Browsing by Subject "Additive"

Now showing 1 - 4 of 4
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    Crucial interactions of functional pyrenes with graphite in electrodes for lithium‐ion batteries
    (2023) Bauer, Marina; Konnerth, Philipp; Radinger, Hannes; Pfeifer, Kristina; Joshi, Yug; Bauer, Felix; Ehrenberg, Helmut; Scheiba, Frieder
    Polycyclic aromatic hydrocarbons, such as pyrenes, are a well‐known material class for non‐covalent modification of carbon surfaces in many applications. In electrochemical energy storage, pyrenes are mostly used in large polymeric structures. This work addresses the use of carboxy‐ and amino‐functionalized pyrenes for graphite electrodes for lithium‐ion batteries (LIBs). Pyrenes are explored as adsorbed species on graphite prior to electrode fabrication and as additives to the electrode composition. Thereby, 1‐pyrenecarboxylic acid, 1‐pyrenebutyric acid, 1‐aminopyrene, and 1‐pyrenebutylamine were under investigation. As additives, pyrenes do not influence the cycling performance of the electrode at low current but deteriorate the performance at high current, regardless of the functional group. However, when the pyrenes are adsorbed to the graphite surface, the influence of the different functional groups becomes clearly visible, revealing that an additional butyl group has a positive impact on the cycling performance and lithium‐ion transport of the electrodes. Electrodes with 1‐pyrenebutyric acid even enhanced the performance compared to the pristine electrode.
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    Dose Titration, Tolerance and Compatibility of some Feed Additives in Broiler
    (2005) Islam, Khan Md. Shaiful; Drochner, Winfried
    In two dose titration studies on chicken for fattening growth promoting efficacy and some aspects of safety of fumaric acid (FA), an approved preservative, and humic acid (HA), approved as veterinary drug, were examined. In a third experiment on chicken for fattening the compatibility of the ionophore coccidiostat semduramicin (AVIAX®), also approved at EU level, with the veterinary antibiotic tiamulin should be investigated. In experiment 1 six diets with increasing FA contents were fed for 26 days to 96 newly hatched male chicks per treatment. Final body weight (feed efficiency) amounted to 1,506 (756), 1,597 (767), 1,532 (754), 1,485 (759), 1,342 (738), and 1,378 g (747 g gain kg-1 feed) for the groups with 0, 1.25, 2.50, 3.75, 5.0, and 7.5 % FA, respectively. The 1.25 % FA group showed significantly (p<0.05) better weight gain than all other groups and better feed efficiency than the groups with 5.0 and 7.5 % FA. Body weight of the 5.0 and 7.5 % FA groups was significantly lower than that of the other groups. The relative organ weight was not affected by the treatment. In experiment 2 six diets containing 0, 0.3, 0.6, 1.2, 2.4, and 4.8 g Huminfeed® (74 % humic acid in DM) kg-1, respectively, were fed for 35 days to 80 newly hatched male chicks per treatment. Initially HA depressed weight gain, but recovery started in the third week, so that at the end no significant differences could be observed. But body weight gain was negatively correlated with the HA content of the diets (y (weight gain) = 2327.98 ? 0.0181x (Huminfeed content), r = -.280*). Feed intake was not affected by the treatment. The relative organ weights did not differ among the groups. Experiment 3 (35 days) with a total of 320 female broilers chicks was conducted to study the effect of 25 mg semduramicin kg-1 feed and the potential interference between semduramicin and tiamulin on zootechnical parameters (10 replicates with 8 chicks each), haematology, blood routine biochemistry and health status (1 chick per replicate). Tiamulin medication (250 mg L-1 water) from day 15 to 19 reduced significantly water intake, especially when concurrently given to birds fed semduramicin. Also feed intake was depressed in that period. Body weight gain of the semduramicin/tiamulin group in the third week was affected too. After 35 days, body weight (feed efficiency) was 2,062 (665), 2,067 (669), 2,084 (678), and 2,008 g (679 g gain kg-1 feed) for the control, the tiamulin, the semduramicin and the semduramicin/tiamulin group, respectively. All data obtained form haematology, blood biochemnistry ad pathology did not give evidence for any adverse influence of the coadministration of tiamulin and semduramicin. After a withdrawal period 20 broilers from the control and the semduramicin group were slaughtered and examined for product quality. No treatment effects (P>0.05) on hot carcass weight, viscera, dressing percentage, edible portions (breast muscles, haunch), fat and skin portions were seen. Also the sensory characteristics (juiciness, tenderness, unpleasant pungent aroma, general impression) except the aroma/flavour were not influenced by the treatment.
