Physics & Engineering Research
Near Space and The Physics of Musical Instruments
Dr. Dan Lawrence
Dr. Lawrence’s research interests lie in the area of the physics of musical instruments. He has three current areas of work. The first is studying the acoustics of trumpets. A question often asked is: “Should I spend $4,000 on a professional trumpet, or will a cheap $500 horn sound just as well?” Or, “Does the finish on the horn make a difference in the sound?” To answer these and other questions, a set of mechanical lips was designed and built so that the input signal into a trumpet could be the same every time.
Various trumpets are being tested on the system and the output sounds are put through a harmonic analysis. Early results seem to indicate that it is the person playing the trumpet that makes all the difference in the sound output, not the quality, type, or finish of the horn.
Using the lips, Dr. Lawrence’s group is also studying the normal modes of vibration on a trumpet. Using interference holography, an image of the trumpet can be made that highlights the nodes and anodes of the vibrating horn. This is a great tool for studying the design of an instrument and improving the efficiency of sound output.
Work is also being done in modeling the pressure waves through a trumpet using finite element analysis. By correctly modeling the wave throughout the horn, we are hoping to get a realistic sound output that, when played, sounds “just like” a real trumpet. Currently, trumpet and brass sounds on an electronic instrument, such as a synthesizer, are either non-realistic and funny sounding, or sampled, meaning recorded and played back. The second method, while it gives a realistic sound, does not allow for much tweaking of the sound to personal taste. A realistic generated sound could give the musician a better method of producing electronic brass sounds that have been synthesized by NNU students during summer research.
Research is also being conducted with a NASA grant in Near Space Exploration. Various experiments have been sent into space on weather balloons that reach 100,000 feet or higher. He is also working on experiments that will go into NASA sounding rockets to explore the world 75 miles above the atmosphere.
Scanning Radio Imagery; The Effect of Vortex Generators on Aircraft Stall Characteristics
Dr. Bill Packard
Dr. Packard is pursuing several areas of research, two of which will be discussed here. The first area is Scanning Radio Imagery (SRI), which was invented at NNU. The imager is an instrument which, by employing scanning techniques, turns an ordinary hand-held metal detector into a camera and takes “pictures” of metal objects. This device was designed at NNU, constructed in the Physics Instrumentation Shop, and then implemented and tested in our laboratory. Undergraduate students participated fully in this process. The instrument allows hidden objects, including weapons, to be easily detected and has implications for such diverse applications as Homeland Security and prospecting. The second area of research being studied is the effect of vortex generators on aircraft stall characteristics. Vortex generators are small tabs of metal strategically placed on aircraft wings that modify the airflow in such a way as to forestall the onset of a stall. A study is underway investigating their effect on the stall characteristics of a Piper Cherokee 140 airplane. The tests indicate that the vortex generators greatly reduce the sharpness of a stall (power-on and power-off) and significantly reduce the rate-of-descent during a stall. v
Unmanned Aerial Vehicles (UAVs)
Dr. Duke Bulanon
The orchards of Parma and Caldwell have been host to some of the newest crop-monitoring software in the nation. Growers rely on accurate, real-time monitoring of crops to ensure that their harvest remains healthy and disease and pest free. Aerial monitoring is by no means a new idea; for years farmers have been paying for satellites to capture images of their crops or for pilots to fly over their land snapping photos to help recognize potential health issues, however both techniques are costly and time consuming.
A new trend has been to employ unmanned aerial vehicles (UAVs) to capture the needed images. The UAVs are controlled remotely and are far cheaper to buy and use than a full-sized airplane. However, even after images are gathered, a grower needs to be able to see what is going on within in the crop. To do this, no ordinary photo will do.
During the 2011-12 school year, Assistant Professor Dr. Duke Bulanon in NNU’s Department of Physics and Engineering, with Paulo Salvador (São Paulo, Brazil) and Mark Horton (Nyssa, Ore.), two undergraduate students, began experimenting with UAVs and the software used to interpret the images gathered. The team from NNU is working to equip a UAV with a multispectral imaging sensor that will capture images in both visible and near-infrared bands. These special images will allow farmers to see invisible changes in how a plant reflects light when it undergoes water stress, nitrogen deficiency or disease infestation, immediately showing growers exactly what changes are needed to produce a healthy crop. “It’s kind of weird,” said Dr. Bulanon, “we are engineers doing agriculture.”
The combination of engineering and agriculture seems to be working. Initial testing has turned up promising results—promising enough for the Idaho State Department of Agriculture to grant the School of Science and Mathematics an $84,000 grant to continue the project in November.
