Discharge Method Research Articles

The direct and indirect effects of length of hospital stay on the costs of inpatients with stroke in Ningxia, China, between 2015 and 2020: A retrospective study using quantile regression and structural equation models.

ImportanceLength of hospital stay (LOHS) is the main cost-determining factor of hospitalization for stroke patients. However, previous analyses involving LOHS did not consider confounding or indirect factors, or the effects of other factors on LOHS and inpatient costs.ObjectiveTo investigate the direct and indirect effects of LOHS on the hospitalization costs of inpatients with ischemic and hemorrhagic stroke.Design, setting, and participantsThis was a population-based, retrospective, and observational study that analyzed data acquired from the Nationwide Inpatient Sample between 2015 and 2020 relating to ischemic and hemorrhagic stroke in Ningxia, China.Main outcomes and measuresHospitalizations were identified by the International Classification of Diseases 10th Revision (ICD-10). Inpatient costs were described by the median M (P25, P75). We used a quantile regression model to estimate the linear relationships between a group of independent variables X and the quantile of the explained variable hospitalization cost (Y). A structural equation model (SEM) was then used to investigate the direct and indirect effects of LOHS on inpatient costs.ResultsThe study included 129,444 patients with ischemic stroke and 15,525 patients with hemorrhagic stroke. The median LOHS was 10 (8–13) days for ischemic stroke and 15 (10–22) days for hemorrhagic stroke. The median M (P25, P75) of inpatient costs was $1020 (742–1545) for ischemic stroke and 2813 (1576–6191) for hemorrhagic stroke. The total effect of LOHS on inpatient costs was 0.795 in patients with ischemic stroke. The effect of yearof discharge (X4) and CCI (X8) on inpatient costs was dominated by an indirect effect through the LOHS. The indirect effect was −0.071 (84.52% of the total effect value) and 0.034 (69.39% of the total effect value), respectively. The total effect of LOHS on inpatient costs in patients with hemorrhagic stroke was 0.754. The influence of CCI on inpatient costs was dominated by an indirect effect through LOHS; the indirect effect value was −0.028 (77.78% of the total effect value). The payment type, surgery, method of discharge, and hospital level also exerted an impact on inpatient costs by direct and indirect effects through the LOHS.Conclusions and relevanceLength of hospital stay (LOHS) was identified as the main factor influencing hospitalization costs. However, other social factors were shown to indirectly influence hospitalization costs through the LOHS. Taking effective measures to further reduce hospitalization costs remains an effective way to control hospitalization costs for stroke patients.

Influence of Different Dielectrics and Machining Parameters for Electrical Discharge-Assisted Milling of Titanium Alloy

The machinability of the hybrid machining method for electrical discharge assisted milling (EDAM) has been validated in previous research. The influence of three different dielectrics (kerosene, EDM oil, and deionized water) on the performance of the EDAM was investigated in this study. An analysis of the discharged signal, surface morphology, and elemental composition of the electrode under different machining parameters reveals the influence of different dielectrics. The results show that compared with deionized water, kerosene and EDM oil have a higher discharge frequency. After long-term discharge, debris and carbides will be generated during processing, which will affect the microhardness and discharge stability of the processed material. Among the result of EDAM, EDM oil produced the best surface integrity, with surface roughness values 34.93%, 87.92%, and 121.68% lower than those of kerosene, deionized water, and conventional milling (CM), respectively. The results show that EDAM reduces the microhardness after machining by reducing the plastic deformation of the surface.

