bluuebunny/crossref_metadata_2025 huggingface dataset:
Slow and Steady: A Systematic Review of ICU Care Models Relevant to Pediatric Chronic Critical Illness
Authors: Troch Rachel , Schwartz Jamie , Boss Renee
Published: June 2020

There is a growing population of children with prolonged intensive care unit (ICU) hospitalization. These children with chronic critical illness (CCI) have a high health care utilization. Emerging data suggest a mismatch between the ICU acute care models and the daily care needs of these patients. Clinicians and parents report that the frequent treatment alterations typical for ICU care may be interrupting and jeopardizing the slow recoveries typical for children with CCI. These frequent treatment titrations could therefore be prolonging ICU stays even further. The aim of this study is to evaluate and summarize existing literature regarding pace and consistency of ICU care for patients with CCI. We performed a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (of September 2018). PubMed (biomedical and life sciences literature), Excerpta Medica database (EMBASE), and The Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched for English-language studies with data about CCI, care models, and pacing of clinical management. Four unique papers were identified. Our most important finding was that quality data on chronic ICU management, particularly for children, is sparse. All papers in this review confirmed the unique needs of chronic patients, particularly related to respiratory management, which is a common driver of ICU length of stay. Taken together, the papers support the hypothesis that protocols to reduce interdisciplinary management variability and to allow for slower management pacing should be studied for their impact on patient and health system outcomes. Optimizing value in ICU care requires mapping of resources to patient needs, particularly for patients with the most intense resource utilization. For children with CCI, parents and clinicians report that rapid treatment changes undermine recovery and prolong ICU stays. This review highlights the lack of quality pediatric research in this area and supports further investigation of a “slow and steady” approach to ICU management for children with CCI.
Surgery for Spinal Trauma: Early Days at a Young Institution in a Hilly State
Authors: Patil Aditya , Goyal Nishant , Basu Garga , Arora Rajnish Kumar , Chaturvedi Jitender , Gupta Priyanka
Published: June 2020

Background Spinal trauma is associated with significant morbidity and affects the overall quality of life of the patient as well as their family. The aim of this study was to study the epidemiology, in-hospital outcome, and follow-up of patients undergoing surgery for spinal trauma.

Methods All patients who underwent surgery for spinal trauma at the Department of Neurosurgery between June 2016 and October 2019 were studied retrospectively. Data collected from patient record included demographic profile, mode of injury, level of injury, neurological status at admission, time from injury to operative intervention, hospital stay, neurological outcome at discharge, and follow-up. Postoperative computed tomography scans were done in all patients to check for adequacy of screw placement.

Results A total of 70 patients (45 males, 25 females) with a mean age of 36 years (range: 16–65 years) were operated for spinal injuries at our department during the study period. Fall was the most common mode of injury (77.1%), followed by road traffic accident (28.5%). Most common site of injury was lumbar spine (38.6%), followed by dorsal (32.9%) and cervical (28.5%). Out of the total, 27.1% of our patients were American Spinal Injury Association (ASIA) grade A at presentation whereas 18.6% were ASIA E. Remaining 54.3% patients had incomplete injuries (ASIA B, C, and D). Burst fracture was the most common morphology of injury (60%), followed by translational injuries (30%). Mean duration between injury and operative intervention was 20.8 days. The mean duration of hospital stay was 21.4 days (range: 8–90 days). Six patients expired during hospitalization. All these six cases had cervical spinal injury. One patient of dorsal spine injury with a complete neurological injury expired 6 months after discharge from the hospital (cause unknown). Nine of our cases showed neurological improvement on follow-up and in rest of the patients, neurological status remained same as preoperative status.

Conclusion Neurological status at admission (ASIA grade) and level of injury remain the most important predictor of the outcome. Spinal injury patients must be managed with a holistic and multidisciplinary approach. Rehabilitation is important for helping these patients in leading a productive life.
Modification of momentum flux lost to a radial wall of a helicon source by neutral injection
Authors: Takahashi Kazunori , Sugawara Takeharu , Ando Akira
Published: June 2020

The profiles of the axial and radial momentum fluxes lost to the radial wall are experimentally investigated in a helicon source by using a momentum vector measurement instrument, where two gas injection configurations from the upstream of the source tube and from the downstream open source exit are tested. It is observed that the axial position of the maximum density is shifted to the source exit side for the downstream gas injection, compared with the upstream one. The measurement shows that the axial momentum flux transferred to the radial wall for the upstream gas injection is larger than that for the downstream gas injection, indicating that the axially accelerated ions are lost to the source wall. It is demonstrated that the loss of the axial momentum can be reduced by injecting the neutral gas near the open source exit, i.e., for the downstream gas injection.
Nonlocal electron heat transport under the non-Maxwellian distribution function
Authors: Li Kai , Huo Wen Yi
Published: June 2020

