992 resultados para BACKGROUND MATTER


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When laboratory intercomparison exercises are conducted, there is no a priori dependence of the concentration of a certain compound determined in one laboratory to that determined by another(s). The same applies when comparing different methodologies. A existing data set of total mercury readings in fish muscle samples involved in a Brazilian intercomparison exercise was used to show that correlation analysis is the most effective statistical tool in this kind of experiments. Problems associated with alternative analytical tools such as mean or paired 't'-test comparison and regression analysis are discussed.

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A recent publication reported an exciting polygenic effect of schizophrenia (SCZ) risk variants, identified by a large genome-wide association study (GWAS), on total brain and white matter volumes in schizophrenic patients and, even more prominently, in healthy subjects. The aim of the present work was to replicate and then potentially extend these findings. According to the original publication, polygenic risk scores using single nucleotide polymorphism (SNP) information of SCZ GWAS (polygenic SCZ risk scores; PSS) were calculated in 122 healthy subjects, enrolled in a structural magnetic resonance imaging (MRI) study. These scores were computed based on P-values and odds ratios available through the Psychiatric GWAS Consortium. In addition, polygenic white matter scores (PWM) were calculated, using the respective SNP subset in the original publication. None of the polygenic scores, either PSS or PWM, were found to be associated with total brain, white matter or gray matter volume in our replicate sample. Minor differences between the original and the present study that might have contributed to lack of reproducibility (but unlikely explain it fully), are number of subjects, ethnicity, age distribution, array technology, SNP imputation quality and MRI scanner type. In contrast to the original publication, our results do not reveal the slightest signal of association of the described sets of GWAS-identified SCZ risk variants with brain volumes in adults. Caution is indicated in interpreting studies building on polygenic risk scores without replication sample.

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We investigated the effect of benthic substratum type (sand and rocks) and nutrient supply (N and P) on biofilm structure and heterotrophic metabolism in a field experiment in a forested Mediterranean stream (Fuirosos). Rock and sand colonization and biofilm formation was intensively studied for 44 d at two stream reaches: control and experimental (continuous addition of phosphate, ammonia, and nitrate). Structural (C, N, and polysaccharide content and bacterial and chlorophyll density) and metabolic biofilm parameters (b-glucosidase, peptidase, and phosphatase enzyme activities) were analyzed throughout the colonization process. The epilithic biofilm (grown on rocks) had a higher peptidase activity at the impacted reach, together with a higher algal and bacterial biomass. The positive relationship between the peptidase activity per cell and the N content of the epilithic biofilm suggested that heterotrophic utilization of proteinaceous compounds from within the biofilm was occurring. In contrast, nutrient addition caused the epipsammic biofilm (grown on sand) to exhibit lower b-glucosidase and phosphatase activities, without a significant increase in bacterial and algal biomass. The differential response to nutrient addition was related to different structural characteristics within each biofilm. The epipsammic biofilm had a constant and high C:N ratio (22.7) throughout the colonization. The epilithic biofilm had a higher C:N ratio at the beginning of the colonization (43.2) and evolved toward a more complex structure (high polysaccharide content and low C:N ratio) during later stages. The epipsammic biofilm was a site for the accumulation and degradation of organic matter: polysaccharides and organic phosphorus compounds had higher degradation activities

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A dual model with a nonlinear proton Regge trajectory in the missing mass (M_X^2) channel is constructed. A background based on a direct-channel exotic trajectory, developed and applied earlier for the inclusive electron-proton cross section description in the nucleon resonance region, is used. The parameters of the model are determined from the extrapolations to earlier experiments. Predictions for the low-mass (2 < M_X^2 < 8GeV^2) diffraction dissociation cross sections at the LHC energies are given.

