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487 results on '"White, Timothy J."'

8. Variable Temperature Behaviour of the Hybrid Double Perovskite MA2KBiCl6

Author

Wei, Fengxia, Wu, Yue, Sun, Shijing, Deng, Zeyu, Chew, Li Tian, Cheng, Baisong, Tan, Cheng Cheh, White, Timothy J, and Cheetham, Anthony K

Subjects
Inorganic Chemistry, Macromolecular and Materials Chemistry, Chemical Sciences, Physical Chemistry, hybrid halide perovskite, phase transition, Pb-free, Medicinal and Biomolecular Chemistry, Organic Chemistry, Theoretical and Computational Chemistry, Medicinal and biomolecular chemistry, Organic chemistry
Abstract

Perovskite-related materials show very promising properties in many fields. Pb-free perovskites are particularly interesting, because of the toxicity of Pb. In this study, hybrid double perovskite MA2KBiCl6 (MA = methylammonium cation) was found to have interesting variable temperature behaviours. Both variable temperature single crystal X-ray diffraction, synchrotron powder diffraction, and Raman spectroscopy were conducted to reveal a rhombohedral to cubic phase transition at around 330 K and an order to disorder transition for inorganic cage below 210 K.

Published
2023

14. Networks between Ireland and the Irish American Diaspora during the Northern Ireland Peace Process.

Author

White, Timothy J.

Subjects
*PEACE negotiations, *ROLE conflict, *THE Troubles, 1969-1994, *INTERNATIONAL relations, *DIASPORA
Abstract

This article explores the complex relationship between the network of actors in the United States and Ireland who sought to influence American foreign policy in the Northern Ireland peace process. These networks operated in civil society, representing numerous Irish American organizations linking corporate and church leaders and the media to members of the Irish American diaspora in government to influence the United States' diplomacy. These Irish American groups and individuals interested in influencing events in Northern Ireland were linked with a wide array of governmental and non-governmental actors in Ireland. Often, Americans were quite deferential to leaders and groups in Ireland and Northern Ireland who sought to mobilize the Irish diaspora in the United States for their cause. Thus, the United States' role in Ireland and Northern Ireland was not that of a hegemonic power but one of an empathetic actor responding to developments and cues provided by various actors in the Irish context. Transatlantic networking, made more possible due to technological changes in communication and transportation, facilitated increased exchanges of ideas, agents, and information. These networks allowed groups across the Atlantic to elicit support for local groups in Northern Ireland and mobilize the US government to play a political and diplomatic role in the conflict and peace process. Ultimately, the majority of Irish Americans moved from supporting the nationalist/republican side in the early years of the Troubles to becoming strong supporters of the peace process in the 1990s. [ABSTRACT FROM AUTHOR]

Published
2024
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26. Enhanced Electromechanical Output in Liquid Crystal Elastomers Prepared by Thiol‐ene Photopolymerization.

Author

Fowler, Hayden E., Pearl, Harrison M., and White, Timothy J.

Subjects
LIQUID crystals, ELASTOMERS, PHOTOPOLYMERIZATION, YOUNG'S modulus, FUNCTIONAL integration, POLYMER liquid crystals, POLYMERIZATION
Abstract

The electrically‐directed, isothermal response of liquid crystal elastomers (LCEs) to an applied electric field is a compelling approach to realize spatially tailorable, sequence‐controllable, and high‐frequency deformation. The electromechanical response is facilitated by coating aligned LCEs with compliant electrodes. Upon application of an electric field, the electrodes attract and generate Maxwell stress. The directional difference in moduli for aligned LCEs produces directional deformation of the material and does not require mechanical bias or framing. Here, LCEs prepared from a newly reported thiol‐ene reaction are explored as DEAs with improved mechanical and dielectric properties. This report details that incorporating a difunctional liquid crystalline monomer composed of allyl ether functional groups reduces Young's modulus, increases the dielectric constant, and improves cyclic recovery compared to an analogous LCE prepared by thiol‐ene polymerization. Electrically‐induced, isothermal deformation of as much as 30% strain is reported. The facile chemistry and enhanced electromechanical response reported here may enable the functional integration of LCEs in applications such as robotics. [ABSTRACT FROM AUTHOR]

Published
2024
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28. Enhancing the electro-optic response of polymer stabilised cholesteric liquid crystals with ionic dopants.

