Children’s interactions with water in city centres: a case study from Sheffield,UK

Children’s experiences of outdoor environments have been studied now for more than 40 years yet no research has specifically focussed on children’s experiences of water play in constructed spaces of city centres. This article discusses the development of an observational mapping tool, called TOWEC, to record the interaction of children with water. It then reports findings and analysis from observations over a year-long period of 3,399 children interacting with water in the award winning public open space of the Peace Gardens in the centre of the City of Sheffield, UK. The findings reveal that children undertake both active and passive activities associated with the constructed water features and that these activities are influenced by gender, age and temperature, but not ethnicity. The water features were not designed for children to play in but the children realise the potential affordance that the water features provide.     

Influence of infrared final cooking on polycyclic aromatic hydrocarbon formation in ohmically pre-cooked beef meatballs

Effects of infrared cooking on polycyclic aromatic hydrocarbon (PAH) formation in ohmically pre-cooked beef meatballs were investigated. Samples were pre-cooked in a specially designed-continuous type ohmic cooking at a voltage gradient of 15.26 V/cm for 92 s. Infrared cooking was applied as a final cooking method at different combinations of heat fluxes (3.706, 5.678, 8.475 kW/m²), application distances (10.5, 13.5, 16.5 cm) and application durations (4, 8, 12 min). PAHs were analyzed by using high performance liquid chromatography (HPLC) equipped with a fluorescence detector. The total PAH levels were detected to be between 4.47 and 64 μg/kg. Benzo[a] pyrene (B[a]P) and PAH4 (sum of B[a]P, chrysene (Chr), benzo[a]anthracene (B[a]A) and benzo[b]fluoranthene (B[b]F)) levels detected in meatballs were below the EC limits. Ohmic pre-cooking followed by infrared cooking may be regarded as a safe cooking procedure of meatballs from a PAH contamination point of view.     

Novel triazole functional sol-gel derived inorganic-organic hybrid networks as anhydrous proton conducting membranes

In this work, novel inorganic-organic hybrid networks were prepared to obtain anhydrous proton conducting membranes for fuel cells. 3-glycidoxypropyl trimethoxy silane (GPTMS) was functionalized with 1H-1,2,4-triazole (Tri) and 3-aminotriazole (ATri) via ring opening of the epoxide ring and then sol-gel polymerization was performed to produce triazole containing silane networks abbreviated as Si-Tri and Si-ATri. In addition during sol-gel process trifluoromethane sulfonic acid (TA) was introduced into the matrix with several stoichometric ratios. Fourier transform infrared spectroscopy (FT-IR) confirmed the tethering of the Tri and ATri into the silane compound and the sol-gel reaction. Thermogravimetry analysis (TGA) showed that the membranes are thermally stable up to 200 °C. Differential scanning calorimeter (DSC) verified the softening effect of the dopant. The morphology of the membranes was analyzed with SEM images. The proton conductivity of these novel silane networks were studied by dielectric-impedance spectroscopy. Although proton conductivity of these membrane electrolytes depends on the acid ratio, the membrane without dopant produced a proton conductivity of 8.7 × 10⁻⁵ S/cm at 150 °C in dry state. The conductivity isotherms show Vogel-Tamman-Fulcher (VTF) behavior which implies the coupling of the charge carriers with the segmental motion of the polymer chains. A maximum proton conductivity of 8.9 × 10⁻⁴ S/cm was obtained for the sample Si-TriTA1 in the anhydrous condition.     

