A comparison of landfill leachates based on waste composition.

Samples of leachate were collected from fourteen landfills in the state of Florida, United States that contained primarily putrescible waste (municipal solid waste, MSW, and yard waste), MSW incinerator (MSWI) ash, or a combination of both. Assessment of leachates included trace metals, anions, and nutrients in order to create a mass balance of total dissolved solids (TDS). As expected from previously literature, MSW leached a complex matrix of contaminants while MSWI ash leachate TDS was more than 98% metallic salts. The pH of the MSWI ash leachate samples was slightly acidic or neutral in character, which is contradictory to the results commonly reported in the literature. The cause of this is hypothesized to be a short-circuiting of rainfall in the landfill due to low hydraulic conductivities reported in ash landfills. The difference in pH likely contributed to the findings with respect to MSWI ash-characteristic trace metals in leachates such as aluminum. The authors have concluded that the research findings in this study are an indication of the differences between laboratory leachate quality studies and the conditions encountered in the field. In addition, a characterization of organic matter using qualitative and quantitative analyses determined that COD is not an accurate indicator of organic matter in leachates from landfills with a significant fraction of MSWI ash.

A Capacitance-Based Sensor for Hemodialysis Cannulation Training: A Proof-of-Concept Study.

In this work, we present a novel capacitance-based sensor for teaching hemodialysis cannulation skills. Initial results from a pilot experiment suggest that data from the sensor could be used to indicate puncture events in tissue-like materials.

Analysis of black writing ink by electrospray ionization mass spectrometry.

A method for the analysis of dyes and vehicles within writing inks was developed. The method was tested on a set of 18 black ink pens comprised of 6 ballpoint, 6 gel, and 6 rollerball pens. The sampling procedure utilized a small number of ink-coated paper fibers collected surreptitiously from the document, causing minimal damage and providing a sufficient quantity of ink for analysis. Methanol proved suitable for the extraction of ink components from ballpoint, gel and rollerball pens. Three separate electrospray ionisation-mass spectrometry (ESI-MS) methods were required to detect the dyes and vehicles from the inks. The ions present in the ESI-MS spectra at a signal-to-noise ratio of greater than 3:1 provided sufficient information to allow differentiation between the inks of each type. A tentative identification of the ink components was made based on a comparison of the ions present in the ink extract ESI-MS spectra with the ions present in a series of standards. The limits of detection for the standards were generally in the 2.5-10 ppm range. The method reported here extends the ESI-MS method of ink analysis to include gel and rollerball pens, includes the analysis of vehicles as well as dyes in the inks and demonstrates a minimally destructive sampling method that does not require a "biopsy" of the document.

In-depth mental health evaluation of a community sample of nonreferred infants with feeding difficulties.

OBJECTIVE: Evaluate the clinical characteristics of feeding difficulties in 30 community (i.e., nonreferred) infants in the first 2 years of life, and their correlation with mother/child interactions. METHOD: An "in depth" mental health evaluation of feeding difficulties, and the psychosocial functioning of the child in other areas. The mother-infant relationship and the feeding interactions were also assessed. RESULTS: Four "groups" were identified. (1) Young infant with difficulties in regulating states and sucking. (2) Older infant with difficulties in self-regulation, focusing, hyper-alert, and with aversion to feeding. (3) Older infants hypersensitive to stimuli (taste, odor) and with difficulties in chewing. (4) Group of with varied and unique feeding problems (pica, rumination). CONCLUSION: Feeding problems tend to have patterns according to the age of the baby in a nonreferred sample. They are not associated with an altered parent-infant relationship nor poor feeding technique. Parents often adapt successfully to the uniqueness of the baby to maintain weight gain.