bluuebunny/crossref_metadata_2025_split huggingface dataset:
A supplementary subsynchronous Damping Controller to damp Subsynchronous Oscillation in Muti-infeed LCC-HVDC system
Authors: Hu Sile , Zhen Zijing 
Published: July 2021

Abstract
As more and more clean energy sources are integrated to the power system through HVDC transmission system, two or more LCC-HVDC system will feed in to the same system forming multi-feed LCC-HVDC system. The inverters of different LCC-HVDC systems may interact with each other to cause subsynchronous oscillation. Firstly, a muti-input muti-output interconnected model with variable speed is established to investigate the cause of the oscillation. Secondly, a supplementary subsynchronous damping controller (SSDC) on each LCC-HVDC system is designed to damp the oscillation. At last, a small test system with two LCC-HVDC systems is used to verify the effectiveness of the controllers.
Target Positioning Optimization Method in Power System
Authors: Ba S , Hou Z B , Wang D W , Shi G Y , Zhang W H , Han X J , Dong C Y , Liu J J 
Published: July 2021

Abstract
This thesis presents a method that a position measurement method for moving targets is proposed based on the positioning method based on the time difference of arrival (TDOA) which is based on the research on the positioning problem of station inspection operators and equipment in complex working conditions. The probability error method is introduced to optimize the traditional positioning method that realizes the target node positioning by optimizing the distance difference between the target node to be located in the network domain environment and different base stations, which can effectively improve the positioning accuracy of staff and equipment in the station. Through experiments in a complex power frequency electric field environment, the test results show that the results calculated by the optimization method are better than the existing traditional positioning methods, and can effectively improve the positioning accuracy under the condition of line-of-sight, and realize the substation space Mobile target positioning to ensure the safety of operators.
Construction of BiOBr0.5Cl0.5 heterojunctions for photocatalytic treatment of waste drilling fluid in oilfield
Authors: Li Yizheng , Jiang Guancheng , Dong Tengfei , Li Xiaoqing , Yang Lili 
Published: July 2021

Abstract
Drilling fluid is very essential for oil and gas drilling process. However, the treatment of the waste drilling fluid becomes an urgent issue because of the large amount and the lack in effective degradation method. Photocatalysis as an advanced strategy to solve the environmental pollution, has drawn widely attention. In this contribution, BiOBr0.5Cl0.5 heterojunctions are constructed through a hydrothermal method to act as a photocatalyst for photocatalytic degradation of waste drilling fluid. The successful construction of BiOBr0.5Cl0.5 heterojunctions is confirmed by XRD, SEM, EDS, and BET analysis and the results show that BiOBr0.5Cl0.5 is not a simple mechanical mixture. These heterojunctions in synthesis of photocatalyst is conducive to the photoactivity, which would lead to relatively high surface area and pore width in photocatalyst. It is found that photocatalytic degradation over BiOBr0.5Cl0.5 is a feasible approach for solving waste drilling fluid pollution. From the results of evaluation experiments, it can be seen that the colored materials and macromolecular organic polymers can be both degraded by BiOBr0.5Cl0.5. The presence of Br and Cl in the composite could promote the effective separation of photogenerated carriers and the construction of the active species ·O2- and ·H+, enhancing the photocatalytic activity of BiOBr0.5Cl0.5 heterojunctions. Given that the outstanding performance in degrading RhB or HPAM and the sustainability of BiOBr0.5Cl0.5, The photocatalytic offers a promising reference to the treatment of waste drilling fluid.
Numerical simulation of stress field distribution before re-fracturing treatment
Authors: Liu Xiaoqiang , Qu Zhanqing , Guo Tiankui , Huang Wenjie 
Published: July 2021

