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1.
Phys Chem Chem Phys ; 26(4): 3614-3622, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38223943

RESUMO

Over the past decade, perovskites have received considerable attention because of their record power conversion efficiency (25.7%) in solar cells. These materials have also received recent research interest in thermoelectrics, most likely due to their high carrier mobility, large power factor, and ultralow thermal conductivity. Therefore, in the present work, we have examined the optoelectronic and thermoelectric properties of A2NaIO6 (A = Ca, Sr) double perovskites using first-principles calculations. Stability has been confirmed using reliable and accurate descriptors of formation energy and phonon calculations. The optimized lattice constant and volume show an increasing tendency with changing A site cation (Ca → Sr). The computed band structures depict the semiconducting nature with direct band gap values of 2.64 eV (Ca2NaIO6) and 2.48 eV (Sr2NaIO6). The absorption was found to start in the visible range where the reflectivity was less than 10%. Moreover, the high Seebeck coefficient, large electrical conductivity, and fairly low thermal conductivity result in ZT values of 0.724 for Ca2NaIO6 and 0.686 for Sr2NaIO6 at 1000 K. With their optimum band gap, excellent light absorption capacity, and high ZT values, A2NaIO6 emerge as promising candidates for optoelectronic and thermoelectric applications.

2.
Surg Innov ; 31(1): 26-32, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37926929

RESUMO

INTRODUCTION: Cholelithiasis is one of the most common diseases encountered in gastroenterology. Laparoscopic cholecystectomy can be labelled as difficult if the surgery continues for more than 60 minutes or if the cystic artery is injured before ligation or clipping. Predicting difficult laparoscopic cholecystectomy can help the surgeon to be prepared for intraoperative challenges such as adhesions in triangle of Calot, injury to cystic artery or gall stone spillage; and improve patient counseling. METHODS: In this cross-sectional study, we evaluated 269 patients with diagnosed cholelithiasis and planned for laparoscopic cholecystectomy in the general surgery department of Civil Hospital Karachi. After approval of the institution review board of the Civil Hospital, the data of all the patients was collected along with informed consent. The patients were selected via nonprobability, consecutive sampling. RESULTS: The prevalence of difficult LC during procedure was 14.5% (39/269). Contingency table showed the true positive, negative and false positive and negative observation and using these observation to compute accuracy. Sensitivity, specificity, PPV, NPV and accuracy of serum c-reactive protein (CRP) in predicting the difficult laparoscopic cholecystectomy in patients of cholelithiasis was 87.2%, 97%, 82.9%, 97.8% and 95.5% respectively. Effect modifiers like age, gender and BMI were controlled by stratification analysis and observed that diagnostic accuracy was above 90% in all stratified groups as presented in the following tables. 175 (65.06%) of 279 patients were females indicating female predominance. In general, 41 patients (15.05%) had CRP serum levels greater than 11 mg/dL out of which 34 patients had to undergo difficult laparoscopic cholecystectomy (DLC), while 223 out of 228 patients with serum CRP levels of less than 11 mg/dL did not face any difficulty during their cholecystectomy. Similar results have been acquired across all age groups and both genders. CONCLUSION: C Reactive Protein is a potent predictor of difficult laparoscopic cholecystectomy and its conversion preoperatively. Patients with preoperatively high C Reactive Protein CRP levels in serum have more chances of complication intraoperatively and increased chances of conversion from laparoscopic to open surgery. Preoperative C Reactive Protein (CRP) with values >11 mg/dL was associated with the highest odds of presenting difficult laparoscopic cholecystectomy (DLC) in our study. This value possesses good sensitivity, specificity, PPV, and NPV for predicting DLC in our population.


Assuntos
Colecistectomia Laparoscópica , Cálculos Biliares , Humanos , Feminino , Masculino , Colecistectomia Laparoscópica/efeitos adversos , Colecistectomia Laparoscópica/métodos , Proteína C-Reativa/análise , Estudos Transversais , Colecistectomia , Cálculos Biliares/cirurgia
3.
Molecules ; 29(6)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38542903

