Environmental assessment of the valorisation and recycling of selected food production side flows

Abstract Residues from the food manufacturing industry require management options with the best overall environmental outcome. The identification of sustainable solutions depends however, on many influencing factors such as energy input, transport distance, and substituted product. This study shows the influence of the choice of substituted products on the overall greenhouse gas (GHG) emissions for three specific food side-flows and their treatment in the European Union: animal blood, apple pomace and brewers' spent grain (BSG). In a direct comparison of possible treatment options, it is notable that the conversion to food ingredients (valorisation) does not always result in reduced environmental net impacts (GHG savings), which means that other options at lower levels of the waste hierarchy might be more beneficial to the environment. The further use of apple pomace or BSG for the production of food ingredients is only advantageous if the processing emissions are smaller than the emissions from the substituted products. The use of food side-flows as animal feed shows environmental advantages in all scenarios, as the use of conventional feed, such as soybean meal or hay, is reduced and so are the GHG emissions. The anaerobic digestion of food side-flows is associated with significant GHG emissions, but alternative energy also display a high GHG factor when based on fossil resources. The measuring of circularity in the food sector is a challenge in itself due to the complexity of renewable materials. This study shall help to understand the interwoven influences of certain parameters to the results

Weak magnetic fields in Ap/Bp stars: evidence for a dipole field lower limit and a tentative interpretation of the magnetic dichotomy

Publisher's version/PDFAims. We investigated a sample of 28 well-known spectroscopically-identified magnetic Ap/Bp stars, with weak, poorly-determined or previously undetected magnetic fields. The aim of this study is to explore the weak part of the magnetic field distribution of Ap/Bp stars. Methods. Using the MuSiCoS and NARVAL spectropolarimeters at Télescope Bernard Lyot (Observatoire du Pic du Midi, France) and the cross-correlation technique Least Squares Deconvolution (LSD), we obtained 282 LSD Stokes V signatures of our 28 sample stars, in order to detect the magnetic field and to infer its longitudinal component with high precision (median [sigma] = 40 G). Results. For the 28 studied stars, we obtained 27 detections of Stokes V Zeeman signatures from the MuSiCoS observations. Detection of the Stokes V signature of the 28th star (HD 32650) was obtained during science demonstration time of the new NARVAL spectropolarimeter at Pic du Midi. This result clearly shows that when observed with sufficient precision, all firmly classified Ap/Bp stars show detectable surface magnetic fields. Furthermore, all detected magnetic fields correspond to longitudinal fields which are significantly greater than some tens of G. To better characterise the surface magnetic field intensities and geometries of the sample, we phased the longitudinal field measurements of each star using new and previously-published rotational periods, and modeled them to infer the dipolar field intensity (B[subscript d], measured at the magnetic pole) and the magnetic obliquity ([Beta]). The distribution of derived dipole strengths for these stars exhibits a plateau at about 1 kG, falling off to larger and smaller field strengths. Remarkably, in this sample of stars selected for their presumably weak magnetic fields, we find only 2 stars for which the derived dipole strength is weaker than 300 G.We interpret this “magnetic threshold” as a critical value necessary for the stability of large-scale magnetic fields, and develop a simple quantitative model that is able to approximately reproduce the observed threshold characteristics. This scenario leads to a natural explanation of the small fraction of intermediate-mass magnetic stars. It may also explain the near-absence of magnetic fields in more massive B and O-type stars

Exploring natural and social drivers of forest degradation in post-Soviet Georgia

The Caucasus Mountains harbor high concentrations of endemic species and provide an abundance of ecosystem services yet are significantly understudied compared to other ecosystems in Eurasia. In the country of Georgia, at the heart of the Caucasus region, forest degradation has been the largest land change process over the last thirty years. The prevailing narrative is that legal and illegal cutting of trees for fuelwood is primarily responsible for this process. Yet, since independence from the Soviet Union in 1991, the country has undergone rapid socioeconomic and institutional changes which have not been explored as drivers of forest change. We combine newly available land-cover change estimates, Georgian statistical data, and historical institutional change data to examine socioeconomic drivers of forest degradation. Our analysis controls for concurrent changes in climate that would affect degradation and examines variation at the regional (state) level from 2011 to 2019, as well as at the national level from 1987 to 2019. We find that higher winter temperature and drought are associated with higher degradation at the regional scale, while major institutional changes and drought are associated with higher forest degradation at the national level. Access to natural gas, the major energy alternative to fuelwood, had no significant association with degradation. Our results challenge the narrative that poverty and a lack of alternative energy infrastructure drive forest degradation and suggest that government policies banning household fuelwood cutting, including the new Forest Code of 2020, may not reduce forest degradation. Given these results, improved data on wood harvesting and more research on the commercial drivers of degradation and their links to economic and political reforms is needed to better inform forest policy in the region, especially given ongoing risks from climate change

Environmental assessment of the valorisation and recycling of selected food production side flows

Residues from the food manufacturing industry require management options with the best overall environmental outcome. The identification of sustainable solutions depends however, on many influencing factors such as energy input, transport distance, and substituted product. This study shows the influence of the choice of substituted products on the overall greenhouse gas (GHG) emissions for three specific food side-flows and their treatment in the European Union: animal blood, apple pomace and brewers\u2019 spent grain (BSG). In a direct comparison of possible treatment options, it is notable that the conversion to food ingredients (valorisation) does not always result in reduced environmental net impacts (GHG savings), which means that other options at lower levels of the waste hierarchy might be more beneficial to the environment. The further use of apple pomace or BSG for the production of food ingredients is only advantageous if the processing emissions are smaller than the emissions from the substituted products. The use of food side-flows as animal feed shows environmental advantages in all scenarios, as the use of conventional feed, such as soybean meal or hay, is reduced and so are the GHG emissions. The anaerobic digestion of food side-flows is associated with significant GHG emissions, but alternative energy also display a high GHG factor when based on fossil resources. The measuring of circularity in the food sector is a challenge in itself due to the complexity of renewable materials. This study shall help to understand the interwoven influences of certain parameters to the results