Emisi Gas Metana dan Karbon Dioksida pada Proses Pengolahan Limbah Cair Kelapa Sawit

Purpose: The purpose of this study was to know, calculate and evaluate the concentration of methane gas and carbon dioxide produced in each wastewater treatment plant (WWTP) pond.Method: This research was a qualitative research, using case study design and explanatory approach. The object of this research was the emission of methane gas and carbon dioxide emitted from 12 WWTP ponds.Results: The highest COD and BOD decrement occurred in pond 4 of 39% COD and 61.2% BOD. The highest total methane gas emission was 1.49 x 109 kg hours-1 (1.49 x 106 tons hour-1) occurring in the morning, while the highest total carbon dioxide emission was 2.59 x 109 kg per hour (2.59 x 106 ton hour-1). Conclusion: The concentrations of methane and carbon dioxide gas produced by each WWTP pool varied greatly depending on temperature, residence time and the amount of mud. Methane gas emissions and carbon dioxide emissions occurred in each WWTP pool with the highest methane gas emission value occurring in pond 3 in the afternoon at 356,64 x 106 mg m-2minute-1 and the highest carbon dioxide emissions occur in pond 3 in the afternoon at 402.145 x 106 mg m-2minute-1. The decrease of COD value in whole anaerobic pool was 52,1% and the decrease of COD value in aerobic pool was 27,2%

Electromagnetic wave absorption and structural properties of wide-band absorber made of graphene-printed glass-fibre composite

Lightweight composites combining electromagnetic wave absorption and excellent mechanical properties are required in spacecraft and aircraft. A one- dimensional metamaterial absorber consisting of a stack of glass fibre/epoxy layers and graphene nanoplatelets/epoxy films was proposed and fabricated through a facile air-spraying based printing technology and a liquid resin infusion method. The production process allows an optimum dispersion of graphene nanoplatelets, promoting adhesion and mechanical integration of the glass fibre/epoxy layers with the graphene nanoplatelets/epoxy films. According to experimental results, the proposed wide-band absorber provides a reflection coefficient lower than −10 dB in the range 8.5–16.7 GHz and an improvement of flexural modulus of more than 15%, with a total thickness of ∼1 mm. Outstanding electromagnetic wave absorption and mechanical performance make the proposed absorber more competitive in aeronautical and aerospace applications

Infrared Screening of Residential Buildings for Energy Audit Purposes: Results of a Field Test

Abstract: In the European Union (EU), the building sector is responsible for approximately 40% of total energy consumption. The existing building stock is inefficient and can, and indeed must be retrofitted to address this issue. The practical implementation of the European strategies requires knowledge of the energy performance of existing buildings through energy audit techniques. Application of thermography in the fields of energy are very widespread, since, through such a non-invasive investigation, and through correct interpretation of infrared images, it is possible to highlight inefficiencies in buildings and related facilities. The paper shows and discusses the results of an infrared audit campaign on 14 existing buildings located in Milan Province (Italy) made in different construction periods and characterised, therefore, by different building technologies. The U-values obtained in an indirect way through the thermography of the opaque walls of the buildings investigated, were compared with the actual known values in order to verify the reliability of the method and the possible margin of error. The study indicated that the category of buildings in which the application of this method is sufficiently reliable is that of solid-mass structure buildings, the most widespread in Italy, whereas in the case of buildings whose external walls are insulated, the percentage of deviation is very high

Risk shifting consequences depending on manager characteristics

This paper investigates the performance consequences of the risk shifting behavior shown by domestic equity mutual funds through the analysis of monthly portfolio holdings. The objective of this paper is to assess the implications of risk shifting for mutual fund investors. Specifically, we study the performance consequences of different mechanisms of risk shifting, such as the change in the composition between equity and cash holdings and the change of the systematic or idiosyncratic risk within the equity positions. We find that funds that increase their risk level obtain significantly better performance than funds with stable or reduced risk levels. This finding is robust when controlling for fund characteristics such as past performance and fund size. Additionally, we examine whether the performance consequences of risk shifting depends on fund manager characteristics and find that manager gender, education and level of specialization are revealed as important variables to differentiate the performance consequences of risk shifting

The convergence between sustainability and conventional stock indices. Are we on the right track?

The growth of passive and socially responsible (SR) investment makes that sustainability indices play an important role in defining what constitutes a sustainable investment. In order to know the suitability of sustainability indices as benchmarks for SR investors, we used different linear regressions to compare the compositions of sustainability indices and their conventional counterparts and to compare the levels of corporate social responsibility (CSR) of both types of indices. We showed that the composition of sustainability indices gradually converged towards their conventional peers. Moreover, the difference between the CSR levels of both type of indices remained the same or even decreased over time. We concluded that a change in the weighting method of sustainability indices such as the equally weighted criterion would significantly increase the difference from their conventional counterparts. However, due to the relationship between CSR and size, this change would penalize the CSR level of the index. These results raise the question of whether SR passive investors will be able to meet their non-financial expectations as a consequence of the convergence. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Mutual fund performance attribution and market timing using portfolio holdings

We propose a novel performance attribution model for equity fund portfolios. The model analyses investment decisions based on portfolio holdings and measures the value added from different sources of performance such as past return strategies, security selection, market timing and passive timing. The model was tested for a sample of mutual funds. Empirical results show that security selection is the main contributor to fund performance regardless of the sample period considered or the asset pricing model used. The evidence of timing ability is mixed with low significance. Nevertheless there are noticeable differences between the timing ability of the best and worst performing funds, especially in crisis periods. Analysing the relationship between mutual fund performance (and its different components) and fund characteristics, we find that top funds are significantly smaller and more concentrated than other funds. Finally, we also examine the persistence in the performance and in its components finding evidence of positive persistence in past return strategies and picking skills although this persistence is not shown in the overall performance

Electrocatalytic properties of Pd-based nano-structured material for application in fuel cells

Fuel cells, especially low temperature fuel cells, are clean-energy devices that have high potentiality for use in electric power production and non-polluting vehicles. Platinum is commonly used as electrocatalysts in fuel cell electrodes, because of its excellent electrocatalytic activity and chemical stability. But, because of its high cost and limited resources, its use represents a bottleneck for large-scale application and commercialization of fuel cells. Palladium could be a good substitute for Pt, because of its similar chemical and physical properties, lower cost and higher abundance. Main challenges concern the development of Pd-based materials with high catalytic activity and durability at a reduced cost (i.e. metal content). Crucial technological issue is the optimization of the active surface of the catalysts, by the control of the morphology, shape and dispersion of the metal particles. The talk will describe the main results of the research activity carried out during the second year of the Italia-USA Bilateral Project in ENEA, concerning the fabrication and characterization of different kinds of nanostructured Pd-based electrocatalysts, by using both electrochemical and vacuum thin film deposition techniques