The Design and Construction of a Reinforced Embankment on Soft Compressible Soil

The paper centres on the design and construction of a leachate lagoon at a landfill site located in Essex, United Kingdom (UK). The lagoon is to be used for the storage of between 150,000m3 and 200,000m3 of leachate generated by the adjacent landfill site as part of its treatment process. The location of the lagoon is on the southern boundary of the site, and is bounded to the north by the landfill itself, to the east by an existing leachate treatment lagoon and to the south and west by a flood defence bund for an adjacent creek and the Thames estuary beyond. Due to the proposed capacity and size of the lagoon, it qualifies in the UK as a reservoir under the 1975 Reservoirs Act and the design and construction is therefore constrained by this legislation. The area proposed for the lagoon is generally level, but with groundwater levels close to, or at, the ground surface. Waste dating from the 1950’s underlies the site and this overlies a generally soft stratum of alluvial clays and sands. A similar, but earlier, lagoon encountered significant difficulties during construction associated with the high groundwater levels and the trafficability of the waste and the soft alluvial materials. A discussion of the geotechnical and environmental issues considered during the design process is presented and the need for responsive design during the construction phase of a project is highlighted. The benefits of value engineering in civil engineering are also discussed in the context of design and construction projects. By their very nature, civil engineering projects such as this require imaginative and innovative design solutions, coupled with the use of non-traditional geomaterials. A discussion of the geosynthetics employed at this site is provided, in the context of their primary and secondary applications

Diammonium biphenyl-4,4′-disulfonate

In the title salt, 2NH4 +·C12H8O6S2 2−, the dianion has crystallographic inversion symmetry. A three-dimensional framework is formed from primary hydrogen-bonded sheet structures comprising ammonium N—H⋯Osulfonate inter­actions and is linked peripherally through the biphenyl residues of the anions. This open framework has 43 Å3 solvent-accessible voids

Particle Image Velocimetry Measurements to Evaluate the Effectiveness of Deck-Edge Columnar Vortex Generators on Aircraft Carriers

Candidate passive flow control devices were chosen from a NASA flow visualization study to investigate their effectiveness at improving flow quality over a flat-top carrier model. Flow over the deck was analyzed using a particle image velocimeter and a 1/120th scaled carrier model in a low-speed wind tunnel. Baseline (no devices) flow quality was compared to flow quality from combinations of bow and deck-edge devices at both zero and 20 degrees yaw. Devices included plain flaps and spiral cross-section columnar vortex generators attached in various combinations to the front and sides of the deck. Centerline and cross plane measurements were made with velocity and average turbulence measurements reported. Results show that the bow/deck-edge flap and bow/deck-edge columnar vortex generator pairs reduce flight deck turbulence both at zero yaw and at 20 degrees yaw by a factor of approximately 20. Of the devices tested, the most effective bow-only device appears to be the plain flap

Advanced propfan analysis for the family of commuter airplanes

Advanced propfans were selected to be used throughout the family of commuters. These propulsion systems offer a 25 to 28 percent fuel savings over comparably sized turbofans operating in the 1990s. A brief study of the propulsion systems available for the family of commuters is provided and the selection of the advanced turboprops justified. The propeller and engine designs and performance are discussed. The integration of these designs are examined. Also addressed is the noise considerations and constraints due to propfan installation

Elucidation of Essential Metabolic Pathways in the Apicoplast Organelle of Plasmodium falciparum

The apicoplast within Plasmodium falciparum has been thought of as an attractive source of potential drug targets since its discovery. While the apicoplast is essential throughout the parasite lifecycle it has been demonstrated that the organelle is dispensable in the asexual blood-stage of the parasite as long as the isoprenoid precursor isopentenyl pyrophosphate (IPP) is supplemented. IPP supplementation thus provides a bypass system which allows for the investigation and deletion of essential apicoplast specific proteins that would otherwise be impossible. Building on this work, we were successful in optimizing this system though the creation of a parasite line containing a genetically encoded alternative bypass we are calling PfMev. We have validated the functionality of the PfMev line and have established it as a new user-friendly platform that more easily allows for the investigation of essential apicoplast processes. Using PfMev line we elucidated the essentiality of numerous proteins and pathways within the apicoplast including multiple components of the SUF iron-sulfur cluster biosynthetic pathway and the proteins within the organelle that are reliant on these cofactors, the various proteins involved in carbon metabolism and the production of energy and reducing power within the organelle, in addition to the proteins involved in the generation and utilization of CoA within the apicoplast, among others. Not only were we able to determine which components of these pathways are essential for blood stage parasite survival, we also were able to determine which are required for the maintenance of the apicoplast organelle. Additionally, we made considerable progress in uncovering the functions of these proteins, and determining the ultimate roles that these various proteins play in the maintenance of the organelle

