155 research outputs found
Through a Glass Darkly: Recollecting, Representing, and Interpreting the Past
Special Issue: The Ontology of Memory and the Horizon of History, Part II
Innovative Desinfektionsverfahren zur Brauchwassergewinnung in der dezentralen Abwasserbehandlung - Elektrolyse und UV/Elektrolyse-Hybridtechnik
According to estimates of the United Nations Environment Programme (UNEP), more than 1.8 billion people will be living in countries or regions with absolute water scarcity by 2025. The pressure on water resources is increased not only in arid and semiarid regions, but also in fast growing megacities around the world as a result of, amongst other factors, the changing nutritional and consumer behavior (rising living standards). Over 90 % of the annual water consumption of the newly industrializing and developing countries in the arid and semiarid climate zone is used for agricultural irrigation to ensure the nutrition of the population. Thus, since the beginning of the 20th century, the planned/controlled reuse of wastewater has developed into a central task of the sustainable water resources management. Wastewater represents a valuable resource in view of its composition (e. g. nutrients P, N for soil fertilizing) and its reliable, weather-independent availability in every household. The establishment of a closed-loop water management can enhance the efficiency of water usage. Therefore, activities in research and development are currently focused on decentralized and semi-centralized concepts, since their structures offer better conditions for the establishment of closed-loop systems and innovations in wastewater technology can be implemented more easily.
In general, the hygienic quality requirements for wastewater reuse are predominantly oriented towards the planned usage. These are, in turn, regulated by thresholds and guidance values, e. g. for faecal indicator bacteria (e. g. faecal coliforms: E. coli), in widely differing norms and legal provisions specific to the respective countries. In Germany since 2005, small wastewater treatment plants can obtain the discharge class +H by the German Institute for Civil Engineering (DIBt: Deutsches Institut fĂŒr Bautechnik) if secondary effluents contain less than 100 faecal coliforms (E. coli) per 100 mL. This ensures a safe effluent seepage in karst and water protection areas. Due to the infectious risk caused by a multitude of pathogens (bacteria, viruses, worm eggs, protozoa) which are still contained in wastewater after mechanical-biological treatment, specific disinfection methods are indispensable for their satisfactory reduction. Demands on disinfection methods for wastewater reclamation are quite complex. They should be characterized by a high and constant disinfection efficiency at low or moderate formation of disinfection by-products. The reclaimed wastewater should be able to be stored safely. Moreover, the disinfection method should be technically simple, scaleable, space-saving, subjected to low maintenance and realized at moderate investment and operating costs without applying external toxic chemicals. Established methods in decentralized wastewater disinfection are mainly based on membrane and UV technologies. However, these methods are currently working under high operating costs (high maintenance and cleaning efforts). Furthermore, the high investment costs of the membrane filtration are disadvantageous. In addition, both methods do not provide a disinfection residual. Thus, further research is required for the development and testing of alternative disinfection technologies. Against this background, the applicability of the electrolysis and UV/electrolysis hybrid technology for the decentralized wastewater reclamation was investigated and assessed in this dissertation.
Results have shown that the electrochemical disinfection of biologically treated wastewater represents an efficient method at temperatures of > 6 °C, pH values of < 8.5 and DOC con-centrations of < 22 mg L-1. Under these conditions, an E. coli reduction of four log levels was achieved at a concentration of free chlorine ranging from 0.4 mg L-1 to 0.6 mg L-1 and at an after-reaction time of 15...20 min. However, it becomes simultaneously apparent that low temperatures, high pH values and high DOC concentrations are limiting parameters for this disinfection method to reclaim biologically treated wastewater. A high energy consumption of the electrolysis cell equipped with boron-doped diamond (BDD) electrodes (2...2.6 kWh m-3) represents a further unfavourable effect. Moreover, the undesired formation of chlorate (c = 1.3 mg L-1) and perchlorate (c = 18 mg L-1) at BDD electrodes can be considered as critical, since these disinfection by-products are, amongst others, human-toxicologically relevant. The concentration of adsorbable organically bound halogens (AOX) and trihalomethanes (THMs) proved to be marginal to moderate.