Effects of amplitude modulated discharge on growth of nanoparticles in TEOS/O2/Ar capacitively coupled plasma

We investigate the effects of the amplitude modulation (AM) discharge method on the growth of nanoparticles and the relation between growth of nanoparticles and plasma generation in tetraethylorthosilicate (TEOS)/O2/Ar plasma. The laser-light scattering (LLS) intensity, which is proportional to the density and the sixth power of the size of nanoparticles in the Rayleigh scattering regime, decreases by 18% at an AM level of 10% and by 60% at an AM level of 50%. On the other hand, the ArI emission intensity, which is roughly proportional to plasma density, is higher than that for the continuous wave discharge. Thus, AM discharges suppress growth of nanoparticles in TEOS plasma. We have shown oscillations of the axial electric field Ez with the AM frequency for AM discharge by electric field measurement using an electro-optic probe. We have discussed that these fluctuations of Ez mainly lead to the vertical oscillation of the levitation position of nanoparticles trapped in the plasma sheath boundary region by taking into account the force balance equation in the axial direction on these negatively charged nanoparticles.

On-Line Partial Discharge Localization in Power Cables Based on Electromagnetic Time Reversal Theory - Numerical Validation

This paper presents the numerical validation of a new on-line location method of partial discharge (PD) in cables of Medium Voltage (MV) power networks based on the electromagnetic time reversal (EMTR) theory. Because PD events are a symptom of cable insulation degradation, PDs localization is a key topic for fault prevention on power networks, increasing their reliability and resilience and to guaranteeing electricity security. A description of the proposed EMTR PD location method is given and its effectiveness and accuracy are analyzed in lines with both homogeneous and inhomogeneous power cables. The accuracy of PD location methods is strongly affected by the distortion of the PD pulses during their propagation on power lines, caused mainly by the skin effect. For this reason, the accuracy of the proposed location method is analyzed using a lossy model of power networks that is able to reproduce PD signals distortion. The model used, realized using the transmission line matrix (TLM) method, is also presented here and theoretically validated.

Intensification of the Processes of Extraction of Humic Acids from Biosubstrates under the Action of Electric Discharges

The article deals with the study of factors participating in the extraction of humic acids from plant substrates under the action of electric discharges. Using the example of the electric discharge treat-ment of the peat-water suspension, it was demonstrated that the main factor affecting the intensity of extraction is the degree of the solid phase of the biosubstrate-water suspension grinding, which depends on the pressure amplitude at a distance of the inner radius of the chamber and the number of discharge pulses. Experimental studies have shown that the amount of chemical reagents (alkalis) commonly used in the extraction of humic acids from peat can be significantly reduced due to the appearance of radicals and peroxide compounds in the peat-water suspension during the ac-tion of an electric discharge. The perspectives of a non-thermal electric discharge meth-od for intensifying the extraction of humic acids from biosubstrates are determined.

Plasma Non Thermal Sebagai Sterilisasi Masker untuk Inaktivasi Virus Corona (COVID-19)

We used non-thermal plasma generators to sterilize textile materials, especially in personal protective equipment for masks, to inactivate viruses and bacteria attached to the mask material in this study. The design of the ozone generator utilizes the non-thermal plasma method of corona discharge using a high voltage generator with an output voltage of 3.,000 V. The sterilization process was carried out with variations in sterilization time (10,15 and 20 minutes) and an active electrode height of 3 cm. This research was carried out using CT RT-PCR testing to determine the cycle threshold value contained in the nucleic acid RNA of the COVID-19 virus before and after sterilization. Changes in CT values obtained after sterilization for 20 cycle threshold (CT) values were 37.07 for the N gene and 35,67 for the ORF. Based on the sterilization test results, no data stated that the virus was harmful. Based on these results, the increase in CT numbers is directly proportional to the length of time for sterilization so that the RNA content of the COVID-19 virus decreases. To determine the effect of the sterilization process on the hydrophilic properties of the maks, the Fourier Transform Infra-Red (FTIR) test was carried out. The study results show that non-thermal plasma can sterilize masks from the coronavirus. This study concludes that the plasma method can be used to sterilize masks from the coronavirus

