971 resultados para Atmosphere.


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Dicobalt(II) complexes [{(B)Co-11)(2)(mu-dtdp)(2)] (1-3) of 3,3'-dithiodipropionic acid (dtdp) and phenanthroline bases (B), viz. 1,10-phenanthroline (phen in 1), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 2) and dipyrido13,2-a:2',3'-clphenazine (dppz in 3), have been prepared, characterized and their photo-induced anaerobic DNA cleavage activity studied. The elemental analysis and mass spectral data suggest binuclear formulation of the complexes. The redox inactive complexes have magnetically non-interacting dicobalt(II) core showing magnetic moment of similar to 3.9 p per cobalt(II) center. The complexes show good binding propensity to calf thymus DNA giving K-b values within 4.3 x 10(5)-4.0 x 10(6) M-1. Thermal melting and viscosity data predict DNA groove binding and/or partial intercalative nature of the complexes. The complexes show significant anaerobic DNA cleavage activity in green light under argon atmosphere possibly involving radical species generated from the disulfide moiety in a type-I pathway. The DNA cleavage reaction under aerobic medium in green light is found to involve hydroxyl radical species. The dppz complex 3 exhibits significant photocytotoxicity in HeLa cervical cancer cells with an IC50 value of 2.31 mu M in UV-A light of 365 nm, while it is essentially non-toxic in dark giving an IC50 value of >200 mu M. A significant reduction of the dark toxicity of the organic dppz base (IC50 = 8.3 mu M in dark) is observed on binding to the cobalt(II) center while essentially retaining its photocytotoxicity in UV-A light (IC50 = 0.4 mu M). (C) 2010 Elsevier Ltd. All rights reserved.

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An attempt to diagnose the dominant forcings which drive the large-scale vertical velocities over the monsoon region has been made by computing the forcings like diabatic heating fields,etc. and the large-scale vertical velocities driven by these forcings for the contrasting periods of active and break monsoon situations; in order to understand the rainfall variability associated with them. Computation of diabatic heating fields show us that among different components of diabatic heating it is the convective heating that dominates at mid-tropospheric levels during an active monsoon period; whereas it is the sensible heating at the surface that is important during a break period. From vertical velocity calculations we infer that the prime differences in the large-scale vertical velocities seen throughout the depth of the atmosphere are due to the differences in the orders of convective heating; the maximum rate of latent heating being more than 10 degrees Kelvin per day during an active monsoon period; whereas during a break monsoon period it is of the order of 2 degrees Kelvin per day at mid-tropospheric levels. At low levels of the atmosphere, computations show that there is large-scale ascent occurring over a large spatial region, driven only by the dynamic forcing associated with vorticity and temperature advection during an active monsoon period. However, during a break monsoon period such large-scale spatial organization in rising motion is not seen. It is speculated that these differences in the low-level large-scale ascent might be causing differences in convective heating because the weaker the low level ascent, the lesser the convective instability which produces deep cumulus clouds and hence lesser the associated latent heat release. The forcings due to other components of diabatic heating, namely, the sensible heating and long wave radiative cooling do not influence the large-scale vertical velocities significantly.

