Microbial fuel cells (MFCs) utilize the metabolic activities of microorganisms, through which the chemical energy is directly converted into electrical energy. Bacteria produce electrons by means of oxidation of organ...
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Microbial fuel cells (MFCs) utilize the metabolic activities of microorganisms, through which the chemical energy is directly converted into electrical energy. Bacteria produce electrons by means of oxidation of organic/inorganic substrates within the MFCs. Metal organic frameworks (MOFs) that are porous coordination polymers have gained much interest in the field of efficient catalysts due to their unique characteristics. The utilization of MOF catalysts for oxygen reduction reaction (ORR) in the MFC cathode is one of the most remarkable research areas in material science. MOF (zeolitic imidazole framework-leaf like, ZIF-L) decorated cathode system was employed for the first time in MFC to monitor the improvement in performance by taking advantages of both electrocatalytic activity and porosity of MOFs for the utilization of bioelectrons for ORR. Analysis of ORR performance of ZIF-L/carbon black (CB) composite cathode demonstrated that ZIF-L containing cathode system had an improved ORR activity compared to MFC cathode materials in the literature. The remarkable current density value of 2.1 mA cm-2 and the maximum power density value of 1,462 mW m-2 at room temperature revealed that ZIF-L decorated cathode is an excellent alternative for efficient reduction of oxygen in MFCs.
Depending on various indicators, climate change may affect each region globally at varying risk levels. Therefore, identifying the 'hotspots' most likely to be affected by climate change in the future is a cru...
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Depending on various indicators, climate change may affect each region globally at varying risk levels. Therefore, identifying the 'hotspots' most likely to be affected by climate change in the future is a crucial step in ensuring those areas rapidly adapt to it. The study estimated the Standard Euclidean Distance (SED) for identifying hotspots of T & uuml;rkiye using high-resolution climate projection data (10 x 10 km) and examined regional vulnerability in the long-term future over a 75-year period (2024-2099). The projections were made using RegCM4.4 driven by MPI-ESM-MR under the optimistic (RCP4.5) and pessimistic (RCP8.5) scenarios. The findings indicate that the hotspot regions in T & uuml;rkiye are Southeastern Anatolia, Eastern Anatolia and the Mediterranean for RCP4.5, and Southeastern Anatolia, Eastern Anatolia, the Mediterranean and Central Anatolia for RCP8.5. The most critical indicators, however, are temperature-related indicators (i.e., Mean Air Temperature, Hot Seasons and Temperature Variability). Based on the findings, it is necessary to take preventive measures, particularly in highly vulnerable regions, to minimise potential damage. Additionally, multi-model ensemble studies should be applied to reduce the uncertainties and model-related variability, as well as to provide robust evidence of climate change.
Carbon fiber-reinforced plastic (CFRP) composites perform remarkably as crashworthy structures in transport vehicles. They promise to improve the crashworthiness of vehicles in addition to weight savings thanks to the...
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Carbon fiber-reinforced plastic (CFRP) composites perform remarkably as crashworthy structures in transport vehicles. They promise to improve the crashworthiness of vehicles in addition to weight savings thanks to their superior strength-to-weight ratio. However, designing composite crashworthy structures is challenging since predicting the energy absorption values and crushing behavior are not straightforward. Finite element modeling is a very effective numerical technique to predict energy absorption values and shorten the design process of composite structures, yet it is also quite hard to simulate the crushing of composite structures due to their complex damage mechanisms. This paper presents an investigation of the axial crushing behavior of composite tubes made of woven fabric CFRP and the influence of the different modeling techniques. Macro-scale stacked shell modeling approach is adopted to model the composite tubes. Various virtual debris wedge models are incorporated to obtain realistic failure modes in simulations. Simulated crushing morphologies and energy absorption values are compared with the experimental test results. Furthermore, the prediction capability of the models and the influence of mesh geometry used for rigid flat platen crushers are examined. It is found that the geometry of the virtual debris wedge and mesh geometry of the flat platen crusher affect the simulated crushing modes and level of the absorbed energy predicted.
Polymer brush-coated magnetic nanoparticles find applications in areas from diagnostics to drug delivery. Generally, the brushes are irreversibly tethered onto the nanoparticle surface through robust chemical linkages...
