Cleanup Operations Research Articles

Status of heavy metal in sediments of the Turag river in Bangladesh

The experiment was conducted to appraise the level of Cr, Pb, Cd, Ni, Zn, Cu, Fe and Mn contamination in 15 sediment samples of upstream of Turag river, at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh. The concentrations of Cr, Pb, Cd, Ni, Zn, Cu, Fe and Mn were 178.0, 18.3, 0.8, 155.4, 194.1, 54.8, 13679 and 5501.6 µg g-1 and the pH and EC ranged from 2.01-7.85 and 391-3910µS cm-1, respectively. Heavy metal concentrations were compared with geochemical background and standard values of previous report on the Turag and other rivers in Bangladesh. The average concentrations of Cr, Zn and Ni in sediments of the Turag are almost twice of the geochemical background i.e. average worldwide shale standard and continental upper crust. Cadmium is about three times higher than the geochemical background values. Chromium and Ni concentration exceeded the severe effect level (SEL), where as Cd, Zn and Cu exceeded toxicity reference values (TRV). The average Enrichment Factors (EFc) for Mn, Cd, Cr and Ni reflected moderate to extremely contaminated pollution. The pollution load index (PLI) varied from 1.65 to 3.21. The geoaccumulation index (Igeo) for Mn of 11 locations and Cd for a single location were greater than 2.0, and exhibited moderately to strongly polluted sediment quality. The Igeo for Zn in two locations and Ni in one location were greater than 1.0, indicated moderately polluted sediment quality. Sediment pollution load signaled alarming condition for city dwellers and aquatic ecosystem of the Turag river. Pollution sources to be sealed immediately and continuous monitoring on pollution prevention and cleanup operation is suggested.Progressive Agriculture 27 (2): 78-85, 2016

Mercury concentrations in urine of amerindian populations near oil fields in the peruvian and ecuadorian amazon

BackgroundMercury is a global contaminant with toxic, persistent effects on human health. Petroleum extraction is an important source of elemental mercury; little is known about human exposure levels near oil fields in the Amazon basin. ObjectivesTo characterize mercury levels in people living near oil production sites in the Peruvian and Ecuadorian Amazon, controlling for fish consumption, occupation, source of water and socio-demographic characteristics. MethodsAnalyze mercury levels in urine samples using cold vapour atomic fluorescence spectrometry from 76 indigenous men and women in eight riverine communities situated near oil wells or pipelines. Subjects answered a questionnaire soliciting socio-demographic, occupational and dietary information. Data were analyzed using multiple linear regression modeling. ResultsThe mean value of U-Hg was 2.61μg/g creatinine (95% CI: 2.14–3.08), with 7% of the sample recording values above the global background standard suggested by The World Health Organization (5μg/g creatinine). Women who used water from a surface source had two and a half times the amount of mercury in their urine (mean=3.70μg/g creatinine, 95% CI: 2.26–5.15) compared with women who used other water sources (mean =1.39μg/g creatinine, 95% CI: 0.51–2.25). Men who were involved in an oil clean-up operation had twice as much mercury in their urine (mean =3.07μg/g creatinine, 95% CI: 1.97–4.16) as did those who worked on other tasks (mean =1.56μg/g creatinine, 95% CI: 1.48–2.65). Mercury levels were not associated with the number of fish meals per week. ConclusionsIndigenous peoples of the Peruvian and Ecuadorian Amazon living near oil production sites generally had urine mercury levels within the global background standard suggested by the World Health Organization. Increased levels of mercury in urine were detected for men involved in oil spill remediation and for women who relied on surface water for household needs. These findings signal the need for strict safety measures to limit the amount of oil entering the waterways in Andean Amazonia so as to protect the health of indigenous people.

Impact on water surface due to deepwater gas blowouts

This paper presents a study on the impact of underwater gas blowouts near the ocean surface, which has a greater relevance to assess Health, Safety, and Environmental risks. In this analysis the gas flux near the surface, reduction of bulk density, and gas surfacing area are studied for different scenarios. The simulations include a matrix of scenarios for different release depths, release rates, and initial bubble size distributions. The simulations are carried out using the MEGADEEP model, for a location in East China Sea. Significant changes in bulk density and gas surface flux near the surface are observed under different release conditions, which can pose a potential threat for cleanup and rescue operations. Furthermore, the effect of hydrate formation on gas surfacing is studied for much greater release depths. The type of outcomes of this study is important to conduct prior risk assessments and contingency planning for underwater gas blowouts.

