A Few Questions About the Social-Obligation Norm

Reponse to an article by Gregory S. Alexander, \u27The Social-obligation Norm in American Property Law,\u27 in a Special Issue of the Journal on Property Obligation

Adsorption isotherms of H2_{2} and mixtures of H2_{2}, CH4_{4}, CO and CO2_{2} on copper plated stainless steel at 4.2 K

Adsorption isotherms in the pressure range 10$^{-11}$ to 10$^{-6} Torr have been measured for H$_2$and mixtures of H$_2$and CH$_4$, CO and CO$_2$on copper plated stainless steel at 4.2 K. The measurements have been focused on the behaviour of the isotherms at low surface coverage, up to a few monolayers of adsorbed gas on the cold surface. The isotherms were measured in a static situation with a small amount of gas injected for each point on the isotherm. Co-adsorption measurements of H$_2$with CH$_4$, CO and CO$_2$as well as adsorption of H$_2$on condensates of CH$_4$, CO and CO$_2$have been made. A cryotrapping effect of H$_2$is seen when co-adsorbing the gas mixtures, especially strong for the mixture of H$_2$and CO$_2$. The measurements show that CO$_2$condensed at 4.2 K may have a porous structure that H$_2$can penetrate, while CO and CH$_4$have rather dense structures when adsorbed at 4.2K. The measurements have been done within the framework of the Large Hadron Collider (LHC) project at CERN, Geneva, Switzerland, where superconducting magnets will be used to produce a magnetic field of about 9 T around the arcs of the 27 km long quasi-circular accelerator. Synchrotron radiation produced by the circulating proton beam in the superconducting magnets will induce desorption of neutral gas molecules, mainly H$_2$, CH$_4$, CO and CO$_2$, from the inner surface of the vacuum chamber. The desorbed gas molecules will be physisorbed on the cold surfaces in the vacuum chamber and they may induce vacuum instabilities in the accelerator. Hence it is of importance to have knowledge of the mixed adsorption isotherms of these gases at low temperatures

Images and plane waves : efficient field computation in electromagnetics and acoustics

In some simple or canonical problems, analytical solutions offer the most efficient way to compute the electromagnetic or acoustic fields. For arbitrary geometries, efficient numerical methods are needed. This thesis contains new or improved solutions of classical electrostatic problems and some further developments of a variant of the fast multipole method (FMM). In the first part, the electrostatic problems of pairs of both orthogonally intersecting and non-intersecting conducting spheres are solved using Kelvin's image theory. A new efficient method for evaluating the polarizability of two non-intersecting spheres is presented. Novel analytical solutions, and also computationally efficient approximative solutions, are obtained by applying Kelvin's inversion to the electrostatic image solution of a conducting wedge. Integral equation methods are popular for both electrodynamic and acoustic scattering problems. However, to be able to use very large number of unknowns, fast iterative methods, such as the fast multipole method, must be used. In the second part of this thesis, a new broadband variant of the multilevel fast multipole algorithm (MLFMA) is described and used for both acoustic and electromagnetic scattering problems. In particular, the implementation overcomes the low-frequency breakdown of the MLFMA using a combination of the spectral representation of the Green's function and Rokhlin's translation formula.reviewe

Dynamic Tyre Models in Adaptive Slip Control

When designing an automatic brake control system for a car it is important to have a mathematical model of the vehicle to base the design upon. Since careful modeling of the entire car would encompass far too many variables, the most care is usually taken to the wheels and the tyres, as those parts contain most of the dynamics influential to the process. During braking the tyres deform because of the forces between road and tyres. Because of this deformation the braking force from the brake discs is not immediately transmitted to road surface, resulting in a delay of the decelerating force. Tire models mainly aims at describing the friction force between tyre and road surface, and most does this with a function where the friction force is mapped as a static function of the relative velocity between vehicle and tyre. Such a static model considers the tyre to be so sti that it does not deform at all during braking, and does not take deformation into account when calculating the friction force. In this report it is investigated how influential the dynamics from the tire deformation are. By using measurement data from a real car a model for the dynamics is made. This model is made so that it can easily be added to already existing models of tyre and car. Then by the use of this model a controller is designed which takes the tire dynamics into account. It is implemented in simulink and compared to another controller that has been designed based on the non-dynamic tyre model

The effectiveness and cost-effectiveness of cognitive behavioral therapy administered in group or via the internet for patients with irritable bowel syndrome

