| 1. |
- Hermansson, Ann-Charlotte, et al.
(författare)
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Mathematical model for paved surface summer and winter temperature : Comparison of calculated and measured temperatures
- 2004
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Ingår i: Cold Regions Science and Technology. - : Elsevier BV. - 0165-232X .- 1872-7441. ; 40:1-2
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Tidskriftsartikel (refereegranskat)abstract
- A simulation model has been developed to calculate pavement temperature for both summer and winter conditions. Input data are hourly values for solar radiation, air temperature and wind velocity. Longwave radiation, incident to and outgoing from the pavement surface, is calculated from the air and pavement surface temperature, respectively. The portion of the incident shortwave radiation absorbed by the pavement surface is calculated from the albedo of the surface. By means of a finite difference approximation of the equation for conduction of heat, the pavement temperature profile is calculated. Apart from radiation and heat conduction, convection losses from the pavement surface are also calculated based on wind velocity, air temperature and surface temperature. The model is validated by using data from three different sections in the LTPP program USA and six different sections in Sweden. Here, hourly meteorological data as well as surface temperature are taken. One set of parameter values for albedo, emissivity, atmospheric downwelling longwave radiation and convection losses, giving a good correspondence for asphalt concrete pavement for summer conditions, and one set for winter conditions are given. © 2004 Elsevier B.V. All rights reserved.
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| 2. |
- Isacsson, G., et al.
(författare)
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Bibloc and Monobloc Oral appliances in the Treatment of Obstructive Sleep apnoea : a Multicenter, Randomized, Blinded, Parallel-Group Trial
- 2017
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Ingår i: Sleep Medicine. - : Elsevier. - 1389-9457 .- 1878-5506. ; 40:Suppl 1, s. E142-E143
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: The clinical benefit of bibloc over monobloc appliances has not been established in randomized trials treating obstructive sleep apnoea (OSA). We hypothesized that the two types of appliances are equally effective in treating moderate to severe OSA. Materials and methods: We performed a blinded, multicenter, randomized, controlled, prospective, parallel-group trial including patients aged 18 years or older who had moderate-to-severe OSA. Patients were randomly assigned to receive either a bibloc or a monobloc appliance with the intention to protrude the mandible 75% of the individual maximal protrusion capacity. At baseline a one-night respiratory polygraphy was done without any respiratory support. The polygraphy was iterated with the appliance in place at a 6-week follow-up. The primary outcome was the absolute change in the apnoea-hypopnea-index (AHI) from baseline to the 6-week follow-up, analysed in the per-protocol population. All patients who received an appliance were included in the safety analysis. This trial is registered with ClinicalTrials.gov, number NCT02148510, and approved by Uppsala Regional Ethical Review Board, Sweden (#2014/021). Results: We recruited patients from three dental specialist clinics in Sweden; enrolment of 302 patients was done between March 2014 and April 2016; 146 randomized to bibloc and 156 to monobloc appliance. Twenty-three patients in the bibloc group and 17 in the monobloc group were withdrawn due to reasons like appliance could not be fitted, lack of compliance, adverse events or non-valid follow-up polygraphy i.e. a per-protocol group of 123 bibloc and 139 monobloc treated patients. The mean change of AHI from baseline to 6 weeks of treatment was -13.8 (95% CI -16.1 to -11.5; p < 0.001) in the bibloc group and -12.5 (95% CI -14.8 to -10.3; p < 0.001) in the monobloc group. The mean difference was not significant between the groups (-1.3 (95% CI -4.5 to 1.9). The most common adverse event in the orofacial region was upper airway infection followed by complains from various parts of the mouth, jaws and teeth. Conclusions: Bibloc and monobloc appliance treatment was equal in their effects in treating OSA as measured by at home polygraphic respiratory measures and the appliances were associated with a similar degree of adverse events. Acknowledgements: Funding from Uppsala-Örebro Regional Research Council and Vastmanland County Council, Sweden.
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| 3. |
- Bhattacharyya, Anirban, et al.
(författare)
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ESS RF Source and Spoke Cavity Test Plan
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report describes the test plan for the first high power RF source, ESS prototype double spoke cavity and ESS prototype cryomodule at the FREIA Laboratory.
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| 4. |
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| 5. |
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| 6. |
- Hermansson Adler, Magnus, 1951, et al.
(författare)
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Religionskunskap Kompakt
- 1996
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Bok (övrigt vetenskapligt/konstnärligt)
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| 7. |
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| 8. |
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| 9. |
- Hermansson, Veronica, et al.
