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3. The Association of Urinary Sodium Excretion with Glaucoma and Related Traits in a Large United Kingdom Population

Author

Aschard, Hugues, Chia, Mark, Chua, Sharon, Do, Ron, Foster, Paul, Kang, Jae, Kastner, Alan, Khawaja, Anthony, Kim, Jihye, Lentjes, Marleen, Luben, Robert, Madjedi, Kian, Montesano, Giovanni, Pasquale, Louis, Stuart, Kelsey, Warwick, Alasdair, Wiggs, Janey, Allen, Naomi, Aslam, Tariq, Atan, Denize, Barman, Sarah, Barrett, Jenny, Bishop, Paul, Black, Graeme, Braithwaite, Tasanee, Carare, Roxana, Chakravarthy, Usha, Chan, Michelle, Day, Alexander, Desai, Parul, Dhillon, Bal, Dick, Andrew, Doney, Alexander, Egan, Cathy, Ennis, Sarah, Fruttiger, Marcus, Garway-Heath, David (Ted), Gibson, Jane, Guggenheim, Jeremy, Hammond, Chris, Hardcastle, Alison, Harding, Simon, Hogg, Ruth, Hysi, Pirro, Keane, Pearse, Khaw, Peng Tee, Lascaratos, Gerassimos, Littlejohns, Thomas, Lotery, Andrew, Luthert, Phil, MacGillivray, Tom, Mackie, Sarah, McGuinness, Bernadette, McKay, Gareth, McKibbin, Martin, Moore, Tony, Morgan, James, O'Sullivan, Eoin, Oram, Richard, Owen, Chris, Patel, Praveen, Paterson, Euan, Peto, Tunde, Petzold, Axel, Pontikos, Nikolas, Rahi, Jugnoo, Rudnicka, Alicja, Sattar, Naveed, Self, Jay, Sergouniotis, Panagiotis, Sivaprasad, Sobha, Steel, David, Stratton, Irene, Strouthidis, Nicholas, Sudlow, Cathie, Sun, Zihan, Tapp, Robyn, Thomas, Dhanes, Trucco, Emanuele, Tufail, Adnan, Viswanathan, Ananth, Vitart, Veronique, Weedon, Mike, Williams, Katie, Williams, Cathy, Woodside, Jayne, Yates, Max, Yip, Jennifer, Zheng, Yalin, Aung, Tin, Burdon, Kathryn, Chen, Li, Cheng, Ching-Yu, Craig, Jamie, Cree, Angela, de Vries, Victor, Driessen, Sjoerd, Fingert, John, Gharahkhani, Puya, Hammond, Christopher, Hayward, Caroline, Hewitt, Alex, Jansonius, Nomdo, Jonansson, Fridbert, Jonas, Jost, Kass, Michael, Khor, Chiea, Klaver, Caroline, Koh, Jacyline, MacGregor, Stuart, Mackey, David, Mitchell, Paul, Pang, Calvin, Pasutto, Francesca, Pfeiffer, Norbert, Polašek, Ozren, Ramdas, Wishal, Schuster, Alexander, Segrè, Ayellet, Stefansson, Einer, Stefánsson, Kári, Thorleifsson, Gudmar, Thorsteinsdottir, Unnur, van Duijn, Cornelia, Vergroesen, Joëlle, Vithana, Eranga, Wilson, James, Wojciechowski, Robert, Wong, Tien, Young, Terri, Stuart, Kelsey V., Biradar, Mahantesh I., Luben, Robert N., Dhaun, Neeraj, Wagner, Siegfried K., Warwick, Alasdair N., Madjedi, Kian M., Pasquale, Louis R., Wiggs, Janey L., Kang, Jae H., Lentjes, Marleen A.H., Foster, Paul J., and Khawaja, Anthony P.

Published
2024
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4. Periodontitis and Outer Retinal Thickness: a Cross-Sectional Analysis of the United Kingdom Biobank Cohort

Author

Allen, Naomi, Aslam, Tariq, Atan, Denize, Balaskas, Konsantinos, Barman, Sarah A., Barrett, Jenny H., Bishop, Paul, Black, Graeme, Braithwaite, Tasanee, Carare, Roxana O., Chakravarthy, Usha, Chan, Michelle, Chua, Sharon Y.L., Day, Alexander, Desai, Parul, Dhillon, Bal, Dick, Andrew D., Doney, Alexander, Egan, Cathy, Ennis, Sarah, Foster, Paul, Fruttiger, Marcus, Gallacher, John E.J., Garway-Heath, David F., Gibson, Jane, Guggenheim, Jeremy A., Hammond, Chris J., Hardcastle, Alison, Harding, Simon P., Hogg, Ruth E., Hysi, Pirro, Keane, Pearse A., Khaw, Sir Peng T., Khawaja, Anthony P., Lascaratos, Gerassimos, Littlejohns, Thoams, Lotery, Andrew J., Luben, Robert, Luthert, Phil, Macgillivray, Tom, Mackie, Sarah, McGuinness, Bernadette, McKay, Gareth J., McKibbin, Martin, Moore, Tony, Morgan, James E., O’Sullivan, Eoin, Oram, Richard, Owen, Chris G., Patel, Praveen, Paterson, Euan, Peto, Tunde, Petzold, Axel, Rahi, Jugnoo S., Rudnikca, Alicja R., Sattar, Naveed, Self, Jay, Sergouniotis, Panagiotis, Sivaprasad, Sobha, Steel, David, Stratton, Irene, Strouthidis, Nicholas, Sudlow, Cathie, Sun, Zihan, Tapp, Robyn, Thomas, Dhanes, Trucco, Emanuele, Tufail, Adnan, Vitart, Veronique, Viswanathan, Ananth C., Weedon, Mike, Williams, Cathy, Williams, Katie, Woodside, Jayne V., Yates, Max M., Yip, Jennifer, Zheng, Yalin, Wagner, Siegfried K., Patel, Praveen J., Huemer, Josef, Khalid, Hagar, Stuart, Kelsey V., Chu, Colin J., Williamson, Dominic J., Struyven, Robbert R., Romero-Bascones, David, Foster, Paul J., Balaskas, Konstantinos, Cortina-Borja, Mario, Chapple, Iain, Dietrich, Thomas, and Denniston, Alastair K.