Heavy metal pollution load in sediment samples of the Buriganga river in Bangladesh

A study was conducted to assess the level of Cr, Pb, Cd, Ni, Zn, Cu, Fe and Mn contamination in the sediment samples of the Buriganga river, at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh. Total 14 sediment samples were collected from different areas of upstream of the Buriganga river. The mean concentrations of total Cr, Pb, Cd, Ni, Fe, Cu, Zn and Mn in the sediment samples were 173.4, 31.4, 1.5, 153.3, 481.8, 344.2, 12989 and 4036 ?g g-1, respectively. The range of pH and EC of sediment were 5.87-8.21 and 230-707 ?S cm-1, respectively. The mean value of organic matter in sediment samples was 13.4%. Heavy metal concentrations in sediment were compared with geochemical background and standard values, previous report on the Buriganga river and other rivers in Bangladesh. The average concentration of Cr, Pb and Ni in sediments of the Buriganga river is almost twice of the geochemical background i.e. average worldwide shale standard and continental upper crust value, Cd and Zn is about five times and Cu content is about ten times higher than the geochemical background values. Average concentration of Cr, Cu and Ni exceeded the severe effect level (SEL) values, where as Pb, Cd and Zn exceeded toxicity reference values (TRV). However, the concentration of heavy metal in the sediment samples of the Buriganga river for the year 2009 of the same river reported by corresponding author was relatively higher than this study average. The average Enrichment factors (EFc) for Zn, Cu, Mn and Cd reflects extremely contaminated pollution level which implies that these metals originated from point source of pollution and very severely enriched in river sediments. The pollution load index (PLI) of sediments of the studied region varied from 1.61-7.51. The geoaccumulation index (Igeo) for Cu of five locations was greater than 3.0, which exhibited strongly polluted sediment quality. The Igeo for Mn in 11 locations and Zn in 12 sites were greater than 1.0, indicated moderately polluted sediment quality. Heavy metal pollution intensity in the Buriganga river water and sediments signaled alarming condition for city dwellers and aquatic ecosystem of the river. Sustainable steps and continuous monitoring on pollution prevention and cleanup operation is suggested to minimize pollution.J. Bangladesh Agril. Univ. 13(2): 229-238, December 2015

The DEW Line and Canada’s Arctic Waste: Legacy and Futurity

During the Cold War, the United States and Canada embarked on an ambitious military construction project in the Arctic to protect North America from a northern Soviet attack. Comprised of sixty-three stations stretching across Alaska, Canada’s Arctic, Greenland, and Iceland, the Distant Early Warning (DEW) Line constitutes both the largest military exercise and waste remediation project in Canadian Arctic history. Despite the massive cleanup operation undertaken, the DEW Line’s waste legacy endures as a prominent and deeply rooted feature of Canada’s Arctic history. Drawing upon a rich historical, anthropological, military, political science, and environmental studies literature, this article explores waste as a key issue in the shifting narratives concerned with the modernization of the Canadian Arctic. While the DEW Line has been extensively analyzed in terms of its effects on the modernization of the Arctic, this article seeks to link Canadian sovereignty, security, resource exploitation, environmental stewardship, and Inuit self-determination directly to waste issues. As industrial activity and military exercises stand to significantly increase in the Arctic, I want to draw attention to the lessons of the DEW Line; that ”develop now; remediate later” incurs steep human health, environmental, financial, and political costs.

