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Mitigating cavitation effects on Francis turbine performance: A two-phase flow analysis
No full text<p>Due to their ability to operate over a wide range of flow rates and generate high power, Francis turbines are the most widely used of hydroturbine type. Hydraulic turbines, are designed for specific flow and head conditions tailored to site conditions. However, Francis turbines can also be operated outside of design conditions due to varying flow and head values. Operation outside of design conditions can lead to cavitation. In this study, singlephase steady-state an alyses were conducted initially to examine cavitation in detail, followed by two-phase transient analyses. The results obtained from these analyses were compared to determine the cavitation characteristics of the designed turbine. The steady-state simulation results indicate the occurrence of cavitation, including traveling bubble and draft tube cavitation, under overload operating conditions. However, these cavitation characteristics are not observed in the two-phase transient simulation results under the same operating conditions. Additionally, the turbine efficiency is predicted to be higher in the transient simulation results. This is attributed to the frozen rotor interface used in the steady-state simulations, which over predicts flow irregularities. The reduced flow irregularities in the transient results have resulted in lower cavitation and losses, leading to higher predicted turbine efficiency.</p>
Cardiac evaluation of patients with juvenile dermatomyositis
No full text<p>Background The present study aims to evaluate possible cardiac involvement in juvenile dermatomyositis (JDM) patients by conventional methods and cardiac magnetic resonance imaging (MRI) along with a systematic review of the literature on cardiac features in JDM.Methods The study group consisted of JDM patients who underwent cardiac MRI. We conducted a systematic review of the published literature involving JDM patients with cardiac involvement.Results In the present study, although baseline cardiologic evaluations including electrocardiography and echocardiography were within normal limits, we showed late gadolinium enhancement on cardiac MRI in 3 of 11 JDM patients. In the literature review, we identified 25 articles related to cardiac involvement in JDM. However, none of them, except one case report, included cardiac MRI of JDM patients.Conclusion Cardiac abnormalities have been reported among the less frequent findings in patients with JDM. Cardiovascular complications during the long-term disease course are a leading cause of morbidity and mortality in these patients. Early detection of cardiac involvement by cardiac MRI in patients with JDM and aggressive treatment of them may improve the clinical course of these patients.Impact The myocardium in patients with JDM may be involved by inflammation. Myocardial involvement may be evaluated by using contrast-enhanced cardiac MRI. This is the first study evaluating cardiac involvement by cardiac MRI in JDM patients. MRI may show early cardiac involvement in patients whose baseline cardiologic evaluations are within normal limits. Early detection of cardiac involvement by cardiac MRI may improve the long-term prognosis of patients with JDM.</p>
A moment resistant beam end connection using energy dissipative couplers for precast concrete structures
No full text<p>There is an increasing demand for precast reinforced concrete (RC) structures due to their undeniable advantages, such as rapid assembly, material standardization, and labor quality. The structural performance of precast RC structures depends not only on the quality of the precast members but also on joints and connections. In recent years, significant attention has been given to replaceable energy-dissipative devices for beam-to-column connections in precast RC structures. This paper proposes a novel moment-resisting energy-dissipative beam end connection in precast RC systems. The proposal is based on the results of intensive experimental and numerical studies conducted in the research project. The beam longitudinal reinforcements are connected to the joint using the developed fuse-type mechanical couplers (FTMCs) that have energy dissipation capability. While the bending moment in the connection is transformed into an axial force couple and transferred by FTMCs, the shear force is transmitted through the steel hinge at the center of the beam. The cyclic behavior of the proposed connection was experimentally investigated, resulting in a robust numerical model for the connection. The experiments demonstrated that the proper configuration of FTMCs in the connection enables reaching a 4% drift ratio without causing major damage to the RC beams. Macro models adopting pivot and kinematic hysteresis approaches for FTMCs were built in the numerical part. The pivot model reasonably and consistently predicted the experimental force-displacement relations of the proposed connections. The ability of the pivot model to estimate the energy dissipation capacities varies almost 6 similar to 16%.</p>
High-temperature performance of geopolymer mortars containing ceramic filter press cake and pottery waste powders
