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1.
Small ; : e2400824, 2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38764257

RESUMO

Halide perovskite, renowned for its multifunctional properties, shows considerable promise for realizing self-charging power systems. In this study, a lead-free methylammonium bismuth iodide (MA3Bi2I9) perovskite is used to create a self-charging power unit (SPU). This involves constructing a hybrid piezoelectric-triboelectric nanogenerator (Hybrid-TENG) and utilizing MA3Bi2I9 for energy storage as an anode in a lithium-ion battery (LIB). Initially, MA3Bi2I9 nanorods are synthesized and composited with a polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene polymer. The dielectric and mechanical properties of composite films having perovskite loading content are investigated. The optimized Hybrid-TENG exhibits superior performance, generating a voltage of 537 V, current density of 13.2 µA cm- 2, and maximum power density of 3.04 mW cm-2, which can be attributed to the high piezoelectric coefficient of MA3Bi2I9 nanorods (≈20.6 pm V-1). A MA3Bi2I9 thin film, serving as an electrode in LIB, demonstrates a high specific capacity of 2378.9 mAh cm-3 (578.8 mAh g-1) with a capacity retention of ≈87.5% over 100 cycles, underscoring its stable performance. Furthermore, a Hybrid-TENG is employed to charge the MA3Bi2I9-based LIB, thus realizing an SPU for driving portable electronics. This study highlights the promising potential of perovskites for developing efficient nanogenerators and LIBs, paving the way for sustainable energy solutions in small-scale electronics.

2.
Adv Mater ; 36(14): e2309183, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38160321

RESUMO

Development of miniaturized thin-film lithium-ion batteries (TF-LIBs) using vacuum deposition techniques is crucial for low-scale applications, but addressing low energy density remains a challenge. In this work, structures analogous to SiOx-based thin-film electrodes are designed with close resemblance to traditional LIB slurry formulations including active material, conductive agent, and binder. The thin-film is produced using mid-frequency sputtering with a single hybrid target consisting of SiOx nanoparticles, carbon nanotubes, and polytetrafluoroethylene. The thin-film SiOx/PPFC (plasma-polymerized fluorocarbon) involves a combination of SiOx and conductive carbon within the PPFC matrix. This results in enhanced electronic conductivity and superior elasticity and hardness in comparison to a conventional pure SiOx-based thin-film. The electrochemical performance of the half-cell consisting of thin-film SiOx/PPFC demonstrates remarkable cycling stability, with a capacity retention of 74.8% up to the 1000th cycle at 0.5 C. In addition, a full cell using the LiNi0.6Co0.2Mn0.2O2 thin-film as the cathode material exhibits an exceptional initial capacity of ≈120 mAh g-1 at 0.1 C and cycle performance, marked by a capacity retention of 90.8% from the first cycle to the 500th cycle at a 1 C rate. This work will be a stepping stone for the AM/CB/B composite electrodes in TF-LIBs.

3.
Avicenna J Med ; 11(1): 15-19, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33520784

RESUMO

BACKGROUND: The irrational use of antibiotics is a global issue and it can lead to morbidity, mortality, and increased health care costs. Hence, proper use of antibiotics is imperative and should be included in the pharmaceutical care plan. OBJECTIVE: The objective of this study was to evaluate the prescribing pattern of antibiotics for children using WHO core prescribing indicators. MATERIALS AND METHODS: A prospective, observational study was carried for 6 months in the pediatric department at a tertiary care hospital, Pune. The WHO prescribing indicators were used to evaluate the prescriptions, and the ideal WHO range was considered as a determining factor for rational prescription. RESULTS: A total of 302 patients were included in the study, with a mean patient age of 4.92 ± 4 years. The average number of drugs per encounter was 6.12 (WHO standard is less than 2). The percentage of antibiotics prescribed was 26.3% with an average of 1.63 antibiotics per prescription. Of the 493 antibiotics, 85.59% were injectable which is higher than the WHO standard of 13.4-24.1%. A near-optimal value of 99.59% antibiotics was prescribed from the hospital formulary which is similar to WHO standards, and the antibiotics prescribed with generic names were 25.76%. The most common class of antibiotics prescribed were cephalosporins and penicillins. CONCLUSION: Polypharmacy, high injectable use, and non-adherence to generic prescription were common in our tertiary care center. Continuous audits, training, and new treatment protocols are recommended.

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