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1. Optical properties of two-dimensional tin nanosheets epitaxially grown on graphene

Author

Bonaventura, Eleonora, Martella, Christian, Macis, Salvatore, Dhungana, Daya S., Krotkus, Simonas, Heuken, Michael, Lupi, Stefano, Molle, Alessandro, and Grazianetti, Carlo

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Heterostacks formed by combining two-dimensional materials show novel properties which are of great interest for new applications in electronics, photonics and even twistronics, the new emerging field born after the outstanding discoveries on twisted graphene. Here, we report the direct growth of tin nanosheets at the two-dimensional limit via molecular beam epitaxy on chemical vapor deposited graphene on Al2O3(0001). The mutual interaction between the tin nanosheets and graphene is evidenced by structural and chemical investigations. On the one hand, Raman spectroscopy indicates that graphene undergoes compressive strain after the tin growth, while no charge transfer is observed. On the other hand, chemical analysis shows that tin nanosheets interaction with sapphire is mediated by graphene avoiding the tin oxidation occurring in the direct growth on this substrate. Remarkably, optical measurements show that the absorption of tin nanosheets show a graphene-like behavior with a strong absorption in the ultraviolet photon energy range, therein resulting in a different optical response compared to tin nanosheets on bare sapphire. The optical properties of tin nanosheets therefore represent an open and flexible playground for the absorption of light in a broad range of the electromagnetic spectrum and technologically relevant applications for photon harvesting and sensors., Comment: 14 pages, 7 figures

Published
2023

2. Visual and Refractive Outcomes of a New Hydrophobic Trifocal Toric Intraocular Lens

Author

Daya S and Espinosa Lagana M

Subjects
astigmatism, trifocal, toric, multifocal, cataract, Ophthalmology, RE1-994
Abstract

Sheraz Daya, Marcela Espinosa Lagana Centre for Sight, East Grinstead, West Sussex, UKCorrespondence: Sheraz Daya, Centre for Sight, East Grinstead, West Sussex, RH19 4RH, UK, Email sdaya@centreforsight.comPurpose: To evaluate the visual outcomes and efficacy of astigmatism correction using a new hydrophobic trifocal toric intraocular lens (IOL).Methods: This study involved 62 eyes implanted with the FineVision HP Toric IOL. The visual and refractive outcomes were assessed preoperatively and 6 weeks after the surgery. Specifically, monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA) at 80 and 60 cm and uncorrected near visual acuity at (UNVA) at 40 cm were evaluated. The rotational stability of the lens was also assessed.Results: Sixty-one eyes (98.39%) were within ± 1.00D and 55 eyes (88.71%) were within ± 0.50 D of spherical equivalent, with a mean value of 0.09± 0.39 D. 51 (82.26%) and 61 (98.39%) eyes had a UDVA of ≥ 20/20 and ≥ 20/25, respectively, and for CDVA these values were as follows: 59 (95.16%) and 62 eyes (100%), respectively. The mean UDVA and CDVA were 0.01± 0.06 and − 0.01± 0.04logMAR, respectively. Greater than or equal to unaided 20/20 vision was achieved at 40 cm in 42 (67.74%), UIVA at 60 cm in 42 (67.74%) and 50 eyes (80.65%) at 80 cm. Those achieving ≥ 20/25 were 56 (90.32%, 40 cm), 59 (95.16%, 60 cm), and 62 eyes (100%, 80 cm). Postoperative mean values were 0.04± 0.07, 0.03± 0.07, and 0.00± 0.07logMAR for UCNVA, UIVA at 60 cm, and UIVA at 80 cm, respectively. The mean rotation of the IOL was 5.8 degrees.Conclusion: This hydrophobic trifocal toric IOL provides good refractive outcomes with excellent visual acuity across multiple distances, providing a full range of focus.Keywords: astigmatism, trifocal, toric, multifocal, cataract

Published
2024

5. Effective Out‐Of‐Plane Thermal Conductivity of Silicene by Optothermal Raman Spectroscopy.

Author

Bonaventura, Eleonora, Dhungana, Daya. S., Massetti, Chiara, Pedrini, Jacopo, Grazianetti, Carlo, Martella, Christian, Pezzoli, Fabio, Molle, Alessandro, and Bonera, Emiliano

Subjects
*PHOTOTHERMAL spectroscopy, *RAMAN spectroscopy, *THERMAL conductivity, *SUBSTRATES (Materials science), *THERMAL properties
Abstract

