Dunn's Method Research Articles

High-performance, high energy density symmetric supercapacitors based on δ-MnO2 nanoflower electrodes incorporated with an ion-conducting polymer.

The present work investigates liquid-based and liquid-free supercapacitors assembled using δ-MnO2-nanoflower-based electrodes. An optimized electrode composition was prepared using acetylene black (AB), a polymer (PEO), a salt (LiClO4), and δ-MnO2 and used for device fabrication. The composite electrode was tested against a liquid electrolyte and a 'liquid-free' composite solid polymer electrolyte (CSPE) membrane. In a three electrode geometry, with 1 M solution of LiClO4 as an electrolyte, the specific capacitance of the electrode was found to be ∼385 F g-1, with a specific energy of ∼23 W h kg-1 and specific power of ∼341 W kg-1 (at 1 mA, 1 V). Dunn's method confirmed that the charge storage process was predominantly pseudocapacitive. When the device was assembled in a two-electrode Swagelok cell, a stable specific capacitance of ∼216 F g-1 was observed with a specific energy of 30 W h kg-1 and a specific power of 417 W kg-1. The supercapacitors exhibited stable performance up to ∼7000 cycles with ∼90% capacitance retention and ∼97% coulombic efficiency. A combination of these cells could light two white light-emitting diodes (LEDs, 3 V) for at least ∼10 minutes. Further, all-solid-state supercapacitors (ASSCs) were fabricated using a Li+ ion (CSPE) membrane. The ASSCs exhibited a specific capacitance of ∼496 F g-1 after ∼500 cycles, with a specific energy and power of ∼19 W h kg-1 and ∼367 W kg-1, respectively. The investigation reveals that the electrodes are versatile and show compatibility with liquid and solid electrolytes. The polymer in the electrode matrix plays an important role in enhancing device performance.

Effect of replacing Bis-GMA with a biobased trimethacrylate on the physicochemical and mechanical properties of experimental resin composites.

To analyze the incorporation of cardanol trimethacrylate monomer (CTMA), derived from the cashew nut shell liquid, as a substitute for Bis-GMA in acrylic resins formulations and its effect on experimental resin composites' physicochemical and mechanical properties. The intermediary cardanol epoxy was synthesized via cardanol epoxidation, followed by the synthesis of CTMA through methacrylic anhydride solvent-free esterification. Experimental resin composites were formulated with an organic matrix composed of Bis-GMA/TEGDMA (50/50 wt %) (control). CTMA was gradually added to replace different proportions of Bis-GMA: 10 wt % (CTMA-10), 20 wt % (CTMA-20), 40 wt % (CTMA-40), and 50 wt % (CTMA-50). The composites were characterized by degree of conversion, water sorption and solubility, viscosity, thermogravimetric analysis, dynamic mechanical analysis, flexural strength and elastic modulus. Data were analyzed with one-way ANOVA and Tukey's post-hoc test (α = 0.05), except for water sorption data, which were analyzed by Kruskall-Wallis and Dunn's method. CTMA-based and control composites did not show statistically significant differences regarding degree of conversion, flexural strength and elastic modulus. CTMA reduced the viscosity and solubility compared to the Bis-GMA-based composite. The CTMA-40 and CTMA-50 exhibited significantly lower water sorption compared to the control. Also, acceptable thermal stability and viscoelastic properties were obtained for safe use in the oral cavity. Incorporating CTMA into composites resulted in similar chemical and mechanical properties compared to Bis-GMA-based material while reducing viscosity, water sorption and solubility. CTMA could be used as a trimethacrylate monomer replacing Bis-GMA in resin composites, thereby minimizing BPA exposure.