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This doctoral thesis is about the solar wind influence on the atmosphere of the planet Venus. A numerical plasma simulation model was developed for the interaction between Venus and the solar wind to study the erosion of charged particles from the Venus upper atmosphere. The developed model is a hybrid simulation where ions are treated as particles and electrons are modelled as a fluid. The simulation was used to study the solar wind induced ion escape from Venus as observed by the European Space Agency's Venus Express and NASA's Pioneer Venus Orbiter spacecraft. Especially, observations made by the ASPERA-4 particle instrument onboard Venus Express were studied. The thesis consists of an introductory part and four peer-reviewed articles published in scientific journals. In the introduction Venus is presented as one of the terrestrial planets in the Solar System and the main findings of the work are discussed within the wider context of planetary physics. Venus is the closest neighbouring planet to the Earth and the most earthlike planet in its size and mass orbiting the Sun. Whereas the atmosphere of the Earth consists mainly of nitrogen and oxygen, Venus has a hot carbon dioxide atmosphere, which is dominated by the greenhouse effect. Venus has all of its water in the atmosphere, which is only a fraction of the Earth's total water supply. Since planets developed presumably in similar conditions in the young Solar System, why Venus and Earth became so different in many respects? One important feature of Venus is that the planet does not have an intrinsic magnetic field. This makes it possible for the solar wind, a continuous stream of charged particles from the Sun, to flow close to Venus and to pick up ions from the planet's upper atmosphere. The strong intrinsic magnetic field of the Earth dominates the terrestrial magnetosphere and deflects the solar wind flow far away from the atmosphere. The region around Venus where the planet's atmosphere interacts with the solar wind is called the plasma environment or the induced magnetosphere. Main findings of the work include new knowledge about the movement of escaping planetary ions in the Venusian induced magnetosphere. Further, the developed simulation model was used to study how the solar wind conditions affect the ion escape from Venus. Especially, the global three-dimensional structure of the Venusian particle and magnetic environment was studied. The results help to interpret spacecraft observations around the planet. Finally, several remaining questions were identified, which could potentially improve our knowledge of the Venus ion escape and guide the future development of planetary plasma simulations.

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Several investigators in the past have used the radiance depression (with respect to clear-sky infrared radiance), resulting from the presence of mineral dust aerosols in the atmosphere, as an index of dust aerosol load in the atmosphere during local noon. Here, we have used a modified approach to retrieve dust index during night since assessment of diurnal average infrared dust forcing essentially requires information on dust aerosols during night. For this purpose, we used infrared radiance (10.5-12.5 mu m), acquired from the METEOSAT-5 satellite (similar to 5 km resolution). We found that the `dust index' algorithm, valid for daytime, will no longer hold during the night because dust is then hotter than the theoretical dust-free reference. Hence we followed a `minimum reference' approach instead of a conventional `maximum reference' approach. A detailed analysis suggests that the maximum dust load occurs during the daytime. Over the desert regions of India and Africa, maximum change in dust load is as much as a factor of four between day and night and factor of two variations are commonly observed. By realizing the consequent impact on long wave dust forcing, sensitivity studies were carried out, which indicate that utilizing day time data for estimating the diurnally averaged long-wave dust radiative forcing results in significant errors (as much as 50 to 70%). Annually and regionally averaged long wave dust radiative forcing (which account for the diurnal variation of dust) at the top of the atmosphere over Afro-Asian region is 2.6 +/- 1.8 W m(-2), which is 30 to 50% lower than those reported earlier. Our studies indicate that neglecting diurnal variation of dust while assessing its radiative impact leads to an overestimation of dust radiative forcing, which in turn result in underestimation of the radiative impact of anthropogenic aerosols.

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Aerosol particles play an important role in the Earth s atmosphere and in the climate system: they scatter and absorb solar radiation, facilitate chemical processes, and serve as seeds for cloud formation. Secondary new particle formation (NPF) is a globally important source of these particles. Currently, the mechanisms of particle formation and the vapors participating in this process are, however, not truly understood. In order to fully explain atmospheric NPF and subsequent growth, we need to measure directly the very initial steps of the formation processes. This thesis investigates the possibility to study atmospheric particle formation using a recently developed Neutral cluster and Air Ion Spectrometer (NAIS). First, the NAIS was calibrated and intercompared, and found to be in good agreement with the reference instruments both in the laboratory and in the field. It was concluded that NAIS can be reliably used to measure small atmospheric ions and particles directly at the sizes where NPF begins. Second, several NAIS systems were deployed simultaneously at 12 European measurement sites to quantify the spatial and temporal distribution of particle formation events. The sites represented a variety of geographical and atmospheric conditions. The NPF events were detected using NAIS systems at all of the sites during the year-long measurement period. Various particle formation characteristics, such as formation and growth rates, were used as indicators of the relevant processes and participating compounds in the initial formation. In a case of parallel ion and neutral cluster measurements, we also estimated the relative contribution of ion-induced and neutral nucleation to the total particle formation. At most sites, the particle growth rate increased with the increasing particle size indicating that different condensing vapors are participating in the growth of different-sized particles. The results suggest that, in addition to sulfuric acid, organic vapors contribute to the initial steps of NPF and to the subsequent growth, not just later steps of the particle growth. As a significant new result, we found out that the total particle formation rate varied much more between the different sites than the formation rate of charged particles. The results infer that the ion-induced nucleation has a minor contribution to particle formation in the boundary layer in most of the environments. These results give tools to better quantify the aerosol source provided by secondary NPF in various environments. The particle formation characteristics determined in this thesis can be used in global models to assess NPF s climatic effects.