In laser plasmas, the electron distribution function is not Maxwellian but super-Gaussian due to the inverse bremsstrahlung heating, and the electron heat transport is generally nonlocal because of the large Knudsen number. Starting from the Fokker–Planck equation, we develop a nonlocal electron heat transport model based on the non-Maxwellian distribution function. In our study, we follow the method in Schurtz et al. [Phys. Plasmas 7, 4238 (2000)] and derive a differential equation for calculating the nonlocal electron heat flux based on the non-Maxwellian distribution function. The numerical results show that the non-Maxwellian distribution function would reduce the nonlocal heat flux in the laser heated region. The preheat effect due to nonlocal electron heat transport in the conduction region is also reduced by the non-Maxwellian distribution function. This nonlocal electron heat transport model can be easily implemented in two-dimensional and three-dimensional hydrodynamics codes.
Birefringence in thermally anisotropic relativistic plasmas and its impact on laser–plasma interactions
Authors: Arefiev A. , Stark D. J. , Toncian T. , Murakami M.
Published: June 2020

One of the paradigm-shifting phenomena triggered in laser–plasma interactions at relativistic intensities is the so-called relativistic transparency. As the electrons become heated by the laser to relativistic energies, the plasma becomes transparent to the laser light even though the plasma density is sufficiently high to reflect the laser pulse in the non-relativistic case. This paper highlights the impact that relativistic transparency can have on laser-matter interactions by focusing on a collective phenomenon that is associated with the onset of relativistic transparency: plasma birefringence in thermally anisotropic relativistic plasmas. The optical properties of such a system become dependent on the polarization of light, and this can serve as the basis for plasma-based optical devices or novel diagnostic capabilities.
Existence and concentration of ground state solution to a nonlocal Schrödinger equation
Authors: Mao Anmin , Zhang Qian
Published: June 2020

We study a class of Schrödinger–Kirchhoff system involving a critical exponent. We aim to find suitable conditions to assure the existence of a positive ground state solution of Nehari–Pohoz̆aev type uε with exponential decay at infinity for ε, and uε concentrates around a global minimum point of V as ε → 0+. The nonlinear term includes the nonlinearity f(u) ∼ |u|p−1u for the well-studied case p ∈ [3, 5) and the less-studied case p ∈ (2, 3).
Zero-shear viscosity of Fraenkel dumbbell suspensions
Authors: Piette Jourdain H. , Saengow Chaimongkol , Giacomin A. Jeffrey
Published: June 2020

Whereas rigid dumbbell suspensions predict, at least qualitatively, most of the viscoelastic material functions measured in the laboratory, Hookean dumbbells predict few of these. For instance, whereas rigid dumbbells predict a shear-thinning viscosity curve, as they should, Hookean dumbbells yield a constant for the steady shear viscosity. In this paper, we explore the addition of a Hookean spring to the end of a rigid rod, a dumbbell attributed to Fraenkel. In this way, we focus our attention on how macromolecular extensibility affects the configuration distribution in steady shear flow. We arrive at the exact solution to this configuration distribution in steady shear flow at low shear rate and then insert it into the Giesekus expression for the stress tensor to arrive at an exact solution for the zero-shear viscosity and the zero-shear values of the normal stress differences.
Radio-frequency stress-induced modulation of CdTe/ZnTe quantum dots
Authors: Tiwari V. , Makita K. , Arino M. , Morita M. , Crozes T. , Bellet-Amalric E. , Kuroda S. , Boukari H. , Besombes L.
Published: June 2020

We demonstrate radio-frequency tuning of the energy of individual CdTe/ZnTe quantum dots (QDs) by Surface Acoustic Waves (SAWs). Despite the very weak piezoelectric coefficient of ZnTe, SAW in the GHz range can be launched on a ZnTe surface using interdigitated transducers deposited on a c-axis oriented ZnO layer grown on ZnTe containing CdTe QDs. The photoluminescence (PL) of individual QDs is used as a nanometer-scale sensor of the acoustic strain field. The energy of QDs is modulated by SAW in the GHz range and leads to the characteristic broadening of time-integrated PL spectra. The dynamic modulation of the QD PL energy can also be detected in the time domain using phase-locked time domain spectroscopy. This technique is, in particular, used for monitoring complex local acoustic fields resulting from the superposition of two or more SAW pulses in a cavity. Under a magnetic field, the dynamic spectral tuning of a single QD by SAW can be used to generate single photons with alternating circular polarization controlled in the GHz range.
Spring-sown winter-type canola (
Authors: Raeside M. C. , Byron J. , Cameron F. , MacDonald C. , Partington D. L. , Kearney G. A. , Behrendt R.
Published: June 2020

