bluuebunny/crossref_metadata_2025 huggingface dataset:
Bianchi-III inflationary universe with flat potential in general relativity
Authors: Kumawat Sunil , Poonia Laxmi , Sharma Sanjay
Published: June 2021

A study of an inflationary universe in recent scenario under effect of the scalar field with presence of flat potential is discussed in this paper to observe the of behavior of universe. For this purpose we have considered the proportionality relation between shear and expansion coefficient, it leads to condition B = Cα where B and C are the coefficients of line element, Here, α is positive integer other than one. The kinematical and structural features of constructed model are also pointed.
Mathematical representation of Wind Turbine Power reliability
Authors: Indhumathy D , Narmatha D , Rojamary T
Published: June 2021

Nowadays wind resource assessment utilize new advanced technologies and appropriate analytical methods which are applied to estimate how much wind as a fossil free fuel will be available from a wind farm over the period of its performance. The utmost important piece of information is determining the expected generation of energy from the power plant and ultimately how much cost effective it will be. In our study we have proposed a new method, the improved mixture Weibull distribution produced from the combination of two and three parameter Weibull distribution with six parameters which include shape, scale, location parameter and the weight component or the mixing parameter. The basic properties of the improved mixture Weibull distribution and the estimation of parameters using maximum likelihood method are discussed. The estimated parameters are used to derive a mathematical model to compute the capacity factor and wind power density.
Performance of an OWC device placed over multi-stepped bottom in random waves environment
Authors: Koley Santanu , Trivedi Kshma
Published: June 2021

The performance of an OWC device placed over multi-stepped bottom is analyzed in random incident waves environment. To model the irregular local wave climate, the Pierson-Moskowitz spectrum along with two different sea states are considered. The effect of chamber width, lip-wall thickness and draft, and turbine damping coefficient of the OWC device on the performance and efficiency are discussed in a detailed manner. It is observed that the OWC device parameters and the local wave climate play a crucial role on the performance and efficiency of the OWC device.
Study on non-linearity response of 4H-SiC APD
Authors: Liu Fei , Huo Feifei
Published: June 2021

UV photon counting detection technology based on 4H-SiC Avalanche photodiodes (APDs) has been widely used in virus inactivation system, quantum communication and other UV detection fields. When the ultraviolet signal is enhanced, the detection accuracy will also decrease due to the nonlinear characteristics of the photoelectric response. Therefore, the physical mechanism and nonlinear error source of the photoelectric response of 4H-SiC APD were analysed, and a photoelectric response characteristic testing system was built. The theoretical and experimental results show that the photocurrent increases linearly when the incident photon number is high, and the multi-photon incident results in the nonlinear phenomenon of photon count. Reducing device bias and increasing threshold voltage can significantly improve the nonlinear phenomenon of photoelectric response, and the maximum linear operating range of the device can be extended from 10 7s -1 to more than 10 9s -1.
A Multi-Sensor Data Fusion Fault Diagnosis Method for Rail Vehicle Transmission System
Authors: Qiao Ningguo , Hou Haijing , Chen Qiang , Zhai Naibin , Peng Tao
Published: June 2021

The transmission system is a critical part of the rail vehicle bogie, mainly responsible for power drive and transmission. The performance of the transmission system directly affects the safe operation of trains. This paper proposes a multi-sensor data fusion method combined with deep belief nets (DBN) and fuzzy integral algorithm (FI) to improve the accuracy and reliability of fault diagnosis for rail vehicle transmission systems. First, multi DBN classifiers are established for the vibration signals collected from the key components of transmission systems to carry out preliminary fault diagnosis. Then, FI is applied to fuse the preliminary diagnosis results of DBNs to obtain comprehensive judgment. The effectiveness of the approach is verified by the bearing dataset collected in lab. This method is simple and practicable, and possesses certain applicability.
Image Classification Method Based on Improved KNN Algorithm
Authors: Fan Zhu , Xie Jia-kun , Wang Zhong-yu , Liu Pei-Chen , Qu Shu-jun , Huo Lei
Published: June 2021

As the development of machine vision technology, artificial intelligence algorithms are gradually popularized for identifying images. However, traditional KNN algorithm actually costs too much time when classifying images, which is not qualified to actual application scenes. An improved algorithm is proposed in the paper. The test time has been greatly shortened and the efficiency of KNN algorithm is improved by increasing the screening of data sets. By setting STM32F103 as master control and OV7670 as camera, actual detection of volleyball, football, and basketball was carried out after test environment was set up. And the test time is shorter compared with that of general KNN algorithm. At the same time, the identification accuracy is high, which indicates that the method has good practicability.
Research progress of smart phone positioning and navigation sensors
Authors: Wen DanQi
Published: June 2021

