bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on junction termination of 6500V IGBT
Authors: Gao Mingchao , Jin Rui , Wang Yaohua , Lili  , Liu Jiang , Li Cui , Sun Wanru , Nie Ruifen , Wu Junmin
Published: March 2021

In this paper, a novel junction termination design for 6500V IGBT is proposed. A floating P+ rings termination where the P+ rings are highly doped is less than 2500um. The termination is immune to interface charges at the Si/SiO2 interface and other layers at the top as well as in the moulding compound. The simulation results show that the breakdown voltages are all above 7000V when the interface charges change from -3E11cm−2 to 5E11cm−2. This device was fabricated and the test results show that the breakdown voltage is more than 7000V, which is agreement with the simulation results.
Multifeature pool importance fusion based GBDT (MPIF-GBDT) for short-term electricity load prediction
Authors: Lv Shengwei , Liu Gang , Bai Xue
Published: March 2021

Feature selection is one of the key factors in predicting. Different feature selection algorithms have their unique preferences for elemental analysis of the data. This results in failing to determine the optimal features when a dataset goes through different feature selection algorithms to get different pools of input features, which in turn affects the prediction quality. To address this problem, the method integrates and fuses the feature importance values of two different feature selection methods. Then the input feature pools are optimized and filtered for the prediction model. Finally, the multifeature pool importance fusion based GBDT (MPIF-GBDT) is developed, which integrates the different feature selection methods and predicts the short-term power load in combination with the gradient boosting decision tree algorithm. In this paper, the tree model feature selection and the Recursive Feature Elimination (RFE) are chosen as feature selection methods. The experimental results show that MPIF-GBDT can significantly improve the accuracy of the prediction compared with the benchmark model.
Sentiment analysis measure of topic mapping in LDA-LSTM combination model
Authors: Lv Yi-hang , Liu Qin , Jiang Chang-bin
Published: March 2021

New energy market competition incentive, how to improve the product accurately, so as to attract consumers, will become the key point for enterprises to occupy the market. From the perspective of improving products, this paper constructs a review information dimension mapping theme emotion analysis model. Firstly, LDA model is used to extract the topic of comment information. Secondly, topic mapping is carried out on the comment information to get the correlation degree between each comment information and each dimension topic. Finally, the LSTM model is constructed for sentiment analysis, and the emotional intensity of consumers in each dimension theme is measured.
Short-term wind power forecasting model based on multi-feature extraction and CNN-LSTM
Authors: Kuang Honghai , Guo Qian , Li Shengqing , Zhong Hao
Published: March 2021

Improving the accuracy of short-term wind power forecasting is critical to wind power consumption. This paper establishes a short-term wind power prediction model based on the multi-feature extraction and deep learning network CNN-LSTM. Muti-features are extracted from original data to improve the accuracy of training. In addition, clustering algorithm is used to classify training data and train the models corresponding to those classes. CNN-LSTM prediction models are established for each cluster and compared with ARIMA, RNN, CNN and LSTM models.
Research on Statcom Current Detection Method and Control Technology Based on Instantaneous Reactive Power Theory
Authors: Yang Linguo
Published: March 2021

The increase and decrease of non-linear load and impact load of power grid lead to lower and lower power quality, which has become a hot issue in reactive power compensation and harmonic suppression technology research. As one of the AC output equipments, the static synchronous compensator has strong compensation performance and can provide technical support for no power compensation. Therefore, based on the theory of instantaneous reactive power, the current detection method and related control technology of the static synchronous compensator are proposed, and finally the experimental simulation is carried out. The simulation results show that the improved detection algorithm can detect the reactive current of the system efficiently and accurately. Using STATCOM current detection method and control technology, it can adjust reactive power in time, compensate for actual power demand, further suppress system voltage fluctuations and improve system performance.
Mechanical and electronic properties of 2D black phosphorene nanoribbons: A first-principles study
Authors: Miao Yufei , He Luwu
Published: March 2021

The mechanical and electronic properties of black phosphorene nanoribbons are studied using the first-principles calculations. The armchair black phosphorene nanoribbons (APNR) are obtained and the atomic reconstruction is found at the edge of the nanoribbons. In addition, the strain field is applied on the nanoribbons, and its stress-strain curve, Young’s modulus, and Poisson’s ratio are calculating by stretching APNR. It is found that the Young’s modulus enhanced with the increase of nanoribbons width. It is significantly lower than the Young’s modulus of monolayer black phosphorene. On the contrary, the Poisson’s ratio hardly changes with the increase of nanoribbons width. Finally, it is found that the band gap of APNR decreases with the increase of nanoribbons width and increases monotonically with the increase of strain.
Simulation and optimization of NO generation characteristics of ultra supercritical compact boiler
Authors: Dai Wentai , Liu Jianquan , Zhong Li
Published: March 2021

