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Hydrogen production at intermediate temperatures with proton conducting ceramic cells:Electrocatalytic activity,durability and energy efficiency

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Journal of Energy Chemistry 2023年第11期86卷 437-446,I0010页

作者： Haoyu Zheng Feng Han Noriko Sata Rémi costa Institute of Engineering Thermodynamics German Aerospace Center (DLR) Institute for Building Energetics Thermotechnology and Energy Storage (IGTE) University of Stuttgart

Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion ***,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam *** faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into *** increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits.

关键词： Steam electrolysis Hydrogen production Proton conducting ceramics Intermediate temperature Energy efficiency

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Application of a validated HPLC-PDA method for the determination of melatonin content and its release from poly(lactic acid)nanoparticles

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Journal of Pharmaceutical Analysis 2017年第6期7卷 388-393页

作者： Leiziani Gnatkowski martins Najeh Maissar Khalil Rubiana Mara Mainardes Department of Pharmacy Universidade Estadual do Centro-Oeste/UNICENTRORua Simeao Camargo Varela de Sd 0385040-080 GuarapuavaPRBrazil

Melatonin is a natural hormone and with the advancement of age its production declines and thereby may result in some neurological disorders. Exogenous administration of melatonin has been suggested as a neuroprotective agent. Due to its low oral bioavailability, the loading of melatonin in polymeric nanoparticles could be an important tool to effectively use exogenous melatonin. The quantification of the incorporated drug within polymeric nanoparticles is an important step in nanoparticles characterization. An analytical method using high performance liquid chromatography equipped with photodiode array detector （HPLC-PDA） was developed and validated for melatonin determination in poly （lactic acid） nanoparticles obtained by a single emulsion-solvent evaporation technique. The melatonin in vitro release profile also was determined by the HPLC method. Mobile phase consisted of acetonitrile： water （65：35, v/v） pumped at a flow rate of 0.9 mL/min, in the isocratic mode and PDA detector was set at 220 nm. The method was validated in terms of the selectivity, linearity, precision, accuracy, robustness, limits of detection and quantification. Analytical curve was linear over the concentration range of 10-100 ~tg/mL, and limits of detection and quantification were 25.9 ng/mL and 78.7 ng/mL, respectively. The mean recovery for melatonin was 100.47% （RSD = 1.25%, n = 9）. In the intra- and inter- assay, the coefficient of variation was less than 2%. Robustness was proved performing changes in mobile phase, column temperature and flow rate. The method was suitable for the determination of melatonin encapsulation efficiency in poly（lactic acid） nanopartieles and for the evaluation of melatonin in vitro release profile.

关键词： High-performance liquid chromatography Validation Melatonin Polymeric nanoparticles

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Analysis of long-term dependence phenomenon in Benue River flow process and its hypothesis testing

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Chinese Journal of Oceanology and Limnology 2008年第3期26卷 313-322页

作者： martins Y. OTACHE 李致家 Mohammad BAKIR State Key Laboratory of Hydrology-Water Resources ＆ Hydraulic Engineering Hohai University Nanjing 210098 China

In this paper, the long-term dependence phenomenon （the Hurst Effect） which characterizes hydrological and other geophysical times series is studied. The long-term memory is analysed for both daily and monthly streamflow series of the Benue River at Makurdi, Nigeria by using heuristic methods and testing specifically the null hypothesis of short-term memory in the monthly flow series. Results obtained by applying heuristic procedures indicated that there may be the presence of long-term memory component in mean daily flow series but there is no discernible reason to suspect the presence in both average monthly and maximum monthly flow series （extreme event）. Hypothesis testing was conducted by using original and modified versions of rescaled range statistic. When the modified rescaled range, which accounts for short-term memory in the series, is used, the null hypothesis is accepted for both the average monthly and maximum monthly flow series, indicating little or no probable presence of long-term memory in the series. An identical conclusion is also arrived at when second null hypothesis for independence of the monthly flow series is tested. Therefore, apart from the mean daily flow series, there is little evidence of long-term dependence in the Benue River streamflow series at Makurdi. However, considering the limited length of data used, the results are inconclusive.

关键词： Hurst exponent hydrological method time series river flow long memory Nigeria

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Traction power substation balance and losses estimation in AC railways using a power transfer device through Monte Carlo analysis

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Railway Engineering Science 2022年第1期30卷 71-95页

作者： Vitor A.Morais Antonio P.martins Department of Electrical and Computer Engineering Faculty of EngineeringUniversity of PortoPorto 4200465Portugal

The high dynamic power requirements present in modern railway transportation systems raise research challenges for an optimal operation of railway electrification. This paper presents a Monte Carlo analysis on the application of a power transfer device installed in the neutral zone and exchanging active power between two sections. The main analyzed parameters are the active power balance in the two neighbor traction power substations and the system power losses. A simulation framework is presented to comprise the desired analysis and a universe of randomly distributed scenarios are tested to evaluate the effectiveness of the power transfer device system. The results show that the density of trains and the relative branch length of a traction power substation should be considered in the evaluation phase of the best place to install a power transfer device, towards the reduction of the operational power losses, while maintaining the two substations balanced in terms of active power.

