Influence of Polymeric Suspension Characteristics on the Particle Coating in a Spouted Bed

The influence of the coating suspensions and particle properties on the coating process in a conventional spouted bed is presented. Glass beads were coated at fixed operating conditions with different formulations of aqueous polymeric coating suspensions in a spouted bed of laboratory scale. The wettability of the solids by the liquid was quantified by the contact angle and surface tension of the coating suspensions. The coating efficiency and particle growth were correlated with the adhesion of the coating suspension to the solid particle, which is a function of the solids and liquid characteristics. The physical properties of the coated particles—particle mean diameter, sphericity, bulk, absolute and apparent densities, porosity and flow velocity—were determined and compared to the properties of uncoated particles.     

Material and social incentives to participation in behavioral interventions: A meta-analysis of gender disparities in enrollment and retention in experimental human immunodeficiency virus prevention interventions.

Objective: A meta-analysis was conducted to test theoretical hypotheses about the predictors of enrollment and completion of condom-use-promotion interventions among men and women. Design: A meta-analysis summarized research reports of the efficacy of experimental interventions on human immunodeficiency virus (HIV) prevention. Main Outcome Measures: The outcome measure consisted of (a) a measure of participation, obtained by subtracting the actual number of participants from the number of the invited people, and (b) a measure of retention was obtained by subtracting the number of participants who completed the intervention from the number of commencers. Results: Experimental interventions providing instrumental and financial resources (e.g., payments) increased initiation and retention more among predominantly male samples, whereas experimental interventions using group formats increased initiation and retention more among predominantly female samples. These patterns remained while controlling for past condom use, other HIV-risk behaviors, and demographics associated with gender composition. Conclusion: People seek out HIV-prevention interventions to fulfill gender-specific needs, and these differences must be taken into account in the design of HIV-prevention interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unravelling daily human mobility motifs

Human mobility is differentiated by time scales. While the mechanism for long time scales has been studied, the underlying mechanism on the daily scale is still unrevealed. Here, we uncover the mechanism responsible for the daily mobility patterns by analysing the temporal and spatial trajectories of thousands of persons as individual networks. Using the concept of motifs from network theory, we find only 17 unique networks are present in daily mobility and they follow simple rules. These networks, called here motifs, are sufficient to capture up to 90 per cent of the population in surveys and mobile phone datasets for different countries. Each individual exhibits a characteristic motif, which seems to be stable over several months. Consequently, daily human mobility can be reproduced by an analytically tractable framework for Markov chains by modelling periods of high-frequency trips followed by periods of lower activity as the key ingredient.     

First-Grade Latino English-Language Learners’ Performance on Story Problems in English Versus Spanish

Abstract

To explore whether teaching English-language learners (ELLs) with an emphasis on English story problems is appropriate, we compared the performance of a group of Latino first graders when working in Spanish and in English on two equivalent sets of story problems. The students’ performance was slightly higher in English than in Spanish but lower than monolingual students from other studies. ELLs’ success in English indicated that the children's knowledge of conversational English was sufficient to comprehend story problems, leading us to conclude that teaching through story problems is a viable approach with ELLs.     

Effects of irradiation and storage on the physico-chemical and sensory properties of hamburgers enriched with lycopene

In order to increase their safety and shelf-life, raw hamburgers containing 30, 45 and 60 g kg⁻¹ dry tomato peel (DTP) as a source of lycopene were manufactured, vacuum-packed and irradiated with 2 or 4 kGy. The effects of this treatment on microbial load, lycopene concentration, physico-chemical and sensory properties were studied during 17 days of refrigerated storage. After irradiation with 4 kGy and 17 days of storage, microbial levels fell, four logarithmic cycles and the lycopene concentration fell to 15% of the initial value. Even with this decrease, hamburgers containing 6% DTP had a final lycopene concentration of 7.14 mg per 100 g of hamburger, an amount very close to the recommended daily intake for a healthy diet. DTP masks the brownish colour characteristic of irradiated meat, and 6% DTP gives to the hamburger similar redness ( a * parameter), independently of the dose of radiation applied. Sensory characteristics were influenced by irradiation, but the higher lycopene concentration (6 g kg⁻¹) masked these changes sufficiently to assure an acceptable colour and odour in the final product after the storage period.     

