Hallmarks of senescence and aging Dodig, Slavica; Čepelak, Ivana; Pavić, Ivan
Biochemia medica,
2019-Oct-15, Letnik:
29, Številka:
3
Journal Article
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The complex process of biological aging, as an intrinsic feature of living beings, is the result of genetic and, to a greater extent, environmental factors and time. For many of the changes taking ...place in the body during aging, three factors are important: inflammation, immune aging and senescence (cellular aging, biological aging). Senescence is an irreversible form of long-term cell-cycle arrest, caused by excessive intracellular or extracellular stress or damage. The purpose of this cell-cycles arrest is to limit the proliferation of damaged cells, to eliminate accumulated harmful factors and to disable potential malignant cell transformation. As the biological age does not have to be in accordance with the chronological age, it is important to find specific hallmarks and biomarkers that could objectively determine the rate of age of a person. These biomarkers might be a valuable measure of physiological,
biological age. Biomarkers should meet several criteria. For example, they have to predict the rate of aging, monitor a basic process that underlies the aging process, be able to be tested repeatedly without harming the person. In addition, biomarkers have to be indicators of biological processes, pathogenic processes or pharmacological responses to therapeutic intervention. It is considered that the telomere length is the weak biomarker (with poor predictive accuracy), and there is currently no reliable biomarker that meets all the necessary criteria.
•Mixed integer linear programming model for provision of multiple services from electric vehicles.•Flexibility benefits of electric vehicles in provision of spinning reserve and energy.•Impact of ...different electric vehicles charging strategies on electric power system operation.•Assessment of environmental and economic benefits under different energy mix scenarios.•Assessment of wind curtailment reduction under different energy mix scenarios.
As the share of integrated renewable energy sources (RES) increases, traditional operation principles of the power systems need to change in order to maintain reliable and secure service provision, on one hand, and minimal cost and environmentally friendly electricity generation on the other. The challenge of alleviating additional uncertainty and variability brought by new sources to the system operation is seen as defining both flexibility capacities and flexibility requirements through provision of multiple services. In this context the role of emerging technologies, such as electric vehicles (EV) and energy storage (ES), is recognized through their active participation in providing both energy and reserve service.
This paper elaborates on the benefits of active EV participation in multiple system services through various charging strategies. The presented mixed integer linear programming (MILP) unit commitment problem (UC) considers the capability of EV to provide primary, secondary and tertiary reserve as well as energy, however the focus is put on the benefits of EV providing spinning reserve services. The results clearly show benefits of multiple EV role to that of providing energy only. In addition the paper analyses multiple power systems, with regards to their energy mix, and recognizes how integration of EVs reflects on power system flexibility through metrics expressed as operational cost, environmental benefits and reduced wind curtailment.
•Control authority in smart e-mobility is usually on the side of charging stations.•Electric vehicle based concept is an alternative where vehicles control charging.•In a proposed concept charging ...stations are merely an enabling infrastructure.•Electric vehicle based system yields higher revenues for the vehicle owners.
The existing models designed to reap the benefits of electric vehicles’ flexibility in the literature almost exclusively identify charging stations as active players exploiting this flexibility. Such stations are seen as static loads able to provide flexibility only when electric vehicles are connected to them. This standpoint, however, suffers from two major issues. First, the charging stations need to anticipate important parameters of the incoming vehicles, e.g. time of arrival/departure, state-of-energy at arrival/departure. Second, it interacts with vehicles only when connected to a specific charging station, thus overlooking the arbitrage opportunities when they are connected to other stations. This conventional way of addressing the electric vehicles is referred to as charging station-based e-mobility system. A new viewpoint is presented in this paper, where electric vehicles are observed as dynamic movable storage that can provide flexibility at any charging station. The paper defines both the existing system, where the flexibility is viewed from the standpoint of charging stations, and the proposed one, where the flexibility is viewed from the vehicles’ standpoint. The both concepts are mathematically formulated as linear optimization programs and run over a simple case study to numerically evaluate the differences. Each of the four issues identified are individually examined and omission of corresponding constraints is analysed and quantified. The main result is that the proposed system yields better results for the vehicle owners.
•Mixed integer linear programming model for provision of multiple services from EV.•EV energy and reserve services provision effects on power system operation.•Impacts of conventional unit’s ...decommission on system’s operation and flexibility.•Assessment of power system’s flexibility under different wind generation polices.
