bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the Role of Anions in the Adsorption of Pyrrolidinium Based Ionic Liquids on Pt(111) Surface Using Density Functional Theory
Authors: Sarkar Arka Prava
Published: October 2024

The adsorption properties of ionic liquids containing pyrrolidinium cations and various inorganic anions as electrolytes on a platinum surface were analyzed using first principle density functional theory. Three different orientations of the alkyl cation chain were observed during the adsorption process. The strength and structural stability varied between non‐fluorinated and fluorinated anions upon adsorption, with oxygen atoms influencing the mechanism of adsorption and driving the structural stability of the anion, while fluorine atoms played a role in determining the orientation of the cation during adsorption. Net atomic charges analysis, electron density difference methods, and electron density accumulation for this complex system were utilized to further investigate these phenomena. The results of this study provide valuable insights into the role of anions in the adsorption behavior of pyrrolidinium‐based ionic liquids on platinum surfaces, shedding light on the factors that influence their adsorption properties and structural stability on a molecular level. The findings of this study contribute to a better understanding of the interplay between anions and platinum surfaces in the adsorption of pyrrolidinium based ionic liquids, which can have implications for various applications such as electrochemistry, catalysis, and energy storage.
Utilizing Photovoltaic Solar Panels for Real‐Time Localization and Speed Detection of Approaching Illuminated Objects in Humanoid Robots
Authors: Ali Amir R. , Mubarak Abdelhameed
Published: October 2024

In the field of humanoid robotics, this paper showcases a promising method of integrating the photovoltaic (PV) solar panels into the “GUCnoid 1.0” humanoid robot model. Instead of the conventional power generation, solar cells are used to supply electrical energy to various sensors to create a system capable of real‐time sensing and perception. The main focus of the study will be the use of PV panels as receptors that are capable of detecting the light, enabling an adaptive system which perceives environmental changes. The behavior of the PV cell is superbly studied when various light sources are approached or depart. They finally reveal unique patterns in the voltage output signal amplitude. Interestingly, these patterns figure out the same symmetric structure, which reflects on a vertical axis by their mirroring. Using this simplicity, the method involves using an artificial neural network that is able to distinguish the light sources coming towards the detector and the ones running away and the rate at which they approach/recede. Outdoor experiment was organized for verification of methods. GUCnoid 1.0— humanoid robot was placed in front of a moving vehicle with different speeds of approach. To be able to identify the vehicle's position and velocity, a PV sensing technique has to be applied. This innovative technology will have wide applications, with much attention paid to improving the speed of finding nearby objects or vehicles in the scenarios where quick detection is a serious life safety issue. Through the process of PV solar panels' smart sensing, we directly connect the areas of high‐tech robotics and renewable energy. This discovery creates an opportunity for companies to build more responsive and flexible humanoid robots that can effectively collaborate with humans to achieve greater outcomes through more secure and efficient interactions between humans and robots.
Calibration of TEROS 10 and TEROS 12 electromagnetic soil moisture sensors
Authors: Cominelli Sofia , Rivera Leonardo D. , Brown William G. , Ochsner Tyson E. , Patrignani Andres
Published: October 2024

The TEROS 10 and TEROS 12 are widely used capacitance‐based sensors for measuring volumetric water content (), but few systematic studies of the measurement volume and accuracy of these sensors have been published. The objectives of this study were to (1) calibrate and validate these sensors in mineral soils, (2) determine the sensing volume of each sensor, and (3) evaluate the temperature sensitivity of the sensors. Both sensors were calibrated in the laboratory using columns of packed soil at multiple moisture levels from air‐dry to near saturation. Sensors were validated using additional laboratory and field measurements. The sensing volume was determined by quantifying the response of raw sensor outputs while increasing the level of oven‐dry sand, moist sand (0.100 cm3 cm−3), or water around the sensor in the radial and axial directions. Temperature sensitivity was tested in controlled conditions over a range of temperatures from 2°C to 40°C using encapsulated sensors in packed soil columns at constant . Linear calibration models resulted in mean absolute error ≤0.030 cm3 cm−3 for both sensors during laboratory and field validations. In moist sand, the sensing volume contributing 95% of the maximum sensor response was 439 cm3 for the TEROS 10 and 423 cm3 for the TEROS 12. Both sensors exhibited changes in of ≤0.02 cm3 cm−3 when subjected to a temperature change from 2°C to 40°C. For the soils considered here, both sensors demonstrated accuracy that is likely sufficient for a variety of agricultural and hydrological applications.
MCM‐41 Supported Anthracene Based Cu(II)‐Schiff Base Complex: A Heterogeneous Catalyst for the Synthesis of 4H‐Pyrans/Chromene
Authors: Singh Reetika , Malik Arti , Singh Udai P. , Kashyap Sujata
Published: October 2024