Abstract
Due to the first fracturing failure at the middle and final stages of oil and gas field development, re-fracturing technology has become a key method to increase production in oilfield. So, stress field distribution should be the key successful factor to impact re-fracturing technology after the initial fracturing in reservoir. In order to accurately describe the initial stress field distribution of reservoir after fracturing and provide theoretical basis for subsequent re-fracturing, this paper with theory of rock fracture mechanics and fluid-solid coupling equation had built several ABAQUS numerical model of hydraulic fracturing according to the basic theory of XFEM, to analyses the stress influence by horizontal stress difference, rock elastic modulus, Poisson’s ratio and production time before re-fracturing. Numerical simulation results show that due to the initial crack and the change of pore pressure in the process of production, the direction and size of the original stress field change a lot, which lead a stress field redirection; Reservoir and rock physical mechanical parameters bring a significantly change of reservoir stress field distribution; with the difference of horizontal stress, rock elastic modulus and oil field production time increasing, induced stress effect and stress redirection area decrease; the greater of Poisson’s ratio, the induced stress effect and redirection area is smaller.
The Impact of Surface Characteristics of Slightly Soluble Cu (II) and Ni (II) Compounds on their Electroflotation Extraction from Concentrated Solutions of Electrolytes
Authors: Brodskiy V A , Malkova Yu O , Il’yin V I , Soboleva V A 
Published: July 2021

Abstract
The impact of concentrated NaCl, NaNO3, and Na2SO4 solutions on the average hydrodynamic diameter and charge of particles of slightly soluble nickel and copper compounds were found to be rather identical. In electrolytes solutions, the average size of the dispersed phases particles decreased from 50–54 µm to 30–45 µm, the electrokinetic potential became more negative (-(2–10) mV). In a result, the removal of slightly soluble nickel and copper compounds decreased from 98% to 94–97% and 30–94%, respectively. Minimal efficiency of electroflotation-based extraction of nickel was observed in the presence of NaNO3. Cationic flocculants promoted increased extraction up to 98–100% regardless of the electrolyte, and decreased electroflotation duration from10–15 min to 5–7 min.
Analysis of Soft Story and Torsional Irregularity Factors in the Seismic Performance of Reinforced Concrete Buildings by Nonlinear Static Analysis
Authors: Lagos W A , Blas O E , Orihuela J 
Published: July 2021

Abstract
The seismic design of irregular buildings is usually developed using an irregularity factor according to its nature. However, seismic stresses are impacted as the irregularity approaches the extreme limit. In this study, we analyzed the soft story and torsional irregularity factors of reinforced concrete structures with structural system: frame, dual and structural walls of 5, 7 and 10 floors respectively. To this end, a Nonlinear Static Analysis (NLS) - Pushover was carried out. This analysis is carried out in two stages. First, a regular structure is analyzed in plan and in elevation, which is the regular model. Second, the geometry of the regular structure is modified in plan and in elevation in order to perform the same analysis, so as to show irregularity due to soft story and torsion. The purpose is to obtain the structural response with variations of both irregularities from minor to major. Lastly, the seismic stresses obtained from the irregular models are compared with the regular model response, and then, new irregularity factors are proposed for the cases studied.
Problem analysis of residential buildings in Armenia in view of green architecture concept
Authors: Papoyan Atanes , Zhan Changhong , Han Xueying 
Published: July 2021

Abstract
Green buildings starting to become an unavoidable trend due to the introduction of an assessment standard for green construction in Armenia. In the world green residential buildings grow even faster than green public buildings. The total area of residential buildings is approximately two times higher than in public buildings. In this work is eliminated the main problems of residential building in Armenia, in socio-demographic, functional, psychological, economical and technical aspects.
Blasting Excavation Induced Damage Caused to the Rock Mass Surrounding Tunnels
Authors: Lai J , Wang Y C , Liu Y 
Published: July 2021

Abstract
Multi-hole blasting is often used for tunneling, however, blasting can damage the surrounding rock. To study the effect of blasting on surrounding rock and the damage caused, this paper presents an equivalent load method and a damage constitutive model of surrounding rock, based on earlier works and existing literature. A numerical simulation method is adopted to predict the most vulnerable part of the surrounding rock in the tunnel under blasting load. The research results have certain guiding significance for tunnel construction.
Difference-frequency generation in an AlGaAs Bragg-reflection waveguide using an on-chip electrically-pumped quantum dot laser
Authors: Schlager A , Götsch M , Chapman R J , Frick S , Thiel H , Suchomel H , Kamp M , Höfling S , Schneider C , Weihs G 
Published: July 2021

