| 1. |
- Bernson, Jenny M, et al.
(författare)
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'Making dental care possible - a mutual affair'. A grounded theory relating to adult patients with dental fear and regular dental treatment
- 2011
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Ingår i: European Journal of Oral Sciences. - Copenhagen : Munksgaard Forlag. - 0909-8836 .- 1600-0722. ; 119:5, s. 373-380
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Tidskriftsartikel (refereegranskat)abstract
- Dental fear is a common and widespread problem, which can cause severe stress. Even so, most patients with dental fear undergo regular dental treatment in spite of their fear and many enjoy good oral health. The aim of this study was to obtain a deeper understanding of how patients with dental fear manage to undergo dental treatment. Fourteen patients with dental fear, who undergo regular dental care, were interviewed. Qualitative analysis of the transcribed interviews was performed according to the principles of grounded theory. A conceptual framework was generated, and the main concern was identified as 'making dental care possible - a mutual affair'. Four additional categories explained how patients handled their dental fear and how dental care became possible. The strategies were labelled 'taking part in a mental wrestling match', 'trust-filled interaction with dental staff', 'striving for control' and 'seeking and/or receiving social support'. The results showed that making dental care possible for patients with dental fear is a mutual challenge that requires interplay between dental staff and patients, involving verbal and non-verbal communication reflecting respect, attention, and empathy. Moreover, a balance between nearness and distance and between professional and personal treatment is required.
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| 2. |
- Gamage, Sampath, et al.
(författare)
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Reflective and transparent cellulose-based passive radiative coolers
- 2021
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Ingår i: Cellulose. - : Springer. - 0969-0239 .- 1572-882X. ; 28, s. 9383-9393
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Tidskriftsartikel (refereegranskat)abstract
- Radiative cooling passively removes heat from objects via emission of thermal radiation to cold space. Suitable radiative cooling materials absorb infrared light while they avoid solar heating by either reflecting or transmitting solar radiation, depending on the application. Here, we demonstrate a reflective radiative cooler and a transparent radiative cooler solely based on cellulose derivatives manufactured via electrospinning and casting, respectively. By modifying the microstructure of cellulose materials, we control the solar light interaction from highly reflective (> 90%, porous structure) to highly transparent (approximate to 90%, homogenous structure). Both cellulose materials show high thermal emissivity and minimal solar absorption, making them suitable for daytime radiative cooling. Used as coatings on silicon samples exposed to sun light at daytime, the reflective and transparent cellulose coolers could passively reduce sample temperatures by up to 15 degrees C and 5 degrees C, respectively.
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| 3. |
- Hallberg, Jenny, et al.
(författare)
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Genetic and environmental influence on lung function impairment in Swedish twins
- 2010
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Ingår i: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: The understanding of the influence of smoking and sex on lung function and symptoms is important for understanding diseases such as COPD. The influence of both genes and environment on lung function, smoking behaviour and the presence of respiratory symptoms has previously been demonstrated for each of these separately. Hence, smoking can influence lung function by co-varying not only as an environmental factor, but also by shared genetic pathways. Therefore, the objective was to evaluate heritability for different aspects of lung function, and to investigate how the estimates are affected by adjustments for smoking and respiratory symptoms. Methods: The current study is based on a selected sample of adult twins from the Swedish Twin Registry. Pairs were selected based on background data on smoking and respiratory symptoms collected by telephone interview. Lung function was measured as FEV1, VC and DLco. Pack years were quantified, and quantitative genetic analysis was performed on lung function data adjusting stepwise for sex, pack years and respiratory symptoms. Results: Fully adjusted heritability for VC was 59% and did not differ by sex, with smoking and symptoms explaining only a small part of the total variance. Heritabilities for FEV1 and DLco were sex specific. Fully adjusted estimates were 10 and 15% in men and 46% and 39% in women, respectively. Adjustment for smoking and respiratory symptoms altered the estimates differently in men and women. For FEV1 and DLco, the variance explained by smoking and symptoms was larger in men. Further, smoking and symptoms explained genetic variance in women, but was primarily associated with shared environmental effects in men. Conclusion: Differences between men and women were found in how smoking and symptoms influence the variation in lung function. Pulmonary gas transfer variation related to the menstrual cycle has been shown before, and the findings regarding DLco in the present study indicates gender specific environmental susceptibility not shown before. As a consequence the results suggest that patients with lung diseases such as COPD could benefit from interventions that are sex specific.
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| 4. |
- Hallberg, Lillemor R-M, 1942, et al.
(författare)
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Facing a moral dilemma--introducing a dental care insurance within the public dental service.
- 2012
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Ingår i: Swedish dental journal. - : Swedish dental journal. - 0347-9994. ; 36:3, s. 149-56
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Tidskriftsartikel (refereegranskat)abstract
- Through the reform entitled "Dental care insurance-dental care at a fixed price", patients are offered a dental insurance, a capitation plan, that ensures that they can visit the dentist regularly during a period of three years at a fixed price per month (Frisktandvård).This insurance may be offered to all patients. The aim of this study was to generate a theory explaining the main concern for the staff at the public dental service when they have to introduce and advocate dental care insurance to patients. Interview data from 17 persons, representing different professions within the public dental service, were collected and analyzed simultaneously in line with guidelines for grounded theory. The results indicated that dentists/dental hygienists experienced several difficult standpoints concerning the implementation of the dental insurance, somewhat of a moral dilemma. The staff generally had a "cautiously positive attitude" to the forthcoming dental care insurance, but had perceptions how and when the patients should be offered the insurance and what that may mean to the clinic.The respondents reflected about the economic aspects for the clinic and how the oral health may be affected over time for the patients.
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| 5. |
- Svartengren, Magnus, et al.
(författare)
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Twins studies as a model for studies on the interaction between smoking and genetic factors in the development of chronic bronchitis
- 2009
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Ingår i: Biochemical Society Transactions. - 1470-8752 .- 0300-5127. ; 37, s. 814-818
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Konferensbidrag (refereegranskat)abstract
- Smoking is the main risk factor for COPD (chronic obstructive pulmonary disease) but genetic factors are of importance, since only a subset of smokers develops the disease. Sex differences have been suggested both in disease prevalence and response to environmental exposures. Furthermore, it has been shown that acquisition of 'addiction' to smoking is partly genetically mediated. Disease cases and smoking habits were identified in 44919 twins aged > 40 years from the Swedish Twin Registry. Disease was defined as self-reported chronic bronchitis or emphysema, or recurrent cough with phlegm. The results showed that chronic bronchitis seems to be more prevalent among females, and that the heritability estimate for chronic bronchitis was a moderate 40% and only 14% of the genetic influences were shared by smoking. In addition, 392 twins have been invited to a clinical investigation to evaluate: (i) to what extent genetic factors contribute to individual differences (variation) in FEV1 (forced expiratory volume in 1 s), vital capacity and l (diffusion capacity), taking sex into consideration, and (ii) whether smoking behaviour and respiratory symptoms influence these estimates.
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| 6. |
- Almgren, Magnus, 1972, et al.
