bluuebunny/crossref_metadata_2025_split huggingface dataset:
A review on erosion and erosion induced vibrations in Francis turbine
Authors: Shrestha Rakish , Pradhan Samman Singh , Gurung Prithivi , Ghimire Amul , Chitrakar Sailesh 
Published: June 2022

Abstract
Vibrations are one of the major issues observed during the operations of Francis turbine as they are frequently operated outside their optimal operating range, with rapid load changes. In hydropower plants, vibrations occur in various parts which can be classified as: hydraulic civil parts such as reservoir, intake, dam, tail race etc. mechanical parts such as penstock, turbine, draft tube and shaft, and electrical parts such as generator and transformer. However, due to the sediments and cavitation problems, the regions around rotating parts such as turbine experiences severe vibration. In the cases where the turbines need to be operated with high sediment load, the vibration problems could be further aggravated due to sediment carrying flow and declination of the surface morphology after erosion. This paper is based on a literature review to explore the characteristic effects of erosion and cavitation which could result in losses, vibrations, fatigues on the turbine materials and oblivious turbine failure. The study aims to correlate the erosion and cavitation due to abrasion with the pressure fluctuations resulting in vibrations.
Comparative analysis of flow characteristics of different blade inclination outlet schemes of long shaft pumps
Authors: Zhang J F , Zhang W J , Jin S B , Yang Z J , Jin C M , Fu L H , Yu X H , Li G D 
Published: June 2022

Abstract
Multistage space guide vane long shaft pump is widely used in many important fields because of its compact structure, convenient maintenance and simple pipeline. However, due to the complex flow phenomenon in its channel, the space guide vane long shaft pump has the problem of low performance. This paper takes xb4.3/240-300lc vertical long shaft fire pump as the research object. When the blade outlet width is the same, three schemes of impeller outlet inclination angle (0°, 15°and 25°) are designed, and CFX is used for numerical simulation to analyse the difference of internal flow field of each scheme. The results show that compared with the other two schemes, the scheme with an inclination angle of 15° has better performance in efficiency(
η
) and head(
H
). The pressure on the working surface of the blade is higher than that on the back of the blade, and the pressure near the front cover plate increases with the growth of the inclination angle. Under the condition of small flow, the velocity at the impeller outlet increases with the growth of inclination angle. Under the condition of large flow, the velocity at the impeller outlet decreases with the growth of inclination angle. Similarly, the turbulent kinetic energy shares the same pattern with the velocity at the impeller outlet. Under all working conditions, small vortex structure appears in impeller and guide vane. It is found that the scheme with impeller outlet inclination angle of 15° has smaller impeller vortex structure under standard working condition.
Investigation on the Flow Characteristics of Complex Flow Channel System of Mixed-flow Pump with Impulse Operation
Authors: Sun Mingkang , Xu Jin , Huang Chuibing , Zhang Xiaoping , Huang Zhenwei 
Published: June 2022

Abstract
How to construct a turbulence model applicable to the flow characteristics of complex flow channel system in mixed-flow pump with impulse operation is of great importance, both for the numerical simulation accuracy of complex flow channels and the subsequent study of transient flow mechanism. In this paper, based on the closure parameters Cε2
and Cμ
, a new turbulence model is proposed for the study on flow characteristics of complex flow channel system in mixed-flow pump with impulse operation. Experimental measurement and numerical calculation reveal that the closure parameters Cε2
and Cμ
in the turbulence model have an important impact on the calculation accuracy compared with other closure parameters. The results indicate that appropriate reduction of the two parameters can effectively promote the calculation precision. Compared with the traditional turbulence model, the maximum error in the numerical calculation of the new turbulence model is reduced by 30%. The research in this paper lays the theoretical foundation for the transient flow mechanism of complex flow channel system in mixed-flow pump with impulse operation.
Numerical Investigation on Suitable Flow Guide for Performance Enhancement of Darrieus-type Hydraulic Turbine by 2-D Simulation
Authors: Mayuzumi Y , Katayama Y , Watanabe S , Tsuda S 
Published: June 2022