Silicene has recently been revisited as a 2D material with potential thermoelectric applications. Here, the thermal properties of supported silicene are determined by optothermal Raman spectroscopy. Single and multilayer silicene is grown either directly on silver (Ag) substrates or on an intermediate tin (Sn) monolayer, introduced to reduce the influence of the substrate on the physical properties of silicene. Experimental values of an effective cross‐plane thermal conductivity of 0.5 W/mK are obtained for silicene on Ag and 0.3 W/mK for silicene on stanene‐Ag. The values of the interfacial thermal conductance, on the other hand, are 0.3 and 0.5 GW/m2K, respectively. Heterostack engineering is confirmed as a versatile strategy for extracting relevant physical parameters in silicene and for modulating the thermal response in the 2D limit. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Effective Out‐Of‐Plane Thermal Conductivity of Silicene by Optothermal Raman Spectroscopy

Author

Bonaventura, E, Dhungana, D, Massetti, C, Pedrini, J, Grazianetti, C, Martella, C, Pezzoli, F, Molle, A, Bonera, E, Bonaventura, Eleonora, Dhungana, Daya. S., Massetti, Chiara, Pedrini, Jacopo, Grazianetti, Carlo, Martella, Christian, Pezzoli, Fabio, Molle, Alessandro, Bonera, Emiliano, Bonaventura, E, Dhungana, D, Massetti, C, Pedrini, J, Grazianetti, C, Martella, C, Pezzoli, F, Molle, A, Bonera, E, Bonaventura, Eleonora, Dhungana, Daya. S., Massetti, Chiara, Pedrini, Jacopo, Grazianetti, Carlo, Martella, Christian, Pezzoli, Fabio, Molle, Alessandro, and Bonera, Emiliano

Abstract

Silicene has recently been revisited as a 2D material with potential thermoelectric applications. Here, the thermal properties of supported silicene are determined by optothermal Raman spectroscopy. Single and multilayer silicene is grown either directly on silver (Ag) substrates or on an intermediate tin (Sn) monolayer, introduced to reduce the influence of the substrate on the physical properties of silicene. Experimental values of an effective cross-plane thermal conductivity of 0.5 W/mK are obtained for silicene on Ag and 0.3 W/mK for silicene on stanene-Ag. The values of the interfacial thermal conductance, on the other hand, are 0.3 and 0.5 GW/m2K, respectively. Heterostack engineering is confirmed as a versatile strategy for extracting relevant physical parameters in silicene and for modulating the thermal response in the 2D limit.

Published
2024

9. Optical properties of two-dimensional tin nanosheets epitaxially grown on graphene

Author

Bonaventura, E, Martella, C, Macis, S, Dhungana, D, Krotkus, S, Heuken, M, Lupi, S, Molle, A, Grazianetti, C, Bonaventura, Eleonora, Martella, Christian, Macis, Salvatore, Dhungana, Daya S, Krotkus, Simonas, Heuken, Michael, Lupi, Stefano, Molle, Alessandro, Grazianetti, Carlo, Bonaventura, E, Martella, C, Macis, S, Dhungana, D, Krotkus, S, Heuken, M, Lupi, S, Molle, A, Grazianetti, C, Bonaventura, Eleonora, Martella, Christian, Macis, Salvatore, Dhungana, Daya S, Krotkus, Simonas, Heuken, Michael, Lupi, Stefano, Molle, Alessandro, and Grazianetti, Carlo

Abstract

Heterostacks formed by combining two-dimensional materials show novel properties which are of great interest for new applications in electronics, photonics and even twistronics, the new emerging field born after the outstanding discoveries on twisted graphene. Here, we report the direct growth of tin nanosheets at the two-dimensional limit via molecular beam epitaxy on chemical vapor deposited graphene on Al2O3(0001). The mutual interaction between the tin nanosheets and graphene is evidenced by structural and chemical investigations. On the one hand, Raman spectroscopy indicates that graphene undergoes compressive strain after the tin growth, while no charge transfer is observed. On the other hand, chemical analysis shows that tin nanosheets interaction with sapphire is mediated by graphene avoiding the tin oxidation occurring in the direct growth on this substrate. Remarkably, optical measurements show that the absorption of tin nanosheets exhibits a graphene-like behavior with a strong absorption in the ultraviolet photon energy range, therein resulting in a different optical response compared to tin nanosheets on bare sapphire. The optical properties of ultra-thin tin films therefore represent an open and flexible playground for the absorption of light in a broad range of the electromagnetic spectrum and technologically relevant applications for photon harvesting and sensors.

