Matching Items (60)
Description
Eigenvalues of the 3D critical point equation (∇u)ν = λν are normally computed numerically. In the letter, we present analytic solutions for 3D swirling strength in both compressible and incompressible flows. The solutions expose functional dependencies that cannot be seen in numerical solutions. To illustrate, we study the difference between using fluctuating and total velocity gradient tensors for vortex identification. Results show that mean shear influences vortex detection and that distortion can occur, depending on the strength of mean shear relative to the vorticity at the vortex center.
ContributorsChen, Huai (Author) / Adrian, Ronald (Author) / Zhong, Qiang (Author) / Wang, Xingkui (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-08-01
Description
The flexural behavior of epoxies was investigated by performing mechanical tests and applying statistical Weibull theory and analytical methods to the results. The effects of loading systems and environmental conditions were also considered. Three kinds of epoxies were studied: Epon E863, PRI 2002, and PR520. In total, 53 three-point-bending (3PB) Epon E863 samples and 26 3PB PR520 were tested immediately after curing, together with 26 four-point-bending (4PB) PRI2002 samples stored at 60°C and 90% Rh for 48 weeks. The Weibull parameters were estimated using both linear regression and the moments method. The statistical character of the Weibull model leads to uncertainty in the evaluated parameters, even for a large number of experiments. This study analyzed the ratio of flexural strength to tensile strength in bulk epoxy resin polymers. An analytical method previously developed by the authors to study the relationship between uniaxial tension/compression stress-strain curves and flexural load-deflection response was used to obtain the ratio. The results show that the Weibull model overpredicted the aforementioned ratio in different load arrangements.
ContributorsYekani Fard, Masoud (Author) / Raji, B. (Author) / Chattopadhyay, Aditi (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-12-01
Description
Identification of early damage in polymer composites is of great importance. We have incorporated cyclobutane-containing cross-linked polymers into an epoxy matrix, studied the effect on thermal and mechanical properties, and, more importantly, demonstrated early damage detection through mechanically induced fluorescence generation. Two cinnamate derivatives, 1,1,1-tris(cinnamoyloxymethyl) ethane (TCE) and poly(vinyl cinnamate) (PVCi), were photoirradiated to produce cyclobutane-containing polymer. The effects on the thermal and mechanical properties with the addition of cyclobutane-containing polymer into epoxy matrix were investigated. The emergence of cracks was detected by fluorescence at a strain level just beyond the yield point of the polymer blends, and the fluorescence intensified with accumulation of strain. Overall, the results show that damage can be detected through fluorescence generation along crack propagation.
ContributorsZou, Jin (Author) / Liu, Yingtao (Author) / Shan, Bohan (Author) / Chattopadhyay, Aditi (Author) / Dai, Lenore (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-09-01
Description
Fashion is an inherently political and reflective medium for the daily ramblings and revolutions of a society. Much of the time the influence is subtle. Silhouettes and fabrics reflect different stances on conservatism, on sex, on the degrees to which we fetishize luxury, and on infinite other attitudes of an era. Other times the influence is extremely direct, with text printed on the clothing that explicitly articulates a current societal dynamic. I began exploring fashion in 2016, as the country had reached an unprecedented and linguistically weaponized divide.
While taking a fashion technology course under the instruction of Galina Mihaleva, I developed a tracksuit incorporating concealed LED displays that are capable of scrolling customizable text on the sides of the garment. I expanded on this futuristic execution of politically charged clothes by utilizing a more realistic application of the LED technology in the Bouis Vuitton project. This project is a collection of six white vinyl bags with semi-flexible LED displays projecting revolutionary slogans through the vinyl textile.
The bags act as an appropriate housing for technology that is intended for significantly longer use, as bags have a longer lifespan in wardrobes than clothes and return to trend more frequently. The production investment in the technology is more equitable to the investment in the production of a bag and facilitates the wearer’s broadcasting of concise messages. The result is a collection of functional, utilitarian pieces with a clean, futuristic look and a mixed modern and vintage silhouette scrolling pro-revolutionary messages.
Broadcasting the knock-off name ‘BOUIS VUITTON’, I’ve inserted only my first initial into the reputable luxury company and paired it with slogans: ‘EAT THE RICH’ and ‘HEADS WILL ROLL’. The collection articulates a sense of nihilism felt by the youngest generations growing up on the outside of a very exclusive economic and political sphere. Three upcycled vintage luggage pieces evoke associations with the white American upper-class society of the 1960s. The luggage pieces were retrofitted in white vinyl and white-enameled metal fixtures. Three additional soft bags made of the same material reflect a utilitarian style of functional bags on trend with Spring/Summer 2019 streetwear. For the runway presentation of the bags, the models are dressed in navy-colored Dickies boiler suits, white retro-style Fila sneakers, and white ascots reminiscent of the historical male ruffled cravat. The contradictions of iconic silhouettes from both upper and lower-class American fashion history further the juxtaposition of anti-capitalist slogans posted on luxury goods.