Abstract
Nonlinear frequency conversion is ubiquitous in laser engineering and quantum information technology. A long-standing goal in photonics is to integrate on-chip semiconductor laser sources with nonlinear optical components. Engineering waveguide lasers with spectra that phase-match to nonlinear processes on the same device is a formidable challenge. Here, we demonstrate difference-frequency generation in an AlGaAs Bragg reflection waveguide which incorporates the gain medium for the pump laser in its core. We include quantum dot layers in the waveguide that generate electrically driven laser light at ∼790 nm, and engineer the structure to facilitate nonlinear processes at this wavelength. We perform difference-frequency generation between 1540 nm and 1630 nm using the on-chip laser, which is enabled by the broad modal phase-matching of the AlGaAs waveguide, and measure normalized conversion efficiencies up to (

0.64
±
0.21

)% W−1 cm−2. Our work demonstrates a pathway towards devices that utilize on-chip active elements and strong optical nonlinearities to enable highly integrated photonic systems-on-chip.
Room temperature ppt-level NO2 gas sensor based on SnO
x
/SnS nanostructures with rich oxygen vacancies
Authors: Tang Hongyu , Gao Chenshan , Yang Huiru , Sacco Leandro , Sokolovskij Robert , Zheng Hongze , Ye Huaiyu , Vollebregt Sten , Yu Hongyu , Fan Xuejun , Zhang Guoqi 
Published: July 2021

Abstract
In this paper, tin oxidation (SnO
x
)/tin-sulfide (SnS) heterostructures are synthesized by the post-oxidation of liquid-phase exfoliated SnS nanosheets in air. We comparatively analyzed the NO2 gas response of samples with different oxidation levels to study the gas sensing mechanisms. The results show that the samples oxidized at 325 °C are the most sensitive to NO2 gas molecules, followed by the samples oxidated at 350 °C, 400 °C and 450 °C. The repeatabilities of 350 °C samples are better than that of 325 °C, and there is almost no shift in the baseline. Thus this work systematically analyzed the gas sensing performance of SnO
x
/SnS-based sensor oxidized at 350 °C. It exhibits a high response of 171% towards 1 ppb NO2, a wide detecting range (from 1 ppb to 1 ppm), and an ultra-low theoretical detection limit of 5 ppt, and excellent repeatability at room temperature. The sensor also shows superior gas selectivity to NO2 in comparison to several other gas molecules, such as NO, H2, SO2, CO, NH3, and H2O. After x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron
microscopy, transmission electron microscope, and electron paramagnetic resonance characterizations combining first principle analysis, it is found that the outstanding NO2 sensing behavior may be attributed to three factors: the Schottky contact between electrodes and SnO
x
/SnS; active charge transfer in the surface and the interface layer of SnO
x
/SnS heterostructures; and numerous oxygen vacancies generated during the post-oxidation process, which provides more adsorption sites and superior bandgap modulation. Such a heterostructure-based room-temperature sensor can be fabricated in miniaturized size with low cost, making it possible for large-scale applications.
Continuum time-delayed electron hopping in the extended dynamical molecules and entropy-ruled Einstein relation for organic semiconductors
Authors: Navamani K 
Published: July 2021

