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Graphene quantum dots (GQDs) with a band gap have been widely applied in many fields owing to their unique optical properties. To better utilize the optical advantages of GQDs, it is important to understand their optical characteristics. Our study demonstrates the optical properties and carrier behaviors of synthesized graphene oxide quantum dot (GOQD) and reduced graphene oxide quantum dot (rGOQD) pellets via Terahertz time-domain spectroscopy (THz-TDS). The complex permittivity and optical conductivity are obtained in the terahertz region, indicating that the optical conductivity of the GOQD is higher than that of the rGOQD. Although rGOQD has a higher carrier density, approximately 1.5-times than that of GOQD, the lower charge carrier mobility of the rGOQD, which is obtained using Drude–Lorentz oscillator model fitting contributes to a decrease in optical conductivity. This lower mobility can be attributed to the more significant number of defect states within the rGOQD compared to GOQD. To the best of our knowledge, our study initially demonstrates the optical property and carrier behaviors of GOQD and rGOQD in the THz region. Moreover, this study provides important information on factors influencing carrier behavior to various fields in which carrier behavior plays an important role.

Abstract Lithium-ion capacitors (LICs) are next-generation electrochemical storage devices that combine the benefits of both supercapacitors and lithium-ion batteries. Silicon materials have attracted attention for the development of high-performance LICs owing to their high theoretical capacity and low delithiation potential (~0.5 V vs. Li/Li+). However, sluggish ion diffusion has severely restricted the development of LICs. Herein, a binder-free anode of boron-doped silicon nanowires (B-doped SiNWs) on a copper substrate was reported as an anode for LICs. B-doping could significantly improve the conductivity of the SiNW anode, which could enhance electron/ion transfer in LICs. As expected, the B-doped SiNWs//Li half-cell delivered a higher initial discharge capacity of 454 mAh g−1 with excellent cycle stability (capacity retention of 96% after 100 cycles). Furthermore, the near-lithium reaction plateau of Si endows the LICs with a high voltage window (1.5-4.2V), and the as-fabricated B-doped SiNWs//AC LIC possesses the maximum energy density value of 155.8 Wh kg−1) at a battery-inaccessible power density of 275W kg−1. This study provides a new strategy for using Si-based composites to develop high-performance LIC.

This article argues that linguistically endangered minority groups often face endangerment due to structural linguistic injustice that arises from past injustices and ongoing unjust social processes. Language revitalization is often a justified way of reforming unjust social structures. I connect this discussion to another debate, namely, whether historical injustice (and the requirement for its correction) may be superseded. I ask: which changing circumstances might lead to the supersession of structural linguistic injustice? Of the many reasons to reform unjust social structures, I focus on dignity-based concerns. Historically-sensitive dignity-based concerns are relevant for judging whether supersession of structural linguistic injustice has occurred. My view is largely present-oriented, but history still plays a role in deciding the strength of justificatory bases for structural reformation.

There has been growing interest in integrating digital technologies in healthcare. The purpose of this study was to systematically review the economic value of pharmacist-led digital interventions. PubMed, Web of Science, and the Cochrane databases were searched to select studies that had conducted economic evaluations of digital interventions by pharmacists for the period from January 2001 to February 2022. Economic evidence from 14 selected studies was synthesized in our analysis. Pharmacists used telephones, computers, web-based interventions, videotapes, smartphones, and multiple technologies for their digital interventions. Prior studies have reported the results of telephone-based interventions to be cost-effective. Alternatively, these interventions were found to be cost-effective when reevaluated with recently cited willingness-to-pay thresholds. In addition, pharmacist-led interventions based on computers, web-based interventions, smartphones, and multiple technologies have been reported to be cost-effective in previous studies. However, videotape-based intervention was found cost-ineffective because there was no significant difference in outcomes between the intervention and the usual care groups. If this intervention had been intensive enough to improve outcomes in the intervention group, favorable cost-effectiveness results could have been obtained. The economic evidence in the previous studies represented short-term economic values. Economic evaluations of the long-term value of digital interventions are warranted in future studies.

Background The corner pocket (CP) approach for supraclavicular block (SCB) prevents ulnar nerve (UN) sparing due to needle proximity of lower trunk. Improved ultrasound resolution has suggested that the intertruncal (IT) approach is a suitable alternative method. However, the comparative efficiency of these two approaches on UN block has not been evaluated. Methods Sixty patients were randomized to undergo SCB using the ultrasound-guided CP or IT approach. For lower trunk blockade, 10 mL of local anesthetic agents (1:1 mixture of 0.75% ropivacaine and 1% lidocaine) were injected in the CP (CP approach) or between the lower and middle trunk (IT approach). Additional 15mL was injected identically to block the middle and upper trunks in both groups. Sensory and motor blockade was evaluated after intervention. Results Complete sensory blockade (75.9% [22/29] vs 43.3% [13/30], P = 0.023) and complete motor blockade (82.8% [24/29] vs 50.0% [15/30], P = 0.017) of the UN at 15 min after SCB were significantly more frequent in the IT than in the CP group. Sensory block onset time of UN was significantly shorter in the IT compared to the CP group (15.0 [10.0; 15.0] min vs 20.0 [15.0; 20.0] min; P = 0.011). Conclusions The IT approach provided a more rapid onset of sensory and motor block of the UN than the CP approach. These results suggest that the IT approach is a suitable alternative to the CP approach and can provide faster surgical readiness.