Bouis Vuitton: Bags for the Revolution is intended to embody an unapologetic disregard for established wealth and political power in the most public of venues: the sidewalk, the mall, the high and the low-income neighborhoods – wherever people are wearing clothes. Fashion is the modern protest that requires no permit, and the new poster is a luxury bag.
While taking a fashion technology course under the instruction of Galina Mihaleva, I developed a tracksuit incorporating concealed LED displays that are capable of scrolling customizable text on the sides of the garment. I expanded on this futuristic execution of politically charged clothes by utilizing a more realistic application of the LED technology in the Bouis Vuitton project. This project is a collection of six white vinyl bags with semi-flexible LED displays projecting revolutionary slogans through the vinyl textile.
The bags act as an appropriate housing for technology that is intended for significantly longer use, as bags have a longer lifespan in wardrobes than clothes and return to trend more frequently. The production investment in the technology is more equitable to the investment in the production of a bag and facilitates the wearer’s broadcasting of concise messages. The result is a collection of functional, utilitarian pieces with a clean, futuristic look and a mixed modern and vintage silhouette scrolling pro-revolutionary messages.
Broadcasting the knock-off name ‘BOUIS VUITTON’, I’ve inserted only my first initial into the reputable luxury company and paired it with slogans: ‘EAT THE RICH’ and ‘HEADS WILL ROLL’. The collection articulates a sense of nihilism felt by the youngest generations growing up on the outside of a very exclusive economic and political sphere. Three upcycled vintage luggage pieces evoke associations with the white American upper-class society of the 1960s. The luggage pieces were retrofitted in white vinyl and white-enameled metal fixtures. Three additional soft bags made of the same material reflect a utilitarian style of functional bags on trend with Spring/Summer 2019 streetwear. For the runway presentation of the bags, the models are dressed in navy-colored Dickies boiler suits, white retro-style Fila sneakers, and white ascots reminiscent of the historical male ruffled cravat. The contradictions of iconic silhouettes from both upper and lower-class American fashion history further the juxtaposition of anti-capitalist slogans posted on luxury goods.
Bouis Vuitton: Bags for the Revolution is intended to embody an unapologetic disregard for established wealth and political power in the most public of venues: the sidewalk, the mall, the high and the low-income neighborhoods – wherever people are wearing clothes. Fashion is the modern protest that requires no permit, and the new poster is a luxury bag.
ContributorsViton, Benjamin Douglas (Author) / Sewell, Dennita (Thesis director) / Mihaleva, Galina (Committee member) / School of Art (Contributor) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
How does the idea of the visible and invisible, tangible and intangible, interact with the garments on the body? Perception, to become aware through the sense, involves the way in which the eye sees space, both visible and invisible. The way in which we see objects are significant in our everyday life and how we evaluate it. The main pattern the garments encompass are the accordion pleating and the variety in which the pattern can be utilized; the accordion pleating can be scaled, attached together, and twisted around the body. Effervescence is a 6-look collection that entails the idea of perception. The results of the project include 3 completed looks, 3 3D print on fabric, and 8 3D print accessories. In this paper, I will explain the process of creating the collection, the experimentation, and the results.
ContributorsNguyen, Juliana (Author) / Mihaleva, Galina (Thesis director) / Stephenson, Kathy (Committee member) / Tevzadze, Irina (Committee member) / Barrett, The Honors College (Contributor) / School of Art (Contributor)
Created2022-05
Description
The Smoothened receptor (SMO) belongs to the Class Frizzled of the G protein-coupled receptor (GPCR) superfamily, constituting a key component of the Hedgehog signalling pathway. Here we report the crystal structure of the multi-domain human SMO, bound and stabilized by a designed tool ligand TC114, using an X-ray free-electron laser source at 2.9 Å. The structure reveals a precise arrangement of three distinct domains: a seven-transmembrane helices domain (TMD), a hinge domain (HD) and an intact extracellular cysteine-rich domain (CRD). This architecture enables allosteric interactions between the domains that are important for ligand recognition and receptor activation. By combining the structural data, molecular dynamics simulation, and hydrogen-deuterium-exchange analysis, we demonstrate that transmembrane helix VI, extracellular loop 3 and the HD play a central role in transmitting the signal employing a unique GPCR activation mechanism, distinct from other multi-domain GPCRs.
