DuPont model measures

Analysis. The percent solids of each of the latexes was measured using a DuPont Model 950 Thermogravimetric Analyzer. Solution densities were determined using a Parr Mettler Model DMA-60 precision densitometer. The particle density was calculated from the solution density and the percent solids. 

TG-DTG measurements were made with a DuPont Model 951 thermo-gravimetric analyzer equipped with a 1091 disk memory. Weight loss data were obtained as a function of time and temperature. Samples were heated from room temperature to 900°C at a rate of 10°C/min. The purge gas was ultra-pure nitrogen, typically at... 

The DTA measurements were made on a DuPont Model 900 Thermal Analyzer using a heat-up rate of 20°C./min. 

The chromatograph had an all glass linear splitter (split 80 1) and a helium linear velocity of 23 cm/sec. A Perkin-Elmer fused silica column was used which measured 0.235 mm id, x 25 m long and which was coated with OV-101 (methyl silicone) liquid phase. The column was held 4 min at 45°C then programmed at 3°c/min to 120°C. Mass spectra were obtained using tandem gas chromatography/mass spectrometry. The column effluent was passed into the ion source of a DuPont Model 21-491 mass spectrometer (DuPont Instrument Division, Wilmington, Delaware). Mass spectra were obtained at 70 eV and a source temperature of 200°C. 

A DuPont Model 990 thermal analyzer equipped with a DSC cell was used for differential scanning calorimetry. All measurements were made in a nitrogen atmosphere over a temperature range from room temperature to 150°C. 

The DuPont model is useful in communicating how operations affect the company financially. It helps bridge the gap between operations, finance, and accounting. The DuPont model also known as the DuPont equation shows how the return on assets (ROA) and return on equity (ROE) are influenced by business decisions. ROE is a closely watched ratio and is considered a good measure of how well a... 

The DuPont model incorporates profit margin and asset efficiency to find ROA. Profit margin is calculated from values on the income statement. Asset efficiency, as measured by total assets turnover, is calculated from values on the income statement and balance sheet. 

Many times it is difficult to connect operational changes to changes in financial performance. The DuPont model is a useful tool to demonstrate this, especially during meetings with executives. What follows is the use of the DuPont model to demonstrate how inventory levels affect relevant financial and operational performance measures. 

The DuPont model for Mid-Atlantic Hospital System (Figure 9.2 and Table 9.3) identifies the current financial and operational performance of important performance measures. The current DuPont model provides a starting point from which to measure the effect of changing inventory levels. Currently, the inventory account is 30M. Observe the effects of reducing the inventory balance from 30M to 20M (Figure 9.3 and Table 9.3). 

Novolac molecular weights were measured in THF at 35°C by high pressure size exclusion chromatography using a Waters Model 510 pump (flow rate=1.0 ml/min), 401 differential viscometer detector and a set of Dupont PSM 60 silanized columns. A universal calibration curve was obtained with a kit of 10 narrow molecular weight distribution, linear polystyrene standards from Toya Soda Company. Data acquisition and analysis were performed on an AT T 6312 computer using ASYST Unical 3.02 software supplied with the Viscotek instrument. 

The DCP used was a variable speed unit developed in our own laboratory (3-6). (A commercial version of this instrument is mow available as the Brookhaven DCP-1000 Particle Size Analyzer from Brookhaven Instruments Corporation, Ronkonkoma New York. SFFF measurements were performed using a prototype instrument provided by DuPont (.] ) (A commercial version of this instrument is now available as the DuPont SFFF-1000 Particle Size Analyzer.) HDC measurements were made by Micromeritics on their Model HDC-5600 Flowsizer instrument. QELS measurements were made on an instrument constructed by Professor Alex Jamieson at Case Western Reserve University (8). TEM measurements were made by the Pigments Division of SCM Corporation, Adrian Joyce Plant, Baltimore, Maryland. Turbidity measurements were made using a Bausch and Lomb Model Spectronic-20 spectrometer. 

Thermal Characterization. The DuPont 941 Thermal Mechanical Analyzer (TMA), attached to a model 900 thermal analyzer, was used for the measurement of glass transition temperature (Tg). The heating rate was set at 10 C/min. For wet samples, about 0.05 ml of distilled water was dropped into the TMA sample holder tube before running the experiments, to maintain the sample in a water saturated state during the measurement. 

The thermal analytical data was measured with a DuPont 990 using the DSC or TGA (Model 951) module and verified using a Perkin Elmer DSC-2. The analytical methods used have been previously reported. I... 

Heat capacity measurements on polymers using the Perkin and Elmer Model l-B DSC were first reported by Wunderlich (66) and by the author (67) emfdoying a DuPont calorimeter cell. Recently the author has also checked the accuracy and precision of the Mettler Model 2000 microcalorimeter using sapphire as a standard and found that its heat capacity could be measured to an absolute accuracy of 2% and a precision of + 0.5%. So far no heat capacity measurements on polymers have been reported on this instrument. Further improvements in the design and use of these fast calorimeters are surely to come in the near future and should bring these instruments into the range of precision calorimeters. 

Infrared spectra were recorded on a Perkin Elmer model 1310 spectrometer using nujol mull. H-NMR and i C-NMR spectra were done on a Bruker 200 AP instrument using CDCI3 and/or DMSO-de as solvent and TMS as internal standard. Viscosity measurements were carried out in 0.5% (g/mL) solution in DMAc at 27 C. Thermal analysis of the polymers were done on a DuPont 9900 thermal analyzer. The chemical stability of the prepared polymers were checked on keeping them in concentrated sulfuric acid and in 5% aqueous sodium hydroxide solution. Elemental analysis was performed in Schwarzkopf Microanalytical Laboratory. 

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