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Aerosol particles deteriorate air quality, atmospheric visibility and our health. They affect the Earth s climate by absorbing and scattering sunlight, forming clouds, and also via several feed-back mechanisms. The net effect on the radiative balance is negative, i.e. cooling, which means that particles counteract the effect of greenhouse gases. However, particles are one of the poorly known pieces in the climate puzzle. Some of the airborne particles are natural, some anthropogenic; some enter the atmosphere in particle form, while others form by gas-to-particle conversion. Unless the sources and dynamical processes shaping the particle population are quantified, they cannot be incorporated into climate models. The molecular level understanding of new particle formation is still inadequate, mainly due to the lack of suitable measurement techniques to detect the smallest particles and their precursors. This thesis has contributed to our ability to measure newly formed particles. Three new condensation particle counter applications for measuring the concentration of nano-particles were developed. The suitability of the methods for detecting both charged and electrically neutral particles and molecular clusters as small as 1 nm in diameter was thoroughly tested both in laboratory and field conditions. It was shown that condensation particle counting has reached the size scale of individual molecules, and besides measuring the concentration they can be used for getting size information. In addition to atmospheric research, the particle counters could have various applications in other fields, especially in nanotechnology. Using the new instruments, the first continuous time series of neutral sub-3 nm particle concentrations were measured at two field sites, which represent two different kinds of environments: the boreal forest and the Atlantic coastline, both of which are known to be hot-spots for new particle formation. The contribution of ions to the total concentrations in this size range was estimated, and it could be concluded that the fraction of ions was usually minor, especially in boreal forest conditions. Since the ionization rate is connected to the amount of cosmic rays entering the atmosphere, the relative contribution of neutral to charged nucleation mechanisms extends beyond academic interest, and links the research directly to current climate debate.

