bluuebunny/crossref_metadata_2025 huggingface dataset:
A review of flight trajectory optimisations
Authors: Pleter Octavian Thor , Constantinescu Cristian Emil
Published: May 2022

The paper reviews the optimisation methods of the flight trajectory for airliners. In contrast to maritime navigation, where the shortest route (the orthodrome) is preferred, in air navigation, the brachistochrone is the optimal flight trajectory on the sphere or on the ellipsoid, considering the wind vector field (maximising the tail wind and minimising the head wind over the duration of the flight). The major impact of the wind on the flight trajectory results from the possible significant velocity at the normal cruise flight levels, which could reach 200 kts, or 40% of the aircraft true airspeed (TAS). Brachistochrone is independent of the flight performance optimisation (range versus speed), as computed by the flight management system. Whichever cost index (CI) is selected (and consequently, the cruise Mach number), the brachistochrone is the minimum time of flight trajectory at that target Mach number. In cruise flight, the minimum time of flight is also equivalent to the minimum fuel consumption. It concerns just the wind velocity field. All these qualify the brachistochrone as the greenest trajectory, the most fuel and emissions efficient solution relative to the atmosphere. The paper classifies the brachistochrone problems (2D, 3D and 4D brachistochrones, with or without flexible time of departure). Some numerical examples are provided. The overall optimal 4D trajectory considers many aspects, including safety, by minimisation of total costs and risks of the 4D trajectory.
A novel hybrid observation prediction methodology for bridging GNSS outages in INS/GNSS systems
Authors: Chen Linzhouting , Liu Zhanchao , Fang Jiancheng
Published: May 2022

The integration of the inertial navigation system (INS) and global navigation satellite system (GNSS) is suited for localisation and navigation applications, such as aircrafts, land vehicles and ships. The primary challenge is for navigation system to achieve accurate and reliable navigation solution during GNSS outages. This paper presents an observation prediction methodology for INS/GNSS bridging GNSS outages, which combines partial least squares regression (PLSR) and Gaussian process regression (GPR) to model the INS/GNSS observations and enable a Kalman filter to estimate INS errors. The performance of proposed PLSR/GPR prediction methodology was validated through four GNSS outages taken on flight experiment data, including diverse manoeuvre conditions. The experiment results demonstrate that remarkable performance enhancements are achieved through applying the proposed PLSR/GPR prediction methodology into INS/GNSS integration.
Multimodality in webconference-based language tutoring: An ecological approach integrating eye tracking
Authors: Cappellini Marco , Hsu Yu-Yin
Published: May 2022

Drawing on existing research with a holistic stance toward multimodal meaning-making, this paper takes an analytic approach to integrating eye-tracking data to study the perception and use of multimodality by teachers and learners. To illustrate this approach, we analyse two webconference tutoring sessions from a telecollaborative project involving pre-service teachers and learners of Mandarin Chinese. The tutoring sessions were recorded and transcribed multimodally, and our analysis of two types of conversational side sequences shows that the integration of eye-tracking data into an ecological approach provides richer results. Specifically, our proposed approach provided a window on the participants’ cognitive management of graphic and visual affordances during interaction and uncovered episodes of joint attention.
Minimizing Motion Artifacts in Intravital Microscopy Using the Sedative Effect of Dexmedetomidine
Authors: Kim Youngkyu , Cho Minju , Paulson Bjorn , Kim Sung-Hoon , Kim Jun Ki
Published: May 2022

Among intravital imaging instruments, the intravital two-photon fluorescence excitation microscope has the advantage of enabling real-time 3D fluorescence imaging deep into cells and tissues, with reduced photobleaching and photodamage compared with conventional intravital confocal microscopes. However, excessive motion of organs due to involuntary movement such as breathing may result in out-of-focus images and severe fluorescence intensity fluctuations, which hinder meaningful imaging and analysis. The clinically approved alpha-2 adrenergic receptor agonist dexmedetomidine was administered to mice during two-photon fluorescence intravital imaging to alleviate this problem. As dexmedetomidine blocks the release of the neurotransmitter norepinephrine, pain is suppressed, blood pressure is reduced, and a sedation effect is observed. By tracking the quality of focus and stability of detected fluorescence in two-photon fluorescence images of fluorescein isothiocyanate-sensitized liver vasculature in vivo, we demonstrated that intravascular dexmedetomidine can reduce fluorescence fluctuations caused by respiration on a timescale of minutes in mice, improving image quality and resolution. The results indicate that short-term dexmedetomidine treatment is suitable for reducing involuntary motion in preclinical intravital imaging studies. This method may be applicable to other animal models.
SPLICE:a synthetic paid loss and incurred cost experience simulator
Authors: Avanzi Benjamin , Taylor Greg , Wang Melantha
Published: May 2022