Due to the synergistic effect of the combined application of UV irradiation (primary disinfection method) and electrolysis, the disadvantages of the single methods can be compensated. Decisive drawbacks of UV irradiation are photo and dark repair mechanisms of reversibly damaged bacteria. It was observed that the reactivation of reversibly UV-damaged E. coli even occurs at low temperatures (T = 10 °C) and strongly differing pH values (pH = 5.7...8.1) as well as at low light intensities and in darkness to an extent excluding a safe usage and storage of the reclaimed wastewater. The reactivation processes might be lowered by increased UV fluences. However, this is limited by high concentrations of total suspended solids (TSS). In spite of high UV fluences of > 400 J m-1, no complete removal of E. coli bacteria can be achieved at TSS concentrations of > 17 mg L-1. Therefore, it is indispensable to prevent bacterial reactivation caused by photo and dark repair processes. This topic was studied in the current work by electrochemically produced oxidants using an electrolysis cell positioned downstream of the UV unit. Results have shown that photo and dark reactivation were completely prevented by oxidants in a total concentration of 0.5...0.6 mg L-1 at a TSS concentration of 8...11 mg L-1, at pH values ranging from 5.7 to 8.1 and at temperatures ranging from 10 °C to 30 °C (t = 24....72 h). Even at a high TSS concentration of 75 mg L-1, the reactivation of E. coli (ctotal oxidants = 1.8 mg L-1) and, up to a TSS concentration of 32 mg L-1, the reactivation of total coliforms (except E. coli, ctotal oxidants = 1.0 mg L-1) can be prevented at a high initial germ concentration of 2âŠ3 105 per 100 mL. The lowest energy consumption could be observed when mixed oxide electrodes (MOX electrodes) were applied. This result and the fact that no chlorate and perchlorate were observed at MOX electrodes argue for the application of these electrodes in practice.
All in all, the UV/electrolysis hybrid technology represents an energy-efficient method for reclamation of biologically treated wastewater with TSS concentrations ranging from 6 months). The undesired formation of coverings caused by biofouling processes on quartz glass surfaces could be prevented by electrochemically produced oxidants in a total concentration of 1 mg L-1 within an experimental duration of 5.5 months.
However, the application of the UV/electrolysis hybrid technology is limited by increased particle concentrations and faecal loadings (initial E. coli concentration). The resulting enhanced demand of electrochemically produced oxidants for the prevention of bacterial reactivation results in a considerable increase of the electric charge input and energy consumption
Rethinking prefigurative politics: introduction to the special thematic section
This special thematic section responds to the 21st century proliferation of social movements characterised by the slogans âanother world is possibleâ and âbe the change you want to seeâ. It explores prefigurative politics as a means of instantiating radical social change in a context of widening global inequalities, climate change, and the crises and recoveries of neoliberal global capitalism. âPrefigurative politicsâ refers to a range of social experiments that both critique the status quo and offer alternatives by implementing radically democratic practices in pursuit of social justice. This collection of articles makes the case for psychologists to engage with prefigurative politics as sites of psychological and social change, in the dual interests of understanding the world and changing it. The articles bridge psychology and politics in three different ways. One group of articles brings a psychological lens to political phenomena, arguing that attention to the emotional, relational and intergroup dynamics of prefigurative politics is required to understand their trajectories, challenges, and impacts. A second group focuses a political lens on social settings traditionally framed as psychological sites of well-being, enabling an understanding of their political nature. The third group addresses the âborder tensionsâ of the psychological and the political, contextualising and historicising the instantiation of prefigurative ideals and addressing tensions that arise between utopian ideals and various internal and external constraints. This introduction to the special section explores the concept and contemporary debates concerning prefigurative politics, outlines the rationale for a psychological engagement with this phenomenon, and presents the articles in the special thematic section. The general, prefigurative, aim is to advance psychologyâs contribution to rethinking and remaking the world as it could be, not only documenting the world as it is
Menneske eller maskin â hva gjĂžr oss mest tilfreds?
