bluuebunny/crossref_metadata_2025 huggingface dataset:
A Closed Stockyard UAV Intelligent Inventory System
Authors: Qiu Ziyi , Lin Defu , Lv Junning , Sun Zhiwen , Zheng Zhangxiong
Published: June 2023

Strategic resources affect national development and security at all times. Actual utilization of strategic resources is crucial. In recent years, strategic resources such as coal and mineral powder usually need to be stored in closed stockyards after mining due to environmental protection, concealment, and other reasons. The existing stockpiling inventory system cannot autonomously complete the stockpiling inventory in the closed stockyard with low risk, low cost, and high precision. Therefore, this paper proposes a closed stockyard UAV intelligent inventory system. Our inventory system comprises a UAV system, a visual mapping system, and a classification and volume calculation system. In this paper, we focus on the navigation system belonging to the UAV system and propose a GNSS-denied environment navigation system based on lidar and ArUco markers. We conduct experiments in the dry coal shed of thermal power plants, one of the application scenarios. After analysis and comparison, it can be concluded that our intelligent UAV stockpiling inventory system can complete the task with high robustness and high precision with the assistance of our navigation system.
PyCaNet: Pose Estimation of Primary and Middle School Students Using Pyramid Convolutions and Coordinate Attention
Authors: Yi Weike , Chen Ling , Wu Liangdong
Published: June 2023

2D pose estimation task is the basics of action recognition, human-computer interaction and other applications, but there is few research on pose estimation of primary and middle school students. In this paper, we present APMSS: a new dataset based on primary and middle school scenarios. The dataset fills the gap of the current human pose estimation dataset with few campus scenes, and the human keypoints and object bounding boxes in the dataset are manually annotated. In addition, we propose PyCaNet: a new top-down human pose estimation neural network model that uses pyramid convolutions to give the network a larger receptive field for better results. Coordinate attention is also added to the network, which is a kind of channel attention and can significantly improve the network performance. Extensive experiments shows that PyCaNet outperforms the previous methods by at least 1.0 AP on APMSS val and at least 0.7 PCKh on MPII test.
A method of laser stripe centerline extraction based on deep learning for structured light 3D reconstruction
Authors: Huang Ming , Xu Xiao
Published: June 2023

To overcome the stray light noise in the centerline extraction method during line structured light 3D reconstruction process, an end-to-end trainable neural network for laser stripe centerline extraction based on Convolutional Neural Network and Multi-Layer Perception is proposed. The proposed network can self-adapt to a variety of lighting (brightness) conditions and overcome the interference of different stray lights. In addition, unlike prior work on enhancing the accuracy of centerline extraction using deep learning methods that only performs it for noise reduction in pre-processing, the proposed network unifies the noise reduction and prediction processes, so that it can be optimized end-to-end directly on centerline extraction performance. The network learns an intermediate feature representation of noise reduction, which requires less complexity for data annotation, reduces the training difficulty, and has more scalability. Experiments show that the proposed method can perform centerline extraction with relatively high accuracy for laser stripes of different widths, brightness, and inclination, thus obtaining a smooth and stable reconstructed surface in the structured light 3D reconstruction process.
Deep Wyner-Ziv Decoding Using Auxiliary Hierarchical Features
Authors: Zhou Junwei , Yi Xiangbo
Published: June 2023

Wyner-Ziv (WZ) video coding shifts the burden of complex calculations from the encoder to the decoder, making it suitable for video coding scenarios with limited resources. Motivated by deep learning has shown superior performance over traditional methods, this paper proposes deep WZ video coding with the help of auxiliary hierarchical features in the decoder. It uses an autoencoder to encode WZ frames. In the decoder side, an inter-frame correlation model called SI-Net is employed to enhance WZ frame quality with Key frames. The auxiliary hierarchical features are extracted from Key frames through multi-level downsampling and employed in autoencoder to optimize feature extraction, avoiding gradient disappearance caused by deep networks. Since the auxiliary hierarchical features of Key frames describe spatial information and expand the network’s perception of video frame features, a high-quality WZ frame reconstructed can be obtained. Compared with previous work, our method shows obvious superiority on four video datasets with different degrees of motion.
Global Path Link Prediction Method Based on Improved Resource Allocation
Authors: Wang Yu , Ming Liu
Published: June 2023

Link prediction is a basic method to study complex networks, which has important practical application value. This paper proposes a global path link prediction method based on resource allocation for complex network topology information. Firstly, we improve the current quantization method of node resource transmission capability, and then consider the global path information in the network structure comprehensively. Finally, the link prediction method is defined based on the quantized resource transmission capability and global path information. Compared with 11 classical similarity algorithms, the experimental results show that the link prediction accuracy of this method has been improved to some extent, among which the highest improvement is 22.85%.
Fault detection and fault tole rant control of interturn short circuit of double redundancy motor
Authors: Jin Tianbao , Tian Wei , Zhao Wenxiang
Published: June 2023