(författare)
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RICS-el : Building a national testbed for research and training on SCADA security (short paper)
- 2019
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Ingår i: Lect. Notes Comput. Sci.. - Cham : Springer Nature. ; 11260 LNCS, s. 219-225, s. 219-225
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Konferensbidrag (refereegranskat)abstract
- Trends show that cyber attacks targeting critical infrastructures are increasing, but security research for protecting such systems are challenging. There is a gap between the somewhat simplified models researchers at universities can sustain contra the complex systems at infrastructure owners that seldom can be used for direct research. There is also a lack of common datasets for research benchmarking. This paper presents a national experimental testbed for security research within supervisory control and data acquisition systems (SCADA), accessible for both research training and experiments. The virtualized testbed has been designed and implemented with both vendor experts and security researchers to balance the goals of realism with specific research needs. It includes a real SCADA product for energy management, a number of network zones, substation nodes, and a simulated power system. This environment enables creation of scenarios similar to real world utility scenarios, attack generation, development of defence mechanisms, and perhaps just as important: generating open datasets for comparative research evaluation.
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| 7. |
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| 8. |
- Askelöf, U., et al.
(författare)
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Wait a minute? : An observational cohort study comparing iron stores in healthy Swedish infants at 4 months of age after 10-, 60- and 180-second umbilical cord clamping
- 2017
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Ingår i: BMJ Open. - : BMJ Publishing Group. - 2044-6055. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective: Umbilical cord blood (UCB) is a valuable stem cell source used for transplantation. Immediate umbilical cord (UC) clamping is widely practised, but delayed UC clamping is increasingly advocated to reduce possible infant anaemia. The aim of this study was to investigate an intermediate UC clamping time point and to evaluate iron status at the age of 4 months in infants who had the UC clamped after 60 s and compare the results with immediate and late UC clamping. Design: Prospective observational study with two historical controls. Setting: A university hospital in Stockholm, Sweden, and a county hospital in Halland, Sweden. Methods: Iron status was assessed at 4 months in 200 prospectively recruited term infants whose UC was clamped 60 s after birth. The newborn baby was held below the uterine level for the first 30 s before placing the infant on the mother's abdomen for additional 30 s. The results were compared with data from a previously conducted randomised controlled trial including infants subjected to UC clamping at ≤10 s (n=200) or ≥180 s (n=200) after delivery. Results: After adjustment for age differences at the time of follow-up, serum ferritin concentrations were 77, 103 and 114 μg/L in the 10, 60 and 180 s groups, respectively. The adjusted ferritin concentration was significantly higher in the 60 s group compared with the 10 s group (P=0.002), while the difference between the 60 and 180 s groups was not significant (P=0.29). Conclusion: In this study of healthy term infants, 60 s UC clamping with 30 s lowering of the baby below the uterine level resulted in higher serum ferritin concentrations at 4 months compared with 10 s UC clamping. The results suggest that delaying the UC clamping for 60 s reduces the risk for iron deficiency. © 2017 Article author(s).
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| 9. |
- Backman, Sofia, et al.
(författare)
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Swedish consensus reached on recording, interpretation and reporting of neonatal continuous simplified electroencephalography that is supported by amplitude-integrated trend analysis
- 2018
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Ingår i: Acta Paediatrica. - : WILEY. - 0803-5253 .- 1651-2227. ; 107:10, s. 1702-1709
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Tidskriftsartikel (refereegranskat)abstract
- Continuous monitoring of electroencephalography (EEG), with a focus on amplitude-integrated EEG (aEEG), has been used in neonatal intensive care for decades. A number of systems have been suggested for describing and quantifying aEEG patterns. Extensive full-montage EEG monitoring is used in specialised intensive care units. The American Clinical Neurophysiology Society published recommendations for defining and reporting EEG findings in critically ill adults and infants. Swedish neonatologists and clinical neurophysiologists collaborated to optimise simplified neonatal continuous aEEG and EEG recordings based on these American documents. Conclusion: This paper describes the Swedish consensus document produced by those meetings.
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| 10. |
- Balciunas, Darius, et al.
(författare)
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Functional interactions within yeast mediator and evidence of differential subunit modifications
- 2003
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 278:6, s. 3831-3839
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Tidskriftsartikel (refereegranskat)abstract
- It is possible to recruit RNA polymerase II to a target promoter and, thus, activate transcription by fusing Mediator subunits to a DNA binding domain. To investigate functional interactions within Mediator, we have tested such fusions of the lexA DNA binding domain to Med1, Med2, Gal11, Srb7, and Srb10 in wild type, med1, med2, gal11, sin4, srb8, srb10, and srb11 strains. We found that lexA-Med2 and lexA-Gal11 are strong activators that are independent of all Mediator subunits tested. lexA-Srb10 is a weak activator that depends on Srb8 and Srb11. lexA-Med1 and lexA-Srb7 are both cryptic activators that become active in the absence of Srb8, Srb10, Srb11, or Sin4. An unexpected finding was that lexA-VP16 differs from Gal4-VP16 in that it is independent of the activator binding Mediator module. Both lexA-Med1 and lexA-Srb7 are stably associated with Med4 and Med8, which suggests that they are incorporated into Mediator. Med4 and Med8 exist in two mobility forms that differ in their association with lexA-Med1 and lexA-Srb7. Within purified Mediator, Med4 is present as a phosphorylated lower mobility form. Taken together, these results suggest that assembly of Mediator is a multistep process that involves conversion of both Med4 and Med8 to their low mobility forms.
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| 11. |
- Banerjee, Debashree, et al.
(författare)
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Electrical tuning of radiative cooling at ambient conditions
- 2023
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Ingår i: Cell Reports Physical Science. - : ELSEVIER. - 2666-3864. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Passive radiative cooling forms a sustainable means for cooling of objects through thermal radiation. Along with progress on static cooling systems, there is an emerging need for dynamic control to enable thermoregulation. Here, we demonstrate temperature regu-lation of devices at ambient pressure and temperature by electri-cally tuning their radiative cooling power. Our concept exploits the possibility to electrochemically tune the thermal emissivity and thereby cooling power of a conducting polymer, which enabled reversible control of device temperatures of around 0.25 degrees C at ambient conditions in a sky simulator. Besides tuneable radiative cooling by exposure to the sky, the concept could also contribute to reduced needs for indoor climate control by enabling dynamic control of thermal energy flows between indoor objects, such as be-tween people and walls.
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| 12. |
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| 13. |
- Bengtsson, Ulrika, et al.
(författare)
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Improved Blood Pressure Control Using an Interactive Mobile Phone Support System
- 2016
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Ingår i: The Journal of Clinical Hypertension. - : Wiley. - 1524-6175 .- 1751-7176. ; 18:2, s. 101-108
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Tidskriftsartikel (refereegranskat)abstract
- This explorative, longitudinal study evaluated the effect of the daily use of a mobile phone-based self-management support system for hypertension in reducing blood pressure (BP) among 50 primary care patients with hypertension over 8 weeks. The self-management system comprises modules for (1) self-reports of BP, pulse, lifestyle, symptoms, and well-being; (2) delivery of reminders and encouragements; and (3) graphical feedback of self-reports. Daily use of the support system significantly reduced BP (systolic BP 7 mm Hg, diastolic BP 4.9 mm Hg) between baseline and week 8, with daily improvements leveling off as the study progressed. Three homogenous subsets of patients were identified who, despite different initial BP levels, showed similar decreases in BP during the study, indicating that patients benefited irrespective of baseline BP. In showing significant reductions in BP, our results suggest that the self-management support system may be a useful tool in clinical practice to help patients self-manage their hypertension.