The anthracene‐appended Schiff base N1‐(anthracene‐9‐methylene)benzene‐1,2‐diamine and its Cu(II) complex has been synthesized and anchored on MCM‐41 support (MCM@CP@AnL@Cu 1). The synthesized catalyst was characterized by various analytical techniques including single crystal X‐ray. Malononitrile, 1,3‐dione, and aromatic aldehydes with various substituents were used in one‐pot, three‐component synthesis of 2‐amino‐3‐cyano‐4H‐pyran/chromene derivatives using above catalyst 1. All the products of the catalytic reaction were characterized by 1H and 13C NMR spectra. We have also proposed a probable reaction mechanism involved in the catalytic reaction. The present catalyst has several advantages like works in mild reaction conditions, that is, at 80 °C, gives higher yields up to 97%, has thermal stability up to 295 °C, and can be reused up to 5 cycles. The immobilized material did not show any considerable leaching or deterioration throughout the catalytic reactions, confirming that it possesses a practical benefit over homogeneous catalysis. The MCM@CP@AnL@Cu (1) is believed to be a good solid heterogeneous catalyst and meets the need of green chemistry for sustainable environment. To the best of our knowledge, this is first example of anthracene‐based Cu (II)‐Schiff base complexes immobilized on modified MCM‐41 surfaces for the multicomponent synthesis of 4H‐pyrans.
Dynamics and Thermodynamics Study of the Adsorption of Lysozyme to 2D SnSe Nanoflake Surfaces with Associated Unfolding
Authors: Samui Rajesh , Saha Satyajit , Guha Prasanta Kumar , Bhunia Amit Kumar
Published: October 2024

In this work, we explore the interaction as well as corona formation and interfacial phenomena of lysozyme (LYZ) and 2D SnSe nanoflake. The optical results indicate formation of ground state complex with an apparent association constant of 1.5 × 103 (mol)−1. The dynamics of the in situ interaction exhibited surface reorganization (t2 = 73.5 min) and unfolding, which were more prominent than binding (t1 = 3 min) for tryptophan residues of LYZ. The formations of soft and hard corona of the LYZ structure were clearly observed from HRTEM. The emission quenching exhibited tertiary deformation of the LYZ structure with positive cooperative binding (n > 1) and dynamics of quenching followed the sigmoidal Boltzmann nature of the energy transfer process. The ultrafast lifetime of the bioconjugate varied from 1.9–1.35 ns with a maximum 63% energy transfer efficiency within 300 min of the corona evolution. The decrement of α helix (58.87%–21.78%) and increment of β sheet (5.27%–23.98%) were observed after interaction, with the conversion of large amount of α helix into β sheet. The ITC results showed that the injection heat results followed two‐site binding model, and the exothermic binding was dominate over the interaction. The second phase binding is driven by larger positive entropy, where the first binding site has a stronger association.
Hematite Defect Development for Gallic Acid Sensing
Authors: Golovin Mikhail , Seredova Maria , Kuznetsov Mikhail , Stanković Vesna , Mutić Tijana , Stanković Dalibor M. , Bol'shakov Oleg
Published: October 2024

Nanostructured iron (III) oxide was prepared by a facile hydrothermal method using poly(triazine imide) (PTI) as a sacrificial template. The physicochemical properties of pristine iron oxide and its analogue obtained in the presence of PTI confirmed strong effect of the latter as the morphology improving agent. Moreover, application of nitrogen rich semiconducting polymer during hydrothermal synthesis increased number of defects. The obtained sample was used as an electroactive additive for carbon‐paste electrode. PTI‐modified sample demonstrated 1.52 times higher oxidation current, and 1.39 lower charge transfer resistance compared to hematite obtained without PTI, as was confirmed by CV and EIS data. Therefore, it was proposed to use the as a sensor for the detection of gallic acid. The developed method showed excellent linearity within a concentration range of 67 nM to 17.7 µM with a detection limit equal to 44 nM and limit of quantification of 132 nM. Stablitity and reproducibility tests, as well as real sample analysis confirmed applicability of the proposed sensor for practical application. Excellent electrochemical properties of the submicron hematite particles are attributed to the developed lattice defects, which served as reaction centers and charge transducing points.
Greener Approach to Cost‐Effective Electrochemical L‐cysteine Sensing Using Polyaniline‐Modified Carbon Paste Electrodes
Authors: Kamble Abhijeet , Tawade Anita , Kamble Bhagyashri , Nikam Aishwarya , Sharma Kiran Kumar K. , Patil Vidhyadhar , Tayade Shivaji
Published: October 2024

In this study, we present a facile approach for the green synthesis of polyaniline (PANI) through electrochemical polymerization on a graphitic paste electrode, thus enhancing its use in electrochemical sensing applications. The morphology of the synthesized PANI was observed using scanning electron microscopy (SEM), the crystallinity of the material was studied using XRD, and further functional groups were characterized by FT‐IR and UV spectroscopy. PANI, coated on the surface of a graphitic paste ‐modified electrode (P‐GPME) by controlled electrolysis, demonstrated notable electrocatalytic activity toward L‐cysteine (L‐cyst). The redox behavior of L‐cyst at the P‐GPME surface was investigated using cyclic voltammetry. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 2.4 × 10−6 and 1.21 × 10−5 mol L−1, respectively. These results highlight the potential of P‐GPME for selective and sensitive detection of L‐cyst. Furthermore, the designed electrode was effectively employed for the determination of L‐cyst in urine samples.
Amorphous to Polycrystalline Phase Transition of In Situ Annealed Ge Films: Structural, Morphological, Optical, and Electrical Characteristics
Authors: Singh Gurvinder , Gupta Divya , Aggarwal Sanjeev
Published: October 2024

