Determination of halogens in coal after digestion using the microwave-induced combustion technique

The microwave-induced combustion (MIC) technique was applied for coal digestion and further determination of bromide, chloride, fluoride, and iodide by ion chromatography (IC). Samples (up to 500 mg) were combusted at 2 MPa of oxygen. Combustion was complete in less than 50 s, and analytes were absorbed in water or (NH(4))(2)CO(3) solution. A reflux step was applied to improve analyte absorption. Accuracy was evaluated for Br, Cl, and F using certified reference coal and spiked samples for I. For Br, Cl, and F, the agreement was between 96 and 103% using 50 mmol L(-1) (NH(4))(2)CO(3) as the absorbing solution and 5 min of reflux. With the use of the same conditions, the recoveries for I were better than 97%. Br, Cl, and I were also determined in MIC digests by inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, and F was determined by an ion-selective electrode with agreement better than 95% to the values obtained using IC. Temperature during combustion was higher than 1350 degrees C, and the residual carbon content was lower than 1%. With the use of the MIC technique, up to eight samples could be processed simultaneously, and a single absorbing solution was suitable for all analytes and determination techniques (limit of detection by IC was better than 3 microg g(-1) for all halogens).     

An approach for complete molecular weight distribution calculation: Application in ethylene coordination polymerization

The objective of this article is to present an approach to ascertain the molecular weight distribution (MWD) of polymeric systems and its application to an industrial polyethylene reactor. Ascertaining the complete MWD can provide more reliable predictions of polymer end‐use properties, as some of them may depend on specific molecular weight ranges, instead of solely on the averages of the distribution. The proposed method is based on differentiation of the cumulative MWD, where the accumulated concentrations, evaluated at a finite number of chain lengths, are considered components in a reaction medium. Therefore, the dimension of the mathematical model may be suited to the desired level of detail on the MWD. The ethylene polymerization in solution with Ziegler–Natta catalyst is taken as a case study because of the lack of studies in this field. The reaction takes place in continuously stirred and tubular reactors. The results show the potential of the proposed approach and its usefulness in ascertaining the whole MWD, which in turn can be used to predict the polymer end‐use properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Probiotic beverage from cashew apple juice fermented with Lactobacillus casei

This study optimized the conditions of Lactobacillus casei NRRL B-442 cultivation in cashew apple juice, as well as, determined the proper inoculum amount and fermentation time. Moreover, it was investigated the survivability ability of L. casei in cashew apple juice during refrigerated storage (4 °C) for 42 days. The optimum conditions for probiotic cashew apple juice production were initial pH 6.4, fermentation temperature of 30 °C, inoculation level of 7.48 Log CFU/mL (L. casei) and 16 h of fermentation process. It was observed that the L. casei grew during the refrigerated storage. Viable cell counts were higher than 8.00 Log CFU/mL throughout the storage period (42 days). The values of lightness, yellowness and total color change increased and the values of redness reduced along the fermentation and refrigerated storage periods. The fermented juice with L. casei is a good and healthy alternative functional food containing probiotics. Cashew apple juice showed to be as efficient as dairy products for L. casei growth.     

Cinnamon essential oil and cinnamaldehyde in the control of bacterial biofilms formed on stainless steel surfaces

The antibacterial effects of Cinnamomum cassia essential oil (EO) and cinnamaldehyde were evaluated against single- and mixed-species cultivation of enteropathogenic Escherichia coli (EPEC) and Listeria monocytogenes attached to stainless steel. A central composite rotational design with two variables and eleven assays was used to optimize the concentrations (0.00–1.00% v/v for the EO and 0.00–0.80% v/v for cinnamaldehyde) and contact times (1–21 min). The models generated were validated, and the effectiveness of C. cassia EO and cinnamaldehyde was compared with that of commercially available chemical sanitizers. Cinnamaldehyde and C. cassia EO proved to be efficient alternatives to commercial chemical sanitizers in the reduction or elimination of sessile bacterial cells. The activity of these natural compounds was, in most cases, equivalent or superior to that of the chemical sanitizers tested. However, L. monocytogenes was more resistant than EPEC to C. cassia EO and cinnamaldehyde, and the bacterial association in mixed-species biofilms made them more susceptible to these compounds.     

NMR investigation of the behavior of an organothiophosphate pesticide, methyl parathion, sorbed on clays

The decomposition of methyl parathion (an organothiophosphate pesticide) sorbed on partially hydrated kaolin and montmorillonite clays (in Ca2+, Cu2+, Zn2+, and Al3+ forms) at high concentration (typically 1-10 wt %) has been examined by nuclear magnetic resonance (NMR), using solid-state 31P NMR (based on magic-angle spinning and cross polarization or direct polarization) and liquid-state 31P NMR of DMSO and acetone extracts. The results indicate that methyl parathion is initially physisorbed, appearing by solid-state 31P NMR to exhibit substantial molecular-level motion. The signals due to unreacted methyl parathion diminish and are replaced by new 31P NMR peaks resulting from hydrolysis, isomerization, and oxidation reactions over periods ranging from hours to years. 31P NMR characteristics indicate that these decomposition products are much more tightly bound to the clay than is methyl parathion. Methyl parathion decomposition is most effectively catalyzed by partially hydrated Cu(II)- and Al-montmorillonites (but with different product distributions); Ca-montmorillonite and kaolin were least effective.     

