bluuebunny/crossref_metadata_2025 huggingface dataset:
Pyrrolobenzodiazepines as Transcription Factor Inhibitors: An Overview
Authors: Corcoran David B. , Thurston David E. , Rahman Khondaker Miraz
Published: September 2018

Since their discovery in Streptomyces bacteria over half a century ago, pyrrolobenzodiazepines (PBDs) have generated significant interest as potential chemotherapeutic agents due to their sequence-selective DNA alkylating capacity. The development of synthetic PBD compounds from their naturally derived bacterial counterparts has enhanced both the potency and safety profiles of PBDs. Interestingly, such modifications of traditional PBD cores have sometimes led to an expansion of the mechanism of action of these compounds from simple DNA alkylation. This review documents one such change in mechanism of action of the PBDs, which has been engineered through chemical modifications of traditional PBD structures: the inhibition of transcription factor activity.
Small Molecule Inhibitors of NF-κB and Their Therapeutic Potential in Leukaemia
Authors: Pepper Chris , Fegan Chris
Published: September 2018

The transcription factor nuclear factor kappa B (NF-κB) regulates the expression of over 200 genes. Many of these modulate cellular processes involved in the initiation, maintenance and growth of human malignancies. In this regard, both lymphoid and myeloid leukaemia often exhibit aberrant activation of NF-κB, implicating it in the pathology of these diseases and hence making it a promising therapeutic target. In addition, it is now appreciated that conventional cytotoxic agents can induce NF-κB activation, resulting in the suppression of tumour cell apoptosis and the development of drug resistance. Therefore, NF-κB inhibitors may prove clinically useful as single agents and in combination with chemotherapy. In this chapter we will review the current knowledge about the expression and regulation of NF-κB in different types of leukaemia and describe the promise, challenges and alternative strategies associated with the therapeutic targeting of NF-κB.
Targeting Promoter G-Quadruplexes for Transcriptional Control
Authors: Morgan Rhianna K. , Brooks Tracy A.
Published: September 2018

Non-canonical DNA structures are found throughout the genome, transiently interspersed with B-DNA, in regions that are important for the regulation of various cellular processes. G–C-rich tracts, in particular, can form unique higher order G-quadruplex structures, which have been shown to exist in regions of DNA repair, telomeric regulation, centromeres and, most notably, transcriptional control. These structures have been identified in the promoters of an array of proto-oncogenes and represent attractive targets for small molecule development. This chapter focuses on the identification and targeting of G-quadruplex structures found in telomeres and oncogenes, discusses the findings related to the transcriptional regulation of MYC, kRAS, and Bcl-2, and concludes with a discussion on the future of targeting unique G-quadruplexes throughout the genome.
Microfluidic flow confinement to avoid chemotaxis-based upstream growth in a biofilm flow cell reactor
Authors: Asayesh Farnaz , Zarabadi Mir Pouyan , Aznaveh Nahid Babaei , Greener Jesse
Published: September 2018

Introduction of bacterial inoculant into a chemostat bioreactor can lead to unwanted contamination of upstream elementsviachemotaxis. Passive microfluidic elements show the potential to solve this problem.
Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation
Authors: Liu Jiquan , Xu Yeping , Groszewicz Pedro B. , Brodrecht Martin , Fasel Claudia , Hofmann Kathrin , Tan Xijuan , Gutmann Torsten , Buntkowsky Gerd
Published: September 2018

Seven novel dirhodium coordination polymers (Rh2–Ln) (n = 1–7) are prepared by employing bitopic ligands to connect dirhodium nodes.
CO2 formation mechanism in Fischer–Tropsch synthesis over iron-based catalysts: a combined experimental and theoretical study
Authors: Liu Bing , Li Wenping , Zheng Jiao , Lin Qiang , Zhang Xin , Zhang Junwei , Jiang Feng , Xu Yuebing , Liu Xiaohao
Published: September 2018

Our investigation has unveiled that the Boudouard reaction rather than the WGS reaction plays a predominant role in CO2 formation over iron-based FTS catalysts.
Synthesis, characterization, and catalytic evaluation of ruthenium–diphosphine complexes bearing xanthate ligands
Authors: Zain Aldin Mohammed , Maho Anthony , Zaragoza Guillermo , Demonceau Albert , Delaude Lionel
Published: September 2018

Nine ruthenium chelates with the generic formula [Ru(S2COEt)2(diphos)] were synthesized and fully characterized. Their catalytic activity was probed in three distinct reactions.
Correction: Naphthalene flanked diketopyrrolopyrrole based organic semiconductors for high performance organic field effect transistors
Authors: Liu Qian , Sun Huabin , Blaikie Chula , Caporale Chiara , Manzhos Sergei , Feron Krishna , MacLeod Jennifer M. , Massi Massimiliano , Bottle Steven E. , Bell John , Noh Yong-Young , Sonar Prashant
Published: September 2018

Correction for ‘Naphthalene flanked diketopyrrolopyrrole based organic semiconductors for high performance organic field effect transistors’ by Qian Liu et al., New J. Chem., 2018, 42, 12374–12385.
Correction: Recent trends in the structural revision of natural products
Authors: Chhetri Bhuwan Khatri , Lavoie Serge , Sweeney-Jones Anne Marie , Kubanek Julia
Published: September 2018

