Risk Assessment of Hydrogen Fuel Cell Electric Vehicles in Tunnels

The need to understand the risks and implications of traffic incidents involving hydrogen fuel cell electric vehicles in tunnels is increasing in importance with higher numbers of these vehicles being deployed. A risk analysis was performed to capture potential scenarios that could occur in the event of a crash and provide a quantitative calculation for the probability of each scenario occurring, with a qualitative categorization of possible consequences. The risk analysis was structured using an event sequence diagram with probability distributions on each event in the tree and random sampling was used to estimate resulting probability distributions for each end-state scenario. The most likely consequence of a crash is no additional hazard from the hydrogen fuel (98.1–99.9% probability) beyond the existing hazards in a vehicle crash, although some factors need additional data and study to validate. These scenarios include minor crashes with no release or ignition of hydrogen. When the hydrogen does ignite, it is most likely a jet flame from the pressure relief device release due to a hydrocarbon fire (0.03–1.8% probability). This work represents a detailed assessment of the state-of-knowledge of the likelihood associated with various vehicle crash scenarios. This is used in an event sequence framework with uncertainty propagation to estimate uncertainty around the probability of each scenario occurring.     

Silicone based polyurethane materials: a promising biocompatible elastomeric formulation for cardiovascular applications

The biocompatibility of a new material for cardiovascular applications constituted by a poly(ether)urethane (PEtU) and a silicone [polydimethylsiloxane (PDMS)] was evaluated. The achieved material shows properties similar to both polyurethanes and silicones. The material was transformed into porous membranes by a spray-deposition technique. Since any material preparation and manufacturing procedure may introduce some toxicity, in vitro cytotoxicity screening tests were carried out. Human umbilical vein endothelial cells (HUVECs) and a mouse fibroblasts cell line (L929) were cultivated with extracts obtained from materials containing 10, 40 and 100% (w/w) of PDMS. The commercially available Estane 5714-F1 and Cardiothane 51 were used as controls. Extracts were incubated up to 72 hours with HUVECs and L929 cells. The cytotoxic effect was evaluated by light microscopy, cell viability (MTT reduction and neutral red uptake) and proliferation (5-bromo-2'-deoxyuridine incorporation) tests. In vivo studies were carried out using materials containing the same PDMS percentages as for in vitro experiments. The same commercial controls were used. Results obtained with cell culture studies agreed with those obtained in the in vivo experiments and showed that the material preparation and manufacturing procedure do not introduce any toxicity in the products at each PDMS concentration investigated.     

Crosspolarisation measurements using a composite feed with parasitic elements

Measurements using a composite primary feed with parasitic auxiliary elements reveal that both the copolar and crosspolar performances of this feed are better than those of the similar feed employing derived elements. An improvement of 10 dB in the crosspolar peak over that of the single dipole feed was obtained. An increase in antenna gain of about 3.3 dB was measured with a 3 dB suppression in sidelobe level.     

Electro-oxidation and amperometric detection of chlorinated phenols at boron-doped diamond electrodes: a comparison of microcrystalline and nanocrystalline thin films

We report on the electro-oxidation and amperometric detection of phenol and chlorinated phenols, the latter coupled with flow injection analysis (FIA) and high performance liquid chromatography (HPLC), using boron-doped microcrystalline and nanocrystalline diamond thin-film electrodes. The low background current, good response without extensive pretreatment, and low susceptibility to fouling are properties that make diamond an attractive new electrode for monitoring this class of pollutants. Cyclic voltammetric studies were performed to evaluate the redox response of phenol, 2-chlorophenol, 3-chlorophenol,4-chlorophenol, and pentachlorophenol (PCP) in phosphate buffer, pH 3.5, as a function of the potential scan rate and cycle number. The diamond electrode performance for the amperometric detection of these contaminants in FIA-EC and HPLC-EC was evaluated in terms of the linear dynamic range, limit of quantitation, sensitivity, response precision, and response stability. Both diamond types yielded low mass limits of quantitation of 100-1000 pg for all the phenolic compounds in FIA-EC, except PCP which was 3 ng, and 100-600 pg for all the compounds in HPLC-EC. In all cases, the S/N was 3 or greater. Both electrode types also exhibited good sensitivity, excellent response reproducibility (av 2.7% for FIA-EC and av 4.2% for HPLC-EC), and superb response stability for all the analytes. The electrodes could be used from days to weeks in the measurement with only a periodic soak in distilled 2-propanol required to maintain optimum performance. Both types of diamond outperformed glassy carbon, which exhibited short-lived responsiveness as a consequence of fouling by reaction products and potential-dependent changes in the electrode's physiochemical properties. The use of the HPLC-EC assay for the determination of 2-chlorophenol in a contaminated soil sample is also demonstrated.     