Smart phone has gradually become an indispensable mobile device in people’s life, and its built-in sensors develop rapidly with the popularity of smart phones. A variety of sensors built in smart phones can provide different positioning sources for indoor positioning, so as to provide convenience for people’s activities in large public places. Nowadays, multisensor indoor positioning technology based on smart phones has become a research hot spot, such as indoor visual positioning technology developed by Google and ibeacon indoor positioning technology based on low-power Bluetooth launched by apple. This paper summarizes the development status of smart phone built-in sensors for indoor positioning, sorts out the new smart phone built-in sensors of several popular mobile phone brands in the current market, expounds the sensors for indoor positioning in smart phone sensors and related positioning technologies, and finally looks forward to the future development of smart phone positioning and navigation sensors in the field of positioning.
The device and experimental study of the monitoring of the layered soil settlement
Authors: Lv Aoqi , Liang JiaXin , Zou Suian , Chen Xiangyang , Li Qing
Published: June 2021

In order to solve the problems of large measurement error, low efficiency, complex equipment operation and difficult maintenance of layered soil settlement, this paper designed a new monitoring device of layered soil settlement based on Hall effect. A number of Hall elements are arranged on the monitoring circuit board at equal spacing, and the circuit board is fixed in the aluminum tube and sealed. The aluminum tube with multiple settlement magnetic rings is drilled into the earth vertically, and the settlement magnetic rings are distributed in different soil layers. The settlement of the soft soil will move the magnetic ring, causing its position to change, which will cause the change of magnetic flux density around Hall element, and the output voltage of Hall element will also change, and then the voltage signal will be transmitted to Hall signal concentrator through RS-485 bus communication mode. The Hall signal concentrator stores the signal in FLASH and communicates with the upper computer through using the LORA wireless communication module. Through data processing and model analysis in the upper computer, the function between Hall voltage and variation of displacement of the magnetic ring is fitted. Many experimental results indicated that the error of the monitoring device of layered settlement is within 1.0567mm, and the accuracy is high. It can provide real-time monitoring to different soil layers, and the data can be exported at any time, so it has a wider application prospect.
A discrete differential evolution for fuel loading optimization of the DNRR research reactor and comparison with genetic algorithm
Authors: Phan Giang T T , Tran Hoai-Nam , Do Quang Binh , Ngo Quang Huy
Published: June 2021

A discrete differential evolution (DE) method has been applied to the problem of fuel loading pattern optimization of the Dalat Nuclear Research Reactor (DNRR). A classic strategyDE/rand/l/binwas chosen for the mutation of the DE method. Numerical calculations have been performed based on the core configuration of 100 highly enriched uranium (HEU) fuel bundles with various burnup levels. Comparison of the performance between the DE method and a genetic algorithm (GA) was also carried out. The optimal LPs obtained from the two methods are significantly better than the reference core. DE is more advantageous in exploring search space and approaching a global optimum than GA.
Comparison of the contribution of the photon’s vector and scalar Kaluza-Klein partners in the neutron lifetime
Authors: Du Pham Tien , Viet Nguyen Ai , Dat Nguyen Van
Published: June 2021

A discrete extra dimension of size 11.8 fm would imply the existence of vector X and scalar H bosons as photon’s Kaluza-Klein partners. The massive vector X can be identified with the particle X17 suggested by ATOMKI’s experiment. The particle model of extended photon sector coupled to extended nucleon, electron and neutrino also implies the neutron decay to its Kaluza-Klein partner. There are several different channels triggered by X and H. In this paper ve compare the contribution from them and imply some physical consequences on the parameters of the model.
Investigation of the dependence of multiple recollision on laser wavelength in the nonsequential double ionization process
Authors: Truong Thu D H , Quach Mi A , Nguyen Hanh H , Nguyen Uyen T , Dung Do Hung , Pham Vinh N T
Published: June 2021

This paper investigates the recollision dynamics of the nonsequential double ionization process induced by linearly polarized laser pulses with the three-dimensional classical ensemble model. The results show that the correlated two-electron momentum distribution is contaminated by the double recollision events for sufficiently short laser wavelength. When the laser wavelength increases from near-infrared to mid-infrared, the single-recollision events are more prominent than the double-recollision one. Moreover, the mechanisms governing the nonsequential double ionization process are also thoroughly studied in the case of double-recollision.
The influence of confined acoustic phonon on the Quantum Ettingshausen effect in cylindrical quantum wire with an infinite potential in presence of strong electromagnetic wave
Authors: Ngoc Hoang Van , Anh Nguyen Thi Nguyet , Dien Tang Thi , Bau Nguyen Quang , Nhan Nguyen Vu
Published: June 2021

Based on the quantum kinetic equation method, the quantum Ettingshausen effect has been theoretically studied under the influence of confined acoustic phonon in a cylindrical quantum wire (CQW) with infinite potential in the presence of a strong electromagnetic wave. We considered a quantum wire in the presence of a constant electric field, a magnetic field, an electromagnetic wave (EMW) with an assumption that electron – confined acoustic phonon (CAP) scattering is essential. Analytical results obtained show that the EC depends on the amplitude and the frequency of the EMW in a non-linear way. Besides, the impact of phonon confinement on the above effect characterized by m-quantum number in the expression of the EC. The theoretical results have been numerically calculated for the GaAS/AlGaAs cylindrical quantum wire model. The obtained results show that the phonon confinement contributes to the EC quantitatively and qualitatively. On the other hand m is set to zero, the result obtained is similar to the case of unconfined phonon. Furthermore, by considering the quantum size effect, the values of the EC increases, the position of the magnetic-phonon resonance peak changes, and the number of peak resonant peak increases while the radius of quantum wire declines. These obtained results are different from bulk semiconductor and unconfined phonon case which donates to the theory of the Ettingshausen effect in low-dimensional semiconductor systems.
Spin excitations in the Kitaev-Heisenberg model: Popov-Fedotov fermionization
Authors: Nga Pham Thi Thanh , Hinh Nguyen Van , Thang Nguyen Toan
Published: June 2021

