Real-time observations of single bacteriophage λ DNA ejections in vitro

The physical, chemical, and structural features of bacteriophage genome release have been the subject of much recent attention. Many theoretical and experimental studies have centered on the internal forces driving the ejection process. Recently, Mangenot et al. [Mangenot S, Hochrein M, Rädler J, Letellier L (2005) Curr Biol 15:430–435.] reported fluorescence microscopy of phage T5 ejections, which proceeded stepwise between DNA nicks, reaching a translocation speed of 75 kbp/s or higher. It is still unknown how high the speed actually is. This paper reports real-time measurements of ejection from phage {lambda}, revealing how the speed depends on key physical parameters such as genome length and ionic state of the buffer. Except for a pause before DNA is finally released, the entire 48.5-kbp genome is translocated in {approx}1.5 s without interruption, reaching a speed of 60 kbp/s. The process gives insights particularly into the effects of two parameters: a shorter genome length results in lower speed but a shorter total time, and the presence of divalent magnesium ions (replacing sodium) reduces the pressure, increasing ejection time to 8–11 s. Pressure caused by DNA–DNA interactions within the head affects the initiation of ejection, but the close packing is also the dominant source of friction: more tightly packed phages initiate ejection earlier, but with a lower initial speed. The details of ejection revealed in this study are probably generic features of DNA translocation in bacteriophages and have implications for the dynamics of DNA in other biological systems

Fuel economy optimization from the interaction between engine oil and driving conditions