Context Filling the summer–autumn feed gap is a key priority for sheep producers in southern Australia’s high-rainfall zone. Aim Our research aimed to determine whether spring-sown winter-type canola (Brassica napus L.) could increase herbage mass and nutritive characteristics during summer and autumn relative to other forage options in southern Australia’s HRZ. Methods A field experiment was conducted at Hamilton, Victoria, Australia, in 2014 and 2016 testing seven forage treatments replicated four times in the complete block design. The treatments were: canola (two treatments of different cultivars), forage brassica (B. napus), lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.) and perennial ryegrass (Lolium perenne L.). Key results Herbage mass and nutritive characteristics of the canola varieties did not differ (P > 0.05) from forage brassica. Herbage mass in March 2014 was 3.35–3.64 t dry matter (DM)/ha for brassicas; 1.05–1.37 t DM/ha for perennial ryegrass, plantain and chicory; and 2.94 t DM/ha for lucerne (P < 0.001, l.s.d. = 1.20). In March 2016, herbage mass was 1.86–2.05 t DM/ha for brassicas and 2.14–2.49 for the other forage treatments (P < 0.05; l.s.d. = 0.47). Brassicas had higher (P < 0.05) metabolisable energy (ME) concentrations and lower (P < 0.05) neutral detergent fibre (NDF) concentrations on most sampling dates than chicory, plantain, lucerne and perennial ryegrass. The crude protein (CP) concentration of the brassica treatments was not different (P > 0.05) from that of the other forage treatments. Concentrations of ME, CP and NDF were very similar between years for the brassicas, with March ME, CP and NDF concentrations of 12.0–13.2 MJ/kg DM, 14.0–20.1% DM and 16.7–23.6% DM. Conclusion Canola provided increased or equivalent levels of herbage mass and nutritive characteristics compared with other forage options in south-western Victoria on most, but not all, sampling dates. However, the annual spring-sowing requirement is a challenge under variable spring-rainfall conditions and may limit productivity if there is poor establishment. Implications Spring-sown canola is a viable alternative forage for livestock producers and offers a potential second income stream in high-rainfall-zone livestock farming systems.
Bond-breaking induced Lifshitz transition in robust Dirac semimetal VAI
3
Authors: Liu Yiyuan , Liu Yu-Fei , Gui Xin , Xiang Cheng , Zhou Hui-Bin , Hsu Chuang-Han , Lin Hsin , Chang Tay-Rong , Xie Weiwei , Jia Shuang
Published: June 2020

Significance

Understanding the relation between crystal structure and electronic properties is crucial for designing new quantum materials with desired functionality. So far, controlling a chemical bond is less considered as an effective way to manipulate the topological electrons. In this paper, we show that the V–Al bond acts as a shield for protecting the topological electrons in Dirac semimetal

V
A
l

3

. The Dirac electrons remain intact in the

V

1
−
x

T
i

x

A
l

3

solid solutions, even after a substantial part of V atoms have been replaced. A Lifshitz transition from Dirac semimetal to trivial metal occurs as long as the V–Al bond is completely broken. Our finding highlights a rational approach for designing new quantum materials via controlling their chemical bond.
The renin–angiotensin system: An integrated view of lung disease and coagulopathy in COVID-19 and therapeutic implications
Authors: Diamond Betty
Published: June 2020

The renin–angiotensin system (RAS) has long been appreciated as a major regulator of blood pressure, but has more recently been recognized as a mechanism for modulating inflammation as well. While there has been concern in COVID-19 patients over the use of drugs that target this system, the RAS has not been explored fully as a druggable target. The abbreviated description of the RAS suggests that its dysregulation may be at the center of COVID-19.
Investigation of dynamic properties of isotropic and anisotropic magnetorheological elastomers with a hybrid magnet shear test rig
Authors: Li Shaoqi , Liang Yajun , Li Yancheng , Li Jianchun , Zhou Yadong
Published: June 2020

Magnetorheological elastomers (MREs) exhibit instantaneous and reversible adaptability of stiffness and damping properties under the influence of magnetic field, which can be implemented in the development of controllable devices. The main MRE components are normally elastomeric matrix and magnetisable particles. Depending on the distribution of the particles in the matrix, MREs can be classified into isotropic and anisotropic. This work experimentally explored, compared, and modelled the dynamic characteristics of both isotropic and anisotropic MREs with different iron particle weight fractions (17%, 22%, and 32%). A novel shear test rig was designed with hybrid magnets system, i.e. permanent magnet and electromagnets, to fulfil the characterisation tasks. The involvement of the hybrid magnets effectively cuts down the maximum electric current and energy consumption of the rig. The tests were conducted under sinusoidal shear motions with excitation frequency ranging from 0.1 Hz to 2 Hz and shear strain varying from 20% to 60% to record the force-displacement hysteresis of MRE samples. Four different levels of magnetic field (0.02, 0.54, 0.77, 1.01 T) were supplied by the hybrid magnetic system and were considered in the tests to evaluate the influence of the magnetic fields. Furthermore, characterised hysteretic behaviours for both isotropic and anisotropic MRE were modelled by a strain stiffening phenomenological model with ideal accuracy under the shear excitation inputs and magnetic fields considered.
Indoor particulate matter (PM2.5) concentration and lung function impairment among housewives of selected quarters in Mingaladon cantonment
Authors: Aung Zaw Ye , Htut Yin Nyein , Aye Kay Khine , Tun Kyaw Myo , Tun Sai Nyan Lin , Htut Than
Published: June 2020