Correction for ‘Recent trends in the structural revision of natural products’ by Bhuwan Khatri Chhetri et al., Nat. Prod. Rep., 2018, 35, 514–531.
Length-dependent dual-mechanism-controlled failure modes in silver penta-twinned nanowires
Authors: Liang Tianshou , Zhou Dejian , Wu Zhaohua , Shi Pengpeng , Chen Xiaoyong
Published: September 2018

A series of molecular dynamics simulations on silver penta-twinned nanowires are performed to reveal the tensile failure mechanisms that are responsible for the different failure modes and morphologies of fracture surfaces observed in various experimental reports.
One-dimensional nanostructures of II–VI ternary alloys: synthesis, optical properties, and applications
Authors: Lu Junpeng , Liu Hongwei , Zhang Xinhai , Sow Chorng Haur
Published: September 2018

One-dimensional (1D) nanostructures of II–VI ternary alloys are of prime interest due to their compatible features of both 1D nanostructures and semiconducting alloys.
Chiral sensors for determining the absolute configurations of α-amino acid derivatives
Authors: Chen Zhongxiang , Fan Hongjun , Yang Shiwei , Bian Guangling , Song Ling
Published: September 2018

Two simple1H NMR tests give the absolute configurations of α-amino acids.
Correction: Non-covalent polyhedral oligomeric silsesquioxane-polyoxometalates as inorganic–organic–inorganic hybrid materials for visible-light photocatalytic splitting of water
Authors: Prabu Rajendran , Peramaiah Karthik , Palanisami Nallasamy , Pescarmona Paolo P. , Neppolian Bernaurdshaw , Shanmugan Swaminathan
Published: September 2018

Correction for ‘Non-covalent polyhedral oligomeric silsesquioxane-polyoxometalates as inorganic–organic–inorganic hybrid materials for visible-light photocatalytic splitting of water’ by Rajendran Prabu et al., Inorg. Chem. Front., 2018, DOI: 10.1039/c8qi00449h.
Detection of SO2 derivatives using a new chalco-coumarin derivative in cationic micellar media: application to real samples
Authors: Gómez Marisol , Aliaga Margarita E. , Arancibia Verónica , Moya Alexis , Segura Camilo , Nuñez Marco T. , Aguirre Pabla , Nagles Edgar , García-Beltrán Olimpo
Published: September 2018

A new probe ChC16 was synthesized and studied as a turn-on fluorescent probe, based on a Michael addition mechanism for sensing SO2 derivatives, which is favored in the presence of cationic micellar media such as cetylpyridinium bromide (CPB).
Therapeutic efficacy of polydatin for nonalcoholic fatty liver disease via regulating inflammatory response in obese mice
Authors: Mo Juan-Fen , Wu Jia-Yuan , Zheng Li , Yu Ya-Wei , Zhang Tian-Xin , Guo Li , Bao Yi
Published: September 2018

Polydatin (PD), a natural precursor of resveratrol, has been used to treat several diseases, such as cardiovascular diseases, hepatic diseases and various cancers.
Direct laser-patterned ultra-wideband antennae with carbon nanotubes
Authors: Qiu Haochuan , Liu Houfang , Jia Xiufeng , Liu Xiao , Li Yuxing , Feng Jiafeng , Wei Hongxiang , Yang Yi , Ren Tian-ling
Published: September 2018

We report a novel one-step laser-patterning technology for CNT ultra-wideband antennas.
Ratiometric fluorescent probes for capturing endogenous hypochlorous acid in the lungs of mice
Authors: Zhang Xinfu , Zhao Weiyu , Li Bin , Li Wenqing , Zhang Chengxiang , Hou Xucheng , Jiang Justin , Dong Yizhou
Published: September 2018

ClO1, a ratiometric fluorescent probe, effectively captured endogenous HClO in the lungs of a lipopolysaccharide (LPS)-induced lung inflammation mouse model after intravenous administration.
Non-injection synthesis of L-shaped wurtzite Cu–Ga–Zn–S alloyed nanorods and their advantageous application in photocatalytic hydrogen evolution
Authors: Liu Zheming , Tang Aiwei , Liu Jun , Zhu Dongxu , Shi Xifeng , Kong Qinghua , Wang Zhijie , Qu Shengchun , Teng Feng , Wang Zhanguo
Published: September 2018

L-shaped wurtzite Cu–Ga–Zn–S alloyed nanorods are synthesized using a non-injection method for the first time, and they exhibit an enhanced photocatalytic hydrogen evolution compared with their binary or ternary counterparts.
Aqueous-processable polymer binder with strong mechanical and polysulfide-trapping properties for high performance of lithium–sulfur batteries
Authors: Yi Huan , Lan Tu , Yang Yu , Lei Zhiwen , Zeng Hongbo , Tang Tian , Wang Chaoyang , Deng Yonghong
Published: September 2018

A novel aqueous-processable polymer with multiple functional groups of catechol conjugated chitosan sulfate is developed as the binder of lithium sulfur batteries.
The classification, genetic diagnosis and modelling of monogenic autoinflammatory disorders
Authors: Moghaddas Fiona , Masters Seth L.
Published: September 2018

