Polycyclic aromatic hydrocarbons (PAHs) in the atmospheres of two French alpine valleys: sources and temporal patterns

International audienceAlpine valleys represent some of the most important crossroads for international heavy-duty traffic in Europe, but the full impact of this traffic on air quality is not known due to a lack of data concerning these complex systems. As part of the program "Pollution des Vallées Alpines" (POVA), we performed two sampling surveys of polycyclic aromatic hydrocarbons (PAHs) in two sensitive valleys: the Chamonix and Maurienne Valleys, between France and Italy. Sampling campaigns were performed during the summer of 2000 and the winter of 2001, with both periods taking place during the closure of the "Tunnel du Mont-Blanc". The first objective of this paper is to describe the relations between PAH concentrations, external parameters (sampling site localization, meteorological parameters, sources), and aerosol characteristics, including its carbonaceous fraction (OC and EC). The second objective is to study the capacity of PAH profiles to accurately distinguish the different emission sources. Temporal evolution of the relative concentration of an individual PAH (CHR) and the PAH groups BghiP+COR and BbF+BkF is studied in order to differentiate wood combustion, gasoline, and diesel emissions, respectively. The results show that the total particulate PAH concentrations were higher in the Chamonix valley during both seasons, despite the cessation of international traffic. Seasonal cycles, with higher concentrations in winter, are also stronger in this valley. During winter, particulate PAH concentration can reach very high levels (up to 155 ng.m-3) in this valley during cold anticyclonic periods. The examination of sources shows the impact during summer of heavy-duty traffic in the Maurienne valley and of gasoline vehicles in the Chamonix valley. During winter, Chamonix is characterized by the strong influence of wood combustion in residential fireplaces, even if the temporal evolution of specific PAH ratios are difficult to interpret. Information on sources given by PAH profiles can only be considered in qualitative terms

Chevron: Dudley Property

Core Repository Data FilesDriller: ChevronProject: Dudley Propertyhttps://digitalmaine.com/mgs_core_repository/1001/thumbnail.jp

Grid-aware Scheduling and Control of Electric Vehicle Charging Stations for Dispatching Active Distribution Networks. Part-II: Intra-day and Experimental Validation

In Part-I, we presented an optimal day-ahead scheduling scheme for dispatching active distribution networks accounting for the flexibility provided by electric vehicle charging stations (EVCSs) and other controllable resources such as battery energy storage systems (BESSs). Part-II presents the intra-day control layer for tracking the dispatch plan computed from the day-ahead scheduling stage. The control problem is formulated as model predictive control (MPC) with an objective to track the dispatch plan setpoint every 5 minutes, while actuated every 30 seconds. MPC accounts for the uncertainty of the power injections from stochastic resources (such as demand and generation from photovoltaic - PV plants) by short-term forecasts. MPC also accounts for the grid's operational constraints (i.e., the limits on the nodal voltages and the line power-flows) by a linearized optimal power flow (LOPF) model based on the power-flow sensitivity coefficients, and for the operational constraints of the controllable resources (i.e., BESSs and EVCSs). The proposed framework is experimentally validated on a real-life ADN at the EPFL's Distributed Electrical Systems Laboratory and is composed of a medium voltage (MV) bus connected to three low voltage distribution networks. It hosts two controllable EVCSs (172 kWp and 32 F~kWp), multiple PV plants (aggregated generation of 42~kWp), uncontrollable demand from office buildings (20 kWp), and two controllable BESSs (150kW/300kWh and 25kW/25kWh).Comment: 10 pages, 14 Figures, submitted for review in IEEE Transaction

Grid-aware Scheduling and Control of Electric Vehicle Charging Stations for Dispatching Active Distribution Networks. Part-I: Day-ahead and Numerical Validation

This paper proposes a grid-aware scheduling and control framework for Electric Vehicle Charging Stations (EVCSs) for dispatching the operation of an active power distribution network. The framework consists of two stages. In the first stage, we determine an optimal day-ahead power schedule at the grid connection point (GCP), referred to as the dispatch plan. Then, in the second stage, a real-time model predictive control is proposed to track the day-ahead dispatch plan using flexibility from EVCSs. The dispatch plan accounts for the uncertainties of vehicles connected to the EVCS along with other uncontrollable power injections, by day-ahead predicted scenarios. We propose using a Gaussian-Mixture-Model (GMM) for the forecasting of EVCS demand using the historical dataset on arrival, departure times, EV battery capacity, State-of-Charge (SoC) targets, etc. The framework ensures that the grid is operated within its voltage and branches power-flow operational bounds, modeled by a linearized optimal power-flow model, maintaining the tractability of the problem formulation. The scheme is numerically and experimentally validated on a real-life distribution network at the EPFL connected to two EVCSs, two batteries, three photovoltaic plants, and multiple heterogeneous loads. The day-ahead and real-time stages are described in Part-I and Part-II papers respectively.Comment: 10 pages, 13 figures (submitted for review in IEEE Transactions

Analysis of Pressure Transient Response for an Injector under Hydraulic Stimulation at the Salak Geothermal Field, Indonesia

ABSTRACT Four pressure fall-off pressure transient tests were conducted in a well being stimulated by high pressure injection. The tests were analyzed with a technique based on fractional flow in a composite reservoir. The results show the progress of the stimulation process as the measured reservoir properties change from test to test. Novel techniques for analysis of pressure transient tests are demonstrated. The reason for the very large wellbore storage effect usually found in injection fall-off tests is discussed and considered in the analysis