We study a Kitaev-Heisenberg model of spin 1/2 using the Popov-Fedotov fermionization proccedure. We derive the free energy of the quantum spin system on a Bravais lattice within one-loop approximation with exact on-site constraint. We discuss the obtained magnetic excitation spectrum for a particular case of square lattice in relation to the data derived by the equation of motion method and with the result of the linear spin wave theory in Holstein - Primakoff representation.
Application of vibro-acoustic methods in failure diagnostics
Authors: Kriston B J , Jálics K
Published: June 2021

The present study is concerned with the presentation of diagnostic strategies and methods based on vibro-acoustic signals that are able to check the operation of mechanical structures (e.g. internal combustion engines) or to detect faults on test bench during operation. The main goal of this study is to summarize and review the state-of-the art monitoring procedures and diagnostic methods based on vibrational and acoustical signals by the help of literature sources. A further goal is to familiarize the reader with the theoretical background of these procedures and concepts adjusted to the topic. The paper seeks to illustrate the application of each methods through practical examples, so it may be useful for those who wish to understand what kind of fault can be detected by using vibro-acoustic diagnostic systems. Last, but not least, the arose difficulties and limitations associated with use of this methods are mentioned. This paper is focusing principally on some of signal - based methods in time - and frequency domain, such as Fast Fourier Transformation, Short Time Fourier Transformation, orbit portraits, symmetrized dot pattern method and time synchronous average.
GPU based parallel optimization of members of a truck floor
Authors: Nagy Sz. , Jármai K.
Published: June 2021

Grillage - formally lattice - structures are made of longitudinal beams and cross members. Grillages can model vehicle frames, bus floor frames or an entire vehicle. The optimization of the cross members of this structure is shown in this article. The optimization method is a nature-inspired metaheuristic evolutionary method, the flower pollination algorithm. The target function is the total weight and cost of the optimized cross-member. Unknowns are typical cross-sectional dimensions of the cross-member. The design constraints considered are local buckling of web plate and flanges, and fatigue. The calculation was performed assuming the usage of aluminium alloys. In this paper, we propose a possible parallelization method, for computation of base algorithm and one group of fitness functions. The results show, that parallel computations can lead to significant reduction in computational time, if the population size is large and the number of variables are also large.
Probabilistic Uncertainty Analysis of Reliability of Systems with Complex Interconnections
Authors: Pokorádi L.
Published: June 2021

In the present age, modern technical systems, such as vehicles, should have reliability requirements. The sensors and their networks used in modern technical systems can be modelled as a System with Complex Interconnections (SwCI). Most of the real SwCI in the automotive industry are sensory, as Bridge Structure System (BSS). The BSS is widely used as an example in the field of system reliability analysis. The aims of this paper are to apply the True Table Method (TTM) and the Linear Sensitivity Model of System Reliability (LSMoSR), to investigate uncertainties of reliability of BSS in different cases.
The Importance of Virtual Immersion in the Rapid Prototyping of Industrial Products
Authors: Ghinea M. , Deac G.C. , Deac C.N. , Nita F.A.
Published: June 2021

The prototype has played a major role in the design of industrial products since the beginning. The series production was never launched until the designers validated the new product by studying in detail a prototype made identical to the ones that would have come out on the tape. Rapid prototyping, especially through 3D Printing, for small and medium-sized products, managed to improve this design phase by the quality of the prototype obtained and by the short times of its realisation. Recently, virtual immersion tends to replace 3D Printing technology (or work together), the prototype made by this technology offering the designer many more features of the designed product. As a concept, Virtual Reality Aided Design (VRAD) significantly reduces production times, costs and especially allows the rapid modification of the prototype, which is impossible to achieve in 3D Printing. Our article presents the study of a Compressed Air Vehicle (CAV) prototype participating in the international academic competition PNEUMOBILE; it is a study carried out by the UPBAIR team of UPB through virtual immersion. We believe that the study can be extended to the prototyping of any industrial product, adding that our CAV prototype is quite simplistic and quite far from the complexity of a series car.
Design of a measuring system for the testing of pneumatic powertrains
Authors: Szántó Attila , Veszelszki K , Szántó András , Juhász Gy. , Sziki G Á
Published: June 2021

This publication presents a new generation measuring system, designed and constructed for the testing of pneumatic powertrains, at the Faculty of Engineering of the University of Debrecen, as well as its design and assembly process. It also describes test measurements applying the measuring system together with their results. During the test measurements, the pressure in the cylinder and in other parts of the system were measured, as well as the kinematic functions of the piston, during the operation of the powertrain under loaded conditions. Finally, conclusions are drawn, and further development directions are set.
A dynamic model of a pneumobile vehicle
Authors: Szakács Tamás
Published: June 2021

