Phylodynamics of H5N1 Highly Pathogenic Avian Influenza in Europe, 2005-2010: Potential for Molecular Surveillance of New Outbreaks.

Previous Bayesian phylogeographic studies of H5N1 highly pathogenic avian influenza viruses (HPAIVs) explored the origin and spread of the epidemic from China into Russia, indicating that HPAIV circulated in Russia prior to its detection there in 2005. In this study, we extend this research to explore the evolution and spread of HPAIV within Europe during the 2005-2010 epidemic, using all available sequences of the hemagglutinin (HA) and neuraminidase (NA) gene regions that were collected in Europe and Russia during the outbreak. We use discrete-trait phylodynamic models within a Bayesian statistical framework to explore the evolution of HPAIV. Our results indicate that the genetic diversity and effective population size of HPAIV peaked between mid-2005 and early 2006, followed by drastic decline in 2007, which coincides with the end of the epidemic in Europe. Our results also suggest that domestic birds were the most likely source of the spread of the virus from Russia into Europe. Additionally, estimates of viral dispersal routes indicate that Russia, Romania, and Germany were key epicenters of these outbreaks. Our study quantifies the dynamics of a major European HPAIV pandemic and substantiates the ability of phylodynamic models to improve molecular surveillance of novel AIVs

Evaluation of robust epoxy resin sealants for wellbore integrity applications

During the drilling and completion phases of oil and gas wells, cement is placed in the wellbore as a barrier between the casing and the formation. All casing strings must be cemented to protect and support the casing, and to isolate production zones. The primary cement must prevent the wellbore fluids from migrating in an annular flow path so as to allow the wells to be utilized without any control problems. The primary cement may fail to deliver full zonal isolation due to several reasons such as insufficient mud removal before the cementing, casing expansion, and contraction, high fluid losses, cement free fluids, inadequate hydrostatic pressure, high-pressure tests and temperature variations across the cement causing micro-annuli and cracks that may allow fluids to migrate. In addition, if the cement is placed in zones where corrosive fluids are presented, chemical degradation could compromise the cement integrity. If any of these failures occurred during the life of the well, remedial job must be performed to restore the well integrity. Failing to restore the cement integrity may lead to unwanted severe consequences to the environment, the equipment, and personnel. This work presents the results of evaluating several epoxy resin sealants that have the potential to replace the conventional Portland cement used in remedial jobs. This study includes the rheological behavior, curing kinetics, injectivity, plugging performance against water and CO2, chemical resistance, and the mechanical properties of epoxy resin sealants. This work compares the results of epoxy resin sealants to that of the conventional Portland cement. The findings obtained from this work can be utilized in optimizing the cement remedial operations --Abstract, page iv

New wellbore-integrity classification for gas migration problems and new cement formulations using Graphene Nano Platelets to prevent gas migration through cement

Gas migration, one of the primary problems related to the integrity of oil wells, is caused by cement failures. Gas migration can result in costly well repairs and may endanger personal, equipment, and result in severe operational difficulties and environmental issues. The ultimate objectives of this research were to provide a comprehensive review of the problem and to provide a solution to the problem using Graphene Nano Platelets (GNPs). An intensive review was performed to understand the cement failures. The reasons behind these failures were analyzed and classified with respect to their locations in the wellbore. Recommendations and potential solutions for these problems were also suggested. A new classification was established and would work as a roadmap to understand the oil well cement failures and would help prevent their occurrence. An intensive laboratory work was conducted to better understand the cement and the cement testing methodologies. In addition, GNPs were added to the cement to enhance its properties. The evaluation of the neat cement and the new cement formulations included testing their mineralogy by implementing X-ray diffraction (XRD) analysis, testing the mechanical properties of the set cement, testing the stability and rheology of the liquid slurry, and evaluating the chemical shrinkage of the cement. In addition, the effects of adding GNPs on the hydration process of the cement was studied using isothermal calorimeter. The findings of this investigation showed that GNPs played a key role in regulating the microstructure of the hydration products of the cement, which enhanced the toughness of the cement without affecting its stability and flow-ability. The GNPs also aided in controlling the propagation of micro cracks within the cement matrix --Abstract, page iv

Symmetric Conditions for Strain Analysis in a Long Thick Cylinder under Internal Pressure Using NASIR Unstructured GFVM Solver

