The influence of Impedance Boundary Condition (IBC) on transonic compressors is investigated. A systematic input–output analytical framework is developed, which treats the nonlinearities as unknown forcing terms. The...
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The influence of Impedance Boundary Condition (IBC) on transonic compressors is investigated. A systematic input–output analytical framework is developed, which treats the nonlinearities as unknown forcing terms. The framework is validated through the experiments of rotating inlet distortion within a low-speed compressor. The input–output method is subsequently applied to transonic compressors, including NASA Rotor37 and Stage35, wherein impedance optimization is studied along with the exploration of its fundamental mechanisms. The IBC is employed to model the effect of Casing Treatment (CT). The optimal complex impedance values are determined through predicted results and tested across a range of circumferential modes and forcing frequencies. The IBC significantly reduces the energy and Reynolds stress gain, notably at the first-order circumferential mode and within the Rotor Rotating Frequency (RRF) range. output modes reveal that transonic compressors with fine-tuned impedance values exhibit a more confined perturbation distribution and redistribute the perturbations compared to the uncontrolled case. Additionally, the roles of resistance and reactance are elucidated through input–outputanalysis, and resistance determines the energy transfer direction between flow and pressure waves and modulates the amplitude, whereas reactance modifies the phase relationships and attenuates the perturbations.
This paper introduces the concepts of spectral influence and spectral cyclicality, both derived from the largest eigenvalue of a graph's adjacency matrix. These two novel centrality measures capture both diffusion...
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This paper introduces the concepts of spectral influence and spectral cyclicality, both derived from the largest eigenvalue of a graph's adjacency matrix. These two novel centrality measures capture both diffusion and interdependence from a local and global perspective respectively. We propose a new clustering algorithm that identifies communities with high cyclicality and interdependence, allowing for overlaps. To illustrate our method, we apply it to input-output analysis within the context of the Moroccan economy.
PurposeThe purpose of this study is to comprehensively evaluate the impact of the prefabrication rate on greenhouse gas (GHG) emissions and sustainability in prefabricated construction. In addition, it aims to identif...
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PurposeThe purpose of this study is to comprehensively evaluate the impact of the prefabrication rate on greenhouse gas (GHG) emissions and sustainability in prefabricated construction. In addition, it aims to identify the optimal prefabrication rate threshold that can promote the transformation of the construction industry toward more environmentally friendly ***/methodology/approachThis study uses an interdisciplinary methodology that combines emergy analysis with an extended input-output model to develop a GHG emission accounting model tailored for prefabricated buildings. The model assesses various construction schemes based on different rates of prefabrication and uses the emergy phase diagram from ecological economics to quantify the sustainability of these *** study indicates that within a prefabrication rate threshold of 61.27%-71.08%, a 5% increase in the prefabrication rate can significantly reduce emissions by approximately 36,800 kg CO2(e). However, emissions begin to rise when the prefabrication rate exceeds this threshold. The case analysis identifies steel, concrete and electricity as the primary sources of GHG emissions, suggesting strategies for optimizing their usage and promoting the adoption of clean ***/valueThis study represents a novel tool for assessing the environmental impact and sustainability of prefabricated buildings. It offers scientific guidance for the construction industry's environmental protection and sustainable development strategies, thereby contributing to a transition toward more environmentally friendly practices.
The purpose of this study is to analyse the structural interdependency of the agricultural sector and energy sectors in Turkey. The analysis done in this study used the input-output technique. An input-output model is...
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The purpose of this study is to analyse the structural interdependency of the agricultural sector and energy sectors in Turkey. The analysis done in this study used the input-output technique. An input-output model is an accounting system showing economic transactions. The relationships between agriculture and energy can be expressed in concept. The data of this study comes from the State Institute of Statistics Prime Ministry, Republic of Turkey, (SIS) databases for the input-output Structure of the Turkish Economy. (C) 2004 Elsevier Ltd. All rights reserved.
The European Commission (EC) has recognised discards as one of the major challenges facing the Community fishing fleet. The obligation to land all regulated catches has been proposed as a mandatory and essential measu...
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The European Commission (EC) has recognised discards as one of the major challenges facing the Community fishing fleet. The obligation to land all regulated catches has been proposed as a mandatory and essential measure to minimise discarding practices. This paper analyses the economic consequences of enforcement of the Landing Obligation (L.O.) for the Spanish trawler fleet in Iberian Waters. A representative number of in-depth interviews were carried out with ship owners and skippers of the fleet in question, to identify the envisaged operational and logistic problems on board and in port arising from the L.O. Furthermore, the current economic performance of the target fishing companies was analysed using the input-output methodology to identify their most significant activity costs. The combination of both research techniques enabled the evaluation of the potential consequences of the new L.O., concluding that, although it will generate minor positive and negative economic impacts, the main issue stems from the loss of quota. Some recommendations, including complementary measures to improve the implementation of the new rule, will be made.
Energy-related CO2 emissions embodied in international trade have been widely studied at the national level in recent years. The embodiment estimates help to explain the "weak carbon leakage" between industr...
