bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuzzy inference‐based control and decision system for precise aeration of sewage treatment process
Authors: Zeng Wenru , Guo Zhiwei , Zhang Huiyan , Wang Jianhui , Gao Xu , Shen Yu , Gadow Samir Ibrahim
Published: January 2021

The sewage treatment systems manage to reduce pollutants of wastewater to make it reach some requirement. The core of it is to effectively control and determine intermediate aeration amount, which is always challenging. Therefore, a multi‐objective planning mechanism (multi‐objective optimization design combining GRA and fuzzy logic inference) that combines grey relational analysis and fuzzy logic, to find the optimal dissolved oxygen solubility for achieving better outlet water quality, is proposed. First of all, grey correlation coefficient between each optimization target and the reference target is calculated, and are converted into fuzzy inference values through the four steps. After that, it is expected to analyse the average values of process variables to obtain the optimal parameter combinations. A real‐world dataset collected from a realistic sewage treatment plant is utilized as the simulation environment to evaluate the proposed multi‐objective optimization design combining GRA and fuzzy logic inference. Experimental results show that the multi‐objective optimization design combining GRA and fuzzy logic inference makes promotion of 47.34% for fitted outlet water quality compared with the original average annual water quality.
Network slimming for compressed‐sensing cardiac cine MRI
Authors: Park Seong Jae , Lim Chae Guk , Ahn Chang‐Beom
Published: January 2021

The Unet is attempted to be slimmed for compressed‐sensing cardiac cine magnetic resonance imaging. Despite the excellent performance of the U‐net, its heavy structure and long training time restrict its applications in an environment with limited computational resources. We slimmed the U‐net by changing the multiple convolutions to single convolution and the transpose convolution to upsampling and by adopting fewer layers, without performance degradation. The number of trainable weights and training time of the slimmed network was reduced by 87.9% and 48.1%, respectively. The proposed network showed improved performance with a 1.45% reduction in the normalised mean square error.
Performance of probabilistic amplitude shaping with BICM‐ID
Authors: Naka Akira
Published: January 2021

It is numerically shown that bit error rate (BER) performance of probabilistic amplitude shaping (PAS) applying a bit‐to‐symbol mapping of non‐Gray natural binary code assigned to 64‐quadrature amplitude modulation is significantly improved by bit‐interleaved coded modulation with iterative detection (BICM‐ID). The obtained BER performance outperforms the PAS using a standard Gray code mapping. Furthermore, it has been numerically verified that the non‐Gray natural binary code mapping is suitable for BICM‐ID by analysing the extrinsic information transfer chart. In addition, two degradation factors, the shaping and the coding gaps are estimated, from the Shannon limit by analysing mutual information characteristics. The obtained results quantitatively show that BICM‐ID can effectively suppress the coding gap of the PAS applying non‐Gray mapping in BER performance.
Research on suspension control strategy based on finite control set model predictive control with state feedback control‐PID for maglev yaw system of wind turbine
Authors: Wang Nannan , Cai Bin , Chu Xiaoguang , Su Baili
Published: January 2021

The maglev yaw system (MYS) of wind turbine adopts the maglev‐driving technique instead of the traditional gear‐driving technique, so it has the advantages of short downtime and low cost of operation and maintenance. However, it is vulnerable to the nonlinear time‐varying disturbance caused by the random change of wind speed and direction. This paper proposes a dual‐loop suspension control strategy based on the finite control set model predictive control (FCS–MPC) with state feedback control (SFC) to improve the dynamic response and anti‐disturbance ability of the MYS. First, the mathematical models of the MYS are built. Second, in order to realise the stable suspension control, the outer loop controller for suspension air gap tracking is designed by combining SFC with proportional integral differential, and the inner loop controller for maglev current tracking is designed by adopting FCS–MPC with delay compensation. Finally, the simulation and experimental results show that the proposed control strategy has better robustness and dynamic response property comparing with the existing control strategies, and the maglev system of MYS can realise smooth and reliable operation. The proposed suspension control strategy is substantiated to be effective and feasible.
Localised edge‐region‐based active contour for medical image segmentation
Authors: Liu Hua‐Xiang , Fang Jiang‐Xiong , Zhang Zi‐Jian , Lin Yong‐Cheng
Published: January 2021

Segmenting the region of interest (ROI) from medical images is a fundamental but challenging task due to the illumination change and imaging devices. Although many models based on the local region‐based active contour model (LR‐ACM) are proposed to deal with intensity inhomogeneity, it is still difficult for the global energy‐based ACM with local image information to accurately extract the ROI from medical images. To solve this problem, this study proposes a novel localised ACM by constructing the gradient information based on the probability scores from the fuzzy k‐nearest neighbour classifier. Different from the traditional LR‐ACMs, our model is based on local rather than global image statistics, where a probability score‐based edge detector is directly used for gradient information. The energy functional consists of localised region energy and an edge energy. By introducing a local characteristics function, the localised region energy with the probability‐score‐based edge information is formulated, which can make the evolution curve stop on the exact boundaries of ROI. The edge energy including the regularisation and the penalty terms is used to avoid the reinitialisation process and smooth the evolution curve during evolution. To maintain the signed distance property of the evolution curve, a novel potential function in the penalty term is designed, which can consistently control the diffusion direction of the evolution curve. Experiments on the medical images including the cardiac magnetic resonance imaging and the 3DIRCADb databases demonstrate that the proposed model is more robust and accurate to extract the ROI than the popular localised and region‐based ACMs. The code is available at: https://github.com/HuaxiangLiu/Localized_ERAC/.
Rapid and environment‐friendly preparation of silver nanoparticles and their inhibition against phytopathogenic fungi
Authors: Zhao Lei , Gong kun , Wang Yue , Kong Shuang
Published: January 2021

