Determination of PVC in Presence of Reactive Fillers

1987 ◽  
Vol 60 (2) ◽  
pp. 310-318 ◽  
Author(s):  
S. E. Walter
Keyword(s):  
Mass Loss ◽  
Variable Mass ◽  
Bulk Polymerization ◽  
Chlorine Content ◽  
Thermogravimetric Data ◽  
Organic Chlorine ◽  
Halogenated Polymers ◽  
Rule Out ◽  
Co2 Elimination

Abstract PVC content in thermoplastic materials can be determined from the total chlorine or more specifically from organic chlorine content. Organic chlorine content can be determined by ASTM D 1551 using the described modifications. Presence of reactive fillers such as CaCO3 results in large negative errors. When reactive fillers are expected to be present, the quantity of PVC should be determined with methods measuring total chlorine or by TGA. TGA can be used successfully for the analysis of such samples. Plasticizers and PVC stabilizers are extracted before analysis to eliminate interfering or variable mass loss in PVC thermograms. This technique can also be used for the analysis of PVC/NBR mixtures. In unknown compounds, the technique should be used in conjunction with FTIR analysis to facilitate polymer identification and to rule out interference by other halogenated polymers. Excess of unreacted CaCO3 can be observed and the amount determined from thermograms. Remaining CaCO3 can be determined from mass loss due to elimination of CO2. If a cooling step is introduced before the atmosphere is switched from nitrogen to air, a clearer separation of residue oxidation and CO2 elimination are obtained. On reheating, residue oxidation then takes place between 450 and 500°C, well separated from CO2 elimination at about 700°C. Variation of thermograms using PVC obtained by different polymerization procedures needs to be further investigated. Structural differences and thermal stability of PVC samples made by emulsion, suspension, and bulk polymerization have been examined by various techniques, but no thermogravimetric data are given.

Attitude Behavior of a Variable Mass Cylinder

1995 ◽  
Vol 62 (4) ◽  
pp. 935-940 ◽  
Author(s):  
F. O. Eke ◽  
Song-Min Wang
Keyword(s):  
Mass Loss ◽  
Variable Mass ◽  
Cylindrical Body ◽  
Rigid Bodies ◽  
Transverse Motion ◽  
Attitude Motion ◽  
Key Factors ◽  
Great Contrast ◽  
Attitude Behavior

This paper examines the attitude motion of a cylindrical body with mass loss. It is found that mass variation can have a substantial influence on the behavior of such a system. Specifically, the initial dimensions as well as the manner in which mass loss affects system inertia are found to be key factors in the determination of the characteristics of the lateral motion of the system. In great contrast to the attitude behavior of spinning rigid bodies, oblate variable mass cylinders exhibit divergent transverse attitude motion, while the transverse motion of prolate variable mass cylinders is found to be bounded in general.

scholarly journals Chlorine Removal from U.S. Solid Waste Blends through Torrefaction

2020 ◽  
Vol 10 (9) ◽  
pp. 3337
Author(s):  
Zhuo Xu ◽  
Josh W. Albrecht ◽  
Shreyas S. Kolapkar ◽  
Stas Zinchik ◽  
Ezra Bar-Ziv
Keyword(s):  
Hydrochloric Acid ◽  
Mass Loss ◽  
Solid Waste ◽  
Heat Content ◽  
Calorific Value ◽  
Chlorine Content ◽  
Fiber Plastic ◽  
The World ◽  
Organic Chlorine ◽  
Chlorine Removal

The amount of solid waste generated annually is increasing around the world. Although the waste has a high calorific value, one major obstacle that may prevent it from becoming a feedstock for power applications is the existence of polyvinyl chloride (PVC), which causes corrosion and emission issues after combustion due to its high chlorine content. Torrefaction is known to release hydrochloric acid; thus, it has been applied in this study for the reduction of chlorine from potential waste feedstocks. Fiber-plastic (60–40%) waste blends, with different chlorine content levels, as well as PVC were used in the current study. Torrefaction was conducted at 400 °C. Chlorine and heat content were measured. Experimental results showed that organically bonded chlorine was reduced during torrefaction as a function of mass loss. The chlorine removal efficiency was only dependent on temperature and residence time, not chlorine level. The heat content of the sample increased with mass loss up to a maximum of ~34 MJ/kg at ~45% mass loss. It was also observed that at ~30% mass loss, the organic chlorine content per unit heat content reduced by ~90%, while the heat content was ~32 MJ/kg, and ~90% energy was retained.