Evaluation of a new composite prosthesis for the repair of abdominal wall defects

The degree of integration of biomaterials used in the repair of abdominal wall defects seems to depend upon the structure of the prosthesis. The present investigation evaluates the behaviour in terms of adhesion formation and integration of a new composite prosthesis that could be employed in this clinical application. Full-thickness abdominal wall defects (7 × 5 cm) were created in 16 anaesthetized New Zealand white rabbits and the prosthesis were placed in direct contact with the visceral peritoneum during the experiment. The defects were repaired with a composite prosthesis or pure polypropylene mesh to establish two study groups (n = 8 each). The composite device was constituted by a polypropylene mesh physically attached to a poly(ether)urethane–polydimethylsiloxane laminar sheet. Animals were sacrificed 7, 14, 21 and 30 days after implant and prosthesis/surrounding tissue specimens subjected to light and electron microscopy. Firm adhesions were detected in the polypropylene implants, while they were not present in the composite implants. The excellent behaviour of the composite prosthesis shown in this study warrants further investigation on its use for the repair of abdominal wall defects when a prosthetic device needs to be placed in contact with the intestinal loops.     

Iron Reduction in Dermacentor andersoni Tick Cells Inhibits Anaplasma marginale Replication

Anaplasma spp. are obligate intracellular, tick-borne, bacterial pathogens that cause bovine and human anaplasmosis. We lack tools to prevent these diseases in part due to major knowledge gaps in our fundamental understanding of the tick–pathogen interface, including the requirement for and molecules involved in iron transport during tick colonization. We determine that iron is required for the pathogen Anaplasma marginale, which causes bovine anaplasmosis, to replicate in Dermacentor andersoni tick cells. Using bioinformatics and protein modeling, we identified three orthologs of the Gram-negative siderophore-independent iron uptake system, FbpABC. Am069, the A. marginale ortholog of FbpA, lacks predicted iron-binding residues according to the NCBI conserved domain database. However, according to protein modeling, the best structural orthologs of Am069 are iron transport proteins from Cyanobacteria and Campylobacter jejuni. We then determined that all three A. marginale genes are modestly differentially expressed in response to altered host cell iron levels, despite the lack of a Ferric uptake regulator or operon structure. This work is foundational for building a mechanistic understanding of iron uptake, which could lead to interventions to prevent bovine and human anaplasmosis.     

Effect of plasticization on the photodegradation of poly (para-methoxystyrene) films

The influence of dibutyl phthalate, dioctyl phthalate, dimethyl terephthalate, diethyl terephthalate, and dioctyl terephthalate-plasticizers on poly (para-methoxy styrene) photodegradation was investigated by UV–vis, fluorescence, and FT-IR spectroscopic methods. The increase in irradiation time caused an increase in the absorption band of the polymer and an increase in the absorption of new band at longer wavelength, thus indicating a possibility of photodegradation of polymer films. The study on poly (para-methoxy styrene) photodegradation was also compared to varying phthalate and terephthalate plasticizers in order to provide an understanding of its photodegradation vis the presence of phthalates and terephthalates plasticizers. The decrease in the excimer fluorescence upon the increase in the time of exposure to UV-radiation provides an evidence for the degradation of polymeric chains through a chin scission processes. The increase in the photodegradation of the polymer increased with the increase in the bulkiness of added plasticizer molecule. IR-spectra of irradiated pure and blended polymer films indicated that the photodegradation of the polymer occurred, by the formation of new absorption bands, and the increase in the intensity of other bands.     

Techno-economic analysis of microsystem based hybrid energy combination for island application

Microsystem Technologies - The analysis of hybrid PV/diesel/storage energy system in southern island of the province of South Leyte, Philippines is presented in this paper. Appropriate selection of...     

Interleukin-34-CSF1R Signaling Axis Promotes Epithelial Cell Transformation and Breast Tumorigenesis

IL-34 has been recently identified as a ligand for CSF1R that regulates various cellular processes including cell proliferation, survival, and differentiation. Although the binding of IL-34 to CSF1R modulates several cancer-driving signaling pathways, little is known about the role of IL-34/CSF1R signaling in breast cancer. Herein, we report that IL-34 induces epithelial cell transformation and breast tumorigenesis through activation of MEK/ERK and JNK/c-Jun pathways. IL-34 increased the phosphorylation of MEK1/2, ERK1/2, JNK1/2, and c-Jun through CSF1R in mouse skin epidermal JB6 C141 cells and human breast cancer MCF7 cells. IL-34 enhanced c-Fos and c-Jun promoter activity, resulting in increased AP-1 transactivation activity in JB6 Cl41 and MCF7 cells. Moreover, PIN1 enhanced IL-34-induced phosphorylation of MEK1/2, ERK1/2, JNK1/2, and c-Jun in JB6 Cl41 and MCF7 cells. Inhibition of PIN1 using juglone prevented the IL-34-induced transformation of JB6 C141 cells. Similarly, silencing of PIN1 reduced the IL-34-induced tumorigenicity of MCF7 cells. Consistent with these results, the synergistic model showed that treatment with juglone suppressed the IL-34-induced growth of tumors formed by 4T1 cells in BALB/c mice. Our study demonstrates the role of IL-34-induced MEK/ERK and JNK/c-Jun cascades in breast cancer and highlights the regulatory role of PIN1 in IL-34-induced breast tumorigenesis.