关键词： Electric traction systems Monte Carlo analysis Power transfer device Power quality Railway power systems Smart railways

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Perovskite type lanthanum manganite：Morpho-structural analysis and electrical investigations

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Journal of Rare Earths 2018年第5期36卷 499-504页

作者： paula Sfirloaga Maria Poienar Iosif Malaescu Antoanetta Lungu Paulina Vlazan Institute for Research and Development in Electrochemistry and Condensed Matter P. Andronescu Street No.1 300224 Timisoara Romania West University of Timisoara Vasile Parvan 4 300223 Romania

Perovskite-type oxides of LaMnO3 were synthesized by means of the sol-gel method, in the presence of citric acid as gelling agent. The precursors used were Mn（NO3）2·H2O, La2O3, and NaOH,mixed in the stoichiometric ratio to obtain perovskite materials. The obtained gel was heat-treated at 400, 600 and 800 ℃ respectively, for 6 h. X-ray diffraction and FT-IR spectroscopy were used to analyze the phase transformation as a function of temperature, and the Rietveld refinement was used in order to characterize the materials obtained structurally. The average crystallite size of the products was calculated from XRD data and the average particle size was measured from the TEM micrographs. At 600 ℃, the synthesized compound is well-crystallized, showcases a perovskite structure（Pm-3m space group）, and exhibits uniform and homogeneous hexagonally-shaped particles, with sizes in the 20-50 nm *** impedance measurements in the 20-2 × 10^6 Hz frequency range were carried out at different temperatures（26-115 ℃）, and the electrical conduction mechanism is discussed.

关键词： Rare earths Sol-gel method Physico-chemical properties Electrical investigations

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Homeomorphic extension of strongly spirallike mappings in C^n

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Science China Mathematics 2010年第1期53卷 87-100页

作者： CURT paula KOHR Gabriela KOHR Mirela Faculty of Economics and Business Administration Babes-Bolyai University 58-60 Teodor Mihali Str.400591 Cluj-NapocaRomania Faculty of Mathematics and Computer Science Babes-Bolyai University1 M.Kogaǎlniceanu Str.400084 Cluj-NapocaRomania

In this paper we consider a proper subclass nA of the full class of spirallike mappings on the Euclidean unit ball Bn in Cn with respect to a given linear operator A. We use the method of subordination chains to obtain an upper growth result for nA , and we obtain various examples of mappings in the same class of normalized biholomorphic mappings on the unit ball Bn in Cn . We also prove that the class nA is compact, while the full class of spirallike mappings with respect to a linear operator need not be compact in dimension n≥2, even when the operator is diagonal. This is one of the motivations for considering the class nA . Finally we prove that if f is a quasiregular strongly spirallike mapping on Bn such that ||[Df(z)]-1 Af(z)|| is uniformly bounded on Bn , then f extends to a homeomorphism of R2n onto itself. In addition, if A + A* = 2aI n for some a >0, this extension is also quasiconformal on R2n .

关键词： Biholomorphic mapping quasiregular mapping quasiconformal mapping spirallikeness strongly spirallikeness subordination subordination chain

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Oxidative metabolism of photosynthetic species and the exposure to some freshwater and marine biotoxins

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BIOCELL 2021年第4期45卷 813-821页

作者： SUSANA PUNTARULO paula MARIELA GONZÁLEZ Universidad de Buenos Aires Facultad de Farmacia y BioquímicaFisicoquímicaBuenos AiresCP 1113Argentina CONICET-Universidad de Buenos Aires.Instituto de Bioquímica y Medicina Molecular(IBIMOL) Buenos AiresCP 1113Argentina

Environmental climate conditions could lead to an increasing global occurrence of microorganism blooms that synthesize toxins in the aquatic *** blooms could result in significantly toxic *** of photosynthetic organisms to adverse environmental conditions implicate reactive oxygen species generation;but,due to the presence of a varied cellular antioxidant defense system and complex signaling networks,this oxidative stress could act as an important factor in the environmental adaptive *** objective of this review was to assess how some biotoxins are implicated in the generation of oxidative and nitrosative metabolic changes,not only in biotoxin-producing organisms but also in non-producing ***,toxins may modify the oxidative cellular balance of several other ***,the effect of toxins on the oxidative and nitrosative conditions will be evaluated in freshwater and marine algae and vascular *** changing climate conditions could act as agents capable of modifying the community composition leading to alterations in the global health of the habitat,risking the survival of many species with ecological relevance.