Radio Frequency (RF) sputtered germanium (Ge) thin films were deposited on glass substrate at in situ annealing temperatures of 400, 450, 500, 550, and 600 °C. X‐ray diffraction (XRD) and Raman spectroscopy revealed that the Ge films were initially amorphous but transformed to polycrystalline after annealing at 450 °C. Further annealing up to 600 °C resulted in improved crystallinity. Strain studies of the films using XRD and Raman showed compressive (out‐of‐plane) and tensile (in‐plane) strains, respectively, throughout all the annealing temperatures. The surface morphology of the films was recorded using atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), which showed grain growth with annealing temperatures. The optical energy gap evaluated from absorption spectra for crystalline films decreased with annealing temperature, indicating improvement in crystallinity of films. The resistivity of the films deduced using current‐voltage measurements was found to decrease with annealing temperature, which can be attributed to enhancement in grain size. This study establishes a correlation between strain, grain size, optical energy gap, and electrical resistivity with temperature for Ge films deposited on glass substrates. Thus, the present study provides insights into variation in physical and electrical properties of films with in situ annealing temperature for their applicability in optoelectronic devices.
Engineering of Covalent Organic Framework Nanosheet Membranes for Fast and Efficient Ion Sieving: Charge‐Induced Cation Confined Transport
Authors: Wang Rui , Ding Li , Xue Jian , Wu Haoyu , Cai Chengzhi , Qiao Zhiwei , Caro Jürgen , Wang Haihui
Published: October 2024

Artificial membranes with ion‐selective nanochannels for high‐efficiency mono/divalent ion separation are of great significance in water desalination and lithium‐ion extraction, but they remain a great challenge due to the slight physicochemical property differences of various ions. Here, the successful synthesis of two‐dimensional TpEBr‐based covalent organic framework (COF) nanosheets, and the stacking of them as consecutive membranes for efficient mono/divalent ion separation is reported. The obtained COF nanosheet membranes with intrinsic one‐dimensional pores and abundant cationic sites display high permeation rates for monovalent cations (K+, Na+, Li+) of ≈0.1–0.3 mol m−2 h−1, while the value of divalent cations (Ca2+, Mg2+) is two orders of magnitude lower, resulting in an ultrahigh mono/divalent cation separation selectivity up to 130.4, superior to the state‐of‐the‐art ion sieving membranes. Molecular dynamics simulations further confirm that electrostatic interaction controls the confined transport of cations through the cationic COF nanopores, where multivalent cations face i) strong electrostatic repulsion and ii) steric transport hindrance since the large hydrated divalent cations are retarded due to a layer of strongly adsorbed chloride ions at the pore wall, while smaller monovalent cations can swiftly permeate through the nanopores.
Disintegration
Authors: Scheiber Marcus
Published: October 2024

The stereotype of disintegration is conceived as the Jewish tendency for “activity directed towards separation or destruction” of a community or state. Originally used to designate chemical or biological processes that oppose the process of “composition,” the expression underwent a change of meaning when linguistic images of such processes were projected onto developments in social and political spheres. The idea of a disintegrating quality is attributed to Jews in an essentialising way as a habitual, formative behaviour that aims at the dissolution of state, social and spiritual order. The central moment of the stereotype of disintegration manifests itself in the idea of a people as a single organism that can only carry out its activities if all its parts or members are intact and work together. Jews are excluded from this organism as foreign bodies, frequently portrayed in biological terms as “viruses” or “parasites.” Jewish participation in that organism supposedly poses a threat of “infection,” “decay” and finally “dissolution.”
The Other/Foreign
Authors: Ascone Laura
Published: October 2024

The representation of Jews as foreigners or strangers—or simply the Other—constitutes the oldest stereotype on which all antisemitic stereotypes and other concepts are built. While many different groups and peoples have been and are conceptualised as “the other,” Jews and Judaism can be understood as “the paradigmatic other.” The movement of Jewish groups and the formation of the Jewish diaspora created a dynamic where Jews often lived in close proximity to other groups while retaining their own ethnic, cultural and religious identity. This made Jews a common object for practices of in- and out-group identity formation across centuries. Indeed, the twin questions of Jewish “belonging” and “otherness” are deeply woven through the political, cultural and philosophical history of Western and/or Christian societies. They lie at the root of a long tradition of “anti-Judaism,” in which different people in different contexts used the image of “the Jew” to think about and describe the present, to engage and transform their understanding of the past, and to reshape visions of the future. The idea of “the Jew” here is used again and again throughout history as a limit point, the line beyond which one community, history, belief system and understanding of the world, reaches its end—and another, one entirely alien and foreign, begins.
Apartheid Analogy/Racist State
Authors: Bolton Matthew
Published: October 2024