In this article, we present improved short-time Fourier transform for fault detection of field coils, among the most important parts in rotating machinery. It is generally difficult to detect a fault signal of a field coil due to the low signal-to-noise ratio (SNR) associated with these signals. To solve this problem, we constructed a parallel resonance circuit using the inductance of the field coil and improved the SNR of the fault detection signal by using the bandpass filter characteristics of the resonance circuit. The transfer function curve upon parameter changes of the proposed resonance circuit is presented, and the governing equation is derived so that the resonance frequency can be calculated. We also carried out a fault detection test to verify the feasibility of the proposed method. As a result, we demonstrated that the proposed method can enhance the SNR and enable fault detection using the extracted abnormal signal. Also, it was confirmed that the proposed system responds instantaneously to an abnormal signal for fault detection. Therefore, it is proved that the methodology presented in this article is efficient for fault detection in rotating machinery.

In recent years, a new quench protection system using capacitor and switches has been announced to rapidly extract energy from high temperature superconducting (HTS) magnets. When a quench occurs, the quench protection system activates four metal oxide-semiconductor field-effect transistor switches in sequence, and the energy stored in the magnet is extracted by a capacitor to an external resistor. To verify the feasibility of the proposed dual-capacitor switching (DCS) quench protection system, DCS system was tested using a small-scale coil with a 3.3 mH self-inductance. The experimental results show that the energy extraction of the magnet is faster than the quench protection system using a conventional dump resistor. However, as the system is sensitive to the capacitance, inductance, and four resistances, it is necessary to analyze and optimize the design parameters for an application to various magnet systems. In this study, a modified DCS system is introduced to remove the constraints of capacitance, and the effect of all the design parameters on DCS protection performance is analyzed. The optimal design of modified DCS protection system for the best performance is determined. The performance of the system is also evaluated by applying a design that is optimized for the scale-up HTS coil with a 30 mH self-inductance.

The high-temperature superconducting magnets with high magnetic field can store a relatively large amount of energy because of their large inductance and operating current. The magnetic energy stored in the magnet is converted into heat energy when a quench occurs, and the heat generated by the quench resistance and magnet current is sufficient to damage the magnet. Therefore, the large amount of energy stored in a superconducting magnet must be removed quickly to protect the magnet. In this paper, a new quench protection method using a capacitor and dual-switches is proposed and compared to a conventional energy extraction system that uses only a dump resistor. The simulation and test results show that this new protection system is a feasible method for reducing the temperature increase by rapidly reducing the magnet current when a quench occurs.

Background We previously reported that percutaneous dilatational tracheostomy (PDT) can be safely performed 2 cm below the cricothyroid membrane without the aid of a bronchoscope. Although our simplified method is convenient and does not require sophisticated equipment, the precise location for tracheostomy cannot be confirmed. Because it is recommended that tracheostomy be performed at the second tracheal ring, we assessed whether patient characteristics could predict the distance between the cricothyroid membrane and the second tracheal ring. Methods Data from 490 patients who underwent three-dimensional neck computed tomography from January 2012 to December 2015 were analyzed, and the linear distance from the upper part of the cricoid cartilage (CC) to the lower part of the second tracheal ring (2TR) was measured in the sagittal plane. Results The mean CC-to-2TR distance was 25.26 mm (95% CI 25.02–25.48 mm). Linear regression analysis showed that the predicted CC-to-2TR distance could be calculated as −5.73 + 0.2 × height (cm) + 1.22 × sex (male: 1, female: 0) + 0.01 × age (yr) −0.03 × weight (kg) (adj. R2 = 0.55). Conclusions These results suggest that height and sex should be considered when performing PDT without bronchoscope guidance.

