batterydata/paper-abstracts huggingface dataset:
The synthesis of lambda-manganese oxide (λ-MnO2) with a developed porosity and an ordered and interconnected pore structure used as supercapacitor electrode is reported for the first time in the present study. A spinel-type LiMn2O4 material was first prepared by hard-templating pathway using KIT-6 mesoporous silica as a template and metal nitrates as precursors, which was subsequently acid treated leading to λ-MnO2 material. The materials exhibit high surface area (up to 150 m2 g−1), defined pore size distribution with three-dimensional interconnected pores, and crystalline pore walls. The material textural properties as well as the morphologies vary considerably with the synthetic conditions. The as-synthesized porous λ-MnO2 materials exhibit a noticeably better performance (120 F g−1) at high constant currents (1 A g−1) than commercial derived λ-MnO2 (11 F g−1). The extended surface area and the porous and three-dimensional interconnected structures along with the specific morphology significantly enhance the lithium diffusion through the particles and allow for a more effective use of this pseudocapacitive material as an electrode in supercapacitor.
Introduction Contact dermatitis to cosmetics is a common problem in the general population, although its prevalence appears to be underestimated. We reviewed cases of allergic contact dermatitis to cosmetics diagnosed in our dermatology department over a 7-year period with a view to identifying the allergens responsible, the frequency of occurrence of these allergens, and the cosmetic products implicated. Methods Using the database of the skin allergy department, we undertook a search of all cases of allergic contact dermatitis to cosmetics diagnosed in our department from January 2000 through October 2007. Results In this period, patch tests were carried out on 2485 patients, of whom 740 were diagnosed with allergic contact dermatitis and the cause was cosmetics in 202 of these patients (170 women and 32 men), who accounted for 27.3% of all cases. A total of 315 positive results were found for 46 different allergens. Allergens most often responsible for contact dermatitis in a cosmetics user were methylisothiazolinone (19%), paraphenylenediamine (15.2%), and fragrance mixtures (7.8%). Acrylates were the most common allergens in cases of occupational disease. Half of the positive results were obtained with the standard battery of the Spanish Group for Research Into Dermatitis and Skin Allergies (GEIDAC). The cosmetic products most often implicated among cosmetics users were hair dyes (18.5%), gels/soaps (15.7%), and moisturizing creams (12.7%). Conclusion Most patients affected were women. Preservatives, paraphenylenediamine, and fragrances were the most frequently detected cosmetic allergens, in line with previous reports in the literature. Finally, in order to detect new cosmetic allergens, cooperation between physicians and cosmetics producers is needed.
The passivation of pure Zn (99.995wt%) and Zn–0.4Mn (0.4wt% Mn) alloy in a deaerated 0.1M NaOH solution (pH 12.9) was investigated by electrochemical measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The potentiodynamic polarization and electrochemical impedance measurements show that addition of 0.4wt% Mn can decrease the passive current density of Zn in the passive region. XPS surface analysis indicates that there is approximately 1.0–2.0at% Mn2+ being incorporated into the passive film on Zn–0.4Mn alloy with Mn content being higher in the outer layers. Mott–Schottky analysis shows that the incorporated Mn can decrease concentration of defects in the film. AFM observations disclose that Mn can decrease the grain size of the film. The mechanism by which Mn additions improve the passivity of Zn is that the incorporated Mn can inhibit ions transportation in the film and inhibit its growth. Meanwhile, Mn can also promote the nucleation of Zn oxides and decrease film porosity.
The corrosion of titanium in H2SO4 electrolytes (0.001–1.0M) at temperatures from ambient to 98°C has been investigated using steady-state polarization measurements. Four distinct regions of behaviour were identified, namely active corrosion, the active–passive transition, passive region and the dielectric breakdown region. The active corrosion and active–passive transition were characterized by anodic peak current (i m) and voltage (E m), which in turn were found to vary with the experimental conditions, i.e., d ( log ⁡ ( i m ) ) / dpH = − 0.8 ± 0.1 and dE m/dpH which was −71mV at 98°C, −58mV at 80°C and −28mV at 60°C. The activation energy for titanium corrosion, determined from temperature studies, was found to be 67.7kJmol−1 in 0.1M H2SO4 and 56.7kJmol−1 in 1.0M H2SO4. The dielectric breakdown voltage (E d) of the passive TiO2 film was found to vary depending on how much TiO2 was present. The inclusion of Mn2+ into the H2SO4 electrolyte, as is done during the commercial electrodeposition of manganese dioxide, resulted in a decrease in titanium corrosion current, possibly due to Mn2+ adsorption limiting electrolyte access to the substrate.