Lung function parameters (FEV1, FVC, FEV1/FVC ratio) were reduced in women cooking with biomass cook stove (54.5%, 45.5% an21d 57%) compared with those cooking with clean cook stove (42%, 33%, 44%), based on lower limit of normal. Indoor PM2.5 concentrations in both groups were below the reference value level (3mg/m3). Although both PM2.5 concentrations were not exceeded the reference level, PM2.5 concentration was higher in biomass cook stove group (0.055mg/m3) than clean cook stove group (0.501 mg/m3). Relationship between particulate matter concentration and lung function impairments of housewives in both two groups were negatively correlated (r=-0.7538, r=-0.6877 and r=-0.3568). So, lung function was reduced in high PM2.5 concentration generated from biomass cook energy sources. In conclusion, lung function impairments were more detected in high indoor particulate matter (PM2.5) concentration in study populations.
Study on Optimization of Reheat Pressure after Retrofit of Coal-fired Power Plants for Heat Supply
Authors: Zhang Tao , Feng Weizhong , Li Yan
Published: June 2020

After the retrofit of condensing power unit for heat supply, the reheat pressure of the unit deviates from the optimal value. When the heat supply and flow path of the turbine are retrofitted synchronously, or the retrofit of flow path is carried on the units witch heat supply retrofit had been done, the reheat pressure should be redetermined during the design phase of the flow path retrofit and the thermal economy of off-rated load should be taken into account to ensure the best operation efficiency of the unit. Taking 660MW supercritical single reheat unit as an example, the reheat pressure optimization analysis was carried out for the heat supply from the cold end piping of reheat system or the connection pipe between IP and LP in the wide load range. The results show that the optimization of the reheat pressure after the retrofit of heat supply can obtain significant gains of heat rate in the wide load range.
Optimization scheduling model and method for Wind-PV-Pumped joint operation in high proportion renewable energy base
Authors: Lu Zhang , Hailong Guo , Chaozong Da , Liguo Mao
Published: June 2020

Aiming at the uncertainty of wind and PV output and the fluctuation of wind and PV grid connection output, an optimized scheduling model and method for wind-PV-pumped storage combined operation in high proportion renewable energy base is proposed. Firstly, the optimal scheduling model for 96 periods of the whole day was established with the objective of optimal comprehensive benefit, minimum power fluctuation and optimal power demand matching of the wind-PV-pumped storage co-generation system.Then, an NSGA-III algorithm more suitable for high-dimensional multi-objective optimization is introduced to obtain Pareto optimal solution set of co-generation system. Finally, the simulation of jiuquan new energy base was carried out to verify the effectiveness of the proposed model.
Assessing the regional grid-parity potential of utility-scale photovoltaic in China
Authors: Liang Jingjing , Gao Xing
Published: June 2020

Chinese government announced to phase out photovoltaic (PV) generation subsidies in following years, which made analysis of economic feasibility of grid-parity crucial. We present an expression of levelized cost of electricity (LCOE) consistent with Chinese situation, which takes comprehensive life cycle cost, region-specific capital cost, and tax effect into consideration. Based on LCOE calculation, we make regional grid-parity estimation by comparing utility-scale PV LCOE to government benchmark price. Results show a constant progress to achieve grid-parity for utility-scale PV in China. By 2030, most regions will achieve grid-parity of large scale PV projects. More than half of the regions will achieve grid-parity before 2022. Policy suggestions are: (1) Policy should be made to improve developers’ access to low-cost financing; (2) To reduce investment cost, favourable mechanisms related to the profit sharing between land owner and developer could be developed. Local government could also support PV by lowering land tax and fees; (3) Government should plan to construct cross-regional transmission line for PV. In this way, northwest power could be transmitted to middle or eastern China and achieve remote grid-parity.
Legislation of air pollution control in China
Authors: Yan Liu
Published: June 2020

Air pollution bulks large in environmental protection initiatives in China in these years. The increasing emissions of VOCs, fume, ash, sulfides, nitrifying materials, sulfur dioxide, PmM2.5 and PM10 are damaging the atmospheric ecology and affecting people’s life and social development. The root cause is that under the government-dominated governance of pollution control, a relevant legal system is absent and legislation in this aspect seems reaching nowhere. In this regard, the central government of China has established the foundation of the legislation directions, objectives, principles and basic policies, and to establish an elaborate legal system for air pollution control is the key to control air pollution in a scientific manner.
Factors Affecting the Solidification and Stabilization Effect of Hazardous Waste
Authors: Luyao WANG , Sisi YAO
Published: June 2020

Solidification and stabilization is one of the main methods for handling hazardous waste, which can quickly control pollutants, and has the advantages of simple process, low cost and reusable finished products. In this process, the use of curing agents, stabilizers, and other conditions can affect the curing of hazardous wastes and the mechanical properties of the resulting product. This paper summarizes the relevant literature in the past ten years, and describes the effects of waste/binder, water/binder, bulk density, contaminant characteristics, and initial solidification time and carbonization reaction on the stabilization effect of solidification, in order to concretely stabilize the solid waste for solidification. Studies have confirmed that Metal-containing waste may reduce the strength of the final solidified product. Provide theoretical support to meet environmental emission standards and meet corresponding mechanical requirements.
Effect of Transglutaminase on the Quality of Gluten-free Grain Steamed Buns
Authors: Donghong Li , Dayu Zhou , Lijie Zhu , Lina Yang , Tao Ma
Published: June 2020

