Molecular dynamics study of the influence of functionalization on the elastic properties of single and multiwall carbon nanotubes

The effect of carboxylation on axial Young’s modulus of carbon nanotubes is investigated using a molecular dynamics (MD) approach. COMPASS force field is used to model the interatomic interactions in single wall (SWCNT) and multiwall carbon (MWCNT) with different amounts of –COOH groups attached to their surfaces. The results of the MD simulations show how an increase of the number of carboxylic groups on the CNT surface leads to a decrease on the Young moduli of the CNTs. The decrease of MWCNT Young’s modulus is found to be lower than in the case of SWCNT.     

The Effects of Negative Ionisation on Subjective Symptom Intensity and Driver Vigilance in a Moving Vehicle

100 drivers aged 23-65, 53 male and 47 female, were recruited to drive an apparently unmodified passenger car for one hour in city traffic. They were randomly assigned either to a control condition, or to ionised air containing 20 000-30 000 negative ions/ml, but were unaware of the presence of an ioniser in the vehicle. A computer initiated unprepared signals to which drivers should normally be alert. Drivers responded by pressing a foot-switch and reporting verbally. Signals were selected at random from 21 possible signals, and were presented for up to 3 minutes, with a random delay of 30-180 seconds after each response or failure to respond. Subjects reported subjective symptom intensity by marking a set of 11 visual-analogue scales. Eye symptoms were alleviated by ionisation for subjects aged < 40 years (P<0.05), but older female subjects experienced more eye discomfort, headache and fatigue in the ionisation condition (P < 0.05). Detection of 10 of the 21 signals was better (P < 0.05, 2-tail) in the ionisation condition. The effect was more often significant in the second half-hour, for subjects < 40 years, and for women. A significant negative effect (P < 0.05) was observed for the signal indicating speed below true speed.     

Levels and patterns of polycyclic aromatic hydrocarbons in incineration ashes

Polycyclic aromatic hydrocarbons were analysed in weathered bottom ash from municipal solid waste incineration, fly ash from a mixed heating plant and an ash mixture from different kinds of biofuels. Although of different origin and age, all three ashes are evaluated in different small-scale fill applications. The ultimate goal is the usage of these ashes on a larger scale. The samples were Soxhlet extracted and analysed using GC/MS in the full scan mode. The sum of the 16 US EPA PAHs was found to vary from 140 microg/kg up to more than 77000 microg/kg. Total amounts of PAHs were similar in bottom ash and in fly ash. The concentration in the mixed biofuel ash was more than 10 times higher, and exceeded the generic guidelines for PAHs in soil set by the Swedish Environmental Protection Agency. The patterns of the individual PAHs normalised to the total concentration of PAHs were found to be very similar for all the three ashes. Naphthalene and phenanthrene were the dominating PAHs for all ash samples, but the mixed biofuel ash also contained high levels of fluoranthene and pyrene.     

Authentication of marine oils using 13C NMR spectroscopy

NMR spectroscopy has been particularly valuable in the study of lipids, since it provides qualititative and quantitative information on chemically diverse compounds in a non‐destructive and non‐selective fashion. NMR gives a fingerprint of the sample analyzed and may be used as a rapid profiling technique. Combined with chemometrics and databases with relevant authentic samples, ¹³C NMR is a powerful tool for authentication of marine oils.     

Impact of Diet Composition on Blood Glucose Regulation

Nutritional management of blood glucose levels is a strategic target in the prevention and management of type 2 diabetes mellitus (T2DM). To implement such an approach, it is essential to understand the effect of food on glycemic regulation and on the underlying metabolic derangements. This comprehensive review summarizes the results from human dietary interventions exploring the impact of dietary components on blood glucose levels. Included are the major macronutrients; carbohydrate, protein and fat, micronutrient vitamins and minerals, nonnutrient phytochemicals and additional foods including low-calorie sweeteners, vinegar, and alcohol. Based on the evidence presented in this review, it is clear that dietary components have significant and clinically relevant effects on blood glucose modulation. An integrated approach that includes reducing excess body weight, increased physical activity along with a dietary regime to regulate blood glucose levels will not only be advantages in T2DM management, but will benefit the health of the population and limit the increasing worldwide incidence of T2DM.     

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.