Microbial‐assisted biosynthesis of silver nanoparticles (AgNPs) has been developed rapidly in recent years, but their mechanism of synthesis and production are still unknown. This study investigated the roles of nitrate reductase produced by the fungus Trichoderma asperellum in the synthesis of AgNPs. The nitrate reductase activity is activated by nitrate and showed a positive correlation with the quantity of AgNPs, which may lead to the development of a fast bioprocess of AgNPs synthesis. Treatment of silver nitrate with the fungal supernatant containing nitrate reductase produced stable, monodispersed, and spherical AgNPs with an average size of 20 nm, which were characterized by UV–visible spectroscopy, scanning electron microscopy and X‐ray diffraction. SDS‐PAGE implied that nitrate reductases were involved in the synthesis of AgNPs. The antifungal activities of synthesized AgNPs solution were compared with those of silver nitrate solution and AgNPs‐free supernatant solution. The results showed that AgNPs solution exhibited the highest antifungal activity against several selected plant pathogens by the agar well diffusion method. This study firstly concluded that extracellular biosynthesis of AgNPs could be promoted by potassium nitrate in Trichoderma asperellum Q1 media and the AgNPs provided a potential enhancement of biocontrol activity derived from the fungi.
Improved photovoltaic performance of dye‐sensitized solar cells using dual post treatment based on TiCl4 and urea solution
Authors: Bolag Altan , Wang Qiaoling , Liu Linan , Jamiyansuren Tumenkhuslen , Tumurpurev Ugtakhbayar , Tuvjargal Norovsambuu , Bao Tana , Ning Jun , Alata Hexig , Tegus Ojiyed
Published: January 2021

An effective and efficient photovoltaic performance is significantly affected by the interface between different constituents of dye sensitized solar cells (DSSC). A novel dual post treatment of TiCl4 and urea solutions on different layers of TiO2 electrode is addressed and the TiO2 particle morphology, dye‐adsorption amount on the TiO2 electrode and the photovoltaic performance of the DSSC based on those electrodes are characterised in this work. TiCl4 treatment can form more binding site on TiO2 particles and urea treatment structures a thin layer of g‐C3N4 on the surface of TiO2 particles. This strategy can not only effectively increase the dye‐adsorption for light‐harvesting, but also facilitate the electron transfer through inhibiting the charge recombination between TiO2 and electrolyte, and moreover, it provides excess electrons for the photoanodes. The DSSC fabricated from TiO2 electrode processed with urea treatment on the sixth layer exhibited the highest power conversion efficiency of 8.94% with a short current density Jsc of 24.09 mA cm–2, an open circuit voltage Voc of 583 mV and a fill factor of 63.8.
Comparative analysis of switching losses and current ripple of continuous and discontinuous SVPWM strategies for unbalanced two‐phase four‐leg VSI Fed unsymmetrical two‐phase induction motor
Authors: Muangthong Kaset , Charumit Chakrapong
Published: January 2021

This paper presents a comparative analysis of the continuous space vector pulse width modulation and the discontinuous space vector pulse width modulation in terms of the switching losses and current ripple reduction for the unbalanced two‐phase four‐leg voltage source inverter fed unsymmetrical two‐phase induction motor. The main function of both space vector pulse width modulation strategies is to produce unbalanced two‐output voltages with constant phase shift of 90° for main and auxiliary windings. The discontinuous space vector pulse width modulation principle is modified from a traditional two‐phase four‐leg voltage source inverter by placement of the space vectors to alternatively eliminate zero space vector in each switching sequence. As a consequence, the proposed unmodulation region or clamping zone of the discontinuous modulation strategy has 180° all the time. The experimental results illustrate the modulation waveforms of both methods, output voltage spectrum, normalized switching losses, output current ripple and inverter efficiency at high modulation index. The evaluation of the normalized average switching losses and the current ripple of the discontinuous space vector pulse width modulation method can be reduced more than that of the continuous space vector pulse width modulation method.
Unified centralised/decentralised frequency control structure for microgrids
Authors: de Godoy Paulo Thiago , de Almeida Adriano Batista , Marujo Diogo
Published: January 2021

When the microgrid (MG) operates in islanded mode, the frequency adjustment is performed through the secondary control. This control can be achieved through centralised, distributed or decentralised strategies. The centralised strategies are the most applied in the MG due to the facility of the control and coordination of the distributed generations. However, due to centralisation of processing and information, these strategies depend on the continuous operation of the communication channels. The decentralised and distributed strategies are proposed in the literature to avoid the reliability issues of centralised strategies. This paper proposes a new control interface that can combine the centralised and decentralised secondary frequency control strategies in a unique control structure, merging the advantages of each technique. The proposed unified secondary frequency control structure (USFCS) can ensure the benefits of centralised control and can maintain the MG frequency regulation even during control or communication failures. The proposed USFCS is verified on an MG based on the CIGRE benchmark LV distribution network through simulation. The results have shown that the proposed control structure can guarantee the frequency regulation even during failures and can restore it to regular operation after failure.
Cascade‐IλDμN controller design for AGC of thermal and hydro‐thermal power systems integrated with renewable energy sources
Authors: Arya Yogendra , Kumar Nishant , Dahiya Pankaj , Sharma Gulshan , Çelik Emre , Dhundhara Sandeep , Sharma Mandeep
Published: January 2021