Gluten-free steamed buns were made from rice flour and soybean flour with transglutaminase (TG enzyme) as additives to investigate the effect of TG enzyme on the quality of steamed buns. The results showed that when the TG enzyme dosage was 2.0%, the steamed buns had a lower hardness of 5458.43 and a larger elasticity of 0.85, at which time the gluten-free grain dough had a higher elasticity and viscosity, and the brightness of the steamed buns was enhanced. With the addition of TG enzymes, the quality of gluten-free grain steamed buns has been improved, which provides a basis for the future research and development of gluten-free grain steamed buns.
Heavy Metal Contamination in Agricultural Soil, Food Crops and Associated Gastric Cancers Risks for Residents in S County of Hebei Province
Authors: Ting Ren , Li-jiao Zhao , Ru-gang Zhong
Published: June 2020

Because of the anatomic location of stomach and its acid environment which is different from the other organs, food exposure to heavy metals is a well-known risk factor for human gastric cancers. To evaluate the potential risks, we analyzed the concentrations of heavy metals (Cr, Cd, Pb, and As) in agricultural soil and grains in a high incidence area of gastric cancer, S county of Hebei province. Potential carcinogenic risk index for heavy metals in grains were evaluated. The results indicate that the concentrations of Cr, Cd, Pb and As in soils were 36.44, 0.13, 28.01 and 13.72 mg/kg, respectively; and 2.372, 0.051, 0.494 and 0.026 mg/kg in grains, respectively. The potential carcinogenic risk index of Cr, Pb and As in grain exceeded the safety limit level of 10−4 and Cd exceeded the acceptable limit level of 10−6. Therefore, long-term low dose exposure of heavy metals may play an important role in tumorigenesis of human gastric cancers.
An approach to achieve highly soluble bioactive ScFv antibody against staphylococcal enterotoxin A in E.coli with pelB leader
Authors: Chen Weifeng , Wu Jinsong , Chen Wei , Hu Ping , Wang Xiaohong
Published: June 2020

Staphylococcal enterotoxin A (SEA) is an extremely heat stable, highly toxic, and potent gastrointestinal toxin responsible for Staphylococcal intoxication in humans. Therefore, production of immunological reagents used for SEA detection is of prime importance. For this, two fusion expression vectors, one with pelB leader, the other without it were constructed and then transformed into E. coli BL21(DE3) to produce the single chain variable antibodies (ScFv) against SEA. Sodium dodecyl- sulphate-polyacrylamide gel electrophoresis, western blot and enzyme-linked immuno-sorbent assay were used for characterization of the ScFv. Results demonstrate that expression level of the soluble ScFv with pelB leader was 20 times higher than that without it and the binding activity of ScFv without pelB leader was far below as compared to the ScFv with it. This work provides an alternative method of fast and cheap production of soluble ScFv against SEA.
Research on Corrosion Causes of Common Metal Material in Power Grid
Authors: Fang Wenxuan , Chen Hao , Liu Xiaokai
Published: June 2020

The power grid equipment has been serving in the harsh environment for a long term, if reasonable differential design is not adopted, and the operation process is not effectively supervised, the safe and stable operation of power gird system would have greater threats. Aiming at the corrosion problem of common metal material in power transmission and transformation facilities of Inner Mongolia power grid, the corrosion failure factors of carbon steel, stainless steel and copper alloy were studied by methods of energy spectrum analysis, morphology observation and metallographic examination. Then, suggestions and measures have been put forward in adopting differentiated applications, strengthening quality control and improving installation process.
Research on parallel inspection model and key technology of distribution transformer
Authors: Li Xing , Wang Guangtao , Gu Chao , Wang Feifei , Wang Andong , Zhao Fuqiang
Published: June 2020

In this paper, a parallel inspection model based on pipeline and multitask is designed innovatively for the large-scale sampling inspection of distribution transformer before putting into operation. According to the characteristics of inspection resource sharing, the key technologies such as resource allocation and task scheduling are optimized, and the resource optimization allocation method and task parallel scheduling algorithm are proposed. Compared with the former, the optimized parallel inspection model improves the inspection efficiency and resource utilization to a large extent, and has important application value in the modern factoryinspection mode.
110kV Lightning-proof and Ice-proof Insulators and Explosion-proof Research
Authors: Peng Yongjing , Fang Zhen , Wang Bowen , Hu Jianping , Wu Wei
Published: June 2020