RESUMO

Shape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The self-healing capability in polymer nanocomposites depends on several factors, including heat, quadruple hydrogen bonding, π-π stacking, Diels-Alder reactions, and metal-ligand coordination, which collectively govern the interactions within the composite materials. Among possible interactions, only quadruple hydrogen bonding between composite constituents has been shown to be effective in facilitating self-healing at approximately room temperature. Conversely, thermo-responsive self-healing and shape memory polymer nanocomposites require elevated temperatures to initiate the healing and recovery processes. Thermo-responsive (TRSMPs), light-actuated, magnetically actuated, and Electrically actuated Shape Memory Polymer Nanocomposite are discussed. This paper provides a comprehensive overview of the different types of interactions involved in SMP and SHP nanocomposites and examines their behavior at both room temperature and elevated temperature conditions, along with their biomedical applications. Among many applications of SMPs, special attention has been given to biomedical (drug delivery, orthodontics, tissue engineering, orthopedics, endovascular surgery), aerospace (hinges, space deployable structures, morphing aircrafts), textile (breathable fabrics, reinforced fabrics, self-healing electromagnetic interference shielding fabrics), sensor, electrical (triboelectric nanogenerators, information energy storage devices), electronic, paint and self-healing coating, and construction material (polymer cement composites) applications.

4.
J Comput Chem ; 44(19): 1690-1703, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37093704

RESUMO

In this study, structural, electronic, optical, thermoelectric, and thermodynamics properties of vacancy-ordered double perovskites Rb2 XCl6 (X = Se, Ti) were explored theoretically. The results revealed that Rb2SeCl6 and Rb2 TiCl6 are indirect band gap (Eg ) semiconductors with Eg values of 2.95 eV, and 2.84 eV respectively. The calculated properties (phonons, elastic constant, Poisson's ratio, and Pugh's ratio) revealed that both materials are dynamically and chemically stable and can exhibit brittle (Rb2 SeCl6 ) and ductile (Rb2 TiCl6 ) nature. From the analysis of optical parameters, it was noticed that the refractive index of the materials has a value of 1.5-2.0 where light absorption was found from the visible to the ultraviolet region. The thermoelectric properties determined by using the BoltzTrap code demonstrated that at room temperature, the Figure of merit (ZT) was found to be 0.74 and 0.76 for Rb2 SeCl6 and Rb2 TiCl6 , respectively. Despite a moderate value of ZT in such materials, further studies might explore effective methods for tuning the electronic band gap and improving the thermoelectric response of the material for practical energy production applications.


Assuntos
Compostos Inorgânicos , Titânio , Compostos de Cálcio , Óxidos
5.
Small ; 19(8): e2205881, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36504329

RESUMO

Two-dimensional layered transition metal dichalcogenides have emerged as promising materials for supercapacitors and hydrogen evolution reaction (HER) applications. Herein, the molybdenum sulfide (MoS2 )@vanadium sulfide (VS2 ) and tungsten sulfide (WS2 )@VS2  hybrid nano-architectures prepared via a facile one-step hydrothermal approach is reported. Hierarchical hybrids lead to rich exposed active edge sites, tuned porous nanopetals-decorated morphologies, and high intrinsic activity owing to the strong interfacial interaction between the two materials. Fabricated supercapacitors using MoS2 @VS2  and WS2 @VS2  electrodes exhibit high specific capacitances of 513 and 615 F g- 1 , respectively, at an applied current of 2.5 A g- 1  by the three-electrode configuration. The asymmetric device fabricated using WS2 @VS2  electrode exhibits a high specific capacitance of 222 F g- 1  at an applied current of 2.5 A g- 1  with the specific energy of 52 Wh kg- 1  at a specific power of 1 kW kg- 1 . For HER, the WS2 @VS2  catalyst shows noble characteristics with an overpotential of 56 mV to yield 10 mA cm- 2 , a Tafel slope of 39 mV dec-1 , and an exchange current density of 1.73 mA cm- 2 . In addition, density functional theory calculations are used to evaluate the durable heterostructure formation and adsorption of hydrogen atom on the various accessible sites of MoS2 @VS2  and WS2 @VS2  heterostructures.

6.
J Phys Chem A ; 126(26): 4300-4312, 2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35732014

RESUMO

Recognition of structure prototypes from tremendous known inorganic crystal structures has been an important subject beneficial for materials science research and new materials design. The existing databases of inorganic crystal structure prototypes were mostly constructed by classifying materials in terms of the crystallographic space group information. Herein, we employed a distinct strategy to construct the inorganic crystal structure prototype database, relying on the classification of materials in terms of local atomic environments (LAEs) accompanied by unsupervised machine learning method. Specifically, we adopted a hierarchical clustering approach onto all experimentally known inorganic crystal structure data to identify structure prototypes. The criterion for hierarchical clustering is the LAE represented by the state-of-the-art structure fingerprints of the improved bond-orientational order parameters and the smooth overlap of atomic positions. This allows us to build up a LAE-based Inorganic Crystal Structure Prototype Database (LAE-ICSPD) containing 15,613 structure prototypes with defined stoichiometries. In addition, we have developed a Structure Prototype Generator Infrastructure (SPGI) package, which is a useful toolkit for structure prototype generation. Our developed SPGI toolkit and LAE-ICSPD are beneficial for investigating inorganic materials in a global way as well as accelerating the materials discovery process in the data-driven mode.