I denne studien har vi sett pÄ selvbetjeningsteknologien sin pÄvirkning pÄ kundetilfredshet, i
forhold til personlig service. Settingen vi testet dette i var gjennom billettkjĂžp til
kollektivtransport. Det har tidligere vÊrt forsket pÄ dette i andre settinger, som selvbetjening i
hotelltjenester og matbutikker. Vi Þnsket derimot Ä se pÄ dette i en annen sammenheng, hvor
vi antok at selvbetjeningsteknologien ville forenkle tjenesteleveransen i hĂžy grad for kundene.
Vi benyttet i dette studiet kvantitativ metode. Vi forsĂžkte Ă„ hente inn respondenter fra hele
landet, da vi Þnsket Ä se pÄ generelle tendenser for hele befolkningen. Vi fikk inn 329
responser pÄ vÄr undersÞkelse. Denne var utformet som et spÞrreskjema som vi delte gjennom
sosiale medier.
Studien hadde tre hypoteser. De to fĂžrste hypotesene testet om bruk av
selvbetjeningsteknologi og bruk av personlig service hadde en positiv effekt pÄ
kundetilfredshet. Den siste hypotesen testet om selvbetjeningsteknologi hadde en mer positiv
effekt pÄ kundetilfredshet, enn det personlig service hadde. Gjennom vÄre analyser fikk vi
stĂžtte for hypotese 1 og 2, men ikke for hypotese 3. Disse resultatene samsvarer med tidligere
forskning. I fÞlge vÄr forskning ser det ut til at selv om mange kunder mener
tjenesteleveransen blir enklere og mer effektiv ved hjelp av selvbetjeningsteknologi, har
personlig service likevel en stÞrre pÄvirkning pÄ deres tilfredshet
Mental Health, Psychosocial Functioning, and Quality of Life in Adolescents With Hirschsprung Disease
Background: Studies of mental health in adolescents with Hirschsprung disease (HD) are scarce. This cross-sectional study investigates mental health, psychosocial functioning and quality of life in HD adolescents.
Methods: Adolescents (12-18 years) treated at the Department of pediatric surgery at Oslo University Hospital were invited for participation. Mental health was assessed by interview; Child Assessment Schedule (CAS) and questionnaires; parental Child Behavior Checklist (CBCL) and adolescent Youth Self-Report (YSR). Psychosocial functioning was rated by Child Global Assessment Scale (cGAS). Adolescent Quality of Life was assessed by Pediatric Quality of Life inventory (PedsQL) and chronic family difficulties (CFD) by interview. Medical records were reviewed for somatic history.
Results: Thirty-seven adolescents, 28 males, median age 14.3 years, participated. By CAS interview, 8 of 37 (44% of females and 14% of males) fulfilled criteria for psychiatric diagnosis all within emotional and related disorders. Twenty-seven percent had CBCL internalizing scores and 16% had YSR internalizing scores in clinical range indicating emotional problems. By interviewer rated cGAS, 27% were scored in clinical range. By PedsQL 16% reported reduced psychosocial health score. Increased CFD, lower psychosocial functioning and reduced QoL as well as less paternal education were significantly associated with psychiatric diagnosis. Twice as many (4/8) adolescents who either had a stoma or bowel management had a psychiatric diagnosis compared to those who had neither stoma nor bowel management (7/28).
Conclusion: Nearly one in four adolescents with HD fulfilled criteria for psychiatric diagnosis. Mental health problems were associated with reduced psychosocial function and reduced QoL.