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Polymer brush-coated magnetic nanoparticles find applications in areas from diagnostics to drug delivery. Generally, the brushes are irreversibly tethered onto the nanoparticle surface through robust chemical linkages to withstand diverse environments. The ability to trigger the release of the polymer brushes from the nanoparticle surface once they reach the intracellular environment would be a useful attribute. In this study, we report polymer brushes that undergo release from the nanoparticle surface in a redox-responsive fashion. Furthermore, cleaving the polymer brush also enables precise determination of their molecular weight. Also, we show that fluorescently labeled polymer brushes undergo chain-end functionalization using maleimide-containing dye and peptides. Installing integrin-targeting peptides onto the surface enhances their cellular internalization. One could envision that the redox-responsive polymer brush-coated magnetic nanoparticles disclosed here would be an attractive platform for applications where intracellular cleavage of polymeric chains would enhance their performance.
Blockchains are decentralized and immutable databases that are shared among the nodes of the network. Although blockchains have attracted a great scale of attention in the recent years by disrupting the traditional fi...
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Blockchains are decentralized and immutable databases that are shared among the nodes of the network. Although blockchains have attracted a great scale of attention in the recent years by disrupting the traditional financial systems, the transaction privacy is still a challenging issue that needs to be addressed and analyzed. We propose a P rivate T oken T ransfer S ystem (PTTS) for the Ethereum public blockchain in the first part of this paper. For the proposed framework, zero-knowledge based protocol has been designed using Zokrates and integrated into our private token smart contract. With the help of web user interface designed, the end users can interact with the smart contract without any third-party setup. In the second part of the paper, we provide security and privacy analysis including the replay attack and the balance range privacy attack which has been modeled as a network flow problem. It is shown that incase some balance ranges are deliberately leaked out to particular organizations or adversarial entities, it is possible to extract meaningful information about the user balances by employing minimum cost flow network algorithms that have polynomial complexity. The experimental study reports the Ethereum gas consumption and proof generation times for the proposed framework. It also reports network solution times and goodness rates for a subset of addresses under the balance range privacy attack with respect to number of addresses, number of transactions and ratio of leaked transfer transaction amounts.
The growing interest in Conversational AI has led to the development of Conversational OpenQA systems as a crucial step for meeting users' information needs in real world scenarios. Conversational OpenQA systems e...
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The growing interest in Conversational AI has led to the development of Conversational OpenQA systems as a crucial step for meeting users' information needs in real world scenarios. Conversational OpenQA systems enhance standard OpenQA performance by leveraging conversation history of the users. However, building effective Conversational OpenQA systems requires large-scale Conversational OpenQA datasets, often limited to the English language, hindering progress in low-resource languages. We present a robust Conversational OpenQA system enhanced by conversational context, designed for languages with limited resources and exemplified in our case study for Turkish. To address data limitations in a cost-effective way, we repurpose existing datasets like SQuAD-TR and XQuAD-TR, treating them as if they were constructed within a conversational context. Our findings indicate that incorporating conversation signals in the retriever models results in up to an absolute increase of 18.82% in Success@1 for retrievers. This improvement extends to the reader models enhanced by the conversational context, narrowing the gap in EM/F1 scores up to 4.12%/4.43%, respectively, compared to Standard QA readers.
Aldol reactions are one of the most fundamental organic reactions involving the formation of carbon-carbon bonds that are commonly used in the synthesis of complex molecules through the condensation of an enol or enol...
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Aldol reactions are one of the most fundamental organic reactions involving the formation of carbon-carbon bonds that are commonly used in the synthesis of complex molecules through the condensation of an enol or enolate with a carbonyl group. The aldol reaction of thiohydantoin derivatives with benzaldehyde starts with hydrogen removal from C5 by lithium diisopropylamide (LDA) to form the enolate. Benzaldehyde adds to the enolate either at the less or more hindered site. The formed products have 3 chiral centers;thus they exist in 8 isomeric forms, RMS*/SPR*, RMR*/SPS*, SMR*/RPS*, and SMS*/RPR*, which are enantiomeric couples. Experimentally the axial chirality of the reactant is protected throughout the reaction;if the starting thiohydantoin is the M isomer, only RMS*, RMR*, SMR*, and SMS* diastereomers can be obtained. In this study, we aim to report a theoretical study of the aldol reactions between benzaldehyde and thiohydantoin derivatives conducted at the M06-2X/6-311+G(d,p) level of theory using the CPCM solvation model for THF as solvent, at 195 K. The investigation of the effect of substituents at C5 (stereocenter) and X positions on selectivity was performed by varying the substituents R 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 CH3, XCF3;RCH3, XCl;RCH2Ph, XCF3;RCH(CH3)2, and XCF3. Agreement of calculations (M06-2X/6-311+G(d,p)/CPCM(THF)) with experiment suggests that the enantioselectivity is predominantly governed by thermodynamic control.
