bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of Y
x
Yb1-x
Ba2Cu3O7-δ
bulks for superconducting joint between REBCO-coated conductors
Authors: Mun Ka Kei , Murakami Tomoya , Kanazawa Shintetsu , Momono Naoki 
Published: July 2021

Abstract
In this study we prepared Y
x
Yb1-x
Ba2Cu3O7-δ
(x = 0.1, 0.2, 0.3, 0.4, 0.5) powders and bulks to use as intermedium for superconducting joint between REBCO-coated conductors. Superconducting joints are essential in the development of high-field REBCO persistent magnets. All the powders and bulks were sintered at 850 °C for 10 hours in air. Bulks were prepared by pressing at 70 MPa. Calcination of the bulks was performed under the same conditions as the powders. Two joint samples between GdBa2Cu3O7-δ
-coated conductors were prepared by using the bulk samples. For x=0.1, a superconducting joint was successfully obtained.
Development of Superconducting Coils using (Ba, Na)Fe2As2 Round Wires with Large Critical Current
Authors: Pyon S , Mori H , Tamegai T , Kajitani H , Koizumi N , Awaji S , Kito H , Ishida S , Yoshida Y 
Published: July 2021

Abstract
We report the fabrication of 10 m-class (Ba, Na)Fe2As2 long round wires and coils using these round wires. Round wires are fabricated by powder-in-tube (PIT) method and hot-isostatic-press (HIP) technique. To increase Ic
keeping the diameter of the wire constant, the cross section area of the superconducting core is enlarged by changing the dimensions of metal sheaths. At 4.2 K under a high field of 100 kOe, Jc
of a short segment of HIP wire reaches 42 kAcm-2, which is comparable to the highest Jc
of IBS round wires of 44 kAcm-2. Furthermore, Ic
of the HIP wire at 4.2 K under 10 kOe and 100 kOe reaches 95 A and 54 A, respectively, which is about twice the value of the previous report. We also fabricated a small demonstration superconducting coil using 12.5 m long PIT wires by HIP method. Ic
of the whole coil is ∼60 A under the self-field, and magnetic field at the center of the coil reaches 2.6 kOe. The coil generated the magnetic field of 43 Oe/A, which is almost consistent with the calculated field from the coil dimensions.
A Timing Fault Model and an Efficient Timing Fault Simulation Method for Rapid Single-Flux-Quantum Logic Circuits
Authors: Nakamura Shogo , Takagi Kazuyoshi , Kito Nobutaka , Takagi Naofumi 
Published: July 2021

Abstract
We examine digital behavior of faults caused by a change of the order of the pulse arrivals in Rapid Single-Flux-Quantum (RSFQ) logic circuits. Based on the timing fault model, we present a flow of automatic test pattern generation for testing digital RSFQ chips. As the test pattern generation repeatedly executes fault simulation, the scalability depends on computational cost of the simulation. We propose an efficient fault simulation method based on two ideas. First, we share computation for the fault-free circuit and faulty circuits as much as possible. Secondly, we exploit the pipelined behavior of RSFQ logic circuits to suppress computation for unnecessary signals. We have implemented our simulation method and obtained evaluation results to show that our method is effective for large circuits.
Energy Extraction Performance of Tandem Ground-effect Hydrofoils
Authors: Yang Hao , He Guanghua , Mo Weijie , Wang Wei 
Published: July 2021

Abstract
To study the influence of the spatial configuration of two tandem ground-effect hydrofoils on the power-extraction efficiency, this paper uses the overset grid method to establish a two-dimensional numerical calculation model based on the STAR-CCM+ software. The comparison of the numerical results of the single hydrofoil verifies the validity of the method. This paper systematically analyzes the influence of ground effect on the energy extraction performance of the hydrofoil, and further studies the changes in the hydrodynamic performance and energy extraction efficiency of the hydrofoil when two ground effect hydrofoil are tandem. The results show that: compared with a single ordinary hydrofoil, the energy extraction efficiency of the ground-effect hydrofoil is slightly improved. When the hydrofoil is close to the wall, its lift will be significantly increased due to ground effect. When two ground effect hydrofoils are tandem with a phase difference of 180 deg, the vortex generated by the upstream hydrofoil will significantly increase the absolute lift of the downstream hydrofoil, but the energy extraction efficiency will be reduced significantly.
Research on Surveying Technology of Special-shaped Immersed Tube Installation in Hong Kong NSL Tunnel
Authors: Chong-ming Wang , Wanghui Li , Hanbin Zhong 
Published: July 2021