The paper presents a unit commitment model, based on mixed integer linear programming, capable of assessing the impact of electric vehicles (EV) on provision of ancillary services in power systems with high share of renewable energy sources (RES). The analyses show how role of different conventional units changes with integration of variable and uncertain RES and how introducing a flexible sources on the demand side, in this case EV, impact the traditional provision of spinning/contingency reserve services. In addition, technical constraints of conventional units, such as nuclear, gas or coal, limit the inherit flexibility of the system which results in curtailing clean renewable sources and inefficient operation. Following on that, sensitivity analyses of operational cost and wind curtailment shows which techno-economic constraints impact the flexibility of the high RES systems the most and how integration of more flexible units or decommission of conventional nuclear, coal and gas driven power plants would impact the system’s operation. Finally, two different wind generation polices (wind penalization and wind turbines as reserve providers) have been analysed in terms of operational flexibility through different stages of conventional unit’s decommission and compared with the same analyses when EV were used as reserve providers.
Carbon neutrality is one of the main goals in current power system planning and operation. Many different actions and solutions are presented and implemented so far, incorporating renewable energy ...sources at all levels of the system. With the raising prices of natural gas and its negative impact on the environment, particularly emphasised over the past two years, new technologies and energy vectors are emerging as potential for its replacement. High importance of the hydrogen energy vector, especially in the decarbonisation of the industry sector, is being put forward due to its advantages of zero greenhouse gas emissions, its capacity for storing energy and capability to balance the production of renewable energy sources. This paper brings a detailed mathematical model of a price driven, demand responsive, multi-energy industry facility, as a logic first implementer of hydrogen technologies due to its high and multi-energy consumption nature. The systematic analyses are conducted over a set of scenarios of local production, considering different hydrogen technologies as well as range of natural gas and electricity prices. The findings of the paper conclude that hydrogen technology implementation into a realistic industrial consumers processes results in zero local emissions production, high level of autonomy and resistance from the market disturbances. When compared with classic industrial layouts, the overall CO2 footprint is reduced from around 30% to around 85%, depending on the scenario. The sensitivity analysis has proven that hydrogen layouts are comparable to natural gas layouts in terms of total costs, showing that hydrogen options result in lower cost in the range from 25% to 58%, depending on the observed scenario.
•Integration of renewables and hydrogen technologies in industrial plant.•Price sensitivity analysis showcasing economic benefits of different hydrogen technologies.•Carbon footprint reduction up to 80% from the business-as-usual approach.•Complete reduction in local GHG emissions using hydrogen technologies.
While the latest European energy regulations emphasise the active power system participation of the household level end-users, the large industrial facilities are still not fully exploiting all the ...market opportunities to decrease their costs and become more competitive. Significant cost reduction can be achieved by offering flexibility services in the electricity market. This is especially valid in the case when the industrial consumers are multi-energy hubs where shifting and optimising usage of input energy vectors creates additional opportunities. Research gaps were identified and a price responsive demand response model for a multi-energy industry facility under uncertainty was developed. The uncertainty aspects are modelled both by the robust optimisation and by the two-stage stochastic optimisation. Additionally, we develop a linear energy flow-based model of an industrial steam system which better encompasses losses and makes the model more realistic. The model is validated on a real-world case of a multi-energy industry facility and the results indicate that cost savings of up to 18 % can be achieved compared to the passive and deterministic, mass flow-based business-as-usual behaviour.
•Improved energy-based model of a steam driven multi-energy industrial prosumer.•Innovative demand response model decomposing the process into shiftable processes.•Robust market driven model of MES industry facility with integrated DR.•Robust market driven model has up to 18% lower cost than business-as-usual approach.
Raman spectroscopy is a powerful analytical technique based on the inelastic scattering of photons. Conventional macro-Raman spectrometers are suitable for mass analysis but often lack the spatial ...resolution required to accurately examine microscopic regions of interest. For this reason, the development of micro-Raman spectrometers has been driven forward. However, even with micro-Raman spectrometers, high resolution is required to gain better insight into materials that provide low-intensity Raman signals. Here, we show the development of a micro-Raman spectrometer with implemented zoom lens technology. We found that by replacing a second collimating mirror in the monochromator with a zoom lens, the spectral resolution could be continuously adjusted at different zoom factors, i.e., high resolution was achieved at a higher zoom factor and lower spectral resolution was achieved at a lower zoom factor. A quantitative analysis of a micro-Raman spectrometer was performed and the spectral resolution was analysed by FWHM using the Gaussian fit. Validation was also performed by comparing the results obtained with those of a high-grade laboratory Raman spectrometer. A quantitative analysis was also performed using the ANOVA method and by assessing the signal-to-noise ratio between the two systems.