Author

Radka, Brian P., Pande, Gaurav K., and White, Timothy J.

Subjects
CHOLESTERIC liquid crystals, IONIC crystals, CONDUCTING polymers, DOPING agents (Chemistry), POLYMERS, POLYMER networks, IONIC liquids
Abstract

The electro-optic response of polymer stabilised cholesteric liquid crystals can manifest as switching, tuning, or bandwidth broadening. The electro-optic response of these composites is attributed to the delocalisation of the ion-containing, structurally chiral polymer stabilising network to a DC bias. Upon removal of the electric field, the original reflective properties return within seconds. Prior reports have hypothesized that the polymer network trap ionic impurities during polymerization. Here, we explore this hypothesis by introducing ionic liquids as well as copolymerizing ionic monomers into the polymer network. This work further elucidates the contribution of ionic species to the electrochemical properties of the composite material as well as the associated impact on electro-optic performance. [ABSTRACT FROM AUTHOR]

Published
2024
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34. Molecular engineering of the polymer stabilizing network to enhance the electro-optic response of cholesteric liquid crystals.

Author

Pande, Gaurav K., Radka, Brian P., McCracken, Joselle M., and White, Timothy J.

Abstract

The selective reflection inherent to the cholesteric liquid crystal (CLC) phase (in the planar orientation) can be tuned or broadened by the incorporation of polymer stabilizing networks (PSCLC). Prior reports detail that the mechanism is ion-mediated deformation of the polymer stabilizing network, which retains structural chirality. The structural chirality of the polymer stabilizing effectively overpowers the chirality of the CLC mixture. Here, we incorporate monomers containing groups known to trap cationic metal halide ions, into the polymer stabilizing network. Specifically, we incorporate monofunctional control monomers as well as monofunctional acrylate monomers 4-acryloxyhexylterpyridine (TPy-Ac), 4-((6-(acryloyloxy)hexyl)oxy)benzoic-15-crown-5 (OBA-15C5), and 4-((6-(acryloyloxy)hexyl)oxy)benzoic-18-crown-6 (OBA-18C6). The electro-optic response is enhanced only by the inclusion of OBA-15C5 which previously has been shown to selectively trap and interact with sodium (Na+) ions. [ABSTRACT FROM AUTHOR]

Published
2023
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35. Large Range Thermochromism in Liquid Crystalline Elastomers Prepared with Intra‐Mesogenic Supramolecular Bonds.

Author

Schlafmann, Kyle R., Alahmed, Mohammed S., Lewis, Kristin L., and White, Timothy J.

Subjects
THERMOCHROMISM, CHOLESTERIC liquid crystals, ELECTROCHROMIC windows, OPTICAL elements, FOOD packaging, LOW temperatures, ELASTOMERS
Abstract

Liquid crystalline elastomers (LCEs) that retain the cholesteric phase (CLCEs) are soft, polymeric materials that retain periodic structure and exhibit a selective reflection. While prior studies have examined thermochromism in CLCEs, the association of temperature change and reflection wavelength shift has been limited to 1.4 nm °C−1. Here, CLCEs with intra‐mesogenic supramolecular bonds are prepared to enhance tunability as well triple the rate (e.g., 4.8 nm °C−1). Specifically, these materials incorporate liquid crystalline monomers based on dimerized oxy‐benzoic acid (OBA) derivatives. Increasing the concentration of the OBA comonomers increases the magnitude of red‐shifting thermochromism of the selective reflection. At and above a threshold concentration, the selective reflection in the CLCEs can disappear upon heating, analogous to on‐off "switching." Further, the introduction of the supramolecular bonds within the CLCE enable mechanical programming and enhanced one‐time tunable thermochromism via a one‐way shape memory process. Accordingly, this research could enable functional use in low temperature sensitive optical elements, fail‐safe thermal indicators for food packaging, and smart window coatings. [ABSTRACT FROM AUTHOR]

