Hasil untuk "cond-mat.mtrl-sci"

G. Kanyolo, T. Masese, Y. Miyazaki et al.

Silver (Ag+) conducting electrolytes are already being pursued for utilisation in solid-state batteries (e.g. [1] ). Herein, we fortuitously synthesise a novel class of honeycomb layered tellurates, characterised by a global composition of Ag2 M 2TeO6 (where M = Co, Ni etc represents transition metals). These compounds feature argentophilic Ag-atom bilayers (Figure 1), as revealed through aberration-corrected transmission electron microscopy. [2,3,4] Due to metallophilicity and Ag subvalency, impalpable challenges reproducing the Ag bilayered structure exist within standard computational techniques. [5] Thus, the origin of the bilayers is theoretically understood via the emergence of non-commutative gauge interactions with three distinct valency states of Ag associated with well-known subvalent states, alongside the usual electromagnetic interaction. [2,3,4,6] Breaking these gauge symmetries generates a mass term, corresponding to the bifurcation of the Ag honeycomb lattice into argentophilic bilayers. [3,4] Moreover, since this novel class displays oxygen anion electrochemistry and relatively fast ionic conductivities, this work not only promises to inspire next-generation Ag-based honeycomb layered oxide cathodes but also provide a platform for further inquiry into the novel role of non-Euclidean and non-commutative geometries and gauge interactions respectively play within the broader class of honeycomb layered materials typically poised for secondary battery applications. [3,6,7,8,9] References: [1] K. Kirshenbaum et al., Handbook of Solid State Batteries, 779-818 (2016) [2]T. Masese, G. M. Kanyolo, Y. Miyazaki, T. Saito et al., Adv . S ci., 10, 2204672 (2024) [3]G. M. Kanyolo, T. Masese, Y. Miyazaki, T. Saito et al., Prog . Mater. S ci., 141, 101205 (2024) [4]G. M. Kanyolo, T. Masese et al., Mater . Today Chem., 33, 101657 (2024) [5] K. Tada, T. Masese, and G. M. Kanyolo, Comput. Mater. Sci. 207 111322 (2022) [6]G. M. Kanyolo and T. Masese, Mater . Today Phys., 39, 101271 (2024) [7]G. M. Kanyolo, T. Masese et al., Chem. Soc. Rev ., 50, 3990 (2021) [8] G. M. Kanyolo and T. Masese, Sci. Rep. 12 (1) 6465 (2022) [9] G. M. Kanyolo and T. Masese, arXiv:2202.10323 [cond-mat.mtrl-sci] Figure 1. HAADF-STEM image taken along [100] axis illustrating bilayer arrangement of silver atoms in honeycomb layered oxides with a global composition of Ag2Ni2TeO6. [2,3] Figure 1