Vehicle dynamics modelling is a tool in the hands of design engineers, that saves time and cost during the development phase. By using the model for simulation, a real vehicle and the measurements made on it can be generated; optimizations can be done with automated algorithms, sensors and measurements can be replaced, and the development process is simplified. However, for this to be feasible, it is necessary to develop a suitable model, that describes reality, with sufficient accuracy. The paper presents a model, suitable for running dynamic simulations of a pneumatically driven vehicle [1], and [2].
Skilful decadal predictions of subpolar North Atlantic SSTs using CMIP model-analogues
Authors: Menary Matthew B , Mignot Juliette , Robson Jon
Published: June 2021

Predicting regional climate variability is a key goal of initialised decadal predictions and the North Atlantic has been a major focus due to its high level of predictability and potential impact on European climate. These predictions often focus on decadal variability in sea surface temperatures (SSTs) in the North Atlantic subpolar gyre (NA SPG). In order to understand the value of initialisation, and justify the high costs of such systems, predictions are routinely measured against technologically simpler benchmarks. Here, we present a new model-analogue benchmark that aims to leverage the latent information in uninitialised climate model simulations to make decadal predictions of NA SPG SSTs. This system searches through more than one hundred thousand simulated years in Coupled Model Intercomparison Project archives and yields skilful predictions in its target region comparable to initialised systems. Analysis of the underlying behaviour of the system suggests the origins of this skill are physically plausible. Such a system can provide a useful benchmark for initialised systems within the NA SPG and also suggests that the limits in initialised decadal prediction skill in this region have not yet been reached.
Establishing sustainable sediment budgets is critical for climate-resilient mega-deltas
Authors: Vasilopoulos G , Quan Q L , Parsons D R , Darby S E , Tri V P D , Hung N N , Haigh I D , Voepel H E , Nicholas A P , Aalto R
Published: June 2021

Many of the world’s major river deltas face a sustainability crisis, as they come under threat of increases in salinity and the extent of tidal zones forced by combinations of sea-level rise, changes in river discharge and channel geometry. The relative contribution of these factors to future increases in tidal extent remains unconstrained, with most prior work emphasising the role of climate-driven sea-level rise. Here we use new field data from the Mekong delta to measure variations of river discharge and changes of channel geometry, and project them into the future. We combine these with projections of future sea-level rise into a 2D hydrodynamic numerical model and quantify the influence of the different driving factors on future tidal extension into the delta. We show that within the next two decades, tidal extension into the Mekong delta will increase by up to 56 km due to channel deepening (92%), dominantly driven by anthropogenic sediment starvation. Furthermore, even under strong mitigation scenarios, sediment starvation still drives a long-term commitment to future tidal extension. Specifically, by 2098 eustatically rising sea-levels are predicted to contribute only modestly to the projected extension. These findings demonstrate the urgent need for policy makers to adopt evidence-based measures to reverse negative sediment budgets that drive tidal extension into sediment starved deltas.
Classification, inference and segmentation of anomalous diffusion with recurrent neural networks
Authors: Argun Aykut , Volpe Giovanni , Bo Stefano
Published: June 2021

Countless systems in biology, physics, and finance undergo diffusive dynamics. Many of these systems, including biomolecules inside cells, active matter systems and foraging animals, exhibit anomalous dynamics where the growth of the mean squared displacement with time follows a power law with an exponent that deviates from 1. When studying time series recording the evolution of these systems, it is crucial to precisely measure the anomalous exponent and confidently identify the mechanisms responsible for anomalous diffusion. These tasks can be overwhelmingly difficult when only few short trajectories are available, a situation that is common in the study of non-equilibrium and living systems. Here, we present a data-driven method to analyze single anomalous diffusion trajectories employing recurrent neural networks, which we name RANDI. We show that our method can successfully infer the anomalous exponent, identify the type of anomalous diffusion process, and segment the trajectories of systems switching between different behaviors. We benchmark our performance against the state-of-the art techniques for the study of single short trajectories that participated in the Anomalous Diffusion (AnDi) challenge. Our method proved to be the most versatile method, being the only one to consistently rank in the top 3 for all tasks proposed in the AnDi challenge.
Research on the Digital Twin Model of Fuchunjiang Hydropower Plant Based on 3D Laser Scanning Technology
Authors: Yu Hongqun , Hou Jinjiao , Xu Hepeng
Published: June 2021

With the development and application of 3D laser scanning technology, the efficiency and accuracy of 3D reverse modeling have been greatly improved. In this paper, 3D laser scanning technology is used to establish the 3D model of the hydropower house and main equipments of Fuchunjiang Hydropower Plant, which can truly restore the internal structure and equipments layout of the power station, and solve the difficulties in realizing the digital power station construction due to incomplete or missing drawings of the old power station. The 3D model of the hydropower house and main equipments of Fuchunjiang Hydropower Plant established in this paper not only forms the valuable virtual assets of the power station, but also lays the foundation for flood control emergency plan simulation and 3D maintenance training of the power station, which has a wide field of application with good prospects.
Microbiorhodopsin a powerful candidate for a photosensitizer of the TiO2-based pollutant degradation system
Authors: Melissa  , Bayaritu  , Yang Yuxia , Liu Kai , Meng Chaoluo
Published: June 2021

