bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of surface insulating performance for polytetrafluoroethylene film by atmospheric pressure plasma deposition
Authors: Ren Chengyan , Chen Yikai , Wang Haozhou , Zhang Chuansheng , Zhang Cheng , Shao Tao
Published: May 2023

The surface flashover phenomenon across a vacuum-dielectric interface severely limits the service life and operational reliability of high voltage electrical equipment. Surface modification by atmospheric pressure plasma treatment is a promising method to improve the surface insulating performance of polymers. In order to explore the mechanism of plasma processing on the vacuum flashover characteristics of polymer materials, atmospheric pressure plasma deposition was used to treat polytetrafluoroethylene (PTFE) film. The surface parameters under different processing conditions, such as surface chemical composition, surface resistivity, surface charge decay and trap distribution, were tested and analyzed. The space charge distribution of PTFE and the flashover voltage in vacuum were measured. The results show that Si–O–Si and Si–OH groups are introduced on the surface of PTFE, and the characteristic peaks of PTFE are gradually weakened with the increase of processing time. The surface trap density increases and more traps with lower energy level arise with longer processing time. The plasma deposition changes the space charge distribution in PTFE body, and leads to positive charge accumulation inside the sample. The flashover field strength respectively increases by 15% and 70% in direct current (DC) voltage and microsecond pulse voltage after plasma deposition. The rapid dissipation of surface charge is the main reason for pulse flashover voltage enhancement, while the increase of surface leakage current due to lower surface resistivity and space charge accumulation in PTFE body make the DC flashover voltage reach the saturation point. Therefore the surface insulating and body performance of polymer materials after plasma modification processing should be considered comprehensively based on different applications.
Mach–Zehnder-like interferometry with graphene nanoribbon networks
Authors: Sanz Sofia , Papior Nick , Giedke Géza , Sánchez-Portal Daniel , Brandbyge Mads , Frederiksen Thomas
Published: May 2023

We study theoretically electron interference in a Mach–Zehnder-like geometry formed by four zigzag graphene nanoribbons arranged in parallel pairs, one on top of the other, such that they form intersection angles of 60∘. Depending on the interribbon separation, each intersection can be tuned to act either as an electron beam splitter or as a mirror, enabling tuneable circuitry with interfering pathways. Based on the mean-field Hubbard model and Green’s function techniques, we evaluate the electron transport properties of such eight-terminal devices and identify pairs of terminals that are subject to self-interference. We further show that the scattering matrix formalism in the approximation of independent scattering at the four individual junctions provides accurate results as compared with the Green’s function description, allowing for a simple interpretation of the interference process between two dominant pathways. This enables us to characterize the device sensitivity to phase shifts from an external magnetic flux according to the Aharonov–Bohm effect as well as from small geometric variations in the two path lengths. The proposed devices could find applications as magnetic field sensors and as detectors of phase shifts induced by local scatterers on the different segments, such as adsorbates, impurities or defects. The setup could also be used to create and study quantum entanglement.
Single silicon synaptic device for stochastic binary spike-timing-dependent plasticity
Authors: Lim Doohyeok
Published: May 2023

In this paper, we present a single silicon synaptic device that enables stochastic binary spike-timing-dependent plasticity. The single silicon synaptic device, which is similar to a conventional metal-oxide-semiconductor field-effect transistor structure, is implemented using standard complementary metal-oxide-semiconductor technology. The stochastic nature of the feedback mechanism induced by weak impact ionization is experimentally demonstrated. Because of probabilistic dynamics in the feedback mechanism, the single silicon synaptic device features stochastic binary spike-timing-dependent plasticity.
High surface quality heteroepitaxy α-Ga2O3 film on sapphire by mist-CVD technique
Authors: Li Xiongjie , Niu Pingjuan , Ning Pingfan , Jiang Yong
Published: May 2023

An ultra-flat heteroepitaxy α-Ga2O3 thin film, paved a glory future for device fabrication, was successfully obtained on a c-plane sapphire substrate through the employment of the mist chemical vapor deposition technique. Atomic force microscopy measurements revealed an root mean square (RMS) roughness value of 0.309 nm when the carrier gas flow rate was set at 1500 sccm. Furthermore, the full-width at half maximum of the rocking curve was determined to be 43.2 arcsec, indicating a high level of crystallinity in the heteroepitaxy film. The growth rate was calculated as 13.22 nm min−1 through the use of cross-section scanning electron microscope measurements. Additionally, the bandgap of the transparent film was determined to be 5.10 eV through transmittance spectra analysis. The high quality, wide bandgap heteroepitaxy α-Ga2O3 thin film described in this study represents a significant step forward in the preparation of high power and optoelectronic devices.
Comparative study of multilayered graphene using numerical descriptors through M-polynomial
Authors: M C Shanmukha , A Usha , N S Basavarajappa , K C Shilpa
Published: May 2023