In this paper, we first introduce a simulator of cases estimates ofincurred lossescalledSPLICE(SyntheticPaidLoss andIncurredCostExperience). In three modules, case estimates are simulated in continuous time, and a record is output for each individual claim. Revisions for the case estimates are also simulated as a sequence over the lifetime of the claim in a number of different situations. Furthermore, some dependencies in relation to case estimates of incurred losses are incorporated, particularly recognising certain properties of case estimates that are found in practice. For example, the magnitude of revisions depends on ultimate claim size, as does the distribution of the revisions over time. Some of these revisions occur in response to occurrence of claim payments, and soSPLICErequires input of simulated per-claim payment histories. The claim data can be summarised by accident and payment “periods” whose duration is an arbitrary choice (e.g. month, quarter, etc.) available to the user.SPLICEis built on an existing simulator of individual claim experience calledSynthETIC(introduced in Avanziet al. 2021b,Insurance: Mathematics and Economics,100, 296–308), which offers flexible modelling of occurrence, notification, as well as the timing and magnitude of individual partialpayments. This is in contrast with theincurred losses, which constitute the additional contribution ofSPLICE. The inclusion of incurred loss estimates provides a facility that almost no other simulators do.SPLICEis is a fully documented R package that is publicly available and open source (on CRAN).SPLICE, combined withSynthETIC, provides 11 modules (occurrence, notification, etc.), any one or more of which may be re-designed according to the user’s requirements. It comes with a default version that is loosely calibrated to resemble a specific (but anonymous) Auto Bodily Injury portfolio, as well as data generation functionality that outputs alternative data sets under a range of hypothetical scenarios differing in complexity. The general structure is suitable for most lines of business, with some reparameterisation.
Exekutive Probleme bei geriatrischen Patienten und Patientinnen
Authors: Ibert Sophie , Lubitz Alexander F. , Niedeggen Michael , Lämmler Gernot
Published: May 2022

Zusammenfassung: Die Erfassung der Exekutivfunktionen bei älteren Menschen ist von zentraler Bedeutung, da Defizite in kognitiven Kontroll- und Regulationsprozessen nicht nur einen neurodegenerativen Abbauprozess ankündigen, sondern auch Alltagstätigkeiten beeinträchtigen können. Durch etablierte Screeningverfahren wie Mini-Mental-State-Examination (MMSE) oder Montreal Cognitive Assessment (MoCA) wird dieser heterogene Funktionsbereich jedoch nur eingeschränkt erfasst. In der vorliegenden Arbeit wurde die Klassifikationswahrscheinlichkeit dieser Tests mit dem Screeningverfahren für Exekutivfunktionen (SEF) in einer geriatrischen Stichprobe verglichen. Ähnlich dem MMSE und MoCA, verfügte auch der SEF über eine gute klinische Akzeptanz und Handhabbarkeit. Ein Zusammenhang des neuen Screeningverfahrens zeigte sich mit den exekutiven MoCA-Items. Dabei teilt der SEF nicht die geringe Spezifität des MoCA und ermöglicht daher eine umfassendere Beurteilung exekutiver Funktionen von geriatrischen Patient_innen.
Cross‐Slope Buoyancy Fluxes Cause Intense Asymmetric Generation of Submesoscale Eddies on the Periphery of the Black Sea Mesoscale Anticyclones
Authors: Kubryakov A. A. , Puzina O. S. , Mizyuk A. I.
Published: May 2022

Submesoscale dynamics significantly affect the turbulence regime and is characterized by pronounced time variability, the reasons of which are still poorly known. In our study, we use high‐resolution (1 km) numerical model NEMO and satellite data in the Black Sea to demonstrate that one of the main processes impacting on the intensity of submesoscale dynamics in the marginal seas is the cross‐slope advection by mesoscale anticyclones. Such large eddies entrain the brackish shelf waters into their orbital motion and cause the strong rise of vertical and horizontal gradients of buoyancy. The emergence of baroclinic instability causes the generation of periodic submesoscale structures, among which cyclonic eddies have the largest vorticity. Our analysis shows that the presented mechanism is one of the main reasons for the intraannual variability of submesoscale dynamics over the continental slope of the Black Sea. This process also causes a strong asymmetry in the vertical structure of the mesoscale anticyclones. The generation of the submesoscale eddies and related vertical and horizontal exchange are significantly more intense on that side of the anticyclone, where current is directed offshore. Intensification of submesoscale motions in the zone of the brackish water entrainment is one of the probable reasons for the rapid and effective mixing of the shelf and open sea waters, often observed in satellite data.
Biofortified tomatoes provide a new route to vitamin D sufficiency
Authors: Li Jie , Scarano Aurelia , Gonzalez Nestor Mora , D’Orso Fabio , Yue Yajuan , Nemeth Krisztian , Saalbach Gerhard , Hill Lionel , de Oliveira Martins Carlo , Moran Rolando , Santino Angelo , Martin Cathie
Published: May 2022

Poor vitamin D status is a global health problem; insufficiency underpins higher risk of cancer, neurocognitive decline and all-cause mortality. Most foods contain little vitamin D and plants are very poor sources. We have engineered the accumulation of provitamin D3in tomato by genome editing, modifying a duplicated section of phytosterol biosynthesis in Solanaceous plants, to provide a biofortified food with the added possibility of supplement production from waste material.
Effect of crystallinity and thickness on thermal transport in layered PtSe2
Authors: El Sachat Alexandros , Xiao Peng , Donadio Davide , Bonell Frédéric , Sledzinska Marianna , Marty Alain , Vergnaud Céline , Boukari Hervé , Jamet Matthieu , Arregui Guillermo , Chen Zekun , Alzina Francesc , Sotomayor Torres Clivia M. , Chavez-Angel Emigdio
Published: May 2022