The presence of vascular neurocognitive impairment (whatever the severity) is always associated with a functional impact and increased risk of dependency and institutionalization. However, vascular cognitive impairment remains underdiagnosed, and the mechanisms underlying post-stroke cognitive disorders are still poorly understood. However, the advent of new criteria and a standardized international neuropsychological battery is expected to lead to improved diagnosis and management, and the development of novel techniques (such as brain imaging and amyloid PET) should improve our understanding of the mechanisms underlying vascular cognitive impairment and help to identify potential targets for therapy.
Hierarchical NiCoO2 nanosheets nanotubes are successfully prepared by a mild solution method based on the template of polymeric nanotubes (PNT) followed by a thermal annealing treatment. The microstructure and chemical composition of NiCoO2 nanosheets nanotubes are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analyzer, X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). When evaluated as an electrode material for supercapacitors, the results of electrochemical test show that the unique NiCoO2 nanosheets nanotubes exhibit relatively high specific capacitance of 1468, 1352, 1233, 1178, 1020 and 672 F g−1 at the discharge current densities of 2, 4, 8, 10, 20 and 40 A g−1, respectively. They also reveal an excellent cycling stability of 99.2% retention after 3000 cycles at 10 A g−1. The smart nanostructures of the NiCoO2 nanosheets nanotubes make a prominent contribution to the excellent electrochemical performance.
Metal alloys possessing core–shell structures have potential as low-Pt catalysts for the oxygen reduction reaction in fuel cells, but can suffer from poor stability. Using high-resolution microscopy, Li et al. find that a Pt–Pd–Au catalyst undergoes surface atomic rearrangement and becomes more active on electrochemical cycling.
We report that the oxygen reduction reaction (ORR) activities of (001)-oriented manganese perovskite films decrease from 10 to 1 nm by more than an order of magnitude, which can be attributed to the barrier associated with interfacial band bending that impedes electron transfer to the electrolyte, and reduction of Mn3+ due to charge transfer from the Nb:SrTiO3 substrate. Furthermore, we show by substitution in La1−x(Ca,Sr)xMnO3 that Mn3+, not Mn4+, is the active valence state for ORR.
The oceans face a range of complex challenges for which the impacts on society are highly uncertain but mostly negative. Tackling these challenges is testing society’s capacity to mobilise transformative action, engendering a sense of powerlessness. Envisaging positive but realistic visions of the future, and considering how current knowledge, resources, and technology could be used to achieve these futures, may lead to greater action to achieve sustainable transformations. Future Seas (www.FutureSeas2030.org) brought together researchers across career stages, Indigenous Peoples and environmental managers to develop scenarios for 12 challenges facing the oceans, leveraging interdisciplinary knowledge to improve society’s capacity to purposefully shape the direction of marine social-ecological systems over the UN Decade of Ocean Science for Sustainable Development (2021–2030). We describe and reflect on Future Seas, providing guidance for co-developing scenarios in interdisciplinary teams tasked with exploring ocean futures. We detail the narrative development for two futures: our current trajectory based on published evidence, and a more sustainable future, consistent with the UN’s Sustainable Development Goals, which is technically achievable using existing and emerging knowledge. Presentation of Business-as-usual and More Sustainable futures—together—allows communication of both trajectories, whilst also highlighting achievable, sustainable versions of the future. The advantages of the interdisciplinary approach taken include: (1) integrating different perspectives on solutions, (2) capacity to explore interactions between Life Under Water (Goal 14) and other SDGs, and (3) cross-disciplinary learning. This approach allowed participants to conceptualise shared visions of the future and co-design transformative pathways to achieving those futures.