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| 14. |
- Björkander, Sofia, et al.
(författare)
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Childhood allergy is preceded by an absence of gut lactobacilli species and higher levels of atopy-related plasma chemokines
- 2020
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 202:3, s. 288-299
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Tidskriftsartikel (refereegranskat)abstract
- Alterations in the composition and reduced diversity of the infant microbiome are associated with allergic disease in children. Further, an altered microbiota is linked to immune dysregulation, including skewing of different T helper (Th) subsets, which is also seen in atopic individuals. The aim of this study was, therefore, to investigate the associations between gut lactobacilli and Th‐related plasma factors in allergy development during childhood. A total of 194 children with known allergy status at 1 year of age were followed to 10 years of age. We used real‐time polymerase chain reaction (PCR) to investigate the presence of three lactobacilli species (Lactobacillus casei, L. paracasei, L. rhamnosus) in infant fecal samples (collected between 1 week and 2 months of age) from a subgroup of children. Plasma chemokines and cytokines were quantified at 6 months and at 1, 2, 5 and 10 years of age with Luminex or enzyme‐linked immunosorbent assay (ELISA). Fractional exhaled nitrogen oxide (FeNO) was measured and spirometry performed at 10 years of age. The data were analysed by non‐parametric testing and a logistic regression model adjusted for parental allergy. An absence of these lactobacilli and higher levels of the chemokines BCA‐1/CXCL13, CCL17/TARC, MIP‐3α/CCL20 and MDC/CCL22 in plasma at 6 months of age preceded allergy development. The presence of lactobacilli associated with lower levels of atopy‐related chemokines during infancy, together with higher levels of interferon (IFN)‐γ and lower FeNO during later childhood. The results indicate that the presence of certain lactobacilli species in the infant gut may influence allergy‐related parameters in the peripheral immune system, and thereby contribute to allergy protection.
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| 15. |
- Bonamy, Anna-Karin Edstedt, et al.
(författare)
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Blood Pressure in 6-Year-Old Children Born Extremely Preterm
- 2017
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Ingår i: Journal of the American Heart Association. - : WILEY. - 2047-9980. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- Background-Advances in perinatal medicine have increased infant survival after very preterm birth. Although this progress is welcome, there is increasing concern that preterm birth is an emerging risk factor for hypertension at young age, with implications for the lifetime risk of cardiovascular disease. Methods and Results-We measured casual blood pressures (BPs) in a population-based cohort of 6-year-old survivors of extremely preterm birth (< 27 gestational weeks; n=171) and in age-and sex-matched controls born at term (n=172). Measured BP did not differ, but sex, age-, and height-adjusted median z scores were 0.14 SD higher (P=0.02) for systolic BP and 0.10 SD higher (P=0.01) for diastolic BP in children born extremely preterm than in controls. Among children born extremely preterm, shorter gestation, higher body mass index, and higher heart rate at follow-up were all independently associated with higher BP at 6 years of age, whereas preeclampsia, smoking in pregnancy, neonatal morbidity, and perinatal corticosteroid therapy were not. In multivariate regression analyses, systolic BP decreased by 0.10 SD (P=0.08) and diastolic BP by 0.09 SD (P=0.02) for each week-longer gestation. Conclusions-Six-year-old children born extremely preterm have normal but slightly higher BP than their peers born at term. Although this finding is reassuring for children born preterm and their families, follow-up at older age is warranted.
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| 16. |
- Eiken, Ola, et al.
(författare)
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Effects of vision on energy expenditure and kinematics during level walking
- 2022
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Ingår i: European Journal of Applied Physiology. - : Springer Nature. - 1439-6319 .- 1439-6327.
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: We have previously observed substantially higher oxygen uptake in soldiers walking on terrain at night than when performing the same walk in bright daylight. The aims of the present study were to investigate the influence of vision on mechanical efficiency during slow, horizontal, constant-speed walking, and to determine whether any vision influence is modified by load carriage.METHODS: Each subject (n = 15) walked (3.3 km/h) for 10 min on a treadmill in four different conditions: (1) full vision, no carried load, (2) no vision, no carried load, (3) full vision with a 25.5-kg rucksack, (4) no vision with a 25.5-kg rucksack.RESULTS: Oxygen uptake was 0.94 ± 0.12 l/min in condition (1), 1.15 ± 0.20 l/min in (2), 1.15 ± 0.12 l/min in (3) and 1.35 ± 0.19 l/min in (4). Thus, lack of vision increased oxygen uptake by about 19%. Analyses of movement pattern, by use of optical markers attached to the limbs and torso, revealed considerably shorter step length (12 and 10%) in the no vision (2 and 4) than full vision conditions (1 and 3). No vision conditions (2 and 4) increased step width by 6 and 6%, and increased vertical foot clearance by 20 and 16% compared to full vision conditions (1 and 3).CONCLUSION: The results suggest that vision has a marked influence on mechanical efficiency even during entrained, repetitive movements performed on an obstacle-free horizontal surface under highly predictable conditions.
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| 17. |
- Ekstrom, S., et al.
(författare)
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Body mass index status and peripheral airway obstruction in school-age children: a population-based cohort study
- 2018
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Ingår i: Thorax. - : BMJ. - 0040-6376 .- 1468-3296. ; 73:6, s. 538-545
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Tidskriftsartikel (refereegranskat)abstract
- Background Few large prospective studies have investigated the impact of body mass index (BMI) on lung function during childhood. Methods Using data collected between 2002 and 2013, we analysed associations between BMI status and lung function (assessed by spirometry) from 8 to 16 years, as well as cross-sectional associations with small airway function (impulse oscillometry) at 16 years in the BAMSE cohort (n=2889). At 16 years, cross-sectional associations with local and systemic inflammation were investigated by analysing FE NO, blood eosinophils and neutrophils. Results Overweight and obesity at 8 years were associated with higher FVC, but lower FEV 1 /FVC ratio at 8 and 16 years. In boys, but not girls, obesity at 8 years was associated with a further reduction in FEV 1 /FVC between 8 and 16 years. In cross-sectional analyses, overweight and obesity were associated with higher frequency dependence of resistance (R 5-20) and larger area under the reactance curve (AX0.5) at 16 years. Increased blood neutrophil counts were seen in overweight and obese girls, but not in boys. No association was found between BMI status and FE NO. Persistent, but not transient, overweight/obesity between 8 and 16 years was associated with higher R 5-20 and AX0.5 and lower FEV 1 /FVC (-2.8% (95% CI -4.1 to -1.2) in girls and -2.7% (95% CI -4.4 to -1.1) in boys) at 16 years, compared with persistent normal weight. Conclusion I n childhood and adolescence, overweight and obesity, particularly persistent overweight, were associated with evidence of airway obstruction, including the small airways.
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| 18. |
- Fransson, Susanne, 1975, et al.
(författare)
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Intragenic anaplastic lymphoma kinase (ALK) rearrangements: Translocations as a novel mechanism of ALK activation in neuroblastoma tumors.
