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1.
J Chem Phys ; 160(4)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38284656

RESUMO

Lithium bis(fluorosulfonyl)imide (Li-TFSI) is an efficient p-dopant that has been used to enhance the conductivity of perovskite solar cells (PSCs). However, the performance of the corresponding devices is still not satisfactory due to the impact of Li-TFSI on the fill factor and the short-circuit current density of these PSCs. Herein, a new Mn complex [(Mn(Me-tpen)(ClO4)2-)]2+ was introduced as a p-type dopant into spiro-OMeTAD and was successfully applied as a hole transport material (HTM) for PSCs. Analytical studies used for device characterization included scanning electron microscopy, UV-Vis spectroscopy, current-voltage (IV) characteristics, incident photon to current efficiency, power conversion efficiency (PCE), and electrochemical impedance spectroscopy. The UV-Vis spectra displayed oxidation in the HTM by the addition of a dopant. Moreover, the movement of electrons from the higher orbital of the spiro-OMeTAD to the dopant stimulates the generation of the hole carriers in the HTM, enhancing its conductivity with outstanding long-term stability under mild conditions in a humid (RH ∼ 30%) environment. The incorporation of the Mn complex into the composite improved the material's properties and the stability of the fabricated devices. The Mn complex as a p-type dopant for spiro-OMeTAD exhibits a perceptible PCE of 16.39% with an enhanced conductivity of 98.13%. This finding may pave a rational way for developing efficient and stable PSCs in real environments.

2.
RSC Adv ; 14(6): 3985-3995, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38288148

RESUMO

A systematic investigation was conducted in the present study to determine how various cations and anions affected the solubility of CO2. To investigate the influence of different cations and anions on the solubility of CO2, twelve ILs were synthesized, characterized, and utilized. These ILs comprised five distinct anions (dioctylsulfosuccinate [DOSS], triflouromethanesulfonate [TFMS], dodecylsulfate [DDS], 3-sulfobezoate [SBA], and benzene sulfonate [BS]), and four distinct cations (1-butyl-3-propanenitrile imidazolium [C2CN Bim], 1-hexyl-3-propanenitrile imidazolium [C2CN Him], 1-octyl-3-propanenitrile imidazolium [C2CN Oim], and 1-decyl-3-propanenitrile imidazolium [C2CN Dim]). The synthesized ILs were characterized using NMR and elemental analysis. Their moisture and halide contents were determined. The gravimetric method (MSB) was employed to determine the solubility of CO2 at various pressures (20, 15, 10, 5, and 1 bar). In addition, the effects of temperature on the solubility of CO2 were investigated. The constant of Henry's law (kH) was also calculated, along with thermodynamic properties including standard enthalpy (H0), entropy (S0), and Gibbs free energy (G0).

3.
Electrophoresis ; 45(5-6): 400-410, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38100198

RESUMO

The coupling of capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4 D) has become convenient analytical method for determination of small molecules that do not possess chromogenic or fluorogenic group. The implementations of CE with C4 D in the determination of inorganic and organic ions and amino acids in biomedical field are demonstrated. Attention on background electrolyte composition, sample treatment procedures, and the utilize of multi-detection systems are described. A number of tables summarizing highly developed CE-C4 D methods and the figures of merit attained are involved. Lastly, concluding remarks and perspectives are argued.


Assuntos
Aminoácidos , Eletroforese Capilar , Eletroforese Capilar/métodos , Condutividade Elétrica , Íons/análise , Aminoácidos/análise
4.
Materials (Basel) ; 15(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36556884

