Investigation of Tar Conversion Over Biomass Char

Tar release is one of the main challenges for a further development of gasification technology. While heavy aromatic compounds condensation causes installation clogging, lighter molecules remain in a gaseous phase, contaminating producer gas. Therefore, catalytic reforming of tar has been extensively studied. To simplify a conversion mechanism, a single tar compound is often used in a fundamental research. In this dissertation, toluene was selected as a model tar molecule. Biochar was used as a catalyst, as its availability, as a gasification by-product, makes it an economically beneficial material. Toluene conversion over biochars prepared under uniform conditions, from three differentiated tree species, was examined. The comparison of various woods revealed, that toluene conversion over a char prepared from coniferous pine was lower, compared to deciduous-trees chars. It was attributed to less abundant active sites and lower surface area of a pine char. Moreover, a higher microporosity resulted in a quicker deactivation of this char, as suggested by a conversion decrease with time. Since one of the main distinctions between deciduous and coniferous trees is a high resin content in the letter, an acetone extraction of pinewood prior to char preparation was performed. This pre-treatment influenced pyrolysis process, yielding char with slightly improved parameters and an increased short-term performance. Another objective of this work focused on plausible toluene conversion pathways. To this end, along with toluene conversion, a yield of its by-products was also measured. The experiment was carried out under pyrolytic conditions to enable separation of a heterogeneous, catalytic toluene conversion from the effects of an oxidising agent. Then, an H2O/N2 atmosphere was studied to assess the role of steam and a possibility of its interactions with toluene during reforming. It was concluded that a majority of toluene decomposed heterogeneously over char bed, yielding coke and releasing H2. Demethylation was a competitive, less favoured pathway leading to benzene and CH4 formation, with a selectivity up to ∼15 %. Some secondary substitution and dehydrogenation reactions were also observed, leading to xylenes, ethylbenzene and styrene. The steam introduced in a reforming mode did not influence toluene conversion pathways. Its role was limited to char and coke gasification, and thus a prolongation of catalytic activity of the bed. Although the two processes were not directly interacting, a plausible competition for char surface between steam and toluene was suspected. An additional set of tests was designed to further clarify some of toluene conversion aspects, i.e. the roles of an oxidising agent, char surface chemistry and tar molecule’s substituents. An intermittent toluene feeding experiment suggested that no homogeneous toluene conversion was initiated by any char-released radicals. Comparison of benzene, toluene and p-xylene conversion suggested an importance of methyl group presence to the compound’s reactivity and its conversion pathways. An addition of an extra CH3– group did not however improve the conversion any further, although it enhanced secondary, rearrangement reactions. Comparison of O2 and steam as an oxidising agent suggested that while steam favoured char/coke oxidation and did not react directly with toluene, O2 was primarily consumed by toluene in ring-opening, homogeneous reactions thus it did not regenerate catalyst bed. Char pre-treatment, applied to differentiate alkali and alkaline earth metals content, resulted in drastic changes in char’s reactivity towards oxidation, yet it did not affect its performance as a catalyst in pyrolytic toluene conversion

Passivation of contaminated biochars by tar conversion over their surface

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Catalytic conversion of methylated aromatics over wood-derived chars – the role of reforming agents and the effect of methyl groups

Toluene steam reforming was performed over three wood-derived chars and compared with a previously-reported pyrolytic conversion study. The heterogeneous mechanism of toluene decomposition was not directly affected by the introduction of steam, but it caused gasification of char and toluene-derived coke, which prolonged the initial high conversion efficiency. Conversely, when oxygen was used as a substitute for steam, a direct ring-opening reaction of toluene was observed, rather than solid carbon combustion. A comparison of benzene, toluene, and p-xylene conversion revealed that the presence of a methyl group on the aromatic ring enhanced its decomposition, regardless of the catalyst’s activity. However, a second methyl group did not further improve the conversion and only served to increase the intensity of secondary recombination reactions

