Use of biomass fuels in the brick-making industries of Sudan: Implications for deforestation and greenhouse gas emission

The study focuses on the potential roles of the brick making industries in Sudan in deforestation and greenhouse gas emission due to the consumption of biofuels. The results were based on the observation of 25 brick making industries from three administrative regions in Sudan namely, Khartoum, Kassala and Gezira. The methodological approach followed the procedures outlined by the Intergovernmental Panel on Climate Change (IPCC). For predicting a serious deforestation scenario, it was also assumed that all of wood use for this particular purpose is from unsustainable sources. The study revealed that the total annual quantity of fuelwood consumed by the surveyed brick making industries (25) was 2,381 t dm. Accordingly, the observed total potential deforested wood was 10,624 m3, in which the total deforested round wood was 3,664 m3 and deforested branches was 6,961 m3. The study observed that a total of 2,990 t biomass fuels (fuelwood and dung cake) consumed annually by the surveyed brick making industries for brick burning. Consequently, estimated total annual emissions of greenhouse gases were 4,832 t CO2, 21 t CH4, 184 t CO, 0.15 t N20, 5 t NOX and 3.5 t NO while the total carbon released in the atmosphere was 1,318 t. Altogether, the total annual greenhouse gases emissions from biomass fuels burning was 5,046 t; of which 4,104 t from fuelwood and 943 t from dung cake burning. According to the results, due to the consumption of fuelwood in the brick making industries (3,450 units) of Sudan, the amount of wood lost from the total growing stock of wood in forests and trees in Sudan annually would be 1,466,000 m3 encompassing 505,000 m3 round wood and 961,000 m3 branches annually. By considering all categories of biofuels (fuelwood and dung cake), it was estimated that, the total emissions from all the brick making industries of Sudan would be 663,000 t CO2, 2,900 t CH4, 25,300 t CO, 20 t N2O, 720 t NOX and 470 t NO per annum, while the total carbon released in the atmosphere would be 181,000 t annually.

Informational efficiency of the European Union emission allowance market

This thesis studies the informational efficiency of the European Union emission allowance (EUA) market. In an efficient market, the market price is unpredictable and profits above average are impossible in the long run. The main research problem is does the EUA price follow a random walk. The method is an econometric analysis of the price series, which includes an autocorrelation coefficient test and a variance ratio test. The results reveal that the price series is autocorrelated and therefore a nonrandom walk. In order to find out the extent of predictability, the price series is modelled with an autoregressive model. The conclusion is that the EUA price is autocorrelated only to a small degree and that the predictability cannot be used to make extra profits. The EUA market is therefore considered informationally efficient, although the price series does not fulfill the requirements of a random walk. A market review supports the conclusion, but it is clear that the maturing of the market is still in process.

Quality of ALICE SSD modules revealed by electrical tests

ALICE (A Large Ion Collider Experiment) is an experiment at CERN (European Organization for Nuclear Research), where a heavy-ion detector is dedicated to exploit the unique physics potential of nucleus-nucleus interactions at LHC (Large Hadron Collider) energies. In a part of that project, 716 so-called type V4 modules were assembles in Detector Laboratory of Helsinki Institute of Physics during the years 2004 - 2006. Altogether over a million detector strips has made this project the most massive particle detector project in the science history of Finland. One ALICE SSD module consists of a double-sided silicon sensor, two hybrids containing 12 HAL25 front end readout chips and some passive components, such has resistors and capacitors. The components are connected together by TAB (Tape Automated Bonding) microcables. The components of the modules were tested in every assembly phase with comparable electrical tests to ensure the reliable functioning of the detectors and to plot the possible problems. The components were accepted or rejected by the limits confirmed by ALICE collaboration. This study is concentrating on the test results of framed chips, hybrids and modules. The total yield of the framed chips is 90.8%, hybrids 96.1% and modules 86.2%. The individual test results have been investigated in the light of the known error sources that appeared during the project. After solving the problems appearing during the learning-curve of the project, the material problems, such as defected chip cables and sensors, seemed to induce the most of the assembly rejections. The problems were typically seen in tests as too many individual channel failures. Instead, the bonding failures rarely caused the rejections of any component. One sensor type among three different sensor manufacturers has proven to have lower quality than the others. The sensors of this manufacturer are very noisy and their depletion voltage are usually outside of the specification given to the manufacturers. Reaching 95% assembling yield during the module production demonstrates that the assembly process has been highly successful.