Abstract
The advantages of immersed tunnel are shallow depth and large cross-section. Victoria Bay is spanned by the NSL tunnel in Hong Kong. Kowloon and Hong Kong Island are connected. The tunnel consists 11 immersed tubes. Based on the study of the establishment of the coordinate system of special-shaped tube joints, the establishment and calibration of attitude surveying system, and the calibration of RTK-GPS, a set of surveying system for the installation and joint of special-shaped immersed tubes is developed to solve the problem in the construction of NSL tunnel. The installation of the E10 is guided. Compared with the traditional total station survey method, the installation and joint surveying system can meet the accuracy requirements and can be extended to similar immersed tunnel projects in the future.
The Spatial Variation Characteristics and Mechanism of Landing Tropical Cyclones in China
Authors: Li Bei , Gu Chenglin , Zhang Wenwen 
Published: July 2021

AbstractBased on the tropical cyclone (TC) data from the United States Joint Typhoon Center, this paper analyzes the spatial variation characteristics and possible mechanism of the TC that landed in China during the 65 years from 1951 to 2015. The conclusions are as follows. (1) The TC transformation location moves to southeast in El Niño years, and shifts to northeast in La Niña years. (2) In El Niño years, the frequency of TC affecting the coast of Mainland China is relatively low, while the frequency of TCs affecting Japan is increasing. In La Niña years, the frequency of TCs affecting Japan and the surrounding waters, the Yellow Sea, the Bohai Sea and the South China Sea increased, while that of Taiwan province decreased. (3) The changes in the local circulation in the Northwest Pacific increased the sea temperature, increased convection, increased relative humidity in the middle layer, weakened vertical wind shear, increased low-level vorticity, and increased high-level divergence in the southeastern part of the Northwest Pacific during the El Niño year. The large-scale circulation adjustments provided favorable background conditions for the southeast movement of the TC generating position. The southeast movement of the spawning location makes the landing TC activities have a longer moving distance and thus increases the life history. In La Niña years, the subtropical high weakened and moved eastward. This environment is conducive to generating more TCs to land in China in the La Niña year.
Ecosystem Pushing: Coral Restoration in Refugia as an Unexplored Answer to Climate Change Adaptation
Authors: Mertz Edith Maria , McDonald Anne 
Published: July 2021

Abstract
Climate change is driving ecosystem change across the biosphere on an unprecedented scale. Large biogeographic shifts are underway as habitats move their ranges towards the poles in an attempt to remain in zones that adhere to organisms’ preferred temperature ranges. These new areas of shifting climatic ranges, or refugia, represent important opportunities for the future survival of countless species in a warming world. However, many species may have colonisation rates too slow to keep up with climate change. This may be due to barriers to dispersal, long time periods in reproductive cycles, survival and viability of offspring, geographic isolation of suitable new habitats, stochasticity and other environmental factors. Ecosystem pushing proposes to propagate species into refugia using restoration techniques with the aim of supporting species survival and ecosystem conservation. This paper proposes ecosystem pushing as a new management intervention for the field of coral reef restoration. Management considerations will need to include geographic models of refugia projections to ascertain appropriate locations for restoration work. Other important considerations would include assessing the risks of losing one ecosystem type for another, invasive species and disease introductions, issues of intervention scale and time constraints, and levels of stakeholder engagement with local communities.
A Study on Comprehensive Evaluation of Multiple-depth Sea Water Quality in the South China Sea
Authors: Ma Xiaolei , Duan Mengshan , Duan Duomo , Qiu Jinquan , Cao Junrui 
Published: July 2021

