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131.
The introduction of hydrogen in transport, particularly using fuel cell vehicles, faces a number of technical and non-technical hurdles. However, their relative importance is unclear, as are the levels of concern accorded them within the expert community conducting research and development within this area. To understand what issues are considered by experts working in the field to have significant potential to slow down or prevent the introduction of hydrogen technology in transport, a study was undertaken, primarily during 2007. Three key technology areas within hydrogen transport were selected - hydrogen storage, fuel cell drivetrains, and small-scale hydrogen production - and interviews with selected experts conducted. Forty-nine experts from 34 organisations within the fuel cell, automotive, industrial gas and other related industries participated, in addition to some key academic and government figures. The survey was conducted in China, Japan, North America and Europe, and analysed using conventional mathematical techniques to provide weighted and averaged rankings of issues viewed as important by the experts. It became clear both from the interviews and the subsequent analysis that while a primary concern in China was fundamental technical performance, in the other regions cost and policy were rated more highly. Although a few individual experts identified possible technical showstoppers, the overall message was that pre-commercial hydrogen fuel cell vehicles could realistically be on the road in tens of thousands within 5 years, and that full commercialisation could take place within 10-15 years, without the need for radical technical breakthroughs. Perhaps surprisingly, the performance of hydrogen storage technologies was not viewed as a showstopper, though cost was seen as a significant challenge. Overall, however, coherent policy development was more frequently identified as a major issue to address. 相似文献
132.
Nicoleta Stănciuc Mihaela Turturică Ana Maria Oancea Vasilica Barbu Elena Ioniţă Iuliana Aprodu Gabriela Râpeanu 《Food and Bioprocess Technology》2017,10(9):1715-1726
Binding of anthocyanin extract from grapes (Feteasc? neagr? variety) by whey protein isolate was first estimated through fluorescence spectroscopy quenching experiments. The data were analyzed using the modified Stern-Volmer equation, allowing the estimation of binding and thermodynamic parameters. The increase of binding constants, accessible fractions, and number of binding sites was highlighted when increasing the temperature, suggesting the presence of the dynamic quenching process. The HPLC analysis allowed the identification of anthocyanin composition of extract and powders, highlighting the presence of the malvidin-3-glucoside as the main anthocyanin. Molecular docking tests provided strong evidence on the involvement of α-lactalbumin and β-lactoglobulin in the tight binding of malvidin-3-glucoside. Further, grape anthocyanins were encapsulated within whey protein isolate and two different polysaccharides (acacia gum and pectin) by coacervation, followed by freeze-drying. The encapsulating efficiency varied between 94 and 99%. Two size smaller particles were obtained in case of microencapsulation in the presence of pectin when compared with acacia gum, as revealed by laser confocal scanning microscopy investigations. Significantly, the experimental variant with pectin allowed the entrapment of a higher amount of flavonoids. The antioxidant activities of the two experimental variants were comparable. The thermal stability experiments evidenced a relatively higher protective effect on anthocyanin degradation in the variant with pectin. 相似文献
133.
Probing the heat‐induced structural changes in bovine serum albumin by fluorescence spectroscopy and molecular modelling 下载免费PDF全文
Florentina‐Mihaela Ursache Iuliana Aprodu Oana‐Viorela Nistor Mihaela Bratu Elisabeta Botez Nicoleta Stănciuc 《International Journal of Dairy Technology》2017,70(3):424-431
The fluorescence spectroscopy and in silico methods were used to evaluate the structural changes in bovine serum albumin (BSA) over a temperature range of 25–70 °C for 15 min. Experimental results indicated that the polypeptide chain rearrangements at temperatures higher than 40 °C lead to a lower exposure of hydrophobic residues causing the decrease in fluorescence intensity. The nonlinearity of the phase diagram indicated a sequential denaturation process involving several molecular species. The molecular dynamics simulations at the single‐molecule level showed the high stability of the BSA structure, compensating for the entropic costs associated with the prevalent helical folding. 相似文献
134.
