Calcium concentration in tree sap of five species of Minnesota trees as an indicator of sugar sand

Tree sap can be collected from a variety of species (sugar maple, birch, ironwood, box elder, red maple) in Minnesota. When the sap of sugar maple trees and others are cooked into syrup, a cloudy mixture of minerals precipitates out. This precipitate, called sugar sand, gives syrup an unpleasant taste and can clog up machinery if improperly managed. Sugar sand primarily consists primarily of calcium malate. Thus, calcium concentration can be a good indicator of how much sugar sand would precipitate out if sap is processed into syrup. In general, previous literature has shown that sugar maple sap has the highest calcium concentration, followed by box elder, red maple, and paper birch. The purpose of this study was to determine the possible variations in amount of sugar sand found in syrup produced from different species of trees by measuring the calcium concentration in the trees’ sap. In addition, we aimed to determine the pattern of change in concentration of calcium over the course of the season (from March 21 to late April). Two trees each of the five following species were tapped: (Acer saccharum), box elder (Acer negundo), red maple (Acer rubrum), paper birch (Betula papyrifera), and ironwood (Ostrya virginiana). Trees were tapped with 5/16 spiles using standard procedures and the sap collected daily. The volume was measured and calcium concentration of the sap measured using a ion-selective calcium electrode. Results will be presented

Sugar Concentration in the tree sap of five species of Minnesota trees

Tree sap can be collected from a variety of species in Minnesota, including sugar maple (Acer saccharum), box elder (Acer negundo), red maple (Acer rubrum), paper birch (Betula papyrifera), and ironwood (Ostrya virginiana). The sap of different species contain varying concentrations of sugar, important for determining the amount of sap needed to boil down into a volume of syrup. In general, previous literature has shown that sugar maples have the highest concentration of sugar, followed by red maple, birch, and box elder. The sugar concentration of ironwood is as of yet unknown. The purpose of this study was to confirm the concentration of sugar in the sap of these five tree species and record the variation in sugar concentration over the tapping season (generally from early March to late April). Two trees of each species were tapped with 5/16 spiles starting on March 21 using standard procedures and the sap collected daily. The volume was measured and the sugar concentration measured using a digital refractometer. Results will be presented

Primary accumulation in the Soviet transition

The Soviet background to the idea of primary socialist accumulation is presented. The mobilisation of labour power and of products into public sector investment from outside are shown to have been the two original forms of the concept. In Soviet primary accumulation the mobilisation of labour power was apparently more decisive than the mobilisation of products. The primary accumulation process had both intended and unintended results. Intended results included bringing most of the economy into the public sector, and industrialisation of the economy as a whole. Unintended results included substantial economic losses, and the proliferation of coercive institutions damaging to attainment of the ultimate goal - the building of a communist society

Synthesis of a Benzodiazepine-derived Rhodium NHC Complex by C-H Bond Activation

The synthesis and characterization of a Rh(I)-NHC complex generated by C-H activation of 1,4-benzodiazepine heterocycle are reported. This complex constitutes a rare example of a carbene tautomer of a 1,4-benzodiazepine aldimine stabilized by transition metal coordination and demonstrates the ability of the catalytically relevant RhCl(PCy{sub 3}){sub 2} fragment to induce NHC-forming tautomerization of heterocycles possessing a single carbene-stabilizing heteroatom. Implications for the synthesis of benzodiazepines and related pharmacophores via C-H functionalization are discussed