Redox active cobalt based bi-linker metal organic frameworks derived from 5-sulfoisopthalic acid and 4,4-bipyridine for supercapacitor

In this research study, we have synthesized, characterized and extensively compared the electrochemical characteristics of two materials derived from 5-sulphoisophtalic acid, 4,4-bipyridine and cobalt metal using sonochemical method. Cobalt-bipyridine complex with 5-SIP in lattice structure (RG-41) showed predominant capacitive behavior whereas Co-SIP-Bpy MOF (RG-42) exhibited significant pseudocapacitive attributes due to the presence of coordination linkage responsible for the electron transfer. Due to the effective electrochemical properties of RG-42, we implemented it practically by fabricating a hybrid device with outstanding electrochemical features, demonstrating impressive 92 % cyclic stability with energy density and power density of 51.41 Wh/kg and 800 W/kg at 1 A/g, respectively. Dunn's method was employed to obtain capacitive-diffusive contributions for both half-electrochemical cells as well as hybrid device. These results underscored the potential of RG-42 as a competitive electrode material for future energy storage applications.

Ta-ions doping impact on structural modifications and bandgap tuning of NiCo2O4 hexagonal nanosheets for high rated pseudocapacitor electrodes

Getting higher activity, lower cost and especially better stability at the same time is still one of the biggest problems in the supercapacitors research. Morphology tailoring and crystal imperfections induce d due to doping based defects in ternary transition metal oxides at the nano-scale level is crucial for enhancing the performance of supercapacitors. This research investigates of the utilization of Ta-doped NiCo2O4 (Ta-NCO) hexagonal nano-sheets for supercapacitor electrodes. The structural and morphological study of pristine and Ta-doped samples has been determined using XRD, SEM, TEM and HRTEM. The enhanced inherent conductivity and diffusion at the interface are also confirmed using electrochemical measurements study. The NCO-5 material exhibits a notable enhancement in capacitance and cycling retention. The NCO-5 electrode demonstrates a high specific capacitance (Cs) of 2445.7 F/g at 1 A/g. The pseudocapacitive behavior by power law (b = 0.67) and an increase in capacitive contribution with the scan rate reaching a value of 47.2 % at 100 mV/s by Dunn method exhibits it suitability of pseudocapacitors. The low Rct value signifies it improved capacitive performance as deduced from EIS measurements. Crucially, it maintains around 95.3 % of its capacitance after undergoing 10,000 GCD cycles. The high specific capacitance, remarkable capacitive characteristics and high stability of NCO-5 make it an excellent contestant for supercapacitor applications. The fabricated asymmetric supercapacitor (NCO-5//AC) shows exceptional energy density (ED) of 96.35 Wh/kg with power density (PD) of 825.03 W/kg.

Strategically-designed hierarchical polypyrrole-modified manganese-doped tin disulfide (SnS2) nanocomposite electrodes for supercapatteries with high specific capacity

Supercapatteries are novel energy storage devices possessing features of both supercapacitor and battery and evolved to meet the demand for portable electronic devices. An efficient electrode-active material is an important criterion for the fabrication of high performance supercapatteries. We hereby report the rapid synthesis of manganese (Mn)-doped tin disulfide (SnS2) by microwave-assisted hydrothermal method and further use it as an efficient electrode material (positrode) to fabricate a supercapattery. Dunn's kinetic method is adopted to estimate the contribution from the battery-type charge storage which confirm the electrode exhibits charge storage via diffusion-controlled mechanisms. The Mn-doped SnS2 electrode exhibits a specific capacity of 275.4 C g-1 at a scan rate of 10 mV s-1. The specific capacity is further increased by preparing nanocomposite electrodes with polypyrrole at different ratios. The polypyrrole-modified Mn-doped SnS2 electrode delivers a specific capacity of 539 C g-1 at a scan rate of 10 mV s-1. In order to understand its applicability in practical devices, a supercapattery cell is fabricated with polypyrrole-modified Mn-doped SnS2 as positrode and activated carbon as negatrode, which exhibits a mass specific capacity of 204.2 C g-1 along with an area specific capacity of 2.4 C cm-2 at a current density of 2 A g-1. The supercapattery cell possesses an energy density of 42.5 W h kg-1 with a corresponding power density of 2500 W kg-1 at a current density of 2 A g-1. This study proclaims that the polypyrrole-modified Mn-doped SnS2 is an efficient positrode for application in high-performance supercapatteries.