An effective and cleaner discharge method of spent lithium batteries

The rapid development of new energy vehicles has exponentially increased the output of spent lithium-ion batteries (LIBs). The extraction and recovery of valuable metals from spent LIBs are expected to alleviate the shortage of battery materials. However, the spent LIBs to be recycled may still have certain amount of usable output power. If the battery is disassembled and crushed directly, the residual electricity may be hazardous. Therefore, discharge pretreatment should be carried out before disassembling and crushing spent LIBs. To date, electrochemical discharge in conducting solutions has been widely investigated and applied to discharge pretreatment, but there is no convincing evidence of its effectiveness. At the same time, non-electrochemical discharge in conducting powders has been investigated as a possible cleaner and more effective discharge method. Therefore, our current article reports the results of a series of experiments performed with spent LIBs to explore electrochemical discharge in conducting solutions and non-electrochemical discharge in conducting powders. We also systematically discuss the advantages and disadvantages of different discharge media in terms of their discharge efficiency, the potential existence of solid/liquid/gas phase contaminants, and their effectiveness. The experimental results obtained showed that battery discharge reached the safe voltage of 2 V and that the voltage rebound behavior occurs after 48 h standing. This is called the voltage relaxation phenomenon in an electrical field, which could cause certain safety risks during battery disassembly and crushing. Therefore, the effect of voltage rebound was also studied, and the obtained results showed that the voltage was over-discharged after flake-graphite discharge, which would cause irreversible damage to the anode material of the batteries and lead to battery failure. This is of great significance for the discharge pretreatment of spent LIBs. Therefore, flake-graphite discharge is an cleaner and effective discharge method for spent LIBs.

An innovative procedure for synthesizing Al70M20(Fe, Co)Cr10 amorphous nanoparticles by arc discharge method and investigation of their magnetic, hardness, and corrosion resistance properties

Al70Fe20Cr10 and Al70Co20Cr10 amorphous nanoparticles were prepared by plasma arc discharge process under arc current of 50 A and 1 atm. pressure in liquid nitrogen medium. XRD patterns of the as-prepared powders exhibit amorphous nature. According to TEM images, the Al70Fe20Cr10 and Al70Co20Cr10 amorphous nanoparticles have a spherical shape with a mean size of 27 and 35 nm, respectively. Static magnetic measurements using a vibrating sample magnetometer (VSM) indicate that the Al70Co20Cr10 amorphous alloy has a higher saturation magnetization of 9.3 emu/g and a lower coercive field of 14 Oe compared with 3.8 emu/g and 45 Oe for the Al70Fe20Cr10 amorphous alloy. In contrast, the Al70Fe20Cr10 amorphous alloy has a higher hardness and shows approximately 20 times more corrosion resistance than the Al70Co20Cr10 amorphous alloy.

Challenges and Evolution of Water Level Monitoring towards a Comprehensive, World-Scale Coverage with Remote Sensing

Surface water availability is a fundamental environmental variable to implement effective climate adaptation and mitigation plans, as expressed by scientific, financial and political stakeholders. Recently published requirements urge the need for homogenised access to long historical records at a global scale, together with the standardised characterisation of the accuracy of observations. While satellite altimeters offer world coverage measurements, existing initiatives and online platforms provide derived water level data. However, these are sparse, particularly in complex topographies. This study introduces a new methodology in two steps (1) teroVIR, a virtual station extractor for a more comprehensive global and automatic monitoring of water bodies, and (2) teroWAT, a multi-mission, interoperable water level processor, for handling all terrain types. L2 and L1 altimetry products are used, with state-of-the-art retracker algorithms in the methodology. The work presents a benchmark between teroVIR and current platforms in West Africa, Kazakhastan and the Arctic: teroVIR shows an unprecedented increase from 55% to 99% in spatial coverage. A large-scale validation of teroWAT results in an average of unbiased root mean square error ubRMSE of 0.638 m on average for 36 locations in West Africa. Traditional metrics (ubRMSE, median, absolute deviation, Pearson coefficient) disclose significantly better values for teroWAT when compared with existing platforms, of the order of 8 cm and 5% improved respectively in error and correlation. teroWAT shows unprecedented excellent results in the Arctic, using an L1 products-based algorithm instead of L2, reducing the error by almost 4 m on average. To further compare teroWAT with existing methods, a new scoring option, teroSCO, is presented, measuring the quality of the validation of time series transversally and objectively across different strategies. Finally, teroVIR and teroWAT are implemented as platform-agnostic modules and used by flood forecasting and river discharge methods as relevant examples. A review of various applications for miscellaneous end-users is given, tackling the educational challenge raised by the community.

