Disorder-induced superconductivity in ropes of carbon nanotubes

We study the interplay between disorder and superconductivity in a rope of metallic carbon nanotubes. Based on the time dependent Ginzburg Landau theory, we derive the superconducting transition temperature T$_c$ taking into account the critical superconducting fluctuations which are expected to be substantially strong in such low dimensional systems. Our results indicate that, contrary to what is expected, T$_c$ increases by increasing the amount of disorder. We argue that this behavior is due to the dynamics of the tubes which reduces the drastic effect of the local disorder on superconductivity by enhancing the intertube Josephson tunneling. We also found that T$_c$ is enhanced as the effective dimensionality of the rope increases by increasing the number N of the tubes forming the rope. However, T$_c$ tends to saturate for large values of N, expressing the establishment of a bulk three dimensional (3D) superconducting order.Comment: 9 pages, 4 figur

Finite element modeling and experimentation of bone drilling forces

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling. The model incorporates the dynamic characteristics involved in the process along with the accurate geometrical considerations. The average critical thrust forces and torques obtained using FE analysis, for set of machining parameters are found to be in good agreement with the experimental results

Drilling in cortical bone: a finite element model and experimental investigations

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill-bit breakthrough, excessive heat generation, and mechanical damage to the bone. An experimental and computational study of drilling in cortical bone has been conducted. A 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling has been developed. The model incorporates the dynamic characteristics involved in the process along with geometrical considerations. An elastic-plastic material model is used to predict the behaviour of cortical bone during drilling. The average critical thrust forces and torques obtained using FE analysis are found to be in good agreement with the experimental results

Drilling resistance: a method to investigate bone quality

Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r2 = 0.93 for pig bones and r2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery

Finite element modeling and experimentation of bone drilling forces

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling. The model incorporates the dynamic characteristics involved in the process along with the accurate geometrical considerations. The average critical thrust forces and torques obtained using FE analysis, for set of machining parameters are found to be in good agreement with the experimental results

Designing UHF RFID tag antennas with Barcode shape for dual-technology identification

In this paper, a novel methodology to design Ultra High Frequency Radio-Frequency IDentification (UHF RFID) tag antennas with Barcode layout is proposed with the challenging goal of "fusing" both technologies in a single device. Specifically, after a brief recall of the well-known barcode standard, a procedure to design meandered barcode-shaped UHF RFID tags is introduced and discussed leveraging on electromagnetic evidence. The main steps of the proposed method are described by highlighting the constraints inherited by both the adopted technologies, as well as the useful opportunities to automatise the entire antenna design process after a preliminary simulation campaign through a full-wave simulator. Different RFID-Barcode tag antennas are designed, manufactured, and characterised in terms of maximum reading range and tag sensitivity. Obtained results demonstrate the validity of the proposed approach

Competing phases in the high field phase diagram of (TMTSF)2_2ClO4_4

A model is presented for the high field phase diagram of (TMTSF)$_2$ClO$_4$, taking into account the anion ordering, which splits the Fermi surface in two bands. For strong enough field, the largest metal-SDW critical temperature corresponds to the N=0 phase, which originates from two intraband nesting processes. At lower temperature, the competition between these processes puts at disadvantage the N=0 phase vs. the N=1 phase, which is due to interband nesting. A first order transition takes then place from the N=0 to N=1 phase. We ascribe to this effect the experimentally observed phase diagrams.Comment: 5 pages, 3 figures (to appear in Phys. Rev. Lett.

Inhomogeneous superconductivity in organic conductors: role of disorder and magnetic field

Several experimental studies have shown the presence of spatially inhomogeneous phase coexistence of superconducting and non superconducting domains in low dimensional organic superconductors. The superconducting properties of these systems are found to be strongly dependent on the amount of disorder introduced in the sample regardless of its origin. The suppression of the superconducting transition temperature $T_c$ shows clear discrepancy with the result expected from the Abrikosov-Gor'kov law giving the behavior of $T_c$ with impurities. Based on the time dependent Ginzburg-Landau theory, we derive a model to account for the striking feature of $T_c$ in organic superconductors for different types of disorder by considering the segregated texture of the system. We show that the calculated $T_c$ quantitatively agrees with experiments. We also focus on the role of superconducting fluctuations on the upper critical fields $H_{c2}$ of layered superconductors showing slab structure where superconducting domains are sandwiched by non-superconducting regions. We found that $H_{c2}$ may be strongly enhanced by such fluctuations.Comment: to appear in Journal of Physics: Condensed Matte

Aquaporin-3 Re-Expression Induces Differentiation in a Phospholipase D2-Dependent Manner in Aquaporin-3-Knockout Mouse Keratinocytes

Aquaporin-3 (AQP3) is a water and glycerol channel expressed in epidermal keratinocytes. Despite many studies, controversy remains about the role of AQP3 in keratinocyte differentiation. Previously, our laboratory has shown co-localization of AQP3 and phospholipase D2 (PLD2) in caveolin-rich membrane microdomains. We hypothesized that AQP3 transports glycerol and “funnels” this primary alcohol to PLD2 to form a pro-differentiative signal, such that the action of AQP3 to induce differentiation should require PLD2. To test this idea, we re-expressed AQP3 in mouse keratinocytes derived from AQP3-knockout mice. The re-expression of AQP3, which increased [3H]glycerol uptake, also induced mRNA and protein expression of epidermal differentiation markers such as keratin 1, keratin 10, and loricrin, with or without the induction of differentiation by an elevated extracellular calcium concentration. Re-expression of AQP3 had no effect on the expression of the proliferation markers keratin 5 and cyclin D1. Furthermore, a selective inhibitor of PLD2, CAY10594, and a lipase-dead (LD) PLD2 mutant, but not a LD PLD1 mutant, significantly inhibited AQP3 re-expression–induced differentiation marker expression with calcium elevation, suggesting a role for PLD2 in this process. Thus, our results indicate that AQP3 has a pro-differentiative role in epidermal keratinocytes and that PLD2 activity is necessary for this effect

Access to Dental Care for Children and Young People in Care and Care Leavers: A Global Scoping Review

Aims: This scoping review aimed to explore three research questions: 1. What is the dental care access for children and young people (CYP) in care and care leavers? 2. What factors influence CYP in care and care leavers’ access to dental care? 3. What pathways have been developed to improve access to oral health care for CYP in care and care leavers? Methods: Five databases (Ovid MEDLINE, Ovid Embase, CINAHL, SocINDEX and Dentistry and Oral Sciences Source) and grey literature sources were systematically searched. Articles relating to CYP in care or care leavers aged 0–25 years old, published up to January 2023 were included. Abstracts, posters and publications not in the English language were excluded. The data relating to dental care access were analysed using thematic analysis. Results: The search identified 942 articles, of which 247 were excluded as duplicates. A review of the titles and abstracts yielded 149 studies. Thirty-eight were eligible for inclusion in the review: thirty-three peer-reviewed articles, one PhD thesis and four grey literature sources. All papers were published from very high or medium Human Development Index countries. The studies indicate that despite having higher treatment needs, CYP in care and care leavers experience greater difficulty in accessing dental services than those not care-experienced. Organisational, psycho-social and logistical factors influence their access to dental care. Their experience of dental care may be impacted by adverse childhood events. Pathways to dental care have been developed, but little is known of their impact on access. There are very few studies that include care leavers. The voices of care-experienced CYP are missing from dental access research. Conclusions: care-experienced CYP are disadvantaged in their access to dental care, and there are significant barriers to their treatment needs being met