Gas emissions from liquid dairy manure: complete versus partial storage emptying

When manure slurry is removed from storages for land application, there is often ‘aged’ manure that remains because the storages are not completely emptied. Aged manure may act as an inoculum and alter subsequent methane (CH₄), nitrous oxide (N₂O) and ammonia (NH₃) emissions when fresh manure is added to the system, compared to an empty storage that is filled with fresh manure. Completely emptying manure storages may be a practice to decrease gas emissions, however, little pilot-scale research has been conducted to directly quantify the inoculum effect. Therefore, we compared CH₄, N₂O, and NH₃ emissions from three pilot-scale slurry tanks (~10.5 m³ each) filled with a mixture of fresh manure and an inoculum of previously stored manure (i.e., partial emptying) to three tanks that contained only fresh manure (i.e., complete emptying). Gas fluxes were continuously measured over 155 d of warm season storage using flow-through steady-state chambers. The absence of an inoculum significantly reduced CH₄ emissions by 56 % compared to partially emptied (inoculated) tanks, while there was no difference in N₂O emissions. There was a significant 49 % reduction in greenhouse gas (GHG) emissions because the overall budget (as CO₂-eq) was dominated by CH₄. Complete manure storage emptying could be an effective GHG mitigation strategy; however, NH₃ emissions were significantly higher from un-inoculated tanks due to slower crust formation. Therefore additional NH₃ abatement should be considered.     

Supercapacitive properties of polyaniline/hydrous RuO2 composite electrode

A composite electrode based on polyaniline (PANI) and hydrous RuO₂ is prepared by electrochemical deposition of PANI onto hydrous RuO₂ (PANI/RuO₂) and its supercapacitive properties are investigated using cyclic voltammetry. The specific capacitances of PANI/RuO₂ and hydrous RuO₂ electrodes are determined to be 708 and 517 F g⁻¹ at 5 mV s⁻¹, respectively. Simple electrodeposition of PANI on the hydrous RuO₂ can achieve comparatively greater capacitance values.     

Significance of dietary antioxidants for health

Since evidence became available that free radicals were involved in mechanisms for the development of major diseases, including cardiovascular disease and cancer, there has been considerable research into the properties of natural dietary antioxidants. However, it has become clear that dietary antioxidants can only have beneficial effects in vivo by radical scavenging or effects on redox potential if they are present in tissues or bodily fluids at sufficient concentrations. For many dietary components, absorption is limited or metabolism into derivatives reduces the antioxidant capacity. For many dietary phytochemicals, direct antioxidant effects may be less important for health than other effects including effects on cell signalling or gene expression in vivo.     

An intercomparison of aerosol absorption measurements conducted during the SEAC4RS campaign

During the SEAC⁴RS campaign in 2013, inflight measurements of light-absorption by aerosol in biomass burning and agriculture fire plumes were collected along with concomitant measurements of aerosol extinction, scattering, and black carbon mass concentration. Here, we compare three measurements of aerosol absorption coefficients: from a photoacoustic spectrometer (PAS), a particle soot absorption photometer (PSAP), and a continuous light absorption photometer (CLAP). Each of these absorption measurements was collected in three visible spectral regions: red, green, and blue (although the precise wavelength and bandwidth vary with each instrument). The absorption measurements were compared during the plumes, in the boundary layer, and in the free troposphere. The slopes from the comparison ranged from 0.6 to 1.24. For biomass burning plumes, the uncertainty in the absorption measurements translates into a range in single scattering albedos of 0.93–0.94 at a wavelength of 660?nm, 0.94–0.95 at 532?nm and 0.92–0.95 at 405?nm. Overall, the aerosol absorption instruments agreed within their stated accuracies. Comparisons with simultaneous measurements of refractive black carbon mass concentration (collected by a single particle soot photometer), were used to derive the mass absorption coefficients (MAC). For all wavelengths, the MAC was high by greater than a factor of three compared to the expected MAC for black carbon.

© 2018 American Association for Aerosol Research     

Synthesis of polypyrrole–Nafion composite films by gas phase electroformation

Nafion was introduced into polypyrrole (PPy) matrix by gas phase electrochemical polymerisation. This produced a uniform, homogeneous and conductive thin film of composite polymer. The films (PPy/Nafion) also show surface features of highly ordered structural regularity. The composites obtained were characterised by cyclic voltammetry (CV) and redox performance were investigated. The relationship of the anodic current of the composite with the various experimental parameters such as concentration of Nafion, current density, polymerisation time and temperature were investigated. Anodic current increases with the Nafion concentration, polymerising time, temperature and current density.     