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Both the competitive environment and the internal structure of an industrial organization are typically included in the processes which describe the strategic management processes of the firm, but less attention has been paid to the interdependence between these views. Therefore, this research focuses on explaining the particular conditions of an industry change, which lead managers to realign the firm in respect of its environment for generating competitive advantage. The research question that directs the development of the theoretical framework is: Why do firms outsource some of their functions? The three general stages of the analysis are related to the following research topics: (i) understanding forces that shape the industry, (ii) estimating the impacts of transforming customer preferences, rivalry, and changing capability bases on the relevance of existing assets and activities, and emergence of new business models, and (iii) developing optional structures for future value chains and understanding general boundaries for market emergence. The defined research setting contributes to the managerial research questions “Why do firms reorganize their value chains?”, “Why and how are decisions made?” Combining Transaction Cost Economics (TCE) and Resource-Based View (RBV) within an integrated framework makes it possible to evaluate the two dimensions of a company’s resources, namely the strategic value and transferability. The final decision of restructuring will be made based on an analysis of the actual business potential of the outsourcing, where benefits and risks are evaluated. The firm focuses on the risk of opportunism, hold-up problems, pricing, and opportunities to reach a complete contract, and finally on the direct benefits and risks for financial performance. The supplier analyzes the business potential of an activity outside the specific customer, the amount of customer-specific investments, the service provider’s competitive position, abilities to revenue gains in generic segments, and long-term dependence on the customer.

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Fleurbaey and Maniquet have proposed the criteria of conditional equality and of egalitarian equivalence to assess the equity among individuals in an ordinal setting. Empirical applications are rare and only partially consistent with their framework. We propose a new empirical approach that relies on individual preferences, is consistent with the ordinal criteria and enables to compare them with the cardinal criteria. We estimate a utility function that incorporates individual heterogeneous preferences, obtain ordinal measures of well-being and apply conditional equality and egalitarian equivalence. We then propose two cardinal measures of well-being, that are comparable with the ordinal model, to compute Roemer’s and Van de gaer’s criteria. Finally we compare the characteristics of the worst-off displayed by each criterion. We apply this model to a sample of US micro data and obtain that about 18% of the worst-off are not common to all criteria.

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The aim of this thesis was to analyze the background information of an activity-based costing system, which is being used in a domestic forest industry company. The reports produced by the system have not been reliable, and this has caused the utilization of the system to diminish. The study was initiated by examining the theory of activity-based costing. It was also discovered, that the system produces management accounting information and therefore also that theory was introduced briefly. Next the possible sources of errors were examined. The significance of these errors was evaluated and waste handling was chosen as a subject of further study. The problem regarding waste handling was that there is no waste compensation in current model. When paper or board machine produces waste, it can be used as raw material in the process. However, at the moment the product, which is being produced, at the time does not get any compensation. The use of compensation has not been possible due to not knowing the quantity of process waste. As a result of the study a calculatory model, which enables calculating the quantity of process waste based on the data from the mill system, was introduced. This, for one, enables starting to use waste compensation in the future.

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Distribution and stocks of soil organic matter (SOM) compartments after Pinus monoculture introduction in a native pasture area of a Cambisol, Santa Catarina, Brazil, were investigated. Pinus introduction increased soil acidity, content of exchangeable Al+3 and diminished soil nutrients. Nevertheless, soil C stock increased in all humic fractions of the 0-5 cm layer after Pinus afforestation. In the subsurface, the vegetation change only promoted SOM redistribution from the NaOH-extractable humic substances to a less hydrophobic humin fraction. Under Pinus, soil organo-mineral interactions were relevant up to a 15 cm depth, while in pasture environment, this mechanism occurred mainly in the surface layer.

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In this study, the concentration and morphological characteristics of inhalable particulate material (PM10) were evaluated and associated with climatic conditions. The mean annual concentration was 11.0 µg m−3, varying between 0,647 µg m−3 and 36.8 µg m−3. Wind speed has a higher influence on PM10 dispersion, but direction was associated with particle source. During the wet period, wind speed is the main dispersion factor, while speed and direction both are important during the dry period. Based on the morphological characteristics, it is concluded that biogenic particles prevail during the rainy season and terrigenous particles during the dry period, depending on the wind direction and intensity.

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Atmospheric pollutants can have serious impacts on the preservation of São Paulo's tangible cultural heritage. The purpose of this paper is to report the results of a monitoring campaign focussed on particulate matter (PM) that was conducted in three of the most important museums of the São Paulo megacity (Brazil): the Museu de Arqueologia e Etnologia (MAE-USP), the Museu Paulista (MP-USP), and the Pinacoteca do Estado de São Paulo (PE). These museums exhibit indoor PM and black carbon (BC) concentrations consistent with their urban locations and their specific methods for managing the indoor environment.