Molecular descriptors play a powerful role in encoding the information of a chemical compound using its molecular structure based on a defined algorithm. Regardless of the evolution in drug design, the main tool used in discovering the lead molecules of a drug refers to the use of topological descriptors. This article focusses on M-polynomial of multilayered graphene, viz., monolayer, bilayer and trilayer. Using the M-polynomial, eleven degree-based topological indices are derived for the said three structures. 3D-plot of the polynomials shows variation among the three types of graphene. The numerical and graphical comparison of the indices for varying values of n are tabulated for better understanding.
The First Photometric and Spectroscopic Studies of ASASSN-V J015428.67+204247.2 and its Relation to the Population of Low Mass Ratio Contact Binaries
Authors: Li Ke-Xin , Li Kai , Liu Fei , Gao Xing , Sun Guo-You , Wang Xi , Yin Shi-Peng
Published: May 2023

We performed photometric, spectroscopic and orbital period investigations of ASASSN-V J015428.67+204247.2 (hereafter, J015428) for the first time. The light curves of VRI bands were obtained. Through the analysis of Wilson–Devinney program, J015428 was found as an A-subtype medium contact binary system with a low-mass ratio (q = 0.129, f = 26.8%). The atmospheric parameters were determined in spectroscopic analysis. In the orbital period investigations, we found that the orbital period of J015428 decreases at the rate of −7.13 × 10−8 day yr−1. And the long-term orbital period decrease is possibly due to angular momentum loss (AML). The absolute parameters was calculated with the photometric solutions and Gaia distance. Through the analyses of mass–radius and mass–luminosity diagrams of 54 contact binaries with the low mass ratios (0.096 ≤ q ≤ 0.15), the evolutionary states of low mass ratio binaries were investigated. The results by analyzing the energy transfer parameter indicated that energy transfer rate was a function of mass and bolometric luminosity ratio. We estimated the initial masses and the densities of two components and the age of the binary. The analysis of the orbital angular momentum supposed that J015428 may evolved from a short-period detached binary by AML. J015428 is in a stable contact stage at present.
Direct observation of the distribution of impurity in phosphorous/boron co-doped Si nanocrystals
Authors: Li 李 Dongke 东珂 , Han 韩 Junnan 俊楠 , Sun 孙 Teng 腾 , Chen 陈 Jiaming 佳明 , Talbot Etienne , Demoulin Rémi , Chen 陈 Wanghua 王华 , Pi 皮 Xiaodong 孝东 , Xu 徐 Jun 骏 , Chen 陈 Kunji 坤基
Published: May 2023

Doping in Si nanocrystals is an interesting topic and directly studying the distribution of dopants in phosphorous/boron co-doping is an important issue facing the scientific community. In this study, atom probe tomography is performed to study the structures and distribution of impurity in phosphorous/boron co-doped Si nanocrystals/SiO2 multilayers. Compared with phosphorous singly doped Si nanocrystals, it is interesting to find that the concentration of phosphorous in co-doped samples can be significantly improved. Theoretical simulation suggests that phosphorous–boron pairs are formed in co-doped Si nanocrystals with the lowest formation energy, which also reduces the formation energy of phosphorous in Si nanocrystals. The results indicate that co-doping can promote the entry of phosphorous impurities into the near-surface and inner sites of Si nanocrystals, which provides an interesting way to regulate the electronic and optical properties of Si nanocrystals such as the observed enhancement of conductivity and sub-band light emission.
Analysis of radiation diffusion of COVID-19 driven by social attributes
Authors: Nian 年 Fuzhong 福忠 , Yang 杨 Xiaochen 晓晨 , Shi 师 Yayong 亚勇
Published: May 2023

This paper first estimated the infectious capacity of COVID-19 based on the time series evolution data of confirmed cases in multiple countries. Then, a method to infer the cross-regional spread speed of COVID-19 was introduced in this paper, which took the gross domestic product (GDP) of each region as one of the factors that affect the spread speed of COVID-19 and studied the relationship between the GDP and the infection density of each region (mainland China, the United States, and EU countries). In addition, the geographic distance between regions was also considered in this method and the effect of geographic distance on the spread speed of COVID-19 was studied. Studies have shown that the probability of mutual infection of these two regions decreases with increasing geographic distance. Therefore, this paper proposed an epidemic disease spread index based on GDP and geographic distance to quantify the spread speed of COVID-19 in a region. The analysis results showed a strong correlation between the epidemic disease spread index in a region and the number of confirmed cases. This finding provides reasonable suggestions for the control of epidemics. Strengthening the control measures in regions with higher epidemic disease spread index can effectively control the spread of epidemics.
Electromagnetically induced transparency via localized surface plasmon mode-assisted hybrid cavity QED
Authors: Li 李 Xiaomiao 晓苗 , Liu 刘 Famin 发民 , Li 李 Zigeng 子更 , Zhu 朱 Hongyan 虹燕 , Wang 王 Fan 帆 , Zhong 钟 Xiaolan 晓岚
Published: May 2023