Bacteriorhodopsin (BR) is a light driven proton pump firstly found in the membrane of Halobacterium salinarum. Because of its high quantum efficiency, high stability under harsh conditions and many interesting photochemical properties, BR was shown to be able to enhance the performance of TiO2 materials in TiO2-based solar cell, photocatalytic water splitting and photocatalytic degradation of pollutants. However, high cost of the preparation of the BR restricts its industrial application. Although numerous attempts have been made, E. coli-expression system of the BR, which is most economic and fast way to prepare proteins, has not been developed yet. In the present work, we successfully expressed BR homolog, Archaerhodopsin (AR) found in a Halorubrum species by E. coli-expression system. The E. coli expressed AR retained its photoactivity and showed similar photoreaction properties as that of BR. The E. coli expressed AR might be an excellent candidate for a photosensitizer of the TiO2-based solar energy conversion system.
Carbon storage technologies applied to rethinking building construction and carbon emissions
Authors: Chicaiza Cristhian , Bouzerma Myriam , Diéguez-Santana Karel , Chicaiza Ángel , Navarrete Vanessa , Romero José
Published: June 2021

This study has been conducted to offer an insight into the prospect of the building industry decarbonization. The paper aims to analyze the carbon impact of material production, transportation, and construction phases from the construction site perspective in the first section. The focus was on modern alternatives that would allow engineers to include Carbon Capture and Storage (CCS) technologies that could meet the expectations and eventually be a reliable alternative to sustainable economic development. One of the main reasons for climate change is the increasing concentrations of Greenhouse Gases (GHG). There are two ways to reduce the GHG emissions in the atmosphere: first, reducing directly and voluntarily the emissions by stopping polluting activities, second, by capturing and storing the emissions. Among the findings, the first proposed solution was decreasing the reliance on fossil carbon; the second proposed alternative, CCS, is more related to reduce CO2 emissions from energy and other energy-intensive sectors. The formulas and calculations of the Life Cycle Assessment (LCA) were applied in a case study. Technical solutions should be accompanied by legal regulations and policies, socio-cultural considerations. This paper expects to raise the awareness of the readers of the construction sectors related to their GHG emissions participation.
The Effect Analysis Based on Least Square Method on Meteorological Factors to Residential Electricity Consumption in Fujian Province
Authors: Xiaolan Wu , Meina Tang
Published: June 2021

For the purpose of the effect analysis on meteorological factors to residential electricity consumption in Fujian Province, this article used the lowest, highest, and average temperatures and other meteorological factors from January 2019 to June 2019 to process the analysis, building the multiple nonlinear regression. And it also identified the abnormal data from the residual analysis on regression equation coefficients resulting from least square method. Data repair based on the identification was at last applied to testing regression results.
Effects of Light on Callus Multiplication of Actinidia Arguta
Authors: Sui Liyun , Peng Mingchao , Kong Lingling , Que Wenjie , Yuan Hui , Zhang Yong
Published: June 2021

In order to screen out the best culture conditions for the growth of callus of Actinidia arguta, leaf callus and stem callus were used to explore the effect of different light intensity on callus multiplication. The results showed that, light could promote the synthesis of anthocyanins in callus, and low light intensity could keep the callus to maintain a healthy and physiological state with green color and compact structure. In addition, there was a negative correlation between light intensity and callus multiplication, and the stronger the light intensity, the more severe the callus browning. The optimal culture condition for leaf callus multiplication was dark environment, the optimal culture condition for stem callus multiplication was dark environment or 720 Lx light intensity.
Research and Application of Segmentation Unblocking Technology for Horizontal Well Screen
Authors: Shao Yanfeng , Liu Jianfeng , Zhao Zhi , Zhang Zufeng , Zhu Huojun , Dong Yanan
Published: June 2021

Horizontal well screen completion process has its own advantages, but there are also some problems, in which the screen blockage seriously affects its efficacy. However, due to various factors (such as heavy components in crude oil plugging the sand filter), the implementation of conventional pickling and sand washing operations is not ideal. In response to this problem, this paper proposes a new unblocking technology - segmentation unblocking technology for horizontal well screen. Firstly, on the basis of studying principle of the technology, optimization of water jet method and hydraulic sanding nozzle, nitrogen foam water jet experiment and water jet construction displacement experiment are carried out for horizontal well screen, which laying the foundation for application of segmentation unblocking technology. Further, horizontal well screen segmentation unblocking experiment and oilfield application are carried out. Optimization results of water jet method show that, For large displacement construction with still wellhead, whole section construction selects type of inlet liquid through annulus between oil pipe and casing pipe and outlet liquid through oil pipe. For small displacement construction with frequent dynamic wellhead, segmentation construction selects type of inlet liquid through oil pipe and outlet liquid through annulus between oil pipe and casing pipe. Optimization results of hydraulic sanding nozzle show that Streamlined nozzle is better than nozzle with iso variable. Experiment results of horizontal well screen segmentation unblocking show that, segmentation unblocking technology can effectively improve productivity of horizontal well and oilfield application achieved good results. Five wells were shut-in, periodic shut-in or low production before segmentation unblocking. After segmentation unblocking, daily oil increment can reach 23.57 t, and interval cumulative oil increment can reach 4756 t.
Analysis of floating effect of groundwater on built underground structure
Authors: He Luhao , He Zhifeng
Published: June 2021