We present a comparative investigation of the influence of crystallinity and film thickness on the acoustic and thermal properties of layered PtSe2 films of varying thickness (1–40 layers) using frequency-domain thermo-reflectance, low-frequency Raman, and pump-probe coherent phonon spectroscopy. We find ballistic cross-plane heat transport up to ~30 layers PtSe2 and a 35% reduction in the cross-plane thermal conductivity of polycrystalline films with thickness larger than 20 layers compared to the crystalline films of the same thickness. First-principles calculations further reveal a high degree of thermal conductivity anisotropy and a remarkable large contribution of the optical phonons to the thermal conductivity in bulk (~20%) and thin PtSe2 films (~30%). Moreover, we show strong interlayer interactions in PtSe2, short acoustic phonon lifetimes in the range of picoseconds, an out-of-plane elastic constant of 31.8 GPa, and a layer-dependent group velocity ranging from 1340 ms−1 in bilayer to 1873 ms−1 in eight layers of PtSe2. The potential of tuning the lattice thermal conductivity of layered materials with the level of crystallinity and the real-time observation of coherent phonon dynamics open a new playground for research in 2D thermoelectric devices and provides guidelines for thermal management in 2D electronics.
Neural signatures associated with temporal compression in the verbal retelling of past events
Authors: Musz Elizabeth , Chen Janice
Published: May 2022

When we retell our past experiences, we aim to reproduce some version of the original events; this reproduced version is often temporally compressed relative to the original. However, it is currently unclear how this compression manifests in brain activity. One possibility is that a compressed retrieved memory manifests as a neural pattern which is more dissimilar to the original, relative to a more detailed or vivid memory. However, we argue that measuring raw dissimilarity alone is insufficient, as it confuses a variety of interesting and uninteresting changes. To address this problem, we examine brain pattern changes that are consistent across people. We show that temporal compression in individuals’ retelling of past events predicts systematic encoding-to-recall transformations in several higher associative regions. These findings elucidate how neural representations are not simply reactivated, but can also be transformed due to temporal compression during a universal form of human memory expression: verbal retelling.
Large-scale microbiome data integration enables robust biomarker identification
Authors: Xiao Liwen , Zhang Fengyi , Zhao Fangqing
Published: May 2022

The close association between gut microbiota dysbiosis and human diseases is being increasingly recognized. However, contradictory results are frequently reported, as confounding effects exist. The lack of unbiased data integration methods is also impeding the discovery of disease-associated microbial biomarkers from different cohorts. Here we propose an algorithm, NetMoss, for assessing shifts of microbial network modules to identify robust biomarkers associated with various diseases. Compared to previous approaches, the NetMoss method shows better performance in removing batch effects. Through comprehensive evaluations on both simulated and real datasets, we demonstrate that NetMoss has great advantages in the identification of disease-related biomarkers. Based on analysis of pandisease microbiota studies, there is a high prevalence of multidisease-related bacteria in global populations. We believe that large-scale data integration will help in understanding the role of the microbiome from a more comprehensive perspective and that accurate biomarker identification will greatly promote microbiome-based medical diagnosis.
Reactive uptake of ozone to azo dyes in a coated-wall flow tube
Authors: Al-Mashala Habeeb H. , Boone Alison M. , Schnitzler Elijah G.
Published: May 2022

Observations of reactive uptake of ozone to commercial azo dyes used in consumer products suggest multi-phase ozonolysis of azo dyes in the indoor environment.
The application of membrane sequencing batch reactors in high rate activated sludge processes: the effect of the organic loading rate on the bioflocculation and fouling phenomenon
Authors: Shafaei Nader , Bonakdarpour Babak , Faridizad Ghazale
Published: May 2022

The findings of this paper showed the potential of membrane sequencing batch reactors for use in high rate activated sludge processes but further optimization of operating conditions and use of membrane fouling mitigation strategies are required.
Keggin based self-assembled mesoporous materials for the capture of selective guest molecules
Authors: Tandekar Kesar , Tripathi Anjali , Prasad Muvva D. , Supriya Sabbani
Published: May 2022

Keggin-based self-assembled mesoporous materials have been synthesized which show selective uptake of non-polar molecules, e.g. I2 and CS2. The phosphonium cations play an important role in this assembly forming polyoxometalate based porous materials.
Synthesis of porous carbon from a PVC polymer and its application in supercapacitors
Authors: Dhapola Pawan Singh , Singh Abhimanyu , Karakoti Manoj , Singh Manoj K. , Konwar Subhrajit , Dohare Sushil , Madkhli Aysh Y. , Noor I. M. , Singh Pramod K. , Sahoo Nanda Gopal
Published: May 2022

In this study, the laboratory scale production of activated carbon synthesized from PVC with CoCl2 and H3PO4, which is cheaper and has a good yield source material, is reported.
Characterization of student problem solving and development of a general workflow for predicting organic reactivity
Authors: Helix Max R. , Blackford Katherine A. , Firestein Zachary M. , Greenbaum Julia C. , Gibson Katarina , Baranger Anne M.
Published: May 2022

