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1.
ACS Omega ; 8(33): 30621-30629, 2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37636974

ABSTRACT

ZnO is a widely studied material that exhibits versatile doping possibilities. Most research presents singly doped ZnO, leaving the potential of codoping unexplored. Within this study, hafnium-aluminum codoped zinc oxide (HAZO) thin films were grown on a glass substrate using the atomic layer deposition technique at 200 °C. A comprehensive analysis of the surface morphology and electrical and optical properties of the samples was conducted for varying the Al/Hf doping ratio. X-ray diffraction studies showed that the obtained films are polycrystalline, exhibiting a preferential growth direction along the (1 0 0) plane without any detectable precipitates. Moreover, the electrical measurements of HAZO films revealed that they exhibit lower resistivity (∼9.5 × 10-4 Ωcm) than the commonly used aluminum zinc oxide films (AZO). This improvement can be primarily attributed to the promotion of the n-type carrier concentration to 4.45 × 1020 cm-3 while maintaining a mobility value equal to 14.7 cm2/Vs. The doping also influences the optical properties of the material by widening the band gap and changing the refractive index, as observed by spectroscopy and ellipsometry studies. These findings highlight the potential of proposed HAZO thin films for future applications in electronic devices utilizing transparent conducting oxides.

2.
Materials (Basel) ; 15(19)2022 Oct 05.
Article in English | MEDLINE | ID: mdl-36234249

ABSTRACT

Fullerene derivatives offer great scope for modification of the basic molecule, often called a buckyball. In recent years, they have been the subject of numerous studies, in particular in terms of their applications, including in solar cells. Here, the properties of four recently synthesized fullerene C60 derivatives were examined regarding their optical properties and the efficiency of the charge transfer process, both in fullerene derivatives themselves and in their heterojunctions with poly (3-hexylthiophene). Optical absorption, electron spin resonance (ESR), and time-resolved photoluminescence (TRPL) techniques were applied to study the synthesized molecules. It was shown that the absorption processes in fullerene derivatives are dominated by absorption of the fullerene cage and do not significantly depend on the type of the derivative. It was also found by ESR and TRPL studies that asymmetrical, dipole-like derivatives exhibit stronger light-induced charge transfer properties than their symmetrical counterparts. The observed inhomogeneous broadening of the ESR lines indicated a large disorder of all polymer-fullerene derivative blends. The density functional theory was applied to explain the results of the optical absorption experiments.

3.
Molecules ; 26(6)2021 Mar 12.
Article in English | MEDLINE | ID: mdl-33809087

ABSTRACT

In the present work, we report the successful synthesis and characterization of six (two new) fullerene mono- and di-pyrene derivatives based on C60 and C70 fullerenes. The synthesized compounds were characterized by spectral methods (ESI-MS, 1H-NMR, 13C-NMR, UV-Vis, FT-IR, photoluminescence and photocurrent spectroscopy). The energy of HOMO and LUMO levels and the band gaps were determined from cyclic voltammetry and compared with the theoretical values calculated according to the DFT/B3LYP/6-31G(d) and DFT/PBE/6-311G(d,p) approach for fully optimized molecular structures at the DFT/B3LYP/6-31G(d) level. Efficiency of solar cells made of PTB7: C60 and C70 fullerene pyrene derivatives were analyzed based on the determined energy levels of the HOMO and LUMO orbitals of the derivatives as well as the extensive spectral results of fullerene derivatives and their mixtures with PTB7. As a result, we found that the electronic and spectral properties, on which the efficiency of a photovoltaic cell is believed to depend, slightly changes with the number and type of pyrene substituents on the fullerene core. The efficiency of constructed solar cells largely depends on the homogeneity of the photovoltaic layer, which, in turn, is a derivative of the solubility of fullerene derivatives in the solvent used to apply these layers by spincoating.