Background Irritable Bowel Syndrome (IBS) is a benign but debilitating disorder. It is the most commonly diagnosed gastrointestinal condition and affects between 7-21% of the world’s population. It is characterized by abdominal pain and altered bowel habits. Patients with refractory IBS tend to develop behavioral avoidance that may severely affect life quality and lead to aggravated symptoms. Psychological treatment has emerged as a potent way of treating patients with IBS. Professor Brjánn Ljótsson at Karolinska Institutet has developed a cognitive behavioral treatment protocol specific for IBS. One of the core components in the treatment is exposure to feared stimuli such as specific foods or situations. Four different RCTs have proven the efficacy of the treatment. In randomized controlled trials the goal is to find a potential treatment effect and the setting is normally adjusted to eliminate confounding factors (i.e by careful selection of patients and by utilizing specially trained staff that is supervised during the treatment phase and by providing many examinations or questionnaires to patients). Clinical routine care may often differ from the context of a randomized controlled trial, and it is therefore important to examine the effectiveness of a potentially effective treatment under real world circumstances. When a new and potentially more effective treatment is developed health care managers must decide whether it should be implemented in routine care or not, and one of the important questions concerns the costs for the new treatment in comparison to already implemented methods. Knowledge regarding cost-effectiveness is therefore needed. Aims The general aim of the present thesis is to examine the real-world effectiveness of the exposure-based cognitive behavioral treatment (ECBT) our research group has developed and to evaluate its cost-effectiveness to provide managers in health care with a better foundation for good decisions. Specific aims of this theses were to: a) evaluate the cost-effectiveness from a societal perspective of the exposure component in the ECBT when delivered over the internet (study I), b) evaluate the real-world treatment effectiveness of the ECBT when delivered face-to-face in a group format and to investigate possible predictors of treatment outcome (study II), and to evaluate the real-world effectiveness of the ECBT when delivered over the internet and to replicate an earlier finding that behavioral change predicts symptom-reduction and thus a potential working mechanism of the treatment (study III). Methods Study I randomized 309 self-referred patients to internet-delivered CBT (ICBT) with or without exposure (WE) and examined the costs of the intervention as well as potential cost reductions for society and related them to treatment effects. Study II used data from the electronical medical record at a gastroenterological clinic and compared symptom burden before and after patents went through a group based ECBT face-to-face. The study included 129 patients with refractory IBS. Baseline data was used to try to create a prediction model for treatment outcome. Study III included 309 consecutively recruited patients at the Internet Psychiatry Unit who received a 12-week internet-based ECBT for IBS. The effectiveness of the treatment was calculated at the end of treatment and six months after treatment started. In the study a random intercept cross-lagged panel model was used to investigate the relationship between behavioral change and symptom reduction over time. Results In both effectiveness studies (studies II and III) the patients were significantly improved after treatment and the calculated effect sizes indicated that the treatment effect is large. In study II, 52.7% of the patients had a symptomatic reduction measured with GSRS-IBS of 30% or more which is considered a clinically significant improvement. There was not enough support for the construction of a prediction model based on pre-treatment characteristics that would predict symptomatic improvement. The cost-effectiveness study (study I) showed that the exposure component makes the treatment approximately 20% more expensive, but that the money invested in exposure pays back with almost 6 times the investment in saved expenses from a societal perspective during the six months following the treatment. There is an 84% chance that the ECBT will be more cost-effective than ICBT-WE if society is willing to pay no more for the ECBT than for the ECBT-WE. Finally, in study III, we also found support for the hypothesis that the symptom reduction patients experience after ECBT is related to behavior change during the treatment, prior to the outcome. Conclusion ECBT is highly effective, also under real world circumstances, both when delivered face-to-face and over the internet. The exposure component in the treatment is related to behavior change that in turn predicts treatment outcome, thus pointing to a possible chain of events partly explaining the working mechanism of the treatment. Lastly, we conclude that it is very cost-effective from a societal perspective to include exposure in the treatment since the extra costs are weighed out many times by saved expenses down the road

Cardiometabolic health in students and young adults with mild/moderate intellectual disabilities : results from a longitudinal follow-up study and a school intervention