An high temperature superconducting (HTS) quadruple magnet used to focus and defocus beams in particle accelerator has been studied for overcoming the disadvantages of low temperature superconducting (LTS) quadruple magnet. LTS quadruple magnet is hard to withstand radiation and heat load at hot cell because of small thermal margin of LTS, and has a nonlinear magnetic characteristic due to iron-core. The thermal margin is improved by changing the LTS to HTS. The magnetic field components are linear according to the operation current by removing the iron-core. Therefore, the air-core HTS quadruple magnet was designed in the past research. Field qualities that determine the performance of the quadruple magnet are composed of field gradient, field uniformity and effective length, and those of air-core HTS quadruple magnet can be achieved using harmonic matching (HM) method. However, when the quadruple magnet is fabricated, parameters of the fabricated magnet are different from designed parameters due to the manufacturing errors. This manufacturing error, REBCO conductor’s dimensional variation of thickness and width, and human errors during winding and assembling, could crucially influence to the field qualities of the quadruple magnet. In this paper, we present a draft design of air-core HTS quadruple magnet and describes an analytical method to predict change of field gradient, uniformity and effective length caused by manufacturing errors and (3) an evaluation of the permissible manufacturing error for an air-core HTS quadruple magnet.

In this work, deoxyribonucleic acid (DNA)-wrapped multi-walled carbon nanotubes (MWCNTs), denoted as CNT@DNA, were successfully assembled through a facile sonication treatment. By using the as-obtained CNT@DNA as template, a NiCo2O4-CNT@DNA composite with anchored NiCo2O4 nanoparticles was fabricated by coating via in situ precipitation. The nanostructures of the as-synthesized samples were examined via powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) techniques. Subsequently, the NiCo2O4-CNT@DNA and NiCo2O4-CNT (prepared without DNA) samples were used as cathode materials to fabricate supercapacitors with high capacitive performance. The results of electrochemical tests show that the NiCo2O4-CNT@DNA electrode exhibits a high specific capacitance of 760.0 F/g at 5 mV/s, which is higher than that of the NiCo2O4-CNT electrode. The NiCo2O4-CNT@DNA electrode displays a capacitance retention of 96.2% after 5000 cycles at the current density of 5 A/g. Moreover, a NiCo2O4-CNT@DNA//activated carbon (AC) asymmetric supercapacitor, prepared using NiCo2O4-CNT@DNA and activated carbon as the positive and negative electrodes, respectively, shows a specific capacitance of 223.7 F/g and a maximum energy density of 69.7 Wh/kg at a power density of 373.9 W/kg. The NiCo2O4-CNT@DNA//AC asymmetric supercapacitors, integrated in series, powered 5 mm red, yellow, and green light-emitting diodes (LEDs). The above results demonstrate that the novel NiCo2O4-CNT@DNA composites can be promising candidates as electrode materials for high-performance supercapacitors in future applications.

We report a facile and versatile strategy to prepare multi-dimensional nanocarbons hybridized with mesoporous SiO2. Carbon nanoplatelets (CNPs, two-dimensional structure of nanocarbons) were combined with carbon nanotubes (CNTs, one-dimensional nanocarbons) to form multi-dimensional carbons (2D–1D, CNP–CNTs). The CNP–CNTs were synthesized by directly growing CNTs on CNPs. A simple solution-based process using TEOS (tetraethyl orthosilicate) resulted in coating or hybridizing CNP–CNTs with mesoporous silica to produce CNP–CNTs@SiO2. The nanocarbons’ surface area significantly increased as the amount of TEOS increased. Electrochemical characterizations of CNP–CNTs@SiO2 as supercapactior electrodes including cyclic voltammetry and galvanostatic charge–discharge in 3 M KOH (aq) reveal excellent-specific capacitance of 23.84 mF cm−2 at 20 mV s−1, stable charge–discharge operation, and low internal resistance. Our work demonstrates mesoporous SiO2 on nanocarbons have great potential in electrochemical energy storage.

In this paper, a new method is presented for sensitive quench detection in high-temperature superconductor (HTS) rotating machinery. The normal zone propagation velocity of an HTS is about 1000 times slower than that of a low-temperature superconductor. Therefore, the propagation of normal zone resistance, which occurs when the HTS transits from the superconducting state to the normal state, is also slower. Thus, it is difficult to detect the abnormal signals by voltage measurement using voltage taps. Moreover, the monitoring signal includes noise generated by interaction between the HTS rotating machinery and the industrial environment. Therefore, when quenching occurs in the HTS rotating machinery, a thermal runaway occurs in the hot spot. Furthermore, the magnetic energy stored in the HTS coil can damage the machinery. For these reasons, a new method is proposed for sensitive quench detection that reduces the noise generated from the power supply and from the HTS rotating machinery, using both an RLC resonance circuit and fast Fourier transform analysis.

Proposed in this paper is a new procedure of range image (point cloud) registration reducing the risk of the original Iterative Closest Point (ICP) algorithm which gets stuck in a local minimum. To reduce this risk, it is essential to achieve the fine initial alignment of the given range images. The proposed procedure employs a 2D image registration method to achieve the fine initial alignment instead of a 3D feature based registration method. Although the 2D image registration method has also the risk of mismatching, we minimize the risk by increasing the number of test cases and selecting the answer that gains the most votes. To generate effective test cases, multiple 2D images are synthetized from the given range images by varying the orientation and resolution. The proposed procedure is implemented and tested for various examples, with experimental results showing that it outperforms existing methods.