Apartheid Analogy

Accusations of apartheid today constitute one of the strongest moral condemnations a modern nation-state can face. The use of the concept of “apartheid” or “apartheid state” to describe Israel is one of the most common forms of denouncing the Jewish state in contemporary discourse, both in reference to contemporary Israel policies and the historical foundations of the state itself. To accuse Israel of apartheid is to activate the historical memory of the South African apartheid state, in which “whites” and “blacks” were segregated in virtually every area of political, economic and social life by a strict white supremacist racial hierarchy, enforced by state violence. By making an analogy between this system and the current state of Israel, that state is depicted as a colonial, endemically racist state defined by absolute segregation between “races.” The result of such a depiction is the moral delegitimisation and demonisation of Israel, opening up a pathway to the denial of Israel's right to exist.

Racist State

The depiction of Israel as an inherently racist state asserts that Israel is racist in an implacable and totalising sense: that, from its founding, the state, its rationale, its institutions, its leaders and its population—regardless of their individual qualities—have been driven by racist motivations and desires. This portrayal of Israel is frequently entwined with descriptions of Zionism, the national ideology supporting and justifying the national self-determination of a Jewish people, as inherently racist. The highpoint of this argument was the adoption of General Assembly Resolution 3379 by the United Nations in 1975, which declared that “Zionism is a form of racism and racial discrimination.” The passing of the resolution was primarily the work of the Soviet bloc and Arab nationalist governments, who sought to conflate the State of Israel with white supremacist colonial states. It was not revoked until 1991. In contemporary discourse, Israel is regularly accused of spreading state racism across the globe, with police violence against Black Americans or extremist Hindu nationalism in India often being spuriously explained via supposed connections to Israel or Zionism.
Affirming, Desiring, Calling for Violence
Authors: Ascone Laura
Published: October 2024

Even though freedom of speech, which constitutes a pillar of many countries’ constitutions, allows any individual to say and believe in whatever they wish, it is a common consensus that it does not include the right to incite to violence or lawless actions. In the case of antisemitism, according to the IHRA definition, “calling for, aiding, or justifying the killing or harming of Jews” is a form of antisemitism; it is important to recognise that if such speech acts target Israelis, Israel and Zionism or Zionists, they can also be antisemitic. In other terms, in order to establish whether an affirmation of, desire and call for violence is antisemitic, it is first crucial to determine if such a demand or the perpetrated brutality itself is motivated by antisemitic ideology—that is, if it attacks its target for being Jewish.
Observation, Analysis and Evaluation of the Industrial Contribution to the Peer-Reviewed Public Access of the ESRF: A Pilot Study
Authors: Zhang Junhanlu , Capria Ennio
Published: October 2024

Although achieving excellent science remains the primary goal for Research Infrastructures (RIs), RI stakeholders share an increasing interest in understanding the broader contribution of RIs to tackle societal challenges. In such a context, an attempt has been made to identify the direct synergies between the ESRF (European Synchrotron Radiation Facility) and industry, as industrial contribution to publicly funded initiatives provides a key route to understanding the socio-economic impact. While all activities at the ESRF result in effects on the innovation process, direct synergies with industry act as one of the only attributive mode of innovation leading a tangible way to sustain innovation. Therefore, this contribution zooms in on the ESRF’s peer-reviewed public access and how industry is directly and indirectly involved in generating not only scientific but also potentially social and economic impact of the facility.
Introduction to Plenoptic Imaging
Authors: Fang Lu
Published: October 2024

Plenoptic is derived from the Latin words plenus (“full”) + optic and was proposed by Edward Adelson in 1991. The plenoptic function is a seven-dimensional function describing the three-dimensional viewing position, two-dimensional visual angle, one-dimensional wavelength, and one-dimensional time of a light ray in space.
Research on Dam Crack Identification Method Based on Multi-source Information Fusion
Authors: Xin Cun , Yang Dangfeng , Liu Xiaodong , Huang Yong , Qian Xueming
Published: October 2024

Cracks as the main safety concern of dams, high-precision identification of dam cracks is of great application value and scientific significance to ensure the safety of dams. The paper proposes a dam crack identification method based on multi-source information fusion. Specifically, image gray scale and geometric features are extracted based on the image information. And then a single crack identification model based on Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF), XGBoost, and BP Neural Network are established based on the features, respectively. Finally, a multi-classifier fusion algorithm based on D-S evidence theory is established to identify the presence of cracks by fusing single identification models. Experiments are carried out to compare the proposed method with the existing identification methods based on the evaluation metrics such as accuracy, precision, F1-score, and recall. The results show that the accuracy of crack identification of the proposed method in this paper reaches 98.9%, and the crack identification results are better than the existing methods.
Research on the Dispatching Decision Method of Cascade Hydropower Stations Based on the BVWS
Authors: Haoyu Ma , Hui Cao , Yaxin Liu , Yang Xu , Rui Tian
Published: October 2024

