The materiality of the immaterial. Services sectors and CO2 emissions in Uruguay

This paper analyzes the carbon dioxide emissions of the services sectors subsystem of Uruguay in 2004. Services, with the exception of transport, are often considered intangible because of their low level of direct emissions. However, the provision of services requires inputs produced by other sectors, including several highly materialintensive sectors. Through input–output analysis we investigate the relationship between the services subsystem and the rest of the economy as regards carbon dioxide emissions. This approach allows us to study the importance of the set of services branches as a unit in the economic structure as well as to analyze in detail the relationship between the branches. The results depict that services’ direct emissions are the main component, as a consequence of transport-related sectors. However, the pollution that the services subsystem makes the rest of the economy produce is very significant, and it is almost all explained by non-transport-related sectors. This analysis is useful for determining the sectors in which mitigation policies are more effective, and whether they would be better tackled through technical improvements and better practices or through demand policies.

Treatment of oily wastewater by ultrafiltration: The effect of different operating and solution conditions

In many industries, such as petroleum production, and the petrochemical, metal, food and cosmetics industries, wastewaters containing an emulsion of oil in water are often produced. The emulsions consist of water (up to 90%), oils (mineral, animal, vegetable and synthetic), surfactants and other contaminates. In view of its toxic nature and its deleterious effects on the surrounding environment (soil, water) such wastewater needs to be treated before release into natural water ways. Membrane-based processes have successfully been applied in industrial applications and are considered as possible candidates for the treatment of oily wastewaters. Easy operation, lower cost, and in some cases, the ability to reduce contaminants below existing pollution limits are the main advantages of these systems. The main drawback of membranes is flux decline due tofouling and concentration polarisation. The complexity of oil-containing systems demands complementary studies on issues related to the mitigation of fouling and concentration polarisation in membranebased ultrafiltration. In this thesis the effect of different operating conditions (factors) on ultrafiltration of oily water is studied. Important factors are normally correlated and, therefore, their effect should be studied simultaneously. This work uses a novel approach to study different operating conditions, like pressure, flow velocity, and temperature, and solution properties, like oil concentration (cutting oil, diesel, kerosene), pH, and salt concentration (CaCl2 and NaCl)) in the ultrafiltration of oily water, simultaneously and in a systematic way using an experimental design approach. A hypothesis is developed to describe the interaction between the oil drops, salt and the membrane surface. The optimum conditions for ultrafiltration and the contribution of each factor in the ultrafiltration of oily water are evaluated. It is found that the effect on permeate flux of the various factors studied strongly depended on the type of oil, the type of membrane and the amount of salts. The thesis demonstrates that a system containing oil is very complex, and that fouling and flux decline can be observed even at very low pressures. This means that only the weak form of the critical flux exists for such systems. The cleaning of the fouled membranes and the influence of different parameters (flow velocity, temperature, time, pressure, and chemical concentration (SDS, NaOH)) were evaluated in this study. It was observed that fouling, and consequently cleaning, behaved differently for the studied membranes. Of the membranes studied, the membrane with the lowest propensity for fouling and the most easily cleaned was the regenerated cellulose membrane (C100H). In order to get more information about the interaction between the membrane and the components of the emulsion, a streaming potential study was performed on the membrane. The experiments were carried out at different pH and oil concentration. It was seen that oily water changed the surface charge of the membrane significantly. The surface charge and the streaming potential during different stages of filtration were measured and analysed being a new method for fouling of oil in this thesis. The surface charge varied in different stages of filtration. It was found that the surface charge of a cleaned membrane was not the same as initially; however, the permeability was equal to that of a virgin membrane. The effect of filtration mode was studied by performing the filtration in both cross-flow and deadend mode. The effect of salt on performance was considered in both studies. It was found that salt decreased the permeate flux even at low concentration. To test the effect of hydrophilicity change, the commercial membranes used in this thesis were modified by grafting (PNIPAAm) on their surfaces. A new technique (corona treatment) was used for this modification. The effect of modification on permeate flux and retention was evaluated. The modified membranes changed their pore size around 33oC resulting in different retention and permeability. The obtained results in this thesis can be applied to optimise the operation of a membrane plant under normal or shock conditions or to modify the process such that it becomes more efficient or effective.

