Energy Intensity Factor Research Articles

Mode II fracture parameters of dry snow slab avalanche weak layers calculated from the cohesive crack model

Release of dry snow slab avalanches starts with shear failure within a thin weak layer beneath a stronger, cohesive slab. The propagating fracture is within the weak layer as mode II. The fundamental fracture properties include the weak layer critical mode II fracture energy and stress intensity factors. In this paper, mode II fracture energy was calculated from the cohesive crack model from dry slab avalanche fracture line data and in-situ shear fracture tests. One advantage of the cohesive crack model is that it does not require the effective elastic modulus which is highly rate dependent and largely unknown in avalanche release. The results gave weak layer mode II fracture toughness less than mode I fracture toughness for the cohesive slab and fracture energy about one order of magnitude less than for solid ice. From the fracture energy and the mode II stress intensity factor, Irwin’s relation enables calculation of the effective elastic modulus. Calculations of the effective modulus for mode II initiation were compared with other estimates and they were shown to be consistent.

Research on City Energy Intensity Evolution Mechanism and Simulation Planning

In this paper, using the method of membership function in fuzzy mathematics in view of the energy intensity and carbon intensity index data preprocessing, eliminate impact factor smaller indicators, and then build energy - economy - environment three-dimensional index system based on the multi-stage stochastic programming model to simulate the energy intensity influence factors sensitivity analysis, calculating the contribution coefficient of all the factors, find out the regional difference influence factors of energy intensity

Development of a global computable general equilibrium model coupled with detailed energy end-use technology

A global computable general equilibrium (CGE) model integrating detailed energy end-use technologies is developed in this paper. The paper (1) presents how energy end-use technologies are treated within the model and (2) analyzes the characteristics of the model’s behavior. Energy service demand and end-use technologies are explicitly considered, and the share of technologies is determined by a discrete probabilistic function, namely a Logit function, to meet the energy service demand. Coupling with detailed technology information enables the CGE model to have more realistic representation in the energy consumption. The proposed model in this paper is compared with the aggregated traditional model under the same assumptions in scenarios with and without mitigation roughly consistent with the two degree climate mitigation target. Although the results of aggregated energy supply and greenhouse gas emissions are similar, there are three main differences between the aggregated and the detailed technologies models. First, GDP losses in mitigation scenarios are lower in the detailed technology model (2.8% in 2050) as compared with the aggregated model (3.2%). Second, price elasticity and autonomous energy efficiency improvement are heterogeneous across regions and sectors in the detailed technology model, whereas the traditional aggregated model generally utilizes a single value for each of these variables. Third, the magnitude of emissions reduction and factors (energy intensity and carbon factor reduction) related to climate mitigation also varies among sectors in the detailed technology model. The household sector in the detailed technology model has a relatively higher reduction for both energy intensity and the carbon factor.

Forecasting of Pakistan's Net Electricity Energy Consumption on the Basis of Energy Pathway Scenarios

Power Sector pathways for Pakistan is developed in this paper to depict the future challenges & aspects associated with its forecasting and planning on basis of modeling tools. Major pathways will be taken for further study in predicting focus on energy source for power generation. Three scenarios (BAU, NC & GF) will be discussed over a 20 years period (2011 to 2030) and the results from these scenarios will highlight our focus on fossil fuels or either renewable for future endeavors. The result will provide the forecasting of power sector up to 2030 on basis of electric consumers growth, level of activities, final energy intensity, forecasted growth & other factors. Therefore, the overall result will indicate efficient factors for future evaluation of policies on energy planning. The result also provides the vision for other developing countries in the region to make strategy for renewable energy expansion on massive scale.