Computational fluid dynamics numerical simulation method was used to numerically simulate the combustion process in 700 °C ultra-supercritical compact swirl opposed coal-fired boiler. The flow field distribution, composition distribution and NO distribution in the furnace were obtained through simulation. Simulating the NO generation in the boiler when the burner is put into different operation modes under different loads. The results show that the velocity and temperature fields in the ultra-supercritical compact boiler have the same characteristics as the typical swirl opposed coal-fired boiler. The O2 concentration showed good consistency with the main gas products CO and CO2 concentration. To a certain extent, NO generation and distribution characteristics are related with the temperature field. When the burner is put into operation in different ways, NO generation and distribution are different correspondingly. The simulation and test can provide theoretical basis for the technical implementation and structural optimization of the ultra-supercritical compact boiler at 700 °C.
First-principles study on electronic properties of twisted bilayer borophene
Authors: Wu Rongyao , Gao Yang , Wang Xiaoyuan
Published: March 2021

Borophene has received considerable investigations in recent five years that it is reported to possess a series of marvelous properties. However, most of the researches are about its monolayer form, the bilayer borophene, especially the twisted bilayer form which is a hot topic recently, has not been studied in detail. Herein, the first-principles calculations based on the density functional theory (DFT) method was performed to study the electronic properties of three kinds of twisted bilayer borophene that each kind of bilayer borophene is twisted to a certain angle in the plane. For the consideration of structural stability and calculation cost, the bilayer borophene are optimized to be 32.2°, 58.0° and 83.6° using an algorithm based on crystal matching theory. The charge density of relaxed twisted bilayer borophene shows the proximity of boron atoms. The analysis of band structure reveals that the twisted bilayer structure could separate the degenerate band and transform the bands to direct type, thus, modulating the resistance. In addition, a near-zero density of states could be found when bilayer borophene is twisted. This research could provide a basis for the applications of borophene, such as integrated electronic devices and micro/nano electronics.
Calculation of Power Consumption and Junction Temperature of IGBT Module in Inverter
Authors: Wang Bo , Tang Yong
Published: March 2021

Insulated Gate Bipolar Transistor(IGBT) is a fully controlled power electronic device with excellent comprehensive performance, which is widely used in various inverter units. At present, Infineon’s IPOSIM simulation is usually used to obtain the power consumption and junction temperature fluctuation of IGBT modules, but it is only applicable to IGBT modules produced by Infineon. In this paper, the power consumption of IGBT and diode is calculated, and the expression of junction temperature fluctuation is obtained based on junction-shell transient thermal resistance, which is suitable for common IGBT modules. Finally, simulation verifies the correctness of the calculation method.
Proton exchange membrane fuel cell multi-stack parallel gas supply and load-up experiment
Authors: Huang Zhiwei , Zhou Junbo , Cui Yuanshuai , Cao Jiaxu
Published: March 2021

Given the current situation that there is no parallel experiment of multiple stacks in China, this paper uses a fuel cell test platform independently designed and produced by a company to study the performance of three fuel cells. This article describes the construction of the experimental test platform and the multi-stack load-up experiment. The experimental results show that the power generation of the three fuel cells is almost the same, which are 9475W, 9385W, and 9512W. When carrying out multi-stack load-up experiments, it was found that as the number of stacks increased, the voltage efficiency continued to decrease. The Analysis revealed that the parallel gas supply method caused uneven gas distribution, which caused some fuel cells to be in a state of hydrogen deficiency. This article proposes amendments to this problem.
Study on the Rheological Properties of MPCS with Isopropanol/Water as Base Fluid
Authors: Zou Chuansheng , Lv Shan , Qiu Zhongzhu , Li Chunying
Published: March 2021

In order to obtain a good stability of micro-encapsulated phase change suspension, then study its rheological properties, herein formulated a phase change micro-capsulated suspension and utilized isopropanol/water mixed solution as the base fluid. The particle size distribution, viscosity and rheological properties of micro-encapsulated phase change suspension were measured at different concentrations. The effects of mass fraction, temperature on viscosity were discussed. Based on the classic viscosity formula, a correction factor was introduced to get higher precision viscosity formula. The results show that: a volume ratio of 1:1.75 of isopropanol/water suspension, suspension stability is up to 48h. It is also found that the viscosity decreases with the increase of temperature, but it increases with the increases of mass concentration. The fitted Tomas viscosity formula is reliable when the volume concentration is less than 15.58%, the error could be controlled within 5.7%.
Simulation and optimization of distributed energy system based on differential evolution algorithm
Authors: Ni Congqi , Qiu Zhongzhu , Li Chunying , Gao Guishu , Zheng Yurou , Wu Congcong
Published: March 2021

Many parameters can influence performance of a distributed energy system as it involves various kinds of equipment. Proper sizing of various equipment is of great significance for its efficient operation of such systems. This paper took a business district as the research object, predicted and analyzed the hourly cooling/heating load of the system during typical days of different seasons. Based on comprehensive consideration of the user’s usage pattern, load, equipment characteristics and other issues, gas engine was selected as the system’s prime mover, and the system structure was designed accordingly. Mathematical model was developed including gas engine, gas boiler, absorption chiller and other equipment. The differential evolution (DE) algorithm was applied to optimize the equipment capacity of the energy system, with the multi-objective of lower annual total cost and less annual emission. The annual pollutant emission of the plan C is the lowest in the results, which is more suitable for the business district. Compared with the traditional energy system, the annual total cost and pollutant emission of the optimized system were about 22% and 27% lower, respectively. The distributed energy system shows significant advantages.
Research on IGBT Limit Current Based on Heat Balance Analysis
Authors: Wang Bo , Tang Yong
Published: March 2021