Using a simple electrochemical reduction approach, we have produced three-dimensional (3D) graphene foam having high conductivity and well-defined macroporous structure. Through a hydrothermal process, Ni(OH)2 sheets are grown in-situ onto the graphene surface. This monolithic 3D graphene/Ni(OH)2 composite is used as the free-standing electrode for supercapacitor application; it shows a high specific capacitance of 183.1Fg−1 (based on the total mass of the electrode), along with excellent rate capability and cycle performance. The asymmetric supercapacitor based on the 3D graphene/Ni(OH)2 as a positive electrode and active carbon (AC) as a negative electrode is also assembled and it exhibits a specific capacitance of 148.3Fg−1 at 0.56Ag−1 and a high energy density of 52.7Whkg−1 at a power density of 444.4Wkg−1. Moreover, 3D graphene/Ni(OH)2//AC has a good cycle stability (87.9% capacitance retention after 1000 cycles), making it promising as one of the most attractive candidates for electrochemical energy storage. This excellent electrochemical performance results from the multiplexed 3D graphene network facilitating electron transport; the interlaced Ni(OH)2 sheets shorten ion diffusion paths and facilitate the rapid migration of electrolyte ions.
LiMn2O4/multi-walled carbon nanotubes (MWNTs) composite was synthesized by mechanical activation reaction followed by a heat-treatment (500 °C). The LiMn2O4 and LiMn2O4/MWNTs as cathodes were investigated in 1 M Li2SO4 by cyclic voltammetry (CV), galvanostatic charge/discharge (GC), and electrochemical impedance spectroscopy (EIS). The LiMn2O4/MWNTs cathode delivered higher discharge capacity (117 mAh g−1) than LiMn2O4 (84.6 mAh g−1). Furthermore, the results from EIS showed that LiMn2O4/MWNTs had a faster kinetic process for lithium ion intercalation/de-intercalation than LiMn2O4. Besides, LiMn2O4/MWNTs had better cycling stability and rate capability than LiMn2O4, which was confirmed by GC testing. SEM images showed that a three-dimensional network structure was formed during the mechanical activation, giving a decrease of particle size.
Replacing state-of-the-art graphite with metallic Li anodes could dramatically increase the energy density of Li-ion technology. However, efforts to achieve uniform Li plating and stripping in conventional liquid electrolytes have had limited success. An alternative approach is to use a solid electrolyte to stabilize the Li interface during cycling. One of the most promising solid electrolytes is Li7La3Zr2O12, which has high ionic conductivity at room temperature, high shear modulus and chemical and electrochemical stability against Li. Despite these properties, Li filament propagation has been observed through LLZO at current densities below what is practical. By combining recent achievements in reducing interface resistance and optimizing microstructure, we demonstrate Li cycling at current densities competitive with Li-ion. Li|LLZO|Li cells are capable of cycling at up to 0.9 ± 0.7 mA cm−2, 3.8 ± 0.9 mA cm−2, and 6.0 ± 0.7 mA cm-2 at room temperature, 40 and 60 °C, respectively. Extended stability is shown in Li plating/stripping tests that passed 3 mAh cm−2 charge per cycle for a cumulative capacity of 702 mAh cm−2 using a 1 mA cm−2 current density. These results demonstrate that solid-state batteries using metallic Li anodes can approach charge/discharge rates and cycling stability comparable to SOA Li-ion.
Pristine graphene was directly suspended in a variety of organic media, which are used either as electrolyte solvents or deposition media in sensitized solar cells. Dispersion occurred directly through sonication-assisted exfoliation of graphite powder, without adopting the oxidative approach involving intermediate formation of graphene oxide and its subsequent reduction. The concentration of the thus dispersed graphene was relatively low, in the order of a few tens of micrograms per ml, but it was very effective in increasing the efficiency of sensitized solar cells. Dispersed graphene was first deposited on solid substrates and was extensively characterized by TEM, SEM, XPS and Raman spectroscopy. Also dispersed graphene has been introduced in liquid-electrolyte and gel-electrolyte dye-sensitized solar cells by means of sulfolane/3-methoxypropionitrile mixtures and in quantum dot sensitized solid-state solar cells by means of chlorobenzene-based suspensions. Increase of cell efficiency in the presence of the above tiny quantities of graphene was very large, particularly in the case of solid state cells where more than 3-fold increase of efficiency was observed.
