Temperature has a relatively unusual effect on rubber. Assume that the rubber band is governed mainly by entropic elasticity, what do you expect about a stretched rubber band when heated? Why?

The percentage of hardwood concentration in raw pulp, the vat pressure, and the cooking time of the pulp are being investigated for their effects on the strength of paper. Three levels of hardwood concentration, three levels of pressure, and two cooking times are selected. A factorial experiment with two replicates is conducted, and the following data are obtained:

(a) Analyze the data and draw conclusions. Use ? = 0.05.

(b) Prepare appropriate residual plots and comment on the model’s adequacy.

(c) Under what set of conditions would you run the process? Why?

List the differences between deformation by twinning and deformation by slip in terms of (a) mechanism, (b) condition of occurrence and (c) consequences. Any reasonable answer is accepted. Limit your answer to 25 words for each difference.

If a velocity profile of a boundary layer is u= a+by+cy^2, please calculate the value of a, b and c, using the boundary conditions.

Please show all steps. I am trying to understand the process. Thank you (:

Can someone explain how the heated concrete snow melting system works? mainly I need the formula used to express how the heat of the concrete melts the snow. Thank you

If the temperature inside a room is 25°C and the temperature outside is ?10°C:

a. What is the maximum relative humidity that can be accommodated inside the room before the window fogs over? (Assume the inside of the window is not insulated from the outside temperature).

b. If it is a double-pane window such that the inside of the window is perfectly insulated from the outside, what will the maximum relative humidity be?

A steel shaft is to be manufactured either as a solid circular bar or as a circular tube. The shaft is required to transmit a torque of 1200 N_m without exceeding an allowable shear stress of 40 MPa nor an allowable rate of twist of0.75°/m. (The shear modulus of elasticity of the steel is 78 GPa.).

Determine the required outer diameter do of the solid shaft [58.8 mm]

Determine the required diameter d2of the hollow shaft if thethickness t of the shaft is specified as one-tenth of the outer diameter. [67.7 mm]

Determine the ratio of diameters (that is, the ratio d2/d0) and the ratio ofweights of the hollow and solid shafts. [1.14, 0.47]

A gaseous mixture consists of 75 percent methane and 25 percent ethane by mass. 28,000 m³ of this mixture is trapped in a geological formation as natural gas at 150°C and 14 MPa. This natural gas is pumped 2000 m to the surface. At the surface, the gas pressure is 140 kPa and its temperature is 90°C. Using Kay’s rule and the enthalpy-departure charts, calculate the work required to pump this gas.

mechanical vibration

Consider a single cylinder engine such as the one shown here where r is the radius of crank (5.0 cm), l is the length of the connecting rod (16 cm), M_p is the effective mass of piston (1.5 kg), M is total mass of engine (75 kg), w is the engine speed (24p rad/s), k is the spring constant (220 KN/m), and z is the damping ratio (0.02). Assume that the crank and the remaining portion of the connecting-rod mass, which is considered concentrated at the crankpin, is balanced so that its center of gravity is at the axis of rotation O; determine

Equation of motion for the system

Exciting force of the engine and plot it for 30 seconds using 600 equal time intervals.

Absolute maximum steady-state amplitude of the engine

Plot the steady state time responses for the displacement and velocity of the engine for 30 seconds using 600 equal time intervals.

contect my e m a i l l for more information ( [email protected])

8. A Piper Cherokee is flying at 4000 ft standard altitude at 105 mph. The wing has a rectangular planform (shape) with a span of 30 ft and a chord of 5.33 ft. Assuming that the turbulent boundary layer grows as on a smooth plate and a completely turbulent boundary layer flow, determine: (a) The boundary layer thickness at the downstream edge of the wing. (b) The total skin friction drag coefficient of the wing. (c) The total skin friction drag of the wing in pounds.

9. Repeat the analysis for Prob. 8 assuming that the boundary layer is laminar.

Consider a high-speed subsonic wind tunnel. The conditions in the large-diameter section upstream of the test section are V = 228 mph and T = 540°R. At the test section, the temperature is 473°R and the pressure is 2 atm. (a) If a wind tunnel model, placed in the test section, has a wing chord of 12 in., what is the test Reynolds number based on that chord? (b) What is the overall smooth flat-plate skin friction coefficient of the model wing if the boundary later is turbulent? (c) Determine the boundary layer thickness at the trailing edge of the model wing. (d) Calculate the skin friction drag in pounds for a model with a span of 3 ft.

Assume that we wish to design a Mach 10 hypersonic wind tunnel using air as the test medium. We want the static pressure and temperature in the test stream to be that for a standard altitude of 55 km. Calculate (a) the exit-to-throat area ratio, (b) the required reservoir pressure (in atm), (c) the required reservoir temperature, and (d) the exit velocity. What do these results tell you about the special (and sometimes severe) operating requirements for a hypersonic wind tunnel?

On October 3, 1967, test pilot William “Pete” Knight flew the X-15 hypersonic research vehicle to a world’s speed record for an airplane; he achieved Mach 6.7 at an altitude of 102,100 ft. (a) What was the maximum velocity in ft/s? (b) What was the flow temperature at the nose of the vehicle? Assume standard altitude

Water vapor enters a turbine operating at steady state at 480°C, 90 bar, with a velocity of 247 m/s, and expands adiabatically to the exit, where it is saturated vapor at 12 bar, with a velocity of 113 m/s. The exit diameter is 0.22 m. Determine the power developed by the turbine, in kW.

14. Sacrificial anodes are bolted inside the_____ of a heat exchanger

15. Sacrificial anodes minimize______ within a heat exchanger

17. The two factors that determine the choice of tools and equipment for a specific heat exchanger
of a heat exchanger maintenance job are familiarity with the (a)________ and knowledge of the (b)______

18. Blockage in a shell-and-tube heat exchanger may range from relatively light accumulations of (a)_______ and (b)_______ to heavy blockage caused by (c)_______ in cooling water

22. Automatic cleaning systems work by either (a)________or (b)_______ means

23. Some automatic chemical cleaning systems periodically introduce chlorine into the incoming water to kill________ and prevent growth on tube walls

25. When a main condenser is to be flooded, jack or supports may be necessary to________

26. Maintenance of smaller heat exchangers is approached differently from large heat exchangens because the smaller components are (a)______ and can be moved by (b)______