Monogenic autoinflammatory disorders are an increasingly heterogeneous group of conditions characterised by innate immune dysregulation. Improved genetic sequencing in recent years has led not only to the discovery of a plethora of conditions considered to be ‘autoinflammatory’, but also the broadening of the clinical and immunological phenotypic spectra seen in these disorders. This review outlines the classification strategies that have been employed for monogenic autoinflammatory disorders to date, including the primary innate immune pathway or the dominant cytokine implicated in disease pathogenesis, and highlights some of the advantages of these models. Furthermore, the use of the term ‘autoinflammatory’ is discussed in relation to disorders that cross the innate and adaptive immune divide. The utilisation of next-generation sequencing (NGS) in this population is examined, as are potential in vivo and in vitro methods of modelling to determine pathogenicity of novel genetic findings. Finally, areas where our understanding can be improved are highlighted, such as phenotypic variability and genotype–phenotype correlations, with the aim of identifying areas of future research.
Coronary artery disease in post-menopausal women: are there appropriate means of assessment?
Authors: Chiu Michael H. , Heydari Bobak , Batulan Zarah , Maarouf Nadia , Subramanya Vinita , Schenck-Gustafsson Karin , O’Brien Edward R.
Published: September 2018

The recognition of sex differences in cardiovascular disease, particularly the manifestations of coronary artery disease (CAD) in post-menopausal women, has introduced new challenges in not only understanding disease mechanisms but also identifying appropriate clinical means of assessing the efficacy of management strategies. For example, the majority of treatment algorithms for CAD are derived from the study of males, focus on epicardial stenoses, and inadequately account for the small intramyocardial vessel disease in women. However, newer investigational modalities, including stress perfusion cardiac magnetic resonance imaging and positron emission tomography are providing enhanced diagnostic accuracy and prognostication for women with microvascular disease. Moreover, these investigations may soon be complemented by simpler screening tools such as retinal vasculature imaging, as well as novel biomarkers (e.g. heat shock protein 27). Hence, it is vital that robust, sex-specific cardiovascular imaging modalities and biomarkers continue to be developed and are incorporated into practice guidelines that are used to manage women with CAD, as well as gauge the efficacy of any new treatment modalities. This review provides an overview of some of the sex differences in CAD and highlights emerging advances in the investigation of CAD in post-menopausal women.
Distributed architecture for self‐organising smart distribution systems
Authors: Saxena Kritika , Abhyankar Abhijit R.
Published: September 2018

Automation of emerging smart distribution grids is required to operate the grid efficiently and swiftly. This study draws a vision on grid automation with agent‐based cyber‐physical system integration to provide a truly distributed architecture. Furthermore, this study introduces a notion of self‐organising smart distribution grid that promotes the grid capability to heal and organise itself in the best‐suited topology without the intervention of a central operator. The proposed architecture comprises the system of bus agents (BAs) that emulate the given grid. This emulation is used by BAs to comprehend the grid conditions, switch location and compute their representative bus voltage and partial loss and to estimate the best organisation of the BAs as well as the grid. This study details the behavioural designing of BA that incorporates the functioning above. The proposed architecture also uses an event trigger approach to initiate grid organisation, which is showcased by case studies on IEEE 33 bus system. The results showcase the efficiency of the concept regarding solution accuracy with distributed computations; computational efficiency during contingencies; architecture performance under communication latency; and fault‐tolerant characteristics of the proposed architecture.
Disparity among low first ionization potential elements
Authors: Heidrich-Meisner Verena , Berger Lars , Wimmer-Schweingruber Robert F.
Published: September 2018

Context. The elemental composition of the solar wind differs from the solar photospheric composition. Elements with low first ionization potential (FIP) appear enhanced compared to O in the solar wind relative to the respective photospheric abundances. This so-called FIP effect is different in the slow solar wind and the coronal hole wind. However, under the same plasma conditions, for elements with similar FIPs such as Mg, Si, and Fe, comparable enhancements are expected.

Aims. We scrutinize the assumption that the FIP effect is always similar for different low FIP elements, namely Mg, Si, and Fe.

Methods. Here we investigate the dependency of the FIP effect of low FIP elements on the O7+/O6+ charge state ratio depending on time, that is the solar activity cycle, and solar wind type. In addition, we order the observed FIP ratios with respect to the O7+/O6+ charge state ratio into bins and analyze separately the respective distributions of the FIP ratio of Mg, Si, and Fe for each O7+/O6+ charge state ratio bin.

Results. We observe that the FIP effect shows the same qualitative yearly behavior for Mg and Si, while Fe shows significant differences during the solar activity maximum and its declining phase. In each year, the FIP effect for Mg and Si always increases with increasing O7+/O6+ charge state ratio, but for high O7+/O6+ charge state ratios the FIP effect for Fe shows a qualitatively different behavior. During the years 2001–2006, instead of increasing with the O7+/O6+ charge state ratio, the Fe FIP ratio exhibits a broad peak or plateau. In addition, the FIP distribution per O7+/O6+ charge state bin is significantly broader for Fe than for Mg and Si.