Mobile soak pits improve spray team mobility, productivity and safety of PMI malaria control programs

In the President’s Malaria Initiative (PMI)-funded Africa Indoor Residual Spraying Project (AIRS), end-of-day clean-up operations require the safe disposal of wash water resulting from washing the exterior of spray tanks and spray operators’ personal protective equipment. Indoor residual spraying (IRS) programs typically use soak pits - large, in-ground filters – to adsorb, filter and then safely degrade the traces of insecticide found in the wash water. Usually these soak pits are permanent installations serving 30 or more operators, located in a central area that is accessible to multiple spray teams at the end of their workday. However, in remote areas, it is often impractical for teams to return to a central soak pit location for cleanup. To increase operational efficiency and improve environmental compliance, the PMI AIRS Project developed and tested mobile soak pits (MSP) in the laboratory and in field applications in Madagascar, Mali, Senegal, and Ethiopia where the distance between villages can be substantial and the road conditions poor. Laboratory testing confirmed the ability of the easily-assembled MSP to reduce effluent concentrations of two insecticides (Actellic 300-CS and Ficam VC) used by the PMI AIRS Project, and to generate the minimal practicable environmental “footprint” in these remote areas. Field testing in the Mali 2014 IRS campaign demonstrated ease of installation and use, resulted in improved and more consistent standards of clean-up, decreased transportation requirements, improved spray team working conditions, and reduced potential for operator exposure to insecticide.

Effects of exposure to oil spills on human health: Updated review

ABSTRACTOil spills may involve health risks for people participating in the cleanup operations and coastal inhabitants, given the toxicological properties of the oil components. In spite of this, only after a few major oil spills (crude oil or fuel oil no. 6) have studies on effects of exposure to diverse aspects of human health been performed. Previously, Aguilera et al. (2010) examined all documents published to that date dealing with any type of human health outcome in populations exposed to oil spills. The aim of the present review was to compile all new information available and determine whether evidence reported supports the existence of an association between exposure and adverse human health risks. Studies were classified in three groups according to type of health outcome addressed: (i) effects on mental health, (ii) physical/physiological effects, and (iii) genotoxic, immunotoxic, and endocrine toxicity. New studies published on oil-spill-exposed populations—coastal residents in the vicinity of the spills or participants in cleanup operations—provide additional support to previous evidence on adverse health effects related to exposure regarding different parameters in all three categories considered. Some of the observed effects even indicated that several symptoms may persist for some years after exposure. Hence, (1) health protection in these individuals should be a matter of concern; and (2) health risk assessment needs to be carried out not only at the time of exposure but also for prolong periods following exposure, to enable early detection of any potential exposure-related harmful effects.

Physicochemical Properties and Metallic Constituent Load in the Water Samples of the Buriganga of Bangladesh

The study was conducted to assess the level of Cu, Zn, Pb, Cr, Fe, Mn, Cd and Ni contamination in the water samples of the Buriganga river. Total 14 water samples were collected from different areas of upstream of the Buriganga river to determine the physicochemical properties, concentration of different metallic constituents and assess the heavy metal pollution load. Atomic Absorption Spectrometer was used for analyzing the heavy metals of the samples. The mean concentration of Ca, Mg, Na, K in water samples were 0.779, 0.889, 140.39, 26.9 ?g mL-1, respectively. The mean concentration of Cr, Pb, Fe, Cu, Zn and Mn in the water samples were 0.17, 0.05, 0.67, 0.22, 0.55 and 0.17 ?g mL-1, respectively. The amount of Cd in all samples and Pb in 10 samples was below detectable limit of the instrument (0.01 ?g mL-1). Water pH ranged from 4.09 to 7.41 and EC was 346 to 7720 µS cm-1. Magnitude of heavy metal pollution in the Buriganga river system implies that the condition is very alarming and may severely affect the aquatic ecology of the river. To minimize the severe impact on city dwellers and aquatic ecology of the Buriganga river, sustainable steps and continuous monitoring on pollution prevention and cleanup operation is suggested.J. Environ. Sci. & Natural Resources, 8(2): 141-146 2015

Object-based image analysis for mapping earthquake-induced liquefaction ejecta in Christchurch, New Zealand

Earthquake-induced liquefaction poses significant risks to the urban environment and infrastructure lifelines. Following significant liquefaction, surface ejecta can impact facilities, impede transportation systems and complicate emergency response. Few studies have applied remote sensing technologies to map the spatial extent of liquefaction ejecta across entire affected urban areas. Here, we use object-based image analysis (OBIA) of aerial photography and light detection and ranging (LiDAR) data to map the occurrence of liquefaction ejecta following the 22 February 2011 earthquake in Christchurch, New Zealand. The OBIA achieved an 81.8 % overall accuracy for an initial classification that identified the presence or absence of liquefaction ejecta. The overall accuracy decreased to 74.8 % when attempting to distinguish between liquefaction ejecta deposited over differing land covers; this was due to the spectral and textural variation amongst these being insufficiently unique. We suggest that OBIA is useful for efficient determination of the spatial extent of post-disaster liquefaction ejecta in urban environments. This is significant for its potential to support emergency response and clean-up operations as well as longer-term ground performance and infrastructure impact assessments.