Compared with the operation of a single hydropower station, the difficulty of operation and management for cascade hydropower stations increases exponentially. Especially during the critical periods such as concentrated drawdown before flood season and concentrated storage during late flood season, the dispatching strategies of cascade stations are crucial for successfully realizing operation objectives and enhancing power generation benefits of the cascade system. Scientific methods should be used to formulate long-, medium-, and short-term operation strategies, and the sequence of drawdown or storage for cascade reservoirs should be arranged reasonably to maximize the system benefits. Current research typically utilizes reservoir dispatching diagrams or optimal dispatching models to develop scheduling plans. Reservoir dispatching diagrams can be used to quickly access the operation schemes for reservoirs, but it cannot guarantee the optimal power generation benefits within a given dispatching period. Optimal models typically utilize algorithms such as dynamic programming to solve and obtain corresponding scheduling solutions, achieving the maximization of reservoir dispatching objectives. However, the problem of dimension disaster often easily occurs. To balance the optimization of system benefits and the efficiency of formulating operation plan, this paper proposes a benefit evaluation index, namely Benefit Variation from Water Storage (BVWS), which simultaneously couples water head benefits and backwater jacking influence of hydropower stations.Based on this, the graphs of BVWS for cascade stations are drawn, which can assist decision-makers in quickly formulating dispatching strategies for different time scales. Taking a cascade system composed of four hydropower stations in the upper reaches of the Yangtze River as the research object, this paper compares the calculation results and efficiency of the proposed method with the progressive optimality algorithm (POA). The results indicate that the proposed method can remarkably reduce the time required to develop optimal operation schemes, enabling a rational allocation of water resources among the cascade stations, therefore proving the scientific rationality of this method.
Research on Load Distribution Method of Cascade Hydropower Station with Maximum Energy Storage at the End of Dispatching Period
Authors: Li Tianqing , Lu Peng , Zhou Pengcheng , Han Bing , Yang Zijun , Yang Kaibin
Published: October 2024

The paper focuses on how to rationally distribute the load of cascade hydropower station in the short term economic operation to meet the grid requirements and improve the water energy efficiency of cascade hydropower stations. In this paper, a calculation method of energy storage for cascade hydropower station is presented, the change of cascade storage caused by power generation of different hydropower stations is studied, and the influence of reservoir capacity characteristics on load distribution of cascade hydropower stations is analyzed. According to the short term economic operation and dispatching requirements of cascade hydropower station, the load distribution model of cascade hydropower station based on the maximum storage capacity at the end of the term is constructed. Taking the short-term load distribution of cascade hydropower stations in the Nam Ou River Basin of Laos as an example, four scheduling schemes with different boundary conditions are calculated. The results show that the load distribution results of cascade hydropower stations in the Nam Ou River based on the maximum energy storage the end of the period are as follows: Nam Ou4 and Nam Ou1 in the downstream with larger changes in water level per unit storage capacity are preferentially stored, Nam Ou7, Nam Ou6 and Nam Ou2 in the upstream with larger storage capacity are preferentially supplied and generating power. The research results can provide guidance for the short-term economic operation and dispatch of cascade hydropower stations, and help to improve the water energy utilization efficiency of cascade hydropower stations.
Research on Deformation Monitoring and Early Warning and Safety Control of Hydraulic Tunnel in Extremely Fractured Rock Mass
Authors: Duan Bin , Wang Haisheng , Feng Deqiang , Qin Shihe , Li Zhen , Mao Haoyu
Published: October 2024

Taking the underground cavern group of Dadu River Jinchuan Hydropower Station as the research object, the key technology of deformation monitoring, early warning and safety control of hydraulic tunnels in extremely fractured rock mass is systematically studied by theoretical research, on-site monitoring and numerical computation, the characteristics of the surrounding rock of hydraulic tunnels and stability of the import and export slopes are investigated, and the safety coefficient of the side slopes and danger of slope rockfall are evaluated under multiple conditions, and the stress-strain characteristics of the surrounding rock during excavation of the tunnels and the sides of the side slopes under the condition of extremely fractured rock mass are simulated; On this basis, a monitoring system for hydraulic tunnels and slopes in extremely fractured rock mass is constructed, and an index system for judging the risk of surrounding rock stability is established; finally, an intelligent control system for underground cavern group construction based on BIM is constructed, and a platform for the safety and intelligent control of hydraulic tunnels is set up. The results show that the system improves the accuracy of construction risk identification of hydraulic tunnels in extremely fractured rock mass, realizes comprehensive and efficient real-time monitoring of project status, and provides a scientific basis for safety control of tunnels and slopes.
Effects of Rotating Stall on Flow Patterns and Pressure Pulsation in Clearance Flow Channels of Pump-Turbines
Authors: Hou X. X. , Teng S. F. , Xiong C. X. , Yang Z. Y.
Published: October 2024