Expert, intelligent and robust automatic generation control (AGC) scheme is requisite for stable operation and control of power system (PS) integrated with renewable energy sources (RES) under sudden/random small load disturbances. Large frequency deviations appear if AGC capacity is inept to compensate for the imbalances of generation and demand. In this paper, a cascade‐fractional order ID with filter (C‐IλDμN) controller is proposed as an expert supplementary controller to promote AGC recital adequately in electric power systems incorporated with RES like solar, wind and fuel cells. The imperialist competitive algorithm is fruitfully exploited for optimizing the controller parameters. First, a 2‐area reheat thermal system is examined critically and then to authorize the worth of the proposed controller, the study is protracted to a 2‐area multi‐source hydro‐thermal system. The prominent benefits of C‐IλDμN controller with/without renewable energy sources consist of its great indolence to large load disturbances and superiority over various optimized classical/fuzzy controllers published recently. The sensitivity study validates the robustness of the recommended controller against ±20% deviations in the system parameters and random step load perturbations.
Enhanced PI control and adaptive gain tuning schemes for distributed secondary control of an islanded microgrid
Authors: Zhang Yuanshi , Mohammadpour Shotorbani Amin , Wang Liwei , Mohammadi‐Ivatloo Behnam
Published: January 2021

This paper develops an enhanced proportional‐integral distributed control scheme (EPI‐DCS) to regulate the frequency and voltage of a droop‐controlled microgrid and share the power mismatch, simultaneously. The proposed EPI‐DCS is designed by using the control Lyapunov function method and adding a new consensus‐based term to the integrand dynamic of the conventional PI control. In the proposed distributed EPI‐DCS, the distributed generation units intermittently exchange information with the neighbouring distributed generation units, through a communication network. Considering the communication network time delays, the stability of the proposed EPI‐DCS is examined using the Lyapunov–Krasovskii linear matrix inequality conditions, and the maximum stable time delay is calculated. In order to stabilise the system for large destabilising time delays, an adaptive gain scheme is proposed. Effectiveness of the proposed adaptive EPI‐DCS is validated by numerical simulations with detailed models of the components and the converters, including load change, distributed generation outage, and adaptive gain‐scheduling against destabilising communication network time delays.
Quantitative analysis of sustained oscillation associated with saturation non‐linearity in a grid‐connected voltage source converter
Authors: Wu Tianhao , Jiang Qirong , Shair Jan , Xie Xiaorong , Wang Yanhui , Luo Yongzhi , Mao Hangyin
Published: January 2021

The interaction between the voltage source converter (VSC) and weak grid causes a negatively damped or diverging oscillation (DVO). The diverging oscillation generally evolves into a sustained oscillation (STO) when governed by the nonlinearities in the VSC's control system, such as the saturation of pulse width modulation (PWM). The conventional small‐signal impedance/admittance modelling (SSIM/SSAM) and stability analysis methods are not suitable for the characteristic analysis of STO. This paper presents a large‐signal impedance/admittance model (LSIM/LSAM)‐based quantitative analysis method to better understand the mechanism, characteristics, and occurrence conditions of STO. The LSAM extends the SSAM by incorporating the nonlinearity of PWM saturation using the describing function method. First, a unique time‐varying characteristic of the oscillation associated with nonlinearity is investigated. Then, two LSIM/LSAM‐based occurrence criteria for STO are established based on an equivalent RLC circuit model of the system. Three critical pieces of information, including the occurrence condition, frequency, and magnitude, associated with STO are revealed by the criteria. Finally, the LSAM‐based analysis method is applied to investigate the time‐varying admittance of the VSC and to assess the magnitude and frequency of STO. Both the criteria and LSAM‐based analysis results have been verified through time‐domain simulations on a typical grid‐connected VSC.
Effects of process parameters on the physicochemical properties of corn stalk hydrochar and the removal of alkali and alkaline earth metals
Authors: Yang Li , Wang Hui , Sun Jianwei , Xu Yiyun , Li Pengcheng , Xu Youning , Wu Shaohua
Published: January 2021

The advantages of the direct combustion of agricultural biomass for power generation are restricted due to the drawbacks of this biomass and the deep peak shaving trend. Hydrothermal carbonization can improve the physical and thermochemical properties of raw materials. Corn stalk samples were selected as the research object in this study. Corn stalk hydrochars were prepared with reaction pressures of 0–3 MPa, reaction temperatures of 160–240 °C, and residence times of 1–10 h. The effects of the process parameters on the physicochemical properties of hydrochar and on the removal of alkali and alkaline earth metals (AAEMs) were studied by measuring the hydrochar mass, energy yield, product composition, morphology, as well as the removal efficiency of AAEMs. The results indicated that the corn stalk hydrochar had higher mass and energy yields than the raw corn stalk. X‐ray diffraction showed that the carbon content in the hydrochar was greater than that in raw corn stalk. Scanning electron microscopy showed that the reaction temperature played a more significant role in the hydrothermal carbonization process than the reaction pressure and residence time.
Optimal power sharing of wind farms for frequency response
Authors: Tu Ganggang , Junyent‐Ferré Adrià , Xiang Ji , Barria Javier A.
Published: January 2021