Published
2023
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39. Preoperative risk factors for conversion from laparoscopic to open cholecystectomy: a validated risk score derived from a prospective U.K. database of 8820 patients

Author

Fenwick, Stephen, Elmasry, Mohamed, Nunes, Quentin, Kennedy, David, Khan, Raja B., Khan, Muhammad A.S., Magee, Conor J., Jones, Steven M., Mason, Denise, Parappally, Ciny P., Mathur, Pawan, Saunders, Michael, Jamel, Sara, Haque, Samer U.l., Zafar, Sara, Shiwani, Muhammad H., Samuel, Nehemiah, Dar, Farooq, Jackson, Andrew, Lovett, Bryony, Dindyal, Shiva, Winter, Hannah, Rahman, Saquib, Wheatley, Kevin, Nieto, Tom, Ayaani, Soofiyah, Youssef, Haney, Nijjar, Rajwinder S., Watkin, Helen, Naumann, David, Emeshi, Sophie, Sarmah, Piyush B., Lee, Kathryn, Joji, Nikita, Heath, Jonathan, Teasdale, Rebecca L., Weerasinghe, Chamindri, Needham, Paul J., Welbourn, Hannah, Forster, Luke, Finch, David, Blazeby, Jane M., Robb, William, McNair, Angus G.K., Hrycaiczuk, Alex, Charalabopoulos, Alexandros, Kadirkamanathan, Sritharan, Tang, Cheuk-Bong, Jayanthi, Naga V.G., Noor, Nigel, Dobbins, Brian, Cockbain, Andrew J., Nilsen-Nunn, April, de Siqueira, Jonathan, Pellen, Mike, Cowley, Jonathan B., Ho, Wei-Min, Miu, Victor, White, Timothy J., Hodgkins, Kathryn A., Kinghorn, Alison, Tutton, Matthew G., Al-Abed, Yahya A., Menzies, Donald, Ahmad, Anwar, Reed, Joanna, Khan, Shabuddin, Monk, David, Vitone, Louis J., Murtaza, Ghulam, Joel, Abraham, Brennan, Stephen, Shier, David, Zhang, Catherine, Yoganathan, Thusidaran, Robinson, Steven J., McCallum, Iain J.D., Jones, Michael J., Elsayed, Mohammed, Tuck, Liz, Wayman, John, Carney, Kate, Aroori, Somaiah, Hosie, Kenneth B., Kimble, Adam, Bunting, David M., Fawole, Adeshina S., Basheer, Mohammed, Dave, Rajiv V., Sarveswaran, Janahan, Jones, Elinor, Kendal, Chris, Tilston, Michael P., Gough, Martin, Wallace, Tom, Singh, Shailendra, Downing, Justine, Mockford, Katherine A., Issa, Eyad, Shah, Nayab, Chauhan, Neal, Wilson, Timothy R., Forouzanfar, Amir, Wild, Jonathan R.L., Nofal, Emma, Bunnell, Catherine, Madbak, Khaliel, Rao, Sudhindra T.V., Devoto, Laurence, Siddiqi, Najaf, Khawaja, Zechan, Hewes, James C., Gould, Laura, Chambers, Alice, Rodriguez, Daniel U., Sen, Gourab, Robinson, Stuart, Bartlett, Francis, Rae, David M., Stevenson, Thomas E.J., Sarvananthan, Kas, Dwerryhouse, Simon J., Higgs, Simon M., Old, Oliver J., Hardy, Thomas J., Shah, Reena, Hornby, Steve T., Keogh, Ken, Frank, Lucinda, Al-Akash, Musallam, Upchurch, Emma A., Frame, Richard J., Hughes, Michael, Jelley, Clare, Weaver, Simon, Roy, Sudipta, Sillo, Toritseju