Proton conducting properties of ionically cross-linked poly(1-vinyl-1,2,4 triazole) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) electrolytes

The synthesis and thermal as well as proton conducting properties of complex polymer electrolytes based on poly(2-acrylamido-2-methyl-1-propanesulfonic acid) PAMPS and poly(1-vinyl-1,2,4-triazole) PVTri were investigated. The materials were produced by complexation of PAMPS with PVTri at various compositions to get PVTriP(AMPS) _x where x is the molar ratio of the polymer repeating units and varied from 0.25 to 4. The structure of the materials was confirmed by FT-IR spectroscopy. The TGA results verified that the polymer electrolytes are thermally stable up to approximately 200 °C. The DSC and SEM results demonstrated the homogeneity of the materials. The electrochemical stability of the materials was studied by cyclic voltammeter (CV). Proton conductivity, activation energy, and water/methanol uptake of these membranes were also measured. After humidification (RH = 50%), PVTriP(AMPS)₂ and PVTriP(AMPS)₄ showed proton conductivities of 0.30 and 0.06 S/cm at 100 °C, respectively.     

Isolation and identification of Treponema pedis and Treponema phagedenis-like organisms from bovine digital dermatitis lesions found in dairy cattle in Turkey

The isolation and identification of microorganisms associated with digital dermatitis (DD) in Turkish dairy cattle was investigated using punch skin biopsy samples from typical clinical lesions; they were collected from dairy farms and abattoirs in 5 different geographical locations in Turkey. Morphological characteristics and flagellation types were examined using a transmission electron microscope, and their enzyme profiles by enzyme activation kits; their catalase reaction characteristics were evaluated by the addition of 3% H₂O₂. Their phylogenies were identified using 16S rRNA and the results compared with known gene bank data. Bacterial cells were 5.0 to 18.2 µm long, 0.2 to 0.5 µm wide, and their minimum number of periplasmic flagellum was 4 (4:8:4) with a maximum of 8 (8:16:8). All isolates were catalase negative. Of the spirochetes isolated and identified, group I organisms showed close similarity with Treponema pedis (99% genetic homology), whereas those in group II were similar to Treponema phagedenis (98% homology). This is the first report of specific sub-groups of Treponema spp., isolated from Turkish dairy cattle presenting with DD lesions, being associated with this disease; these morphotypes were similar to those found globally in housed dairy cattle units and are probably significant microorganisms associated with the aetiopathogensis of this infectious disease causing acute bovine lameness. These results suggest that the distribution of DD-associated treponemes is not specific to particular geographic regions of Turkey.     

Anhydrous proton conducting membranes for PEM fuel cells based on Nafion/Azole composites

Proton conducting membranes are the most crucial part of energy generating electrochemical systems such as polymer electrolyte membrane fuel cells (PEMFCs). In this work, Nafion based proton conducting anhydrous composite membranes were prepared via two different approaches. In the first, commercial Nafion115 and Nafion112 were swelled in the concentrated solution of azoles such as 1H-1,2,4-triazole (Tri), 3-amino-1,2,4-triazole (ATri) and 5-aminotetrazole (ATet) as heterocyclic protogenic solvents. In the second, the proton conducting films were cast from the Nafion/Azole solutions. The partial protonation of azoles in the anhydrous membranes were studied by Fourier transform infrared (FT-IR) spectroscopy. Thermal properties were investigated via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA results showed that Nafion/ATri and Nafion/ATet electrolytes are thermally stable at least up to 200 °C. Methanol permeability measurements showed that the composite membranes have lower methanol permeability compared to Nafion112. Nafion115/ATri system has better conductivity at 180 °C, exceeding 10⁻³ S/cm compared to other Nafion/heterocycle systems under anhydrous conditions.     

In Situ Transformation of MOFs into Layered Double Hydroxide Embedded Metal Sulfides for Improved Electrocatalytic and Supercapacitive Performance

