Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 34
Filter
Add more filters










Publication year range
1.
Technol Health Care ; 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38517822

ABSTRACT

BACKGROUND: Literature evidence describes various treatment protocols that have been employed for the effectiveness in improving survival and addressing associated symptoms of cracked teeth. OBJECTIVE: This systematic review investigates the survivability of endodontically treated cracked teeth and associated assessments, focusing on various treatment protocols. METHODS: The PRISMA guidelines were utilised for guiding the article selection framework of this review. A comprehensive search of relevant literature was conducted in May 2023 across various databases, and studies meeting the inclusion criteria were selected. Data extraction, guided by a standardized form, captured crucial details, including study characteristics, treatment protocols, and treatment outcomes, enhancing the consistency and accuracy of information collection. Data extraction and synthesis was done by two reviewers independently. The Newcastle Ottawa tool was used to measure the methodological quality of the study. Six observational studies were eventually included. RESULTS: Mandibular molars are particularly prone to developing cracks, with research indicating a heightened susceptibility to this dental issue. Studies reveal that endodontically treated cracked teeth boast robust overall survival rates ranging from 75.8% to 100%. The risk of bias assessment, utilizing the Newcastle Ottawa scale, indicated a moderate risk across studies, highlighting the necessity for careful interpretation of findings. CONCLUSION: Endodontically treated cracked teeth show marked success in survival, with the incorporation of crowns post-endodontic treatment significantly enhancing longevity and resilience.

2.
ACS Appl Mater Interfaces ; 16(5): 5896-5904, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38266753

ABSTRACT

Cationic alteration related to a sodium super ion conductor (NASICON)-structured Na3V2(PO4)3 (NVP) is an effective strategy for formulating high-energy and stable cathodes for sodium-ion batteries (SIBs). In this study, we altered the structure of NVP with dual cations, namely, Cr and Fe, to develop Na3V1.5Cr0.4Fe0.1(PO4)3 cathodes for SIBs with high-rate capability (∼71 mAh g-1 at 100 C) and an extreme cycle life output (∼75 mAh g-1 with 95% capacity retention for 10,000 cycles). These excellent electrochemical properties can be ascribed to the synergistic effects of Cr and Fe in the NVP structure, as verified experimentally and theoretically. Therefore, the proposed cosubstitution method can enhance the performance of SIBs by improving their structural stability, electronic conductivity, and phase-change behavior.

3.
Molecules ; 27(24)2022 Dec 07.
Article in English | MEDLINE | ID: mdl-36557797

ABSTRACT

Recently, a novel electrochemical regulation associated with a deposition/dissolution reaction on an electrode surface has been proven to show superiority in large-scale energy storage systems (ESSs). Hence, in the search for high-performance electrodes showcasing these novel regulations, we utilized a low-cost ZnO microsphere electrode to construct aqueous rechargeable batteries (ARBs) that supplied a harvestable and storable charge through electrochemical deposition/dissolution via a reversible manganese oxidation reaction (MOR)/manganese reduction reaction (MRR), respectively, induced by the inherent formation/dissolution of zinc basic sulfate in a mild aqueous electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4.

