Cost-efficient decarbonization of local energy systems by whole-system based design optimization

On the way toward Net Zero 2050, the UK government set the 2035 target by slashing 78 % emissions compared to the 1990-level. To help understand how an electrified local energy system could contribute to this target and the associated cost, we develop a whole-system based local energy optimization (LEO) model. The model captures a series of state-of-the-art technologies including building fabric retrofit, battery storage, electro-mobility, electro-heating, demand response, distributed renewable, and Peer-to-Peer (P2P) energy trading. And the model enables trade-off assessment between cost and emissions minimization, compares two system operating modes, i.e., cost-oriented and grid-impact-oriented, and evaluates the impacts from weather risks and capital cost assumptions. A case study in Wales reveals (1) capital cost assumptions can lead up to 30.8 % overall cost difference of the local energy system; (2) operating the system in cost-oriented mode can save up to 5 % cost than in the grid-impact-oriented mode; (3) electro-heating by heat pumps has the highest priority among all investigated technologies. Overall, this study demonstrates how to design and operate a cost-efficient and electrified UK local energy system by the whole-system incorporation of near-term technical and business model advances towards a decarbonized future

Effect of Detail Nursing Intervention on Headache and Negative Emotion in Patients with Subarachnoid Hemorrhage

objective: to explore the effect of detail nursing intervention on headache and negative emotion in patients with subarachnoid hemorrhage. Methods: the clinical data of 100 cases of subarachnoid hemorrhage from January 2015 to January 2017 of neurosurgery in our hospital were randomly divided into the control group and the experimental group, Detail nursing intervention inexperimental group, Comparison of two groups of clinical nursing effects. Results the duration of hospitalization and headache in the experimental group were shorter than those in the control group. Fewer headaches than control group (P<0.05) Less headache than control group (p<0.05). Results: the results of SAS and SDS scores were signifcantly lower than those in the control group (p<0.05) after nursing in the experimental group. Conclusion: the patients with subarachnoid hemorrhage receive detailed nursing intervention;contribute to the alleviation of their headache symptoms, Relieves the patient of negative emotional problem

Possibilities of coal–gas substitution in East Asia: A comparison among China, Japan and South Korea

Natural gas is currently playing an increasingly significant role in low carbon development, as it provides a credible pathway to meet rising energy demand while emitting fewer greenhouse gases than from using other fossil fuels such as coal and oil. In this paper, a log linear trans-log production function model is established to investigate inter-fuel elasticity of substitution between coal, oil, natural gas and electricity in China, Japan and South Korea, respectively. In order to overcome the problem of multicollinearity, the ridge regression approach is therefore adopted to estimate the parameters of the function. Results show elasticity estimates of both coal–gas substitution and coal–electricity substitution to be positive over 1985–2012, suggesting that these two energy input pairs are substitutes at least to some extent. It also reveals that relatively higher substitution possibilities between coal and natural gas, and less opportunities to substitute coal with other fuels in China. In addition, the model results also suggest the elasticities of coal–gas substitution in China are much larger than that in Japan and South Korea, indicating there is higher possibilities of coal–gas substitution in China

Parametric analysis and optimization for exergoeconomic performance of a combined system based on solid oxide fuel cell-gas turbine and supercritical carbon dioxide Brayton cycle

Fuel cell-gas turbine hybrid system is a potential field of investigation. This study establishes a modeling and optimization framework for a novel hybrid system consisting of a solid oxide fuel cell, a gas turbine and a supercritical carbon dioxide Brayton cycle. Based on the proposed thermodynamical model, a parametric analysis is investigated to determine the impacts of several key parameters on the system exergoeconomic performance. Meanwhile, bi-objective optimization is conducted for maximizing the exergy efficiency and minimizing the levelized cost of electricity via the Epsilon-constraint approach. The Linear Programming Techniques for Multidimensional Analysis of Preference decision-making approach is further employed to select the Pareto optimum solution from Pareto frontiers. The results show that several extreme values for the exergy efficiency and the levelized cost of electricity exist in a series of sensitivity curves, respectively. The Pareto frontiers indicates that with the increase of the exergy efficiency, the levelized cost of electricity shows a moderately increasing trend at first and increases rapidly afterward. Overall, at the Pareto optimum solution, the combined system can achieve an optimal exergy efficiency and levelized cost of electricity by 68% and 0.0575 $ kWh −1 , respectively

Planning urban energy systems adapting to extreme weather

In the context of increasing urbanization and climate change globally, urban energy systems (UES) planning needs adequate consideration of climate change, particularly to ensure energy supply during extreme weather events (EWE) such as heatwaves, floods, and typhoons. Here we propose a two-layer modeling framework for UES planning considering the impact of EWE. An application of the framework to a typical coastal city of Xiamen, China reveals that deploying energy storage (i.e., pumped hydro and battery) offers significant flexibility to ensure the critical demand is met during typhoon as a typical EWE and avoids over investment in supply technologies. This requires an extra 2.8% total cost on investment and operation of UES for 20 years. Planning energy systems with proper consideration of EWE can ensure robust urban energy services even with increasing penetration of fluctuating renewables, and we offer a flexible and computationally efficient paradigm for UES planning considering the impact of EWE

Volumetric measurement of pulmonary nodules at low-dose chest CT: effect of reconstruction setting on measurement variability

To assess volumetric measurement variability in pulmonary nodules detected at low-dose chest CT with three reconstruction settings. The volume of 200 solid pulmonary nodules was measured three times using commercially available semi-automated software of low-dose chest CT data-sets reconstructed with 1 mm section thickness and a soft kernel (A), 2 mm and a soft kernel (B), and 2 mm and a sharp kernel (C), respectively. Repeatability coefficients of the three measurements within each setting were calculated by the Bland and Altman method. A three-level model was applied to test the impact of reconstruction setting on the measured volume. The repeatability coefficients were 8.9, 22.5 and 37.5% for settings A, B and C. Three-level analysis showed that settings A and C yielded a 1.29 times higher estimate of nodule volume compared with setting B (P = 0.03). The significant interaction among setting, nodule location and morphology demonstrated that the effect of the reconstruction setting was different for different types of nodules. Low-dose CT reconstructed with 1 mm section thickness and a soft kernel provided the most repeatable volume measurement. A wide, nodule-type-dependent range of agreement between volume measurements with different reconstruction settings suggests strict consistency is required for serial CT studies