Abstract
During the investigation in the South China Sea in the summer of 2018, the sea water samples were for temperature, salinity, dissolved oxygen, pH, nutrient salts (NO3-N, NO2-N, NH4-N, PO4-P, SiO3-Si), essential elements (Na, K, Mg, Ca, Sr, Cl, Br, B), trace elements (Cu, Zn, Fe Mn, Ni, Se, Mo, Co and V), heavy metal (Hg, Pb, As, Cd), organic elements (TOC, DOC, GOC), chlorophyll and microorganisms analyses from different layers of 12 stations according to the standard sampling specifications. The seawater samples of different depths were directly measured by inductively coupled plasma mass spectrometry. The distribution of several elements in the South China Sea water was investigated. It could be seen from the analytical results that the water temperature, salinity, pH, dissolved oxygen, the content of NO3-N, PO4-P, SiO3-Si, K+, Mg2+, Ca2+, Sr2+, Cl-, Br-, B3+, Zn, Mn, V, Cr, GOC and Chlorophyll was significantly correlated with depth of seawater.
Spatial and Temporal Variation Characteristics of Northwest Pacific Tropical Cyclone Activity in Global Warming Scenario
Authors: Guo Xinyu , Gu Chenglin , Li Bei , Zhang Wenwen 
Published: July 2021

Abstract
Utilizing the Joint Typhoon Warning Center (JTWC) TC best-track data covering the period of 1951-2015, spatial and temporal variation characteristics of Northwest Pacific tropical cyclone activity in global warming scenario is discussed. The annual frequency trend of TC in the Northwest Pacific is as follows: from the late 1950s to the early 1960s, there was an obvious upward trend, the late 1960s to the early 1980s showed a downward trend, the late 1980s to the mid 1990s showed an upward trend, and the mid-1990s to the late 2010s showed a downward trend. The frequency of super TY in the Northwest Pacific showed a rapid downward trend from the late 1960s to the early 1980s, and then changed to a slow upward trend. The region where the linear change of different stages of TC life cycle stage (genesis, development, mature, decay) frequency is approaching to central Asian coastline. Northwest Pacific TC activity decreases, but from the perspective of spatial distribution of linear changes, the threat of TC towards eastern Asia is enhanced. That is probably because the global warming scenario results in the increasing temperature gradient between Northwest Pacific and central and eastern Pacific, which leads to the strengthening of walker circulation. The strengthening walk circulation could increase the magnitude of the vertical wind sheer and the relative vorticity on the tropical Northwest Pacific, which affects the spatial variation of TC activity in Northwest Pacific.
Geomorphologic Impact of Construction of Breakwaters at Ponnani Fishery Harbour in Kerala
Authors: Paravath Kunhimammu , Parth Jhoga , Nasar T 
Published: July 2021

Abstract
Coast belonging to one particular stretch happens to be versatile because of its dynamicity. This dynamicity is attributed to both natural and anthropogenic activities. Hence, it is important to monitor any fragile coastal stretch’s dynamicity in a temporal basis. In the present study, an attempt is made to analyse the shoreline changes using Digital Shoreline Analysis System (DSAS), by calculating Linear Regression Rate (LRR), in response to the construction of two breakwaters at Ponnani which is a major fish landing centre in Malappuram district of Kerala state in India. Shorelines were extracted from field data, satellite imageries, LANDSAT (1979-2002) and Google earth (2010-2016). From the detailed analyses, before the construction of breakwaters, it is inferred that erosion at the rate of 1.5m/yr and 5.3m/yr was observed on north and south sides of Ponnani estuary respectively. But after construction, an accretion at the rate of 3m/yr on either side of estuary is observed.
The Optimize of Tug Configuration Based on Fuzzy Comprehensive Evaluation and Entropy Weight Analysis
Authors: Jiang Fucai , Han Zhang , Quandang Ma 
Published: July 2021

Abstract
As ships increasingly become larger, the corresponding port facilities can’t meet the requirements of arriving ships. This paper will use fuzzy comprehensive evaluation and analytic hierarchy process to propose an optimization plan for the configuration of port tugboats. In order to obtain the optimal tugboat configuration plan, entropy weight method is introduced in the weight analysis of the original fuzzy comprehensive evaluation to confirm the weight of evaluation factors. The problem of partial subjectivity in the determination of factor weights in the existing fuzzy synthesis method is improved. The tugboat configuration proposed at the end of this article is consistent with the existing Qingdao Port tugboat configuration mode.
Efficiency Evaluation of Major Coastal Ports in China: Application of the Three-stage DEA Model
Authors: Zhang Xinfang , Lu Jing , Peng Yan 
Published: July 2021

