Inductive and non-inductive load tests on type ATB - form E General Electric Co. alternator

Citation: Harold, William H., Burt, Harvy Anson, and Fulton, Robert Anson. Inductive and non-inductive load tests on type ATB - form E General Electric Co. alternator. Senior thesis, Kansas State Agricultural College, 1905.Morse Department of Special CollectionsIntroduction: The generator tested for characteristic action under different load conditions is of the revolving field, separately excited, stationary armature type. The above drawing shows the principal points in the construction of the machine. On the left is the main pulley which is run by the main drive belt; on the right is a smaller one from which a small direct current generator is run for exciting the alternator field. The shaft is lubricated by rings which dip into an oil reservoir. The revolving field receives its exciting current from the exciter through two slip rings. The field spider and pole faces are of laminated steel that in the pole faces is japanned and that in the spider is not. These laminations are held together by bolts as shown in drawing. The armature ring is built of japanned laminations which are held together by bolts and clamps. If the laminations should for any reason become loose and cause a disagreeable humming they may readily be tightened. There are six field coils which are wound as shown; all coils are in series each adjacent one being wound opposite and the terminals brought to the slip rings. One brush on the ring is shown; there are two brushes on each ring. The scheme of an armature slot is shown on drawing and is the construction most commonly employed by modern dynamo builder

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data