Utilization of symmetric condition in NASIR Galerkin Finite Volume Method for linear triangular element unstructured meshes is introduced for numerical solution of two dimensional strain and stress fields in a long thick cylinder section. The developed shape function free Galerkin Finite Volume structural solver explicitly computes stresses and displacements in Cartesian coordinate directions for the two- dimensional solid mechanic problems under either static or dynamic loads. The accuracy of the introduced algorithm is assessed by comparison of computed results of a thick cylinder under internal fluid pressure load with analytical solutions. The performance of the solver for taking advantage of symmetric conditions is presented by computation of stress and strain contours on a half and a quarter of the cylinder section

Utilizing NASIR Galerkin Finite Volume Analyzer for 2D Plane Strain Problems under Static and Vibrating Concentrated Loads

A Numerical Analyzer for Scientific and Industrial Requirements (NASIR) software which utilizes novel matrix free Finite Volume is applied for solving plane strain solid state problems on linear triangular element meshes. The developed shape function free Galerkin Finite Volume structural solver explicitly computes stresses and displacements in Cartezian coordinate directions for the two dimensional solid mechanic problems under either static or dynamic loads. The accuracy of the introduced algorithm is assessed by comparison of computed results of cantilever structural elements under static concentrated load with analytical solutions. Then, the performance of the introduced method to solve structural plane strain problem under forced and vibrating loads is demonstrated. The performance of the solver is presented in terms of stress and strain contours as well as convergence behavior of the method

Semiquantitative Decision Tools for FMD Emergency Vaccination Informed by Field Observations and Simulated Outbreak Data

We present two simple, semiquantitative model-based decision tools, based on the principle of first 14 days incidence (FFI). The aim is to estimate the likelihood and the consequences, respectively, of the ultimate size of an ongoing FMD epidemic. The tools allow risk assessors to communicate timely, objectively, and efficiently to risk managers and less technically inclined stakeholders about the potential of introducing FMD suppressive emergency vaccination. To explore the FFI principle with complementary field data, we analyzed the FMD outbreaks in Argentina in 2001, with the 17 affected provinces as the units of observation. Two different vaccination strategies were applied during this extended epidemic. In a series of 5,000 Danish simulated FMD epidemics, the numbers of outbreak herds at day 14 and at the end of the epidemics were estimated under different control strategies. To simplify and optimize the presentation of the resulting data for urgent decisions to be made by the risk managers, we estimated the sensitivity, specificity, as well as the negative and positive predictive values, using a chosen day-14 outbreak number as predictor of the magnitude of the number of remaining post-day-14 outbreaks under a continued basic control strategy. Furthermore, during an ongoing outbreak, the actual cumulative number of detected infected herds at day 14 will be known exactly. Among the number of epidemics lasting >14 days out of the 5,000 simulations under the basic control scenario, we selected those with an assumed accumulated number of detected outbreaks at day 14. The distribution of the estimated number of detected outbreaks at the end of the simulated epidemics minus the number at day 14 was estimated for the epidemics lasting more than 14 days. For comparison, the same was done for identical epidemics (i.e., seeded with the same primary outbreak herds) under a suppressive vaccination scenario. The results indicate that, during the course of an FMD epidemic, simulated likelihood predictions of the remaining epidemic size and of potential benefits of alternative control strategies can be presented to risk managers and other stakeholders in objective and easily communicable ways

Utilizing a New Eco-Friendly Drilling Mud Additive Generated from Wastes to Minimize the Use of the Conventional Chemical Additives

The cost of the drilling operation is very high. Drilling fluid presents 15 to 30% of the entire expense of the drilling process. Ordinarily, the major drilling fluids additives are viscosity modifiers, filtration control agents, and partial loss treatments. In this experimental work, full-set measurements under fresh and aged conditions, as well as high-temperature and high-pressure (HTHP) API filtration, were conducted to study the impacts of adding 0.5%, 1.5%, 2.5%, and 3.5% of black sunflower seeds’ shell powder (BSSSP) to spud mud. BSSSP of various grain sizes showed their ability to be invested for viscosity modifying, seepage loss controlling, and partial loss remediation. In addition to BSSSP eminent efficiency to be used as a multifunctional additive, the BSSSP is cheap, locally obtainable in commercial quantities, environmentally friendly additive and easy to grind into various desired grain sizes. Besides its outstanding strength to behave under conditions up to 30 h aged time and under 50 °C (122 °F) temperature, the utilization of powdered waste black sunflower shells in the drilling process and other industrial applications can reduce the effects of food waste on the environment and the personnel safety. To sum it up, experimental findings revealed that BSSSP can be used for multiple applications as a novel fibrous and particulate additive. The results elucidated BSSSP suitability in substituting or at least minimizing some of the traditional chemical materials utilized in the petroleum industry such as salt clay, polymers, and lost circulation materials (LCM)