基于LMDI分解的厦门市碳排放强度影响因素分析

PDF HTML阅读 XML下载 导出引用 引用提醒 基于LMDI分解的厦门市碳排放强度影响因素分析 DOI: 10.5846/stxb201304020585 作者: 作者单位: 中国科学院城市环境与健康重点实验室,中国科学院城市环境研究所,水利部珠江水利委员会,中国科学院城市环境与健康重点实验室,中国科学院城市环境研究所,中国科学院研究生院;中国科学院城市环境与健康重点实验室,中国科学院城市环境研究所,赤峰学院，资源与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（71003090和71273252）；福建省自然科学基金资助项目（2012J01306） Factor decomposition of carbon intensity in Xiamen City based on LMDI method Author: Affiliation: Institute of Urban Environment, Chinese Academy of Sciences,,Institute of Urban Environment, Chinese Academy of Sciences,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:研究碳排放强度的变化趋势及其影响因素对于指导低碳城市建设具有重要意义。应用对数平均权重分解法（LMDI），基于厦门市2005-2010年各部门终端消费数据对碳排放强度指标进行因素分解，并将传统分析仅注重产业部门的能源碳排放，拓展到全面考虑产业部门和家庭消费的能源活动和非能源活动影响。研究结果表明：2005-2010年厦门市碳排放强度下降17.29%，其中产业部门能源强度对总碳排放强度变化影响最大（贡献63.07%），家庭消费能源强度是碳排放强度下降的主要抑制因素（-45.46%）。从影响效应角度看，经济效率对碳排放强度下降贡献最大，碳排系数减排贡献最小；从部门减排贡献角度看，第二产业贡献最大，家庭消费贡献最小。总体而言，厦门市未来碳减排重点部门在第二产业，优化产业结构和能源结构有较大减排潜力。 Abstract:It is of great significance for guiding the low-carbon city development to explore the trends and influencing factors of carbon intensity. Most traditional decomposition studies only focused on the energy carbon emissions from industrial sectors. This paper extended the application of the Logarithmic Mean weight Divisia Index (LMDI) method to a full consideration of the industrial and household sectors, as well as their energy and non-energy activities. Taking Xiamen City as a study case, the carbon emissions was calculated by IPCC's methods based on the end-use consumption data of the industrial and household sectors from 2005 to 2010. Then the aggregated carbon intensity was decomposed by LMDI method into ten driving factors, which covering energy and non-energy related emissions from industrial and household sectors. The ten driving factors were further categorized into four groups: carbon emission efficiency effect (including efficiency factors of energy related industrial carbon emissions, energy related household carbon emission, non-energy related industrial carbon intensity, and non-energy related household carbon intensity), energy intensity effect (including industrial energy intensity factor and that of household), industry structure effect (energy related industrial structure factor and non-energy one) and economic efficiency effect (energy related economic efficiency factor and non-energy one). Results showed that carbon intensity of Xiamen City decreased by 17.29% from 2005 to 2010. From perspective of driving factors, the energy intensity of industrial sector had the greatest effect on carbon intensity reduction (a contribution rate of 63.07%), and the energy intensity of household sector was the largest hinder of carbon intensity reduction (-45.46%). So energy intensity had significant impact on carbon intensity reduction for Xiamen City. Except for reducing the energy intensity of industrial sectors, it is also very important to control the growth of household's energy intensity at the same time. From the effect perspective, the economic efficiency effect became the dominant driver of carbon intensity reduction, followed by energy intensity effect and industry structure effect, and carbon emission efficiency effect contributed the less. The economic efficiency contributed 50.85% of total carbon intensity reduction, which greatly promoted household's carbon intensity reduction. Although industrial structure adjustment had relatively small effects at the study periods, the industry structure in which secondary industry has large proportion is anticipated to have large reduction potentials in the future. The carbon emission efficiency effect was chiefly determined by energy structure, and the current carbon-intensive energy structure also has large reduction potentials. From the sector perspective, the contribution of the secondary industry was the largest (contributing 67.04%), sequentially followed by the primary industry, the tertiary industry, and the household sector. The carbon intensity reduction by secondary and tertiary industries mainly lied in energy related carbon emissions; whereas the carbon intensity reduction by the primary industry and household sectors mainly relied on non-energy emissions. Thus the non-energy related carbon emissions were an non-negligible part while analyzing carbon intensity reduction. Even though energy efficiency of household sector was the biggest disincentive to reduce carbon intensity, household sector had the less contribution on carbon intensity reduction due to other factors' offset effect. Furthermore, the key sector for future carbon reduction lies on the secondary industry. However, the primary Industry and household sector has limited reduction potential. Overall, optimizing industry structure and energy structure have large reduction potential, and secondary industry has largest reduction potentials. 参考文献 相似文献 引证文献

Using LMDI to analyze the decoupling of carbon dioxide emissions by China's manufacturing industry

This paper adopts the Log Mean Divisia Index (LMDI) method based on the extended Kaya identity to explore the impacts of industry structure, economic output, energy structure, energy intensity, and emission factors on the total carbon dioxide emissions from China's manufacturing industry during the period 1996–2010. In addition, we calculate the trend of decoupling effects in manufacturing industry in China by presenting a theoretical framework for decoupling. As the results suggest, China’s manufacturing industry has gone through four decoupling stages: strong negative decoupling stage (1996–1999), weak decoupling stage (2000–2001), expansive negative decoupling stage (2002–2004) and weak decoupling stage (2005–2010). Then we analyze the reasons for different decoupling stages during each period. The results show that the increase in economic output has the largest effect on the increase of CO2 emissions and that the decrease in energy intensity has incurred a considerable decrease in CO2 emissions. Moreover, the impacts of emission factors, industry structure, and energy structure on CO2 emissions are relatively small and not the determining factors to the changes of CO2 emissions.