This paper presents a uniform optimal power sharing strategy to coordinate the wind turbines (WTs) in a wind farm (WF) to provide occasional and continuous frequency response (FR). The coordination of WTs is formulated as an optimisation problem that takes into account the WT dynamics and tries to reduce the long term loss of energy yield caused by the provision of FR. This is achieved by maximising the total kinetic energy of the WF over time while reducing wear and tear of WTs. The proposed optimal power sharing strategy relies on periodic communication between each WT and a WF controller. Local linear approximations are employed to predict the system behaviour and the solution of the optimisation problem is obtained using the proposed centralised and/or distributed algorithm. The distributed algorithm only requires one‐way communication between the WF controller and local WTs, reducing the communication overheads. Simulation studies are carried out on a WF model to demonstrate the effectiveness of the proposed strategy. The results show the strategy enables reduction of yield loss over previous methods while avoiding over torque operation during FR provision.
The occurrence mechanism and damping method of ultra‐low‐frequency oscillations
Authors: Wang Peng , Li Baohong , Jiang Qin , Chen Gang , Han Xiaoyan , Dragicevic Tomislav , Liu Tianqi
Published: January 2021

The ultra‐low‐frequency oscillation (ULFO) problem has reappeared in China recently. Although the hydraulic generator is supposed to have a strong connection to this problem, the conditions for ULFO appearance and detailed reasons are not clear yet. In order to clarify the occurrence mechanism of ULFO, this paper studies each important part of hydraulic generator system, including the governor, exciter and power system stabiliser (PSS). The weak connection is confirmed to have an important impact on the occurrence of the ULFO. Nevertheless, by studying each device's contribution to ULFO through the complex torque coefficient method, it is shown that the negative damping effect of the hydraulic governor will cause the instability in the ultra‐low‐frequency band, while the exciter and the PSS have little influence on ULFO. Additionally, the proportional–integral parameters of the hydraulic governor system are also studied to clarify their influence on ULFO based on the complex torque coefficient method. Based on the above analysis, two damping methods for ULFO suppression are finally proposed. To verify theory and damping methods, the simulations are implemented in PSCAD and PSASP software.
Real‐time energy management system for public laundries with demand charge tariff
Authors: Deng Runze , Luo Fengji , Ranzi Gianluca , Qiu Jing
Published: January 2021

A building energy management system can be defined as a building automation system that can facilitate demand response by controlling building‐side energy resources. Here, a real‐time Energy Management System (EMS) is developed to reduce the energy costs charged by the demand charge tariff for a specific commercial building that consists of a public laundry. The authors model the public laundry energy management problem as a multi‐task scheduling problem and design a set of algorithms to heuristically control the operations of washing machines and clothes dryers by taking into account the customer‐specified task requirements and the laundry owner's budget. Numerical case studies are conducted to validate the proposed EMS.
A technical review of the challenges of powder recycling in the laser powder bed fusion additive manufacturing process
Authors: Soundarapandiyan Gowtham , Johnston Carol , Khan Raja H.U. , Chen Bo , Fitzpatrick Michael E.
Published: January 2021

Laser powder bed fusion (L‐PBF) is one of the most widely used additive manufacturing techniques for fabrication of components with complex geometries for various industrial applications including aerospace, medical and automotive. The unconsumed powder after part manufacturing is often recovered and recycled to improve process efficiency. However, some of the particles in the recycled powder can have different physical and chemical properties from those in the virgin powder owing to their exposure to the complex environment during the manufacturing process. In addition, some contaminants can be introduced in the recycled powder due to poor process control. A number of studies have been published in the past few years revealing the effects of powder recycling on the build properties. The present work aims to highlight the key phenomena during the manufacturing process that caused degradation to the recycled powder. Further to this, some comments, gaps and areas that deserve further detailed studies are also highlighted.
A new direction in PWR simplification
Authors: Bonhomme Nicolaas M.
Published: January 2021

A new approach to PWR simplification is presented, in which a compact Reactor Coolant System (RCS) configuration is introduced, particularly suited for a power level in the range of 600 MWe. Customary PWR primary system components are eliminated to achieve this RCS simplification. For example, RCS pressure control through a “self-pressurization” mode, with core exit at saturation temperature with less than 1% steam, allows elimination of a pressurizer. Also, mechanical control rods are replaced by reactivity control using negative moderator void and temperature coefficient together with variable speed primary pumps, and with an upgrade in the safety boration function. Decay heat removal in shutdown conditions is realized through the secondary side rather than through primary side equipment. The compact RCS can be installed in a small volume, high-pressure containment. The containment is divided into two leak-tight zones separated by a partition plate. Safety equipment installed in one of the two zones will be protected against adverse ambient conditions from leaks or breaks in the other zone. The partition facilitates management of coolant inventory within the RCS and the containment following RCS leaks or breaks. In particular, the safety injection system as commonly known, consisting of accumulators and multiple stages of injection pumps can be discarded and replaced by gravity-driven flooding tanks. Space available around major RCS components is adequate to avoid compromising accessibility during maintenance or in-service inspection operations. In addition, the two-zone, high-pressure containment provides extra margins in severe accident mitigation. Finally, the proposed containment has a much smaller size than customary large dry containments in PWR practice and it can be anticipated that Nuclear Island building size will similarly be reduced.
Epidemiological and Therapeutic Developments in Pelvic Ring Fractures Type C from 2004 to 2014 – a Retrospective Data Analysis of 2,042 Patients in the German Pelvic Register (DGU)
Authors: Lang Patricia , Schwabe Kerstin , Riesner Hans-Joachim , Friemert Benedikt , Stuby Fabian , Palm Hans-Georg ,   AG Becken III der Deutschen Gesellschaft für Unfallchirurgie
Published: January 2021

