Text is the embodiment of one's ideas in written language that can be read and understood by the reading community. Argumentation is basically an embodiment of discourse. This study was conducted to ...determine the structure of the argument content in the students' argumentative essays in the formal operation stage by describing the research findings. The approach used in this study is a qualitative approach with the Miles and Huberman analysis model. The data of this research is in the form of a fragment of the student's argumentative text. This data was obtained from students' assignments to write arguments their teachers had given. In collecting data, the method used is the method of listening. The techniques used are free listening and conversation, documentation, and note-taking. The data analysis of this research uses the communication content analysis model. Based on the analysis results, it was found that the structure of the argument content of the students in the formal operation stage consisted of four structures. The four content structures are (1) deductive complex content structure, (2) inductive complex content structure, (3) deductive simple content structure, and (4) deductive complex simple content structure.
Scientific assessment of urban ecological security (ES) is an important prerequisite to realize regional sustainable development. Previous studies lack the consideration of quality and poor ...systematic correlation, which could not reflect the internal dynamic relationship. On the basis of considering the time lag, this study divided the research process into the natural operation stage and the management feedback stage based on the driving forces, pressures, state, impacts, responses, management (DPSIRM) framework model and DEA theory, so as to effectively overcome the above shortcomings. Finally, we analyzed the spatio-temporal characteristics and influencing factors of the ES level of 108 cities in the Yangtze River Economic Belt (YREB) during 2005-2019. The results showed that: (a) both two stages showed a slow and fluctuating upward trend in time series, and the level of urban ES in the management feedback stage was significantly higher than that in the natural operation stage; (b) with the passage of time, the spatial distribution of ES in the natural operation stage gradually developed towards the middle and downstream of the YREB, while the management feedback stage mainly evolved from the midstream to the edge area; (c) the level of urban ES presented a different degree of spatial agglomeration phenomenon, and showed an increasing trend over time; and (d) the key influencing factors gradually changed from pressure to response during 2005-2019. This research aims to provide an innovative perspective for the measurement of urban ES, and provide scientific reference for improving urban ecological sustainable development.
The carbon emissions (CEs) of public buildings (PBs) in the operation stage significantly impact building life cycle assessments (LCA). Energy conservation and carbon reduction during this stage is ...necessary for China to achieve peak CEs and neutralization. Energy consumption and CEs are analyzed using energy audit data for PBs in Xi'an. CEs of PBs in the operation stage are calculated by our prediction method with an average deviation of only 4.41%. Using the logarithmic mean Divisia index (LMDI) method to analyze factors influencing CEs, we find that economic development levels impact CEs the most in the operation stage; the impact coefficient reaches 3.81. This study discusses the contribution of various driving factors of CEs via the stochastic impacts by regression on population, affluence, and technology (STIRPAT) method and simulates seven scenarios to predict change trends of the CEs of PBs in the operation stage. The rough development scenario fails to achieve the peak, the comprehensive optimization development scenario achieves the peak in 2040, and the remaining scenarios achieve the peak in 2050. The results provide practical and theoretical support for CE research and a scientific basis for predicting the CEs of PBs in the operation stage throughout China and worldwide.
•Energy consumption and carbon emissions are analyzed based on energy audit.•Set up a carbon emissions prediction method for public buildings, and evaluate the results.•The influencing factors of carbon emissions were analyzed by the logarithmic mean Divisia index method.•Discuss the contribution of various driving factors and simulate the change trend of the carbon emissions.
This study examines the differential impact of HSR station and airport on local debt risk during the construction and operation stage. Based on the data of China's prefecture-level cities from 2010 ...to 2019, Feasible Generalized Least Square (FGLS) model results show that HSR station under construction reduces local debt risk by attracting extra-municipal capital inflows. However, the more HSR stations and airports are opened, the more local governments invest in other infrastructure, leading to increased local debt risk. By dynamic test, it is found that the longer the opening time, the greater the difference between the positive impact of HSR stations and airports on debt risk. Further synergies suggest that both local governments and investors have high expectations for urban development driven by HSR stations rather than airports, and the presence of HSR station amplifies the positive external effects of the airport construction. These findings not only deepen the understanding of the risk impact of HSR station and airport, but also provide enlightenment for countries to develop HSR station and airport through debt.
•We test diverse impacts of HSR station and airport on local debt risk.•HSR station reduces the local debt risk during construction stage.•The opening of HSR and airport increases the local debt risk.•Government and investors have higher expectations for HSR-led urban development.
Owing to the integration and utilization of the parasitic capacitance of the transformer, the LCC resonant converters with a capacitive output filter are widely used in high-voltage power supplies ...for microwave generation, X-ray, ion implantation, and other fields. However, it is challenging for the LCC to maintain high efficiency in a wide output voltage range. In this article, an optimal control coordinate trajectories (OCCTs) based phase-shift pulse-frequency (PS-PFM) control method is proposed to achieve high efficiency by reducing the switching frequency range and the turn-off current. With the normalized time-domain analysis, the operation stage trajectories of LCC and their boundary conditions under the PS-PFM control are derived. Based on this, the OCCTs of the switching frequency and the duty cycle at different voltage gains are precisely calculated. By associating the duty cycle with the switching frequency and the output voltage gain through a fitted equation based on the OCCTs data, the proposed PS-PFM control strategy can adaptively adjust the optimal duty cycle, simplifying one of the control freedom degrees. Then, an optimization design algorithm for the resonant network parameter is proposed to reduce the conduction loss of LCC. Finally, a 10-20 kV/15 kW LCC resonant high voltage power supply prototype is built to verify the feasibility of the proposed control strategy.