Published
2024

10. Decrease in reaction time for volleyball athletes during saccadic eye movement task: A preliminary study with evoked potentials.

Author

Costa, Élida, Gongora, Mariana, Bittencourt, Juliana, Marinho, Victor, Cagy, Mauricio, Teixeira, Silmar, Nicoliche, Eduardo, Fernandes, Isabelle, Machado, Caroline, Wienecke, Jacob, Ribeiro, Pedro, Gupta, Daya S., Velasques, Bruna, and Budde, Henning

Subjects
SACCADIC eye movements, EVOKED potentials (Electrophysiology), VOLLEYBALL, ATHLETES
Abstract

Aim: This preliminary study investigated the differences in event-related potential and reaction time under two groups (athletes vs. non-athletes). Material and methods: The P300 was analyzed for Fz, Cz, and Pz electrodes in thirty-one healthy volunteers divided into two groups (volleyball athletes and non-athletes). In addition, the participants performed a saccadic eye movement task to measure reaction time. Results: The EEG analysis showed that the athletes, in comparison to the no-athletes, have differences in the P300 in the frontal area (p = 0.021). In relation to reaction time, the results show lower reaction time for athletes (p = 0.001). Conclusions: The volleyball athletes may present a greater allocation of attention during the execution of the inhibition task, since they have a lower reaction time for responses when compared to non-athletes. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Culturally Specific Learning Styles: Some Suggestions for Teachers.

Author

Sandhu, Daya S.

Abstract

This paper examines the importance of culturally-specific learning styles within the context of the Kentucky Education Reform Act of 1990. The Act posits that all students can learn, that students learn differently, and that students learn better when they are taught utilizing their preferred learning modalities. A review of the literature indicates that all cultures, communities, and families can be divided into two major dimensions--traditional and modern--in terms of gender roles, family identity, sense of community, family identification, time orientation, age status, importance of tradition, subservience to convention and authority, and spirituality/religion. Teachers need to understand the cultural style of students; to use a proactive approach to reach out to those students whose values and needs differ from the mainstream; to exhort the message that "to be different means to be distinct but not inferior"; and to accommodate students with differing needs and priorities by changing the system, but not forcing them to change. The main body of the document consists of suggestions to help teachers identify learning styles, and to design teaching strategies to impart instruction through their students' preferred learning modes. (Contains 41 references.) (LL)

Published
1994

14. Shifting Paradigms in Secondary School Counseling: Changing Incidentals to Essentials through Proactive Approaches.

Author

Sandhu, Daya S.

Abstract

There is a general consensus that school counseling is a profession in trouble. Most of the education reform movements underway in various states barely mention, if at all, the importance of school counseling, and counseling positions are in constant danger of being eliminated by school boards faced with budget restraints. Several factors contributing to this low profile and bad image include a lack of recognition of school counseling as a distinct profession, a lack of well-defined school-counselor roles, a burdensome amount of routine administrative assignments, and a very high counselor-student ratio. School counselors need to take steps to empower themselves. They will take a more central place in schools by claiming professional credibility, asserting their significance, and taking a more proactive role in their jobs. The Proactive Model of School Counseling presented here encourages counselors to widen their horizons, not only being responsive to the students seeking counseling on their own, but also reaching out to all students systematically, for the implementation of concrete agendas. The Proactive Model emphasizes the conceptual, operational, evaluative, public relations, and personal development of student counselors. These components are sequenced, interrelated, and precede one another in significance during implementation. Each component is discussed and suggestions for implementation given. (CC)

Published
1993

15. Validation of Eye Movements Model of NLP through Stressed Recalls.

Author

Sandhu, Daya S.

Abstract

Neurolinguistic Progamming (NLP) has emerged as a new approach to counseling and psychotherapy. Though not to be confused with computer programming, NLP does claim to program, deprogram, and reprogram clients' behaviors with the precision and expedition akin to computer processes. It is as a tool for therapeutic communication that NLP has rapidly gained attention among the helping professions since its origins in the 1970s. This study re-examined the Eye Movements Model of NLP--which states that people's primary representational systems (PRS) can be identified through their eye movements--by using the newly developed 52-item inventory with right-handed Louisiana college students (N=102) from educational psychology classes. The results of the study supported claims of NLP proponents that while accessing the memory under stressed recalls to retrieve information, people do use different PRS. Thirteen yes/no type control items were used to demonstrate that identification of PRS is possible only under those conditions when people are made to think hard for information. Furthermore, it was found that the subjects were not aware on their own if they were visuals, auditory, or kinesthetic. This study also found that 13 subjects had more than one representational system. No significant differences were found at alpha level .05 in the distribution of PRS between genders and Cajuns and non-Cajuns as ethnic groups. (Contains 31 references.) (ABL)

