Energy Eco-efficiency Research Articles

Geopolymer eco-cellular concrete (GECC) based on fluid catalytic cracking catalyst residue (FCC) with addition of recycled aluminium foil powder

This study presents a new cellular concrete design focused on the energy eco-efficiency and the sustainability concept: geopolymer eco-cellular concrete (GECC). Geopolymer systems made from alkali-activated fluid cracking catalyst residue (FCC) aerated by recycled aluminium foil powders (R) were designed. Commercial aluminium powder (A) was also used as an aerating agent in GECC matrix and its effect was compared with traditional cellular concrete (TCC) made with ordinary Portland cement (OPC). The more alkaline medium of the GECC system improved the hydrogen reaction rate and consequently a higher efficiency in the pore matrix development can be found. Aluminium powder addition of 0.2% by mass of the precursor (FCC) was enough to yield cellular concrete with a natural density significantly lower than that found for TCC. The replacement of A by R made it possible to produce an alternative GECC in which the recycling of the waste aluminium has an important eco-efficiency role because its low cost and its energy saving function. Ground R has less aeration effectiveness than A. However, when co-milling of FCC + R was carried out, advantageous performance GECC was attained. Very interesting properties were obtained for this material: good pore size and its proper distribution in the matrix, low natural density (600–700 kg/m3), relatively high compressive strength (2.5–3.5 MPa), low open/closed porosity ratio (1.15) and the lowest thermal conductivity (0.581 W/mK). This opens an interesting way of reusing both FCC as precursor and aluminium foil waste as an aerating agent in the preparation of new geopolymer eco-cellular concrete (GECC).

AN ASSESSMENT OF THE PRACTICE OF SOCIAL RESPONSIBILITY ACCOUNTING BY FIRMS IN KENYA: A CASE STUDY OF SAFARICOM KENYA

Purpose: This study was an assessment of the practice of corporate social responsibility accounting by firms in Kenya in the case of Safaricom Kenya.Methodology: A case study design was appropriate for this study. The population used in this study entailed all the 1850 employees of safaricom. Judgmental sampling was used to select the respondents i.e. 24 in number, 8 respondents from the finance department, 8 respondents from the public relations department, 4 respondents from the sales department and 4 committee members of the Safaricom foundation. Primary data was collected by the use of a questionnaire and was the main data used in the research. The data collected was analyzed by use of inferential statistics. In particular, frequency tables, averages and percentages were used. The data was then presented using tables, graphs and charts.Results: The study findings showed that to a large extent, environmental management of the production process and environmental policy were issues reported in the safaricom CSR report. In addition, climate protection and energy eco-efficiency were reported in the safaricom CSR reports to a low extent respectively. Furthermore, its practice of CSR was driven by a genuine concern for creating shareholders wealth (business case) as well as engagement and accountability. It was also observed that another motive for practicing CSR was PR based (striving to better than competitors). However, some of the challenges facing accounting for social responsibility (social accounting) were related to verifiability requirements, comparability requirements, training requirements, standardization requirements, and quantification requirements.Unique contribution to theory, practice and policy: The study recommended that Safaricom should maintain its trend for addressing corporate social responsibility issues and come up with measures that can be used to make social accounting in the firm to be less costly. The researcher recommended an investigative study to establish the level of usefulness of the CSR reports to various users. In addition, a correlation and a regression study explaining the relationship between CSR and firms financial performance would be in order.

Study of spatial patterns and spatial effects of energy eco-efficiency in China

Energy eco-efficiency is a concept integrating ecological and economic benefits arising from energy utilization and serves as a measure of efficiency in the energy–environment–economy system. Using the slacks-based measure (SBM) model considering undesirable output, this study first measures the energy eco-efficiency of provinces in China from 1997 to 2012. It then analyzes the spatial distribution and evolution of energy eco-efficiency from three aspects: scale, intensity, and grain of spatial patterns. Finally, it examines the spatial spillover effects and influencing factors of energy eco-efficiency in different provinces by means of a spatial econometric model. The following conclusions are drawn: (1) The overall energy eco-efficiency is relatively low in China, with energy-inefficient regions accounting for about 40%. Guangdong, Hainan and Fujian provinces enjoy the highest energy eco-efficiency, while Ningxia, Gansu, Qinghai, and Xinjiang are representative regions with low efficiency. Thus, the pattern of evolution of China’s overall energy eco-efficiency is U-shaped. Among local regions, four main patterns of evolution are found: increasing, fluctuating, mutating, and leveling. (2) At the provincial level, China’s energy eco-efficiency features significant spatial agglomeration both globally and locally. High–high agglomeration occurs mainly in the eastern and southern coastal regions and low–low agglomeration in the northwestern region and the middle reaches of the Yellow River. Changes in spatial patterns have occurred mainly in areas with high–low and low–high agglomeration, with the most remarkable change taking place in the Beijing–Tianjin–Hebei region. (3) There exist significant spatial effects of energy eco-efficiency among provinces in China. For the energy eco-efficiency of a given region, spatial spillovers from adjacent regions outweigh the influence of errors in adjacent regions. Industrial structure has the greatest influence on energy eco-efficiency.

Analysis on Evolution of Urban Energy System Structure Based on Information Entropy

Diversity of urban energy system structure (UESS) was analyzed based on information entropy. To find out the evolution law of UESS and thus provide principles to coordinate and optimize the UESS, the correlative relationship model between UESS and its influencing factors can be developed using the partial least square (PLS) regression. Here we took Xiamen City as an example to analyze the evolution tendency and the influencing factors of diversity of energy supply structure (ESS) and energy demand structure (EDS). The results showed that, on the whole, the diversity of ESS in Xiamen was rising over time as a logistic curve from 1996 to 2003, with reducing speed from 1999 though. While in the period, EDS in Xiamen City didn't improve efficiently. Urbanization level, population, gross domestic product (GDP), and the third industrial structure had significantly affected ESS. Meanwhile, number of vehicles, GDP, population, per capita disposable income, and energy eco-efficiency had obvious influences on EDS. As for Xiamen City, the improvement of diversity of EDS should be especially emphasized.