EVALUATING THE PERFORMANCE OF A PIPELINE PROTECTION SYSTEM TO PREVENT DAMAGE TO SUBSEA PIPELINES FROM DROPPED OBJECTS

ABSTRACT One of the primary concerns for subsea pipeline involves damage from dropped objects. Using risk analysis modeling, it is possible to estimate the likelihood of impact, as well as the consequence of damage. Chevron Energy Technology Company, Stress Engineering Services, Inc. (SES) and Geoscience Earth & Marine Services, Inc. (GEMS) conducted a study to evaluate the effectiveness of a pipeline protection system (PPS) designed to protect a subsea 16-inch products pipeline off the coast of Angola in West Africa in approximately 400 feet of water beneath the South Nemba platform. The plan prior to the study was for platform upgrades to be made and concerns existed regarding the potential for dropped objects. Chevron specified that the PPS be designed to withstand a minimum impact of 3 MJ, with the possibility for extending this to 5 MJ if possible. The work involved a combination of testing and analysis methods. Chevron developed the basic design of the PPS that included a large diameter upper (60-inch diameter) and a lower (72-inch diameter) halfpipe assemblies placed over the top of the 16-inch diameter pipeline. Preliminary analyses calculated the potential energy absorption capacity of the design considering variations in thickness of the PPS structural members. Using insights gained from the preliminary analysis, full-scale drop tests were performed on prototype PPS pieces fabricated from rolled and welded steel plate. These drop tests released a 23,850 lbs weight dropped from 25.2 feet, resulting in impact energies of 815 kJ. Significant deformation was inflicted to the PPS tests pieces during the drop tests; however, the 16-inch diameter pipe placed beneath the protection was untouched for all tests except the one that did not include the upper half-pipe shell. Once the full-scale testing efforts were completed, finite element modeling was used to evaluate the PPS to soil interaction. The West Africa soil is rather compliant and concerns existed prior to the final phase of this study regarding the level of rigidity that could be expected from the soil. The ABAQUS Explicit finite element software was used to simulate impact with a dropped object having energy levels up to 5 MJ. Results showed that with contribution from the surrounding soil the system design, including the PPS pieces and the mud mats, can withstand impact energies of 5 MJ when the thickness of the upper shell is 1.25 inches. The results of this study demonstrate that the Chevron energy design requirement can be satisfied using the appropriate PPS design. INTRODUCTION This paper details findings from a study that was performed for Chevron to assess the performance capacity of a pipeline protection system for a 16-inch diameter products pipeline off the coast of Angola in West Afric

Integration & Operation of a Microgrid at Santa Rita Jail

Santa Rita Jail is a 4,500 inmate facility located in Dublin CA, approximately 40 miles (65 km) east of San Francisco. Over the past decade, a series of Distributed Energy Resources (DER) installations and efficiency measures have been undertaken to transform the 3MW facility into a"Green Jail". These include a 1.2MW rated rooftop PV system installed in 2002, a 1MW molten carbonate fuel cell with CHP, and retrofits to lighting and HVAC systems to reduce peak loads. With the upcoming installation of a large-scale battery and fast static disconnect switch, Santa Rita Jail will become a true microgrid, with full CERTS Microgrid functionality. Consequently, the jail will be able to seamlessly disconnect from the grid and operate as an island in the event of a disturbance, reconnecting again once the disturbance has dissipated. The extent to which that jail is capable of islanding is principally dependant on the energy capacity of the battery-one focus of this investigation. Also presented here are overviews of the DER currently installed at the jail, as well as the value it provides by offsetting the purchase of electricity under the current Pacific Gas& Electric (PG&E) tariff

Environmental Technology and the Future of Flight

Purpose To examine the role of new aeronautical technologies in improving commercial aviation’s environmental performance. Methodology/approach Reviews the environmental improvements that may be conferred through the adoption of alternative aviation fuels and new airframe, engine and navigation technologies. Findings Although aeronautical technologies have evolved considerably since the earliest days of powered flight, the aviation industry is now reaching a point of diminishing returns as growing global consumer demand for air transport outstrips incremental improvements in environmental efficiency. The chapter describes some of the technological interventions that are being pursued to improve aviation’s environmental performance and discusses the extent to which these innovations will help to deliver a more sustainable aviation industry

The insecure airway: a comparison of knots and commercial devices for securing endotracheal tubes

BACKGROUND: Endotracheal Tubes (ETTs) are commonly secured using adhesive tape, cloth tape, or commercial devices. The objectives of the study were (1) To compare degrees of movement of ETTs secured with 6 different commercial devices and (2) To compare movement of ETTs secured with cloth tape tied with 3 different knots (hitches). METHODS: A 17 cm diameter PVC tube with 14 mm "mouth" hole in the side served as a mannequin. ETTs were subjected to repeated jerks, using a cable and pulley system. Measurements: (1) Total movement of ETTs relative to "mouth" (measure used for devices) (2) Slippage of ETT through securing knot (measure used for knots). RESULTS: Among commercial devices, the Dale(® )showed less movement than other devices, although some differences between devices did not reach significance. Among knots, Magnus and Clove Hitches produced less slippage than the Cow Hitch, but these differences did not reach statistical significance. CONCLUSION: Among devices tested, the Dale(® )was most secure. Within the scope offered by the small sample sizes, there were no statistically significant differences between the knots in this study