On the anniversary of last year’s total solar eclipse, a team of Portland State University engineering students and alumni released today a spectacular video and high-resolution photos showing the eclipse shadow as it moves across Oregon.
The video is the only one of its kind to have been produced following a nationwide NASA-funded project that sent weather balloons 100,000 feet above the earth’s surface to document the eclipse as it traversed the United States. It was made from panoramic images consisting of over 1,000 stitched photos captured by cameras mounted to weather balloons the team launched from Corvallis, Oregon on August 21, 2017.
Jonathan Bird, mechanical and materials engineering faculty, and student Ho Yin Wong co-authored “Comparative Analysis of a Coaxial Magnetic Gear With a Flux Concentration Rotor and Consequent Pole Rotor Typology,” published in the August 2018 issue of IEEE Transactions on Magnetics.
Abstract: This paper presents the performance comparison between a flux concentration (FC) and triple-permanent magnet (PM) consequent pole (CP) magnetic gear (MG) rotor typology with the same 7.5:1 gear ratio. The triple PM CP MG is unique in that it can create torque change through two field heterodyning pole combinations. The performance with respect to volumetric and mass torque density is considered. It is shown that the FC typology can operate with a higher mass and volumetric torque density, even when using a low FC ratio rotor.
Jun Jiao, Mechanical and Materials Engineering faculty, co-authored “Increased expression of FHL2 promotes tumorigenesis in cervical cancer and is correlated with poor prognosis,” published in the May 2018 issue of Gene.
Purpose: Increasing evidence demonstrates that the four and a half LIM domain (FHL) gene and its protein products have different functions in the progression of various malignancies. However, the role of FHL protein 2 (FHL2) in cervical cancer (CC) has not been fully elucidated. In this study, we investigated the prognostic value of FHL2 expression in human CC tissues and the potential molecular mechanisms through which FHL2 modulates CC cell proliferation and apoptosis. Materials and methods: We measured FHL2 expression in CC cell lines and tissues by quantitative real-time polymerase chain reaction and Western blot assays. The effects of FHL2 knockdown on cell proliferation and apoptosis in two CC cell lines were examined using RNA interference, cell counting kit-8, Western blot and flow cytometry assays. Furthermore, we assessed phosphorylated protein kinase B (p-AKT) and phosphorylated mammalian target of rapamycin (p-mTOR) expression in two CC cell lines to determine whether the AKT/mTOR pathway is involved in the effects of FHL2 silencing on cell proliferation and apoptosis. Nude mice tumorigenicity experiments were also performed to evaluate the effects of FHL2 on HeLa cell growth in vivo. Results: We found that FHL2 was significantly upregulated in CC cell lines and tissues. According to survival curves, high FHL2 expression levels in patients were correlated with poor prognosis. Moreover, by decreasing p-AKT and p-mTOR protein levels, silencing FHL2 significantly inhibited cell proliferation and induced apoptosis. FHL2 knockdown also induced apoptosis by increasing the Bax-to-Bcl2 ratio. By contrast, FHL2 overexpression significantly promoted cell proliferation. Finally, decreased tumour growth in an in vivo animal model also demonstrated the tumour-suppressing effects of FHL2 knockdown. Conclusion: Our findings indicate that FHL2 is an important prognostic factor in CC and that it plays a crucial oncoprotein role by promoting cell proliferation and inhibiting apoptosis in CC, possibly by targeting the AKT/mTOR pathway.
Jun Jiao, Mechanical and Materials Engineering faculty, co-authored “Visible-blind quasi-solid-state UV detector based on SnO 2 -TiO 2 nanoheterostructure arrays,” published in the April 2018 issue of the Journal of Alloys and Compounds 751.
Abstract: Self-powered UV detectors have attracted intensive research interest due to their advantages of low cost fabrication, high efficiency and low power consumption. In this paper, high ordered SnO2-TiO2 nanoheterostructure arrays were synthesized using soft chemical methods. A self-powered quasi-solid-state UV detector was constructed using this nanoheterostructure as the photoanode and a polyethylene oxide based quasi-solid-state electrolyte as the hole transfer layer. Because the SnO2-TiO2 core-shell nanoheterojunction simultaneously offers a high electron-hole separation, a low charge recombination and a direct pathway for electron transport, the nanostructured self-powered detector displayed an excellent performance over that based on bare TiO2 nanostructure arrays. A quite high incident photon-to-current conversion efficiency of 55.8% at 340 nm and a fast response time (0.14 s for rise time and 0.06 s for decay time) were observed. That is quite excellent performance for self-powered UV detector. Moreover, the self-powered UV photodetector also shows an excellent spectral selectivity and long-time stability in the air. These excellent photoelectric characteristics will enable significant advancements for next-generation photodetecting applications.
