The United States has a lot of federally owned land. Unfortunately, uncontrolled natural forest fires destroy large areas in the western US every summer. In 2002, about 1,000,000 acres of standing timber in national forests were consumed. Some consideration is being given to improved management practices that could produce electric power from residual forest thinning. Estimate the lost energy content of burned US forests during 2002. Assuming the US average electricity demand is about 300,000 MW e , how much forested land would be needed to produce all the country ’ s power? Is this a sustainable alternative? How would you manage the forest lands needed? A few facts to consider: the total forested area on US federal lands in the lower 48 states is about 600 million acres with a standing stock density of about 100 dry metric tonnes of wood per acre. Woody plants and trees capture solar energy via photosynthesis at an average rate of about 0.8 W/m 2 , which corresponds to producing about 5 – 10 dry tons of biomass per acre annually with an average heating value of 8000 BTU/dry lb. Note that 1 acre = 43,560 ft 2 = 0.405 hectare = 4047 m 2 and the average heat-to-work conversion efficiency of a biomass-fired electric power plant is about 35%.

Derive the critical fiber volume fraction with respect to strength and explain what is it.

single cylinder naturally aspirated engine (CNG) on engine performance based on high-speed high load comparison with baseline conditions early ignition late ignition and rich and lean PV graph and p theta comparison how to do with results (already obtained) comparing emissions, MFB ( 10 % 50% 90%).......Analysis if it's more or less the values how to analyze the basic comparisons for eg baseline vs high speed vs high load if the values are more why is it?

rich and lean comparisons what happens AT TDC early and late ignition ...what happens to the parameter change

On a cold day during the winter when the relative humidity is ?=70%?=70%, your friend claims that the outside air feels very dry. On a hot day during the summer, the relative humidity is the same, but your friend complains that the air feels very humid. Assuming that your friend isn't just crazy, what explains these statements? Hint: Your discussion should involve relative humidity and the humidity ratio.

When a hydrocarbon burns with 300% of theoretical air, is the adiabatic flame temperature higher than, lower than, or equal to the adiabatic flame temperature when it burns with 100% of theoretical air? Why? Note: You must correctly explain your reasoning to receive credit for this problem.

James would like to invest some money every year-end for 17 years in a money market account earning 5% per year, and then begin to withdraw money from the account to finance his son’s education for 4 years. James thinks that his son should have $35,000 for the first year of college at the start of the 19^th year, and would like to increase that amount by 4% every year to compensate for inflation. How much will James’ first deposit be if he plans to increase the annual deposit by $450? Using Excel formula's. (See 7.15)

First Deposit:

A Carnot engine operates on air between high and low pressures of 3 MPa and 100 kPa with a low temperature of 20°C. For a compression ratio of 15, calculate

the thermal efficiency?,

the MEP?

, and the work output?

A symmetrical wedge with a 12 degree included angle is placed in an air flow which the mach number is 2.3 and the pressure is 60 kPa. If the centerline of the wedge is at an angle of 4 degrees to the direction of the flow, find the pressure difference between the two surfaces of the wedge.

2. What products (at least three different) of biomedical engineering do you expect to encounter in the near future

It is required to lift a skip whose load total is 1kN. Two simple lifting jacks are available both having an effort piston diameter of 10mm and a load piston diameter of 70mm and the load is to be distributed equally between the two.

Calculate:

a) the force ratio and movement ratio of each jack.

b) the pressure within the hydraulic fluid.

I am designing a gas heater and a heat exchanger for a swimming pool. As I am starting with my calculations for the heat exchanger, one of the values that I do not have is the exit temp of the water that enters the swimming pool after the water is heated in the heat exchanger. I know that I need to do a control volume equation to work this out, but I do not know where to go from there. I know that the swimming pool will have some losses like: loss of heat by conduction to the surface that surrounds the pool, loss of heat by evaporation of the water, losses by convection on the free surface of the water. Also just to give more clarity regarding the concept: water will be pumped out of the swimming, sent through a filter, sent through a heat exchanger, and sent back to the swimming pool, what flow rate of water, at what temp, will increase the temp of the swimming pool in a period of time?

If the weight of the contents in a vessel is measured and the density of the material is known, fill in the blanks to describe what steps are required to determine level. Find the ____________________ by dividing weight by ____________________, and then find the ____________________ by dividing ____________________ by the ____________________ of the vessel.

Fill in the blanks?

1. Identify 7-10 primary functions of a common laptop computer.
2. Identify 7-10 primary parts/components of a common laptop computer.
3. Allocate the functions in (a) to the parts/components in (b).

this is related to systems engineering

Discuss the crystal structure of martensite and how this affects its mechanical properties. Identify the advantages and disadvantages of this material, and suitable practical applications. (500 words