This paper presents the robust detection of interturn short circuit fault of double redundant permanent magnet synchronous motor. In the static coordinate system and double dq-axis system, the mathematical model of the fault state is established. Further, the residual signal of the dq-axis current caused by the turn-to-turn short circuit fault is predicted using the Luenberger observer. Next, the fault marker and the fault phase marker are obtained by processing the current residual signal. Finally, the processor performs the excision of the faulty phases and hardware reconfiguration, thus allowing fault-tolerant operation of the motor. The simulation results show the effectiveness of the detection and fault tolerance of double redundant permanent magnet synchronous motor.
A comprehensive evaluation method for economic collaborative planning evaluation of main distribution network based on rough set and scale extension method
Authors: Zhang Xiao , Zheng Chenghao , Su Lingdong
Published: June 2023

The urban 35kV substation is the link between the main network and the distribution network, and the economic power supply and site selection optimization are the keys to the coordinated planning of the main network and the distribution network. A comprehensive evaluation system is established for collaborative economic planning of the main distribution network from three aspects: social benefit, construction economy, and operation economy, and the combination of scale expansion method and rough set method is applied to determine the combined weight of indicators. Based on this index system, a comprehensive evaluation model for economic coordination planning of an intelligent main distribution network is established. It is applied to the economic effect evaluation of the main distribution network planning of a power supply company and the optimal location selection of substations. The results show that the proposed method is a new evaluation method for power grid collaborative planning. Under the premise of ensuring the economy and reliability of power supply, the collaborative planning level of the main distribution network has been significantly improved, and the planning results are better than the traditional site selection results. It not only expands the evaluation system for coordinated planning of the main network and distribution network but also provides guidance for the planning and construction of the main distribution network.
Joint Planning of CSP and New Energy Based on Bi-Level Programming Model
Authors: Chen Xiangdong , Zuo Peng , Yu Xuan , Wan Zhendong , Ren Ziyuan
Published: June 2023

As a flexible unit that can respond quickly, CSP stations can be included in the planned power source of power supply planning, which can effectively improve the consumption of volatile new energy and improve resource utilization. This paper mainly studies the optimal planning of power grids containing CSP stations and fluctuating new energy sources and proposes joint power planning based on the bi-level programming model. The results of calculation examples show that the proposed bi-level programming model considering CSP stations is better in terms of economy, efficiency, and practicality and is of great importance to the improvement in the cleanliness of system operation and energy utilization.
Effect of Synthetic Jet Actuator with Different Pulse Waveforms on Fan Blade Lift
Authors: Xu Junjie , Tang Changjun , Chang Jianlong
Published: June 2023

The lift of wind turbine blades is a significant factor influencing the working efficiency of wind turbines. The influence of synthetic jet actuator on the lift of fan blades is studied in this manuscript. The influence of different pulse waveforms (sine wave, square wave and triangle wave) and different action positions (airfoil front end and rudder front end) on fan blades is analyzed. It is found that when the synthetic jet actuator acts on the airfoil front end, the best lift effect on the fan blade exists in the square wave. While when acting on the front end of the rudder, the best lift effect on the fan blade appears in the triangle wave. When two positions are acted on by the synthetic jet actuator at the same time, the square wave is the best relative to the other two pulse forms. At the same time, the effects of three pulse forms on the surface vortex of airfoil are studied, the flow conditions of the three waveforms are investigated when the airfoil is in a steady state of flow. The vortices formed by square waves can better adhere to the airfoil, while the vortex formed by the triangle wave can be separated from the airfoil faster.
Photovoltaic MPPT Control Strategy Based on Improved Conductance Increment Method
Authors: Liu Xiao Dong
Published: June 2023

In this research, a new incremental conductance approach with variable step size is suggested in order to address the inadequacies of the conventional incremental conductance method in tracking accuracy and dynamic reaction speed. In this paper, an absolute value of dP / (dV – dI) is used as the change in step size, and the step size of the tracking process is dynamically adjusted using the exponential function as the adjustment coefficient to reduce the maximum power point’s tracking duration. Finally, on the Matlab platform, a simulation system was created. According to the simulation findings, the suggested approach has less steady-state oscillations and can track the maximum power point more quickly than the conventional conductance increment method, which increases the efficiency of solar power generation.
Research on Improved Control Technology of Power Converter in DC Grid System
Authors: Hu Jinhao , Zhang Kun
Published: June 2023

With the development of distributed clean energy, the DC grid system begins to highlight its advantages. Based on the virtual motor theory, the control strategy of a DC power converter is proposed. The DC side adopts the virtual DC motor control to enhance the system’s inertia and damping and improve the stability of the DC grid system. Then, the power converter in the DC grid system is designed, and the mathematical model of virtual motor control is established. Finally, for a typical DC grid system, the simulation results using software verify the correctness and effectiveness of the proposed technical path of DC power grid, providing a new technology roadmap for the research of DC power grid and power converter.
Speed Sensorless Control of Doubly Salient Machine Based on Improved Pulsating High-Frequency Injection
Authors: Chen Chao
Published: June 2023

