Wall thickness t = 0.375 in

Internal Pressure P = 60 Psi

Maximum Normal Stress σ = PD / 4t

σ = PD / 4t

σ = (60 psi x 204 in) / (4 x 0.375 in)

σ = 12,240 / 1.5

σ = 8,160 P/in

σ = 8.16 Ksi

Maximum Shearing Stress τ = PD / 8t

τ = PD / 8t

τ = (60 psi x 204 in) / (8 x 0.375 in)

τ = 12,240 / 3

τ = 4,080 P/in

τ = 4.08 Ksi

7 0

3 years ago