bluuebunny/crossref_metadata_2025 huggingface dataset:
Introducing Information Extraction to Radiology Information Systems to Improve the Efficiency on Reading Reports
Authors: Xie Zhe , Yang Yuanyuan , Wang Mingqing , Li Ming , Huang Haozhe , Zheng Dezhong , Shu Rong , Ling Tonghui
Published: September 2019

Background Radiology reports are a permanent record of patient's health information often used in clinical practice and research. Reading radiology reports is common for clinicians and radiologists. However, it is laborious and time-consuming when the amount of reports to be read is large. Assisting clinicians to locate and assimilate the key information of reports is of great significance for improving the efficiency of reading reports. There are few studies on information extraction from Chinese medical texts and its application in radiology information systems (RIS) for efficiency improvement.

Objectives The purpose of this study was to explore methods for extracting, grouping, ranking, delivering, and displaying medical-named entities in radiology reports which can yield efficiency improvement in RISs.

Methods A total of 5,000 reports were obtained from two medical institutions for this study. We proposed a neural network model called Multi-Embedding-BGRU-CRF (bidirectional gated recurrent unit-conditional random field) for medical-named entity recognition and rule-based methods for entity grouping and ranking. Furthermore, a methodology for delivering and displaying entities in RISs was presented.

Results The proposed neural named entity recognition model has achieved a good F1 score of 95.88%. Entity ranking achieved a very high accuracy of 99.23%. The weakness of the system is the entity grouping approach which yield accuracy of 91.03%. The effectiveness of the overall solution was proved by an evaluation task performed by two clinicians based on the setup of actual clinical practice.

Conclusions The neural model shows great potential in extracting medical-named entities from radiology reports, especially for languages, that lack lexicons and natural language processing tools. The pipeline of extracting, grouping, ranking, delivering, and displaying medical-named entities could be a feasible solution to enhance RIS functionality by information extraction. The integration of information extraction and RIS has been demonstrated to be effective in improving the efficiency of reading radiology reports.
Pedicle Corridors and Vessel Options for Free Flap Reconstruction following Endoscopic Endonasal Skull Base Surgery: A Systematic Review
Authors: Dang Rajan P. , Roland Lauren T. , Sharon Jeffrey D. , Doering Michelle , Chicoine Michael R. , Pipkorn Patrik
Published: September 2019

Introduction Microvascular free flaps offer an alternative to local and regional flaps for coverage of complex or large skull base defects. Routes and approaches to these reconstructive options are complicated and require an understanding of complex head and neck anatomy.

Methods A systematic review of the literature was performed using a set of search terms with the help of a qualified librarian. Articles were reviewed and selected for inclusion based on relevance. We were interested in reporting possible routes for free flap accessibility to the skull base as well as microvascular vessel options, as this choice may affect the geometry and accessibility to the defect.

Results A total of 1,917 articles were obtained from a comprehensive search and 11 articles were ultimately found to be relevant to this review. Published options for vessel anastomosis and corridors to the skull base following endoscopic endonasal surgery are reviewed, including Caldwell-Luc/transbuccal space, prevertebral space, transpterygoid/parapharyngeal, and transmaxillary approaches.

Conclusion The field of endoscopic surgery has continued to advance and provide options for tumors of the skull base. This has led to a need for creative routes to the skull base for free flap reconstruction.
Compartmentalization: An Open Technique for Frontal Sinus Repair and Preservation—Description of Technique and Early Case Series
Authors: Miller Christopher , Weisbrod Luke , Beahm David , Chamoun Roukoz
Published: September 2019

Background Cranialization or obliteration is widely accepted intervention for traumatic or intentional breach of the frontal sinus. These techniques, however, result in the loss of frontal sinus function and have a persistent risk of cerebrospinal fluid (CSF) leak and mucocele. Compartmentalization is an open technique for repair of the frontal sinus using allograft onlay and a vascularized periosteal flap that allows for preservation of frontal sinus function.

Objective The main objective of this article is to describe the technique for compartmentalization of the frontal sinus and demonstrate its efficacy and complication rate with an early patient series.

Methods Our technique includes the following key components: harvesting of a pedicled periosteal flap, frontal sinus repair through a bifrontal craniotomy with minimal mucosa removal, ensuring the patency of the nasal frontal outflow tract, and separation of the brain from the frontal sinus with a dual layer of periosteum and allograft.

All cases of frontal sinus repair using the compartmentalization technique at our institution were reviewed. Charts were reviewed for CSF leak, mucocele, and other complications.

Results Twenty-three patients underwent the described frontal sinus repair technique 17 for tumor and 6 for trauma. There were no CSF leaks and no mucoceles. One patient experienced postoperative anemia and a “parameningeal reaction” that were managed with a short course of antibiotics.

