5 results
Search Results
Now showing 1 - 5 of 5
- ItemAssessing the organic fraction of municipal solid wastes for the production of lactic acid(Amsterdam [u.a.] : Elsevier, 2019) López-Gómez, J. Pablo; Latorre-Sánchez, Marcos; Unger, Peter; Schneider, Roland; Coll Lozano, Caterina; Venus, JoachimWith an estimated yearly production of about 140 Mt in the EU, conventionally, the organic fraction of municipal solid wastes (OFMSW) has been disposed in landfills with negative environmental effects. Nonetheless, the chemical composition of this residue make it a substrate with great bioconversion potential. In this study, OFMSW from Spanish municipal treatment plants, were evaluated for the production of LA. Samples were identified according to the sorting mechanisms employed for their collection in: (A) separately collected, (B) non-separately collected and (C) separately collected+paper/cardboard. Enzymatic hydrolysis was used to produce hydrolysates A, B and C accordingly. Hydrolysate A showed the highest total sugars and glucose content with values of 70 and 55 g·L−1, respectively. Following the characterisation, a screening showed that growth of B. coagulans was possible in all three hydrolysates. Furthermore, lab scale fermentations showed that LA final concentrations could reach around 60 g·L−1, with yields from total sugars of above 0.60 g·g−1. A technical scale fermentation of the hydrolysate A resulted in a final LA concentration of 60.7 g·L−1, a yield of 0.71 g·g−1 with a productivity of 2.68 g·L−1·h−1. Overall, it was estimated that 0.23 g of LA could be produced from one g of dry OFMSW.
- ItemAn extended hybrid input-output model applied to fossil- and bio-based plastics(Amsterdam [u.a.] : Elsevier, 2021) Jander, WiebkeMatrix augmentation method is developed further and described transparently for enabling more specific input-output analyses of bio- vs. fossil-based sectors. A number of economic and environmental effects of substitution can be estimated, compared, and managed. While the model was applied for the first time to the German plastics industry, it can be well integrated into existing bioeconomy monitorings to represent substitution in sectors and countries. • Original matrix augmentation method is described in much detail for the first time considering available data for bio- and fossil-based industries. • Particular attention is paid to balancing cost and benefit in model building so that indicators can be integrated in a continuous monitoring of the bioeconomy. Hence, industry data is prefered to process data whenever possible. • Input structures of bio-based imports are considered in single-region input-output analysis.
- ItemIntegrative programming for simulation of packaging headspace and shelf life of fresh produce(Amsterdam [u.a.] : Elsevier, 2021) Jalali, Ali; Linke, Manfred; Geyer, Martin; Mahajan, PramodFresh horticultural products are exposed to different environmental conditions from farm to fork. Barrier properties of packaging and physiological behaviour of produce, namely respiration and transpiration can affect headspace conditions surrounding produce and consequently remaining shelf life. Packaging material also plays a role in heat and mass transfer, such as thermal conduction and permeation of O2, CO2 and water vapour. All of these behaviours are integrated together in the form of ordinary differential equations and solved using numerical methods in MATLAB. • The simulation program is useful for designing the size and number of perforations to achieve equilibrium modified atmosphere alone or in combination with packaging material having a higher water transmission rate or active moisture absorber. • The simulation program is also useful for predicting the shelf life of fresh produce under the actual supply chain conditions. • The simulation program provides a flexible system to input predefined supply chain conditions and the properties of fresh produce and packaging material, thus, minimizing the costly and time consuming experimental procedures for selecting the optimum packaging material for fresh produce.
- ItemLaser induced diffuse reflectance imaging – Monte Carlo simulation of backscattering measured on the surface(Amsterdam [u.a.] : Elsevier, 2020) Baranyai, LászlóThe Monte Carlo simulation algorithm of photon trajectory computation is implemented in object oriented R code. Diffuse reflectance, also called backscattering, is modeled in semi-infinite homogeneous media. Spatial photon flux leaving the surface of the media is collected. The profile of intensity along radii relative to the incident point is used to simulate measurement of computer vision systems. Four optical parameters of the media are used: absorption coefficient, scattering coefficient, anisotropy factor and refractive index. Five parameters are used to describe configuration of the vision system: number of photons, radius of circular light beam, limiting energy level of photons, radius of observed area, spatial resolution of the vision system. • The incident angle of the light beam is included in the photon launch procedure. Initial direction is typically assumed to be normal with x,y,z coordinates of 0,0,1. In the proposed modification, initial move vector is calculated based on the incident angle and refractive index of the media. Additionally, elliptic distortion of the circular light beam on the surface is calculated based on the incident angle. • Photon flux leaving media through the surface is corrected with Lambertian method to measure intensity captured by an imaging device in normal position. • The software implementing the method is written in R language, the R code is available as standard package.
- ItemProteiniphilum saccharofermentans str. M3/6T isolated from a laboratory biogas reactor is versatile in polysaccharide and oligopeptide utilization as deduced from genome-based metabolic reconstructions(Amsterdam [u.a.] : Elsevier, 2018) Tomazetto, Geizecler; Hahnke, Sarah; Wibberg, Daniel; Pühler, Alfred; Klocke, Michael; Schlüter, AndreasProteiniphilum saccharofermentans str. M3/6T is a recently described species within the family Porphyromonadaceae (phylum Bacteroidetes), which was isolated from a mesophilic laboratory-scale biogas reactor. The genome of the strain was completely sequenced and manually annotated to reconstruct its metabolic potential regarding biomass degradation and fermentation pathways. The P. saccharofermentans str. M3/6T genome consists of a 4,414,963 bp chromosome featuring an average GC-content of 43.63%. Genome analyses revealed that the strain possesses 3396 protein-coding sequences. Among them are 158 genes assigned to the carbohydrate-active-enzyme families as defined by the CAZy database, including 116 genes encoding glycosyl hydrolases (GHs) involved in pectin, arabinogalactan, hemicellulose (arabinan, xylan, mannan, β-glucans), starch, fructan and chitin degradation. The strain also features several transporter genes, some of which are located in polysaccharide utilization loci (PUL). PUL gene products are involved in glycan binding, transport and utilization at the cell surface. In the genome of strain M3/6T, 64 PUL are present and most of them in association with genes encoding carbohydrate-active enzymes. Accordingly, the strain was predicted to metabolize several sugars yielding carbon dioxide, hydrogen, acetate, formate, propionate and isovalerate as end-products of the fermentation process. Moreover, P. saccharofermentans str. M3/6T encodes extracellular and intracellular proteases and transporters predicted to be involved in protein and oligopeptide degradation. Comparative analyses between P. saccharofermentans str. M3/6T and its closest described relative P. acetatigenes str. DSM 18083T indicate that both strains share a similar metabolism regarding decomposition of complex carbohydrates and fermentation of sugars. © 2018 The Authors