Bio-ethanol valorization towards C4s including 1-butanol over metal modified alumina and zeolite catalysts

Bio-ethanol has been used as a fuel additive in modern society aimed at reducing CO2-emissions and dependence on oil. However, ethanol is unsuitable as fuel supplement in higher proportions due to its physico-chemical properties. One option to counteract the negative effects is to upgrade ethanol in a continuous fixed bed reactor to more valuable C4 products such as 1-butanol providing chemical similarity with traditional gasoline components. Bio-ethanol based valorization products also have other end-uses than just fuel additives. E.g. 1-butanol and ethyl acetate are well characterised industrial solvents and platform chemicals providing greener alternatives. The modern approach is to apply heterogeneous catalysts in the investigated reactions. The research was concentrated on aluminium oxide (Al2O3) and zeolites that were used as catalysts and catalyst supports. The metals supported (Cu, Ni, Co) gave very different product profiles and, thus, a profound view of different catalyst preparation methods and characterisation techniques was necessary. Additionally, acidity and basicity of the catalyst surface have an important role in determining the product profile. It was observed that ordinary determination of acid strength was not enough to explain all the phenomena e.g. the reaction mechanism. One of the main findings of the thesis is based on the catalytically active site which originates from crystallite structure. As a consequence, the overall evaluation of different by-products and intermediates was carried out by combining the information. Further kinetic analysis was carried out on metal (Cu, Ni, Co) supported self-prepared alumina catalysts. The thesis gives information for further catalyst developments aimed to scale-up towards industrially feasible operations.

PDM system functions and utilizations analysis to improve efficiency of sheet metal product design and manufacturing

This study will concentrate on Product Data Management (PDM) systems, and sheet metal design features and classification. In this thesis, PDM is seen as an individual system which handles all product-related data and information. The meaning of relevant data is to take the manufacturing process further with fewer errors. The features of sheet metals are giving more information and value to the designed models. The possibility of implementing PDM and sheet metal features recognition are the core of this study. Their integration should make the design process faster and manufacturing-friendly products easier to design. The triangulation method is the basis for this research. The sections of this triangle are: scientific literature review, interview using the Delphi method and the author’s experience and observations. The main key findings of this study are: (1) the area of focus in triangle (the triangle of three different point of views: business, information exchange and technical) depends on the person’s background and their role in the company, (2) the classification in the PDM system (and also in the CAD system) should be done using the materials, tools and machines that are in use in the company and (3) the design process has to be more effective because of the increase of industrial production, sheet metal blank production and the designer’s time spent on actual design and (4) because Design For Manufacture (DFM) integration can be done with CAD-programs, DFM integration with the PDM system should also be possible.

Nutrient cycling disturbance in Atlantic Forest sites affected by air pollution coming from the industrial complex of Cubatão, Southeast Brazil

Several aspects of nutrient cycling were studied at two sites of Atlantic Forest, in São Paulo State, Southeast Brazil (23o46’ S; 46o18’ W), which exhibited different degrees of forest structure decline caused by the air pollution emitted by the industrial complex of Cubatão, being referred here as the most and least affected sites (MAS and LAS, respectively). These investigations were developed during 1984 - 1986, a period in which the most severe negative effects of air pollution could be observed. Concentrations and amounts of N, P, K, Ca, Mg and S in four ecosystem compartments (leaves, litter layer, soil and roots) and in rainfall, throughfall and litterfall are briefly presented. At each site, the content of mineral elements generally decreased from leaves to litterfall and litter layer on the forest floor. Soil surface layer (0 - 5 cm) in both sites was the richest in mineral elements. Soil fertility was greater at LAS. In general, nutrient amounts remaining in the compartments and cycling through the ecosystem were greater at LAS as well, which could be due to the higher complexity of the forest structure at this site. Rainfall contributed more to soil inputs of K, Ca, Mg and S than litterfall at both sites. The nutrient residence times in the litter layer were higher and the index of nutrient use efficiency was lower at the most affected site. It was concluded that nutrient cycling was disturbed by air pollution at both sites, but to a greater extent at MAS. The main consequences of the air pollution stress were detected in the flux of nutrients through litterfall and in the litter layer on the forest floor.

