Engineering two-dimensional nodal semimetals in functionalized biphenylene by fluorine adatoms

We propose a new band engineering scheme on the biphenylene network, a newly synthesized carbon allotrope. First, we investigate the mechanism for the appearance of type II Dirac fermion in a pristine biphenylene network. We show that the essential ingredients are mirror symmetries and the stabilization of the compact localized eigenstates via destructive interference. While the former is used for the band-crossing point along high symmetry lines, the latter makes the obtained Dirac dispersion highly inclined. Then, we demonstrate that many other different kinds of Dirac fermions, such as type-I Dirac, gapped type-II Dirac, and nodal line semimetals, can be developed by fluorinating the biphenylene network periodically in various ways. In this program, the key role of the fluorine atoms is manipulating the condition of the destructive interference and mirror symmetries

Nanopores of carbon nanotubes as practical hydrogen storage media

We report on hydrogen desorption mechanisms in the nanopores of multiwalled carbon nanotubes (MWCNTs). The as-grown MWCNTs show continuous walls that do not provide sites for hydrogen storage under ambient conditions. However, after treating the nanotubes with oxygen plasma to create nanopores in the MWCNTs, we observed the appearance of a new hydrogen desorption peak in the 300–350 K range. Furthermore, the calculations of density functional theory and molecular dynamics simulations confirmed that this peak could be attributed to the hydrogen that is physically adsorbed inside nanopores whose diameter is approximately 1 nm. Thus, we demonstrated that 1 nm nanopores in MWCNTs offer a promising route to hydrogen storage media for onboard practical applications

Privacy Protection for Personal Health Device Communication and Healthcare Building Applications

This paper proposes a new method for protecting patient privacy when communicating with a gateway which collects bioinformation through using personal health devices, a type of biosensor for telemedicine, at home and in other buildings. As the suggested method is designed to conform with ISO/IEEE 11073-20601, which is the international standard, interoperability with various health devices was considered. We believe it will be a highly valuable resource for dealing with basic data because it suggests an additional standard for security with the Continua Health Alliance or related international groups in the future

Anti-reflective nano- and micro-structures on 4H-SiC for photodiodes

In this study, nano-scale honeycomb-shaped structures with anti-reflection properties were successfully formed on SiC. The surface of 4H-SiC wafer after a conventional photolithography process was etched by inductively coupled plasma. We demonstrate that the reflection characteristic of the fabricated photodiodes has significantly reduced by 55% compared with the reference devices. As a result, the optical response Iillumination/Idark of the 4H-SiC photodiodes were enhanced up to 178%, which can be ascribed primarily to the improved light trapping in the proposed nano-scale texturing

Oxygen Partial Pressure during Pulsed Laser Deposition: Deterministic Role on Thermodynamic Stability of Atomic Termination Sequence at SrRuO3/BaTiO3 Interface

With recent trends on miniaturizing oxide-based devices, the need for atomic-scale control of surface/interface structures by pulsed laser deposition (PLD) has increased. In particular, realizing uniform atomic termination at the surface/interface is highly desirable. However, a lack of understanding on the surface formation mechanism in PLD has limited a deliberate control of surface/interface atomic stacking sequences. Here, taking the prototypical SrRuO3/BaTiO3/SrRuO3 (SRO/BTO/SRO) heterostructure as a model system, we investigated the formation of different interfacial termination sequences (BaO-RuO2 or TiO2-SrO) with oxygen partial pressure (PO2) during PLD. We found that a uniform SrO-TiO2 termination sequence at the SRO/BTO interface can be achieved by lowering the PO2 to 5 mTorr, regardless of the total background gas pressure (Ptotal), growth mode, or growth rate. Our results indicate that the thermodynamic stability of the BTO surface at the low-energy kinetics stage of PLD can play an important role in surface/interface termination formation. This work paves the way for realizing termination engineering in functional oxide heterostructures.Comment: 27 pages, 6 figures, Supporting Informatio

Evaluation of public’s perception of scar cosmesis after thyroidectomy: Results of a survey of Turkish versus South Korean individuals

Purpose: Visible scars on the neck caused by thyroid surgery give rise to significant aesthetic, functional, and psychosocial problems. The objective of this study is to comparatively investigate the public perception of neck scar cosmesis in Turkish and South Korean populations. Methods: This survey was prepared to collect participants’ demographic and socioeconomic data and determine their perception of scar cosmesis on the neck and consisted of 15 questions. One thousand thirty-nine individuals who did not undergo thyroid surgery completed the survey. The P-values of <0.05 were deemed to indicate statistical significance. Results: There were 1,039 respondents, of whom 525 (50.5%) were Turkish and 514 (49.5%) were South Korean. South Korean respondents stated that they would be significantly more uncomfortable with the thought of having a scar due to thyroid surgery, compared to the Turkish respondents (P < 0.001). The South Korean respondents stated that they would be significantly more concerned about the scar’s length, thickness, and darkening color, compared to the Turkish respondents (P < 0.001 for all cases). Conclusion: Patients’ expectations, which are affected by various sociodemographic factors and cultural characteristics, are as important as the medical condition when deciding on the type of thyroid surgery. The study findings clearly indicated that the South Korean population would be significantly more uncomfortable with having a scar on the neck, compared to the Turkish population. Therefore, in selected cases, a scarless thyroidectomy approach, such as transoral endoscopic thyroidectomy, vestibular approach may be preferable for societies like South Korea