(författare)
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Comparative CYP-dependent binding of the adrenocortical toxicants 3-methylsulfonyl-DDE and o,p′-DDD in Y-1 adrenal cells
- 2007
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Ingår i: Archives of Toxicology. - : Springer Science and Business Media LLC. - 0340-5761 .- 1432-0738. ; 81:11, s. 793-801
-
Tidskriftsartikel (refereegranskat)abstract
- The environmental pollutant 3-MeSO2–DDE [2-(3-methylsulfonyl-4-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethene] is an adrenocortical toxicant in mice, specifically in the glucocorticoid-producing zona fasciculata, due to a cytochrome P450 11B1 (CYP11B1)-catalysed bioactivation and formation of covalently bound protein adducts. o,p′-DDD [2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethane] is toxic and inhibits steroidogenesis in the human adrenal cortex after bioactivation by unidentified CYPs, but does not exert any toxic effects on the mouse adrenal. As a step towards determining in vitro/in vivo relationships for the CYP-catalysed binding and toxicity of 3-MeSO2–DDE and o,p′-DDD, we have investigated the irreversible protein binding of these two toxicants in the murine adrenocortical cell line Y-1. The irreversible binding of 3-MeSO2–DDE previously demonstrated in vivo was successfully reproduced and could be inhibited by the CYP-inhibitors etomidate, ketoconazole and metyrapone. Surprisingly, o,p′-DDD reached similar levels of binding as 3-MeSO2–DDE. The binding of o,p′-DDD was sensitive to etomidate and ketoconazole, but not to metyrapone. Moreover, GSH depletion increased the binding of 3-MeSO2–DDE, but not of o,p′-DDD, indicating an important role of GSH conjugation in the detoxification of the 3-MeSO2–DDE-derived reactive metabolite. In addition, the specificity of CYP11B1 in activating 3-MeSO2–DDE was investigated using structurally analogous compounds. None of the analogues produced histopathological lesions in the mouse adrenal in vivo following a single i.p. injection of 100 mg/kg body weight, but two of the compounds were able to decrease the irreversible binding of 3-MeSO2–DDE to Y-1 cells. These results indicate that the bioactivation of 3-MeSO2–DDE by CYP11B1 is highly structure-dependent. In conclusion, both 3-MeSO2–DDE and o,p′-DDD bind irreversibly to Y-1 cells despite differences in binding and adrenotoxicity in mice in vivo. This reveals a notable in vitro/in vivo discrepancy, the contributing factors of which remain unexplained. We consider the Y-1 cell line as appropriate for studies of the cellular mechanisms behind the adrenocortical toxicity of these substances.
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| 10. |
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| 11. |
- Hermansson, Veronica, et al.
(författare)
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Pharmacokinetics of the adrenocorticolytic compounds 3-methylsulphonyl-DDE and o,p′-DDD (mitotane) in Minipigs
- 2008
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Ingår i: Cancer Chemotherapy and Pharmacology. - : Springer Science and Business Media LLC. - 0344-5704 .- 1432-0843. ; 61:2, s. 267-274
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Tidskriftsartikel (refereegranskat)abstract
- The pharmacokinetics of the adrenocorticolytic drug candidate 3-Methylsulphonyl-DDE (3-MeSO2-DDE) and the anticancer drug o,p′-DDD (mitotane) were studied in Göttingen minipigs. The animals were given 3-MeSO2-DDE or o,p′-DDD as single oral doses (30 mg/kg). Concentrations in plasma and subcutaneous fat were measured by gas chromatography at different time points during 180 days. Maximal plasma concentrations appeared within 24 h for both compounds, but were about 2 times higher for 3-MeSO2-DDE. o,p′-DDD plasma concentrations declined rapidly to low levels during 4 days. 3-MeSO2-DDE also decreased rapidly, but remained at high concentrations throughout the study. In fat, 3-MeSO2-DDE reached about 25-fold higher levels than o,p′-DDD at 30 days, and both substances were eliminated slowly from this tissue. 3-MeSO2-DDE liver concentrations were about 18-fold higher than those in plasma at 180 days. In contrast, o,p′-DDD liver and plasma levels were about equal at 180 days. o,p′-DDD had roughly 45 times larger CL/F than 3-MeSO2-DDE, confirming that the elimination of this compound was more rapid. Both compounds were characterised by their localisation and retention in fat tissue, and the individual size of the fat stores clearly determined the plasma concentrations. It is concluded that although 3-MeSO 2-DDE is an interesting candidate for therapeutic use due to its potential characteristics to specifically target adrenocortical tumour cells the slow elimination of the compound might make it challenging to design appropriate dosage regimes.
