Aperçus sur la Tonotechnie ou le notage des cylindres au XVIIIe siècle
Influence of Potassium and Nitrogen Fertilization on Parasitism by the Root-knot Nematode Meloidogyne javanica.
Published in Journal of nematology
The influence of various c oncentrations of K, nitrogen sources, and inoculation with root-knot nematode Meloidogyne javanica were evaluated in tomato plants. Increased potassium concentration increased top and root fresh weights of intact plants and fresh weights of excised roots. Nitrate-fertilized plants weighed more than plants receiving ammoni...
A comparison of urban and rural aerosol composition using dichotomous samplers
Published in Atmospheric Environment (1967)
The concentrations and composition of atmospheric aerosols have been measured on a daily basis at two sites, one urban and one rural, near Leeds, W. Yorkshire. The aerosols were collected by automatic dichotomous samplers and particles in both size ranges (⩽ 2.5 and 2.5–15 μm) were analysed for SO 4 2−, NO 3 −, Cl − and NH 4 +. Simultaneous measure...
High-performance liquid chromatographic analysis of ammonium in human urine
Published in Analytical Biochemistry
A method for the quantitative determination of ammonium in human urine by high-performance liquid chromatography (HPLC) is described. After making fluorescent substances with fluorescamine, they were separated and quantified by their fluorometric intensity. The intensity (as measured by peak height) was linear between 0.5 and 5.0 μg, and coefficien...
Effects of nitrogen deposition on the acidification of terrestrial and aquatic ecosystems. International Symposium on Ac...
This concentration of ammonium and nitrate in precipitation has increased during this century. The deposition of nitrogen compounds (wet+dry) is a mean reaching 30-40 kg/ha and year in central Europe and above 20 kg in southern Sweden. In areas with high deposition an increased outflow is observed. The increased output is an indication of a nitroge...
FTIR transmission spectrometry for the nondestructive determination of ammonium and sulfate in ambient aerosols collecte...
Published in Atmospheric Environment (1967)
Fourier transform infrared (FTIR) transmission spectrometry has been used to determine ammonium and sulfate in ambient aerosol particles collected on Teflon filters. Integrated absorbance as well as maximum absorbance values for ammonium and sulfate are linearly related to X-ray fluorescence measurements of total sulfur. Apparent detection limits o...
A comparison of three methods for measurement of atmospheric nitric acid and aerosol nitrate and ammonium
Published in Atmospheric Environment (1967)
Three methods for measuring gaseous ambient nitric acid in the low concentration range 0–15 μ m −3 were compared under field conditions in Southwestern Ontario during 1–14 June 1982. The methods employed were (1) tunable diode laser absorption, (2) a tungstic acid denuder tube and (3) a filter pack containing a Teflon-nylon-W41 filter combination o...
Seasonal variation in atmospheric aerosol concentration and composition at urban and rural sites in northern England
Published in Atmospheric Environment (1967)
Seasonal variations in atmospheric aerosol concentration and composition have been determined at two nearby sites, one urban and one rural, near Leeds, W. Yorkshire. Aerosols, sampled on a daily basis and collected in the size ranges
Characteristics of the pH-influenced adaptation of methanogenic sludge to ammonium toxicity.
Development of a Standard Reference Material for Rainwater Analysis
Published in Journal of Research of the National Bureau of Standards
This paper describes the development of Standard Reference Material, SRM 2694, “Simulated Rainwater,” intended to aid in the analysis of acidic rainfall. Details of the formulation and preparation of the two levels of solutions (2694-I and 2694-II) are given. The 10 analytical techniques used to measure the 12 components in the solutions are descri...
