Hydrogen production from ammonia borane via hydrogel template synthesized Cu, Ni, Co composites

In situ Co, Cu and Ni nanoparticles were synthesized by chemical reduction of the absorbed Co (II), Cu (II) and Ni (II) ions inside hydrogel networks prepared from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) and were used as a catalyst system in the generation of hydrogen in hydrolysis of ammonia borane (AB). Several parameters affecting the hydrolysis reaction such as the type of the metal, the amount of catalyst, the initial concentration of AB, and temperature, were investigated. The activation energy values in the hydrolysis reaction of AB solution in the presence p(AMPS)-Co, p(AMPS)-Cu and p(AMPS)-Ni catalyst systems were calculated as E_a = 47.7 kJ mol⁻¹, 48.8 kJ mol⁻¹ and 52.8 kJ mol⁻¹, respectively. Thus, the catalytic activity of the metal nanoparticles prepared inside the same hydrogel matrix was found to be Ni < Cu < Co.     

Affordances of outdoor settings for children in preschool: revisiting heft’s functional taxonomy

Heft’s functional taxonomy for children’s outdoor environment based on the concept of affordances was applied and investigated in a Danish preschool context. Affordances here refer to the meaningful action possibilities of the environment. Two groups of children (3–6 years) enrolled in preschool were observed during times for ‘free play’ in their usual outdoor settings: traditional playground and forest (12 visits, respectively). Modified classes of outdoor features are suggested along with new practical class names: open ground, sloping terrain, shielded places, rigid fixtures, moving fixtures, loose objects, loose material, water, creatures and fire. Each class is specified by distinctive and attractive key activities found by observation. Examining each class indicated that important characteristics apart from availability were variation, sizes and change. The concept of affordances emphasises the ongoing user–environment–activity relationship important for planning with children in mind, but clarification is needed when using the term.     

Isomerization of hop extract α‐acids

An isomerization process of the α‐acids contained in hop extract (with magnesium oxide, potassium hydroxide and magnesium peroxide as catalysts at ambient temperature) was carried out. The influence of two factors (the amount of applied catalyst and the isomerization time) was studied. Ultra‐high performance liquid chromatography was used for the evaluation of the isomerization process. The best results were obtained with magnesium oxide. In this case, the influence of the operating variables on the isomerization process and optimal process parameters were determined using statistical methods. The isomerization method described above could be carried out with high efficiency without heating and could be easily adopted and applied on an industrial scale. Copyright © 2016 The Institute of Brewing & Distilling     

Surface Characteristics,Copper Release,and Toxicity of Nano‐ and Micrometer‐Sized Copper and Copper(II) Oxide Particles: A Cross‐Disciplinary Study

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano‐ and micrometer‐sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer‐sized Cu, release more copper in serum‐containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate‐buffered saline. Sonication of particles for dispersion prior to exposure has a large effect on the initial copper release from Cu nanoparticles. A clear size‐dependent effect is observed from both a copper release and a toxicity perspective. In agreement with greater released amounts of copper per quantity of particles from the nanometer‐sized particles compared to the micrometer‐sized particles, the nanometer particles cause a higher degree of DNA damage (single‐strand breaks) and cause a significantly higher percentage of cell death compared to cytotoxicity induced by micrometer‐sized particles. Cytotoxic effects related to the released copper fraction are found to be significantly lower than the effects related to particles. No DNA damage is induced by the released copper fraction.     

Comparative Neuropharmacology and Pharmacokinetics of Methamphetamine and Its Thiophene Analog Methiopropamine in Rodents

Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (E_max 12.5 mg/kg; i.p.) compared to methamphetamine (E_max 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC₅₀ = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC₅₀ > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine.     

Assessing the degree of osteoporosis in the axial skeleton using the dependence of the fractal dimension on the grey level threshold

Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.     

Monitoring and modeling stress corrosion and corrosion fatigue damage in nuclear reactors

Despite the serious impact of stress-corrosion cracking and corrosion fatigue, the relevant design and operational guidelines for light-water nuclear reactors are often just rules of thumb which identify susceptibility or codes which only quantify the effects of stress. However, quantitative understanding of the crack advance process is unfolding for several alloy types, and modeling now permits accurate prediction of crack growth over a wide range of material, environmental and stress conditions.     

Blockstauchen zwischen ebenen parallelen Bahnen

Verfahren zur Stauchdruckbestimmung und Berechnung plastischer Umformvorgänge. Zweidimensionales Modell für das Blockstauchen. Geschwindigkeitsfeld und obere Schranke. Untersuchungsergebnisse.