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Mechanical Engineering. 2012;134(04):22-27. doi:10.1115/1.2012-APR-1.
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This article examines the impact of automation on jobs. Since the end of the Great Recession in June 2009, the GDP of the United States has grown 75% as fast as its average between 1948 and 2007. Ordinarily, such growth would spur companies to hire more workers. However, the fact is that overall unemployment has hovered above 9% for most of the past three years and remains stubbornly high. The percentage of working adults is at its lowest level since 1983, when women were still entering the workforce. Instead of hiring workers, companies are now investing in equipment and technology, which rebounded quickly after the recession. Some economists contend that advanced information and communications technology is transforming the economy by capturing jobs that only humans could have done before. They even consider digital technology when looking at the potential causes of unemployment. They also believe this is a sign of deeper structural changes in the economy.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):28-32. doi:10.1115/1.2012-APR-2.
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This article discusses the obstacles in producing ultraheavy duty products for nuclear reactors in the United States. There has not been much call for making reactor vessels in the United States for decades. Even in the 1970s, the peak decade for building nuclear power plants in the United States, only around a dozen reactor vessels were installed in the best years. To produce ultraheavy products, entirely new forging facilities would have to be built. As per some estimates, one new ultraheavy forging facility would cost $1.5 billion to $2.5 billion, and it would take five to seven years to build. There is also problem related to profit making. Changing these conditions to favor building domestic ultraheavy forging capability would take a coherent energy policy for the United States regarding nuclear power, making it much more important in the energy capabilities.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):34-39. doi:10.1115/1.2012-APR-3.
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This article analyzes the reasons behind the sinking of the Titanic in the Atlantic Ocean in 1912. The Titanic struck an iceberg in the ocean and sank within hours. Equipped with only 20 lifeboats, the Titanic went down with the loss of 1523 passengers and crew. Recent engineering evidence suggests that the ship experienced a hull failure at the surface and broke into pieces before it went down. The analysis supports some witnesses’ testimony that the ship likely began to fracture at the surface, and that the fracture was completed at some unknown depth below the water’s surface. The resulting stress levels in the strength deck below the root of the second expansion joint (aft), and in the inner bottom structure directly below, were very high because of the unusual flooding occurring in the forward half of the ship. These patterns of stress support the argument that initial hull failure likely occurred at the surface.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):40-41. doi:10.1115/1.2012-APR-4.
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This article discusses the significance of injunctions in patent infringement lawsuits. In earlier times, if a patent owner sued for patent infringement, the patent owner had a good chance of winning a preliminary injunction prohibiting sales of the allegedly infringing product pending the outcome of the trial. If the patent owner then won the trial, a permanent injunction was almost automatic. In 2001, it became much harder to win a preliminary injunction. All the accused infringer had to do was put up some kind of defense in order for the judge to deny the patent holder a preliminary injunction pending the outcome of the trial. The odds of obtaining a permanent injunction has been affected by several fairly recent cases as well. In 2006, the U.S. Supreme Court ruled that permanent injunctions, even when the patent holder wins, are no longer guaranteed. Some judges later ruled that the patent-infringing company, so long as it paid a license, could keep selling the infringing product. The judges even set the royalty rate.

Topics: Patents
Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):42-43. doi:10.1115/1.2012-APR-5.
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This article discusses the performance problems associated with process water pumps. It highlights that at a boiler steam load in the 25% to 40% range, an automatic recirculation (ARC) valve is simply not accurate enough to detect a minimum pressure differential change of possibly 1–2 psig when the boiler drum level control valve closes for short-duration process demand changes. Converting the ARC valve to an electronic controller does not work reliably either. The amperage change is difficult to discern at low feedwater flow rates. Failure of the valve to open is a recipe for pump cavitation and becoming “steam bound.” If the boiler trips on “low water,” plant production can be affected immediately. For larger boilers with high-capacity, high-horsepower feed pumps, the ARC valve often becomes an energy conservation (cost) issue.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):44-46. doi:10.1115/1.2012-APR-6.
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This article discusses how kinematic mechanisms created by Franz Reuleaux are now being made available by Cornell University for students and researchers. The university’s Sibley School of Mechanical and Aerospace Engineering owns the largest set of cast iron and brass models of machines designed by Reuleaux more than 130 years ago. Cornell librarians have helped develop the Kinematic Models for Design Digital Library, or K-MODDL, to allow Internet users to view the models close up. The Cornell Reuleaux Collection contains numerous kinematic mechanisms for rotary and reciprocating engines using both steam and internal combustion. It also includes a dozen working clock escapement mechanisms, from the early verge and foliot escapement to the gravity escapement employed in London’s famous Big Ben. K-MODDL will make the collection available to educators, researchers, and students well beyond the Cornell campus. Those with access to a 3-D printer will be able to build a reproduction of the real thing to see up close how the mechanism works.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):49-50. doi:10.1115/1.2012-APR-7.
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This article discusses the mechanism for prediction of aeroacoustic resonance in cavities of hole-pattern stator seals. A Reynolds-averaged Navier–Stokes (RANS) solver developed in-house was used to simulate grazing channel flow past a cavity located in a channel. The numerical results generated with the RANS solver showed good agreement with those obtained using a commercial large eddy simulation code. In addition, the numerical results agreed well with the experimental data. Rossiter’s formula, a popular semi-empirical model used to predict frequencies of holetone acoustic instabilities caused by grazing fluid flow past open cavities, was modified using the RANS solver results to allow for its application to channel flows. This was done by modifying the empirical constant, the ratio of vortex velocity, and the freestream velocity. The RANS solver accurately captured the salient features of the flow/acoustic interaction and predicted well the dominant acoustic frequencies measured in an experimental investigation. The flow solver also provided detailed physical insight into the cavity flow instability mechanism.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):51. doi:10.1115/1.2012-APR-8.
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This article describes the performance optimization of wind turbine rotors with active flow control. The active Gurney flap concept was tested in the wind tunnel under dynamic AoA variations to simulate unsteady inflow conditions. A high-deflection micro flap was actuated by four digital electric servos with a maximum deflection rate of 360°/sec. A custom code was created to allow dynamic AoA variations of the test wing with simultaneous dynamic force measurements. During the dynamic investigations, various control strategies were tested, starting from standard PID controllers with semi-empirical parameter tuning models to Direct Inverse Controllers with neural network tuning strategies and pure self-learning neural network controllers. The results of the closed-loop measurements using the manually tuned PID controller showed a reduction potential for the dynamic lift loads in the range of 70% as well as a stable controller behavior. The Direct Inverse Controller not only showed a load reduction of 36.8%, but also significant improvement potential with respect to its fine-tuning.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(04):53-54. doi:10.1115/1.2012-APR-9.
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This article describes the lucrative market for single-aisle narrow-body (SANB) commercial aircraft for the next 20 years. The SANB market has been the most lucrative for engine manufacturers. Boeing’s 737 and Airbus’s A320 families are powered by twin 30,000 pounds-thrust engines from CFM International or from International Aero Engines number in the many thousands. Of the 19,400 airplanes now in the worldwide air transport fleet, according to Airbus, for aircraft above 100 seats, 87% of all routes flown and 78% of all seats offered are in SANB airplanes. With the single-aisle jet liner market at record levels, not surprisingly, new players want a piece of this Boeing/Airbus duopoly pie. Both Airbus and Boeing have relied extensively over the last few years on customer financing support from export credit agencies such as the U.S. Export–Import Bank. The Russian and Chinese jets are government funded. Bombardier is getting Canadian and provincial government aid to develop the CSeries.

Commentary by Dr. Valentin Fuster

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