A central practice in the discipline of organic chemistry is the ability to solve certain fundamental problems, including predicting reactivity, proposing mechanisms, and designing syntheses. These problems are encountered frequently by both students and practitioners, who need to utilize vast amounts of content knowledge in specific ways to generate reasonable solutions. To gain insight into how one of these major problem types can be solved, we have investigated student approaches to complex predict-the-product problems through the detailed analysis of think-aloud interviews. This work led to the creation of a general workflow model that describes the reasoning pathways of students with varying levels of expertise when attempting to predict organic reactivity. The problems used in this study were designed to be non-trivial and potentially ambiguous to elicit “true” problem solving and discourage a purely memorization-based approach, even from more experienced organic chemists. Rich descriptions of undergraduate and graduate student interviews are provided, and student thought processes are characterized in terms of common problem-solving actions. These actions were developed into the workflow model using an iterative method that combined results from our analysis with the experiences of instructors and feedback from both undergraduate focus groups and graduate students. The workflow serves as both a potential instructional tool and a model for student thinking. This model is general enough to be applied to both successful and unsuccessful solution pathways by both novice undergraduates and more expert-like graduate students. Characteristics of more successful and more experienced problem solvers are investigated, and concrete strategies that can be recommended to students are discussed. The results of this study complement existing work on other fundamental problem types in organic chemistry and suggest a variety of teaching interventions to develop students into more successful organic problem solvers.
SNG based energy storage systems with subsurface CO2storage
Authors: Fogel Stefan , Yeates Christopher , Unger Sebastian , Rodriguez-Garcia Gonzalo , Baetcke Lars , Dornheim Martin , Schmidt-Hattenberger Cornelia , Bruhn David , Hampel Uwe
Published: May 2022

Power-to-gas-to-power technologies incorporating electrolysis, methanation, SNG-fired Allam cycles and subsurface storages allow for a confined and circular use of CO2/CH4and thus an emission-free seasonal storage of intermittent renewable energy.
Scintillator-based radiocatalytic superoxide radical production for long-term tumor DNA damage
Authors: Wang Cheng , Wang Haoran , Luo Lifeng , Gan Shaoju , Yao Yingfang , Wei Qinhua , Wu Jinhui , Yuan Ahu , Hu Yiqiao , Wu Congping , Zou Zhigang
Published: May 2022

Based on the TiO2-coated lanthanide pyrosilicate scintillator, radiocatalysis was applied to generate with high yield and selectivity, which is beneficial to killing cancer cells as well as inhibiting the DNA self-repair process.
Correction: Cesium carbonate mediated C–H functionalization of perhalogenated 12-vertex carborane anions
Authors: Lovera Sergio O. , Bagdasarian Alex L. , Guo Juchen , Nelson Hosea M. , Lavallo Vincent
Published: May 2022

Correction for ‘Cesium carbonate mediated C–H functionalization of perhalogenated 12-vertex carborane anions’ by Sergio O. Lovera et al., Chem. Commun., 2022, 58, 4060–4062, DOI: https://doi.org/10.1039/D2CC00173J.
Merging of the photocatalyst decatungstate and naphthalene diimide in a hybrid structure for the oxidative coupling of amines
Authors: Liu Zhengfen , Li Xiaobo , Chen Jian , Li Chao , Luo Fumang , Cheng Fei-Xiang , Liu Jian-Jun
Published: May 2022

A novel photoactive hybrid material was prepared based on the electron-deficient naphthalene diimide and the photocatalyst decatungstate, and it exhibits excellent photocatalytic activity towards the oxidation of amines to imines.
Structural, magnetic and photoluminescence properties of new hybrid hypophosphites: discovery of the first noncentrosymmetric and two cobalt-based members
Authors: Mączka Mirosław , Gągor Anna , Stefańska Dagmara , Zaręba Jan K. , Pikul Adam
Published: May 2022

Hybrid hypophosphite perovskites exhibiting ferromagnetism, polar order and photoluminescence.
Surface-enhanced luminescence of Cr3+-doped ZnAl2O4 and MgAl2O4 using Ag@SiO2 and Au@SiO2 core–shell nanoparticles
Authors: Valenzuela-Fernández Rodrigo A. , Cardin Julien , Portier Xavier , Labbé Christophe , Segura Camilo , Vargas Víctor , Galdámez Antonio , Osorio-Román Igor O.
Published: May 2022

We studied the surface-enhanced effect exerted by modified surfaces with Ag@SiO2 and Au@SiO2 core–shell nanoparticles on the photoluminescence of two chromium-doped spinels.
Thermal hysteresis of stress and strain in spin-crossover@polymer composites: towards a rational design of actuator devices
Authors: Angulo-Cervera José Elias , Piedrahita-Bello Mario , Martin Baptiste , Alavi Seyed Ehsan , Nicolazzi William , Salmon Lionel , Molnár Gábor , Bousseksou Azzedine
Published: May 2022

We revealed strain (stress) vs. temperature hysteresis loops in spin-crossover@polymer composite actuator materials. The role of the particle-matrix elastic modulus mismatch is highlighted.
FLT3 inhibitors for acute myeloid leukemia: successes, defeats, and emerging paradigms
Authors: Acharya Baku , Saha Debasmita , Armstrong Daniel , Lakkaniga Naga Rajiv , Frett Brendan
Published: May 2022

Numerous precision medicine therapies for AML have been investigated, but the disease remains difficult to target. Therapies that block common resistance mechanisms are needed to improve treatment durability.
Regioselective conjugate addition of isoxazol-5-ones to ethenesulfonyl fluoride
Authors: Zhu Dong-yu , Chen Yuan , Zhang Xue-jing , Yan Ming
Published: May 2022