Road Dust from Pavement Wear and Traction Sanding

Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is road dust . The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: i) How do traction sanding and physical properties of the traction sand aggregate affect formation of road dust? ii) How do studded tires affect the formation of road dust when compared with friction tires? iii) What are the composition and sources of airborne road dust in a road simulator and during a springtime road dust episode in Finland? iv) What is the size distribution of abrasion particles from tire-road interaction? The studies were conducted both in a road simulator and in field conditions. The test results from the road simulator showed that traction sanding increased road dust emissions, and that the effect became more dominant with increasing sand load. A high percentage of fine-grained anti-skid aggregate of overall grading increased the PM10 concentrations. Anti-skid aggregate with poor resistance to fragmentation resulted in higher PM levels compared with the other aggregates, and the effect became more significant with higher aggregate loads. Glaciofluvial aggregates tended to cause higher particle concentrations than crushed rocks with good fragmentation resistance. Comparison of tire types showed that studded tires result in higher formation of PM emissions compared with friction tires. The same trend between the tires was present in the tests with and without anti-skid aggregate. This finding applies to test conditions of the road simulator with negligible resuspension. Source and composition analysis showed that the particles in the road simulator were mainly minerals and originated from both traction sand and pavement aggregates. A clear contribution of particles from anti-skid aggregate to ambient PM and dust deposition was also observed in urban conditions. The road simulator results showed that the interaction between tires, anti-skid aggregate and road surface is important in dust production and the relative contributions of these sources depend on their properties. Traction sand grains are fragmented into smaller particles under the tires, but they also wear the pavement aggregate. Therefore particles from both aggregates are observed. The mass size distribution of traction sand and pavement wear particles was mainly coarse, but fine and submicron particles were also present.

Two views on interstellar dust: near-infrared scattering and polarized thermal dust emission

Interstellar clouds are not featureless, but show quite complex internal structures of filaments and clumps when observed with high enough resolution. These structures have been generated by 1) turbulent motions driven mainly by supernovae, 2) magnetic fields working on the ions and, through neutral-ion collisions, on neutral gas as well, and 3) self-gravity pulling a dense clump together to form a new star. The study of the cloud structure gives us information on the relative importance of each of these mechanisms, and helps us to gain a better understanding of the details of the star formation process. Interstellar dust is often used as a tracer for the interstellar gas which forms the bulk of the interstellar matter. Some of the methods that are used to derive the column density are summarized in this thesis. A new method, which uses the scattered light to map the column density in large fields with high spatial resolution, is introduced. This thesis also takes a look at the grain alignment with respect to the magnetic fields. The aligned grains give rise to the polarization of starlight and dust emission, thus revealing the magnetic field. The alignment mechanisms have been debated for the last half century. The strongest candidate at present is the radiative torques mechanism. In the first four papers included in this thesis, the scattered light method of column density estimation is formulated, tested in simulations, and finally used to obtain a column density map from observations. They demonstrate that the scattered light method is a very useful and reliable tool in column density estimation, and is able to provide higher resolution than the near-infrared color excess method. These two methods are complementary. The derived column density maps are also used to gain information on the dust emissivity within the observed cloud. The two final papers present simulations of polarized thermal dust emission assuming that the alignment happens by the radiative torques mechanism. We show that the radiative torques can explain the observed decline of the polarization degree towards dense cores. Furthermore, the results indicate that the dense cores themselves might not contribute significantly to the polarized signal, and hence one needs to be careful when interpreting the observations and deriving the magnetic field.