In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the one-sided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of all-optical switching and optical transistors is limited. Herein, we propose a localized surface plasmon (LSP) mode-assisted cavity QED system which consists of a Λ-shaped three-level quantum emitter (QE), a metal nanoparticle and a one-sided optical cavity with a fully reflected mirror. In this system, the QE coherently couples to the cavity and LSP mode respectively, which is manipulated by the control field. As a result, considerably high and stable switch contrast of 90% can be achievable due to the strong confined field of the LSP mode and perfect absorption of the optical medium. In addition, we obtain a power dependent effect between the control field and the transmitted frequency as a result of the converted dark state. We employ the Heisenberg–Langevin equation and numerical master equation formalisms to explain high switching, controllable output light and the dark state. Our system introduces an effective method to improve the performance of optical switches based on the one-sided system in quantum information storage and quantum communication.
Identifying ADHD boys by very-low frequency prefrontal fNIRS fluctuations during a rhythmic mental arithmetic task
Authors: Ortuño-Miró Sergio , Molina-Rodríguez Sergio , Belmonte Carlos , Ibañez-Ballesteros Joaquín
Published: May 2023

Objective. Computer-aided diagnosis of attention-deficit/hyperactivity disorder (ADHD) aims to provide useful adjunctive indicators to support more accurate and cost-effective clinical decisions. Deep- and machine-learning (ML) techniques are increasingly used to identify neuroimaging-based features for objective assessment of ADHD. Despite promising results in diagnostic prediction, substantial barriers still hamper the translation of the research into daily clinic. Few studies have focused on functional near-infrared spectroscopy (fNIRS) data to discriminate ADHD condition at the individual level. This work aims to develop an fNIRS-based methodological approach for effective identification of ADHD boys via technically feasible and explainable methods. Approach. fNIRS signals recorded from superficial and deep tissue layers of the forehead were collected from 15 clinically referred ADHD boys (average age 11.9 years) and 15 non-ADHD controls during the execution of a rhythmic mental arithmetic task. Synchronization measures in the time-frequency plane were computed to find frequency-specific oscillatory patterns maximally representative of the ADHD or control group. Time series distance-based features were fed into four popular ML linear models (support vector machine, logistic regression (LR), discriminant analysis and naïve Bayes) for binary classification. A ‘sequential forward floating selection’ wrapper algorithm was adapted to pick out the most discriminative features. Classifiers performance was evaluated through five-fold and leave-one-out cross-validation (CV) and statistical significance by non-parametric resampling procedures. Main results. LR and linear discriminant analysis achieved accuracy, sensitivity and specificity scores of near 100% (p <.001) for both CV schemes when trained with only three key wrapper-selected features, arising from surface and deep oscillatory components of very low frequency. Significance. We provide preliminary evidence that very-low frequency fNIRS fluctuations induced/modulated by a rhythmic mental task accurately differentiate ADHD boys from non-ADHD controls, outperforming other similar studies. The proposed approach holds promise for finding functional biomarkers reliable and interpretable enough to inform clinical practice.
Study on KIC of TC4-DT titanium alloy electron beam welding
Authors: Xianglin Ye , Yuchun Feng , Jiawen Wang , Linyun Shang
Published: May 2023

With the development and application of TC4-DT titanium alloy and electron beam welding, the research on fatigue crack growth of its joints is very important in engineering. In this paper, the relevant fracture mechanics and crack growth theory are proposed for the fatigue crack growth of TC4-DT titanium alloy electron beam welded joints, and the experimental and finite element method simulation crack growth research is carried out. The results show that: during the fatigue crack test, with the continuous increase of the cycle period, the crack growth rate in different regions increases significantly, among which the growth rate of the weld zone is higher, and the crack propagation path in the weld zone is almost completely along the weld zone. The direction of the axis of symmetry of the center of the crack propagates linearly, and the crack propagation in the base metal area basically expands along the straight line but slightly deviates to the upper base metal area. By calculating the stress intensity factor of different preset crack lengths through simulation, it is found that within the allowable error range, with the increase of the prefabricated crack length, the stress intensity factor k1 of the specimen increases gradually.
Numerical analysis of fuel regression rate and flow field in solid fuel ramjet with the gas generator
Authors: Lu Xuancheng , Zhou Changsheng , Wang Luhao , Zhu Min
Published: May 2023

In this paper, to improve the combustion characteristics and working performance of the solid fuel ramjet, a solid fuel ramjet with a gas generator is proposed. Based on k − ω SST and Eddy-Dissipation equations, the turbulent combustion model is established, and the internal flow field of the ramjet, as well as the regression rate, and species, were numerically analyzed. The results show that the temperature of the ramjet and the regression rate with a gas generator is increased. When the airflow is 0.4kg/s, the increase of the gas generator flow will lead to a more obvious regression rate increase, and the maximum value will increase by 33%. When the airflow is 0.6kg/s, the regression rate with the gas generator is evenly distributed along the axis. The flame with a gas generator makes the head burn more completely, the combustion chamber temperature increases, and the average regression rate of solid fuel increases by 14%.
Fatigue life prediction of aircraft gun cabin structure under impact
Authors: Ding Zhenhao , Wang Ke
Published: May 2023