A. Anghel 《Journal of Nuclear Materials》2009,385(2):242-12
Beryllium is intended to be used as suggested material for the first wall in the thermonuclear power plants. Some tiles of the first wall will be of inconel coated by a beryllium layer that must be adherent to the substrate and have a compact structure in order to resist as much as possible the dramatic interaction with the high energetic plasma particles, ions, electrons and neutrons. Applying bias voltages (−200 to + 700 V) on the substrates, the morphology of the prepared Be layers using the original thermionic vacuum arc method developed at NILPRP was controlled in order to obtain smooth surfaces, free of holes and lamellar structures. The prepared films were studied and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Auger spectroscopy (AES). The films prepared using negative bias voltages were found to be more compact and smooth with an average roughness (Rms) of 7 nm. 相似文献
135.
Nicoleta G. Hădărugă Daniel I. Hădărugă Virgil Păunescu Călin Tatu Valentin L. Ordodi Geza Bandur Alfa X. Lupea 《Food chemistry》2006,99(3):500-508
This paper presents a thermal stability study of the linoleic acid/α- and β-cyclodextrin (α- and βCD) complexes. Bionanoparticles were obtained by a solution method and were characterized by differential scanning calorimetry and transmission electron microscopy. The pure linoleic acid, the corresponding thermally (50–150 °C) degraded raw linoleic acid samples or those recovered from the complexes were analyzed by gas chromatography–mass spectrometry, after conversion to the methyl esters. Nanoparticles were obtained with good yields of 88% and 74% for α- and βCD complexes, respectively. The main degradation products (for the thermally degraded raw samples) were aldehydes, epoxy, dihydroxy derivatives, homologues, and isomers of linoleic acid. A good thermal stability of nanoparticles can be observed, especially for the linoleic acid/αCD complex, which contains a relative concentration above 98% fatty acid in the case of temperature degradations of 50 and 100 °C. A lower concentration of 92% can be observed in the case of the linoleic acid/βCD complex but, for the temperature degradation of 150 °C, the linoleic acid was partially converted to more stable geometrical isomers. 相似文献
136.
Robert Ancuceanu Marilena Viorica Hovane Maria Cojocaru-Toma Adriana-Iuliana Anghel Mihaela Dinu 《International journal of molecular sciences》2022,23(20)
Aspergillus species, especially A. fumigatus, and to a lesser extent others (A. flavus, A. niger, A. terreus), although rarely pathogenic to healthy humans, can be very aggressive to immunocompromised patients (they are opportunistic pathogens). Although survival rates for such infections have improved in recent decades following the introduction of azole derivatives, they remain a clinical challenge. The fact that current antifungals act as fungistatic rather than fungicide, that they have limited safety, and that resistance is becoming increasingly common make the need for new, more effective, and safer therapies to become more acute. Over the last decades, knowledge about the molecular biology of A. fumigatus and other Aspergillus species, and particularly of calcineurin, Hsp90, and their signaling pathway proteins, has progressed remarkably. Although calcineurin has attracted much interest, its adverse effects, particularly its immunosuppressive effects, make it less attractive than it might at first appear. The situation is not very different for Hsp90. Other proteins from their signaling pathways, such as protein kinases phosphorylating the four SPRR serine residues, CrzA, rcnA, pmcA-pmcC (particularly pmcC), rfeF, BAR adapter protein(s), the phkB histidine kinase, sskB MAP kinase kinase, zfpA, htfA, ctfA, SwoH (nucleoside diphosphate kinase), CchA, MidA, FKBP12, the K27 lysine position from Hsp90, PkcA, MpkA, RlmA, brlA, abaA, wetA, other heat shock proteins (Hsp70, Hsp40, Hsp12) currently appear promising and deserve further investigation as potential targets for antifungal drug development. 相似文献
137.