Published
2024
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7. Associations between unilateral amblyopia in childhood and cardiometabolic disorders in adult life: a cross-sectional and longitudinal analysis of the UK Biobank

Author

Allen, Naomi, Aslam, Tariq, Atan, Denize, Balaskas, Konstantinos, Barman, Sarah, Barrett, Jenny, Bishop, Paul, Black, Graeme, Braithwaite, Tasanee, Carare, Roxana, Chakravarthy, Usha, Chan, Michelle, Chua, Sharon, Day, Alexander, Desai, Parul, Dhillon, Bal, Dick, Andrew, Doney, Alexander, Egan, Cathy, Ennis, Sarah, Foster, Paul, Fruttiger, Marcus, Gallacher, John, Garway-heath, David (Ted), Gibson, Jane, Guggenheim, Jeremy, Hammond, Chris, Hardcastle, Alison, Harding, Simon, Hogg, Ruth, Hysi, Pirro, Keane, Pearse, Tee Khaw, Sir Peng, Khawaja, Anthony, Lascaratos, Gerassimos, Littlejohns, Thomas, Lotery, Andrew, Luben, Robert, Luthert, Phil, Macgillivray, Tom, Mackie, Sarah, Madhusudhan, Savita, Mcguinness, Bernadette, Mckay, Gareth, Mckibbin, Martin, Moore, Tony, Morgan, James, O'sullivan, Eoin, Oram, Richard, Owen, Chris, Patel, Praveen, Paterson, Euan, Peto, Tunde, Petzold, Axel, Pontikos, Nikolas, Rahi, Jugnoo, Rudnicka, Alicja, Sattar, Naveed, Self, Jay, Sergouniotis, Panagiotis, Sivaprasad, Sobha, Steel, David, Stratton, Irene, Strouthidis, Nicholas, Sudlow, Cathie, Sun, Zihan, Tapp, Robyn, Thomas, Dhanes, Trucco, Emanuele, Tufail, Adnan, Viswanathan, Ananth, Vitart, Veronique, Weedon, Mike, Williams, Katie, Williams, Cathy, Woodside, Jayne, Yates, Max, Zheng, Yalin, Thomas, Mervyn, Wagner, Siegfried Karl, Bountziouka, Vasiliki, and Rahi, Jugnoo Sangeeta

Published
2024
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13. The Association of Alcohol Consumption with Glaucoma and Related Traits: Findings from the UK Biobank

Author

Aschard, Hugues, Chia, Mark, Chua, Sharon, Do, Ron, Foster, Paul, Kang, Jae, Kastner, Alan, Khawaja, Anthony, Kim, Jihye, Lentjes, Marleen, Luben, Robert, Madjedi, Kian, Montesano, Giovanni, Pasquale, Louis, Stuart, Kelsey, Warwick, Alasdair, Wiggs, Janey, Allen, Naomi, Aslam, Tariq, Atan, Denize, Barman, Sarah, Barrett, Jenny, Bishop, Paul, Black, Graeme, Braithwaite, Tasanee, Carare, Roxana, Chakravarthy, Usha, Chan, Michelle, Day, Alexander, Desai, Parul, Dhillon, Bal, Dick, Andrew, Doney, Alexander, Egan, Cathy, Ennis, Sarah, Fruttiger, Marcus, Gallacher, John, Garway-Heath, David (Ted), Gibson, Jane, Guggenheim, Jeremy, Hammond, Chris, Hardcastle, Alison, Harding, Simon, Hogg, Ruth, Hysi, Pirro, Keane, Pearse, Khaw, Peng Tee, Lascaratos, Gerassimos, Littlejohns, Thomas, Lotery, Andrew, Luthert, Phil, MacGillivray, Tom, Mackie, Sarah, McGuinness, Bernadette, McKay, Gareth, McKibbin, Martin, Moore, Tony, Morgan, James, O'Sullivan, Eoin, Oram, Richard, Owen, Chris, Patel, Praveen, Paterson, Euan, Peto, Tunde, Petzold, Axel, Pontikos, Nikolas, Rahi, Jugnoo, Rudnicka, Alicja, Sattar, Naveed, Self, Jay, Sergouniotis, Panagiotis, Sivaprasad, Sobha, Steel, David, Stratton, Irene, Strouthidis, Nicholas, Sudlow, Cathie, Sun, Zihan, Tapp, Robyn, Thomas, Dhanes, Trucco, Emanuele, Tufail, Adnan, Viswanathan, Ananth, Vitart, Veronique, Weedon, Mike, Williams, Katie, Williams, Cathy, Woodside, Jayne, Yates, Max, Yip, Jennifer, Zheng, Yalin, Aung, Tin, Burdon, Kathryn, Chen, Li, Cheng, Ching-Yu, Craig, Jamie, Cree, Angela, de Vries, Victor, Driessen, Sjoerd, Fingert, John, Gharahkhani, Puya, Hammond, Christopher, Hayward, Caroline, Hewitt, Alex, Jansonius, Nomdo, Jonansson, Fridbert, Jonas, Jost, Kass, Michael, Khor, Chiea, Klaver, Caroline, Koh, Jacyline, MacGregor, Stuart, Mackey, David, Mitchell, Paul, Pang, Calvin, Pasutto, Francesca, Pfeiffer, Norbert, Polašek, Ozren, Ramdas, Wishal, Schuster, Alexander, Segrè, Ayellet, Stefansson, Einer, Stefánsson, Kári, Thorleifsson, Gudmar, Thorsteinsdottir, Unnur, van Duijn, Cornelia, Vergroesen, Joëlle, Vithana, Eranga, Wilson, James, Wojciechowski, Robert, Wong, Tien, Young, Terri, Stuart, Kelsey V., Luben, Robert N., Warwick, Alasdair N., Madjedi, Kian M., Patel, Praveen J., Biradar, Mahantesh I., Chia, Mark A., Pasquale, Louis R., Wiggs, Janey L., Kang, Jae H., Tran, Jessica H., Lentjes, Marleen A.H., Foster, Paul J., and Khawaja, Anthony P.

