Years Of Operating Experience Research Articles

Design and operation of a local cogeneration plant supplying a multi-family house (9,5 kW electrical / 35 kW thermic power) – a field report

In the paper at hand a small cogeneration plant that is suitable to supply heat and electric power to a three family house is presented. The plant is capable of delivering 9.5 kW electrical power to the mains and 30 kW thermal power used for heating the domestic hot water and the building respectively. Woodchips, a renewable energy carrier, are used to power the plant, so it is CO2 neutral. Powering an internal combustion engine with wood gas made from woodchips has turned out to be the right technology for small cogeneration plants. Such units are not available from stock; hence a prototype has been constructed. More than two years of operation experience with this prototype show the practicability of the system. The amount of maintenance work is acceptable and will be reduced in the future by optimization. Measurements concerning the electrical as well as the thermal efficiency are presented. During these measurements further room for improvement has been discovered to maximise output power and to lower losses. In summary it figured out that the plant operates reliable with acceptable amount of maintenance work. And, if we don’t calculate the amount of development work for the prototype, it is profitable.

MiniDAQ-3: Providing concurrent independent subdetector data-taking on CMS production DAQ resources

The data acquisition (DAQ) of the Compact Muon Solenoid (CMS) experiment at CERN, collects data for events accepted by the Level-1 Trigger from the different detector systems and assembles them in an event builder prior to making them available for further selection in the High Level Trigger, and finally storing the selected events for offline analysis. In addition to the central DAQ providing global acquisition functionality, several separate, so-called “MiniDAQ” setups allow operating independent data acquisition runs using an arbitrary subset of the CMS subdetectors. During Run 2 of the LHC, MiniDAQ setups were running their event builder and High Level Trigger applications on dedicated resources, separate from those used for the central DAQ. This cleanly separated MiniDAQ setups from the central DAQ system, but also meant limited throughput and a fixed number of possible MiniDAQ setups. In Run 3, MiniDAQ-3 setups share production resources with the new central DAQ system, allowing each setup to operate at the maximum Level-1 rate thanks to the reuse of the resources and network bandwidth. Configuration management tools had to be significantly extended to support the synchronization of the DAQ configurations needed for the various setups. We report on the new configuration management features and on the first year of operational experience with the new MiniDAQ-3 system.

Long-term experience of the thermo-active ground source system at the metro station Taborstrasse in Vienna

Four of the stations newly opened during the underground extension of the U2 line in Vienna in 2008 have been covering a large part of their heating and cooling needs for now almost one and a half decades by using geothermal energy, which is generated by means of energy diaphragm walls, energy piles and energy bottom slabs of the station buildings. As this was the first infrastructure building of this type and scale worldwide at the time of construction, one of the diaphragm walls of the Taborstraße station was equipped with numerous sensors to obtain data sets for the thermo-mechanical long-term behavior of these wall elements for the very first time. Continuous measurements with automatic data recording were initially carried out from April 2008 until May 2011. In October 2020, the measurements were resumed with the existing sensors, this time manually and once a month, in order to carry out a long-term comparison of the measurement data and to create a basis for assessing the effects of the geothermal operation on its structural components. This paper gives an overview of the Taborstraße station with a focus on the thermally activated geostructures and their instrumentation. A comparison of the recorded generated energy with the predicted heating and cooling demand is discussed in the context of the energy data. In addition, the temperature and the strain behavior of the observed energy diaphragm wall is discussed based on the measurement data collected over a period of around 14 years of operational experience.

Indikátor přívalových povodní – zkušenosti z provozu

Flash floods are one of the most risky natural phenomena. It is very difficult to predict exactly where they will occur and they usually come very quickly. When there is a threat of flash floods, early warning is exactly what decides on the protection of the lives and property of inhabitants. For these reasons, a Flash Flood Indicator (FFI) has being developed in the Czech Hydrometeorological Institute (CHMI) for a long time, aiming to draw attention to the possibility of a flash flood or local flooding. The main purpose of this contribution is not to describe details of FFI algorithms, but to evaluate the functioning of the FFI on the basis of more than ten years of operation experience. On a basis of specific cases of significant rainfall episodes, especially from recent years, the potential benefits of FFI are shown, not only for the operational forecasting service of the CHMI, but also for wider public. At the end of the contribution, the possibilities of further development of FFI are outlined.