Conclusions Compartmentalization, due to its sinus preservation and low complication rate, represents a meaningful step forward in neurosurgical technique for open frontal sinus repair. However, long-term outcomes are necessary to fully evaluate risk of mucocele.
A versatile experimental system for tracking ultrafast chemical reactions with X-ray free-electron lasers
Authors: Katayama Tetsuo , Nozawa Shunsuke , Umena Yasufumi , Lee SungHee , Togashi Tadashi , Owada Shigeki , Yabashi Makina
Published: September 2019

An experimental system, SPINETT (SACLA Pump-probe INstrumEnt for Tracking Transient dynamics), dedicated for ultrafast pump-probe experiments using X-ray free-electron lasers has been developed. SPINETT consists of a chamber operated under 1 atm helium pressure, two Von Hamos spectrometers, and a large two-dimensional detector having a short work distance. This platform covers complementary X-ray techniques; one can perform time-resolved X-ray absorption spectroscopy, time-resolved X-ray emission spectroscopy, and time-resolved X-ray diffuse scattering. Two types of liquid injectors have been prepared for low-viscosity chemical solutions and for protein microcrystals embedded in a matrix. We performed a test experiment at SPring-8 Angstrom Compact free-electron LAser and demonstrated the capability of SPINETT to obtain the local electronic structure and geometrical information simultaneously.
Chemical Modification of Cellulose Membranes for SPOT Synthesis
Authors: Li Wenyi , Wade John D. , Reynolds Eric , O'Brien-Simpson Neil M.
Published: September 2019

Since the development of solid-phase peptide synthesis in the 1960s, many laboratories have modified the technology for the production of peptide arrays to facilitate the discovery of novel peptide mimetics and therapeutics. One of these, known as SPOT synthesis, enables parallel peptide synthesis on cellulose paper sheets and has several advantages over other peptide arrays methods. Today, the SPOT technique remains one of the most frequently used methods for synthesis and screening of peptides on arrays. Although polypropylene and glass can be used for the preparation of peptide arrays, the most commonly used material for SPOT membranes is cellulose. Critical to the success of the SPOT synthesis is the ability to modify a cellulose membrane to make it more suitable for solid-phase peptide synthesis of peptides and their analogues. In this review, we highlight the current range of chemical modifications of cellulose that have been developed to enable SPOT synthesis and further enhance its impact on peptide drug discovery. This will contribute to further chemical modifications and applications of SPOT synthesis for peptide arrays and peptide therapeutic screening.
Biological deposits for patenting purposes under the Budapest Treaty
Authors: Fitzgerald Tim
Published: September 2019

A patent confers a limited-term right to exclude other parties from using an invention, in exchange for a comprehensive description of the invention. The granted claims of a patent define the scope of the right that is conferred.
Innovation to prevent sudden infant death: the wahakura as an Indigenous vision for a safe sleep environment
Authors: Tipene-Leach David , Abel Sally
Published: September 2019

The bassinet-like wahakura is an Indigenous initiative for the prevention of Sudden Unexpected Death in Infancy (SUDI). It was developed by New Zealand Māori in 2005 when Māori were rejecting the ‘stop bedsharing’ SUDI prevention message and the SUDI disparity between Māori and non-Māori had become entrenched. Made of native flax, the wahakura was promoted as a culturally resonant, in-bed safe sleep device that would disrupt the SUDI risk associated with ‘bedsharing where there was smoking in pregnancy’ without relying on smoking cessation. A significant movement of weavers and health professionals grew around the wahakura program. A body of research, including infant care surveys, retrospective case review, qualitative enquiry and a randomised controlled trial comparing wahakura and bassinet safety demonstrated the device’s public health plausibility, acceptability to Māori women and its essential safety. This facilitated the distribution, by District Health Boards, of safe sleep devices, including a related device called the Pēpi-Pod, and safe sleep education to high-risk, mainly Māori, mothers. Infant mortality in New Zealand fell by 29%, primarily among Māori infants, over the period 2009–15, suggesting that Māori cultural concepts, traditional activities and community engagement can have a significant effect on ethnic inequities in infant mortality.
Arcuate nucleus kisspeptin response to increased nutrition in rams
Authors: Rietema S. E. , Hawken P. A. R. , Scott C. J. , Lehman M. N. , Martin G. B. , Smith J. T.
Published: September 2019

Rams respond to acute nutritional supplementation by increasing the frequency of gonadotrophin-releasing hormone (GnRH) pulses. Kisspeptin neurons may mediate the effect of environmental cues on GnRH secretion, so we tested whether the ram response to nutrition involves activation of kisspeptin neurons in the arcuate nucleus (ARC), namely kisspeptin, neurokin B, dynorphin (KNDy) neurons. Rams were given extra lupin grain with their normal ration. Blood was sampled before feeding, and continued until animals were killed for collection of brain tissue at 2 or 11h after supplementation. In supplemented rams, LH pulse frequency increased after feeding, whereas control animals showed no change. Within the caudal ARC, there were more kisspeptin neurons in supplemented rams than in controls and a higher proportion of kisspeptin cells coexpressed Fos, regardless of the time the rams were killed. There were more Fos cells in the mid-ARC and mid-dorsomedial hypothalamus of the supplemented compared with control rams. No effect of nutrition was found on kisspeptin expression in the rostral or mid-ARC, or on GnRH expression in the preoptic area. Kisspeptin neurons in the caudal ARC appear to mediate the increase in GnRH and LH production due to acute nutritional supplementation, supporting the hypothesised role of the KNDy neurons as the pulse generator for GnRH.
TNNT1, a prognostic indicator in colon adenocarcinoma, regulates cell behaviors and mediates EMT process
Authors: Hao Yun-He , Yu Shu-Yong , Tu Rui-Sha , Cai Yao-Qing
Published: September 2019