No full text<p>The sustainable management of Ceramic Tile Filter Press Cake Powder (FPW) and Pottery Shard Waste Powder (PW) is crucial to reducing environmental harm in the ceramics sector. These ceramic byproducts offer a valuable source of aluminosilicate powders, which can be used in the synthesis of geopolymer mortars as an innovative alternative to traditional raw materials. This study focuses on repurposing these materials as binders in geopolymer mortars and evaluating their performance after exposure to elevated temperatures. Geopolymers were formulated with varying FPW/PW ratios (100/0, 75/25, 50/50, 25/75, 0/100) and cured thermally at 90 degrees C for either 6 or 24 h. Strength tests were conducted on mortars before and after heating at 400, 600, and 800 degrees C. Selected samples underwent crystal structure (XRD) and microstructural (SEM/EDX) analyses both before and after thermal exposure. The results indicated that 24-hour cured geopolymers exhibited better initial strength, while the 6-hour cured mortars demonstrated superior residual strength post-heating. Geopolymers with higher FPW content displayed greater thermal resistance than those with higher PW content. Overall, ceramic waste proved to be a viable alternative material for producing geopolymers, offering an effective solution for waste reduction in the ceramics industry. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.</p>
Development of Specially Designed Nanoparticle-coated 3D-printed Gelatin Methacryloyl Patches for Potential Tissue Engineering Applications
No full text<p>Tympanic membrane (TM) perforation is a serious ear discomfort that can cause hearing loss and make the middle ear vulnerable to infections. In this study, a unique TM patch is designed to mimic the structure of the natural eardrum for tissue engineering of TM perforations. Gelatin methacryloyl (GelMA)-based TM patches are equipped with microneedles (MNs) to better adhere to the perforation site and developed using the digital light processing (DLP) based 3D printing technique. To impart biofunctionality to the 3D-printed patches, their surfaces are coated with gentamicin (GEN) loaded poly(vinyl alcohol) (PVA) nanoparticles (NPs) using the Electrohydrodynamic Atomization (EHDA) method. The physicochemical characteristics, drug release behaviour, antimicrobial properties and biocompatibility of GelMA, PVA NP-coated GelMA, and GEN@PVA NP-coated GelMA patches are investigated. Morphological analyses confirmed that 3D-printed GelMA patches are fabricated in desired sizes and geometries and successfully coated with NPs. In vitro antibacterial tests revealed that GEN@PVA NP-coated GelMA patches have antibacterial activities against Staphylococcus aureus and Escherichia coli. Moreover, in vitro cell culture studies indicated that all GelMA-based patches have no cytotoxic effect on L929 mouse fibroblast cells. Considering all, these specially designed biofunctional 3D-printed GelMA patches can be an effective therapeutic approach for repairing TM perforations.</p>
<p>This study aims to design a unique tympanic membrane (TM) patch model for tissue engineering of TM perforations. The edges of the patch are donated with microneedles (MNs) for improved attachment to the perforation site. Gelatin methacryloyl (GelMA)-based TM patches are fabricated using the digital light processing (DLP) based 3D printing technique. To enhance the biofunctionality of the 3D-printed GelMA patches, the patches are coated with gentamicin (GEN) loaded poly(vinyl alcohol) (PVA) nanoparticles (NPs) employing the Electrohydrodynamic Atomization (EHDA) technique. These specially designed biofunctional patches can serve as a promising treatment method for repairing TM perforations. image</p>
Synthesis, structural studies and Hirshfeld surface analysis of the substituted isoindole-1,3-dione derivatives
No full text<p>In this study, we have performed the ring-opening reaction of 5-benzyl/ethyl-2-hydroxyhexahydro-4H-oxireno [2,3-e] isoindole-4,6(5H)-dione (10) with HBr to the corresponding bromodiols, regioselectively. Structures of the synthesized compounds are elucidated through spectral methods (1H NMR,13C NMR and HRMS) Afterwards, the racemic products 11a-b were purified and the absolute geometries of 5-bromo-2-ethyl-4,6-dihydroxyhexahydro-1H-isoindole 1,3(2H)-dione (11a) and 2-benzyl-5-bromo-4,6-dihydroxyhexahydro-1H-isoindole-1,3 (2H)-dione (11b) was determined by X-ray diffraction analysis. Effective O- H center dot center dot center dot O (2.738-2.874 & Aring;) hydrogen bonds between diol and ketone units are important interactions between the molecules. Hirshfeld surface analyses of the compounds (11a-b) have provided further insights into molecular, crystal structure and intermolecular interactions. The results indicated that the most important contributions for the crystal packings are from H center dot center dot center dot H, O center dot center dot center dot H/H center dot center dot center dot O, C center dot center dot center dot H/H center dot center dot center dot C and Br center dot center dot center dot H/H center dot center dot center dot Br interactions. Finally, energy frameworks were analyzed to a better understanding of the packing of crystal structure and the supramolecular rearrangements for the structures (11a-b).</p>
Lateral growth of WSe<sub>2</sub> monolayer film in a confined reaction environment via an Au vapor-assisted CVD: A systematic and comparative study with a NaCl-assisted CVD
No full text<p>Two-dimensional (2D) monolayer tungsten diselenide (WSe2) is of great interest in optoelectronic and photo (electro)catalytic applications due to its direct optical band gap characteristic which is highly dependent on the number of layers. Achieving uniform, high-purity, large-area monolayer WSe2 with the traditional salt-assisted chemical vapor deposition method (CVD) remains challenging due to the issues controlling the growth mechanisms and number of layers. Recent studies have demonstrated that metal vapor-assisted CVD can achieve uniform development of large-scale WSe2 monolayers. It is critical to comprehensively examine the influence of metal vapor-assisted CVD parameters on lateral WSe2 growth relative to salt-assisted CVD and to analyze the underlying mechanisms. Here, we carried out a systematic and comparable study assessing the effect of several CVD parameters on lateral WSe2 monolayer growth in the presence of a NaCl and an Au vapor catalyst, respectively. Detailed characterization of the grown WSe2 materials confirmed that using only a gold vapor catalyst in a confined micro-reactor space of sapphires allows for the ultrafast growth of highly crystalline, uniform, and sub-centimeter-sized monolayer WSe2 films without any residual ions, which can be scalable for reliable high-performance device fabrication and photocatalytic applications. Moreover, we observed that in-situ etching could occur on the film by the increased reaction time. Overall, this study paves the way for future research on fabricating large-area monolayer transition metal dichalcogenides and reaction mechanisms using gold or other metal vapor-assisted CVD in a confined reaction environment.</p>