Partial discharge calibrator of a cavity inside high-voltage insulator

Abstract This article displayed the method of partial discharge (PD) measurement in high-voltage insulator and calibrating the effective element (capacitor) to enhance the PD signal. The cavity shapes were plate–plate, cylindrical and spherical inside the solid insulator. The proposed system enables from detecting the reverse and main discharge, respectively, through the rise and tail time of the pulses. PD that took place was bounded with internal cavities. Proteus simulator and Matlab simulation models were used to measure and display the PD signal. The results showed PD-calibrated waveforms and the voltage values across the cavity (V c). Finally, this work concluded that the spherical cavity shape gave a higher value of the calibrated capacitor and lower voltage across the cavity (V c) for both models.

Commercial Screen-Printed Electrode Decorated with Carbonaceous Binary Sulfides for Direct Glucose Detection in Human Fluid Samples

We hereby demonstrate a highly controllable, green, and rapid synthesis strategy for the production of binary metal sulfides on carbon nano-horns (CNHs) for the fabrication of non-enzymatic glucose sensor using commercial graphite screen-printed electrodes (GSPEs). CNHs were synthesized using the submerged arc discharge method as described elsewhere. In the next step, one droplet (50 µL) of the well-dispersed CNHs was carefully cast on the surface of the GCE (and GSPE). In the final step of preparing the modified electrodes, CNH/GCEs were covered by a thin layer of nickel cobalt sulfide by a simple electrochemical deposition procedure.Following the structural examination of the prepared electrocatalyst were examined. In this regard, several microscopic methods like FE-SEM or TEM were used to know more regard the morphology of the material. The FE-SEM images confirmed the successful formation of sponge like nanosheets of NiCo-S on carbonaceous material. Since CNHs are prepared from graphene sheets with open ends in horn-like shapes, they can be considered as being formed from the origami-like or crushing contortion of a single graphene sheet. According to the FE-SEM images, the agglomeration of CNHs establishes discrete nano-sphere structures with diameters in the range of 50 to 150 nm. The TEM images also confirm this nano-sphere strictures.Following detailed structural characterization, the electrocatalytic activity of the fabricated NiCo-S/CNH electrodes toward electro-oxidation of glucose is examined in detail. The cyclic voltammetry was also used for glucose electro-oxidation mechanism investigation. In addition, parameter optimization was also done by utilizing cyclic voltammetry technique. These include medium pH, deposition cycles, and metals mole ration. Moreover, the effect of the presence and absence of CNH on the electrochemical performance of glucose oxidation were also examined. It shows that in the presence of CNH the peak current density for glucose oxidation is higher that is perfect for analytical purposes and increase the analytical sensitivity. The structural properties and electrochemical response of the fabricated electrodes were also compared to their corresponding mono-metallic counterparts.The amperometric method was utilized as one of the most prevalent and momentous techniques for the quantitative determination of glucose. The applied potential in amperometric tests was optimized to be +0.5 V (vs. Ag/AgCl). The proposed electrodes were operated within two distinct linear dynamic ranges of 0.001- 0.330 mM and 0.330 - 4.53 mM of standard glucose with sensitivities of 1842 µA.mM-1.cm-2, and 854 µA.mM-1.cm-2, respectively. On the other hand, an analytical sensitivity of 467 µA.mM-1.cm-2, within the linear dynamic range of 0.5 - 6 mM was obtained for the static chronoamperometric measurements for modified commercial screen-printed electrode (GSPE). The proposed sensor showed outstanding selectivity against iso-structures and co-existing interferences, long-term durability, rapid response (1.7 s), excellent poisoning resistance against chloride ions, good repeatability, and reproducibility. The tested interferences were 0.1 mM solutions of fructose, galactose, sucrose, lactose, ascorbic acid, uric acid, dopamine hydrochloride, and NaCl. In order to demonstrate the capability of the fabricated electrodes and to evaluate their potential for glucose measurements in real physiological specimens, the glucose level was successfully measured in human blood serum, urine, and saliva samples, without any sample pre-treatment. All in all, the encouraging results make NiCo-S/CNH electrodes immensely promising for clinical and physiological glucose-level measurements.Figure 1. (a) FE-SEM image of CNH. (b) FE-SEM image of NiCo-S/CNH. (c) TEM image of CNHs. (d) Cyclic voltammogarm of NiCo-S/CNH in the absence and presence of various concentration of glucose. (e) The amperometric responses of the NiCo-S/CNH/GCEs after addition of 1 mM glucose followed by successive injection of 0.1 mM fructose, galactose, sucrose, lactose, AA, UA, DA, and NaCl. (f) Chrono amperograms of the NiCo-S/CNH/GSPEs in the presence of the different glucose concentration ranging from 0.5 ~ 10.0 mM under applying +0.5 V. Amperogram of the NiCo-S/GCEs current response obtained from the addition of (g) 50 µL human blood serum, (h) 200 µL urine, and (i) 100 µL saliva followed by injection of 400 µM standard glucose solutions under the optimum potential of +0.5 V, the amperograms of five successive glucose addition. Figure 1

