Search results for "Iode"
showing 10 items of 1284 documents
Internal photoemission in solar blind AlGaN Schottky barrier photodiodes
2005
We have analyzed the photoresponse of solar blind AlGaN Schottky barrier photodiodes below the alloy band gap energy, in the 3.5-4.5 eV range, and we show that it is dominated by internal photoemission. The n-type Schottky barrier height is shown to increase linearly with the band gap energy of the AlGaN alloy. The amplitude of the internal photoemission signal is about 20 times smaller than the value given by the Fowler theory based on a free electron model. We explain this result by taking into account the interband transitions and the ballistic transport of photoexcited electrons in the metal. This low value of internal photoemission allows us to achieve a spectral rejection ratio betwee…
Interface engineering in efficient vacuum deposited perovskite solar cells
2016
Abstract We studied the effect of the charge transport layers in p-i-n perovskite solar cells using vacuum deposited methylammonium lead iodide thin-film absorbers. While solution-processed perovskite films are frequently deposited directly on PEDOT:PSS leading to good solar cell performances, in some cases even to very good Voc values, we show that in devices employing vacuum deposited MAPbI3 perovskites, the removal of the polyTPD electron blocker substantially reduces the photovoltaic behavior. This is indicative of rather different charge transport properties in the vacuum deposited MAPbI3 perovskites compared to those prepared from solution. On the other hand, we investigated the use o…
Implications of cysteine metabolism in the heavy metal response in Trichoderma harzianum and in three Fusarium species
2009
We studied the ability of four different fungal species, Trichoderma harzianum, Fusarium antophyllum, Fusarium compactum and Fusarium phyllophilum, to grow in the presence of heavy metals, and monitored their cysteine and glutathione content and the activity of O-acetylserine(thiol)lyase (OASTL), which is involved in cysteine biosynthesis. Zn and Pb did not affect fungal growth or sporulation at the concentrations used, whereas Cd and Hg did. In most cases, cysteine and glutathione content was higher when fungi were grown in the presence of toxic metals. As T. harzianum and F. phyllophilum presented the best growth rate on Cd and Hg, they were selected to further analyse the accumulation of…
The use of glyphosate as the sole source of phosphorus or carbon for the selection of soil-borne fungal strains capable to degrade this herbicide
1997
Abstract The herbicide glyphosate was used as a selection agent for isolation of fungal strains capable to degrade phosphorus-to-carbon bond from standard sandy-clay soil. The studies have shown that the herbicide used in Martin medium as a sole source of phosphorus br carbon caused the decrease of the fungal population and substantially changed strain composition, thus selecting those which are able to degrade glyphosate.
Further data on the levels of emerging Fusarium mycotoxins enniatins (A, A1, B, B1), beauvericin and fusaproliferin in breakfast and infant cereals f…
2011
Abstract Sixty-eight samples of cereals products, including breakfast cereals ( n = 48) and infant cereals ( n = 20), purchased from supermarkets and pharmacies in Rabat-Sale area from Morocco were analysed for the determination of six emerging mycotoxins: four enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of acetonitrile:water (85:15, v/v), using an Ultra-Turrax® homogeniser. Mycotoxins were then identified and quantified by liquid chromatography (LC) with diode array detection (DAD). Positive samples were confirmed by LC–MS/MS. Analytical results showed that the percentages of analysed samples contaminated with…
Challenges of Lactobacillus fermentation in combination with acoustic screening for deoxynivalenol and deoxynivalenol conjugates reduction in contami…
2022
Abstract This study was dedicated to apply biological treatment using Lactobacillus (LAB) fermentation separately or in combination with an acoustic screening method for the prevention of mycotoxins in Fusarium spp. contaminated wheat-based products. Wheat samples of different contamination were treated separately using antimicrobial LAB strains (L. casei, L. plantarum, L. paracasei, and L. uvarum) and the changes on the level of deoxynivalenol (DON) and its conjugates such as 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and DON-3-β-D-glucoside (D3G)) were evaluated using UHPLC-QqQ-MS/MS and UHPLC-Orbitrap-HRMS. Additionally, an acoustic device was used to analyse DON…
Mitigation of enniatins in edible fish tissues by thermal processes and identification of degradation products.
2017
Emerging mycotoxins, such as enniatins and beauvericin, are common contaminants in vegetal matrices, but recently, the occurrence of mycotoxins in foodstuffs from animal origin has been also reported as they can be present in edible tissues of animals fed with contaminated feedstuffs. Sea bass, sea bream, Atlantic salmon and rainbow trout from aquaculture analyzed in the present survey showed contamination by emerging Fusarium mycotoxins enniatins (ENs). ENs were extracted from raw and cooked fish with acetonitrile and analyzed by Liquid Chromatography coupled to Mass Spectrometry. In this study, the stability of ENs was evaluated during food processing by the application of different cooki…
N-(2-PIRYDYLAMINO) METHYLENEBISPHOSPHONIC ACID AS A SOLE SOURCE OF A FUNGI FUSARIUM STRAINS GROWING
2016
The active substance of new herbicide generation is N-(2-pirydyloamino) methylenobisphosphonic acid. Two strains Fusarium culmorum CB3 and Fusarium oxysporum XVI, isolated from soil treated with examined substance, were chosen to investigation of using it as a sole source of phosphorus, nitrogen or carbon in the concentrations at 1.0 mM. Interactions between the dominating strains of fungi and N-(2-pirydyloamino) methylenobisphosphonic acid, mycelium growth rate, the spore germinate index, the level chemical changes of N-(2-pirydyloamino) methylenobisphosphonic acid and pH were investigated after cultivation in mineral medium and its modifications. The results of growth kinetics of the stud…
Etude des effets cohérents dans la vapeur de rubidium atomique sous irradiation laser bi-chromatique
2013
The effect of electromagnetically induced transparency is observed, using nanocelland microcell. The EIT-resonance with good parameters (high contrast and small FWHM) is obtained in thick cells. The EIT-resonance splitting in magnetic field is observed for the cases of D1-line of 85Rb and 85Rb. The theoretical model, explaining the EIT-resonance components frequency shift dependence on magnetic field strength is presented. The theoretical and experimental results are compared and good agreement is shown. Also the EIT-resonance behavior in hyperfine Paschen-Back regime is presented and explained. For the first time the N-type resonance in microcell is observed. Good parameters of theN-type r…
Study of optical and magneto processes in Rb atomic vapor layer of nanometric thickness
2012
Using a narrow-band resonant fluorescence spectra from a nano-cell with a thickness of L= [lambda]/2, and VSOP resonances formed at a thickness L =[lambda] ([lambda] is the wavelength of the resonant radiation), for the first time it was experimentally investigated the behaviour of the frequency and intensity (transition probabilities) of the atomic hyperfine structure transitions between the 85Rb, 87Rb, D1 and D2 lines Zeeman sublevels in external magnetic fields in range 5 - 7000G. The behaviour of tens of previously unstudied atomic transitions was analyzed and it is demonstrated that the intensities of these lines can both greatly increase, and decrease (tenfold). For the first time it …