Determinants of Tax Non-compliance Behaviour of Small and Medium Scale Enterprises in Nigeria

The unpredictable nature of crude oil prices in the market requires the government of any economy to develop solid tax bases by generating income from sources especially small and medium enterprises (SMEs) to guarantee revenue that can engender sustainable fiscal policy. This study, therefore, focuses on evaluating and prioritizing the motive toward tax compliance and avoidance among registered SMEs, with at least five years of operational experience, in Lagos, Nigeria. A cross-sectional survey design was adopted with primary data gathered from 382 SME owners/managers derived from the multi-stage sampling technique. Utilizing the Analytical Hierarchy Process (AHP), data gathered were analysed. The results revealed that, out of the six tested, economic criteria and their factors are the most important criteria influencing both tax avoidance and compliance decision. Moreover, to strategically enhance SMEs’ tax compliance, government spending, economy, and fiscal policy need to be logically positioned in favour of SME operators.

Evaluation of the aging management system for the Triga research nuclear reactor in Brazil / Avaliação do sistema de gerenciamento do envelhecimento do reator nuclear de pesquisa Triga no Brasil

As most research reactors have over 40 years of operational experience, maintenance, modernization and renovation are increasingly important for safety and operational life extension. This is due to the monitoring and development of techniques to control and mitigate the negative effects of operating conditions on structures, systems and components. Aging management is a strategy of engineering, operation, maintenance and other actions to control, within acceptable limits, the aging degradation of the facility. The first criticality of the IPR-R1 Triga research reactor (Training, Research, Isotopes, Atomics) occurred in 1960 with a maximum thermal power of 30 kW. Therefore, this reactor has been operating for more than 60 years. One of the issues that comes from the long time of the operation is the management of aging. This includes functions and issues related to operation, inspections, design changes, testing, and others. The IPR-R1 reactor is a North American project. So, the requirements of United State Nuclear Regulatory Commission (U.S.NRC) are applicable. This article discusses the International Atomic Energy Agency (IAEA), and U.S.NRC requirements to implement an aging management system for the CDTN IPR-R1 Triga Reactor.

Comparison of woven endobridge device sizing with conventional measurements and virtual simulation using the sim&size software: a multicenter experience

Selection of the appropriate device size mandatory during aneurysm treatment with a Woven EndoBridge (WEB). We aimed to investigate if virtual simulation with Sim&Size software may have an impact on technical, angiographic, and clinical outcomes after WEB treatment. Data from two large-volume centers were collected and compared (January 2017–January 2020). Virtual simulation was systematically adopted in one center, while conventional sizing was used in the other one. Outcomes were the duration of intervention, the radiation dose (in milligrays, the number of corrective interventions for inappropriate WEB size, the number of WEBs not deployed, angiographic occlusion, and complications. Univariate and multivariate linear models were adopted. A total of 186 aneurysms were treated with WEB (109 with and 77 without virtual simulation). Patient characteristics and aneurysm features were comparable among virtual and conventional sizing, except for mean age (62.2±11.8 years and 56.2±10.1 years, P=0.0004) and median aspect ratio (1.6, IQR=1.2–2 and 1.2, IQR=1–1.6, P=0.0001). Years of operator experience were comparable. Virtual simulation was independently associated with shorter intervention time (45min, IQR=33–63.5min vs 63.5min, IQR=41– 84.7 min, P=0.0001), lower radiation dose (1051 mGy, IQR=815–1399mGy vs 1207 mGy, IQR=898–2084 mGy, P=0.0001), and lower number of WEBs not deployed (26/77=33.7%vs 8/109=7.3%, P=0.0001). The need for additional maneuvers was significantly lower in the virtual simulation group (5/109=4.6%vs 12/77=15.6%, P=0.021). Angiographic outcomes and complications were comparable. In this multicenter experience, virtual simulation with Sim&Size software seems to facilitate the selection of the appropriate WEB device for aneurysm treatment, reducing the time of intervention, the radiation dose, the number of devices not deployed, and the need for corrective interventions (references 1 to 15)

On the Future of Fission and Solar Energy

Our attitudes towards the risks of climate change must be reconsidered. We must recognise that the consequences will be huge and inevitable if we do not act now. Better to accept a few false alarms rather than be unprepared for a climate catastrophe. An outstanding example is the calculation by groups from Germany and the UK in 2009 (1) of the allowable emissions of CO2 before a 2°C increase in global temperature is exceeded. This leaves very little time, only 4 to 8 years, for mitigation measures.
 Nuclear fission now presents a formidable fleet of some 450 reactors benefitting from over 50 years of operational experience. Throughout decades of development, they reached outstanding safety standards, exceeding those of most renewable sources. However, the threat of climate change is calling this perspective into question as nuclear technology requires long-term stability of institutions. The future of nuclear fission will be determined after the expiration of the next decade with the development of hydro, solar and wind energy as replacements. For Croatia, in view of future climate insecurity, we cannot recommend the construction of a nuclear power plant built to operate from 2043 to 2083 (2) as a replacement for the outgoing NE Krško plant. Instead, we should intensify the development of our renewable resources.

An autonomous drone-based system for inspection of electrical substations

In the years to come, large power grid operators will operate and maintain an ever-increasing asset base. New innovative solutions are needed to increase the quality and efficiency of asset management to avoid corresponding growth in resources and cost. To this end, autonomous unmanned aerial vehicles (UAVs) provide a range of possibilities. Here, we present a novel prototype solution for autonomous and remotely operated inspection missions with resident drones on electrical substations, comprising: (1) an autonomous drone with sense and avoid and robustness to harsh weather capability; (2) a drone hangar for remote operations; and (3) drone operations and data acquisition management software. Further, we discuss the possibilities and challenges that such a system offers and give an overview of requirements that are key to realizing the potential of drones for improved asset management. These requirements are based on years of operational experience with electrical substations combined with the lessons learned during the development and testing of our drone system. We also experimentally investigate safety distances between the drone and high-voltage infrastructure. We demonstrate the usefulness of our autonomous inspection solution through extensive field testing at one of Statnett’s fully operational electrical substations.

Operational and economic analysis of a Velox-type combined heat & power plant with a throttle valve

For many years, the Department of Power Engineering and Turbomachinery of the Silesian University of Technology has been using a small-capacity (about 500 kWe) steam-gas power plant. Based on many years of experience in operation of this power plant utilizing the Velox-type gas-steam system, an idea arose to modify this type of thermal power cycle to create a combined heat and power (CHP) plant of small capacity, dedicated for distributed heat and power production or production process steam with high temperature. Previous thermodynamic and economic analysis of that type of low-power CHP plant confirmed many advantages of using this type of solution in low-power engineering. The new idea is to add a throttle valve between the economizer and the evaporator for the reference cycle of the gas-steam Velox-type CHP plant. It was further assumed that water would partially be vaporized on the valve. This paper presents a thermodynamic and economic analysis of this type of a system with an added throttle valve. Downstream the valve, the evaporated water fraction is fed directly into the steam superheater. It is determined how such a retrofit affects the system thermodynamic and economic characteristics. The system is modelled in the EBSILON® Professional 14 software.

Comparison of Woven EndoBridge device sizing with conventional measurements and virtual simulation using the Sim&Size software: a multicenter experience

BackgroundSelection of the appropriate device size mandatory during aneurysm treatment with a Woven EndoBridge (WEB). We aimed to investigate if virtual simulation with Sim&Size software may have an impact on...

The impact of surgeon experience on perioperative complications and operative measures following thoracolumbar 3-column osteotomy for adult spinal deformity: overcoming the learning curve.

