Improvement in sulfur desorption of NOX storage and reduction catalysts using a Ba–Ti composite oxide

A Ba-Ti composite oxide was formed on a NOx storage and reduction catalyst via impregnation of a Ba-Ti precursor solution composed of H(2)O(2) added to a complex prepared using the citric acid method. The structure of the Ba-Ti composite in solution was analyzed by chemical composition analysis and FT-Raman and UV-vis spectroscopy. MM2 calculations were performed to propose its chemical structure. Both Ba and Ti together were found to form a composite molecule in the solution. Furthermore, TEM-EDX and XRD analyses of the Ba-Ti composite oxide on the catalyst prepared by impregnation with the Ba-Ti composite aqueous solution revealed that Ba and Ti in the catalyst were highly dispersed at the nm scale. The formation of the Ba-Ti composite oxide on the NSR catalyst enhanced sulfur desorption efficiency and led to high-performance NO(X) conversion as a NO(X) storage and reduction activity catalyst after desulfation treatment. It was assumed that the existence of nano-scaled Ba compounds combined with Ti was efficient for the inhibition of the sintering of barium sulfate and its facile decomposition. It was found that dispersion of Ba compounds for NO(X) storage materials using a Ba-Ti complex solution is an efficient way to improve the durability of NSR catalysts

Vitamin D intake and determinants of vitamin D status during pregnancy in The Norwegian Mother, Father and Child Cohort Study

BackgroundNorwegian data on vitamin D status among pregnant women indicate a moderate to high prevalence of insufficient vitamin D status (25-hydroxyvitamin D (25OHD) concentrations ≤50  nmol/L). There is a lack of population-based research on vitamin D intake and determinants of 25OHD in pregnant women from northern latitudes. The aims of this study were (1) to evaluate total vitamin D intake from both diet and supplements, (2) to investigate determinants of vitamin D status, and (3) to investigate the predicted response in vitamin D status by total vitamin D intake, in pregnant Norwegian women.MethodsIn total, 2,960 pregnant women from The Norwegian Environmental Biobank, a sub-study within The Norwegian Mother, Father and Child Cohort Study (MoBa), were included. Total vitamin D intake was estimated from a food frequency questionnaire in gestational week 22. Concentrations of plasma 25OHD was analyzed by automated chemiluminescent microparticle immunoassay method in gestational week 18. Candidate determinant variables of 25OHD were chosen using stepwise backward selection and investigated using multivariable linear regression. Predicted 25OHD by total vitamin D intake, overall and stratified by season and pre-pregnancy BMI, was explored using restricted cubic splines in an adjusted linear regression.ResultsOverall, about 61% of the women had a total vitamin D intake below the recommended intake. The main contributors to total vitamin D intake were vitamin D supplements, fish, and fortified margarine. Higher 25OHD concentrations were associated with (in descending order of the beta estimates) summer season, use of solarium, higher vitamin D intake from supplements, origin from high income country, lower pre-pregnancy BMI, higher age, higher vitamin D intake from foods, no smoking during pregnancy, higher education and energy intake. During October–May, a vitamin D intake according to the recommended intake was predicted to reach sufficient 25OHD concentrations >50  nmoL/L.ConclusionThe findings from this study highlight the importance of the vitamin D intake, as one of few modifiable determinants, to reach sufficient 25OHD concentrations during months when dermal synthesis of vitamin D is absent

The Past of Present Livelihoods. Historical perspectives on modernisation, rural policy regimes and smallholder poverty - a case from Eastern Zambia