The aircraft gun firing will cause serious impact on airframe structure. According to the gun firing principle, the muzzle blast wave is simulated by chemical explosion. ALE method is used to deal with the fluid-structure interaction between high-pressure flowing air and the surface of the cabin. Then the expression model of the impact load is established. The numerical calculation is completed to analyse the dynamic response of the cabin structure under the impact load. The parameters of load and cabin model are modified by using the experiment results. Comparing the calculated dynamic response with the experiment results, the error is within acceptable range. Multiaxial stress equivalence and rain-flow counting method are used to process the simulation impact response data to estimate the impact fatigue life. In conclusion, the paper provides a feasible method for analysing dynamic response and fatigue life of gun cabin structure.
Prediction model of GEO spacecraft position after maneuver based on causal Bayesian network
Authors: Long X , Yang L P , Chen S Y , Xu S
Published: May 2023

Predicting the position of Geosynchronous (GEO) spacecraft under maneuver is a crucial work for space domain awareness (SDA) as it can help to improve the flexibility and operational efficiency of space surveillance network (SSN). The longitude is a unique freely assigned parameter for GEO spacecraft, in this paper, a predictive model of GEO spacecraft longitude based on causal Bayesian network is proposed. Firstly, the causal parameters of longitude is found by Gaussian perturbation equation. Secondly, the Markov order of the causal parameters is obtained by transfer entropy. Finally, the linear expressions for Gaussian functions is proved and a causal Bayesian network (CBN) prediction model for longitude is constructed. After experimental analysis, the mean absolute error (MAE) and mean square error (MSE) of the proposed method are decreased by 71.88% and 72.18%, respectively compared with the traditional Long short-term memory (LSTM) method.
Adaptive attitude control of UAV based on neural network compensation
Authors: Li Yihang , Lei Zhongkui , Guo Yueru , Chen Kuiyu , Jin Jie , Yang Yixin
Published: May 2023

Aiming at the problem of unmanned aerial vehicle (UAV) attitude control with insufficient robustness and anti-disturbance, this paper proposes a UAV attitude control method combining incremental nonlinear dynamic inverse (INDI) and neural network (NN) adaptive compensation. Firstly, the attitude model of UAV with time scale separation is proposed. On this basis, the INDI control law is derived, and the angular acceleration information required by INDI method is feedback by the filter. Then, the adaptive NN compensation structure is introduced to eliminate the uncertainty caused by model mismatch, sensor delay and external disturbance. Finally, the UAV simulation is carried out. The result shows that this method improves robustness and anti-disturbance of original INDI method without changing structure and parameters of controller, and has a certain adaptive compensation ability for system uncertainty.
Efficiency analysis of intercepting UAV swarm by various air defense methods
Authors: Hu S G , Ru L , Lu B , Wang W F
Published: May 2023

In order to accurately intercept incoming swarm targets and improve interception efficiency, the interception efficiency of various air defense equipment was studied. The paper introduces the current ways to deal with the UAV swarm, and establishes the mathematical model of different types of interception equipment; Under the premise of given interception probability, the time and cost of different interception methods are calculated respectively, and the weight distribution is used to analyze the interception efficiency of different weapons. According to the analysis process and results, the interception effectiveness of different weapons is sorted. The analysis results show that the analysis has certain practicability, which can support the development and application of air defense interception weapons and equipment to a certain extent, and has practical reference value and significance.
Thermal design and analysis of JZJ-5 CubeSat
Authors: Zhou Yudong , Zhang Xiang , Xu Chang , Yang Xudong
Published: May 2023

JZJ-5 is a 3U commercial CubeSat contracted by Nanjing University of Science and Technology. This paper first introduces the thermal control design of the CubeSat, then calculates the temperature field in the high and low temperature conditions by using the finite element method, and finally compares the measured temperature data in orbit with the thermal simulation data. The data results show that the temperature state of the CubeSat in orbit meets the requirements of thermal design, and the thermal control design scheme and simulation model are reasonable.
Experimental research on effect of zonal heating airfoil about boundary layer flow and heat transfer
Authors: Dong Meijuan , Sang Weimin , Yang Guangjun , Jiang Feng
Published: May 2023

The anti-icing of aircraft and large wind turbines, where the wall temperature is higher than the fluid temperature, can significantly alter the flow evolution characteristics of the boundary layer. Local heating strategies for the manifold state need to be designed based on the changing characteristics of the flow velocity and temperature field in order to precisely control the heat supply and reduce inefficient energy consumption. In order to obtain accurate heat transfer characteristics of the airfoil’s boundary layer flow, it is necessary to refine the measurement of the boundary layer characteristics during flow and heat transfer. In this paper, wind tunnel experiments are carried out on the NACA2412 model with full surface’s zonal electric heating. The wall surface is equipped with a built-in heater and the temperature of the wall surface is obtained through the corresponding temperature sensor. By studying layer characteristics of the four heated regions, namely the laminar flow region near leading edge, the laminar flow destabilisation region, the transition region and the fully turbulent flow region, and comparing them with the boundary layer characteristics of the unheated airfoil, the effects of the presence of heat sources in different regions on the stability of the flow field and the spatial heat transfer pattern are revealed. The results show that heating in the laminar and turbulent zones maintains the stability of the flow field to a greater extent and achieves better heat transfer strength, while heating in the unstable zone brings forward the turbulence and heating in the fully turbulent zone intensifies the flow separation at the trailing edge of the airfoil. This study can be used as a reference for the design of efficient anti-icing systems on full wing surfaces.
Multivariable steady-state control of variable cycle engine based on LQG/LTR
Authors: Dong Yunhui , Guo Yingqing , He Jiale , Guo Pengfei , Zhao Wanli
Published: May 2023