Jabr Aljedani, Michael J. Chen, B. Cox

The chemical vapour deposition method is widely used to synthesise high quality graphene with a large surface area. However, the cooling process leads to the formations of ripples and wrinkles in the graphene structure. When a self-adhered wrinkle achieves the maximum height, it then folds onto the surface and leads to a collapsed wrinkle. The presence of such deformations often affects the properties of graphene. In this article, we describe a novel mathematical model to understand the formation and geometry of these wrinkles. The stability of these wrinkles is examined based on variational derivations for the energy of each structure. The model provides detailed explanations for the geometry of these wrinkles which would help in tuning their properties. References J. Aljedani, M. J. Chen, and B. J. Cox. Variational model for collapsed graphene wrinkles. Appl. Phys. A 127.11, 886 (2021), pp. 1–13. doi: 10.1007/s00339-021-05000-y A. A. Balandin, S. Ghosh, W. Bao, I. Calizo, D. Teweldebrhan, F. Miao, and C. N. Lau. Superior thermal conductivity of single-layer graphene. Nano Lett. 8.3 (2008), pp. 902–907. doi: 10.1021/nl0731872 S. Chen, Q. Li, Q. Zhang, Y. Qu, H. Ji, R. S. Ruoff, and W. Cai. Thermal conductivity measurements of suspended graphene with and without wrinkles by micro-Raman mapping. Nanotech. 23.36, 365701 (2012). doi: 10.1088/0957-4484/23/36/365701 on p. C85). B. J. Cox, T. Dyer, and N. Thamwattana. A variational model for conformation of graphene wrinkles formed on a shrinking solid metal substrate. Mat. Res. Express 7.8, 085001 (2020). doi: 10.1088/2053-1591/abaa8f A. K. Geim. Graphene: Status and prospects. Science 324.5934 (2009), pp. 1530–1534. doi: 10.1126/science.1158877 on p. C85). K. Kostarelos and K. S. Novoselov. Graphene devices for life. Nature Nanotech. 9 (2014), pp. 744–745. doi: 10.1038/nnano.2014.224 F. Long, P. Yasaei, R. Sanoj, W. Yao, P. Král, A. Salehi-Khojin, and R. Shahbazian-Yassar. Characteristic work function variations of graphene line defects. ACS Appl. Mat. Inter. 8.28 (2016), pp. 18360–18366. doi: 10.1021/acsami.6b04853 R. Muñoz and C. Gómez-Aleixandre. Review of CVD synthesis of graphene. Chem. Vapor Dep. 19.10–12 (2013), pp. 297–322. doi: 10.1002/cvde.201300051 L. Spanu, S. Sorella, and G. Galli. Nature and strength of interlayer binding in graphite. Phys. Rev. Lett. 103.19, 196401 (2009). doi: 10.1103/PhysRevLett.103.196401 T. Verhagen, B. Pacakova, M. Bousa, U. Hübner, M. Kalbac, J. Vejpravova, and O. Frank. Superlattice in collapsed graphene wrinkles. Sci. Rep. 9.1, 9972 (2019). doi: 10.1038/s41598-019-46372-9 C. Wang, Y. Liu, L. Li, and H. Tan. Anisotropic thermal conductivity of graphene wrinkles. Nanoscale 6.11 (2014), pp. 5703–5707. doi: 10.1039/C4NR00423J W. Wang, S. Yang, and A. Wang. Observation of the unexpected morphology of graphene wrinkle on copper substrate. Sci. Rep. 7.1 (2017), pp. 1–6. doi: 10.1038/s41598-017-08159-8 Y. Wang, R. Yang, Z. Shi, L. Zhang, D. Shi, E. Wang, and G. Zhang. Super-elastic graphene ripples for flexible strain sensors. ACS Nano 5.5 (2011), pp. 3645–3650. doi: 10.1021/nn103523t Y. Wei, B. Wang, J. Wu, R. Yang, and M. L. Dunn. Bending rigidity and Gaussian bending stiffness of single-layered graphene. Nano Lett. 13.1 (2013), pp. 26–30. doi: 10.1021/nl303168w Z. Xu and M. J. Buehler. Interface structure and mechanics between graphene and metal substrates: A first-principles study. J. Phys.: Cond. Mat. 22.48, 485301 (2010). doi: 10.1088/0953-8984/22/48/485301 Y. Zhang, N. Wei, J. Zhao, Y. Gong, and T. Rabczuk. Quasi-analytical solution for the stable system of the multi-layer folded graphene wrinkles. J. Appl. Phys. 114.6, 063511 (2013). doi: 10.1063/1.4817768 W. Zhu, T. Low, V. Perebeinos, A. A. Bol, Y. Zhu, H. Yan, J. Tersoff, and P. Avouris. Structure and electronic transport in graphene wrinkles. Nano Lett. 12.7 (2012), pp. 3431–3436. doi: 10.1021/nl300563h

Ksenia V. Bets, N. Gupta, B. Yakobson

Large 2D monocrystals are highly sought after yet hard to achieve; unlike graphene, most dichalcogenides and h-BN possess low symmetry, which allows for nucleation of mutually inverted pieces, merging into polycrystals replete with grain boundaries. On vicinal substrate surfaces such growing pieces were observed to orient alike, and very recently this effect apparently enabled the growth of large single crystal h-BN. Addressing the compelling questions of how such a growth process can operate and what the key mechanisms are is crucial in guiding the substrate selection for optimal synthesis of perhaps many materials. To this end, the basic crystallography and atomistic-modeling theory presented here reveal (i) how the undulations of the ever-wandering steps do not, surprisingly, disturb the orientations of the attached 2D-nuclei, whose direction remains robust owing to complementarity between the meandering step and h-BN counterpart if their kinks have similar size of negligible misfit, δ k < 0.1 Å. (ii) Stronger chemical affinity of metal to the N atoms at the zigzag edge of h-BN singles out its particular orientation, without evidence of any epitaxy, at the edge or to the surface. (iii) The monocrystal integrity requires unhindered growth spillover across the steps and the seamless healing of the residual fissures, caused by the very same steps necessary for co-orientation. Molecular dynamics simulations show this happening for the steps not taller than the BN bond, s < 1.44 Å. These criteria point to [-1 1 2] steps on the Cu (110) surface, in accord with experimental results (Wang et al. Towards the growth of single-crystal boron nitride monolayer on Cu. arXiv:1811.06688 Cond. Mat. Mtrl. Sci., 2018), while other possibilities can also be predicted.

Pip Lambrechtse, V. Ziesenitz, A. Atkinson et al.