Studies on Aerosol Particle Emission, Sampling and Authenticity

Emissions of coal combustion fly ash through real scale ElectroStatic Precipitators (ESP) were studied in different coal combustion and operation conditions. Sub-micron fly-ash aerosol emission from a power plant boiler and the ESP were determined and consequently the aerosol penetration, as based on electrical mobility measurements, thus giving thereby an indication for an estimate on the size and the maximum extent that the small particles can escape. The experimentals indicate a maximum penetration of 4% to 20 % of the small particles, as counted on number basis instead of the normally used mass basis, while simultaneously the ESP is operating at a nearly 100% collection efficiency on mass basis. Although the size range as such seems to appear independent of the coal, of the boiler or even of the device used for the emission control, the maximum penetration level on the number basis depends on the ESP operating parameters. The measured emissions were stable during stable boiler operation for a fired coal, and the emissions seemed each to be different indicating that the sub-micron size distribution of the fly-ash could be used as a specific characteristics for recognition, for instance for authenticity, provided with an indication of known stable operation. Consequently, the results on the emissions suggest an optimum particle size range for environmental monitoring in respect to the probability of finding traces from the samples. The current work embodies also an authentication system for aerosol samples for post-inspection from any macroscopic sample piece. The system can comprise newly introduced new devices, for mutually independent use, or, for use in a combination with each other, as arranged in order to promote the sampling operation length and/or the tag selection diversity. The tag for the samples can be based on naturally occurring measures and/or added measures of authenticity in a suitable combination. The method involves not only military related applications but those in civil industries as well. Alternatively to the samples, the system can be applied to ink for note printing or other monetary valued papers, but also in a filter manufacturing for marking fibrous filters.

Development of biogenic VOC emission inventories for the boreal forest

Luonnosta haihtuvat orgaaniset yhdisteet, joita pääsee ilmaan etenkin metsistä, voivat vaikuttaa paikalliseen ja alueelliseen ilmanlaatuun, koska ne reagoivat ilmakehässä. Niiden reaktiotuotteet voivat myös osallistua uusien hiukkasten muodostumiseen ja kasvuun, millä voi olla vaikutusta ilmakehän säteilytaseeseen ja tätä kautta myös ilmastoon. Hiukkaset absorboivat ja sirottavat auringon säteilyä ja maapallon lämpösäteilyä minkä lisäksi ne vaikuttavat pilvien säteilyominaisuuksiin, määrään ja elinikään. Koko maapallon mittakaavassa luonnosta tulevat hiilivetypäästöt ylittävät ihmistoiminnan aiheuttamat päästöt moninkertaisesti. Tämän vuoksi luonnon päästöjen arviointi on tärkeää kun halutaan kehittää tehokkaita ilmanlaatu- ja ilmastostrategioita. Tämä tutkimus käsittelee boreaalisen metsän hiilivetypäästöjä. Boreaalinen metsä eli pohjoinen havumetsä on suurin maanpäällinen ekosysteemi, ja se ulottuu lähes yhtenäisenä nauhana koko pohjoisen pallonpuoliskon ympäri. Sille on tyypillistä puulajien suhteellisen pieni kirjo sekä olosuhteiden ja kasvun voimakkaat vuodenaikaisvaihtelut. Työssä on tutkittu Suomen yleisimmän boreaalisen puun eli männyn hiilivetypäästöjen vuodenaikaisvaihtelua sekä päästöjen riippuvuutta lämpötilasta ja valosta. Saatuja tuloksia on käytetty yhdessä muiden boreaalisilla puilla tehtyjen päästömittaustulosten kanssa Suomen metsiä varten kehitetyssä päästömallissa. Malli perustuu lisäksi maankäyttötietoihin, suomen metsille kehitettyyn luokitukseen ja meteorologisiin tietoihin, joiden avulla se laskee metsien hiilivetypäästöt kasvukauden aikana. Suomen metsien päästöt koostuvat koko kasvukauden ajan suurelta osin alfa- ja beta-pineenistä sekä delta-kareenista. Kesällä ja syksyllä päästöissä on myös paljon sabineenia, jota tulee etenkin lehtipuista. Päästöt seuraavat lämpötilan keskimääräistä vaihtelua, ovat suurimmillaan maan eteläosissa ja laskevat tasaisesti pohjoiseen siirryttäessä. Metsän isopreenipäästö on suhteellisen pieni – Suomessa tärkein isopreeniä päästävä puu on vähäpäästöinen kuusi, koska runsaspäästöisten pajun ja haavan osuus metsän lehtimassasta on hyvin pieni. Tässä työssä on myös laskettu ensimmäinen arvio metsän seskviterpeenipäästöistä. Seskviterpeenipäästöt alkavat Juhannuksen jälkeen ja ovat kasvukauden aikana samaa suuruusluokkaa kuin isopreenipäästöt. Vuositasolla Suomen metsien hiilivetypäästöt ovat noin kaksinkertaiset ihmistoiminnasta aiheutuviin päästöihin verrattuna.