4.
ACS Appl Mater Interfaces ; 13(45): 53877-53891, 2021 Nov 17.
Article in English | MEDLINE | ID: mdl-34743513

ABSTRACT

In this study, magnesium-ion-substituted, sodium-deficient, P3- and P2-layered manganese oxide cathodes (Na0.67Mg0.1Mn0.9O2) were synthesized through a facile polyol-assisted combustion technique for applications in sodium-ion batteries. The electrochemical reaction pathways, structural integrity, and long cycling ability at low current rates of the P3- and P2-phases of the Na0.67Mg0.1Mn0.9O2 cathodes were investigated using time-consuming techniques, such as galvanostatic titration and series cyclic voltammetry. The results obtained from these techniques were supported by those obtained from operando X-ray diffraction (XRD) analysis. Particularly, the P2-phase provided excellent structural stability owing to its intrinsic crystal structure, thereby exhibiting a reversible capacity retention of 82.6% after 262 cycles at a low rate of 0.1 C; in contrast, the P3-phase exhibited a capacity retention of 38.7% after 241 cycles at a similar current rate. The air stability of these as-prepared powders, which were stored under ambient conditions, was progressively analyzed over a period of 6 months through XRD without conducting any special experiments. The results suggest that in the P3-phase, the formation of NaHCO3 and hydrated phase impurities, resulting from Na+/H+ exchange and hydration reactions, respectively, was likely to occur more quickly, that is, within a few days, compared to that in the P2-phase.

5.
Nanomaterials (Basel) ; 11(8)2021 Jul 24.
Article in English | MEDLINE | ID: mdl-34443735

ABSTRACT

Aqueous rechargeable zinc ion batteries (ARZIBs) have gained wide interest in recent years as prospective high power and high energy devices to meet the ever-rising commercial needs for large-scale eco-friendly energy storage applications. The advancement in the development of electrodes, especially cathodes for ARZIB, is faced with hurdles related to the shortage of host materials that support divalent zinc storage. Even the existing materials, mostly based on transition metal compounds, have limitations of poor electrochemical stability, low specific capacity, and hence apparently low specific energies. Herein, NH4V4O10 (NHVO), a layered oxide electrode material with a uniquely mixed morphology of plate and belt-like particles is synthesized by a microwave method utilizing a short reaction time (~0.5 h) for use as a high energy cathode for ARZIB applications. The remarkable electrochemical reversibility of Zn2+/H+ intercalation in this layered electrode contributes to impressive specific capacity (417 mAh g-1 at 0.25 A g-1) and high rate performance (170 mAh g-1 at 6.4 A g-1) with almost 100% Coulombic efficiencies. Further, a very high specific energy of 306 Wh Kg-1 at a specific power of 72 W Kg-1 was achieved by the ARZIB using the present NHVO cathode. The present study thus facilitates the opportunity for developing high energy ARZIB electrodes even under short reaction time to explore potential materials for safe and sustainable green energy storage devices.

6.
Adv Sci (Weinh) ; 8(4): 2002636, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33643793

ABSTRACT

Manganese (Mn)-based cathode materials have garnered huge research interest for rechargeable aqueous zinc-ion batteries (AZIBs) due to the abundance and low cost of manganese and the plentiful advantages of manganese oxides including their different structures, wide range of phases, and various stoichiometries. A novel in situ generated Mn-deficient ZnMn2O4@C (Mn-d-ZMO@C) nanoarchitecture cathode material from self-assembly of ZnO-MnO@C for rechargeable AZIBs is reported. Analytical techniques confirm the porous and crystalline structure of ZnO-MnO@C and the in situ growth of Mn deficient ZnMn2O4@C. The Zn/Mn-d-ZMO@C cell displays a promising capacity of 194 mAh g-1 at a current density of 100 mA g-1 with 84% of capacity retained after 2000 cycles (at 3000 mA g-1 rate). The improved performance of this cathode originates from in situ orientation, porosity, and carbon coating. Additionally, first-principles calculations confirm the high electronic conductivity of Mn-d-ZMO@C cathode. Importantly, a good capacity retention (86%) is obtained with a year-old cell (after 150 cycles) at 100 mA g-1 current density. This study, therefore, indicates that the in situ grown Mn-d-ZMO@C nanoarchitecture cathode is a promising material to prepare a durable AZIB.