This study is an enquiry into the processes shaping rural livelihoods in peripheral areas. The study is situated in the field of livelihood research and departs in the persistent crisis within African smallholder agriculture and in rural policy debates during the postindependence era. The research takes a critical stance to the way that people-centred and actor-oriented approaches have dominated livelihood research, thereby over-shadowing structural and macro-oriented features. The aim of this study is to, through a historical perspective on rural livelihoods and policy regimes, uncover the political and economic processes, with their discursive foundations, that shape contemporary rural livelihoods in peripheral areas. The analytical framework emphasises four key factors: ideas of development and modernity; the terms of incorporation into the global economy; rural policy regimes; smallholders’ ways of making a living. Inspiration is gained from critical political geography, world-systems analysis and different perspectives on rural livelihoods and development. The empirical study is based on fieldwork in Chipata District in Eastern Zambia, investigations at the National Archives of Zambia, the British National Archives and library research. The findings are presented in three parts. The first part looks into contemporary policies and the situation among smallholders in Chipata District. The second part examines the history of the area up to independence in 1964. The third part examines the post-independence period which links colonial experience to the contemporary situation. The findings suggest that smallholders’ livelihoods are shaped by long-term politicaleconomic- discursive processes, rooted in the terms of the study area’s integration into the world-economy in the colonial period. Colonial policies peripheralised the area through tax, labour, and market policies and the creation of native reserves, all of which have led to contemporary problems of food insecurity, soil depletion and a marginal role in agricultural markets. Since the inception of colonial rule, semi-proletarianisation has been a dominant process in the area. Current diversified livelihoods are more a contemporary expression of this semi-proletarianisation than a consequence of postcolonial policies. The households in the study area show preference for a farming way of life. However, the development goal of modernity has since long led to an ‘othering’ of smallholders, labelling them backwards and resistant to change. In the early twenty-first century this ‘othering’ has been played out through a development programme aimed at changing attitudes and mindsets among the farmers in line with individualistic and entrepreneurial behaviour. The ‘othering’ discourses of contemporary and colonial policymakers display striking similarities in this case

Experimental Studies of NOx Catalysts; Storage, Reduction and Sulphur Deactivation

The aim of this thesis work was to investigate how different gaseous compounds, present in an automotive exhaust from lean-tuned combustion, interact with so-called NOx storage catalysts containing Al2O3 as a support, BaO as the NOx storage compound and noble metals to provide oxidation and reduction functions. The investigations included model sample preparations, flow reactor studies with various gas mixtures and spectroscopic experiments (FTIR and XPS). The results show that several of the exhaust gas components (CO2, NOx, SO2, O2) interact strongly with the catalyst, and both the storage compound (BaO) and the noble metals are affected. Due to the affinity of barium oxide for sulphate formation, and since sulphur is present in significant amounts in gasoline, diesel and lubricants, special attention was paid to sulphur compounds in the exhaust gas. The sulphur studies indicated that deactivation (poisoning) occurs in both net oxidising and net reducing gas mixtures containing SO2. After exposure in oxygen excess significant amounts of sulphates were detected with XPS and FTIR. Sulphates were also detected during net reducing sulphur exposure, but in much smaller amounts. It is suggested that the mechanism for sulphur deactivation under net oxidising and net reducing conditions are different. During lean conditions sulphate formation on the NOx storage sites on BaO seems to be the dominant mechanism. The results obtained during rich conditions, with SO2 in the gas mixture, suggest a mechanism dominated by deactivation of the NO oxidation and NOx reduction functions of the catalyst, e.g. by formation of (reduced) sulphur species on the noble metal particles

A study about the school nurse experience with high school students sleep habits in relation to the use of digital media