In traditional pulsating high-frequency injection (PHFVI), the PI regulator is usually used to extract rotor position information of the machine. The PI regulator has some shortcomings, such as poor tracking performance and weak anti-interference ability. Thus a new full-order state observer is proposed to extract rotor position information in this paper. This method firstly uses the PHFVI to get the rotor position error signal and then establishes a full-order state observer according to the mechanical motion equation of the machine to estimate the rotor position and speed. This paper introduces a new coordinate transformation to further decouple the mathematical model of the double salient machine (DSM). The results of simulation in MATLAB/Simulink show that the method proposed in this paper has effectiveness and anti-interference performance and has a certain reference value for the research of speed sensorless control of DSM.
Research on the Effect and Dynamics of Calcium Oxide on Pyrolysis Behavior of Medium and Low-Rank Coal
Authors: Liu Shuanglin
Published: June 2023

With a self-developed laboratory pyrolysis device, the effects of the materials particle size on the yield of Jinjie coal and lime co-pyrolysis products and gas components were investigated. The results shows that the raw material particle size has a significant effect on the coal pyrolysis process. With the decrease of raw material particle size, the tar yield in the pyrolysis product decreases, while the pyrolysis gas yield increases, and the H2 content in the pyrolysis gas increases. As the same time, the temperature distribution and volatiles precipitation rate of materials with different particle sizes were measured, and the macro-reaction kinetic parameters of the co-pyrolysis of coal and lime have been obtained.
Short-term Wind Power Prediction Method Based on Genetic Algorithm Optimized XGBoost Regression Model
Authors: Li Xiangcheng , Wang Jialong , Geng Zhirui , Jin Yang , Xu Jiawei
Published: June 2023

In order to solve the problem of accuracy and rapidity of short-term prediction of wind power output, the eXtreme Gradient Boosting (XGBoost) regression model is used in this paper to predict wind power output. For the models commonly used at the present stage, such as Long Short Term Memory (LSTM), random forest and ordinary XGBoost model, the modelling time is long, and the accuracy is not enough. In this paper, a genetic algorithm (GA) is introduced to improve the accuracy and speed of prediction of the XGBoost regression model. Firstly, the learning rate of the XGBoost model is optimized by using the good searching ability and flexibility of the genetic algorithm. Then variable weight combination prediction is carried out. The objective function for this problem is the mean square error that occurs between the value that is predicted and the value that actually occurs in the training set. GA is responsible for determining the model’s final weight. The historical output data of the wind plant is used in this paper to verify the XGBoost regression model based on a genetic algorithm and get the predicted value, which is then compared with the prediction results of LSTM and random forest algorithm. Example simulation and analysis show that the XGBoost regression model optimized by the genetic algorithm can be more significantly in solving the accuracy and rapidity of the prediction of short-term wind power output.
Design of 2.45-GHz High-Efficiency Miniaturized Power Oscillator Using GaN HEMT
Authors: Guo Qingyu , Lu Yifeng , Mao Chaowu , Zhou Jianyang
Published: June 2023

This study presents a method for designing a highly efficient miniaturized power oscillator with gallium nitride high electron mobility transistor (GaN HEMT). A harmonic-tuning highly efficient power amplifier (PA) using GaN HEMT is designed firstly by finding optimal fundamental, 2nd and 3rd harmonic load impedances. After the performance of PA meets the requirements, the feedback circuit that is made of a hairpin resonator and a coupler is studied based on the power gain of PA and the required frequency. Both the size of the PA and the feedback circuit should be taken into account to minimize the oscillator at last. Finally, the PA and feedback circuit are combined into a power oscillator. Through this way, the highly efficient miniaturized power oscillator with a size of 2.7*4.9 cm2 fabricated on substrate of FR4 outputs 37.7 dBm power and 72% efficiency at 2.4518 GHz under the bias condition of Vgs = - 3.21V, Vds = 28V, Ids = 25mA.
A Method for Calculating Aggregate Flexibility Parameters of Virtual Power Plant Based on Improved Column and Constraint Generation Algorithm
Authors: He Yongsheng , Xie Yanbin , Cheng Chao , Liu Baoshan , Xiao Qiang , Fan Xuan , Liang Huishi , Gong Xiaoxu
Published: June 2023