Level of evidence: III.The study has financial support from the Norwegian DAM foundation (2019/FO249474).publishedVersio
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Ultrasound processing of liquid system(s) and its antimicrobial mechanism of action
Ultrasound creates cavitation phenomena, resulting in the formation of several free radicals, namely OH and H, due to the breakdown of the H2O molecule. These radicals affect the cellular integrity of the bacteria, causing the inactivation of several processes, and thus it is important to unravel the mechanism of action of this technology. This research looks into the application and mechanism of action of ultrasound technology as a means of disinfection by acoustic cavitation. Sterile water and synthetic waste water were inoculated with different mutants of E. coli K12 strains containing deletions in genes affecting specific functional properties of E. coli. These were: dnak soxR, soxS, oxyR, rpoS, gadA/gadB, gadC and yneL. E. coli K-12 ÎoxyR, appeared to be more resistant to the treatment together with gadW, gadX, gabT and gabD, whereas the mutant K-12 ÎdnaK was more sensitive with approximately 2.5 log (CFU/mL) reduction in comparison to their isogenic wild type E. coli K-12. This indicates that the dnaK gene participates in general stress response and more specifically to hyperosmotic stress. The other E. coli deleted genes tested (soxS, rpoS, gadB, gadC, yneL) did not appear to be involved in protection of microbial cells against ultrasoun
Art therapy, arts-based research and transitional stories of domestic violence and abuse
Visual imagery within qualitative research is an established method of gathering data that has parallels to the way in which images are used within art therapy. This paper explores how visual imagery was used to investigate womenâs responses to domestic violence and abuse and examines how art therapy principles shaped the development and conducting of that research. Through the use of collage, participants created visual representations of their responses to experiences of domestic violence and abuse. The visual representations were, when combined with spoken words, created stories that reference the past, present and future. The stories created have been termed transitional stories of domestic violence. These stories show that the home has special significance for women as they transition away from domestic violence and plan for their future. The home becomes both a metaphorical and physical manifestation and container of hopes for a harmonious future that often incorporates the desire for the return to the idea of a complete family. This paper will present the findings of the arts-based research conducted, and consider the implications upon art therapy practice of those findings.N
Researching Memory in Early Modern Studies
This essay pursues the study of early modern memory across a chronologically, conceptually and thematically broad canvas in order to address key questions about the historicity of memory and the methodologies of memory studies. First, what is the value for our understanding of early modern memory practices of transporting the methodologies of contemporary memory studies backwards, using them to study the memorial culture of a time before living memory? Second, what happens to the cross-disciplinary project of memory studies when it is taken to a distant period, one that had its own highly self-conscious and much debated cultures of remembering? Drawing on evidence and debates from a range of disciplinary locations, but primarily focusing on literary and historical studies, the essay interrogates crucial differences and commonalities between memory studies and early modern studies
Exploring gender and fear retrospectively:stories of womenâs fear during the âYorkshire Ripperâ murders
The murder of 13 women in the North of England between 1975 and 1979 by Peter Sutcliffe who became known as the Yorkshire Ripper can be viewed as a significant criminal event due to the level of fear generated and the impact on local communities more generally. Drawing upon oral history interviews carried out with individuals living in Leeds at the time of the murders, this article explores womenâs accounts of their fears from the time. This offers the opportunity to explore the gender/fear nexus from the unique perspective of a clearly defined object of fear situated within a specific spatial and historical setting. Findings revealed a range of anticipated fear-related emotions and practices which confirm popular âhigh-fearâ motifs; however, narrative analysis of interviews also highlighted more nuanced articulations of resistance and fearlessness based upon class, place and biographies of violence, as well as the way in which women drew upon fear/fearlessness in their overall construction of self. It is argued that using narrative approaches is a valuable means of uncovering the complexity of fear of crime and more specifically provides renewed insight onto womenâs fear
Healing Multiculturalism: Middle-Ground Liberal Forgiveness in a Diverse Public Realm
This article examines debates about political forgiveness in liberal, pluralist societies. Although the concept of forgiveness is not usually taken up by liberals, I outline a plausible conception by exploring two recent approaches. The first, âunattached articulationâ, concept requires no real emotional change on the forgiverâs part, but rather a form of civic restraint. In contrast, the second version highlights a strong form of empathy for perpetrators. In spite of their advantages, each concept proves too extreme. The problems are revealed by focusing on the case of the Harkis, who fought for the French during the Algerian war. Often still marginalised in French society, their case helps to highlight the conceivability of a âmiddle-groundâ or moderate concept of political forgiveness. Its core rests on the forgiverâs care for the social world. While this concept brings considerable challenges also, and is not inevitable in any particular case, it entails a more plausible combination of emotional and rational shifts in the forgiverâs world-view. Although the article does not recommend forgiveness by any person or group, it observes, recalling Arendtâs idea of amor mundi or âlove of the worldâ, that political forgiveness may sustain a viable connection between diverse citizensâ public and non-public lives
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