In order to improve the steady-state control performance of variable cycle engine, a steady-state multivariable control method based on LQG/LTR is proposed in this paper. The working characteristics and control laws of variable cycle engine are analyzed, and the linearized model of engine design point is obtained by system identification. Based on the LQG/LTR control method and the linear model, a multivariable steady-state controller for the variable cycle engine is designed. Through simulation verification and comparison with the control performance of the three-loop univariate PI controller, it is concluded that the multivariable LQG/LTR controller has excellent disturbance suppression and command tracking ability, and has a wider application range and better control effect than PI controller.
Aerodynamic design of wind turbine blade with second derivative of thickness distribution as constraint
Authors: Xu Jianhua , Zhang Shiqiang , Song Wenping , Han Zhonghua , Zhou Shaojun , Li Xinlong
Published: May 2023

In order to make more use of wind energy, large-scale wind turbine blade size is the trend of development. With the increasing of blade length, the design and manufacture of the structure with the requirements of safety and economy are faced with great challenges. It is most sensitive to the blade manufacturer to reduce the composite lamination and production cost as long as the stress and strain level of the structure is satisfied. Therefore, the ideal thickness distribution requires not only the thickness monotonically decrease along the radial direction, but also the concavity and convexity of the thickness distribution function are required to be constant. Based on the in-house design code SurroOpt and the momentum-blade theory method, an optimization design platform for wind turbine blades was established. A 400kW wind turbine blade design was carried out with the aim of maximizing the output power and the constraint of the second derivative of the thickness distribution. The results show that the concave-convex characteristic of thickness distribution function has not changed, which is beneficial to the structural design. The designed blades have been manufactured and installed for operation. For the whole device, the maximum coefficient of wind energy utilization (including the loss of motor and machinery) reaches 0.42, which is 2.4% higher than 0.41 of the same kind of products.
Study of dynamic load identification under unknown initial conditions
Authors: Chen Shuang , Jiang Jinhui
Published: May 2023

Dynamic load identification belongs to the second inverse problem of structural dynamics, i.e. the inversion of the load history in the real state by collecting the measured data of structural vibration. Some traditional dynamic load identification methods do not consider the initial conditions, i.e. the initial conditions of the structure are assumed to be zero, however, the structure is not always at rest during the process of collecting the vibration response, which leads to a large error between the identified force and the actual force using traditional methods. Since the measurement of initial conditions is very difficult, in order to solve the influence brought by the initial conditions to the dynamic load identification process, this paper proposes a method based on sparse regularization to identify the load history under unknown initial conditions. Firstly, the unknown force is represented using basis functions, and the vibration response of the structure is divided into two parts: forced vibration caused by the force and free vibration under the initial conditions, and finally sparse regularization is used to solve the ill-conditioned equation. The experimental and simulation results also further verify the applicability and robustness of the method proposed in this paper in dealing with the load identification problem under unknown initial conditions.
Dynamic simulation of nozzle structure based on thermal-fluid-solid coupling analysis
Authors: Jia-hui Yuan , Ke Wang , Xiu-cong Gu
Published: May 2023

Many engineering structures are subjected to the combined action of thermal field, flow field and vibration load during use. The mechanical analysis of this kind of structure has important theoretical significance and engineering practical value. However, due to the complexity of multi-field coupling, it is difficult to analyze dynamic response and dynamic strength. A method to simplify the thermal-fluid-solid coupling model for specific engineering issues was proposed aiming at modeling the actual situation in which the high temperature field of the engine nozzle structure is relatively stable. Heated grid reconstruction, thermal modal analysis technology, and fluid-structure coupling response calculation method based on modal superposition were taken to obtain the load distribution and dynamic response level of the engine nozzle structure under the condition of thermal-fluid-solid coupling, which created conditions for structural dynamic strength evaluation including the prediction of vibration fatigue life. The test structure of an engine nozzle was taken as an example to perform dynamic response calculation and fatigue life prediction under thermal fluid-solid coupling conditions. Then the location of weak parts of the structure was identified, and effective suggestions for design improvement was put forward. Compared with the actual test results, the feasibility and accuracy of the method are preliminarily verified.
A use-case-driven approach for demonstrating the added value of digitalisation in wind energy
Authors: Barber S , Sempreviva A M , Sheng S , Farren D , Zappalá D
Published: May 2023

