Fullerene-modified polyamide 6 by in situ anionic polymerization in the presence of PCBM

Activated anionic ring-opening polymerization of ε-caprolactam (ECL) was carried out for the first time in the presence of [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) to prepare polyamide 6 (PA6)-based composites comprising up to 3 wt% of this fullerene derivative. This in situ polymerization process produced high molecular weight composites containing 52–80 % of gel fraction at PCBM concentration ≥0.5 wt%. Spectral, thermo-mechanical, synchrotron X-ray, and scanning electron microscopy data were used to elucidate the structure and morphology of the PA6/PCBM composites. A mechanism of the chemical structure evolution was proposed starting with incipient complexation between ECL and PCBM, via subsequent chemical linking of ECL moieties on the C₆₀ spheroid and final formation of star-burst and cross-linked morphologies. PCBM amounts of 0.1 wt% and more decreased the volume resistivity from 10¹² Ω cm (neat PA6) to 10⁹–10⁷ Ω cm, thus opening the way for new applications of anionic PA6.     

Preparation of rigid,low-density,flame-retardant polyurethane foams from whey permeate

The disposal of whey and whey permeate derived from the cheese industry is a serious economic and environmental problem. Lactose in whey permeate was used to synthesise polyether polyols from which rigid, low-density polyurethane foams were prepared. Resultant foams were comparable to those made from commercially available sucrose-based polyether polyols. Brown-coloured lactose polyether polyols are characterised by low viscosity and high carbonyl content. Urea incorporated into these polyether polyols yields flame retardant (self-extinguishing) foams. Urea also reduced the amount of phosphorus and/or halogen based fire retardants needed to make the foams non-burning. A preliminary economic analysis indicates that whey-based polyether polyols can be prepared at a cost savings of up to 36% compared to the sucrose counterparts.     

Brain metastases from cervical carcinoma

Central nervous system (CNS) involvement by cervical carcinoma is uncommon. Out of 1,184 patients registered for invasive cervical carcinoma at our institution between 1982 and 1994, 14 (1.18%) developed brain metastases. Median age at the time of CNS metastasis diagnosis was 52 years. Median interval between diagnosis of cervical cancer and documentation of brain involvement was 18 months. Clinical manifestation included motor weakness, headache, seizures, dizziness and visual disturbances. All lesions (8 multiple, 6 single) were contrast enhanced on computerized tomography scans and were located in the cerebrum (n = 10), in the cerebellum (n = 2), or in both (n = 2). The CNS was the only site of detectable disease in 7 patients with recurrent disease. Eleven patients received only steroids, and 3 patients received radiotherapy. All 14 patients died, and median survival from diagnosis of brain metastases for the entire series was 4 months (range, 1-21). CNS metastases from cervical cancer are rare, and the prognosis for such patients appears poor.     

Albert Einstein and Arnold Schönberg Correspondence

Ohne Zusammenfassung

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No one should consider unbelievable that there should come out of astrological foolishness and godlessness also cleverness and holiness… out of evil-smelling dung a golden corn scraped by an industrious hen. Johannes Kepler.     

Photoluminescent, transparent and flexible di-ureasil hybrids containing CdSe/ZnS quantum dots

We describe, in this paper, the sol-gel synthesis of di-ureasil based nanocomposites prepared in situ in the presence of organically capped CdSe quantum dots (QDs) or CdSe QDs which have been coated with a ZnS shell. For the latter a new chemical route to coat the CdSe QDs with ZnS shells was investigated and is now reported. The QDs became well dispersed in the final nanocomposites, whose microstructural homogeneity was evaluated by atomic force microscopy (AFM) and transmission electron microscopy (TEM) analyses. In order to understand the optical behaviour of di-ureasil containing QDs, a detailed photoluminescent study was undertaken for a selected particle size distribution of ZnS coated CdSe QDs (d～4.5?nm). Emission quantum yields up to 0.11 were measured in the final nanocomposites that present a huge (between 3 and 6 orders of magnitude) increase in the lifetime of the QDs (relative to that of isolated ones), as a result of energy transfer occurring between the intimately mixed di-ureasil host and the QDs.     