The effect of boron-doped carbon nanotubes blended with active layers in achieving high-efficiency polymer solar cells and X-ray detectors

Polymer solar cells (PSCs) usually offer inferior power conversion efficiency (PCE), lower open-circuit voltage (Voc), and inefficient charge extraction abilities. We studied boron-doped carbon nanotubes (B-CNTs) as the third active layer (AL) component to improve the PCE and Voc, due to their tunable work function, superior conductivity, and transport behavior. A novel arc discharge (AD) method produced B-CNTs without any residual catalysts. This work utilized PBDB-T: ITIC as the initial AL to prepare PSCs and X-ray detectors with glass/ITO/PEDOT: PSS/AL/LiF/Al structure. The excitation effects of PSC and X-ray detector devices based on ALs embedded with different amounts of B-CNTs were also studied. The derived outcomes revealed a PCE of 10.21 % for the constructed PSC with 3 wt% of B-CNTs blended AL. Furthermore, the fabricated X-ray photodetector with 3 wt% of B-CNTs obtained an excellent sensitivity of 2.49 mA/Gy·cm2. These results show that B-CNTs can act as both an exciton dissociation center and a charge transfer channel, promoting charge separation and transport in the AL.

Non-noble metal FeMn and single-walled carbon nanotubes nanocomposites as effective bifunctional electrocatalysts in alkaline media for oxygen/hydrogen revolution reactions

Single-walled carbon nanotubes (SWCNTs) are one of electrochemical materials with excellent electrical properties. Herein, we design the new FeMn x /SWCNTs nanocomposites which are synthesized in one step by the direct current (DC) arc discharge method. The overpotentials of oxygen/hydrogen revolution reactions of FeMn 1 /SWCNTs electrodes in alkaline solution are 190 and 317 mV respectively when the current density reaches 10 mA cm −2 . The synergistic effect between FeMn compounds and single-walled carbon nanotubes can not only increase the active sites of the composites, but also optimize the electronic structure of the composites, thereby significantly improving the OER and HER performance of the materials. This work provides an idea that the composites of SWCNTs and bimetallic hybrids have excellent electrocatalytic performance.