Highly regioselective conjugate addition of isoxazol-5-ones to ESF gave N2-/C4-alkylated isoxazol-5-ones with a sulfonyl fluoride group in good to excellent yields.
Electrochemically controlled dearomative 2,3-difunctionalization of indoles to synthesize oxoindoline derivatives
Authors: Peng Xichao , Wen Linzi , Ning Zuozhou , Zhang Zhicheng , Sun Chengbo , Tang Yu , Feng Pengju
Published: May 2022

Electrochemistry-controlled dearomative 2,3-difunctionalization of indoles via electrochemically anode-selective oxidative cross coupling was achieved, allowing tunable access to a wide variety of synthetically useful oxindole derivatives.
Light-assisted anti-wrinkling on azobenzene-containing polyblend films
Authors: Wang Juanjuan , Ji Haipeng , Guo Yanqian , Wang Bin , Han Xue , Li Lele , Wu Fuqi , Li Jingqing , Lu Conghua
Published: May 2022

A light-assisted strategy based on the photo-responsive behavior of azobenzene moieties is developed to prevent surface wrinkling on azobenzene-containing polyblend films.
Improved OER performance of an Anderson-supported cobalt coordination polymer by assembling with acetylene black
Authors: Joshi Arti , Sood Parul , Gaur Ashish , Rani Deepika , Madaan Venika , Singh Monika
Published: May 2022

First report on POM based hybridi.e.Anderson cluster based solid for OER in a basic medium. Increased efficiencyviaassembly with acetylene black. The composite shows an overpotential of 330 mV to achieve a current density of 100 mA cm−2with a stability of 40 h.
Post-oxidation of a fully conjugated benzotrithiophene-based COF for photocatalytic detoxification of a sulfur mustard simulant
Authors: Li Shuai , Dai Lu , Li Li , Dong Anwang , Li Jiani , Meng Xiangjian , Wang Bo , Li Pengfei
Published: May 2022

Through the introduction of sulfone groups, BTT-TPh-O-COF shows a 5-fold enhancement for the photocatalytic detoxification of a sulfur mustard simulant, and was further used to fabricate highly active composite protective films.
Composite gel-polymer electrolyte for high-loading polysulfide cathodes
Authors: Chiu Li-Ling , Chung Sheng-Heng
Published: May 2022

The PMMA-based gel-polymer electrolyte (GPE) featuring the ester group (R–COO–R′) demonstrates high ionic conductivity and strong polysulfide retention for designing safe lithium–sulfur cells with high energy density.
Near-infrared irradiation controlled thermo-switchable polymeric photosensitizer against β-amyloid fibrillation
Authors: Chen Li , Zhou Zhe , Zhang Yuexing , Pan Jie , Wang Kai , Wang Hang-Xing
Published: May 2022

Phase transition switchable combination of photothermal therapy against amyloid-β (Aβ) aggregation through a NIR light-driven thermo-switchable polymeric photosensitizer prepared by conjugating hydroxypropyl cellulose with boron dipyrromethene.
Near-infrared heterojunction field modulated phototransistors with distinct photodetection/photostorage switching features for artificial visuals
Authors: Han Jiayue , Du Xiaoyang , Zhang Zhenhan , He Zeyu , Han Chao , Xie Runzhang , Wang Fang , Tao Silu , Hu Weida , Shan Chongxin , Yang Ming , Gou Jun , Wu Zhiming , Jiang Yadong , Wang Jun
Published: May 2022

By incorporating organic BHJ onto graphene, graphene/ZnO/PTB7-Th:IEICO-4F shows gate tunable photodetection/photostorage switching features for the implementation of both retinomorphic vision and memorial preprocessing functions.
Consequence of optimal bonding on cation ordering and enhanced near-infrared luminescence in Cr3+-doped pyroxene oxides
Authors: Liu Hongzhen , Zhao Fangyi , Cai Hao , Song Zhen , Liu Quanlin
Published: May 2022

The intermediate compositions in Ge-based pyroxene solid-solutions, (Mg1-yLiy)(Mg1-yScy)Ge2O6:4%Cr3+ (y = 0–1), are better phosphor hosts for Cr3+, possessing higher internal quantum efficiency and thermal luminescence stability.
Probing the nature of dissipation in compressible MHD turbulence
Authors: Richard Thibaud , Lesaffre Pierre , Falgarone Edith , Lehmann Andrew
Published: May 2022

Context. An essential facet of turbulence is the space–time intermittency of the cascade of energy that leads to coherent structures of high dissipation.

Aims. In this work, we aim to systematically investigate the physical nature of the intense dissipation regions in decaying isothermal magnetohydrodynamical (MHD) turbulence.

Methods. We probed the turbulent dissipation with grid-based simulations of compressible isothermal decaying MHD turbulence. We took unprecedented care in resolving and controlling dissipation: we designed methods to locally recover the dissipation due to the numerical scheme. We locally investigated the geometry of the gradients of the fluid state variables. We developed a method to assess the physical nature of the largest gradients in simulations and to estimate their travelling velocity. Finally, we investigated their statistics.

Results. We find that intense dissipation regions mainly correspond to sheets; locally, density, velocity, and magnetic fields vary primarily in one direction. We identify these highly dissipative regions as fast and slow shocks or Alfvén discontinuities (Parker sheets or rotational discontinuities). On these structures, we find the main deviation from a 1D planar steady-state is mass loss in the plane of the structure. We investigated the effect of initial conditions, which yield different imprints at an early time on the relative distributions among these four categories. However, these differences fade out after about one turnover time, at which point they become dominated by weakly compressible Alfvén discontinuities. We show that the magnetic Prandtl number has little influence on the statistics of these discontinuities, but it controls the ohmic versus viscous heating rates within them. Finally, we find that the entrance characteristics of the structures (such as entrance velocity and magnetic pressure) are strongly correlated.