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The Earth s climate is a highly dynamic and complex system in which atmospheric aerosols have been increasingly recognized to play a key role. Aerosol particles affect the climate through a multitude of processes, directly by absorbing and reflecting radiation and indirectly by changing the properties of clouds. Because of the complexity, quantification of the effects of aerosols continues to be a highly uncertain science. Better understanding of the effects of aerosols requires more information on aerosol chemistry. Before the determination of aerosol chemical composition by the various available analytical techniques, aerosol particles must be reliably sampled and prepared. Indeed, sampling is one of the most challenging steps in aerosol studies, since all available sampling techniques harbor drawbacks. In this study, novel methodologies were developed for sampling and determination of the chemical composition of atmospheric aerosols. In the particle-into-liquid sampler (PILS), aerosol particles grow in saturated water vapor with further impaction and dissolution in liquid water. Once in water, the aerosol sample can then be transported and analyzed by various off-line or on-line techniques. In this study, PILS was modified and the sampling procedure was optimized to obtain less altered aerosol samples with good time resolution. A combination of denuders with different coatings was tested to adsorb gas phase compounds before PILS. Mixtures of water with alcohols were introduced to increase the solubility of aerosols. Minimum sampling time required was determined by collecting samples off-line every hour and proceeding with liquid-liquid extraction (LLE) and analysis by gas chromatography-mass spectrometry (GC-MS). The laboriousness of LLE followed by GC-MS analysis next prompted an evaluation of solid-phase extraction (SPE) for the extraction of aldehydes and acids in aerosol samples. These two compound groups are thought to be key for aerosol growth. Octadecylsilica, hydrophilic-lipophilic balance (HLB), and mixed phase anion exchange (MAX) were tested as extraction materials. MAX proved to be efficient for acids, but no tested material offered sufficient adsorption for aldehydes. Thus, PILS samples were extracted only with MAX to guarantee good results for organic acids determined by liquid chromatography-mass spectrometry (HPLC-MS). On-line coupling of SPE with HPLC-MS is relatively easy, and here on-line coupling of PILS with HPLC-MS through the SPE trap produced some interesting data on relevant acids in atmospheric aerosol samples. A completely different approach to aerosol sampling, namely, differential mobility analyzer (DMA)-assisted filter sampling, was employed in this study to provide information about the size dependent chemical composition of aerosols and understanding of the processes driving aerosol growth from nano-size clusters to climatically relevant particles (>40 nm). The DMA was set to sample particles with diameters of 50, 40, and 30 nm and aerosols were collected on teflon or quartz fiber filters. To clarify the gas-phase contribution, zero gas-phase samples were collected by switching off the DMA every other 15 minutes. Gas-phase compounds were adsorbed equally well on both types of filter, and were found to contribute significantly to the total compound mass. Gas-phase adsorption is especially significant during the collection of nanometer-size aerosols and needs always to be taken into account. Other aims of this study were to determine the oxidation products of β-caryophyllene (the major sesquiterpene in boreal forest) in aerosol particles. Since reference compounds are needed for verification of the accuracy of analytical measurements, three oxidation products of β-caryophyllene were synthesized: β-caryophyllene aldehyde, β-nocaryophyllene aldehyde, and β-caryophyllinic acid. All three were identified for the first time in ambient aerosol samples, at relatively high concentrations, and their contribution to the aerosol mass (and probably growth) was concluded to be significant. Methodological and instrumental developments presented in this work enable fuller understanding of the processes behind biogenic aerosol formation and provide new tools for more precise determination of biosphere-atmosphere interactions.

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In the present investigation, a very good combination of strength and ductility, 630MPa 0.2% proof stress and 14.8% elongation to fracture in tensile test, has been obtained for the 7075 Al alloy after optimizing the processing parameters for spray forming, hot extruding the spray deposit, and peak aging the samples taken from the extruded rod. The spray deposits contained some porosity but it was almost eliminated on hot extrusion. Electron probe microanalysis revealed that even though spray forming was carried out in an open atmosphere, it did not affect the oxygen content and its distribution in the material on spray forming, because the atomizing argon gas provided a protective cover to molten droplets and prevented their oxidation. The chemical composition of the spray-formed material was found to be almost the same as the raw material, and the major alloying elements were found to be uniformly distributed in the extruded rod.