NMR investigation of the behavior of an organothiophosphate pesticide, chlorpyrifos, sorbed on montmorillonite clays

Phosphorus-31 nuclear magnetic resonance (31P NMR) was used to explore the decomposition of chlorpyrifos (an organothiophosphate pesticide) sorbed at high concentration (typically 2-10 wt %) on partially hydrated montmorillonite clays in four different cation-exchanged forms (Ca2+, Cu2+, Zn2+, and Al3+). Solid-state 31P NMR (using magic-angle spinning and cross polarization or direct polarization) and liquid-solution 31P NMR of DMSO and acetone extracts indicate that chlorpyrifos is initially physisorbed, appearing by solid-state 31P NMR to exhibit significant motion on the molecular level, which results in almost liquidlike solid-state spectra. Over periods ranging from hours to years, the signals due to unreacted chlorpyrifos diminish and are replaced by new 31P NMR peaks resulting from hydrolysis, isomerization, mineralization, and oxidation reactions. The 31P NMR signal characteristics indicate that these decomposition products are much more tightly bound to the clay than is chlorpyrifos. Partially hydrated Cu(II)- and Al-montmorillonites most effectively catalyzed chlorpyrifos decomposition (but with different product distributions); Ca-montmorillonites (and, as previously shown, kaolin) were least effective. Solid-state 13C and 27Al NMR spectra were less useful for following the decomposition of chlorpyrifos than those obtained by 31P NMR. Pesticide loading levels (1-10% w/w) that are very much higher than those typically found in the environment were used to facilitate 31P NMR detection of less-than-dominant decomposition species.     

Effects of feeding rations with genetically modified whole cottonseed to lactating Holstein cows

Two experiments were conducted to evaluate dry matter intake (DMI), milk yield, and milk composition from feeding rations that contained different sources of genetically modified whole cottonseed to Argentinean Holstein dairy cows. Twenty-four lactating multiparous Argentinean Holstein dairy cows were used in 2 experiments with a replicated 4 x 4 Latin square design, with cows averaging 565 kg body weight and 53 d in milk at the beginning of the experiments. Treatments in Experiment 1 were: Bollgard cotton containing the cry1Ac gene, Bollgard II cotton containing cry1Ac and cry2Ab genes, Roundup Ready cotton containing the cp4 epsps gene, and a control nongenetically modified but genetically similar cottonseed. In Experiment 2, two commercial sources, a parental control line, and the transgenic cotton containing both cry1Ac and cp4 epsps genes were used as treatments. All cows received the same total mixed ration but with different whole cottonseed sources. Cottonseed was included to provide 2.50 kg per cow daily (dry matter [DM] basis) or about 10% of the total diet DM. The ingredient composition of the total mixed ration was 32% alfalfa hay, 28% corn silage, 22% corn grain, 17% soybean meal, and 2% minerals and vitamins. In addition, genomic DNA was extracted from a subset of milk samples and analyzed by polymerase chain reaction followed by Southern blot hybridization for small fragments of the cry1Ac transgene and an endogenous cotton gene, acp1. No sample was positive for transgenic or plant DNA fragments at the limits of detection for the assays following detailed data evaluation criteria. The DMI, milk yield, milk composition, body weight, and body condition score did not differ among treatments. Cottonseed from genetically modified varieties used in these studies yielded similar performance in lactating dairy cows when compared to non-transgenic control and reference cottonseed.     

Raman active E2 modes in aluminum nitride films

The vibrational spectrum of AlN thin films has been studied in recent years by theoretical and experimental methods, but there is still a lack of full knowledge of the Raman shift of the active E₂ modes of this material. Early work by Carlone et al. [1] has indicated that the E₂ modes of AlN deposited on Si occur at frequencies of 303cm^-1 and 426cm^-1. In the present study, Raman spectra of AlN deposited by magnetron sputtering on polished Si, quartz and BK7 substrates and also the Raman spectrum of pure Si, were compared to show that these peaks can actually be assigned as Raman peaks of Si, instead of AlN Raman peaks. We show that the Raman lines at 240cm^-1 and 650cm^-1 are the true AlN E₂ Raman peaks in agreement with calculated and experimental works reported in the literature that indicate the occurrence of the low and high E₂ Raman modes of AlN in the ranges (228-252)cm^-1 and (631-665)cm^-1, respectively.     

Usability of a telehealth solution based on TV interaction for the elderly: the VITASENIOR-MT case study

Universal Access in the Information Society - Remote monitoring of biometric data in the elderly population is an important asset for improving the quality of life and level of independence of...     

Front-of-package nutrition labeling as a driver for healthier food choices: Lessons learned and future perspectives

This work aims to provide a comprehensive overview of the use of front-of-package nutritional labeling (FOPL), identify and characterize the major existing FOPL systems, examine the impact of FOPL systems on consumer behavior, and discuss future perspectives. The searched databases were PubMed, Scopus, and Web of Science, and papers in English, Portuguese, Spanish, and French were considered. The integrative review method was used, comprising 68 papers. The FOPL system from more than 47 countries from North America, South America, Africa, Europe, Australia, and Asia was included in this study. The two main ways to characterize FOPL are the level of interpretation and the type of information provided. Interpretive schemes (such as warning labels, multiple traffic lights, and Nutri-Score) appear to lead to better consumer understanding and support healthier food purchases. However, due to the differences among the results and the specificity of the contexts in which they are used, it is impossible to define one FOPL interpretation scheme superior to the others. Some potential factors that influence the effectiveness of FOPL on consumer attitudes have been identified, such as food taste, as a major intrinsic factor. Extrinsic factors, such as price, food category, cultural diversity, politics, and economics, were also relevant. The lack of availability of similar alternatives, lack of understanding of the importance of FOPL, and lower levels of income and education were also some cognitive and social aspects impairing FOPL effectiveness. Prospects for the United States, Europe, Brazil, Colombia, and Argentina were discussed.