7.
R Soc Open Sci ; 6(4): 181978, 2019 Apr.
Article in English | MEDLINE | ID: mdl-31183129

ABSTRACT

Reduced graphene oxide (rGO) sheets were synthesized by a modified Hummer's method without additional reducing procedures, such as chemical and thermal treatment, by appropriate drying of graphite oxide under ambient atmosphere. The use of a moderate drying temperature (250°C) led to mesoporous characteristics with enhanced electrochemical activity, as confirmed by electron microscopy and N2 adsorption studies. The dimensions of the sheets ranged from nanometres to micrometres and these sheets were entangled with each other. These morphological features of rGO tend to facilitate the movement of guest ions larger than Li+. Impressive electrochemical properties were achieved with the rGO electrodes using various charge-transfer ions, such as Li+, Na+ and K+, along with high porosity. Notably, the feasibility of this system as the carbonaceous anode material for sodium battery systems is demonstrated. Furthermore, the results also suggest that the high-rate capability of the present rGO electrode can pave the way for improving the full cell characteristics, especially for preventing the potential drop in sodium-ion batteries and potassium-ion batteries, which are expected to replace the lithium-ion battery system.

8.
Chem Commun (Camb) ; 55(26): 3793-3796, 2019 Mar 26.
Article in English | MEDLINE | ID: mdl-30864605

ABSTRACT

We explore NaV6O15 (NVO) nanorod cathodes prepared by a sol-gel method for aqueous rechargeable zinc-ion battery applications for the first time. The NVO cathode delivers a high capacity of 427 mA h g-1 at 50 mA g-1 current density. Furthermore, based on the mass of the active materials, it exhibits a high energy density of 337 W h kg-1.

9.
RSC Adv ; 9(42): 24030-24038, 2019 Aug 02.
Article in English | MEDLINE | ID: mdl-35527880

ABSTRACT

A simple one-pot polyol-assisted pyro-technique has been adopted to synthesize highly crystalline, carbon-coated LiMn2O4 (LMO/C) nanoparticles for use as a cathode material in rechargeable Li-ion battery (LIB) applications. The phase purity, structure and stoichiometry of the prepared cathode was confirmed using X-ray techniques that included high-resolution powder X-ray diffraction and X-ray absorption fine structure spectroscopy. Electron microscopy studies established that the synthetic technique facilitated the production of nano-sized LMO particles with uniform carbon coating. The prepared LMO/C cathode demonstrates excellent electrochemical properties (cycling stabilities of 86% and 77.5% and high rate capabilities of 79% and 36% within the potential windows of 3.3-4.3 V and 2.5-4.3 V, respectively). The high electrochemical performance of the LMO/C cathode is attributed to the nano-size of the LiMn2O4 particles enabling high surface area and hence greater lithium insertion and also the uniform amorphous carbon coating facilitating effective reduction in manganese dissolution and volume expansion during the lithium de-intercalation/intercalation reactions. In addition, cyclic voltametry and impedance characterization confirm the reversible Li-intercalation and the role of the solid electrolyte interface layer (SEI) in the stable electrochemical reaction of the LMO/C electrode. Furthermore, this study shows the efficacy of a simple and low-cost pyro-synthetic method to realize high performance nano-sized particle electrodes with uniform carbon coating for useful energy storage applications.

10.
ChemSusChem ; 11(13): 2239-2247, 2018 Jul 11.
Article in English | MEDLINE | ID: mdl-29708309

ABSTRACT

Rechargeable hybrid aqueous batteries (ReHABs) have emerged as promising sustainable energy-storage devices because all components are environmentally benign and abundant. In this study, a carbon-wrapped sponge-like Na3 V2 (PO4 )3 nanoparticle (NVP@C) cathode is prepared by a simple pyrosynthesis for use in the ReHAB system with impressive rate capability and high cyclability. A high-resolution X-ray diffraction study confirmed the formation of pure Na ion superionic conductor (NASICON) NVP with rhombohedral structure. When tested in the ReHAB system, the NVP@C demonstrated high rate capability (66 mAh g-1 at 32 C) and remarkable cyclability over 1000 cycles (about 72 % of the initial capacity is retained at 30 C). Structural transformation and oxidation change studies of the electrode evaluated by using in situ synchrotron X-ray diffraction and ex situ X-ray photoelectron spectroscopy, respectively, confirmed the high reversibility of the NVP@C electrode in the ReHAB system through a two-phase reaction. The combined strategy of nanosizing and carbon-wrapping in the NVP particles is responsible for the remarkable electrochemical properties. The pyrosynthesis technique appears to be a promising and feasible approach to prepare a high-performance electrode for safe and low-cost ReHAB systems as nextgeneration large-scale energy storage devices.