Posterior-based thoracolumbar 3-column osteotomy (3CO) is a formidable surgical procedure. Surgeon experience and case volume are known factors that influence surgical complication rates, but these factors have not been studied well in cases of adult spinal deformity (ASD). This study examines how surgeon experience affects perioperative complications and operative measures following thoracolumbar 3CO in ASD. A retrospective study was performed of a consecutive cohort of thoracolumbar ASD patients who underwent 3CO performed by the senior authors from 2006 to 2018. Multivariate analysis was used to assess whether experience (years of experience and/or number of procedures) is associated with perioperative complications, operative duration, and blood loss. A total of 362 patients underwent 66 vertebral column resections (VCRs) and 296 pedicle subtraction osteotomies (PSOs). The overall complication rate was 29.4%, and the surgical complication rate was 8.0%. The rate of postoperative neurological deficits was 6.2%. There was a trend toward lower overall complication rates with greater operative years of experience (from 44.4% to 28.0%) (p = 0.115). Years of operative experience was associated with a significantly lower rate of neurological deficits (p = 0.027); the incidence dropped from 22.2% to 4.0%. The mean operative time was 310.7 minutes overall. Both increased years of experience and higher case numbers were significantly associated with shorter operative times (p < 0.001 and p = 0.001, respectively). Only operative years of experience was independently associated with operative times (p < 0.001): 358.3 minutes from 2006 to 2008 to 275.5 minutes in 2018 (82.8 minutes shorter). Over time, there was less deviation and more consistency in operative times, despite the implementation of various interventions to promote fusion and prevent construct failure: utilization of multiple-rod constructs (standard, satellite, and nested rods), bone morphogenetic protein, vertebroplasty, and ligament augmentation. Of note, the use of tranexamic acid did not significantly lower blood loss. Surgeon years of experience, rather than number of 3COs performed, was a significant factor in mitigating neurological complications and improving quality measures following thoracolumbar 3CO for ASD. The 3- to 5-year experience mark was when the senior surgeon overcame a learning curve and was able to minimize neurological complication rates. There was a continuous decrease in operative time as the surgeon's experience increased; this was in concurrence with the implementation of additional preventative surgical interventions. Ongoing practice changes should be implemented and can be done safely, but it is imperative to self-assess the risks and benefits of those practice changes.

12 More Books Every Green Beret Should Read: An Annotated Bibliography

In 2018, three Special Forces personnel published an annotated biography called “12 Books Every Green Beret Should Read”. The authors’ purpose was to provide new members of Special Forces a concise reading list that would expand their knowledge of unconventional warfare. This version focuses on the development of mid-career officers, warrant officers, and noncommissioned officers with multiple years of operational experience. Like the original work, the idea of this recent version is that mid-career green berets would read one book per month over a year-long period to better prepare themselves for planning and executing challenging UW operations.

Residual airway foreign bodies in children who underwent rigid bronchoscopy

ObjectiveTo analyze the causes of residual airway foreign bodies in children who underwent rigid bronchoscopy in order to improve the success rate of primary surgery. MethodsClinical data from 1130 children with airway foreign bodies, including 736 males and 394 females aged 0.42–14 years, who underwent rigid bronchoscopy in our hospital from January 2015 to May 2018 were retrospectively collected and analyzed by cluster sampling. Clinical characteristics including sex, age, time of onset, location of the foreign body, type of foreign body and experience of surgeon were gathered. All patients were classified into two groups as Group A (with residual airway foreign bodies) and Group B (without residual airway foreign bodies) according to chest CT scans and fiberoptic bronchoscope examinations after rigid bronchoscopy. The values were compared between the two groups. ResultsThirty-one patients with residual foreign bodies were confirmed by fiberoptic bronchoscopy among 1130 children with airway foreign bodies who underwent rigid bronchoscopy under general anesthesia. The percentage of residual airway foreign body was 2.7%. The mean age was 1.55 ± 0.46 years (range 1–3 years). There were 24 male patients (77.4%), and 7 female patients (22.6%), with a male/female ratio of 3.43:1. The time of onset was 1.0 (interquartile range: 1.0–8.0) day. There were no significant difference in age, sex and time of onset between the two groups. Most residual foreign bodies were food-related: nuts (n = 27, 87.1%), beans (n = 3, 9.7%), and one case was unclear in nature (3.2%). The residual incidence of fragile foreign bodies was higher than non-friable foreign bodies (P = 0.028). The most common residual foreign body locations were left superior lobar bronchi (32.3%), left inferior lobar bronchi (25.8%) and right inferior lobar bronchi (25.8%). The residual rate of foreign bodies for surgeons with more than 5 years of operative experience was 1.92%, and 4.25% for surgeons with less than 5 years of operation experience, showing a significant difference (P = 0.022). ConclusionFriable foods, the complicated structure of the bronchus tree and the surgeon's experience are important causes of residual foreign bodies in the airway. Surgeons with sufficient experience are important for the success of the procedure, which is supported by chest CT and flexible bronchoscopy.