Treatment of Fe-containing Acid Mine Waters in Fixed Bed Adsorption Column with Calcite Side-Stone

The acid mining drainage is considered the most significant environmental pollution problem around the world for the extensive formation acidic leachates containing heavy metals. Adsorption is widely used methods in water treatment due to it easy operation and the availability of a wide variety of commercial adsorbent (low cost). The primary goal of this thesis was to investigate the efficiency of neutralizing agents, CaCO3 and CaSiO3, and metal adsorption materials with unmodified limestone from Company Nordkalk Oy. In addition to this, the side materials of limestone mining were tested for iron adsorption from acidic model solution. This study was executed at Lappeenranta University of Technology, Finland. The work utilised fixed-bed adsorption column as the main equipment and large fluidized column. Atomic absorption spectroscopy (AAS) and x-ray diffraction (XRD) was used to determine ferric removal and the composition of material respectively. The results suggest a high potential for the studied materials to be used a low cost adsorbents in acid mine drainage treatment. From the two studied adsorbents, the FS material was more suitable than the Gotland material. Based on the findings, it is recommended that further studies might include detailed analysis of Gotland materials.

Megaspore germination and initial development of Regnellidium diphyllum Lindman (Pteridophyta, Marsileaceae) sporophytes in the presence of cadmium

Regnellidium diphyllum has its distribution restricted to Southern Brazil and adjoining localities in Uruguay and Argentina. Currently it is on the list of threatened species of Rio Grande do Sul. The conversion of wetlands into agricultural areas or soil contamination by the introduction of waste products and fertilizers may compromise the establishment and survival of this species. Among the pollutants are heavy metals, such as cadmium (Cd). Megaspores were germinated in liquid culture medium, with concentrations 0 (control), 0.39; 0.78; 1.56; 3.12; 6.25; 12.5; 25; 50 and 100 mg L-1 of Cd, starting from a standard solution of Titrisol® at 1000 mg L-1. The increase of Cd in the growth medium to 50 mg L-1 resulted in low germinability (58%), and no germination was observed on 100 mg L-1. In apomictical sporophytes, the growth of primary root and leaf was significantly reduced and no secondary leaf was formed at Cd concentrations of 12.5 and higher than this. The results indicated that R. diphyllum is tolerant to the presence of Cd up to considerably higher concentrations (0.78 mg L-1) than that normally found in unpolluted aquatic ecosystems (0.01 mg L-1), although the sensitivity to higher concentrations might endanger the establishment and permanence of this species in habitats exposed to contamination with this metal.

Artificial Ribonucleases: Oligonucleotides Conjugated with Metal Ion Chelates of Azacrowns

Ribonucleic acid (RNA) has many biological roles in cells: it takes part in coding, decoding, regulating and expressing of the genes as well as has the capacity to work as a catalyst in numerous biological reactions. These qualities make RNA an interesting object of various studies. Development of useful tools with which to investigate RNA is a prerequisite for more advanced research in the field. One of such tools may be the artificial ribonucleases, which are oligonucleotide conjugates that sequence-selectively cleave complementary RNA targets. This thesis is aimed at developing new efficient metal-ion-based artificial ribonucleases. On one hand, to solve the challenges related to solid-supported synthesis of metal-ion-binding conjugates of oligonucleotides, and on the other hand, to quantify their ability to cleave various oligoribonucleotide targets in a pre-designed sequence selective manner. In this study several artificial ribonucleases based on cleaving capability of metal ion chelated azacrown moiety were designed and synthesized successfully. The most efficient ribonucleases were the ones with two azacrowns close to the 3´- end of the oligonucleotide strand. Different transition metal ions were introduced into the azacrown moiety and among them, the Zn2+ ion was found to be better than Cu2+ and Ni2+ ions.

