The maintenance manager of your facility has asked you to evaluate a particular welding booth that utilizes a local exhaust ventilation (lev) system to remove the contaminant at the source. the exhaust system does not appear to be drawing enough of the welding fumes away from the employees to reduce the iron oxide below the permissible exposure limit (pel) of 10 mg/m3. during your investigation, you determine that the diameter of the duct system is 8 inches and has an air velocity of 350 fpm (feet per minute). the welding operation is performed at a distance of 1.5 feet from the exhaust opening. determine the flow rate, and provide your recommendations on the control measures that could improve the capture of the iron oxide contaminant.

Ifa component is made of two or more materials with different modulus of elasticity (e), it is called a composite member and we calculate the factor·n". mention the formula for calculating n". also, ifn> 1, explain what will happen to the 1. transformed.gi) ifn 1, what will happen to the material when transformed material when

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?