Conclusions. These observations support the conclusion that the elemental fractionation is only partly determined by FIP. In particular, the qualitative difference in behavior with increasing O7+/O6+ charge state ratio between Fe on the one hand and Mg and Si on the other hand is not yet well explained by models of fractionation.
The Rhône River, France: applying integrative sciences to sustainable management
Authors: Piégay Hervé
Published: September 2018

The Rhône River is one of the main European alpine rivers (watershed: 98 500 km2; length: 812 km total, 560 km in France; mean annual discharge at its mouth: 1700 m3 s-1; annual flood: 4000 m3/s), and the primary freshwater input to the western Mediterranean basin. It was mainly an upland river transporting gravel up to its delta and continuously supplied in sediments by its Alpine braided tributaries. The Durance River was one of the most active system before being controlled for producing electricity and supplying water for irrigation. The fluvial landscape has been engineered for more than 150 years, leading to altered aquatic and riparian ecosystems and social tensions in terms of local development scenarios. The channel was regulated between 1850 and 1930 for navigation purposes (embankments, groynes, dykes), then dammed for producing electricity (1898-1986: 21 hydroelectric dams, most of them with derivation canals). It is also equipped with 4 nuclear powerplants that use the river water for their cooling. After more than a century of developments leading to major biological and physical changes due to a significant artificialization of the river corridor, problems and stakes are still existing in terms of human safety, user satisfaction and local development and the aim is now to improve existing conditions and promote a sustainable development, shared by all actors. Today, stakeholders face tension in balancing various user interests regarding nature conservation, flood control, economic and recreational activities, ecological improvement. The French Rhône stakeholders have beencommitted since 2003 in implementing a large inter-regional sustainable development masterplan funded by the European Union (ERDF) called Plan Rhône I and II, focused on the whole river corridor. They created a collective framework grouping local actors to go beyond the complex and sometimes contradictory logics of each of them.
Impacts of gravel-bed rivers transformation on fluvial ecosystems and human society: Examples from the Czech flysch Carpathians
Authors: Škarpich Václav , Kubín Miroslav , Galia Tomáš , Ruman Stanislav , Hradecký Jan
Published: September 2018

In the last centuries, gravel-bed rivers in developed countries have undergone rapid changes in channel morphology. The most serious problems include channel transformation related to progressive channel narrowing, incision or bed sediment coarsening. The main reasons for transformations were connected to the human interventions, which affected water and sediment fluxes in the basins. This paper summarizes contemporary research activities focused on these negative effects of channel transformations in the Czech flysch Carpathian rivers (the Morávka, the Olše and the Ostravice draining the highest mountainous areas of the Beskydy Mts). As the result of channel transformations, progressive changes in fluvial ecosystem were observed. The initial phytosociological survey demonstrates a higher biodiversity in the floodplain along the preserved multi-thread river channel than along the deeply incised channel in the Morávka River basin. Our observations of aquatic communities demonstrated that the channel transformation connected with incision and coarsening of bed sediments negatively affected fish or lamprey populations in the studied rivers. Regulation, damming and incision of channels caused changes of hydrological regime linked with gradual drying of floodplain. Additionally, a large set of hydraulic structures, bridges or weirs were affected by undercutting and progressive destruction in the Ostravice, Olše and Morávka River basins, which is assigned to increased transport capacity of regulated channels together with decreased sediment supply from mountainous parts.
Influence of flood regime on riparian vegetation dynamics in rivers with alternate bars
Authors: Jourdain Camille , Claude Nicolas , Antoine Germain , Tassi Pablo , Cordier Florian
Published: September 2018

Throughout the 20th century, many rivers worldwide have undergone important riparian vegetation encroachment, which can be problematic in terms of flood risks and biodiversity. Nowadays, controlled floods is often considered as a management option in anthropized rivers, with the aim of limiting vegetation encroachment within river channels, as well as maintaining a diverse habitat by reactivating natural channel dynamics. In this context, this study aims at investigating the influence of different flood regimes on river bar vegetation development and dynamics, focussing on alternate bar systems which are typically found in embanked streams. This question has been addressed through two-dimensional bio-morphodynamic modeling of a simplified gravel bed river reach. Four hydrological scenarios with different flood peak discharges have been run for 50 years. For all scenarios, a steady increase in vegetation cover strongly impacts the evolution of bar morphology, until a relatively stable equilibrium is reached after one to three decades. Numerical results suggest that vegetation development on bars is associated to an increase in bar wavelength and a decrease in bar width. Higher peak flood discharges lead to narrower and longer bars, and a longer adjustment duration. When vegetation cover is fully developed, interannual flood variability seems crucial to maintain bedform and vegetation turnover.
Bedload transport in a steep alpine stream: Assessment of sediment mobility and virtual velocity using the bedload tracking
Authors: Rainato Riccardo , Picco Lorenzo , Cazzador Daniele Oss , Mao Luca
Published: September 2018