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| 12. |
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| 13. |
- Hermansson, Åke
(författare)
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Frost modelling and pavement temperatures : summer pavement temperaures and frost modelling
- 2000
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Three papers form the present thesis. In paper I a numerical model for calculation of surface temperatures on a highway is presented. The model takes all relevant factors into consideration, i.e. conduction, wind, short- and long wave radiation. Temperatures obtained by the model are compared with those measured in a highway pavement. A good correlation is obtained. The model is using the position of the sun as input data and is not considering noon time conditions all the day, as in many other models for surface temperature calculation. In paper II and III a simple numerical model for calculation of frost depth and frost heave in highways is presented. Calculation results are compared with data obtained from two different test sites. Comparison is also made to laboratory tests conducted by using a new laboratory-testing device, developed by the author. The equipment is described in paper III. It is further argued, that frost heave to great extent is caused by ice lenses formed by water from the pores in unfrozen soil and only to a minor extent by water taken from the ground water, which is normally assumed. Good correlation is found between calculated and observed frost penetration and frost heave, in both field and laboratory condition. Special attention is paid to the influence of heave rate and water intake rate.
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| 14. |
- Hermansson, Åke
(författare)
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Frost modelling and pavement temperatures : summer pavement temperatures and frost modelling: licentiate thesis
- 2001
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Rapport (populärvet., debatt m.m.)abstract
- Temperature and moisture are very essential parameters when describing the condition of a pavement. In most cases, a high moisture content involves a decreased bearing capacity and, consequently, a shorter durability of the pavement. A frozen pavement has a greater bearing capacity than the corresponding construction in spring or late autumn. However, the freezing itself also implies strains to the pavement, as it heaves to different extent and in different directions in connection with the frost heave. The properties of an asphalt concrete pavement vary dramatically according to temperature. A cold asphalt concrete is hard, stiff and brittle, and therefore, cracks easily occur, whereas its bearing capacity decreases at high temperatures as softening progresses.A numerical model has been developed for calculation of the temperatures in a road pavement during summer condition, especially emphasizing the asphalt concrete. Further, in order to also model temperatures and other conditions, occurring during winter conditions in the pavement, such as frost heave, a frost heave model has been developed. The aim of this is to gain a better insight into the freezing process of a road structure. The model also provides an efficient tool for a better understanding of important factors related to frost depth and frost heave. In the present work, numerical analysis of frost heave and frost front propagation has been performed and compared with some field observations.Furthermore, equipment for freezing tests in laboratory has also been developed. Experiences from such tests and field measurements have been used when developing the numerical model for the freezing of pavements. At the laboratory freezing tests, a special interest has been devoted to heave rate, water intake rate and cooling rate. The experiences, obtained from both the laboratory tests, as well as the field observations, have been compared to what has been reported in literature.Temperatures obtained from the numerical model for summer temperatures have turned out to correspond well to measurements of pavement temperatures on three different levels below the road surface on a road west of Stockholm, Sweden. Calculated temperatures were also compared with temperatures calculated by using a model presented by SUPERPAVE (i.e. the asphalt binder specification, developed under the Strategic Highway Research Program (SHRP) USA). This model gives the highest temperature of asphalt concrete during daytime. According to the opinion of the author it is found that SUPERPAVE uses an erroneous assumption that there is equilibrium when the highest temperature is reached in the pavement on a hot summer day. This, of course, leads to an overestimation of the temperature, which is compensated in SUPERPAVE by assuming that the highest temperature is reached at a relatively high wind velocity of 4.5 m/s instead of at feeble winds, which is more realistic according to the author.
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| 15. |
- Hermansson, Åke, et al.
(författare)
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Heat Transfer in Soils
- 2009
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Ingår i: Water in Road Structures. - Dordrecht : Springer. ; , s. 69-79
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Bokkapitel (refereegranskat)abstract
- Temperature highly affects pavement performance. High and low temperatures not only affects the viscosity of asphalt concrete but also has an impact on the moisture flow within pavements. At temperatures below 0°C the freezing of pavements dramatically changes the permeability and frost action might occur forcing water to flow upwards to the freezing front resulting in frost heave and other pavement distress.
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| 16. |
- Hermansson, Åke
(författare)
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Influence of steel reinforced pavements on aircraft system
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This research investigated how steel nets used as reinforcement in taxiwaysandrunways affect systems on board aircraft. It is stated that for HighIntensityRadiated Fields from radio- or radar transmitters, steel nets have asmootheningeffect and therefore decrease the risk of interference with aircraft systems.Foraircraft compasses it is concluded that permanently magnetic steel netsconstitutea significant source of interference. It was further concluded that steelnets,typically used as reinforcement, have such properties that they do not becomepermanently magnetic and consequently there is no risk of interference withaircraft compasses. Diverging compasses at Arlanda airport are explained as aconsequence of using permanently magnetic steel nets of non-typical quality.This report is a short version of the Swedish VTI notat 13-2004, Stålarmeringi flygfält - kan stålnät i banor påverka flygplansinstrument?