[EN] Low viscosity engine oils have shown to be an effective solution to the fuel consumption reduction target, however, their potential is closely linked to the vehicle and engine design and to the real driving conditions. In this study the interaction between engine oil and driving conditions of two urban routes and one rural route in Spain and the United Kingdom has been put to test with the aim to evaluate their joint effect over fuel economy of a freight transport vehicle. In a first approximation, six different oil formulations, three of them belonging to the new API CK-4 and FA-4 categories and two with molybdenum-based friction modifier, were tested under stationary conditions with a medium-duty diesel engine. Followed by tests under real driving conditions of a freight transport vehicle, developed by means of computer simulations with an adjusted vehicle model, taking the fuel consumption maps of the six oil formulations, vehicle characteristics and the selected driving cycles as inputs to the model. Results of engine bench tests and simulations with oils of lower HTHS viscosity showed fuel consumption reduction values as expected. However unexpected results were found between the oils with molybdenum-based friction modifier added to their formulation.The authors would like to thank to the Spanish Ministerio de Economia y Competitividad for supporting the EFICOIL project (TRA2015-70785-R) and to the program Ayudas de Investigacion y Desarrollo (PAID-01-17) of the Universitat Politecnica de Valencia.Tormos, B.; Pla Moreno, B.; Bastidas-Moncayo, KS.; Ramirez-Roa, LA.; Perez, T. (2019). Fuel economy optimization from the interaction between engine oil and driving conditions. Tribology International. 138:263-270. https://doi.org/10.1016/j.triboint.2019.05.042S263270138Edwards, M. R., Klemun, M. M., Kim, H. C., Wallington, T. J., Winkler, S. L., Tamor, M. A., & Trancik, J. E. (2017). Vehicle emissions of short-lived and long-lived climate forcers: trends and tradeoffs. Faraday Discussions, 200, 453-474. doi:10.1039/c7fd00063dDente, S. M. R., & Tavasszy, L. (2018). Policy oriented emission factors for road freight transport. Transportation Research Part D: Transport and Environment, 61, 33-41. doi:10.1016/j.trd.2017.03.021Hofer, C., Jäger, G., & Füllsack, M. (2018). Large scale simulation of CO2 emissions caused by urban car traffic: An agent-based network approach. Journal of Cleaner Production, 183, 1-10. doi:10.1016/j.jclepro.2018.02.113Lepitzki, J., & Axsen, J. (2018). The role of a low carbon fuel standard in achieving long-term GHG reduction targets. Energy Policy, 119, 423-440. doi:10.1016/j.enpol.2018.03.067Solaymani, S. (2019). CO2 emissions patterns in 7 top carbon emitter economies: The case of transport sector. Energy, 168, 989-1001. doi:10.1016/j.energy.2018.11.145European Union, The European Union explained: transport, EU publications doi:10.2775/13082.Eurostat statistics explained. road freight transport statistics, [Accessed: 10/01/2019]. URL https://ec.europa.eu/eurostat/statistics-explained/index.php/Road_freight_transport_statistics.Kin, B., Spoor, J., Verlinde, S., Macharis, C., & Van Woensel, T. (2018). Modelling alternative distribution set-ups for fragmented last mile transport: Towards more efficient and sustainable urban freight transport. Case Studies on Transport Policy, 6(1), 125-132. doi:10.1016/j.cstp.2017.11.009Edwards, J. B., McKinnon, A. C., & Cullinane, S. L. (2010). Comparative analysis of the carbon footprints of conventional and online retailing. International Journal of Physical Distribution & Logistics Management, 40(1/2), 103-123. doi:10.1108/09600031011018055Manerba, D., Mansini, R., & Zanotti, R. (2018). Attended Home Delivery: reducing last-mile environmental impact by changing customer habits. IFAC-PapersOnLine, 51(5), 55-60. doi:10.1016/j.ifacol.2018.06.199Gao, J., Chen, H., Tian, G., Ma, C., & Zhu, F. (2019). An analysis of energy flow in a turbocharged diesel engine of a heavy truck and potentials of improving fuel economy and reducing exhaust emissions. Energy Conversion and Management, 184, 456-465. doi:10.1016/j.enconman.2019.01.053O. Delgado, F. Rodríguez, R. Muncrief, Fuel efficiency technology in european heavy-duty vehicles: baseline and potential for the 2020 2030 time frame, Tech. rep., Int. Counc. Clean. Transport.