- 2015
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Ingår i: Genes, chromosomes & cancer. - : Wiley. - 1098-2264 .- 1045-2257. ; 54:2, s. 99-109
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Tidskriftsartikel (refereegranskat)abstract
- Anaplastic lymphoma kinase (ALK) has been demonstrated to be deregulated in sporadic as well as in familiar cases of neuroblastoma (NB). Whereas ALK-fusion proteins are common in lymphoma and lung cancer, there are few reports of ALK rearrangements in NB indicating that ALK mainly exerts its oncogenic capacity via activating mutations and/or overexpression in this tumor type. In this study, 332 NB tumors and 13 cell lines were screened by high resolution single nucleotide polymorphism microarray. Gain of 2p was detected in 23% (60/332) of primary tumors and 46% (6/13) of cell lines, while breakpoints at the ALK locus were detected in four primary tumors and two cell lines. These were further analyzed by next generation sequencing and a targeted enrichment approach. Samples with both ALK and MYCN amplification displayed complex genomic rearrangements with multiple breakpoints within the amplicon. None of the translocations characterized in primary NB tumors are likely to result in a chimeric protein. However, immunohistochemical analysis reveals high levels of phosphorylated ALK in these samples despite lack of initial exons, possibly due to alternative transcription initiation sites. Both ALK proteins predicted to arise from such alterations and from the abnormal ALK exon 4-11 deletion observed in the CLB-BAR cell line show strong activation of downstream targets STAT3 and extracellular signal-regulated kinase (ERK) when expressed in PC12 cells. Taken together, our data indicate a novel, although rare, mechanism of ALK activation with implications for NB tumorigenesis.
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| 19. |
- Gleisner, Magdalena, 1972-
(författare)
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Quantification of mineral weathering rates in sulfidic mine tailings under water-saturated conditions
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tailings are a fine-grained waste product produced during the metal recovery process. Tailings consist mostly of different silicates but also sulfides (e.g. pyrite), since 100 % metal recovery is not possible. Freshly processed tailings are deposited in large impoundments. If the mine tailings in the impoundments are exposed to water and oxygen, the sulfides will oxidize and release acidity and metals such as Fe, Cu, Zn, and Pb. The sulfide mineral oxidation reactions are catalyzed by sulfur and iron oxidizing bacteria (principally Acidithiobacillus ferrooxidans) that oxidize ferrous iron to ferric iron, which then oxidizes pyrite. When the leachate produced by this process discharges from the impoundment, it is called acid mine drainage, which may lead to the pollution of adjacent streams and lakes.The intention with this thesis is to investigate and quantify mineral weathering processes and element release rates occurring in water-saturated and soil-covered sulfidic mine tailings. The study was performed in different batch and column experiments in room temperature and in the laboratory. The batch experiments were conducted for ca. three months and investigated: a) microbial and abiotic sulfide oxidation in freshly processed tailings under oxic conditions at pH 2-3 and pH 8, b) microbial oxidation of pure pyrite grains at pH 2-3 under different oxygen concentrations ranging from anoxic to oxic conditions. The column experiments, consisting of unoxidized tailings in water-saturated columns, were conducted for up to three years. In these experiments, an oxygen-saturated solution was continually pumped into the column inlet, and investigated: a) differences in oxidation rates between tailings of two different grain sizes, b) factors affecting element discharge rates, acid neutralization, and sulfide oxidation, c) the effect of ions released in a soil cover on release rates in the tailings.Sulfide oxidation processes within the batch experiments were limited by surface kinetics. The microbial oxidation of pure pyrite at atmospheric conditions produced the most rapid rate, while the microbial oxidation of pure pyrite at anoxic conditions was slower by 1.8 orders of magnitude. Microbial and abiotic oxidation of pyrite in freshly-processed tailings resulted in pyrite oxidation rates that were intermediate between these two extremes. The results from the microbial experiments with pure pyrite indicated a positive correlation between the concentration of dissolved oxygen, ferric iron and bacterial cells (at a total cell concentration > 106 cells/mL and a dissolved oxygen concentration ≥ 13.2 µM), which implies an interdependence of these factors. The results from these batch experiments support the indirect mechanism for microbial oxidation by the ferric oxidation pathway. Pyrite oxidation rates estimated from the batch experiments may be comparable with oxidation rates in the unsaturated zone and at the groundwater table in a tailings impoundment.Acid neutralization reactions in the column experiments resulted in the release of base cations to the column leachate. Calcite was the most important neutralizing mineral despite that it was only present in minor amounts in the tailings. It was confirmed that acidity forced the calcite dissolution. Element release rates in the column experiments were controlled by the availability of dissolved oxygen, which was a function of the water flow rate into the column. These column experiments also showed that the results are comparable with results from field studies, justifying the use of column experiments to study processes within tailings impoundments.
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| 20. |
- Guan, Jikui, et al.
(författare)
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Clinical response of the novel activating ALK-I1171T mutation in neuroblastoma to the ALK inhibitor ceritinib.
- 2018
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Ingår i: Cold Spring Harbor molecular case studies. - : Cold Spring Harbor Laboratory. - 2373-2873. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- Tumors with Anaplastic Lymphoma Kinase (ALK) fusion rearrangements, including non-small cell lung cancer and anaplastic large cell lymphoma, are highly sensitive to ALK tyrosine kinase inhibitors (TKIs), underscoring the notion that such cancers are addicted to ALK activity. While mutations in ALK are heavily implicated in childhood neuroblastoma, response to the ALK TKI crizotinib has been disappointing. Embryonal tumors in patients with DNA repair defects such as Fanconi anemia (FA) often have a poor prognosis, due to lack of therapeutic options. Here we report a child with underlying FA and ALK mutant high-risk neuroblastoma responding strongly to precision therapy with the ALK TKI ceritinib. Conventional chemotherapy treatment caused severe, life-threatening toxicity. Genomic analysis of the initial biopsy identified germ-line FANCA mutations as well as a novel ALK-I1171T variant. ALK-I1171T generates a potent gain-of-function mutant, as measured in PC12 cell neurite outgrowth and NIH3T3 transformation. Pharmacological inhibition profiling of ALK-I1171T in response to various ALK TKIs identified an 11-fold improved inhibition of ALK-I1171T with ceritinib when compared with crizotinib. Immunoaffinity-coupled LC-MS/MS phosphoproteomics analysis indicated a decrease in ALK signaling in response to ceritinib. Ceritinib was therefore selected for treatment in this child. Mono-therapy with ceritinib was well tolerated and resulted in normalized catecholamine markers and tumor shrinkage. After 7.5 months treatment, residual primary tumor was surgically removed and exhibited hallmarks of differentiation together with reduced Ki67 levels. Clinical follow-up after 21 months treatment revealed complete clinical remission including all metastatic sites. Therefore, ceritinib presents a viable therapeutic option for ALK-positive neuroblastoma.
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| 21. |
- Hakeberg, Magnus, 1954, et al.
(författare)
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Burning mouth syndrome: experiences from the perspective of female patients.