Abstract
The aim of this investigation is improvement of the performance of Darrieus-type hydraulic turbines operated in an open channel. Since the output power is very small in such a utilization of small hydropower, it is important to get more power for the cost reduction. In our previous experimental investigation, the performance of turbine runner installed near the side wall of the channel was better than that installed at the center of the channel. In order to enhance the output power, a flat guide was installed upstream of the runner on the opposite side of the side wall. In the present study, we parametrically investigate the effects of flow guiding angle and installation position of the guide on the turbine performance. Two-dimensional unsteady CFD simulations are carried out to qualitatively understand the flow mechanism leading to the better performance of turbine. As a result, it is found that the turbine performance can be significantly enhanced by the appropriately placed flow guide. This enhancement is found to be achieved by the improvement of turbine efficiency and the increase of the input power.
Numerical investigation of a Pelton turbine at several operating conditions
Authors: Gautam Saroj , Chitrakar Sailesh , Neopane Hari Prasad , Solemslie Bjørn W , Dahlhaug Ole Gunnar 
Published: June 2022

Abstract
The use of Computational Fluid Dynamics (CFD) for predicting the flow behaviour in Pelton turbines is limited by the complex nature of the flow, interaction between the jets and interference of the water after the impact on the buckets. Besides, validation of the numerical results in such turbines is usually challenging due to the unsteadiness of the flow properties. Hence, time-dependent analysis with multi-phase models is required for obtaining such solutions. This paper conducts a CFD analysis on a Pelton turbine using RANS based Eulerian scheme. The fluid domain consists of three successive buckets placed in their corresponding circumferential locations, along with a spear valve, which is adjusted for various operating conditions. Such a domain assumes that the interaction of the jet on the buckets takes place for a maximum of three buckets at any particular time. The results of the CFD analysis are compared with the experimental results for all the studied opening conditions. The objective of this work is to build a suitable numerical model that can be applied to any Pelton turbines, such that a complete performance curve of the turbine can be generated. The flow pattern between entry and exit of the bucket obtained from CFD is compared with images taken from a high speed camera in rotating frame of reference. The results of the numerical analysis are found to be in a good agreement with the experimental data.
Parametric modeling of re-electrification by green hydrogen as an alternative to backup power
Authors: Subedi A , Thapa B S 
Published: June 2022

Abstract
Electricity backup systems are needed to address the temporary grid failure, short-term electricity supply at the locations without grids, power surges, and massive blackouts. These power backup technologies include a combination of batteries and generators operating mostly on fossil fuels. Concerns regarding instant start capability with generators, noise, and mainly due to carbon emissions have encouraged to look for alternatives with low carbon technologies based on renewable energy sources. Stored electricity from solar, wind and other renewable sources are emerging and cost-competitive alternatives to fossil fuels-based power backup systems. Due to the high energy density, unlimited production source, and easy storage and transportation, hydrogen is emerging as an effective and efficient energy carrier and its applications for an alternative to power supply systems. Hydrogen produced from the electrolysis of water by renewable electricity makes it green and has minimum carbon emissions among the other alternatives and operates in real-time startups with no mechanical noise.
Fuel cell is a growing technology and has the potential to channelize hydrogen energy as an alternative to carbon-intensive power supply systems. In a fuel cell, hydrogen combines with oxygen and produces electricity. The fuel cell is a robust design with several parameters that control its operation and capacity. This paper identifies the parameter-based modeling approach to establish a connection of power demand with hydrogen production. A mathematical model for system sizing of hydrogen production and fuel cell for re-electrification for a reference case is developed.
Effect of Mechanical Vibration in a Power House Located in the Nepal Himalaya
Authors: Chhushyabaga B , Karki S , Khadka S S 
Published: June 2022

Abstract
Design of powerhouse is a major concern in hydropower project located in Nepal Himalaya. Nepal is located in seismically active zone. The structures built in this region have to be seismic resistant in addition to dynamic loads, produced in power house due to the vibration of turbine and generator set. The structural elements of the power such as slab, column, foundation, wind cover, wall need to sustain produced vibration. It should also be earthquake resistant at the same time. Using finite element methods, the transmission of the produced vibration in powerhouse was analyzed for a selected case study located in lesser Himalaya of Nepal. The nature transfer of vibration loads through all the supporting structure beam, column, foundation raft is analyzed. The critical nature and path of energy transfer due to dynamic load was recognized in terms of the displacement produced with the comparative study in the model without mechanical vibrations.
Co-production of schizophyllan and cellulolytic enzymes from bagasse by Schizophyllum commune
Authors: Arunrattanamook Nattapol , Sornlake Warasirin , Champreda Verawat 
Published: June 2022