Utilizing FeS2 Deposition on 3D Printed Carbon Microlattices as Free-Standing Electrodes in Lithium-Ion Batteries

Free-standing electrodes are a great alternative to slurry-coated battery electrodes as they eliminate the need for inactive components and shorten the fabrication process. In this work, carbon microlattice templates are designed and fabricated through the use of 3D stereolithography followed by pyrolysis to create a well-defined carbon template with a resolution >35 µm. Iron disulfide, a material with a high specific theoretical capacity, is then deposited on the surface and used as electrode material in lithium-ion batteries. To date, there have been no reports of FeS2 combined with 3D printed free-standing electrodes. The design utilizes controlled microchannels along the thickness direction to facilitate efficient ion transfer and interconnected carbon skeletons for electron transfer throughout the entire electrode. When directly applied in a lithium-ion battery, the composite material displayed a specific capacity of 562.5 mAh g-1 after 200 cycles with a current density of 500 mA g-1. A high-rate capability was also achieved. Stepwise cyclic voltammetry and Dunn Method confirm that the dominant mechanism guiding the excellent electrochemical performance is diffusion-controlled process, further highlighting the benefits of the organized microchannels. These results will advance the development of composite electrodes as well as shine light on the immense potential to develop high energy density batteries utilizing 3D printing, advocating for sustainable energy from both a research-driven and practical stance.

Investigations on supercapacitor performance of novel ZnO-CeO2-rGO nanohybrid prepared via hydrothermal method for energy storage applications and their charge storage mechanism

Nanohybrids which can utilize the synergistic effect to enhance the electrochemical activity as an electrode material for supercapacitor has gained immense interest recently.Here,we report a ZnO-CeO2-rGO ternary nanohybrid synthesized via hydrothermal method which can combine the pesuedocapacitance nature of transition metal oxide and electric double layer behavior of reduced graphene oxide. The electrochemical activity was thoroughly investigated using cyclic voltammometry(CV) and galvanostatic charge discharge for the ternary using a two electrode set up with 2 M KOH as the electrolyte. Cyclic stability analysis was done and impedance analysis was carried out using electrochemical impedance spectroscopy. Among the samples the best electrochemical performance was observed for ZnO –CeO2-rGO (Ter-2) with weight ratio 85:10:5. Ter-2 exhibited specific capacitance of 26 F/g from CV in the 2-electrode setup and a capacity retention as high as 93 % even after 5000 cycles of charge-discharge. It was observed that the addition of rGO improved the cyclic stablity as well as specific capacitance. Systematic analysis of charge storage mechanism was done using Dunn's and Trasatti's method. The results substantiate that Ter-2 is a potential supercapacitor electrode material with excellent electrochemical activity.

Supercapacitive performance of 3D-cobalt oxide (Co3O4) nanowires grown onto anodized stainless-steel substrate: Effect of anodization time

3D-Co3O4 nanowires were grown on anodized stainless steel (SSA) using a simple hydrothermal technique, with SSA as a cost-effective porous substrate. The originality of this work is to enhance surface activity and material adhesion by anodizing stainless steel (SS). After growth, the nanowires were thermally treated at 400 °C for 2 h. By varying the SS anodization time from 0 to 900s, changes in the structural, morphological, and electrochemical properties of Co3O4 were observed. XRD analysis confirmed the polycrystalline nature of Co3O4 with a face-centered cubic phase. SEM imaging showed noticeable changes in density and surface roughness. Supercapacitive properties were evaluated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) techniques, with SSANWs-300 exhibiting the highest specific capacitance of 529 Fg-1. Dunn's method was used to analyze the contribution of capacitive and diffusive mechanisms to charge storage. EIS results indicated excellent electronic conductivity. The study suggests that SSANWs-300 holds promise for energy storage applications.

