Sampling plant tissue and soil for analysis

"Spectrographic analysis of plant tissue is a relatively new and accurate method for determining levels of major and minor elements in growing crops. However, good results make proper sampling of crops necessary. Keep the following points in mind when taking samples: Take plant samples at the proper stage of growth. Select tissue from proper portion of plant. Handle samples properly after collection. Take soil sample at the same time tissue is collected. If you follow the suggestions provided here, results of tests should be helpful. They can aid in diagnosing problem areas within fields, or in evaluating the fertility practices being followed on fields, or farms, where maximum yield is the goal."--First page.Roger Hanson (Department of Agronomy)"Revised September 2019 by Gene Stevens

Sampling plant tissue and soil for analysis (1993)

Spectrographic analysis of plant tissue is a relatively new and accurate method for determining levels of major and minor elements in growing crops. However, good results make proper sampling of crops necessary. If you follow the suggestions provided here, results of tests should be helpful. They can aid in diagnosing problem areas within fields, or in evaluating the fertility practices being followed on fields, or farms, where maximum yield is the goal

Reviews

P. Race, 500 Tips on Group Learning, London: Kogan Page, 2000. ISBN: 0–7494–2884–8. Softback, vii + 135 pages, £15.99

Assessing Consistency and Fairness in Sentencing: A Comparative Study in Three States

Summarizes a study of sentencing guidelines in Michigan, Minnesota, and Virginia comparing levels of predictability and judicial discretion under different guideline systems, effectiveness in limiting discriminatory disparities, and lessons learned

Buckling Rate and Overhang Development at a Calving Face

Using the finite-element we have modeled the stress field near the calving face of an idealized tidewater glacier under a variety of assumptions about submarine calving-face height, subaerial calving-face height, and ice rheology These simulations all suggest that a speed maximum should be present at the calving face near the waterline. In experiments without crevassing, the decrease in horizontal velocity above this maximum culminates in a zone of longitudinal compression at the surface somewhat Up-glacier from the face. This zone of compression appears to be a consequence of the non-linear rheology of ice. It disappears when a linear rheology is assumed. Explorations of the near-surface stress field indicate that when pervasive crevassing of the surface ice is accounted for in the simulations (by rheological softening), the zone of compressive strain rates does not develop. Variations in the pattern of horizontal velocity with glacier thickness support the contention that calving rates should increase with water depth at the calving face. In addition, the height of the subaerial calving face may have an importance that is not visible ill Current field data owing to the lack of variation in height of such faces in nature. Glaciers with lower calving faces may not have sufficient tensile stress to calve actively, while tensile stresses in simulated higher faces are sufficiently high that such faces will be unlikely to build in nature

Glacier Calving: A Numerical Model of Forces in the Calving-Speed/Water-Depth Relation

Empirical data suggest that the race of calving of grounded glaciers terminating in water is directly proportional to the water depth. Important controls on calving may be the extent to which a calving face tends to become oversteepened by differential flow within the ice and the extent to which bending moments promote extrusion and bottom crevassing at the base of a calving face. Numerical modelling suggests that the tendency to become oversteepened increases roughly linearly with water depth. In addition, extending longitudinal deviatoric stresses at the base of a calving face increase with water depth. These processes provide a possible physical explanation for the observed calving-rate/water-depth relation

Influence of time and temperature in the roasting of sulphides

The original object of this work was to determine the relation between the quantities of oxide and sulphate formed in roasting a sulphide under known conditions of temperature, time and supply of air. But difficulties arose in constructing apparatus, which in the short time allotted could not be overcome. These are mentioned in description of apparatus, and were of such a nature that the relations between products and conditions are for the most part qualitative --page 1