|
|
|
Combination of mid- and near-infrared spectroscopy for the [An article from: Analytica Chimica Acta]
This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The combination of infrared (MIR) and near-infrared (NIR) spectroscopy has been employed for the determination of important quality parameters of beers, such as original and real extract and alcohol content. A population of 43 samples obtained from the Spanish market and including different types of beer, was evaluated. For each technique, spectra were obtained in triplicate. In the case of NIR a 1mm pathlength quartz flow cell was used, whereas attenuated total reflectance measurements were used in MIR. Cluster hierarchical analysis was employed to select calibration and validation data sets. The calibration set was composed of 15 samples, thus leaving 28 for validation. A critical evaluation of the prediction capability of multivariate methods established from the combination of NIR and MIR spectra was made. Partial least squares (PLS) and artificial neural networks (ANN) were evaluated for the treatment of data obtained in each individual technique and the combination of both. Different parameters of each methodology were optimized. A slightly better predictive performance was obtained for NIR-MIR combined spectra, and in all the cases ANN performs better than PLS, which may be interpreted from the existence of some non-linearity in the data. The root-mean-sqare-error of prediction (RMSEP) values obtained for the combined NIR-MIR spectra for the determination of real extract, original extract and ethanol were 0.076% w/w, 0.14% w/w and 0.091% v/v. .
Price: $10.95
[ Notify me when price goes down.]
|
|
Reducing the risks of children living near the site of a former lead smeltery [An article from: Science of the Total Environment, The]
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The sources of lead exposure, soil, household dust, diet and ambient air near a former lead smeltery were studied. The blood lead level of small children was also determined. The aim of the study was to define, based primarily on blood lead measurements, whether children living in the contaminated area may be at risk. Within 500 m from the site of the smeltery, there were several areas where the Finnish limit value for soil Pb, i.e. 300 mg/kg, was exceeded. In the recently built areas, the surface soil has been replaced and soil remediation has taken place in schoolyards and the playgrounds of children's day-care centres. Lead content in household dust was clearly elevated in the contaminated areas. In approximately 20 years, after the smeltery was closed in 1984, the lead concentrations of the fruits and berries in local gardens have decreased to one-tenth. In some samples, the limit values are still exceeded. The lead concentration in ambient air is now 50 times lower than in the 1970s. The blood lead level of the children living in the area is slightly but statistically significantly higher than that of the children in the control areas. The critical blood lead level, i.e. 10 @mg/100 ml, was not exceeded in any of the children examined. The average and maximum lead concentrations of 63 analysed blood samples were 2.2 and 5 @mg/100 ml, respectively. In contrast, the average and maximum blood lead levels of school children in 1981 were 6.7 and 13.0 @mg/100 ml, respectively. The risk reduction measures undertaken during the past 20 years are described. .
Price: $8.95
[ Notify me when price goes down.]
|
|
Air travel nears pre-9/11 totals at Lindbergh field: Chick-fil-A Inc. setting up shop in San Diego.(Tourism): An article from: San Diego Business Journal
This digital document is an article from San Diego Business Journal, published by CBJ, L.P. on May 10, 2004. The length of the article is 452 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation DetailsTitle: Air travel nears pre-9/11 totals at Lindbergh field: Chick-fil-A Inc. setting up shop in San Diego.(Tourism) Author: Connie Lewis Publication:San Diego Business Journal (Magazine/Journal) Date: May 10, 2004 Publisher: CBJ, L.P. Volume: 25 Issue: 19 Page: 6(1) Distributed by Thomson Gale.
Price: $5.95
[ Notify me when price goes down.]
|
|
Cadmium exposure pathways in a population living near a battery plant [An article from: Science of the Total Environment, The]
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Objectives: The objectives of the present study were to assess the relative impact of different pathways of environmental cadmium (Cd) exposure and to evaluate the contribution from locally produced vegetables and root crops to the total dietary intake of Cd. Methods: Cadmium in urine was determined for 492 individuals living near a closed down battery factory in Sweden. For each individual we created an environmental exposure-index based on Cd emissions to ambient air and number of years living at various distances from the plant. This information as well as dietary data were collected via questionnaires. Samples of soil, carrots and/or potatoes were collected from 37 gardens and analysed for Cd concentration. Results: Eating homegrown vegetables/potatoes, environmental Cd-exposure-index, female gender, age above 30 years and smoking more than one pack of cigarettes daily for at least 10 years were found to be significantly associated with increased urine concentrations of Cd (UCd>1.0 nmol/mmol creatinine). We found a statistically significant relation between Cd in urine and environmental Cd-exposure-index in persons eating homegrown vegetables/potatoes regularly. Cd concentrations in homegrown carrots, potatoes and in garden soil were highest in the area closest to the factory. Daily consumption of potatoes and vegetables cultivated in the vicinity of the closed battery factory was estimated to increase Cd intake by 18-38%. Conclusion: The present study shows that consumption of locally grown vegetables and root crops was an important exposure pathway, in subjects living near a nickel-cadmium battery plant, whereas direct exposure via ambient air was less important. .