Background Adults with intellectual disabilities (ID) develop the metabolic syndrome and cardiovascular disease more frequently than individuals without ID. The knowledge about cardiometabolic risk factors in adolescents with mild/moderate ID is scarce. Aims The aims were 1) to examine cardiometabolic health among adolescents with ID 2) to study the progress of cardiometabolic risk factors from adolescence to young adulthood among young adults with and without ID 3) to evaluate whether a health-promoting program in an upper secondary school for students with ID could reduce cardiometabolic risk factors 4) to evaluate whether the plate model pattern, inlayed in a specially designed lunch plate, increases vegetable intake. Material and Methods Sixty-six adolescents with mild/moderate ID, mean age 18.6y recruited from one upper secondary school for students with ID (year 1-4) were investigated in a cross sectional study (Paper I). Controls were 90 students without ID, mean age 17.8y, recruited from practical and theoretical programs at schools nearby. In the follow-up study five years later 35% (n=23) of the now young adults with ID and 33% (n =30) from the control group were re-investigated (Paper II). Measures were anthropometrics, blood pressure, DXA, fasting blood samples and a submaximal cardiovascular fitness test. The multifactorial school intervention was evaluated on last year students after two years of intervention (n = 11) and compared with their base-line data (Paper I) and with last year students in Paper I (Paper III). The special plate with the plate model inlayed was evaluated in an observational study. The intervention group (n = 27) had eaten on the special plate during school lunches for at least six months. The control group (n=62) was recruited from two other upper secondary schools for students with ID. Food intake was estimated from video recordings and digital photos (Paper IV). Results Adolescents with ID had a higher prevalence and severity of cardiometabolic risk factors together with low cardiovascular fitness compared to the control group. At follow-up as young adults (mean age 24.3) 35% were classified as obese and 22% had developed the metabolic syndrome. Those without ID from practical educational programs also developed cardiometabolic risk factors but they did not reach the same level as the group with ID. After two years of school intervention cardiometabolic risk factors had decreased and no one were obese. Evaluation of the special plate showed no difference in vegetable intake between intervention and control group. Eighty-eight percent ate ≥ 37.5% vegetables. The intervention group chose food with a lower fat content and with more carbohydrates, had less plate waste and took fewer portions. Conclusions Already during adolescence individuals with ID have more cardiometabolic risk factors than those without ID and as young adults individuals with ID in this study has a cardiometabolic health and cardiovascular fitness similar to the Swedish middle-age population. Actions to promote healthy living habits during school hours including the use of the special plate were promising. This indicates that it is not the ID condition itself but the effects ID has on the living conditions that causes the high cardiometabolic risk. Thus, the results in this thesis shows that initiatives especially designed for individuals with ID to promote healthier living habits are required and are likely to be effective

Electrostatic resonances of a negative-permittivity hemisphere

This article studies the electric response of an electrically small hemispherical object with negative permittivity by computing its polarizability which is determined by two orthogonal components, the axial one and the transverse one. A certain range of negative permittivity values is found where the mathematical determination of the polarizability becomes impossible due to an unlimited number of singularities. These singularities are due to surface plasmons, also referred to as electrostatic resonances, caused by the sharp edge of the hemisphere. It is also found that the planar surface of the hemisphere may support resonant surface modes. Furthermore, there exists a dipolar resonance determined by the overall geometry. In addition, it is shown that the resonances can be smoothened by introducing losses and, even more importantly, rounding the edge.Peer reviewe

Strategy for Neutralizing the Impact of Insertion Devices on the MAX IV 3 GeV Storage Ring

In order to prepare for the potentially negative influence of insertion devices (IDs) on beam lifetime, injection effi- ciency and beam size in the MAX IV 3 GeV storage ring, a strategy for neutralizing the foreseen effects of the IDs has been developed. The strategy involves a local correction of the betatron phase advance by adjusting the strength of the quadrupoles adjacent to the ID as well as a global tune correction in order to avoid drift of the working point of the storage ring during operation. Air coils with empirical feed forward tables for the excitation current will compen- sate for field integral errors. The lattice of the MAX IV 3 GeV storage ring appears to be robust and it tolerates the dynamic multipoles created by the expected initial set of IDs provided that the linear optics matching has been carried out

Resonances in small scatterers with impedance boundary

With analytical (generalized Mie scattering) and numerical (integral-equation-based) considerations we show the existence of strong resonances in the scattering response of small spheres with lossless impedance boundary. With increasing size, these multipolar resonances are damped and shifted with respect to the magnitude of the surface impedance. The electric-type resonances are inductive and magnetic ones capacitive. Interestingly, these subwavelength resonances resemble plasmonic resonances in small negative-permittivity scatterers and dielectric resonances in small high-permittivity scatterers. The fundamental dipolar mode is also analyzed from the point of view of surface currents and the effect of the change of the shape into a non-spherical geometry