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| 17. |
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| 18. |
- Hermansson, Åke
(författare)
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Laboratory and field testing on rate of frost heave versus heat extraction
- 2004
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Ingår i: Cold Regions Science and Technology. - : Elsevier BV. - 0165-232X .- 1872-7441. ; 38:2-3, s. 137-151
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Tidskriftsartikel (refereegranskat)abstract
- Equipment for performing laboratory freezing tests on soils has been developed to study the relation between the rates of heave and heat extraction. Laboratory freezing tests are performed on specimens over 500 min tall. In addition, field equipment for automatically recording frost depth and heave has been installed in a pavement. The equipment gives temperature readings for every 50 mm. Temperature gradients at different depths, from laboratory as well as field, are calculated to estimate the rate of liberation of latent heat as a function of time. The calculations indicate that, for the laboratory testing, the heave rate is almost independent of the heat extraction rate for fairly long periods at a constant frost penetration rate. The recorded field data indicate that the heave rate is on average almost constant for relatively long periods of time with a continuous frost penetration, thereby supporting the existence of a maximum heave rate that can not be surpassed persistently. However, heave rate varies greatly if the heat extraction rate often changes between a high and a low level and can for short periods widely exceed the maximum average heave rate possible over long periods. The observed behavior is explained as a consequence of a limited capacity in the redistribution of water to the frost front to supply the heaving.
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| 19. |
- Hermansson, Åke
(författare)
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Modeling of frost heave and surface temperatures in roads
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Temperature and moisture are very essential parameters when describing the condition of a pavement. In most cases, a high moisture content involves a decreased bearing capacity and, consequently, a shorter durability of the pavement. A frozen pavement has a greater bearing capacity than the corresponding construction in spring or late autumn. However, the freezing itself also implies strains to the pavement, as it heaves to different extent and in different directions in connection with the frost heave. The properties of an asphalt concrete pavement vary dramatically according to temperature. Cold asphalt concrete is hard, stiff and brittle, and therefore, cracks easily occur, whereas its bearing capacity decreases at high temperatures as softening progresses. Emphasizing the asphalt concrete, a numerical model has been developed for calculation of temperatures for summer condition, by means of recorded values for solar radiation, air temperature and wind velocity. Further, in order to also model temperatures and other conditions, occurring in the pavement during winter, a frost heave module has been developed and included in the model. The aim of this is to gain a better insight into the freezing process of a road structure. The model also provides an efficient tool for a better understanding of important factors related to frost depth and frost heave. A modified version of the model, is tested for falling weight deflectometer analysis. Input here, is a series of measured pavement surface temperatures and the output is calculated temperature distributions for the asphalt layer. Measuring equipment, developed at VTI, has been used to, in the field, automatically record frost heave and pavement temperature distribution. Furthermore, equipment for freezing tests in laboratory has also been developed. Experiences from such tests and field measurements have been used when developing the numerical model for freezing of pavements. At the laboratory freezing tests, a special interest has been devoted to water intake rate and heave rate related to cooling rate. The experiences, obtained from both the laboratory tests, as well as the field observations, have been compared to what has been reported in literature. Temperatures obtained from the numerical model for summer and winter temperatures have turned out to correspond well to measurements of pavement temperatures at all test sections studied, 12 in US and 3 in Sweden. The freezing tests in laboratory have shown, that a strong frost heave can exist without addition of external water to the samples. The natural water content is, consequently, sufficient to provide enough water for the heave. This "in-situ" water can be redistributed in the structure, thus providing water to the frozen portion of the profile to cause significant frost heave. Frost heave caused by a process like this, is not bound to uptake of external water, which normally is assumed in the relevant literature. Frost heave in freezing tests is often explained by 10 % volume expansion of the freezing water, which is sucked up by samples during the test. The freezing tests in laboratory have also shown, that the ratio (heave/water uptake) increases with frost susceptibility, i.e. the most frost susceptible soils require comparatively less added water for the heaving. The freezing tests in laboratory and field tests, have also shown that the relation between heave rate and heat extraction rate at the frost front, is weak. This is also in contradiction to what normally is stated in literature. The weak relation is found during longer periods of continous frost penetration. However, when heat extraction rate is varied at short time intervals, a strong dependency between heave rate and heat extraction rate is found.
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| 20. |
- Hermansson, Åke, et al.