The analysis of a Velox-type CHP plant for various gaseous fuels

For many years, the Institute of Power Engineering and Turbomachinery of the Silesian University of Technology has been using a small-capacity (about 500 kWe) steam-gas power plant. Based on many yearsof experience in operation of this power plant utilizing the Velox-type gas-steam system, an idea arose to modify this type of thermal power cycle to create a combined heat and power (CHP) plant of small capacity, dedicated for distributed heat and power production of the range up to 500 kW or production process steam with high temperature. Previous thermodynamic and economic analysis of that type of CHP plant were conducted for natural gas as afuel. The new idea is use the alternative gas fuels or waste heat for Velox-type CHP plant. An adaptation of the Velox-type CHP plant for various fuelscan be done in simple way by moving the combustion chamber out from the setof heat exchangers, in similar way as it is done for HRSG. This paper presents a thermodynamic analysis of the Velox-type steam-gas cycle fired with various alternative gas fuels such as coke gas, blast furnace gas, biogas orgas from gasification. The systems are modelled in the EBSILON® Professional 13 program.

Potential analyses for dynamic rating optimization on basis of four years of operational experience in Austria

The paper presents the results of the potential analyses for dynamic rating optimization on the basis of five years operational experience in Austria. The results are shown for two exemplary overhead lines in APG’s grid, both with approx. 100 km length of route. One line is located in a mountainous landscape where the weather conditions along the line can widely vary. Another line is located in a flat landscape where the changes of wind speed and ambient temperature along the line are smaller. Because APG tried to minimize the number of weather stations, the weather conditions have to be estimated conservatively along the lines from weather data measured in two substations per line only. Therefore, factors for reducing the wind speed and offset values for increasing the ambient temperature are used. To estimate the gain in ampacity that could be reached as a maximum value, the reduction factors and the offset values are adapted. Based on this approach it can be evaluated if the possibly available gain in ampacity justifies necessary measures e. g. for setting up and implementing new weather stations. The results show that the ampacity possible with dynamic rating is already utilized very well using two weather stations per OHL. Using a higher number of weather stations and assuming that this could decrease the necessary conservative reduction factors and offset values would result in additional ampacity in average in the range of some percent. Furthermore, the additional ampacity can reach peak values up to some ten percent. Exemplary days with high ( $n-1$ ) loads are shown where this additional ampacity could be sufficient to avoid congestion management measures. The ex-post analysis of saved congestion management expenditures shows a significant effect of dynamic rating on the costs.

Diagnostic value and influencing factors of endoscopic ultrasound-guided fine needle aspiration for space-occupying lesions of gastrointestinal adjacent tissue

Objective To investigate the diagnostic value of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) on malignant lesions in gastrointestinal adjacent tissue, and further to analyze the risk factors influencing positive rate of EUS-FNA. Methods The clinical data of 171 patients undergoing EUS-FNA from January 2009 to May 2016 were collected. The lesion location, size and characteristics, the number of needle passes, puncture suction negative pressure, size of puncture needle, and years of operator experience in EUS were retrospectively analyzed. Results The overall sensitivity, specificity, and accuracy of EUS-FNA in the diagnosis of malignant lesions were 78.3% (83/106), 100.0% (65/65), and 86.5% (148/171), respectively. The univariable logistic regression analysis demonstrated that the risk factors of EUS-FNA were lesion location, lesion characteristics, and lesion size. In multivariate analysis, larger lesion size (OR=1.029, 95%CI: 1.011-1.047, P=0.001) and lesion characteristics of solid (OR=5.098, 95%CI: 1.324-19.633, P=0.018) were independent factors affecting the positive rate of EUS-FNA. Among 171 cases performed by EUS-FNA, the incidence of postoperative complications was 1.75% (3/171) included 2 cases of fever and 1 case of acute pancreatitis, which were improved after conservative treatment. Conclusion EUS-FNA is a safe and effective method of cytological and histological diagnosis with high accuracy and sensitivity, importantly in distinguish malignancy from benign lesion in gastrointestinal adjacent tissue. Positive rate of diagnosis on malignant lesions by EUS-FNA is positively correlated with lesion size, and EUS-FNA positive rate of solid malignant lesions is significantly higher than that of cystic lesions. Key words: Endosonography; Fine-needle aspiration; Diagnosis; Influencing factors; Space-occupying lesions

