Search results for "AMMONIA"

MOLECULAR AND METABOLIC ANALYSES IN DEVELOPING OLIVE FRUIT IN RELATION TO DIFFERENT WATER REGIMES

2011

Despite the global economic importance of olive (Olea europaea L.), little is known about the molecular and metabolic changes during fruit development and the modulation of quality-related metabolic pathways during drought stress. In this work, we report the expression pattern of genes involved in important pathways of secondary metabolism (polyphenols, terpenoids) during fruit development in rainfed or fully irrigated olive plants. Phenolic compounds represent a complex mixture in both olive fruits and oil. The interest on these compounds is due to their demonstrated anti-atherogenic and anti-cancerogenic effects providing to the olive oil important nutraceutical properties. Several parame…

Short hydrogen bonds enhance nonaromatic protein-related fluorescence

2021

Significance Intrinsic fluorescence of nonaromatic amino acids is a puzzling phenomenon with an enormous potential in biophotonic applications. The physical origins of this effect, however, remain elusive. Herein, we demonstrate how specific hydrogen bond networks can modulate fluorescence. We highlight the key role played by short hydrogen bonds, present in the protein structure, on the ensuing fluorescence. We provide detailed experimental and molecular evidence to explain these unusual nonaromatic optical properties. Our findings should benefit the design of novel optically active biomaterials for applications in biosensing and imaging.

High activity of brookite TiO2 nanoparticles in the photocatalytic abatement of ammonia in water

2015

Abstract The effects of the TiO 2 crystal structure and its surface modification with Pt nanoparticles on the photocatalytic oxidation of NH 3 in the aqueous phase were studied with home-made TiO 2 photocatalyst powders synthesized by a thermo-hydrolysis approach that allowed a fine control of the crystallographic phase composition. Ammonia conversion and the selectivity toward mildly oxidized N 2 and highly oxidized nitrite and nitrate anions were monitored during the runs. Pure brookite powders modified by Pt nanoparticles, deposited either from a colloidal suspension or by deposition–precipitation, were found to be the most efficient photocatalysts in NH 3 degradation, with a desired goo…

High-Temperature Ammonolysis of Uranium Trichloride and Tetrachloride

1965

Gaseous sensors based on solid proton conductors

1992

Abstract he chemical sensors for different gaseous (alcohol, acetone, ammonia, water vapour) detection at room temperature are developed by using polycrystalline β-alumina and xerogel of antimonic acid hydrate (AAH). The sensitivity and selectivity of sensors depend on the ion-exchange and preparative methods. The possibility of producing different types of potentiometric, amperometric, voltammetric and resistance sensors on the basis of these ion-conducting materials is shown. More success is achieved by producing ammonia-sensitive devices on β-alumina as well as on AAH xerogel.

Struktur-Wirkungs-Beziehungen bei Histaminanaloga, 9. Mitt.: Aminobenzyl- und Aminocyclohexylmethyl-imidazole

1975

Aus den durch Arndt-Eistert-Synthese dargestellten isomeren Brommethyl-nitro benzyl-ketonen 7a–c wurden 4-Nitrobenzyl-imidazole 8a–c durch Cyclisierung mit Formamidinacetat (6) in flussigem Ammoniak oder Bredereck-Synthese dargestellt und durch stufenweise Hydrierung in 4-Aminobenzyl-imidazole 9a–c sowie 4-Aminocyclohexylmethyl-imidazole 10a–c uberfuhrt. 9 und 10 wurden auf ihre histaminartige Wirksamkeit untersucht. Aminobenzyl- and Aminocyclohexylmethyl-imidazoles. From the isomeric bromomethyl-nitrobenzyl ketones 7a–c, produced by Arndt-Eistert synthesis, the 4-nitrobenzyl imidazoles 8a–c were synthesized by cyclisation with formamidineacetate (6) in liquid ammonia or by Bredereck synthe…

A microscale Kjeldahl nitrogen determination for environmental waters.

2008

A microscale Kjeldahl system has been designed which has been homemade reduced. The digestor unit of a macroKjeldahl system and a modified glassware microdistillation unit have been used. The optimal conditions for digestion and distillation have been established for ammonium and methylamine as model compound of organic amino nitrogen. The optimised procedure has been applied to the determination of Kjeldahl nitrogen in water samples. Recoveries near 100% and good precision have been achieved. This procedure combines nitrogen miniaturized system and the use of a selective ion electrode for ammonia detection. The analysis time was reduced 4.8 times and the analysis cost 6.6 times compared wi…

Quality control of commercial mustard by thin-layer chromatography

2005

Horseradish samples ( Cochlearis armoracia L. ) and mustard samples ( Sinapis alba L. ) were extracted with 70:30 ( v/v ) methanol-water in accordance with ISO method 91671. Samples of commercial mustard with and without horseradish were submitted to the same extraction procedure. Separation of the active compounds from these samples were performed on silica gel 60 plates with preconcentration zone and on silica gel F 254 high-performance thin-layer chromatography plates, with iso -propanol-25% ammonia, 90 + 10 ( v/v ), containing different volumes of distilled water (1, 2, 3, or 5 parts), as mobile phases. After development the compounds were visualized in UV light at λ = 254 nm or by expo…

First Steps of µTAS in Latvia

1995

Owing to participation of Latvian and Swedish scientists in the field of chemically sensitive FET and MOS structures it was possible to utilize the technological facilities of the Microelectronics enterprise in Latvia in making an integrated smart sensor as a matrix of chemically sensitive FETs by using silicon based microtechnology. Thereby the first steps of µTAS in Latvia are made in the direction of integration of solid state ionic materials with FET and MOS structures to develop new chemically sensitive structures and systems.

Tuning Of Organic Heterojunction Conductivity By The Substituents' Electronic Effects In Phthalocyanines For Ambipolar Gas Sensors

2021

Abstract Exploiting organic heterojunction effects in electrical devices are an important strategy to improve the electrical conductivity, which can be utilized into improving the conductometric gas sensors performances. In this endeavor, the present article reports fabrication of organic heterostructures in a bilayer device configuration incorporating octa-substituted nickel phthalocyanines (NiPc) and radical lutetium bis-phthalocyanine (LuPc2) and investigates their sensing properties towards NH3 vapor. NiPc having hexyl sulfanyl, hexyl sulfonyl and p-carboxyphenoxy moieties are synthesized, which electronic effects are electron donating, accepting and moderate accepting, respectively, al…