(författare)
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Prediction of Pavement Fatigue Life with Simulated Temperature Profile from Hourly Surface Temperatures
- 2003
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Ingår i: International Journal on Road Materials and Pavement Design. - : Informa UK Limited. - 1468-0629 .- 2164-7402. ; 4:3, s. 293-308
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Tidskriftsartikel (refereegranskat)abstract
- A typical model for predicting the fatigue life of an asphalt pavement involves mid-depth temperature and the elastic horizontal strains at the bottom of the asphalt layer. Strains are studied at the bottom of the asphalt layer as cracks are assumed to originate there. Pavement temperatures naturally experience daily fluctuations as a result of varying air temperature and solar radiation.The amplitude of the oscillation decreases with depth and maximum temperature is reached later in the day at greater depth. During warming up, strain levels under loading increase as stiffness decreases, while the bottom of the asphalt layer is rather cold and thus sensitive to strains. At cooling down, strain decreases and the bottom layer is warm and withstands strains more easily. It is therefore proposed in this paper to use the temperature at the bottom of the asphalt layer instead of the mid-depth temperature when calculating fatigue damage. It is also proposed to use the complete temperature profile to improve the calculation of strain levels under loading. As the fatigue damage caused each hour will vary with temperature during the course of the day, it is also pointed out that the calculations might be improved by relating the distribution of traffic to the distribution of incremental fatigue damage.A simulation model calculating the temperature profile and strain levels was developed and run for three different pavements with different thicknesses of asphalt layer. It was found that the distribution of incremental fatigue damage over a typical summer day could be completely different for different pavements.
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| 21. |
- Hermansson, Åke
(författare)
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Simulation of Asphalt Concrete (AC) Pavement Temperatures for use with FWD
- 2002
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Ingår i: International Journal on Road Materials and Pavement Design. - : Informa UK Limited. - 1468-0629 .- 2164-7402. ; 3:3, s. 281-297
-
Tidskriftsartikel (refereegranskat)abstract
- A simulation model to be used primarily for falling weight deflectometer (FWD) testing has been developed to calculate temperatures of asphalt concrete (AC) layers. Input to the model is a series of measured temperatures at the surface of AC layer. The measuring series need to be started in the morning, before the sun has strongly heated up the AC layers. A start-up procedure is proposed to follow, if the measuring series lacks the early morning data. By means of a finite difference approximation of the heat transfer equation, the temperatures below the AC surface are calculated.Parameter values were adapted using data for 8 days during the period June 20 to June 27, 2001 from 3 different locations in Sweden. Two other locations in Sweden were used for validation. For the measuring data, the proposed model gives essentially better results than the commonly used BELLS method, as well as the improved version BELLS3 and a method recently proposed by researchers at the Michigan State University.Comparisons with measured temperatures, show that the proposed method calculates the temperature distribution of the AC layers with good accuracy. This includes cloudy as well as sunny days. The method also accurately handles the change between cloudy and sunny weather during the day.
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| 22. |
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| 23. |
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| 24. |
- Isacsson, Göran, et al.
(författare)
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Use of bibloc and monobloc oral appliances in obstructive sleep apnoea : a multicentre, randomized, blinded, parallel-group equivalence trial
- 2019
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Ingår i: European Journal of Orthodontics. - : Oxford University Press. - 0141-5387 .- 1460-2210. ; 41:1, s. 80-88
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Tidskriftsartikel (refereegranskat)abstract
- Background: The clinical benefit of bibloc over monobloc appliances in treating obstructive sleep apnoea (OSA) has not been evaluated in randomized trials. We hypothesized that the two types of appliances are equally effective in treating OSA.Objective: To compare the efficacy of monobloc versus bibloc appliances in a short-term perspective.Patients and methods: In this multicentre, randomized, blinded, controlled, parallel-group equivalence trial, patients with OSA were randomly assigned to use either a bibloc or a monobloc appliance. One-night respiratory polygraphy without respiratory support was performed at baseline, and participants were re-examined with the appliance in place at short-term follow-up. The primary outcome was the change in the apnoea-hypopnea index (AHI). An independent person prepared a randomization list and sealed envelopes. Evaluating dentist and the biomedical analysts who evaluated the polygraphy were blinded to the choice of therapy.Results: Of 302 patients, 146 were randomly assigned to use the bibloc and 156 the monobloc device; 123 and 139 patients, respectively, were analysed as per protocol. The mean changes in AHI were -13.8 (95% confidence interval -16.1 to -11.5) in the bibloc group and -12.5 (-14.8 to -10.3) in the monobloc group. The difference of -1.3 (-4.5 to 1.9) was significant within the equivalence interval (P = 0.011; the greater of the two P values) and was confirmed by the intention-to-treat analysis (P = 0.001). The adverse events were of mild character and were experienced by similar percentages of patients in both groups (39 and 40 per cent for the bibloc and monobloc group, respectively).Limitations: The study shows short-term results with a median time from commencing treatment to the evaluation visit of 56 days and long-term data on efficacy and harm are needed to be fully conclusive.Conclusion: In a short-term perspective, both appliances were equivalent in terms of their positive effects for treating OSA and caused adverse events of similar magnitude.Trial registration: Registered with ClinicalTrials.gov (#NCT02148510).
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| 25. |
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| 26. |
- Mikaelsson, Lars-Åke, et al.