RESUMO

In hot and humid climates, a significant part of the energy is used to cool the building. There are several ways to reduce this air conditioning load, but one standout is through the selection and design of the right building envelope and its components. The thermal characteristics of the building envelope, in particular the thermal resistance of the insulation used, have an impact on the thermal and energy performance of building structures. Thermal conductivity, which indicates the ability of heat to move through a material given a temperature difference, is the primary factor affecting the performance of a thermal insulation material. Both temperature and humidity changes can affect a material's thermal conductivity value, which can then change. In fact, due to the fluctuating ambient air temperature and solar radiation, thermal insulation in buildings is susceptible to significant and continuous temperature variations. Thermal insulation used in building walls and roofs helps to reduce the energy demand of the building. It improves thermal comfort and, if used correctly, reduces the operational cost of the building. The present study has focused on the effects of location and insulation material on the energy performance of a residential building by considering five climatic locations in the Kingdom of Saudi Arabia (KSA). Five commonly used insulation materials with different thermal characteristics, namely polyurethane board (PU), expanded polystyrene (EPS), glass wool (GW), urea-formaldehyde foam (UFF), and expanded perlite (EP), were analyzed under various climatic zones as per the Saudi Building Code 601/602. The selected cities were categorized based on cooling degree days (CDD) and outdoor dry bulb temperature (DBT) as hot, very hot, and extremely hot climatic zones. Insulation improves thermal comfort and, if used correctly, reduces running costs. Experiments were conducted to determine the thermal conductivity, and the energy simulation was performed by employing IES-VE software for various insulation options. The findings indicate that the location has a significant impact on the energy performance of the insulating materials. The energy saving potential of polyurethane board (PU) insulation is more attractive in cities with higher DBTs and CDDs than in cities with lower DBTs and CDDs. The benefit of installing insulation ranged from a 2 to 14% decrease in energy demand for the climate zones studied. The sensitivity analysis showed that the energy saving potential of the insulation materials is sensitive to the set-point temperature (ST) band.

5.
MethodsX ; 9: 101742, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35677843

RESUMO

A modified sol-gel method was developed for the synthesis of pure and transition-metal-doped titanium dioxide. The process involves the hydrolysis of titanium tetraisopropoxide, which was used as a catalyst precursor, and molybdenum chloride, which was used as a doping agent. The shape and size of the final product were characterized by scanning electron microscopy, and the catalyst activity for the photocatalytic degradation of methylene blue in aqueous solutions was tested. The results indicate significant improvements in both the morphology and performance of the catalyst synthesized by the proposed method when compared to those obtained via the conventional approach using the same materials and quantities.•The main highlights of the proposed method are as follows.•Utilization of a double-jacketed cooling system to control and prevent temperature fluctuations during hydrolysis.•Ultrasonication during the reaction minimizes particle agglomeration during nanoparticle formation.•The use of two different alcohols and separation into two mixtures were experimentally demonstrated to delay gel formation, and hence, morphologically homogeneous catalyst nanoparticles were achieved.

6.
Saudi J Kidney Dis Transpl ; 25(2): 321-5, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24625998

RESUMO

To evaluate the accuracy of different single plasma sample methods (SPSM) 99m Tc-DTPA clearances and to test whether the SPSM can replace the dual plasma samples method (DPSM) in the measurement of glomerular filtration rate (GFR), we studied 430 subjects counting renal patients and donors (240 male, 190 female; mean age 43.40 ± 16.30 years). All the subjects underwent dynamic renal scintigraphy after injection of 99m Tc-DTPA; the GFR was calculated by seven SPSMs in addition to DPSM as a reference. Each of the SPSM clearance was compared with the DPSM measurement. There was a high correlation of all the SPSMs and the DPSM. The limits of agreement (95%) were found between the DPSM and all the SPSMs. Overall, the best method among the SPSMs, which is closest to the DPSM, is Fleming's single method as it has a statistically significant low mean difference (bias), low standard error, close mean ± SD to the reference method, good limits of agreement and high correlation co-efficient. This study concludes that, among the SPSMs, Fleming can reflect GFR more accurately than other methods, particularly when the expected serum creatinine is normal.


Assuntos
Taxa de Filtração Glomerular , Renografia por Radioisótopo/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Pentetato de Tecnécio Tc 99m , Adulto Jovem
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