A Regional-Scale Landslide Warning System Based on 20 Years of Operational Experience

SIGMA is a regional landslide warning system based on statistical rainfall thresholds that operates in Emilia Romagna (Italy). In this work, we depict its birth and the continuous development process, still ongoing, after two decades of operational employ. Indeed, a constant work was carried out to gather and incorporate in the modeling new data (extended rainfall recordings, updated landslides inventories, temperature and soil moisture data). The use of these data allowed for regular updates of the model and some conceptual improvements, which consistently increased the forecasting effectiveness of the warning system through time. Landslide forecasting at regional scale is a very complex task, but this paper shows that, as time passes by, the systematic gathering and analysis of new data and the continuous progresses of research activity, uncertainties can be progressively reduced. Thus, by the setting up of forward-looking research programs, the performances and the reliability of regional scale warning systems can be increased with time.

DEVELOPING A SUCCESSFUL, PERSON-CENTERED MEMORY CARE WORKFORCE: 2018 DEMENTIA CARE PRACTICE RECOMMENDATIONS

It is imperative that long-term care begins to utilize leadership programs that espouse a person-centered approach by all staff, particularly for memory care. Employees who are prepared for their role - educated, supported, included in decisions, valued, cared for and nurtured - have greater job satisfaction and enhanced performance, and in turn will provide enhanced dementia care for those they serve. This session will share workforce recommendations from the Alzheimer's Association 2018 Dementia Care Practice Recommendations based on review of current evidence, best practice and expert opinion. The session will also incorporate a “people-centered” organizational and leadership model, “SERVICE,” developed in a successful Alzheimer's facility. SERVICE is grounded in the literature and based on 25 years of operational experience, incorporating domains of practice including: Service; Education; Respect; Vision; Inclusion; Communication; and Enrichment. This program will address the 2018 recommendations including: 1) Provide a thorough orientation and training program for new staff, as well as ongoing training; 2) Develop systems for collecting and disseminating person-centered information; 3) Encourage communication, teamwork, and interdepartmental/interdisciplinary collaboration; 4) Establish an involved, caring and supportive leadership team; 5) Promote and encourage resident, staff and family relationships; and 6) Evaluate systems and progress routinely for continuous improvement. Additional components to be discussed include expectations for performance, respect as a foundation, shared visioning, and creating an enriching environment for those who live and work in the community. Success is found in ongoing evaluation, process improvement strategies and collective information sharing, which will also be addressed. Attendees will learn how person-centered memory care based on the needs of residents, families and staff is addressed by the model and the impact made on resident and staff satisfaction, employee retention, facility reputation and overall quality. Research and results on the initial framework will be discussed, including a 90% employee retention rate and 98.5% family recommendation rate, multiple consecutive deficiency-free surveys, and several state and national awards. Outcomes from the replication of the model from other organizations will be shared as well as practical, effective tools and ideas for attendees to develop an effective memory care staff culture in their own environment.

National and International Guidelines for the Use of Reagents Containing Film-Forming Amines for the Organization of TPP Water Chemistry Regime

The reliability and economy of thermal power plant equipment, including combined-cycle plants, are affected by corrosion of structural materials and deposit formation in the water-steam circuit. To reduce the rate of these processes, coolant treatment is used. Ammonia, hydrazine, phosphates, etc. have been traditionally used as reagents. Recently, much attention has been paid to the use of water chemistry with the addition of complex reagents based on film-forming amines, not only for the equipment protection during the established operation mode but also for start-stops and preservation. Such water chemistry regimes are used not only in Russia but also in other countries for steam turbine and combined-cycle TPP, including biomass TPPs. The International Association for the Properties of Water and Steam, uniting specialists from all over the world, developed a guideline in 2016 for the use of such reagents based on theoretical studies and years of operational experience in power equipment in 21 countries. The review of domestic and international guidelines containing conditions for the use of film-forming amines and amine-based reagents for the organization of TPP water chemistry regimes for steam turbines and combined-cycle plants is presented.