Metrology Arrangement for Measuring the Positions of Mirrors of a Submillimeter Telescope

The position of the secondary mirror of a submillimeter telescope with respect to the primary mirror needs to be known .0.03 mm in three dimensions. At the time of this reporting, no convenient, reasonably priced arrangement that offers this capability exists. The solution proposed here relies on measurement devices developed and deployed for the GeoSAR mission, and later adapted for the ISAT (Innovative Space Based Radar Antenna Technology) demonstration. The measurement arrangement consists of four metrology heads, located on an optical bench, attached to the secondary mirror. Each metrology head has a dedicated target located at the edge of the primary mirror. One laser beam, launched from the head and returned by the target, is used to measure distance. Another beam, launched from a beacon on the target, is monitored by the metrology head and generates a measurement of the target position in the plane perpendicular to the laser beam. A 100-MHz modulation is carried by a collimated laser beam. The relevant wavelength is the RF one, 3 m, divided by two, because the light carries it to the target and back. The phase change due to travel to the target and back is measured by timing the zero-crossing of the RF modulation, using a 100-MHz clock. In order to obtain good resolution, the 100-MHz modulation signal is down-converted to 1 kHz. Then, the phase change corresponding to the round-trip to the target is carried by a 1-kHz signal. Since the 100-MHz clock beats 100,000 times during one period of the 1-kHz signal, the least-significant-bit (LSB) resolution is LSB = 0.015 mm

Design of A Modern Hydrogen Production and Recovery Facility (Spring 2003) IPRO 304C

The objective of this project is to design and provide an economic assessment of new flue gas cleanup processes to meet new and future environmental emissions standards. The issues to be considered in this project include technical viability, process integration, economic feasibility, and environmental disposal of waste streams. An economic assessment of the market-based prices of emissions allowances will be used to determine the best long-run strategy. An assessment will be made on the effects of implementation of new technologies on the cost of electricity for both low sulfur western coal, and high sulfur Illinois coal to determine if governmental incentives are needed to promote the use of Illinois coal. Students may focus on an existing power plant in Illinois which uses western coals and is not equipped with SOx/NOx/Hg control systems. Students are expected to use the principles of process design, to evaluate commercially available technologies for various pollutants or propose new approaches to the problem, integrate various technologies in the cleanup train, and perform an economic analysis of the overall processes.Sponsorship: IIT Collaboratory for Interprofessional StudiesProject Plan for IPRO 304C: Design of A Modern Hydrogen Production and Recovery Facility for the Spring 2003 semeste

Solar/Wind Hydrogen Fueling Station at IIT (semester?), IPRO 304B

The objective of this project is to design a renewably powered hydrogen fuelling station at IIT to be part of the Illinois Hydrogen Highway. Based on past recommendations a project site will be selected for the fuelling station. This site will also include a wind turbine and solar panel array to capture renewable energy. The principles of process design will be used to layout hydrogen production, storage, and implementation of renewable energy technologies. The stations will meet all local codes for hydrogen storage, production, and usage. This station will be designed in conjunction with the House of the Future, which is part of IIT’s Sustainable Village.Deliverables for IPRO 304B: Solar/Wind Hydrogen Fueling Station at IIT for the Spring 2005 semeste

Solar/Wind Hydrogen Fueling Station at IIT (semester?), IPRO 304B: Solar Wind Hydrogen Fueling Station IPRO 304B Project Plan Sp05

The objective of this project is to design a renewably powered hydrogen fuelling station at IIT to be part of the Illinois Hydrogen Highway. Based on past recommendations a project site will be selected for the fuelling station. This site will also include a wind turbine and solar panel array to capture renewable energy. The principles of process design will be used to layout hydrogen production, storage, and implementation of renewable energy technologies. The stations will meet all local codes for hydrogen storage, production, and usage. This station will be designed in conjunction with the House of the Future, which is part of IIT’s Sustainable Village.Deliverables for IPRO 304B: Solar/Wind Hydrogen Fueling Station at IIT for the Spring 2005 semeste

Solar/Wind Hydrogen Fueling Station at IIT (semester?), IPRO 304B: Solar Wind Hydrogen Fueling Station IPRO 304B Poster Sp05

The objective of this project is to design a renewably powered hydrogen fuelling station at IIT to be part of the Illinois Hydrogen Highway. Based on past recommendations a project site will be selected for the fuelling station. This site will also include a wind turbine and solar panel array to capture renewable energy. The principles of process design will be used to layout hydrogen production, storage, and implementation of renewable energy technologies. The stations will meet all local codes for hydrogen storage, production, and usage. This station will be designed in conjunction with the House of the Future, which is part of IIT’s Sustainable Village.Deliverables for IPRO 304B: Solar/Wind Hydrogen Fueling Station at IIT for the Spring 2005 semeste

Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, $\alpha=2$ as established in prior literature, then there should be a sufficient abundance of nanoflares to explain coronal heating. We performed $>$600 case studies of solar flares, made possible by an unprecedented number of data analysts via three semesters of an undergraduate physics laboratory course. This allowed us to include two crucial, but nontrivial, analysis methods: pre-flare baseline subtraction and computation of the flare energy, which requires determining flare start and stop times. We aggregated the results of these analyses into a statistical study to determine that $\alpha = 1.63 \pm 0.03$. This is below the critical threshold, suggesting that Alfv\'en waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The Astrophysical Journal on 2023-05-09, volume 948, page 7