Insulated Gate Bipolar Transistor(IGBT) is the most widely used fully-controlled power electronic device at present, and the rated DC current and maximum pulse current given in the manual can’t reflect the working limit current. In this paper, considering the influence of temperature, the electrical model of IGBT is extended to electro-thermal model, and the stable point, unstable point and critical point of junction temperature are obtained by combining IGBT power consumption-temperature curve and heat transfer curve, thus the limit power consumption at the critical point is obtained, and the limit current is designed. Finally, experimental verification is carried out.
Research on Electro-thermal Model Simulation of IGBT Switching Transient
Authors: Wang Bo
Published: March 2021

The electro-thermal model of Insulated Gate Bipolar Transistor(IGBT) can be used to simulate the operating characteristics of devices at different temperatures. Considering the relationship between internal parameters, semiconductor physical constants and temperature, the electrical model of IGBT at a single temperature is extended to an electro-thermal model which can reflect the working characteristics at different temperatures. This model takes into account both simulation accuracy and simulation speed. Finally, the IGB model is selected, and the IGBT switching transient at different temperatures is verified by experiments.
Research on Classification and Application of Comprehensive Energy Load of Important Users
Authors: Wu Tianjiao , Li Qifen , Yang Yongwen , Li Long , Ning Ning
Published: March 2021

Important load users are the lifeline of urban development, and their energy security system is not yet complete. According to the existing power load classification guarantee principle, the comprehensive energy load classification and guarantee measures of important users are discussed. At the same time, it analyzes the characteristics of existing security resources, selects the semiconductor manufacturing industry as the application scenario, and explores more possibilities for flexible configuration of security resources for users with important loads. Finally, the distributed energy system is proposed as a security resource for semiconductor companies, and it is used as a backup with the mains, replacing conventional diesel generating sets, and switching from cold standby to hot standby. This will reduce the initial investment in enterprise construction, improve the utilization of security resources, and the reliability of energy supply for important load users.
Role of graphene on the enhancement of near-field radiative heat transfer between two homogeneous lossy media plates
Authors: Gou Yuchun , Fang Junfei , Huang Jinguo
Published: March 2021

In this paper, the near-field radiative heat transfer between two semi-infinite plates with different temperatures, which are composed of homogeneous lossy media, has been studied firstly. Attributed to the evanescent wave generated by total internal reflection, the near-field radiative heat transfer is much larger than the far-field radiative heat transfer. And, the closer the distance between the two plates is, the greater the heat transfer is. Then, a graphene layer has been used to cover on the surface of the plate with lower temperature to study the effect of graphene on the near-field radiative heat transfer. The results show that the existence of graphene can promote the near-field radiative heat transfer due to the excitation of surface plasmon polaritons on the surface of graphene. In addition, the heat transfer varies with chemical potential of graphene, which indicates that the near-field radiative heat transfer can be controlled by an external gate circuit. In the presence of graphene, the thermal resistance between the two plates ranges from 6.7×10−4 to 0.18 K/(W/m2) and increases with the increase of the thickness of vacuum gap between the plates.
Numerical Analysis of Influence Factors on Operation Performance of an Axial Exhaust Condenser
Authors: Xu Wenqiang , Zhang Li , Niu Hao
Published: March 2021

Taking the axial exhaust condenser of one gas-steam combined cycle unit as the research object, the steam flow in the shell side of the condenser was simulated under summer operating conditions. The flow distribution of the condenser in the shell side was obtained. Through the extraction of simulation data, the pressure of the condenser was obtained. The simulation results of single factor influence showed that the main factors leading to high operating pressure of the condenser under summer working condition were steam load, circulating water inlet temperature, circulating water flow and vacuum tightness.
An Improved MPPT Method with Dynamic Voltage Error Compensation under Two Varying External Conditions
Authors: Liu Sijia , Huang Yong , Dai Gaoqiang , Zhou Xun
Published: March 2021

This paper presents a new maximum power point tracking (MPPT) method which can improve the dynamic tracking ability under two varying external conditions, rapid irradiance variation and grid voltage fluctuation. Different from irradiance variation, the dynamic error of tracking voltage caused by grid voltage fluctuation is usually ignored by MPPT methods. The dynamic error of tracking voltage can make the unexpected power change of photovoltaic system and influence the dynamic MPPT efficiency. According to the different current increment changes under the irradiance variation and the grid voltage fluctuation, the reasons of dynamic voltage errors are analyzed and distinguished. And two corresponding modes of variable step size are designed in the tracking algorithm to regulate the voltage deviation from MPPs. The effectiveness and the improved dynamic tracking performance of the proposed MPPT method are verified by simulation results under the above two varying external conditions.
Effect of in Situ Formed Emulsions on Enhanced Extra-Heavy Oil Recovery by Surfactant Flooding
Authors: Wang Xiuyu , Wang Xiaoqiu , Lei Lichuan , Guo Yang , Yang Yongzhi , Xu Yaping , Hao Huimin
Published: March 2021

