| 61. |
- Carlsson, Bo, et al.
(författare)
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The Swedish industrial support program of the 1970s revisited
- 2018
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Ingår i: Journal of evolutionary economics. - : Springer. - 0936-9937 .- 1432-1386. ; 28:4, s. 805-835
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Tidskriftsartikel (refereegranskat)abstract
- The economy-wide dynamic cost-benefit study of the Swedish industrial subsidy program 1976 through 1984 (Carlsson et al. Res Policy 10(43):336-354 1981; Carlsson J Ind Econ 32(1):9-14, 1983a, b) is revisited in light of later economic development. Since the Swedish Micro to Macro model (Eliasson Am Econ Rev 67(1):277-281 1977a, 2017a) was used for quantification, this article is both (1) a study on the calibration of high dimensional micro-based and nonlinear economic systems models, and (2) a post inquiry into the empirical credibility of the cost-benefit calculations performed. We find that the Micro-based Macro model represents the minimum of detailed resolution necessary for the dynamic cost benefit calculations of the micro interventions in the Swedish economy we study. Even though the increased model complexity meant significant parameter calibration difficulties, a thoroughly researched model specification with exactly defined policy interfaces (with the markets of the economy) should take priority over parameter estimation problems, and always be preferred to estimating the parameters of a wrongly specified model perfectly. The oil price shocks of the 1970s caused radical market disorder in the western economies, bankrupting some 35% of Swedish manufacturing and threatening the Swedish government with massive unemployment. We confirm the earlier results that the government choice of a radical employment rescue policy came at enormous social cost in the form of economic stagnation, and still did not prevent the unemployment of the rest of OECD Europe from hitting Sweden a decade later, and persisting well into the next millennium. According to an alternative simulated policy scenario on the model, had the subsidies been replaced with a general lowering of the payroll tax of the same magnitude and the consequent increase in unemployment taken immediately during 1976-1980, production structures would have been radically and rapidly reorganized, normal employment would have been rapidly restored, and neither the stagnation nor the radical increase in unemployment of the early 1990s would have occurred. In retrospect we see no reason to worry about the empirical credibility of this computed dynamic trade off between Keynesian demand and Schumpeterian supply effects (caused by resource reallocations and endogenous structural change due to the price change), as we did then. We conclude with certainty that this trade-off would not even have been discovered as a possibility had we used a traditional model that did not embody these micro-macro linkages.
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| 62. |
- Carlsson, Lars, et al.
(författare)
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Enhanced systolic myocardial function in elite endurance athletes during combined arm-and-leg exercise
- 2011
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 111:6, s. 905-913
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Tidskriftsartikel (refereegranskat)abstract
- The aim here was to employ color tissue velocity imaging (TVI), to test the hypothesis that highly trained endurance athletes exhibit enhanced systolic function of the left ventricular (LV) myocardium both at rest and during combined arm-and-leg exercise in comparison with untrained subjects. For each of the ten elite male (EG) and ten matched control participants (CG), LV dimensions and systolic function were assessed at rest using echocardiography. Subsequently, these subjects exercised continuously on a combined arm-and-leg cycle ergometer for 3 min each at 50, 60, 70, 80, 90 and 100% of VO2max. Oxygen uptake, heart rate, systolic blood pressure (SBP) and peak contraction systolic velocities of the LV myocardium (PSV) were recorded in the end of each level. At rest, the trained and untrained groups differed with respect to LV dimensions, but not systolic function. At 60–100% VO2max, the EG group demonstrated both higher PSV and SBP. The observation that the EG athletes had higher PSV than CG during exercise at 60–100% VO2max, but not at rest or at 50% of VO2max, suggested an enhanced systolic capacity. This improvement is likely to be due to an enhanced inotropic contractility, which only becomes apparent during exercise.
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| 63. |
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| 64. |
- Carrick, Christopher, et al.
(författare)
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Lightweight, Highly Compressible, Noncrystalline Cellulose Capsules
- 2014
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 30:26, s. 7635-7644
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate how to prepare extraordinarily deformable, gas-filled, spherical capsules from nonmodified cellulose. These capsules have a low nominal density, ranging from 7.6 to 14.2 kg/m(3), and can be deformed elastically to 70% deformation at 50% relative humidity. No compressive strain-at-break could be detected for these dry cellulose capsules, since they did not rupture even when compressed into a disk with pockets of highly compressed air. A quantitative constitutive model for the large deformation compression of these capsules is derived, including their high-frequency mechanical response and their low-frequency force relaxation, where the latter is governed by the gas barrier properties of the dry capsule. Mechanical testing corroborated these models with good accuracy. Force relaxation measurements at a constant compression rendered an estimate for the gas permeability of air through the capsule wall, calculated to 0.4 mL mu m/m(2) days kPa at 50% relative humidity. These properties taken together open up a large application area for the capsules, and they could most likely be used for applications in compressible, lightweight materials and also constitute excellent model materials for adsorption and adhesion studies.
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| 65. |
- Castleton, Christopher, 1969-, et al.
(författare)
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Managing the supercell approximation for charged defects in semiconductors : Finite-size scaling, charge correction factors, the band-gap problem, and the ab initio dielectric constant
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:035215, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- The errors arising in ab initio density functional theory studies of semiconductor point defects using the supercell approximation are analyzed. It is demonstrated that (a) the leading finite size errors are inverse linear and inverse cubic in the supercell size and (b) finite size scaling over a series of supercells gives reliable isolated charged defect formation energies to around +-0.05 eV. The scaled results are used to test three correction methods. The Makov-Payne method is insufficient, but combined with the scaling parameters yields an ab initio dielectric constant of 11.6+-4.1 for InP. Gamma point corrections for defect level dispersion are completely incorrect, even for shallow levels, but realigning the total potential in real-space between defect and bulk cells actually corrects the electrostatic defect-defect interaction errors as well. Isolated defect energies to +-0.1 eV are then obtained using a 64 atom supercell, though this does not improve for larger cells. Finally, finite size scaling of known dopant levels shows how to treat the band gap problem: in < or = 200 atom supercells with no corrections, continuing to consider levels into the theoretical conductin band (extended gap) comes closest to experiment. However, for larger cells or when supercell approximation errors are removed, a scissors scheme stretching the theoretical band gap onto the experimental one is in fact correct.