- 2003
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Ingår i: European journal of oral sciences. - 0909-8836 .- 1600-0722. ; 111:4, s. 305-11
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to gain a deeper understanding of the development of burning mouth syndrome (BMS). Eighteen females (43-80 yr old), referred to the Clinic of Oral Medicine, formed the study group. Oral examination did not reveal any mucosal lesion or dental pathology, blood analyses of vitamin B12 and serum iron levels were within normal reference values, and no allergies to dental materials were reported. Reported pain/discomfort was 49.4 (mean) on a 100-mm visual analog scale and duration of symptoms was, on average, 8.1 yr (median = 1.5 yr). Taped semistructured interviews were transcribed and analysed in line with grounded theory methodology. In the analysis, a core category emerged, labeled communicating psychological discomfort. This category indicated musings about the meaning of life and interacted with a personality characterized by a strong need for conscientiousness, a life style including long-standing struggle with psychosocial overload, and external social and cultural influences. The debut of the BMS was then preceded by an acutely stressful event. A psychosocial history, in addition to a detailed dental and medical history, seems to be crucial in diagnosing patients. If a psychological disorder and somatization of anxiety and depression is suggested, as indicated in our study, the patient should be offered counseling by a psychologist.
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| 22. |
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| 23. |
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| 24. |
- Hallberg Hofstrand, Erik, et al.
(författare)
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Dynamic Measurements of Nip Force Variations during Post-Printing of Corrugated Board
- 2006
-
Ingår i: Nordic Pulp & Paper Research Journal, 21(1), 111-114 (2006).
-
Tidskriftsartikel (refereegranskat)abstract
- A method has been developed in order to measure nip force variations during flexographic post-printing of corrugated board. This method can be used to study the influence of the nip mechanics on the final print quality
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| 25. |
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| 26. |
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| 27. |
- Hallberg Hofstrand, Erik, 1975-
(författare)
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Flexographic Post-Printing of Corrugated Board : Contact Mechanics and Print Quality
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As the corrugated board industry strives to produce products with a higher print quality in the converting stage, there is a need for a greater understanding of the factors influencing the final print quality and how we perceive the print. In this work, a method for quantifying the print quality of printed corrugated board is presented as well as methods that quantitatively characterize the mechanical interaction between the printing form and the corrugated board in the printing nip. The results of investigations addressing the impact of the mechanical properties of the printing form on ink transfer are also presented. A band-pass image analysis method adapted to the spatial wavelength of B-flute corrugated board was used to quantify the print quality on the board in terms of print banding. The findings were substantiated by a perceptual evaluation which showed a high correlation to the instrumental quantification. The main cause of print banding is a higher local contact pressure on the fluting tips than in the fluting valleys, which leads to a higher ink transfer to the fluting tips. A greater difference between the local contact pressure on the fluting tips than in the fluting valleys generated a higher degree of banding. The difference in local contact pressure as well as nip force variations could be measured using the proposed methods to characterize the interaction between the printing form and the corrugated board. The difference in local contact pressure was highly dependent on the mechanical properties of the components of the printing form. An increase in the stiffness in compression mode and in the bending stiffness of the printing form led to a smaller contact area in the printing nip and consequently a higher external pressure on the ink, resulting in an overall higher ink transfer but also a higher degree of banding. The influence of the mechanical properties of the printing form components was supported by the results of numerical simulations of the contact between the printing form and the corrugated board. Contact area, pressure level and texture of the local contact pressure were compared with measurements of local contact pressures for different printing forms and the results showed a high degree of agreement. Numerical simulations could thus predict the print quality achieved with different printing forms under different printing conditions.
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| 28. |
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| 29. |
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| 30. |
- Hallberg, Magnus, et al.
(författare)
-
Assessment of suspended solids concentration in highway runoff and its treatment implication
- 2006
-
Ingår i: Environmental technology. - : Informa UK Limited. - 0959-3330 .- 1479-487X. ; 27:9, s. 945-950
-
Tidskriftsartikel (refereegranskat)abstract
- It is understood that the major pollution from storm water is related to the content of particulate matter. One treatment practice is based on the first flush, i.e. detention of the initial part of the runoff that is considered to contain the highest concentrations of pollutants, This study has evaluated the concentration of total suspended solids in 30 consecutive runoff events during the winter season for an area of 6.7 hectares. A six-lane highway (E4) that has an annual average daily traffic load of 120,000 dominates the area and road de-icing salt (NaCl) and studded tires were in regular use during the studied period. The effluent standard for wastewater of 60 mg TSS per litre applied in EU was used to assess the treatment requirement of storm water. In only two of the events the event mean concentration was below 60 mg V. In four runoff events a partial event mean concentration below 60 mg l(-1) was found, in 26 %, 12 %, 11 %, and 2 % respectively of the runoff volume. This would suggest that a capture of the initial part of the runoff for subsequent treatment is less applicable in this type of urban watershed.
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| 31. |
- Hallberg, Magnus, et al.
(författare)
-
Evaluation of a sand filter material for road runoff treatment– Pilot-scale field trial focused on copper and zinc removal
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The negative effects of stormwater discharges on receiving aquatic environments and the need for their purification were highlighted by the EU courts' "Weser-Ruling" in May 2020. The ruling stated the need for removal of dissolved pollutants. The decision justifies field studies for development of far-reaching methods for runoff treatment. In this in situ study, a standard sand was used as medium for road runoff filtration and removal of dissolved and particle-bound (< 0.45 µm) zinc (Zn) and copper (Cu), Data collected included 24 road runoff events, mimicking the flow variations and pollutant emissions over a seven-month period. The findings showed that filter sand can be used to remove Zn and Cu from road runoff in a gravity fed treatment system. The removal of total Zn and Cu was 93% and 67%, respectively. Dissolved Zn was efficiently removed by the sand (87%), however not Cu (19%). The sand efficiently removed total suspended solids (TSS) from maximum occurring 443 mg L-1 to below 5 mg L-1. No head loss due to the TSS loadings was observed. The initial studies show the sand's potential to remove the investigated metals, but in the longer term, effluent concentrations may exceed emission permit values.
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| 32. |
- Hallberg, Magnus, et al.
(författare)
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Evaluation of a sand filter material for road runoff treatment- pilot-scale field trial focused on copper and zinc removal
- 2022
-
Ingår i: Water practice and technology. - : IWA Publishing. - 1751-231X. ; 17:8, s. 1652-1665
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of stormwater discharges on receiving aquatic environments and the need for their purification were highlighted by an EU court in May 2020. The ruling stated the need for removal of dissolved pollutants, which justifies field studies for development of far-reaching methods for runoff treatment. In this study, a standard sand was used as medium for road runoff filtration and removal of dissolved and particle-bound (<0.45 mu m) zinc (Zn) and copper (Cu). Data included 24 road runoff events, mimicking the flow variations and pollutant emissions over a seven-month period. The findings showed that sand can be used to remove Zn and Cu from road runoff in a gravity fed treatment system at a surface load ranging from 16.8 to 201 L m(-2) h(-1). The removal of total Zn and Cu was 93 and 67%, respectively. Dissolved Zn was efficiently removed by the sand (87%), however not Cu (19%). The sand efficiently removed total suspended solids (TSS) from the maximum occurring 443 mg L-1 to below 5 mg L-1. No head loss due to the TSS loadings was observed. The sand's potential to remove the investigated metals was shown, but in the longer term, effluent concentrations may exceed permitted values.
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| 33. |
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| 34. |
- Hallberg, Magnus, et al.
