| 161. |
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| 162. |
- Hedström, Brita, et al.
(författare)
-
Visby Innerstad : En användningsplan
- 1973
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Rapport (populärvet., debatt m.m.)abstract
- Sedan lång tid föreligger i stort sett enighet om att bevara innerstadens bebyggelse och att anpassa eventuella nytillskott till det redan bestående. Med den inställningen har förändringsprocessen både dämpats och mildrats men ändå inte bragts att avstanna. Förändringar sker ständigt om det också huvudsakligen i smått: de många synbart så anspråkslösa byggnadsåtgärderna adderar efterhand ihop sig till något större och mer genomgripande. Långsamt, nästan omärkligt, ändrar innerstaden sitt ansikte.Ändå är det inte själva husen som förändrats mest utan användningen av dem. Ur funktionell synpunkt har 1950 - och 60-talen har varit något av en omstörtning i innerstadens historia: den har förlorat nästan hälften av de boende, en stor del av detaljhandeln och praktiskt taget helt sin gamla roll som skolcentrum. I gengäld har ytterstaden vuxit ut till ett sammanhängande kilometerbrett bälte. Till stor del av denna funktionella förändring en följd av beslutet att bevara innerstadens bebyggelse. Vad som inte fått plats inom den gamla ramen har etablerats utandör den.Föreliggande arbete vill ge en översiktlig bild av förändringsförloppen, sedda i ett långt tidsperspektiv men med tonvikt på dagsläget. Bebyggelsen tas upp till utförlig granskning men också användningen av den. Det är just samspelet mellan husen och de funtkioner, de fyller, som kan sägas utgöra bokens huvudtema. I de flesta fall är detta sammanhang hus-användning alldeles konfliktfritt och föranleder därför inte heller någon diskussion. Vad som behandlas är de relativt få problematiska fallen, hus som borde rustas upp för att fylla sin uppgift, hus som är olämpligt nyttjade eller inte använda alls. En serie sådana fall tas upp till systematisk genomgång; samtidigt berörs också de trafik - och miljömässiga konsekvenserna. Bokens syfte är alltså klart: den ger ett underlag av fakta för arbetet med att jämka samman byggnader och användningsformer. I den meningen kan skriften kallas en anvädningsplan för Visby innanför murarna.Arkitekturskolanas arbete har bedrivitis parallellt med den kommunala Innerstadskommitténs verksamhet. Något organiserat samarbete har inte förekommit med de informella kontakterna har varit både täta och goda. Att likheterna mellan Innerstadskommittén och Arkitekturskolans slutsatser blivit så pass stora, kan tillskrivas en gemensam helhetssyn.En av Arkitekturskolans elever, arkitekt Lars-Ingvar Larsson, har tidigare självständigt genomfört en undersökning av förändringar i innerstaden 1945-70- Denna studie publicerats separat och bör uppfattas som ett komplement till den hör föreliggande.Förutom de i innehållsförteckningen nämnda har ytterligare några aktivt medverkat i arbetet. Studiet av trafikfrågorna i innerstaden, i hamnen och öster om ringmuren leddes av Åke Claesson, I fältstudier och diskussioner medverkande Göran Månsson.Arkitekturskolan har fått god hjälp av ett antal initierade personer i Visby. Särskild tacksamhet är vi skyldiga byggnadsnämnden ordförande Henning Jacobson, kommunalrådet C B Stenström, stadsarkitekten Måns Hagbergm f. länsbostadsdorektören Åke Malmberg och landsantikvarien Gunnar Svahnström. I boken publiceringskostnaderna har ekonomiskt bidrag lämnats av Gotlands kommun och Riksantikvarieämbetet.Boken har redigerats av Sture Balgård och Ann Mari Westerlind med hjälp av Henrik O Andersson, Bo Ek, Göran Lindahl, Fredrik von Platen, John Sjöström Gunnar Westerlind och Hans Wetterfors.Skeppsholmen, Stockholm, sommaren 1973.Arkitekturskolans lärare och elever.
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| 163. |
- Hsu, Ying-Jui, et al.