The clearance flow channel (CFC) of pump-turbine is a thin cavity composed of a runner and head cover or bottom ring, but excessive pressure pulsation in a flat CFC is easy to cause the head cover excitation. At present, there are insufficient studies on the flow patterns, and pressure pulsations in CFC. In this paper, the 3D CFD numerical simulation method was used to reveal the flow patterns, and pressure pulsations in the CFC of a low specific speed pump-turbine under rotational stall condition. The results showed that the stall vortexes rotated in the vaneless region of the main flow channel (MFC) when the rotating stall occurred in the pump mode; while that rotated in the runner flow channels, causing circumferentially imbalanced pressure at the runner inlet, as well as a low-frequency and high-amplitude pulsation in MFC. In CFC, uneven pressure distribution in the external cavity was formed when the clearance inlet pressure was unbalanced in the circumferential direction in turbine braking mode. The pulsation generated by the rotating stall in the MFC could be transmitted to the CFC, but the pulsation amplitude dropped sharply at the clearance inlet position, then increased first and ultimately decreased inward along the clearance flow channel. This study provides a reference for the study of hydraulic excitation of the head cover.
Technical Challenges and Environmental Governance in the Construction of Pumped Storage Power Stations
Authors: Wang Song , Yang Yongkang
Published: October 2024

With the continuous deepening of China’s reform and opening-up, the coordinated development of environmental protection and economic development has become the focus of social attention. As a key new energy technology, pumped storage power stations have functions such as peak power regulation and energy storage, and play an important role in new energy construction. However, its application in China is still in its infancy and lags behind the international advanced level. This paper uses the methods of literature review and practical experience induction to conduct a detailed analysis of the technical issues in the construction of pumped storage power stations. Through an in-depth discussion of the development status of China’s pumped storage power stations, as well as technical problems and governance measures that may arise during their construction, we will provide support for promoting ecological environmental protection, responding to the demand for new energy construction, and creating a green-friendly construction environment. This paper focuses on the technical difficulties encountered during the construction process and proposes corresponding management measures. At the same time, an in-depth analysis of the challenges faced by pumped hydro storage technology and construction was conducted. Through research, it is found that the development of pumped storage power stations in China has made some progress, but there are still some necessary technical challenges. In response to these problems, a series of effective governance measures are proposed, and future development prospects are forecast. Comprehensive research results show that pumped storage power stations occupy an important position and have great potential in China’s new energy construction. Through scientific planning and effective management, problems that may arise during their construction and operation can be overcome, and their wider application in China can be promoted, making positive contributions to ecological environmental protection and sustainable development.
Optimization of Ultra-High Voltage Direct Current Power Transmission Curve for High Proportion New Energy Bases
Authors: Yi Bo , Liu Yunhe , Wang Xiao
Published: October 2024

With the increase in demand for the construction of high proportion new energy base, the power transmission scale of Ultra-High Voltage Direct Current(UHVDC) is growing rapidly, and the characteristics of inter-provincial and inter-regional power transmission are affected by multiple factors, such as the randomness and volatility of new energy in the sending province, the peaks and valleys of the loads, the process of power shortages, and the new time-of use electricity pricing policy in the receiving province. Uncertainty issues are more prominent, and it has changed significantly compared with the traditional UHVDC power transmission methods. It is urgent to study the UHVDC transmission curve planning method in new period. Taking a new energy base in Northwest China as a typical example, a UHVDC power transmission system optimization model is constructed. A UHVDC power transmission curve optimization method that takes into account the power shortages process and the time-of use electricity pricing is proposed, and the Cplex12.6 Solver is used to carry out the 8760 h time series power production simulation. The results show that the obtained 12 curves by the new method can cope with the price-based response demand. Compared with the traditional method, the total cost present value is reduced by RMB 6.10 billion, the power shortage rate is reduced to 0.56%, and the proportion of new energy power is increased to 88.58%. Especially, the power output of pumped storage can track the transmission curve well, and alleviate the requirements for peak regulation flexibility of thermal power units. The power configuration scheme is technically feasible and economical, which verifies the effectiveness of the proposed method. It is suitable for the planning of large-scale UHVDC power transmission schemes. In the meantime, it plays an important role in promoting the level of new energy consumption and helping the low-carbon energy transformation.
Optimal Scheduling of Wind-Thermal-Hydro-Storage Multi-Energy Complementary System with Pumped Hydro and Battery Storage
Authors: Zou Zehua , Zhao Quan , Deng Miao , Gao Chong , Zhou Liangsong
Published: October 2024

