1,441 research outputs found

    USPOREDBA PROIZVODNJE BIOPLINA IZMEĐU GNOJA NESILICA I BROJLERA

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    Biogas plants that process raw materials from agriculture, such as poultry manure, are one of the most significant applications of anaerobic fermentation. In Asian countries, particularly in China, India, Nepal and Vietnam, there are several million very simple, small biogas plants that produce gas for household cooking and lighting. In Europe and North America a number of agricultural biogas plants now, are increasing daily, a few thousand biogas plants exist, most of which use modern technologies, anaerobic fermentation. The aim of this paper is to determine the possibility of biogas production from poultry manure with 10% of total solids and through the segments of the quality and quantity, determine the content of total solids (DM), volatile solids (OM), and the amount and composition of biogas. The aim was also to justify the use of poultry manure in biogas production and its application for specific purposes Laboratory research showed that 1 kg of poultry 10% of poultry manure produced 47.01 l of biogas during the 40 days of anaerobic fermentation under mezofilic conditions. Production of biogas has a good potential for development in Croatia, especially in the continental part. Usages of this technology are multiple because of the fact that the Republic of Croatia imports most of the energy. Usage of biogas would reduce the import of certain energy and thus reduce energy dependence; it would increase the number of employers and ease the obligation of Croatia toward EU in replacing some fossil fuels with renewable ones.Bioplinski pogoni koji prerađuju sirovine iz poljoprivrede, poput izmeta peradi, predstavljaju jednu od najvažnijih primjena anaerobne fermentacije. Samo u azijskim zemljama, osobito u Kini, Indiji, Nepalu i Vijetnamu, postoji nekoliko milijuna vrlo jednostavnih, malih bioplinskih reaktora koji proizvode plin za kuhanje i rasvjetu kućanstava. U Europi i Sjevernoj Americi svakodnevno raste broj poljoprivrednih bioplinskih pogona, a danas ih funkcionira nekoliko tisuća, od kojih se većina koristi suvremenim tehnologijama anaerobne fermentacije. Cilj rada je utvrditi mogućnost proizvodnje bioplina iz pilećega gnoja s 10% suhe tvari. S pomoću segmenata kvalitete i kvantitete tijekom istraživanja utvrditi udio suhe tvari (ST), organske tvari (OT), količinu i sastav bioplina te dokazati opravdanost uporabe pilećega gnoja u proizvodnji bioplina i njegove primjene u određene svrhe. Na temelju provedenoga laboratorijskoga istraživanja, dokazana je proizvodnja bioplina iz izmeta peradi i svinjske gnojovke. Anaerobnom fermentacijom u trajanju od 40 dana pri mezofilnim uvjetima proizvedeno je iz 1 kg izmeta nesilica 25 litara bioplina, a iz svinjske gnojovke u kombinaciji s 10% brojlerskoga stajnjaka 47,01 litara bioplina. Proizvodnja bioplina ima dobre uvjete za razvoj u Republici Hrvatskoj, posebice u kontinentalnome dijelu. Koristi od te tehnologije viÅ”estruke su, jer je RH prisiljena uvoziti većinu energenata. KoriÅ”tenjem bioplina smanjio bi se uvoz pojedinih energenata, čime bi se umanjila i energetska ovisnost o drugim državama; povećao bi se broj zaposlenih i RH bi ostvarila lakÅ”e svoju obvezu prema EU-u, da zamijeni dio fosilnih goriva obnovljivima

    Using 18O/2H, 3H/3He, 85Kr and CFCs to determine mean residence times and water origin in the Grazer and Leibnitzer Feld groundwater bodies (Austria)

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    Two groundwater bodies, Grazer Feld and Leibnitzer Feld, with surface areas of 166 and 103 km2 respectively are characterised for the first time by measuring the combination of Ī“18O/Ī“2H, 3H/3He, 85Kr, CFC-11, CFC-12 and hydrochemistry in 34 monitoring wells in 2009/2010. The timescales of groundwater recharge have been characterised by 131 Ī“18O measurements of well and surface water sampled on a seasonal basis. Most monitoring wells show a seasonal variation or indicate variable contributions of the main river Mur (0ā€“30%, max. 70%) and/or other rivers having their recharge areas in higher altitudes. Combined Ī“18O/Ī“2H-measurements indicate that 65ā€“75% of groundwater recharge in the unusual wet year of 2009 was from precipitation in the summer based on values from the Graz meteorological station. Monitoring wells downstream of gravel pit lakes show a clear evaporation trend. A boronā€“nitrate differentiation plot shows more frequent boron-rich water in the more urbanised Grazer Feld and more frequent nitrate-rich water in the more agricultural used Leibnitzer Feld indicating that a some of the nitrate load in the Grazer Feld comes from urban sewer water. Several lumped parameter models based on tritium input data from Graz and monthly data from the river Mur (Spielfeld) since 1977 yield a Mean Residence Time (MRT) for the Mur-water itself between 3 and 4 years in this area. Data from Ī“18O, 3H/3He measurements at the Wagna lysimeter station supports the conclusion that 90% of the groundwaters in the Grazer Feld and 73% in the Leibnitzer Feld have MRTs of 20 m) with relative thicker unsaturated zones. The young MRT of groundwater from two monitoring wells in the Leibnitzer Feld was confirmed by 85Kr-measurements. Most CFC-11 and CFC-12 concentrations in the groundwater exceed the equilibration concentrations of modern concentrations in water and are therefore unsuitable for dating purposes. An enrichment factor up to 100 compared to atmospheric equilibrium concentrations and the obvious correlation of CFC-12 with SO4, Na, Cl and B in the ground waters of the Grazer Feld suggest that waste water in contact with CFC-containing material above and below ground is the source for the contamination. The dominance of very young groundwater (<5 years) indicates a recent origin of the contamination by nitrate and many other components observed in parts of the groundwater bodies. Rapid measures to reduce those sources are needed to mitigate against further deterioration of these waters

