| 30861. |
- Malein, Viktor, et al.
(författare)
-
Culture, Economic Stress, and Missing Girls
- 2024
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Cultural norms play a pivotal role in shaping how societies respond to crises. This study examines the causal effect of ethnic-specific gender norms on gender-biased mortality during resource shocks. Studying the 1891-1892 Russian famine, we compare cohorts born before and after the famine in districts differentially affected by the famine and with diverse gender norms. Our findings reveal that areas where women were depicted more negatively suffered a more skewed sex ratio favouring male survival. Our empirical exercise further stresses the importance of the cultural channel in driving these results and emphasizes the role of agency in survival outcomes. This study sheds light on the profound influence of cultural norms on survival-relevant decisions during crises, pointing at culturally ingrained channels of discrimination.
|
|
| 30862. |
- Malein, Viktor
(författare)
-
Human Capital, Institutions and Development: Insights from German Migration in the Russian Empire
- 2023
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper examines the economic effects of German settlers on Imperial Russia’s transition to advanced industrialization in the late nineteenth and early twentieth century. Between 1763 and 1860, thousands of German migrants came to the country’s frontier regions, drawn by a state-sponsored settlement policy. Using accidental elements in German migration induced by policy, the paper demonstrates that the migrants generated significant long-term benefits in their regions through improved schooling infrastructure and increased literacy among the non-German population. The paper shows that educational improvements translated into higher growth of technologically advanced industries and increased the share of skillful occupations.
|
|
| 30863. |
- Malein, Viktor
(författare)
-
The Persistence of the Economic Power of Elites, Expansion of Education and Industrial Transition
- 2024
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper studies the economic impacts of land ownership concentration among the aristocratic elite in the Russian Empire. I document that areas with a higher concentration of noble land ownership were associated with lower levels of primary education during 1880-1911. Exploring the mechanisms, I show that by controlling local governments the landed elites decreased public spending on education, shifting the financial burden to peasant households. Furthermore, I demonstrate that the presence of large noble estates established constraints on educational demand by diminishing relative agricultural wages. Finally, the paper identifies a significant negative influence of landed elites on industrial growth and firm productivity, with up to 56% of this effect attributable to the human capital channel.
|
|
| 30864. |
- Malek, Laura, et al.
(författare)
-
Measuring and ensuring the gas quality of the Swedish gas grid
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- When there is more renewable gas being produced, and exported to the natural gas grid, there is a new situation for the grid operators which, in extension, creates new circumstances with respect to measuring and ensuring the gas quality on the grid. The renewable gas is today mainly produced by anaerobic digestion, but near-term future sources may be methane from thermochemical conversion of lignocellulose and hydrogen produced from intermittent electricity stemming from wind and solar resources; indeed, the first type of gas is currently demonstrated in the Swedish context in Gothenburg and the second type in Germany.
|
|
| 30865. |
- Malek, Laura
(författare)
-
Renewable gas in a Swedish context
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to increase the use of sustainable energy in Sweden, it is necessary to substitute fossil energy carriers with renewable counterparts. Synthetic natural gas (SNG) produced from renewable resources via biomass gasification and methanation could replace a proportion of the natural gas used in Sweden. In order to facilitate the implementation and expansion of SNG production and use in Sweden, development is necessary at multiple levels. In this thesis I have dentified and investigated possible improvements for three different levels: national distribution, industrial production and specific plant improvements. There is a clear advantage in using the existing Swedish gas grid for the transportation and distribution of renewable gas. However, in order to inject renewable gas into the gas grid, strategies are required for handling gases of mixed qualities. An industry-wide task group was formed to develop guidelines for mixed quality gas for the Swedish gas grid, and Lund University and E.ON were assigned the task of drawing upon experience from other European countries to identify suitable strategies. Two strategies were identified: the flow-weighted heating value method and the state reconstruction tool. As a result of the work performed by the task group, the Swedish gas industry standard has been updated to include these two methods. By integrating biomass gasification and the SNG production process with an existing host plant, it is possible to reduce the investment and operating costs, compared to stand-alone production, while simultaneously exploiting synergistic effects by exchanging material and energy streams with the host plant. The majority of the integrated systems studied showed a system efficiency equal to those of stand alone plants. The estimated SNG production cost for integrated cases is sufficiently low to compete with the cost of natural gas to household consumers, but not with the cost to commercial customers. It is imperative that SNG can be produced free from impurities in order to be approved for injection into the grid. Different aspects of gas cleaning technologies for tar and ammonia removal were studied. First, a proof-of-concept regenerative reverse flow reactor was constructed for thermal cracking of tars. This method showed the ability to