O., Galanopoulos, Giorgios, Cuming, Tamzin, Cunha, Pedro, Tayeh, Salim, Kaptanis, Sarantos, Heshaishi, Mohamed, Eisawi, Abdalla, Abayomi, Michael, Ngu, Wee S., Fleming, Katie, Bajwa, Dalvir S., Chitre, Vivek, Aryal, Kamal, Ferris, Paul, Silva, Michael, Lammy, Simon, Mohamed, Sarah, Khawaja, Amir, Hussain, Adnan, Ghazanfar, Mudassar A., Bellini, Maria I., Ebdewi, Hamdi, Elshaer, Mohamed, Gravante, Gianpiero, Drake, Benjamin, Ogedegbe, Arikoge, Mukherjee, Dipankar, Arhi, Chanpreet, Giwa, Lola, Iqbal, Nusrat, Watson, Nicholas F., Aggarwal, Smeer K., Orchard, Philippa, Villatoro, Eduardo, Willson, Peter D., Mok, Kam W.J., Woodman, Thomas, Deguara, Jean, Garcea, Giuseppe, Babu, Benoy I., Dennison, Alistair R., Malde, Deep, Lloyd, David, Slavin, John P., Jones, Robert P., Ballance, Laura, Gerakopoulos, Stratos, Jambulingam, Periyathambi, Mansour, Sami, Sakai, Naomi, Acharya, Vikas, Sadat, Mohammed M., Karim, Lawen, Larkin, David, Amin, Khalid, Khan, Amarah, Law, Jennifer, Jamdar, Saurabh, Smith, Stella R., Sampat, Keerthika, O'shea, Kathryn M., Manu, Mangta, Asprou, Fotini M., Malik, Nabeela S., Chang, Jessica, Johnstone, Marianne, Lewis, Michael, Roberts, Geoffrey P., Karavadra, Babu, Photi, Evangelos, Hewes, James, Rodriguez, Dan, O'Reilly, Derek A., Rate, Anthony J., Sekhar, Hema, Henderson, Lucy T., Starmer, Benjamin Z., Coe, Peter O., Tolofari, Sotonye, Barrie, Jenifer, Bashir, Gareth, Sloane, Jake, Madanipour, Suroosh, Halkias, Constantine, Trevatt, Alexander E.J., Borowski, David W., Hornsby, Jane, Courtney, Michael J., Virupaksha, Suvi, Seymour, Keith, Robinson, Sarah, Hawkins, Helen, Bawa, Sadiq, Gallagher, Paul V., Reid, Alistair, Wood, Peter, Finch, Jonathan G., Finch, J.Guy, Parmar, Jitesh, Stirland, Euan, Gardner-Thorpe, James, Al-Muhktar, Ahmed, Peterson, Mark, Majeed, Ali, Bajwa, Farrukh M., Martin, Jack, Choy, Alfred, Tsang, Andrew, Pore, Naresh, Andrew, David R., Al-Khyatt, Waleed, Santosh Bhandari, Christopher Taylor, Chambers, Adam, Subramanium, Dhivya, Toh, Simon K.C., Carter, Nicholas C., Mercer, Stuart J., Knight, Benjamin, Vijay, Vardhini, Alagaratnam, Swethan, Sinha, Sidhartha, Khan, Shahab, El-Hasani, Shamsi S., Hussain, Abdulzahra A., Bhattacharya, Vish, Kansal, Nisheeth, Fasih, Tani, Jackson, Claire, Siddiqui, Midhat N., Chishti, Imran A., Fordham, Imogen J., Siddiqui, Zohaib, Bausbacher, Harald, Geogloma, Ileana, Gurung, Kabita, Tsavellas, George, Basynat, Pradeep, Shrestha, Ashish K., Basu, Sanjoy, Chhabra, Alok, Harilingam, Mohan, Rabie, Mohamed, Akhtar, Mansoor, Kumar, Pradeep, Jafferbhoy, Sadaf F., Hussain, Najam, Raza, Soulat, Haque, Manzarul, Alam, Imran, Aseem, Rabiya, Patel, Shakira, Asad, Mehek, Booth, Michael I., Ball, William