Slow skeletal muscle troponin T (TNNT1) has been reported to be correlated with several cancers, but there are no evidences proving that TNNT1 is required in colon adenocarcinoma (COAD). TNNT1 expression in COAD tissues and its prognostic significance were acquired from TCGA database. The proliferative, migratory, and invasive abilities of COAD cells were detected by CCK-8 and transwell assays, respectively. Correlations between TNNT1 and epithelial–mesenchymal transition (EMT)-related markers were determined using western blotting and Pearson’s analysis. Our results stated that TNNT1 expression was high-regulated in COAD tissues, which was related with unfavorable prognosis of COAD patients. Functional analyses suggested that TNNT1 promoted the cellular behaviors. Moreover, aberrant expression of TNNT1 affected the expression level of EMT-related proteins. And TNNT1 was negatively linked with E-cadherin. In conclusion, our findings indicated that TNNT1 may promote the progression of COAD, mediating EMT process, and thus shed a novel light on COAD therapeutic treatments.
Effect of magnetic flow and external forcing current on mixed bursting in the pre-Bötzinger complex*
Authors: Guo Dou-Dou , Lü Zhuo-Sheng
Published: September 2019

The pre-Bötzinger complex (pre-BötC) in mammalian brainstem is essential for the generation of respiratory rhythms. Most dynamic studies on the pre-BötC neuron have been focused on its firing activities modulated by the ion conductances rather than that by the electromagnetic radiation or the external forcing current. In this paper, by adding the electromagnetic radiation and external forcing current to Park and Rubin’s model, we mainly investigate the influences of those two factors on the mixed bursting (MB) of single pre-BötC neuron. First, we explore how the variation of external forcing current affects the MB patterns of the system with non-vanishing magnetic flux. We classify the MB patterns and show their dynamic mechanism through fast-slow decomposition and bifurcation analysis. Then, by modifying the feedback coefficient, we further analyze the sole effect of electromagnetic radiation on the firing activities of the system. Our results may be instructive in understanding the dynamical behavior of pre-BötC neuron.
Development of “Parameter space screening”-based single-wavelength anomalous diffraction phasing and structure determination pipeline
Authors: Ding Wei , Wang Xiao-Ting , Yi Yang-Yang
Published: September 2019

In this paper, we present a highly efficient structure determination pipeline software suite (X2DF) that is based on the “Parameter space screening” method, by combining the popular crystallographic structure determination programs and high-performance parallel computing. The phasing method employed in X2DF is based on the single-wavelength anomalous diffraction (SAD) theory. In the X2DF, the choice of crystallographic software, the input parameters to this software and the results display layout, are all parameters which users can select and screen automatically. Users may submit multiple structure determination jobs each time, and each job uses a slightly different set of input parameters or programs. Upon completion, the results of the calculation performed can be displayed, harvested, and analyzed by using the graphical user interface (GUI) of the system. We have applied the X2DF successfully to many cases including the cases that the structure solutions fail to be yielded by using manual approaches.
Highly sensitive optical fiber temperature sensor based on resonance in sidewall of liquid-filled silica capillary tube*
Authors: Li Min , Feng Biao , Yin Jiwen
Published: September 2019

A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube (SCT) between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by using femtosecond laser micromachining, and liquid polymer is filled into the SCT through the micro-holes without any air bubbles and then sealed by using ultra-violet (UV) cure adhesive. The sidewall of the SCT forms a Fabry–Perot resonator, and loss peaks are achieved in the transmission spectrum of the SCT at the resonant wavelength. The resonance condition can be influenced by the refractive index variation of the liquid polymer filled in SCT, which is sensitive to temperature due to its high thermo-optical coefficient (−2.98 × 10−4 °C−1). The experimental result shows that the temperature sensitivity of the proposed fiber structure reaches 5.09 nm/°C with a perfect linearity of 99.8%. In addition, it exhibits good repeatability and reliability in temperature sensing application.
Vibrational modes in La2Zr2O7 pyrochlore irradiated with disparate electrical energy losses*
Authors: Zhang Sheng-Xia , Liu Jie , Xie Hua , Xu Li-Jun , Hu Pei-Pei , Zeng Jian , Li Zong-Zhen , Liu Li , Ai Wen-Si , Zhai Peng-Fei
Published: September 2019

Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss (dE/dx)e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1 × 1011 ions/cm2 to 6 × 1015 ions/cm2. Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1u at 192, 308, and 651 cm−1 appear in Raman spectra, and the F2g band at 265 cm−1 rises up due to the irradiation by 200-MeV Kr ions with (dE/dx)e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with (dE/dx)e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1u 651 cm−1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with (dE/dx)e of 39.6 keV/nm.
Output characteristic analysis and delivery line capacity exploration of large-scale offshore wind power
Authors: Li Nan , Wang Xiaochen , Liu Jun
Published: September 2019

