174 research outputs found
The Impact of Fabrication Errors of Double-layer BOE on Diffraction Efficiency
No full text
With the development of optical technology, optical instruments become smaller and more integrated. Because of the high diffraction efficiency and light weight, binary optical elements become more and more popular. Binary optical element can only blaze at one wavelength, it has high diffraction efficiency at design wavelength. But the diffraction efficiency of binary optical elements will decrease quickly with the change of wavelength. And this situation will have big impact on image quality. Since double-layer BOE can blaze at two wavelengths, it has high diffraction efficiency at wide spectral bandwidth. There are kinds of fabrication errors. Based on scalar diffraction theory, this paper analyzes the diffraction efficiency of double-layer BOE with fabrication errors and simulates it in MATLAB. Simulation shows the diffraction efficiency decreases quickly if the depth errors of two layers are opposite, and this situation should avoid. As for periodic errors, tilt errors and angular errors, these fabrication errors have different impact of double-layer BOE on diffraction efficiency.</p
Don't Call Me Professor!
No full textJohn Boe responds to David Bartholomae's “Teaching On and Off the Tenure Track: Highlights from the ADE Survey of Staffing Patterns in English.” Using his experience in a thirty-year career as a nontenured lecturer, the author addresses the discrimination lecturers face even in the most generous and democratic of institutions. It discusses the difficulty of finding an appropriate term for nontenured faculty, the unlikelihood of untenured faculty ever having full participation in the lives of their departments and institutions, the inequity of support given to the tenured for research and of support continuing to be given even when the tenured stop producing valuable (or any) research, the financial benefits that accrue to institutions through exploitation of the nontenured, the culpability of those in power for the flaws in the tenure system, and the solution to the aforesaid problems: eliminating tenure.</jats:p
RC Baja Car Drivetrain & Chassis
No full textThe object of this report is to design, manufacturer, and build an RC Baja Car to compete in the annual ASME RC Baja Competition.
In order to design, manufacture, and build the RC Baja Car, various methods and approaches are utilized throughout to meet the specified criteria of the competition along with the teams’ personal requirements. Initially, after an overall design was acquired, analysis is done to ensure a working device. Analysis such as power requirements to verify the motor will meet ROAR requirements and suffice for the 4wd system utilized in the device. Statics and dynamics analysis are utilized on individual components accounting for the overall weight to ensure the device withstands all forms of testing along with the abuse of the competition. In addition, decision matrices and material research are conducted to certify the best material is chosen for device. Next the manufacturing methods utilized such as, 3D printing for the chassis and differential housing’s along with machining for the drivetrain components are performed in order to assemble/build and test the RC Baja Car.
Testing of the device shows to meet the specified requirements along with competitively competing in the competition. The RC Baja Car is capable of achieving 15 mph in 5 seconds. Each component of the device is able to withstand the torque the car experiences underload when achieving maximum speed off 22.5 mph. The chassis of the RC Baja Car does not deflect more than 5/16 of an inch during testing and standard driving
Validation of the FACSCount AF system for determination of sperm concentration in boar semen
No full textA flow cytometric method has been developed for rapid determination of sperm concentration in semen from various mammalian species.* All cells containing DNA are stained with SYBR-14 or propidium iodide (PI) and sperm concentration is determined in relation to an internal standard of fluorescent microspheres ( beads). Satisfactory staining can be achieved within 2-3 min and the following flow cytometric analysis on the FACSCount AF System rapidly provides the user with a precise and accurate assessment of the sperm concentration. In this study, the FACSCount AF System and Sperm Counting Reagent ( BD Biosciences) was compared with microscopic counting using a Burker-Turk haemocytometer. In addition, sperm concentration was determined using the Corning 254 spectrophotometer which is used routinely by Danish artificial insemination stations for boars. The results show that the agreement between flow cytometry and microscopic