7.
Phys Chem Chem Phys ; 23(28): 15386, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34232234

RESUMO

Correction for 'A first-principles study of the stability, electronic structure, and optical properties of halide double perovskite Rb2Sn1-xTexI6 for solar cell applications' by Muhammad Faizan et al., Phys. Chem. Chem. Phys., 2021, 23, 4646-4657, DOI: 10.1039/D0CP05827K.

8.
Phys Chem Chem Phys ; 23(8): 4646-4657, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33587059

RESUMO

Owing to their emerging role in solar cell technology, lead halide perovskites have aroused significant research interest in the recent past. However, due to its obvious toxicity, looking for a potential alternative to lead is becoming one of the most important pursuits in present times. We present our work based on density functional theory (DFT) investigating lead free defect perovskites (Rb2Sn1-xTexI6 (0 ≤x≤ 1)). In particular, we explore the crystal structure, thermodynamic stability, electronic structure, and optical properties of Rb2Sn1-xTexI6 (0 ≤x≤ 1) as a function of increasing Te concentration. Our results show that the Sn-Te alloyed perovskites exhibit considerable stability, a suitable band gap, small effective mass, and excellent light absorption. Especially, Rb2Sn0.75Te0.25I6 and Rb2Sn0.50Te0.50I6 have a direct band gap of 1.35 and 1.44 eV, respectively, which is highly favorable for use in a single-junction photovoltaic cell. We hope that our work will arouse the interest of experimental as well as theoretical scientists for synthesizing new materials and/or exploring the Sn-Te mix as a potential substitute for lead in photovoltaic materials.

9.
Photodermatol Photoimmunol Photomed ; 35(2): 93-99, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30251290

RESUMO

Harmful effects of ultraviolet rays and protection against them have been long discussed. Numerous synthetic dyes, finishes, UV absorbers, and optical brightening agents are present in the market for decades for achieving UV protection through textiles. However, due to environmental impacts of these chemical agents, textile industry is looking for alternatives. In this regard, some natural dyes and plant extracts have shown promising results. However, use of colorless plant extracts as UV protective finishes is still rare. In this study, ultraviolet protection factor (UPF) rating of bleached cotton fabric has been improved by the application of plant extracts with minimal change in fabric's color. For this purpose, two medicinal plants, that is, Solanum nigrum and Amaranthus viridis were selected and bleached cotton fabric was treated with their methanolic and aqueous extracts. Fabrics treated with both extracts exhibited excellent UPF ratings.


Assuntos
Amaranthus/química , Metanol/química , Extratos Vegetais/química , Solanum nigrum/química , Protetores Solares/química , Têxteis , Humanos , Queimadura Solar/prevenção & controle
10.
Int J Mol Sci ; 20(14)2019 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-31337099

RESUMO

The pharmaceutical clay montmorillonite (MMT) is, for the first time, explored as a carbon monoxide-releasing material (CORMat). MMT consists of silicate double layered structure; its exfoliation feature intercalate the CORM-2 [RuCl(µ-Cl)(CO)3]2 inside the layers to suppress the toxicity of organometallic segment. The infrared spectroscopy (IR) confirmed the existence of ruthenium coordinated carbonyl ligand in MMT layers. The energy-dispersive X-ray spectroscopy (EDX) analysis showed that ruthenium element in this material was about 5%. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) images showed that the layer-structure of MMT has been maintained after loading the ruthenium carbonyl segment. Moreover, the layers have been stretched out, which was confirmed by X-ray diffraction (XRD) analysis. Thermogravimetric (TG) curves with huge weight loss around 100-200 °C were attributed to the CO hot-release of ruthenium carbonyl as well as the loss of the adsorbed solvent molecules and the water molecules between the layers. The CO-liberating properties have been assessed through myoglobin assay. The horse myoglobin test showed that the material could be hydrolyzed to slowly release carbon monoxide in physiological environments. The half-life of CO release was much longer than that of CORM-3, and it has an excellent environmental tolerance and slow release effect.


