Search results for "bee"
showing 10 items of 628 documents
Automatic analysis of multiple Beerkan infiltration experiments for soil Hydraulic Characterization
2013
The BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization appears promising for intensively sample field areas with a reasonable effort both in terms of equipment and time passed in the field. Two alternative algorithms, i.e. BEST-slope and BEST-intercept, have been suggested to determine soil sorptivity and field-saturated soil hydraulic conductivity from a simply measured cumulative infiltration curve. With both algorithms, calculations have to be repeated also many times, depending on the number of collected infiltration data, that should vary between eight and 15. The need to consider a varying number of infiltration data is related to the fa…
Laboratory testing of Beerkan infiltration experiments for assessing the role of soil sealing on water infiltration
2018
Abstract Soil surface sealing is a major cause of decreased infiltration rates and increased surface runoff and erosion during a rainstorm. The objective of this paper is to quantify the effect of surface sealing on infiltration for 3 layered soils with different textures for the upper layer and investigate the capability of BEST procedure to catch the formation of the seal and related consequences on water infiltration. Rainfall experiments were carried out to induce the formation of the seal. Meanwhile, Beerkan infiltration runs were carried out pouring water at different distances from the soil surface (BEST-H versus BEST-L runs, with a High and Low water pouring heights, respectively) f…
Estimating saturated soil hydraulic conductivity by the near steady-state phase of a Beerkan infiltration test
2017
Abstract Single-ring infiltration experiments carried out in the field, such as the Beerkan runs, allow easy and inexpensive characterization of soil hydraulic properties, and specifically saturated soil hydraulic conductivity, Ks, by maintaining the functional connection of the sampled soil volume with the surrounding soil. However, a single infiltration experiment is not enough to determine Ks. The simplest way to obtain the necessary additional data is based on the assessment of the soil texture and structure characteristics. In this investigation, a simplified method, named SSBI (Steady version of the Simplified method based on a Beerkan infiltration run), was developed to estimate Ks b…
Beeswax cleaning by solvent extraction of pesticides
2018
We set out to test if the methodology used to clean sheep wool wax (Lanolin) from pesticides could be used to clean beeswax as well. We first made an aggregate sample of brood comb wax from three different US beekeepers. Sub-samples of these aggregate wax samples were analyzed for pesticide contamination. The remaining wax, was then dissolved into hexane solution and run through four N, N-Dimethylformamide (DMF) washes. During these extractions, the pesticides partitioned into the DMF, and so were removed from the beeswax. Following the solvent extractions, the beeswax was tested again for pesticides. An average of 95% of the pesticide contamination was removed by the chemical wash procedur…
Testing a new automated single ring infiltrometer for Beerkan infiltration experiments
2015
International audience; The Beerkan method along with BEST algorithms is an alternative technique to conventional laboratory or field measurements for rapid and low-cost estimation of soil hydraulic properties. The Beerkan method is simple to conduct but requires an operator to repeatedly pour known volumes of water through a ring positioned at the soil surface. A cheap infiltrometer equipped with a data acquisition system was recently designed to automate Beerkan infiltration experiments. In this paper, the current prototype of the automated infiltrometer was tested to validate its applicability to the Beerkan infiltration experiment under several experimental circumstances. In addition, t…
The southernmost beech (Fagus sylvatica) forests of Europe (Mount Etna, Italy): ecology, structural stand-type diversity and management implications
2013
The southernmost European beech forests are located in the upper forest vegetation belt on Mount Etna volcano. Their standstructural patterns were analysed to assess the effects of the site-ecological factors and previous management practices on the forest structure. Five main structural-silvicultural types were identified among the main beech forest types: coppice, highmountain coppice (HMCo), high forest, coppice in conversion to high-forest and non-formal stand. A detailed standstructural analysis was carried out through measured dendrometric parameters and derived structural characters linked to both the horizontal and the vertical profiles. Plant regeneration processes were also assess…
Sulphur Stored in Forest Soils and the Relative Importance of Organic and Inorganic Forms. Examples from Mont-Lozère (Southern Massif Central)
1995
From studies initiated in 1981, the mean annual hydrochemical budget established in three experiment watersheds at Mont-Lozere demonstrated that sulphur is retained in soils and in arenaceous formations (Lelong et al. 1990). Soils were developed on weathered granite materials that were strongly reworked by periglacial processes. One watershed is covered with grasses (Bassin de la Cloutasse) and the two others by forest. A beech coppice (Fagus sylvatica L.) and a Norway spruce forest (Picea abies (L.) Karst., hereafter shortened to “spruce”) occupy the Bassin de La Sapine (54 ha) and the Bassin of La Latte (20 ha), respectively. Unfortunately, as a result of a parasite attack, a large part o…
Clerodane diterpenoids from Salvia splendens.
2006
Four new clerodane diterpenoids, salvisplendins A-D (1-4), have been isolated from an acetone extract of the flowers of SalVia splendens, together with an artifact (5), arising from salvisplendin D (4) by addition of diazomethane, and the already known clerodane olearin (6). The structures of the new compounds (1-5) were established mainly by 1D and 2D NMR spectroscopic studies and, in the case of salvisplendin A (1), by chemical correlation with splenolide B (7). Complete 1H and 13C NMR assignments for olearin (6), not published hitherto, are also reported.
Modeling sequential production: the migratory beekeeper case
2018
This paper formalizes a bio-economic model of migratory beekeeping activities, during the annual production cycle, so as to discern the optimal sequence of foraging sites for migratory beekeepers; it then proceeds to empirically verify the model via a case study. The model assumes that the apiary farm produces three marketable outputs under conditions of certainty with disjunctive resources at the sites. In particular, honey, commercial pollination services and nucleus colonies are produced sequentially at foraging sites throughout the year. The model determines a migratory beekeeperâs revenues, variable costs, gross income from each sequence of foraging sites under the constraint that th…
Sugar beet diffusion juice and syrup as media for ethanol and levan production byZymomonas mobilis
1999
Abstract Sugar beet is an important crop cultivated widely in Europe. Roots contain up to 6–9 t/ha of fermentable sugar. Our laboratory is targeting to investigate the production possibilities of ethanol and levan by Zymomonas mobilis bacteria, using sugar beet juice or their syrup as raw material. The Z.mobilis strain 113 “S”;, selected in our institute, produces simultaneously with ethanol up to 40–70 g/1 fructose polymer levan in sucrose medium. It was established that Z.mobilis can convert sucrose into ethanol and levan in batch fermentation using natural sugar beet diffusion juice, without additives of mineral salts and growth factors. Syrup obtained in sugar industrial production by c…