Conclusions. These new methods allow us to consider developed compressible turbulence as a statistical collection of intense dissipation structures. This can be used to post-process 3D turbulence with detailed 1D models apt for comparison with observations. It could also be useful as a framework to formulate new dynamical properties of turbulence.
Water management strategies for desirable IWRM implementation and application to the initiative projects, Korea
Authors: Kang Dongwon , Park Hyunchul , Chae Miae
Published: May 2022

K-water has led national policymaking in South Korea through a master plan established in 2015 to raise national awareness on integrated water resources management (IWRM). It has promoted leading pilot projects as a short-term plan. Since the construction of the initial dam on the Seomjin River in 1928, inefficient water management has persisted. There was a jumble of agreements, treaties, regulations, and various institutions that could not keep up with the changing conditions in dam operation and water use caused by the construction of the new dam and auxiliary spillways on the river. Also, there were four agencies designated as dam usage rightholders: Two more were added to the original two dam licensees. Accordingly, the initiative project established a consensus on the need to streamline dam operations and promoted deriving social agreements through a council composed of the field-level departments of each water management agency. After government mediation, dam management regulations were revised to determine adjustments in the dam usage rights and the basic priorities in water use. This IWRM pilot model, which promotes the rational use of a dam by multiple users, successfully satisfied each stakeholder’s agreed-upon rights in 2019, the first project year.
Expérience du bassin de la Dordogne, au service de l’adaptation de la gestion des grands ouvrages hydroélectriques aux nouveaux enjeux sociaux, économiques et environnementaux
Authors: Dusservais Céline , Guerri Olivier
Published: May 2022

Le bassin de la Dordogne abrite l’un des principaux complexes français de barrages hydroélectriques, construit pour contribuer à l’autonomie énergétique du pays, puis à la régulation du réseau électrique. Depuis leur construction, le contexte de gestion des barrages a profondément changé. En plus des évolutions propres au domaine de l’énergie, de nouveaux enjeux de multiusages et d’environnement se sont affirmés comme des éléments stratégiques d’avenir: l’évolution, due au changement climatique, de la cartographie des ressources en eau disponibles pour les services d’adduction en eau potable et pour l’agriculture; la nécessité, pour enrayer l’effondrement de certaines formes de biodiversité, de réduire tous les impacts écologiques dont ceux des barrages; les nouvelles fonctions sociales et économiques des retenues et cours d’eau en matière de paysage, de loisirs et de tourisme. Plusieurs expériences innovantes ont été menées dans le bassin de la Dordogne: la convention sur la réduction de l’impact des éclusées hydroélectriques (depuis 2004); le programme de restauration écologique Initiative Biosphère Dordogne (2013-2015); l’exercice prospectif Dordogne 2050 (2017-2020). Ces démarches contribuent à l’engagement du bassin versant, reconnu comme Réserve de Biosphère depuis 2012 par l’UNESCO.
La Durance du future (France) : le projet R2D2-250, la démarche C3PO ou la modélisation prospective pour aider la décision
Authors: Dumoulin Pascal , Le Normant Catherine , Samie René
Published: May 2022

Le bassin hydrographique de la Durance constitue l’essentiel des ressources en eau de la région Sud-Provence-Alpes-Côte d’Azur. Une gestion durable des eaux et des nombreux aménagements multifonction est indispensable à l’économie régionale. En 2015, le projet R2D2-2050 a mené un exercice de prospective participative afin d’identifier les enjeux futurs liés à la disponibilité et à l’utilisation de la ressource en eau pour plusieurs scénarios d’évolution du climat et des territoires. Les résultats font présager des épisodes de tensions sur la ressource dans le futur et ont montré la nécessité de poursuivre et de renforcer les mesures d’adaptation. Pour répondre aux enjeux futurs liés à l’eau de la Durance, le SMAVD porte la démarche d’élaboration d’un des plus grands SAGE de France. Pour accompagner ce projet politique ambitieux sur le plan technique, le SMAVD développe un outil d’aide à la décision C3PO (modélisation ressourceusages-infrastructures sous WEAP). Cette démarche innovante associe les acteurs du bassin versant et du monde scientifique et permettra d’identifier les leviers d’adaptation durables aux changements globaux. Les intérêts réciproques autour de cet outil ont donné lieu à un partenariat exemplaire entre le SMAVD et EDF gestionnaire des aménagements hydroélectriques, bien au-delà de l’échange de données.
Projet Roselend - Ensemble, faire vivre notre patrimoine
Authors: Bouvier Anne-Lise , Mailland-Rosset Sébastien
Published: May 2022