Synthesis of a new tetrafunctional monomer, 1,4‐di(2‐hydroxy‐3‐methacryloyloxypropoxy)phenol,and its copolymerization

The new aromatic tetrafunctional methacrylate monomer, 1,4‐di(2‐hydroxy‐3‐methacryloyloxypropoxy) phenol, and its application for the synthesis of porous microspheres have been presented. It was copolymerized with trimethylolpropane trimethacrylate in the presence of pore‐forming diluents mixture (chlorobenzene and 1‐decanol). The results indicate that composition of diluents mixture influence porous structure of copolymers. The porous structure of the copolymer obtained in the presence of 50% chlorobenzene was studied in detail. The results show that pore volume and the most probable pore size diameters determined for the copolymer in the dry and in the wetted states are different. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The role of the Yala swamp lakes in the conservation of Lake Victoria region haplochromine cichlids: Evidence from genetic and trophic ecology studies

Lake Kanyaboli, an isolated satellite lake of Lake Victoria, has been suggested as a potential refugium for haplochromine cichlids that have gone extinct in the main basin of Lake Victoria. Mitochondrial DNA (mtDNA) molecular markers, as well as feeding ecology studies, were employed in this study to re‐evaluate the evolutionary and ecological significance of six common Lake Kanyaboli haplochromines. The mtDNA marker revealed high genetic variability within four of the six haplochromine cichlids. Five haplotypes were discerned in Astatoreochromis alluaudi (n = 27), seven in Lipochromis maxillaris (n = 29), five in Astatotilapia nubila (n = 12) and 11 in the endangered Xystichromis phytophagus (n = 205). A haplotype genealogy suggests that Lake Kanyaboli harbours mtDNA haplotypes that could have been lost or not sampled in Lake Victoria, or could have arisen in situ. Lipochromis maxillaris appears to have undergone a recent demographic expansion. The pairwise F_STs indicated that only the comparison between X. phytophagus and A. nubila led to a non‐significant F_ST value. All other comparisons were significant at the 0.01 level, indicating the genetic distinctiveness of the haplochromines in the satellite lake. This could suggest that the lake harbours ‘pure’ relict populations of the haplochromines and therefore that Lake Kanyaboli can be considered a ‘genetic reservoir’. Gut content analysis of the six haplochromine species revealed that eight different food items were consumed. No single species fed exclusively on a single food item, but certain food items contributed higher proportions of the fish diet for each fish species. Resource partitioning therefore could be discerned within this haplochromine community. Thus, Lake Kanyaboli and similar satellite lakes provide an opportunity for conservation of both genetic and trophic diversity threatened by introduction of exotics in the Lake Victoria basin. Lake Kanyaboli should be recognized and conserved as important evolutionary significant units for Lake Victoria region haplochromine species.     

Liquidus Projection of the B-Fe-U Diagram: The Boron-Rich Corner

The liquidus projection at the boron-rich corner of the B-Fe-U phase diagram is proposed based on powder X-ray diffraction measurements, heating curves, and scanning electron microscopy observations, complemented with both energy dispersive X-ray spectroscopy and electron probe microanalysis. Evidence for six ternary reactions is presented, the corresponding 12 monovariant lines are drawn, and the nature and location of the ternary reactions are given. The ternary compounds existing in this region of the B-Fe-U ternary phase diagram, UFeB₄ and UFe₂B₆, were confirmed to be formed by ternary peritectic reactions, yet UFeB₄ has a considerably larger primary crystallization field, which points to an easier preparation of single crystals of this compound, when compared with UFe₂B₆.     

Sequential hydrogen and methane production using the residual biocatalyst of biodiesel synthesis as raw material

Residual Fermented Solid (RFS) is the used biocatalyst obtained after enzymatic biodiesel production carried out applying the fermented solid (FS) with lipase activity. Approximately 350 g of RFS are generated for each liter of biodiesel produced from palm residues fermented solid. In this study, this residue was used for the first time as a raw material for biological hydrogen production through dark fermentation and sequential application of the hydrogen production liquid waste (HPLW) for methane obtainment via anaerobic digestion. The RFS was composed mostly of oils and fats (60% wt.%), and carbohydrates, such as mannose, glucose, and xylose. Hydrogen yield reached 239 ± 44 mL H₂/L after 24 h of fermentation using 31 g_RFS/L at the beginning of the process. Additionally, 204 ± 13 mL CH₄/g COD were produced through the anaerobic digestion of HPLW, which represented 61% of efficiency.