R., Wood, Christopher P.J., Pinho-Gomes, Ana C., Kausar, Ambareen, Obeidallah, Mohammed, Varghase, Joseph, Lodhia, Joshil, Bradley, Donal, Rengifo, Carla, Lindsay, David, Gopalswamy, Sivakumar, Finlay, Ian, Wardle, Stacy, Bullen, Naomi, Iftikhar, Syed Y., Awan, Altaf, Ahmed, Javed, Leeder, Paul, Fusai, Guiseppe, Bond-Smith, Giles, Psica, Alicja, Puri, Yogesh, Hou, David, Noble, Fergus, Szentpali, Karoly, Broadhurst, Jack, Date, Ravindra, Hossack, Martin R., Goh, Yan L., Turner, Paul, Shetty, Vinutha, Riera, Manel, Macano, Christina A.W., Sukha, Anisha, Preston, Shaun R., Hoban, Jennifer R., Puntis, Daniel J., Williams, Sophie V., Krysztopik, Richard, Kynaston, James, Batt, Jeremy, Doe, Matthew, Goscimski, Andrzej, Jones, Gareth H., Hall, Claire, Carty, Nick, Ahmed, Jamil, Panteleimonitis, Sofoklis, Gunasekera, Rohan T., Sheel, Andrea R.G., Lennon, Hannah, Hindley, Caroline, Reddy, Marcus, Kenny, Ross, Elkheir, Natalie, McGlone, Emma R., Rajaganeshan, Rajasundaram, Hancorn, Kate, Hargreaves, Anita, Prasad, Raj, Longbotham, David A., Vijayanand, Dhakshinamoorthy, Wijetunga, Imeshi, Ziprin, Paul, Nicolay, Christopher R., Yeldham, Geoffrey, Read, Edward, Gossage, James A., Rolph, Rachel C., Ebied, Husam, Phull, Manraj, Khan, Mohammad A., Popplewell, Matthew, Kyriakidis, Dimitrios, Hussain, Anwar, Henley, Natasha, Packer, Jessica R., Derbyshire, Laura, Porter, Jonathan, Appleton, Shaun, Farouk, Marwan, Basra, Melvinder, Jennings, Neil A., Ali, Shahda, Kanakala, Venkatesh, Ali, Haythem, Lane, Risha, Dickson-Lowe, Richard, Zarsadias, Prizzi, Mirza, Darius, Puig, Sonia, Al Amari, Khalid, Vijayan, Deepak, Sutcliffe, Robert, Marudanayagam, Ravi, Hamady, Zayed, Prasad, Abheesh R., Patel, Abhilasha, Durkin, Damien, Kaur, Parminder, Bowen, Laura, Byrne, James P., Pearson, Katherine L., Delisle, Theo G., Davies, James, Tomlinson, Mark A., Johnpulle, Michelle A., Slawinski, Corinna, Macdonald, Andrew, Nicholson, James, Newton, Katy, Mbuvi, James, Farooq, Ansar, Mothe, Bhavani S., Zafrani, Zakhi, Brett, Daniel, Francombe, James, Spreadborough, Philip, Barnes, James, Cheung, Melanie, Al-Bahrani, Ahmed Z., Preziosi, Giuseppe, Urbonas, Tomas, Alberts, Justin, Mallik, Mekhlola, Patel, Krashna, Segaran, Ashvina, Doulias, Triantafyllos, Sufi, Pratik A., Yao, Caroline, Pollock, Sarah, Manzelli, Antonio, Wajed, Saj, Kourkulos, Michail, Pezzuto, Roberto, Wadley, Martin, Hamilton, Emma, Jaunoo, Shameen, Padwick, Robert, Sayegh, Mazin, Newton, Richard C., Hebbar, Madhusoodhana, Farag, Sameh F., Hebbar, Madhu, Spearman, John, Hamdan, Mohammed F., D'Costa, Conrad, Blane, Christine, Giles, Mathew, Peter, Mark B., Hirst, Natalie