Thermochemical flooding is becoming more popular nowadays as a subsequent EOR method after thermal recovery in extra-heavy oil reservoirs. During this process, in-situ emulsions could happen due to interfacial active components existing in heavy crude oil. The enhanced oil recovery is inevitably related with the formation of emulsions, which is one of the main mechanisms and deserves a thorough study. Also, the features of relative permeability curves during thermochemical flooding should be investigated further, because they are very important but usually are difficult to obtain since physical reactions could happen.

Based on core-flooding experiments, combined with careful observation of produced crude oil emulsion morphology, this paper compared and analyzed the features of relative permeability curves and displacement efficiency at different conditions, and the mechanisms of extra-heavy oil production by surfactant displacement is then investigated. The surfactant used are provided by the oilfield at a varied mass fraction of 0.1%, 0.2% and 0.3% and under temperature of 100, 150 and 180 °C. The relative permeability data were processed with JBN method.

The experimental results show that both the oil and water relative permeability increase as the temperature increases. As surfactant concentration increases, the relative permeability of the aqueous phase decreases as opposite to oil. The ultimate recovery increased with the increase of temperature and surfactant concentration. Except for the oil viscosity reduction by surfactant, it is interesting to note that the formation of crude oil emulsions (mainly O/W emulsions) are observed to be positively impacting the oil recovery factor. As surfactant concentration increases, larger size of dispersed phase in the emulsions were observed in the effluent corresponding to a higher oil recovery factor. This work is of great significance for heavy oil research and field development.
A novel direction relation reasoning model based Environmental Protection GIS
Authors: Xiang Jun
Published: March 2021

To make the complicated environmental protection work simple, environmental protection GIS is widely used. Direction relation reasoning is an important branch of spatial reasoning, it is also one of the most basic theoretical issues in the Environmental Protection Geographic Information System. This paper proposes a modelling method of combining the cone-shaped direction relation model with the direction relation matrix to determine the fuzzy direction relation between spatial entities on the basis of the cone-shaped direction relation model and direction relation matrix in Environmental Protection Geographic Information System, the advantages of the two models are fully utilized to overcome the disadvantages of them. Firstly, “central-region” is divided into nine equal internal sub-regions on the basis of the Minimum Bounding Rectangle (MBR) model. Then, the central-region of the direction relation matrix is divided again by using the cone-shaped direction relation model, and a fuzzy formal description model is given by taking point entity and area entity as research objects. The application of direction relation reasoning model in Environmental Protection GIS is helpful to improve the efficiency of judging the direction of pollution sources and the level of environmental protection.
A brief analysis method in plant landscape design of motorway
Authors: Que Yi , Tang Haiyan , Zhang Zhiwei , Zhao Hengyi
Published: March 2021

Plant landscape design is one of the main contents of highway design. This paper sums up the principles and methods for plant landscape design based on the compositions of expressway landscape, and discusses in detail the point of plant landscape design for the green belt on both sides of the expressway, the central separation belt and the subsidiary green area.
Study on Start-up Performance of Anammox Process
Authors: Li Yafeng , Wu Jianbo
Published: March 2021

Anammox, as one of the most revolutionary new denitrification technologies so far, has broad application prospects. In order to explore the start-up process of the anaerobic ammonia oxidation process, the experiment was conducted to domesticate anaerobic sludge in an up-flow anaerobic sludge bed reactor. The results showed that the reactor reached a stable operation stage from the 95th day to the 112th day. The removal rate of NH4
+-N and the removal rate of NO2
−-N were stabilized at 94.12% and 97.70%, respectively. According to the removal of NH4
+-N and NO2
−-N in the reactor, the start-up process can be divided into 4 stages, and there is denitrification and synergistic anaerobic ammonia oxidation in the reactor.
Preparation of sulfamethazine molecularly imprinted polymer by electron beam irradiation polymerization
Authors: Liu J , Yuan K F , Liu J H
Published: March 2021

Molecularly imprinted polymers (MIPs) of sulfamethazine (SMZ) were prepared initiated by election beam irradiation in acetonitrile (ACN) with the use of SMZ as template molecule, acrylamide (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent. The combination of SMZ with MaA and EGDMA was studied by infrared spectroscopy. The adsorption kinetics experiment and selectivity of sulfamethazine imprinted polymers were investigated by ultraviolet spectrometry. The experimental results showed that there was a binding effect among SMZ, MAA and EGDMA. When the molar ratio of SMZ, MAA and EGDMA was 1 : 4 : 20, and the irradiation dose was 150 kGy, the adsorption capacity of MIP for sulfamethazine (Q
MIP) was the largest (31 mg·g−1). Furthermore, the imprinting factor (F) was 12.91, and the separation factor (α) for SMZ and sulfonamide (SNM) was 1.77.
Effect of Low temperature treatment on dormancy release of Sedum aizoon L.
Authors: Liu Yuhang , He Zhongqun , Zhang Ruijie , Li Chunyan
Published: March 2021