Published
1991

19. All-around encapsulation of silicene

Author

Dhungana, D, Massetti, C, Martella, C, Grazianetti, C, Molle, A, Dhungana, Daya S, Massetti, Chiara, Martella, Christian, Grazianetti, Carlo, Molle, Alessandro, Dhungana, D, Massetti, C, Martella, C, Grazianetti, C, Molle, A, Dhungana, Daya S, Massetti, Chiara, Martella, Christian, Grazianetti, Carlo, and Molle, Alessandro

Abstract

Silicene or the two-dimensional (2D) graphene-like silicon allotrope has recently emerged as a promising candidate for various applications in nanotechnology. However, concerns on the silicene stability still persist to date and need to be addressed aiming at the fabrication of competing and durable silicene-based devices. Here, we present an all-around encapsulation methodology beyond the current state-of-the-art silicene configuration, namely silicene sandwiched in between a capping layer (e.g., Al2O3) and the supporting substrate (e.g., Ag). In this framework, the insertion of one or two sacrificial 2D Sn layers enables the realization of different atomically thin encapsulation schemes, preserving the pristine properties of silicene while decoupling it from the growth template. On one hand, the epitaxy of a 2D Sn layer before silicene allows for the removal of the Ag substrate with no effect on silicene which in turn can be easily gated, for example, with an oxide layer on its top face. On the other hand, a full 2D encapsulation scheme, where top and bottom faces of silicene are protected by 2D Sn layers, gives rise to an atomically thin and cm2-scaled membrane preventing degradation of silicene for months. Both schemes thus constitute an advancement for the silicene stability and encapsulation in ambient conditions, paving the way to further exploitation in flexible electronics and photonics.

Published
2023

25. Affordable Broadband with Software Defined IPv6 Network for Developing Rural Communities

Author

Babu R. Dawadi, Danda B. Rawat, Shashidhar R. Joshi, and Daya S. Baral

Subjects
affordable broadband, rural communities, sustainable societies, sdn, ipv6, sodip6, energy efficiency, Technology, Applied mathematics. Quantitative methods, T57-57.97
Abstract

The software defined networking (SDN) paradigm with enhanced features of IPv6 offers flexible network management and better network visibility for enhancing overall network performance, network manageability, and security. Thus, along with the IPv6 network deployment worldwide, SDN migration has emerged worldwide, but network service providers suffer from different issues when migrating their existing legacy network into operable SDN and IPv6 enabled networks. In this paper, we investigate the affordability of broadband network services for the rural communities in the context of information and communication technology (ICT) infrastructure deployment throughout Nepal. During the phase of network transformation, it will be more challenging for the service providers of Nepal to have a proper choice of technologies to expand the network while considering the proper policy formulation, affordability, need of skilled human resources, deployment cost, and many other aspects. We also present the service provider affordability via energy optimization in software defined IPv6 network (SoDIP6) implementation that contributes to a reduction in organizational operational expenditure (OpEX). We perform an experimental analysis over an SoDIP6 network testbed and present a comparison of the annual energy and OpEX savings for network service providers. Our empirical analysis shows that an energy saving of 31.50% on switches and 55.44% on links can be achieved with an SoDIP6 network compared to a network with legacy devices and network management. Optimization on service provider network operational cost leads to sustainability and affordable services to both customers and service providers

Published
2019
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29. DFT and In-silico Investigations along with In-vitro Antitumor and Antimicrobial Assessments of Pharmacological Molecules

Author

Arshi Naqvi, Tarek H. Afifi, Mosa H. Alsehli, Daya S. Seth, Mohamed S.A. El-Gaby, Rawda M. Okasha, and Mohamed Hagar