(författare)
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Sustainable building engineering by blended learning
- 2020
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Ingår i: IOP Conference Series. - : Institute of Physics Publishing (IOPP).
-
Konferensbidrag (refereegranskat)abstract
- The sustainable building engineering education at Mid Sweden University has since it started 1994 a strong focus on sustainable building. It is also committed to be a pilot case for blended learning. All courses in the building engineering program were from the autumn 2012 adapted to a blended learning concept. That means that all courses are available in an integrated mix of ordinary campus and online distance education in real time. Blended learning is a way of taking in account different needs concerning student study situation. Adult students, bound with house and families, often prefer more distance education while younger students need more campus education. The results of the case study show that blended learning attracts more students, and allows students with different backgrounds to study and gives a more solid base of students for the program. It also allows a more flexible way of allocating resources by integrating two previous modes of delivery for the same program. This provides an education with a well thought through quality assurance. Another strength of blended learning is the possibility to connect individual students to a larger collective of students, making it possible for them to relate to and learn with and from others by social interactions that are difficult to achieve in solely online education. The pilot case is so far limited to the sustainable building engineering program but in a next stage the concept is planned to be spread to other engineering programs and other education programs at Mid Sweden University.
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| 27. |
- Olvegård, Maja, et al.
(författare)
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PROGRESS AT THE FREIA LABORATORY
- 2015
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Ingår i: Proceedings of IPAC'15. - JACoW : The Joint Accelerator Conferences Website.
-
Konferensbidrag (refereegranskat)abstract
- The FREIA Facility for Research Instrumentation and Accelerator Development at Uppsala University, Sweden, has reached the stage where the testing of superconducting cavities for the European Spallation Source (ESS) is starting. The new helium liquefaction plant has been commissioned and now supplies a custom-made, versatile horizontal cryostat, HNOSS, with liquid helium at up to 140 l/h. The cryostat has been designed and built to house up to two accelerating cavities, or, later on, other superconducting equipment such as magnets or crab cavities. A prototype cavity for the spoke section of the ESS linac will arrive mid 2015 for high-power testing in the horizontal cryostat. Two tetrode-based commercial RF power stations will deliver 400 kW peak power each, at 352 MHz, to the cavity through an RF distribution line developed at FREIA. In addition, significant progress has been made with in-house development of solid state amplifier modules and powercombiners for future use in particle accelerators. We report here on these and other ongoing activities at the FREIA laboratory.
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| 28. |
- Ruber, Roger, et al.
(författare)
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Accelerator development at the FREIA Laboratory
- 2021
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Ingår i: Journal of Instrumentation. - : Institute of Physics Publishing (IOPP). - 1748-0221. ; 16:7
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Tidskriftsartikel (refereegranskat)abstract
- The FREIA Laboratory at Uppsala University focuses on superconducting technology and accelerator development. It actively supports the development of the European Spallation Source, CERN, and MAX IV, among others. FREIA has developed test facilities for superconducting accelerator technology such as a double-cavity horizontal test cryostat, a vertical cryostat with a novel magnetic field compensation scheme, and a test stand for short cryomodules. Accelerating cavities have been tested in the horizontal cryostat, crab-cavities cavities in the vertical cryostat, and cryomodules for ESS on the cryomodule test stand. High power radio-frequency amplifier prototypes based on vacuum tube technology were developed for driving spoke cavities. Solid-state amplifiers and power combiners are under development for future projects. We present the status of the FREIA Laboratory complemented with results of recent projects and future prospects.
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| 29. |
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| 30. |
- Said, Safwat, et al.
(författare)
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Beläggningslagers temperaturer
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Beläggningars temperatur och dess variation under året har stor effekt på bitumenbundna beläggningars beteende under olika belastningstyper. Beläggningstemperatur varierar också med djupet i en vägkropp. Vid val av beläggning till ett specifikt objekt måste man bl.a. ta hänsyn till förväntade temperaturer i det aktuella lagret. Det geografiska läget för ett vägobjekt och lagrets placering i en vägkonstruktion kan vara avgörande för skadeutveckling av en asfaltbeläggning. Två identiska beläggningar med identiska trafikbelastningar fast med olika geografiska läge kan ha helt olika beteende (t.ex. deformation i asfaltlager) beroende på temperaturen i lagren. Av den anledningen behövs beläggningstemperaturer under sommarperioden för utvärderings- och prognosmodeller med avseende på spårbildning och bestämning av gränsvärde på funktionsegenskaper. Beläggningstemperaturer under vinterperioden behövs med avseende på sprickor vid trafikbelastning och termiska sprickor. Målsättningen är att ta fram indata till modell för stabilitetsspår. Temperaturfördelningen ska kunna användas som dimensionerade temperatur. Mätdata från VVIS-stationer har samlats in från stationer spridda över landet för bearbetning. Dessa data innehåller beläggningens yttemperatur. Temperaturmätare har också monterats vid teststräckor på tre olika djup i beläggningen för validering av beräknade temperaturer i beläggningarna.