Testing Contamination Source Identification Methods for Water Distribution Networks

AbstractIn the event of contamination in a water distribution network (WDN), source identification (SI) methods that analyze sensor data can be used to identify the source location(s). Knowledge of the source location and characteristics are important to inform contamination control and cleanup operations. Various SI strategies that have been developed by researchers differ in their underlying assumptions and solution techniques. The following manuscript presents a systematic procedure for testing and evaluating SI methods. The performance of these SI methods is affected by various factors including the size of WDN model, measurement error, modeling error, time and number of contaminant injections, and time and number of measurements. This paper includes test cases that vary these factors and evaluates three SI methods on the basis of accuracy and specificity. The tests are used to review and compare these different SI methods, highlighting their strengths in handling various identification scenarios. The...

The Chernobyl – Thirty Years After The Post – Accidental Radiological – Hygienic and Medical Consequences

As the result of the Chernobyl NPP accident more than 200 thousand square kilometers of the European territories were contaminated by Cs-137 in the amount of above 37 kBq/m2 (1 Ci/km2 ). Belorussia, Russia and Ukraine amount up to 70% of this entire affected area. More than 600 000 people were engaged in the accidental cleanup operations, 340000 were evacuated or relocated within 1986-1991. The early stage evacuation efficacy is confirmed by the absence of acute radiation syndrome among the population and by the prevented collective dose which amounts to no less than 10 000 man/Sv. The effective measure to reduce the internal radiation dose to the population at the early accidental stage was introduction of maximum tentative permissive levels of radionuclide content in the foodstuffs.Among the identified post -accident medical consequences of the Chernobyl is the radiation syndrome found in 134 emergency cleanup workers within the first 24 hours of the accident’s development. Out of that number, 28 people died within the first four months, 19 people died before 2006. The accident’s liquidators developed radiation -induced leukemia ( the attributive risk value is 45-60% ). People exposed to high radiation doses display the statistically significant 18% morbidity increase of all types of solid cancers at the doses above 150 mSv. There is the statistically significant information indicating the increased amount of thyroid cancer morbidity among those who were just children and teenagers at the time of the accident. The adverse psychological consequences are accounted for not just the fear of overexposure but also for the disturbance of the habitual lifestyle especially mindful of the forced relocation.The longterm protection measures, radionuclide decay and selfcleaning of the contaminated areas resulted in the drastic reduction of the population dose in the radioactively contaminated territories. In 2015, only in some settlements of the Briansk Region’s the mean annual effective dose to the population exceeds 1 mSv. Presently the major goal is to transfer to normal human life with the change of the legal status of radioactively contaminated settlements in which the radiation situation is back to normal.The article provides the comparative data on the Chernobyl and the Fukushima - 1 accidental consequences and emphasizes the necessity of retaining the Chernobyl experience because the rapid advancement of the atomic energy around the world makes the mitigation of the accident’s consequences a truly international mission.

Technological and environmental challenges of Arctic shipping—a case study of a fictional voyage in the Arctic