Assuntos
Bentonita/química , Monóxido de Carbono/química , Substâncias Intercalantes/química , Compostos Organometálicos/química , Monóxido de Carbono/uso terapêutico , Argila , Microscopia Eletrônica de Varredura , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Mioglobina/química , Análise Espectral , Termogravimetria
12.
Neurosciences (Riyadh) ; 20(3): 213-24, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26166588

RESUMO

The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia.


Assuntos
Lobo Occipital/fisiopatologia , Esquizofrenia/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Lobo Occipital/metabolismo , Esquizofrenia/etiologia
13.
Nanoscale ; 16(6): 2913-2922, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38247404

RESUMO

Moiré superlattices (MSLs) in twisted two-dimensional van der Waals materials feature twist-angle-dependent crystal symmetry and strong optical nonlinearities. By adjusting the twist angle in bilayer van der Waals materials, the second-harmonic generation (SHG) can be controlled. Here, we focus on exploring the electronic and SHG properties of MSLs in 2D bilayer transition metal dichalcogenides (TMDs) with different twist angles through first-principles calculations. We constructed MSL structures of five TMD materials, including three single-phase materials (MoS2, WS2, and MoSe2) and two heterojunctions (MoS2/MoSe2 and MoS2/WS2) with twist angles of 9.4°, 13.2°, 21.8°, 32.2°, and 42.1° without lattice mismatch. Our findings demonstrate a consistent variation in the SHG susceptibility among different TMD MSLs as a response to twist-angle changes. The underlying reason for the twist-angle dependence of SHG is that the twist angle regulates the interlayer coupling strength, affecting the optical band gap of MSLs and subsequently tuning the SHG susceptibility. Through a comparison of the static SHG susceptibility values, we identified the twist angle of 9.4° as the configuration that yields the highest SHG susceptibility (e.g. 358.5 pm V-1 for the 9.4° MoSe2 MSL). This value is even twice that of the monolayer (173.3 pm V-1 for monolayer MoSe2) and AA'-stacked bilayer structures (139.8 pm V-1 for AA' MoSe2). This high SHG susceptibility is attributed to the strong interlayer coupling in the 9.4° MSL, which enhances the valence band energy (contributed by the antibonding orbitals of chalcogen-pz and transition metal-dz2) and consequently leads to a small optical band gap, thus improving the optical transitions. The findings of this study provide a straightforward way to improve the SHG performance of bilayer TMDs and also throw light on the sensitive relationship between the twist angle, band structure and SHG properties of TMD MSLs.

14.
Nat Comput Sci ; 4(5): 322-333, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38783137

RESUMO

In the post-Moore's law era, the progress of electronics relies on discovering superior semiconductor materials and optimizing device fabrication. Computational methods, augmented by emerging data-driven strategies, offer a promising alternative to the traditional trial-and-error approach. In this Perspective, we highlight data-driven computational frameworks for enhancing semiconductor discovery and device development by elaborating on their advances in exploring the materials design space, predicting semiconductor properties and optimizing device fabrication, with a concluding discussion on the challenges and opportunities in these areas.

15.
Int Urol Nephrol ; 56(8): 2607-2613, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38549000

RESUMO

INTRODUCTION: Ureteropelvic junction obstruction (UPJO) is a commonly encountered abnormality and it can lead to serious consequences such as renal dysplasia eventually resulting in loss of kidney. Hence, early diagnosis and timely management remains the cornerstone of the treatment. The most anticipated technique amongst modern day urologist is the robot-assisted laparoscopic pyeloplasty (RALP). The study aims to determine early post-operative outcomes of robot-assisted laparoscopic transperitoneal pyeloplasty procedure in patients presenting with unilateral ureteropelvic junction obstruction to establish the local perspective. METHODOLOGY: This is a descriptive study involving patients with ureteropelvic junction obstruction in a tertiary care facility in Karachi; Sindh Institute of Urology and Transplant (SIUT). A total of 46 participants were recruited. Robot-assisted laparoscopic transperitoneal dismembered Hynes-Anderson pyeloplasty was performed by a single surgeon with over 3 years of experience in the presence of the researcher. Early postoperative outcome total operative time, length of hospital stay, console time and blood loss were noted by the researcher as per operational definition. Data were analyzed on SPSS Version 22. RESULTS: Mean age in our study was 46.51 years with the standard deviation of ± 10.87. Whereas, mean length of hospital stay, total operative time, total blood loss, console time, pre-hemoglobin, posthemoglobin, height, weight and BMI in our study was 1.19 ± 0.40 days, 64.58 ± 17.59 min, 9.56 ± 6.13 ml, 30.17 ± 4.99 min, 12.66 ± 1.47 ml, 11.79 ± 1.93 ml, 165.62 ± 8.23 cm, 68.34 ± 8.23 kg and 24.85 ± 3.34 kg/m2, respectively. CONCLUSION: Recent advancements in technology have yielded the latest RALP technique which has been proven significantly better than existing approaches and similar results are reported by this study demonstrating improvement in peri-operative and post-operative outcomes ultimately ameliorating the quality of life of patients with UPJO.


