Tools for moulding � Ejector sleeves with cylindrical head � Basic series for general purposes

The same fuel-rich, premixed, conical, methane–oxygen flame at 2200 K and atmospheric pressure used for studies of Fe, Co, Ni, Cu, and Zn in Part I (1) is doped with the same concentration (~1 ppm) of Sc, Ti, V, Cr, and Mn to complete the first row of ten transition metals. Metallic ions of these metals and their compounds formed by chemical ionization reactions with H3O+ are observed by sampling the flame through a nozzle into a quadrupole mass spectrometer. Concentration profiles of individual and total cations are measured as a function of distance along the flame axis, and also mass spectra at a fixed point in the burnt gas. If A is the metal atom, the observed ions can be represented by four hydrate series including (a) A+•nH2O, (b) AOH+•nH2O, (c) AO+•nH2O, and (d) AO2H+•nH2O with n = 0–3 or 4, giving a maximum of four ligands around the metal atom. However, alternative isomeric structures are possible for each of the four basic series (e.g. AO+•2H2O ~ A(OH)2+•H2O ~ A(OH)3H+). The ions observed with Cr and Mn, in common with those of Fe, Co, Ni, and Cu, strongly favour series (a). On the other hand, Sc is completely different; the ions of series (c) are dominant. All four series are observed with each of Ti and V. Series (b) dominates for Ti and series (c) for V; ions from series (d) were observed for the first time. The ion chemistry of these metals is discussed in detail with emphasis on the probable chemical ionization reactions responsible for metallic ion formation. The pre-eminent role of proton transfer processes is apparent.

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Risk Factors Associated with Failure to Receive Vaccinations

PEDIATRICS ◽

10.1542/peds.64.3.304 ◽

1979 ◽

Vol 64 (3) ◽

pp. 304-309 ◽

Cited By ~ 2

Author(s):

James S. Marks ◽

Thomas J. Halpin ◽

John J. Irvin ◽

Deane A. Johnson ◽

John R. Keller

Keyword(s):

Socioeconomic Status ◽

Family Size ◽

Parental Education ◽

Maternal Education ◽

Oral Polio Vaccine ◽

Health Department ◽

Major Purpose ◽

Factors Associated ◽

Basic Series ◽

To Receive

A major purpose of a state-wide survey to document the vaccination status of 1,003 2-year-old children was to identify factors associated with failure to receive the recommended vaccinations. With a basic series of immunization defined as three doses of diphtheriatetanus-pertussis (DTP), three oral polio vaccine (OPV), one measles, and one rubella, 72.5% of the children had completed the series. When the completed series was redefined to include a fourth DTP and mumps vaccine the rate of completion dropped to 40.8%. However, 59.1% of the children who had not completed this optimal series could be brought up-to-date with a single visit to their provider of medical care. Demographic variables independently associated with completion of the basic series were increased paternal education (P < .001), increased maternal education (P < .02), smaller family size (P < .01) and higher socioeconomic status, as determined by census tract or rural town of residence (P < .02). Race was not found to be a factor associated with vaccination rates when socioeconomic status was controlled. Patients who received their vaccinations from private physicians had a better vaccination rate than those who attended health department clinics. This difference persisted even when socioeconomic status was controlled by residence (P < .02). The simultaneous comparison of parental education and family size demonstrated that a child having one parent with < 12 years education or having at least three siblings has a fourfold greater risk of failure to complete his immunization than children whose parents are both college graduates. By using paternal and maternal education level and family size as screening variables, children at high risk for failure to complete their immunizations could be identified prospectively and made the target of intervention programs to improve compliance.

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