crack tar compounds and has the potential to be a highly efficient process step in a biomass gasification gas-cleaning train. Secondly, the possibility of regenerating the spent scrubber liquid used for tar removal in gasification pants, via centrifugation, was studied in order to improve the process economy. The results showed that centrifugation is a suitable method for removing heavy insoluble tars from the scrubber liquid, thus extending its lifetime considerably. Lastly, the possibility of removing ammonia by reaction with nitrous oxides over a vanadium-based or zeolite catalyst was investigated. Neither of these catalysts was deemed suitable due to either poor conversion or deactivation of the catalyst over time. From the results of these studies, it was concluded that the current outlook for Swedish SNG production by biomass gasification is not very promising. As natural gas in Sweden is used mainly as a fuel for industrial heat and power production, producing renewable SNG from biomass would appear to be a wasteful detour compared to the direct combustion of the biomass. This is especially true as the production of SNG is currently not sufficiently efficient for SNG to be produced at a cost that is competitive with that of natural gas. Transforming biomass into a useful vehicle fuel would be a far better use of renewable resources. However, clear regulations regarding the end use of renewable SNG would then have to be developed.
|
|
| 30866. |
- Malik, Azhar
(författare)
-
Characteristic Properties and Applications of Fine Particles in Biomass Gasification
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The gasification of biomass is a promising route to increase the share of renewable sources in the energy mix. Besides having an overall higher thermal efficiency than combustion, it also offers the possibility of producing gaseous and liquid biofuels that can be used in the transport sector. The use of biomass gasification for energy purposes can help lower the net emissions of greenhouse gases, and hence help counter the global warming. One of the problems impeding the exploitation of this technology is the lack of efficient high-temperature cleaning systems to limit the release of fine particle contaminants after gasification. These contaminants can penetrate through the filters presently in use, and be deposited on the surfaces of integrated thermal plants leading to corrosion and on catalysts in downstream upgrading processes. Condensable material may also pass through the high-temperature filters in the gas phase, and form significant amounts of particulate matter if the temperature is decreased for operational reasons. The overall aim of this work was to develop methodologies to aid the further development of post-gasification high-temperature cleaning systems. It included the high-temperature dilution particle sampling techniques, detection of agglomerated soot particles using a novel sensor concept and the investigation of catalysts deactivation due to particulates present in the producer gas. To accomplish this, a laboratory-based method of generating well-characterized model aerosol particles was developed. These particles were compact KCl particles generated by a nebulizer in order to represent the alkali particles, and soot generated by a flame soot generator to represent agglomerated particles in the gasifier. Di-octyl-sebacate (DOS) was used to model tar forming compounds present in gasifier producer gas. The characteristic properties of the particles, such as size, concentration, morphology and mass fraction of organic coating, were analyzed using sophisticated on-line aerosol characterization techniques, including a Scanning Mobility Particle Sizer (SMPS), and a Differential Mobility Analyzer – heater – Aerosol Particle Mass Analyzer (DMA-heater-APM). This provided useful information regarding the morphology and density of agglomerated particulate with a condensed phase, which is not possible with the SMPS technique. The soot and KCl particles mixed with DOS were sampled with a probe-denuder setup at 200 °C, and the effects of the concentration of condensable material, the dilution ratio in the probe, and the flow rate through the denuder were investigated. This setup demonstrated the capacity to collect >99% of organics when the denuder inlet concentration of DOS was below 6 mg/m3. The soot sampling was also performed by replacing the denuder with a packed bed, which exhibited an enhanced collection capacity for condensable material for inlet concentrations of up to 15 mg/m3. The sampling system developed was used to sample particles from a circulating fluidized bed gasifier downstream of an existing filter to assess the filtration performance and to allow characterization of the particulates released from the gasifier. This demonstrated the usefulness of the setup by revealing the presence of coarse particles of calcium and silica from bed material, and fine particles dominated by K and Cl released from biomass feedstock. In catalytic activity measurements on Ni and Pt/Rh catalysts, it was found that potassium and soot particles could reduce the activity by up to 50% when the catalyst was exposed to very small amounts of model particles (soot 0.5 wt %; potassium 0.0038 wt %). The physical blocking of the active sites, and hence reduced active metal surface area is thought to be the main cause of activity loss. The model soot particles were also used to develop an online detection method for soot particles detection at the high temperatures. The performance of the soot sensor was satisfactory in the soot concentration limits tested, with the possibility of enhancing the sensitivity by improving the design. Such soot sensors could be installed after downstream cleaning devices in thermochemical conversion processes. The research presented in this thesis contributes to the development of effective cleaning systems in the biomass gasification process by improving our understanding of particle formation, deposition and catalyst deactivation mechanisms. This will help us move towards renewable energy sources in an efficient way.