Assuntos
Pelve Renal , Procedimentos Cirúrgicos Robóticos , Obstrução Ureteral , Procedimentos Cirúrgicos Urológicos , Humanos , Obstrução Ureteral/cirurgia , Procedimentos Cirúrgicos Robóticos/métodos , Pelve Renal/cirurgia , Masculino , Feminino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto , Procedimentos Cirúrgicos Urológicos/métodos , Laparoscopia/métodos , Fatores de Tempo , Tempo de Internação , Duração da Cirurgia
16.
J Appl Genet ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38261266

RESUMO

Enalapril is an orally administered angiotensin-converting enzyme inhibitor which is widely prescribed to treat hypertension, chronic kidney disease, and heart failure. It is an ester prodrug that needs to be activated by carboxylesterase 1 (CES1). CES1 is a hepatic hydrolase that in vivo biotransforms enalapril to its active form enalaprilat in order to produce its desired pharmacological impact. Several single nucleotide polymorphisms in CES1 gene are reported to alter the catalytic activity of CES1 enzyme and influence enalapril metabolism. G143E, L40T, G142E, G147C, Y170D, and R171C can completely block the enalapril metabolism. Some polymorphisms like Q169P, E220G, and D269fs do not completely block the CES1 function; however, they reduce the catalytic activity of CES1 enzyme. The prevalence of these polymorphisms is not the same among all populations which necessitate to consider the genetic panel of respective population before prescribing enalapril. These genetic variations are also responsible for interindividual variability of CES1 enzyme activity which ultimately affects the pharmacokinetics and pharmacodynamics of enalapril. The current review summarizes the CES1 polymorphisms which influence the enalapril metabolism and efficacy. The structure of CES1 catalytic domain and important amino acids impacting the catalytic activity of CES1 enzyme are also discussed. This review also highlights the importance of pharmacogenomics in personalized medicine.

17.
Curr Protoc ; 4(2): e989, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38363064

RESUMO

Acne vulgaris (acne) effects nearly 90% of all Western teenagers, and the only pharmaceutical class of agents to treat severe forms of this skin condition are the retinoids, which are well-described teratogens. Yet about 50% of the patients receiving this class of therapeutics are women of child-bearing age, in their peak years of reproductive potential. On this basis, there is a significant unmet medical need for agents to treat severe forms of acne that do not carry this liability. As a means to assess potential agents of this type, here we describe methods for estimating the relative amount of sebum that a mouse produces based on the water retention on fur following a thorough wetting procedure. We have shown that a compound that is clinically effective in reducing sebum production demonstrates activity in this model. The method is therefore useful for evaluating therapeutic candidates for reducing sebum production, which would in turn be useful for treating acne. We have broken the entire procedure down into two phases/two protocols, as listed below. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Pre-wash wet weight measurement Basic Protocol 2: Post-wash wet-weight measurement.


Assuntos
Acne Vulgar , Sebo , Adolescente , Humanos , Feminino , Camundongos , Animais , Masculino , Modelos Animais de Doenças , Acne Vulgar/tratamento farmacológico , Retinoides/uso terapêutico , Equilíbrio Hidroeletrolítico
18.
ACS Appl Mater Interfaces ; 16(8): 10104-10115, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38361321