Jun Jiao, Mechanical and Materials Engineering faculty member, co-authored “High-Performance Self-Powered UV Detector Based on SnO2-TiO2 Nanomace Arrays,” published in the April 2018 issue of Nanoscale Research Letters.
Abstract: Photoelectrochemical cell-typed self-powered UV detectors have attracted intensive research interest due to their low cost, simple fabrication process, and fast response. In this paper, SnO2-TiO2 nanomace arrays composed of SnO2 nanotube trunk and TiO2 nanobranches were prepared using soft chemical methods, and an environment-friendly self-powered UV photodetector using this nanostructure as the photoanode was assembled. Due to the synergistic effect of greatly accelerated electron-hole separation, enhanced surface area, and reduced charge recombination provided by SnO2-TiO2 nanomace array, the nanostructured detector displays an excellent performance over that based on bare SnO2 arrays. The impact of the growing time of TiO2 branches on the performance of UV photodetector was systematically studied. The device based on optimized SnO2-TiO2 nanomace arrays exhibits a high responsivity of 0.145 A/W at 365 nm, a fast rising time of 0.037 s, and a decay time of 0.015 s, as well as excellent spectral selectivity. This self-powered photodetector is a promising candidate for high-sensitivity, high-speed UV-detecting application.
Raul Bayoan Cal, Mechanical and Materials Engineering faculty member received a $371K grant from the Department of Energy for the project Enhanced convection for higher module and system efficiency. The goal of project is to develop new solar photovoltaic (PV) modules and solar system-scale
designs that promote an increase of the convective heat transfer coefficient of at least 40%, reducing the operating temperature of the solar PV panels, and leading to a boost on the annual energy yield by at least 5%. By achieving this goal, we further foresee decreasing solar panel degradation by +0.3%/year, reducing the LCOE by 2.9-4.5¢/kWh.
Mark Weislogel, mechanical and materials engineering faculty member, recently received the 2017 Space Processing Award from the American Institute of Aeronautics and Astronautics. The award is presented for significant contributions in space processing or in furthering the use of microgravity for space processing. Reactivated in 2007, this award is presented biennially (in odd-numbered years) generally at the American Society for Gravitational and Space Research (ASGSR).
Portland State Spinoff Receives Grant to Improve Drinking Water Delivery in Developing Countries
SweetSense, Inc., a Portland State University spinoff company that helps bring clean drinking water rural areas in developing countries, has been awarded the second phase of a nearly $1 million grant from the National Science Foundation (NSF).
The grant will help pay for technology improvements that will predict problems and trigger preemptive fixes in the way water is delivered in countries such as Rwanda, Kenya, Ethiopia and Bangladesh.
The grant will help pay for technology improvements that will predict problems and trigger preemptive fixes in the way water is delivered in countries such as Rwanda, Kenya, Ethiopia and Bangladesh.
SweetSense uses electronic sensors that connect with cellular and satellite networks and internet databases – part of the Internet of Things -- to identify broken water delivery systems and dispatch delivery teams to fix them.
For example, in 2014 it installed about 200 sensors in rural water pumps in Rwanda.
“Before the sensors were installed, about 44 percent of the area’s pumps were broken at any given time, and it took an average of about seven months to get a pump repaired,” said CEO Evan Thomas, Portland State engineering professor and a founder of SweetSense. “After the sensors were in place, the repair interval was reduced to just 26 days. Consequently, only 9 percent of pumps were broken at a time. We’re now working to achieve 100 percent uptime.”
SweetSense has deployed more than 1,000 sensors in 15 countries. They’re being used on water pumps, water filters and latrines to measure use and performance. They’re also used to monitor the emissions from high-efficiency cookstoves installed in developing communities.
“There’s been a rapid, explosive growth in access to cellular data in developing countries, while access to water and sanitation is essentially flat-lined. This grant gives us an opportunity to leverage cellular and satellite data to help deliver these critical health services,” Thomas said.
In addition to the NSF award, SweetSense is in the midst of raising $2 million in investments to be able to expand and improve, with the goal of reaching more than 50 million people in the next five years.