    Herpes Simplex Virus 1 and Chlamydophila (Chlamydia) pneumoniae promote Ab 1-42 amyloid processing in murine astrocytes linking an infectious process to Alzheimer\u27s disease

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    Background: Several studies have suggested an infectious etiology for Alzheimer\u27s disease (AD). Previously, our laboratory identified Chlamydia pneumoniae (Cpn) from autopsied sporadic AD brains, as well as developed a BALB/c mouse model that demonstrated infection-induced amyloid plaques similar to those found in AD. Hypothesis: We propose that an additional pathogen such as herpes simplex virus type 1 (HSV1), also may be a contributing factor in toin the pathology seen in AD. HSV1, in addition to Cpn, may be triggering the abnormal cleavage of the beta amyloid precursor protein (bAPP) into Ab1-42 , thereby contributing to amyloid plaque formation. Our current study examines amyloid processing following infection of primary and C8-DIA murine astrocytes with Cpn and HSV1. Materials and Methods: Immunocytochemistry and western analysis was used to analyze the outcome of infection by these two pathogens. Results: Cpn infection resulted in an increase in cytoplasmic labeling of Ab 1-42 relative to uninfected cells, while increased nuclear labeling of Ab 1-42 was observed following HSV1 infection. Co-infections with Cpn and HSV1 resulted in amyloid labeling resembling that of HSV1 infection alone, though Ab 1-42 labeling appeared decreased specifically in Cpn-infected cells of the co-infected monolayers. Conclusions: These data suggest that infection of astrocytic cells by HSV1 and (Cpn) alter the processing of bAPP, thereby producing Ab1-42. Therefore, these studies, inaddition to the previous research reported by our laboratory, support an emerging linkage of the infectious processs to the neuropathology characteristic of Alzheimer\u27s disease.https://digitalcommons.pcom.edu/posters/1008/thumbnail.jp

    Graphene-based photovoltaic cells for near-field thermal energy conversion

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    Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. In far field, the efficiency of these systems is limited by the thermodynamic Schockley-Queisser limit corresponding to the case where the source is a black body. On the other hand, in near field, the heat flux which can be transferred to a photovoltaic cell can be several orders of magnitude larger because of the contribution of evanescent photons. This is particularly true when the source supports surface polaritons. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. Here we show that graphene-based hybrid photovoltaic cells can significantly enhance the generated power paving the way to a promising technology for an intensive production of electricity from waste heat.Comment: 5 pages, 4 figure

    Study of a Nonlocal Density scheme for electronic--structure calculations

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    An exchange-correlation energy functional beyond the local density approximation, based on the exchange-correlation kernel of the homogeneous electron gas and originally introduced by Kohn and Sham, is considered for electronic structure calculations of semiconductors and atoms. Calculations are carried out for diamond, silicon, silicon carbide and gallium arsenide. The lattice constants and gaps show a small improvement with respect to the LDA results. However, the corresponding corrections to the total energy of the isolated atoms are not large enough to yield a substantial improvement for the cohesive energy of solids, which remains hence overestimated as in the LDA.Comment: 4 postscript figure

    Skyrmions and edge spin excitations in quantum Hall droplets

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    We present an analysis of spin-textures in Quantum Hall droplets, for filling factors Ī½ā‰ƒ1\nu \simeq 1. Analytical wavefunctions with well defined quantum numbers are given for the low-lying states of the system which result to be either bulk skyrmions or edge spin excitations. We compute dispersion relations and study how skyrmions become ground states of the Quantum Hall droplet at Ī½ā‰³1\nu \gtrsim 1. A Hartree-Fock approximation is recovered and discussed for those spin textures.Comment: RevTeX, four postscript figures appende
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