RESUMO

Hierarchical porous nanowire-like MoS2/CoNiO2 nanohybrids were synthesized via the hydrothermal process. CoNiO2 nanowires were selected due to the edge site, high surface/volume ratio, and superior electrochemical characteristics as the porous backbone for decoration of layered MoS2 nanoflakes to construct innovative structure hierarchical three-dimensional (3D) porous NWs MoS2/CoNiO2 hybrids with excellent charge accumulation and efficient ion transport capabilities. Physicochemical analyses were conducted on the developed hybrid composite, revealing conclusive evidence that the CoNiO2 nanowires have been securely anchored onto the surface of the MoS2 nanoflake array. The electrochemical results strongly proved the benefit of the hierarchical 3D porous MoS2/CoNiO2 hybrid structure for the charge storage kinetics. The synergistic characteristics arising from the MoS2/CoNiO2 composite yielded a notably high specific capacitance of 1340 F/g at a current density of 0.5 A/g. Furthermore, the material exhibited sustained cycling stability, retaining 95.6% of its initial capacitance after 10 000 long cycles. The asymmetric device comprising porous MoS2/CoNiO2//activated carbon encompassed outstanding energy density (93.02 Wh/kg at 0.85 kW/kg) and cycling stability (94.1% capacitance retention after 10 000 cycles). Additionally, the successful illumination of light-emitting diodes underscores the significant potential of the synthesized MoS2/CoNiO2 (2D/1D) hybrid for practical high-energy storage applications.

19.
J Mol Graph Model ; 129: 108729, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38479238

RESUMO

The recent discovery of superconductivity behavior in the mother BiS2-layered compounds has captivated the attention of several physicists. The crystal structure of superconductors with alternate layers of BiS2 is homologous to that of cuprates and Fe-based superconductors. The full-potential linearized augmented plane-wave (FP-LAPW) technique was utilized to investigate the electronic structures and density of states in the vicinity of the Fermi energy of SrFBiS2 and BaFBiS2 compounds under the electron carriers doping. The introduction of electron doping (carries doping) reveals that the host compounds SrFBiS2 and BaFBiS2 exhibit features indicative of superconductivity. This carrier doping of SrFBiS2 and BaFBiS2 compounds (electron-doped) has a significant impact on the lowest conduction states near the Fermi level for the emergence of the superconducting aspect. The electron doping modifies and induces changes in the electronic structures with superconducting behavior in (Ae)1.7FBiS2(Ae=Sr,Ba) compounds. A Fermi surface nesting occurred under the modification of electrons (carriers) doping in the host compounds SrFBiS2 and BaFBiS2. Furthermore, the optical characteristics of the carrier-doped SrFBiS2 and BaFBiS2 compounds are simulated. Due to the anisotropic behavior, the optical properties of these materials based on BiS2 demonstrate a pronounced polarization dependency. The starting point at zero photon energy in the infrared region is elucidated by considering the Drude features in the optical conductivity spectra of SrFBiS2 and BaFBiS2 compounds, when the electron carriers doping is applied. It was clearly noticed that the spin-orbit coupling (SOC) influences the electronic band structures, density of states, Femi surface, and optical features because of the heavy Bismuth atom, which may disclose fascinating aspects. Further, we conducted simulations to assess the thermoelectric properties of these mother compounds. The two BiS2-layered compounds could be suitable for practical thermoelectric purposes and are highlighted through assessment of electrical conductivity, thermal conductivity, Seebeck coefficient, and power factor. As a result, we propose that the mechanisms of superconducting behavior in BiS2 family may pave new avenues for investigating the field of unconventional superconductivity. It may also provide new insights into the origin of high-Tc superconductivity nature.


Assuntos
Bismuto , Eletrônica , Condutividade Elétrica , Anisotropia , Elétrons
20.
Adv Sci (Weinh) ; 11(22): e2400258, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38526197

RESUMO

Due to their amorphous-like ultralow lattice thermal conductivity both below and above the superionic phase transition, crystalline Cu- and Ag-based superionic argyrodites have garnered widespread attention as promising thermoelectric materials. However, despite their intriguing properties, quantifying their lattice thermal conductivities and a comprehensive understanding of the microscopic dynamics that drive these extraordinary properties are still lacking. Here, an integrated experimental and theoretical approach is adopted to reveal the presence of Cu-dominated low-energy optical phonons in the Cu-based argyrodite Cu7PS6. These phonons yield strong acoustic-optical phonon scattering through avoided crossing, enabling ultralow lattice thermal conductivity. The Unified Theory of thermal transport is employed to analyze heat conduction and successfully reproduce the experimental amorphous-like ultralow lattice thermal conductivities, ranging from 0.43 to 0.58 W m-1 K-1, in the temperature range of 100-400 K. The study reveals that the amorphous-like ultralow thermal conductivity of Cu7PS6 stems from a significantly dominant wave-like conduction mechanism. Moreover, the simulations elucidate the wave-like thermal transport mainly results from the contribution of Cu-associated low-energy overlapping optical phonons. This study highlights the crucial role of low-energy and overlapping optical modes in facilitating amorphous-like ultralow thermal transport, providing a thorough understanding of the underlying complex dynamics of argyrodites.

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