The complexity and challenges of determining GHG (greenhouse gas) emissions from grid electricity consumption and conservation in LCA (life cycle assessment) – A methodological review

The way in which GHG (greenhouse gas) emissions associated with grid electricity consumption is handled in different LCA (life cycle assessment) studies, varies significantly. Apart from differences in actual research questions, methodological choices and data set selection have a significant impact on the outcomes. These inconsistencies result in difficulties to compare the findings of various LCA studies. This review paper explores the issue from a methodological point of view. The perspectives of ALCA (attributional life cycle assessment) and CLCA (consequential life cycle assessment) are reflected. Finally, the paper summarizes the key issues and provides suggestions on the way forward. The major challenge related to both of the LCA categories is to determine the GHG emissions of the power production technologies under consideration. Furthermore, the specific challenge in ALCA is to determine the appropriate electricity production mix, and in CLCA, to identify the marginal technologies affected and related consequences. Significant uncertainties are involved, particularly in future-related LCAs, and these should not be ignored. Harmonization of the methods and data sets for various purposes is suggested, acknowledging that selections might be subjective.     

Simple parameterizations of the radiation budget of uniform broadleaved and coniferous canopies

Simulations of the different components of the spectral radiation budget of structurally simple leaf and shoot canopies with varying canopy leaf area index (LAI) were performed. The aims were (1) to test a proposed parameterization of the budget using two spectrally invariant canopy structural parameters (p and p_t) governing canopy absorption and transmittance, respectively, and (2) to incorporate the effect of within-shoot scattering in the parameterization for shoot canopies. Results showed that canopy spectral absorption and scattering were well described by a single parameter, the canopy p value or ‘recollision probability’, which was closely related to LAI. The relationship between p and LAI was however different in leaf and shoot canopy: e.g., at the same LAI the recollision probability was larger in the shoot canopy. It was shown that the p value of the shoot canopy could be decomposed into the p value of an individual shoot (p_sh) and the p value of the leaf canopy with the same effective LAI (LAI_e). The canopy p value allows calculation of canopy absorption and scattering at any given wavelength from the leaf (or needle) scattering coefficient at the same wavelength. To calculate canopy reflectance, separation of the downward and upward scattered parts is needed in addition. The proposed parameter p_t worked rather well in the leaf canopy at moderate values of LAI, but not in the coniferous shoot canopy nor at high values of LAI. However, the simulated fraction of upward scattered radiation increased in a straightforward manner with LAI, and was not particularly sensitive to the leaf (or needle) scattering coefficient. Judged by this ‘smooth’ behavior, the existence of another kind of simple parameterization for this separation remains an interesting possibility.     

Oxidation products of α-tocopherol formed in autoxidizing methyl linoleate

The oxidation products of¹⁴C-α-tocopherol formed by heating with methyl linoleate in an air atmosphere at 60 C or 100 C were investigated. The products included a dimer, trimer and dihydroxy dimer, α-tocopherol quinone and unidentified degradation compounds. The dimer and trimer constituted the major products present after heating for 70 hr at 60 C. After 70 hr at 100 C most of the¹⁴C-α-tocopherol had been converted to degradation products; part of the¹⁴C originallt present in the 5-methyl group was recovered as¹⁴CO₂ and¹⁴CH₃OH.     

Modelling the bioelectric behaviour of halo pin-patient structures during magnetic resonance imaging

Bioelectric compatibility of electrically conductive halo fixation devices and magnetic resonance (MR) imaging has been largely based on resulting image quality. Previous studies have focused primarily on improving image quality and, although the electrical characteristics of the system during imaging may have been noted, they have not been studied in depth. Utilizing both a theoretical and experimental approximation, this study focuses on the bioelectric characteristics of the pin-patient structures typically enountered in clinical halo fixation systems. Results indicate that the halo pin-patient system can be modelled using a resistor-inductor-capacitor circuit and that simple attempts at improving compatibility through increasing interface resistance by the use of insulated pins may not be an effective approach to improving halo instrumentation compatibility with new, stronger magnetic and higher-frequency resonance imaging systems.     