Studies of electronic structure by x-ray Raman and emission spectroscopy: applications to MgB2 superconductors and high pressure physics

X-ray Raman scattering and x-ray emission spectroscopies were used to study the electronic properties and phase transitions in several condensed matter systems. The experimental work, carried out at the European Synchrotron Radiation Facility, was complemented by theoretical calculations of the x-ray spectra and of the electronic structure. The electronic structure of MgB2 at the Fermi level is dominated by the boron σ and π bands. The high density of states provided by these bands is the key feature of the electronic structure contributing to the high critical temperature of superconductivity in MgB2. The electronic structure of MgB2 can be modified by atomic substitutions, which introduce extra electrons or holes into the bands. X ray Raman scattering was used to probe the interesting σ and π band hole states in pure and aluminum substituted MgB2. A method for determining the final state density of electron states from experimental x-ray Raman scattering spectra was examined and applied to the experimental data on both pure MgB2 and on Mg(0.83)Al(0.17)B2. The extracted final state density of electron states for the pure and aluminum substituted samples revealed clear substitution induced changes in the σ and π bands. The experimental work was supported by theoretical calculations of the electronic structure and x-ray Raman spectra. X-ray emission at the metal Kβ line was applied to the studies of pressure and temperature induced spin state transitions in transition metal oxides. The experimental studies were complemented by cluster multiplet calculations of the electronic structure and emission spectra. In LaCoO3 evidence for the appearance of an intermediate spin state was found and the presence of a pressure induced spin transition was confirmed. Pressure induced changes in the electronic structure of transition metal monoxides were studied experimentally and were analyzed using the cluster multiplet approach. The effects of hybridization, bandwidth and crystal field splitting in stabilizing the high pressure spin state were discussed. Emission spectroscopy at the Kβ line was also applied to FeCO3 and a pressure induced iron spin state transition was discovered.