Introduction Wearable activity trackers are increasingly incorporated into daily life and are advancing in their technology in means of accuracy, validity and acceptability,1-6 however there is deficient knowledge on using these devices in a paediatric setting. The objective of this pilot study was to assess the feasibility of physical activity tracking in children7 before and after a standardized surgical intervention and to assess the recovery time after surgery. Methods This was a single centre, open-label, prospective feasibility study. We aimed at recruiting 24 children and adolescents 4–16 years of age undergoing elective tonsillectomy. The preoperative period was 10 days before surgery and the postoperative period was 28 days. Activity data were gathered with activity trackers.8 Reference activity was defined as the individual mean of daily steps preoperatively. Recovery time was defined as the number of days that the patient needed to reach reference activity postoperatively. The population was stratified according to age (4–7, 8–16 years). Results Twelve male and twelve female patients participated (mean age 6yr, mean BMI percentile 44.7). The age group 4–7 years had a mean recovery time of 11.2 days (SD 5.0) compared to 8.3 days (SD 1.7) in the age group 8–16. The difference was 2.9 days. The tracker datasets were 58% complete. The rate of technical failures of the trackers was 29.2% for the total study period. Conclusions Activity trackers are a potential tool viable to assess recovery time after surgery in children. Recovery time after tonsillectomy seems to be age-dependent with older children recovering faster. For future studies, we recommend using trackers as a part of assessing physical activity as a parameter of general wellbeing of child during or after an intervention. Using wearable activity trackers is a more modern and appropriate method to assess physical activity,9-14 especially in a paediatric population. References Brooke SM, An HS, Kang SK, Noble JM, Berg KE, Lee JM. Concurrent validity of wearable activity trackers under free-living conditions. J Strength Cond Res 2017;31(4). Fokkema T, Kooiman TJM, Krijnen WP, Van Der Schans CP, De Groot M. Reliability and validity of ten consumer activity trackers depend on walking speed. Med Sci Sports Exerc. 2017;49(4). Evenson KR, Goto MM, Furberg RD. Systematic review of the validity and reliability of consumer-wearable activity trackers. Vol. 12, International Journal of Behavioral Nutrition and Physical Activity 2015. Huang Y, Xu J, Yu B, Shull PB. Validity of FitBit, Jawbone UP, Nike+ and other wearable devices for level and stair walking. Gait Posture 2016; Hein IM, Troost PW, De Vries MC, Knibbe CAJ, Van Goudoever JB, Lindauer RJL. Why do children decide not to participate in clinical research: A quantitative and qualitative study. Pediatr Res 2015; Van Berge Henegouwen MTH, Van Driel HF, Kasteleijn-Nolst Trenité DGA. A patient diary as a tool to improve medicine compliance. Pharm World Sci 1999;21(1):21–4. Stone AA. Patient non-compliance with paper diaries. BMJ 2002; Disclosure(s) Nothing to disclose

S. Ito

S. Olthof, W. Frencken, K. Lemmink

S. Olthof, W. Frencken, K. Lemmink

Stefano Villa, A. Stocco, C. Blanc et al.

S. Olthof, W. Frencken, K. Lemmink

Bud Wing-Yun, Hardaway Chun-Kwan Chan, P. Yung et al.

B. Hoogenboom

S. Liou

C. Ağartan, S. Öner

ABS TRACT Objective: In this study, the 4th, 5th, 6th and 7th ba bi es born with dif fe rent ano ma li es that had be en des cri bed in the Su me ri an myth of “En ki and Nim nah: Cre a ti on of Ma n”, ha ve be en eva lu a ted. Material and Methods: The myth was eva lu a ted with the help of arc he o lo gi cal so ur ces, on li ne muse um ca ta lo gu es, re vi ews writ ten on this sub ject and get ting opi ni ons of va ri o us ex perts. Results: In the first part of the myth, a fe ast gi ven by the gods to ce leb ra te the cre a ti on of the per fect man had be en des cri bed. In the se cond part, the God dess Nim nah, had be co me je a lo us of En ki’s suc cess and cre a ted 6 de fec ti ve, cripp led ba bi es out of mud. As En ki had got angry with Nim nah’s act, he had cre a ted the 7th de fec ti ve baby. Ba sed on the des crip ti ons of the ba bi es in the myth, the 4th one had uri nary con ti nen ce, the 5th one was an in fer ti le girl, the 6th one had am bi gi o us ge ni ta li a, and the 7th one had pro bably Wolf-Hirsc hhorn syndro me. The cre a ti ons of the se seven ba bi es we re do ne du ring abo ve-men ti o ned fe ast un der the inf lu en ce of al co hol. To the best of our know led ge, this myth pre sen ted on the Su me ri an clay tab lets has an im por tan ce as they are the first writ ten do cu ments des cri bing uri nary in con ti nen ce, in fer ti lity and am bi gi u o us ge ni ta li a. Conclusion: It can be spe cu la ted that, Su me ri ans, who had pi o ne e red va ri o us fi elds of sci en ce and tech no logy might ha ve ob ser ved the te ra to ge nic ef fects of pa ren tal use of al co hol and wan ted to send a mes sa ge to the fol lo wing ge ne ra ti ons by this myth.

Wu Xiao-huang

D. Klug, Yansun Yao, J. Tse et al.

H. Ohno, F., Matsukura et al.

B. García-Landa, M. Ibarra, R. Mahendiran et al.

Y. Popov, A. M. Kadomtseva, G. P. Vorob'ev et al.

Tohru OgawaSB, K. Arai, Tuneko OkazakiS

B. Teo, N. Mathur, J. Evetts et al.