Offshore wind power slightly differs from onshore wind power in output characteristics due to the impact of wind resources and maritime environment. This paper analyses the characteristics of offshore wind power from the perspectives of resource characteristic, output characteristic and operational characteristic, illustrates the matching between offshore wind power and regional loads, and finally explores a capacity design strategy on a delivery line of offshore wind power based on the abandonment of wind power, to provide a reference for optimization of regional wind power layout and reduction of costs arising from new energy consumption.
Assessment of power generation performance characteristics using different solar photovoltaic technologies
Authors: Liu Rensheng , Bimenyimana Samuel , Osarumwense Asemota Godwin Norense , Xu Miaoyan , Dieu Niyonteze Jean De , Li Lingling
Published: September 2019

Solar energy is a relatively free renewable, clean, green, and environmentally friendly energy resource produced from the sun, using different technologies like solar thermal and photovoltaic (PV) modules to generate heat and electricity, respectively. This paper aims to assess and compare the power generation performance characteristics of different solar PV module technologies by simulation, deploying identical input temperature and irradiance parameters. The solar PV designs were simulated using PVsyst Version 6.73 for 26.0 kW annual power and 42.9 MWh/year annual yields using the climate data of Sydney, Australia. The results show that monocrystalline solar technologies needed an area of 163m2, while polycrystalline and thin films needed areas of 173m2 and 260m2 respectively to generate 42.9MWh annual yield. The monocrystalline PV modules are more efficient at solar energy conversion than polycrystalline and thin film technologies, respectively (94.2% and 62.7%). The symmetric semi-toroid dome of sun heights against azimuthal angles show 13 bimodal pyriforms, that cut the azimuths at least twice on each of the optimisation lines. These optimal solution points were visible for every sunlight hour of between 6 and 18 hours (inclusive). They show convex sets of global optima (or local optima) with one minimum in the interval of convexity. Also, each of the minimum points for each of the 13 directed fish-like bimodal pyriforms was on ±60° azimuth. However, the assessment of respective PV module characteristics with respect to variation of irradiation and temperature, show that the general results from simulation displayed disparate changes in the voltages and currents of the generated power with respect to different solar PV modules. The proposed semi-toroid model indicates that many optimisation solutions for easier, cheaper, quicker and more efficient power generation are possible with appropriate design. It is recommended that the installation of a single-axis solar tracker or maximum power point tracker could overcome the azimuth angle effect.
PFC fault detection method for EV wireless charging system based on hidden markov model
Authors: Xu Changfu , Bo Bin , Wang Ruoyin , Zhang Ming , Xu Jiayuan
Published: September 2019

The PFC device serves as an important bridge between rectifier module and high-frequency inverter module in the wireless charging system of electric vehicle (EV). Once this device fails, it will not only have a serious impact on the power grid, but also cause irreversible damage to the back-end high-frequency inverter module. Traditional fault diagnosis methods are difficult to meet the requirements of complex systems. In this paper, HMM which has unique advantages in training model and fault identification is used for fault diagnosis of PFC device of EV wireless charging system. Firstly, the model is initialized and the initial values of HMM are determined. Then, Baum-Welch algorithm is used for iterative training. Finally, Viterbi algorithm is used for fault diagnosis. The test results show that the PFC fault diagnosis accuracy of EV wireless charging system using HMM is about 25% higher than the traditional method, and the recognition speed is significantly improved.
Electromagnetic vibration analysis method of short circuit in transformer winding based on field circuit coupling
Authors: Hao FangZhou , Wen Haiyan , Zhao Hongshan , Li Zili
Published: September 2019

The short circuit fault may cause serious deformation of the transformer winding even affect the safety and stability of the equipment and the whole power system. This paper mainly studies the flux leakage, electromagnetic force and vibration characteristics of winding under short-circuit fault based on field circuit coupling model. Firstly, the 10kV power transformer is modeled as the research object to analyze the flux leakage and electromagnetic force of the transformer windings in short circuit condition based on the field-circuit coupling principle. Then, the electromagnetic excitation is extracted for harmonic response analysis to investigate the electromagnetic vibration characteristics of the windings. Finally, the short circuit experiment is designed to verify the above research. It is found in this paper that the flux leakage, electromagnetic force and vibration amplitude of the transformer windings are all strengthened sharply under short circuit fault. This conclusion provides an important basis for transformer design and condition.
Fault diagnosis of vacuum circuit breaker based on coil current of release
Authors: Chen Ben-bin , Shi Hao , Zhuang Zhi-jian
Published: September 2019