Shipping in Arctic seas is challenging and poses an environmental risk. This paper presents a fictional case involving a multipurpose supply vessel transporting one large object (a 750-tonne compressor) and 24 containers loaded with chemicals and equipment for use by the petroleum industry in western Siberia. With technical details representative of vessels navigating the Arctic today, the fictitious ship Oleum has an ice class sufficient for navigating unaccompanied in the Barents and Kara seas, so no assistance is in range when, in late October, clogged fuel filters cause engine failure and the vessel eventually drifts ashore. Heeling over, Oleum loses both cargo and marine diesel oil. The scenario includes a successful helicopter rescue of the 16 crewmembers and a partial recovery of oil and chemicals by booms and skimmers. Recovery of chemicals with physical properties not allowing mechanical collection is not attempted. The scenario ends as the abandoned wreck is broken down at the stranding location, and containers rupture and discharge their cargo. The scenario postulates a moderate and short-lived environmental impact. The most visible effects of the grounding are the hull itself, the compressor and the spreading effects and degradation of oil and chemicals unmanageable for the clean-up operations. Keywords: Arctic shipping; technology; scenario; grounding; Northern Sea Route; environmental impact. (Published: 26 May 2016) To access the supplementary material for this article, please see the supplementary file in the column to the right (under Article Tools). Citation: Polar Research 2016, 35 , 27977, http://dx.doi.org/10.3402/polar.v35.27977

Fukushima: The Geo-trauma of a Futural Wave

The enduring effects of the March 2011 tsunami and nuclear meltdown at the Fukushima Dai-ichi Nuclear Power Station in Japan are explored in this paper through the notions of “geo-trauma” in the authors’ work and geophilosophy in Deleuze and Guattari’s philosophy. At the fulcrum of the 2011 global disaster was the nuclear meltdown and the emittance of radioactive material such as Caesium-137 and Strontium-90. This event mattered and matters, dispersing and deterritorializing organic, non-organic, and anorganic life in all of its articulations. In the wake of the singularity of Fukushima and the Anthropocene epoch more generally, it is timely to ruminate upon in what way this event as a futural wave makes “us” as the present generation both responsible for and part of the ongoing Fukushima meltdown. The questions that Fukushima provokes are not about the specific clean-up operation and environmental impacts around the plant, but more about how we can understand Fukushima as an event in nuclear history, or a singularity of “geo-trauma.” The folly of Fukushima and its aftermath, points to something fundamental about the Anthropocene, in the sense that the interconnected patterning that one may derive from the site of the disaster, gives new life to understanding the darker/non-human sides of ecology, the media, the unconscious, contamination, and space. The posthumanism of Deleuze and Guattari combined with the extinctional impetus of the Anthropocene will drive this analysis forward in terms of uncovering new forms of understanding about the Earth, World, territory, land, and Nature.

Correlation between Serum Levels of 3,3',5'-Triiodothyronine and Thyroid Hormones Measured by Liquid Chromatography-Tandem Mass Spectrometry and Immunoassay.

ObjectiveFor measuring serum 3,3′,5′-triiodothyronine (rT3) levels, radioimmunoassay (RIA) has traditionally been used owing to the lack of other reliable methods; however, it has recently become difficult to perform. Meanwhile, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently been attracting attention as a novel alternative method in clinical chemistry. To the best of our knowledge, there are no studies to date comparing results of the quantification of human serum rT3 between LC-MS/MS and RIA. We therefore examined the feasibility of LC-MS/MS as a novel alternative method for measuring serum rT3, thyroxine (T4), and 3,5,3′-triiodothyronine (T3) levels.MethodsAssay validation was performed by LC-MS/MS using quality control samples of rT3, T4, and T3 at 4 various concentrations which were prepared from reference compounds. Serum samples of 50 outpatients in our department were quantified both by LC-MS/MS and conventional immunoassay for rT3, T4, and T3. Correlation coefficients between the 2 measurement methods were statistically analyzed respectively.ResultsMatrix effects were not observed with our method. Intra-day and inter-day precisions were less than 10.8% and 9.6% for each analyte at each quality control level, respectively. Intra-day and inter-day accuracies were between 96.2% and 110%, and between 98.3% and 108.6%, respectively. The lower limit of quantification was 0.05 ng/mL. Strong correlations were observed between the 2 measurement methods (correlation coefficient, T4: 0.976, p < 0.001; T3: 0.912, p < 0.001; rT3: 0.928, p < 0.001).ConclusionsOur LC-MS/MS system requires no manual cleanup operation, and the process after application of a sample is fully automated; furthermore, it was found to be highly sensitive, and superior in both precision and accuracy. The correlation between the 2 methods over a wide range of concentrations was strong. LC-MS/MS is therefore expected to become a useful tool for clinical diagnosis and research.