ABSTRACT
Schizophyllum commune is a mushroom-forming fungus well-known for its ability to degrade lignocellulosic materials and production of schizophyllan, a high added-value product for cosmeceutical, pharmaceutical, and biomaterial industries. Conventionally, schizophyllan is produced by submerged fermentation using glucose as a carbon source. In this work, we demonstrate that alkaline pretreated bagasse can be used by Schizophyllum commune as an alternative carbon source for the production of schizophyllan. The influence of different factors was investigated including cultivation time, biomass loading, and culturing media component and a co-product correlation model was proposed. In this lab-scale study, a yield of 4.4 g/L of schizophyllan containing 89% glucose was achieved. In addition to schizophyllan, the cellulolytic enzymes co-produced during this process were isolated and characterized and could find applications in a range of industrial processes. This demonstrates the potential of using agricultural waste as a cheaper alternative feedstock for this biorefinery process.
Exposure Outcomes in Fully Vaccinated Healthcare Personnel With Known Severe Acute Respiratory Syndrome Coronavirus 2 Exposure—Minnesota, January–August 2021
Authors: Ruhland Abbey , Fell Ashley , Holzbauer Stacy M , D’Heilly Paige , Curtis Kris , Wick Holly , Friedman Bree , Mumm Erica , Ireland Malia , Estey-Dix Carrie , Betts-Roelike Melissa , Beaudoin Amanda 
Published: June 2022

Abstract
Healthcare personnel (HCP) are at potential risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in occupational and nonoccupational settings, even when fully vaccinated. This risk increased during Delta variant circulation. SARS-CoV-2 testing of fully vaccinated HCP working in the 14 days after exposure is important to prevent virus introduction into healthcare settings.
Broad Antimicrobial Resistance in a Case of Relapsing Babesiosis Successfully Treated With Tafenoquine
Authors: Rogers Ralph , Krause Peter J , Norris Ashlyn M , Ting Michelle H , Nagami Ellen H , Cilley Brian , Vannier Edouard 
Published: June 2022

AbstractWe describe a case of relapsing babesiosis in an immunocompromised patient. A point mutation in the Babesia microti 23S rRNA gene predicted resistance to azithromycin and clindamycin, whereas an amino acid change in the parasite cytochrome b predicted resistance to atovaquone. Following initiation of tafenoquine, symptoms and parasitemia resolved.
Walras, a novel lncRNA linked to cardiomyocyte cytoarchitecture and atrial fibrillation
Authors: Franco D , Dominguez J , Lodde V , Munk R , Abdelmohsen K , Gorospe M , Jimenez-Sabado V , Ginel A , Hove-Madsen L , Aranega A , Garcia-Padilla C 
Published: June 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Junta de Andalucia
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in humans. Genetic and genomic analyses have recently demonstrated that the homeobox transcription factor Pitx2 plays a fundamental role regulating expression of distinct growth factors, microRNAs and ion channels leading to morphological and molecular alterations that promote the onset of AF. Here we address the plausible contribution of long non-coding (lnc)RNAs within the Pitx2&gt;Wnt&gt;miRNA signaling pathway. In silico analyses of annotated lncRNAs in the vicinity of the Pitx2, Wnt8 and Wnt11 chromosomal loci identified five novel lncRNAs with differential expression during cardiac development. Importantly, three of them, Walaa, Walras and Wallrd, are evolutionarily conserved in humans and displayed preferential atrial expression during embryogenesis. In addition, Walrad displayed moderate expression during embryogenesis but was more abundant in the right atrium. Walaa, Walras and Wallrd were distinctly regulated by Pitx2, Wnt8, and Wnt11, and Wallrd was severely elevated in conditional atrium-specific Pitx2-deficient mice. Furthermore, pro-arrhythmogenic and pro-hypertrophic substrate administration to primary cardiomyocyte cell cultures consistently modulate expression of these lncRNAs, supporting distinct modulatory roles of the AF cardiovascular risk factors in the regulation of these lncRNAs. Walras affinity pulldown assays revealed its association with distinct cytoplasmic and nuclear proteins previously involved in cardiac pathophysiology, while loss-of-function assays further support a pivotal role of this lncRNA in cytoskeletal organization. We propose that lncRNAs Walaa, Walras and Wallrd, distinctly regulated by Pitx2&gt;Wnt&gt;miRNA signaling and pro-arrhythmogenic and pro-hypertrophic factors, are implicated in atrial arrhythmogenesis, and Walras additionally in cardiomyocyte cytoarchitecture.
Telomerase and myocardin co-expressing mesenchymal cells increase survival and induce cardiac and vascular markers in cardiac stromal cells undergoing simulated ischemia/reperfusion
Authors: Madonna R , Guarnieri SG , Kovacshazi CK , Gorbe AG , Giricz ZG , Geng YJ , Mariggio MA , Ferdinandy PF , De Caterina RD 
Published: June 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Cardiac stromal cells (CSCs) contain a pool of cells with supportive and paracrine functions. Various types of mesenchymal stromal cells (MSCs) can influence CSCs in the cardiac niche through their paracrine activity. Ischemia/reperfusion (I/R) leads to cell death and reduction of the paracrine activity of CSCs. The forced coexpression of telomerase reverse transcriptase (TERT) and myocardin (MYOCD), known to potentiate anti-apoptotic, pro-survival and pro-angiogenic activities of MSCs isolated from the adipose tissue (AT-MSCs), may increase CSC survival, favoring their paracrine activities.