The release is the key component of operation mechanism of circuit breaker. Its current waveform contains many information. The fault diagnosis of circuit breaker can be realized by analyzing the current waveform of coil. Firstly, the combination method of wavelet analysis and seeking extreme points in region extremum is proposed to obtain the feature values of coil current of circuit breakers. Then, a novel intelligent particle swarm optimization (PSO) algorithm was adopted to search the optimal parameters of support vector machine (SVM). Finally, a high-performance SVM with optimal parameters is constructed for fault diagnosis. The experimental results show that the method can achieve a high fault diagnosis accuracy.
Toward a framework of social welfare assessment of wind energy systems
Authors: Hayajneh Hassan , Zhang Xuewei
Published: September 2019

Wind energy systems have seen substantial growth over the past decades. It is important to assess the impacts of wind energy systems on the wellbeing of all aspects of life and society. Previous works have been conducting life cycle assessments to evaluate the environmental impacts of wind energy systems; in social research, studies have also been conducted to clarify people’s attitude and perception of wind energy systems. However, to assess social welfare, it is needed to integrate these two approaches and generate indicators on a comparable and objective basis. In this work, we propose such a framework in which community survey designs and data analysis methods are specified. To correct the subjectivity in the answers of individuals, an inverse map of that used in prospect theory is used. Based on the indicators of the five aspects of social welfare evaluated by an individual, the individual utility function can be constructed, which, in turn, can be averaged over the individual’s cluster or group. The cluster averaged individual utility functions will lead to definitions of social welfare function. This work then discusses the effects of cluster weight parameters, social welfare function definitions, as well as the inclusion of the prospect theory concept. The proposed social welfare assessment framework could be valuable for future wind energy system planning and operation.
Optimization of controlling parameters of DFIG and battery energy storage combined frequency modulation based on PSO
Authors: Lei Changyan , Wang Qi , Wang Shun
Published: September 2019

Wind power has randomicity and intermittence. As the wind power penetration rate increases, it poses a threat to the frequency of the power grid. In the power systems with high-permeability of wind power, relying solely on conventional crew tuning is no longer sufficient to ensure that the frequency is within safe limits. The battery energy storage has a fast response speed, but it is expensive. The frequency regulation provided by the wind farm itself has a short inertial control support time, the pitch control response is slow, and both frequency modulation methods are subject to wind speed. In order to improve the frequency adjustment capability of the wind farm, the battery energy storage and the wind farm’s own frequency modulation means are combined to adjust the system frequency. However, how to set the battery energy storage output to make the system frequency characteristics optimal hasn’t been studied. In this paper, the particle swarm optimization algorithm is used to select the optimal parameters, so that the frequency characteristics are optimal. The example shows that compared with the unoptimized energy storage frequency modulation coefficient, the optimal frequency modulation coefficient found by the PSO algorithm can greatly reduce the maximum frequency drop of the power system and improve the frequency stability of the power system.
Design and performance analysis of a retractable electric vehicle based on modern numerical simulation theory
Authors: Zhang Yuanyuan , Xin Jianghui , Zhao Zhendong
Published: September 2019

In view of environmental pollution, energy shortage and urban traffic congestion and other issues, a drawer type retractable electric vehicle (REV) is designed. Through the establishment of the frame and the vehicle’s three-dimensional entity model, the frame of the static characteristics and modal characteristics are analyzed by using the finite element numerical simulation theory. The results show that the frame vertical stiffness is not reasonable, thereby improving the frame structure. Based on multi-body dynamics theory, the vehicle dynamics model is established, and the ride comfort of the vehicle is checked. The results show that the comfort of the vehicle is in line with the general requirements of the vehicle. The design and analysis method of this paper has enriched the design method of modern electric vehicle, which can embody the characteristics of light weight, clean energy, effective space utilization and so on, as well as has certain engineering application value.
Experimental study on the natural frequency of tunable piezoelectric cantilever plate
Authors: Chen Lihua , Chang Liqi , Xue Jiangtao , Yang Fenghong
Published: September 2019

PEH (piezoelectric energy harvester) outputs a higher voltage when the natural frequency matches ambient vibration frequency. How to widen working frequency band is a hot issue in study of PEH. In this paper, an auto-tuning PEH is presented by attaching a box to each corner of its free sides and a ball is placed in each box. Change of the balls position makes natural frequency of PEH variable, which expands working bandwidth of the device to accommodate complex ambient vibration. Fixing the equipment on experimental platform by designing fixture, hammering experiments are carried out to measure natural frequency of the structure when balls are in different positions. It is found that the maximum and minimum natural frequencies exist in the auto-tuning PEH, which form a resonance bandwidth. Moreover, there are multiple position combinations of two balls at the same natural frequency in the range of resonance bandwidth. Fixed the apparatus on exciter by the fixture, and a constant excitation frequency is selected in the bandwidth to perform auto-tuning experiments on the instrument. It is observed that location of balls is automatically changed to make natural frequency of the system coincide with the excitation, and the law of variation in balls position is obtained. The converter is subjected to sweeping experiments through an exciter and an oscilloscope. Using voltage-frequency diagrams, it is shown that the auto-tuning PEH outputs a higher voltage and its frequency band is wider when the ball rolls freely compared to two cases where balls are fixed.
Orbital transport system - the concept and mechanics of orbital motion
Authors: Chen Danhe , Koryanov Vsevolod V. , Kazakovtsev Victor P. , Zhang Budang
Published: September 2019