Explanatory factors of CO2 per capita emission inequality in the European Union

The design of European mitigation policies requires a detailed examination of the factors explaining the unequal emissions in the different countries. This research analyzes the evolution of inequality in CO2 emissions per capita in the European Union (EU-27) in the period 1990–2009 and its explanatory factors. For this purpose, we decompose the Theil index of inequality into the contributions of the different Kaya factors. The decomposition is also applied to the inequality between and within groups of countries (North Europe, South Europe, and East Europe). The analysis shows an important reduction in inequality, to a large extent due to the smaller differences between groups and because of the lower contribution of the energy intensity factor. The importance of the GDP per capita factor increases and becomes the main explanatory factor. However, within the different groups of countries the carbonization index appears to be the most relevant factor in explaining inequalities. The policy implications of the results are discussed.

Decomposition of China’s Carbon Emissions Intensity from 1995 to 2010: An Extended Kaya Identity

This paper employs an extended Kaya identity as the scheme and utilizes the Logarithmic Mean Divisia Index (LMDI II) as the decomposition technique based on analyzing CO2emissions trends in China. Change in CO2emissions intensity is decomposed from 1995 to 2010 and includes measures of the effect of Industrial structure, energy intensity, energy structure, and carbon emission factors. Results illustrate that changes in energy intensity act to decrease carbon emissions intensity significantly and changes in industrial structure and energy structure do not act to reduce carbon emissions intensity effectively. Policy will need to significantly optimize energy structure and adjust industrial structure if China’s emission reduction targets in 2020 are to be reached. This requires a change in China’s economic development path and energy consumption path for optimal outcomes.

河南省工业能源消费及大气污染物排放预测研究

本文首先对“十二五”期间河南省的工业能源消费情况进行分析，进而估算其SO2，NOx，PM10，PM2.5等大气污染物的直接排放量，并在此基础上，采用LEAP模型和情景分析法对“十二五”期间河南省工业能源消费量与大气污染物的排放量进行了预测，使用LMDI分解方法对预测结果进行分析。研究表明，“十二五”期间河南省的能源消费量仍保持增长，而大气污染物排放量均有所下降；影响排放变化的主要因素是活动水平的增长，能源强度和排放因子的下降。 In this paper, industrial energy consumption of Henan in 12th Five Years Plan was analyzed firstly and then the direct emissions of air pollutions caused by industrial energy consumption which included SO2, NOx, PM10, PM2.5 were calculated. And on this basis, the industrial energy consumption and air pollution emis- sions of Henan in 12th Five Years Plan were forecasted by LEAP model and scenario analysis method, at last, the results were analyzed by using LMDI method. The study shows that Henan’s energy consumption keeps growing and air pollutant emission decreases during 12th Five Years Plan, main driving factors resulting in emis- sions’ change are the increase of the activity level and the decrease of the energy intensity and emission factors.

Analysis on Influencing Factors of Energy Intensity in Anhui Province

Based on analysis on dynamic characteristics of energy intensity in three industries of Anhui province from 1995 to 2009, decompositions of energy intensity’s dynamic change was investigated proceed year by year, by the Laspeyres model. The result showed that: the reduction of energy intensity in the past decades was attributed to the improvement of industries’ energy efficiency, especially the improvement of secondary industries’ energy efficiency. At last, theoretical basis was provided for the adjustment of the secondary industries’ energy structure, by contrasting correlation coefficient of energy structure and energy intensity in the secondary industry.

Experimental Study on Mixed-Mode Fracture for Concrete

A new criterion (failure stress criterion) is presented for the mixed-mode fracture of concrete by comprehensively evaluating several mixed-mode crack criteria. The new criterion absorbs some results fitting in with concrete from G.C.Sih and Erdogen’s maximum circumference stress criterion and G.C.Sih’s minimum strain energy intensity factor criterion. It combines concrete material fracture property with the condition of loads at the moment of concrete fracture by Weibull theory. It is concluded that concrete crack expands neither along the direction of maximum circumference stress nor along minimum strain energy factor S. The crack extends along the direction limited in the area controlled by two criteria. The accurate crack position is determined by failure probability of the strength of concrete structure. The experimental results indicate that the new criterion has better precision and adaptability comparing with other criteria and it can be applied to engineering very well.