With the continuous transformation of cities in China, urban land resources are becoming increasingly tense and traffic is becoming increasingly crowded. By building underground buildings such as subways, underground passages and underground shopping malls, we can not only make up for the shortage of existing space, but also rationally plan the urban layout. Therefore, it has become the first choice of urban construction in China. With the diversification of layout forms, the underground structure is increasingly developed in the depth direction, which highlights the anti-floating problem of underground structure. At present, the anti-floating design and construction of underground structures are not clearly defined by regulations in China, only the description of water buoyancy and requirements. In the actual underground structure engineering, the floating problem of underground structure is not uncommon. Therefore, how to design anti-floating measures is studied to ensure the reasonable application of anti-floating measures in the construction process.
Changes in the footprint of grey water from 2005 to 2017 in Fuzhou City
Authors: Cai Xiaohe , Wu Yonghong , Jin Shaofei
Published: June 2021

Based on the concept of grey water footprint, this study quantified the pollutants generated by agricultural, industrial and tertiary industries in Fuzhou City from 2005 to 2017 using the diluted water demands. The results showed: 1) the mean agricultural grey water footprint of Fuzhou City was 15.88×108 m3/a at the study period, which is about 16.69% of the water consumption; 2) among three sectors, grey water footprint in the living sectorsis the largest, and agricultural grey water footprint is the smallest; 3) the grey water footprint of Fuzhou City shows a declining trend from 2005 to 2017, with the agricultural, industrial and living sectors decreasing by 24.92%, 60.78% and 17.11%, respectively; 4) the footprint of Fuzhou City’s grey water showed a downward trend, while the water quality in urban areas also showed a downward trend. The footprint of grey water is greater than the amount of water resources, implying the limited water resources in Fuzhou City can not fully dilute the pollutants for the environmental water quality standards.
Capacity Optimal Configuration of Wind-Hydrogen Low Carbon Energy System
Authors: Cao Jilei , Yuan Tiejiang , Teng Yue
Published: June 2021

Wind power is the most promising renewable energy source, and hydrogen energy is a clean energy carrier. The combination of the two will provide a feasible solution for achieving carbon neutrality. We combine natural gas and carbon capture systems with typical wind-hydrogen coupling systems to improve system economy, and hydrogen power generation is not considered. Oxygen-enriched combustion technology uses the oxygen obtained from hydrogen production to realize the coupling of natural gas and wind energy hydrogen production systems, which improves the efficiency of gas turbines and reduces Energy consumption of carbon capture. Then, with the goal of minimizing the annualized cost including the cost of investment, maintenance, operation and wind curtailment penalty, and taking wind curtailment, carbon capture, gas storage, and power balance as constraints, construct a wind-hydrogen low carbon energy system optimal configuration model. Finally, based on CPLEX to simulate the energy supply system in a certain area, the optimal configuration plan of the system’s wind power, gas storage capacity, electrolytic cell.
Research on assessments of Water-Energy-Food security
Authors: Li Chenxin
Published: June 2021

This article which is based on the analysis of the W-E-F coupling relationship constructs W-E-F security assessment index system and adopts coupling method of entropy method and analytic hierarchy process to define the weights of each index. On the basis of the index system, the article makes an assessment on the security of W-E-F system. Finally, the article takes Inner Mongolia as an example to carry out empirical research on W-E-F system security assessment. This research can provide reference for water resources, energy and food management decision-making.
Sustainable development strategy of beverage straws for environmental load reduction
Authors: Zhou Xi , Yi Cen , Deng Dexiang
Published: June 2021

The destruction of the ecological environment by white pollution is a serious threat to the survival and development of mankind, and the small drinking straws have become the main plastic waste increasing the environmental load due to their huge daily use. In line with the background of the strongest “Plastic bags ban”, plastic drinking straws are completely removed from the shelves, and the sustainable development strategy of drinking straws is explored from many aspects, such as the development of new environmentally friendly material drinking straws, beverage price incentive mechanism, public guidance and brand reputation win-win, policy promotion and market activation.
Antiplatelet therapy with or without anticoagulant therapy for lower extremity peripheral artery disease: A systematic review
Authors: Rahmatian Donna , Barry Arden R
Published: June 2021

Purpose

To identify randomized controlled trials that compared antiplatelet monotherapy to combination antiplatelet plus anticoagulant therapy and evaluated major adverse cardiovascular events (MACE) or major adverse limb events (MALE), death, or bleeding in patients with lower extremity peripheral artery disease (PAD).