The virtual power plant (VPP) can aggregate massive, dispersed, and heterogeneous distributed energy resources (DERs) and provide an effective energy management way for an active distribution system (ADS). In this paper, three parameters of upper and lower limits of active power output, ramping, and discharging energy is used to describe the aggregate flexibility of VPP. Based on this, a two-stage robust optimization (RO) model with dispatch instructions (DI) from the superior power grid (SPG) as uncertainty variables was constructed. Considering that the range of DI from the SPG changes during the iteration of the column and constraint generation (C&CG) algorithm, a position set is proposed to record the boundary information of the uncertain set of DI issued by the SPG when the sub-problem (SP) finds the worst scenario in each iteration, and the corresponding constraints are added to the master problem (MP). For the solution of SP, the bilevel max-min model is firstly transformed into a single-level bilinear programming (BLP) model by the duality theory and then solved by the concave-convex process (CCP) iterative method. Compared with transforming the BLP problem to a mixed integer programming (MILP) problem based on Karush-Kuhn-Tucker (KKT) condition, it can not only meet the engineering accuracy but also greatly save the solution time. Finally, the effectiveness of the proposed model and algorithm was verified on a modified IEEE 33-bus system.
Transmission Line External Breakage Early Warning Method Based on Electric Field Perception
Authors: Tang HaiTao , Li MengXuan , Zhao ZhenQiang , Ma Xiao , Li YuWen , Yang Zhi , Yu JinDong
Published: June 2023

To prevent construction machinery from intruding into the transmission corridor during operation and causing damage to the normal operation of the line, this paper uses the relationship between the horizontal distance of the boom measurement point at the minimum safe distance, the angle of the boom to the ground and the field strength as a comprehensive criterion to carry out an early warning of the transmission line breaking. The method studied in this paper can provide a simple and accurate distance warning method for various types of construction machinery when they work in the vicinity of different types of transmission lines.
Optimization of short-term wind power prediction of Multi-kernel Extreme Learning Machine based on Sparrow Search Algorithm
Authors: Wang Fan , Gao Guige
Published: June 2023

Aiming at the problem that the single kernel function of kernel extreme learning machine (KELM) cannot adapt to the variable actual wind power. This paper proposes a modified prediction model which can increase the accuracy of prediction. The prediction model uses multiple kernel functions instead of a single kernel function and optimizes the kernel parameters by using a sparrow search algorithm (SSA). Finally, through the simulation and comparison experiments, the proposed prediction model has better prediction accuracy than the conventional prediction model.
The novel XYU-GEM to resolve ambiguities
Authors: Flöthner K.J. , Brunbauer F. , Ferry S. , Garcia F. , Janssens D. , Ketzer B. , Lisowska M. , Muller H. , de Oliveira R. , Oliveri E. , Orlandini G. , Pfeiffer D. , Ropelewski L. , Samarati J. , Sauli F. , Scharenberg L. , van Stenis M. , Utrobicic A. , Veenhof R.
Published: June 2023

Removing ambiguities within a single stage becomes crucial when one can not use multiple
detectors behind each other to resolve them which naturally is the case for neutral radiation. An
example would be RICH detectors. Commonly, pixilated readout is choosen for this
purpose. However, this causes a remarkable increase in quantity of channels. Thus, the overall
costs of the detector would increase. Therefore, the XYU-GEM was proposed as a three coordinate
strip-readout which is combined with a triple GEM detector. The readout complements a common XY
readout with an additional projection which is tilted by 45°. The overdetermination due to three
projections can be used to resovle ambiguities. Following the detector design will be explained,
first measurements discussed to understand the response of the detector and a way to change the
charge sharing without changing the manufacturing parameters of the readout.
Design of a compact Thomson Parabola Spectrometer for diagnostics of proton-boron fusion reaction products initiated by laser
Authors: Kurmanova A. , Petringa G. , Catalano R. , Cirrone G.A.P.
Published: June 2023

The proton-boron aneutronic fusion reaction has numerous potential applications varying
from controlled nuclear fusion reactor to broad-energy spectrum α-particle source, as well
as uses in medicine, where it can serve as a source for radioisotope production, or directly in
proton boron capture therapy. However, proton-boron fusion reaction and its by-products should be
investigated extensively to provide a stable and controlled secondary ion source. In order to
monitor the multi-ion beam emitted and accelerated from the target surface after interaction with
laser pulses, a new Thomson Parabola Spectrometer (TPS) has been designed to differentiate proton
and alpha traces in the energy ranges 0.5–5 MeV and 1–10 MeV respectively,
with a high energy resolution (≤ 1%), while maintaining compactness of the spectrometer
(∼ 20 cm).
The construction and characterization of MgO transmission dynodes
Authors: Chan H.W. , Prodanović V. , Theulings A.M.M.G. , Tao S. , Smedley J. , Hagen C.W. , Sarro P.M. , Graaf H.v.d.
Published: June 2023