Ocena częstości występowania hipoglikemii w zależności od aktywności fizycznej

  Aim. Assessment of the effect of the physical activity level in diabetic patients on the occurrence of hypo­glycaemia. Material and methods. The survey was conducted in a group of 422 diabetic patients: 209 patients with type 1 diabetes mellitus (129 women, 80 men, mean age 30 ± 11 years, mean duration of diabetes 12 ± 8 years, HbA1c: 7.5 ± 1.4%) and 213 patients with type 2 diabetes mellitus (119 women, 94 men, mean age 60 ± 12 years, mean duration of diabetes 10 ± 9 years, HbA1c: 8 ± 1.5%). Patients filled in the questionnaire covering data on diabetes control and physical activity (based on the International Physical Activity Question­naire — IPAQ). Results. Overall the number of patients with hypogly­cemia was significantly higher in patients with high physical activity (65%) when compared to low activity (43%; p &lt; 0.01). Patients with moderate activity did not differ from remaining groups. In type 1 diabetes mellitus number of episodes was significantly lower in low activity group (4%) when compared to high activity (61%; p &lt; 0.001) and moderate activity (17%; p &lt; 0.001). Also significant difference was found be­tween high and moderate activity (p &lt; 0.001). In type 2 diabetes mellitus the relation was similar. 23% patients with hypoglycemia in high activity; 11% in moder­ate activity (p &lt; 0.005) and 5% in low activity group (p &lt; 0.001 vs. high and moderate activity respectively). Conclusions. The incidence of hypoglycaemia increases along with increasing physical activity. This indicates the necessity of an increased education in patients planning physical activity.   Cel. Ocena wpływu poziomu aktywności fizycznej u chorych na cukrzycę na występowanie hipoglikemii. Materiał i metody. Badanie zostało przeprowadzone w grupie 422 pacjentów chorych na cukrzycę: 209 chorych na cukrzycę typu 1 (129 kobiet, 80 mężczyzn, średni wiek: 30 ± 11 lat, średni czas trwania cukrzy­cy: 12 ± 8 lat, HbA1c: 7,5 ± 1,4%) oraz 213 chorych na cukrzycę typu 2 (119 kobiet, 94 mężczyzn, średni wiek: 60 ± 12 lat, średni czas trwania cukrzycy: 10 ± 9 lat, HbA1c: 8 ± 1,5%). Pacjenci uzupełnili ankietę obejmującą dane dotyczące wyrównania cukrzycy oraz aktywności fizycznej (wg Międzynarodowego Kwestio­nariusza Aktywności Fizycznej — IPAQ). Wyniki. Ogółem liczba pacjentów z hipoglikemią była istotnie wyższa u pacjentów cechujących się wysoką aktywnością fizyczną (65%) w porównaniu z niską aktywnością (43%, p < 0,01). Pacjenci z umiarkowa­ną aktywnością nie różnili się od pozostałych grup. W przypadku cukrzycy typu 1 liczba epizodów była istotnie niższa w grupie o niskiej aktywności (4%) w porównaniu z wysoką aktywnością (61%, p < 0,001) i umiarkowaną aktywnością (17%, p < 0,001). Stwierdzono również istotną różnicę pomiędzy wysoką i umiarkowaną aktywnością (p < 0,001). U chorych na cukrzycę typu 2 relacja była podobna: 23% pacjentów z hipoglikemią w przypadku wysokiej aktywności, 11% — w umiarkowanej (p < 0,005) i 5% w grupie o niskiej aktywności (odpowiednio p < 0,001 vs. wy­soka i umiarkowana aktywność). Wnioski. Częstość występowania hipoglikemii zwiększa się wraz ze wzrostem aktywności fizycznej. Wskazuje to na konieczność zwiększenia edukacji pacjentów planujących aktywność fizyczną

D3.4 Fuel conversion phenomena

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Współczesne kierunki w medycynie prewencyjnej