(2017) https://www.theicct.org/publications/fuel-efficiency-technology-european-heavy-duty-vehicles-baseline-and-potential-2020.J. Norris, G. Escher, Heavy duty vehicles technology potential and cost study, Tech. rep., Int. Counc. Clean. Transport. (2017)https://www.theicct.org/publications/heavy-duty-vehicles-technology-potential-and-cost-study.Ezhilmaran, V., Vasa, N. J., & Vijayaraghavan, L. (2018). Investigation on generation of laser assisted dimples on piston ring surface and influence of dimple parameters on friction. Surface and Coatings Technology, 335, 314-326. doi:10.1016/j.surfcoat.2017.12.052Arslan, A., Masjuki, H. H., Kalam, M. A., Varman, M., Mosarof, M. H., Mufti, R. A., … Khurram, M. (2017). Investigation of laser texture density and diameter on the tribological behavior of hydrogenated DLC coating with line contact configuration. Surface and Coatings Technology, 322, 31-37. doi:10.1016/j.surfcoat.2017.05.037Marian, M., Tremmel, S., & Wartzack, S. (2018). Microtextured surfaces in higher loaded rolling-sliding EHL line-contacts. Tribology International, 127, 420-432. doi:10.1016/j.triboint.2018.06.024Triantafyllopoulos, G., Kontses, A., Tsokolis, D., Ntziachristos, L., & Samaras, Z. (2017). Potential of energy efficiency technologies in reducing vehicle consumption under type approval and real world conditions. Energy, 140, 365-373. doi:10.1016/j.energy.2017.09.023Macián, V., Tormos, B., Bermúdez, V., & Ramírez, L. (2014). Assessment of the effect of low viscosity oils usage on a light duty diesel engine fuel consumption in stationary and transient conditions. Tribology International, 79, 132-139. doi:10.1016/j.triboint.2014.06.003Macián, V., Tormos, B., Ruíz, S., & Ramírez, L. (2015). Potential of low viscosity oils to reduce CO2 emissions and fuel consumption of urban buses fleets. Transportation Research Part D: Transport and Environment, 39, 76-88. doi:10.1016/j.trd.2015.06.006Souza de Carvalho, M. J., Rudolf Seidl, P., Pereira Belchior, C. R., & Ricardo Sodré, J. (2010). Lubricant viscosity and viscosity improver additive effects on diesel fuel economy. Tribology International, 43(12), 2298-2302. doi:10.1016/j.triboint.2010.07.014Macián, V., Tormos, B., Ruiz, S., & Miró, G. (2016). Low viscosity engine oils: Study of wear effects and oil key parameters in a heavy duty engine fleet test. Tribology International, 94, 240-248. doi:10.1016/j.triboint.2015.08.028Taylor, R., Selby, K., Herrera, R., & Green, D. A. (2011). The Effect of Engine, Axle and Transmission Lubricant, and Operating Conditions on Heavy Duty Diesel Fuel Economy: Part 2: Predictions. SAE International Journal of Fuels and Lubricants, 5(1), 488-495. doi:10.4271/2011-01-2130Permude, A., Pathak, M., Kumar, V., & Singh, S. (2012). Influence of Low Viscosity Lubricating Oils on Fuel Economy and Durability of Passenger Car Diesel Engine. SAE International Journal of Fuels and Lubricants, 5(3), 1426-1435. doi:10.4271/2012-28-0010Tormos, B., Ramírez, L., Johansson, J., Björling, M., & Larsson, R. (2017). Fuel consumption and friction benefits of low viscosity engine oils for heavy duty applications. Tribology International, 110, 23-34. doi:10.1016/j.triboint.2017.02.007Van Dam, W., Miller, T., Parsons, G. M., & Takeuchi, Y. (2011). The Impact of Lubricant Viscosity and Additive Chemistry on Fuel Economy in Heavy Duty Diesel Engines. SAE International Journal of Fuels and Lubricants, 5(1), 459-469. doi:10.4271/2011-01-2124Skjoedt, M., Butts, R., Assanis, D. N., & Bohac, S. V. (2008). Effects of oil properties on spark-ignition gasoline engine friction. Tribology International, 41(6), 556-563. doi:10.1016/j.triboint.2007.12.001Rao, L., Zhang, Y., Kook, S., Kim, K. S., & Kweon, C.-B. (2019). Understanding in-cylinder soot reduction in the use of high pressure fuel injection in a small-bore diesel engine. Proceedings of the Combustion Institute, 37(4), 4839-4846. doi:10.1016/j.proci.2018.09.013Fan, C., Song, C., Lv, G., Wei, J., Zhang, X., Qiao, Y., & Liu, Y. (2019). Impact of post-injection strategy on the physicochemical properties and reactivity of diesel in-cylinder soot. Proceedings of the Combustion Institute, 37(4), 4821-4829. doi:10.1016/j.proci.2018.08.001Yamamoto, K., Kotaka, A., & Umehara, K. (2010). Additives for Improving the Fuel Economy of Diesel Engine Systems. Tribology Online, 5(4), 195-198. doi:10.2474/trol.5.195Marx, N., Ponjavic, A., Taylor, R. I., & Spikes, H. A. (2017). Study of Permanent Shear Thinning of VM Polymer Solutions. Tribology Letters, 65(3). doi:10.1007/s11249-017-0888-7Cui, J., Oberoi, S., Goldmints, I., & Briggs, S. (2014). Field and Bench Study of Shear Stability of Heavy Duty Diesel Lubricants. SAE International Journal of Fuels and Lubricants, 7(3), 882-889. doi:10.4271/2014-01-2791Rizzoni, G., Guzzella, L., & Baumann, B. M. (1999). Unified modeling of hybrid electric vehicle drivetrains. IEEE/ASME Transactions on Mechatronics, 4(3), 246-257. doi:10.1109/3516.789683Green, D. A., Selby, K., Mainwaring, R., & Herrera, R. (2011). The Effect of Engine, Axle and Transmission Lubricant, and Operating Conditions on Heavy Duty Diesel Fuel Economy. Part 1: Measurements. SAE International Journal of Fuels and Lubricants, 5(1), 480-487. doi:10.4271/2011-01-212