High-resolution seismic tomographic images of active fault zones are essential for linking physical processes and observations during large ruptures. The 1999 Izmit and D & uuml;zce earthquakes offer a valuable op...
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High-resolution seismic tomographic images of active fault zones are essential for linking physical processes and observations during large ruptures. The 1999 Izmit and D & uuml;zce earthquakes offer a valuable opportunity to study local fault geology, fault structure and rupture characteristics. By analysing seismic data from the aftershocks of these earthquakes and long-term seismic observations in the region, I computed P-wave velocity variations along similar to 160 km long ruptured segments of the North Anatolian Fault (NAF) at km-scale *** large velocity perturbations (+/- 10 per cent) at depths of less than 5 km are associated with known geological structures alongside the fault zone. Lower velocities are observed in the & Ccedil;& imath;narc & imath;k, Izmit, Adapazar & imath;and D & uuml;zce basins, while higher velocities are associated with the metamorphic and ultramafic rocks of the Armutlu-Almac & imath;k zone.A sharp velocity contrast (+/- 10 per cent) is observed along the 1999 Izmit rupture zone at depths of less than 5 km, but this contrast diminishes at greater depths. The Izmit rupture zone does not hold a large-scale bimaterial interface, but instead exhibits heterogeneties on shorter length-scales. The low-velocity fault zones, similar to 3 km thick, detected only in a limited section of the rupture *** Almac & imath;k block, with its high-velocity core (6.0-6.6 km s-1) extending to a depth of about 13 km, plays a crucial role in shaping the multiple branches of the NAF and in the partitioning of strain. The rupture arrests of both 1999 Izmit and D & uuml;zce earthquakes occurred in the transition of D & uuml;zce and Karadere faults, where a transtensional structure develops at depth of 8-12 km within the zone along the northern boundary of the Almac & imath;k *** appears to be a link between the coseismic slip during the Izmit earthquake and P-wave velocity gradient along the fault zone. Nonetheless, this apparent correl
Since rivers are major transport routes for microplastics, developing novel modeling approaches has become a subject of research to better understand the transport behavior of these particles in river systems. This st...
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Since rivers are major transport routes for microplastics, developing novel modeling approaches has become a subject of research to better understand the transport behavior of these particles in river systems. This study aims to model the vertical transport of microplastics at selected sites of the Ergene River, T & uuml;rkiye, simulate the concentration dynamics of these particles in water and sediment under different hydrodynamic and morphological conditions, and determine the sensitivity of the model results to parameters related to the physical characteristics of microplastics, as well as river hydrodynamics and morphology. A mechanistic model was developed using data on microplastics, river hydrodynamics and morphology. Mass-balance and hydrodynamic equations were utilized for model construction in GoldSim to predict the transport of microplastics between the water column and sediment. The model results revealed that the residence time of microplastics in water was directly related to flow characteristics and river hydraulics, while the initial concentration of particles in water dominated other parameters in influencing the settling and resuspension fluxes of microplastics. Turbulent conditions affected both flow rate and particle resuspension, suggesting that turbulence can either increase or decrease microplastic concentrations and their residence time in the water column and sediment. The model results for both compartments were most sensitive to changes in water and plastic density, whereas Nikuradse sand roughness was the least significant parameter affecting the model outcomes for both compartments.
ObjectiveResearch suggests that executive functions and metacognitive abilities, including self-reflection and insight, may share underlying mechanisms since both rely on top-down cognitive processes and require self-...
ObjectiveResearch suggests that executive functions and metacognitive abilities, including self-reflection and insight, may share underlying mechanisms since both rely on top-down cognitive processes and require self-regulation. However, these relationships have not been thoroughly examined by empirical research. The current study investigated the relationship between insight, self-reflection, and executive functions cross-sectionally across different stages of *** were 1284 (655 men and 629 women) cognitively healthy community dwellers with an age range of 18-89 years (M = 47.91, SD = 19.83). The sample was divided into three groups based on age, e.g., the young adults (18-34 years-old), the middle-aged adults (35-59 years-old), and older adults (60 years and older). Participants completed multiple executive function tasks (including trail making, verbal fluency, Stroop, digit span) and a self-report insight and self-reflection measure individually in face-to-face *** results show that education, age, digit span forward, which is a measure of short-term memory and phonemic fluency were significant predictors of self-reported insight. Furthermore, insight, but not self-reflection, had significant positive correlations with short-term memory and phonemic fluency across three age ***, the results indicate that performance on executive function measures and self-reported self-reflection and insight are relatively independent cognitive abilities.
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