The influence on biogas production of three slurry-handling systems in dairy farms

Handling systems can influence the production of biogas and methane from dairy farm manures. A comparative work performed in three different Italian dairy farms showed how the most common techniques (scraper, slatted floor, flushing) can change the characteristics of collected manure. Scraper appears to be the most neutral choice, as it does not significantly affect the original characteristics of manure. Slatted floor produces a manure that has a lower methane potential in comparison with scraper, due to: a lower content of volatile solids caused by the biodegradation occurring in the deep pit, and a lower specific biogas production caused by the change in the characteristics of organic matter. Flushing can produce three different fluxes: diluted flushed manure, solid separated manure and liquid separated manure. The diluted fraction appears to be unsuitable for conventional anaerobic digestion in completely stirred reactors (CSTR), since its content of organic matter is too low to be worthwhile. The liquid separated fraction could represent an interesting material, as it appears to accumulate the most biodegradable organic fraction, but not as primary substrate in CSTR as the organic matter concentration is too low. Finally, the solid-liquid separation process tends to accumulate inert matter in the solid separated fraction and, therefore, its specific methane production is low

Synthesis of Aluminum-Aluminum Nitride Nanocomposites by Gas-Liquid Reactions

An innovative method has been developed for synthesizing aluminum-aluminum nitride nanocomposite materials wherein the reinforcing nano-sized aluminum nitride particles are formed in-situ in a molten aluminum alloy. This method, which circumvents most issues associated with the traditional ways of making nanocomposites, involves reacting a nitrogen-bearing gas with a specially designed molten aluminum alloy. The method ensures excellent dispersion of the nanoparticles in the matrix alloy, which is reflected in enhanced mechanical properties. In this thesis, the author reviews the limitations of the conventional methods of manufacturing nanocomposites and develops thermodynamic and kinetic models that allow optimizing the in-situ gas-liquid process to produce quality nanocomposite material. Also, in this thesis, the author reports the measured room temperature and elevated temperature tensile properties of materials that were made by the optimized process and compares the measured values to their counterparts obtained for the base alloy. A 75 pct. increase in room temperature yield strength is obtained when the base alloy is reinforced with one pct. nano-size aluminum nitride particles and this significant increase in yield strength is accompanied by only negligible loss of ductility

Aluminum Nano-composites for Elevated Temperature Applications

Conventional manufacturing methods are sub-optimal for nano-composites fabrication. Inhomogeneous dispersion of the secondary phase and scalability issues are the main issues. This work focuses on an innovative method where the reinforcement is formed in-situ in the melt. It involves the reaction of the molten aluminum with a nitrogen- bearing gas injected through the melt at around 1273 K. AlN particles are expected to form through this in situ reaction. A model has been developed to predict the amount of reinforced phase. Experiments have been carried out to confirm the feasibility of the process and the mechanism of AlN formation discussed. The detrimental effect of oxygen in the melt which hinders the nitridation reaction has been proved. The effect of process times and the addition of alloying elements (Mg and Si) have also been investigated

Cultivo de Brassica

Fil: Tuma Borgonovo, María Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Ceva, María Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Müller Andrades, Edwin Santiago. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Zumelzú, Guillermo. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Fitopatología; Argentina.Este manual práctico corresponde a una serie de cuadernillos de cultivos de flores realizados en otras ediciones. El mismo pretende facilitar al técnico y al floricultor información que responda a aquellas consideraciones previas al establecimiento del cultivo, como así también las prácticas específicas, cosecha y poscosecha. Todas las actividades propuestas sugieren un uso sustentable de los recursos. En Córdoba, el desarrollo de la Floricultura puede constituirse como una actividad productiva sustentable que contribuya a la generación de empleo y cubra la demanda de un mercado local actualmente insatisfecho. Desde la Facultad de Ciencias Agropecuarias de la UNC se trabaja para el Desarrollo de la Floricultura a través de la docencia en la carrera de Ingeniero Agrónomo (Plan de estudio 2004) y en la Tecnicatura en Jardinería y Floricultura (Plan de estudio 2013), además de realizar numerosas investigaciones y participación en actividades científicas y de divulgación. Para realizar esta Guía práctica del cultivo de , se evaluó el Brassica oleracea comportamiento de diferentes variedades medido como productividad y calidad de flores. Las actividades de investigación se centraron en la evaluación de desarrollo en las condiciones agroecológicas sustentables, midiendo el efecto del uso de Trichoderma y solarización sobre la calidad del cultivo (Tuma et al., 2018).Fil: Tuma Borgonovo, María Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Ceva, María Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Müller Andrades, Edwin Santiago. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Floricultura; Argentina.Fil: Zumelzú, Guillermo. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Fitopatología; Argentina

