Experimental and Numerical Characterization of the Influence of a Smoldering Cellulosic Substrate on a Cigarette’s Ignition Propensity Test

An experimental and numerical investigation was conducted to characterize the influence of the cellulosic substrate used to assess the ignition propensity (IP) of cigarettes. Such an IP test is currently prescribed by the ISO 12863 standard and its results typically show poor repeatability. It is believed that such a low reproducibility is mainly due to the variability of the cigarette itself but it is unclear as to what extent the substrate also influences the variability of the test results. Therefore, the objective of this investigation was to analyze the potential influence of the substrate by first characterizing the thermodynamic behavior experimentally and then constructing a numerical model that can quantify the relative influence of the distinct parameters. A suite of experimental methods that included TGA, DSC, infrared measurements and laser triangulation among others was used to measure the thermophysical properties of the substrate. These properties were then used to build a CFD model that simulated the smoldering combustion experienced by the substrate during the IP test. After validating the model against contactless temperature measurements, a parametric study consisting of 363 IP simulations was performed, which served to quantify the relative importance of 13 thermophysical parameters when varying in ranges of about 5%–50%. The results indicated that the heat capacity, pyrolysis activation energy, and air gap thickness are the most influencing aspects of the substrate because they influence the heat absorbed by the substrate about 7%, 26% and 33%, respectively. The latter parameter was found to significantly vary with each test and its influence was comparable to that of some major properties of the cigarette such as the cigarette’s temperature and burning rate. It is therefore postulated that the variability of the substrate itself plays an important role on the poor repeatability of the test and it may comprise its reliability.     

Review of Benthic Invertebrate Fauna in Extremely Acidic Environments (pH ≤ 3)

Some benthic invertebrate species are able to colonise habitats in extremely acidic waters. We compiled a list of acid-resistant benthic invertebrates from the literature and extended it by studying extremely acidic mining lakes in eastern Germany. Acid-resistant species were registered for some habitats with pH ≤ 3, such as volcanic lakes, acid strip streams, and acidic mining lakes. Twenty nine taxa were found in waters with pH below 3. Diptera comprised 48.3% of the total number of taxa, followed by Coleoptera with 10.3%, Trichoptera 10.3%, Ephemeroptera, Megaloptera, and Plecoptera each with 6.9%, and Odonata, Hirudinea, and Acari each with 3.5%. Chironomus (Diptera: Chironomidae) were the most common genus in extremely acidic environments with 9 species. In Germany, Chironomus crassimanus was found to be the most abundant species in extremely acidic mining lakes. Generally, aquatic insects were the most common group of benthic invertebrates.     

Biofuel support policies in Europe: Lessons learnt for the long way ahead

Biofuel consumption in the EU is growing rapidly but major efforts will need to be undertaken if the EU's objectives for 2010 and beyond are to be achieved. This article analyses the strengths and weaknesses of different biofuel support policies based on the experiences gained in pioneering countries and explores scenarios for their possible impacts in the long-term. It comes to the conclusion that important pre-conditions such as fuel standards and compatibility with engines are in place or being introduced on an EU-wide basis. Current and future policy support therefore focuses on creating favourable economic or legal frameworks to accelerate the market penetration of biofuels. The ambitious targets endorsed in terms of biofuel market shares require the implementation of efficient policy instruments. At the same time, large consumption volumes and the advent of innovative production technologies make it possible for Member States to promote specific types of biofuels, depending on their main objectives and natural potentials. This will require complementary instruments such as subsidies for production facilities, user incentives or feedstock subsidies.     

Trichogin GA IV Alignment and Oligomerization in Phospholipid Bilayers

Trichogin GA IV is a short peptaibol with antimicrobial activity. This uncharged, but amphipathic, sequence is aligned at the membrane interface and undergoes a transition to an aggregated state that inserts more deeply into the membrane, an assembly that predominates at a peptide-to-lipid ratio (P/L) of 1:20. In this work, the natural trichogin sequence was prepared and reconstituted into oriented lipid bilayers. The ¹⁵N NMR chemical shift is indicative of a well-defined alignment of the peptide parallel to the membrane surface at P/Ls of 1:120 and 1:20. When the P/L is increased to 1:8, an additional peptide topology is observed that is indicative of a heterogeneous orientation, with helix alignments ranging from around the magic angle to perfectly in-plane. The topological preference of the trichogin helix for an orientation parallel to the membrane surface was confirmed by attenuated total reflection FTIR spectroscopy. Furthermore, ¹⁹F CODEX experiments were performed on a trichogin sequence with ¹⁹F-Phe at position 10. The CODEX decay is in agreement with a tetrameric complex, in which the ¹⁹F sites are about 9–9.5 Å apart. Thus, a model emerges in which the monomeric peptide aligns along the membrane surface. When the peptide concentration increases, first dimeric and then tetrameric assemblies form, made up from helices oriented predominantly parallel to the membrane surface. The formation of these aggregates correlates with the release of vesicle contents including relatively large molecules.     

