Spectrophotometers are commonly used to measure the concentrations of a wide variety of analytes in drinking water and other matrixes; however, many laboratories with limited resources cannot afford to buy these very useful instruments. To meet this need, an accurate, precise, and affordable light emitting diode (LED) spectrophotometer was designed and built using best engineering practices and modern circuit design. The cost and performance of this LED spectrophotometer was compared against 4 common commercial spectrophotometers. More specifically, the performance of these spectrophotometers was evaluated from the upper limits of linear range, upper limits of operational range, calibration sensitivities, R 2 values, precisions of standards, estimated limits of detection, and percent calibration check standard recoveries for the determinations of iron (Fe), manganese (Mn), and fluoride (F −) in drinking water. This evaluation was done in the United States (U.S.

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A two-semester Introduction to Engineering course sequence at Norwich University has Mechanical Engineering (ME), Civil and Environmental Engineering (CEE) and Electrical and Computer Engineering (ECE) students together for the first semester, and they are separated into their disciplines during the second semester. A final project in the second semester was desired that could bring the students back together to make discipline-specific contributions to a multidisciplinary project. The chosen project was a hydroelectric generation project in which the ME students designed a water wheel to work in a laboratory flume, the ECE students designed a permanent-magnet generator with wireless monitoring, and the CEE students designed a structure to support the wheel and generator. In addition to designing their respective components, the students had to communicate between disciplines to define interfaces and requirements for their designs so all the components could work together as a larger system. The first year of the project was successful in that the student teams were able to design working components that functioned together in a system to generate electricity, and the experience generated several lessons-learned that will be used to enhance the experience for the next class of freshmen. The paper will discuss the scope of the design problem and the resulting design solutions, the lessons learned, and the improvements for the second cycle of the project.

Senior capstone design projects can often expand in complexity to include systems of systems, particularly in projects involving embedded systems to control a larger system. Principles of Systems Engineering (SE) can be integrated into the capstone course to help students-who may not have been exposed previously-manage this increased complexity. This paper presents an evolving framework of essential SE fundamental elements, including the top-level processes of Requirements Analysis, Functional Analysis and Allocation, Design or Synthesis, and Analysis & Control. A case study of a mechatronic system (a robotic tin whistle player) was used in a two-semester Electrical and Computer Engineering capstone design course in which the students had no prior exposure to formal SE processes. The students still had to design, build and test their projects' systems, so a balance had to be struck between teaching basic SE principles with its various reporting opportunities, and leaving enough time to do the hands-on engineering required to produce a prototype at the end of the year. The result is a capstone design course that exposes students to the language of SE so that they will be able to recognize its processes when encountered after graduation.

The northern Chinese xiao is an end-blown flute characterized by an array of two to three pairs of holes that separate the main bore from an extended foot. The top pair are tuning holes and the lower ones are described as vent holes, but the design of the latter have shown an influence in the attainability of the third octave as well as the timbre of the notes (G. Ellis, personal communication, 3 March 2014). We analyze these holes in the context of an infinite lattice with a cutoff frequency fc determined by the geometry and spacing of the top holes, and compare the results to that of the pole frequency of the calculated impedance of the actual, irregular lattice below the tuning holes. The input impedance of a cylindrical pipe with a tonehole lattice is calculated, and pressure standing waves are predicted for the peaks of the resulting admittance spectra. The standing waves are compared to experimental results to confirm the high-pass filter properties of the lattice above fc. The effects of varying lattice dimensions on fc and the alignment of upper harmonics with peaks in the spectra will be presented.