This paper investigates the detection of broken rotor bar in squirrel cage induction motors using a novel approach of randomly positioning a triaxial sensor over the motor surface. This study is ...conducted on two motors under laboratory conditions, where one motor is kept in a healthy state, and the other is subjected to a broken rotor bar (BRB) fault. The induced electromotive force of the triaxial coils, recorded over ten days with 100 measurements per day, is statistically analyzed. Normality tests and graphical interpretation methods are used to evaluate the data distribution. Parametric and non-parametric approaches are used to analyze the data. Both approaches show that the measurement method is valid and consistent over time and statistically distinguishes healthy motors from those with BRB defects when a reference or threshold value is specified. While the comparison between healthy motors shows a discrepancy, the quantitative analysis shows a smaller estimated difference in mean values between healthy motors than comparing healthy and BRB motors.
Integration of renewable energy sources as one of the pillars of the power system decarbonization efforts is making a significant progress. However, large shares of renewables require additional ...flexibility to keep the system stable. Battery storage was identified as one of the solutions to restore the grid balance in short timeframes, from day-ahead to real time. Currently, the research community is trying to find an adequate technology for longer duration energy storage. Hydrogen, as an energy carrier, appears as a good choice for such task. Apart from hydrogen energy storage potential, it can also be used to implement power-to-gas technology able to mitigate renewable energy curtailment through the process of electrolysis. The produced hydrogen gas can be either used to partially decarbonize the natural gas grids or simply sold as hydrogen fuel.
The main novelty of this paper is the creation of a mathematical model of a renewable power plant coupled with a battery storage and a hydrogen facility for trading in three day-ahead energy markets, i.e. electricity, natural gas and hydrogen, plus in the power balancing market subject to the imbalance settlement mechanism. This approach enables a long-term profitability analysis of different renewable, battery and hydrogen architectures (hydrogen energy storage, power-to-gas and their combination) and their participation in different markets.
The results indicate that the battery energy storage provides balancing services to the transmission system operator almost exclusively, while it never provides balancing for its own imbalance needs, since this option is less financially attractive. The electrolyzer and the fuel cell operate at least one third of the year, depending on the observed case, and often provide a reserve. When considering the hydrogen market, the electrolyzer operates almost the entire year due to lucrative hydrogen prices. Both the battery storage and the hydrogen tank perform arbitrage in the day-ahead market, where the battery optimizes its operation on an hourly basis (short-term) and the hydrogen tank on a daily basis (medium- to long-term).
•Participation on three energy systems: electricity, hydrogen, natural gas.•Multi-service electricity system participation.•Battery energy storage provides balancing services almost all the time.•When hydrogen market is also allowed, the electrolyzer operates almost whole year.•Balancing plant’s own imbalance is less lucrative than balancing the power system.
Hydrogen technologies have gained momentum in recent years in the context of achieving fully renewable energy systems. Apart from the ability of electrolyzers and fuel cells to consume and generate ...green energy, the latest research on their technical characteristics also promotes them as providers of balancing services in both power and gas (either hydrogen or natural gas) systems. The balancing services provision is a highly uncertain process and is not scheduled in advance, however, due to signed contracts and rules, the provision of these services to the TSO is not considered as a deviation from the agreed schedule. Contrary to battery storage, whose operation only affects the power system power flows, the operation of power-to-hydrogen and hydrogen-to-power units in one system (e.g. power system) has an impact on the other system (e.g. gas) as well. Because of that, the unscheduled balancing services provision to one TSO will cause an imbalance towards the TSO in the other system. This impact remains unexplored in the available literature.
In this paper, we propose a model of a PV-battery-hydrogen power plant participating in both the power and gas (hydrogen) system markets while acting as a provider of balancing services and the responsible party of its own balancing group in both systems as well. We analyze how considering the influence that energy-conversion units simultaneously have on both observed systems affects the realized profit of the power plant and we show that neglecting this impact increases the total imbalance costs of the power plant, and consequently reduces its overall profit.
•Operational model of a hybrid power plant connecting power and gas systems.•Hybrid power plant providing balancing services to power and gas TSOs.•Impact of balancing services provision on power flows in both systems.•A larger balancing group enables easier imbalance resolving.•Considering balancing services’ impact on power flows increases profitability.
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