In this work we demonstrate that ultra-thin (5 and 15 nm) MgO transmission dynodes
with sufficient high transmission electron yield (TEY) can be constructed. These
transmission dynodes act as electron amplification stages in a novel vacuum electron multiplier:
the Timed Photon Counter. The ultra-thin membranes with a diameter of 30 μm are arranged in
a square 64-by-64-array. The TEY was determined with a scanning electron microscope using primary
electrons with primary energies of 0.75–5 keV. The method allows a TEY map of the surface
to be made while simultaneously imaging the surface. The TEY of individual membranes can be
extracted from the TEY map. An averaged maximum TEY of 4.6±0.2 was achieved by using
1.35 keV primary electrons on a TiN/MgO bi-layer membrane with a layer thickness of 2 and
5 nm, respectively. The TiN/MgO membrane with a layer thickness of 2 and 15 nm,
respectively, has a maximum TEY of 3.3±0.1 (2.35 keV). Furthermore, the effect of the
electric field strength on transmission (secondary) electron emission was investigated by placing
the emission surface of a transmission dynode in close proximity to a planar collector. By
increasing the electric potential between the transmission dynode and the collector, from
-50 V to -100 V, the averaged maximum TEY improved from 4.6±0.2 to 5.0±0.3
at a primary energy of 1.35 keV with an upper limit of 5.5 on one of the membranes.
The Economic Value of Forest Environmental Services for Mitigating Human-Wildlife Conflict in the Village Around Management Section of National Park (MNSP) VI Besitang, Gunung Leuser National Park
Authors: Sulistiyono N , Marsudi S , Ahda M , Asmanijar W , Tobing G L , Zahirah A
Published: June 2023

Human-wildlife conflicts is a serious problem that has been increasing in recent times. Conflict occurs as a result of high human activities around wildlife habitats. Conflict mitigation aims to reduce the problem of human conflict with wildlife. The valuation of forest environmental services was based on the quantitative value generated by natural resources and the environment, regardless of the market value of these goods and services. This study aims to determine the community’s willingness to pay (WTP) for forest environmental services in mitigating human-wildlife conflicts in Besitang, Langkat, North Sumatera. The study found five variables that affect the respondent’s WTP for environmental services to mitigate human-wildlife conflicts, there are monthly income, community perception of forest protection and conservation, community behavior utilizing forest products, community behavior in forest protection efforts, and community behavior in efforts to improve forest function. Utilizing the Contingent Valuation Method (CVM) as methodology, this study revealed the value of Rp.78,290/household/year contributes to paying for forest environmental services with a total WTP value of Rp. 739,992,105/year.
The properties of hardness and swelling of styrene butadiene rubber/silica/oleamide composites
Authors: Surya I , Anto J , Marpongahtun
Published: June 2023

This paper reports the results of the effects of oleamide addition on hardness, as one of the mechanical behaviours, of styrene butadiene rubber/silica (SBR/silica) composite. The base SBR was compounded with silica, as a reinforcing filler, and others compounding chemicals. The silica was compounded into the rubber matrix at 30 phr and others compounding chemicals were added based on the semi-efficient rubber compounding formulation. The compounding has been done using opened two-roll mills. Oleamide was added to the SBR/silica to improve the rubber-to-filler interaction and the mechanical properties of the SBR/silica composite. The oleamide was a lab-synthesizing chemical and was added into the SBR/silica with 4 different concentrations (2, 4, 6 and 8 phr). The SBR/silica compounds with and without oleamide were vulcanized at 150 °C using a typical cure meter. From the results; it was noticed that the hardness of the SBR/Si composite was increased as the oleamide was added to the SBR/Si compound. It was considered that the hardness improvement was attributed to the result of crosslinks improvement of the NR/silica/oleamide composites. The additions of the oleamide convert the rubber composites into more resistance to swelling. A greater degree of crosslinks would increase the swelling rejection/resistance but decrease the interpenetration of the toluene solution to the rubber composites. The oleamide acted as an additive which improved the properties of swelling and hardness of the SBR/Si mixtures/compounds and, a 2 phr of oleamide addition was the optimum concentration for the SBR/Si compound.
An Adaptive Reuse Development Through Highest and Best Use Assessment: Case Study the Ex-Warenhuis, Medan, Indonesia
Authors: Fitri I , Siregar F , Silvana  , Ariffin N F M , Ginting R , Indira S S
Published: June 2023

The ex-Warenhuis, built in 1919, is one of the remained heritage buildings in the city center of Medan, North Sumatra, Indonesia. It has been abandoned for years and experiencing deterioration; therefore, Medan Municipality Government is conducting an investigation and planning to adapt and reuse the building. The study aims to find opportunities and new functions which able to enhance the economic value of the building by carrying out a field survey to collect the data. Noteworthy that it considers creating new functions while advancing social development and environmental sustainability. In addition, the adaptation of this building continues to prioritize the aspects of authenticity and the principle of minimal intervention. This study performs the highest and best use assessment which consists of five stages, namely 1) Location Analysis, 2) Market Analysis, 3) Combination of stages 1 and 2, 4) Financial Eligibility, and 5) Best Alternative Recommendation to obtain new alternative functions that are following market trends and locations. The result of the highest and best uses analysis highlights the highest and best use as an adaptation of the ex-Warenhuis function as a commercial building consisting of multi purposes such as hall, retail, working space, restaurant, café, gallery.
Characterization and Antioxidant Activity of Phaleria macrocarpa (Scheff.) Boerl Leaf Ethanol Extract
Authors: Lestari I C , Lindarto D , Ilyas S , Widyawati T , Mustofa  , Jusuf N K , Hasibuan P A Z , Siahaan L
Published: June 2023