11.
Nanoscale ; 10(13): 5938-5949, 2018 Mar 29.
Article in English | MEDLINE | ID: mdl-29542744

ABSTRACT

Pyrite (FeS2) is a promising electrode material for lithium ion batteries (LIBs) because of its high natural availability, low toxicity, cost-effectiveness, high theoretical capacity (894 mA h g-1) and high theoretical specific energy density (1270 W h kg-1, 4e-/FeS2). Nevertheless, the use of FeS2 in electrochemical capacitors was restricted due to fast capacity fading as a result of polysulfide (S/Sn2-) formation during the initial electrochemical cycling. In order to avoid the formation of polysulfides, we employed the strategy of utilizing an ether based electrolyte (1.0 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/diglyme (DGM)). Herein, we introduce FeS2/C as the Faradaic electrode for a non-aqueous hybrid electrochemical capacitor (NHEC) in combination with activated carbon (AC) as a non-Faradaic electrode, and 1.0 M LiTFSI/DGM as a non-aqueous electrolyte. Specifically, FeS2/C nanoparticles have been prepared via the sulfidation of a room temperature synthesized Fe-based MOF (metal organic framework) precursor. The fabricated FeS2/C∥AC NHEC, operating within the chosen voltage window of 0-3.2 V, delivered energy densities in the range of 63-9 W h kg-1 at power densities of 152-3240 W kg-1. Remarkable cycling stability with stable energy density retention for 2500 cycles at high power densities (729, 1186 and 3240 W kg-1) was observed.

12.
Nano Lett ; 18(4): 2402-2410, 2018 04 11.
Article in English | MEDLINE | ID: mdl-29570307

ABSTRACT

Owing to their safety and low cost, aqueous rechargeable Zn-ion batteries (ARZIBs) are currently more feasible for grid-scale applications, as compared to their alkali counterparts such as lithium- and sodium-ion batteries (LIBs and SIBs), for both aqueous and nonaqueous systems. However, the materials used in ARZIBs have a poor rate capability and inadequate cycle lifespan, serving as a major handicap for long-term storage applications. Here, we report vanadium-based Na2V6O16·3H2O nanorods employed as a positive electrode for ARZIBs, which display superior electrochemical Zn storage properties. A reversible Zn2+-ion (de)intercalation reaction describing the storage mechanism is revealed using the in situ synchrotron X-ray diffraction technique. This cathode material delivers a very high rate capability and high capacity retention of more than 80% over 1000 cycles, at a current rate of 40C (1C = 361 mA g-1). The battery offers a specific energy of 90 W h kg-1 at a specific power of 15.8 KW kg-1, enlightening the material advantages for an eco-friendly atmosphere.

13.
J Colloid Interface Sci ; 501: 133-141, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28448833

ABSTRACT

In the present study, a metal-organic framework (MOF) derived from a facile water-assisted green precipitation technique is employed to synthesize phase-pure cobalt vanadate (Co3V2O8, CVO) anode for lithium-ion battery (LIB) application. The material obtained by this eco-friendly method is systematically characterized using various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption measurements. By using as an anode, an initial discharge capacity of 1640mAhg-1 and a reversible capacity of 1194mAhg-1 are obtained at the applied current densities after the 240th cycle (2Ag-1 for 200 cycles followed by 0.2Ag-1 for 40 cycles). Moreover, a reversible capacity as high as 962mAhg-1 is retained at high current densities even after 240 cycles (4Ag-1 for 200 cycles followed by 2Ag-1 for 40 cycles), revealing the long life stability of the electrode. Significantly, CVO anode composed of fine nanoparticles (NPs) registered a substantial rate performance and reversible specific capacities of 275, 390, 543 and 699mAhg-1 at high reversibly altered current densities of 10, 5, 2, and 1Ag-1, respectively.