A., Hossain, Tanvir, Pannu, Arslan, El-Dhuwaib, Yesar, Morrison, Tamsin E.M., Taylor, Greg W., Thompson, Ronald L.E., McCune, Ken, Loughlin, Paula, Lawther, Roger, Byrnes, Colman K., Simpson, Duncan J., Mawhinney, Abi, Warren, Conor, McKay, Damian, McIlmunn, Colin, Martin, Serena, MacArtney, Matthew, Diamond, Tom, Davey, Phil, Jones, Claire, Clements, Joshua M., Digney, Ruairi, Chan, Wei M., McCain, Stephen, Gull, Sadaf, Janeczko, Adam, Dorrian, Emmet, Harris, Andrew, Dawson, Suzanne, Johnston, Dorothy, McAree, Barry, Ghareeb, Essam, Thomas, George, Connelly, Martin, McKenzie, Stephen, Cieplucha, Krzysztos, Spence, Gary, Campbell, William, Hooks, Gareth, Bradley, Neil, Hill, Arnold D.K., Cassidy, John T., Boland, Michael, Burke, Paul, Nally, Deirdre M., Khogali, Elmoataz, Shabo, Wael, Iskandar, Edrin, McEntee, Gerry P., O'Neill, Maeve A., Peirce, Colin, Lyons, Emma M., O'Sullivan, Adrian W., Thakkar, Rohan, Carroll, Paul, Ivanovski, Ivan, Balfe, Paul, Lee, Matthew, Winter, Des C., Kelly, Michael E., Hoti, Emir, Maguire, Donal, Karunakaran, Priyadarssini, Geoghegan, Justin G., Martin, Sean T., Cross, Keith S., Cooke, Fiachra, Zeeshan, Saquib, Murphy, James O., Mealy, Ken, Mohan, Helen M., Nedujchelyn, Yuwaraja, Ullah, Muhammad F., Ahmed, Irfan, Giovinazzo, Francesco, Milburn, James, Prince, Sarah, Brooke, Eleanor, Buchan, Joanna, Khalil, Ahmed M., Vaughan, Elizabeth M., Ramage, Michael I., Aldridge, Roland C., Gibson, Simon, Nicholson, Gary A., Vass, David G., Grant, Alan J., Holroyd, David J., Jones, Angharad, Sutton, Cherith M.L.R., O'Dwyer, Patrick, Nilsson, Frida, Weber, Beatrix, Williamson, Tracey K., Lalla, Kushik, Bryant, Alice, Carter, Ross, Forrest, Craig R., Hunter, David I., Nassar, Ahmad H., Orizu, Mavis N., Knight, Katrina, Qandeel, Haitham, Suttie, Stuart, Belding, Rowena, McClarey, Andrew, Boyd, Alan T., Guthrie, Graeme J.K., Lim, Pei J., Luhmann, Andreas, Watson, Angus J.M., Richards, Colin H., Nicol, Laura, Madurska, Marta, Harrison, Ewen, Boyce, Kathryn M., Roebuck, Amanda, Ferguson, Graeme, Pati, Pradeep, Wilson, Michael S.J., Dalgaty, Faith, Fothergill, Laura, Driscoll, Peter J., Mozolowski, Kirsty L., Banwell, Victoria, Bennett, Stephen P., Rogers, Paul N., Skelly, Brendan L., Rutherford, Claire L., Mirza, Ahmed K., Lazim, Taha, Lim, Henry C.C., Duke, Diana, Ahmed, Talat, Beasley, William D., Wilkinson, Marc D., Maharaj, Geta, Malcolm, Cathy, Brown, Timothy H., Shingler, Guy M., Mowbray, Nicholas, Radwan, Rami, Morcous, Paul, Wood, Simon, Kadhim, Abbas, Stewart, Duncan J., Baker, Andrew L., Tanner, Nicola, Shenoy, Hrishikesh, Sutcliffe, Robert P., Hollyman, Marianne, Hodson, James, Bonney, Glenn, Vohra, Ravi S., and Griffiths, Ewen A.