This work presents a probabilistic sequential framework for short‐term operation of distribution companies (DisCos) participating in the day‐ahead (DA) and real‐time (RT) markets. In the proposed ...framework, the DisCo's operating decisions are sequentially optimised; first, in a DA operation stage, and then in RT. The DA decisions are driven by the DisCo's profit maximisation, while the DisCo aims to minimise the actions required to accommodate deviations from forecasted quantities (i.e. the DA decisions) in the RT operation stage. This sequential approach considers realistic voltage‐sensitive loads and full ac power flow equations to represent the realistic network's active and reactive power injections. In addition, the operation of stationary batteries and the demand elasticity under time‐varying retail prices are explicitly modelled. The two resulting models are large‐scale highly non‐linear non‐convex mathematical problems with continuous and discrete variables. A pseudo‐dynamic tabu‐search‐based solution algorithm is used as an alternative to conventional optimisation solvers in order to tackle the problem in an effective manner, without linearisations. Numerical results from 69‐ and 135‐bus distribution systems illustrate the performance and the scalability of the proposed approach.
Abstract
In order to effectively improve the structural safety status of suspension bridges, this paper proposes a design and static analysis method of long span steel truss suspension bridge based ...on Midas civil finite element calculation software. Taking the Guojiatuo Yangtze River Bridge as a case, the paper studies the mechanical characteristics of the key parts of the bridge in the completion state and operation stage, and determines the structural safety state. The results show that the minimum safety factor of main cable is 2.64, and the minimum safety factor of the suspender is 3.90, and the maximum downward deflection of the main beam is 1.231m < L/400. The structural strength and stiffness can meet the design requirements.
This study aims to solve the problem of uncoordinated interests among the stakeholders in the operation stage (OS) of green buildings (GBs). First, the requirements and conflicts between the owners ...and property service enterprises (PSEs) are analysed. Secondly, the evolutionary game model of owners and PSEs is developed. It was found that the game system will evolve towards the ideal equilibrium stability strategy only under the following conditions: (i) the income of owners in green property management (GPM) is greater than the sum of the income of PSEs shared by the owner in GPM and the transaction costs generated when the owners choose to support GPM, and (ii) the sum of the income of PSEs shared by the owner in GPM and the additional benefits that PSEs can get by choosing GPM is greater than the total cost incurred by PSEs in choosing GPM. We carried out quantitative tests for equilibrium stability results and analysed the factor that influence the evolution path based on simulations performed in MATLAB. The results show that improving the operational income of GBs, increasing the additional income of PSEs, reducing the operating transaction costs and adopting a reasonable revenue sharing method are effective ways to coordinate the interests of all parties involved in the OS of GBs.
Listeriosis occurs due to consumption of contaminated food including raw milk. This study was aimed to assess the occurrence of Listeria species along Haramaya University Dairy Farm's operational ...stages with antibiotic resistance test on the isolates in oromia-Ethiopia. Study involves 30 lactating cows and 170 randomly collected different types of dairy environmental samples. The samples were examined for Listeria species. The isolates were tested against eight antibiotics. Out of 200 samples, 10 (20%) were positive for Listeria species. Listeria was isolated from cow barn, milk supply, silage feed and milk from cow teat, milking operation and milk auditing at 30%, 26.7%, 20%, 18.6% and 10%, respectively. Listeria species including L. monocytogenes (5.5%), L. innocua (5%), L. gray (3%), L. ivanovii (2.5%), L. seeligeri (2%) and L. welshimeri (2%) were also isolated. High resistant L. monocytogene to tetracycline (54.5%), L. ivanovii to amoxicillin (40%), L. innocua to each of penicillin and tetracycline (60%), L. seeligeri to tetracycline (100%), L. welsheri to penicillin (75%) and L. gray to each of penicillin and tetracycline (66.7%) were observed. Of all the 40 Listeria species isolates, 35%, 25%, 17.5% and 5% isolates were resistant to single, two, three and four drugs, respectively. Detection of considerable proportion of, different species of and antibiotic resistant Listeria isolates in the studied dairy sampling location shows there rere risk for raw milk contamination. Thus application of basic hygiene along the studied dairy operational stages could reduce consumer infection.
The article discusses the research on CO2 emissions at the stage of electric engine vehicle operation. The operation stage includes, among others use of the vehicle as well as maintenance and ...charging for the vehicle's propulsion. The origin of the electricity consumed during charging has an impact on the vehicle's emissions balance. The scope of considerations concerns coal as the main energy carrier in Poland. The obtained results can be a benchmark for comparing other primary energy sources used for electricity production. Based on the collected technical data of electric cars, the values of CO2 emission factors from electricity production in thermal power plants and data on the state and structure of electricity production in Poland, an analysis of CO2 emissions from electric vehicles in the operational stage was performed. The vehicle's electricity consumption of 0.14-0.16 kWh/km is accompanied by CO2 emissions of 100.94-115.36 g/km. The calculated CO2 exceeds the EU limit value from 01/01/2020 (95 g/km) for average CO2 emissions from new passenger vehicles. The main message of the work is the statement that increasing the efficiency of the electricity generation process in commercial thermal power plants in Poland will translate into a reduction in the emission of electric cars consuming this energy for propulsion. The research shows that the change in the efficiency of energy transformations in a thermal power plant from 38% to 46% leads to a reduction in the emission of an electric vehicle by over 17%. The emission of CO2 from a passenger car with a compression-ignition engine is discussed. The considerations include the stage of the use of the vehicle and the stage of production of diesel oil, which is consumed during the use of the vehicle.
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