Unleashing the power of Fe2(MoO4)3 as a multifunctional material for energy storage and photocatalysis with theoretical insight from density functional theory

In a world facing urgent environmental issues and an increasing demand for sustainable energy solutions, the quest for versatile materials that can tackle a wide range of energy challenges has become essential. This paper aims to capture the diverse capabilities of Fe2(MoO4)3, highlighting its role as a multifunctional material applicable in both photocatalysis and energy storage. A simple strategy for the synthesis of Fe2(MoO4)3 via a one-step hydrothermal route is designed to allow for multifunctional properties, such as high photocatalytic activity under visible light irradiation and excellent electrochemical behaviour for its use as the electrode in a supercapacitor.The photodegradation tests reveal that Fe2(MoO4)3 can efficiently degrade 96 % of methylene blue (MB) dye within only 70 min of exposure to visible light. The maximum Langmuir adsorption capacity of Fe2(MoO4)3 was 94.33 mg/g at 30 °C and it also followed pseudo-second order kinetic models as well. The result of thermodynamic data showed that the adsorption was spontaneous and endothermic in nature. At the same time the use of Fe2(MoO4)3 as an electrode material for supercapacitors exhibits impressive characteristics, including a high specific capacitance (472 F/g at 1 A/g), excellent cycling stability (85.4 % retention after 10,000 cycles), impressive rate capability (323 F/g even at 6 A/g), as well as noteworthy energy and power density (16 Wh/kg and 1497 W/kg). The capacitive and diffusion-controlled contribution is also investigated for Fe2(MoO4)3 using Dunn's method. First-principles Density Functional Theory simulations also support our experimental findings by demonstrating that maximum quantum capacitance can reach 580 F/g at an electrode potential of 0.65 V. All of these promising results demonstrate the multifunctionality of Fe2(MoO4)3 as a potential electrode material as well as a novel photocatalytic candidate for organic contaminant removal in water.

Rapid and stable energy storage using MoN/Mo2N composite electrodes

Molybdenum nitride-based composites, specifically the two-dimensional MoN/Mo2N variants, emerge as promising electrode materials for next-generation energy storage devices. This research presents a facile synthesis approach involving a mechanochemical method followed by heat treatment at 900 ֯C in a nitrogen atmosphere to produce the MoN/Mo2N composite material. Crystallographic analysis using X-ray diffraction (XRD) and morphological characterization via high-resolution scanning electron microscopy (HRSEM) were conducted. The electrochemical evaluation demonstrated remarkable supercapacitor performance, with a specific capacitance of 306.7 F/g at 1 A/g, highlighting exceptional charge storage capacity. Even at a higher current density of 2 A/g, the composite maintained substantial reversible capacity (198.6 F/g), higher capacitance retention (95.7 %), and Coulombic efficiency (86.2 %) over 6000 cycles, showcasing its robust stability. At a challenging current density of 10 A/g, the specific capacitance remained high at 85.4 F/g. Detailed charge storage mechanism analysis, employing the Dunn method, revealed a complex interplay of capacitive and diffusive processes. Particularly noteworthy was the predominance of capacitive behavior, constituting 78.4 % at an accelerated scan rate of 100 mV/s. This observation underscores the material's advantageous propensity for a higher proportion of capacitive behavior in the charge storage mechanism at elevated scan rates, making it well-suited for applications requiring rapid energy storage and release.

Aloe vera extract-assisted sol-gel synthesis of NiOx nanopyramids for supercapacitor application