Plasma assists titanium nitride and surface modified titanium nitride nanoparticles from titanium scraps for magnetic properties and supercapacitor applications

Plasma methods are efficient processing for metal recovery from metal scrap, bearing minerals, electronic waste, etc. In this work, pure titanium nitride nanoparticles (TiN NPs) were synthesized from titanium scraps by the thermal plasma arc discharge (TPAD) method. TPAD synthesized TiN NPs have a highly crystalline nature with cubic and spherical morphologies with average particle sizes of 30–100 nm. Further, prepared TiN NPs involving surface modification (SM) or etching processes were investigated by using the non-thermal DC glow discharge plasma technique with air atmosphere at different processing times. SM@TiN NPs have a comparatively low crystalline, which was confirmed from the powder X-ray diffraction technique. SM@TiN NPs have very interesting core shell morphologies, which are due to the surface interactions of ionized air molecules. TiN and SM@TiN NPs have room-temperature ferromagnetic properties with high saturation magnetization (Ms) up to 2.6 and 3.0 emu/g and very high coercivity (Hc) of 235.5 Oe, respectively. TiN and SM@TiN NPs have superior energy storage performance with an outstanding specific capacitance of 192.8 and 435.1 F/g at a current density of 2 A/g with pseudocapacitive behavior. These results reveal that TiN and SM@TiN NPs have highly promising electrodes for supercapacitor applications.

Application of a staggered symmetrical spiral groove wheel on a quantitative feeding device and investigation of particle motion characteristics based on DEM

The uniformity of particle flow is the key to the research of quantitative feeding devices. Ensuring particle motion characteristics will help improve the working performance of the device. In this work, a quantitative feeding device with a staggered symmetrical spiral groove wheel is studied by using the DEM method. The effects of the inclination angle and the length of the staggered symmetrical spiral groove wheel on the uniformity of particle flow are examined and analyzed. The results show that with the decrease of the inclination angle, the change of particle discharge method from passive pushing to active sliding, the uniformity of particle flow is improved. A small inclination angle results in less disturbance of seed particles and reduces the uniformity of particle flow. When the feeding rate is constant, shortening the length of the grooved wheel (corresponding to increasing the rotational speed) causes shorter filling time and more leakage filling. Compared with the traditional straight groove wheel and spiral groove wheel, the force on the seed particles is smaller. The appropriate inclination angle and length (e.g.,45°, 50 mm) can effectively enhance the uniform stability of seed particle flow, reduce the risk of seed particles damage, and improve feeding performance.

3D Localization Method of Partial Discharge in Air-Insulated Substation Based on Improved Particle Swarm Optimization Algorithm

Partial discharge (PD) localization in an air-insulated substation (AIS) can be used to assess insulation conditions efficiently. Many localization methods have been reported during the past few years. However, the error of the localization results has been large or the localization algorithm too inefficient. The reason is that the localization equation set is nonlinear and non-symmetrical. In this paper, an improved particle swarm optimization (PSO) algorithm is proposed to improve the localization accuracy in 3D. Firstly, the proposed localization method is based on the symmetrical antenna array and the location error distribution is analyzed. Secondly, the objective function of PSO is constructed using the error distribution. Specifically, the 3D location target is divided into two steps—plane coordinates and height. The two targets are optimized respectively. To verify the method, a test is carried out by a prefabricated fault bushing in the laboratory to compare with the existing methods. According to the results, the localization error is 0.21 m, which can locate the PD source accurately. A complete calculation takes 42.29 s, and the efficiency is increased by 16.13 times under the same accuracy. The comparison results show that the proposed method can greatly improve the efficiency while ensuring accuracy.

Numerical investigation on indicated power and discharge process of three different discharge methods of swing compressor

Pressure variation during the discharge process is important to the discharge flow loss and indicated power of swing compressor. Due to the small effective discharge area and the large discharge volume flow rate at the beginning of discharge process, pressure shoots up to a high value, which is 25%-35% higher than the nominal discharge pressure. Using a suitable discharge method is beneficial to reduce the maximum pressure and indicated power. This paper presents a numerical model to study the indicated power and pressure variation of three different discharge methods. The power consumption per revolution has been discussed to analyze the discharge flow loss. And the effects of over-compression, under-compression and operation speed have been analyzed. Simulation results show that the errors of indicated power are within 3% and the errors of mass flow rates are within 2%, which proves that the accuracy of the presented model is good enough. Furthermore, the major reason affecting the discharge flow loss is the effective discharge area rather than over-compression or under-compression. And compared with the discharge port with valve, the discharge port without valve has a larger effective discharge area. Adding discharge port without valve in swing compressor can reduce the indicated power.