Published
2023
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14. A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

Author

Bailey-Wilson, Joan E., Baird, Paul N., Barathi, Veluchamy A., Biino, Ginevra, Burdon, Kathryn P., Campbell, Harry, Chen, Li Jia, Cheng, Ching-Yu, Chew, Emily Y., Craig, Jamie E., Deangelis, Margaret M., Delcourt, Cécile, Ding, Xiaohu, Fan, Qiao, Fossarello, Maurizio, Foster, Paul J., Gharahkhani, Puya, Guggenheim, Jeremy A., Guo, Xiaobo, Haarman, Annechien E.G., Haller, Toomas, Hammond, Christopher J., Han, Xikun, Hayward, Caroline, He, Mingguang, Hewitt, Alex W., Hoang, Quan, Hysi, Pirro G., Iglesias, Adriana I., Igo, Robert P., Iyengar, Sudha K., Jonas, Jost B., Kähönen, Mika, Kaprio, Jaakko, Khawaja, Anthony P., Klein, Barbara E., Lass, Jonathan H., Lee, Kris, Lehtimäki, Terho, Lewis, Deyana, Li, Qing, Li, Shi-Ming, Lyytikäinen, Leo-Pekka, MacGregor, Stuart, Mackey, David A., Martin, Nicholas G., Meguro, Akira, Metspalu, Andres, Middlebrooks, Candace, Miyake, Masahiro, Mizuki, Nobuhisa, Musolf, Anthony, Nickels, Stefan, Oexle, Konrad, Pang, Chi Pui, Pärssinen, Olavi, Paterson, Andrew D., Pfeiffer, Norbert, Polasek, Ozren, Rahi, Jugnoo S., Raitakari, Olli, Rudan, Igor, Sahebjada, Srujana, Saw, Seang-Mei, Simpson, Claire L., Stambolian, Dwight, Tai, E-Shyong, Tedja, Milly S., Tideman, J. Willem L., Tsujikawa, Akitaka, van Duijn, Cornelia M., Verhoeven, Virginie J.M., Vitart, Veronique, Wang, Ningli, Wang, Ya Xing, Wedenoja, Juho, Wei, Wen Bin, Williams, Cathy, Williams, Katie M., Wilson, James F., Wojciechowski, Robert, Yam, Jason C.S., Yamashiro, Kenji, Yap, Maurice K.H., Yazar, Seyhan, Yip, Shea Ping, Young, Terri L., Zhou, Xiangtian, Allen, Naomi, Aslam, Tariq, Atan, Denize, Barman, Sarah, Barrett, Jenny, Bishop, Paul, Black, Graeme, Bunce, Catey, Carare, Roxana, Chakravarthy, Usha, Chan, Michelle, Chua, Sharon, Cipriani, Valentina, Day, Alexander, Desai, Parul, Dhillon, Bal, Dick, Andrew, Doney, Alexander, Egan, Cathy, Ennis, Sarah, Foster, Paul, Fruttiger, Marcus, Gallacher, John, Garway-Heath, David, Gibson, Jane, Gore, Dan, Guggenheim, Jeremy, Hammond, Chris, Hardcastle, Alison, Harding, Simon, Hogg, Ruth, Hysi, Pirro, Keane, Pearse A., Khaw, Peng Tee, Khawaja, Anthony, Lascaratos, Gerassimos, Littlejohns, Thomas, Lotery, Andrew, Luthert, Phil, MacGillivray, Tom, Mackie, Sarah, McGuinness, Bernadette, McKay, Gareth, McKibbin, Martin, Mitry, Danny, Moore, Tony, Morgan, James, Muthy, Zaynah, O'Sullivan, Eoin, Owen, Chris, Patel, Praveen, Paterson, Euan, Peto, Tunde, Petzold, Axel, Pontikos, Nikolas, Rahi, Jugnoo, Rudnicka, Alicja, Self, Jay, Sergouniotis, Panagiotis, Sivaprasad, Sobha, Steel, David, Stratton, Irene, Strouthidis, Nicholas, Sudlow, Cathie, Tapp, Robyn, Thaung, Caroline, Thomas, Dhanes, Trucco, Emanuele, Tufail, Adnan, Vernon, Stephen, Viswanathan, Ananth, Williams, Katie, Woodside, Jayne, Yates, Max, Yip, Jennifer, Zheng, Yalin, Clark, Rosie, Lee, Samantha Sze-Yee, Du, Ran, Wang, Yining, Kneepkens, Sander C.M., Charng, Jason, Huang, Yu, Hunter, Michael L., Jiang, Chen, Tideman, J.Willem L., Melles, Ronald B., Klaver, Caroline C.W., Choquet, Hélène, and Ohno-Matsui, Kyoko