The bedload transport is challenging to analyze in field, consequently, several assumptions about it were made basing on laboratory researches or on short-term field studies. During the last decades several monitoring methods were developed to assess the bedload transport in the fluvial systems. The aim of this work is to investigate the transport of the coarse sediment material in a steep alpine stream, using the bedload tracking. The Rio Cordon is a typical alpine channel, located in the northeast of Italy. It is characterized by a rough streambed with a prevalent boulder-cascade and step pool morphology. Since 2011, 250 clasts equipped with Passive Integrated Transponders (PIT) were installed in the main channel, to analyze their mobility along a reach 320 m long. From November 2012 to August 2015, the transport induced by a range of hydraulic forcing between 0.44 m3 s-1 and 2.10 m3 s-1 was assessed by 10 PIT-surveys. First, the mobility expressed by the tracers was analyzed, observing marked differences in terms of travel distance. Then, the average recovery rate achieved during the tracer inventories (Rr > 70%) permitted to define the threshold discharge for each grain size class analyzed and, then, to assess the virtual velocity experienced by the tracers.
Development and implementation of ecological and economical flood protection measures at an alpine river
Authors: Stephan Ursula , Kainz Silke , Hengl Michael , Bickel Alexander , Mähr Markus , Burtscher Wolfgang
Published: September 2018

The river Lutz as many other rivers in Austria was forced into a straight and narrow river bed. Several weirs were erected to stabilise the river bed, but which, too, impeded organism passability. After decades with several floods the protection measures were in bad condition. In 2005, a 500-years flood caused heavy damage along the river and destroyed a main railway line. This incident initiated comprehensive planning activities to improve both, the flood protection as well as the ecological status of the river. Several technical measures focussing on stabilising the river bed, increasing the discharge capacity and improving the ecological status such as a step-pool-ramp with variable width, an open rip-rap, an increased river width as well as embankment groynes as an ecological and dynamic bank protection instead of a bank reinforcement were proposed. These measures were tested for feasibility and optimized in a physical model experiment.
Morphodynamic effects of stone and wooden groynes in a restored river reach
Authors: Zaid Bahaeldeen , Nardone Paride , Nones Michael , Gerstgraser Christoph , Koll Katinka
Published: September 2018

Restoration works on an 11 km long reach of the Spree River near Cottbus in Germany were accomplished in 2014. The overall objective was to improve the biodiversity, changing the morphological structure from a straight single-thread river to a braiding one with reshaped thalweg, and creating zones with varying flow velocities required for fish spawning. Several interventions were made, among which also two types of groynes were constructed along the reach: impermeable stone groynes, with an inclined crest so that only the tip is typically submerged during normal flow conditions, and wooden groynes made of several large trunks, which are mainly submerged at normal flow conditions. To compare local morphodynamic effects caused by the different types, flow velocities and bed topography were measured at distances of 12 m upstream and 16 m downstream of two selected groynes. The vertical profile was captured by measuring at five levels above the bed. Bed material was sampled at several locations around the groynes. The analysis of the measurements showed the effect of each groyne type on the flow velocity, bed topography and bed material. Furthermore, the differences in the effects of each groyne type on the flow, bed topography and bed material were highlighted.
Quantification of the morphodynamics and ecological functionality of a Mediterranean river
Authors: Chapuis Margot , Ait Elabas Amine , Souriguére Katia , Compagnon Franck , Mayen Vincent , Terrier Benoît
Published: September 2018

The Var River (South-East France) was extensively modified (channelization, dams…) on the 21th century and is currently undergoing an ambitious restoration project to restore its 'natural' active braiding pattern on the downstream reach of the river. As part of the feedback evaluation of the project, this study aims at: (1) quantifying the morphological evolution of the bed that is recovering from sediment discontinuity; (2) identifying and/or developing hydromorphological and ecological indicators which quantify improvement in the river system from hydrosedimentary and ecological points of view. We used LiDAR and orthophoto datasets and performed analyses for unchannelized braiding rivers [1, 2]. Active width (Wrestored = 242 ± 19 m vs. values ranging from 103 ± 53 to 163 ± 53 m for 'unrestored' reaches) and normalized bed relief index values (BRI*restored = 0,003 ± 0,001 vs. 0,003 ± 0,003 to 0,007 ± 0,004 for 'unrestored' reaches) indicate a combination of low roughness and wide active width. Thus the 'restored' reach shows a different set of indices compared to nearby 'unrestored' reaches, suggesting these tools are promising in discriminating 'restored' vs. 'unrestored' reaches. Adapting existing methods from 'natural' to 'channelized' braiding rivers widened the potential application of the tools developed by Lallias-Tacon [2] to modified braiding river systems.
Roots Characteristics of a flexible and mature vegetation: Preliminary results of experimental investigation in a meandering laboratory flume
Authors: Termini Donatella , Di Leonardo Alice
Published: September 2018

Vegetation controls sediment dynamics and affects the kinematic characteristics of flow in rivers. The uprooting mechanism is strongly affected by mechanical properties, morphology and branching of the roots system. This work presents preliminary results of experimental work conducted in a laboratory meandering flume. The work aims to investigate how the geometrical and mechanical characteristics of the roots of a real, flexible and mature vegetation could vary along the bend. Results show that both the geometrical and the mechanical characteristics of the roots assume higher/lower values in peculiar sections of the bend suggesting that they could be affected by the kinematic characteristic of flow.
Performance of a fish pass for multiple species: Scale model investigation
Authors: Bousmar Didier , Courtois Estelle , Van Audenhaege Loïc , Rollin Xavier
Published: September 2018