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Floating in the air that surrounds us is a number of small particles, invisible to the human eye. The mixture of air and particles, liquid or solid, is called an aerosol. Aerosols have significant effects on air quality, visibility and health, and on the Earth's climate. Their effect on the Earth's climate is the least understood of climatically relevant effects. They can scatter the incoming radiation from the Sun, or they can act as seeds onto which cloud droplets are formed. Aerosol particles are created directly, by human activity or natural reasons such as breaking ocean waves or sandstorms. They can also be created indirectly as vapors or very small particles are emitted into the atmosphere and they combine to form small particles that later grow to reach climatically or health relevant sizes. The mechanisms through which those particles are formed is still under scientific discussion, even though this knowledge is crucial to make air quality or climate predictions, or to understand how aerosols will influence and will be influenced by the climate's feedback loops. One of the proposed mechanisms responsible for new particle formation is ion-induced nucleation. This mechanism is based on the idea that newly formed particles were ultimately formed around an electric charge. The amount of available charges in the atmosphere varies depending on radon concentrations in the soil and in the air, as well as incoming ionizing radiation from outer space. In this thesis, ion-induced nucleation is investigated through long-term measurements in two different environments: in the background site of Hyytiälä and in the urban site that is Helsinki. The main conclusion of this thesis is that ion-induced nucleation generally plays a minor role in new particle formation. The fraction of particles formed varies from day to day and from place to place. The relative importance of ion-induced nucleation, i.e. the fraction of particles formed through ion-induced nucleation, is bigger in cleaner areas where the absolute number of particles formed is smaller. Moreover, ion-induced nucleation contributes to a bigger fraction of particles on warmer days, when the sulfuric acid and water vapor saturation ratios are lower. This analysis will help to understand the feedbacks associated with climate change.

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Tutkielmassa tarkastellaan jalkapallon seuraamista elämyskuluttamisen näkökulmasta. Elämyskulutuksella tarkoitetaan tässä yhteydessä tapahtumia ja hetkiä, jolloin ihminen kokee tavallisuudesta poikkeavan ja mieleenpainuvan tunnetilan. Elämyksiä tarjoavat palvelut ovat lisänneet jatkuvasti suosiotaan, kun arjessa rationaalisuus ylikorostuu ja sille halutaan vastapainoa. Aihetta taustoitetaan elämysyhteiskunnan, yhteisöllisyyden ja kuluttajaheimojen käsitteiden avulla. Erityishuomion saavat kulttuuritapahtumat elämystuotteina, penkkiurheilu yhteiskunnallisena ilmiönä sekä erilaiset jalkapalloon liittyvät kulutustavat. Tutkielma on luonteeltaan fenomenologis-etnografinen kuvaileva tutkimus. Tutkimusmenetelminä on käytetty osallistuvaa havainnointia ja haastatteluita. Tutkimusperinteen mukaisesti ilmiön ymmärtäminen, kuvaaminen ja kirjoittaminen ovat tärkeässä osassa. Havainnointiaineisto on kerätty kolmessa eri tapahtumassa seuraamalla katsojien käyttäytymistä ja tunnelman syntymiseen vaikuttavia tekijöitä. Haastateltavat on valittu harkinnanvaraisesti jalkapalloa aktiivisesti seuraavista henkilöistä ja menetelmänä on käytetty avoimia teemahaastatteluita. Urheilun vetovoima ajanvietteenä perustuu vahvojen tunteiden herättämiseen, joten penkkiurheilu on elämyskulutusta puhtaimmillaan. Urheilu elämystuotteena on oivallinen, sillä sen lukuisten kulutustapojen lisäksi tapahtumat muodostavat päättymättömän jatkumon. Myös oman aineistoni perusteella osoittautui, että menneiden tapahtumien avulla ankkuroidutaan yhteisöön ja tulevien tapahtumien avulla pidetään innostusta yllä. Pettymysten hetkelläkään koukusta ei haluta irti, sillä jokainen kokemus lisää tunteita omaa urheilulajia ja yhteisöä kohtaan. Urheilutapahtumissa katsojan elämys syntyy subjektiivisen kokemuksen kautta, mutta yhteisö luo elämyksen toteutumisen välttämättömät edellytykset. Jalkapalloyleisöön kuuluvissa henkilöissä yhdistyvät halu kuulua ryhmään ja olla samaan aikaan sen ulkopuolella. Peliä voidaan tarkkailla itsekseen ja keskittyneesti suuren joukon keskellä tai hurrata muiden mukana. Aineistoni perusteella jalkapallofanin innostus pulppuaa kahdesta lähteestä: yhteisöllisyydestä ja kiinnostuksesta lajiin. Yhteisöllisyyden tunne syntyy kuulumisesta globaaliin jalkapalloyhteisöön, oman suosikkijoukkueen kannattajiin ja samaa lajia seuraavien kaverien muodostamaan lähipiiriin. Urheilullinen puoli innostuksesta syntyy kiinnostuksesta jalkapalloa kohtaan lajina, aktiivisesti seuratuista säännöllisistä tapahtumista ja oman joukkueen kannattamisesta. Jalkapallon seuraajiin teoria jatkuvasti muuttuvista uusyhteisöistä pätee melko huonosti, sillä lajille ja seuralle ollaan hyvin uskollisia. Faneille on tärkeää sitoutua pieneen lähiyhteisöön, jonka kanssa heillä on yhteinen historia ja mahdollisuus jakaa kokemuksia keskustelemalla ja muistelemalla.