Digitalisation is one of the key drivers for reducing the costs and risks of wind energy. When considering whether to embark on a digitalisation initiative, two key questions arise. The first is what business or operational opportunities might feasibly be addressed and the second is which of the many potential aspects of digitalisation are relevant to those opportunities. In this work, we show how these questions can be answered with a use-case-driven approach, based around a survey aiming to collect and collate the main ”pain points” (or everyday challenges) of people in the wind energy sector. Although the relatively low number of participants of the survey (46) means that the results should only be used indicatively, it is still possible to make some general recommendations for priorities for digitalisation efforts in the wind energy sector. Firstly, digitalisation efforts should focus both on supporting people carrying out cross-lifecycle tasks, in particular sharing data, managing data, undertaking general data analyses and accessing data. Tools to do this should deal with varying data formats and naming conventions, make metadata more accessible, define data and metadata standards, make more data publicly available and improve the quality of data. Secondly, efforts should also focus on supporting people in the wind farm operational phase, in particular with failure detection, fault diagnosis, failure rate modelling and predictive maintenance. Solutions to do this should focus on accessible and validated tools for fault detection, cloud or other data pipeline solutions for SCADA data and tools for exhaustive data documentation. Finally, digitalisation efforts should focus on better communicating and helping people become aware of existing solutions and tools, as well as on helping people to exert a stronger influence on possible solutions.
Development of an aerodynamic measurement system for wind turbines
Authors: Fredebohm Malte , Theron Johannes N. , Höning Leo , Weis Sanaz , Stoevesandt Bernhard , Wegner Anna , Denecke Nora , Rosemann Heiko , Huhn Matthias Leonhard
Published: May 2023

In this paper an aerodynamic measurement system is presented that can be installed as a retrofit on virtually any onshore turbine. The aerodynamic measurement system consists of pressure sensors embedded in thin glass-fiber shells, which are glued to the rotor blades. Additionally, an aerodynamic probe is attached to outboard side the shells with a thin flange. In this study the system was installed on an 8 MW offshore prototype turbine located in Bremerhaven. It was mounted at two sections of one of the rotor blades with 72 pressure sensors in total (18 sensors each on the pressure side and suction side, respectively). Additionally, at each section an aerodynamic probe with 5 sensors was installed in front of the leading edge to measure inflow speed and direction. Results were compared to CFD simulations.
Wind tunnel test of airfoil with erosion and leading edge protection
Authors: Bak C , Olsen A S , Forsting A M , Bjerge M H , Handberg M E , Shkalov H
Published: May 2023

This paper describes wind tunnel tests of a NACA 633 – 418 airfoil with erosion and leading edge protection. Measurements are carried out at high Reynolds number (Re = 5 million) representing modern wind turbines. Three examples of deviations from the perfect airfoil surface are shown. It is seen how the presence of a roughness mesh degrades the aerodynamics and that the presence of the mesh is more important than the actual topology of the mesh. That is also the case for the stall strips where a small strip influences the performance slightly less than a big stall strip, but the presence of the stall strip alone is influencing the performance significantly. Finally, a simulated leading edge protection (LEP), represented by a sheet of paper, can influence the performance significantly as the paper leads to a backward facing step. Furthermore, the measurements showed that correct mounting of LEP is important to avoid too big losses in aerodynamic performance. Investigating the impact of reduced airfoil performance for the rotor performance showed losses in annual energy production of between 0.3% and 4.0%. All in all the wind tunnel tests reflected that leading edge damages have a significant impact on the aerodynamic performance.
Design, construction and commissioning of the PandaX-30T liquid xenon management system
Authors: Wang Xiuli , Lei Zhuoqun , Ju Yonglin , Liu Jianglai , Zhou Ning , Chen Yu , Wang Zhou , Cui Xiangyi , Meng Yue , Zhao Li
Published: May 2023

The PandaX-30T is a proposed next-generation experiment to
study dark matter and neutrinos using a dual-phase time projection
chamber with ∼ 30 tons of liquid xenon. An innovative xenon
handling subsystem of the PandaX-30T, the First-X, is described in
this paper. The First-X is developed to handle liquid xenon safely
and efficiently, including liquefying and long-term storing xenon
without losses or contamination, and transferring cryogenic liquid
xenon between the storage module and the detector safely and
effectively without venting out. The storage module of the First-X
is five specially designed double-walled cylindrical vessels (Center
Tanks) equipped with three heat exchangers each for pressure and
temperature regulation. Each Center Tank is designed with a vacuum
and multi-layer insulation and a maximum allowable working pressure
of 7.1 MPa, allowing 6 tons of xenon to be stored at 165–178 K at
0.1–0.2 MPa in the liquid phase or up to 300 K and up to
6.95 MPa in the supercritical phase. High-pressure storage
(> 0.2 MPa) only occurs in case of long-term detector shutdown or
lack of nitrogen, ensuring no-loss storage of 6 tons of xenon in the
range 178–300 K. In this paper, the thermophysical performances of
the First-X and innovative scenario to conduct non-vented cryogen
transportation were experimentally conducted and reported using
liquid argon. The non-vented cryogenic liquid filling and
pump-assisted cryogenic liquid recovery have been conducted with
liquid argon at a mass flow rate of 1390 kg/h, corresponding to a
xenon mass flow rate of 2140 kg/h. Compared with the PandaX-4T, the
transportation of xenon between the detector and the storage module
is conducted in the liquid phase rather than in the gaseous phase,
and the filling rate (fill the detector) and the recovery rate
(recover xenon from the detector) are increased by approximately 50
times and 30 times, respectively.
Population and damage intensity of the yellow rice stem borer and its natural enemies in the jajar legowo rice planting system
Authors: Sholahuddin S , Wijayanti R , Supriyadi S , Sulistya A , Subagiya S , Haq A
Published: May 2023