Abstract
With the increasing competition between ports, how to improve port efficiency and promote the sustainable development of ports becomes the focus of attention. The paper applies the three-stage data envelopment analysis (T-S DEA) model to measure the efficiency of top 10 Chinese coastal ports, including the scale efficiency (SE) and technical efficiency (TE). Besides, the principle component analysis approach is adopted to reduce the influence of redundant information of evaluation indicators on results. The stochastic frontier analysis regression model is applied to eliminate the effects of environmental factors and stochastic errors under similar exterior conditions. The results show: (1) The ports efficiency (SE and TE) in different regions is quite different; the efficiency of Chinese coastal ports is generally low, which is mainly caused by scale inefficiency; (2) The SE and TE are improved and the input and output redundancy ratio are decreased significantly by comparing the results of traditional DEA model. (3) Shanghai, Ningbo-Zhoushan, Shenzhen, Hong Kong and Kaohsiung have relatively high comprehensive efficiency. This study provides valuable information for estimating port efficiency and establishing competitive strategies in the future.
Application of Mechanical Relations in Mathematical Modeling to Oxygenate Synthetic Wastewater through a Circular Rotary Aerator
Authors: Jose Vladimir Cornejo Tueros , Elias Adrian Sanabria Perez , Adrian Elias , Danitza Mayli Cuñivo Muñico , Pascual Victor Guevara Yanqui , del Pilar Huanca Villanes Yanett 
Published: July 2021

Abstract
This paper expounds the issue about the evolution of the dissolved oxygen concentration in synthetic wastewater with a circular rotary by setting a mathematical model. The mathematical model is based on the Lewis and Whitman relations to transfer oxygen to water, and includes the mechanistic models proposed by Lee, to determine the global oxygen transfer coefficient and the oxygen saturation concentration in water, as a function of the fifth power temperature. For this purpose, historical data from aeration experiments with two types of discs and two levels of COD concentration were compared. The equation allows to include the effect of the variation of the temperature and atmospheric pressure. Finally, through the data obtained, it’s concluded that the estimation error is not affected by the type of disc, the COD concentration of the synthetic wastewater or by the interaction of both, and is less than + - 0.086 mg / L dissolved oxygen.
Techno-Financial comparison between photovoltaic systems with bifacial and monofacial technology in the location of Naco and Marcovia, Honduras
Authors: Núñez C , Reyes Duke A M 
Published: July 2021

Abstract
Technology is constantly growing, however, in the same way energy demand; over the years, different ways have been sought to better use of renewable resources in order to achieve better results in energy generation and supply that energy demand, but in turn to be feasible methods, an example of this is bifacial photovoltaic systems. This research carried out a Techno-Financial comparison between bifacial and monofacial systems for the locations of Naco, Cortés and Marcovia, Choluteca. In which the design of a bifacial photovoltaic installation was carried out assuming three types of land, being grass, soil and white gravel, with the purpose of analyzing the increase in albedo, and consequently the increase in energy production. Similarly, a monofacial system was designed for the same locations with the same capacity. The research made use of a quantitative methodology with a correlational focus, in which LCOE was established as the main research variable. In this way it was determined which photovoltaic system of those analyzed presents the lowest LCOE for both locations, of which it was made based on two assumptions, considering the value of the terrain and without considering it. Finally it was possible to determine that the lowest LCOE in a scenario where the value of the terrain is considered is obtained by the monofacial system for both localities, otherwise the scenario without considering the value of the terrain, the lowest LCOE presented by the bifacial system.
Characters of Different Materials as Supercapacitor Electrodes
Authors: Song Ziqing 
Published: July 2021