|
|
| 30867. |
- Malina, Martin
(författare)
-
Endovascular Repair of Abdominal Aortic Aneurysms. Aspects on a Novel Technique
- 1998
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A new concept of treating abdominal aortic aneurysms was studied during a three-year period. Instead of open repair, graft insertion was accomplished endovascularly from the groins. The graft was attached by expandable stents to the non-dilated infrarenal aorta, i.e. the aneurysmal neck, and to the iliac artery/ies. Pre- and postoperative work-up included CT-scanning, angiography and ultrasonography on a regular basis. Six papers are included focusing on the fate of the excluded aneurysmal sac and on proximal stentgraft fixation. The median pulsatile wall motion of the sac was postoperatively reduced from 1 mm (I.Q.R 0.8 mm - 1.3 mm) to 0.3 mm (0.2 mm - 0.4 mm) and then remained stable. During the first year, the diameter of the sac was reduced by a median of 6 mm (2 mm 11 mm) but the neck dilated by 2 mm (0.5 - 3.5). Aneurysms with contrast accumulation in the sac (endoleak) were not reduced in size and the wall motion was ~50 % higher than expected. Rigid balloon-expanded stents detached in dilating porcine aortae. Self-expandable stents, on the other hand, complied with the pulsatile motion of the arterial walls and maintained apposition. In animal experiments, aortic stents placed over the renal arteries did not affect renal function and blood flow within one week. In a clinical trial, the proximal, graft anchoring stents, placed across the renal arteries, were not dislodged within six months. The renal function, as assessed by creatinine, CT-scanning, angiography and blood pressure was unaffected. Stents with hooks and barbs penetrating the aortic wall, improved stentgraft fixation tenfold in a cadaveric model.
|
|
| 30868. |
- Malinauskiene, Laura
(författare)
-
Contact allergy to textile dyes. Clinical and experimental studies on disperse azo dyes
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Disperse dyes are the most common allergens among textile dyes. It is not known whether the purified dyes, impurities in the commercial dyes, or metabolites are the actual sensitisers. Moreover, it is not known whether those disperse dyes that are now present in test series are actually used in textile dyeing today. The aim of this thesis was A) to evaluate the significance of the impurities found in the commercial dyes Disperse Orange 1 and Disperse Yellow 3 and their potential metabolites from azo reduction regarding contact allergy; B) to investigate the sensitising capacity of Disperse Orange 1 and its metabolites and their cross-reactivity to Disperse Yellow 3, its metabolites, and PPD; and C) to determine whether eight disperse dyes, hitherto the most widely quoted as allergenic, are still used in textiles sold in various countries all over the world. Evaluation of the many published studies on contact allergy to disperse dyes used for dyeing textiles was also performed. It was shown that the commercial dyes Disperse Orange 1 and Disperse Yellow 3 each contain at least one impurity acting as a sensitiser. Positive patch test reactions to Disperse Orange 1 and Disperse Yellow 3 were linked to positive reactions to some of their metabolites: p-aminodiphenylamine and 2 –amino-p-cresol, respectively. It was found that Disperse Orange 1 and p-aminodiphenylamine are strong sensitisers and cross-react with each other in the guinea pig maximisation test. PPD, 4-nitroaniline, 4-aminoacetanilide, 2-amino-p-cresol, or Disperse Yellow 3 did not show any cross-reactivity to them. Our observations did not directly support the metabolite theory, and the results regarding elicitation thresholds spoke against this theory. Available data in the medical literature indicated that positive patch test reaction prevalence rates to Disperse Blue 106 and 124, and Disperse Orange 3 were over 1% when screening dermatitis patients. From 121 analyzed items, Disperse Yellow 3, Disperse Blue 124 and 106 and Disperse Orange 1 were detected in three garments made in the European Union and India.
|
|
| 30869. |
|
|
| 30870. |
|
|