Full-Set Measurements Dataset for a Water-Based Drilling Fluid Utilizing Biodegradable Environmentally Friendly Drilling Fluid Additives Generated from Waste

The oil and gas industry is moving towards more environmentally friendly practices. The environmental regulations regarding drilling waste management and disposal are motivating the industry to be more efficient with drilling operations. Environmentally friendly drilling fluid additives used in drilling operations reduces not only the negative implications on the environment but also reduces costs. This paper provides an experimental dataset of utilizing biodegradable waste materials as environmentally friendly drilling fluid additives. The data were collected through experimental evaluations of several waste materials including Potato Peels Powder (PPP), Mandarin Peels Powder (MPP), Fibrous Food Waste Material (FFWM), Palm Tree Leaves Powder (PTLP), Grass Powder (GP), and Green Olive Pits\u27 Powder (GOPP). The data presented herein are the raw results of the experiments, which were conducted to examine the ability of the biodegradable waste materials to improve the water-based drilling fluids. The data include the effects of adding these waste materials on different drilling fluid properties such as mud weight, filtration, pH, and the rheology. The mud weight was measured using mud balance, the filtration data were collected using API filter press for both low/high pressure and temperature, the pH was measured using pH meter, and the rheology was characterized using viscometer. The dataset is potentially useful to assist researchers working on developing environmentally friendly drilling fluid additives

Temporal dynamics of Middle East respiratory syndrome coronavirus in the Arabian Peninsula, 2012-2017

Altres ajuts: CERCA Programme/Generalitat de CatalunyaMiddle East respiratory syndrome coronavirus (MERS-CoV) remains a notable disease and poses a significant threat to global public health. The Arabian Peninsula is considered a major global epicentre for the disease and the virus has crossed regional and continental boundaries since 2012. In this study, we focused on exploring the temporal dynamics of MERS-CoV in human populations in the Arabian Peninsula between 2012 and 2017, using publicly available data on case counts and combining two analytical methods. Disease progression was assessed by quantifying the time-dependent reproductive number (TD-Rs), while case series temporal pattern was modelled using the AutoRegressive Integrated Moving Average (ARIMA). We accounted for geographical variability between three major affected regions in Saudi Arabia including Eastern Province, Riyadh and Makkah. In Saudi Arabia, the epidemic size was large with TD-Rs >1, indicating significant spread until 2017. In both Makkah and Riyadh regions, the epidemic progression reached its peak in April 2014 (TD-Rs > 7), during the highest incidence period of MERS-CoV cases. In Eastern Province, one unique super-spreading event (TD-R > 10) was identified in May 2013, which comprised of the most notable cases of human-to-human transmission. Best-fitting ARIMA model inferred statistically significant biannual seasonality in Riyadh region, a region characterised by heavy seasonal camel-related activities. However, no statistical evidence of seasonality was identified in Eastern Province and Makkah. Instead, both areas were marked by an endemic pattern of cases with sporadic outbreaks. Our study suggested new insights into the epidemiology of the virus, including inferences about epidemic progression and evidence for seasonality. Despite the inherent limitations of the available data, our conclusions provide further guidance to currently implement risk-based surveillance in high-risk populations and, subsequently, improve related interventions strategies against the epidemic at country and regional levels

Experimental Investigation of Environmentally Friendly Drilling Fluid Additives (Mandarin Peels Powder) to Substitute the Conventional Chemicals Used in Water-Based Drilling Fluid

The non-biodegradable additives used in controlling drilling fluid properties cause harm to the environment and personal safety. Thus, there is a need for alternative drilling fluid additives to reduce the amount of non-biodegradable waste disposed to the environment. This work investigates the potential of using mandarin peels powder (MPP), a food waste product, as a new environmentally friendly drilling fluid additive. A complete set of tests were conducted to recognize the impact of MPP on the drilling fluid properties. The results of MPP were compared to low viscosity polyanionic cellulose (PAC-LV), commonly used chemical additive for the drilling fluid. The results showed that MPP reduced the alkalinity by 20-32% and modified the rheological properties (plastic viscosity, yield point, and gel strength) of the drilling fluid. The fluid loss decreased by 44-68% at concentrations of MPP as less as 1-4%, and filter cake was enhanced as well when comparing to the reference mud. In addition, MPP had a negligible to minor impact on mud weight, and this effect was resulted due to foaming issues. Other properties such as salinity, calcium content, and resistivity were negligibly affected by MPP. This makes MPP an effective material to be used as pH reducer, a viscosity modifier, and an excellent fluid loss agent. This work also provides a practical guide for minimizing the cost of the drilling fluid through economic, environmental, and safety considerations, by comparing MPP with PAC-LV