Background Pelvic ring fractures type C present a special challenge due to their high instability, the possible accompanying injuries and the high mortality rate of up to 18.9%. The aim of this retrospective analysis was to use the data from the DGU pelvic register to identify changes in the epidemiology and therapy for type C pelvic ring fractures between 2004 and 2014.

Materials and Methods 2,042 patients with type C pelvic ring injury were retrospectively included. Three time periods with roughly equal patient groups were specified and differences in epidemiology and the type of therapy were evaluated. For the surgical cases, the time of the operation, the duration of the operation, blood loss, the location of the fracture and the type of osteosynthesis were evaluated and the reduction result was recorded.

Results For the period under review, there is an age shift in the incidence of a type C pelvic ring fracture towards older age. The isolated pelvic injury has increased, while the proportion of pelvic injuries in the context of polytrauma has steadily decreased. Complications and mortality decreased as a percentage. The tendency towards minimally invasive procedures could be shown in the surgical care. Navigated procedures in the area of the pelvic ring have so far not proven successful.

Conclusions We were able to show that the majority of the patients are increasingly old, that there is no relevant trauma in the history and that there is an increase in the isolated pelvic fracture type C and a decrease in the number of polytraumatised or multiply injured patients. In conjunction with mortality from pelvic ring injuries, the successes of standardised, pelvic-specific emergency management, an adapted time of operation outside the vulnerable phase and stable osteosynthesis care, which enable early functional follow-up treatment, are also evident.
Nutzungsformen psychosomatischer Rehabilitation
Authors: von Kardorff Ernst , Meschnig Alexander , Klaus Sebastian
Published: January 2021

Hintergrund Die Studie untersucht die subjektiven Erwartungen an die psychosomatische Rehabilitation und die dort gemachten Erfahrungen im Verhältnis zum nachträglich eingeschätzten Nutzen für die Rückkehr in Arbeit (RTW). Ein besonderer Fokus liegt dabei auf den Verlaufskurven von Beginn der ersten Symptome an bis zur Klinikaufnahme und der dadurch beeinflussten Nutzung und Beurteilung der Maßnahme über den gesamten Krankheits- und Rehabilitationsverlauf bis zum RTW.

Ziele Im Kern zielt die Studie auf die individuellen und kontextbezogenen Bedingungen und Verläufe einer gelingenden Rückkehr an den Arbeitsplatz und eines nachhaltigen Verbleibs in Arbeit bei psychisch beeinträchtigten Rehabilitanden aus der retrospektiven verlaufsbezogenen Sicht der Betroffenen selbst. In diesem Beitrag steht die Frage nach den Erwartungen und dem Hilfebedarf beim Zugang zur medizinischen Rehabilitation und nach den Formen der Nutzung ihrer Behandlungsangebote in Abhängigkeit von der individuellen Problemkonstellation beim Zugang in die stationäre Rehabilitation im Zentrum.

Methode In der qualitativen Studie wurden 105 Teilnehmer zunächst mittels eines Fragebogens zu ihrer Situation am Beginn der Medizinischen Rehabilitation befragt. Von diesen wurden 33 auf Basis des theoretical sampling ausgewählte Personen, die den Interviews zugestimmt hatten mit episodisch-narrativen Interviews zu 3 Zeitpunkten nach Ende der Maßnahme (6, 12 und 18 Monate) befragt, Fallverläufe erstellt und miteinander verglichen.

Ergebnisse Es zeigten sich charakteristische Nutzungserwartungen an die psychosomatische Rehabilitation und darauf basierende unterschiedliche Nutzungsformen ihrer Angebote, die sich nur teilweise mit den Zielen der Rehabilitationsmedizin und den Angeboten der Kliniken decken. Dies verweist auf unterschiedliche Bedarfslagen, die mit dem Stand der Auseinandersetzung mit der Krankheit und anderen personalen Konstellationen korrelieren, in denen sich der Rehabilitand auf einer idealtypischen Verlaufskurve zum Zeitpunkt der Klinikaufnahme befindet. Darauf sollte sich das klinische Setting im Sinne eines personalisierten Case Management einstellen.
Examining the Hand in the Video Consultation
Authors: Welle Kristian , Täger Stefan , Hackenberg Roslind Karolina , Markowetz Alexander , Schildberg Frank Alexander , Burger Christof , Wirtz Dieter Christian , Jansen Tom , Kabir Koroush
Published: January 2021

Background Video consultations could support patient care in hand surgery during social distancing in the COVID-19 era. According to the literature, images of hand and fingers can support telediagnosis in hand emergencies. We present this feasibility study on online video consultation in hand surgery.

