Estimating homelessness in the Netherlands using a capture-recapture approach

This study focuses on the homeless population in the Netherlands, as an indicator of social exclusion. By applying the capture-recapture (CRC) methodology to three registers, not only the size of the homeless population could be estimated, but also its composition in terms of gender, age, place of living, and origin could be depicted. Because of the use of three registers and the availability of background characteristics for each of the registers, the usual stringent assumptions of capture recapture methodology is circumvented. This advanced application of CRC to estimate the homeless population on the national level, has led to official figures for five subsequent reference dates (January 1st of 2009, 2010, 2011, 2012 and 2013). In 2009 the size of the total homeless population in the Netherlands was estimated at 17,767, of which 5169 were registered on one of the three lists. Between 2009 and 2012 the estimated size of the population increased, which was largely due to the financial crisis. For all reference dates, the composition of this population showed that generally more men than women were registered and that homeless people in the age category of 30–49 years old were registered more than the younger or older age groups. Compared to the general Dutch population, the homeless population includes relatively many men, many people aged 30–49 years and people with a non-western backgroun

Application of Ligninolytic Enzymes in the Production of Biofuels from Cotton Wastes

The application of ligninolytic fungi and enzymes is an option to overcome the issues related with the production of biofuels using cotton wastes. In this dissertation, the ligninolytic fungus and enzymes were evaluated as pretreatment for the biochemical conversion of Cotton Gin Trash (CGT) in ethanol and as a treatment for the transformation of cotton wastes biochar in other substances. In biochemical conversion, seven combinations of three pretreatments (ultrasonication, liquid hot water and ligninolytic enzymes) were evaluated on CGT. The best results were achieved by the sequential combination of ultrasonication, hot water, and ligninolytic enzymes with an improvement of 10% in ethanol yield. To improve these results, alkaline-ultrasonication was evaluated. Additionally, Fourier Transform Infrared (FT-IR) and principal component analysis (PCA) were employed as fast methodology to identify structural differences in the biomass. The combination of ultrasonication-alkali hydrolysis, hot liquid water, and ligninolytic enzymes using 15% of NaOH improved 35% ethanol yield compared with the original treatment. Additionally, FT-IR and PCA identified modifications in the biomass structure after different types of pretreatments and conditions. In thermal conversion, this study evaluated the biodepolymerization of cotton wastes biochar using chemical and biological treatments. The chemical depolymerization evaluated three chemical agents (KMnO4, H2SO4, and NaOH), with three concentrations and two environmental conditions. The sulfuric acid treatments performed the largest transformations of the biochar solid phase; whereas, the KMnO4 treatments achieved the largest depolymerizations. The compounds released into the liquid phase were correlated with fulvic and humic acids and silicon compounds. The biological depolymerization utilized four ligninolytic fungi Phanerochaete chrysosporium, Ceriporiopsis subvermispora, Postia placenta, and Bjerkandera adusta. The greatest depolymerization was obtained by C. subvermispora. The depolymerization kinetics of C. subvermispora evidenced the production of laccase and manganese peroxidase and a correlation between depolymerization and production of ligninolytic enzymes. The modifications obtained in the liquid and solid phases showed the production of humic and fulvic acids from the cultures with C. subvermispora. The results of this research are the initial steps for the development of new processes using the ligninolytic fungus and their enzymes for the production of biofuels from cotton wastes