counting is very high. The slope for the regression line was 1.12 (SE = 0.03) with an estimated intercept with the Y-axis of 22 x 10(6) sperm/ml (SE = 10 x 10(6) sperm/ml) and an estimated error of the model of 10 x 10(6) sperm/ml. For the spectrophotometer, the slope of the regression line was 1.09 (SE = 0.07) with an estimated intercept of 137 x 10(6) sperm/ml (SE = 25 x 10(6) sperm/ml). The average error made by the spectrophotometer was 55 x 10(6) sperm/ml. In addition, the results obtained using flow cytometry was highly repeatable ( CV = 2.7%) in comparison with the spectrophotometric method ( CV = 6.3%). These results indicate that the FACSCount AF System is a valuable tool for precise and accurate assessment of sperm concentration in boar semen and that use of this system may lead to production of more uniform insemination doses containing a specific number of sperm per dose
Image simulation for biological microscopy : microlith
No full textAuthor Posting. © Optical Society, 2014. This article is posted here by permission of Optical Society for personal use, not for redistribution. The definitive version was published in Biomedical Optics Express 5 (2014): 1822-1838, doi:10.1364/BOE.5.001822.Image simulation remains under-exploited for the most widely used biological phase microscopy methods, because of difficulties in simulating partially coherent illumination. We describe an open-source toolbox, microlith (https://code.google.com/p/microlith), which accurately predicts three-dimensional images of a thin specimen observed with any partially coherent imaging system, as well as images of coherently illuminated and self-luminous incoherent specimens. Its accuracy is demonstrated by comparing simulated and experimental bright-field and dark-field images of well-characterized amplitude and phase targets, respectively. The comparison provides new insights about the sensitivity of the dark-field microscope to mass distributions in isolated or periodic specimens at the length-scale of 10nm. Based on predictions using microlith, we propose a novel approach for detecting nanoscale structural changes in a beating axoneme using a dark-field microscope.This study was funded by National Institutes of Health grant RO1 EB00258
High throughput instrument to screen fluorescent proteins under two-photon excitation
No full textAuthor Posting. © Optical Society of America , 2020. This article is posted here by permission of Optical Society of America for personal use, not for redistribution. The definitive version was published in Molina, R. S., King, J., Franklin, J., Clack, N., McRaven, C., Goncharov, V., Flickinger, D., Svoboda, K., Drobizhev, M., & Hughes, T. E. High throughput instrument to screen fluorescent proteins under two-photon excitation. Biomedical Optics Express, 11(12), (2020): 7192-7203, https://doi.org/10.1364/BOE.409353.Two-photon microscopy together with fluorescent proteins and fluorescent protein-based biosensors are commonly used tools in neuroscience. To enhance their experimental scope, it is important to optimize fluorescent proteins for two-photon excitation. Directed evolution of fluorescent proteins under one-photon excitation is common, but many one-photon properties do not correlate with two-photon properties. A simple system for expressing fluorescent protein mutants is E. coli colonies on an agar plate. The small focal volume of two-photon excitation makes creating a high throughput screen in this system a challenge for a conventional point-scanning approach. We present an instrument and accompanying software that solves this challenge by selectively scanning each colony based on a colony map captured under one-photon excitation. This instrument, called the GIZMO, can measure the two-photon excited fluorescence of 10,000 E. coli colonies in 7 hours. We show that the GIZMO can be used to evolve a fluorescent protein under two-photon excitation.National Institute of Neurological Disorders and Stroke (F31 NS108593, U01 NS094246, U24 NS109107); Howard Hughes Medical Institute
Quantification of collagen organization in histopathology samples using liquid crystal based polarization microscopy
No full textAuthor Posting. © The Optical Society, 2017. This article is posted here by permission of The Optical Society for personal use, not for redistribution. The definitive version was published in Biomedical Optics Express 8 (2017): 4243-4256, doi:10.1364/BOE.8.004243.A number of histopathology studies have utilized the label free microscopy method of Second Harmonic Generation (SHG) to investigate collagen organization in disease onset and progression. Here we explored an alternative label free imaging approach, LC-PolScope that is based on liquid crystal based polarized light imaging. We demonstrated that this more accessible technology has the ability to visualize all fibers of interest and has a good to excellent correlation between SHG and LC-PolScope measurements in fibrillar collagen orientation and alignment. This study supports that LC-PolScope is a viable alternative to SHG for label free collagen organization measurements in thin histology sections.Morgridge Institute for Research and National Institutes of Health (NIH) (U54DK104310 and R01GM114274); The University of Wisconsin Carbone Cancer Center Cancer Center Biocore and Histology core (UWCCC) (P30 CA014520)