At present, the transmission line realizes the effect of lightning protection and supporting wires by connecting insulators and lightning arresters in parallel. However, due to the large weight and volume of lightning arresters, the space of the cross arm of the iron tower is limited, the workload of lightning arresters installation and line operation and maintenance is greatly increased, and the live operation is more difficult. Aiming at the problems that lightning arresters do not have the ability to hang wires, and additional hanging points are needed during installation, and the cross arm of iron tower is reformed, this paper proposes a lightning protection composite insulator combining lightning arresters and insulators. In view of the anti-explosion performance of lightning arresters, the existing research mostly focuses on the discussion and theoretical analysis of lightning arresters explosion accidents, and seldom involves the anti-explosion performance test of lightning arresters. In this paper, the practicability and reliability of the 110kV lightning-proof and ice-proof insulator are illustrated through the explosion-proof performance test and mechanical performance test of the proposed 110kV lightning-proof and ice-proof insulator.
Research on Hydrogen Energy and Fuel Cell Vehicle Roadmap in Various Countries
Authors: Yunzhe Jiang , Bowei Zou , Feifei Wang , Mengmeng Liu
Published: June 2020

This paper studied the roadmap of the hydrogen energy and fuel cell vehicle (FCV) industry in the US, Japan and the EU, and summarized the development goals, promotion paths and development plans of the hydrogen energy industry in developed countries. On this basis, the development prospect of hydrogen energy and FCV industry in China is further analysed based on resource endowment and current situation of FCV industry in China. Finally, by comparing the development plans and characteristics of hydrogen energy and FCV industry in various countries, the deficiencies of hydrogen energy and FCV industry in China are found, and suggestions are put forward for the development of hydrogen energy and FCV industry in China.
Cause analysis of circumferential cracking of reheat steam hot section pipeline of 300MW unit
Authors: Zhang Yanfei , Lv Lei , Fang Wenxuan , Li Zefeng
Published: June 2020

During the operation of reheat steam hot leg pipeline, circumferential cracking occurs, leading to the failure of high temperature steam leakage. In order to find out the causes of the cracking of the reheat steam pipeline and understand its health status, the comprehensive inspection and analysis of the cracked reheat steam pipeline are carried out by using the test methods of macro morphology analysis, non-destructive testing analysis, chemical composition analysis, microstructure analysis, mechanical property testing and scanning electron micro area analysis. The results show that the chemical composition of the cracked reheat steam pipeline meets the requirements of the design standard, the metallographic microstructure is ferrite + bainite + pearlite, the tensile strength and elongation after fracture are qualified, and the yield strength is slightly lower than the requirements of the standard. The main causes of the pipeline circumferential cracking: the low-temperature medium in the cold section of reheat steam is continuously discharged into the high-temperature pipeline and directly contacts with the inner wall of the pipeline repeatedly, forming alternating thermal stress, which causes the pipeline thermal fatigue damage cracking to leakage; and the insufficient yield strength will accelerate the speed of fatigue cracking to a certain extent.
Study on the Transmission Characteristics of the Multi-gear Multi-degree-of-freedom Hybrid Planetary Gear Automatic Transmission Based on the Line Method
Authors: Fan Yi
Published: June 2020

Planetary gear transmission is widely used in vehicle automatic transmission because of its compact structure and good working conditions of gears and bearings. The transmission characteristic analysis of planetary gear automatic transmission has become one of the most important contents of automatic transmission design and maintenance. This paper takes the typical multi-gear multi-degree-of-freedom hybrid planetary gear automatic transmission Ford 10R80 as an example. Firstly, its structure is analysed, and its degree of freedom is calculated to be 5. According to this, Further analysis is made on the shift logic of the sequential up and down gears, skipping-level shifting gears and the multi-level down gears such as from© to© orfrom © to©. Then, the overall transmission nomogram is established based on the improved line method, and the power transmission characteristics of typical gears are analyzed. Finally, the transmission ratios of all gears are calculated according to the nomogram, and the calculated results are completely consistent with the data provided in the patent documents. The results show that the nomogram can not only clearly describe the speed of all the basic components in each gear but also calculate the transmission ratio of each gear quickly.
Reconstruction of facies conditions of the sedimentation of bitumen-bearing sandstones according to granulometry data (Volga-Ural oil and gas province, Russian Federation)
Authors: Dudyak R , Mullakaev A , Khasanov R
Published: June 2020

For 60 years in the Volga-Ural oil and gas province, the study of Paleozoic sediments was carried out taking into account their industrial oil and gas potential. Therefore, the most studied are deposits of the Devonian and Carboniferous periods. Today, most of the Devonian and Carboniferous oil fields are close to depletion. In recent years, in order to maintain production volumes, oil companies are increasingly focusing on the study of Permian deposits, in which significant resources of natural bitumen and super-viscous oils are concentrated. Their industrial resources are associated with psammite (sandy) deposits of the Sheshmian horizon of the Ufimian stage of lower-Permian period. In this regard, the task of a more detailed study of the conditions for the formation of Sheshmian deposits, which are characterized by a complex geological structure, is becoming ever more acute. Formation conditions affect the spatial distribution and features of geological structures, the definition and refinement of which is important for building high-quality 3D geological models and improving the efficiency of exploration and development of deposits. To determine these characteristics, facies analysis is successfully used, which is carried out on the basis of granulometric and mineralogical studies of sediments to obtain ideas about sedimentation conditions. Lithological-facies studies also make it possible to determine the structural features of the terrigenous rock and its reservoir properties.
The influence of the scale effect on the connected porosity in Bashkirian limestones
Authors: Khassanov D , Lonshakov M
Published: June 2020

