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B Presenter: b Charles Vining MD | University of Chicago B Background: b Recent NSQIP analysis has shown a decrease in clinically relevant post-operative pancreatic fistula (CR-POPF) for minimally invasive pancreaticoduodenectomy (PD) with time. On subgroup analysis, OPD had higher CR-POPF in high risk patients (32.9% vs 19.4%; p=0.007), but a trend in intermediate risk (17.8% vs 11.8%; p=0.070) and no difference for negligible and low risk groups (table). [Extracted from the article]

We report a new high vacuum instrument which is dedicated to the preparation of well-defined clusters supported on model and technologically relevant supports for catalytic and materials investigations. The instrument is based on deposition of size selected metallic cluster ions that are produced by a high flux magnetron cluster source. The throughput of the apparatus is maximized by collecting and focusing ions utilizing a conical octupole ion guide and a linear ion guide. The size selection is achieved by a quadrupole mass filter. The new design of the sample holder provides for the preparation of multiple samples on supports of various sizes and shapes in one session. After cluster deposition onto the support of interest, samples will be taken out of the chamber for a variety of testing and characterization. [ABSTRACT FROM AUTHOR]

In biomethane potential (BMP) tests, different sources and origins of inocula might cause significant variations in the tests' results, preventing from acquiring a harmonised and standardised evaluation of the different substrates. In this study, a method to produce standardised and storable inocula was elaborated. For the development of the different investigation steps a control sludge originated from a wastewater treatment plant was utilised. Freeze-drying was applied in the framework of this study as a long-term conservation method for the anaerobic inocula. In order to ensure a closed system with anaerobic conditions at all times, a test system was developed to allow accurate and representative mass-balance experiments. The test results demonstrated that inocula conservation and re-suspension in BMP tests is possible; the limit value of the expected methane yield of a positive and lyophilised reference-control, was reached. However, a lag phase of 7–10 days was obtained, possibly due to the damage of microorganisms as a consequence of the conservation process. Further investigations need to be carried out to optimise the conservation process of the produced inocula or an initial preparation phase should be considered to reduce the lag phase. Image 1094 • Producing standardised and storable inocula for biomethane potential tests (MBP). • Lyophilisation was applied as a long-term conservation method for the anaerobic inocula. • Developing a test system to allow accurate and representative mass-balance experiments. • The conservation of inocula, produced under standardised conditions, is possible. • An extended lag phase of 7–10 days within the methane production was obtained. [ABSTRACT FROM AUTHOR]

Abstract Impurities in bio-waste enter biogas and compost facilities during bio-waste treatment. The plastic fraction is usually separated and sent for incineration. This study is aimed at evaluating the quality of low density polyethylene after being exposed to anaerobic digestion, composting or both processes sequentially, in order to assess for the optimum post-processing of these plastic fractions, eventually undergoing recycling processes. The alteration in the polymer's quality was first analyzed by non-destructive optical methods, including FTIR, NIR, SEM and EDX. These tests were followed by thermal and mechanical properties' assessment. The surface of the specimens showed signs of degradation, yet the extent of the changes was microscopic. The FTIR and NIR spectra showed higher intensities for C-H bonds in treated samples, which might be an indication of shorter polymer's chain length and/or higher chain scissoring. FTIR showed weak transmission spectral changes at regions representing C-O and O-H bonds for anaerobically digested and sequentially anaerobically digested and composted samples, indicating the existence of oxidized products, which was confirmed by the EDX analysis, where slightly higher oxygen content on the surface of specimens underwent the anaerobic digestion process was observed. However, NIR spectra did not show conforming spectra. It was accordingly concluded that the oxidized products are contaminants (residues on the specimens' surfaces), which was as well confirmed by the DSC analysis. The thermal analysis indicated a decrease in the polymer's crystallinity after being treated, where the decrease effect was the highest by anaerobic digestion, however, the mechanical properties (including tensile strength, elastic modulus and strain at break) pointed out minor quality alteration in treated samples, especially for samples underwent both processes successively. Based on the provided assessment, the general properties of LDPE plastic specimens are acceptable to be recycled, even after undergoing accelerated aging conditions, such as anaerobic digestion and composting. Further analyses are needed to evaluate plastics with additives as well as bags and films. Highlights • Analysis of the quality of LDPE after undergoing anaerobic digestion and composting conditions. • Comparison between the different aging conditions' effect on the quality deterioration of LDPE specimens. • Overall evaluation of LDPE quality for recycling purposes. • Results support recovery of plastic material for further processing. [ABSTRACT FROM AUTHOR]