Artificial fish passes are often the most effective solution to restore the ecological continuity of a dammed river. Such a pass can be built for specifically targeted fish species, based on the existing knowledge on its swimming capacity and behaviour. Usually, a wider range of possible species are present in the river and may use the fish pass. In the present study, a vertical slot fish pass has been designed for salmonid fish (namely Atlantic salmon Salmo Salar). This fish pass layout was initially tested using a scale model where juvenile fish were introduced. The study has now been extended to other species, some of them having weaker swimming capacity: bleak (Alburnus alburnus); chub (Squalius cephalus); and bullhead (Cottus gobio). Fish behaviour in the pass was observed using PIT-tag and video. PIT-tag tracking enabled to characterise the capability of the fish to cross the whole fish pass. Video recording was used to analyse in more details the behaviour of the fish in a specific pool.
Hydraulic potential of the Lower Vistula (Poland)
Authors: Szydlowski Michal , Szymkiewicz Romuald , Gasiorowski Dariusz , Hakiel Jakub , Zima Piotr
Published: September 2018

The Vistula is the largest river in Poland. Lower Vistula (part of the river discussed in this paper) is almost four hundred kilometers long river section extending from the tributary Narew to the outflow to the Baltic Sea. In the 17th century the Vistula was the most navigable river in Europe. After partitioning of Poland the Vistula lost its significance. Now the Lower Vistula should provide a navigation connection to the Europe forming water routes E70 and E40. However it does not meet the criteria required for the international waterways. Moreover, the river has a quite large hydro-energy potential. There have been many plans for the development of the Lower Vistula River so far. Unfortunately none of them has been implemented. In this paper, the authors would like to present their own arguments to reactivate the Lower Vistula Cascade (LVC) project. In order to analyse the LVC idea and Lower Vistula hydraulic potential, a numerical hydraulic model of the Lower Vistula was developed at the Department of Hydraulic Engineering of Gdansk University of Technology. Various aspects of the LVC concept, such a potential inland waterways, hydropower, flood control and water retention, are discussed in the article.
Influence of lateral embayments on suspended sediment transport under unsteady flow conditions
Authors: Juez Carmelo , Thalmann Matthias , Schleiss Anton J. , Franca Mário J.
Published: September 2018

Local widening in a channelized river is a common practice in restoration projects. The lateral embayments built for this purpose in the river banks are partially filled up by fine sediments. This allows the formation of aquatic habitats with hydraulic and morphologic diversity. However, the design of these lateral cavities may be compromised by the fluctuations in the water discharge. To address this problem, systematic experimental investigations have been carried out with five different fluctuating hydrograph scenarios. Water depth, sediment concentration and area covered by the settled sediments are analysed in each experiment. The process of sedimentation in the lateral embayments proved to be, in general, resilient to flow fluctuations. However, there were several differences observed during the high flow phase fluctuation phase depending on the geometric configuration of the embayments and the applied hydrograph: (i) a higher peak in discharge means that more sediments are resuspended and a complete remobilization of the in-cavity sediment deposits is possible. (ii) Long and short cavities are more resilient to high flow events than cavities with an intermediate length.
Numerical modelling of cantilever failure and effect of slump blocks on meander migration
Authors: Arnez Ferrel Kattia Rubi , Kimura Ichiro , Shimizu Yasuyuki
Published: September 2018

This study proposes a new numerical model to study cantilever failures and the effect of slump blocks on meander migration in cohesive river banks. Previous models have incorporated the effect of slump blocks using different methodologies but most of them used an “indirect approach” (such as increasing the critical shear stresses or introducing armouring factors) which does not allow to evaluate the effect of slump blocks directly. The new numerical model introduces an explicit representation of slump blocks and it was obtained by coupling two models available on the literature. The model was able to represent the mechanisms of cantilever failure with slump blocks and their effect in meander migration in a hypothetical small scale channel.
Similitude of Scour around Bridge Piers
Authors: Link Oscar , Ettmer Bernd
Published: September 2018

Scales involved in bridge pier scour include the Reynolds number, the Froude number, and the ratio of the pier to the sediment diameter, among others. Consequently, it is not possible to achieve perfect similitude, and thus scale effects between model and prototype arise. In fact, these scale effects distort the scour estimations typically used in hydraulic design of bridges, as scour formulas are based mainly on results from scour experiments at the laboratory scale. In this paper, proper scales of the flow, sediment, and scour are derived theoretically. The suitability of these scales to achieve perfect similitude of scour is tested through carefully designed laboratory experiments conducted in three different flumes having different sizes and piers of different diameters, with five bed materials of different sizes and densities. Results show that the dimensionless effective flow work, W* is a suitable criteria for scaling the effects of river flows on the local scour process around a pier in a bed composed by grains represented by the dimensionless grain diameter D*. In this context, scale effects of the ratio of the pier to the sediment diameter is quantified and shown to be negligible.
Experimental study of the velocity field induced by a propeller jet in an inland-ship model and the related bed scour
Authors: Núñez-González Francisco , Koll Katinka , Spitzer Detlef
Published: September 2018