The concepts of the representative elementary volume and the scale effect for terrigenous and carbonaceous reservoirs have been considered. Various approaches of representative elementary volume calculations have been investigated. The whole core segment connected porosity is evaluated in two ways using the 7.3 cm diameter core samples in the first approach and the core samples 10 cm long by 3 cm in diameter in the second way. Logging porosity data and core samples values have been studied to identify optimal core sizes for the estimation of the relationship between core and well log data.
Mineralogical and lithological properties of Domanikites from the south-east of Tatarstan Republic
Authors: Khayuzkin A S , Morozov V P , Kolchugin A N , Eskin A A , Eskina G M , Korolev E A , Zakharova N S
Published: June 2020

The article was described main types of rocks – mudstones, carbonate-siliceous rocks, containing organic matter and carbonate breccia, based on detailed analysis of rock samples from Semiluksky horizons of Upper Devonian black shale formations, Volga-Ural region, Russian Federation. Different structures and texture features, mineral composition, and content of organic matter characterized selected types of rocks. Only in the carbonate-siliceous type of rocks is the high content of organic matter, about 9%. It was found direct dependence between the content organic matter and content in rocks silica minerals (quartz and chalcedony). Such dependence caused by joint precipitation silica minerals and accumulation of organic matter in the seafloor in conditions of active seepage of hydrothermal fluids. The presence of an abundance of biophilic elements in ascending fluids led to an explosion of biota and widespread of silica organisms. This hypothesis doesn’t disagree with any authors but considers the significant contribution of fluid factor to the deposition of Semiluksky formations.
Hydrogeological systems of landslides in central part of the Volga-Ural region
Authors: Korolev E A , Eskin A A , Petrova D I , Korolev A E , Barieva E R
Published: June 2020

The study of landslide massifs made it possible to identify two types of hydrogeological systems that differ by feeding area structure and transit zone. In landslide bodies of Urzhuminan stage, composed by dolomites and marls, hydrogeological systems are simple stratal. The aquifers are localized in fractured marls, which, under the influence of infiltration water seeping through them, have turned into a poorly structured gruss-rock cover, which lies on dense dolomites - water-resistant. The inclined bedding of dolomite layers creates the prerequisites for directed filtration of groundwater towards natural lowering. Here forming areas of ground water discharge as low-water springs. In landslides composed of the Upper Jurassic series clays and marls, hydrogeological systems are distinguished by the prevailing vertical groundwater infiltration in transit zone. Theirs’s water source is shallow lakes formed on the surfaces of landslide terraces. Under water pressure influence of in the lake basins and gravity, infiltration groundwaters leaking through the systems of cracks in clays penetrate to a more dense clay layers which are fluid trap. Here, directly under the lake basin, a dome of groundwater is formed. The flow of groundwater from the dome towards inclined depressions leads to creation of unloading areas. They are presented by permanently wet land (flarks) or low-water infiltration springs that come to the surface at the same hypsometric level.
In situ formed carboxylic acids effect on light hydrocarbons oxidation in a carbonate reservoir
Authors: Shageev A , Ganeeva Y , Lukyanov O , Erokhin A , Ziganshina M
Published: June 2020

Enhancing heavy oil recovery is attracting a considerable interest due to the depletion of conventional oil resources. In fact, thermal enhanced oil recovery methods are presenting a potential impact on improving heavy oil recovery especially for terrigenous reservoirs, where they are able to increase oil mobility due to heating (steam and thermal exposure) or due to its in-situ conversion to light fractions during ignition of the reservoir. At the same time, it is worthy to note that steam-thermal methods are accompanied by a significant heat loss when injecting steam into great depths heat. Moreover, oil deposits in heterogeneous low-permeability reservoirs (for example, carbonate) are among the potential unconventional oil resources. Along with geological heterogeneity, low porosity and permeability, fracturing, these reservoirs contain, in most cases, heavy oils with a high content of resins, asphaltenes and hard paraffins, characterized by a non-Newtonian fluid property. All this taken together makes the extraction of oil from such reservoirs a hard task to implement.
Modeling of hydrothermal processes of transformation of super-viscous oil of the Ekaterinovsky deposit in the presence of clay minerals
Authors: Kayukova G , Mikhailova A , Nasyrova Z , Gerasimov A , Ziganshin I , Vandyukova I , Gareev B
Published: June 2020