Spectral information to get beyond color in the analysis of water‑soluble varnish degradation

Spectral images were captured of paper samples varnished with two water-soluble materials: gum arabic and egg white. The samples were submitted to degradation processes that partially or totally eliminated the varnish from the substrate (water immersion and ageing). The spectral information was used to obtain average color data and to characterize the spatial and color inhomogeneity across pixels, showing that the pixel spectral data are critical for an accurate characterization of the degradation process of the varnishes. Since the varnishes typically become yellower with ageing, this study introduces two novel and simple-to-compute yellowness indices based on the spectral information, which are validated against a standard colorimetric index (ASTM-E313 2015). The potential uses of spectral information are demonstrated with several pieces of a real antique map sample by comparing the spectral information measured before and after cleaning the sample. To sum up, the main contributions of this study are the characterization of the spatial homogeneity through pixel-based spectral and color information and the proposal of spectral-based yellowing indices for two critical applications (ageing process follow-up and effect of cleaning), as demonstrated with synthetic and historical samples of varnished paper respectively.Spanish Ministry of Economy and Competitiveness, under research Grant DPI2015-64571-R. Spanish State Agency of Research (AEI) and the Ministry for Economy, Industry and Competitiveness (MIMECO) by means of the Grant Number FIS2017-89258-P with European Union FEDER (European Regional Development Funds) support

A collective effort to identify and quantify geo-energy risks

The increasing global demand for energy and the imminent need to reduce carbon emissions in our planet has led mankind to find new solutions. Some in the energy industry have taken special interest in geothermal reservoirs, a resource with the potential to provide large amounts of renewable energy. Meanwhile, the storage of carbon dioxide in underground geological formations presents a fantastic opportunity to discard CO2 and mitigate global warming. This study links efforts from academic institutions, industry energy operators, industrial partners and research institutes to answer fundamental scientific questions that can help us understand the subsurface and generate better exploitation practices. We examine the geology of reservoirs used for geothermal energy extraction and carbon dioxide capture. We use a combination of field geology, photogrammetry, mineral analysis and experimental rock mechanics to understand fracture networks and fluid flow paths of two geologically diverse reservoirs in Europe: 1) the Hengill geothermal system in south-west Iceland, and 2) the Carnmenellis granite geothermal system in Cornwall (UK). These results aim to provide experimental data to refine numerical models predicting fluid flow and contribute to the quantification of the associated risks of exploiting the subsurface

Functional behavior of the anomalous magnetic relaxation observed in melt-textured YBa2Cu3O7-δ samples showing the paramagnetic Meissner effect

We have studied the functional behavior of the field-cooled (FC) magnetic relaxation observed in melt-textured YBa2Cu3O7-δ (Y123) samples with 30 wt% of Y2Ba1Cu1O5 (Y211) phase, in order to investigate anomalous paramagnetic moments observed during the experiments. FC magnetic relaxation experiments were performed under controlled conditions, such as cooling rate and temperature. Magnetic fields up to 5T were applied parallel to the ab plane and along the c-axis. Our results are associated with the paramagnetic Meissner effect (PME), characterized by positive moments during FC experiments, and related to the magnetic flux compression into the samples. After different attempts our experimental data could be adequately fitted by an exponential decay function with different relaxation times. We discuss our results suggesting the existence of different and preferential flux dynamics governing the anomalous FC paramagnetic relaxation in different time intervals. This work is one of the first attempts to interpret this controversial effect in a simple analysis of the pinning mechanisms and flux dynamics acting during the time evolution of the magnetic moment. However, the results may be useful to develop models to explain this interesting and still misunderstood feature of the paramagnetic Meissner effect

Deformation of polycrystalline TRIP stainless steel micropillars

The deformation mechanisms of the metastable austenite phase of a transformation induced plasticity (TRIP) stainless steel, AISI 301LN, have been investigated by compression of multicrystalline micropillars of different crystallographic orientations, with particular attention on the strain-induced phase transformation from austenite to martensite. Intergranular shearing and twinning were observed to be the primary deformation mechanisms, with a predominant orientation developed in the austenitic phase, combined with limited planar slip within single grains of austenite. The phase transformation from austenite to ¿ and ¿’-martensite was clearly observed adjacent to the sheared regions using TEM-EBSD techniques. The ¿-martensite phase was found to be preferentially located in the regions near the grain boundaries which experienced higher shear stresses during compression.Peer ReviewedPostprint (author's final draft