The highly turbulent flow induced by ship propellers has a great potential to scour the alluvial bottom of navigational rivers and canals. Characterization of the complex flow field behind propellers is essential for forecasting the scouring action. In this study the velocity field and scour induced by two standard arrangements of propeller, nozzle and rudder from inland vessels are investigated experimentally with a ship model on a scale of 1:16. There are two objectives: first, to identify the influence of the ship stern on the flow field, and second, to assess induced scour depths in relation to maximum current velocities close to the bottom. It is found that the equilibrium scour depths for the two propeller arrangements are of the same order of magnitude, but that the time development of scour is different. The differences can be explained by the converging trend of the flow velocities at the bottom level for the two situations, when the vertical distance between the propeller and the bottom is high. It is also shown that existing relations for the velocity field require amendment when the propeller is ducted, and for adequately considering the effect of the ship stern and rudder type.
Experimental investigation of reservoir sediments
Authors: Beckers Felix , Haun Stefan , Noack Markus
Published: September 2018

This study presents an experimental approach to investigate cohesive reservoir sediments. It is shown, how adjacent sediment cores can be extracted from reservoir beds with a Frahm Sediment Sampler. The cores are subsequently used for detailed investigations in a hydraulic laboratory. In a first step, related cores are identified based on their bulk density profiles. One part of the related cores is used to analyze the sediment properties over depth by means of potential stability parameters. The other part is used to determine the depth-dependent erosion stability in an erosion flume (SETEG-system). In the SETEG-system, a photogrammetric method is applied to measure the erosion rates of pre-defined sediment layers at different exposed shear stresses. Subsequently, the critical shear stress can be derived, which leads to an objective evaluation and allows a systematic approach. Finally, both results are combined to investigate possible correlations between the evaluated depth-dependent stability parameters and the measured erosion stability. The approach is presented on sediment cores from the case study “Kleiner Brombachsee”, a reservoir that is located in Middle Franconia, Germany.
Temporal variability of partially-contaminated sediments in a strongly regulated reservoir of the upper Rhine River
Authors: Antoine Germain , Pretet Thomas , Secher Matthieu , Clutier Anne
Published: September 2018

The upper Rhine River is a highly harnessed and regulated river. EDF (a French electricity company) is in charge of eight dams on the upper Rhine River for producing hydro-electricity. In order to increase the safety and the competitiveness of the installations, but also to reduce their environmental impact, the sediment dynamics in these reservoirs has become a key factor to control and predict. In this study, we focused on the Marckolsheim reservoir, which is located 50 kilometers upstream the city of Strasbourg. Since its construction in 1961, this reservoir has been filled continuously with cohesive sediments, partially contaminated. Two field campaigns were performed in 2015 and 2016 under two different discharge conditions, with the objectives of quantifying the complex velocity fields on this site. The numerical codes TELEMAC-2D and SISYPHE were used to simulate in 2D the hydrodynamic and the suspended sediment transport of the reservoir. A ten kilometers long model was built and calibrated with the measured data of the 2015 and 2016 field campaigns, but also with measurements of sediment parameters that have been done separately. The originality of this model consists in an explicit 3D representation of the dam gates. An algorithm was implemented in TELEMAC in order to adapt the gates position at each time step, in conformity with the real regulation rules followed by the dam operator. By using upstream measured data of discharge and suspended sediment concentration, a four months period was simulated. The comparison of the simulated results with bathymetric surveys shows good agreements if specific properties of sediments related to settling processes are taken into account. Finally, the dynamics of the contaminated sediments was simulated. A 3D spatial distribution of the contaminated sediments in the reservoir was defined at the initial state by using in situ measurements. The fully coupled hydraulic-sediment-pollutant simulation performed over a single flood event gives first interesting highlights on the resuspension conditions of the contaminated sediments.
Vortex-Resistance Hypothesis: Large Eddy Simulation of Turbulent Flow in Isolated Pool- Riffle Units
Authors: Dashtpeyma Hamed , MacVicar Bruce
Published: September 2018

By numerical simulations of turbulent flow in isolated poolriffle units with various riffle heights, four different types of vortices were found and named as follows: surface rollers (SR), corner rollers (CR), ramp rollers (CR), and axial tails (AT). Surface rollers are shaped on the flow surface due to submerged hydraulic jump or any obstacles in the forced poolriffle units. Corner rollers are shaped close to the corners near the walls at the pool head. Ramp rollers are formed at the bed of the channel on the ramp into the head of the pool. All kinds of vortices stretch in the streamwise direction as they travel to the downstream, which they are called axial tails. The simulations showed that all four types of vortices interact with each other, combine, amplify or cancel out each other as they travel downstream. The strength of vortices and how they interact result into different types of flow patterns. The surface rollers combine with corner rollers to make a jet like plunging flow near the pool bed. In other cases with lower riffle heights, ramp rollers tend to push the flow up, which in turn leads to higher turbulence near the bed and higher velocity near the flow surface (skimming flow). Moreover, if both surface rollers and ramp rollers have the similar strength (e.g., vorticity) and scale, the streamwise velocity profile has a peak around the middle of the flow, and minimum velocities near the bed and free surface. This flow pattern was named as “rifting flow.” Based on these findings, a new hypothesis is proposed called ‘vortex-resistance,’ which states that the turbulent structures, by increasing the eddy viscosity and changing the pressure domain, act as an obstacle that steers the flow. Plunging and skimming flow can thus be understood as the products of different types of turbulent structures. These findings provide new clarifications to long-standing questions related to the hydraulics of pools and riffles.
Numerical analysis of flood with a double grid model
Authors: Morikawa Go , Kimura Ichiro
Published: September 2018