Numerical Simulation and Hazard Analysis of Debris Flows in Guxiang Gully, Tibet, China

Guxiang Gully, located in Bome county in southwest Tibet, China, is a right-bank tributary of the Purlung Tsangpo River. Hanging glaciers are widely distributed upstream of the gully, and a large number of moraines can cause debris flows triggered by run-offs generated by the rainstorm and melting water of glaciers deposited in this gully. The debris flow in the Guxiang Gully can frequently pose a serious threat to the Sichuan–Tibet highway. Due to the lack of field observation data, in this study, the flood discharge method combining the run-off generated by rainstorms and melting water of glaciers was employed to determine the magnitudes of debris flows under once-in-a-century, once-in-two-century, and once-in-three-century flood return periods. Furthermore, a numerical simulation is implemented to determine the maximum flow depth and velocity of the debris flow in each grid cell and the inundated debris flow area in Guxiang Gully with different return periods. Subsequently, each grid cell’s maximum flow depth and velocity are used to assess buried hazards and impact hazards, respectively. The integrated hazard could be calculated by combining the buried hazard and the impact hazard. The result shows that the hazard of the top of the fan and Purlung Tsangpo River affected by the debris flow is highest, and the debris flow is likely to block the Purlung Tsangpo River.

An Approach to Recover Energy From Discarded Primary Batteries Before Being Disassembled

This article demonstrates the feasibility of recovering energy from discarded primary batteries (e.g., alkaline or zinc-carbon) that would be disposed of as normal household waste based on self-adaptive pulse discharge (SAPD) method. The SAPD approach is utilized to search the optimal pulse frequency and duty cycle for different types of used batteries with the maximum allowed discharge current. To assess the performance of the proposed approach, a prototype including improved passive cell balancing circuit, SAPD control circuit, and series–parallel switching circuit of supercapacitor banks was designed and implemented to drain a battery bank that consisted of at least 6 but at most 10 used cells of different brands in series. Discharging experiments show that the energy recovery with six to ten used batteries ranges from 798 to 1455 J, and the corresponding recovery efficiency is about 33.49%–46.43%. Although outcomes are still far from being satisfactory in the efficiency with the proposed approach, the rate of energy recovery may depend on the remaining capacity of discarded batteries and so may be advantageous if the battery has a high remaining capacity. Therefore, authors conclude that there is possibly a direct link between the recovery efficiency and the remaining capacity of discarded batteries.

Room temperature ferromagnetism in Gd-doped AlN hierarchical microstructures: Experimental and theoretical insights

Diluted magnetic semiconductor materials have attracted extensive attention as candidate materials for a new generation of multifunctional spintronic devices. At present, doping is an effective method to adjust the physical properties of semiconductor materials. Here, the Gd doped AlN (AlN:Gd) hierarchical microstructures were synthesized from mixtures of Al and Gd2O3 powder and N2 working medium by improved arc discharge method. The samples were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy, photoluminescence (PL) spectroscopy and vibrating sample magnetometer. The analysis results show that Gd ions are successfully doped into AlN hierarchical microstructures. The PL spectrum excited by 200 nm exhibits a sharp emission line at 318 nm corresponding to 6P7/2-8S7/2 transitions of the Gd3+ ion, and a broad emission band round at 395 nm, which is related to with Al vacancy and O impurity defects. The magnetization curves suggest AlN:Gd hierarchical microstructures process room-temperature ferromagnetic behavior. The latter first-principle calculations indicate that the main origin of the magnetism in AlN:Gd arise from Al vacancies rather than magnetic Gd dopants. Our results suggest that the AlN:Gd hierarchical microstructures are promising materials for spintronic applications.