With increasing scale of renewable energy integrated into the power system, the power system needs more flexible regulating resources. At present, besides traditional thermal and hydro power plants, pumped hydro storage and battery storage are the most commonly used resources, and they form a wind-thermal-hydro-storage multi-energy complementary system. This paper proposes an optimal scheduling strategy to dispatch the resources in the multi-energy complementary system. First, models of diverse types of resources. i.e., hydro power, pumped hydro storage, and battery storage, are established. Then, a day-ahead optimization scheduling model is proposed for the multi-energy complementary system. Finally, case study is conducted on a revised IEEE 30 node system. Simulation results demonstrate that the proposed method can fully utilize the characteristics of different kinds of power resources to consume renewable energy and enhance the safety and economy of the multi-energy complementary system.
Wide-Area Long Sequence Photovoltaic Power Simulation Based on ERA5 Reanalysis Data
Authors: Tang Siwei , Wang Xu , Gao Jie , Zhu Fangliang , Yang Jianzan
Published: October 2024

The long-sequence hourly photovoltaic power simulation sequence is an important reference information in the stage of power station planning, designing and dispatching operation. Based on the ERA5 reanalysis data, this paper adopts the tilted plane radiation model and the photoelectric conversion model to construct a photovoltaic power physical simulation model, and conducts hourly power simulation study for a total of 23 years from 2000 to 2022 for 30 existing photovoltaic power stations in China, and analyzes the simulation effect and the interannual volatility of power generation capacity in different temporal and spatial ranges. The results show that: on different time scales, the power simulation results are different, and the long time scale is better than the short time scale. The root mean square errors of the monthly average, daily average and hourly scales are 0.89–20.8, 0.43–9.61, and 0.3–3.42 respectively; in different spatial ranges, the power simulation results are also different, and the power stations with relatively low simulation effect are mainly distributed in the western region with smaller longitude; there are great differences in the interannual power generation capacity volatility of each power station, and the volatility between years of the power stations at low latitudes is relatively large. In general, the power simulation result of the ERA5 reanalysis data can better reflect the actual operation law of the power station, and carrying out long-sequence power simulation through the ERA5 reanalysis data can provide relatively reliable data support for the planning and operation of the power station.
Application of Flow Prediction Models to the HPP Castro Alves for Planning Preventive Actions Against Extreme Events
Authors: Pires Beatriz Sepulveda , Chen Xinjian , Zhang Huiyi
Published: October 2024

Today, the effects of climate change are increasingly evident. In the southern region of Brazil, significant impacts have been observed, such as the peak flows in November 2023, when a state of emergency was declared in the areas of the municipalities of Rio das Antas, Rio Grande do Sul, due to the impacts of heavy rainfall in the region. Such events may become more frequent in the coming years, so that the forecasting of hydroelectric inflows is necessary to plan the operation of the plants and to carry out preventive actions to deal with extreme events. The Ceran complex is located on the Antas River and consists of three hydroelectric plants, the Castro Alves, Monte Claro and Quartorze de Julho plants, and with a view to the sustainable operation of the projects in order to make conscious use of water resources, optimize operations and minimize the impact on the well-being of local populations, it has been studied and applied that rainfall-runoff models to forecast the inflows to the projects on the Antas River cascade. Rainfall-runoff models are essential for predicting extreme flows and taking preventive action, providing the operations center and the team involved with information for prior decision-making and, if necessary, evacuation of operators and potentially affected communities. In view of the above, this paper will apply the MEL model to convert rainfall into flow and compare the predicted results with the observed ones.
Research on the Design Method of Ultimate Pressure for Compressed Air Energy Storage in Hydroelectric Tunnels
Authors: Han Yue , Gao Yaohui , Cui Hao , Ning Liu  , Chen Pingzhi
Published: October 2024

The design of storage pressure is an indispensable step for reusing the existing hydropower tunnels into compressed air storage cavern, which directly affects the safety and economy of the plant. To design appropriate pressure, firstly the three anti lifting theoretical models are adopted to establish the analytical ultimate pressure methods in this paper and the ultimate pressure obtained under different parameters are compraed and anyasided. Based on multi-layer thick-walled cylinder theory, an improved calculation method for the ultimate pressure is proposed. Then parameter sensitivity analysis are conducted to reveal the key coefficient affecting the ultimate pressure corresponding to the model. Finallly, the proposed method is applied in the traffic tunnel of Baihetan Hydropower Station as an example.The results show that the straight failure plane (SFP) model is relatively conservative, resulting in lower ultimate pressure. The shear resistance of the conical failure surface surface will increase the ultimate pressure. The newly proposed model takes into account the influence of structures, and obtains a more reasonable ultimate pressure by limiting the tension stress of the steel lining. The surrounding rock's elastic modulus and burial depth exert the most significant influence on the ultimate pressure. In contrast, the effects of tunnel radius, steel grade, and concrete lining thickness are of moderate importance. The impact of steel lining thickness, concrete grade, Poisson's ratio of the surrounding rock, and surrounding rock density on the ultimate pressure is comparatively minor. The ultimate pressure of the Baihetan traffic tunnel by this method is 23.6 MPa. This study is of great significance for the renovation of compressed air storage in hydropower tunnles.
Study on the Impact of Flood Season Operating Water Level on Flood Control of the Three Gorges Reservoir
Authors: Zhai Yan-wei , Jiang Ding-guo , Ji Guo-liang , Lv Zhen-yu
Published: October 2024