An account of a copy from the 15th century of a map of the world engraved on metal, which is preserved in cardinal Stephan Borgia's museum at Velletri

Erip.: Ymer 1891.

Welding of additively manufactured stainless steel parts: Comparative study between sheet metal and selective laser melted parts

Additive manufacturing is a fast growing manufacturing technology capable of producing complex objects without the need for conventional manufacturing process planning. During the process the work piece is built by adding material one layer at a time according to a digital 3D CAD model. At first additive manufacturing was mainly used to make prototypes but the development of the technology has made it possible to also make final products. Welding is the most common joining method for metallic materials. As the maximum part size of additive manufacturing is often limited, it may sometimes be required to join two or more additively manufactured parts together. However there has been almost no research on the welding of additively manufactured parts so far, which means that there has been very little information available on the possible differences compared to the welding of sheet metal parts. The aim of this study was to compare the weld joint properties of additively manufactured parts to those of sheet metal parts. The welding process that was used was TIG welding and the test material was 316L austenitic stainless steel. Weld joint properties were studied by making tensile, bend and hardness tests and by studying the weld microstructures with a microscope. Results show that there are certain characteristics in the welds of additively manufactured parts. The building direction of the test pieces has some impact on the mechanical properties of the weld. Nevertheless all the welds exhibited higher yield strength than the sheet metal welds but at the same time elongation at break was lower. It was concluded that TIG welding is a feasible process for welding additively manufactured parts.

Effects of formaldehyde on the frog's mucociliary epithelium as a surrogate to evaluate air pollution effects on the respiratory epithelium

The increasing use of alcohol as an alternative fuel to gasoline or diesel can increase emission of formaldehyde, an organic gas that is irritant to the mucous membranes. The respiratory system is the major target of air pollutants and its major defense mechanism depends on the continuous activity of the cilia and the resulting constant transportation of mucous secretion. The present study was designed to evaluate the effects of formaldehyde on the ciliated epithelium through a relative large dose range around the threshold limit value adopted by the Brazilian legislation, namely 1.6 ppm (1.25 to 5 ppm). For this purpose, the isolated frog palate preparation was used as the target of toxic injury. Four groups of frog palates were exposed to diluted Ringer solution (control, N = 8) and formaldehyde diluted in Ringer solution at three different concentrations (1.25, 2.5 and 5.0 ppm, N = 10 for each group). Mucociliary clearance and ciliary beat frequency decreased significantly in contact with formaldehyde at the concentrations of 2.5 and 5.0 ppm after 60 min of exposure (P<0.05). We conclude that relatively low concentrations of formaldehyde, which is even below the Brazilian threshold limit value, are sufficient to cause short-term mucociliary impairment.

Influence of season and pollution on the antioxidant defenses of the cichlid fish acará (Geophagus brasiliensis)

The livers of Geophagus brasiliensis collected from both a non-polluted site and a polluted site were analyzed for different antioxidant defenses, O2 consumption, thiobarbituric acid-reactive substance (TBARS) levels, and histological damage. Compared to controls (116.6 ± 26.1 nmol g-1), TBARS levels were enhanced at the polluted site (284.2 ± 25.6 nmol g-1), as also was oxygen consumption (86.6 ± 11.3 and 128.5 ± 9.8 µmol O2 min-1 g-1, respectively). With respect to enzymatic antioxidants, increased catalase activities (8.7 ± 1.3 and 29.2 ± 2.4 mmol min-1 g-1, respectively), unchanged superoxide dismutase activities (767.2 ± 113.3 and 563.3 ± 70.2 U g-1, respectively), and diminished glutathione S-transferase activities (29.0 ± 3.2 and 14.9 ± 3.2 µmol min-1 g-1, respectively) were detected. Reduced glutathione (1.91 ± 0.17 and 1.37 ± 0.25 mM, respectively), oxidized glutathione (1.50 ± 0.20 and 0.73 ± 0.17 mM, respectively), and total glutathione (3.40 ± 0.26 and 2.07 ± 0.27 mM, respectively) concentrations were also below control values at the polluted site. Nevertheless, the observed ethoxyresorufin-O-deethylase activities (1.34 ± 0.11 and 16.7 ± 0.21 pmol min-1 mg-1, respectively) showed enhanced values at the polluted site. The main histological damage observed in the hepatocytes from fish collected at the polluted site was characterized by heavy lipid infiltration. Fish collected at the end of spring showed higher O2 consumption, higher superoxide dismutase and glutathione S-transferase activities, and higher total and oxidized glutathione concentrations compared to the beginning of autumn. No seasonal changes were observed in catalase activities, glutathione or TBARS levels. Fish chronically exposed to relatively high pollution levels seem to be unable to set up adequate antioxidant defenses, probably due to severe injury to their hepatocytes. The higher antioxidant defenses found at the end of spring are probably related to the enhanced activities during high temperature periods in thermoconforming organisms.

