Search results for "Dahl"
showing 10 items of 29 documents
Ledus sastrēgumi Daugavā: Doles sala (17.04. 1904.; Kupfer)
1904
K. R. Kupfera 1904. gada 17. aprīlī fotografētie ledus sastrēgumi Daugavā pie Doles salas ar autora aprakstu. K. R. Kupfer's photographed ice jams in Daugava near Dole Island on 17 April 1904, with an autor's description. K. R. Kupfer fotografierte am 17. April 1904 Eisstauungen in der Daugava bei Dole Island mit einer Beschreibungvom Autor.
Mesophilic and thermophilic anaerobic co-digestion of rendering plant and slaughterhouse wastes.
2011
Co-digestion of rendering and slaughterhouse wastes was studied in laboratory scale semi-continuously fed continuously stirred tank reactors (CSTRs) at 35 and 55 °C. All in all, 10 different rendering plant and slaughterhouse waste fractions were characterised showing high contents of lipids and proteins, and methane potentials of 262-572 dm(3)CH(4)/kg volatile solids(VS)(added). In mesophilic CSTR methane yields of ca 720 dm(3) CH(4)/kg VS(fed) were obtained with organic loading rates (OLR) of 1.0 and 1.5 kg VS/m(3) d, and hydraulic retention time (HRT) of 50 d. For thermophilic process, the lowest studied OLR of 1.5 kg VS/m(3) d, turned to be unstable after operation of 1.5 HRT, due to ac…
Two-stage anaerobic digestion of tomato, cucumber, common reed and grass silage in leach-bed reactors and upflow anaerobic sludge blanket reactors
2010
Abstract Anaerobic digestion of tomato, cucumber, common reed and grass silage was studied in four separate two-stage reactor configuration consisting of leach bed reactor (LBR) and upflow anaerobic sludge blanket reactor (UASB). LBR studies showed that COD solubilization for cucumber and grass silage was higher (50%) than tomato (35%) and common reed (15%). Results also showed that 31–39% of initial TKN present in tomato and cucumber was solubilized in the leachates and 47–54% of the solubilized TKN was converted to NH4-N. The corresponding values for common reed and grass silage were 38–50% and 18–36%, respectively. Biomethanation of the leachates in UASB reactors resulted in methane yiel…
Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp
2014
In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resu…
Administration of L-carnitine and mildronate improves endothelial function and decreases mortality in hypertensive Dahl rats.
2010
Hypertension is a well established risk factor for the development of cardiovascular diseases and increased mortality. This study was performed to investigate the effects of the administration of L-carnitine or mildronate, an inhibitor of L-carnitine biosynthesis, or their combination on the development of hypertension-related complications in Dahl salt-sensitive (DS) rats fed with a high salt diet. Male DS rats were fed laboratory chow containing 8% NaCl from 7 weeks of age. Experimental animals were divided into five groups and treated for 8 weeks with vehicle (water; n = 10), L-carnitine (100 mg/kg, n = 10), mildronate (100 mg/kg, n = 10) or a combination of L-carnitine and mildronate at…
Evaluation of criteria for species delimitation of bagworm moths (Lepidoptera: Psychidae)
2014
Accurate identification of species is fundamental for biological research and necessary for species conservation. DNA bar- coding is particularly useful when identification using morphological characteristics is laborious and/or unreliable. However, bar- codes for species are dependent on the availability of reference sequences from correctly identified specimens. The traditional use of morphology to delimit the species boundaries of Finnish bagworm moths (Lepidoptera: Psychidae: Naryciinae: Dahliciini) is contro- versial because there is overlap in their morphological characteristics. In addition, there are no suitable molecular markers. We veri- fied the delimitation of seven out of eight…
Thermophilic anaerobic digestion of pulp and paper mill primary sludge and co-digestion of primary and secondary sludge
2012
Anaerobic digestion of pulp and paper mill primary sludge and co-digestion of primary and secondary sludge were studied for the first time in semi-continuously fed continuously stirred tank reactors (CSTR) in thermophilic conditions. Additionally, in batch experiments, methane potentials of 210 and 230 m³CH₄/t volatile solids (VS)(added) were obtained for primary, and 50 and 100 m³CH₄/tVS(added) for secondary sludge at 35 °C and 55 °C, respectively. Anaerobic digestion of primary sludge was shown to be feasible with organic loading rates (OLR) of 1-1.4 kgVS/m³d and hydraulic retention times (HRT) of 16-32 d resulting in methane yields of 190-240 m³CH₄/tVS(fed). Also the highest tested OLR o…
Lineare polyester mit alkoholischen endgruppen und deren bestimmung
1955
Lineare Bernsteinsaure-1,6-Hexandiol-Polyester mit alkoholischen Endgruppen werden mit einem uberschus des Diols durch Schmelz- und durch Losungskondensation hergestellt. Hohermolekulare Polyester mit uberwiegend alkoholischen Endgruppen werden durch. Nachkondensation mit dem Diol erhalten. Die Umsetzung der Produkte mit Phenylisocyanat fuhrt zu Polyesterdiurethanen. Die Ermittlung des Stickstoffs nach Kjeldahl liefert mit befriedigender Genauigkeit Endgruppenmolekulargewichte bis zum Molgewicht ∼5 · 103. Bei der Totalhydrolyse der Polyesterdiurethane bildet sich Anilin, das mit einem empfindlichen, photometrischen Verfahren quantitative erfast wird. Aus der so bestimmten Anilinmenge wurden…
El protagonismo de las fundaciones americanas en la institucionalización de la sociología (1945-1960)
2001
Este artículo expone el protagonismo que desempeñaron las fundaciones Rockefeller, Carnegie y Ford en la institucionalización de la sociología después de la Segunda Guerra Mundial. Estas instituciones han tenido grandes cantidades de dinero a su disposición y la mayor parte del trabajo empírico en ciencias sociales sólo se puede llevar a cabo si hay dinero disponible para cubrir sus gastos. Pero, ¿quiénes se beneficiaron de estas ayudas en Europa y Estados Unidos? El dinero público y privado ha desempeñado un papel significativo y cada vez mayor en el desarrollo de la sociología, pero cabe también preguntarse cómo ha afectado a la investigación el origen de este dinero. La Ford, por ejemplo…
Determination of ammonia and primary amine compounds and Kjeldahl nitrogen in water samples with a modified Roth's fluorimetric method.
2005
Abstract A method for the simultaneous determination of primary amino groups and ammonium ion has been proposed. The method is based in solution derivatization with o-Phthaldialdehyde/N-acetyl-cisteine (OPA/NAC) and fluorescence measurement of the formed isoindols. Analytical characteristics and description of the developed procedure have been provided. The calibration graphs for ammonium (up to 1.44 mg L−1 of N) and methylamine as primary amino model compound (up to 0.282 mg L−1 of N), were obtained. Bivariate and multivariate calibration models have been tested. The limits of detection were 0.07 mg L−1 of N and 0.004 mg L−1 of N for ammonium and amine, respectively. The procedure was firs…