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Hach Company manufactures and distributes analytical instruments and reagents used to test the quality of water and other liquid solutions. Manufactured and distributed worldwide, Hach systems are designed to simplify analysis by offering on-line instrumentation, portable laboratory equipment, prepared reagents, easy-to-follow methods, and technical support.
The Mohr method may be adapted to determine the total chlorine content of a sample by igniting the sample with calcium, then ferric acetate. Calcium acetate "fixes" free chlorine, precipitates carbonates, and neutralizes the resultant solution. Ferric acetate removes phosphates. All chlorides are dissolved out of the residue, and titrated. [1]
The conjugate gradient method can also be used to solve unconstrained optimization problems such as energy minimization. It is commonly attributed to Magnus Hestenes and Eduard Stiefel, [1] [2] who programmed it on the Z4, [3] and extensively researched it. [4] [5] The biconjugate gradient method provides a generalization to non-symmetric matrices.
To apply this method, analysts prepare multiple solutions containing equal amounts of unknown and spike them with varying concentrations of the analyte. The amount of unknown and the total volume are the same across the standards and the only difference between the standards is the amount of analyte spiked.
In this method, a pulsed UV laser is focused on the sample and creates a plume of ablated material, which can be swept into the plasma. This allows geochemists to spatially map the isotope composition in cross-sections of rock samples, a tool which is lost if the rock is digested and introduced as a liquid sample.
Spectral methods are a class of techniques used in applied mathematics and scientific computing to numerically solve certain differential equations.
The video encoding was done for entertainment applications and twelve different bitrates were made for the nine video test sequences with a HM-8.0 HEVC encoder being used. Of the nine video test sequences, five were at HD resolution, while four were at WVGA (800×480) resolution. The bit rate reductions for HEVC were determined based on PSNR ...
All are implicit methods, have order 2s − 2 and they all have c 1 = 0 and c s = 1. Unlike any explicit method, it's possible for these methods to have the order greater than the number of stages. Lobatto lived before the classic fourth-order method was popularized by Runge and Kutta.