Long-term sequestration process in the Borzęcin structure – observation evidence of the injected acid gas migration and possible leakage

2020 ◽  
Author(s):  
Jan Lubaś ◽  
Wiesław Szott ◽  
Piotr Łętkowski ◽  
Andrzej Gołąbek ◽  
Krzysztof Miłek ◽  
...  
Keyword(s):  
Ground Surface ◽  
Gas Migration ◽  
Acid Gas ◽  
Gas Leakage ◽  
Additional Information ◽  
Well Completion ◽  
Future Performance ◽  
Structure Observation ◽  
Basic Characteristics

The monograph presents the results of research carried out under the European SECURe (Subsurface Evaluation of CCS and Unconventional Risks) project in the years 2018-2020. A significant part of the SECURe project comprised evaluation of the effects of the long-term CO₂-H₂S sequestration process in the Borzęcin reservoir structure. This monograph includes all historical operational data determining assumed and implemented parameters of the process and various tests and analyses performed on downhole, as well as surface samples of reservoir fluids, taken from selected wells of the structure. They were aimed at identifying the propagation and intensity of acid gas migration within the structure and potential leakage pathways towards the ground surface. Some of the tests such as analysis of soil gas samples or samples of gas dissolved in brine have never been conducted before, and provided additional information on the safety of geological storage of acid gases within the Borzęcin structure. Corrosion potentials of well tubing and cement were also examined and analysed as they are crucial factors of well completion and leakage prevention. Key components of performed studies and analyses included a simulation model of the Borzęcin structure, constructed from a broad set of geological, geophysical and petrophysical data. The model was calibrated against available operational and measured data, and used to determine basic characteristics of the sequestration process such as: fluid saturations and compositions, their variation in time due to fluid migrations and the transition between various phases. The observation evidence indicating the absence of acid gas leakage from the Borzęcin structure was confirmed and explained by the simulation results of the sequestration process. The constructed and calibrated model of the structure was also used to predict the future performance of the current sequestration project. In addition, the capacity of the Borzęcin structure for increased sequestration was assessed by finding the optimum scenario of the risk-free sequestration performance.

scholarly journals Modelling of the Long-Term Acid Gas Sequestration and Its Prediction: A Unique Case Study

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4701
Author(s):  
Wiesław Szott ◽  
Piotr Łętkowski ◽  
Andrzej Gołąbek ◽  
Krzysztof Miłek
Keyword(s):  
Geological Structure ◽  
Monitoring Data ◽  
Large Set ◽  
Unique Case ◽  
Acid Gas ◽  
Gas Leakage ◽  
Simulation Results ◽  
Basic Characteristics

A twenty-four-year on-going project of acid gas sequestration in a deep geological structure was subject to detailed modelling based upon a large set of geological, geophysical, and petrophysical data. The model was calibrated against available operational and monitoring data and used to determine basic characteristics of the sequestration process, such as fluid saturations and compositions, their variation in time due to fluid migrations, and the gas transition between free and aqueous phases. The simulation results were analysed with respect to various gas leakage risks. The contribution of various trapping mechanisms to the total sequestrated amount of injected gas was estimated. The observation evidence of no acid gas leakage from the structure was confirmed and explained by the simulation results of the sequestration process. The constructed and calibrated model of the structure was also used to predict the capacity of the analysed structure for increased sequestration by finding the optimum scenario of the risk-free sequestration performance.

Repeated Occupational Exposure to Low-level Blast in the Canadian Armed Forces: Effects on Hearing, Balance, and Ataxia

2021 ◽  
Author(s):  
Ann Nakashima ◽  
Oshin Vartanian ◽  
Shawn G Rhind ◽  
Kristen King ◽  
Catherine Tenn ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Occupational Exposure ◽  
Armed Forces ◽  
Cross Sectional ◽  
Low Level ◽  
Additional Information ◽  
Adverse Health Effects ◽  
Blast Overpressure ◽  
Blast Exposure

ABSTRACT Introduction Recently, there has been increasing concern about the adverse health effects of long-term occupational exposure to low-level blast in military personnel. Occupational blast exposure occurs routinely in garrison through use of armaments and controlled blast detonations. In the current study, we focused on a population of breaching instructors and range staff. Breaching is a tactical technique that is used to gain entry into closed spaces, often through the use of explosives. Materials and Methods Initial measurements of blast overpressure collected during breaching courses found that up to 10% of the blasts for range staff and up to 32% of the blasts for instructors exceeded the recommended 3 psi exposure limit. Using a cross-sectional design, we used tests of balance, ataxia, and hearing to compare a sample of breachers (n = 19) to age-and sex-matched military controls (n = 19). Results There were no significant differences between the two groups on the balance and ataxia tests, although the average scores of both groups were lower than would be expected in a normative population. The prevalence of hearing loss was low in the breacher group (4 of 19), and hearing thresholds were not significantly different from the controls. However, the prevalence of self-reported tinnitus was significantly higher in the breacher group (12 of 19) compared with the controls (4 of 19), and all breachers who were identified as having hearing loss also reported tinnitus. Conclusions Our results suggest that basic tests of balance, ataxia, and hearing on their own were not sensitive to the effects of long-term occupational exposure to low-level blast. Some of the blast exposure levels exceeded limits, and there was a significant association of exposure with tinnitus. Future studies should supplement with additional information including exposure history and functional hearing assessments. These findings should be considered in the design of future acute and longitudinal studies of low-level blast exposure.