Abstract
Charge transport (CT) in dynamically disordered molecular systems is still unclear; though it is fundamentally important to understand the semiconducting properties of molecular devices. In this regard, we explore vibronically coupled polaron hopping transport in the extended hopping systems (N + 1 sites) of thiazolothiazole (TZTZ) based molecules. The molecular vibrations correlated charge transfer integral and site energy fluctuation effects on polaron transport are analyzed by kinetic Monte-Carlo simulations. In order to quantify the CT properties more precisely, we have proposed the continuum time delayed CT mechanism, which takes account of typical disordered (static or dynamic) effect via dispersion on each CT quantity (like charge transfer rate, diffusion coefficient, mobility, current density and etc) at each hopping. The charge compressibility analysis further addresses the electronic level understanding of all CT quantities, which originally relates the thermodynamic density of states with CT. Using differential entropy-dependent charge density and diffusion expressions, the drift-diffusion transport has been elucidated for different extended systems of TZTZ derivatives. Besides, we have mainly developed entropy-ruled diffusion-mobility relation for both degenerate and nondegenerate materials to study the validity and limitations of original Einstein relation, which directly pertain to the device performance. Here, the traversing chemical potential along the hopping sites is the deterministic parameter of diffusion-mobility ratio. Using our continuum time delayed model, we can categorize the typical disordered transport in the molecular semiconductors; whether is dynamic or static or intermediate disordered transport.
Integrated farm management systems to improve nutrient management using semi-virtual Farmlets: agronomic responses
Authors: Li Carson , Hunt Derek , Koenig Karen , Smukler Sean , Bittman Shabtai 
Published: July 2021

Abstract
With increasing demand for land and food, there is growing interest in sustainable intensification of agricultural production. Here we investigated sustainable intensification of grass and corn production for dairy farms using a system of semi-virtual farmlets that combine replicated field research plots with feed modelling. We improved manure N capture by spreading separated liquid fraction with a low emission sliding shoe applicator on grass, and manure P capture by precision injecting separated sludge into corn. Reducing the number of annual harvests (5 to 3) increased grass yield and inter-seeding Italian ryegrass in early maturing corn increased fall growth of the cover crop, thus helping to protect soil over winter and providing additional high quality herbage in spring. Irrigation improved yield and potentially yield stability of corn and grass, and adding a nitrification inhibitor to reduce N2O emission may help reduce pollution swapping especially from injected manure. Overall, allocating more land to corn than grass will increase farm productivity but effectiveness of measures to reduce pollution and pollution swapping need to be evaluated. Results show that good practices ensuring vigorous crops are challenging to implement but critical for achieving sustainable intensification. The semi-virtual farmlet system is very helpful for developing and evaluating sustainable production measures for corn and grass.
Maternal Cardiovascular and Cerebrovascular Health After Placental Abruption: A Systematic Review and Meta-Analysis (CHAP-SR)
Authors: Ananth Cande V , Patrick Haylea S , Ananth Srinidhi , Zhang Yingting , Kostis William J , Schuster Meike 
Published: July 2021

Abstract
Placental abruption and cardiovascular disease (CVD) have common etiological underpinnings, and there is accumulating evidence that abruption may be associated with future CVD. We estimated associations between abruption and coronary heart disease (CHD) and stroke. The meta-analysis was based on the random-effects risk ratio (RR) and 95% confidence interval (CI) as the effect measure. We conducted a bias analysis to account for abruption misclassification, selection bias, and unmeasured confounding. We included 11 cohort studies comprising 6,325,152 pregnancies, 69,759 abruptions, and 49,265 CHD and stroke cases (1967–2016). Risks of combined CVD morbidity-mortality among abruption and nonabruption groups were 16.7 and 9.3 per 1,000 births, respectively (RR = 1.76, 95% CI: 1.24, 2.50; I2 = 94%; τ2 = 0.22). Women who suffered abruption were at 2.65-fold (95% CI: 1.55, 4.54; I2 = 85%; τ2 = 0.36) higher risk of death related to CHD/stroke than nonfatal CHD/stroke complications (RR = 1.32, 95% CI: 0.91, 1.92; I2 = 93%; τ2 = 0.15). Abruption was associated with higher mortality from CHD (RR = 2.64, 95% CI: 1.57, 4.44; I2 = 76%; τ2 = 0.31) than stroke (RR = 1.70, 95% CI: 1.19, 2.42; I2 = 40%; τ2 = 0.05). Corrections for the aforementioned biases increased these estimates. Women with pregnancies complicated by placental abruption may benefit from postpartum screening or therapeutic interventions to help mitigate CVD risks.
Mapping and Monitoring Zero-Deforestation Commitments
Authors: Austin Kemen G , Heilmayr Robert , Benedict Jason J , Burns David N , Eggen Michael , Grantham Hedley , Greenbury Aida , Hill Jane K , Jenkins Clinton N , Luskin Matthew S , Manurung Timer , Rasmussen Laura V , Rosoman Grant , Rudorff Bernardo , Satar Musnanda , Smith Charlotte , Carlson Kimberly M 
Published: July 2021