A systematic search of MEDLINE, Embase, and CENTRAL databases revealed 5 trials. Two trials consisted of patients with stable PAD, while 3 trials examined patients with PAD post revascularization. Antiplatelet therapy was mostly aspirin (81-325 mg daily), and anticoagulation included rivaroxaban 2.5 mg twice daily or warfarin. Duration of follow-up ranged from 12 to 38 months. Two trials had low risk of bias, whereas 3 trials had high/unclear risk of bias. For patients with stable PAD, one trial showed that use of warfarin (or acenocoumarol) with antiplatelet therapy did not reduce MACE, MALE, or cardiovascular or all-cause death but increased the risk of life-threatening bleeding. A second trial demonstrated that low-dose rivaroxaban plus antiplatelet therapy lowered the risk of MACE and MALE, with no effect in preventing cardiovascular or all-cause death, but increased the risk of major bleeding. For patients with PAD post revascularization receiving warfarin and antiplatelet therapy, 2 trials showed no benefit in MACE or MALE but increased or similar rates of all-cause death and major bleeding. In a third trial, low-dose rivaroxaban plus aspirin reduced occurrence of the composite of MACE and MALE but increased major bleeding, with no effect on cardiovascular or all-cause death.

Conclusion

Dual-pathway inhibition with low-dose rivaroxaban and aspirin reduced MACE and MALE in patients with stable or revascularized PAD, but net clinical benefit is questionable.
‘Surveillance Capitalism, COVID-19 and Social Work’: A Note on Uncertain Future(s)
Authors: Garrett Paul Michael
Published: June 2021

Drawing on Shoshana Zuboff's (2019) The Age of Surveillance Capitalism, along with additional sources not ordinarily referenced in the social work literature, the article examines some of the economic and political imperatives that are driving forward new surveillance practices. The aspiration is to provide conceptual coordinates enabling practitioners, educators and those receiving social work services to arrive at a theoretically expansive sense of what may be occurring across a societal canvas. The focus is on a cluster of five enmeshed themes: first, what Zuboff means by ‘surveillance capitalism’; second, why this form of capitalism has appeared so quickly over the past couple of decades; third, what the tech corporations, such as Google, seek to achieve; fourth, how surveillance capitalists aim to eliminate chance by refining technologies so as to try and constitute us as predictable human subjects; fifth, the trajectory of surveillance capitalist interventions and how they are ‘doubling down’ on the processes of data extraction. Zuboff’s book was completed prior to the COVID-19 global pandemic and, in the latter part of article, it is argued that the current crisis will result in new forms of surveillance becoming socially embedded.
Relief and the Structure of Intentions in Late Palaeolithic Cave Art
Authors: Hughes Fiona
Published: June 2021

Artworks at Lascaux and other late Palaeolithic caves integrate geological features or “relief” of the cave wall in a way that suggests a symbiotic relation between nature and culture. I argue this qualifies as “receptivity to a situation,” which is neither fully active nor merely passive and emerges as a necessary element of the intentions made apparent by such cave art. I argue against prominent interpretations of cave art, including the shamanist account and propose a structural interpretation attentive to particular cases. Seen in this way, cave art displays intentions that are analyzable as having a tripartite structure: mentally directed, embedded in actions and receptive to a situation. Moreover, the latter is the medium through which the other two elements are conjoined. Drawing on a range of archaeological and philosophical resources from both analytical philosophy and phenomenology, I argue that what I call cave art’s “intentional story” is important for the philosophy of intentions more generally.
Effectiveness of integrase strand transfer inhibitor-based regimens in HIV-infected treatment-naive individuals: results from a European multi-cohort study
Authors: Rossetti Barbara , Fabbiani Massimiliano , Di Carlo Domenico , Incardona Francesca , Abecasis Ana , Gomes Perpetua , Geretti Anna Maria , Seguin-Devaux Carole , Garcia Federico , Kaiser Rolf , Modica Sara , Shallvari Adrian , Sönnerborg Anders , Zazzi Maurizio ,   EuResist Network, INTEGRATE study group, Abecasis A , Bobkova M , Seguin-Devaux C , Fabbiani M , Garcia F , Geretti A. M. , Gomes P , Incardona F , Kaiser R , Paredes R , Rossetti B , Sayan M , Sönnerborg A , Vandamme A. M , Zazzi M
Published: June 2021

Background

INSTIs have become a pillar of first-line ART. Real-world data are needed to assess their effectiveness in routine care.

Objectives

We analysed ART-naive patients who started INSTI-based regimens in 2012–19 whose data were collected by INTEGRATE, a European collaborative study including seven national cohorts.

Methods

Kaplan–Meier analyses assessed time to virological failure (VF), defined as one viral load (VL) ≥1000 copies/mL, two consecutive VLs ≥50 copies/mL, or one VL ≥50 copies/mL followed by treatment change after ≥24 weeks of follow-up, and time to INSTIs discontinuation (INSTI-DC) for any reason. Factors associated with VF and INSTI-DC were explored by logistic regression analysis.