Published
2023
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15. Quantitative x ray phase contrast imaging of oblique shock wave–interface interactions.

Author

Leong, Andrew F. T., Romick, Christopher M., Bolme, Cynthia A., Aslam, Tariq D., Sinclair, Nicholas W., Kozlowski, Pawel M., Montgomery, David S., and Ramos, Kyle J.

Subjects
X-rays, SHOCK waves, PROBABILITY density function, SHOCK tubes, VISIBLE spectra, HOUGH transforms
Abstract

Oblique shock wave–interface interactions of gases and liquids have been extensively studied in shock tubes using optical methods to measure equation-of-state (EOS) parameters. However, this is difficult with solids due to their opaqueness to visible light. X ray phase contrast imaging (XPCI) has the penetrative strength to probe solids while still being sensitive to mass density and enhancing the visibility of material boundaries. We investigate the accuracy and repeatability of measuring the mean value of the average mass density (areal density divided by thickness) over region S (B S) and flow deflection angle (θ) from XPCI images of a sample. To that end, a Hough transform-based method for measuring θ is developed. To measure B S , the XPCI image intensity probability density function (PDF) is modeled accounting for the spatial distribution of x ray energy, scintillator response, and pulse-to-pulse variation in the x ray intensity. In addition, a Monte Carlo-based algorithm for computing the B S PDF is developed. Both methods are validated on an impact-generated oblique shock wave interacting at a solid polymer-to-polymer interface. This is accomplished through a comparison to hydrodynamic simulations using well-established EOS. Under the modeling framework for the XPCI image intensity, B S is computed with an accuracy of < 0.1 % and precision of 3%–5%, while θ has an uncertainty of 0.2 ° , respectively. This shows that the XPCI-based model that is developed here could be an invaluable tool for high-fidelity testing of hydrodynamic models in shock polar configurations. [ABSTRACT FROM AUTHOR]

Published
2023
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16. Current status and practical considerations of artificial intelligence use in screening and diagnosing retinal diseases: Vision Academy retinal expert consensus

Author

Chou, Yu-Bai, Kale, Aditya U., Lanzetta, Paolo, Aslam, Tariq, Barratt, Jane, Danese, Carla, Eldem, Bora, Eter, Nicole, Gale, Richard, Korobelnik, Jean-François, Kozak, Igor, Li, Xiaorong, Li, Xiaoxin, Loewenstein, Anat, Ruamviboonsuk, Paisan, Sakamoto, Taiji, Ting, Daniel S.W., van Wijngaarden, Peter, Waldstein, Sebastian M., Wong, David, Wu, Lihteh, Zapata, Miguel A., and Zarranz-Ventura, Javier

Published
2023
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17. The impact of artificial intelligence on retinal disease management: Vision Academy retinal expert consensus

Author

Danese, Carla, Kale, Aditya U., Aslam, Tariq, Lanzetta, Paolo, Barratt, Jane, Chou, Yu-Bai, Eldem, Bora, Eter, Nicole, Gale, Richard, Korobelnik, Jean-François, Kozak, Igor, Li, Xiaorong, Li, Xiaoxin, Loewenstein, Anat, Ruamviboonsuk, Paisan, Sakamoto, Taiji, Ting, Daniel S.W., van Wijngaarden, Peter, Waldstein, Sebastian M., Wong, David, Wu, Lihteh, Zapata, Miguel A., and Zarranz-Ventura, Javier

Published
2023
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20. An analytic and complete equation of state for condensed phase materials.

Author

Lozano, Eduardo, Cawkwell, Marc J., and Aslam, Tariq D.

Subjects
CONDENSED matter, EQUATIONS of state, SPECIFIC heat capacity, MOLECULAR crystals, PENTAERYTHRITOL tetranitrate, ISENTROPIC compression, MOLECULAR dynamics, SPECIFIC heat
Abstract

Analytic equations of state (EOS) are intended to reproduce theoretical and experimental data in a single phase portion of the thermodynamic space. We devise a complete and thermodynamically consistent model with four distinct features: (1) a reference isotherm that remains thermodynamically stable, (2) a flexible specific heat model based on a fourth-order rational polynomial, (3) a Grüneisen parameter that depends on specific volume and temperature, and (4) pressure and internal energy functions that can be inverted analytically in temperature. The model aims to improve the accuracy of existing equations of state while remaining computationally efficient. To demonstrate its features, we include calibrations for single-crystal pentaerythritol tetranitrate (PETN), liquid nitromethane (NM), and hexagonal close-packed beryllium (Be) metal. The parameter optimization uses the specific heat capacity, Grüneisen parameter, and static compression curves obtained from density functional theory for the crystalline solids and molecular dynamics simulations for liquid NM. We also present a velocity autocorrelation function that yields accurate phonon densities of states for the EOS calibration from the molecular dynamics trajectories. Each of the three calibrations is constrained to enforce the ambient state from experimental measurements and validated against experimental Hugoniot data from multiple sources. We also include one-dimensional hydrodynamic simulations of the isentropic compression experiments for beryllium conducted at the Z facility. [ABSTRACT FROM AUTHOR]

Published
2023
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26. Flash x-ray radiography analysis of detonation wave propagation in additive-manufactured high explosives.