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| 31. |
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| 32. |
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| 33. |
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| 34. |
- Skyttä, Pietari, et al.
(författare)
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Magnetic fabrics as constraints on the kinematic history of a pre-tectonic granitoid intrusion, Kristineberg, northern Sweden
- 2010
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Ingår i: Journal of Structural Geology. - : Elsevier BV. - 0191-8141 .- 1873-1201. ; 32:8, s. 1125-1136
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Tidskriftsartikel (refereegranskat)abstract
- Outcrop-scale correlations of deformation fabrics with low-field anisotropy of magnetic susceptibility (AMS) measurements revealed a two-stage structural evolution of the pre-tectonic, Palaeoproterozoic Viterliden intrusion in the Skellefte District, Sweden. The first deformation event reflected ˜N-S compression during basin inversion, and comprised reverse dip-slip shearing along major ˜E-W faults, whereas the low-strain lenses in between experienced penetrative deformation with a component of NE-SW elongation along the main foliation. This event is largely responsible for the present structural geometry regionally and locally, and also for the magnetic fabric of the rocks. In particular, the sub-vertical maximum principal susceptibility axes (Kmax) within the high-strain zones are related to early dip-slip deformation, and were virtually unaffected by subsequent dextral strike-slip reactivation, which is recorded by sub-horizontal rock lineations. The strike-slip deformation reflects ˜E-W bulk shortening and may regionally be correlated with reverse faulting along a ˜N-S trending major shear zone east of the study area.
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| 35. |
- Snir, Omri, et al.
(författare)
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Antibodies to several citrullinated antigens are enriched in the joints of rheumatoid arthritis patients
- 2010
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 62:1, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- MCV and CCP positivity represent a similar subset of RA patients, whereas ACPAs with different fine specificities fall into subgroups of anti-CCP+/anti-MCV+ patients. The levels of all specific ACPAs were elevated in synovial fluid, suggesting that there is local antibody production and/or retention of ACPAs at the site of inflammation governed by RA-predisposing genes.
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| 36. |
- Svedberg, Bo, et al.
(författare)
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FUD - SALA : provsträcka med stabilisering av obundna lager
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The objective of the project is to develop two applications, in which a subbase is stabilized using binders, for full scale demonstration. The binders that were used are cement, Merit 5000 and fly ash. The work indicates that stabilization of unbound layers are expected to improve the bearing capacity of the road construction though the total depth of the structure is reduced. The developed applications are durable against freezing and thawing cycles, will not be lifting due to frost and are not considerably insulating. In a life cycle cost perspective the applications are likely to be favourable. Next step is to perform a full scale demonstration where amongst other knowledge regarding determination of modulus, frost durability and cost aspects related to maintenance should be developed further.
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| 37. |
- Tegelberg, Åke, et al.
(författare)
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Respiratory outcome after one-year treatment of obstructive sleep apnea with bibloc versus monobloc oral appliances : a multicenter, randomized equivalence trial
- 2019
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Ingår i: Sleep Medicine. - : Elsevier. - 1389-9457 .- 1878-5506. ; 64:Suppl. 1, s. S378-S378
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: The benefit of bibloc over monobloc appliances in one-year obstructive sleep apnea (OSA) has not been evaluated in randomized trials. We hypothesized that these types of appliances are equally effective.Methods: In this multicenter, randomized equivalence trial patients with OSA were assigned to either bibloc or monobloc appliance treatment. At baseline a one-night home respiratory polygraphy was done without respiratory support, and at one-year follow-up examination iterated with the appliance in place. The outcome was the change in the apnea-hypopnea-index (AHI) and the equivalence limits were set at ±5.Results: Out of 302 patients 146 were randomly assigned to bibloc and 156 to monobloc. In 88 and 104 patients, respectively, were analysed per-protocol with a significant reduction of AHI with a mean change -16.7 (95% CI -19.4 to -14.1) in the bibloc and -11.8 (-14.9 to -8.7) in the monobloc and not significantly equivalent. The proportion of responders defined as AHI < 10 at the follow-up was 68% and 65% for bibloc and monobloc, respectively. Treatment related adverse events were generally mild and transient and occurred similar in frequencies between groups.Conclusions: Bibloc and monobloc appliance treatment gave a significant positive effect in treating OSA. The treatment modalities were not statistically equivalent, with a numerically greater reduction with bibloc, and, were associated with a similar degree of adverse events.
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| 38. |
- Tegelberg, Åke, et al.