Results

Of 2976 regimens started, 1901 (63.9%) contained dolutegravir, 631 (21.2%) elvitegravir and 444 (14.9%) raltegravir. The 1 year estimated probabilities of VF and INSTI-DC were 5.6% (95% CI 4.5–6.7) and 16.2% (95% CI 14.9–17.6), respectively, and were higher for raltegravir versus both elvitegravir and dolutegravir. A baseline VL ≥100 000 copies/mL [adjusted HR (aHR) 2.17, 95% CI 1.55–3.04, P < 0.001] increased the risk of VF, while a pre-treatment CD4 count ≥200 cells/mm3 reduced the risk (aHR 0.52, 95% CI 0.37–0.74, P < 0.001). Predictors of INSTI-DC included use of raltegravir versus dolutegravir (aHR 3.03, 95% CI 2.34–3.92, P < 0.001), use of >3 drugs versus 3 drugs (aHR 2.73, 95% CI 1.55–4.79, P < 0.001) and starting ART following availability of dolutegravir (aHR 0.64, 95% CI 0.48–0.83, P = 0.001). Major INSTI mutations indicative of transmitted drug resistance occurred in 2/1114 (0.2%) individuals.

Conclusions

This large multi-cohort study indicates high effectiveness of elvitegravir- or dolutegravir-based first-line ART in routine practice across Europe.
Incidence of Clostridioides difficile infection (CDI) related to antibiotic prescribing by GP surgeries in Wales
Authors: Tydeman Florence , Craine Noel , Kavanagh Kimberley , Adams Helen , Reynolds Rosy , McClure Victoria , Hughes Harriet , Hickman Matt , Robertson Chris
Published: June 2021

Background

Clostridioides difficile infection (CDI) is a healthcare-acquired infection (HAI) causing significant morbidity and mortality. Welsh CDI rates are high in comparison with those in England and Scotland.

Objectives

This retrospective ecological study used aggregated disease surveillance data to understand the impact of total and high-risk Welsh GP antibiotic prescribing on total and stratified inpatient/non-inpatient CDI incidence.

Methods

All cases of confirmed CDI, during the financial years 2014–15 to 2017–18, were linked to aggregated rates of antibiotic prescribing in their GP surgery and classified as ‘inpatient’, ‘non-inpatient’ or ‘unknown’ by Public Health Wales. Multivariable negative-binomial regression models, comparing CDI incidence with antibiotic prescribing rates, were adjusted for potential confounders: location; age; social deprivation; comorbidities (estimated from prevalence of key health indicators) and proton pump inhibitor (PPI) prescription rates.

Results

There were 4613 confirmed CDI cases, with an incidence (95% CI) of 1.44 (1.40–1.48) per 1000 registered patients. Unadjusted analysis showed that an increased risk of total CDI incidence was associated with higher total antibiotic prescribing [relative risk (RR) (95% CI) = 1.338 (1.170–1.529) per 1000 items per 1000 specific therapeutic group age-sex related GP prescribing units (STAR-PU)] and that high-risk antibiotic classes were positively associated with total CDI incidence. Location, age ≥65 years and diabetes were associated with increased risk of CDI. After adjusting for confounders, prescribing of clindamycin showed a positive association with total CDI incidence [RR (95% CI) = 1.079 (1.001–1.162) log items per 1000 registered patients].

Conclusions

An increased risk of CDI is demonstrated at a primary care practice population level, reflecting their antibiotic prescribing rates, particularly clindamycin, and population demographics.
Adolescents’ Exposure to and Experiences of Weight Stigma During the COVID-19 Pandemic
Authors: Lessard Leah M , Puhl Rebecca M
Published: June 2021

Objective

The COVID-19 pandemic has increased attention to the proliferation of pediatric obesity amidst significant changes in weight-related health functioning (e.g., compromised physical activity, limited food access, increased stress). The present cross-sectional study investigated adolescents’ feelings about their bodies and perceived changes in weight stigma from peers, parents, and social media during the pandemic.

Methods

Four hundred fifty-two adolescents (11–17 years old) completed an online survey during the Fall of 2020. Measures assessed perceived changes in exposure to weight stigmatizing social media content (stress eating jokes, weight gain memes) and experiences of weight stigma (weight-based bullying, teasing, hurtful comments) by parents and peers, as well as body dissatisfaction, during the COVID-19 pandemic. Weight status and gender were examined as individual difference variables.

Results

The majority (53%) of adolescents reported increased exposure to at least one form of weight stigmatizing social media content during the pandemic. Additionally, pandemic-related increases in body dissatisfaction were prevalent (41%), especially among girls with higher body mass index (≥85th percentile; 67%). On average, the extent to which adolescents experienced weight-based mistreatment from parents and peers remained consistent with their pre-pandemic experiences.

Conclusions

Overall, these findings highlight changes in the social messages that adolescents receive about their bodies, as well as their subjective body satisfaction, during the pandemic. Results underscore the need for healthcare providers and mental health professionals to be aware of the potential rise in weight stigma during the pandemic, and encourage families and schools to engage in supportive, rather than stigmatizing, weight-related communication with youth.