The objective of this study is to verify the validity of a hyper grid type (double grid model) computational model, for calculating flood flows with inundations. Nowadays, detailed information of the bathymetry is available due to improved measurement techniques, such as LP data. However, the number of grid cells used in the computation is limited because of the limitation of computational infrastructures. A double grid approach based on the model proposed by Volp et. al.(2013) is employed to overcome this problem.This model directly uses the high resolution topographic data though the discretization of the governing equations are made on coarser grid. The computational results showed that the present numerical model can compute the large scale flood phenomena efficiently and accurately.
Effect of aspect ratio on higher order moments of velocity fluctuations in hydraulically rough open channel flow
Authors: Mahananda Minakshee , Reddy Hanmaiahgari Prashanth
Published: September 2018

The effect of aspect ratio on the higher order statistics of velocity fluctuations in a hydraulically rough turbulent open channel flow is investigated. In this regard, an experiment was conducted in a rough bed narrow open channel flow of aspect ratio equal to three and the instantaneous flow velocities were measured using a Nortek Vectrino+ Acoustic Doppler Velocimeter. To understand the effect of aspect ratio, the results obtained from the present study are compared with the literature data of approximately same Reynolds number and bed roughness in a wide open channel flow for turbulence intensities and higher order statistics of velocity fluctuations. Comparison of turbulence intensities between Narrow OCF and Wide OCF shows occurrence of higher streamwise and vertical turbulence intensities in the outer region of Narrow OCF. The results of third order moments of velocity fluctuations are sensitive to aspect ratio in the outer region.
Impact of initial conditions on the prediction of the spread of thermal pollution in rivers
Authors: Kalinowska Monika B. , Rowiński Pawel M. , Magnuszewski Artur
Published: September 2018

The influence of initial conditions on the prediction of the increase of river temperature below the point of release of heated water for a designed power plant has been analysed in this study. The results for different assumed values of river flow and different temperatures of the discharged heated water have been presented. The results have been analysed taking into account existing legal frames. The two-dimensional inhouse RivMix model has been used to simulate the temperature distribution whereas the two-dimensional depth-averaged turbulent open channel flow model CCHE2D has been used to simulate the velocity fields and the water depths for the selected flows of the river.
Non-intrusive techniques to measure roll waves level evolving in a flume
Authors: Maciel Geraldo de Freitas , Cunha Evandro Fernandes da , Sao Yuri Taglieri , Toniati André Luis , Fiorot Guilherme Henrique , Ferreira Fabiana de Oliveira , Kitano Cláudio , Gonçalves Junior Vicente de Paula
Published: September 2018

An open-channel experimental set-up is presented in this paper as a tool for examining the presence of instabilities on free-surfaces flows of non-Newtonian fluid. When these flows occur in favorable conditions of inclination, discharge and rheological properties, the propagation of instabilities can evolve into a specific type of wave, known as roll waves. The experimental apparatus developed allows study of stabilized roll waves in many scenarios for non-Newtonian rheology fluids, thereby constituting a highly useful tool for the understanding and control of roll waves. The test fluid used in the experiments was carbopol gel which is rheometrically representative of the muddy material from natural disasters, such as mudflows. Two non-intrusive level measurement systems are proposed (ultrasonic transducer and laser-based absorption technique), and the efficiency of each technique is presented and discussed. Both methods presented relatively low-cost implementation, and calibration procedure assured the quality of the results. The results from the experimental set-up were in agreement in shape and amplitude.
New methods for predicting and measuring dispersion in rivers
Authors: Nelson Jonathan , McDonald Richard , Legleiter Carl , Kinzel Paul , Terrell-Ramos Travis , Higashi Yutaka , Seo Il Won , Baek Donghae , Lee Du Han , Ryu Yonguk
Published: September 2018

To develop a better predictive tool for dispersion in rivers over a range of temporal and spatial scales, our group has developed a simple Lagrangian model that is applicable for a wide range of coordinate systems and flow modeling methodologies. The approach allows dispersion computations for a large suite of discretizations, model dimensions (1-, 2-, or 3-dimensional), spatial and temporal discretization, and turbulence closures. As the model is based on a discrete non-interacting particle approach, parallelization is straightforward, such that simulations with large numbers of particles are tractable. Results from the approach are compared to dispersion measurements made with conventional Rhodamine WT dye experiment in which typical at-a-point sensors are employed to determine concentration. The model performs well, but spatial resolution for experiments over large and or complex river flows was inadequate for model testing. To address this issue, we explored the idea of measuring spatial concentrations in river flows using hyperspectral remote sensing. Experiments both for idealized channels and real rivers show that this technique is viable and can provide high levels of spatial detail in concentration measurements with quantitatively accurate concentrations.