L’ambition de ce projet est de favoriser le développement équilibré d’un territoire emblématique de la Savoie, celui des alpages de Roselend dans le Beaufortain, en ayant recours aux formes les plus innovantes de concertation, de gouvernance et de financement. Il est né d’un constat partagé de multi-usages sur un secteur où l’hydroélectricité, le tourisme et le pastoralisme coexistent, depuis la construction du barrage, dans un espace riche d’une biodiversité remarquable. Avec le Projet Roselend, tous les acteurs se retrouvent dans un collectif, sous-tendu par des valeurs fortes, qui permet à chacun de comprendre et s’approprier les enjeux des autres et d’agir en co-responsabilité, pour le bien commun. La gouvernance territoriale partagée mise en place par les 4 partenaires fondateurs : EDF, la Commune de Beaufort, la Société d’Économie Alpestre de Savoie et le Conservatoire des Espaces Naturels de Savoie, permet de garantir l’organisation du cadre d’échanges, proposer des solutions adaptées et partagées et fédérer un écosystème dense d’acteurs privés, institutionnels et issus de la société civile. Le mode de financement des actions mêlant argent public et fonds privés, assure la pérennité du projet qui compte déjà 8 réalisations, 5 actions engagées et 8 projets en réflexion à suivre sur www.projetroselend.com.
PNPCA Consultation and Improvement for Hydro-power Development on Mekong River
Authors: Yu Haomiao , Chen Shaojun
Published: May 2022

As a trans-boundary river, the hydro-power development on the Mekong River has attracted the attention of the international community. Since the 1950s, the countries along the Mekong River discussed, consulted and established a multilateral mechanism to resolve disputes, reduce differences, authorize management, and share benefits. However it was not until 1995 that the available Procedures for Notification, Prior Consultation and Agreement (PNPCA) was basically established. This paper reviews the history of the development of a multilateral consultation mechanism by the countries along the Mekong River, analyzes the current consultation mechanism through a case example, and proposes relevant issues and corresponding improvement scheme.
Virtual stakeholder engagement for transboundary water management: approach, challenges, and limitations
Authors: Gilroy Kristin , Avisse Nicholas , Nieto Cristian , Riffard-Chenet Marine
Published: May 2022

Water security is a complex challenge in transboundary basins: competing upstream-downstream demands and the pursuit of sovereign interests are key factors often responsible for fragmented water resource management. Designing a transboundary structure under these conditions requires common interests from which each country can benefit. On the Ruzizi River, which delimits the border between Rwanda and the Democratic Republic of Congo (DRC) upstream and between the DRC and Burundi downstream, two structures have already been built. The three riparian countries have been engaged since 1976 within the Economic Community of the Great Lakes Countries. It is through this body that the three member states decided to build a third dam to complete the cascade. TRACTEBEL is involved through a climate change resilience assessment which requires stakeholder engagement from the three countries. While stakeholder engagement is generally a difficult exercise, the process has been exacerbated by the COVID-19 epidemic. To adapt, the TRACTEBEL team proposed virtual workshops for local stakeholders, as well as the launch of a project website to encourage maximum interaction. The challenges and limitations of these solutions will be presented. This approach is the first step towards establishing a sustainable governance of the Ruzizi cascade.
Sharing transboundary waters
Authors: Türk Özge , Türk Necdet
Published: May 2022

Sharing the water of transboundary watercourses sometimes become a source of dispute between riparian states. A general method to share the water of transboundary watercourses has not yet been applied. This article examines existing practices, disputes, and criteria of some of the international financial institutions to propose a simple water-sharing method to allocate the water of the transboundary watercourses between riparian states. This method will help each riparian country to know how much water it will get from the transboundary water flow. So, states can plan on how to divide water between different uses and on building infrastructures on the watercourse or not. The proposed method is expected to decrease water disputes between riparian states as it clarifies the amount of water every riparian state gets from the transboundary watercourse. This article proposes a simple water-sharing method based on sharing the transboundary water quantity by 1/3 ratio for the downstream state and 2/3 for the upstream state. The method envisages compensation payments to other riparian states in different forms in case of excess water usage. As the environment needs a regular water flow, the proposed method also inquiries about some water to be released for the environment.
Pwalugu Multipurpose Dam Project: story of a major collaborative project
Authors: Cornille Oriane , Bocquet Jean-Michel , Wiafe Kwaku
Published: May 2022

The Volta River Authority is starting this year the construction of the Pwalugu Multipurpose Dam Project (PMDP) on the White Volta River across the Upper East and Northern regions of Ghana with the aim to foster economic development in several ways: (i) developing the irrigation potential of the White Volta plains, (ii) mitigating the flood impacts downstream of the dam, (iii) improving Ghana’s power system and (iv) generating secondary benefits through related activities such as fishery and domestic water supply. This project, studied by Tractebel since the early 1990s, was always governed by the principle to balance the benefits between antagonistic objectives. Dedicated operation rules have been defined to improve the overall benefits. Limitation of the extent of the reservoir and its related environmental and social impacts have also been taken into account to define the final design. This paper aims to present how all these benefits have been estimated and compared to lead to the final design under implementation.
Establishment of the comprehensive river environment conservation system in collaboration with river stakeholders on the Tenryu River
Authors: Kitamura Yuichi
Published: May 2022