Subjects
Organic Chemistry, Biochemistry
Abstract

Background: Molecules, bearing an active methylene bridge, are deemed to be one of the most fruitful and remarkable precursors that have been incorporated in the synthetic strategy of an assortment of bioactive compounds. Objective: The reactive methylene derivatives have been endowed with multiple reactions, which target biological and medicinal applications and are resultant from their structural multiplicity and discrete reactivity. Methods: The present report endeavors to synthesize, characterize, and in-vitro evaluate several novel propanoic acid, coumarin, and pyrazole derivatives as antimicrobial and antiproliferative agents. The in-silico molecular docking, physicochemical, pharmacokinetic/ADMET, bioactivity, and drug likeness predictions were conducted for all the synthesized compounds. Results: The highest docking score is -9.9 and -8.3 kcal/mol respectively for compound 9 (azo-coumarin) and 13 (acrylic acid derivative) with the target proteins E. coli topoisomerase II, DNA gyrase subunit B and PI3K p110α domain, respectively. Moreover, this study predicts the synthesized molecules that may inhibit the novel COVID-19, obtained through virtual screenings only, where compounds 9, 13, 14, 17, and 19 came to the limelight with good docking scores i.e more than 8 Kcal/mol. Safety profiling of the most potent compound 9 was utilized against normal cell line and hemolytic effect on RBCs. Conclusion: The in-silico ADMET studies of the synthesized compounds revealed moderate to good drug likeness, high gastro intestinal (GI) absorption, inhibits the Cytochrome CYP2C19 and CYP2C9 and all the derivatives possess non-cancerous nature. The in-vitro screening demonstrated that several of the novel molecules are promising drug candidates. The density function theory (DFT) theoretical calculations were performed to calculate the energy levels of the FMOs and their energy gabs, dipole moment as well as the molecular electrostatic potential. Such parameters along with the physicochemical parameters could be good tool to confirm the biological activity.

Published
2022

30. Toward a Positive Perspective on Violence Prevention in Schools: Building Connections

Author

Smith, Douglas C. and Sandhu, Daya S.

Abstract

As concerns about the level of school violence have increased in recent years, many schools have instituted policies designed to deter or prohibit violent and aggressive acts on school campuses. Although well intentioned, most such policies tend to be reactive and punitive in nature. In contrast, this article proposes a positive approach to violence prevention based on establishing meaningful connections between students, their families, peers, and school.

Published
2004

32. Time perception mechanisms at central nervous system

Author

Rhailana Fontes, Jéssica Ribeiro, Daya S. Gupta, Dionis Machado, Fernando Lopes-Júnior, Francisco Magalhães, Victor Hugo Bastos, Kaline Rocha, Victor Marinho, Gildário Lima, Bruna Velasques, Pedro Ribeiro, Marco Orsini, Bruno Pessoa, Marco Antonio Araujo Leite, and Silmar Teixeira

Subjects
Time perception, time cells, memory, psychiatric diseases, Medicine, Internal medicine, RC31-1245, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

The five senses have specific ways to receive environmental information and lead to central nervous system. The perception of time is the sum of stimuli associated with cognitive processes and environmental changes. Thus, the perception of time requires a complex neural mechanism and may be changed by emotional state, level of attention, memory and diseases. Despite this knowledge, the neural mechanisms of time perception are not yet fully understood. The objective is to relate the mechanisms involved the neurofunctional aspects, theories, executive functions and pathologies that contribute the understanding of temporal perception. Articles form 1980 to 2015 were searched by using the key themes: neuroanatomy, neurophysiology, theories, time cells, memory, schizophrenia, depression, attention-deficit hyperactivity disorder and Parkinson’s disease combined with the term perception of time. We evaluated 158 articles within the inclusion criteria for the purpose of the study. We conclude that research about the holdings of the frontal cortex, parietal, basal ganglia, cerebellum and hippocampus have provided advances in the understanding of the regions related to the perception of time. In neurological and psychiatric disorders, the understanding of time depends on the severity of the diseases and the type of tasks.

Published
2016
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33. Non-immersive 3D virtual stimulus alter the time production task performance and increase the EEG theta power in dorsolateral prefrontal cortex

Author

Monara Nunes, Silmar Teixeira, Thayaná Ribeiro Silva Fernandes, Juliana Bittencourt Marques, Ana Claúdia Mota de Freitas, Marcos Ayres, Gabriela Teles, Victor Hugo Bastos, Daya S. Gupta, Mauricio Cagy, Diandra Caroline Martins e Silva, João Carlos Marques, Anderson de Sousa Escórcio, Victor Marinho, and Carla Ayres

Subjects
0301 basic medicine, Prefrontal Cortex, Stimulus (physiology), Virtual reality, Electroencephalography, Theta power, 03 medical and health sciences, Dorsolateral Prefrontal Cortex, 0302 clinical medicine, Task Performance and Analysis, medicine, Humans, Attention, skin and connective tissue diseases, Cross-Over Studies, medicine.diagnostic_test, General Neuroscience, Virtual Reality, General Medicine, Time perception, Dorsolateral prefrontal cortex, 030104 developmental biology, medicine.anatomical_structure, Theta band, Time Perception, sense organs, Psychology, Neuroscience, 030217 neurology & neurosurgery
Abstract