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Soilla on merkittävä rooli ilmastonmuutoksen hillitsemisessä suuren hiilivarastonsa sekä ekosysteemin ja ilmakehän välisen kaasunvaihdon ansiosta. Ilmastonmuutoksen ennustetaan vaikuttavan suokasvillisuuteen ja suon toimintaan epäsuorasti. Vedenpinnan ennustetaan laskevan 14–21 cm johtuen kasveista ja avoimilta pinnoilta tapahtuvan haihdunnan lisääntymisestä lämpötilan noustessa, mikäli sadanta ei lisäänny. Aiemmat vedenpinnan laskun jälkeistä kasvillisuutta seuranneet tutkimukset ovat osoittaneet, että putkilokasvit hyötyvät alhaisemmasta vedenpinnan tasosta ja että kuljuun sopeutuneet rahkasammalet kärsivät kuivuneista oloista. Kasvillisuuden runsaussuhteiden muuttumisen lisäksi kasviyhteisöjen monimuotoisuus vähenee. Erityisen herkkiä vedenpinnan laskulle ovat olleet välipinta- ja kuljurahkasammalet ja sarat. Funktionaalisten kasviryhmien vasteiden selvittämiksesi käytettiin BACI (before-after-control-impact) –tutkimusotetta. Tutkimuksessa oli kolme verrokkialaa ja kolme käsittelyalaa, joissa vedenpintaa oli laskettu 14–21 senttimetriin. Lisäksi vertailukohdaksi tutkimuksessa oli mukana kolme alaa, joissa oli tehty metsäojitus n. 50 vuotta sitten. Nämä toistot sijaitsivat meso-, oligo ombrotrofisilla suotyypeillä Oriveden Lakkasuolla. Kasvillisuus kartoitettiin ja vedenpinnat mitattiin aloilta ennen käsittelyä vuonna 2000 sekä vuosina 2001–2003 ja 2009. Aineisto analysoitiin TWINSPAN- (PC-Ord), PRC ja DCA (CANOCO)-monimuuttujamenetelmillä. Tulokset osoittivat, että verrokki- ja käsittelyalat olivat samanlaisia lähtökohdiltaan, joten niitä voitiin käsittelyn jälkeen verrata toisiinsa. Kasvillisuuden rakenne vaihteli vuosien välillä myös verrokkialoilla, mikä osoittaa kasvien sopeutumiskyvyn muuttuviin sääoloihin (lämpötila, sademäärä). Vuosi 2003 erottui tutkimuksessa alhaisella vedenpinnantasolla, mutta toisaalta myös ainavihantien varpujen suuren peittävyyden osalta. Vuoteen 2009 mennessä kasvillisuuden erityisesti sarojen peittävyys väheni. Ravinteikkaimmilla toistoilla kasvillisuuden vasteet vaikuttivat olevan vahvemmat kuin vähäravinteisilla toistoilla. Kasviryhmistä kulju- ja välipintasammalilla oli vahvimmat vasteetvedenpinnan laskuun ja mätäslajeilla heikoimmat. Tulosten mukaan kasviryhmien vasteet vaihtelevat riippuen tarkasteltavasta aikajaksosta: ensimmäiset kolme vuotta käsittelyn jälkeen suo oli häiriötilassa ja vasta sen jälkeen kasvillisuus sopeutui muuttuneisiin oloihin.