Author

Brown, Cameron B., Smilowitz, Laura B., Remelius, Dennis K., Schmalzer, Andrew M., Tappan, Bryce C., Aslam, Tariq D., Sridhar, Seetharaman, and Mueller, Alexander H.

Subjects
THEORY of wave motion, DETONATION waves, WAVE analysis, RADIOGRAPHY, EXPLOSIVES, WAVEGUIDES
Abstract

Recent research has demonstrated that additive manufacturing (AM) can be used to produce directionally sensitive high explosives (HEs), but detonation wave propagation in AM HEs with variable internal structure has not been studied. In this work, samples were printed using a 73 wt. % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine-based HE ink. Flash x-ray radiography imaging was used to observe density changes in two imaging planes of each sample during detonation, and high-speed imaging was used to calculate the detonation velocity at the HE surface. The detonation front initially appears to fail in internal channel regions of the HE, but late reactions occurred in two samples, which increased the material bulk density by 2.8%, possibly due to shock convergence phenomena. The calculated detonation wave pressure similarly increased, but the accuracy of the results is uncertain because of the deviation of the low bulk density printed samples from the cast charge principal isentrope. This work demonstrates that structure can be effectively utilized to guide detonation wave propagation through HE charges. [ABSTRACT FROM AUTHOR]

Published
2023
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28. Measuring quality of vision including negative dysphotopsia.

Author

Makhotkina, Natalia Y., Nijkamp, Marjan D., Berendschot, Tos T. J. M., van den Borne, Bart, Aelen‐van Kruchten, Moniek, van Vught, Luc, Beenakker, Jan‐Willem M., Krijgh, Edwin, Aslam, Tariq, Pesudovs, Konrad, and Nuijts, Rudy M. M. A.

Subjects
LITERATURE reviews, VISUAL acuity, PSYCHOMETRICS, ASYMPTOMATIC patients, CLASSICAL test theory, INTRAOCULAR lenses, SOFT contact lenses
Abstract

Purpose: To adapt the Quality of Vision Questionnaire (QoV) for measuring negative dysphotopsia and to validate the original and modified versions in the Dutch population. Methods: The QoV was translated into Dutch according to standardized methodology. Negative dysphotopsia items were constructed based on focus group interviews, literature review and clinical data. The questionnaire was completed by 404 subjects, including contact lens wearers, patients with cataract and after cataract surgery (95.5% with a monofocal, 4.5% with a multifocal intraocular lens). Rasch analysis was applied for evaluation of reliability and validity of the original QoV and modified version, Negative Dysphotopsia QoV (ND‐QoV). Results: The frequency, severity and bothersome scales of the QoV and ND‐QoV demonstrated good measurement precision, good fit statistics for all but one item, but significant mistargeting of more than one logit. Item estimations were stable across the study groups and scales were unidimensional with more than 50% of variance explained by the measurements. There was a positive correlation between questionnaire scores and best corrected visual acuity (r = 0.3, p < 0.01). The quality of vision measured by all three scales was significantly poorer (p < 0.01) in patients with negative dysphotopsia compared to asymptomatic pseudophakic patients. Conclusion: The Dutch version of the QoV questionnaire has shown good psychometric properties comparable to the native version as well as good reliability and validity. The addition of negative dysphotopsia items is a valuable modification for the reliable assessment of quality of vision in pseudophakic patients. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Modeling atomically mixed graded density impactors.

Author

Aslam, Tariq D., McBride, Michael A., Rai, Nirmal, Hooks, Daniel E., Stull, Jamie A., and Jensen, Brian J.

Subjects
*CASCADE impactors (Meteorological instruments), *MULTIPHASE flow, *TRAFFIC safety, *DENSITY, *TIME pressure, *FUNCTIONALLY gradient materials
Abstract

Graded density impactors (GDIs) are multi-material composite impactors used in gas gun experiments to tailor the drive conditions imparted to a sample test material. Previous graded density impactors generally rely on thin, but discrete, layers of different materials. The thinner and the greater number of layers will result in smoother compression. Taken to the limit of very thin layers would be pure material 1 at one surface, such as the front surface of an impactor, smoothly transitioning at the atomic scale to pure material 2 on the back surface. Such an impactor can initially shock, then smoothly compresses a material during a dynamic experiment. This type of experiment can serve to explore a larger region of thermodynamic space than a single or even multi-shock experiments. An overview of how graded density impactors are made is reviewed and sample results are given. A strategy for modeling these kinds of impactors is presented. The length scales of constituent mixing are given from the experimental build through electrochemical-deposition. Equation of state models for pure constituents and their subsequent mixtures are presented. It is demonstrated that the time scales for pressure and temperature equilibration, for atomically mixed GDIs, are short enough to be a justifiable closure for the resulting multiphase flow. Furthermore, we present simulation results of dynamic shock followed by a ramp compression, utilizing a silver/gold graded density impactor, onto a tantalum sample. [ABSTRACT FROM AUTHOR]

Published
2022
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34. Evaluation of thermodynamic closure models for partially reacted two-phase mixture of condensed phase explosives.