Climate change has resulted in an increase in extreme weather events, with a sharp rise in droughts and floods. To establish a long-term mechanism for ensuring the safe operation of the Three Gorges Project, it is imperative to utilize hydrodynamic methods to analyze the water level operation mode during the flood season. This is crucial to enhancing the flood control safety and maximizing the overall benefits of this project. Therefore, this study obtained four different frequency design flood processes for each year by utilizing data from typical years. And the influence of different starting water level and discharge flows on the high water level and excess flood volume of flood regulation were revealed under the existing scheduling protocols and a one-dimensional hydrodynamic model. The results indicated that the water level operation modes of floods from different typical years were significantly different under the same scheduling rules, and when faced with the extreme flood conditions, discharge flow is a primary determinant of reservoir safety. Furthermore, the current scheduling scheme for the Three Gorges Reservoir has an extra safety margin. As a result, even without forecasting inflows, elevating the operating water level to 155 m during the flood season effectively mitigates risks from floods with a return period of 100 years or less, while maintaining risk control over floods with 1,000-year or 10,000-year return periods.
AdS/CFT correspondence for the O(N) invariant critical φ4 model in 3-dimensions by the conformal smearing
Authors: Aoki Sinya , Kawana Kiyoharu , Shimada Kengo
Published: October 2024

Abstract

We investigate a structure of a 4-dimensional bulk space constructed from the O(N) invariant critical φ4 model in 3-dimension using the conformal smearing. We calculate a bulk metric corresponding to the information metric and the bulk-to-boundary propagator for a composite scalar field φ2 in the large N expansion. We show that the bulk metric describes an asymptotic AdS space at both UV (near boundary) and IR (deep in the bulk) limits, which correspond to the asymptotic free UV fixed point and the Wilson-Fisher IR fixed point of the 3-dimensional φ4 model, respectively. The bulk-to-boundary scalar propagator, on the other hand, encodes $$ {\Delta }_{\varphi^2} $$

∆

φ
2

(the conformal dimension of φ2) into its z (a coordinate in the extra direction of the AdS space) dependence. Namely it correctly reproduces not only $$ {\Delta }_{\varphi^2} $$

∆

φ
2

= 1 at UV fixed point but also $$ {\Delta }_{\varphi^2} $$

∆

φ
2

= 2 at the IR fixed point for the boundary theory. Moreover, we confirm consistency with the GKP-Witten relation in the interacting theory that the coefficient of the $$ {z}^{\Delta _{\varphi^2}} $$

z

∆

φ
2

term in z → 0 limit agrees exactly with the two-point function of φ2 including an effect of the φ4 interaction.
Characterizing spatial patterns among freshwater fishes and shrimps of the Poso River (Sulawesi, Indonesia) using DNA barcoding
Authors: Wibowo Arif , Kurniawan Kurniawan , Prakoso Vitas Atmadi , Ginanjar Rendy , Rochman Fathur , Zamroni Mochammad , Atminarso Dwi , Sumarto Bayu Kreshna Adhitya , Chadijah Andi , Irawan Deni , Deniansen Tri , Suriani Irma , Syamsi Agus Noor , Achmadi Andi , Surbani Indah Lestari , Akbar Sabda Alam , Hubert Nicolas , Robinson Wayne , Stuart Ivor G. , Baumgartner Lee J.
Published: October 2024

Fish biodiversity assessments are vital for understanding threats and aquatic ecosystem health. In the Poso River, Central Sulawesi, changes in biodiversity are influenced by habitat alteration, non-native species, and overfishing. This study evaluates fish and crustacean biodiversity in the Poso River system to address these challenges for improving fisheries management, conservation, and fish passage integration into hydropower development. The present biodiversity study utilized a comprehensive methodology that encompassed both traditional taxonomic approaches and DNA barcoding, specifically targeting the mitochondrial cytochrome c oxidase subunit-1 (COI) gene for accurate species identification and spatial boundary validation. The survey was conducted in the upstream, hydropower area and downstream areas of the river. We found 27 species of fish in the Poso River, including both native (e.g., Anguilla celebesensis, Oryzias nebulosus, Rhyacichthys aspro) and non-native species (e.g., Melanochromis auratus, Amphilophus trimaculatus, Oreochromis niloticus). Two International Union for Conservation of Nature (IUCN) red listed endangered species were also observed (e.g., Adrianichthys poptae and Mugilogobius sarasinorum). DNA barcoding was performed to examine species spatial boundaries. The fish population in the Poso River was dominated by non-native species, accounting for 85.70% of the total population. The upstream reaches had the highest fish abundance and diversity, while the downstream reaches had the lowest. There was, however, no significant difference in species richness and diversity across different locations and seasons. The dominance of non-native species in the Poso River necessitates the improvement of existing fishways within the hydropower dams potentially through the development of selective technology that can block the distribution of these non-native species. This research highlights the critical issue of non-native species proliferation and the potential threat they pose to native fish populations, providing valuable insights for conservation and management efforts in Indonesia and similar ecosystems worldwide.