Acetylation of corn silk and its application for oil sorption

Oil sorbents for cleanup operation should be of high sorption capacity, biodegradable, readily available, and low-cost. This is important for protection of the water environment, especially for oil spillage. Corn silk is a low-cost sorbent. In this study corn silk was treated by acetylation process to improve the sorption capacity. The process involved acetylation by acetic anhydride using N-bromosuccinimide (NBS) as a catalyst. Reaction time of 1, 3, 6, and 9 h, temperature of 90-120 °C and percentage of catalyst of 1-3 % were used in the experiment. The results showed that the highest oil sorption was 11.45 % weight percent gain (WPG). This was achieved at 3 % catalyst concentration in acetic anhydride and temperature of 120 °C for 6 h. A weight percent gain of 11.45 % was achieved. The effect of contact time on oil sorption capacity for different crude oil (Tapis and Arabian crude oils) was investigated. In general the sorption capacity reduced after the fifth cycle of sorption/ desorption. The characteristics of raw and treated corn silk were examined using FT-IR and FE-SEM. The treated corn silk as an organic waste material was found to have higher sorption capacity than that of the commercial synthetic sorbents such as polypropylene. This agriculture waste may be used to replace those of non-biodegradable oil sorbents.

Remediating Platforms by Raising Topsides

Technology Update The design of fixed offshore platforms requires a minimum clearance from the mean water level to the topsides structure. This clearance is generally referred to as an air gap. The air gap is determined such that under the maximum design conditions, the crest of the wave passing through the platform does not make contact with or inundate the topsides. Design codes such as API RP2A assess the air gap using the 1,000-year return period crest elevation combined with storm surge effects. Platform loads (shear and overturning moment) can increase by between 50% and 100% when the storm crest elevation exceeds the air gap and inundates the structure of the topsides. The consequences of a storm wave impact on a platform’s topsides can be catastrophic. This was graphically shown by the collapse or near destruction of a number of offshore structures in the US Gulf of Mexico (GOM) during hurricanes Ivan in 2004 and Katrina and Rita in 2005. Approximately 250 significant structures, including eight-leg drilling and production platforms in water depths of up to 450 ft, were destroyed by these storms collectively. Cleanup operations for the destroyed platforms remain ongoing. Costs for decommissioning a hurricane-destroyed platform are 10 times or greater the cost of decommissioning the same standing platform in a planned manner, excluding the value of lost or deferred oil and gas production. Given that the destroyed platforms were designed according to approved standards and guidelines, why did the structures collapse? Three primary reasons have been identified. The platforms were in poor condition (suffering from corrosion and historical damage) and thus had design resistances less than planned for in the original design. The maximum wave or waves experienced during these hurricanes were larger than assumed during the original design. Because wave loading on fixed offshore platforms varies with the square of the wave height, the actual loads experienced would be greater than those accounted for in the original design. And if the extreme wave crest exceeded the air gap, the design loads would increase exponentially and greatly exceed the original design case. The air gap for certain platforms was less than at the original time of installation, which resulted in unexpected topsides inundation. An Unacceptable Air Gap In view of the critical nature of the air gap in the design and long-term viability of an offshore platform, what are the circumstances under which the air gap distance would no longer be acceptable? Three specific cases should be considered. Actual design waves and storm surges are greater than those contemplated in the original design. The consequence factor used for the design of the platform has changed, thereby requiring the use of new and more onerous conditions (larger design waves). The platform air gap has decreased because of the offshore platform settling vertically relative to the mean sea level. Research conducted after the major hurricanes in 2004 and 2005 showed that the numerical storm wave hindcast models, which add updated information to original forecast models, underpredicted extreme wave heights for the central portion of the GOM, compared with data measured during these storms. The environmental criteria for the 100-year and 1,000-year return periods used for offshore platform design must be extrapolated from historical data recorded over much shorter time frames. Large variations in predicted values can arise from small errors made in fitting the historical data to complex statistical models. For example, the 100-year design wave in the GOM before these major storms was specified with a height of 72 ft. The updated 100-year design wave is now 91 ft, an increase of more than 25%. This would imply that the air gap selected for platforms designed to handle the smaller design wave will now be too small for the larger design wave condition.

