DuPont Model 1090 system

The pyrolysis of wood, oxygen chemisorption and oxidation of wood chars were carried out in a computerized coupled TG-FTIR system containing Cahn-R-100 electric balance, DuPont Model 990 thermal analyzer and Nicolet MX-1 Fourier transform infrared spectrometer. All of these sequential processes are carried out within the thermal balance without interruption. 

The DSC thermogram of procaine hydrochloride was obtained using a DuPont model TA 9900 computer / thermal analyzer system. The analysis was carried out between 60 and 240"C, and the resulting thermogram is found in Figure 2. The compound was found to exhibit a clear and well-defined melting endotherm, whose temperature inflection was observed at 159<>C. 

The DuPont Model 830 liquid chromatograph (Fig.3.32) makes use of a pneumatic single-displacement pump which works on the pneumatic amplification principle (Fig.3.33). Compressed gas at a pressure of 0—100 p.s.i. is delivered to the large piston head. The amplification factor for this pump is 45 1. Thus pressures of up to 4500 p.s.i. are possible for solvent delivery, although the system has a recommended working range of up to... 

A DuPont model 21-492B GC/MS with an Incos data system was used to confirm the presence of thiazolidine and nitrosated thiazolidine. A 30 m x 0.24 mm id glass capillary column coated with SP-2250 was used for GC/MS analyses with a 30 1 split ratio (with the larger fraction vented to atmosphere through a charcoal trap). Electron impact ionization was used at 70 eV. The data system generated total ion current chromatograms and recorded mass spectra. 

A DuPont Model 990 Thermal Analysis Console with Model 910 DSC accessory was interfaced to a minicomputer system by means of a microcomputer for automated data collection. A program to provide the analysis of reaction kinetics data by the single dynamic scan method for DSC kinetics was developed. Features of this program include a fit of the data to a single equation by multiple regression techniques to yield the reaction order, the energy of activation and the Arrhenius frequency factor. The rate constant k(T) is then calculated and conversion data as a function of time and temperature can be generated at the operator s option. 

Photolysis studies were performed on freshly prepared solutions of the photoinitiator, (4xlO-3g/mL in hexane), the stabilizers (lxlO 3g/mL hexane), and combinations of the photoinitiator and stabilizer solutions. Solutions were degassed with dried N2 and photolyzed for 27 s with a broad band, high pressure Hg lamp (200-400 nm 0.030 J/s-cm2). The photolyzed samples were analyzed within 4 h on a DuPont Model 850 HPLC System equipped with a CN column. The solvent systems, CHCl3/hexane or IPA/hexane, were pumped at 1.5 mL/min. Products were detected at 280 nm with a minimum of five injections used for each analysis. 

Doelman et al. (6) described an on-line data acquisition system for TG using an IBM S/7 computer followed by data reduction on an IBM 360 195 computer. A DuPont Model 990 thermo balance was interfaced to the IBM S/7 computer using the system previously described for DTA data collection (53). The thermobalance must have the electrical zero (zero weight) signal established at the beginning of the run. Unlike DTA, the thermobalance does not have a completely linear temperature change with time. The non-... 

Dunn et al. (58) interfaced a DEC PDP 11-10 computer to a DuPont Model 990 thermal analysis system. The BCD-binary converter used a cascade of 15 6 bit BCD-binary ROMs to convert the 4.5-digit BCD output of the Hewlett-Packard Model HP 3430D digital voltmeter to bit binary for input to the DEC DR-11C general input-output device. All software was written in FOCAL, under the RT-11 operating system. 

On the DuPont Model 830 gradient elution accessory, Micromeritics Model 7OD0 gradient system, Perkin-Elmer Model 601 gradient system, Spectra-Physics Chromatronix Model 744 solvent programmer, Waters Model 660 sol vent prograimer,... 

Thermal analysis of polymers was performed on DuPont Model 910 Differential Scanning Calorimeter and a Perkin Elmer Model TQS-2 Thermal Gravimetric Analyzer using a heating rate of 10°C/min. Both systems were interfaced to an Omnitherm Data Station for experiment control, and data acquisition and processing. 