Governmental Measures to Enhance the Finnish Innovation System to Respond to the Challenge of Mitigating Climate Change

Climate innovations, that cover both technological applications and process and service innovations, play a key role in climate change mitigation. The purpose of this study was to examine how the Finnish innovation system could be enhanced with governmental measures so that the diffusion of climate innovations could be speeded up. During the study, it became evident that the governmental measures need to support the whole innovation chain, which comprises of research, development, demonstration and deployment. Only this can lead to the successful birth and diffusion of low carbon innovations. The study found that the strengths of the Finnish innovation system are research and development, and the current national innovation policies strongly support these activities. However, these have been emphasised at the expense of the demonstration and deployment. Consequently, the biggest bottlenecks in the Finnish innovation landscape are the lack of pilot and demonstration projects and slow commercialisation, thus the high price of the innovation. To meet with the challenge, the government should firstly promote strict greenhouse gas emission reduction targets. This would boost up the innovation activities, which would also lower the prices of the innovations. To speed up the commercialisation process, measures that stimulate the domestic market, such as feed-in-tariffs and public procurements, are needed. Special attention should also be paid to the measures that could shift the traditional closed innovation chain towards open innovation. This means that the product development should involve experts from several fields such as the user and marketing experts to speed up the commercialisation. In addition, efficient innovation co-operation between both private and public sector is essential. Finally, as the domestic resources are not adequate for producing all the innovations needed, the domestic innovation activities should be focused on a few sectors, and at the same time promote efficient import policies.

Perda química de carbono e cinética do crescimento celular em cultivos de Spirulina

Photosynthetic microorganism cultures, such as microalgae, represent one of the alternatives for fossil CO2 emissions mitigation. Carbon supply is the major cost component in microalgal cultures. Aiming to enhance the dissolved inorganic carbon uptake efficiency in microalgal cultures, Spirulina sp LEB-18 was cultivated in mediums containing NaHCO3 concentrations ranging from 2.8 to 100 g L-1. Results indicated that lower dissolved inorganic carbon concentratios (2.8 g L-1 NaHCO3) produce higher growth parameters (Xmax = 0.75 g L-1; Pmax = 0.145 g L-1 d-1; µmax = 0.254 d-1) and lower carbon losses (13.61%). At 50 g L-1 of NaHCO3 cell growth was inhibited and carbon losses reached 38.73%.

Inventário de emissão de fontes veiculares da Região Metropolitana de Campinas, São Paulo

The degradation of air quality in great urban centers is noted by frequent critical episodes of air pollution and public health issues, and vehicles are a great source of pollutant emissions, mainly derived from combustion processes. A database is needed to direct mitigation of emissions. The main objective of this work is to present it as an emissions inventory. The results show that vehicular sources of CO, HC and NOx represent over 75% of total emissions in the MRC. Besides, the proposed methodology presented results consistent with the literature

Formaldeído em escolas: uma revisão

Formaldehyde has been classified as a probable human carcinogen. Indoor air quality measurements carried out worldwide in schools indicate that levels may be of concern. This paper provides an overview of emission sources, properties and methods for quantification of formaldehyde. Quantitative information from studies performed in school environments was compiled and a comprehensive picture of the causal relationships between pollutant exposures and children's health given. Mitigation actions to reduce formaldehyde levels and its adverse impacts in school buildings are recommended.