Valdosta Project Change, Scrapbook, July 1997
No full textValdosta Project Change. “Valdosta Project Change Scrapbook, July 1997.” Lowndes County Historical Society, repository. Digital Copy—Valdosta State University Archives and Special Collections, Valdosta Project Change Collection, 1997-2003. Retrieved from https://vtext.valdosta.edu/xmlui/handle/10428/6886. 1 pdf document, 31 pages, 529 MB (555,178,001 bytes).7/2- Public transportation worthy of study- no author; 7/2- City schools group sets priorities- Pamala J. Williams; 7/3- BOE attorney holding interviews in ongoing investigation- Pamala J. Williams; 7/3- BOE has responsibility to parents- Charlene Davis, Valdosta; 7/4- City school investment not ‘paying off’- Wesley Force, Valdosta; 7/6- Officials shouldn’t bow to special interests- William M. Eanes, Valdosta; 7/7- Does Valdosta Middle School discriminate?: Federal investigation seeks to determine whether classes are grouped by ability or race- Pamala J. Williams; 7/7- There is a better way than ability grouping- Sheryl Giddens, Valdosta; 7/7- Gifted program reaches out to minorities- Pamala J. Williams; 7/9- Race is not the issue in school controversy- Chris Keener, Valdosta; 7/11- Hardee (from page 1-A)- no author; 7/12- Parent’s mad over math test with drug, murder questions- Associated Press; 7/13- There is hope for city school system- Ernest and Gwendolyn Robinson, Hermitage TN; 7/14- The betrayal of Supreme Court Justice Thurgood Marshall- Nat Hentoff; 7/14- Teachers respond to federal review- Pamala J. Williams; 7/14- School board got no mandate to restructure- Jacqueline Clark, Valdosta; 7/14- Parents important to students’ success- Pamala J. Williams; 7/15- BOE (from page 1-A)- no author; 7/15- Segregation in integrated public schools?- Kirk Johnson Jr., Valdosta; 7/15- Speakers question BOE policies- Pamala J. Williams; 7/22- Transcripts from investigation read in BOE closed-door session- Pamala J. Williams; 7/22- BOE- Pamala J. Williams; July 1997- Hardee looking ahead- Jodi M. Scott; July 1997-Twin Lakes VFD- Shelby G. Spires; July 1997- Hardee leaving VSU- Jodi M. Scott
Valdosta Project Change, Scrapbook, July 1997
No full textValdosta Project Change. “Valdosta Project Change Scrapbook, July 1997. Lowndes County Historical Society, repository. Digital Copy--Valdosta State University Archives and Special Collections, Valdosta Project Change Collection, 1997-2003. 1 pdf document, 31 pages. 534 MB (560,014,241 bytes).Included Articles: 7/2- Public transportation worthy of study- no author; 7/2- City schools group sets priorities- Pamala J. Williams; 7/3- BOE attorney holding interviews in ongoing investigation- Pamala J. Williams; 7/3- BOE has responsibility to parents- Charlene Davis, Valdosta; 7/3 1997- Hardee leaving VSU- Jodi M. Scott; 7/4- City school investment not ‘paying off’- Wesley Force, Valdosta; 7/6- Officials shouldn’t bow to special interests- William M. Eanes, Valdosta; 7/7- Does Valdosta Middle School discriminate?: Federal investigation seeks to determine whether classes are grouped by ability or race- Pamala J. Williams; 7/7- There is a better way than ability grouping- Sheryl Giddens, Valdosta; 7/7- Gifted program reaches out to minorities- Pamala J. Williams; 7/9- Race is not the issue in school controversy- Chris Keener, Valdosta; 7/11- Hardee looking ahead- Jodi M. Scott; 7/11- Hardee (from page 1-A and 2-A)- Jodi M. Scott; 7/11-Twin Lakes VFD- Shelby G. Spires; 7/12- Parent’s mad over math test with drug, murder questions- Associated Press; 7/13- There is hope for city school system- Ernest and Gwendolyn Robinson, Hermitage TN; 7/14- The betrayal of Supreme Court Justice Thurgood Marshall- Nat Hentoff; 7/14- Teachers respond to federal review- Pamala J. Williams; 7/14- School board got no mandate to restructure- Jacqueline Clark, Valdosta; 7/14- Parents important to students’ success- Pamala J. Williams; 7/15- BOE (from page 1-A)- no author; 7/15- Segregation in integrated public schools?- Kirk Johnson Jr., Valdosta; 7/15- Speakers question BOE policies- Pamala J. Williams; 7/22- Transcripts from investigation read in BOE closed-door session- Pamala J. Williams; 7/22- BOE- Pamala J. Williams
- …