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The aim of this study was to investigate the relationship between merit pay system and work environment and foremen´s work satisfaction and work motivation. There has been a lot of investigation on rewarding. Less research has been done on previous surveys among the merit pay systems and motivation investigations. According to former surveys, rewarding systems cannot be released from its context. Therefore this survey expanded to deal with work environment. It was also essential to investigate different dimensions of extrinsic and intrinsic motivation and equity of rewarding. Investigation or work motivation and work satisfaction was challenging because both of these concepts have been investigated under quite traditional frame of reference of work motivation theories. In some surveys, the concepts have not been even separated or they have been used even as synonyms. The data were collected with the 193 foremen working in the profit centers of the different chains of the company in the field of retail trade. The questions were: Are the experiences of merit pay system and work environment related to foremen´s work satisfaction and work motivation? Are the backround variables related to foremen´s work satisfaction and work motivation? The data collection was carried out by an electronic inquiry during May 2010. 137 replied from foremen working under merit pay system. The research material was analyzed with PASW-software. Various analyzing methods were used: factor analyses, regression analyses and group of different parametric and non-parametric analyses. In contrast to theoretical framework in the factor analyses work satisfaction and work motivation clustered into the same dimension. As a main result the atmosphere, possibilities to influence and the atmosphere of leading were strongly positively related to foremen´s work satisfaction and work motivation. According to regression analyses these factors were able to explain 55 % of the foremen´s work satisfaction and work motivation. The best explanatory variable was atmosphere. Instead, the backround variables (age, sex, working years, group of profession, education) were not associated with work satisfaction and work motivation.

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Aerosol particles have effect on climate, visibility, air quality and human health. However, the strength of which aerosol particles affect our everyday life is not well described or entirely understood. Therefore, investigations of different processes and phenomena including e.g. primary particle sources, initial steps of secondary particle formation and growth, significance of charged particles in particle formation, as well as redistribution mechanisms in the atmosphere are required. In this work sources, sinks and concentrations of air ions (charged molecules, cluster and particles) were investigated directly by measuring air molecule ionising components (i.e. radon activity concentrations and external radiation dose rates) and charged particle size distributions, as well as based on literature review. The obtained results gave comprehensive and valuable picture of the spatial and temporal variation of the air ion sources, sinks and concentrations to use as input parameters in local and global scale climate models. Newly developed air ion spectrometers (Airel Ltd.) offered a possibility to investigate atmospheric (charged) particle formation and growth at sub-3 nm sizes. Therefore, new visual classification schemes for charged particle formation events were developed, and a newly developed particle growth rate method was tested with over one year dataset. These data analysis methods have been widely utilised by other researchers since introducing them. This thesis resulted interesting characteristics of atmospheric particle formation and growth: e.g. particle growth may sometimes be suppressed before detection limit (~ 3 nm) of traditional aerosol instruments, particle formation may take place during daytime as well as in the evening, growth rates of sub-3 nm particles were quite constant throughout the year while growth rates of larger particles (3-20 nm in diameter) were higher during summer compared to winter. These observations were thought to be a consequence of availability of condensing vapours. The observations of this thesis offered new understanding of the particle formation in the atmosphere. However, the role of ions in particle formation, which is not well understood with current knowledge, requires further research in future.