scholarly journals Performance of Norton Quantum Grinding Wheels

2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Removal Rates ◽  
Surface Burn ◽  
Conventional Grinding

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.

scholarly journals The MODIS Global Vegetation Fractional Cover Product 2001–2018: Characteristics of Vegetation Fractional Cover in Grasslands and Savanna Woodlands

2020 ◽  
Vol 12 (3) ◽  
pp. 406 ◽  
Author(s):  
Michael J. Hill ◽  
Juan P. Guerschman
Keyword(s):  
Land Use ◽  
Production Systems ◽  
Land Use Changes ◽  
Bare Soil ◽  
Additional Information ◽  
Fractional Cover ◽  
Grassland Type ◽  
Global Vegetation ◽  
Global Indicator

Vegetation Fractional Cover (VFC) is an important global indicator of land cover change, land use practice and landscape, and ecosystem function. In this study, we present the Global Vegetation Fractional Cover Product (GVFCP) and explore the levels and trends in VFC across World Grassland Type (WGT) Ecoregions considering variation associated with Global Livestock Production Systems (GLPS). Long-term average levels and trends in fractional cover of photosynthetic vegetation (FPV), non-photosynthetic vegetation (FNPV), and bare soil (FBS) are mapped, and variation among GLPS types within WGT Divisions and Ecoregions is explored. Analysis also focused on the savanna-woodland WGT Formations. Many WGT Divisions showed wide variation in long-term average VFC and trends in VFC across GLPS types. Results showed large areas of many ecoregions experiencing significant positive and negative trends in VFC. East Africa, Patagonia, and the Mitchell Grasslands of Australia exhibited large areas of negative trends in FNPV and positive trends FBS. These trends may reflect interactions between extended drought, heavy livestock utilization, expanded agriculture, and other land use changes. Compared to previous studies, explicit measurement of FNPV revealed interesting additional information about vegetation cover and trends in many ecoregions. The Australian and Global products are available via the GEOGLAM RAPP (Group on Earth Observations Global Agricultural Monitoring Rangeland and Pasture Productivity) website, and the scientific community is encouraged to utilize the data and contribute to improved validation.

scholarly journals Predictive Value of Technical Throwing Skills on Nomination Status in Youth and Long-Term Career Attainment in Handball

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Till Koopmann ◽  
Franziska Lath ◽  
Dirk Büsch ◽  
Jörg Schorer
Keyword(s):  
Logistic Regression ◽  
National Level ◽  
Age Groups ◽  
Age Group ◽  
Regression Analyses ◽  
Chi Square ◽  
Career Attainment ◽  
Future Performance ◽  
Younger Age

Abstract Background Research on talent in sports aims to identify predictors of future performance. This study retrospectively investigated 1) relationships between young handball field players’ technical throwing skills and (a) their potential nomination to youth national teams and (b) their long-term career attainment 10 years later, and 2) associations between nomination status and career attainment. Results Results from retrospectively predicting nomination status and career attainment using logistic regression analyses show that technical throwing skills were partly able to explain players’ nomination status (Nagelkerke R2: females 9.2%, males 13.1%) and career attainment (Nagelkerke R2: 9.8% for female players). Here, variables throwing velocity and time on exercise showed statistically significant effects. In addition, nomination status and career attainment were shown to be associated using chi-square tests (w of .37 and .23 for female and male players, respectively) and nomination status as a predictor increased the prediction of career attainment remarkably (Nagelkerke R2: females 20.3%, males 12.7%). Conclusions Given these results, basic technical throwing skills may serve rather as a prerequisite in this age group on national level, emphasizing its importance already on lower levels and in younger age groups. Furthermore, advantages from entering the national TID system early especially for females are discussed.

scholarly journals Virtual Connections: Improving Global Neurosurgery Through Immersive Technologies

2021 ◽  
Vol 8 ◽  
Author(s):  
George Higginbotham
Keyword(s):  
Geographical Location ◽  
Long Term Outcomes ◽  
Middle Income ◽  
Novel Technologies ◽  
Additional Information ◽  
Middle Income Countries ◽  
Travel Restrictions ◽  
Development Goals ◽  
Immersive Technologies

The field of neurosurgery has always been propelled by the adoption of novel technologies to improve practice. Although advancements have occurred in the diagnosis, treatment, and long-term outcomes of patients, these have not translated to global patient benefit. Up to five million people each year do not have access to safe and affordable neurosurgical interventions, and those in low- and middle-income countries (LMICs) are disproportionately affected. Current approaches to increase neurosurgical capacity are unlikely to meet the UN Sustainable Development Goals target by 2030, and many of the most successful programs have been disrupted by the travel restrictions of the COVID-19 pandemic. There is therefore a pressing need for creative virtual solutions. An area of growing relevance is the use of immersive technologies: virtual reality (VR) and augmented reality (AR). AR allows additional information to be superimposed onto the surgeon's visual field, thus enhancing intra-operative visualization. This can be used for remote tele-proctoring, whereby an experienced surgeon can virtually assist with a procedure regardless of geographical location. Expert guidance can therefore be given to both neurosurgical trainees and non-neurosurgical practitioners, further facilitating the growing practice of neurosurgical task-shifting in LMICs. VR simulation is another useful tool in remote neurosurgical training, with the potential to reduce the learning curve of complex procedures whilst conserving supplies in low-resource settings. The adoption of immersive technologies into practice is therefore a promising approach for achieving global neurosurgical equity, whilst adapting to the long-term disruptions of the pandemic.

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