Model of an openable Faraday-effect hybrid-current optical transducer based on a square-shaped structure with internal mirror

A new type of clamp-on magneto-optical current transducer based on the Faraday effect is presented. It is openable, hybrid, and square-shaped, and it has an internal mirror that allows the current sensitivity to improve and the effects of the optical activity and temperature-dependent linear birefringence to be rejected. The design and the simulated behavior of the proposed device are described and compared with the conventional (no mirror) transducer.     

Characterization of aquatic groundwater colloids by a laser-induced breakdown detection and ICP-MS combined with an asymmetric flow field-flow fractionation

This study investigated the characteristics of natural groundwater colloids by a laser-induced breakdown detection (LIBD) and inductively-coupled plasma mass spectrometry (ICP-MS) in a combination with an asymmetrical flow field-flow fractionation (AsymFFFF). The groundwater was sampled from a borehole in the Yuseong area of Daejeon, Korea at different geological depths from 30 to 460 m and its geochemical parameters were measured. The combination of AsymFFFF and LIBD revealed a heterogeneous size fraction with a relatively broad size distribution of the groundwater colloids. One of the size fractions of the groundwater colloids was about 20 nm up to smaller than 100 nm, and the other fractions were larger than 100 nm. The elemental composition of the groundwater colloids was also analyzed by the AsymFFFF coupled with an ICP-MS. Results from the ICP-MS coupled with the AsymFFFF provided us with information about the size-specific elemental composition. The smaller sized fractions mainly consisted of calcite colloids with strontium, whereas the larger fractions were comprised of colloids such as aluminosilicates and iron oxides. The observations of all the groundwater samples indicate a similar pattern for the colloid fractions in size and in element composition except in the concentration.     

Hydrido‐Cobalt Catalyst as a Selective Tool for the Dimerisation of Arylacetylenes: Scope and Theoretical Studies

A simple hydrido‐cobalt complex efficiently catalyses the highly regio‐ and stereoselective dimerisation of various terminal arylacetylenes under mild conditions. The corresponding (E)‐1,4‐enynes are obtained as sole isomers with good to excellent yields. DFT calculations revealed that the reaction proceeds via a C H activation/hydrocobaltation pathway.

     

Investigation into the sequential application of cationic/anionic fixing agents to improve the oxidative washing resistance of CI Leuco Sulphur Black 1‐dyed cotton fabric

Sulphur‐dyed cellulosic textiles are susceptible to washing powders containing activated peracid formulations resulting in obvious fading during repeated laundering. This study presents a novel one‐bath/two‐stage exhaust finishing process to improve the oxidative wash fastness of CI Leuco Sulphur Black 1‐dyed cotton fabric. The effect of the combined Tinofix ECO and Bayprotect Cl after‐treatment was to impart better colour fastness to oxidative International Organisation for Standardisation (ISO) 105 CO9 washing of the dyed cotton compared with those dyed fabrics after‐treated with Tinofix ECO alone. In addition, while the dyed fabrics rub and light fastness performances were unchanged by the after‐treatments, some improvement in the tensile strength of the combined Tinofix ECO and Bayprotect Cl after‐treated fabrics was observed.     

Ribbon-like Foldamers for Cellular Uptake and Drug Delivery

Different intracellular delivery systems of bioactive compounds have been developed, including cell-penetrating peptides. Although usually nontoxic and biocompatible, these vectors share some of the general drawbacks of peptides, notably low bioavailability and susceptibility to protease degradation, that limit their use. Herein, the conversion of short peptide sequences into poly-α-amino-γ-lactam foldamers that adopt a ribbon-like structure is investigated. This template is used to distribute critical cationic and/or hydrophobic groups on both sides of the backbone, leading to potent short, cell-permeable foldamers with a low positive-charge content. The lead compound showed dramatically improved protease resistance and was able to efficiently deliver a biologically relevant cargo inside cells. This study provided a simple strategy to convert short peptide sequences into efficient protease-resistant cell-penetrating foldamers.     

Some mechanistic aspects of a nickel-catalyzed electrochemical cross-coupling between aryl halides and substituted chloropyridazines

The nickel-2,2′-bipyridine catalyzed electrochemical cross-coupling reaction between an aryl halide and a chloropyridazine was investigated by an electrochemical study. The electrochemical behavior of the divalent nickel complex is affected by the presence of pyridazine rings which act as co-ligands of nickel. Cyclic voltammetry indicates that the cross-coupling reaction involves first a rapid oxidative addition of the chloropyridazine on the electrogenerated zerovalent nickel complex. The coupling product is then obtained by reaction with the aryl halide.     

Use of a predictive model for food insecurity estimates in Brazil

In 2004 the National Household Survey (Pesquisa Nacional por Amostras de Domicilios-PNAD) estimated the prevalence of food and nutrition insecurity in Brazil. However, PNAD data cannot be disaggregated at the municipal level. The objective of this study was to build a statistical model to predict severe food insecurity for Brazilian municipalities based on the PNAD dataset. Exclusion criteria were: incomplete food security data (19.30%); informants younger than 18 years old (0.07%); collective households (0.05%); households headed by indigenous persons (0.19%). The modeling was carried out in three stages, beginning with the selection of variables related to food insecurity using univariate logistic regression. The variables chosen to construct the municipal estimates were selected from those included in PNAD as well as the 2000 Census. Multivariate logistic regression was then initiated, removing the non-significant variables with odds ratios adjusted by multiple logistic regression. The Wald Test was applied to check the significance of the coefficients in the logistic equation. The final model included the variables: per capita income; years of schooling; race and gender of the household head; urban or rural residence; access to public water supply; presence of children; total number of household inhabitants and state of residence. The adequacy of the model was tested using the Hosmer-Lemeshow test (p = 0.561) and ROC curve (area = 0.823). Tests indicated that the model has strong predictive power and can be used to determine household food insecurity in Brazilian municipalities, suggesting that similar predictive models may be useful tools in other Latin American countries.     

Contribution to the clarification of surface water from the Moringa oleifera: Case M’Poko River to Bangui,Central African Republic

Moringa seeds can be effective in the treatment of water because they contain a cationic electrolyte. They can then replace the sulfate of alumina or other flocculants. In this study, we opted for the clarification of surface water from the river M’Poko using seeds of Moringa oleifera dried and transformed into powder. In the literature, we can find very different quantities of seeds used. We have used a method of experimental design to optimize the treatment of our samples of raw water with the seeds of Moringa. The experimental design used is a full factorial design that determines the importance of various factors and also the relationship between these factors so as to identify the best conditions to meet the target set by this study, which is to clarify a maximum quantity of raw water from the river. Another problem, met in the use of Moringa, is the important contribution of organic matter in the water treated by this natural coagulant. To avoid a bacterial proliferation, in time, in the water so treated, we used sand/coal filtration, which proved to be very effective. The water, treated by Moringa and filtered, possesses turbidity and a quantity of organic matter corresponding to the required standards. Such water can thus, be disinfected by chlorination for human consumption.     

Constraint Techniques for Authoring Multimedia Documents

Authoring a multimedia document requires to specify both its spatial layout and its temporal organization, i.e. when and where objects such as pictures, texts and videos appear/disappear on /from the screen and when objects such as audios and videos start/end to play. In this paper, we present some benefits authors can gain when using an authoring tool in which constraints are used to specify these two kinds of information. We describe our experience in building Madeus, a constraint-based environment to design multimedia documents and we point out technical problems that still need to be solved to more completely satisfy author requirements.