The leaves of Phaleria macrocarpa (Scheff.) Boerl is traditionally used to treat various diseases. Phaleria macrocarpa leaves contain flavonoids, alkaloids, tannins, glycosides, saponins, and steroids. This study aimed to identify the simplicia and extract, as well as the ethanol extract’s antioxidant activity, from Phaleria macrocarpa leaves. The extract was quantitatively tested using UV-Visible Spectrophotometry for its total phenol and flavonoid content. The DPPH IC50 test determined the antioxidant capacity. The simplicia characterization revealed a water content of 6.68 %, a water-soluble extract of 19.28 %, an ethanol-soluble extract of 19.31 %, a total ash content of 12.27 %, and an acid-insoluble ash content of 4.84 %. The ethanol extract’s characterization revealed a water content of 17.29 %, total ash content of 4.48 %, and acid insoluble ash content of 0.63 %. The flavonoid content was 55.08 mgGAE/g extracts, and the phenol level was 76.96 mgGAE/g extracts. The results of the DPPH test indicated that the ethanol extract of the leaves of Phaleria macrocarpa had a high potential for antioxidant activity, with an IC50 value of 73.91 ppm.
A review of the contribution of smoke management systems in building design by CFD analysis
Authors: Sotiriadis J V , Kontoleon K J
Published: June 2023

As it is broadly known smoke is the major cause of casualties in the event of fire incidents in buildings. Accordingly, the majority of fire related-deaths are not caused by fire flames, but by inhaling smoke. Apart from that, as fire-generated gases exceed a certain level, lower visibility can be attained. Aiming to break this vicious cycle between building design and fire safety, smoke management systems underline a fruitful way to tackle this problem. Within this framework, this work focuses on a thorough presentation of smoke control systems in building design. In an effort to assess the significance of such kinds of systems, as well as to justify their contribution from a quotative point of view, highly sophisticated numerical approaches are mostly adopted. In this context, CFD techniques illustrate a rational way to enhance the arrangement of buildings in terms of fire safety (risk assessment). In a nutshell, this paper discusses the main conclusions of earlier research in this important area of study.
Energy saving in industrial buildings using advanced concentrated solar thermal systems
Authors: Androutsopoulos A , Drosou V , Christodoulaki R , Rovira A J , Enríquez J , Abbas R , Reay D
Published: June 2023

Saving energy in industrial buildings is one of the ten pillars of the European Green Deal. The application of renewable energy technologies in industrial processes and their buildings is an appropriate way to support the European energy goals. The paper presents an innovative solar heating method for industrial buildings that focuses on overcoming the current limitations of these systems. The method is based on the modular and flexible integration of two innovative technologies for the solar collector (SunDial technology – parabolic collectors) and thermal energy storage (based on phase change materials, PCM) which, through a control system, allow flexible operation to maintain continuous use against the unpredictable nature of the solar source and partly even during the night. The method can cover a significant percentage of the heat demand in industrial processes that use temperatures above 150°C. At the same time, there is the possibility of meeting cooling needs using an absorption chiller.

The work describes the technologies of centralized solar collectors and the connection, operation, control and monitoring systems as well as the possibilities of covering thermal and cooling loads in an industrial building. This technology can be applied to both commercial and residential buildings. The purpose of this application is to contribute to the reduction of the requirements for heating and cooling in industrial buildings of the European Union which is estimated at approximately 72TWh per year.
Performance assessment of the ecosystem services provided by urban Nature-based solutions: focus on rainwater management
Authors: Valois L , Brachet A , Schiopu N , Barot S
Published: June 2023

Nature-based solutions (NBS) in cities are known to provide numerous ecosystem services that contribute to the well-being of city inhabitants and to climate change attenuation and adaptation. Common services provided by the NBS are urban heat island reduction, provision of habitat for biodiversity, rainwater management, indoor summer comfort, etc. To provide science-based arguments for the choice of the adapted solutions to a specific context, the assessment of those services is necessary. The aim of this paper is to review models assessing the service of rainwater management for three green infrastructures: green roofs, urban trees (stand-alone or micro-forest) and vegetated permeable pavements. The final goal of this work is to help improve the decision aid tools for the environmental assessment of the performance of buildings and districts. The characteristics of each model are presented and analyzed, in terms of robustness, parsimony and operationality. We for example compared the number of required parameters (e.g., plant species, substrate type and depth of green roofs, soil moisture, etc.), the availability of these parameters, etc. The multifunctionality of NBS (i.e., other services provided beyond the contribution to the rainwater management) is also considered in the analysis. In addition, as NBS are living systems, their specific needs (such as water and mineral nutrients), as well as the influence of the local context (e.g., climatic, topographic, cultural) are discussed. Finally, some paths for the implementation of the models into the decision tools are highlighted. The main challenge for the implementation in decision tools could be the harmonization between different expertises and stakes.
Applying EU Level(s) framework indicators to improve circularity: A case study
Authors: Honic M , De Wolf C
Published: June 2023