Aim
To investigate the hypothesis that CSCs feature improved resistance to simulated I/R (SI/R) and increased commitment toward the cardiovascular lineage when preconditioned with conditioned media (CM) or extracellular vesicles (EV) released from AT-MSCs overexpressing TERT and MYOCD (T/M AT-MSCs).

Methods and Results
Murine CSCs were isolated with the cardiosphere (CSps) isolation technique.
T/M AT-MSCs and their secretome improved spontaneous intracellular calcium changes (Figure 1) and ryanodine receptor expression in aged CSps. The cytoprotective effect of AT-MSCs was tested in CSCs subjected to SI/R. SI/R induced cell death as compared to normoxia (28±4 vs 10±3%, p=0.02). Pretreatment with CM (15±2, p=0.02) or with the EV-enriched fraction (10±1%, p=0.02) obtained from mock-transduced AT-MSCs in normoxia reduced cell death after SI/R. The effect was more prononunced with CM (7±1%, p=0.01) or the EV-enriched fraction (2±1%, p=0.01) obtained from T/M AT-MSCs subjected to SI/R. In parallel, we observed lower expression of the apoptosis marker cleaved caspase-3 and higher expression of cardiac and vascular markers eNOS, sarcomeric α-actinin and cardiac actin.

Conclusions
The T/M AT-MSCs secretome exerts a cytoprotective effect and promotes development of CSCs undergoing SI/R towards a cardiovascular phenotype.
The role of tachycardia and beta-adrenergic stimulation in inducing early cardiac remodelling
Authors: Kiessling M , Djalinac N , Matzer I , Voglhuber J , Ljubojevic-Holzer S 
Published: June 2022

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): BioTechMed Graz

Objective
Cardiac remodelling encompasses changes at the molecular, cellular and gene expression level following pathologic insult to the heart. Initially, it maintains cardiovascular homeostasis and allows patients to remain asymptomatic, but if untreated, it eventually progresses to symptomatic heart failure. Excessive β-adrenergic stimulation and tachycardia are potent triggers of cardiac remodelling; however, the underlying mechanisms of their cellular effects are not fully understood. Using neonatal rat ventricular cardiac myocytes (NRVCMs), we studied individual and synergistic potency of ß-adrenergic stimulation and tachycardia to modulate pathological gene expression profiles, as well as the effectiveness of ß-blockers (BB) in preventing these alterations.

Methods
Primary NRVCMs were isolated from 1-day-old neonatal Wistar rats, cultured for 3 days and subsequently stimulated for 3h at basal (1Hz) and tachycardia (8Hz) conditions either in (1) cell culture medium to determine the sole effect of tachycardia, (2) cell culture medium supplemented with ß-adrenergic agonist isoprenaline (ISO; 10µM) to investigate the influence of ß-adrenergic stimulation and signalling or (3) cell culture medium supplemented with ISO following 1h preincubation with propranolol (ISO+BB; 1µM) to assess the potential of BB in preventing gene reprogramming. Screening of relative mRNA levels of hypertrophic marker genes and regulators of ion homeostasis in cardiomyocytes was performed by qPCR and calculated using the 2-ΔΔCt quantification method.