Green synthesis of metal oxide nanoparticles is a cost-effective and sustainable approach that allows tailoring of the size and shape of the nanostructures for versatile applications. In this study, aloe vera extract-assisted sol-gel synthesis of nickel oxide nanoparticles (NiOx NPs) was explored for supercapacitor application. The NiOx NPs were synthesized at different aloe vera concentrations (2.5 and 5 wt%) and calcination temperatures (300, 400 and 500 °C). The phytochemical-assisted synthesis yielded NiOx nanopyramids with pores on their surface which widens as calcination temperature increases. As confirmed by XRD analysis, NiOx crystallite size also increased at higher calcination temperatures. Upon electrochemical characterization, NiOx-400B which was synthesized with 5 wt% aloe vera extract at 400 °C recorded the highest specific capacitance of 721 F g−1 at 1 A g-1 current density with the energy and power density of 10.38 Whkg−1 and 241.08 W kg-1 respectively. The charge storage mechanisms in the samples were gauged using Dunn's method which revealed that NiOx synthesized at higher calcination temperatures exhibited a greater contribution of the diffusion-controlled process. The optimized composition, NiOx-400B, also demonstrated excellent cycle stability by retaining up to 90.4 % of its original capacitance over 1500 cycles. This work is an attempt to investigate the viability of green synthesized nanoparticles in energy storage applications and the novel NiOx nanopyramid substantiates its prospect as a good electrode material for supercapacitors.

Психологические аспекты профессиональной деятельности и благополучие женщин в сфере образования: возрастная динамика и гендерное сравнительное корреляционное исследование

The problem of the psychological well-being of women employed in the educational field currently still has a fairly wide range of unexplored issues. In this paper, well-being is considered in connection with the components of professional satisfaction and motivation, taking into account gender and age aspects. The study involved 140 people, including 103 women aged 20 to 75 years. The study was carried out using theoretical analysis of scientific literature, the Method for diagnosing the subjective well-being of a person (Shamionov & Beskova), Motivation Sources Inventory (version of Sidorenko), Job Satisfaction Survey (P. Spektor), Maslach Burnout Inventory (version by Vodopyanova & Starchenkova), Izard's Differential Emotions Scale adapted by Leonov and Kapitsa, test “Personal differential” (adapted at the Bekhterev Research Institute). Statistical methods: Shapiro-Wilk test, non-parametric Kruskal-Wallis test, pairwise comparison using the Dunn method, Spearman's rank correlation coefficient, Cohen's q and z- test for comparing two sample correlation coefficients. As a result, differences between different age groups of women were revealed in terms of professional stress, well-being and burnout, as well as differences for women and men in relationship between the psychological aspects of their professional activities and personality traits, emotions and well-being.

Decoupling Reaction, Diffusion and Ohmic Processes in Fast-Charging Electrodes: A New Model for CV Data Analysis

Fast charging is critical for the efficient storage of energy in devices like electric vehicles and portable electronics. The rate performance of electrodes is limited by the electron transfer rate, the ohmic resistance of the electrode, the size and shape of the primary electrode particles, and the charge carrier diffusion process within the electrodes. However, separating the intrinsic contributions of mass transport and charge transfer from non-equilibrium data obtained under large interfacial polarization is very complex, which limits our understanding of high rate electrodes during charging and discharging. While it is possible to extract the diffusive and capacitive components of an electrode’s capacity from cyclic voltammetry (CV) data using the Dunn method, the Dunn model assumes a constant diffusional overpotential. In reality the ohmic resistance scales with the current, so that the ohmic potential drop across the electrode cannot be neglected a priori for fast charging electrodes in which high current densities are a requirement.We recently developed a new model based on the Butler-Volmer equation for the kinetics of the electron exchange process, and incorporated the charge carrier diffusion process and the internal ohmic losses, as well as the effect of the shape and dimensions of the primary electrode particles on the effective diffusion rate [1]. The model can provide the relation between current peak voltages and peak currents from a series of sweep rate CV measurements. The ohmic resistance, equilibrium voltage, exchange current (related to the electrochemical reaction rate) and limiting current (related to the charge carrier diffusion coefficient and Nernst diffusion layer thickness) can be extracted as independent variables from the fitted experimental data.By simulating a range of different high rate Li electrode materials (both cathodes and anodes), we identified influence of the reaction rate on the overpotential as a common significant factor, which explains the nonlinear relation between the potential and the current at peak position in different CV measurements. Our analysis suggests that a higher electrochemical reaction rate seems to be more important for the realization of faster charging batteries than a larger carrier diffusion coefficient.Finally, our extended model also enables us to predict the overpotential at any applied potential, which is not possible with other current models known till date. This insight helps us to gain more detailed understanding of the relationship between the intrinsic properties of the electrode materials and their rate performance in different reaction stages. This may facilitate further modification of electrode material towards enhanced high rate performance in next-generation batteries.[1] R. Xia et al., Energy Storage Mater. 53 (2022) 381-390.

