In this work, the structural transformations of a suboxide vacuum-deposited film of SiO1.3 composition annealed in an inert atmosphere in a wide temperature range of 100 °C–1100 °C were characterized by the reflection-transmission spectroscopy technique. The experimental spectroscopic data were used to obtain the spectra of the absorption coefficient α(hν) in the absorption edge region of the film. Based on their processing, the dependences of Urbach energy EU and optical (Tauc) bandgap Eo on the annealing temperature were obtained. An assessment of the electronic band gap (mobility gap) Eg was also carried out. Analysis of these dependences allowed us to trace dynamics of thermally stimulated disproportionation of the suboxide film and the features of the formation of nanocomposites consisting of amorphous and/or crystalline silicon nanoparticles in an oxide matrix.
Molybdenum (Mo) is considered and described as an essential element for living organisms’ development. Until now, no studies have been performed on genes involved in the Mo transporter in ancestral Ipomoea species. This study aimed to identify potential Mo genes in Ipomoea trifida and I. triloba genomes using bioinformatics tools. We identified four Mo transporter genes, two in I. trifida and two in I. triloba. Based on the RNA-seq datasets, we observed that Mo genes are expressed (in silico) and present different mechanisms between the tissues analyzed. The information generated in this study fills missing gaps in the literature on the Mo gene in an important agronomic crop.
Every production day in Nigeria, and in other oil producing countries, millions of barrels of produced water is generated. Being very toxic, remediation of the produced water before discharge into environment or re-use is very essential. An eco-friendly and cost effective approach is hereby reported for remediative pre-treatment of produced water (PW) obtained from Nigerian oilfield. In this approach, Telfairia occidentalis stem extract-silver nanoparticles (TOSE-AgNPs) were synthesized, characterized and applied as bio-based adsorbent for treating the PW in situ. The nanoparticles were of average size 42.8 nm ± 5.3 nm, spherical to round shaped and mainly composed of nitrogen and oxygen as major atoms on the surface. Owing to the effect of addition of TOSE-AgNPs, the initially high levels (mg/L) of Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and TSS of 607, 3.78 and 48.4 in the PW were reduced to 381, 1.22 and 19.6, respectively, whereas DO and COD improved from 161 and 48.4 to 276 and 19.6 respectively, most of which fell within WHO and US-EPA safe limits. Particularly, the added TOSE-AgNPs efficiently removed Pb (II) ions from the PW at temperatures between 25 ℃ to 50 ℃. Removal of TOSE-AgNPs occurred through the adsorption mechanism and was dependent contact time, temperature and dose of TOSE-AgNPs added. Optimal remediation was achieved with 0.5 g/L TOSE-AgNPs at 30 ℃ after 5 h contact time. Adsorption of Pb (Ⅱ) ions on TOSE-AgNPs was spontaneous and physical in nature with remediation efficiency of over 82% of the Pb (Ⅱ) ions in solution. Instead of discarding the stem of Telfairia occidentalis, it can be extracted and prepared into a new material and applied in the oilfield as reported here for the first time.
Cellulose nanocrystal, known as CNCs, is a form of material that can be produced by synthesizing carbon from naturally occurring substances, such as plants. Due to the unique properties it possesses, including a large surface area, impressive mechanical strength, and the ability to biodegrade, it draws significant attention from researchers nowadays. Several methods are available to prepare CNC, such as acid hydrolysis, enzymatic hydrolysis, and mechanical procedures. The characteristics of CNC include X-ray diffraction, transmission electron microscopy, dynamic light scattering, etc. In this article, the recent development of CNC preparation and its characterizations are thoroughly discussed. Significant breakthroughs are listed accordingly. Furthermore, a variety of CNC applications, such as paper and packaging, biological applications, energy storage, etc., are illustrated. This study demonstrates the insights gained from using CNC as a potential environmentally friendly material with remarkable properties.
Introduction: In Colombia, the last oral health study showed that about 70% of the population has partial edentulism while 5.2% will have lost all their teeth between the age of 65 and 79. Rehabilitation with implants is an increasingly used option, which requires clinical and radiographic follow-up. Panoramic radiography is a low-cost option, in which it is possible to observe areas of bone loss, mesiodistal angulation of the implant, relationship with anatomical structures and lesions suggestive of peri-implantitis. Reports and analysis of relevant data on radiographic findings associated with dental implants are required to determine the risk factors for their success in patients who use them. Objective: To determine the prevalence and characterize the findings associated with osseointegration implants in panoramic radiographs. Methods: A descriptive cross-sectional observational study was carried out with 10,000 digital panoramic radiographs selected by convenience from radiological centers in the city of Bogota, Colombia, of which 543 corresponded to the sample analyzed for the presence of implants. The following were evaluated for each implant: location, position, angulation and distances to adjacent structures, using the Clínicalview® program (Orthopantomograph OP200D, Instrumentarium, USA). Results: The frequency of radiographs with implants was 5.43% with a total of 1,791 implants, with an average of 3.2 per radiograph. They were found in greater proportion in the upper jaw with a supracrestal location and an angulation of 10.3 degrees. 32% had implant/tooth or implant/implant distances that were less than optimal. 40.9% were restored and 1.2% showed lesions compatible with periimplantitis. Conclusions: A high percentage of the implants reviewed have a risk factor that affects their long-term viability, either due to angulation, supracrestal or crestal position, proximity to teeth or other implants, or because they are not restorable.
With the progress of science and technology, the research and development of silver nanoparticles has also developed. This paper attempts to prepare a silver nanoparticle by electrolyzing AgNO3 solution with electrochemical reduction method and citric acid as a complexing agent in a certain current and time. The crystal morphology and sample purity of silver nanoparticles were analyzed by X-ray diffractometer. The crystal structure of the nanoparticles was analyzed by scanning electron microscopy (SEM). The crystal structure of the nanoparticles was analyzed by X-ray diffraction. The particle size distribution of the particles was in the range of 125-199 nm, and the carbon paste electrode was modified with the prepared silver nanoparticles. The electrocatalytic activity of the carbon paste electrode was preliminarily explored.
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