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The goal of this study was to investigate the effect of composted pig slurry (PS) on the organic matter concentration and distribution of humic acid (HA), fulvic acid (FA) and humin (HU) fractions. The fractions were quantified following the addition of composted PS to the soil, which was produced with no acidification (T2) or with acidification with H3PO4 (T3); and in soil without compost addition (T1). The HA chemical composition was analyzed by FTIR spectroscopy. The addition of the two composts did not change the soil carbon concentration but affected the distribution of the humic fractions. For the three treatments, the carbon concentration of humic substances increased until 52 days following compost addition, with more pronounced increases with the addition of non-acidified PS compost (14.5 g kg-1) and acidified PS compost (15.1 g kg-1). This increase was reflected in both the FA and HA concentrations. The addition of compost with PS acidification resulted in the formation of larger humic micelles (HA) with higher aromatic content and fewer functional groups than the non-acidified PS compost. These findings, together with a lower proportion of carbohydrate-type structures, indicated the presence of more stable humic micelles in the soil treated with acidified PS compost.

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The dissertation is based on four articles dealing with recalcitrant lignin water purification. Lignin, a complicated substance and recalcitrant to most treatment technologies, inhibits seriously pulp and paper industry waste management. Therefore, lignin is studied, using WO as a process method for its degradation. A special attention is paid to the improvement in biodegradability and the reduction of lignin content, since they have special importance for any following biological treatment. In most cases wet oxidation is not used as a complete ' mineralization method but as a pre treatment in order to eliminate toxic components and to reduce the high level of organics produced. The combination of wet oxidation with a biological treatment can be a good option due to its effectiveness and its relatively low technology cost. The literature part gives an overview of Advanced Oxidation Processes (AOPs). A hot oxidation process, wet oxidation (WO), is investigated in detail and is the AOP process used in the research. The background and main principles of wet oxidation, its industrial applications, the combination of wet oxidation with other water treatment technologies, principal reactions in WO, and key aspects of modelling and reaction kinetics are presented. There is also given a wood composition and lignin characterization (chemical composition, structure and origin), lignin containing waters, lignin degradation and reuse possibilities, and purification practices for lignin containing waters. The aim of the research was to investigate the effect of the operating conditions of WO, such as temperature, partial pressure of oxygen, pH and initial concentration of wastewater, on the efficiency, and to enhance the process and estimate optimal conditions for WO of recalcitrant lignin waters. Two different waters are studied (a lignin water model solution and debarking water from paper industry) to give as appropriate conditions as possible. Due to the great importance of re using and minimizing the residues of industries, further research is carried out using residual ash of an Estonian power plant as a catalyst in wet oxidation of lignin-containing water. Developing a kinetic model that includes in the prediction such parameters as TOC gives the opportunity to estimate the amount of emerging inorganic substances (degradation rate of waste) and not only the decrease of COD and BOD. The degradation target compound, lignin is included into the model through its COD value (CODligning). Such a kinetic model can be valuable in developing WO treatment processes for lignin containing waters, or other wastewaters containing one or more target compounds. In the first article, wet oxidation of "pure" lignin water was investigated as a model case with the aim of degrading lignin and enhancing water biodegradability. The experiments were performed at various temperatures (110 -190°C), partial oxygen pressures (0.5 -1.5 MPa) and pH (5, 9 and 12). The experiments showed that increasing the temperature notably improved the processes efficiency. 75% lignin reduction was detected at the lowest temperature tested and lignin removal improved to 100% at 190°C. The effect of temperature on the COD removal rate was lower, but clearly detectable. 53% of organics were oxidized at 190°C. The effect of pH occurred mostly on lignin removal. Increasing the pH enhanced the lignin removal efficiency from 60% to nearly 100%. A good biodegradability ratio (over 0.5) was generally achieved. The aim of the second article was to develop a mathematical model for "pure" lignin wet oxidation using lumped characteristics of water (COD, BOD, TOC) and lignin concentration. The model agreed well with the experimental data (R2 = 0.93 at pH 5 and 12) and concentration changes during wet oxidation followed adequately the experimental results. The model also showed correctly the trend of biodegradability (BOD/COD) changes. In the third article, the purpose of the research was to estimate optimal conditions for wet oxidation (WO) of debarking water from the paper industry. The WO experiments were' performed at various temperatures, partial oxygen pressures and pH. The experiments showed that lignin degradation and organics removal are affected remarkably by temperature and pH. 78-97% lignin reduction was detected at different WO conditions. Initial pH 12 caused faster removal of tannins/lignin content; but initial pH 5 was more effective for removal of total organics, represented by COD and TOC. Most of the decrease in organic substances concentrations occurred in the first 60 minutes. The aim of the fourth article was to compare the behaviour of two reaction kinetic models, based on experiments of wet oxidation of industrial debarking water under different conditions. The simpler model took into account only the changes in COD, BOD and TOC; the advanced model was similar to the model used in the second article. Comparing the results of the models, the second model was found to be more suitable for describing the kinetics of wet oxidation of debarking water. The significance of the reactions involved was compared on the basis of the model: for instance, lignin degraded first to other chemically oxidizable compounds rather than directly to biodegradable products. Catalytic wet oxidation of lignin containing waters is briefly presented at the end of the dissertation. Two completely different catalysts were used: a commercial Pt catalyst and waste power plant ash. CWO showed good performance using 1 g/L of residual ash gave lignin removal of 86% and COD removal of 39% at 150°C (a lower temperature and pressure than with WO). It was noted that the ash catalyst caused a remarkable removal rate for lignin degradation already during the pre heating for `zero' time, 58% of lignin was degraded. In general, wet oxidation is not recommended for use as a complete mineralization method, but as a pre treatment phase to eliminate toxic or difficultly biodegradable components and to reduce the high level of organics. Biological treatment is an appropriate post treatment method since easily biodegradable organic matter remains after the WO process. The combination of wet oxidation with subsequent biological treatment can be an effective option for the treatment of lignin containing waters.