Results
qPCR screening of the known hypertrophic marker genes revealed that tachycardia caused significant transcriptional upregulation of regulator of calcineurin 1 (RCAN1) and interleukin-6 receptor (IL6R). Treatment with ISO additionally upregulated RCAN1, while preincubation with BB resulted in a return towards baseline expression of both genes, completely blocking the effects of tachycardia alone or when combined with ISO stimulation. Interestingly, two potassium channel genes, KCNH2 and KCNJ2, responsible for expression of hERG and Kir2.1 channels, respectively, were unchanged with tachycardia alone but significantly downregulated upon additional stimulation with ISO. Preincubation with BB could - at least partially - reverse the effect.

Conclusion
In conclusion, we could show that apart from the well-documented effect of excessive ß-adrenergic stimulation on hypertrophic signalling in cardiomyocytes, it also has a direct, non-tachypacing mediated effect on the expression levels of hERG and Kir2.1 potassium channels, which may be causally involved in inducing early cardiac remodelling. Thus, a previously unidentified benefit of BB therapy may be restoring potassium homeostasis contributing to the prevention of adverse cardiac remodelling and its progression to heart failure.
Propafenone as potential AgoKir: exploration of long-term effects and mechanisms of propafenone on Kir2.1 channel
Authors: Li E , Kool W , Woolschot L , Van Der Heyden MAG 
Published: June 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Chinese Scholarship Council

Background
Inward rectifying potassium (Kir) channel expression and activity are tightly regulated within the heart. Kir channels play key roles in shaping cardiac action potentials, having a reduced conductance at depolarized potentials but contributing to the final stage of repolarization and resting membrane stability. The Kir2.1 channel protein has polyamine binding residues in both the transmembrane (D172) and the cytoplasmic domains (E224,E299), responsible for the process of inward rectification. A reduced functioning of Kir2.1 causes 1) Andersen-Tawil Syndrom and 2) is present in a subset of heart failure patients. Restoration of normal Kir2.1 function by agonists of Kir2.1 (AgoKirs) would be beneficial. The drug propafenone is identified as an AgoKir, but its long-term effects on Kir2.1 protein expression and subcellular localisation is unknown.

Purpose
To investigate propafenone's long-term effect on Kir2.1 expression and its underlying mechanisms in cell systems.

Methods
GFP, Dendra2 or non-tagged wildtype (WT) and mutant Kir2.1 expression constructs were transiently or stably (HEK-KWGF; CHO-KD cell lines) expressed in Human Embryonic Kidney and Chinese Hamster Ovary cells. Kir2.1 carried currents were measured by single cell patch clamp electrophysiology. Kir2.1 proteins expression levels were determined by Western blot analysis, whereas conventional immunofluorescence and advanced live-imaging microscopy were used to assess the subcellular localisation of Kir2.1 proteins. Propafenone was dissolved in DMSO,BaCl2 was used as Kir2.1 channel inhibitor.

Results
Acute administration of 0.1 and 0.5 µM propafenone increased Kir2.1 carried outward current confirming the drug's Agokir status. Propafenone dose-dependently increased WT Kir2.1 expression levels (2.63±0.40 fold increase at 25 µM and 2.75±0.56 fold increase at 50 µM, 24h) in a process that is independent of the E224, E299 and D172 polyamine binding sites, and the R312 residue which is adjacent to the proposed propafenone binding site. Propafenone (25, 50 µM, 24h) induced intracellular accumulation of WT and mutant Kir2.1 proteins in the late endosome/lysosome compartment (Figure). Channel inhibition by BaCl2 did not affect the propafenone responses on Kir2.1 expression levels or subcellular localisation.

Conclusion
Acute administration of propafenone at low concentrations increases Kir2.1 currents. Chronic propafenone treatment at only 25-100 times higher concentrations results in increased Kir2.1 protein expression levels and intracellular accumulation in late endosomes and/or lysosomes. Our data support the ability of propafenone at low concentrations to function as AgoKirs without disturbing Kir2.1 protein handing.