In this chapter we wUI describe some recent investigations of the formation and interfacial structure of a series of commercially produced sUica sols (Nalco, Dupont, and Ludox) with different diameters in the range 1-30 nm. This type of sol, which has wide industrial applications, has been used as a model system in numerous studies of coUoidal silica, although in general, the nature of the silica-water interface has received little attention. The interfacial structure may well explain some of the unusual properties of silica sols, such as the high surface charge and exceptional colloidal stability together with the enhanced capacity for sorption and com-plexation of ionic species in solution. Indeed in the past these features have been ascribed to a surface gel layer ... 

This system consisted of a TGA, GC, HRMS, GC to HRMS interface unit, and a GC interface unit. The TGA was a DuPont model 950 of the DuPont Thermal Analysis System (El DuPont de Nemours Co., Wilmington, DE, USA). The heating rate was 10-15 C per minute. The sample size was about 2-20 mg. Helium was used as the TGA carrier gas at a flow rate of 60-80 cm per minute. 

The DuPont model in Figure 8.7 shows how the revised network (adding a fourth distribution center) affects the hospital system s financial and operational performance from an accounting perspective. The revised network DuPont model represents your best estimate of how the hospital system s financial performance will change based on this network change. 

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). 

General. Toluene, chlorobenzene, and o-dichlorobenzene were distilled from calcium hydride prior to use. 4-Dimethylaminopyridine (Aldrich Chemical Co) was recrystalled (EtOAc), and the other 4-dialkylaminopyridines were distilled prior to use. PEG S, PEGM s, PVP s, and crown ethers were obtained from Aldrich Chemical Co., and were used without purification. BuJ r and BU. PBr were recrystallized (toluene). A Varian 3700 VrC interfaced with a Spectraphysics SP-4000 data system was used for VPC analyses. A Dupont Instruments Model 850 HPLC (also interfaced with the SP-4000) was used for LC analyses. All products of nucleophilic aromatic substitution were identified by comparison to authentic material prepared from reaction in DMF or DMAc. Alkali phenolates or thiol ates were pre-formed via reaction of aqueous NaOH or KOH and the requisite phenol or thiophenol in water under nitrogen, followed by azeotropic removal of water with toluene. The salts were transferred to jars under nitrogen, and were dried at 120 under vacuum for 20 hr, and were stored and handled in a nitrogen dry box. 

Resin Analysis. Thermal analysis of the BCB resin systems included Differential Scanning Calorisietry (DSC) using a DuPont 010 cell and Thermal Gravimetric Analysis (TGA) run on a DuPont 951 TGA, the entire thermal analysis system run using an Omnitherm model 35053... 

The cost of a vertical Lasagna system was evaluated by DuPont using a cost optimization model. For remediation of TCE to a depth of 40 to 50 ft (12 to 15 m) in clay on a 1-acre (4047-m ) site, costs were estimated to range from 40 to 90/yd ( 52 to 117/m ). Soil properties, depth of contamination, cost of emplacing electrodes and treatment zones, required purge water volume, cleanup time, and cost of electrical power were all included in the estimate (D12500Y, p. 10). 

On the other hand, the alkoxide system presented several problems in formulation. The system first chosen as a model consisted of a trimethoxymethyl silane crosslinker, 8000 centistoke HEB siloxane, and a catalyst. A number of catalysts were used and each exhibited different cure rates and electrical properties. DuPont tetraalkoxytitante-Tyzor appears to he one of the better catalysts used in this type of curing system. Fillers are usually incorporated into the silicone formulation to improve mechanical properties, promote adhesion, and to serve as light screening and pigment agents. Cab-o-sil, a form of fumed silica, carbon-black, titanium dioxide and calcium carbonate are then used as RTV fillers. 

Differential scanning calorimetry of acetylcholine chloride was performed using a Dupont DSC Model TA 9900 thermal analyzer system, interfaced to a Dupont data collection system. Figure 2 shows the DSC thermogram, which was recorded from 50 to 350°C. 

The differential scanning calorimetry characterization of dipyridamole was performed using a Dupont DSC model TA 9900 compiler thermal analyzer system. The DSC thermogram shown in Figure 2 was recorded at a heating rate of 10°C/min (under a nitrogen flow) over a temperature range of 50-450°C. The compound was found to melt at 169.32°C, with an enthalpy of fusion equal to 4.400 J/g. 

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