4.
J Surfactants Deterg ; 19(6): 1315-1326, 2016.
Article in English | MEDLINE | ID: mdl-27795665

ABSTRACT

We investigated the effect of hydrophobic extract concentration on the safety of using hand dishwashing liquids (HDL). A series of formulations was prepared, differing in the concentration of the hydrophobic chamomile extract obtained in supercritical CO2 conditions (from 0 to 0.7 %). We found that an increase in the concentration of the extract led to a decrease in the zein number, and reduced changes in the pH level of bovine serum albumin solution (i.e., two parameters determining the irritant activity of the formulations). It was also found that the additives reduced transepidermal water loss and improved the skin hydration level. Based on the findings of the study, a mechanism has been proposed, according to which hydrophobic plant extracts form aggregates in the volume phase of the washing bath. The surface of the aggregates is the adsorption area for surfactant monomers responsible for the irritant effect. Increasing the addition of the extract was shown to reduce the negative impact of the formulations on the skin of the hands, thus contributing to a greater safety of use of HDL.

5.
Ginekol Pol ; 79(11): 746-53, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19140496

ABSTRACT

OBJECTIVE: Ultrasound estimating of fetal weight is one of the most frequent examinations during pregnancy. Hitherto, foreign fetometry curves have mostly been used in Poland as there are no national available reference charts that are based on ultrasound fetal biometry. The aim of the present study was to construct new charts based on ultrasound fetometry reference for Polish population. STUDY DESIGN: A group of 959 healthy volunteers with uncomplicated singleton pregnancy joined in a cross-sectional study. The study was designed prospectively to evaluate normal reference charts for fetal ultrasound measurements and estimated fetal weight. Four biometric parameters were studied: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Estimated fetal weight (EFW) was calculated using Hadlock et al. formula from 1985. RESULTS: In the course of normal pregnancy an acceleration of growth rate was seen, but with a slight decline at the end of pregnancy. Reference curves for mean, 90th and 95th percentile were constructed for BPD, HC, AC and FL. Estimated fetal weight curves were outlined for both boys and girls. CONCLUSION: Reference charts for Polish population are similar to foreign curves. Less variation was seen in comparison with national charts based on postnatal weight. Ultrasound method seems to be better than birthweight curves especially in preterm pregnancies. This will improve the diagnosis of a small for gestational age newborn.


Subject(s)
Abdomen/diagnostic imaging , Abdomen/embryology , Cephalometry/statistics & numerical data , Femur/diagnostic imaging , Femur/embryology , Fetal Development/physiology , Adult , Biometry/methods , Cross-Sectional Studies , Female , Fetal Weight/physiology , Humans , Poland/epidemiology , Pregnancy , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Prospective Studies , Reference Values , Sensitivity and Specificity , Ultrasonography, Prenatal/statistics & numerical data
6.
Am J Dermatopathol ; 27(6): 489-96, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16314704

ABSTRACT

The aim of this study was to compare alterations of the basement membrane zone (BMZ) and to visualize changes within the skin vascular network in morphea and extragenital lichen sclerosus with the use of laser scanning confocal microscopy. This work was performed in eight plaques of morphea (three active and five inactive) and eight of lichen sclerosus (three of short duration and five long-lasting). Biopsy specimens from six healthy individuals served as controls. The biopsies were cut into 40-microm-thick sections, labeled with antibodies against beta4-intergin (a lamina lucida marker), collagen IV, and the N-terminal end of collagen VII (lamina densa markers) and C-terminal end of collagen VII (a sublamina densa marker) and studied using laser scanning confocal microscopy. Three-dimensional reconstruction of various regions of the BMZ showed a decreased number and size of the dermal papillae both in morphea and lichen sclerosus compared with normal skin. In morphea, the continuity of the BMZ at the level of lamina lucida, lamina densa, and sublamina densa was preserved whereas in LS numerous invaginations and holes were present in the BMZ at the level of the lamina lucida and lamina densa. Thus the alterations of the BMZ in morphea differ from those in lichen sclerosus. Three-dimensional reconstruction of the skin vascular network showed increased angiogenesis only in the early inflammatory stage of morphea, whereas in inactive morphea and lichen sclerosus various numbers of enlarged vessels were visible. The changes in the vascular network in morphea appear to be related to the activity of the disease.


Subject(s)
Basement Membrane/pathology , Lichen Sclerosus et Atrophicus/pathology , Neovascularization, Pathologic/pathology , Scleroderma, Localized/pathology , Skin/blood supply , Adult , Aged , Basement Membrane/ultrastructure , Female , Humans , Imaging, Three-Dimensional , Male , Microscopy, Confocal , Middle Aged , Skin/pathology
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