Search results for "medium"

Copper and iron homeostasis inArabidopsis: responses to metal deficiencies, interactions and biotechnological applications

2007

Plants have developed sophisticated mechanisms to tightly control the acquisition and distribution of copper and iron in response to environmental fluctuations. Recent studies with Arabidopsis thaliana are allowing the characterization of the diverse families and components involved in metal uptake, such as metal-chelate reductases and plasma membrane transporters. In parallel, emerging data on both intra- and intercellular metal distribution, as well as on long-distance transport, are contributing to the understanding of metal homeostatic networks in plants. Furthermore, gene expression analyses are deciphering coordinated mechanisms of regulation and response to copper and iron limitation…

Transport and Relaxation Phenomena in Porous Media

2007

Structure alteration of a sandy-clay soil by biochar amendments

2014

The aim of the present study was to investigate structure alterations of a sandy-clay soil upon addition of different amounts of biochar (f bc ). All the f bc samples were analyzed by high energy moisture characteristic (HEMC) technique and 1H nuclear magnetic resonance (NMR) relaxometry. HEMC was applied in order to evaluate aggregate stability of biochar-amended soil samples. 1H NMR relaxometry experiments were conducted for the evaluation of the pore distributions through the investigation of water dynamics of the same samples. The HEMC technique revealed improvement in aggregate stability through measurements of the amount of drainable pores and the stability ratio. The latter increased…

Effect of application time and concentration of silver diamine fluoride on the enamel remineralization

2021

Background Silver diamine fluoride has attracted attention because of its clinical success in arresting dental caries. Thus, the aim of this study was to evaluate the effect of different application times and concentrations of silver diamine fluoride (SDF) on deciduous tooth enamel remineralization. Material and Methods Blocks of deciduous tooth enamel were categorized into six groups of 11 each: 2 control groups: intact enamel, and demineralized enamel; 38% SDF and 30% SDF which were subdivided according to application times (1 and 3 min). The microhardness of samples was determined, and all groups except the intact enamel group were subjected to pH cycling to produce initial carious lesio…

Evaluation of diode laser application on chemical analysis and surface microhardness of white spots enamel lesions with two remineralizing agents

2020

Background To investigate the effect of diode laser application and two commercial remineralizing agents on the remineralization and surface microhardness of white spot enamel lesions. Material and methods Sixty specimens were prepared then equally divided into six groups (n=10/group), according to the diode laser and the two commercial remineralizing agents applied to demineralized enamel surfaces (APF gel and sodium fluoride NaF mousse) with or without diode Laser application as follows; Group A; control, Group B; diode Laser application, Group C; APF gel application, Group D; NaF mousse application, Group E; APF gel application + diode Laser, Group F; NaF mousse application+ diode Laser.…

Enamel remineralization and surface roughness after treatment with herbal-containing toothpastes

2021

Background Oral care products containing bioactive agents obtained from extracts of plant drugs were launched. This in vitro study investigated the effects of herbal-containing toothpastes associated or not with fluoride to remineralize the enamel after cariogenic challenge with pH cycling. The chemical and physical factors of toothpastes and the enamel surface roughness after brushing were also analyzed. Material and methods Sixty bovine enamel blocks were obtained and divided into 3 thirds: intact (untreated), demineralized (artificial caries lesion), and treated (caries lesion, pH cycling, and brushing with toothpastes). Toothpastes containing herbal compounds contained no fluoride [Gall…

Evaluation of the fuel potential of sewage sludge mixtures with beech sawdust and lignite

2018

Sewage sludge (SS) from municipal wastewater treatment has drawn serious attention of scientists around the world in the attempt to find feasible disposal methods. Therefore, in this work, a solution for valorisation of SS as solid fuel is proposed based on an advanced compositional investigation of SS versus conventional solid fuels, namely, lignite (L) and beech sawdust (BS). A characterisation in terms of proximate analysis and ultimate analysis was performed for the studied materials, both to SS, L, and BS as single fuel and to bi-component mixture formulas of SS and L/BS, in variable proportions of 30:70, 50:50, and 70:30. SS:BS based blends had higher hydrogen (from 4.43 wt. % to 5.14…

Interference of EDTA in the treatment of metal plating wastewater by biosorption

2012

Ab initio modelling of oxygen vacancies and protonic defects in La1−xSrxFeO3−δ perovskite solid solutions

2016

Using hybrid density functionals, detailed ab initio calculations were performed for oxygen vacancies and protons in La1−xSrxFeO3−δ perovskite solid solutions which may serve as a cathode material in protonic ceramic fuel cells. The atomic and electronic structures of different configurations of defects and the role of Fe oxidation state are analyzed in detail. The energetics of the reduction and hydration reactions are investigated. The hydration energy is found to be significantly smaller than for Ba(Zr1−xYx)O3−x/2 electrolyte materials, and the role of basicity as one decisive factor is discussed.

Catalytic performance of CoAlZn and NiAlZn mixed oxides in hydrogen production by bio-ethanol partial oxidation

2013

CoAlZn and NiAlZn mixed oxides were prepared by sol-gel method and tested in partial oxidation of bio-ethanol (POE). At lower temperatures, CoAlZn showed higher ethanol conversion and higher selectivity to H2 and CO than NiAlZn. At higher temperatures, ethanol conversion on both catalysts reached 100%, while selectivity (S) to H2 and CO became higher on NiAlZn. At 750 C, NiAlZn showed S(H2) of 95%, S(CO) of 90%, while for CoAlZn these values were 90% and 83% respectively. Both catalysts were resistant to coking, but the amount of carbon deposits was still lower on NiAlZn. During 50 h on-stream, ethanol conversion and selectivity to H2 and CO on NiAlZn remained unchanged demonstrating stable…