Tutor profile: Lakota G.
Subject: Nuclear Engineering
What are the main differences and similarities in a BWR, and PWR? Explain your answer
Differences The main difference is the PWR uses a two loop system for steam generation and a BWR uses a single loop system. In a typical PWR the coolant is kept under pressure so that it remains a liquid inside the reactor. The coolant in the primary loop then flows through a heat exchanger and the heat energy is transferred to the coolant in the secondary loop. In the secondary loop the coolant is not under pressure this allows it to turn into steam and flow through steam generator. In a BWR the coolant is allowed to boil inside the reactor and the steam is moved through a steam separator and then goes directly to the steam generators. Similarities In both reactor types the coolant is typically light water (normal water H2O). The light water also serves as a moderator in both PWR and BWR. They both use enriched uranium in cylindrical vessels also known as fuel rods. They both have a containment vessel, a reactor vessel (contains the reactor core) and a steam generating turbine.
Subject: Electrical Engineering
What are the three layer that facilitate diode functionality and how does charge flow through a diode?
A typical diode is made of a p-n junction that has three main section the p-type semiconductor, depletion zone, and the n-type semiconductor. A typical p-type silicon semiconductor layer is doped with boron this causes an overall positive charge (holes) and is considered the acceptor. A typical n type silicon semiconductor layer is doped with phosphorus which causes an overall negative charge ( free electrons) and is considered the donor. The depletion region is create by the interaction between the p-type and n-type layers and has no charge or free electrons. The free electrons in the n-type semiconductor will cross the depletion region to the p-type layer when excited. This mechanic allows charge to flow from the n-type to the p-type which is why in forward bias current flows through the diode. In most cases current does not flow through the diode in reverse bias without damaging the p-n junction.
Simplify: 12x^3 - 3(2x^3 + 4x -1) - 5x + 7
Step 1: expand -3(2x^3 + 4x -1) (-3*2x^3) + (-3*4x)+(-1*-3) = -6x^3-12x+3 Step 2: combine like terms 12x^3 - 6x^3-12x+3 - 5x + 7 (12x^3 -6x^3) + ( 12x+5x)+(3+7) = 6x^3 -17x + 10 Final answer 6x^3 -17x + 10
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