Author

Rai, Nirmal K. and Aslam, Tariq D.

Abstract

One of the key fundamental issues that is crucial in the continuum modeling of reactive flow phenomena is the thermodynamically consistent description of reaction mixture properties. To define the mixture properties, thermodynamic closure rules that relate the properties of the individual reaction components to the mixture properties are required. In the context of reactive two-phase modeling approaches, various strategies to define the thermodynamic closures have been adopted such as pressure temperature (PT) equilibrium between the individual reaction components, pressure (specific) volume (PV) equilibrium, etc. The choice of closure rules determines the relative distribution of specific volume and energy across the reaction components that comprise the mixture. Therefore, depending on the choice of the closure, the mixture thermodynamic behavior can vary. The present work examines the effect of different closure approaches on the thermodynamic properties of the reaction mixture. The analysis is performed for a condensed phase HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) based plastic bonded explosive (PBX) 9501 explosive using four different thermodynamic closures, viz., PT equilibrium, PV equilibrium, volume temperature (VT) equilibrium, and pressure (P) equilibrium with reactants on an isentrope. The relative variations in the thermodynamic properties of the mixture are analyzed and compared under both compression and expansion loading regimes. It is shown that out of the four closure models, only PT equilibrium and P equilibrium closures lead to a thermodynamically accurate description of the mixture under both compression and expansion. [ABSTRACT FROM AUTHOR]

Published
2022
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35. An exploration of novel applications and investigations at the interface of computing and ophthalmology

Author

Aslam, Tariq Mehmood, Dhillon, Baljean, and Aspinall, Peter

Subjects
617.7
Abstract

The aim of this thesis is to explore how modern computing technology can advance clinical ophthalmology. In particular it will investigate the potential for computer programming in developing measures for assessment of ophthalmic disease. Such measures could be used to advance clinical care or as research tools, providing objective outcomes to power more robust clinical trials. Key aspects of clinical ophthalmic assessment are measurement of visual function and observation of anatomical structures. To provide a full demonstration of the scope for computing this thesis will demonstrate innovative measures for both peripheral and central vision as well as image analysis algorithms applicable to structures from the anterior of the eye to the posterior. For peripheral vision testing we investigated a novel technique for assessment of young children using computer games to hold their attention. Our device demonstrated the potential for drastically improving compliance to obtain useful and accurate visual field results. For central vision assessment we developed a prototype visual function tester for patients with macular degeneration. Specifically we were able to demonstrate the feasibility of programming an iPad© such that patients with macular degeneration could perform and physically respond satisfactorily when self testing their vision. Combining advances in electronics and computing we present data to support the potential for using iris recognition cameras to image eyes of children with diseases that cause their corneas to become cloudy and lose transparency. We were subsequently able to apply our own algorithms to produce a score for the opacification of the cornea that would be useful in quantifying these diseases. Finally, with regard to image analysis applications, we describe the development and validation of algorithms for assessment of posterior capsule opacification (re-growth of cataract) and for haemorrhage assessment. All programming and scientific development was done by the author and this thesis therefore presents the potential for computer software development by an ophthalmologist as a model for the invention of new and novel measures at the interface of computing and ophthalmology.

Published
2012

38. A robust three-parameter reference curve for condensed phase materials.

Author

Lozano, Eduardo and Aslam, Tariq D.

Subjects
*CONDENSED matter, *BULK modulus, *ROOT-mean-squares, *EQUATIONS of state, *CURVES
Abstract

Many isothermal equations of state lead to numerical problems under tension conditions due to negative bulk modulus. We summarize the properties of four existing models and devise a continuous non-piecewise reference curve to address this issue. The final functional form contains three fitting parameters that are directly related to the bulk modulus and its pressure derivative at the reference state and at infinite pressures. We also include bounds that guarantee the monotonicity of its pressure derivative in all volume space. To demonstrate the qualitative features of each isotherm, we conduct calibrations against experimental data for cyclotetramethylene tetranitramine, magnesium oxide, gold, and platinum. Pressure residuals and root mean square deviations show that the proposed functional form is capable of adequately fitting the data compared to other three-parameter models. [ABSTRACT FROM AUTHOR]

Published
2022
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42. A reactive flow model for the 3,3′-diamino-4,4′-azoxyfurazan based plastic bonded explosive (PBX 9701).