(författare)
-
Development of a high pressure stirring cell up to 2 GPa : a new window for chemical reactions and material synthesis
- 2020
-
Ingår i: High Pressure Research. - : Informa UK Limited. - 0895-7959 .- 1477-2299. ; 40:3, s. 358-368
-
Tidskriftsartikel (refereegranskat)abstract
- A new method for stirring under high pressure conditions has been developed and tested. The key component is a Teflon cell assembly equipped with magnetic stirring function, which is capable to operate across a wide pressure range, up to at least 2 GPa, in a large volume press. The setup enables adjustable stirrer rotation rate and detection of stirring in a sample,e.g.to observe liquid-solid phase transitions at high pressure. The viscosity limit of stirring is ca. 500 times that of water at room temperature (i.e.similar to 500 mPas). Moreover, we show that zinc oxide nanoparticles hydrothermally synthesized at 0.5 GPa and 100 degrees C under stirring conditions show an order of magnitude smaller size (100 nm) compared to those synthesized under non-stirring conditions (1 mu m). The wide pressure range for stirring of viscous media opens interesting possibilities to produce novel materials via hydrothermal synthesis and chemical reactions.
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| 164. |
- Hudson, John A., et al.
(författare)
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Guidance on numerical modelling of thermo-hydro-mechanical coupled processes for performance assessment of radioactive waste repositories
- 2005
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - : Elsevier BV. - 1365-1609 .- 1873-4545. ; 42:5-6, s. 850-870
-
Tidskriftsartikel (refereegranskat)abstract
- This paper provides advice on how to incorporate thermo-hydro-mechanical (THM) coupled processes into performance and safety assessments and design studies for radioactive waste disposal in geological formations. The advice is based on work conducted for the EU research project BENCHPAR: "Benchmark Tests and Guidance on Coupled Processes for Performance Assessment of Nuclear Waste Repositories". In Section 1, there is an explanation of why numerical analyses incorporating THM mechanisms are required for radioactive waste studies and background material on the subject is provided. Then, the THM processes and their interactions are explained in Section 2. Three case examples of THM numerical analysis are presented in Section 3 to illustrate the type of work that can be conducted to study the near-field, upscaling, and the far-field. The importance and priority of the THM couplings are summarized in Section 4. Recommended soft and hard auditing procedures are presented in Section 5. We place special emphasis on the fact that the most important step in numerical modelling is not executing the calculations per se, but the earlier conceptualization of the problem regarding the dominant processes, the material properties and parameters, the engineering perturbations, and their mathematical presentations. The associated modelling component of addressing the uncertainties and estimating their influence on the results is also important. Thus, the specific models and codes should be studied first to evaluate the harmony between the nature of the problem and the nature of the codes. The tactical use of particular numerical techniques will then be based on a sound strategic foundation. An associated listing of bullet point recommendations and issues for future directions for this THM subject area is given in Section 6.
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| 165. |
- Inaba, Akira, et al.
(författare)
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Multiple glass transitions and two step crystallization for the binary system of water and glycerol
- 2007
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Ingår i: Thermochimica Acta 461, issue 1-2. - : Elsevier BV. ; , s. 44-49
-
Konferensbidrag (refereegranskat)abstract
- Glass formation/crystallization phenomena were studied in water and glycerol mixtures using adiabatic calorimetry. The sample was cooled rapidly from room temperature and its thermal response was followed on heating from 80 to 300 K. The binary mixtures with the glycerol contents more than 55% (w/w) (19 mol%) yielded the homogeneous glassy states, consisting of randomly mixed water and glycerol molecules. Their glass transition temperatures showed the composition dependence of the Gordon-Taylor equation, and extrapolated exactly to that of pure water (135 K). The mixtures in the 0-55% (w/w) glycerol range crystallized partly on cooling and exhibited three anomalies in the temperature drift rate on heating. The first of these three is associated with the onset of reorientational motions of water molecules in the hexagonal ice which increases from 107 to 120 K on increasing the glycerol composition. The second is the composition independent temperature of 164 K that corresponds to the mixture with 76% (w/w) glycerol (38 mol%, known as the maximally freeze-concentrated solution), which is the mixture with the maximum composition of water that can be cooled without crystallization. The third is associated with the ice crystallization followed by ice dissolution in the range 185-202 K. In addition, the sample with 60% (w/w) glycerol composition (23 mol%) exhibited two distinguishable exothermic peaks on heating. The initial one is large and is attributed to crystallization into a novel two-dimensionally ordered structure of ice, and the second is due to the transformation of the layered structures into the hexagonal ice.