Published
2016
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45. Direct Ink Writing of Enzyme‐Containing Liquid Crystal Elastomers as Versatile Biomolecular‐Responsive Actuators.

Author

Velasco Abadia, Albert, Bauman, Grant E., White, Timothy J., Schwartz, Daniel K., and Kaar, Joel L.

Subjects
LIQUID crystals, HYDROLASES, ELASTOMERS, ACTUATORS, SMART materials, SHAPE memory polymers, CONDUCTING polymers
Abstract

The combination of enzymes and chemically responsive smart materials presents considerable opportunities in anti‐fouling, sensing or medicine. Among stimuli‐responsive polymers, liquid crystal elastomers (LCEs) have emerged as a leading actuator platform due to their inherent programmability, realizing large shape transformations upon exposure to stimuli. Herein, three different hydrolytic enzymes are immobilized into acid‐responsive LCEs, which impart the LCEs with sensitivity to three distinctive classes of biomolecules: lipids, carbohydrates, and peptides. Dye‐doped biocatalytic LCEs readily switch their color and shape upon exposure to the appropriate substrate. Twisted nematic patterning and direct ink writing are used to showcase the versatility of shape changes the enzyme‐containing LCEs may undergo. Multiplexed responsiveness is also demonstrated using a connected array of 3D printed disks, each containing a different enzyme, highlighting the excellent chemical selectivity of the LCEs. This work presents a novel platform of versatile bioresponsive color‐switchable actuators that may have application in a wide range of fields. [ABSTRACT FROM AUTHOR]

Published
2023
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46. Millimeter‐Thick Liquid Crystalline Elastomer Actuators Prepared by‐Surface‐Enforced Alignment.

Author

McCracken, Joselle M., Hoang, Jonathan D., Herman, Jeremy A., Lynch, Kelsey M., and White, Timothy J.

Subjects
ELASTOMERS, ACTUATORS, DISCLINATIONS, MEDICAL equipment, SOFT robotics
Abstract

Liquid crystalline elastomers (LCE) are thermally cyclable, compliant actuators with compelling mechanical properties. The large and programmable deformation of LCE has led to numerous functional examinations spanning optics, medical devices, and robotics. A well‐established method to prepare complex LCE actuators is to utilize surface‐enforced photoalignment. Herein, a facile and scalable approach is reported to circumvent the physical limits of surface‐enforced alignment (e.g., samples that are 50 µm or less) to amplify the achievable force output in LCE. Applying an approach termed direct layering, the thermomechanical response of LCE elements prepared with +1 disclination patterns in a range of compositions and thicknesses is contrasted. The design and preparation of +1 disclination patterns and arrays is explored to assess the contribution of sample geometry and overlap to deformation and force output. The methodology detailed in this contribution allows for the preparation of elements ≈1 mm in thickness that are capable of actuating large objects. Furthermore, the fabrication of these elements uniquely enables the realization of mechanical instabilities to hasten the actuation rate in response to thermal change and to enable leaping. [ABSTRACT FROM AUTHOR]

Published
2023
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48. The Challenges of Powersharing in Implementing the Good Friday Agreement: Twenty-Five Years of Intermittent Shared Governance.

Author

White, Timothy J.

Subjects
GOOD Friday Agreement (1998), REFERENDUM
Abstract

Copyright of Treaties & Documents / Razprave in Gradivo is the property of Institut za Narodnostna Vprasanja and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2023
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