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Energy-related CO2 emissions embodied in international trade have been widely studied at the national level in recent years. The embodiment estimates help to explain the "weak carbon leakage" between industrial and developing countries and to reveal the so-called "consumption-based" emissions (or carbon footprint). These findings have implications on national climate policy and international negotiations. For a large country like China, spatial aggregation issues are important in embodied emission studies. Dividing the country into several regions, previous studies propose the hybrid emissions embodied in trade (HEET) approach for regional emission studies and use step-wise distribution of emissions embodied in trade (SWD-EET) analysis to explain indirect absorption patterns. In this paper, we combine the HEET approach and SWD-EET analysis to conduct a comprehensive study of China's regional emission embodiments. We explain how inter-regional trade and international trade affect China's regional domestic emissions, and present the resulting regional carbon footprint. Policy implications from the empirical results obtained are discussed. (C) 2013 Elsevier Ltd. All rights reserved.
Ireland is committed to limiting its greenhouse gas (GHG) emissions to 113% of 1990 levels over the period 2008-12 and to 84% of 2005 levels by 2020 under the Kyoto Agreement and the EU's 2020 target by 2020 respe...
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Ireland is committed to limiting its greenhouse gas (GHG) emissions to 113% of 1990 levels over the period 2008-12 and to 84% of 2005 levels by 2020 under the Kyoto Agreement and the EU's 2020 target by 2020 respectively. National policies have targeted many industry sectors but have failed to directly tackle GHG emissions associated with construction activity. This paper estimates energy and GHG emissions intensities of the Irish construction sector and subsectors and estimates its contribution to Irish national emissions. This information is used to identify and assess the impacts of policy measures which would result in a reduction in emissions from the sector in a cost-effective manner. Energy and emissions intensities are estimated using input-output analysis techniques applied to Irish construction sector. In 2005 the Irish construction sector was responsible for the emission of 13.81 mtCO(2eq), comprising 2.37 mt (17%) of direct on-site emissions, 5.69 mt (41%) upstream indirect domestic emissions and 5.75 mt (42%) upstream indirect emissions outside the state. Domestically arising direct and indirect emissions accounted for 3.44% and 8.26% of national emissions respectively. Approximately three-quarters of construction sector emissions were the result of activities relating to NACE 45.2 'civil and structural construction works, etc'. Given the potential importance of the construction sector to national emissions, there is scope for the implementation of policies which specifically target it. Two such policies are proposed: direct emissions mitigation through a construction EcoDriving initiative;and the provision of information to allow the design and specification of low-emissions materials. (C) 2009 Elsevier Ltd. All rights reserved.
Local and inter-area oscillations in bulk power systems are typically identified using spatial profiles of poorly damped modes, and they are mitigated via carefully tuned decentralized controllers. In this paper, we e...
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Local and inter-area oscillations in bulk power systems are typically identified using spatial profiles of poorly damped modes, and they are mitigated via carefully tuned decentralized controllers. In this paper, we employ non-modal tools to analyze and control inter-area oscillations. Our input-output analysis examines power spectral density and variance amplification of stochastically forced systems and offers new insights relative to modal approaches. To improve upon the limitations of conventional wide-area control strategies, we also study the problem of signal selection and optimal design of sparse and block-sparse wide-area controllers. In our design, we preserve rotational symmetry of the power system by allowing only relative angle measurements in the distributed controllers. For the IEEE 39 New England model, we examine performance tradeoffs and robustness of different control architectures and show that optimal retuning of fully-decentralized control strategies can effectively guard against local and inter-area oscillations.
The present study applies the input-output model (IOM) to quantify direct and indirect impacts of the textile supply chain in Brazil. The objective was to identify environmental and social aspects obtained by the IOM....
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The present study applies the input-output model (IOM) to quantify direct and indirect impacts of the textile supply chain in Brazil. The objective was to identify environmental and social aspects obtained by the IOM. The textile supply chain was selected due to its economic, social and environmental importance to the country. The IOM model was built based on data from the System of National Accounts, National Energy Balance, Annual Estimates of Greenhouse Gas Emissions in Brazil, and Statistics from the Brazilian Central Employment Registry, the data refer to the year 2015. The results show that the greatest energy use in the textile supply chain occurs in scope 3, a 75% share. The textile supply chain released a total of 2.88 kgCO2e/dollar, 95.5% of this total are indirect emissions attributed to scope 3. The study has showed that there is a wide disparity between direct (15%) and indirect (85%) jobs, and there is also a gender gap across the supply chain (61% are men). The data show that 95% of direct employees and 85% of indirect employees do not have a high level of education. The IOM proved useful for identifying socio-environmental aspects, providing quantitative and accurate information on the entire supply chain (scope 3). The information is useful for identifying bottlenecks along supply chains, as well as for policymakers, who can use the results to evaluate standards and regulations throughout the supply chain.
Energy-related CO2 emissions embodied in international trade have been widely studied by researchers using the environmental input-output analysis framework It is well known that both sector aggregation and spatial ag...
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Energy-related CO2 emissions embodied in international trade have been widely studied by researchers using the environmental input-output analysis framework It is well known that both sector aggregation and spatial aggregation affect the results obtained in such studies With regard to the latter past studies are often conducted at the national level irrespective of country or economy size For a large economy with the needed data studies may be conducted at different levels of spatial aggregation We examine this problem analytically by extending the work of Su et al ([Su B Huang H C Ang B W Zhou P 2010 input-output analysis of CO2 emissions embodied in trade The effects of sector aggregation Energy Economics 32 (1) 166-175]) on sector aggregation We present a numerical example using the data of China and by dividing the country into eight regions It is found that the results are highly dependent on spatial aggregation Our study shows that for a large country like China it is meaningful to look Into the effect of spatial aggregation (C) 2010 Elsevier B V All rights reserved
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