关键词： Blooms Climate change Metabolic stress Photosynthetic organisms Toxins

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The cost-effectiveness of hypertonic saline inhalations for infant bronchiolitis: a decision analysis

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World Journal of Pediatrics 2018年第1期14卷 26-34页

作者： paula Heikkila Minna Mecklin Matti Korppi Tampere Center for Child Health Research Universityof Tampere and Tampere University HospitalTampereFinland Department of Pediatrics Tampere University HospitalPOBOX200033521T ampereFinland

Background This study evaluated the cost-effectiveness of hypertonic saline (HS) inhalations for infant bronchiolitis, com-pared to normal saline inhalations or standard treatment without inhalations as controls. Methods The decision tree in the decision analysis was used to calculate the expected costs. Actual cost data were obtained from our retrospective case-control study on bronchiolitis treatment. The effectiveness of treatment, based on the hospitaliza-tion rate of those admitted to the emergency department and the length of stay (LOS) of those who were hospitalized, was collected from previous studies. For the effectiveness estimations, we made a meta-analysis summarizing the results of the meta-analysis of the Cochrane review in 2013 and the results of 10 studies published after it. Results The mean hospitalization rate was 24.7% in the HS inhalation group and 32.6% in the control group [risk ratio: 0.80, 95% confidence interval (CI) 0.67–0.96] and the mean LOS was 3.736 (HS group) and 4.292 (controls) days (mean difference: ? 0.55 days, 95% CI ? 0.96 to ? 0.15), respectively. The expected costs per patient, when both inpatients and outpatients were included, were €816 ($1111) in the HS inhalation group and €962 ($1310) in the control group. The expected costs per hospitalization, when only inpatients were included, were €2600 ($3540) in the HS inhalation group and €2890 ($3935) in the control group. Conclusions HS inhalations slightly reduced the expected hospitalization costs of infant bronchiolitis. However, the low effectiveness, rather than the cost, is the factor that will limit the use of HS inhalations in infant bronchiolitis.

关键词： Bronchiolitis Cost-effectiveness Decision analysis Hospitalization costs Hypertonic saline

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Patient-derived iPSC models of Friedreich ataxia:a new frontier for understanding disease mechanisms and therapeutic application

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Translational Neurodegeneration 2023年第1期12卷 258-280页

作者： Saumya Maheshwari Gabriela Vilema-Enríquez Richard Wade-martins Department of Physiology Anatomy and GeneticsKavli Institute for Nanoscience DiscoveryUniversity of OxfordSouth Parks RoadOxford OX13QUUK

Friedreich ataxia(FRDA)is a rare genetic multisystem disorder caused by a pathological GAA trinucleotide repeat expansion in the FXN *** numerous drawbacks of historical cellular and rodent models of FRDA have caused difficulty in performing effective mechanistic and translational studies to investigate the *** recent discovery and subsequent development of induced pluripotent stem cell(iPSC)technology provides an exciting platform to enable enhanced disease modelling for studies of rare genetic *** iPSCs,researchers have created phenotypically relevant and previously inaccessible cellular models of *** models enable studies of the molecular mechanisms underlying GAA-induced pathology,as well as providing an exciting tool for the screening and testing of novel disease-modifying *** review explores how the use of iPSCs to study FRDA has developed over the past decade,as well as discussing the enormous therapeutic potentials of iPSC-derived models,their current limitations and their future direction within the field of FRDA research.

关键词： Friedreich ataxia Induced pluripotent stem cells Disease modelling Disease pathogenesis Drug development

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My enemy’s enemies are my friends:Alternative sources of support in multi-party races

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Economic and Political Studies 2024年第3期12卷 285-317页

作者： Carlos costa School of Public and International Affairs Wright State UniversityDaytonOHUSA

The research on redistributive strategies to secure support has been dominated by a core and swing voter model,which pits two parties against each other in a costly race for *** are other options beyond targeting either swing or one’s own core voters?This paper identifies a political scenario where core supporters from other parties are viable targets and sets out to test three dimensions that indicate when actors can effectively target *** paper’s main expectation is that by accounting for voters’ideological affinity,levels of fragmentation,and the potential to deliver their votes,parties can effectively target other parties’core *** case of Brazil’s Bolsa Famılia delivers evidence for the hypotheses.

关键词： Multi-party races coreand swing conditionalcash transfer Bolsa Familia

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