Subscale Ship Airwake Studies Using Novel Vortex Flow Devices with Smoke, Laser-Vapor-Screen and Particle Image Velocimetry

Ships produce vortices and air-wakes while either underway or stationary in a wind. These flow fields can be detrimental to the conduction of air operations in that they can adversely impact the air vehicles and flight crews. There are potential solutions to these problems for both frigates/destroyers and carriers through the use of novel vortex flow or flow control devices. This appendix highlights several devices which may have application and points out that traditional wind-tunnel testing using smoke, laser-vapor screen, and Particle Image Velocimetry can be useful in sorting out the effectiveness of different devices

Bis(2-hy­droxy­ethanaminium) biphenyl-4,4′-dicarboxyl­ate

In the title compound, 2C2H8NO+·C14H8O4 2−, the dihedral angle between the benzene rings of the dianion is 9.95 (12)°. In the crystal, the cations and anions are linked via inter­molecular O—H⋯O and N—H⋯O hydrogen bonds, generating layers lying parallel to (001)

Influenza Vaccine Effectiveness among US Military Basic Trainees, 2005–06 Season

Virtually all US military basic trainees receive seasonal influenza vaccine. Surveillance data collected from December 2005 through March 2006 were evaluated to estimate effectiveness of the influenza vaccine at 6 US military basic training centers. Vaccine effectiveness against laboratory-confirmed influenza was 92% (95% confidence interval 85%–96%)

Time-lapse monitoring of climate effects on earthworks using surface waves

The UK’s transportation network is supported by critical geotechnical assets (cuttings/embankments/dams) that require sustainable, cost-effective management, while maintaining an appropriate service level to meet social, economic, and environmental needs. Recent effects of extreme weather on these geotechnical assets have highlighted their vulnerability to climate variations. We have assessed the potential of surface wave data to portray the climate-related variations in mechanical properties of a clay-filled railway embankment. Seismic data were acquired bimonthly from July 2013 to November 2014 along the crest of a heritage railway embankment in southwest England. For each acquisition, the collected data were first processed to obtain a set of Rayleigh-wave dispersion and attenuation curves, referenced to the same spatial locations. These data were then analyzed to identify a coherent trend in their spatial and temporal variability. The relevance of the observed temporal variations was also verified with respect to the experimental data uncertainties. Finally, the surface wave dispersion data sets were inverted to reconstruct a time-lapse model of S-wave velocity for the embankment structure, using a least-squares laterally constrained inversion scheme. A key point of the inversion process was constituted by the estimation of a suitable initial model and the selection of adequate levels of spatial regularization. The initial model and the strength of spatial smoothing were then kept constant throughout the processing of all available data sets to ensure homogeneity of the procedure and comparability among the obtained V S VS sections. A continuous and coherent temporal pattern of surface wave data, and consequently of the reconstructed V S VS models, was identified. This pattern is related to the seasonal distribution of precipitation and soil water content measured on site

Time-lapse monitoring of fluid-induced geophysical property variations within an unstable earthwork using P-wave refraction

A significant portion of the UK’s transportation system relies on a network of geotechnical earthworks (cuttings and embankments) that were constructed more than 100 years ago, whose stability is affected by the change in precipitation patterns experienced over the past few decades. The vulnerability of these structures requires a reliable, cost- and time-effective monitoring of their geomechanical condition. We have assessed the potential application of P-wave refraction for tracking the seasonal variations of seismic properties within an aged clay-filled railway embankment, located in southwest England. Seismic data were acquired repeatedly along the crest of the earthwork at regular time intervals, for a total period of 16 months. P-wave first-break times were picked from all available recorded traces, to obtain a set of hodocrones referenced to the same spatial locations, for various dates along the surveyed period of time. Traveltimes extracted from each acquisition were then compared to track the pattern of their temporal variability. The relevance of such variations over time was compared with the data experimental uncertainty. The multiple set of hodocrones was subsequently inverted using a tomographic approach, to retrieve a time-lapse model of VP for the embankment structure. To directly compare the reconstructed VP sections, identical initial models and spatial regularization were used for the inversion of all available data sets. A consistent temporal trend for P-wave traveltimes, and consequently for the reconstructed VP models, was identified. This pattern could be related to the seasonal distribution of precipitation and soil-water content measured on site