The dormant Sedum aizoon L.seedlings were treated with different days(1d, 3d, 5d and 7d) of low temperature (5°C), and restored to grow for 40d (25°C).The growth indexes, photosynthetic characteristics and carbohydrate metabolism indexes were measured to compare the dormancy relieving effects of the seedlings. The results showed that Sedum aizoon L. was physiologic dormancy, and the effect was the best when it was treated at 5°C for 5 days, and the dormancy was completely relieved.
Application of Ergonomics in Health Care
Authors: Chen X , Wang X , Ai Cq
Published: March 2021

This paper defines the definition of human ergonomics, and introducing human ergonomics as an important subject in the medical and health services, and discusses the technical skills associated with human ergonomics and medical and health services, let us on the non-technical skills in medical and health services with the understanding of the important role. This paper analyzes the current situation of some non-technical skills in our hospital, and summarizes some effective methods and measures at home and abroad to reduce the influence of human factors in recent years.
Design and research of underwater hydraulic driven diamond chain saw cutting machine
Authors: Yang Shao-Rong , Wang Zhi-Ming , Yu Yue , Lu Yun-Feng
Published: March 2021

The hydraulic driven chain saw is a cutting tool for underwater operation. The hydraulic driven chain saw was designed, the hydraulic adjusting device was designed, the hydraulic chain saw experimental platform was designed, the sawing efficiency and power consumption experiments were carried out, and the diamond saw chain wear experiment was carried out. The experimental results show that:When cutting C25 standard reinforced concrete floor plate, the tension of tight edge of diamond saw chain is large; the dynamic load of diamond saw chain has the greatest influence on the tension of diamond saw chain, and the dynamic load is proportional to the rotation speed of chain wheel, the pitch of diamond saw chain, the weight per meter of diamond saw chain and the length of tight edge, among which the rotation speed of chain wheel has an effect on it The noise is the largest; the power consumption of cutting concrete is 2.85kw, the efficiency of sawing concrete is 0.93m2/h, and the sawing area of diamond saw chain per meter is 16.7m2/m.
Bacillus tequilensis Isolated from Fermented Intestine of Holothuria Scabra Produces Fibrinolytic Protease with Thrombolysis Activity
Authors: Hidayati Nur , Nurrahman Nurrahman , Fuad Hayatun , Munandar Hendra , Zilda Dewi Seswita , Ernanto Aditya Rahman , Samiasih Amin , Oedjijono Oedjijono , Ethica Stalis Norma
Published: March 2021

Among essential treatment of cardiovascular disorders are fibrinolytic proteases. Most thrombolysis agents are fibrinolytic enzymes from group of bacterial proteases. This work reports a potent bacterium isolated from fermented intestine of H. scabra, which could produce fibrinolytic protease with high thrombolysis activity. Bacterial selection was conducted based on proteolytic and fibrinolytic activities indicated as clear zone on skim milk and fibrin agar media, respectively. Crude proteases from the selected bacterial isolates were subjected to thrombolytic activity test based on gravimetric method, which results were confirmed after 7 repetitions. As result, 4 fibrinolytic protease-producing bacterial isolates HFSI-3, HFSI-4, HFSI-5 and HFSI-8 were obtained. Among them, HFSI-5 isolate identified as Bacillus tequilensis on the basis of the 16S rRNA gene sequencing and morphological properties produced crude protease with the highest thrombolytic activity. The thrombolytic activity of crude protease produced by B. tequilensis HFSI-5 is worthy of comparing to that of standard fibrinolytic enzyme Nattokinase showing its potential as thrombolysis agent.
High-speed generation of singular beams through random spatial multiplexing
Authors: Hu Xiao-Bo , Ma Si-Yuan , Rosales-Guzmán Carmelo
Published: March 2021

Complex vector modes have become topical of late due to their fascinating properties and the many applications they have found across a broad variety of research fields. Even though such modes can be generated in a wide variety of ways, digital holography stands out as one of the most flexible and versatile. Along this line, digital micromirror devices (DMDs) have gained popularity in recent times due to their high refresh rates, which allows the generation of vector modes at kHz rates. Nonetheless, most techniques are limited either by the diversity of vector modes that can be generated or by the speed at which they can be switched. Here we propose a technique based on the concept of random encoding, which allows the generation of arbitrary vector beams at speeds limited only by the refresh rate of the DMD. Our technique will be of great relevance in research fields such as optical communications, laser material processing and optical manipulation, amongst others.
Effect of plasma step gradient modification on surface electrical properties of epoxy resin
Authors: YAN Jiyuan , LIANG Guishu , LIAN Hongliang , SONG Yanze , PENG Chengkai , KANG Yuchan , XIE Qing
Published: March 2021