(författare)
-
Functional and physical interactions within the middle domain of the yeast mediator
- 2006
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Ingår i: Molecular Genetics and Genomics. - : Springer Science and Business Media LLC. - 1617-4615 .- 1617-4623. ; 276:2, s. 197-210
-
Tidskriftsartikel (refereegranskat)abstract
- Med21 (Srb7) is a small essential subunit of the middle domain of the Mediator, which is conserved in all eukaryotes. It is thought to play an important role in both transcriptional activation and repression. In the yeast Saccharomyces cerevisiae, Med21 is known to interact both with the Mediator subunit Med6 and the global co-repressor Tup1. We have made a temperature-sensitive med21-ts mutant, which we used in a high copy number suppressor screen. We found ten yeast genes that can suppress the med21-ts mutation in high copy number. The three strongest suppressors were MED7 and MED10 (NUT2), which encode other Mediator subunits, and ASH1, which encodes a repressor of the HO gene. 2-Hybrid experiments confirmed multiple interactions between Med21, Med10, Med7 and Med4, and also revealed a Med21 self-interaction. The interactions of Med21 with Med7 and Med10 were verified by co-immunoprecipitation of tagged proteins produced in insect cells and E. coli, where both interactions were found to depend strongly on the amino acid residues 2-8 of Med21. These interactions, and the interactions of Med21 with Med6 and Tup1, suggest that Med21 may serve as a molecular switchboard that integrates different signals before they reach the core polymerase.
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| 35. |
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| 36. |
- Hallberg, Magnus, et al.
(författare)
-
Reactive filters for removal of dissolved metals in highway runoff
- 2007
-
Ingår i: Highway And Urban Environment. - 9781402060090 ; , s. 465-474
-
Konferensbidrag (refereegranskat)abstract
- A pilot-scale system consisting of presedimentation and a saturated down-flow reactive bed filter was used for cleaning highway runoff. Blast furnace slag (BFS) and Polonite were selected as filter materials. A total suspended solids (TSSs) removal of over 99% was achieved. High removal performance was observed for dissolved Mn, Ni, Co, and Cu. In contrast Al was released after filtration. Metals were retained in the upper layer of the bed filters while a desorption was suggested to take place in the downward layers. This was probably attributed to the elevated salt levels during winter and the intermittent operation.
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| 37. |
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| 38. |
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| 39. |
- Hallberg, Magnus, et al.
(författare)
-
Seasonal variations of ten metals in highway runoff and their partition between dissolved and particulate matter
- 2007
-
Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 181:1-4, s. 183-191
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of differentiation of pollutants in urban runoff between dissolved and particulate matter is of great concern for a successful design of a water treatment process. Seasonal variations in pollutant load are of equal importance. Ten metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), as dissolved and particulate bound, was studied in the runoff from a major urban highway during a winter season and its following summer. Studded tyres and winter salting were expected to have an impact on the runoff water quality. The dissolved part of Al, Cd, Co, Cr, Mn and Ni was significantly higher in winter in comparison with summer (p < 0.01). For Fe, however, the dissolved part was lower during winter. No significant difference was found for Cu, Pb and Zn between the two seasons. The mass concentration (mg kg(-1)) for all metals was significantly higher over the summer except for Al and Co, which showed a higher mass concentration during the winter. The concentration of selected metals vs. total suspended solids (TSS) showed a linear relationship (r(2)> 0.95) during winter runoff events except for Cd. A good correlation (r (2)> 0.90) was also found for the summer period for Al, Cu, Fe, Mn, Ni and Zn. It is suggested that the metal pollutant load during winter could be assessed indirectly by measurement of TSS.
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| 40. |
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| 41. |
- Hallberg, Magnus, 1974-
(författare)
-
Studies of Functional Interactions within Yeast Mediator and a Proposed Novel Mechanism for Regulation of Gene Expression
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The yeast Mediator complex is required for transcriptional regulation both in vivo and in vitro and the identification of similar complexes from metazoans indicates that its function is conserved through evolution. Mediator subunit composition and structure is well characterized both by biochemical, genetic and biophysical methods. In contrast, little is known about the mechanisms by which Mediator operates and how the complex is regulated. The aim of my thesis was to elucidate how Mediator functions at the molecular level and to investigate functional interactions within Mediator. It is possible to recruit RNA polymerase II to a target promoter and thus to activate transcription by fusing Mediator subunits to a DNA binding domain. In order to investigate functional interactions within Mediator, we made such fusion proteins where different Mediator subunits were fused to the DNA binding domain of lexA. The expression of a reporter gene containing binding sites for lexA was subsequently measured in both a wild type strain and in strains where genes encoding specific Mediator subunits had been disrupted. We found that lexA-Med2 and lexA-Gal11 are strong activators that function independently of all Mediator subunits tested. On the other hand, lexA-Srb10 is a weak activator that depends on Srb8 and Srb11 and lexA-Med1 and lexA-Srb7 are both cryptic activators that become active in the absence of Srb8, Srb10, Srb11, or Sin4. Both lexA-Med1 and lexA-Srb7 proteins showed a stable association with the Mediator subunits Med4 and Med8 in wild type cells and in all deletion strains tested, indicating that they were functionally incorporated into the Mediator complex. We also showed that both Med4 and Med8 exist in two forms that differed in electrophoretic mobility and that these forms differed in their ability to associate with Mediator immuno-purified from the LEXA-SRB7 and LEXA-MED1 strains. Dephosphorylation assays of purified Mediator indicated that the two mobility forms of Med4 corresponded to the phosphorylated and unphosphorylated forms of the Med4 protein respectively. Some of the data presented in this study as well as previous genetic and biochemical data obtained in our lab suggested a functional link between the Med1, Med2, Srb10 and Srb11 proteins. We extended these findings by showing that the Srb10 kinase phosphorylates the Med2 protein at residue serine 208, both in vitro and in vivo. We also showed that a point mutation of the single phosphorylation site to an alanine or to an aspartic acid residue altered the gene expression of a specific set of genes. Taken together, these data indicate that posttranslational modification of Mediator subunits is a so far uncharacterized mechanism for regulation of gene expression. In order to study the function of the Srb7 subunit of Mediator, we isolated a temperature sensitive strain where the amino acids 2 to 8 of srb7 were deleted. The Mediator subunits Nut2 and Med7 were isolated as high copy suppressor of srb7-∆(2-8) and we were also able to show that Srb7 interacted with Nut2 and Med7 both in a 2-hybrid system and in co-immuno precipitation experiments using recombinantly expressed proteins. Interestingly, a deletion of amino acids 2 to 8 of Srb7 abolishes its interaction with both Med7 and Nut2 in vitro. Med4 also interacted with Srb7 in the 2-hybrid system and surprisingly, the first eight amino acids of Srb7 were shown to be sufficient for this interaction.
