We hope that our Fish Clay sample (termed by us "Mesozoic Midnight") after analysis in other laboratories and by other analytical methods may qualify as reference material in analytical work on boundary clay material.ĭrying Affects the Fiber Network in Low Molecular Weight Hydrogels The preliminary results show that our KT boundary sample (1) is very homogeneous, (2) is very close in composition to other K-T boundary clays analyzed by us or described in the literature, and (3) has an Ir concentration of 32 +- 2 ng/g. INAA was made on 20 aliquots with weight about 300 mg, 20 aliquots with weight about 80 mg, and 30 with weights between 10 and 20 mg. The material was analyzed by instrumental neutron activation analysis, atomic absorption and X-ray fluorescence analysis for about 40 elements. The 40- kg powder was mixed in a rotating polyethylene drum for three weeks.
The fraction larger than 200 mesh was reduced to about 7 kg. After four repetitions the amount of material with grain size less than 200 mesh was about 40 kg. The fraction larger than 200 mesh was collected and powdered again in an agate mortar. The powdered material was sieved through 200 mesh nylon gauze. After drying, the material was homogenized using a wooden pestle and an agate mortar. Due to this extraordinary event we were able to pick by hand about 50 kg black KT boundary layer material. In March 1986 a 50-m-long exposure of the cliff at Stevns Klint fell down and exposed about 40 square meters of Fish Clay. Bioimpedance will improve dry weight assessment, but further refinement of the methods as well as large-scale clinical studies to demonstrate the accuracy and the clinical value of objective dry weight determination are needed.Ĥ0 KG Sample of Fish-Clay from Stevns Klint, Denmark Although promising, none of these methods has gained much popularity, probably due to the difficulties in understanding bioimpedance and the lack of gold standard methods for dry weight determination. Dry weight by this method is defined as the weight at which calf extracellular volume is not further reduced despite ongoing ultrafiltration. An alternative method uses segmental bioimpedance in the form of continuous intradialytic calf bioimpedance to record changes in calf extracellular volume during dialysis. The resulting resistance-reactance vector is set in relation to a distribution range in a normovolemic population. The resistance-reactance graph method uses whole body single frequency bioimpedance for assessment of hydration state and nutritional status from height-adjusted resistance and reactance. The normovolemic/hypervolemic slope method applies whole body multifrequency bioimpedance to assess predialysis total body extracellular fluid volume and compares the extracellular fluid volume/body weight relation at hypervolemia with the standard value in normovolemic individuals. Three different bioimpedance approaches to determine dry weight have been published. This review covers recent innovative approaches to dry weight assessment using bioimpedance technology. Bioimpedance technology offers the potential to quantify body fluid compartments and to facilitate dry weight prescription. Assessment of dry weight is highly dependent on clinical assessment. Kuhlmann, Martin K Zhu, Fansan Seibert, E Levin, Nathan WĬhronic overhydration contributes to the development of left ventricular hypertrophy and a high cardiovascular mortality in end-stage renal disease. Weight increase of stems was a logarithmic function ,of both stem diameter and height, whereas for.īioimpedance, dry weight and blood pressure control: new methods and consequences. Tree, stand, and site variables were tested for significant relationships with dry weight of tree parts. The results of density measurement will be evaluated as uncertainties for weights of 1 kg to 20 kg.įorty-four sample hardwood trees felled on 24 plots were separated into three above-ground components- stem, branches, and leaves-and weighed for dry matter content. Main parts of the setup are an electronic balance, a thermostat controlled liquid bath, reference weights designed for bottom weighing, dual purpose immersion pans and stepping motors to load and unload in weighing process. A new immersion pan is designed for dual purpose to carry the density sphere and the cylindrical test weight for weighing in liquid. Density sphere is used as standard density ball to determine density of the reference liquid. The density of reference liquid is determined using this setup while determining the density of the test weight.
The system works based on Archimedes principle.
This paper presents a density measurement system to determine density of weights from 1 kg to 20 kg using hydrostatic weighing. Lee, Yong Jae Lee, Woo Gab Abdurahman, Mohammed Kim, Kwang Pyo Density Measurement System for Weights of 1 kg to 20 kg Using Hydrostatic Weighing
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