Author

Price, Matthew A., Leiding, Jeffery A., Aslam, Tariq D., Coe, Joshua D., Ramos, Kyle J., Bolme, Cynthia A., Francois, Elizabeth G., Lichthardt, Joseph P., Bowden, Pat P., Thompson, Darla G., and Ticknor, Christopher

Subjects
REACTIVE flow, PLASTICS, MODEL validation, CALIBRATION, BIOCHEMICAL substrates, EQUATIONS of state
Abstract

This paper describes the calibration of the Arrhenius Wescott–Stewart–Davis (AWSD) reactive flow model for the recently developed high explosive PBX 9701, which consists of 97% 3, 3 ′ -diamino-4, 4 ′ -azoxyfurazan (DAAF) and 3% FK-800 binder by weight. DAAF-based explosive formulations have several desirable qualities as they are relatively insensitive to non-shock insults but have higher performance than triaminotrinitrobenzene based formulations. Equations of state for the explosive reactants and products are calibrated using a combination of existing and new experimental data and theoretical calculations. The AWSD rate law calibration utilizes both one-dimensional shock-to-detonation and multidimensional rate stick experiments to capture the shock initiation and propagating detonation regimes. Validation of the calibrated model is demonstrated through comparison with recent gas-gun experiments. [ABSTRACT FROM AUTHOR]

Published
2021
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43. Retinal Microvasculature Image Analysis Using Optical Coherence Tomography Angiography in Patients with Post-COVID-19 Syndrome.

Author

Noor, Maha, McGrath, Orlaith, Drira, Ines, and Aslam, Tariq

Subjects
OPTICAL coherence tomography, IMAGE analysis, RETINAL imaging, COVID-19 pandemic, ANGIOGRAPHY, SYNDROMES
Abstract

Several optical coherence tomography angiography (OCT-A) studies have demonstrated retinal microvascular changes in patients post-SARS-CoV-2 infection, reflecting retinal-systemic microvasculature homology. Post-COVID-19 syndrome (PCS) entails persistent symptoms following SARS-CoV-2 infection. In this study, we investigated the retinal microvasculature in PCS patients using OCT-angiography and analysed the macular retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness via spectral domain-OCT (SD-OCT). Conducted at the Manchester Royal Eye Hospital, UK, this cross-sectional study compared 40 PCS participants with 40 healthy controls, who underwent ophthalmic assessments, SD-OCT, and OCT-A imaging. OCT-A images from the superficial capillary plexus (SCP) were analysed using an in-house specialised software, OCT-A vascular image analysis (OCTAVIA), measuring the mean large vessel and capillary intensity, vessel density, ischaemia areas, and foveal avascular zone (FAZ) area and circularity. RNFL and GCL thickness was measured using the OCT machine's software. Retinal evaluations occurred at an average of 15.2 ± 6.9 months post SARS-CoV-2 infection in PCS participants. Our findings revealed no significant differences between the PCS and control groups in the OCT-A parameters or RNFL and GCL thicknesses, indicating that no long-term damage ensued in the vascular bed or retinal layers within our cohort, providing a degree of reassurance for PCS patients. [ABSTRACT FROM AUTHOR]

Published
2023
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44. Dynamic small resolved heat release model for programmed burn calculations.

Author

Lozano, Eduardo, Aslam, Tariq D., Culp, David B., and Price, Matthew A.

Subjects
*DETONATION waves, *EVOLUTION equations, *EQUATIONS of state, *CHEMICAL energy, *CURVATURE
Abstract

The disparity between the reaction and the engineering length scales in high-explosive (HE) systems motivates the use of programmed burn methods where the detonation wave is replaced with a surface and an evolution equation. When the normal detonation velocity differs from the nominal Chapman–Jouguet value (non-zero curvature), the local expansion isentrope of the HE detonation products must be mathematically consistent with the post-flow state to yield the correct detonation energy. The hydrodynamic step associated with the HE energy release is typically treated using a velocity-adjusted equation of state or a pseudo-reaction zone model. This paper describes a model where the bulk of the chemical energy is released instantaneously at the shock and the remainder is released at the finite rate dictated by a base reactive burn model. The implementation steps rely on existing code infrastructure and use the same parameter calibration as the base burn model. Two one-dimensional test cases are presented for a spherically diverging and a spherically converging detonation. The results show that the proposed methodology is able to capture the main flow features at coarse resolutions while retaining a strong hydrodynamic coupling. [ABSTRACT FROM AUTHOR]

Published
2023
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45. Examination of thermodynamic space for classes of experiments.

Author

Aslam, Tariq D. and Hill, Larry G.

Subjects
*REACTIVE flow, *ISOTHERMAL compression, *DETONATION waves, *ISENTROPIC compression, *DYNAMIC simulation, *BIOCHEMICAL substrates
Abstract

Understanding the path through thermodynamic space that a high explosive experiences during shock to detonation transition (SDT), detonation propagation and failure are important for understanding the roles of these experiments for reactive flow model calibration. SDT, steady detonation propagation, corner turning (ECOT), multi-shock, isothermal and isentropic compression, shock release and re-shock, GapStick and other experiments may "overlap" with respect to the thermodynamic states attained. The focus of this study is to explore a methodology to examine where the reactants equation of state are taken by experiments. To that end, clearly a complete reactive flow model is needed to faithfully ascertain the dynamics of each experiment. For this exploration, an Arrhenius-Wescott-Stewart-Davis (AWSD) model is utilized for dynamic simulations of the tri-amino-tri-nitro-benzene (TATB) based plastic bonded explosive PBX 9502. Here, only an example of SDT will be given, as it serves as a validation of the more general methodology. [ABSTRACT FROM AUTHOR]

Published
2023
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46. Uncertainty quantified reactant and product equation of state for Composition B.

Author

Jadrich, Ryan B., Lindquist, Beth A., Leiding, Jeffery A., and Aslam, Tariq D.