Angler catch data as a monitoring tool for European barbel Barbus barbus in a data limited recreational fishery
No full text<p>Large bodied freshwater fishes can be important target species for recreational anglers, with some species introduced intentionally to diversify angling experiences. European barbel Barbus barbus is an important target species in many riverine fisheries, including the River Severn and its River Teme tributary, western England, where it has supported a catch-and-release recreational fishery for approximately 50 years. The River Teme was renowned for the quality of its barbel angling from the 1980s. Since 2007, angler dissatisfaction has increased substantially in this fishery, being associated with alleged declines in the number of barbel being captured and in their population abundances. As there were few data available at that time to investigate these declines, data from periodic electric fishing surveys and some angler catch data were sourced. Analyses revealed temporal declines in the number of sampled barbel during electric fishing surveys, although the number of surveys was low, varied between years and did not target barbel specifically. Analyses of four angler catch data sets (1995-2022) involving more than 1000 captured barbel of 0.5-5.3 kg also revealed significant temporal declines in barbel catches (by number and catch-per-unit-effort). These catch declines were generally coincident with reductions in angler presence and effort on the river, suggesting low catches were a driver of angler dissatisfaction. These results provide empirical support for angler claims of substantial declines in barbel catches and abundances, and emphasise that even limited volumes of angler catch data are useful for understanding temporal changes in exploited but data limited fish populations.</p>
Constructing Turkish Identity as the "Other": The Erasure of a Civilization in Balkan Memory
No full text<p>This article examines how European discourses that othered the “Turk” were taken up by Balkan nationalisms and translated into violent policies during the transition to nation-states from the late nineteenth century onward. It shows how a Europe-made adversarial frame legitimated this shift and fed practices of forced displacement and mass killing. Methodologically, the study draws on a systematic review of the literature and comparative readings in historiography. Backed by Western and Russian powers, separatist movements targeted the Ottoman legacy, dismantled a long-standing multi-confessional order, and normalised a security politics that accelerated ethnic homogenisation. The findings indicate that claims to legitimacy advanced in step with waves of violence, fracturing cultural and social continuities. Building the post-imperial political architecture on this basis kept the regional order brittle well into the twentieth century, helped trigger genocides, and left durable effects that marginalised minority communities. Without a careful reckoning with this trajectory, Europe’s self-narrative will remain partial and misleading</p>
A three-phase framework for mapping barriers to blockchain adoption in sustainable supply chain
No full text<p>Purpose - Blockchain technology is one of the major contributors to supply chain sustainability because of its inherent features. However, its adoption rate is relatively low due to reasons such as the diverse barriers impeding blockchain adoption. The purpose of this study is to identify blockchain adoption barriers in sustainable supply chain and uncovers their interrelationships. Design/methodology/approach - A three-phase framework that combines machine learning (ML) classifiers, BORUTA feature selection algorithm, and Grey-DEMATEL method. From the literature review, 26 potential barriers were identified and evaluated through the performance of ML models with accuracy and f-score. Findings - The findings reveal that feature selection algorithm detected 15 prominent barriers, and random forest (RF) classifier performed with the highest accuracy and f-score. Moreover, the performance of the RF increased by 2.38% accuracy and 2.19% f-score after removing irrelevant barriers, confirming the validity of feature selection algorithm. An RF classifier ranked the prominent barriers and according to ranking, financial constraints, immaturity, security, knowledge and expertise, and cultural differences resided at the top of the list. Furthermore, a Grey-DEMATEL method is employed to expose interrelationships between prominent barriers and to provide an overview of the cause-and-effect group. Practical implications - The outcome of this study can help industry practitioners develop new strategies and plans for blockchain adoption in sustainable supply chains. Originality/value - The research on the adoption of blockchain technology in sustainable supply chains is still evolving. This study contributes to the ongoing debate by exploring how practitioners and decision- makers adopt blockchain technology, developing strategies and plans in the process.</p>