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Tutkimuksen tavoitteena on tutkia teollisuudelle aineita maahantuovan perheyrityksen toimintaympäristössä tapahtuvaa muutosta. Tutkimuksessa lähestytään yrityksen muuttuvaa toimintaympäristöä strategian näkökulmasta ja otetaan huomioon muuttuvana seikkana lainsäädäntö eli REACH -kemikaaliasetus. Tutkimuksen tutkimusongelmaa käsitellään konstruktiivisen tutkimuksen tapaan. Tutkimuksen aineisto on kerätty kvalitatiivisen tutkimuksen tapaan keräämällä tutkimustietoa valmiista aineistosta kuten arkistoista, dokumenteista ja kirjallisuudesta. Tutkimukseen on myös käytetty havaintoja, haastatteluja ja arkikokemuksia tutkimuksen kohteesta. Tutkimuksen viitekehyksessä käytiin läpi strategian teoriaa ulkoisesta toimintaympäristöstä yrityksen sisäiseen toimintaympäristöön. Yritykselle laadittiin strategiakeskeinen malli ottaen huomioon uuden lain tuomat vaikutukset yrityksen sisäiseen ja ulkoiseen toimintaympäristöön. Lakimuutoksen vaikutuspintoja löytyi kaksi: yrityksen toimialan toimintaympäristö ja sisäinen toimintaympäristö. Toimialan toimintaympäristössä eriteltiin lakimuutoksen rajapinnat viiden kilpailuvoiman avulla. Tulokseksi saatiin, että REACH vaikuttaa vahvasti läpi koko toimitusketjun. Vaikutustavat ovat korvaavat tuotteet, ostajien vaikutusvalta ja toimittajien vaikutusvalta. Lisäksi yhtenä vaikuttajana voidaan pitää uusia tulijoita sekä kilpailua nykyisten yritysten kanssa. Yrityksen sisäisestä toimintaympäristöstä löydettiin arvoketjun avulla lisää vaikutuskohtia. Ne olivat raaka-aineiden hankinnat, dokumentointi, näytteiden lähetys, varastointi ja varastokirjanpito. Lisäksi huomioitiin tukitoiminnoista lakiasiat ja henkilöstön koulutus.