Methods A structured examination was designed to query the medical history and examine motor skills, sensitivity, strength and function tests of the hand. Thirty examinations on both hands were carried out by online video consultation, then in direct contact and compared with each other.

Results With 4560 evaluated range of movement of the hand and finger joints, there was a high correlation between the measurement methods of R = 0.995 (p < 0.0001, confidence interval 0.9946 – 0.9954). In the video-based examination, 84.6% of the measured values showed a deviation of less than 5° compared to the direct examination, 92.8% less than 10° deviation. Good accordance was also found in the patientʼs medical history. An estimating examination of sensitivity, function and strength during video examination is feasible with simple auxiliary aids. Deficits are evident in the detection of scars, in function tests and the absence of haptic findings.

Conclusion Online video consultation allows hand examination with sufficient documentation of hand and finger movements (range of motion) and proper evaluation of symptoms. It cannot replace direct examination but complement patient care in hand surgery even beyond the current COVID-19 pandemic.
Paravertebral Block versus Thoracic Epidural Analgesia for Postthoracotomy Pain Relief: A Meta-Analysis of Randomized Trials
Authors: Xu Mu , Hu Jiajia , Yan Jianqin , Yan Hong , Zhang Chengliang
Published: January 2021

Objective Paravertebral block (PVB) and thoracic epidural analgesia (TEA) are commonly used for postthoracotomy pain management. The purpose of this research is to evaluate the effects of TEA versus PVB for postthoracotomy pain relief.

Methods A systematic literature search was conducted in PubMed, EMBASE, Web of Science, and the Cochrane Library (last performed on August 2020) to identify randomized controlled trials comparing PVB and TEA for thoracotomy. The rest and dynamic visual analog scale (VAS) scores, rescue analgesic consumption, the incidences of side effects were pooled.

Results Sixteen trials involving 1,000 patients were included in this meta-analysis. The pooled results showed that the rest and dynamic VAS at 12, 24, and rest VAS at 48 hours were similar between PVB and TEA groups. The rescue analgesic consumption (weighted mean differences: 3.81; 95% confidence interval [CI]: 0.982–6.638, p < 0.01) and the incidence of rescue analgesia (relative risk [RR]: 1.963; 95% CI: 1.336–2.884, p < 0.01) were less in TEA group. However, the incidence of hypotension (RR: 0.228; 95% CI: 0.137–0.380, p < 0.001), urinary retention (RR: 0.392; 95% CI: 0.198–0.776, p < 0.01), and vomiting (RR: 0.665; 95% CI: 0.451–0.981, p < 0.05) was less in PVB group.

Conclusion For thoracotomy, PVB may provide no superior analgesia compared with TEA but PVB can reduce side effects. Thus, individualized treatment is recommended. Further study is still necessary to determine which concentration of local anesthetics can be used for PVB and can provide equal analgesic efficiency to TEA.
Development of an experimental facility for the study of microparticle initiated radio frequency vacuum breakdown
Authors: Casagrande R. , Faugel H. , Fischer F. , Fünfgelder H. , Riedl F. , Siegl G. , Bettini P. , Noterdaeme J.-M. , Crombé K.
Published: January 2021

An ongoing objective in the ion cyclotron range of frequencies (ICRF) systems is the improvement of power coupling to the plasma. During the last decade, this goal has been mainly pursued through the study of the coupling resistance, either by optimizing the antenna layout or by tailoring the scrape-off layer profile with gas puffing. Another approach is to increase the voltage handling capability of the ICRF system, limited by breakdown in the launchers or in the transmission lines. This paper describes the design of the ICRF Breakdown EXperiment (IBEX), a device to investigate fundamental aspects of radio frequency arcs under ICRF-relevant conditions. IBEX can achieve a peak voltage of 48 kV at 54 MHz with a 5 kW input power.
Simulating multi-scale gated field emitters—A hybrid approach
Authors: Sarkar Shreya G. , Kumar Raghwendra , Singh Gaurav , Biswas Debabrata
Published: January 2021

Multi-stage cathodes are promising candidates for field emission due to the multiplicative effect in local field predicted by the Schottky conjecture and its recently corrected counterpart [Biswas, J. Vac. Sci. Technol. B 38, 023208 (2020)]. Due to the large variation in length scales even in a 2-stage compound structure consisting of a macroscopic base and a microscopic protrusion, the simulation methodology of a gated field emitting compound diode needs to be revisited. As part of this strategy, the authors investigate the variation of local field on the surface of a compound emitter near its apex and find that the generalized cosine law continues to hold locally near the tip of a multi-scale gated cathode. This is used to emit electrons with appropriate distributions in position and velocity components with a knowledge of only the electric field at the apex. The distributions are consistent with contemporary free-electron field emission model and follow from the joint distribution of launch angle, total energy, and normal energy. For a compound geometry with local field enhancement by a factor of around 1000, a hybrid model is used where the vacuum field calculated using COMSOL is imported into the Particle-In-Cell code PASUPAT, where the emission module is implemented. Space charge effects are incorporated in a multi-scale adaptation of PASUPAT using a truncated geometry with “open electrostatic boundary” condition. The space charge field, combined with the vacuum field, is used for particle-emission and tracking.
Fingerprints of the electron skew scattering on paramagnetic impurities in semiconductor systems
Authors: Rakitskii M. A. , Denisov K. S. , Rozhansky I. V. , Averkiev N. S.
Published: January 2021