Direct adoption of metal‐organic frameworks (MOFs) as electrode materials shows impoverished electrochemical performance owing to low electrical conductivity and poor chemical stability. In this study, we demonstrate self‐templated pseudomorphic transformation of MOF into surface chemistry rich hollow framework that delivers highly reactive, durable, and universal electrochemically active energy conversion and storage functionalities. In situ pseudomorphic transformation of MOF‐derived hollow rhombic dodecahedron template and sulfurization of nickel cobalt layered double hydroxides (NiCo‐LDHs) lead to the construction of interlayered metal sulfides (NiCo‐LDH/Co₉S₈) system. The embedment of metal sulfide species (Co₉S₈) at the LDH intergalleries offers optimal interfacing of the hybrid constituent elements and materials stability. The hybrid NiCo‐LDH/Co₉S₈ system collectively presents an ideal porous structure, rich redox chemistry, and high electrical conductivity matrix. This leads to a significant enhancement in its complementary electrocatalytic hydrogen evolution and supercapacitive energy storage properties. This work establishes the potential of MOF derived scaffold for designing of novel class hybrid inorganic–organic functional materials for electrochemical applications and beyond.     

Effects of naloxone on beta-endorphin and cortisol release in sepsis

This study assessed sepsis-induced changes in the contents of calpain and cathepsin B in rat soleus muscle. Sepsis was induced in rats by intra-abdominally implanting fecal pellets containing Escherichia coil and Bacteroides fragilis. Intact soleus muscles were isolated from non-operated control rats, and from rats sacrificed 1 and 2 days after they were implanted with bacteria-free (sterile implanted) or bacteria-laden (septic implanted) pellets. Western blot analyses of muscle homogenates were performed to identify and quantitate these proteinases using specific antibodies. No significant differences in cathepsin B contents were observed between the septic and nonseptic animals on days 1 and 2, post-implantation. Among the three distinct bands recognized by anti-calpain, two prominent bands of 80 and 76 kDa, representing calpain subunits, did not seem to be altered in septic rats compared to the nonseptic groups. The content of the 45-kDa subunit decreased in both the septic and sterile groups compared with non-operated control. These results along with our previous observations suggest that although Gram-negative sepsis does not appear to have an effect on Ca2(+)-insensitive lysosomal cathepsin B content or activity, it upregulates the activity of the Ca2(+)-dependent calpain but not its content in the skeletal muscle during sepsis.     

How do people make a decision on bottled or tap water? Preference elicitation with nonparametric bootstrap simulations

People in the United States drink almost four times the amount of bottled water than they did 20 years ago, even though tap water supplies in the United States are considered to be among the safest in the world. To understand ‘how do people make a decision on tap or bottled water’, a consumer preferences survey was administered to the Civil and Environmental Engineering students attending a US university. The survey elicited information on participants’ preferences and real life attitude/preferences and included a multi‐criteria pairwise comparison. The pairwise comparison preferences were further analysed by integrating nonparametric bootstrap simulations to determine the underlying uncertainty. The results revealed that although safety issues were deemed most important, participants were also subconsciously aware of other crucial issues related to drinking water. These findings provide useful information for drinking water policy experts and water utilities about consumer perceptions of the relative virtues of tap and bottled water.     

Synthesis and properties of starch-graft-acrylic acid/Na-montmorillonite superabsorbent nanocomposite hydrogels

The graft copolymerization of acrylic acid (AA) onto starch was carried out with monomer/starch weight ratio = 1.5. Cerium ammonium nitrate (CAN) and N,N′-methylenebis acrylamide (NMBA) were used as initiator and crosslink agent, respectively. Na-montmorillonite was used as nanoparticles. Starch-graft-acrylic acid/Na-MMT (S-g-AA/MMT) nanocomposite hydrogels were characterized by X-ray diffraction (XRD) and FTIR analysis. The effect of Na-MMT content in nanocomposite hydrogels on the swelling behavior was investigated. Increasing the Na-MMT/monomers ratio up to 1% causes an increment in water absorbency, which indicates that Na-MMT can improve the ability of water absorbency but further increase of Na-MMT causes a decrease in water absorbency. In addition, we describe the removal of safranine T from aqueous solutions using S-g-AA/MMT nanocomposite hydrogels. Effects of various parameters such as treatment time, initial dye concentration, and amount of the Na-MMT were investigated. The Freundlich equations were used to fit the equilibrium isotherms. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008