Freeze-Drying-Assisted ZIF-67 Template-Derived Co@NCS Porous Composite as Sulfur Cathode Host for Improved Li-S Battery Performance: Deconvolution of Diffusive and Capacitive Li+ Storage.

A zeolitic imidazole framework (ZIF-67) template-derived cobalt@nitrogen-doped carbon-sulfur composite (ZIF-Co@NCS) was synthesized using a freeze-drying method and explored for lithium-sulfur (Li-S) batteries. Material characterizations confirmed the formation of the ZIF-Co@NCS composite. To fabricate the Li-S battery in a coin-type CR-2032 cell, the as-synthesized ZIF-Co@NCS composite having a sulfur content of ∼65% was used as a cathode material and coupled with a lithium metal anode. This battery demonstrated exceptional cycling stability over 600 charge-discharge cycles with a steady capacity of 550 mAh g-1 at 0.05 C-rate. The good electrochemical performance of the cathode was ascribed to the nanofeatures associated with the freeze-dried porous carbon structure, which offered enough space for the sulfur cathode. The enhanced trapping of polysulfide facilitated by the presence of the Co-N sites in the ZIF-Co@NCS composite led to excellent cycling stability. The derived cathode composite showed a high specific capacity, outstanding rate capability, and excellent cyclic stability rendering it a promising candidate for high-performance Li-S batteries. Detailed Li+ ion charge storage examined by means of Dunn's method revealed a significant capacitive mode of charge storage both at peak currents and nonpeak currents. The post-mortem analysis of the cycled cathode using X-ray diffraction and scanning electron microscopy at different depth-of-discharge (DOD) values revealed the stepwise formation of discharge products.

3D-graphene hydrogel and tungsten trioxide-MnO2 composite for ultra-high-capacity asymmetric supercapacitors: A comparative study

Researchers worldwide use graphene extensively in its powder form for various applications such as supercapacitors, solar cells, drug delivery, and polymer composites, owing to its considerably valuable properties. However, relatively few studies have been made on the 3D-hydrogel form of graphene for these applications. Here we report a simple and fresh method to prepare 3D graphene hydrogel (3DGH) and its bimetal composite with tungsten trioxide (WO3) and manganese dioxide (MnO2). The structure of 3DGH and its composite is confirmed by advanced characterization techniques viz. Raman Spectroscopy, X-Ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and tunneling electron microscope (TEM). Further, two symmetric devices using 3DGH, 3DGH-metal composite (3DGHMC), and one asymmetric 3DGHMC-3DGH device are comparatively studied using two electrode systems. The effects of scan rates, current densities, voltage window, and frequency were examined for each device by cyclic voltammetry (CV), galvanic charge-discharge (GCD), and Electron impedance spectroscopy (EIS). The asymmetric device showed a high specific capacitance of 657 F g−1 with an excellent energy density of 48.25 W h kg−1 and a high-power density of 596.06 W kg−1 at the current density of 1 A g−1. Also, the asymmetric device retains 100 % of its initial capacitance after 1000 charging-discharging cycles, also extends its stability after 1000 cycling test. Moreover, the quantitative analysis of the device is also made by Dunn's method to evaluate the percentage contribution from surface and diffusion capacitance.