Abstract
A growing number of companies have announced zero-deforestation commitments (ZDCs) to eliminate commodities produced at the expense of forests from their supply chains. Translating these aspirational goals into forest conservation requires forest mapping and monitoring (M&M) systems that are technically adequate and therefore credible, salient so that they address the needs of decision makers, legitimate in that they are fair and unbiased, and scalable over space and time. We identify 12 attributes of M&M that contribute to these goals and assess how two prominent ZDC programs, the Amazon Soy Moratorium and the High Carbon Stock Approach, integrate these attributes into their M&M systems. These programs prioritize different attributes, highlighting fundamental trade-offs in M&M design. Rather than prescribe a one-size-fits-all solution, we provide policymakers and practitioners with guidance on the design of ZDC M&M systems that fit their specific use case and that may contribute to more effective implementation of ZDCs.
MRI safety wih abandoned or functional epicardial pacing leads
Authors: Vuorinen AM , Paakkanen R , Karvonen J , Sinisalo J , Holmstrom M , Kivisto S , Peltonen J , Kaasalainen T 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public hospital(s). Main funding source(s): HUS Medical Imaging Center research grant

Background
The Heart and Rhythm Society’s consensus statement 2017 approves magnetic resonance imaging (MRI) with cardiac implantable electronic devices (CIED), but excludes patients with epicardial and abandoned leads. Potential safety hazards of an MRI with epicardial pacing leads include heating of the tip of the lead and induction of current in the pacing lead resulting in inappropriate cardiac stimulation. Only a few small studies of MRI safety with epicardial pacing leads have been published and adverse events have been rare. The clinical dilemma remains, whether performing an MRI on a patient with CIED and epicardial pacing leads is safe.
We have performed MRIs on patients with CIED and epicardial pacing leads when benefits have been considered to outweigh the risks after careful case-by-case evaluation following our institutional MRI with CIED safety protocol.

Purpose
The aim of this study was to evaluate the safety of performing an MRI scan on patients with CIED and abandoned or functional epicardial pacing leads.

Methods
All the clinically indicated MRI examinations conducted on adult patients with CIED and functional or abandoned epicardial leads (n = 24) performed in our hospital between November 2011 and October 2019 were included in this observational retrospective study. The data were retrospectively collected from electronic medical records.

Results
Altogether 24 MRIs were performed to 16 patients with functional or abandoned epicardial pacing leads (Table). 93.8% (15/16) patients had congenital heart disease. Cardiac MRI was the most frequent examination (21/24, 91.7%). 66.7% of the MRI scans (16/24) were conducted on patients with functional epicardial pacing leads. In 5/24 (20.8%) MRIs, the patient was pacemaker-dependent.
A clinically significant event occurred in one MRI scan. This was transient elevation of the pacing lead threshold in a patient with functional epicardial ventricular pacing lead, that was implanted 29 years prior to the MRI. In another patient with 30-year-old functional epicardial pacing leads, clinically significant irreversible elevation in atrial pacing lead impedance was detected 6 months after the MRI and unlikely related to previous MRI examination.
None of the patients experienced sensations leading to cessation of the MRI scans. No clinically significant pacing lead parameter changes were detected after MRIs performed on patients with modern (implanted year 2000 or later) functional epicardial pacing leads or functional endocardial leads and abandoned epicardial leads.

Conclusions
MRI examinations in patients with CIED and modern functional epicardial pacing leads were performed without detectable adverse events. Performing an MRI with old functional epicardial pacing leads may involve more risks.