The study investigated the cortical activity changes and time production task performance induced by changes in motion speed of a non-immersive 3D virtual stimulus.Twenty-one individuals were participated in the crossover study with the visual-time reproduction task under three-speed conditions: original, slow and fast virtual stimulus. In addition, the electroencephalographic analysis of the theta band power in the dorsolateral prefrontal cortex was done simultaneously with time production task execution.The results demonstrated that in the slow speed condition, there is an increase in the error in the time production task after virtual reality (We propose that the modulations of speed of virtual stimulus may underlie the accumulation of temporal pulses, which could be responsible for changes in the performance of the production task of the time intervals and a substantial increase in right dorsolateral prefrontal cortex activity related to attention and memory, acting in cognitive domains of supraseconds.

Published
2020
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35. Understanding Adolescent Suicide: A Psychosocial Interpretation of Developmental and Contextual Factors.

Author

Portes, Pedro R., Sandhu, Daya S., and Longwell-Grice, Robert

Abstract

Using Erikson's theories on identity development as a framework, this paper examines the motives for and contexts of suicide among preadolescents, adolescents, and young adults, identifies specific school-age populations that are vulnerable to suicide, and discusses implications. (Contains 45 references.) (GCP)

Published
2002

36. Optical and thermal responses of silicene in Xene heterostructures

Author

Bonaventura, E, Dhungana, D, Martella, C, Grazianetti, C, Macis, S, Lupi, S, Bonera, E, Molle, A, Bonaventura, Eleonora, Dhungana, Daya S, Martella, Christian, Grazianetti, Carlo, Macis, Salvatore, Lupi, Stefano, Bonera, Emiliano, Molle, Alessandro, Bonaventura, E, Dhungana, D, Martella, C, Grazianetti, C, Macis, S, Lupi, S, Bonera, E, Molle, A, Bonaventura, Eleonora, Dhungana, Daya S, Martella, Christian, Grazianetti, Carlo, Macis, Salvatore, Lupi, Stefano, Bonera, Emiliano, and Molle, Alessandro

Abstract

Stabilization of silicene and preservation of its structural and electronic properties are essential for its processing and future integration into devices. The stacking of silicene on stanene, creating a Xene-based heterostructure, proves to be a viable new route in this respect. Here we demonstrate the effectiveness of a stanene layer in breaking the strong interaction between silicene and the Ag(111) substrate. The role of stanene as a ‘buffer’ layer is investigated by analyzing the optical response of epitaxial silicene through both power-dependent Raman spectroscopy and reflectivity measurements in the near infrared (NIR)-ultraviolet (UV) spectral range. Finally, we point out a Xene-induced shift of the silver plasma edge that paves the way for the development of a new approach to engineering the metal plasmonic response.

Published
2022

38. Optical and thermal responses of silicene in Xene heterostructures

Author

Eleonora Bonaventura, Daya S. Dhungana, Christian Martella, Carlo Grazianetti, Salvatore Macis, Stefano Lupi, Emiliano Bonera, Alessandro Molle, Bonaventura, E, Dhungana, D, Martella, C, Grazianetti, C, Macis, S, Lupi, S, Bonera, E, and Molle, A

Subjects
optical propertie, othothermal, General Materials Science, Raman, silicene, stanene
Abstract

Stabilization of silicene and preservation of its structural and electronic properties are essential for its processing and future integration into devices. The stacking of silicene on stanene, creat- ing a Xene-based heterostructure, proves to be a viable new route in this respect. Here we demonstrate the effectiveness of a stanene layer in breaking the strong interaction between silicene and the Ag(111) substrate. The role of stanene as a ‘buffer’ layer is investi- gated by analyzing the optical response of epitaxial silicene through both power-dependent Raman spectroscopy and reflectivity mea- surements in the near infrared (NIR)–ultraviolet (UV) spectral range. Finally, we point out a Xene-induced shift of the silver plasma edge that paves the way for the development of a new approach to engineering the metal plasmonic response.