Highly performed electrochemical activities of hybrid supercapacitors based on CeO2-Sm2O3 nanocomposites

The highly performed electrochemical energy storage systems have been required to rectify the reduction of sustainable energies in recent times. Herein, we investigate a facile hydrothermal synthesis of binary cerium oxide-samarium oxide nanocomposites (CeO2-Sm2O3 NCs) and study their electrochemical performance of Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS) analysis. The structure, chemical bonds, and morphology of the synthesized nanocomposites have been analyzed by XRD, FTIR, SEM with EDX, and HR-TEM with SAED pattern. From the CV study, the binary CeO2-Sm2O3 NCs reveal 397.50 C/g of higher specific capacity compared to individual CeO2 (72.85 C/g) and Sm2O3 (122.80 C/g). The Trasatti and Dunn's method manifests the outer (Co), total (CT), and inner (Ci) capacities of 165.05, 531.91, and 366.86 C/g for the prepared binary CeO2-Sm2O3 NCs. The stability of CeO2-Sm2O3 NCs delivers 97.84% excellent retention and 101.21% coulombic efficiency over 3000 cycles. Furthermore, the hybrid supercapacitor (CeO2-Sm2O3//AC) device has been developed and their electrochemical behaviors were analyzed in two electrode setup. The constructed device manifests a higher specific capacity of 139.97 C/g at 0.5 A/g current density, better retention of 86.92% and coulombic efficiency of 100.02% at 5 A/g over 3000 cycles, the higher energy density of 32.85 Wh/kg, and a higher power density of 4223.91 W/kg respectively.

Wisely Choosing a Fast-Food Burger Meal Results in Meaningful Reduction in Sodium: Implications for Kidney Stone Patients

Stone formers trying to limit dietary sodium may be unable to give up fast food. For the classic American hamburger, it is unclear if lower sodium preparations of this item are available and how this could affect sodium intake. We determined the impact of careful selection at national chains. Nutritional guides for 14 national chains were analyzed for all beef-based burgers and french fries. A meal was defined as 1 burger and an order of fries. The daily sodium limit (recommended daily sodium allowance [RDA]) was considered to be 2,300mg. The maximal sodium reduction was defined as the difference between the highest and lowest sodium-containing meals. The Kruskal-Wallis test with Dunn's method was used to compare food items among the chains. Of the total 263 different burgers and 74 different fries, median sodium was 1130mg (range 180-3520) and 565mg (range 30-1480), respectively. Mean sodium for burgers at individual chains ranged from a low of 590mg to a high of 1721mg (P<.001). The mean sodium for fries at individual chains ranged from a low of 245mg to a high of 947mg (P<.001). Post-hoc testing revealed 26 significant differences between pairs of restaurants for sodium content of burgers with P<.05 for each. The median maximal sodium reduction among the different chains was 1925mg. Depending on the chain, sodium content of 1 meal could be reduced by as little as 830mg (36% RDA) or as much as 3360mg (146% RDA) by careful selection. Stone formers should be aware of significant variation in sodium content of burgers and fries among chains and within a chain. Wisely selecting just 1 fast-food burger meal can significantly reduce sodium intake.

The Contribution of Various In Vitro Methodologies to Comprehending the Filling Ability of Root Canal Pastes in Primary Teeth.

A void-free obturation during root canal treatment on primary teeth is currently very difficult to attain. In this study, the pulpectomy filling abilities of Bio-C Pulpecto (Angelus, Basil, Londrina, Paraná, Brazil) and of zinc oxide eugenol, or "ZOE" (DenPro, Prevest, New York, NY, USA), were compared using several in vitro techniques. Therefore, 30 primary anterior teeth were used in the present in vitro study. Analysis of variance (ANOVA), including a multiple comparison procedure (Holm-Sidak method, Dunn's Method, or Tukey test), was used. On micro-CT, Bio-C Pulpecto exhibited higher void percentages than did ZOE (10.3 ± 3.8%, and 3.5 ± 1.3%), respectively (p < 0.05). With digital microscopy, higher total void percentages were found in the BC (13.2 ± 26.7%) group compared to the ZOE (2.7 ± 2.8%) group (p < 0.05). With the CLSM, mean tubular penetration depths were higher for Bio-C Pulpecto than for ZOE in all canal thirds (p < 0.05). SEM images demonstrated no tags into dentinal tubules in either group throughout the three thirds. Moreover, higher statistically significant flowability was found for Bio-C (2.657 ± 0.06 mm) compared to ZOE (1.8 ± 0.13 mm) (p < 0.05). The findings of this study indicate that neither ZOE nor Bio-C Pulpecto appears to meet the criteria for an ideal root canal filling paste for primary teeth. This study laid the groundwork for future research by determining how micro-CT, digital microscopy, SEM, and CLSM contribute to our understanding of the filling process of primary teeth. More thorough research on the mechanism of root canal obturation on primary teeth is required to achieve a long-term successful root canal therapy in young children.