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| 166. |
- Johansson, Andreas, et al.
(författare)
-
Influence from the cross-angle on piston forces and bending moments in variable hydraulic piston pumps
- 2003
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- By implementing an additional incline (cross-angle) of the swash plate of an axial piston pump, in the direction perpendicular to the traditional displacement direction, the piston dead-centre points will move as the displacement angle varies. The cross-angle is fixed and normally very small (1-4°). If designed correctly, the movement of the dead-centre points achieved by using a cross-angle coincides with the dead centres desired for optimal cylinder pre-compression and decompression for all displacement angles. It has in earlier works been described how the cross-angle enables minimisation of discharge and inlet peak-to-peak flow ripple for all displacement angles simultaneously. In this paper, it is also investigated how the piston forces and the bending moments are influenced.The cross-angle is designed using simulation-based multi-objective optimisation. It is investigated how objective functions can be made up from peak-to-peak values as well as from frequency spectrum of signals. The trade-offs between the conflicting objectives considered are elucidated by using the concept of Pareto optimality. The result from such a Pareto optimisation is not one optimal solution, but a set of optimal solutions. With the technique presented, it is thus possible to investigate an optimal value for the cross-angle that the most beneficial impact on all factors that influence the noise level of the pump.
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| 167. |
- Johansson, Andreas, et al.
(författare)
-
Optimal design of the cross-angle for pulsation reduction in variable displacement pumps
- 2002
-
Ingår i: Power Transmission and Motion Control: PTMC 2002. - : Wiley-Blackwell. - 1860583792 - 9781860583797 ; , s. 319-333
-
Konferensbidrag (refereegranskat)abstract
- The cross-angle, illustrated in this paper, is a fixed displacement angle around the axis perpendicular to the normal trunnion axis. With the cross-angle, the traditional piston dead centres will change as the normal displacement angle is varied. The result is a behaviour similar to thal of the revolving valve plate technique. but without any movable parts. When the cross-angle is used in a constant pressure system with a variable pump, the desired dead centre for optimal pro-compression coincides with the obtained dead centre for a wide range of displacement angles. This implies that when the cross-angle is used, the flow ripple becomes less sensitive to changes in displacement angles. The cross-angle does not constitute an alternative to the different design features developed, but rather as complement for preserved effective flow ripple reduction over a wide range of displacement angles.ln this study. simulation-based optimisations, employing non-gradient optimisation techniques such as genetic algorithms and the Complex method, are used in order to find the optimal cross-angle for a variable displacement pump. Furthermore. with the help of optimisation, the trade-offs between attributes such as low flow ripples, avoidance of large cylinder pressure-peaks, and cavitation have been studied. Increased insight is thereby gained into what possibilities the cross-angle offers regarding reduction of pump ripple for a variable displacement pump.
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| 168. |
- Johansson, Jan-Erik, et al.
(författare)
-
Natural history of early, localized prostate cancer
- 2004
-
Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 291:22, s. 2713-2719
-
Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Among men with early prostate cancer, the natural history without initial therapy determines the potential for survival benefit following radical local treatment. However, little is known about disease progression and mortality beyond 10 to 15 years of watchful waiting. OBJECTIVE: To examine the long-term natural history of untreated, early stage prostatic cancer. DESIGN: Population-based, cohort study with a mean observation period of 21 years. SETTING: Regionally well-defined catchment area in central Sweden (recruitment March 1977 through February 1984). PATIENTS: A consecutive sample of 223 patients (98% of all eligible) with early-stage (T0-T2 NX M0 classification), initially untreated prostatic cancer. Patients with tumor progression were hormonally treated (either by orchiectomy or estrogens) if they had symptoms. MAIN OUTCOME MEASURES: Progression-free, cause-specific, and overall survival. RESULTS: After complete follow-up, 39 (17%) of all patients experienced generalized disease. Most cancers had an indolent course during the first 10 to 15 years. However, further follow-up from 15 (when 49 patients were still alive) to 20 years revealed a substantial decrease in cumulative progression-free survival (from 45.0% to 36.0%), survival without metastases (from 76.9% to 51.2%), and prostate cancer-specific survival (from 78.7% to 54.4%). The prostate cancer mortality rate increased from 15 per 1000 person-years (95% confidence interval, 10-21) during the first 15 years to 44 per 1000 person-years (95% confidence interval, 22-88) beyond 15 years of follow-up (P =.01). CONCLUSION: Although most prostate cancers diagnosed at an early stage have an indolent course, local tumor progression and aggressive metastatic disease may develop in the long term. These findings would support early radical treatment, notably among patients with an estimated life expectancy exceeding 15 years.