Air pollution and neonatal deaths in São Paulo, Brazil

Air pollution has been associated with health effects on different age groups. The present study was designed to assess the impact of daily changes in air pollutants (NO2, SO2, CO, O3, and particle matter (PM10)) on total number of daily neonatal deaths (those that occur between the first and the 28th days of life) in São Paulo, from January 1998 to December 2000, since adverse outcomes such as neonatal deaths associated with air pollution in Brazil have not been evaluated before. Generalized additive Poisson regression models were used and nonparametric smooth functions (loess) were adopted to control long-term trend, temperature, humidity, and short-term trends. A linear term was used for holidays. The association between air pollutants and neonatal deaths showed a short time lag. Interquartile range increases in PM10 (23.3 µg/m³) and SO2 (9.2 µg/m³) were associated with increases of 4% (95% CI, 2-6) and 6% (95% CI, 4-8), respectively. Instead of adopting a two-pollutant model we created an index to represent PM10 and SO2 effects. For an interquartile range increase in the index an increase of 6.3% (95% CI, 6.1-6.5) in neonatal deaths was observed. These results agree with previous studies performed by our group showing the deleterious effects of air pollutants during the perinatal period. The method reported here represents an alternative approach to analyze the relationship between highly correlated pollutants and public health problems, reinforcing the idea of the synergic effects of air pollutants in public health.

Temperature, air pollution, and mortality from myocardial infarction in São Paulo, Brazil

An increase in daily mortality from myocardial infarction has been observed in association with meteorological factors and air pollution in several cities in the world, mainly in the northern hemisphere. The objective of the present study was to analyze the independent effects of environmental variables on daily counts of death from myocardial infarction in a subtropical region in South America. We used the robust Poisson regression to investigate associations between weather (temperature, humidity and barometric pressure), air pollution (sulfur dioxide, carbon monoxide, and inhalable particulate), and the daily death counts attributed to myocardial infarction in the city of São Paulo in Brazil, where 12,007 fatal events were observed from 1996 to 1998. The model was adjusted in a linear fashion for relative humidity and day-of-week, while nonparametric smoothing factors were used for seasonal trend and temperature. We found a significant association of daily temperature with deaths due to myocardial infarction (P < 0.001), with the lowest mortality being observed at temperatures between 21.6 and 22.6ºC. Relative humidity appeared to exert a protective effect. Sulfur dioxide concentrations correlated linearly with myocardial infarction deaths, increasing the number of fatal events by 3.4% (relative risk of 1.03; 95% confidence interval = 1.02-1.05) for each 10 µg/m³ increase. In conclusion, this study provides evidence of important associations between daily temperature and air pollution and mortality from myocardial infarction in a subtropical region, even after a comprehensive control for confounding factors.