Using a set of physicochemical methods, the influence of hydrothermal effects on the composition of super-heavy oil of the Ekaterinovsky field in a carbon dioxide medium in the presence of a composition of catalysts - metals of variable valence in model experiments on clay rock-forming minerals was studied. Peculiarities of the transformation of the oil composition associated with the destruction of its high molecular weight components - resins and asphaltenes, and the formation of light saturated and aromatic hydrocarbons are revealed. Changes in the structural-group composition indicate an increase in the aromaticity of the products of the experiments. The greatest changes occur in the composition of resins and asphaltenes, which is reflected in a change in their structural-group composition and their paramagnetic properties. The high sorption ability of the rock to metals included in the composition of the used catalyst composition was revealed.
Modern modifiers for obtaining polymer-bitumen binders
Authors: Khaibullina A , Vagapov B , Galimullin I , Mukhamatdinov I
Published: June 2020

Currently, studying additives to petroleum road bitumen for improving their quality generates a growing interest in research field. Actually, this is related to the requirements for polymer-bitumen materials which are constantly becoming tougher, and therefore the need to develop and produce new polymer-bitumen binders. In this paper we considered the most frequently used effective additives and analyzed their positive and negative sides.
Production of binding materials based on high-viscosity oils and natural bitumens
Authors: Kutlizamaev R , Ivanova I , Popkov A , Tajik A
Published: June 2020

Due to the growing market demand for road bitumen, there is a need to increase the rate of its production. Among the promising technologies currently available, the oxidation of heavy hydrocarbon raw materials with air oxygen is the most optimal technology for producing bituminous binders. In turn, substandard oil reserves are suitable raw materials for this process. Thus, the study of the regularities between the composition of the oxidation products of ultra-viscous oil and the physicochemical properties of the oxidation conditions will contribute to the development of the binding materials production technology.
Using of ethylene-vinyl acetate copolymer for manufacture of road surfaces
Authors: Ivanova I , Kutlizamaev R , Popkov A , Tajik A
Published: June 2020

The trend of European road companies to use an ethylene-vinyl acetate (EVA) copolymer is related to its ability to provide the necessary properties for the road surface, as well as its comparative cheapness and safety. The paper presents a study of bitumen modified by EVA, changes in the physicochemical properties of binders modified by EVA in concentrations from 1 to 10% and the influence of the number of vinyl acetate groups in the polymer composition on the properties of bitumen have been studied. Changes in physicochemical properties of bitumen in dependence on the molecular weight of EVA have been explored, as well as physicomechanical properties of asphalt mixtures with different contents of EVA have been evaluated.
Loss of Taste and Smell as Distinguishing Symptoms of Coronavirus Disease 2019
Authors: Dawson Patrick , Rabold Elizabeth M , Laws Rebecca L , Conners Erin E , Gharpure Radhika , Yin Sherry , Buono Sean A , Dasu Trivikram , Bhattacharyya Sanjib , Westergaard Ryan P , Pray Ian W , Ye Dongni , Nabity Scott A , Tate Jacqueline E , Kirking Hannah L
Published: June 2020

In a household study, loss of taste and/or smell was the fourth most reported symptom (26/42 [62%]) among coronavirus disease 2019 (COVID-19) case patients and had the highest positive predictive value (83% [95% confidence interval [CI], 55%–95%) among household contacts. Olfactory and taste dysfunctions should be considered for COVID-19 case identification and testing prioritization.
1321From high-density mapping to low-density mapping: an approach to delineate the active circuit in complex atrial reentrant tachycardias
Authors: Alonso C , Rodriguez Font E , Guerra Ramos J , Campos Garcia B , Mendez Zurita F , Moreno Weidman Z , Espinosa Viamonte H , Garcia Mancebo S , Mogro J , Gonzalez Matos C , Maldonado Chavez J , Vinolas Prat X
Published: June 2020

Funding Acknowledgements

NA

OnBehalf

NA

Background

High-density activation maps during complex atrial reentrant tachycardias are challenging to interpret as they include the activation patterns of active and passive circuits. Entrainment mapping provides the identification of the active tachycardia circuit. However, current electroanatomic mapping systems are not capable to color-coded the information obtained from entrainment maneuvers.

Objectives

 We sought to describe a mapping approach for ablation of complex atrial reentrant tachycardias in which high-density activation maps are transformed into low-density activation maps only displaying the active part of the tachycardia circuit.

Methods

We included consecutive patients with atypical atrial flutter. A high-density activation map was acquired during the index tachycardia. Subsequently, entrainment maneuvers were performed to generate a low-density activation map in which only the activation of the atria directly involved in the flutter circuit was displayed.

Results

 Seventeen patients were included 82%  male, mean age was 62 ± 7 years. Structural heart disease was present in 59% and 53% had a prior left atrial ablation procedure. Low-density activation maps were successfully generated from an average of  14 ± 3 entrainment points. Twenty circuits (95%) were identified in the left atrium and 1 (5%) in the right atrium. Ablation guided by low-density mapping successfully terminated all ARTs in 267 ± 353 seconds of radiofrequency application.

Conclusion

Low-density mapping based on entrainment maneuvers provides a precise delineation of the active circuit during complex ARTs and resulted in successful arrhythmia termination. This approach can be easily incorporated into clinical practice.