Ioana Madalina Zota Cristina Andreea Adam Drago Traian Marius Marcu Cristian Sttescu Radu Sascu Larisa Anghel Daniela Boiteanu Mihai Roca Corina Lucia Dima Cozma Alexandra Mataleru Maria Magdalena Leon Constantin Elena Andreea Moale Florin Mitu 《International journal of molecular sciences》2022,23(20)
Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse, chronic hypoxia and a proinflammatory phenotype. The purpose of our study was to evaluate readily available inflammatory biomarkers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), WBC-to-MPV ratio (WMR) and lymphocyte-to-C-reactive protein ratio (LCR)) before and after CPAP in patients with moderate–severe OSA. We performed a prospective study that included patients with newly-diagnosed moderate–severe OSA. The control groups (patients without OSA and with mild OSA) were selected from the hospital polygraphy database. All subjects underwent routine blood panel, which was repeated in moderate–severe OSA patients after 8 weeks of CPAP. Our final study group included 31 controls, 33 patients with mild, 22 patients with moderate and 37 patients with severe OSA. CRP, ESR, NLR and WMR were correlated with OSA severity. After 8-week CPAP therapy, we documented a decrease in weight status, which remained statistically significant in both CPAP-adherent and non-adherent subgroups. Readily available, inexpensive inflammatory parameters can predict the presence of moderate–severe OSA, but are not influenced by short-term CPAP. 相似文献
138.
Christine Norton Ian Cameron Nicoleta Balliu David Shallcross Geoff Barton 《Education for Chemical Engineers》2008,3(2):e75
This work differentiates itself from most educational based multimedia resources by catering for two distinct audience groups. The first group is undergraduate process engineering students in a number of Australian institutions, whereas the second group represents operational staff at the industrial facilities covered by the interface. This presents challenges in pedagogy, educational pitch, industrial relations and project management. It has also added a sales driver to the project as we market the resource to industry as an operator training resource.The learning environment is based around spherical imagery of real operating plants coupled with interactive embedded activities and content. This virtual reality (VR) learning tool has been developed by applying aspects of relevant educational theory and proven instructive teaching approaches. Principles such as constructivism, interactivity, cognitive load and learner-centred design have been central considerations when constructing and structuring this resource. Structural challenges include determining a framework for the basic environment, the repository for the VR and activities, as well as the development of a learning platform arrangement to support self-directed learning in the interface. Some of the system's current functionality is demonstrated through snapshots of the screen configuration. Future developments within the interface are revealed. 相似文献
139.
Ina Turcan Vlad Alexandru Lukacs Lavinia Curecheriu Leontin Padurariu Cristina Elena Ciomaga Mirela Airimioaei George Stoian Nicoleta Lupu Liliana Mitoseriu 《Journal of the European Ceramic Society》2018,38(16):5420-5429
Di-phase composite ceramics based on BaTiO3 with 5?vol% of Ag filler have been prepared by sintering the mixture of powders at temperatures above the silver melting point (1000?°C–1300?°C/2?h). As predicted by finite element calculations, the addition of metallic particles should produce a field concentration in some regions of the BaTiO3 matrix and therefore, an enhanced dielectric response with respect to pure BaTiO3. The role of oxygen vacancies on the dielectric relaxation mechanisms of Ag-BaTiO3 composites has been investigated. The sintering temperature of 1200?°C provided optimized ceramics with excellent dielectric properties, i.e. with low losses (tanδ?<?3%) and room temperature permittivity measured at 50?kHz exceeding 6500 (and above 13,000 at the Curie temperature), as result of a good densification (94% relative density) and a synergy effect of the metallic particles inclusions and ceramic grain size in the range of ≈1?μm, where BaTiO3 has a well-known maximum of its permittivity. 相似文献
140.
A. Anghel C. Porosnicu I. Mustata K. Sugiyama K. Krieger A. Nastuta G. Popa 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(2):426-429
In a plasma-confinement device, material eroded from plasma facing components will be transported and re-deposited at other locations inside the reaction chamber. Since beryllium from the first wall of the ITER fusion reactor will be eroded, ionized in the scrape-off layer plasma and finally re-deposited on divertor surfaces flowing along the magnetic field, it is important to study the properties of divertor armour materials (C, W) coated with beryllium.By applying different bias voltages (−200 V to +700 V) to the substrates during deposition, the morphology of the obtained films was modified. The films’ morphology was characterized by means of AFM and SEM, and it was found that the coatings prepared using negative bias voltage at the substrate during deposition are more compact and have a smoother surface compared to the samples prepared with positive bias voltage. The thickness and composition of each film were measured using Rutherford backscattering spectrometry (RBS). A study of deuterium implantation and retention into the prepared films was performed at IPP Garching in the high current ion source. 相似文献