AbstractAs a new type of energy storage device between traditional capacitors and batteries, supercapacitors have the properties of fast charging and discharging of capacitors, as well as the energy storage characteristics of batteries. With the deterioration of the global climate and the reduction of resources, supercapacitors have received widespread attention. Electrode materials take an important part of ultracapacitors, which affect the performance and production of ultracapacitors. This paper studies the effects of different preparation methods and different dopants on the performance of activated carbon electrodes. The purpose of this article is to summarize the methods and research directions for improving the performance of activated carbon electrodes. Through the summary, it can be found that the specific capacity, internal resistance and cycle life of the activated carbon electrode are greatly improved by forming the composite electrode material of the metal compound or polymer and activated carbon. But whether it can be put into mass production has also become one of the factors to be considered in future research.
Conformal screen printed graphene 4 × 4 wideband MIMO antenna on flexible substrate for 5G communication and IoT applications
Authors: Zhou Xinyao , Leng Ting , Pan Kewen , Abdalla Mahmoud , Novoselov Kostya S , Hu Zhirun 
Published: July 2021

Abstract
Screen-printed graphene is integrated with multiple-input multiple-output (MIMO) technology to conquer the most concerned surge in electronic waste caused by the mass deployment of Internet of things (IoT) applications. A flexible MIMO antenna is implemented with simple fabrication process suitable for large-scale production by screen printing graphene highly conductive ink on paper substrate, ensuring high-speed 5G mass data wireless transmission without damaging the ecological environment. This environmental-friendly, low-cost, flexible and conformal MIMO antenna with orthogonal polarization diversity employs co-planar waveguide feed and planar pattern for achieving high space utilization and better integration in most scenarios, for instance, body centric networks and monitoring systems. Excellent performance has been achieved due to the high conductivity of the graphene: the fabricated antenna exhibits an average sheet resistance of

1.9

Ω

s

q

−
1

. The bandwidth of the antenna ranges from

2.22

GHz to

3.85

GHz

(53.71% fractional bandwidth), covering

4

G

long term evolution, sub-6 GHz

5

G

mobile communication networks, 2.5 and 3.5 GHz WiMAX, and 2.4 and 3.6 GHz WLAN. Within this range, the antenna exhibits effective radiation, also its envelope correlation coefficient remains below

0.2
×

10

−
6

, manifesting outstanding signal transmission quality in a variety of wireless networks. This work illustrates a novel aggregation of MIMO technology and graphene printing electronics, enabling cheap accessible and green MIMO antennas to be massively integrated in IoT applications.
A combinatorial study of electrochemical anion intercalation into graphite
Authors: Chugh Manjusha , Jain Mitisha , Wang Gang , Nia Ali Shaygan , Mirhosseini Hossein , Kühne Thomas D 
Published: July 2021

Abstract
Dual-ion batteries are considered to be an emerging viable energy storage technology owing to their safety, high power capability, low cost, and scalability. Intercalation of anions into a graphite positive electrode provides high operating voltage and improved energy density to such dual-ion batteries. In this work, we have performed a combinatorial study of graphite intercalation compounds considering four anions, namely hexafluorophosphate (PF

6

−

), perchlorate (ClO

4

−

), bis(fluorosulfonyl)imide (FSI−), and bis(trifluoromethanesulfonyl)imide (TFSI−), via first-principles calculations. The structural properties and energetics of the intercalation compounds are compared based on different sizes, geometries, and the physical and chemical properties of the intercalated anions. The staging mechanism of anion intercalation into graphite and the specific capacities, and voltage profiles of the intercalated compounds are investigated. A comparison regarding battery electrochemistry is also done with available experimental observations. Our calculated intercalation energies and voltage profiles show that the initial anion intercalation into graphite is less favorable than subsequent ones for all the anions considered in this study. Although the effect of the size of anions in a graphite cathode on various properties of the intercalated compounds is not as significant as the size of cations in a graphite anode, some distinction between the studied anions can still be made. Among the studied anions, the intercalation compounds based on PF

6

−

are the most stable ones. These PF

6

−

anions cause relatively small structural deformations of the graphite and have the highest oxidative ability, highest onset voltage, and highest diffusion barrier along the graphene sheets. The overall small diffusion barriers of the anions within graphite explain the high rate capability of dual-ion batteries.