Superhydrophobic Nanomaterials in Microgravity (sponsored by NASA)
Patrick, Turner, Halle, Larson, Baggenstos, Hush, Dr. Parke, Dr. Lawrence, Dr. Packard
In spaceflight and during lunar or Martian exploration, water is a precious resource that must be conserved and reused. In order for it to be reused and to reduce pumping energy, water should not stick to the plumbing through which it moves. Water adheres to equipment surfaces due to surface tension forces, which vary according to the type of surface coating used. New superhydrophobic SH (water repellant) surface coatings have recently been created and studied in 1g . This experiment seeks to extend this research to both 2g and 0g in order to determine the fluid dynamics of water droplets impinging on SH coated surfaces. Anodized aluminum, PTFE-coated aluminum, and stainless steel surfaces as well as spinodal glass and diatomaceous earth nanomaterial coated surfaces, supplied by our collaborator, Dr. John Simpson from Oak Ridge National Lab, will be compared in zero-g, one-g, and two-g. The Principal Investigator of this project is Gregory Pace, of NASA Ames Research Center. The primary objective of this project is to produce data useful to NASA researchers in determining the feasibility of using these novel SH nanomaterials as coatings inside future spacecraft plumbing systems. This data was collected using a high-speed video camera to photograph the fluid dynamics of various 0.1-10mm diameter water droplets impinging at various 0.1-10m/s velocities on the variously coated surfaces mentioned above. In addition, continuous video observation of the ‘Moses Effect” from 2g through 0g and back again was performed for the first time ever. Direct involvement of K-12 students in the development of our experiment and the post-flight video analysis is a key part of our outreach plan.
Flexible, Printable Photovoltaics and Integrated Circuits
Flexible semiconductor devices fabricated on substrates such as plastic, paper, fabrics, i.e. “Macroelectronics” is an emerging field which we have become quite interested in over the past couple of years. This research field includes large area semiconductor devices built on or in flexible plastic, metal, fabric, and paper sheets, and capable of being manufactured with low-cost, high-volume methods such as roll-to-roll, ink-jet printing, and other printing industry methods. The potential of using these low-cost printing technologies for the fabrication of large area displays, sensors, solar cells, antennas, and radio frequency (RF) circuits is incredible.
Some of the applications for this new technology include RFID circuits printed directly onto product packaging (replacing barcodes), large flexible transparent video displays, and massively distributed arrays of sensors and wireless communication built into fabrics, carpets (e-textiles) , wall & window coverings, and structural surfaces for monitoring environment, structural health, security, etc. Other applications are wearable electronics, 3-D medical imaging, lightweight square kilometer active membrane solar cells/sails for use in space, and military RF surveillance with plastic active antenna arrays conformally mounted to wing or airship surfaces.
Large area flexible, conformable electronics are now known as “macroelectronics.” Although, amorphous and polycrystalline silicon thin-film transistor (TFT) electronics built on rigid silicon or glass substrates are quite mature technologies now, with large active matrix liquid crystal flat panel displays as large as one square meter being routinely produced, silicon CMOS microelectronics costs about $10/cm2, there are many new large area macroelectronics applications that will require at least a 100X cost reduction to $.10/cm2. Also, the quality and performance of current TFT technologies, particularly on flexible substrates, is one to two orders of magnitude worse than typical CMOS IC’s built on crystalline silicon wafers. The material properties and low-temperature process limitations result in device mobilities in the range of 1cm2/Vsec, only capable of supporting very low-frequency circuit operation. Many new materials and fabrication methods to improve the device mobility are already under investigation.
The transfer of ultra-thin crystalline silicon wafer sheets containing fully-integrated and fabricated CMOS circuits and photovoltaic arrays onto flexible, foldable polymer sheets is one of the ultimate goals of this research, in collaboration with American Semiconductor, Inc. of Boise, utilizing their FleX Silicon-on-Polymer technology.
Nano based solar cells have a tremendous potential to boost efficiencies thereby bringing the overall cost down. Nano based solar cell technologies can be divided in to four categories: Nanotubes, quantum dots, hot carrier cells, and space PV cells. Fabrication cost is a major consideration for all of these except the space PV cells. It has been demonstrated in a laboratory that multiple exciton generation processes can lead to quantum yield of the order of 3 as compared to less than 1 in a traditional solar cell. Solar cells which use this and other effects can reach efficiencies of the order of 47 % in quantum dots and 66 % in hot carrier cells. These efficiencies are well above those observed in traditional solar cells (5-22% with a theoretical limit of 33%) as well as those in an ideal solar thermal power plant (~ 50%).
Engineering “Lego” Churches for Peru
Michael Whiting, Luke Hetrick, Andrew Peterson, Dr. Stephen Parke
A team of Northwest Nazarene University (NNU) Engineering seniors are collaborating with the Extreme Nazarene mission organization in Peru to develop a new building technology using styrofoam snap-together blocks (called ICFs) filled with steel reinforced concrete to permit the construction of 30 strong, yet inexpensive, churches to be built in remote parts of Peru over the next four years. The challenge presented to this NNU senior team for 2011was to design a process in which these ICFs can be produced by local unskilled labor on the actual church construction site using a portable block molding plant powered by diesel generator. The ICF materials may be either expanded or extruded polystyrene or sprayed polyurethane. The NNU senior team, under the guidance of Dr. Stephen Parke, has investigated several polystyrene and polyurethane production methods and companies. We are researching the chemistry, properties, and manufacturing processes of both of these materials. In this poster, we will present a comparison of these manufacturing processes, raw materials availability, flammability, strength, energy consumption, quantity of concrete/rebar required, and the transportation logistics of using polystyrene or polyurethane ICFs for construction in Peru and other similar third world countries. Currently our design team is exploring possibilities of partnering with ThermoBlock, EnergyLock, and Lazarian World Homes. Our NNU team will be traveling to Peru in July 2011, to help build the first Lego church there in order to gain insight into the building process and local availability of chemicals, materials, and power. Our team hopes to deliver a prototype portable foam block molding plant in a shipping cargo container/trailer to Peru by early 2012.