The sedimentation, turbid water and water quality are typical environmental issues for dams and reservoirs which have impact on the reservoir and downstream of dams. These impacts are influenced from the upstream of a dam, and influence to the downstream. Therefore, a more integrated environmental management approach and consideration have been required for the whole river system. The Tenryu River in Japan flows through the erodible area near the Median Tectonic Line on Honshu, the main island of Japan, and continuously carries a lot of sediment during floods. The “Tenryu River Natural Resources Rebirth Promotion Committee” was established in 2012. The purpose of the committee is to restore fish resources and improve the river environment. The feature of the liaison committee is that it is composed of the Tenryu River fisheries association, academic experts, and dam owner and exchanges knowledge and technology information in spite of each interest. The current activities are related to the theme of “attached algae/environmental DNA survey”, “turbid water measures in reservoir/spawning bed construction technique at downstream,” and “information dissemination”. In this paper, the activities of the comprehensive reservoir and river environment conservation system in collaboration with river stakeholders are introduced and described, including future prospects.
Optimization of multipurpose reservoir system operation (Case study: Sefidrud and Shahryar reservoir dams)
Authors: Abolvaset Naeemeh , shahradfar Simin , Mihandoost Atosa
Published: May 2022

Nowadays, effective water management becomes more vital all over the worlds. Due to the effect of climate change and population growth, reservoirs play a more important role in water resources management. Reservoirs can be used for multiple purposes such as irrigation, industrial water supply, hydropower generation, flood protection, water quality management, recreation and so on. In this paper, an optimized model have been considered and solved based on the goal programming method for the optimal operation of a multi-objective two reservoir systems in Sefidrud watershed. Release for irrigation demand and environment, flood controlling and recreation are represented as objectives. Then, to consider uncertainties and also for achieving the general method for reservoirs operation, because of the considerable advantages of linguistic rules in better inferring and interpretation of systems, an adaptive neuro based fuzzy inference system (ANFIS) approach is used to construct operation rules for these multipurpose reservoirs. The results of the ANFIS models show that they can be applied successfully to provide high accuracy for the management of the reservoirs system.
Complementarities and synergies with intermittent renewable energy, related issues - Burkina Faso cases studies
Authors: Nombré Adama , Lemperière François , Millogo Founemé , Kaboré Moussa
Published: May 2022

Pumped Storage Plants (PSP) offer opportunities for better water mobilization and to unlock the development of hydropower in Burkina Faso. The revolution in photovoltaic energy, which has greatly improved reliability and production costs, has opened up major prospects for the energy development of Sahelian countries with a very large solar energy deposit that has remained fallow for the time being. The lower production cost of solar energy makes it more attractive to mobilize water in offshore (outside rivers) basins and reservoirs in areas where there are few underground water resources and where flat land limits the construction of dams. This paper will develop these perspectives for a country like Burkina and the Sahel in general where access to electricity is one of the lowest in the world which, paradoxically, have a very large solar deposit and insufficient water resource mobilization.
Hydro-solaire : une nouvelle utilisation des réservoirs
Authors: Deroo Luc , Sahut Yves , Defrance Benoit
Published: May 2022

Les retenues de barrages peuvent offrir de nouveaux services pour le développement de vastes capacités d’électricité solaires, que ce soit par l’implantation de panneaux solaires flottants, mais aussi en offrant une capacité de stockage hydraulique pouvant être mobilisée en hybridation avec la ferme solaire, pour produire une électricité dispatchable. L’article aborde dans un premier temps les intérêts principaux d’une telle hybridation, ainsi que les contraintes et enjeux qui lui sont associés, notamment pour un développement sur le continent africain. Plusieurs fonctionnements sont ensuite décrits à travers le prisme de trois pas de temps : le pas de temps de la minute (pour des études à dominance dynamique), le pas de temps journalier (pour étudier le placement de l’énergie) et le pas de temps annuel (pour étudier les influences saisonnières et optimiser la gestion de la retenue). Deux exemples sont enfin donnés pour illustrer l’intérêt actuel porté à cette nouvelle façon de produire de l’électricité.
The huge potential of new dams is based upon pumping
Authors: Lemperière François , Nombre Adama , Fry Jean-Jacques , Deroo Luc
Published: May 2022

Existing dams are mainly used for creating along river reservoirs filled by gravity. The potential of new dams for such uses is limited in most countries by the lack of sites, the competitive cost of wind or solar energy supply and the criticism of environmental impacts. But there is a huge potential of large new reservoirs filled by pumping. Such use will probably be very important after 2030 for storage of wind and solar energy which will become the main sources of electricity. Very large off rivers reservoirs have a huge future as well for seasonal water storage as for floods mitigation. Environmental impacts of such uses are usually better than for traditional ones. Yearly investments for new dams may be in 2040 much more important than ever in the past. Dams’ designs may be traditional or innovative.
Synergie hydro-solaire : Recherche d’un optimum
Authors: Bernicot Marine , Deroo Luc , Peltié Benjamin
Published: May 2022

L’hydroélectricité doit aujourd’hui répondre à de nombreux défis : dimension des retenues et impacts associés, gestion de la ressource en eau et résilience au changement climatique, pilotabilité de la production électrique et positionnement vis-à-vis des énergies renouvelables intermittentes… Dans ce contexte, l’hybridation des centrales hydroélectriques avec des centrales solaires semble une opportunité prometteuse et pourvoyeuse de solutions. Au travers d’exemples, l’article explore les tenants et aboutissants d’une telle hybridation aux trois pas de temps d’étude, annuel, journalier / horaire et minute. Il illustre en particulier la méthode de définition du couple solaire / hydro optimum, en fonction d’un certain nombre de paramètres spécifiques à chaque site : débit écologique, variations acceptables de débit en aval, niveau de service rendu au réseau (réserve tournante, passage d’un nuage), forme de la courbe de charge journalière, prise en compte des autres usages de l’eau, objectifs de gestion annuelle, etc.