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| 42. |
- Hallberg, Magnus
(författare)
-
Suspended solids and metals in highway runoff : implications for treatment systems
- 2006
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- It is known that traffic is a source of pollutants and that pollutant loads increase with elevated traffic densities. Studies executed in Stockholm, Sweden advocate that highway runoff from roads with an annual average daily traffic (AADT) exceeding 30,000 vehicles need treatment before discharge to the receiving water. It is common knowledge that sedimentation is the most expedient method for stormwater treatment. However, sedimentation units are area demanding and in highly urbanised watersheds the land use is often restricted. Studies have implied the occurrence of first flush, i.e. an initially higher pollutant load in the beginning of the runoff event, in highway watersheds. With an emphasized first flush it would be possible to treat only a part of the total runoff volume reducing the area needed for a sedimentation basin. In general two methods are used to design stormwater treatment ponds. One method is based on the reduced catchment area and pond surface and the other is based on an average runoff volume and a permanent pond volume. The methods are relaying on data from routine monitoring of various treatment systems and suggest removal efficiencies for pollutants. Applying general removal efficiencies for design it can be intricate to estimate an outlet concentration when the specific removal efficiency may be dependent on the initial concentration of the pollutant. Consequently, knowledge of the removal efficiencies dependence on initial concentration would be helpful to optimise stormwater treatment systems. This research has studied runoff from highly trafficated watersheds. The aim has been to evaluate the mass transport, stormwater quality and sedimentation behaviour and their implications for stormwater treatment. The study sites, Eugenia and Fredhäll, are located along the six-lane highway E4 through Stockholm that has an AADT load of 120,000 vehicles and a speed limit of 70 km/h. In lack of a unified definition of first flush the mass transport was studied using the EU directive 1991/271/EEC discharge demand for TSS of 60 mg/l. It was found that for the majority of the runoff events during winter the event mean concentration exceeded 60 mg/l suggesting that the complete runoff volume should be captured during winter. The dissolved concentration of metals showed significant variations between winter and summer, as did the concentration in the particulate matter (mg/kg). It was possible to correlate total metal concentration to total suspended solids with good correlation (r2 >0.90) for the majority of studied metals in winter and summer. The findings would imply that a successful treatment of the studied metal pollutants could be carried out by sedimentation. However, depending on discharge criteria, the elevated levels of dissolved matter, especially during winter, have to be considered with regards to the selection of the appropriate water treatment process. The sedimentation process could be described by a logarithmical function and initial turbidity. Good correlation (r2 >0.90) was indicated between turbidity and TSS. The sedimentation process of the studied highway runoff varied significantly (p<0.05) when elevated levels of NaCl could be found in the runoff. A significant difference (p<0.05) was shown for turbidity and TSS between summer and winter, which was assumed to be related to the use of studded tires. This study implies that the entire runoff volume must be treated and that the use of first flush as a design criterion is less applicable for the winter period. The study implies good correlation between total metal concentration and TSS. In addition the indicated correlation between turbidity and TSS would point to the possibility to use turbidity as a surrogate measurement for TSS and the studied metals. Moreover, the possibility to describe the sedimentation process by the initial concentration of turbidity would infer the utilisation of turbidity as a tool for process control for stormwater treatment systems. In addition, the novel results for the dependence on the sedimentation process could be incorporated in existing models for design of stormwater treatment systems in similar watersheds.
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| 43. |
- Hallberg, Magnus, et al.
(författare)
-
Suspended solids concentration in highway runoff during summer conditions
- 2008
-
Ingår i: Polish Journal of Environmental Studies. - 1230-1485 .- 2083-5906. ; 17:2, s. 237-241
-
Tidskriftsartikel (refereegranskat)abstract
- One treatment practice for storm water is detention of the initial part of the runoff that is considered to contain the highest concentration of pollutants. This study has evaluated the concentration of total suspended solids (TSS) in 44 consecutive runoff events from a highway watershed. The effluent TSS standard for wastewater of 60 mg/l applied in the EU was used to assess the required treatment. In 35 of the runoff events the TSS partial event mean concentration exceeded 60 mg/l for the duration of the runoff event. Thus, a partial capture of the runoff volume should not be used as a treatment option in similar conditions that prevailed in this study.
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| 44. |
- Hallberg, Magnus, 1963-
(författare)
-
Treatment conditions for the removal of contaminants from road runoff
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The pollutant load in road runoff is related to traffic densities and road maintenance activities. Inurbanised areas treatment of road runoff is common and often considered necessary. The pollutantsare partitioned between the particulate and dissolved matter. However, the contaminantstend to have an affinity to the particulate material. Sedimentation, the predominant treatmentmethod for road runoff uses various types of ponds. Design tools used for stormwater treatmentsystems are based on extensive data from existing treatment systems. The variations in the empiricaldata make it difficult when attempting to evaluate precise conditions for pollutant removaland thereby minimising the land use for a treatment facility. This is a concern in highly urbanisedareas where land use often is restricted.In this work, field studies were conducted in three separate watersheds along the same motorwaywith an annual average daily traffic exceeding 120,000 vehicles. The aim was to assess treatmentconditions for the removal of contaminants from road runoff.The study of mass transport of total suspended solids used the EU Directive (1991/271/EEC)discharge requirement for urban wastewater treatment: 60 mg/l during winter and summer. Theresults showed that a capture of the total runoff volume was necessary during both seasons. Tenmetals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), as dissolved and particulate bound, werestudied in the road runoff during a winter season and the following summer period. The dissolvedpart of Al, Cd, Co, Cr, Mn, and Ni was significantly higher in winter. The mass concentration(mg/kg) for all metals was significantly higher over the summer except for Al and Co, whichshowed a higher mass concentration during the winter. The total metal concentration showed agood correlation to total suspended solids (TSS) during winter with exception for Cd. Good correlationto TSS was also found for the summer period for Al, Cu, Fe, Mn, Ni, and Zn. A simplemodel could describe sedimentation by the initial concentration of TSS, albeit road salt (NaCl)had a significant impact on the sedimentation process during winter. Removal of dissolved metalswas studied by column experiments using water granulated blast furnace slag. The result showedgood removal for Cd, Cu, Ni, and Zn independent of NaCl concentrations. Sediment accumulation(mg sediment/mm precipitation) was relatively consistent for the studied summer seasons asopposed to winter. The sediment differed in metal mass concentrations (mg/kg) between theseasons. Concentrations of Cu and Zn were high in regard to the guidelines for sensitivity ofsediment dwelling organisms and Swedish guidelines for contaminated soils.The findings suggest that the entire runoff volume must be captured for treatment. The reductionof TSS concentration could be estimated for a specific surface load (m/h). This would alsoapply for majority of the studied metals that correlated well to the particulate material. Reactivefilter technology using water granulated blast furnace slag could be applied for treatment of runofffor the reduction of dissolved metals. However, long-term studies are necessary for its practicalimplementation. Furthermore; the work shows that on-line turbidity measurements could beused for expedient process control for treatment facilities in similar watersheds dominated byroads. The work could be used together with existing design methods and models to evaluate andoptimise road runoff treatment.
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| 45. |
- Hallberg, Magnus, et al.
(författare)
-
Treatment of polluted road run-off water : Problems and possibilities
- 2004
-
Ingår i: Annals of Warsaw Agricultural University / Land Reclamation. - Warzaw : Warsaw Agricultural University Press. - 0208-5771. ; :35, s. 55-64
-
Tidskriftsartikel (refereegranskat)abstract
- The legal aspects for conventional water production and treatment are clearly defined and not ambiguous. This is not the case for handling and treatment of run-off water. In the EU directive 1991/271/EEC run-off water is defined as sewage water. The EU Water Directive refers to 1991/271/EEC and points to run-off water as a pollutant source for ground water. Elevated levels of pollutant can be found in run-off water from catchment areas with dense traffic loads. Depending on road maintenance, use of studded tires, type of pavement, traffic flow, velocity, type of vehicle, residential and industrial areas, tunnels the degree of mobility of the pollutants will vary in the ambient air and the run-off water. An aspect that only to some extent has been elaborated on is the influence of pavement types and its wear with regard to the mobility of the pollutants. A treatment technique commonly used in many countries is storm water ponds. The pollutant removal efficiency varies for different ponds, due to different specific pond areas, i.e. pond area in relation to catchment area. Ponds act as sedimentation basins, collecting particles and bounded pollutants. However, the solute transport of e.g. heavy metals should be trapped by other means. For that purpose a filtration unit has been developed and tested in Sweden.