ContributorsZhang, Xianjun (Author) / Zhao, Fei (Author) / Wu, Yiran (Author) / Yang, Jun (Author) / Han, Gye Won (Author) / Zhao, Suwen (Author) / Ishchenko, Andrii (Author) / Ye, Lintao (Author) / Lin, Xi (Author) / Ding, Kang (Author) / Dharmarajan, Venkatasubramaniam (Author) / Griffin, Patrick R. (Author) / Gati, Cornelius (Author) / Nelson, Garrett (Author) / Hunter, Mark S. (Author) / Hanson, Michael A. (Author) / Cherezov, Vadim (Author) / Stevens, Raymond C. (Author) / Tan, Wenfu (Author) / Tao, Houchao (Author) / Xu, Fei (Author) / College of Liberal Arts and Sciences (Contributor)
Created2017-05-17
Description
Crystal structure determination of biological macromolecules using the novel technique of serial femtosecond crystallography (SFX) is severely limited by the scarcity of X-ray free-electron laser (XFEL) sources. However, recent and future upgrades render microfocus beamlines at synchrotron-radiation sources suitable for room-temperature serial crystallography data collection also. Owing to the longer exposure times that are needed at synchrotrons, serial data collection is termed serial millisecond crystallography (SMX). As a result, the number of SMX experiments is growing rapidly, with a dozen experiments reported so far. Here, the first high-viscosity injector-based SMX experiments carried out at a US synchrotron source, the Advanced Photon Source (APS), are reported. Microcrystals (5–20 µm) of a wide variety of proteins, including lysozyme, thaumatin, phycocyanin, the human A[subscript 2A] adenosine receptor (A[subscript 2A]AR), the soluble fragment of the membrane lipoprotein Flpp3 and proteinase K, were screened. Crystals suspended in lipidic cubic phase (LCP) or a high-molecular-weight poly(ethylene oxide) (PEO; molecular weight 8 000 000) were delivered to the beam using a high-viscosity injector. In-house data-reduction (hit-finding) software developed at APS as well as the SFX data-reduction and analysis software suites Cheetah and CrystFEL enabled efficient on-site SMX data monitoring, reduction and processing. Complete data sets were collected for A[subscript 2A]AR, phycocyanin, Flpp3, proteinase K and lysozyme, and the structures of A[subscript 2A]AR, phycocyanin, proteinase K and lysozyme were determined at 3.2, 3.1, 2.65 and 2.05 Å resolution, respectively. The data demonstrate the feasibility of serial millisecond crystallography from 5–20 µm crystals using a high-viscosity injector at APS. The resolution of the crystal structures obtained in this study was dictated by the current flux density and crystal size, but upcoming developments in beamline optics and the planned APS-U upgrade will increase the intensity by two orders of magnitude. These developments will enable structure determination from smaller and/or weakly diffracting microcrystals.
ContributorsMartin Garcia, Jose Manuel (Author) / Conrad, Chelsie (Author) / Nelson, Garrett (Author) / Stander, Natasha (Author) / Zatsepin, Nadia (Author) / Zook, James (Author) / Zhu, Lan (Author) / Geiger, James (Author) / Chun, Eugene (Author) / Kissick, David (Author) / Hilgart, Mark C. (Author) / Ogata, Craig (Author) / Ishchenko, Andrii (Author) / Nagaratnam, Nirupa (Author) / Roy Chowdhury, Shatabdi (Author) / Coe, Jesse (Author) / Subramanian, Ganesh (Author) / Schaffer, Alexander (Author) / James, Daniel (Author) / Ketwala, Gihan (Author) / Venugopalan, Nagarajan (Author) / Xu, Shenglan (Author) / Corcoran, Stephen (Author) / Ferguson, Dale (Author) / Weierstall, Uwe (Author) / Spence, John (Author) / Cherezov, Vadim (Author) / Fromme, Petra (Author) / Fischetti, Robert F. (Author) / Liu, Wei (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2017-05-24
Description
The advent and application of the X-ray free-electron laser (XFEL) has uncovered the structures of proteins that could not previously be solved using traditional crystallography. While this new technology is powerful, optimization of the process is still needed to improve data quality and analysis efficiency. One area is sample heterogeneity, where variations in crystal size (among other factors) lead to the requirement of large data sets (and thus 10–100 mg of protein) for determining accurate structure factors. To decrease sample dispersity, we developed a high-throughput microfluidic sorter operating on the principle of dielectrophoresis, whereby polydisperse particles can be transported into various fluid streams for size fractionation. Using this microsorter, we isolated several milliliters of photosystem I nanocrystal fractions ranging from 200 to 600 nm in size as characterized by dynamic light scattering, nanoparticle tracking, and electron microscopy. Sorted nanocrystals were delivered in a liquid jet via the gas dynamic virtual nozzle into the path of the XFEL at the Linac Coherent Light Source. We obtained diffraction to ∼4 Å resolution, indicating that the small crystals were not damaged by the sorting process. We also observed the shape transforms of photosystem I nanocrystals, demonstrating that our device can optimize data collection for the shape transform-based phasing method. Using simulations, we show that narrow crystal size distributions can significantly improve merged data quality in serial crystallography. From this proof-of-concept work, we expect that the automated size-sorting of protein crystals will become an important step for sample production by reducing the amount of protein needed for a high quality final structure and the development of novel phasing methods that exploit inter-Bragg reflection intensities or use variations in beam intensity for radiation damage-induced phasing. This method will also permit an analysis of the dependence of crystal quality on crystal size.