In this paper, plasma fluorination is combined with plasma silicon deposition to achieve step gradient modification on an epoxy resin surface. The physicochemical characteristics of samples are investigated and the electrical performances measured. The obtained results show that compared with untreated and single treated samples, the samples treated by step gradient modification significantly improve the flashover performance. According to experiment and simulation, the mechanism explanations are summarized as follows. First, it is found that the step gradient conductivity can effectively optimize the electric field distribution of a needle-needle electrode. Then, step gradient modification suppresses the accumulation of surface charge at the triple junction and makes the charge distribution more uniform. Furthermore, it can accelerate the surface dissipation on a high electrical field region and control the dissipation rate on a low electrical field region. All these results can restrain surface discharge and increase the flashover voltage. The step gradient modification method proposed in this paper provides a new idea for improving the surface insulation performance.
8 Improving Delirium Screening and Recognition Through Quality Improvement Crowdsourcing: Results of A Panspecialty Multi-Centre Project
Authors:   Geriatric Medicine Research Collaborative
Published: March 2021

Background

Delirium is common in hospitalised older adults. It is distressing and devastating. Unfortunately, delirium remains under-recognised in clinical practice.

Methods

We conducted a multi-centre crowdsourced quality improvement project, with three rounds of data collection. We shared guidelines, toolkits, and educational tools in web-based folders, alongside social media and conference dissemination. We recorded delirium screening completion within 48 hours of admission and delirium recognition by the usual care team in unscheduled admissions (≥65 years). Delirium was diagnosed prospectively in Round-1 (R1) and Round-3 (R3), and retrospectively in Round-2 (R2) (validated approach).

Results

Across all rounds (82 sites), delirium prevalence was 16.3% (491/3013). Delirium screening (R1: 27.3%, R2: 29.6%, R3: 37.1%; p < 0.001) and recognition (R1: 34.2%, R2: 57.1%, R3: 63.2%; p < 0.001) improved across each round. Odds of screening (OR 1.52, CI 1.19–1.93) and recognition (OR 3.65, CI 1.94–6.87) were greater in R3 compared to R1 in multivariable analysis. Likelihoods of delirium screening (OR 0.49, CI 0.28–0.85) and recognition (OR 0.15, CI 0.03–0.82) were reduced in patients admitted under other surgery specialties. Local delirium teams were associated with increased screening odds (OR 1.75, CI 1.40–2.18), and geriatrics teams embedded into admissions units were associated with increased recognition odds (OR 1.66, CI 1.03–2.69). Documentation of delirium on discharge summaries also improved (R1: 28.6%, R2: 48.4%, R3: 46.6%). Odds of discharge documentation (OR 3.19, CI 1.18–8.82) were greater in R2 compared to R1 in multivariable analysis. Across all rounds, delirium was associated with increased hospital mortality (HR 1.83, CI 1.30–2.60) and length of stay (+3.18 days; p < 0.001) in multivariable analysis.

Conclusion

Delirium is common across all specialties. It is associated with increased mortality and length of stay. Trainee-led quality improvement crowdsourcing can be used to improve delirium screening, recognition, and documentation on discharge summaries.
9 Patient Outcomes From A General Inpatient Rehabilitation Ward, Does Frailty or Reason for Admission Make A Difference to Patient Outcome?
Authors: Alcorn E , Wentworth L
Published: March 2021

Introduction

With our ageing population there is increasing number of patients who experience a decline in their mobility either because of their underlying diagnosis or as a consequence of their hospital stay. There are only a limited number of inpatient rehabilitation beds and it is therefore important to identify those that would benefit the most from inpatient rehabilitation.

Method

We undertook a retrospective study looking at three months of discharges from an inpatient rehabilitation ward in Manchester. Patients were categorised based on diagnosis (Pubic rami fracture, other fractures, fall with no bony injury and finally medical reasons) and Clinical Frailty Score to see if either had any effect on whether patients mobility improved and to what degree.

Results

Patients with a reduced mobility on admission were identified and then categorised based on diagnosis. Of those patients admitted with a pubic rami fracture 66.7% improved on the ward with 33.3% of patients reaching their baseline mobility. The mobility of 85.7% of patients with other fractures improved with 42.9% reaching their baseline. Patients admitted following a fall without bony injury showed, 75% improvement with 50% reaching their baseline. Of those admitted for medical reasons 88.9% of those improved but only 22.2% reaching their baseline mobility. The lowest proportion of any category. Those admitted for medical reasons also had the longest median average stay on the rehab ward (33.5 days) followed by other fractures (33 days) then fall with no bony injury (21.5 days) and finally the shortest average stay, pubic rami fractures (20 days).

Patients were also grouped occurring to their preadmission Clinical Frailty Score. With the exception of those who scored four (only a small number of patients), there was a negative correlation between an increasing frailty score and the proportion of patients whose mobility improved. However as frailty score increased the proportion of patients who improved to their baseline increased.