Price: $10.95
[ Notify me when price goes down.]
|
|
Distribution and mobility of chromium, copper, and arsenic in soils collected near CCA-treated wood structures in Korea [An article from: Science of the Total Environment, The]
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Chromated copper arsenate (CCA) is currently the most commonly used wood preservative in Korea. Questions, however, have been raised regarding the potential environmental impacts of metal leaching from CCA-treated wood to soil. Although a number of researchers from other countries have reported that chromium, copper, and arsenic do leach from CCA-treated wood over time, to date few field studies have been performed on those metals in soils adjacent to CCA-treated wood structures in Korea. The present study was conducted to determine the lateral and vertical distributions and accumulation of chromium, copper, and arsenic in soils collected from CCA-treated wood structures. A total of fifty-five composite soil samples were collected from four CCA-treated wood structures of approximately one year in age. The samples were analyzed for physicochemical properties as well as for the total chromium, copper, and arsenic concentrations. The chromium, copper, and arsenic concentrations in soil samples adjacent to the structures were as high as 79.0, 98.9, and 128 mg/kg, respectively, compared to background soil samples (48.2, 26.9, and 6.27 mg/kg, respectively). Arsenic was more mobile in soil than chromium and copper. The concentration gradient of arsenic in soil was observed only to the depth of approximately 5 cm in one year of outdoor exposure, whereas chromium and copper apparently remained near the surface (approximately less than 1 cm) after their release. Future efforts should be made to observe seasonal impacts on the release of metals and incorporate metal speciation into determining more detailed mobility and distribution. .
Price: $10.95
[ Notify me when price goes down.]
|
|
Lead fluxes, isotopic and concentration profiles in a peat deposit near a lead smelter (Pribram, Czech Republic) [An article from: Science of the Total Environment, The]
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The content and the isotopic composition of lead (Pb) were studied in a peat deposit on the ridge of the Brdy Hills, in the vicinity of the Pribram metallurgical works, in the Czech Republic. Quadrupole ICP MS was employed to determine the elemental composition and ^2^0^6Pb/^2^0^7Pb and ^2^0^8Pb/^2^0^6Pb isotope ratios. The individual layers were dated using @a spectrometric measurement of the ^2^1^0Pb activity. The historical time period covered by the studied cores reached back to the 18th century. The Pb concentration in the studied profiles varied from 10 to 550 mg kg^-^1. The ^2^0^6Pb/^2^0^7Pb ratio varied in the range from 1.154 to 1.194 in the individual parts of the profile. The metallurgy of the Pb ores (^2^0^6Pb/^2^0^7Pb~1.16), lithogenic Pb (^2^0^6Pb/^2^0^7Pb~1.2), metallurgical processing of automobile batteries (^2^0^6Pb/^2^0^7Pb~1.17) and the combustion of coal (^2^0^6Pb/^2^0^7Pb~1.17-1.19) yield isotopic signatures that determine the isotope compositions of the individual profiles. Deposition rates between 15 mg m^-^2 year^-^1 at the beginning of the 19th century and 320 mg m^-^2 year^-^1 in the 1980s were determined in the dated profiles. The increased deposition rates determined on the dated profiles correspond to the increasing production of Pb ores in the Pribram mining area at the turn of the 19th and 20th centuries. The maximum for metallurgical production corresponds to the highest deposition rates recorded in 1960s and 1970s. The current deposition rate of 5-89 mg m^-^2 year^-^1 Pb is related to erosion of contaminated soils and waste dumps. .
Price: $10.95
[ Notify me when price goes down.]
|
|
Extremely-low-frequency magnetic field exposure of children at schools near high voltage transmission lines [An article from: Science of the Total Environment, The]
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Many epidemiological studies have investigated residential exposure to extremely-low-frequency magnetic field (ELF-MF) for children, but exposure at schools where children may stay up to 8 h every weekday was rarely considered. Between March and June 2004, we carried out a field study in Taipei City and County of northern Taiwan to explore ELF-MF exposure pattern among children at schools with high voltage transmission lines (HVTL) running through the campuses. One hundred and one children attending 14 schools with nearby HVTL (exposed group) and 123 children of 18 schools at least 100 m away from HVTL (unexposed group) were monitored for 24-hour personal ELF-MF exposure. Selected classrooms and playgrounds within the buffer regions (i.e., within 30 m of HVTL) and those away from the buffer regions were also assessed, using spot measurements, to determine the extent to which HVTL may contribute to the environmental exposure on campuses. Results show that the two groups didn't differ significantly for both mean exposure and proportion of exposure greater than 0.4 micro-Tesla (@mT) estimated for 24 h. However, we noted that 17.8% of the exposed children had a personal mean exposure greater than 0.4 @mT during school hours, significantly (p=0.011) higher than that (6.5%) estimated for the unexposed children. An even higher percentage (27.3%) was observed for 11 students with their classrooms intersecting the buffer regions. Playgrounds near buffer regions showed a significantly higher ELF-MF than the other areas of the exposed schools (0.70 vs 0.18 @mT, p=0.043). The study demonstrates a wide range of exposures to ELF-MF among school children at campuses adjacent to HVTL. Children attending the exposed schools may have a higher chance of experiencing a mean exposure greater than 0.4 @mT during school hours. .
Price: $10.95
[ Notify me when price goes down.]
|
|
|
|
|