ContributorsAbdallah, Bahige (Author) / Zatsepin, Nadia (Author) / Roy Chowdhury, Shatabdi (Author) / Coe, Jesse (Author) / Conrad, Chelsie (Author) / Dorner, Katerina (Author) / Sierra, Raymond G. (Author) / Stevenson, Hilary P. (Author) / Camacho Alanis, Fernanda (Author) / Grant, Thomas D. (Author) / Nelson, Garrett (Author) / James, Daniel (Author) / Calero, Guillermo (Author) / Wachter, Rebekka (Author) / Spence, John (Author) / Weierstall, Uwe (Author) / Fromme, Petra (Author) / Ros, Alexandra (Author) / Department of Chemistry and Biochemistry (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2015-08-19
Description
We studied left ventricular flow patterns for a range of rotational orientations of a bileaflet mechanical heart valve (MHV) implanted in the mitral position of an elastic model of a beating left ventricle (LV). The valve was rotated through 3 angular positions (0, 45, and 90 degrees) about the LV long axis. Ultrasound scans of the elastic LV were obtained in four apical 2-dimensional (2D) imaging projections, each with 45 degrees of separation. Particle imaging velocimetry was performed during the diastolic period to quantify the in-plane velocity field obtained by computer tracking of diluted microbubbles in the acquired ultrasound projections. The resulting velocity field, vorticity, and shear stresses were statistically significantly altered by angular positioning of the mechanical valve, although the results did not show any specific trend with the valve angular position and were highly dependent on the orientation of the imaging plane with respect to the valve. We conclude that bileaflet MHV orientation influences hemodynamics of LV filling. However, determination of ‘optimal’ valve orientation cannot be made without measurement techniques that account for the highly 3-dimensional (3D) intraventricular flow.
ContributorsWesterdale, John (Author) / Adrian, Ronald (Author) / Squires, Kyle (Author) / Chaliki, Hari (Author) / Belohlavek, Marek (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2015-06-26
Description
Serial femtosecond crystallography (SFX) takes advantage of extremely bright and ultrashort pulses produced by x-ray free-electron lasers (XFELs), allowing for the collection of high-resolution diffraction intensities from micrometer-sized crystals at room temperature with minimal radiation damage, using the principle of “diffraction-before-destruction.” However, de novo structure factor phase determination using XFELs has been difficult so far. We demonstrate the ability to solve the crystallographic phase problem for SFX data collected with an XFEL using the anomalous signal from native sulfur atoms, leading to a bias-free room temperature structure of the human A[subscript 2A] adenosine receptor at 1.9 Å resolution. The advancement was made possible by recent improvements in SFX data analysis and the design of injectors and delivery media for streaming hydrated microcrystals. This general method should accelerate structural studies of novel difficult-to-crystallize macromolecules and their complexes.
ContributorsBatyuk, Alexander (Author) / Galli, Lorenzo (Author) / Ishchenko, Andrii (Author) / Han, Gye Won (Author) / Gati, Cornelius (Author) / Popov, Petr A. (Author) / Lee, Ming-Yue (Author) / Stauch, Benjamin (Author) / White, Thomas A. (Author) / Barty, Anton (Author) / Aquila, Andrew (Author) / Hunter, Mark S. (Author) / Liang, Mengning (Author) / Boutet, Sebastien (Author) / Pu, Mengchen (Author) / Liu, Zhi-jie (Author) / Nelson, Garrett (Author) / James, Daniel (Author) / Li, Chufeng (Author) / Zhao, Yun (Author) / Spence, John (Author) / Liu, Wei (Author) / Fromme, Petra (Author) / Katritch, Vsevolod (Author) / Weierstall, Uwe (Author) / Stevens, Raymond C. (Author) / Cherezov, Vadim (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / School of Molecular Sciences (Contributor)
Created2016-09-23