Conclusion

Our study has shown that the majority of patients benefitted from their admission regardless of diagnosis, however those admitted for medical reasons had the lowest chance of reaching their baseline mobility despite the longest admissions on the ward. Further research may be beneficial to investigate if they do better in a different rehabilitation setting.
13 Caregiving Burden and Unmet Support Needs in Chinese Caregivers and Cancer Patients
Authors: Leung D Y P
Published: March 2021

Introduction

Cancer burden continues to rise globally and locally. Due to the shift of the cancer care from the hospital to the community, many cancer patients requiring needs in palliative care from their informal caregivers. Many caregivers often taking up the important roles and responsibilities but their own needs are largely neglected, and hence may induce caregiving burden. This study aims to explore the relationships of caregiving burden with unmet support needs in both cancer patients and their caregivers.

Method

A convenience sample of 280 patient-caregiver dyads was recruited from the oncology outpatient clinic of two hospitals in Hong Kong between April and June 2018. Among them, 258 (92.1%) patient-caregiver dyads provided complete information on unmet supportive care needs (Patient: the 34-item SCNS-SF34-C, Caregivers: the 26-item SPUNS-SF), and caregiving burden (Caregiver Strain Index).

Results

Among the patients, their mean age was 60.8 (SD = 13.6) and 66% were female. Among the caregivers, their mean age was 49.3 (SD = 14.6), 67.2% were female, and 38.2% were children of the patient. Mean level caregiving burden in caregivers was 4.87 (SD = 3.75) out of a range 0–13. Regression analysis showed that higher caregiving burden was associated significantly with higher caregiver’s unmet support in personal and emotional needs (βstd = 0.348) and future concerns (βstd = 0.204), and patient’s unmet support in physical and daily living needs (βstd = 0.201), but lower caregiver’s unmet support in information needs (βstd = −0.233) after controlling for age, gender, and education level of both patients and caregivers.

Conclusions

The findings shed lights in designing interventions aim at reducing caregiving burden by targeting caregiver’s unmet support in personal and emotional need and those caregivers are taking care of cancer patients with unmet support in physical and daily living needs. However, the finding on caregiver’s unmet support in information needs was a protective factor of caregiving burden warrants further exploration.
14 A Systematic Review of the Prevalence and Implications of Frailty in Diabetes Mellitus
Authors: Hanlon P , Faure I , Corcoran N , Butterly E , Lewsey J , McAllister D A , Mair F S
Published: March 2021

Background

Frailty, an age-related state of vulnerability to adverse health outcomes, is an important factor in the management of diabetes. This systematic review aims to summarise the observational data on prevalence of frailty in diabetes and the association between frailty and generic (e.g. mortality) and diabetes specific (e.g. hypoglycaemia) outcomes.

Methods

We searched three electronic databases for observational studies assessing frailty in adults (≥18 years) with diabetes (type 1, type 2, or unspecified). Eligible studies quantified the prevalence or incidence of frailty or the association between frailty and clinical outcomes in the context of diabetes.

Results

118 studies included, using 18 different frailty measures. Frailty phenotype was the most used (n = 69) followed by frailty index (n = 16) and the FRAIL scale (n = 10). Studies were highly heterogenous in terms of setting (88 community, 18 outpatient, 10 inpatient, 2 residential care), population demographics, and inclusion criteria. The median frailty prevalence in community-based studies using the frailty phenotype was 13% (interquartile range 7-18%). Frailty was identified in “middle-aged” (<65 years) as well as older people with diabetes. Diabetes was consistently associated with incident frailty. Frailty was associated with higher mortality, hospital admission, incident disability. Frailty was associated with hypoglycemic events in 1/1 study. Frailty was also associated cross-sectionally with micro- and macro-vascular complications, lower quality of life, and cognitive impairment. Frailty was not associated with difference in mean HbA1c, however people with frailty were more likely to have high (>9%) or low (<6.5%) HbA1c.

Conclusions

Frailty in diabetes is common but inconsistently measured. Frailty is associated with a range of adverse outcomes. Research gaps include the relationship between frailty and glycaemia (particularly hypoglycaemia and the relationship between HbA1c and outcomes in the context of frailty), and the impact of frailty in specific groups such as middle-aged people and in low and low-middle income countries.
19 Integrated Falls Prevention Pathways; the Benefits of Organisational Collaboration
Authors: Tanks E , Michael A
Published: March 2021

Introduction

There is continuous increased demand on the NHS, while resources are finite. Developing pathways with Integration and streamlining of services is crucial to achieve good outcome and better use of resources. Falls service is a good example. In Dudley, three separate services existed for managing falls: a local authority team, a NHS therapy team and a Consultant-led Falls & Syncope clinic. We collaborated and reorganised the services to improve patient care and achieve better outcome.