Effects of Temperature and Heating Time on the Formation of Four Toxic α,β‐Unsaturated‐4‐Hydroxyaldehydes in Vegetable Oils

The formation of four α,β‐unsaturated hydroxyaldehydes, 4‐hydroxy‐2‐trans‐hexenal (HHE), 4‐hydroxy‐2‐trans‐octenal (HOE), 4‐hydroxy‐2‐trans‐nonenal (HNE), and 4‐hydroxy‐2‐trans‐decenal (HDE), was detected in commercial corn, soybean, peanut, and canola oils heated for 1, 3, and 5 hours at 145, 165, and 185 °C. These four toxic aldehydes were investigated using high‐performance liquid chromatography (HPLC). These oils were selected based upon different degrees of unsaturations, especially their linoleic and linolenic acid concentrations. To select the appropriate conditions of temperatures and heating times, preliminary experiments were conducted using the thiobarbituric acid assay, which detects the formation of secondary‐oxidation products such as aldehydes and related carbonyl compounds. After various heat treatments, the formation of HHE, HOE, HNE, and HDE was detected as 2,4‐dinitrophenyl hydrazine derivatives using HPLC. In general, HHE, HOE, HNE, and HDE formation increased in all four oils with higher temperatures, longer heating times, and higher concentrations of linoleic and linolenic acids in the oils. The formation of HNE in the oils was mostly much higher than the other three 4‐hydroxyaldehyde isomers under the same conditions.     

Additive manufacturing of monolithic supercapacitors with biopolymer separator

Journal of Applied Electrochemistry - In this paper, additive layer-by-layer fabrication of a fully screen printed monolithic supercapacitor exhibiting performance comparable with supercapacitors...     

Triboelectric charging of fungal spores during resuspension and rebound

The triboelectric charging of fungal spores was experimentally characterized during rebound and resuspension. A fungal spore source strength tester (FSSST) was used as a primary aerosol generator for spores of three fungal species and two powders (silicon carbide and silver). The critical velocity of rebound was determined using a variable nozzle area impactor (VNAI), and the charging state of particles after resuspension and rebound was measured using the FSSST, different impactor setups, electrometers, and optical particle counters. In the impactor setups and the FSSST, five different surface materials relevant for indoor environments were used (steel, glass, polystyrene, paper, and polytetrafluoroethylene). The critical velocity of rebound was determined to be 0.57 m/s for fungal spores, which is relatively low compared to silicon carbide and previous results for micron-sized aerosol particles. Based on the rebound impactor measurements, we were able to define the crucial parameters of charge transfer for different particle–surface material pairs. A contact charge parameter, which describes the triboelectric charging during rebound, was found to have a negative correlation with the charging state of the particles after the resuspension from an impactor. This connects the triboelectric charging during rebound and resuspension to each other. Based on the contact charge parameter values, quantified triboelectric series could be formed. The results of this work show that fungal spores can be charged both positively and negatively during rebound and resuspension depending on the fungal species and surface material.

Copyright © 2016 American Association for Aerosol Research     

Efficacy of training procedures in implementing a legislated safety programme

This study examines the effect of training procedures, as measured by the results of a test, on the level of assimilation of a new safety programme in 80 Quebec companies. The Workplace Hazardous Materials Information System (WHMIS) was introduced in the province in 1989. The bipartite safety association representing the manufacturers of transportation equipment and machinery offered two types of WHMIS training services to their members: (a) 4 h employee training courses, and (b) two-day trainer training courses. Companies were free to choose from these and other services to comply with the WHMIS training requirements. A test was issued to a stratified sample of 862 employees approximately one year after the training. On average, the scores were best in plants having employees trained directly by experts from the safety association (type a). The training of internal trainers for companies produced slightly inferior learning results (type b).     

About malicious software in smartphones

Phones with some of the capabilities of modern computers also have the same kind of drawbacks. These phones are commonly referred to as smartphones. They have both phone and personal digital assistant (PDA) functionality. Typical to these devices is to have a wide selection of different connectivity options from general packet radio service (GPRS) data transfer to multi media messages (MMS) and wireless local area network (WLAN) capabilities. They also have standardized operating systems, which makes smartphones a viable platform for malware writers. Since the design of the operating systems is recent, many common security holes and vulnerabilities have been taken into account during the design. However, these precautions have not fully protected these devices. Even now, when smartphones are not that common, there is a handful of viruses for them. In this paper we will discuss some of the most typical viruses in the mobile environment and propose guidelines and predictions for the future.     

Alkaline fuel cell: A test plant,measurements and analysis of the results

An experimental study of an alkaline fuel cell test plant with a 0.5 kW fuel cell module is presented in this paper. The characteristics of the fuel cell module are measured in different steady state load conditions and with different electrolyte temperatures. The results are analysed by calculating the different efficiencies of the module.