Search results for "AMMONIA"

Effect of a novel chemical mixture on senescence processes and plant--fungus interaction in Solanaceae plants.

2001

The effects of exogenous application of a chemical mixture consisting of adipic acid monoethyl ester, furfurylamine, and 1,2,3,4-tetra-O-acetyl-beta-D-glucopyranose (FGA) on various metabolic pathways and the plant-fungus interaction have been studied in Solanaceae plants. Tomato and pepper plants were sprayed with the FGA mixture, and different biochemical parameters such as gas exchange, chlorophyll concentration, protein, cell wall sugar and phenolics contents, and peroxidase and phenylalanine ammonia lyase (PAL) activities were measured. FGA-treated plants showed, in general, an increase in cell wall sugar content and decreases in the chlorophyll degrading rate and the peroxidase activi…

Darstellung, eigenschaften und umsetzungen von polyvinylsulfofluoriden

1960

Vinylsulfofluorid wurde mit Azo-bis-isobutyronitril polymerisiert. Es wurden Polymerisationsgrade bis 390 erreicht. Die Molekulargewichte wurden durch Viskositatsmessungen an den durch Verseifung der Polyvinylsulfofluoride gewonnenen Natriumsalzen der Polyvinylsulfonsaure ermittelt. Die Polyvinylsulfofluoride wurden mit Ammoniak, aliphatischen und aromatischen Aminen umgesetzt. Dabei wurden Umsatze bis zu 80 Mol% erreicht. Vinylsulfofluoride was polymerized with azo-bis-isobutyronitrile. The degree of polymerisation was up to 390. The molecular-weights were determined by measuring the viscosity of the sodium-salts of polyvinylsulfonic acids obtained by saponification of polyvinylsulfofluori…

Critical Influence of Dielectric Sensitive Material and Manufactured Process in Microwave Gas-Sensing: Application of Ammonia Detection with an Inter…

2020

In this paper, authors propose a study on microwave gas sensors and the influence of critical key parameters such as the sensitive material and the circuit conception process. This work aims to determine the influence of these parameters on the quality of the final response of the microwave gas sensor. The fixed geometry of the sensor is a microstrip interdigital capacitor coated with a sensitive layer excited with two 50 Ω SMA ports. The sensitive material has been chosen in order to interact with the target gas: ammonia. Indeed, this gas interacts with phthalocyanine and metal oxides like hematite, TiO2. To explore the effect of the circuit manufacturing process, three series of samples a…

Microwave-based gas sensor with phthalocyanine film at room temperature

2013

Abstract This work presents the development of a microwave gas sensor at room temperature. The design of the sensor includes a coplanar grounded wave guide where is deposited a molecular gas sensing material. In this study, the sensitive material is a thin layer of cobalt phthalocyanine (CoPc), sensitive to ammonia and toluene. Submitted to an electromagnetic incident wave in the microwave range, the sensor response is a reflected wave. In the presence of pollutant, the reflected wave shape is specific to the species concentrations. The results interpretation is led at each frequency by the evaluation of the reflected coefficient, which traduces the ratio between the reflected wave over the…

Determinants of the distribution of nitrogen-cycling microbial communities at the landscape-scale

2010

Little information is available regarding the landscape-scale distribution of microbial communities and its environmental determinants. However, a landscape perspective is needed to understand the relative importance of local and regional factors and land management for the microbial communities. In this manuscript, we investigated the distribution of functional microbial communities involved in N-cycling and of the total bacterial and crenarchaeal communities over 107 sites using a grid with a 16 km lag distance within Burgundy, a 31 500 km2 region in France. After quantifying the abundances of the total bacterial, crenarchaeal, nitrate-reducing, denitrifying and ammonia-oxidizing communit…

Determination of taste-active compounds of a bitter camembert cheese by omission tests

2001

The taste-active compounds of a Camembert cheese selected for its intense bitterness defect were investigated. The water-soluble fraction (WSE) was extracted with pure water and fractionated by successive tangential ultrafiltrations and nanofiltration. The physicochemical assessment of these fractions led to the construction of a model WSE which was compared by sensory evaluation to the crude water-soluble extract, using a panel of 16 trained tasters. As no significant difference was perceived, this model WSE was then used directly or mixed with other cheese components for omission tests. Among the main taste characteristics of the WSE (salty, sour, umami and bitter), bitterness was found t…

Spatial distribution of ammonia oxidizing bacteria and archaea across a 44-hectare farm related to ecosystem functioning

2011

Technosols to reclaim industrial wastelands: depth distribution of abundance and activity of N-cycling microbial communities

2012

International audience; Construction of Technosols through assemblage of treated soil and recycled wastes is an innovative option for the restoration of degraded lands and re-use of industrial wastes. Recent studies have evidenced that Technosols could support soil functions such as primary production but the knowledge about other ecosystemic services, such as nutrient cycling, is limited. In this work, we investigated the abundance and the activity of microbial communities involved in N-cycling in different horizons (0–15, 15–35, 35–70 cm) of two types of Technosols constructed to reclaim an industrial wasteland. The estimation by real-time PCR of the abundances of the different microbial …

Spatial distribution of ammonia-oxidizing bacteria and archaea across a 44-hectare farm related to ecosystem functioning

2011

Characterization of spatial patterns of functional microbial communities could facilitate the understanding of the relationships between the ecology of microbial communities, the biogeochemical processes they perform and the corresponding ecosystem functions. Because of the important role the ammonia-oxidizing bacteria (AOB) and archaea (AOA) have in nitrogen cycling and nitrate leaching, we explored the spatial distribution of their activity, abundance and community composition across a 44-ha large farm divided into an organic and an integrated farming system. The spatial patterns were mapped by geostatistical modeling and correlations to soil properties and ecosystem functioning in terms …

Effet de l'humidité sur la réponse à l'ammoniac de capteurs conductimétriques à base de matériaux moléculaires

2012

Many ammonia sensors are available but the consideration of the humidity effect is scarcely insured even by manufacturers. The aim of this thesis is to propose a conductimetric transducer capable tomeasure ammonia selectively, with enough accuracy for air quality control, in a variable humidity environment. To reach this goal, we used thin film resistors made of cobalt phthalocyanines as semiconductor. This study deals with thin films processing made by vacuum evaporation, solventcast and electrodeposition. Automated workbenches were developed to perform electrical measurements under argon and to study the response of sensors to dry or humid ammonia by meansof 1 min / 4 min-long exposure / …