A brief introduction to the meaning of on-orbit services and research on space-based services is provided in this work. In the context of on-orbit service, the near-circular orbit is idealized as a disturbed circular orbit, and a general equation for the optimal maneuver of the near-circle orbit is presented. The examples of coplanar on-orbit services in low, medium and high orbits are analyzed respectively, and the best maneuvering scheme for orbit transfer is solved by special software. Further analysis of the impact of different heights of parking orbit on the optimal maneuvering scheme reveals that the closer parking orbit to the target orbit, the less energy is required for maneuvering, but the phase-modulation time and the transport capacity of the launch vehicle should be considered comprehensively.
Effect of temperature cycling on performance of epoxy resin and evaluation of state
Authors: Chen Xiwen , Lu Bing , Zhang Dandan , Zhang Jun , Chen Jingting
Published: September 2019

Epoxy resin samples were prepared according to the most common types of epoxy resins and curing agents in the market. The material was temperature-circulated at -40 to 150°C to investigate the effect of temperature cycling on the dielectric properties and bending properties of the material. The results show that with the increase of the number of temperature cycles, the relative dielectric constant, dielectric loss, flexural strength and flexural modulus of epoxy resin increase first, then decrease and then increase, and the electrical conductivity increases. Based on the samples of various performance values of epoxy resin in different times, an evaluation model based on BP neural network was established to evaluate the state of epoxy resin.
Predictive direct torque control for permanent-magnet synchronous machines based on duty ratio modulation
Authors: Guo Tingting , Deng Lihui , Miao Zichao
Published: September 2019

In this paper, Two-step model predictive control based on duty ratio modulation of permanent magnet synchronous machine (PMSM) is proposed. There is a large amount of computation in the two-step predictive control. In this paper, a fast vector selection method is proposed to solve the problem of computational complexity. The proposed voltage vector selection method avoids the complete enumeration for testing all feasible voltage vector, and the calculation method of duty are discussed. This control method achieves a constant switching frequency, and the torque fluctuation is smaller, inheriting the advantages of predictive control response speed. To investigate the effectiveness of the proposed method, two-step predictive direct torque control based on duty ratio modulation (TSPTC-DM), comparison of one-step predictive direct torque control based on duty ratio modulation (OSPTC-DM) and finite control set model predictive torque control (FCS-MPTC) is shown.
Error analysis for the rate azimuth platform INS
Authors: Wang Fenglin
Published: September 2019

To lower the cost of passive gravity navigation and dynamic gravity measurement, a rate azimuth inertial platform with a gravity sensor on it was put forward to compose a navigator with gravity measuring. Some research about this rate azimuth platform inertial navigation system was carried out, the rate azimuth horizontal reference frame and actual platform reference frame were set up, the error equationuations, which including position error, velocity error, platform angle error, course error were put up, which would contribute to the integrated system, and the simulation of error for the rate azimuth inertial platform was shown of system errors was shown.
Semi-captiveperiod projectile motion gesture test system
Authors: Zhang Feimeng , Huang Xin , Zhang Chongjie
Published: September 2019

A newly active photoelectric testing approach is introduced in this paper to effectively tackle the pressing problems of artillery testing, considering the current existing problems of semi-captiveperiod projectile motion gesture test. This testing system is composed of seven parts, whose test error is no more than 0.1’, achieving advanced level in this domain.
Capacitive sensor and its calibration- A technique for the estimation of solid particles flow concentration
Authors: Abrar Usama , Shi Liu , Jaffri Nasif R. , Li Qin , Omar Mian W. , Sindhu Hassan R.
Published: September 2019

The precise and accurate measurement of flow rate in the batch flow of the solid particles is of primary importance in many process industries for the improvement of the efficiency of the system. Many techniques developed for the measurement of mass flow rate. The capacitive sensors has a significance of being non-invasive, higher accuracy and low cost for mass flow measurement despite the fact that many factors adversely affect the performance- including non-uniform flow, multiphase flow, temperature, pressure, and moisture in the solid particles. This paper covers preliminary investigations of the offline estimation of mass flow concentration based upon the calibration of capacitance electrodes to quantify the mass of dielectric as a function of capacitance variation between the electrodes.
Modeling and simulation of constant current converter in energy branch unit
Authors: Tian-shu Wu , Xue-jun Zhou , Zheng Zhang , Xi-chen Wang
Published: September 2019

As an important part of electric energy branch unit, constant current converter has the characteristics of simple structure and high efficiency. In this paper, a constant-current converter used in underwater power branching unit is modeled and simulated. The model of constant-current converter circuit is established by using state space method, and the steady-state operating point of DC is calculated. Based on the model, maximum impulse current and drain-source voltage of switching transistor in constant current converter are studied. The simulation test of constant-current converter is carried out by Saber simulation software. The results show that the circuit efficiency can be maintained above 90% while the reliability of the converter is guaranteed, which provides a theoretical basis for the analysis and research of efficient and reliable underwater power branch units.
Development of scroll vacuum pump characteristics by thermal deformations compensation
Authors: Burmistrov A V , Salikeev S I , Raykov A A , Tyurin A V
Published: September 2019