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The thesis aims at investigating the local dimension of the EU cohesion policy through the utilization of an alternative approach, which aims at the analysis of discourse and structures of power. The concrete case under analysis is the Interreg IV programme “Alpenrhein-Bodensee-Hochrhein”, which is conducted in the border region between Germany, Switzerland, Austria and the principality of Liechtenstein. The main research question is stated as such: What governmental rationalities can be found at work in the field of EU cross-border cooperation programmes? How is directive action and cooperation envisioned? How coherent are the different rationalities, which are found at work? The theoretical framework is based on a Foucaultian understanding of power and discourse and utilizes the notion of governmentalities as a way to de-stabilize the understanding of directive action and in order to highlight the dispersed and heterogeneous nature of governmental activity. The approach is situated within the general field of research on the European Union connected to basic conceptualisations such as the nature of power, the role of discourse and modes of subjectification. An approach termed “analytics of government”, based on the work of researchers like Mitchell Dean is introduced as the basic framework for the analysis. Four dimensions (visiblities, subjectivities, techniques/practices, problematisations) are presented as a set of tools with which governmental regimes of practices can be analysed. The empirical part of the thesis starts out with a discussion of the general framework of the European Union's cohesion policy and places the Interreg IV Alpenrhein-Bodensee-Hochrhein programme in this general context. The main analysis is based on eleven interviews which were conducted with different individuals, participating in the programme on different levels. The selection of interview partners aimed at maximising heterogeneity through including individuals from all parts of the programme region, obtaining different functions within the programme. The analysis reveals interesting aspects pertaining to the implementation and routine aspects of work within initiatives conducted under the heading of the EU cohesion policy. The central aspects of an Interreg IV Alpenrhein-Bodensee-Hochrhein – governmentality are sketched out. This includes a positive perception of the work atmosphere, administrative/professional characterisation of the selves and a de-politicization of the programme. Characteristic is the experience of tensions by interview partners and the use of discoursive strategies to resolve them. Negative perceptions play an important role for the specific governmental rationality. The thesis contributes to a better understanding of the local dimension of the European Union cohesion policy and questions established ways of thinking about governmental activity. It provides an insight into the working of power mechanisms in the constitution of fields of discourse and points out matters of practical importance as well as subsequent research questions.

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This study uses the European Centre for Medium-Range Weather Forecasts (ECMWF) model-generated high-resolution 10-day-long predictions for the Year of Tropical Convection (YOTC) 2008. Precipitation forecast skills of the model over the tropics are evaluated against the Tropical Rainfall Measuring Mission (TRMM) estimates. It has been shown that the model was able to capture the monthly to seasonal mean features of tropical convection reasonably. Northward propagation of convective bands over the Bay of Bengal was also forecasted realistically up to 5 days in advance, including the onset phase of the monsoon during the first half of June 2008. However, large errors exist in the daily datasets especially for longer lead times over smaller domains. For shorter lead times (less than 4-5 days), forecast errors are much smaller over the oceans than over land. Moreover, the rate of increase of errors with lead time is rapid over the oceans and is confined to the regions where observed precipitation shows large day-to-day variability. It has been shown that this rapid growth of errors over the oceans is related to the spatial pattern of near-surface air temperature. This is probably due to the one-way air-sea interaction in the atmosphere-only model used for forecasting. While the prescribed surface temperature over the oceans remain realistic at shorter lead times, the pattern and hence the gradient of the surface temperature is not altered with change in atmospheric parameters at longer lead times. It has also been shown that the ECMWF model had considerable difficulties in forecasting very low and very heavy intensity of precipitation over South Asia. The model has too few grids with ``zero'' precipitation and heavy (>40 mm day(-1)) precipitation. On the other hand, drizzle-like precipitation is too frequent in the model compared to that in the TRMM datasets. Further analysis shows that a major source of error in the ECMWF precipitation forecasts is the diurnal cycle over the South Asian monsoon region. The peak intensity of precipitation in the model forecasts over land (ocean) appear about 6 (9) h earlier than that in the observations. Moreover, the amplitude of the diurnal cycle is much higher in the model forecasts compared to that in the TRMM estimates. It has been seen that the phase error of the diurnal cycle increases with forecast lead time. The error in monthly mean 3-hourly precipitation forecasts is about 2-4 times of the error in the daily mean datasets. Thus, effort should be given to improve the phase and amplitude forecast of the diurnal cycle of precipitation from the model.