In this paper, we argue that the electron skew scattering on paramagnetic impurities in non-magnetic systems, such as bulk semiconductors, possesses a remarkable fingerprint, allowing us to differentiate it directly from other microscopic mechanisms of the emergent Hall response. We demonstrate theoretically that the exchange interaction between the impurity magnetic moment and mobile electrons leads to the emergence of an electric Hall current persisting even at zero electron spin polarization. We describe two microscopic mechanisms behind this effect, namely, the exchange interaction-assisted skew scattering and the conversion of the spin Hall effect-induced transverse spin current to the charge one owing to the difference between the spin-up and spin-down conductivities. We propose an essentially all-electric scheme based on a spin-injection ferromagnetic-semiconductor device, which allows one to reveal the effect of paramagnetic impurities on the Hall phenomena via the detection of the spin polarization-independent terms in the Hall voltage.
Fundamental study on cancer therapy by blocking newborn blood vessels with surface modified magnetite particles
Authors: Kirimura Makoto , Akiyama Yoko , Sato Fuminobu
Published: January 2021

We propose a novel cancer treatment which involves blocking newborn blood vessels around the diseased part. This treatment has minimal side effects and is less invasive. In the therapy, ferromagnetic particles administered into the body are accumulated in the newborn blood vessels. Next, the particles are aggregated to block the blood vessels to prevent cancer growth and metastasis. In this study, we modified the surface of magnetite particles with biocompatible polyacrylic acid to design particles that form irreversible aggregation on the application of a magnetic field. We succeeded in blocking only the flow path under a uniform magnetic field using the prepared particles, as is verified by the results of a model experiment. We assume that the blockage occurred due to the formation of chain aggregation under the magnetic field and the increase in pressure loss.
Thermal decomposition of GdCrO4 to GdCrO3: Structure and magnetism
Authors: Mohanty P. , Jacobs B. S. , Prinsloo A. R. E. , Sheppard C. J.
Published: January 2021

Rare-earth orthochromites (RCrO3) with orthorhombically distorted perovskite (ABO3) structure exhibit a wealth of magnetic phenomena including temperature-induced magnetization reversal (TMR), spin-reorientation (SR), spin-flipping (SF) and exchange-bias (EB). These occur as a result of magnetic interactions among the cations such as Cr3+–Cr3+, Cr3+–R3+ and R3+–R3+, where R is the rare earth element. In the present work, GdCrO4 samples were prepared using the sol-gel technique. The as-synthesized samples are amorphous in nature. Calcination of the samples at 600 °C for 1 h leads to the formation of the GdCrO4 phase whereas increasing the calcination temperature to 1000 °C for 1 h triggers the decomposition of GdCrO4 into GdCrO3. The role of thermal decomposition of GdCrO4 to GdCrO3 on crystal structure and magnetic transitions are discussed in this paper. Microstructure analyses show that the GdCrO4 powders have an intercalated porous structure that comprises a core-shell like construction with undistinguishable grain boundaries, whereas the morphology of the GdCrO3 demonstrates bulk nature with particles having micrometer size. Magnetization measurements as a function of temperature (M-T) with different probing magnetic fields show the ferromagnetic Curie temperature, (TC), of the GdCrO4 sample to be 24 K. GdCrO3 orders antiferromagnetically with a Néel temperature, TN (Cr), ascribed to the Cr magnetic moment at 171 K. A spin-flip transition (TSF) occurred at 22 K indicating the flipping of Cr3+ and Gd3+ spins and the spin-reorientation (TSR) transition is located at 5 K. The hysteresis loops measured across the transition temperatures validate the magnetic transitions as observed in the M-T curves.
Effect of strong local stretching of sensing fibre on the operation of a phase-sensitive optical time-domain reflectometer
Authors: Bengalskii D.M. , Kharasov D.R. , Fomiryakov E.A. , Nikitin S.P. , Nanii O.E. , Treshchikov V.N.
Published: January 2021

It has been shown experimentally and confirmed by numerical simulation that strong local stretching of sensing fibre distorts the signal detected by a phase-sensitive optical time-domain reflectometer (OTDR) from the fibre section behind the local disturbance region. Comparison of experimental data with theoretical estimates and numerical simulation results leads us to conclude that the physical mechanism underlying the distortion of the OTDR trace is related to the external disturbance-induced variable shift of the optical carrier frequency of probe pulses.
Thermal optical properties, Q-switching and frequency tuning of an Nd : LGGG laser based on the 4F3/2 → 4I13/2 transition of a neodymium ion
Authors: Gao Shang , Wang Wei
Published: January 2021

Laser characteristics of continuous-wave (cw) and passively Q-switched Nd : LGGG lasers based on the 4F3/2 → 4I13/2 transition of an neodymium ion are investigated. The lasing spectra of the cw and the Q-switching regimes are studied in detail. The thermal optical coefficient for the Nd : LGGG crystal at a wavelength of 1.33 μm is estimated to be 15.3 × 10−6 K−1. By inserting a quartz plate at the Brewster angle, the frequency of the Nd : LGGG laser is tuned. In the cw regime, the maximum output power at an incident pump power of 7.09 W is 802 mW and a slope efficiency is 13.2%. In the Q-switching regime, a minimum pulse duration of 9.75 ns is obtained with an output power of 176 mW and a repetition rate of 8 kHz. The maximum pulse energy and the highest peak power are 25.4 μJ and 2.4 kW, respectively.
THz laser generation on a hybrid surface plasmon in a HgCdTe-based structure
Authors: Dubinov A.A. , Aleshkin V.Ya. , Gavrilenko V.I. , Rumyantsev V.V. , Mikhailov N.N. , Dvoretskii S.A. , Utochkin V.V. , Morozov S.V.
Published: January 2021