Influence of thermal deformations of scroll vacuum pumps working elements on clearances in working mechanism is considered. Analysis of influence of a clearance value on indicator diagrams and pumping speed was carried out. It is shown that alteration of a clearance due to thermal deformations decreases pumping speed at low pressures. The design of scroll elements compensating clearances alteration in pump operation and improving pumping characteristics is presented.
A composite substrate of dissimilar materials temperature determination in the process of infrared heating in vacuum
Authors: Bychkov S P
Published: September 2019

The problem of determining the temperature of a substrate of dissimilar materials fragments in the process of infrared heating in vacuum solution, obtained using the algebraic method of calculating radiant fluxes, is presented.
Effective sputtering yields of alloys chromel and kopel with argon ions in magnetron sputtering system
Authors: Dukhopelnikov D V , Riazanov V A , Plotnikova O P
Published: September 2019

This article presents the results of research on sputtering of thermoelectric alloys chromel and kopel. Sputtering was performed in argon atmosphere with magnetron sputtering system. Results of this work can be used in creation of thin-film thermoelectric generators.
Calculation features of the magnetic and temperature fields of planar magnetron system when sputtering magnetic targets
Authors: Goncharov V D , Yashkardin R V
Published: September 2019

Mathematical model for temperature fields calculation in targets of magnetron sputtering systems is described. The paper shows the main ways in which the power supplied to the discharge is removed. The results of numerical simulation of the spatial temperature distribution of a magnetic target are presented. The paper also shows the results of numerical simulation, which allow to link the input power and the shape of the target with the distribution of its temperature. For the obtained temperature distributions magnetic induction distributions are calculated taking into account the loss of magnetic properties of a material when its temperature exceeds the Curie point.
Development electrode of deformation capacitive vacuum gauge
Authors: Gorobei V N , Kuvandykov R E
Published: September 2019

The article is devoted to the development of high-precision details of the vacuum transducer designed to reproduce the unit of absolute pressure.
Development of a temperature controlled container for high accuracy capacitance manometers
Authors: Kangi R
Published: September 2019

National Institute of Metrology of Turkey (UME) has developed a new temperature-controlled container for high accuracy capacitance manometers (CDG). In the proposed design, due to the direct (metal-metal) contact of the temperature-controlled plate of the container with the aluminum shell of the sensor, the influence of the temperature of the electronics on the pressure sensor is minimized. Inside the aluminum shell, the temperature of the pressure sensor can be controlled at any fixed temperature with stability of ± 2 mK in the temperature range from 15 °C to 30 °C. The use of a pressure sensor inside an appropriate container minimizes the effect of the ambient temperature on the sensor, eliminates the need for correction for the effect of thermal transpiration and thus improves sensor accuracy. CDGs inside containers showed excellent short-term stability at zero pressure, which does not exceed ± 5 mPa as well as a maximum drift rate of 0.03 mPa h−1. The measurement results of ambient temperature influence on CDG’s zero showed a maximum change of 0.001% of full scale per degree Celsius. Control of CDG at ambient temperature significantly reduces the effects of thermal transpiration, which increases slightly to a maximum of 0.3% at the lowest pressures.
Dynamic properties of a glow discharge in long tubes
Authors: Kiselev A S , Menshchikova V V , Seyfulina N A , Smirnov E A
Published: September 2019

The impedance of a glow discharge in narrow long tubes characteristic of gas-discharge lasers is investigated. An expression for the impedance is obtained taking into account the falling character of the current-voltage characteristics, the dynamic properties of the positive table and the cathode region. Satisfactory consistent calculated and experimental results are achieved.
Features of vanadium dioxide films deposition by reactive magnetron sputtering
Authors: Komlev A E , Shutova E S , Sypko M P
Published: September 2019

In this work, influence of substrate material and technological process parameters on the stoichiometric composition, crystal structure and phase transition character in vanadium oxide films deposited by the magnetron sputtering method is investigated.
Development, synthesis and production of multilayer thin-film filters for infrared sensors for monitoring of flammable gases and vapors of flammable liquids
Authors: Makeenkov A A , Baranov A M
Published: September 2019

We present the results of development and production of multilayer thin-film filters for infrared sensors for monitoring of flammable gases and vapors of flammable liquids. This paper addresses technological peculiarities of their production. A theoretical simulation of multilayer filter parameters to provide the transparency in wavelength range 3.3 - 3.5 μm was carried out. It is demonstrated that spectral characteristics of produced multilayer filter correspond to the calculated ones.
I-V characteristics of magnetron with hot titanium target sputtered in argon-oxygen mixture
Authors: Minzhulina E A , Shapovalov V I , Aslan N , Shestakov D S
Published: September 2019