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| 169. |
- Johari, G.P., et al.
(författare)
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Effects of pressure-temperature protocols on the properties of crystals and ageing effects : an analogy with glasses
- 2022
-
Ingår i: Philosophical Magazine. - : Taylor & Francis. - 1478-6435 .- 1478-6443. ; 102:4, s. 299-320
-
Tidskriftsartikel (refereegranskat)abstract
- Properties of a crystal are used to determine the point defects concentration, n, the self diffusion coefficient, D and variation of n and D with tempertaure, T. Also, spontaneous change in the properties of a crystal’s non-equilibrium state is used to determine the decrease in n with time. Both n and D decrease with increase in the pressure, P, until the pressurising-rate dependent, kinetic-freezing pressure for defects disorder, PD-F, is reached. At P > PD-F, a crystal is in a non-equilibrium state. We consider such configurationally-frozen states of a crystal produced by using three unusual P-T protocols: (i) pressurising a crystal to P > PD-F, cooling to a low T and depressurising, (ii) pressurising to P < PD-F, cooling through the defects freezing temperature, TD-F, and depressurising, and (iii) cooling a crystal at 1 bar to T D-F pressurising and maintaining at high P. The non-equilibrium state of the crystal would have defect concentration that kinetically froze at P = PD-F or T = TD-F, but its volume and phonon properties would not correspond to the kinetically-frozen state at P = PD-F or at T = TD-F. On aging, their properties would change differently than those of a non-equilibrium state of a crystal produced by quenching at a fixed P. We relate n, D and the electrical resistivity to thermal conductivity, κ, by the Wiedemann-Franz equation, and discuss how κ would change on aging of a crystal. The above-given effects alter the properties of metallic and non-metallic, metastable materials during their commercial use.
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| 170. |
- Johari, G. P., et al.
(författare)
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Effects of stacking disorder on thermal conductivity of cubic ice
- 2015
-
Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 143:5
-
Tidskriftsartikel (refereegranskat)abstract
- Cubic ice is said to have stacking disorder when the H2O sequences in its structure (space group Fd (3) over barm) are interlaced with hexagonal ice (space group P6(3)/mmc) sequences, known as stacking faults. Diffraction methods have shown that the extent of this disorder varies in samples made by different methods, thermal history, and the temperature T, but other physical properties of cubic and hexagonal ices barely differ. We had found that at 160 K, the thermal conductivity, kappa, of cubic ice is similar to 20% less than that of hexagonal ice, and this difference varies for cubic ice samples prepared by different methods and/or subjected to different thermal history. After reviewing the methods of forming cubic ice, we report an investigation of the effects of stacking disorder and other features by using new data, and by analyzing our previous data on the dependence of kappa on T and on the pressure. We conclude that the lower kappa of cubic ice and its weaker T-dependence is due mainly to stacking disorder and small crystal sizes. On in situ heating at 20-50 MPa pressure, kappa increases and cubic ice irreversibly transforms more sharply to ice Ih, and at a higher T of similar to 220 K, than it does in ex situ studies. Cooling and heating between 115 and 130 K at 0.1 K min(-1) rate yield the same kappa value, indicating that the state of cubic ice in these conditions does not change with time and T. The increase in kappa of cubic ice observed on heat-annealing before its conversion to hexagonal ice is attributed to the loss of stacking faults and other types of disorders, and to grain growth. After discussing the consequences of our findings on other properties, we suggest that detailed studies of variation of a given property of cubic ice with the fraction of stacking faults in its structure may reveal more about the effect of this disorder. A similar disorder may occur in the mono-layers of H2O adsorbed on a substrate, in bulk materials comprised of two dimensional layers, in diamond and in Zirconium and in numerous other crystals.
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