The influential factors of China's regional energy intensity and its spatial linkages: 1988–2007

A large amount of literature on China's energy intensity seldom considers the regional differences of energy intensity inside China and the spatial effects. Based on spatial statistics methods, this paper explores the regional imbalance of China's provincial energy intensity and the spatially correlation of energy intensity among provinces. Using spatial panel data models, this paper finds that GDP per capita, transportation infrastructure, the level of marketization, and scientific and technological input significantly reduce the energy intensity; the ratio of heavy industries to total industries and the ratio of coal consumption to total energy consumption significantly expand the energy intensity; meanwhile, the coefficient of the ratio of export to GDP is not significant. Then, the spillover and convergence of China's regional energy intensity have been tested. The results indicate that the spillover effect between the eastern and western China is remarkable, and there exist absolute β-convergence of provincial energy intensity. Moreover, GDP per capita, transportation infrastructure, the level of marketization and scientific & technological input are conducive to conditional convergence after the spatial effects are controlled. According to the empirical results, this paper proposes some policy suggestions on reducing China's energy intensity.

Mode III cleavage of a coin-shaped titanium implant in bone: Effect of friction and crack propagation

Endosseous cementless implants are widely used in orthopaedic, maxillofacial and oral surgery. However, failures are still observed and remain difficult to anticipate as remodelling phenomena at the bone–implant interface are poorly understood. The assessment of the biomechanical strength of the bone–implant interface may improve the understanding of the osseointegration process.An experimental approach based on a mode III cleavage mechanical device aims at understanding the behaviour of a planar bone–implant interface submitted to torsional loading. To do so, coin-shaped titanium implants were inserted on the tibiae of a New Zealand white rabbit for seven weeks. After the sacrifice, mode III cleavage experiments were performed on bone samples. An analytical model was developed to understand the debonding process of the bone–implant interface. The model allowed to assess the values of different parameters related to bone tissue at the vicinity of the implant with the additional assumption that bone adhesion occurs over around 70% of the implant surface, which is confirmed by microscopy images. The approach allows to estimate different quantities related to the bone–implant interface such as: torsional stiffness (around 20.5 N m rad−1), shear modulus (around 240 MPa), maximal torsional loading (around 0.056 N.m), mode III fracture energy (around 77.5 N m−1) and stress intensity factor (0.27 MPa m1/2).This study paves the way for the use of mode III cleavage testing for the investigation of torsional loading strength of the bone–implant interface, which might help for the development and optimization of implant biomaterial, surface treatment and medical treatment investigations.

China's demand for natural gas: drivers and prospects

Sustained economic growth in China has triggered a surge of energy and mineral consumption and imports, including natural gas. This study presents recent trends in China’s demand for natural gas in a global context and discusses its drivers and prospects. In the past decade, drivers of China’s demand for natural gas are mainly associated with its rapid economic growth, path of industrialisation and urbanisation. With more than 1.3 billion people and a rapidly rising income level, China’s demand for energy has surged. It is increasingly difficult for domestic production capacity to supply all of this demand, especially when China’s limited domestic reserves are considered. The prospect of potential growth in natural gas consumption and imports is expected not only due to China’s economic growth, but also a policy imperative (e.g. the 12th Five Year Plan) to increase the share of clean energy sources such as gas and efficient fuels in the energy supply mix, as well as improving energy intensity and other factors that will influence energy sector outcomes. It also establishes that LNG, in addition to pipeline supplied gas, is likely to be an important source of energy in China in the coming decade; therefore, due to rebalancing its energy mix and increasing the share of non-coal energy sources in China’s energy market, it is anticipated that China will be more dependent on overseas supply of natural gas to fill the gap between domestic production and consumption.

Decomposition analysis of energy-related carbon emissions from UK manufacturing

Energy-related carbon emissions from UK manufacturing have fallen, between 1990 and 2007, by approximately 2% per annum. This reduction could be caused by a number of effects that can act to increase or decrease the level of emissions. Decomposition analysis has been used to separate the contributions of changes in output, industrial structure, energy intensity, fuel mix and electricity emission factor to the reduction in carbon emissions. The primary reason for the fall in emissions was found to be a reduction in energy intensity. The manufacturing sector was also split into two subsectors: the energy-intensive (EI) subsector, and the non-energy-intensive (NEI) subsector. The NEI subsector, somewhat surprisingly, was found to have made greater relative reductions in its energy-related carbon emissions over the study period. This was principally due to much greater relative improvements in energy intensity. There is evidence that the EI subsector had made greater relative improvements in energy intensity in the period preceding 1990, and so this may have limited improvements post 1990.