(författare)
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Respiratory outcomes after a 1-year treatment of obstructive sleep apnoea with bibloc versus monobloc oral appliances : a multicentre, randomized equivalence trial
- 2020
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Ingår i: Acta Odontologica Scandinavica. - : Taylor & Francis. - 0001-6357 .- 1502-3850. ; 78:6, s. 401-408
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The benefit of bibloc over monobloc appliances in treating obstructive sleep apnoea (OSA) has not been evaluated in randomized trials. We hypothesized that these types of appliances would be equally effective.Material and methods: In this multicentre, randomized equivalence trial, patients with OSA received one type of bibloc or one type of monobloc treatment. At baseline, a 1-night polygraphy study was done, and this was repeated after 1 year. The outcome was any change in the apnoea-hypopnoea index (AHI) and the limits of equivalence between the two devices were set at ±5 AHI units.Results: Of 302 patients, 146 were randomly assigned to bibloc and 156 to monobloc appliances. In 88 and 104 patients, respectively, there were significant reductions in the AHI (p < .001) with a mean change of -16.7 (95% CI -19.4 to -14.1) in the bibloc and -11.8 (-14.9 to -8.7) in the monobloc groups. The proportions of responders defined as having an AHI <10 were 68% and 65% for the bibloc and monobloc groups, respectively. Treatment-related adverse events were mild, transient and the dropouts were more frequent in the bibloc group.Conclusions: Both types of treatments positively and significantly reduced respiratory disturbances, but at the 1-year follow-up, they were not significantly different in treating OSA, with a numerically greater reduction of the AHI value with the bibloc appliance. However, the higher proportion of treatment-related adverse events and higher proportion of dropouts among bibloc users should be balanced against the advantage of a greater reduction in the AHI.
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| 39. |
- Viman, Leif, et al.
(författare)
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Stålarmering i flygfält : kan stålnät i banor påverka flygplansinstrument?
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här studien har haft tre syften, dels att förklara de störningar ijordens magnetfält som uppmätts av Sveriges geologiska undersökning (SGU), pånorra delen av taxibana till startbana 01/19 Arlanda, dels att allmänt utredahur stålnätsarmering stör jordens magnetfält och dels belysa hur dagens ochkommande flygplans instrument påverkas av sådana störningar. Vad gäller SGU:smätningar på Arlanda har vi, efter utredningar som gjorts tidigaretillsammans med det arbete som utförts inom projektet, kommit till slutsatsenatt de störningar i jordens magnetfält som uppmätts på taxibana tillstartbana 01/19 Arlanda har sin mest troliga förklaring i att armeringsnätmagnetiserats permanent av den magnetvagn som använts för att städa banan.Armeringsnätet i den aktuella banan var av annan sort än vad som normaltanvänds, med en högre benägenhet för permanent magnetisering, medan stål somnormalt används i armeringsnät är i princip omöjligt att magnetiserapermanent. Beräkningar utförda av AerotechTelub bekräftar att permanentmagnetism skulle kunna ge det mönster som SGU redovisar. Beräkningar hargjorts för en stor mängd olika fall - nät med och utan permanent magnetism,nät med olika riktning i förhållande till jordens magnetfält, för punkter inärheten av ett näts kant, i närheten av ett gap mellan två nät och förpunkter över ett nät långt ifrån kant och gap. I det andra syftet att utredahur stålnätsarmering allmänt stör instrument, och då speciellt en kompass,kan beräkningarna för fallet utan permanent magnetism sammanfattas som attdet är endast på mycket låga höjder, upp till ett par dm över nätet, sommätbara störningar kan förekomma. Om en armeringsmatta inte är permanentmagnetiserad kan den alltså inte skapa problem för ett flygplansnavigationssystem. Våra egna mätningar utförda med ett precisionsinstrumentöver ett armeringsnät styrker detta, bilaga 3. Kommer man att utsätta en banaför mycket starka magnetfält, till exempel från en magnetvagn, är det alltsåväsentligt att man väljer en typ av stålnätsarmering som inte kanmagnetiseras permanent. I den tredje frågan - hur känsliga är dagens ochkommande flygplan för störningar i jordens magnetfält - har vi kontaktatAerotechTelub som utvecklar instrument till såväl civila som militäraflygplan. De menar att problemet med störningar i magnetfältet får alltmindre betydelse eftersom utvecklingen går från traditionella kompasser ochmot system som inte är beroende av magnetfält. Vi har alltså funnit detsannolikt att de störningar som SGU redovisar har sin förklaring i permanentmagnetisering som framkallats av magnetvagnen i armeringsnät som är av annansort än vad som normalt används. Vi har därför också valt att kommentera ochförklara tillgängliga utredningar och inlägg utifrån den övertygelsen attproblem inte uppstår om man använder normalt armeringsstål.
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