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    Nitrogen-rich and lignocellulosic biomass for biogas production : methane yield potentials, process stability and nutrient management
    (2023) Morozova, Ievgeniia; Lemmer, Andreas
    A sustainable energy supply and bio-based economic processes are of central importance for the future development of many Eastern European countries. Due to the large agricultural potentials of these countries, bioenergy systems can make a significant contribution to sustainable electricity and heat production if they are reasonably integrated into an energy supply structure based on various renewable energy sources. This requires the use of regenerative starting products and the complete utilisation of all by-products of the overall process. With such a cradle-to-cradle approach, biogas technology can be a central component of future energy systems. The focus of this study is on Ukraine. In the future, bioenergy villages can make a decentralised contribution to a sustainable energy supply in this country. This study aims to determine the methane yield potential of various energy crops from Ukraine, investigate the process stability during fermentation in biogas plants and derive concepts for optimized digestate management. Seven different crops with a total of 22 varieties were investigated for their specific biomass yields, methane yields and areal methane yields. The crops were cultivated in Ukraine. The biogas production potential of the collected crop samples was determined using the Hohenheim Biogas Test in Germany. The Ukrainian variety “Osinnii zoretsvit” of miscanthus, “Giganteus” species, from the 8th year of vegetation, harvested at the stem elongation stage, resulted in the highest areal methane yield of 7404.55 ± 199.00 m3*ha-1 and the lowest N requirement per unit methane produced (23.41 ± 7.18 gN*m-3) among all the studied crops. The maize variety "Svitanok MV" (FAO 250) had the highest value of areal methane yield of 6365.67 ± 55.49 m3*ha-1 among the annual crops when harvested at the stage of wax maturity; remarkable was its unusually high specific methane yield of 0.41 ± 0.00 m3*kg-1VS. The Ukrainian sugar sorghum variety "Favoryt", harvested at the beginning of flowering, had an areal methane yield of 5968.90 ± 82.70 m3*ha-1, making it an attractive alternative energy crop for Ukraine. In the second part of the work, experimental investigations were carried out to test how N-rich substrates influence the stability and efficiency of the biogas process. For this purpose, different variants with various N-increase rates of the input materials at two initial concentrations were evaluated in the laboratory. The continuous trials were conducted over a period of 33 weeks. The modelling procedure was applied to evaluate the effects of TAN (total ammonia nitrogen) and FAN (free ammonia nitrogen) on the degree of methane production inhibition for all scenarios studied. It was concluded that the higher the N-increase rate in the feeding regime, the more methane production is inhibited. The maximum nitrogen concentration in the digestate achieved during stable fermentation processes in this study was 11.5 g*kg-1FM, which corresponded to the values of TAN and FAN of 9.07 g*kg-1FM and 0.85 g*kg-1FM, respectively. These values are much higher than those reported up to now in the literature. At the same time, process efficiency decreased with increasing nitrogen concentrations. As a final step, the technology for nutrients recovery from digestate was developed and tested in this work. First, the digestate separation with a screw press separator was carried out as a "benchmark" at the research biogas plant "Unterer Lindenhof" on a technical scale. Subsequently, a methodology for digestate separation at laboratory scale was developed based on a tincture press, which corresponds to the technology used in practice. The effect of pretreatment of digestate with various biocoal-based additives was studied. In this study, six variants of biocoals synthesized at either 350 °C or 600 °C and partially impregnated with Mg or Ca before pyrolysis were produced. Different reaction times and conditions between the biocoals and the digestate were tested. The results on nutrient removal showed that the biocoals impregnated with Mg prior to pyrolysis had a positive effect on nutrient removal efficiency. The Mg-impregnated biocoal synthesised at 600 °C showed removal efficiencies for NH4+, P and K of 56.04%, 66.66% and 51.77%, respectively. These values were much higher than those for the control variant and much higher than the values found up to now in the literature. By using the nutrient-rich solid fraction of the digestate as fertiliser to cultivate bioenergy crops for further use in biogas production, the production cycle is closed, and the cradle-to-cradle approach is achieved.