Published
2022

44. Integration of the Rhombohedral BiSb(0001) Topological Insulator on a Cubic GaAs(001) Substrate

Author

Fuccio Cristiano, Emmanuelle Daran, Arnaud Proietti, Corentin Durand, Quentin Gravelier, Sebastien Plissard, Benjamin Reig, Alexandre Arnoult, Daya S. Dhungana, Roland Coratger, Dima Sadek, Pier-Francesco Fazzini, Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Centre de microcaractérisation Raimond Castaing (CMCR), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), ANR-17-PIRE-0001,Hybrid,Hybrid Materials for Quantum Science and Engineering(2017), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Centre de microcaractérisation Raimond Castaing (Centre Castaing), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Magnetoresistive random-access memory, Materials science, Condensed matter physics, Spintronics, Magnetoresistance, Chalcogenide, chemistry.chemical_element, 02 engineering and technology, Substrate (electronics), [CHIM.MATE]Chemical Sciences/Material chemistry, Conductivity, 021001 nanoscience & nanotechnology, 01 natural sciences, Bismuth, chemistry.chemical_compound, chemistry, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Topological insulator, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, 010306 general physics, 0210 nano-technology
Abstract

International audience; Bismuth-Antimony alloys () is the first reported 3D Topological Insulator (TI). Among many TIs reported to the date, it remains the most promising for spintronic applications thanks to its large conductivity, its colossal spin Hall angle, and the possibility to build low current spin-orbit-torque (SOT) magnetoresistive random access memories (MRAM). Nevertheless, the 2D integration of TIs on industrial standards is lacking. In this work, we report the inte

Published
2021
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46. Cross-Cultural Counseling and Neurolinguistic Mirroring with Native American Adolescents.

Author

Sandhu, Daya S.

Abstract

Examined effects of neurolinguistic mirroring versus nonmirroring of selected nonverbal behaviors on empathy, trustworthiness, and positive interaction in cross-cultural setting among 60 Choctaw adolescents and Caucasian female counselors. Results indicated significant mirroring effects on the empathy scale of the Barrett-Lennard Relationship Inventory. (Author)

Published
1993

47. Time estimation exposure modifies cognitive aspects and cortical activity of attention deficit hyperactivity disorder adults

Author

Rhailana Medeiros Fontes, Victor Hugo Bastos, Pedro Ribeiro, Victor Marinho, Mauricio Cagy, Valécia Carvalho, Iris Moura, Silmar Teixeira, Ariel Soares Teles, Kaline Rocha, Bruna Velasques, Daya S. Gupta, and Francisco Magalhães

Subjects
Adult, Male, 0301 basic medicine, medicine.medical_specialty, Prefrontal Cortex, Dorsolateral, Audiology, Electroencephalography, behavioral disciplines and activities, Task (project management), 03 medical and health sciences, 0302 clinical medicine, Time estimation, medicine, Humans, Attention deficit hyperactivity disorder, Theta Rhythm, Cross-Over Studies, medicine.diagnostic_test, General Neuroscience, Time Management, Cognition, General Medicine, Time perception, medicine.disease, Cognitive Remediation, 030104 developmental biology, Theta band, Attention Deficit Disorder with Hyperactivity, Time Perception, Visual Perception, Female, Psychology, 030217 neurology & neurosurgery
Abstract

This study investigated whether time-estimation task exposure influences the severity of Attention Deficit Hyperactivity Disorder (ADHD), as well as theta band activity in the dorsolateral prefrontal cortex and ventrolateral prefrontal cortex.Twenty-two patients with ADHD participated in a crossover experiment with a visual time-estimation task under control conditions (without exposure to time estimation tasks) and experimental (thirty days exposure to time-estimation tasks) in association with electroencephalographic analysis of theta band.ADHD patients with thirty days of time-estimation task exposure presented a worse performance of the time-estimation task, as revealed by the measurements of the absolute error and relative error (We propose that the decrease in EEG theta power may indicate an efficient accumulation of temporal pulses, which could be responsible for the improvement in the patient cognitive aspects as demonstrated by the current study. Time-estimation task improves ADHD cognitive symptoms, with a substantial increase in cortical areas activity related to attention and memory, suggesting its use as a tool for cognitive timing function management and non-invasive therapeutic aid in ADHD.