The construction industry is the main consumer of raw materials and simultaneously responsible for 36% of solid waste in the EU, wherefore the implementation of a circular economy in the industry is urgently needed. The European Commission developed the Level(s) framework to help measure the environmental impact and improve the circularity of buildings. Yet applying the framework’s indicators with the provided templates is a challenging task due to the comprehensive nature and size of EU documents and the lack of clarity on how to use the templates. This paper applies Indicators 2.1 (Bill of quantities, materials, and lifespans) and 2.2 (Construction and demolition waste and materials) to a case study to provide a better understanding of using them in practice. The findings will help actors throughout the whole value chain to implement required information into their building models for assessing and improving circularity in their buildings.
Investigation of thermal properties of pykrete
Authors: Bošnjak J , Bodrožić Ćoko N , Jurčević M , Primorac I , Nižetić S
Published: June 2023

Experimental investigation of the thermal properties of ice reinforced with sawdust is presented in this paper. Mechanical properties of pykrete are fairly covered in literature, while there are no data about its thermal properties. For the purposes of this examination, ice made of 215 ml of tap water was reinforced by adding 35 g of sawdust. Transient Plane Source (TPS) method was employed to measure the thermal conductivity and thermal diffusivity in a temperature range from -15 °C to -33 °C. Blocks of pykrete were placed in an expanded polystyrene (EPS) box in the freezer where the measurements took place. Thermal conductivity of pykrete was observed to vary from 1.64 Wm−1K−1 at -15 °C to 1.75 Wm−1K−1 at -33 °C while thermal diffusivity in the same temperature interval exhibited growth at a larger scale, from 0.88 mm2s−1 to 1.10 mm2s−1. Measured values showed an average decrease of approx. 21% in thermal conductivity and approx. 23% in thermal diffusivity when compared with results obtained for frozen pure tap water. Measured thermal constants were shown to be similar to the ones obtained in literature for concrete.
Data driven economic scenarios for retrofitting residential buildings in a northern Italian region
Authors: Cecconi Fulvio Re , Rampini Luca
Published: June 2023

European directives and strategies, such as the ‘European Green Deal’ and the ‘Ren-ovation Wave’, point out the importance of the building sector in achieving the climate goals set by the European Union for 2050. However, a higher renovation rate for the existing buildings is required to achieve these goals. Many barriers prevent the renovation rate from growing. Regarding financial barriers, the long payback times of renovation interventions and the high risk perceived by the potential investors make the renovation rate remain low. Based on data from energy performance certificates, this research proposes a data-driven method to create economic retrofit scenarios for residential buildings using Artificial Intelligence techniques and Monte Carlo simulations. Namely, energy savings have been predicted using an Artificial Neural Network on clusters of residential buildings and the Life Cycle Costs forecasted by Monte Carlo simulations taking into account the uncertainty in many of the inputs. Results obtained by applying the method to a region in northern Italy illustrate two scenarios for the energy retrofit of the built environment, one assuming a payback time of fifteen years and the other of twenty-five years. In both cases, the maximum allowable investment, which varies according to the specific characteristics of the buildings, is much lower than the retrofit costs recorded in the same area in recent years.
Microgravity facilities for cold atom experiments
Authors: Raudonis Matthias , Roura Albert , Meister Matthias , Lotz Christoph , Overmeyer Ludger , Herrmann Sven , Gierse Andreas , Lämmerzahl Claus , Bigelow Nicholas P , Lachmann Maike , Piest Baptist , Gaaloul Naceur , Rasel Ernst M , Schubert Christian , Herr Waldemar , Deppner Christian , Ahlers Holger , Ertmer Wolfgang , R Williams Jason , Lundblad Nathan , Wörner Lisa
Published: June 2023

Microgravity platforms enable cold atom research beyond experiments in typical laboratories by removing restrictions due to the gravitational acceleration or compensation techniques. While research in space allows for undisturbed experimentation, technological readiness, availability and accessibility present challenges for experimental operation. In this work we focus on the main capabilities and unique features of ground-based microgravity facilities for cold atom research. A selection of current and future scientific opportunities and their high demands on the microgravity environment are presented, and some relevant ground-based facilities are discussed and compared. Specifically, we point out the applicable free fall times, repetition rates, stability and payload capabilities, as well as programmatic and operational aspects of these facilities. These are contrasted with the requirements of various cold atom experiments. Besides being an accelerator for technology development, ground-based microgravity facilities allow fundamental and applied research with the additional benefit of enabling hands-on access to the experiment for modifications and adjustments.
Graph test of controllability in qubit arrays: a systematic way to determine the minimum number of external controls
Authors: Gago-Encinas Fernando , Leibscher Monika , Koch Christiane P
Published: June 2023