Multidimensional CoMoO4@Ni(OH)2 nanocomposite materials are fabricated on the nickel modified surface and channels of an ordered macro-porous electrode plate (OMEP) by a multistep high temperature hydrothermal method as the supercapacitor electrode in a high power density energy storage device. The effects, morphology, capacitive properties, and formation mechanism of the CoMoO4@Ni(OH)2 composite materials are systematically investigated. Compared to nanostructured nickel grown on the OMEP or CoMoO4@Ni(OH)2 on nickel plate with the same area, the CoMoO4@Ni(OH)2/OMEP shows enhanced electrochemical energy storage properties such as high energy capacitance of 8.55 F cm−2 (1812.42 F g−1) at 2 mA cm−2 and good cycling stability of 87.42% capacity retention after 5000 cycles. An asymmetrical supercapacitor (ASC) device is assembled with a polyethylene (PE) membrane, CoMoO4@Ni(OH)2/OMEP, and active carbon covered nickel foam. The ASC with the CoMoO4@Ni(OH)2/OMEP has an energy density of 9.66 Wh Kg−1 even at a power density of 3000 W Kg−1 as well as stable power characteristics with 86.5% retention after 10,000 cycles at a current of 0.06 A. The device produces large instantaneous power after charging at 2.8 V for 10 s one ASC can power a 5 mm red LED with high efficiency.
Presenting Author details:joselito600@yahoo.es La Fuente s/n, 31003 Burlada (Navarra), Spain, Tel.: +34 656740772. Background: Cannabis abuse is thought to increase the risk of developing schizophrenia. However several studies have examined the influence of current cannabis abuse on illness characteristics, little is known about the antecedents of pre-psychotic cannabis abuse in patients with psychosis and its effects on the clinical picture of the subsequent illness. In this study we aimed to examine in a sample of patients already diagnosed with a psychotic disorder, the predictors and consequences of: (1) pre-psychotic cannabis abuse, (2) early cannabis abuse and (3) current cannabis abuse. Methods: Pre-psychotic characteristics included sociodemographic variables, childhood and adolescence adjustment. Phenotypic measures included age of illness onset, psychopathology (OPCRIT) and a short neuropsychological battery. These characteristics were then compared according to patients' pre-psychotic and current history of cannabis abuse. Results: A sample of 337 patients with psychosis was included. It was found that pre-psychotic cannabis abuse was associated with better social but worse school premorbid adjustment. Early cannabis abuse predicted an earlier age of illness onset and more negative and cognitive symptoms. Finally, current cannabis abuse was associated with more severe positive, manic and depressive symptoms. Conclusions: While psychotic patients who comorbidly abuse cannabis may have more prominent positive and affective symptoms, those who started abusing cannabis during their early adolescence have poor adolescent school adjustment, early onset of illness and more prominent negative symptoms and cognitive abnormalities.
A Ni/Mn composite precursor was prepared as the precursor for Li-rich cathode materials under an air-precipitation atmosphere in a continuous stirred-tank reactor (CSTR). The nucleation and growth of precursor particles were investigated during the CSTR process by monitoring particle morphology, chemical composition, and phase composition. It was found that the particle shape and chemical composition were not homogeneous in the early stages of co-precipitation and did not become so until after 4 h. Mn2+ ion oxidation was verified to occur during the entire course of precipitation by X-ray diffraction. The final precipitate was identified as a two-phase system consisting of a Ni/Mn layered double hydroxide phase and a Mn3O4 phase. Scanning electron microscopy and an N2 adsorption–desorption test revealed the porosity and surface area of the material. A Li-rich cathode material was synthesized using the final precipitate as a precursor; the electrochemical performance of this cathode material is reported in this article.