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    Prüfung von Citral als Zusatzstoff zu Pheromon zur Bekämpfung des Apfelwicklers Cydia pomonella L. (Lepidoptera, Tortricidae) und des Apfelbaumglasflüglers Synanthedon myopaeformis Borkh. (Lepidoptera, Sesiidae)
    (2003) Hapke, Christine; Zebitz, Claus P. W.
    In the years 1998 til 2000, a modification of the confusion technique was tested against two pest insects in apple, the Codling moth Cydia pomonella L. and the Apple clearwing Synanthedon myopaeformis Borkh. The respective pheromone was combined with the tentative monoterpene synergist Citral, and applied in the orchard at a density of 125 per hectare as recommended. Laboratory tests were conducted to characterize the effects of Citral mode on individuals of the pests. Field tests with Codling moth revealed no essential differences in the efficiency between the common confusion method with 500 pheromondispensers per hectare and the new technology with Citral (125 dispensers/ha) as expressed in numbers of male caught in pheromone traps or in percent fruit damage under low pest pressure. Both methods failed under high pest pressure. Weighing the dispensers weekly followed up the release of Citral and the pheromone. In semi-field tests in large cages (2 m  2 m  2 m) pest population density seemed to have no impact on control success. In small cages (30 cm height, 30 cm ) the copulation rate in the pheromone plot was significantly lesser than in the Citral-treated atmosphere and in the untreated control plot. Using a laboratory wind tunnel undiluted and 10-1 diluted Citral resulted in a significant decrease of the attractiveness of pheromone. After 24 hours this effect diminished. Half-life of released Citral was approximately two hours. After four hours about 100 µg/h 10-1 diluted Citral was still released into the tunnel. Electroantennogrammes of both, male and female antennae of C. pomonella showed a strong reaction to Citral. The reaction of the antennas to pheromone was strongly overlaid by Citral. In laboratory tests in a closed system, copulation of the moths could be prevented starting from a Citral concentration of 2000 mg/l. Male moths, previously exposed to Citral for 24 h, were not able to copulate with mature, unmated females. Citral-exposed females (24 h exposure time), however, were successfully mated by mature untretaed males. Any impact of Citral in concentrations up to 1,500 mg/l on oviposition could not be proven. Furthermore, first larvae of the Codling moth were not prevented to penetrate into an apple with up to 5,000 mg/l Citral. Field tests with the Apple clearwing proved significantly lesser pheromone trap catches in the Citral-treated plots than in the control plots on five alternatively six test orchards. The plots with 500 and 250 pheromone dispensers per hectare also exerted rates of confusion of up to 100 %. In a plot with 250 Citral dispensers per hectare, an effect of confusion could not be observed. Catches in lure pots showed no difference in the amount of mated or unmated females between plots. The amount of mated females in all plots was much higher than those of the unmated. The amount of fresh frass in treated and untreated plots was too small for proving a success of control. The quantitative preparation of the larvae in coincidentally selected trees on a plant showed a significant difference between the Citral-treated plot and the untreated control plot. However this difference is based only on a reduced number of larvae up to 7 mm body length. Tests with S. myopaeformis in a laboratory wind tunnel were not successful, because the attractiveness of the traps baited with pheromone were not very high. Investigating the environmental conditions for a successful copulation of S. myopaeformis the light intensity did not prove to play the major role. Temperature and wind velocity seem to possess a substantial meaning, dominating light. The copulation rate in small cages (30 cm height, 30 cm ) generally hardly reached 50 % and was very small thereby. In the laboratory moths of the apple clearwing could not be brought to copulation. Synergisation of pheromones with Citral seem to be not recommendable under practical conditions.