Subjects
BIOCHEMICAL substrates, PHYSICS
Abstract

Capturing the entirety of possible high explosive performance outcomes given limited calibration data necessitates a full uncertainty quantification study. This is in contrast to the historical approach of fitting or calibrating a single deterministic physics model–which can be very loosely interpreted as the most likely outcome. As a step in the direction for providing high explosive equations of state with rigorous uncertainty modeling, we demonstrate an uncertainty quantification framework in the context of the high explosive Composition B. Our focus in this study is on the combined reactant and product equation of state. [ABSTRACT FROM AUTHOR]

Published
2023
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47. Experimental and modelling study of the effect of pre-shock duration on the double shock initiation response of PBX 9501.

Author

Whitworth, Nicholas, Lang, John, Aslam, Tariq, Price, Matthew, and Henrick, Andrew

Subjects
EXPLOSIVES, VELOCITY
Abstract

A series of double shock initiation gas-gun experiments have been performed on PBX 9501 (95% weight HMX, 5% binder) in which the input conditions were nominally the same, but the time delay between the two shocks was explicitly varied. The impact conditions generated pre- and main shock pressures of 2.9 and 6.2 GPa respectively, with time delays between them ranging from 0.56 to 1.10 µs. This resulted in different levels of reaction behind the pre-shock prior to the main shock traversing the explosive samples, with the growth of reaction monitored using embedded particle velocity and shock tracker gauges. Simulated results from three reactive burn models (CREST, AWSD and SURF) are compared with the measured data to assess their ability to predict the response of PBX 9501 under such double shock conditions. The described experiments add to the body of evidence to help improve our understanding of the double shock initiation response of explosives, and the data obtained provide an excellent test for reactive burn models. [ABSTRACT FROM AUTHOR]

Published
2023
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48. Connecting details of heterogeneous explosive reactive wave profiles to the hydrodynamic reaction rate.

Author

Perry, W. Lee, Burns, Malcolm, and Aslam, Tariq

Subjects
SHOCK waves, CURIOSITY, MOTIVATION (Psychology), SURFACE waves (Seismic waves), EXPLOSIVES
Abstract

The future of high-performance high explosives development demands new efficient and cost-effective methods to understand new materials when only limited quantities are available. We also need efficient methods to understand the effects of manufacturing variability, service environment, and aging effects. Here, we explore the relationship between reactive wave profiles and the hydrodynamic reaction rate for use in model-based assessments. The acceleration of the lead shock wave directly reflects the reaction rate. With this knowledge, and equations-of-state information, relatively sparse data allows us to estimate the reaction rate for use in large-scale simulations. We deem the approach useful for efficient evaluation of new explosive formulations and variations in existing formulations. Our study of this topic is ongoing – the intent of this paper is to motivate curiosity and thought about how we interpret shock initiation data. [ABSTRACT FROM AUTHOR]

Published
2023
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49. A semi formal graphical approach to protocol design

Author

Aslam, Tariq

Subjects
621.382
Abstract

Communication protocols play a central role in modern telecommunication systems. Protocols are developed to assure that a given service by a system can be provided to an end user in a reliable and efficient manner. The ever-growing influence of telecommunication and distributed systems over daily life require the protocols developed to be free from design errors. One can easily imagine the consequences of protocol failure in the automatic teller machines (ATM), the failure of protocols while making phone calls or failure of protocols in safety critical system such as nuclear power plants and aeroplanes. Any subtle design errors in these protocols can lead to expensive and dangerous consequences. The traditional methodologies such as simulation and design by intuition of protocols are already showing weaknesses and can no longer be relied upon in order to develop modern large complex communication and distribution systems. The formal methods are being deployed in the industry and research institute to develop protocols that are highly reliable and ideally do not contain any errors. Generally, speaking these formal methods can be divided into two categories namely analytic versus synthetic. The analytical methods to design protocols are relatively simple but by no mean guarantee the generation of protocols that are free from design errors. The methods used can only detect errors after the protocol has been designed by means of simulation and validation using automated tools. The synthetic methods allow the generation of protocols that are free from design errors using advanced discrete mathematical concepts and state theory. The complexity of the methods proposed makes it extremely difficult to use them for the protocol of even simplistic natures. The methods proposed so far as shown their usability to the protocol of academic nature only. A semi formal graphical method proposed by this study to design protocol suggest a synthesis method that uses formal graphical language to synthesis the protocols. It overcomes a number of difficulties that are present in formal synthetical methods and early results show that the method can be applied to the protocol of realistic nature. This method also has some weaknesses but it is hoped that future research in this area will overcome some of these.

Published
2001

50. Publisher's Note: "An analytic and complete equation of state for condensed phase materials" [J. Appl. Phys. 134, 125102 (2023)].

Author

Lozano, Eduardo, Cawkwell, Marc J., and Aslam, Tariq D.

Subjects
CONDENSED matter, EQUATIONS of state, BERYLLIUM, NITROMETHANE, INTERNET publishing
Abstract

This article, titled "An analytic and complete equation of state for condensed phase materials," was originally published online on September 22, 2023, with incorrect captions for Figures 7-10. However, the figures and captions have been corrected and are now accurate. The article discusses thermal and cold calibration for various materials, including single-crystal PETN, liquid nitromethane, and HCP beryllium. It also presents the Grüneisen parameter calibration for HCP beryllium and includes graphs illustrating the Grüneisen parameter surface and non-dimensional thermodynamic space. The online versions of the article were corrected on October 23, 2023. [Extracted from the article]

Published
2023
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