A comparison of human papillomavirus genotype-specific DNA and E6/E7 mRNA detection to identify anal precancer among HIV-infected men who have sex with men.

BackgroundHuman papillomavirus (HPV) RNA detection is reportedly more specific for the detection of anogenital precancer than HPV DNA but it is unknown whether this is due to detection of RNA or due to HPV genotype restriction.MethodsA total of 363 human immunodeficiency virus (HIV)-positive men who have sex with men had two anal cytology samples taken and were evaluated using high-resolution anoscopy and biopsies of visible lesions. Anal specimens were tested for E6/E7 RNA for five carcinogenic HPV genotypes (HPV16, 18, 31, 33, and 45) and tested for the DNA of 13 carcinogenic HPV genotypes.ResultsDNA testing was more likely to be positive than RNA testing (53% vs. 48%; P = 0.02) for the same five HPV genotypes in aggregate. When restricted to five HPV genotypes targeted by the RNA test, the sensitivity to detect anal precancer was the same for DNA and RNA (81%), whereas RNA was more specific than DNA (65% vs. 58%; P = 0.007). In comparison, DNA detection of all 13 carcinogenic HPV genotypes was more sensitive (96% vs. 81%; P = 0.001) but much less specific (65% vs. 33%; P < 0.001) as compared with RNA detection of the five HPV genotypes.ConclusionAfter controlling for HPV genotypes, RNA was only slightly more specific than DNA detection for anal precancer.ImpactDNA or RNA testing for a subset of the most carcinogenic HPV genotypes may be useful for distinguishing between those HPV-positive men at higher and lower risk of anal precancer and cancer

A Comparison of Human Papillomavirus Genotype-Specific DNA and E6/E7 mRNA Detection to Identify Anal Precancer among HIV-Infected Men Who Have Sex with Men

BACKGROUND: Human papillomavirus (HPV) RNA detection is reportedly more specific for the detection of anogenital precancer than HPV DNA but it is unknown whether this is due to detection of RNA or due to HPV genotype restriction. MATERIALS AND METHODS: 363 human immunodeficiency virus (HIV)-positive men who have sex with men had two anal cytology samples taken and were evaluated using high-resolution anoscopy and biopsies of visible lesions. Anal specimens were tested for E6/E7 RNA for 5 carcinogenic HPV genotypes (HPV16, 18, 31, 33, and 45) and tested for the DNA of 13 carcinogenic HPV genotypes. RESULTS: DNA testing was more likely to be positive than RNA testing (53% vs. 48%, p = 0.02) for the same 5 HPV genotypes in aggregate. When restricted to 5 HPV genotypes targeted by the RNA test, the sensitivity to detect anal precancer was the same for DNA and RNA (81%) while RNA was more specific than DNA (65% vs. 58%, p = 0.007). By comparison, DNA detection of all 13 carcinogenic HPV genotypes was more sensitive (96% vs. 81%, p = 0.001) but much less specific (65% vs. 33%, p < 0.001) compared to RNA detection of the 5 HPV genotypes. CONCLUSION: After controlling for HPV genotypes, RNA was only slightly more specific than DNA detection for anal precancer. IMPACT: DNA or RNA testing for a subset of the most carcinogenic HPV genotypes may be useful for distinguishing between those HPV-positive men at higher and lower risk of anal precancer and cancer