Facile synthesis of 2D acid-etched g-C3N4 nanosheets with 1D ZnO nanorods as a promising electrode material for supercapacitor

A low-cost, non-toxic nanocomposite of two-dimensional (2D) nanosheets of acid-etched graphitic carbon nitride (TGCN) and one-dimensional (1D) nanorods of zinc oxide (ZnO NRs) is prepared using one-step calcination method. The average size and diameter of ZnO nanorods in TGCN/ZnO (T-ZnO) nanocomposite is reduced to 0.5 and 0.73 times than pristine ZnO NRs, respectively. After the acid-etching process, the size of the T-ZnO nanocomposite is further reduced which enhanced its specific surface area to 16.82 m2/g as compared to pristine ZnO NRs (3.56 m2/g). T-ZnO NRs shows a specific capacitance of 398.47 F/g using 0.5 M H2SO4 which is higher as compared to T-ZnO NRs using 0.5 M Na2SO4 (278.16 F/g) and 6 M KOH (106.10 F/g). Using Electrochemical impedance spectroscopy, diffusion coefficient (D) value 1.85 × 10−11 is obtained for T-ZnO NRs (0.5 M H2SO4). T-ZnO NRs also exhibits a higher specific capacitance of 311.80 F/g at 1 A/g using 0.5 M H2SO4. The nanocomposite shows superior energy density of 97.43 Wh/kg at 750 W/kg of power density. The superior capacitance retention (>95 %) and stable coulombic efficiency (>80 %) of T-ZnO NRs enables the nanocomposite for practical applications in energy storage devices. The electric double layer (EDL) and pseudocapacitive (PC) contribution of 6.04 % and 93.96 % to the total specific capacitance of T-ZnO NRs is evaluated using Trasatti method. The capacitive and diffusion-controlled contribution is also investigated for T-ZnO NRs using Dunn's method. The practical aspect of a supercapacitor using leakage current and self-discharge is also tested for the T-ZnO NRs. T-ZnO NRs is a promising energy storage material to fill the gap in the ongoing energy crisis.

Electrochemical performance optimization of the polyaniline electrodeposited on ITO substrate.

We have elaborated polyaniline films on ITO substrate (indium tin oxide), by electrochemical process in different electrolytes (HCl, H2SO4, HNO3, and H3BO3), which allowed us to study the effect of the counter ion on electrochemical energy storage performances of polyaniline as electrode material in supercapacitors. The study of the different obtained films performances was carried out by cyclic voltammetry and galvanostatic charge-discharge method and is interpreted by the SEM technique. We found that there is a clear dependence on the specific capacitance of the counter ion. Justified by its porous structure, the PANI/ITO electrode doped with SO42- has the highest specific capacitance, 57.3 mF/cm2 at a current density of 0.2mA/cm2 and 64.8 mF/cm2 at 5mV/s. The deep analysis by Dunn's method allowed us to conclude that the faradic process dominates the energy storage in the case of PANI/ITO electrode elaborated in boric acid (99%). On the contrary, the capacitive character is the most contributory in the case of electrodes elaborated in H2SO4, HCl, and HNO3. The study at different potentials (0.80, 0.85, 0.90, 0.95, and 1.0V/SCE) from 0.2M monomer aniline showed that the deposition at 0.95V/SCE leads to higher specific capacitance (24.3 mF/cm2 at scan rate 5mV/s and 23.6 mF/cm2 at 0.2mA/cm2) with a coulombic efficiency of 94%. By varying the concentration of the monomer while keeping a potential fixed at 0.95V/SCE, we also found that the specific capacitance increases with monomeric concentration.