Published
2020
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48. Impaired decision-making and time perception in individuals with stroke: Behavioral and neural correlates

Author

Victor Marinho, Valécia Carvalho, Victor Hugo Bastos, Juliete Bandeira, Thomaz Oliveira, V.G. de Sousa, Marco Orsini, Kaline Rocha, Silmar Teixeira, Giovanny R. Pinto, Daya S. Gupta, and Francisco Magalhães

Subjects
Elementary cognitive task, Decision Making, Prefrontal Cortex, Context (language use), 03 medical and health sciences, Cognition, 0302 clinical medicine, Cerebellum, Neural Pathways, Humans, 030212 general & internal medicine, Prefrontal cortex, Behavior, Neural correlates of consciousness, Motor control, Time perception, Executive functions, Stroke, Neurology, Time Perception, Neurology (clinical), Cognition Disorders, Psychology, 030217 neurology & neurosurgery, Cognitive psychology
Abstract

Several studies have demonstrated that stroke subjects present impairment of functions related to decision-making and timing, involving the information processing in the neural circuits of the cerebellum in association with the prefrontal cortex. This review is aimed to identify the gaps, and demonstrate a better understanding of decision-making and timing functions in the patients with stroke. Electronic literature database was searched and the findings of relevant studies were used to explore the mechanisms of decision-making and timing in patients with stroke, as well as the circuit connections in timing mediated by prefrontal cortex and cerebellum. A literature review was conducted with 65 studies that synthesized findings on decision-making and time perception in individuals with stroke. Types of neurobiological modalities in this study included: Relationships among decision-making, time perception, related cognitive aspects (such as discrimination tasks, verbal estimation, bisection tasks, time production and motor reproduction), and motor control. We demonstrate that the timing processes are important for the performance in cognitive tasks and that the cerebellum and prefrontal cortex are involved in decision-making and time perception. In the context, the decision-making is impaired in stroke patients has a great impact on executive functions, and this seems to be important in determining neurobiological aspects relevant to the time interval interpretation.

Published
2019
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49. Self-catalyzed InAs nanowires grown on Si: the key role of kinetics on their morphology

Author

Daya S Dhungana, Nicolas Mallet, Pier-Francesco Fazzini, Guilhem Larrieu, Fuccio Cristiano, Sébastien R Plissard, Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MBE, Mechanical Engineering, CMOS, Bioengineering, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, nanowires, InAs, Mechanics of Materials, hydrogen, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, surface preparation, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Electrical and Electronic Engineering, patterned substrates
Abstract

Integrating self-catalyzed InAs nanowires on Si(111) is an important step toward building vertical gate-all-around transistors. The complementary metal oxide semiconductor (CMOS) compatibility and the nanowire aspect ratio are two crucial parameters to consider. In this work, we optimize the InAs nanowire morphology by changing the growth mode from Vapor–Solid to Vapor–Liquid–Solid in a CMOS compatible process. We study the key role of the Hydrogen surface preparation on nanowire growths and bound it to a change of the chemical potential and adatoms diffusion length on the substrate. We transfer the optimized process to patterned wafers and adapt both the surface preparation and the growth conditions. Once group III and V fluxes are balances, aspect ratio can be improved by increasing the system kinetics. Overall, we propose a method for large scale integration of CMOS compatible InAs nanowire on silicon and highlight the major role of kinetics on the growth mechanism.

Published
2022
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50. Cross-Cultural Counseling and Neurolinguistic Mirroring: An Exploration of Empathy, Trustworthiness, and Positive Interaction with Native American Adolescents.

Author

Sandhu, Daya S.

Abstract

The quality of the therapeutic relationship is a prime consideration in counseling and psychotherapy. Good rapport in the counseling relationship has consistently been associated with beneficial changes. This study examined the effects of neurolinguistic mirroring versus non-mirroring of selected nonverbal behaviors on empathy, trustworthiness, and positive interaction in a cross-cultural setting. Choctaw adolescents (N=60) between 14 and 19 years of age were randomly assigned to experimental and control groups. Two Caucasian female counselors mirrored and non-mirrored equal numbers of subjects for 10 minutes. Each dyad was videotaped. Data were collected by using the revised empathy scale of the Barrett-Lennard Relationship Inventory and the trustworthiness dimension of the Counselor Rating Form to assess the degree of empathy and trustworthiness as perceived by the subjects. Each videotaped dyad was rated with the Leathers Non-verbal Feedback Rating Instrument. The findings suggest that mirroring of kinesics enhances clients' perceived empathy, at least with adolescents of a different culture than their counselors. The significance of these mirroring meta-tactics lies in the fact that they may be helpful in both mono- and cross-cultural counseling. In the presence of barriers between the clients and the counselors relating to differences of languages, world views, values, and a host of other factors, this technique may prove effective in the initial stages of counseling. (Author/LLL)

Published
1991

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