Jajar legowo (Jarwo) is a rice planting system that is widely practiced by farmers, but information regarding its effects on pests and natural enemies is limited. This study aimed to identify how the Jarwo planting system affects the population and damage intensity of the yellow rice stem borer (Scirpophaga incertulas) and its predators. The research was conducted in Wonosari-Klaten, Central Java, during the dry season of 2020. The Jarwo 2:1 planting system was used in this study. The variables of the research were population of S. incertulas, its damage intensity, and its natural enemies. Observations by field inspection were carried out every week from 14 to 94 days after transplanting (DAT). The results showed that the population of egg clusters and damage intensity of the rice stem borer in the Jarwo planting system were lower than in the conventional planting system (control plot). However, this planting system did not affect the kinds of predators and parasitoids. The predators found were generalists, which were dominated by spiders, namely Atypena sp. (Araneae), Araneus sp. (Araneae), Lycosa sp. (Araneae), Plexippus sp. (Araneae), and Oxyopes sp. (Araneae), Paederus sp. (Coleoptera) was recorded as predatory insects. Meanwhile, the main egg parasitoid found was Telenomus sp. (Hymenoptera) with 31.2% parasitization.
Water availability identification of underground river in the Gunung Sewu karst area using inverse model
Authors: Daffaedra A H , Mawandha H G , Ersavan F , Setyawan C , Kesuma L M , Wijayanti Y
Published: May 2023

The karst area is identified in the Gunung Kidul Regency, the so-called Gunung Sewu karst area, as one of the Geopark areas in Indonesia. Gunungkidul Regency has had moderate to high yearly rainfall for the last ten years. However, this region has a problem with a surface water shortage. It is due to the characteristics of the karst, which allows rainwater to penetrate the geological layers accumulating in the certain noose yielding abundant underground water reserves. The purpose of this study is to assess the underground river water availability and the hydrological characteristics in the karst region using Inverse Modeling. Inverse Modeling is a method to identify the features of the underground river by adjusting the hydrological variables as an input and output discharge as a control. The FJ Mock Model as a surface hydrological model is used to characterize the Karst region’s underground river. There were five models in total to be simulated. The conditions under the Mock model show consistent results compared to the stepwise model in terms of low discharge conditions; Coefficient Correlation, RMSE, and R2 values obtain 0.637, 17.29, and 0.407, respectively. In this case, estimating the low flow conditions is more accurate than the high-rate flow conditions. The results are closer to the stepwise model without the infiltration variable involved.
Stakeholder engagement in irrigation water management: the case of Karanganyar Regency, Indonesia
Authors: Suminar Lintang , Werdiningtyas Ratri , Kusumastuti  , Rahayu Paramita
Published: May 2023

The increasing level of water demand leads to higher pressure in the water irrigation system due to environmental degradation in watersheds and irrigation canals. Irrigation water management requires the involvement of stakeholders, including the government and farmers, as the water user association. Stakeholders are expected to be able to carry out their respective roles and be engaged in solving problems of proper irrigation water management. This paper uses a qualitative approach to stakeholders’ roles, challenges, and opportunities in irrigation water management in Karanganyar Regency. It aims to understand stakeholder engagement in irrigation water management. The data were collected by observation and interviews with stakeholders such as national irrigation commissions, provinces, local governments, and water user associations. The results show that there has been a clear division of roles and responsibilities among the stakeholders included in the irrigation commission. However, it is found that there is an asynchronous regulation in implementing irrigation water management at the national, provincial, and local levels. The lack of human resources is another obstacle faced in irrigation water management in Karanganyar Regency.
Connecting student to the ecology: content knowledge for conservation education in Indonesia
Authors: Karyanto P , Oetomo D , Nuri TSK , Fudolla U , Hidayat N , Lhota S
Published: May 2023

One of the keys to meaningful environmental and conservation education depends on the design of appropriate content knowledge, enhancing the ecological literacy of the student. Here, we scrutinize essential content knowledge and develop subject-specific pedagogy for teaching ecology regarding high school conservation education. We stood on the qualitative research by employing the R & D methods according to the ADDIE design. We employed inductive techniques to gain essential ecological concepts and principles from related references. We identified fourteen ecological concepts and principles, namely population and community properties, biological interaction, keystone species, species with a large impact, energy flows, biogeochemical cycle, conservation ecology, diversity index measurement, factors affecting distribution and abundance, the linkage between genetic diversity and population persistency, fragmentation and population size, diversity and community stability, carrying capacity, and ecological succession as important content in ecology that is essential for conservation education. We developed the subject-specific pedagogy for teaching ecology and gained an effective result during its implementation on both the cognitive aspects and the behavioral intention. Our results clearly imply the importance of knowledge of essential concepts and principles in ecology in engendering sympathy towards nature and conservation.
Effect of mulching on soil loss and total N through erosion during upland rice planting season on latosol
Authors: Arifien Y , Sinurat J , Susdiyanti T
Published: May 2023