Diagnostic Tests Based on Quantile Residuals for Nonlinear Time Series Models

This thesis studies quantile residuals and uses different methodologies to develop test statistics that are applicable in evaluating linear and nonlinear time series models based on continuous distributions. Models based on mixtures of distributions are of special interest because it turns out that for those models traditional residuals, often referred to as Pearson's residuals, are not appropriate. As such models have become more and more popular in practice, especially with financial time series data there is a need for reliable diagnostic tools that can be used to evaluate them. The aim of the thesis is to show how such diagnostic tools can be obtained and used in model evaluation. The quantile residuals considered here are defined in such a way that, when the model is correctly specified and its parameters are consistently estimated, they are approximately independent with standard normal distribution. All the tests derived in the thesis are pure significance type tests and are theoretically sound in that they properly take the uncertainty caused by parameter estimation into account. -- In Chapter 2 a general framework based on the likelihood function and smooth functions of univariate quantile residuals is derived that can be used to obtain misspecification tests for various purposes. Three easy-to-use tests aimed at detecting non-normality, autocorrelation, and conditional heteroscedasticity in quantile residuals are formulated. It also turns out that these tests can be interpreted as Lagrange Multiplier or score tests so that they are asymptotically optimal against local alternatives. Chapter 3 extends the concept of quantile residuals to multivariate models. The framework of Chapter 2 is generalized and tests aimed at detecting non-normality, serial correlation, and conditional heteroscedasticity in multivariate quantile residuals are derived based on it. Score test interpretations are obtained for the serial correlation and conditional heteroscedasticity tests and in a rather restricted special case for the normality test. In Chapter 4 the tests are constructed using the empirical distribution function of quantile residuals. So-called Khmaladze s martingale transformation is applied in order to eliminate the uncertainty caused by parameter estimation. Various test statistics are considered so that critical bounds for histogram type plots as well as Quantile-Quantile and Probability-Probability type plots of quantile residuals are obtained. Chapters 2, 3, and 4 contain simulations and empirical examples which illustrate the finite sample size and power properties of the derived tests and also how the tests and related graphical tools based on residuals are applied in practice.

Tests of a Roman Pot Prototype for the TOTEM Experiment

The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC. TOTEM Roman Pots contain stacks of 10 silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10 sigma + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place first in a fixed-target muon beam at CERN's SPS, and then in the proton beam-line of the SPS accelerator ring. We present the test beam results demonstrating the successful functionality of the system despite slight technical shortcomings to be improved in the near future.

Loading of itraconazole into porous silica and silicon microparticles: characterization and dissolution tests

Most new drug molecules discovered today suffer from poor bioavailability. Poor oral bioavailability results mainly from poor dissolution properties of hydrophobic drug molecules, because the drug dissolution is often the rate-limiting event of the drug’s absorption through the intestinal wall into the systemic circulation. During the last few years, the use of mesoporous silica and silicon particles as oral drug delivery vehicles has been widely studied, and there have been promising results of their suitability to enhance the physicochemical properties of poorly soluble drug molecules. Mesoporous silica and silicon particles can be used to enhance the solubility and dissolution rate of a drug by incorporating the drug inside the pores, which are only a few times larger than the drug molecules, and thus, breaking the crystalline structure into a disordered, amorphous form with better dissolution properties. Also, the high surface area of the mesoporous particles improves the dissolution rate of the incorporated drug. In addition, the mesoporous materials can also enhance the permeability of large, hydrophilic drug substances across biological barriers. T he loading process of drugs into silica and silicon mesopores is mainly based on the adsorption of drug molecules from a loading solution into the silica or silicon pore walls. There are several factors that affect the loading process: the surface area, the pore size, the total pore volume, the pore geometry and surface chemistry of the mesoporous material, as well as the chemical nature of the drugs and the solvents. Furthermore, both the pore and the surface structure of the particles also affect the drug release kinetics. In this study, the loading of itraconazole into mesoporous silica (Syloid AL-1 and Syloid 244) and silicon (TOPSi and TCPSi) microparticles was studied, as well as the release of itraconazole from the microparticles and its stability after loading. Itraconazole was selected for this study because of its highly hydrophobic and poorly soluble nature. Different mesoporous materials with different surface structures, pore volumes and surface areas were selected in order to evaluate the structural effect of the particles on the loading degree and dissolution behaviour of the drug using different loading parameters. The loaded particles were characterized with various analytical methods, and the drug release from the particles was assessed by in vitro dissolution tests. The results showed that the loaded drug was apparently in amorphous form after loading, and that the loading process did not alter the chemical structure of the silica or silicon surface. Both the mesoporous silica and silicon microparticles enhanced the solubility and dissolution rate of itraconazole. Moreover, the physicochemical properties of the particles and the loading procedure were shown to have an effect on the drug loading efficiency and drug release kinetics. Finally, the mesoporous silicon particles loaded with itraconazole were found to be unstable under stressed conditions (at 38 qC and 70 % relative humidity).