Effect of air pollution on pediatric respiratory emergency room visits and hospital admissions

In order to assess the effect of air pollution on pediatric respiratory morbidity, we carried out a time series study using daily levels of PM10, SO2, NO2, ozone, and CO and daily numbers of pediatric respiratory emergency room visits and hospital admissions at the Children's Institute of the University of São Paulo Medical School, from August 1996 to August 1997. In this period there were 43,635 hospital emergency room visits, 4534 of which were due to lower respiratory tract disease. The total number of hospital admissions was 6785, 1021 of which were due to lower respiratory tract infectious and/or obstructive diseases. The three health end-points under investigation were the daily number of emergency room visits due to lower respiratory tract diseases, hospital admissions due to pneumonia, and hospital admissions due to asthma or bronchiolitis. Generalized additive Poisson regression models were fitted, controlling for smooth functions of time, temperature and humidity, and an indicator of weekdays. NO2 was positively associated with all outcomes. Interquartile range increases (65.04 µg/m³) in NO2 moving averages were associated with an 18.4% increase (95% confidence interval, 95% CI = 12.5-24.3) in emergency room visits due to lower respiratory tract diseases (4-day moving average), a 17.6% increase (95% CI = 3.3-32.7) in hospital admissions due to pneumonia or bronchopneumonia (3-day moving average), and a 31.4% increase (95% CI = 7.2-55.7) in hospital admissions due to asthma or bronchiolitis (2-day moving average). The study showed that air pollution considerably affects children's respiratory morbidity, deserving attention from the health authorities.

Metal additive manufacturing of internal flow channels with powder bed fusion processes

This thesis studies the advantages, disadvantages and possibilities of additive manufacturing in making components with internal flow channels. These include hydraulic components, components with cooling channels and heat exchangers. Processes studied in this work are selective laser sintering and selective laser melting of metallic materials. The basic principles of processes and parameters involved in the process are presented and different possibilities of internal channel manufacturing and flow improvement are introduced

Emission, kinetic and magnetic phenomena in rare-earth and transition metal doped ZnSe single crystals

In this work emission, optical, electrical and magnetic properties of the d- and f- elements doped zinc selenide crystals were investigated within a wide temperature range. Doping was performed in various technological processes: during the growth by chemical vapor transport method; by thermal diffusion from the Bi or Zn melt. Concentration of the doping impurity in the crystals was controlled by amount of the dopant in the source material or by its concentration in the doping media. Special interest in the work was paid to the influence of the different concentrations of Cr and Yb impurities on ZnSe crystals’ properties, correlations between observed effects and similarities with the Ni, Mn and Gd dopants are analysed. Possibility of formation of the excitons bound to the doping d-ions was shown. In contrast to this, it was observed that f-elements do not bound excitons, but prevent formation of excitons bound to some uncontrolled impurities. A mechanism of Cr doping impurity interaction with background impurities and zinc selenide structural defects was proposed based on experimental data. An assumption about resonant energy transfer between double charged chromium ions and complexes based on crystals’ vacancy defects was made. A correlation between emission and magnetic properties of the d- ions doped samples was established. Based on this correlation a mechanism explaining the concentration quench of the emission was proposed. It was found that f-ions bind electrically active shallow and deep donor and acceptor states of background impurity to electrically neutral complexes. This may be observed as “purification” of ZnSe crystals by doping with the rare-earth elements, resulting i tendency of the properties of f-ion doped crystals to the properties of intrinsic crystals, but with smaller concentration of uncontrolled native and impurity defects. A possible interpretation of this effect was proposed. It was shown that selenium substituting impurities decrease efficiency of the Yb doping. Based on this experimental results an attempt to determine ytterbium ion surroundings in the crystal lattice was made. It was shown that co-doping of zinc selenide crystals with the d- and f- ions leads to the combination of the impurities influence on the material’s properties. On the basis of obtained data an interaction mechanism of the d- and f-elements co-dopants was proposed. Guided by the model of the ytterbium ion incorporation in the selenide sublattice of the ZnSe crystals, an assumption about stabilization of single charged chromium ions in the zinc sublattice crystal nodes, by means of formation of the local charge compensating clusters, was made.