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| 66. |
- Castleton, C W M, et al.
(författare)
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Finite-size scaling as a cure for supercell approximation errors in calculations of neutral native defects in InP
- 2004
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 70:19, s. 195202-
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Tidskriftsartikel (refereegranskat)abstract
- The relaxed and unrelaxed formation energies of neutral antisites and interstitial defects in InP are calculated using ab initio density functional theory and simple cubic supercells of up to 512 atoms. The finite-size errors in the formation energies of all the neutral defects arising from the supercell approximation are examined and corrected for using finite-size scaling methods, which are shown to be a very promising approach to the problem. Elastic errors scale linearly, while the errors arising from charge multipole interactions between the defect and its images in the periodic boundary conditions have a linear plus a higher order term, for which a cubic provides the best fit. These latter errors are shown to be significant even for neutral defects. Instances are also presented where even the 512 atom supercell is not sufficiently converged. Instead, physically relevant results can be obtained only by finite-size scaling the results of calculations in several supercells, up to and including the 512 atom cell and in extreme cases possibly even including the 1000 atom supercell.
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| 67. |
- Chen, Fei, et al.
(författare)
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Chitosan extrusion at high solids content : An orthogonal experimental design study
- 2014
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Ingår i: Polymers from Renewable Resources. - : SAGE Publications. - 2041-2479 .- 2045-1377. ; 5:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- For economic reasons and to save time there is a need to shorten the drying operation associated with the production of chitosan materials. Hence it is of interest to extrude chitosan at as high a solids content as possible. This is, to our knowledge, the first systematic study of the extrusion of chitosan at high solids content (60 wt%). An orthogonal experimental design was used to evaluate the effect of processing conditions and material factors on the extrudability of chitosan. This, together with the examination of the evenness and surface finish of the extrudate, made it possible to determine the best conditions for obtaining a readily extrudable high quality material. It was observed that a 1/1 ratio of chitosans with molar masses of 12 and 133 kDa, a process liquid containing 30 wt% acetic acid and 70 wt% water, and extrusion at 50 rpm and 50°C were the optimal material and processing conditions. Materials processed under these conditions were evaluated mechanically at different times after extrusion (stored at 50% RH) in order to see when the properties stabilized. Most mass loss occurred within the first three days after extrusion and this governed the mechanical properties (stiffness and extensibility), which also exhibited the largest changes within these three days (an increase in modulus from 18 to 830 MPa and a decrease in elongation at break from 17 to 3%).
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| 68. |
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| 69. |
- Cortes Ruiz, Maria F., et al.
(författare)
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Shape-recovering nanocellulose networks : Preparation, characterization and modeling
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 315, s. 120950-
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Tidskriftsartikel (refereegranskat)abstract
- Development of strong cellulose nanofibril (CNF) networks for advanced applications, such as in the biomedical field, is of high importance owing to the biocompatible nature and plant-based origin of cellulose nanofibrils. Nevertheless, lack of mechanical strength and complex synthesis methods hinder the application of these ma-terials in areas where both toughness and manufacturing simplicity are required. In this work, we introduce a facile method for the synthesis of a low solid content (< 2 wt%), covalently crosslinked CNF hydrogel where Poly (N-isopropylacrylamide) (NIPAM) chains are utilized as crosslinks between the nanofibrils. The resulting net-works have the capability to fully recover the shape in which they were formed after various drying and rewetting cycles. Characterization of the hydrogel and its constitutive components was performed using X-ray scattering, rheological investigations and uniaxial testing in compression. Influence of covalent crosslinks was compared with networks crosslinked by the addition of CaCl2. Among other things the results show that the mechanical properties of the hydrogels can be tuned by controlling the ionic strength of the surrounding me-dium. Finally, a mathematical model was developed based on the experimental results, which describes and predicts to a decent degree the large-deformation, elastoplastic behavior, and fracture of these networks.
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| 70. |
- Cozzolino, Carlo A., et al.
(författare)
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Dye release behavior from polyvinyl alcohol films in a hydro-alcoholic medium : Influence of physicochemical heterogeneity
- 2012
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Ingår i: Colloids and Surfaces A. - : Elsevier BV. - 0927-7757 .- 1873-4359. ; 403, s. 45-53
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we investigated the release kinetics of a model drug-like compound (Coomassie brilliant blue) from polyvinyl alcohol (PVOH) films into a hydro-alcoholic solution as a function of the physicochemical properties of the polymer matrix. After 33 days of monitoring, the total amount released ranged from 10% for the high hydrolysis degree/low molecular weight PVOH films to 60% for the low hydrolysis degree/low molecular weight films. Mathematical modeling allowed for an estimation of the two diffusion coefficients (D 1 and D 2) that characterized the release profile of the dye from the films. The degree of hydrolysis dramatically affected both the morphology and the physical structure of the polymer network. A high hydroxyl group content was also associated with the shifting of second order and first order transitions toward higher temperatures, with a concurrent increase in crystallinity. Moreover, the higher the degree of hydrolysis, the higher the affinity of the polymer to the negatively charged molecule dye. Selection of the polymer matrix based on physicochemical criteria may help in achieving different release patterns, thereby representing the first step for the production of polymer systems with modulated release properties.
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