Flavour retention during high temperature short time extrusion cooking process: a review

Research on the stability of flavours during high temperature extrusion cooking is reviewed. The important factors that affect flavour and aroma retention during the process of extrusion are illustrated. A substantial number of flavour volatiles which are incorporated prior to extrusion are normally lost during expansion, this is because of steam distillation. Therefore, a general practice has been to introduce a flavour mix after the extrusion process. This extra operation requires a binding agent (normally oil), and may also result in a non-uniform distribution of the flavour and low oxidative stability of the flavours exposed on the surface. Therefore, the importance of encapsulated flavours, particularly the β-cyclodextrin-flavour complex, is highlighted in this paper.     

The relationship between employment-related self-efficacy and quality of life following traumatic brain injury.

Objectives: This study examines the relative contribution of employment-related and general self-efficacy to perceptions of quality of life (QoL) for individuals with traumatic brain injury. Design: Correlational. Setting: Community-based research and training center. Participants: 427 individuals with self-reported TBI under the age of 65 were included in analysis. Main Outcome Measure: Employment-related self-efficacy, general self-efficacy, perceived quality of life (PQoL), unmet important needs (UIN). Results: Significant correlations were found between income, injury severity, age at injury, and employment and the QoL variables. In addition, employment-related and general self-efficacy correlated positively with both PQoL and UIN. Employment-related and general self-efficacy accounted for 16% of the variance in PQoL and 9.5% of the variance in UIN, over and above other variables traditionally associated with QoL. Conclusions: These findings highlight the importance of including subjective appraisals of employment, such as perceived self-efficacy at the workplace, in assessing QoL and successful return to work following TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nonmarket cobenefits and economic feasibility of on-farm biogas energy production

Standard analysis of the economic feasibility of on-farm biogas energy production tend to emphasize primarily on direct financial benefits to farmers, and abstracts from the nonmarket cobenefits associated with anaerobic digestion of livestock manure and other biomass feedstock. This shortcoming of the standard feasibility analysis raises a fundamental question: How is the economic feasibility of on-farm anaerobic biogas energy production affected by the associated nonpecuniary cobenefits? Incorporating key nonmarket cobenefits from biogas energy production extends the standard economic feasibility analysis, and provides important insights. When nonmarket cobenefits were excluded, on-farm biogas energy production was generally not financially feasible for the dairy and swine farm size ranges studied (except for 600- and 800-sow farms). Overall, results of the financial feasibility analysis did not change compared to a base scenario (without nonmarket cobenefits) when an estimated annual total nonmarket cobenefits of CND$5000 was incorporated into the analysis, for both dairy and swine farms. Biogas energy production was generally financially viable for small-size dairy (i.e., 50-cow) and swine (i.e., 200-sow) farms when the nonmarket cobenefits were valued at CND$15,000 (or higher). Improvements in financial feasibility were more dramatic for dairy than for swine farms.     

Control of morphology in inert-gas condensation of metal oxide nanoparticles

We report preparation conditions to obtain different morphologies of as-deposited refractory metal-oxide nanoparticles using inert-gas condensation with CO₂ laser heating. The micrometer-scale morphology of the nanoparticles depends on the specific metal oxide, the buffer gas composition and pressure, and the target-to-substrate distance. These parameters control the extent to which a plume of nonagglomerated nanoparticles can reach a deposition substrate. Buffer gas pressure has the largest influence for a given material, with lower pressures producing a dense columnar morphology and higher pressures resulting in an open networked morphology. An estimate based on the geometry of the gas-phase plume and experimental results for Y₂O₃ nanoparticles produced in 4 Torr N₂ gives a critical concentration of tens of nanoparticles per μm³ for the transition of agglomerates versus isolated nanoparticles reaching a deposition substrate.     

Prediction of environmental stress cracking resistance in linear low density polyethylenes

Recently it has been shown that the strain hardening modulus (G_p) at 80°C can be used to predict the environmental stress cracking (ESC) resistance of polyethylenes. The advantage of using strain hardening to determine ESC resistance is that the data may be obtained relatively easily and quickly using simple tensile test equipment. In this article, the strain hardening modulus has been used to predict the ESC resistance of three grades of linear low‐density polyethylene. Unlike in the previous research, the measurements were conducted at room temperature enabling tests to be performed without the need of a temperature‐controlled oven. This was achieved by reducing the strain rate to increase the sensitivity of the technique and increasing the thickness of the specimens to improve the repeatability. The strain hardening modulus data were found to correlate well with the ESC results obtained from long‐term full notch creep tests and are consistent with the known molecular structure of the polyethylene grades. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers