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I was recently retained as an engineering expert in a lawsuit in which I had to determine the force acting upon an object. In order to quantify that force, I employed Gaspard Gustave de Coriolis‘ Principle of Work, an engineering concept he introduced in his 1829 textbook, Calculation of the Effects of Machines. We’ll take our first look at de Coriolis’ Principle of Work today, along with the term he used to quantify work, the dynamode. As a scientist living during the time of the great Industrial Revolution, de Coriolis was interested in lots of things, and he was particularly interested in quantifying the effort involved to accomplish tasks, like how many men, horses, or steam engines were required to move a stationary object. He defined this activity as work, and he hoped its study would lead to a broadly accepted engineering principle which could be applied across industrial functions. According to de Coriolis, work is the force acting upon a stationary object which causes it to move, multiplied by the distance moved. Work could also be defined as the force acting upon an object already in motion, multiplied by the distance traveled before it comes to a stop. To quantify work, de Coriolis proposed the dynamode as its unit of measure, a term which derives from the Greek words dynamis, meaning power, and odos, meaning path. He went on to define one dynamode as the amount of work required to lift an object with a mass of 1,000 Kg, or kilograms, one meter above the ground.
de Coriolis’ Dynamode Quantity
Catchy as it may sound, the word dynamode is all but forgotten today. But de Coriolis’ Principle of Work and his formula to calculate work remain to the present day as fundamental concept in engineering. We’ll present that formula next time. Copyright 2015 – Philip J. O’Keefe, PE Engineering Expert Witness Blog ____________________________________ |
Posts Tagged ‘lawsuit’
de Coriolis’ Principle of Work and Dynamode
Sunday, November 15th, 2015
Determining Patent Eligibility – Part 7, Process
Sunday, May 26th, 2013|
We’ve been discussing hurtles which must be jumped in order for an inventor’s creation to be considered for a patent. Federal statutes, namely 35 USC § 101, define the bases of patentability, including providing definitions on key terms, such as what constitutes a machine, an article of manufacture, and a composition of matter. Today we’ll wrap up our discussion on determining patent eligibility when we explore the final hurtle by defining process. To get an understanding of what is meant by process, we must look to the lawsuit of Gottschalk v. Benson, a case involving patentability of a mathematical algorithm within a computer program. In this case the US Supreme Court held that a process is a series of steps or operations that transform substances or came about by way of a newly invented machine. Based on the Court’s definition, a process can be many things, from a production line that transforms corn into corn chips within a food manufacturing plant to a mathematical algorithm running within software on the platform of a newly devised type of computer. However, the term usually pertains to a series of operations or steps, most frequently manufacturing in nature, where physical substances are transformed into useful products, that is, they possess the quality of utility, as discussed earlier in this blog series. A “physical substance” is anything of a physical nature existing on our planet.
Before I end this series I’d like to mention that under 35 USC § 101 an invention can be eligible for a patent if it makes a useful and beneficial improvement to an existing machine, article of manufacture, composition of matter, or process. That is to say, something may have already been patented which performs a specific function, but if that is improved upon in any significant way, it may receive a new patent. For example, suppose an improved process for manufacturing food products was developed by adding additional steps to an existing patented process. If this improvement results in benefits such as lowered production costs, increased production rate, or reduced health risks to consumers, then this improved process may be eligible for a patent under 35 USC § 101. Next time we’ll begin an exploration of the growing presence of 3D animations within the courtroom, specifically how they bring static 2D patent drawings to life. ___________________________________________ |
Forensic Engineering Focus On Electrical Fires
Sunday, October 4th, 2009|
Property damage and loss of lives, these are often the result of fires. But did you know that one of the leading causes of fire is electricity? Residential electrical fires claim the lives of nearly 500 Americans each year and injure another 2300. Annually, these fires result in over $800 million in property losses. Approximately one third of the nearly 70,000 home electrical fires that occur each year are traceable to design and manufacturing defects in electrical products. The rest are caused by the misuse and poor maintenance of electrical products, overloaded circuits and extension cords, and incorrectly installed wiring. The three components that must be present in order for a fire to manifest and sustain itself are well known. These components make up the “Fire Triangle,” a potentially lethal combination of heat, fuel, and oxygen. If any one of these three components is missing from the triangle, a fire can’t be started or sustained. In the case of an electrical fire, it’s electricity that creates the heat component of the Fire Triangle.
The Fire Triangle How does electricity contribute to fires? One example would be an overloaded extension cord. Homeowners are sometimes unaware that extension cords must be sized appropriately for their ultimate usage. If not, they can overheat, particularly if they are damaged. Damage to cords can result from a myriad of factors, from factory production errors to kinking when heavy furniture is carelessly placed on top of them. The same principle holds true for electrical products. If their internal wiring or a component is insufficiently sized or damaged, overheating can result. If things get hot enough and there is sufficient airflow (oxygen) and combustible material (fuel) in the vicinity, then the fire triangle is complete. The fire starts internally and can soon spread to other objects in the area. Electrical arcing can occur when an energized electrical circuit is broken. For example, suppose a wire carrying current is suddenly broken in two. If the voltage is high enough, the electricity will want to continue to flow through the air across the break to form an electrical arc. If the power flowing through the arc is great enough, heat can once again complete the Fire Triangle, resulting in fire. Forensic engineering analysis of evidence collected from a fire scene often yields telltale signs of overheating due to overloaded electrical circuits or damaged wiring in components. Under close examination by an experienced professional, even the smallest strand of wire can point to the cause of an electrical fire. CSI skills aren’t only employed at crime scenes. Forensic engineers also use similar techniques to get to the true story of cause and effect. _________________________________________________________________ |