Praca recenzowana / Peer-reviewed paperTreści artykułów w niniejszej monografii odnoszą czytelnika nie tylko do bardzo różnych kierunków prozdrowotnych, ale także do leczenia schorzeń już występujących. Zamierzeniem autorów było przedstawienie wybranych zagadnień z zakresu profilaktyki prozdrowotnej cukrzycy, otyłości, zaburzeń lipidowych i zmian skórnych, pielęgnacji w tych schorzeniach, a także problemów kosmetologicznych skóry, towarzyszącym tymże zaburzeniom. Autorzy poszczególnych rozdziałów starali się przedstawić poruszane problemy w oparciu o aktualną dokumentację medyczną z nadzieją, że pozwoliło to kompleksowo wyjaśnić poruszane w monografii problemy

Beyond restitution? Gender-just remedies for displacement and dispossession in Sudan and Ethiopia

This thesis examines the mainstream approaches to women’s housing, land and property rights in the context of internal displacement and dispossession. The research adopted feminist methodological framework and case study approach to explore these issues in Darfur, Sudan and the Somali-Oromia regions of Ethiopia. Furthermore, the research was undertaken in a dual role as a practitioner-researcher. This study makes several original contributions. Using feminist theories and methods, the study developed a different perspective regarding remedies for forced displacement and HLP losses, a perspective which takes gender harms as a starting point. This approach problematised harms and drew attention to their multifaceted nature, specifically social, political and economic inequalities that affect women’s vulnerability to become victims of violence. By adopting intersectionality as a critical feminist lens, the research drew attention to variety of conflict-related experiences, nuanced account of relations of power on the ground, and multiple manifestations of agency. Finally, the study drew attention to displacement and HLP losses, the most common features of modern conflicts but ones that are considered natural and inevitable consequences of war for which there are limited remedies. HLP is an essential concept in the context of conflictinduced displacement and remedies that can be used as a platform to transform ideas about femininity and masculinity that perpetuate harms and gender inequality. By pointing out the multidimensional character of HLP, not only as an economic asset but a source of social status, cultural identity, representation and political power, the study highlights similarly multifaceted nature of harm and the ways in which economic disadvantage and cultural disrespect are entwined and support one another and the ways this relationship influences access to economic resources, such as HLP and political power.</p

Dual-task walking and falls in the elderly

Dual-task walking is a common activity in everyday life. The dual-task paradigm is a procedure in experimental psychology that involves examining the performance of two tasks separately and simultaneously, allowing researchers to determine the extent to which different mental abilities compete for information-processing resources in the brain. This information can help identify whether tasks interfere with each other. This study aimed to analyse publications, gather knowledge on gait with an additional task, and determine the impact of dual-task conditions on gait parameters among the elderly. In October 2022, we conducted a comprehensive review of available literature in databases such as Pubmed, Cochrane, and Google Scholar, as well as research carried out at the Central Laboratory of Motion Analysis of the University of Physical Education in Krakow. We identified 11 publications on dual-task gait in the elderly, focusing exclusively on healthy individuals. Studies on the effects of training on dual-task gait were not included in our analysis. Research conducted to date in older adults has shown that dual-task conditions have a negative effect on gait speed, step frequency, gait cycle time, and gait variability indices, among other parameters

Factors infulencing gait in dual-task walking

Gait with an additional task commonly occurs in everyday life, e.g., simultaneously walking and talking on the phone. The dual-task paradigm (comparison of task performance efficiency under single-task conditions and simultaneous performance of both tasks) has found application in gait research. It is a test that allows assessing the quality of gait in clinical settings but also lets us analyse the quality of gait under the conditions of everyday life. It also allows the identification of people at risk of falling. A review of the available literature and research conducted at the Central Laboratory of Motion Analysis at AWF Krakow has been made, which may be useful for identifying factors that increase the risk of falls