Erosion is a natural phenomenon in the form of erosion of the upper soil surface by the movement of water, therefore soil conservation actions are carried out, one of which is the provision of organic matter. This research was conducted on the Kemang Bogor latosol with a soil slope of 7, 9 and 14 percent which was given organic material in the form of mulch as much as 3 tons/ha and 6 tons/ha which was spread evenly over the soil surface, and included and mixed evenly into the soil. The results showed that the application of mulch and slope had a significant effect on soil loss and total N through erosion. Giving mulch can suppress erosion and spread over the soil surface more effectively. Applying mulch to soils with a slope of 7 and 9 percent can suppress erosion which can still be allowed, while on soils with a slope of 14 percent, it should be as much as 6 tons/ha.
The dynamic linkage among carbon emissions, energy consumption, and economic sustainability in the Asia Pacific
Authors: Rahmayani D , Sugiharti R R , Rahman Y A , Vikia Y M
Published: May 2023

Environmental degradation is caused by the high level of energy use, which becomes a major problem in the world. This research will investigate how energy consumption, economic growth, and population affect carbon emissions in the Asia Pacific region, with data from 15 countries spanning the 1988-2021 period. The energy consumption was measured by how much oil and coal were used. The research used panel Autoregressive Distributed Lag (ARDL) models to study carbon emissions, oil consumption, coal consumption, economic growth, and population. The study found that growth in coal consumption, oil consumption, and population has a positive significant effect on carbon emissions in the long term. Conversely, economic growth has a significant negative impact. Meanwhile, in the short term, both coal consumption and economic growth have a positive impact on increasing carbon emissions. The results of this study support the hypothesis that there is an Environmental Kuznets Curve (EKC). This paper suggests that increasing green investment and shifting from fossil-based to eco-friendly sectors would be beneficial. Second, the resilience of economic growth is important. The third way to preserve the environment is to control the rate of population growth.
Nature-Based solutions for landslide risk reduction: a critcal review of academic literature
Authors: Dewi Rika Kurnia , Wijayanti Pipit
Published: May 2023

Landslides are a widespread natural hazard that threatens the built and natural environment and increases the areas of deforestation. Landslides have an impact on human life, the impact can be reduced by reducing the risk of landslides, reducing the risk of landslides aims to reduce the number of people affected, deaths and economic losses. Forests and vegetation can provide a protective function against landslides consisting of hydrological and soil conditions, such as soil moisture, water infiltration, and others. This ability of vegetation is called nature based solutions. The 46 studies selected for this landslide nature-based solution were analyzed with a focus on an in-depth literature review. The articles were analyzed with three focus reviews, namely: 1) types of landslides, 2) solutions regarding landslide mitigation, and 3) landslide risks. The types of landslides discussed in this article are 73% shallow landslide types, 22% landslide types rotation and 5% flow landslide type. The risk in this article regarding hazards/threats is discussed at 57%, exposure around 21% and vulnerability around 22%. Landslide risk reduction solutions in the articles reviewed, as many as 44% discussed nature-based solutions, 30% about other solutions, and 30% there were no solutions in reducing landslide risk. In the publication of 46 articles, nature-based solution approaches that are widely mentioned are environmental engineering, soil bioengineering and protected forests. The nature-based solution in this research shows that vegetation is the main solution in disaster mitigation measures.
Assessment of cultivation techniques and agroforestry systems on cinnamon (case study in Jaya Village, Tidore Island)
Authors: Salatalohy A. , Ryadin A.R.
Published: May 2023

The cultivation technique attempts to modify the growing environment to be suitable for plant growth to achieve maximum and sustainable yields. At the same time, agroforestry design aims to improve the existing system by providing food agriculture directions based on physical, economic, and socio-cultural conditions. The method of the established system relates to pre-diagnosis and diagnostic activities that aim to find problems that exist in the system, followed by technological intervention to improve the system and determine the best agroforestry system in critical land conditions. The descriptive method was used in this research by identifying existing agroforestry systems. This study found three agroforestry systems: agrisilviculture, silvopasture, and agrosilvopasture. Cropping patterns generally use a randomly mixed. Cultivation techniques are still not optimal because they still rely on traditional gardens. Land suitability evaluation shows that, in general, the land suitability assessment for woody plants and annual crops is categorized as moderately suitable (S2). Agroforestry design on land cinnamon-based agroforestry is recommended for woody plant species; non-MPT species are more adaptable if grown on ridges; MPTs and annual crops are more directed at slopes and valleys, while secondary crops are better planted in the valleys.