Latest Cases

Errata in CPUs: Designers Need to Manage them Better

By Glenn Galvan, Sr. Principal Consulting Engineer; Sandharbor, LP.

A cell phone crashes or a Notebook laptop ceases to function. There are countless reasons why these unwanted events happen. It could stem from human body electrostatic discharge (ESD), software operating issues, an incompatible application loaded into the platform, memory errors heat or even errata in the main Central Processor Unit (CPU).  This article will focus on errata in CPUs and how computer designers and other corporate personnel, such as project managers, can better manage CPUs through knowledge and tools for a specific product’s life cycle .

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Choosing Smart Water-Conserving Plumbing Fixtures

By R. Dodge Woodson, .

Codes and equipment evolve over time. I have been a master plumber since 1979 and have seen ongoing improvements in plumbing fixtures. The move to “go green” and meet Leadership in Energy and Environmental Design (LEED) requirements has also affected the design and manufacture of plumbing fixtures.

When I entered the plumbing trade, toilets used an average of five gallons of water each time they were flushed. Later on, the water conservation demands brought the use of three-gallon-per-flush toilets. After that the usage went down to 1.6 gallons per flush.

The use of low-flush and ultra-low flush fixtures did not go smoothly in the beginning. Since drainage piping was designed and installed for a larger flow of water, when a toilet was flushed the low-flush toilets often clogged piping or had to be flushed twice when flushing solids. This defeated the purpose of 1.6-gallon flush toilets.

Toilets are not the only plumbing fixtures that have been updated in design. Lavatory faucets that use about half has much water as old faucets did are now common. The same is true of shower heads. All in all, the goal to make plumbing function with the use of less water has been ongoing.

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Santos Takes Physics-Based Approach to Human Motion Prediction

By Karim Abdel-Malek, PhD; Director, US Army Virtual Soldier Research program; Director, Center for Computer-Aided Design; Professor, Department of Biomedical Engineering, University of Iowa, Iowa City.

By simulating human motion in a virtual world, Santos is helping companies and the U.S. military develop safer, more ergonomically correct factories and products.

What do the U.S. Army, Ford Motor Company, and a handful of leading global manufacturers have in common? They are among the pioneers experimenting with a new method for human motion prediction that is the first to incorporate physics.

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Lean Design with a Systems Engineering View

By Bob Hildebrand, Strategic Services Manager, Xerox Corp.

The Xerox iGen 4 development team modified lean principles to take a systems-level view of design, ensuring that its large-scale digital production press met both customer requirements and aggressive time-to-market goals.

In building a product as complex as a large-scale digital production press, there are constant fluctuations in everything from market requirements to the way those requirements translate into design and configuration changes. Managing those variations inevitably extends the development cycle, and Xerox Corporation did not have the luxury of time on its iGen4 project, the next-generation color digital production press intended to be the successor to the iGen3.

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Determination of Run Length for Direct Fired Heaters

By Alan Cross, M.S.ChE. .

Introduction

Direct fired heaters are used extensively in the oil refining and chemical process industries. In many instances, those heaters are relied on to heat hydrocarbon liquids or gases to temperatures of 900 to 1500°F or higher. At those temperatures, the stationary fluid film on the inside tube surfaces is subject to thermal decomposition, resulting in the deposition of coke at that location. The coke layer behaves as an insulating barrier between the process fluid and the tube wall, gradually increasing in thickness; this causes the tube wall to reach higher and higher temperatures to transfer the required heat input to the fluid. With the passage of a sufficient amount of time, the tube wall temperature reaches the design temperature, and tube damage occurs if operation at design throughput is continued. At that point, the heater must be shut down and the coke deposits removed. This is accomplished mechanically by “pigging,” the process of passing a cleaning plug driven by fluid pressure through the tubes by using compressed air–driven rotary cutting tools passed through the tubes by an armored compressed air cable, or by controlled burning of the coke at a high temperature—about 1300°F—in an oxygen-rich atmosphere. The interval between the start-up with clean tubes and the shutdown for decoking is termed the run length.

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On the Characteristic Frequency of a Filter

By Ramkumar Ramaswamy, PhD, Partner, Performance Engineering Associates, Chief Scientist, Audesine, USA LLC.

What does the characteristic frequency of a filter polynomial really represent? This article provides an intuitive insight into this question with a rigorous graphical and mathematical treatment.

Electronic filter design is a well-established subject. Nevertheless, there are certain conceptual stumbling blocks that the student—and even the experienced designer—sometimes encounter when dealing with filter polynomials (transfer functions). In this article we deal with one such concept that underlies the design of a filter that is described by a polynomial transfer function, whether implemented in analog or digital form, active or passive— the so-called characteristic frequency of the filter.

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Case Study: Waste Reduction for a Metal Finishing Company

By Mujde Erten-Unal, Department of Civil and Environmental Engineering, Old Dominion University, Norfolk, Virginia.

A pollution prevention/waste minimization opportunity assessment was conducted for a metal finishing and fabricating facility (Company X). The scope of the business activity of that company included the design, production, assembly, and sale of rubber-coated rollers for office automation equipment; the design, production, and sale of valve stem seals, oil seals and O-rings for automotive engines and components; and the design, production, and sale of custom-molded commercial-grade rubber products. Company X is a supplier for several major automobile, copier, and printer industries.  The main activities of Company X took place in three buildings: machining (Building I), plating operations (Building II), and rubber mixing and molding operations (Building III).

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Basics of Blast Resilient Design of Concrete Frame Buildings

By Zafar Ahmad Khan, Staff Engineer (Civil) at Descon Integrated Projects (Pvt.) Ltd. , Pakistan.

Introduction

In this article I will explain the nature of blast forces and their effects on buildings, in a straightforward manner. I will also clarify the difference between blast resistance and blast resilience. Various measures to improve blast resilience in buildings will be described, with the intent that an experienced architect or structural engineer can make informed decisions in the early stages of planning and design.

The premise is consideration of blast loadings in the context of terrorist threats.

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Electrochemical Impedance Spectroscopy Characterization of Electrorheological Fluids

By Vadim Lvovich, Crane Aerospace and Electronics, Elyria, Ohio.

Abstract

Electrorheological fluids (ERFs) have been described as highly engineered variable-impedance fluids that possess rheological and electrical properties that demonstrate dramatic nonlinear change with an applied electric field.  ERF is a two-phase composite colloidal suspension of electrically polarizable particles dispersed in insulating media.  This article describes an application of low-voltage electrochemical impedance spectroscopy (EIS) to comparative characterization of four different ERFs and a prediction of their performance in ER-activated commercial devices.

The ERF impedance response is interpreted in the context of a classical Debye relaxation model.  EIS data analysis allows the determination of the electrical characteristics of polarizable particles and base fluid, an investigation of the preferred conduction mechanisms in the fluid, an evaluation of the potential for chemical agglomeration, and modification of the electrical properties of the ERF to achieve better fluid performance.  The ERF performance improves significantly for highly concentrated suspensions of well-dispersed, small, closely packed particles.  The recent introduction of nanoparticles-based ERF has created an opportunity for further development of fluids with transformationally superior performance.

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Solar in the City: Avoiding the Pitfalls of Adding Solar Power to Existing Structures

By David L. Grower, Director of Solar Operations for Skyline Steel, Inc..

As the world guides its industries and citizens to become more environmentally friendly in their use of energy, and demanding the elimination of fossil fuels to generate power, many businesses are looking toward solar power to reduce their carbon footprints.  Government-funded tax incentives, utility company rebates, and reduced energy costs for the customer are viable reasons for the integration of solar power generation into existing building infrastructure.

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