One-vs-One (OVO) and One-vs-All (OVA) are decomposition methods for multi-class strategies used to allow binary Support-Vector Machines (SVM) to transform a given k-class problem into pairwise small problems. In this context, the present work proposes the analysis of these two decomposition methods applied to the hand posture recognition problem in which the sEMG data of eight participants were collected by means of an 8-channel armband bracelet located on the forearm. Linear, Polynomial and Radial Basis Function kernels functions and its adjustments level were implemented combined to the strategies OVO and OVA to compare the performance of the SVM when mapping posture data into the classification spaces spanned by the studied kernels. Acquired sEMG signals were segmented considering 0.16 s e 0.32 s time windows. Root Mean Square (RMS) feature was extracted from each time window of each posture and used for SVM training. The present work focused in investigating the relationship between the multi-class strategies combined to kernels adjustments levels and SVM classification performance. Promising results were observed using OVA strategy which presents a reduced number of binary SVM implementation achieved a mean accuracy of 97.63%.
Phase transition in lithium manganese oxide spinel synthesized by sol–gel technique and in samples prepared from commercially available powders of LiMn2O4 (Alfa-Aesar and Sigma–Aldrich) was investigated. In addition to the standard impedance measurements and the X-ray diffraction in Bragg–Brentano geometry, simultaneous measurements of impedance spectrum and X-ray pattern in non-focusing geometry were performed in the temperature range between −25 and +100°C. Correlation between the XRD profile parameters and the electrical conductivity was evidenced. Spinel synthesized by the sol–gel technique and heat-treated at 800°C as well as samples prepared from Alfa-Aesar powder exhibited a distinctive phase transition from cubic to orthorhombic structure upon cooling below room temperature. Structural transition was visible in the X-ray pattern as splitting of the 400 reflection of cubic structure, and was accompanied by a decrease of conductivity by a factor of about 10. In the sample prepared from powder supplied by Sigma–Aldrich the phase transition was not complete even upon cooling to −25°C, and no stepwise change of conductivity was observed. Differences in behavior of the spinel samples can be related to the presence of additional phases (Mn3O4 or Li2MnO3), which were found in commercial powders, whereas the sol–gel synthesized samples were single phase.
Separator papers are an essential component of a valve regulated lead/acid (VRLA) battery. In addition to separating the positive and negative electrodes, they provide a constant pressure on the active materials thereby reducing the rate of degradation during cycling. Dendrites formed from the negative active material are also less likely to cause short circuits in batteries where a separator is employed. The level to which a separator will influence the performance of a VRLA battery it strongly dependent on its properties. This paper describes the results from a series of tests used to characterise the properties of separators most influential to battery performance. These properties include, the macroscopic structure, permittivity and wicking rates. During the operational life of a VRLA battery the volume of electrolyte will decrease, due mainly to the electrolysis of water during overcharging. The consequence of this process is a variation of acid saturation during the life of the battery, which will have a direct influence on the compressive and diffusive properties of the separator. Compressive and diffusive characteristics were therefore measured over a range of saturation levels. Characterisation was conducted on three separator types. Types A and B were 100% glass but had slightly different structures and type C contained 8% polyester fibres mixed with glass.
An all-soft, highly stretchable liquid metal (LM) conductor with high electrical conductivity, excellent electrical conductivity stability under various mechanical deformations and good mechanical properties was achieved. The stretchable conductor was prepared by infiltrating Gallium-indium-tin (GIT) LM into porous polyurethane sponge (PUS) with large porosity and small pores using a vacuumizing method followed by encapsulation with Polydimethylsiloxane (PDMS) to prevent the leakage of GIT-LM and to improve the mechanical properties. The as-made PDMS/PUS/LM composite shows a high tensile strength (1.11 MPa), high elongation at break (419%), excellent electrical conductivity (104 S/cm) and electrical conductivity stability under various mechanical deformations. The normalized resistance is of highly repeatability in stretch-release and bend-release cycle experiments.
Wind energy conversion systems have become a focal point in the research of renewable energy sources. This is in no small part due to the rapid advances in the size of wind generators as well as the development of power electronics and their applicability in wind energy extraction. This paper provides a comprehensive review of past and present converter topologies applicable to permanent magnet generators, induction generators, synchronous generators and doubly fed induction generators. The many different generator–converter combinations are compared on the basis of topology, cost, efficiency, power consumption and control complexity. The features of each generator–converter configuration are considered in the context of wind turbine systems.