MCS: Strategies for Individuals

There are several strategies that can be adopted so that you can return to normal health as soon as possible if you have MCS (Multiple Chemical Sensitivity

MCS: Materials to Avoid

Volatile organic compounds (VOCs) are compounds that vaporize or become a gas at room temperature (EPA 2003). These compounds may be natural or synthetic (Godish 2001) and may include formaldehyde, pesticides, and solvents. VOCs and other chemicals such as petrochemicals affect indoor air quality and can be found in many products and materials used every day. For this reason, it is important to know the sources of indoor air contaminants and avoid them if you or someone in your family suffers from MCS (Multiple Chemical Sensitivity)

MCS: Types of Housing

Our homes should be a retreat from the hustle and bustle of the daily routine, but for many individuals, their homes are potentially dangerous. Many interior materials and products that are used every day emit chemicals into the air and affect the indoor air quality (IAQ). One reason for this problem is that we spend more time indoors within airtight buildings. Another is that our energy-efficient houses do not allow gases emitted from products to escape from the building. Thus, more of us are at risk of developing multiple chemical sensitivity (MCS) because we spend the greatest amount of our time indoors in our airtight, energy efficient houses (EPA 1994, Pilatowicz 1995)

Multiple Chemical Sensitivity (MCS)

MCS affects many individuals, and the number of people suffering from MCS is on the increase. It is not a new illness. It has been a problem since the 1940s when people began experiencing health problems and becoming ill from poor indoor air quality

MCS: Interior Finishes

For individuals with Multiple Chemical Sensitivity (MCS), selecting safe, healthy materials or products to furnish a home can be a challenge. Many materials that are labeled as environmentally friendly may not promote good indoor air quality (IAQ) (Wasley 2000). For example, an environmentally friendly product may be produced from recycled materials to conserve resources, but this same product may be glued togther with formaldehyde-based resins—unsafe for persons with MCS. Consequently, materials must be analyzed before they are selected. There are safe, healthy interior materials or products for you to use in furnishing your home. You just have to do your homework before buying

Modeling RR Tel through the Evolution of the Spectra

We investigate the evolution of RR Tel after the outburst by fitting the emission spectra in two epochs. The first one (1978) is characterized by large fluctuations in the light curve and the second one (1993) by the slow fading trend. In the frame of a colliding wind model two shocks are present: the reverse shock propagates in the direction of the white dwarf and the other one expands towards or beyond the giant. The results of our modeling show that in 1993 the expanding shock has overcome the system and is propagating in the nearby ISM. The large fluctuations observed in the 1978 light curve result from line intensity rather than from continuum variation. These variations are explained by fragmentation of matter at the time of head-on collision of the winds from the two stars. A high velocity (500 km/s) wind component is revealed from the fit of the SED of the continuum in the X-ray range in 1978, but is quite unobservable in the line profiles. The geometrical thickness of the emitting clumps is the critical parameter which can explain the short time scale variabilities of the spectrum and the trend of slow line intensity decrease.Comment: 26 pages, LaTeX (including 5 Tables) + 6 PostScript figures. To appear in "The Astrophysical Journal

Silicates in D-type symbiotic stars: an ISO overview

We investigate the IR spectral features of a sample of D-type symbiotic stars. Analyzing unexploited ISO-SWS data, deriving the basic observational parameters of dust bands and comparing them with respect to those observed in other astronomical sources, we try to highlight the effect of environment on grain chemistry and physic. We find strong amorphous silicate emission bands at 10 micron and 18 micron in a large fraction of the sample. The analysis of the 10 micron band, along with a direct comparison with several astronomical sources, reveals that silicate dust in symbiotic stars shows features between the characteristic circumstellar environments and the interstellar medium. This indicates an increasing reprocessing of grains in relation to specific symbiotic behavior of the objects. A correlation between the central wavelength of the 10 and 18 micron dust bands is found. By the modeling of IR spectral lines we investigate also dust grains conditions within the shocked nebulae. Both the unusual depletion values and the high sputtering efficiency might be explained by the formation of SiO moleculae, which are known to be a very reliable shock tracer. We conclude that the signature of dust chemical disturbance due to symbiotic activity should be looked for in the outer, circumbinary, expanding shells where the environmental conditions for grain processing might be achieved. Symbiotic stars are thus attractive targets for new mid-infrared and mm observations.Comment: 24 pages, 6 figures, 5 tables - to be published in A

Illumination in symbiotic binary stars: Non-LTE photoionization models. II. Wind case

We describe a non-LTE photoionization code to calculate the wind structure and emergent spectrum of a red giant wind illuminated by the hot component of a symbiotic binary system. We consider spherically symmetric winds with several different velocity and temperature laws and derive predicted line fluxes as a function of the red giant mass loss rate, \mdot. Our models generally match observations of the symbiotic stars EG And and AG Peg for \mdot about 10^{-8} \msunyr to 10^{-7} \msunyr. The optically thick cross- section of the red giant wind as viewed from the hot component is a crucial parameter in these models. Winds with cross-sections of 2--3 red giant radii reproduce the observed fluxes, because the wind density is then high, about 10^9 cm^{-3}. Our models favor winds with acceleration regions that either lie far from the red giant photosphere or extend for 2--3 red giant radii.Comment: 51 pages, LaTeX including three tables, requires 15 Encapsulated Postscript figures, to appear in Ap

Multiwavelength evidence for a 15-year periodic activity in the symbiotic nova V1016 Cygni

The ~15.1 years period found in the long-term UBV photoelectric and photographic photometry of the symbiotic nova V1016 Cyg is detected also in the (J-K) colour index and in the UV continuum and emission line fluxes from IUE and HUT spectra. It could be interpreted either as the effect of recurrent enhanced mass loss episodes from the Mira type variable companion to a hot component along its ultra-wide orbit (proposed from recent HST observations) or the true orbital period of the inner, unresolved binary of a triple system. A 410-day delay of the maximum of UV emission lines fluxes with respect to the maximum of continuum was found. The pulsation period of the Mira type variable was improved to 474+/-6 days.Comment: 7 pages, 7 PostScript figures. Accepted for pubblication in A&