Radiation Source Mapping with Bayesian Inverse Methods

We present a method to map the spectral and spatial distributions of radioactive sources using a limited number of detectors. Locating and identifying radioactive materials is important for border monitoring, in accounting for special nuclear material in processing facilities, and in cleanup operations following a radioactive material spill. Most methods to analyze these types of problems make restrictive assumptions about the distribution of the source. In contrast, the source mapping method presented here allows an arbitrary three-dimensional distribution in space and a gamma peak distribution in energy. To apply the method, the problem is cast as an inverse problem where the system’s geometry and material composition are known and fixed, while the radiation source distribution is sought. A probabilistic Bayesian approach is used to solve the resulting inverse problem since the system of equations is ill-posed. The posterior is maximized with a Newton optimization method. The probabilistic approach also provides estimates of the confidence in the final source map prediction. A set of adjoint, discrete ordinates flux solutions, obtained in this work by the Denovo code, is required to efficiently compute detector responses from a candidate source distribution. These adjoint fluxes form the linear mapping from the state space to the response space. The test of the method’s success is simultaneously locating a set of 137Cs and 60Co gamma sources in a room. This test problem is solved using experimental measurements that we collected for this purpose. Because of the weak sources available for use in the experiment, some of the expected photopeaks were not distinguishable from the Compton continuum. However, by supplanting 14 flawed measurements (out of a total of 69) with synthetic responses computed by MCNP, the proof-of-principle source mapping was successful. The locations of the sources were predicted within 25 cm for two of the sources and 90 cm for the third, in a room with an ˜4-× 4-m floor plan. The predicted source intensities were within a factor of ten of their true value.

Mechanic simulator fluids for clean-up operations and phases separation in vertical and horizontal wells with coiled tubing technology

This Project look for the processes simulation that take place in the oil Wells that operate the coiled tubing technique, so its workers, Company personal and anyone that wants to look these processes, can prove that consist in their cleaning methods and phase separation in these Wells, and at the same time, in what way the substances that in and out of well are controlled, show their physical features and allow that a person, without previous knowledge about the topic, may understand easily what is it injection fluid purpose by means of the C. T. in oil Wells.

Results of the clean-up operation to reduce pollution on flooded agricultural fields after the red mud spill in Hungary

In Hungary, the dam of a red mud reservoir breached shortly after noon on October 4, 2010. Approximately 0.7-1 million m(3) highly alkaline red mud with very low dry matter content flowed into the Torna Creek and the surrounding area, covering 1017 ha of agricultural land. Results of the risk assessment of the accident indicated that the red mud should be removed from the surface of fields where it formed a continuous layer of more than 5 cm. After the removal, samples were taken manually from depths of 0.0-0.2 m and 0.2-0.4 m in a sampling grid and background samples unaffected by red mud from the depth of 0.0-0.3 m. Total element contents (Ag, As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sn, Zn, and Na) and pH values were measured, and the results were analysed using correlation analysis and the Kruskal-Wallis probe. Dependence of the measured variables from elevation above sea level was studied using a 10 m by 10 m digital elevation model. Only ∼6.5% of the flooded area was temporarily designated as unsuitable for the production of food and fodder crops. In summary, the clean-up operation can be said to have been a success.

Fill removal from horizontal wellbore using foam in different coiled tubing/annulus diameter ratios

Coiled tubing is extensively used in oil industry to clean the wellbore to increase the productivity of oil/gas well by removing the fill/sand downhole. Well cleanup operation for low bottomhole pressure is problematic and common cleanout fluids are not effective as a circulation fluid due to severe pressure losses and low suspension capability. The use of foam as cleaning agent has become more popular due to its low density and high viscosity. The objective of this paper is to investigate the effect of foam quality and velocity on fill concentration and pressure loss during horizontal wellbore cleanup operation at different CT/annulus diameter ratios using Herschel-Buckley viscosity model. Results showed that foam quality and velocity are two deciding factors for the fill transport. Present study also showed that for all size of fill particles, lower foam quality removes fill more efficiently than higher foam quality. It is noticed that diameter ratio has high effect on particle removal when foam quality is 70%. Surprisingly, it is found that the effect of diameter ratio on fill concentration decreases when foam quality is 90%. Also, it is found that there is linear increase in pressure drop with increases of foam velocity.