14.
ACS Appl Mater Interfaces ; 8(51): 35235-35242, 2016 Dec 28.
Article in English | MEDLINE | ID: mdl-27977124

ABSTRACT

Herein, we report on a high-discharge-rate Na3V2(PO4)3-Ni2P/C (NVP-NP/C) composite cathode prepared using a polyol-based pyro synthesis for Na-ion battery applications. X-ray diffraction and electron microscopy studies established the presence of Na3V2(PO4)3 and Ni2P, respectively, in the NVP-NP/C composite. As a cathode material, the obtained NVP-NP/C composite electrode exhibits higher discharge capacities (100.8 mAhg-1 at 10.8 C and 73.9 mAhg-1 at 34 C) than the NVP/C counterpart electrode (62.7 mAhg-1 at 10.8 C and 4.7 mAhg-1 at 34 C), and the composite electrode retained 95.3% of the initial capacity even after 1500 cycles at 16 C. The enhanced performance could be attributed to the synergetic effect of the Ni2P phase and nanoscale NVP particles, which ultimately results in noticeably enhancing the electrical conductivity of the composite. The present study thus demonstrates that the Na3V2(PO4)3-Ni2P/C nanocomposite is a prospective candidate for NIB with a high power/energy density.

15.
J Forensic Dent Sci ; 8(2): 79-82, 2016.
Article in English | MEDLINE | ID: mdl-27555723

ABSTRACT

OBJECTIVE: Comparative evaluation of the location of mental foramen in different age groups. Determine the variation in position of mental foramen with gender using digital panoramic radiography. MATERIALS AND METHODS: Digital panoramic radiographs of 250 patients were reviewed. The study population was divided into five age groups with 50 patients each. Radiographic position of mental foramen was evaluated in each radiograph based on three parameters. Measurements were taken in each radiograph using Planmeca Dimaxis pro version 4.4.0 (Helsinki, Finland). The collected data were subjected to statistical analysis using paired Student's t-test. RESULTS: The mean distance of position of mental foramen showed a significant variation within the five age groups. In the first group, female patients showed an increase in mean distance of mental foramen position in relation to three parameters. From the second to fifth groups, male patient showed an increase in the mean distance of mental foramen position. The first and fifth group showed a reduced mean distance of mental foramen position when compared to other age groups. CONCLUSION: This study concluded that the position of mental foramen varies with age. There was a gender-related variation in position of mental foramen within the population too.

16.
Sci Rep ; 6: 23394, 2016 Mar 22.
Article in English | MEDLINE | ID: mdl-27001370

ABSTRACT

The real time detection of quantitative oxygen release from the cathode is performed by in-situ Gas Chromatography as a tool to not only determine the amount of oxygen release from a lithium-ion cell but also to address the safety concerns. This in-situ gas chromatography technique monitoring the gas evolution during electrochemical reaction presents opportunities to clearly understand the effect of surface modification and predict on the cathode stability. The oxide cathode, 0.5Li2MnO3∙0.5LiNi0.4Co0.2Mn0.4O2, surface modified by amorphous cobalt-phosphate nanoparticles (a-CoPO4) is prepared by a simple co-precipitation reaction followed by a mild heat treatment. The presence of a 40 nm thick a-CoPO4 coating layer wrapping the oxide powders is confirmed by electron microscopy. The electrochemical measurements reveal that the a-CoPO4 coated overlithiated layered oxide cathode shows better performances than the pristine counterpart. The enhanced performance of the surface modified oxide is attributed to the uniformly coated Co-P-O layer facilitating the suppression of O2 evolution and offering potential lithium host sites. Further, the formation of a stable SEI layer protecting electrolyte decomposition also contributes to enhanced stabilities with lesser voltage decay. The in-situ gas chromatography technique to study electrode safety offers opportunities to investigate the safety issues of a variety of nanostructured electrodes.