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| 46. |
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| 47. |
- Hallberg, Peter, 1984, et al.
(författare)
-
CaMnO3-δ Made from Low Cost Material Examined as Oxygen Carrier in Chemical-looping Combustion
- 2014
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 63, s. 80-86
-
Konferensbidrag (refereegranskat)abstract
- Carbon Capture and Storage is a promising method to limit the increasing amount of greenhouse gases in the atmosphere. In this method high purity carbon dioxide is captured at large emission sources, e. g. fossil fuelled power plants. The carbon dioxide can then be transported to a long term storage site, rather than being emitted to the atmosphere. Among the different alternatives for obtaining high purity carbon dioxide during combustion of fossil fuels, Chemical-looping Combustion (CLC) is one of the most promising. Here, the oxygen needed to oxidize a fuel is provided by a solid oxygen carrier. The oxygen carrier is subsequently circulated to another reactor where it is reoxidized with air. By separating these two operations mixing of the combustion products and the nitrogen in the air is avoided. An energy demanding gas separation is thus not necessary.The most crucial part of Chemical-looping Combustion is the solid oxygen carrier. The oxygen carrier should have high reactivity with fuel and oxygen, sufficient oxygen carrying capacity and preferably also low cost. Furthermore it is important that it is able to withstand the tough conditions it is exposed to in a hot fluidizing environment, both with respect to physical attrition and chemical degradation. The most commonly suggested setup of Chemical- looping Combustion is a dual fluidized bed system where gas velocities and mechanical abrasion can be high. When the technology was first demonstrated, nickel oxide based oxygen carriers were typically used. But as nickel is quite costly as well as potentially harmful, alternatives have been sought after.In 2009 Leion et al. [1] investigated an oxygen carrier based on calcium manganite of perovskite structure CaMnO3-δ for chemical looping combustion. The results were very promising and similar materials have since then been successfully tested in pilot rigs up to 120 kWth, including extended operation in continuously operating 10 kWth reactor with very positive results, see Källén et al. [2]. A key feature of these materials is that they are able to release gas phase oxygen at relevant conditions, so called Chemical-looping with Oxygen Uncoupling, see Rydén et al. [3]. Having gas phase oxygen available for fuel oxidation makes gas-solid mixing less critical and thus makes it easier to reach complete fuel conversion.Most studies in which CaMnO3-δ based oxygen carriers have been examined have been using particles manufactured from high quality chemicals. While that is reasonable in the early stages of development, cheaper raw materials would be favourable for industrial applications. Promising oxygen carriers based on manganese ores have been manufactured and characterized by Fossdal et al. [4] and Mohammad Pour et al. [5].This study aims to further examine CaMnO3-δ based oxygen carriers made from low cost, commercial raw materials available in large quantities such as manganese ore. The materials are examined during continuous Chemical- looping Combustion and Oxygen Uncoupling in an experimental reactor with the nominal fuel power 300 Wth. The reactor has previously been used in numerous studies which make comparisons with materials made from high purity chemicals straightforward. During operation several gas concentrations as well as temperatures and pressure drops are measured which allows monitoring of the chemical reactions and fluidization behaviour in the reactor.Fines (particles
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| 48. |
- Hallberg, Peter, 1984, et al.
(författare)
-
Chemical Looping Combustion and Chemical Looping with Oxygen Uncoupling Experiments in a Batch Reactor Using Spray-Dried CaMn1–xMxO3−δ (M = Ti, Fe, Mg) Particles as Oxygen Carriers
- 2013
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 27:3, s. 1473-1481
-
Tidskriftsartikel (refereegranskat)abstract
- Chemical looping combustion and chemical looping with oxygen uncoupling (CLOU) with oxygen carrier particles consisting of CaMn1-xMxO3-delta (M = Ti, Fe, Mg) has been studied by consecutive oxidation and reduction experiments in a fluidized-bed batch reactor. The examined particles were produced by spray drying, and all did show a significant release of gas-phase oxygen to the inert atmosphere at 900 and 1000 degrees C. All particles also provided very high reactivity with syngas and methane. Some of the examined particles showed unfavorable fluidization characteristics, i.e., they formed dust during operation or showed agglomeration or defluidization tendencies. The crushing strength of the particles that formed dust was typically
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| 49. |
- Hallberg, Peter, 1984, et al.
(författare)
-
Experimental investigation of CaMnO3-δ based oxygen carriers used in continuous Chemical-Looping Combustion
- 2014
-
Ingår i: International Journal of Chemical Engineering. - : Hindawi Limited. - 1687-806X .- 1687-8078. ; 2014:412517
-
Tidskriftsartikel (refereegranskat)abstract
- Three materials of perovskite structure, (M = Mg or Mg and Ti), have been examined as oxygen carriers in continuous operation of chemical-looping combustion (CLC) in a circulating fluidized bed system with the designed fuel power 300 W. Natural gas was used as fuel. All three materials were capable of completely converting the fuel to carbon dioxide and water at 900°C. All materials also showed the ability to release gas phase oxygen when fluidized by inert gas at elevated temperature (700–950°C); that is, they were suitable for chemical looping with oxygen uncoupling (CLOU). Both fuel conversion and oxygen release improved with temperature. All three materials also showed good mechanical integrity, as the fraction of fines collected during experiments was small. These results indicate that the materials are promising oxygen carriers for chemical-looping combustion.
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| 50. |
- Hallberg, Peter, 1984, et al.
(författare)
-
Investigation of a calcium manganite as oxygen carrier during 99 h of operation of chemical-looping combustion in a 10 kWth reactor unit
- 2016
-
Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 53, s. 222-229
-
Tidskriftsartikel (refereegranskat)abstract
- Chemical-looping with oxygen uncoupling is a technology for combustion with inherent carbon dioxide separation. A solid oxygen carrier circulates between the fuel reactor, where it provides oxygen for fuel oxidation, and the air reactor, where it is reoxidized. In this study a 10 kWth pilot reactor was used to examine a calcium manganite based oxygen carrier in continuous operation with natural gas as fuel during 99 h. The composition of the oxygen carrier can be described by the formula CaMn0.775Ti0.125Mg0.1O3-δ. The main part of the material forms a perovskite crystal structure which has oxygen releasing properties. The fuel conversion was generally above 95% and full conversion was reached for certain operating conditions. The elutriation of fines, defined as particles smaller than 45 μm, decreased over time to eventually be below detection limit. That suggested a loss of fines of less than 0.011 wt%/h, indicating a lifetime of over 9000 h. A high fuel conversion with no thermodynamic limitation, good mechanical strength, low cost and very low toxicity shows that this calcium manganite material qualifies as a very promising oxygen carrier.
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