MiR-205 Is Progressively Down-Regulated in Lymph Node Metastasis but Fails as a Prognostic Biomarker in High-Risk Prostate Cancer

The treatment of high-risk prostate cancer (HRPCa) is a tremendous challenge for uro-oncologists. The identification of predictive moleculobiological markers allowing risk assessment of lymph node metastasis and systemic progression is essential in establishing effective treatment. In the current study, we investigate the prognostic potential of miR-205 in HRPCa study and validation cohorts, setting defined clinical endpoints for both. We demonstrate miR-205 to be significantly down-regulated in over 70% of the HRPCa samples analysed and that reconstitution of miR-205 causes inhibition of proliferation and invasiveness in prostate cancer (PCa) cell lines. Additionally, miR-205 is increasingly down-regulated in lymph node metastases compared to the primary tumour indicating that miR-205 plays a role in migration of PCa cells from the original location into extraprostatic tissue. Nevertheless, down-regulation of miR-205 in primary PCa was not correlated to the synchronous presence of metastasis and failed to predict the outcome for HRPCa patients. Moreover, we found a tendency for miR-205 up-regulation to correlate with an adverse outcome of PCa patients suggesting a pivotal role of miR-205 in tumourigenesis. Overall, we showed that miR-205 is involved in the development and metastasis of PCa, but failed to work as a useful clinical biomarker in HRPCa. These findings might have implications for the use of miR-205 as a prognostic or therapeutic target in HRPCa.     

CO2 aided H2 recovery from water splitting processes

Solar energy can be utilized to produce H₂ via photocatalytic water splitting. One major drawback of the one-step approach is the co-production of H₂ and O₂ in the same reactor environment creating a potentially hazardous scenario. This obstacle can be avoided by utilizing CO₂ as a flammability suppressant which is proven to be more effective than N₂. In this case study, several membrane cascade designs were implemented to recover the H₂ while maintaining compositions outside the flammability range. The optimizations are based on the use of commercially available composite polymer membranes from Membrane Technology and Research, Inc. (MTR) in the spiral wound architecture. Both the H₂-selective membrane (Proteus?) and CO₂-selective membrane (Polaris?) were explored in three layouts. The process optimization is solved by nonlinear programming. The aim of the study was to minimize the present value of all outgoing cash flow (no income) for the separation process and achieving 99% product (H₂) purity. Optimization results showed that utilizing three membrane units of Proteus? material with one recycle stream is the optimum layout over a wide range of recovery values. Incorporating the CO₂-selective membrane (Polaris?) leads to more expensive process due to higher recycle flow rates to compensate for the low selectivity of this material. Overall, the best economic results for this process were obtained at 85% recovery rate with 99% product purity at a cost of 6.40 $/kg. Comparing to our previous study using a N₂ diluent, higher purity product with lower specific cost can be achieved with CO₂ diluent system but with slight decrease in recovery rate. As a final element to this study, comparative simulations were executed to demonstrate the potentially added value of using hollow fiber membranes versus spiral wound for this separation process.     

Investigation of a force-locked connection of micro piezo elements with aluminium carrier material

Within the Transregional Collaborative Research Centre PT-PIESA “High-Volume Production-Compatible Production Technologies for Lightmetal and Fiber Composite-Based Components with Integrated Piezo Sensors and Actuators” effective technologies for the production of active components are investigated. One concept is the direct integration of piezo material as fibers or rods in sheet metal like for instance aluminum sheets. This paper deals with the production step of the joining process. Based on a finite element simulation different dimensional layouts are experimentally investigated. The results show, that with an appropriate fill ratio a force-locked connection between piezo material and carrier material can be achieved.