The thermal conductivity (κ) of polymer nanocomposites with boron nitride (BN) nanoplates is critically dependent on the distribution of BN in the polymer matrix. Here, we heavily functionalized BN nanoplates with hydroxyl groups by ultrasonication in solution with boric acid. Then, the hydroxylated BN nanoplates could be homogeneously distributed in an epoxy matrix, which improved the through-plane κ of 2.09 and 1.96 W/m·K at 25 and -90 °C, respectively. Processable composite resin with hydroxylated BN was utilized as an adhesive for a low-temperature superconducting (LTS) coil to enhance its normal zone propagation velocity (NZPV) and cooling rate performance. Consequently, fast heat dissipation through the adhesive between superconductors contributed to a 65.8% of increase in NZPV and a 13.1% improvement in the cooling rate of the device compared with a commercial adhesive.

Background Intraoperative hypothermia is common in patients undergoing general anesthesia during arthroscopic hip surgery. In the present study, we assessed the effect of heating and humidifying the airway with a heated wire humidification circuit (HHC) to attenuate the decrease of core temperature and prevent hypothermia in patients undergoing arthroscopic hip surgery under general anesthesia. Methods Fifty-six patients scheduled for arthroscopic hip surgery were randomly assigned to either a control group using a breathing circuit connected with a heat and moisture exchanger (HME) (n = 28) or an HHC group using a heated wire humidification circuit (n = 28). The decrease in core temperature was measured from anesthetic induction and every 15 minutes thereafter using an esophageal stethoscope. Results Decrease in core temperature from anesthetic induction to 120 minutes after induction was lower in the HHC group (-0.60 ± 0.27℃) compared to the control group (-0.86 ± 0.29℃) (P = 0.001). However, there was no statistically significant difference in the incidence of intraoperative hypothermia or the incidence of shivering in the postanesthetic care unit. Conclusions The use of HHC may be considered as a method to attenuate intraoperative decrease in core temperature during arthroscopic hip surgery performed under general anesthesia and exceeding 2 hours in duration.

This paper reports the feasibility of the impregnation of no-insulation (NI) high-temperature superconducting (HTS) coils using an electrically conductive epoxy resin. Recently, several studies of HTS coils without turn-to-turn insulation have been reported for field coils used in rotating machines such as motors and generators. The NI winding technique enhances the thermal stability of the HTS coil without requiring complicated protection techniques because the quench current is automatically bypassed through the turn-to-turn contacts within the HTS coil. Nevertheless, there is still a question as to whether the NI technique can be applied to rotating machines. To utilize an HTS coil under high mechanical loads such as field coils for rotating machines, the HTS tapes must be stabilized mechanically. For HTS field coils intended for use in rotating machines, epoxy impregnation is generally necessary to protect the HTS field coil from mechanical disturbances caused by the magnetic field and rotational vibration of the rotor to enhance the mechanical stability [1] , [2] . However, the NI HTS coil cannot be fabricated by wet winding using epoxy resin because epoxy resins such as Stycast 2850 FT and CTD 521 are electrically insulating materials. This study examines the electrical stability of an NI HTS coil impregnated with an epoxy resin containing electrically conductive particles. The results are likely to present useful data for the application of electrically conductive epoxy impregnated NI HTS coils to rotating machines.

The Jackson table has minimal effects on cardiac function because it does not elevate abdominal and thoracic pressures. In addition, it decreases venous congestion and increases exposure of the surgical field. However, the hips and knees are flexed with inappropriate padding, and venostasis is promoted and increased. Pulmonary thromboembolism (PTE) is fatal; thus immediate diagnosis and treatment are essential. However, clinical signs of intraoperative PTE are difficult to discern. Thrombolytic therapy can be considered as first-line therapy, but bleeding limits its use. The authors report a case of PTE resulting from patient positional change after spine surgery, and the use of immediate postoperative recombinant tissue-type plasminogen activator.

Regional anesthesia for non-obstetric surgery in parturients is a method to decrease patient and fetal risk during general anesthesia. Thoracic interfascial nerve block can be used as an analgesic technique for surgical procedures of the thorax. The Pecs II block is an interfascial block that targets not only the medial and lateral pectoral nerves, but also the lateral cutaneous branch of the intercostal nerve. Pecto-intercostal fascial block (PIFB) targets the anterior cutaneous branch of the intercostal nerve. The authors successfully performed a modified Pecs II block and PIFB without complications in a parturient who refused general anesthesia for breast surgery.