Evaluation of the Heat Treatment Response of a Multiphase Hot-Rolled Steel Processed by Controlled Rolling and Accelerated Cooling

The tensile properties of hot-rolled multiphase steel after heat treatment were analyzed on a laboratory scale. Subcritical treatments applied to the hot-rolled strip revealed an increase in the yield stress and elongation with increasing temperature. Normalizing of the strip at 920°C notably improved the ductile response, while both the yield stress and the anisotropy of every property evaluated at 0°, 45°, and 90° to the rolling direction in the rolling plane were significantly reduced.     

On the explicit dead-time compensation for robust model predictive control

Computational simplicity is one of the most important aspects to take into account in robust model predictive control (MPC). In dead-time processes, it is common to use an augmented state-space representation in order to apply robust MPC strategies but, this procedure may affect computational aspects. In this paper, explicit dead-time compensation will be used to avoid augmented representation. This technique will be analyzed in terms of robust stability and constraint satisfaction for discrete-time linear systems. The results of this discussion will be applied to a robust tube-based MPC strategy which is able to guarantee robust stability and constraint satisfaction of a dead-time system by considering a prediction model without dead-time. Moreover, taking advantage of the proposed scheme, the robust MPC will be particularized for first-order plus dead-time models which simplifies significantly controller synthesis. The proposed dead-time compensation method will be applied to different robust MPC strategies in two case studies: (i) a simulated quadruple-tank system, and (ii) an experimental scaled laboratory heater process.     

Roof selection for rainwater harvesting: quantity and quality assessments in Spain

Roofs are the first candidates for rainwater harvesting in urban areas. This research integrates quantitative and qualitative data of rooftop stormwater runoff in an urban Mediterranean-weather environment. The objective of this paper is to provide criteria for the roof selection in order to maximise the availability and quality of rainwater. Four roofs have been selected and monitored over a period of 2 years (2008-2010): three sloping roofs - clay tiles, metal sheet and polycarbonate plastic - and one flat gravel roof. The authors offer a model for the estimation of the runoff volume and the initial abstraction of each roof, and assess the physicochemical contamination of roof runoff. Great differences in the runoff coefficient (RC) are observed, depending mostly on the slope and the roughness of the roof. Thus, sloping smooth roofs (RC > 0.90) may harvest up to about 50% more rainwater than flat rough roofs (RC = 0.62). Physicochemical runoff quality appears to be generally better than the average quality found in the literature review (conductivity: 85.0 ± 10.0 μS/cm, total suspended solids: 5.98 ± 0.95 mg/L, total organic carbon: 11.6 ± 1.7 mg/L, pH: 7.59 ± 0.07 upH). However, statistically significant differences are found between sloping and flat rough roofs for some parameters (conductivity, total organic carbon, total carbonates system and ammonium), with the former presenting better quality in all parameters (except for ammonium). The results have an important significance for local governments and urban planners in the (re)design of buildings and cities from the perspective of sustainable rainwater management. The inclusion of criteria related to the roof’s slope and roughness in city planning may be useful to promote rainwater as an alternative water supply while preventing flooding and water scarcity.     

The imprecision of micronutrient requirement values: the example of vitamin D

Food, not nutrients, is the fundamental unit in nutrition. Nutrient requirement values and recommended daily intakes have long been determined and organized in tables by several regulators. These figures, however, overlook the complexity of mixing different foods in a diet and the mediation by human gut microbiota on digestion, metabolism, and health. The microbiome molecular mechanisms and its potential influence on nutrient requirements are far from clear. Guidelines should depend on the sort of intake, along with the dietary habits, rather than focusing on single nutrients. Despite many decades of attempts to investigate the proximate nutrient composition of foods consumed by different world populations, there are still neither standardization of food composition databases nor harmonized dietary intake methods of assessment of nutrients. No all-inclusive attempt was yet made to emphasize the requirements of the various micronutrients, phytonutrients, and non-nutrients on gut microbiota and vice versa, and thereafter reflected into dietary guidelines. New multifaceted methods have been advanced to reevaluate the way nutrients and nutrient requirements are assessed within the intricate biological systems. Our main goal here was to enhance the fact that existing food guidelines hold inherent strengths and limitations but fail, in many aspects, namely, in not taking into account essential geographical, ethnic and cultural differences, and the different stages of life, infant nutrition, and the microbiota impact on several micronutrient requirements. Vitamin D is given as an illustration on present inaccuracy of its requirements. Defining dietary reference intakes is therefore an ongoing process specific for each population.