The possibility of amplifying a THz hybrid surface plasmon in a structure with an Hg0.82Cd0.18Te epitaxial film grown on a GaAs substrate and covered with a metal layer is investigated. It is shown that for a film thickness of 100 nm and a temperature of 80 K, the hybrid surface plasmon mode gain can be greater than external losses at a pump radiation intensity with a wavelength of 2.3 μm, exceeding 850 kW cm−2. Additional doping of the Hg0.82Cd0.18Te layer with a donor impurity having a concentration of 4 × 1017 cm−3 will lead to a 1.5-fold decrease in the threshold pump intensity.
Semiconductor AlGaInAs/InP lasers (λ = 1450 – 1500 nm) with a strongly asymmetric waveguide
Authors: Volkov N.A. , Andreev A.Yu. , Yarotskaya I.V. , Ryaboshtan Yu.L. , Svetogorov V.N. , Ladugin M.A. , Padalitsa A.A. , Marmalyuk A.A. , Slipchenko S.O. , Lyutetskii A.V. , Veselov D.A. , Pikhtin N.A.
Published: January 2021

Semiconductor lasers based on AlGaInAs/InP heterostructures with a strongly asymmetric waveguide are studied. It is shown that the use of such a waveguide simultaneously with an increased quantum well energy depth provides conditions for increasing the output laser power. The semiconductor AlGaInAs/InP lasers based on a strongly asymmetric waveguide with a stripe contact width of 100 μm demonstrated an output optical power of 5 W (pump current 11.5 A) in a continuous-wave regime and 19 W (100 A) in a pulsed regime (100 ns, 1 kHz) at a wavelength of 1450 – 1500 nm at room temperature. The obtained data are compared with the output characteristics of lasers based on a symmetric waveguide.
Post-fire recruitment and resprouting of a threatened montane eucalypt
Authors: Zimmer Heidi , Allen Jan , Smith Rob , Gibson Rebecca , Auld Tony
Published: January 2021

Changing climate is predicted to result in increased frequency and size of wildfires in south-eastern Australia. With increasing area burnt there is increased potential for entire species distributions to be burnt in a single fire event. This is particularly the case for range-restricted threatened species. Eucalyptus canobolensis (L.A.S.Johnson & K.D.Hill) J.T.Hunter is restricted to Mount Canobolas, New South Wales, Australia. In 2018, the majority of the E. canobolensis population was burnt by wildfire. One-year post-fire, we measured recruitment, resprouting and mortality of E. canobolensis. At higher fire severities, smaller trees were more likely to resprout from their bases only, as their stems were killed (i.e. ‘top kill’). Seedling regeneration only occurred in burnt plots. Our study demonstrates that E. canobolensis has a fire response typical of many eucalypts, characterised by seedling recruitment and larger trees resprouting epicormically, even after high-severity fire. Nevertheless, E. canobolensis response to repeat and short-interval fire remains unknown, and smaller trees appear to be vulnerable to top kill. Although much of Australia’s flora can respond to fire, this response is likely to be challenged as fire extents increase, especially if this is combined with increasing fire severity and/or frequency. These changes to the fire regime are a particular threat to species with restricted distributions.
Microbial dynamics of elevated carbon flux in the open ocean’s abyss
Authors: Poff Kirsten E. , Leu Andy O. , Eppley John M. , Karl David M. , DeLong Edward F.
Published: January 2021

Significance

The ocean’s “biological pump” exports sinking particles containing carbon, nutrients, and energy to the deep sea, contributing centrally to the global carbon cycle. Here, we identify key organisms and biological processes associated with elevated carbon flux to the abyss. Our analyses reveal that, during summer export, specific populations of photosynthetic algae, heterotrophic protists, and bacteria reach the abyss on sinking particles. Deep-sea bacteria respond rapidly to this elevated nutrient delivery to the abyss in summer. During other seasons, different organisms and processes appear responsible for particle export to the deep sea. Our analyses reveal key biota and biological processes that interconnect surface productivity, particle export, and the deep-sea ecosystem, thereby influencing the function and efficiency of the ocean’s biological pump.
Negation, Expectation and Ideology in Written Texts
Authors: Nahajec Lisa
Published: January 2021

During an election campaign in 2008, Ken Livingstone said to a newspaper reporter “this election is not a joke”. By doing so, he introduced an expectation into the discourse that someone does, in fact, think it is a joke. This book explores how it is that saying what is not the case communicates something about what is. Bringing together a focus on text with cognitive and pragmatic approaches, a case is made for an application of linguistic negation as a tool of analysis. This tool is used to explore the ideological implications of projecting or reflecting readerly expectations. This book contributes to the growing field of Critical stylistics and aims to add to the range of stylistic insights which anchor the analysis of discourse to a consideration of the nuances of language choice.