The discharge current-voltage characteristics of a dc magnetron with a single hot titanium target in Ar + O2 environment are studied. It was found that the I-V characteristics measured in the range of current densities of 10-200 mA/cm2 have three inflection points and a maximum. The competition of several processes can cause the discovered features. In the oxide target operating mode, these processes include the chemical reaction for the formation of oxide on the surface of the target and its sputtering by argon ions. In the metal mode, gas rarefaction near the target and thermionic emission compete.
Optical and mechanical properties of fluorocarbon coatings formed in a matrix mode of deposition using an atmospheric pressure plasmatron
Authors: Shvedov A V , Elinson V M , Shchur P A , Kirillov D V
Published: September 2019

This paper is devoted to study of the formation of fluorocarbon coatings, which were obtained by using a low-frequency plasmatron of a low-temperature plasma at atmospheric pressure. The possibility of forming fluorocarbon coatings on silicon, and PET and polystyrene substrates is shown. The spectra of the UV and visible ranges were obtained, the width of the band gap of the obtained coatings was established by the Tauc method. The nanohardness of the obtained coatings was studied by the Oliver-Farr method.
Thermal stability, mechanical and tribological behavior of Ti-Al-Si-N ion-plasma coating
Authors: Volkhonskii A O , Belov D S , Demirov A P , Shestakov V M , Kiselyov T V
Published: September 2019

It is shown that the elemental and phase composition does not change, and the architecture with clearly defined layer boundaries is preserved when annealing the amorphous-nanocrystalline Ti-Al-Si-N multilayer coatings in the vacuum at temperatures of 700-1100 °C. At the same time, the coherent scattering regions of X-ray radiation increase from 8.5-9.5 to 11-12 nm while the microstrains in the crystal lattice decrease from 1.1 to 0.6-0.7%. Structural changes are accompanied by a slight decrease in hardness. Thermal treatment does not change the nature of cohesive fracture of coatings and does not affect their adhesive strength. The decrease in wear resistance after thermal treatment of coatings, manifested in the increasing wear and friction coefficient, is probably due to the changing nature of the cohesive fracture accompanied by the appearance of large fragments that act like high-abrasive particles between friction surfaces. Ti-Al-Si-N coating is characterized by partial oxidation when heated in air up to 800 °C and complete nitride phases transition to oxides and oxynitride compounds at 900 °C.
Experimental Investigation of Aluminum Graphite and MOS2 Composite Materials
Authors: Malaiyappan Prakash , Vignesh S.
Published: September 2019

Metal Matrix Composites (MMCs) have light weight, high quality, firmness and display more prominent protection from consumption, oxidation, and wear. In this investigation half and half Aluminum network composite was created through blend throwing course. Molybdenum disulfide (MoS2) and graphite (Gr) particles were utilized as fortification stages for the present investigation. Three grinding material examples were created dependent on a trial detailing, and vol. % graphite + vol. % MoS2, individually.
Mechanical behavior of nanoparticulate TiO2 reinforced magnesium matrix composite
Authors: Radhakrishnan Ganesh , Anirudh P V , Anujan Kumar S
Published: September 2019

In this study, nano-sized titanium dioxide particulate reinforced pure magnesium matrix composite has been fabricated by powder metallurgy technique for five different weight fractions of reinforcement such as 4 wt%, 8 wt%, 12 wt%, 16 wt%, and 20 wt% respectively. Samples of these compositions are iso-statically cold compacted into cylindrical specimens of diameter and length each 15 mm respectively, followed by sintering and hot extrusion with an extrusion ratio of 1.56:1. SEM micrographs of blended composite powders before compaction confirmed the uniform distribution of reinforcement throughout the matrix without any agglomeration. Microstructural analysis of extruded specimens revealed the refined matrix grains and grain boundary. The reinforcement may interrupt the matrix grain growth on grain boundaries during extrusion. Targeting for biomedical applications like bone implants, kneecap surgery etc., the mechanical behavior of the composite such as microhardness, and compressive strength have been studied. It was observed from the study that the mechanical properties have been significantly improved by adding reinforcement compared to pure magnesium and better mechanical behavior have been noticed for composite with higher contribution of reinforcement.
Experimental and Numerical Study on Modified Vertical Axis Wind Turbine
Authors: Abraham Eben Andrews A. , Karthick P , Allan Jeraled A. , Anuroop K , Chidanand G
Published: September 2019

Wind energy is very important in the development of sustainable energy with the growing focus on renewable energy; interest in design of wind turbines has also been expanding. In today’s market, the horizontal axis turbine is the most common type in use; Experimental data of this research is to compare the CFD Analysis with the Experimental Data of hybrid Modified vertical axis wind turbine. The graphical data based on the parameters such as Velocity, Power Coefficient, Tip Speed Ratio Vs Power Coefficient and Wind Velocity Vs Power Coefficient, which are discussed in this research. The Savonius turbine (Lift Turbine) was attach with the Gorlov turbine (Drag driven turbine) for the self-starting of the hybrid-modified turbine. Here the design, construction and testing of vertical axis wind turbine with three blades, starting solely from low energy of the wind. The velocities such as 5, 7, 9 and 11 m/s are tested in CFD Analysis for checking from which maximum power can be extracted so it can be used in desert area.