The ability to implement any desired quantum logic gate on a quantum processing unit is equivalent to evolution-operator controllability of the qubits. Conversely, controllability analysis can be used to minimize the resources, i.e. the number of external controls and qubit–qubit couplings, required for universal quantum computing. Standard controllability analysis, consisting in the construction of the dynamical Lie algebra, is, however, impractical already for a comparatively small number of qubits. Here, we show how to leverage an alternative approach, based on a graph representation of the Hamiltonian, to determine controllability of arrays of coupled qubits. We provide a complete computational framework and exemplify it for arrays of five qubits, inspired by the ibmq_quito architecture. We find that the number of controls can be reduced from five to one for complex qubit–qubit couplings and to two for standard qubit–qubit couplings.
Effect of TiC particle size on physical, mechanical and tribological properties of Cu-TiC metal matrix composites
Authors: Agrawal J P , Gupta Nitin Kumar , Somani Nalin
Published: June 2023

This research article aims to produce a metal matrix composite (MMC) material consisting of Cu-20%TiC using the powder metallurgy route, followed by sintering. The study provides insight into the impact of different TiC particle sizes on the physical, mechanical, and wear properties of the MMC. The surface morphology of the samples was analyzed using scanning electron microscopy, while Vickers hardness and tensile tests were employed to determine mechanical properties. Additionally, sliding wear tests and frictional tests were performed to assess tribological properties. The results show that varying the particle size of the reinforcement material significantly affects physical, mechanical, and tribological properties. Larger TiC particle sizes yielded better mechanical properties due to reduced interfacial area for load transformation and higher stress concentration endurance, but better wear and anti-frictional properties were observed for better-dispersed larger particles. SEM micrographs indicated homogeneous distribution of metal matrix particles. The worn surface was smoother for larger particle sizes, and abrasive wear was the dominant wear mechanism. Results were similar for TiC particles with average sizes of 45 μm and 60 μm. The sample having particle sizes of 45 μm has shown the best results with relative density of 96.92%, micro-hardness of 168.09 Hv, and tensile strength of 369.24 MPa. The wear rate was reduced by 21%–28%, and the frictional coefficient was reduced by 24%–50% for a particle size of 45 μm compared to a particle size of 15 μm.
Stasis in heterogeneous networks of coupled oscillators: discontinuous transition with hysteresis
Authors: Sahoo Samir , Prasad Awadhesh , Ramaswamy Ramakrishna
Published: June 2023

We consider a heterogeneous ensemble of dynamical systems in

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that individually are either attracted to fixed points (and are termed inactive) or to limit cycles (in which case they are termed active). These distinct states are separated by bifurcations that are controlled by a single parameter. Upon coupling them globally, we find a discontinuous transition to global inactivity (or stasis) when the proportion of inactive components in the ensemble exceeds a threshold: there is a first–order phase transition from a globally oscillatory state to global oscillation death. There is hysteresis associated with these phase transitions. Numerical results for a representative system are supported by analysis using a system-reduction technique and different dynamical regimes can be rationalised through the corresponding bifurcation diagrams of the reduced set of equations.
Aerosol formation during foam application of non-volatile biocidal substances
Authors: Schwarz Katharina , Blümlein Katharina , Göen Thomas , Hahn Stefan , Hebisch Ralph , Koch Wolfgang , Poppek Ulrich , Schäferhenrich Anja , Schlüter Urs , Krug Monika
Published: June 2023

The application of biocidal products by foam is considered an alternative to droplet spraying when disinfecting surfaces or fighting infestations. Inhalation exposure to aerosols containing the biocidal substances cannot be ruled out during foaming. In contrast to droplet spraying, very little is known about aerosol source strength during foaming. In this study, the formation of inhalable aerosols was quantified according to the aerosol release fractions of the active substance. The aerosol release fraction is defined as the mass of active substance transferred into inhalable airborne particles during foaming, normalised to the total amount of active substance released through the foam nozzle. Aerosol release fractions were measured in control chamber experiments where common foaming technologies were operated according to their typical conditions of use. These investigations include foams generated mechanically by actively mixing air with a foaming liquid as well as systems that use a blowing agent for foam formation. The values of the aerosol release fraction ranged from 3.4 × 10−6 to 5.7 × 10−3 (average values). For foaming processes based on mixing air and the foaming liquid, the release fractions could be correlated to the process and foam parameters such as foam exit velocity, nozzle dimensions, and foam expansion ratio.