scholarly journals Predictions of variable mass loss for Luminous Blue Variables

2002 ◽  
Vol 393 (2) ◽  
pp. 543-553 ◽  
Author(s):  
Jorick S. Vink ◽  
A. de Koter
Keyword(s):  
Mass Loss ◽  
Variable Mass ◽  
Luminous Blue Variables

scholarly journals Nonlinear features of equatorial baroclinic Rossby waves detected in Topex altimeter observations

1996 ◽  
Vol 3 (2) ◽  
pp. 115-126 ◽  
Author(s):  
R. E. Glazman ◽  
A. Fabrikant ◽  
A. M. Greysukh
Keyword(s):  
Rossby Waves ◽  
Propagation Speed ◽  
Altimeter Data ◽  
Satellite Altimeter ◽  
Wave Regime ◽  
Nonlinear Features ◽  
Wavenumber Spectrum ◽  
Satellite Altimeter Data ◽  
Rule Out

Abstract. Using a recently proposed technique for statistical analysis of non-gridded satellite altimeter data, regime of long equatorially-trapped baroclinic Rossby waves is studied. One-dimensional spatial and spatiotemporal autocorrelation functions of sea surface height (SSH) variations yield a broad spectrum of baroclinic Rossby waves and permit determination of their propagation speed. The 1-d wavenumber spectrum of zonal variations is given by a power-law k-2 on scales from about 103 km to 104 km. We demonstrate that the observed wave regime exhibits features of soliton turbulence developing in the long baroclinic Rossby waves. However, being limited to second statistical moments, the present analysis does not allow us to rule out a possibility of weak wave turbulence.

scholarly journals Variability in X-ray line ratios in helium-like ions of massive stars: the wind-driven case

2019 ◽  
Vol 625 ◽  
pp. A86 ◽  
Author(s):  
R. Ignace ◽  
Z. Damrau ◽  
K. T. Hole
Keyword(s):  
Mass Loss ◽  
Massive Stars ◽  
Mass Loss Rate ◽  
Variable Mass ◽  
Line Ratio ◽  
High Spectral Resolution ◽  
X Rays ◽  
Wind Integration ◽  
X Ray ◽  
Wind Variability

Context. High spectral resolution and long exposure times are providing unprecedented levels of data quality of massive stars at X-ray wavelengths. Aims. A key diagnostic of the X-ray emitting plasma are the fir lines for He-like triplets. In particular, owing to radiative pumping effects, the forbidden-to-intercombination line luminosity ratio, R = f∕i, can be used to determine the proximity of the hot plasma to the UV-bright photospheres of massive stars. Moreover, the era of large observing programs additionally allows for investigation of line variability. Methods. This contribution is the second to explore how variability in the line ratio can provide new diagnostic information about distributed X-rays in a massive star wind. We focus on wind integration for total line luminosities, taking account of radiative pumping and stellar occultation. While the case of a variable stellar radiation field was explored in the first paper, the effects of wind variability are emphasized in this work. Results. We formulate an expression for the ratio of line luminosities f∕i that closely resembles the classic expression for the on-the-spot result. While there are many ways to drive variability in the line ratio, we use variable mass loss as an illustrative example for wind integration, particularly since this produces no variability for the on-the-spot case. The f∕i ratio can be significantly modulated owing to evolving wind properties. The extent of the variation depends on how the timescale for the wind flow compares to the timescale over which the line emissivities change. Conclusions. While a variety of factors can ellicit variable line ratios, a time-varying mass-loss rate serves to demonstrate the range of amplitude and phased-dependent behavior in f∕i line ratios. Importantly, we evaluate how variable mass loss might bias measures of f∕i. For observational exposures that are less than the timescale of variable mass loss, biased measures (relative to the time-averaged wind) can result; if exposures are long, the f∕i ratio is reflective of the time-averaged spherical wind.

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