Methods

We integrated services into one pathway, where patients are triaged to the relevant service based on clinical need via a Single Point of Access. One multifactorial assessment- based on NICE guideline CG161 and Quality Standard QS86- was developed, which is completed by all services (streams). This allows their assessment to be transferred to another stream if clinically indicated, saving repetition/duplication. An extensive training programme was delivered to up-skill staff across the pathway in completing areas of best practice (e.g. postural BP measurement, balance/mobility assessments, cognitive assessment, FRAX score, medication issues). Additionally we established a Falls MDT meeting with representation from all streams, to discuss complex cases, and developed a shared, electronic database to track patient journeys and monitor service outcomes.

Results

Falls admission rate decreased by 29.4% for patients 65 y and over and 25.2% for 80+. This equates to 433 fewer falls compared to peak rate; saving an estimated £3.4million. Also, hip fracture admission rate decreased by 19.2% for patients 65 y and over and 23.5% for 80+. This equates to 91 fewer hip fractures compared to peak rate; saving an estimated £1.3million. Much improved service collaboration and resource sharing.

Conclusion

A collaborative approach between organisations, utilising existing resources in a system that places patients at the heart of the service, improves patient experience and outcomes, alongside significant financial savings.
27 Can Sarcopenia be Used to Estimate Outcomes in Elderly Patients Treated with Chemoradiotherapy for Bladder Cancer?
Authors: Corden M
Published: March 2021

Introduction

Ageing is a risk factor for bladder cancer, with a median age at diagnosis of 71 years. In addition, sarcopenia shows promise as a prognostic biomarker for bladder cancer. This study evaluates sarcopenia as a predictor of overall survival (OS) for older patients treated with chemoradiotherapy for bladder cancer.

Methods

185 bladder cancer patients treated (from 2010–2017) with chemoradiotherapy were available for analysis. Pre-therapeutic computed tomography scans were identified and single slices at the L3 level were identified. Machine learning software was used to segment skeletal muscle and obtain its cross-sectional area. This was normalised against height squared to calculate a skeletal muscle index for each patient. Sarcopenia was defined using international consensus definitions (<39 cm2/m2 in females and < 55 cm2/m2 in males). Differences in survival function between patients ≤75 and > 75 years were visualised using Kaplan–Meier curves. Age distribution between sarcopenic and non-sarcopenic patients was also explored. Finally, a multivariable Cox proportional hazards model was conducted to investigate interactions between sarcopenia and increased age with respect to OS.

Results

Of 185 patients, 114 (61.6%) were sarcopenic and 71 (38.4%) were non-sarcopenic; 101 (54.6%) and 84 (45.4%) patients were ≤ 75 and > 75 years old respectively. No differences in OS were observed between the two age groups (p = 0.50). There was no interaction between sarcopenia and age as a continuous variable was observed with respect to OS (p = 0.682); however, when age was categorised an interaction was seen (p = 0.058). Nevertheless, after adjusting for performance status, T-stage, hydronephrosis, albumin, haemoglobin, neutrophil and lymphocyte counts, the interactions between age and sarcopenia were no longer observed (age continuous, p = 0.474; age categorized, p = 0.765).

Conclusions

Patients with bladder cancer over 75 years of age have a modest increase in probability of developing sarcopenia but this does not impact on OS.
36 Feasibility of Resistance Exercise to Failure at Different Loads in Frail and Healthy Older Adults?
Authors: Marshall-McKenna R , Campbell E , Ho F , Banger M , Rowe P , McAlpine C , McArthur K , Quinn T J , Gray S R
Published: March 2021

Introduction

Resistance training (RT) is the most effective way to increase muscle mass and function in older adults both with/without sarcopenia/frailty. In younger adults, when RT is performed to muscle failure the load lifted does not mediate the magnitude of response, but there are no studies in older adults. We aimed to determine the feasibility of recruitment to a RT intervention working to muscle failure at different loads in frail and healthy older adults.

Methods

We performed an 8-week randomised feasibility trial of lower limb RT to volitional muscular failure, at high and low load. Participants were recruited via hospital outpatient clinics and newspaper advertisements. Outcomes included: frailty assessment (Fried criteria); muscle strength (maximum voluntary contraction/one-repetition maximum); functional abilities (Short Physical Performance Battery); safety/adverse events were recorded via a log, and patient experiences from focus groups.

Results

110 people were assessed for eligibility, and 58 randomised (frail n = 6, prefrail n = 20, robust n = 32) to either high (n = 30) or low load (n = 28) groups. Mean age of participants was 72 years (range 65–93), 36 were female, 22 male. Session attendance was 95% (high load) and 90.4% (low load). Most participants were recruited via advertisements. All participants reported feeling safe and reassured in the RT sessions. Two participants had a serious adverse event, one related to RT (hypotension) and several had adverse events (three intervention-related). Pain was reported at both loads (high n = 9, low n = 8) yet all completed. There were no differences (P > 0.05) in effects of RT outcome variables between low and high load groups.

Conclusion

In this feasibility trial the recruitment of frail patients via clinics was limited. Performing supervised RT to muscle failure in older adults was safe/acceptable and the load at which RT was performed did not influence its efficacy. Future research into the effectiveness of such RT is warranted.