Bakgrund: Sömn är ett grundläggande behov för människan. I dagens samhälle har digitala medier blivit en stor del av ungdomars vardag. Tidigare studier har visat att digitala medier har en stark inverkan på människans sömnvanor. Skolsköterskan arbetar hälsofrämjande och förebyggande och skall genom regelbunden kontakt med eleverna identifiera riskfaktorer för beteenden som kan komma att påverka hälsan negativt. Syfte: Syftet med studien var att undersöka hur skolsköterskor erfar högstadieelevers sömnvanor i relation till användandet av digitala medier. Metod: Studien har en kvalitativ design med semistrukturerade intervjuer och en manifest innehållsanalys. Resultat: Resultatet består av tre kategorier samt nio subkategorier. Den första kategorin är källa till sömnbrist med subkategorierna oförmåga till begränsningar, nattlig skärmtid och bristande föräldrainsikt. Andra kategorin var arbeta hälsofrämjande, med subkategorierna, tolka tecken, samtalets påverkan och minska hälsorisken. Den tredje huvudkategorin är utmana utmaningar i arbetet med subkategorierna bygga förtroendeingivande relationer, tid att förmedla kunskap samt hälsofrämjande prioriteringar i samverkan. Slutsats: Det saknas insikt och kunskap hos elever och föräldrar om sömnens betydelse och hur den påverkas av användandet digitala medier. Skolsköterskorna ser ett behov av att synas mer i klasserna och på föräldramöten för att bygga upp förtroendefulla relationer både till elever och föräldrar vilket är grunden för att förmedla kunskap och tillsammans sträva mot en förändring. Det finns ett behov av fördjupad kunskap även inom elevhälsan och mer tid att arbeta hälsofrämjande och förebyggande kring ungdomars sömnvanor i relation till digitala medier. Detta då bristande sömn kan leda till negativa konsekvenser för individen men också för samhället i stort.Background: For humans’ sleep is a basic need. In today’s society digital media has become an integral part of many adolescent lives. Previous studies have shown that digital media has a strong impact on human sleep habit. Through continuous contact with students the school nurse aims to improve health and be proactive in identifying risk factors that could affect the health negatively. Purpose: The aim of the study was to examine how the school nurse experience high school students sleep habits in relation to the use of digital media. Method: The study used a qualitative methodology with semi structured interviews with a manifest content analysis. Results: The results can be divided in to three categories and nine subcategories. The first category was source of sleep deprivation with the subcategories inability to set limits, nightly screen time and lack of parental insight. The second category was work health promotive with the subcategories interpret signs, impact of the conversation and reduce health hazard. The third category was challenge challenges in work with the subcategories build confidence in relationship, time for presenting knowledge and cooperation for health prioritization. Conclusion: There is a lack of insight and knowledge among students and parents in the importance of sleep and how it is affected by the use of digital media. The school nurses see a need to be more visible in the classes and parent meetings in order to establish relationships that are trustful towards both students and parents and the foundation for mediation of knowledge and together aim for change. There is a need for in depth knowledge also within the school health service and also more time to work with promoting health and prevention with respect to adolescent’s sleep habits in relation to the use of digital media. Especially since the lack of sleep can have negative consequences for the individual but also for the society in general. Keywords: Adolescent, digital media, school nurse, sleep habit

Strategimodell för storhushåll - en anpassning till tjänstelogiken

Syftet med uppsatsen är att beskriva och analysera välkända strategimodellers applikationsförmåga för de specifika förutsättningar som tjänsteföretag inom storhushåll verkar inom. Metoden som vi valt är kvalitativ och materialet som används tar sin utgångspunkt i sekundärdata i form av offentliga och institutionella källor från kända strategiforskare och branschspecialister. Uppsatsen utgår teorimässigt från de tre strategiska analysmodellerna, Five Forces, SWOT och VRIO-modellen. Dessa analyseras i förhållande till den inriktning av storhushållsföretag som vi valt. Vi har i analys och slutsatser visat på vissa svagheter hos Five Forces-modellen, SWOT-modellen och VRIO-modellen när det gäller dessa modellers respektive applikationsförmåga på tjänsteföretag inom storhushåll. De svagheter som redovisats är att modellerna saknar viktiga yttre påverkansfaktorer som bör uppmärksammas av företag verksamma inom denna kategori samt att den mänskliga faktorn kommer i skymundan. Detta måste anses som viktigt i en strategimodell för storhushållsföretag då människan är utgångspunkten inom den serviceverksamhet som bedrivs. Slutsatserna har vidareutvecklats till en egenskapad modell som ska vara mer anpassad till tjänsteföretag inom storhushålls specifika förutsättningar