Analysis of Energy Consumption Influence Factors in Japan Based on LMDI Model

After World War Ⅱ Japanese economy has undergone three periods: the rapid industrialization period, the industrial structure adjustment period and the economy depression period. Affected by the speed of economic development, industrial structure and other factors, Japanese energy consumption has shown different features during specific period of time. This article use the LMDI model, analyze the effect of different factors on Japanese energy consumption which include economic development, energy intensity, energy consumption structure and population size, research on the weight of specific factors during each developing period. The results show that all the factors show positive effect in the rapid industrialization period; in the industrial structure adjustment period, economic development factor shows positive effect while energy consumed factor shows negative; and in the depression period, the trend of all the factors contribution rate are slowly, economic development and energy consumption structure also show negative effect besides the energy intensity factor.

Mode I fracture analysis of a piezoelectric strip based on real fundamental solutions

Abstract In existing papers, mode I crack problems of piezoelectric ceramics are generally solved in complex domain because of the complex fundamental solutions of in-plane piezoelectric governing equations. In fact, these problems can alternatively be analyzed in real number field by recasting the solutions in real form instead. The main purpose of the present work is to develop such real fundamental solutions by detailed eigenvalue and eigenvector analyses. As an example of application, the widely studied fracture problem of a piezoelectric strip with a center-situated crack under mode I loading condition is then revisited based on the real fundamental solutions. Mixed boundary value conditions of the crack are transformed into Cauchy singular integral equations, which are then solved numerically to get fracture parameters including the energy release rate and intensity factors. Convergence behaviors of the kernel functions are surveyed. Theoretical derivation and computation are validated by the exact solution in a special case. The effect of a combined geometrical parameter on the crack is also investigated.

Determination of interfacial properties of thermal barrier coatings by shear test and inverse finite element method

Determination of interfacial properties of thermal barrier coatings (TBCs) is very important for designing and evaluating the durability of TBCs. A new method combining a simple shear test and an inverse finite element analysis was developed and applied to measure the interfacial properties of two flame-sprayed yttria-stabilized zirconia TBCs. Nanoindentation testing was performed to determine the mechanical properties of different materials of the TBC systems. Variation of the lateral force during the shear test was recorded and analyzed to obtain the nominal ultimate shear strength of TBCs. The interfacial properties, namely fracture energy and stress intensity factor (mode II), of different TBC systems under both as-deposited and heat-treated conditions were determined through inverse finite element analysis.

A multifractal analysis of fatigue crack growth and its application to concrete

As is well-known, strength of materials is influenced by the specimen or structure size. In particular, several experimental campaigns have shown a decrease of the material strength under static or fatigue loading with increasing structure size, and some theoretical arguments have been proposed to interpret such a phenomenon. As far as fatigue crack growth is concerned, limited information on size effect is available in the literature, particularly for so-called quasi-brittle materials like concrete. In the present paper, by exploiting concepts of fractal geometry, some definitions of fracture energy and stress intensity factor based on physical dimensions different from the classical ones are discussed. A multifractal size-dependent fatigue crack growth law (expressing crack growth rate against stress intensity factor range) is proposed and used to interpret relevant experimental data related to concrete.

The wave propagation and vibrational energy flow characteristics of a plate with a part-through surface crack

In the view of structure-borne sound, vibrational wave and energy flow characteristics of infinite thin plate of finite width with a part-through surface crack are investigated. The case of an all-over part-through crack parallel to the finite side of the plate is considered. The crack is modeled as a line spring and the flexibility of the spring is deduced from the relationship between the strain energy and stress intensity factor in fracture mechanics. The responses of both intact plate and cracked plate under the excitation of harmonic force are reduced with wave propagation approach, then the input energy flow and transmitted energy flow of intact and cracked plates are calculated. The results show that the vibrational energy flow of cracked plate is highly related to the depth and location of the part-through crack. The location and the depth of the crack can be identified by the contour lines of normalized input energy flow with different driving frequencies. The research provides theoretical basis for the crack detection by measuring the vibrational energy flow in cracked plate structures.