17.
ACS Appl Mater Interfaces ; 8(13): 8546-53, 2016 Apr 06.
Article in English | MEDLINE | ID: mdl-26983348

ABSTRACT

Metal-organic framework (MOF)-based synthesis of battery electrodes has presntly become a topic of significant research interest. Considering the complications to prepare Co3V2O8 due to the criticality of its stoichiometric composition, we report on a simple MOF-based solvothermal synthesis of Co3V2O8 for use as potential anodes for lithium battery applications. Characterizations by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution electron microscopy, and porous studies revealed that the phase pure Co3V2O8 nanoparticles are interconnected to form a sponge-like morphology with porous properties. Electrochemical measurements exposed the excellent lithium storage (∼1000 mAh g(-1) at 200 mA g(-1)) and retention properties (501 mAh g(-1) at 1000 mA g(-1) after 700 cycles) of the prepared Co3V2O8 electrode. A notable rate performance of 430 mAh g(-1) at 3200 mA g(-1) was also observed, and ex situ investigations confirmed the morphological and structural stability of this material. These results validate that the unique nanostructured morphology arising from the use of the ordered array of MOF networks is favorable for improving the cyclability and rate capability in battery electrodes. The synthetic strategy presented herein may provide solutions to develop phase pure mixed metal oxides for high-performance electrodes for useful energy storage applications.

18.
Chemistry ; 22(6): 2039-2045, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26749376

ABSTRACT

A nanostructured Mn3 O4 /C electrode was prepared by a one-step polyol-assisted pyro-synthesis without any post-heat treatments. The as-prepared Mn3 O4 /C revealed nanostructured morphology comprised of secondary aggregates formed from carbon-coated primary particles of average diameters ranging between 20 and 40 nm, as evidenced from the electron microscopy studies. The N2 adsorption studies reveal a hierarchical porous feature in the nanostructured electrode. The nanostructured morphology appears to be related to the present rapid combustion strategy. The nanostructured porous Mn3 O4 /C electrode demonstrated impressive electrode properties with reversible capacities of 666 mAh g-1 at a current density of 33 mA g-1 , good capacity retentions (1141 mAh g-1 with 100 % Coulombic efficiencies at the 100th cycle), and rate capabilities (307 and 202 mAh g-1 at 528 and 1056 mA g-1 , respectively) when tested as an anode for lithium-ion battery applications.

19.
J Nanosci Nanotechnol ; 15(1): 540-3, 2015 Jan.
Article in English | MEDLINE | ID: mdl-26328398

ABSTRACT

A simple and low cost urea-assisted auto-combustion route was investigated for the synthesis of carbon coated CoO nanocomposite. CHN analysis determined the carbon content in CoO/C nanocomposite to be very low as 0.27 wt%. The results show that the CoO/C nanocomposite electrode displays marked lower charge transfer resistance, high lithium storage capacity, and much better rate capability than original CoO nanoparticles electrode.

20.
Chem Commun (Camb) ; 51(61): 12274-7, 2015 Aug 07.
Article in English | MEDLINE | ID: mdl-26137998

ABSTRACT

Hierarchical meso-/macroporous anatase TiO2 was synthesized by the hydrolysis of a titanium metal-organic framework precursor followed by calcination in air. This unique porous feature enables the superior rate capability and excellent cycling stability of anatase TiO2 as an anode for rechargeable lithium-ion batteries.


Subject(s)
Electric Power Supplies , Lithium/chemistry , Organometallic Compounds/chemistry , Titanium/chemistry , Electrodes , Ions/chemistry , Particle Size , Porosity , Surface Properties
SELECTION OF CITATIONS
SEARCH DETAIL
...