Oceanografia e Química: unindo conhecimentos em prol dos oceanos e da sociedade

The marine environment is certainly one of the most complex systems to study, not only because of the challenges posed by the nature of the waters, but especially due to the interactions of physical, chemical and biological processes that control the cycles of the elements. Together with analytical chemists, oceanographers have been making a great effort in the advancement of knowledge of the distribution patterns of trace elements and processes that determine their biogeochemical cycles and influences on the climate of the planet. The international academic community is now in prime position to perform the first study on a global scale for observation of trace elements and their isotopes in the marine environment (GEOTRACES) and to evaluate the effects of major global changes associated with the influences of megacities distributed around the globe. This action can only be performed due to the development of highly sensitive detection methods and the use of clean sampling and handling techniques, together with a joint international program working toward the clear objective of expanding the frontiers of the biogeochemistry of the oceans and related topics, including climate change issues and ocean acidification associated with alterations in the carbon cycle. It is expected that the oceanographic data produced this coming decade will allow a better understanding of biogeochemical cycles, and especially the assessment of changes in trace elements and contaminants in the oceans due to anthropogenic influences, as well as its effects on ecosystems and climate. Computational models are to be constructed to simulate the conditions and processes of the modern oceans and to allow predictions. The environmental changes arising from human activity since the 18th century (also called the Anthropocene) have made the Earth System even more complex. Anthropogenic activities have altered both terrestrial and marine ecosystems, and the legacy of these impacts in the oceans include: a) pollution of the marine environment by solid waste, including plastics; b) pollution by chemical and medical (including those for veterinary use) substances such as hormones, antibiotics, legal and illegal drugs, leading to possible endocrine disruption of marine organisms; and c) ocean acidification, the collateral effect of anthropogenic emissions of CO2 into the atmosphere, irreversible in the human life time scale. Unfortunately, the anthropogenic alteration of the hydrosphere due to inputs of plastics, metal, hydrocarbons, contaminants of emerging concern and even with formerly "exotic" trace elements, such us rare earth elements is likely to accelerate in the near future. These emerging contaminants would likely soon present difficulties for studies in pristine environments. All this knowledge brings with it a great responsibility: helping to envisage viable adaptation and mitigation solutions to the problems identified. The greatest challenge faced by Brazil is currently to create a framework project to develop education, science and technology applied to oceanography and related areas. This framework would strengthen the present working groups and enhance capacity building, allowing a broader Brazilian participation in joint international actions and scientific programs. Recently, the establishment of the National Institutes of Science and Technology (INCTs) for marine science, and the creation of the National Institute of Oceanographic and Hydrological Research represent an exemplary start. However, the participation of the Brazilian academic community in the latest assaults on the frontier of chemical oceanography is extremely limited, largely due to: i. absence of physical infrastructure for the preparation and processing of field samples at ultra-trace level; ii. limited access to oceanographic cruises, due to the small number of Brazilian vessels and/or absence of "clean" laboratories on board; iii. restricted international cooperation; iv. limited analytical capacity of Brazilian institutions for the analysis of trace elements in seawater; v. high cost of ultrapure reagents associated with processing a large number of samples, and vi. lack of qualified technical staff. Advances in knowledge, analytic capabilities and the increasing availability of analytical resources available today offer favorable conditions for chemical oceanography to grow. The Brazilian academic community is maturing and willing to play a role in strengthening the marine science research programs by connecting them with educational and technological initiatives in order to preserve the oceans and to promote the development of society.

Química Sem Fronteiras: o desafio da energia

Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great effort to develop "second-generation" technologies to produce methanol, ethanol, butanol, biodiesel, biogas (methane), bio-oils, syngas and synthetic fuels from lower grade renewable feedstocks such as lignocellulosic materials whose consumption would not interfere with the rather sensitive issues of food security. Advanced fermentation processes are envisaged as "third generation" technologies and these are primarily linked to the use of algae feedstocks as well as other organisms that could produce biofuels or simply provide microbial biomass for the processes listed above. Due to the complexity and cost of their production chain, "third generation" technologies usually aim at high value added biofuels such as biojet fuel, biohydrogen and hydrocarbons with a fuel performance similar to diesel or gasoline, situations in which the use of genetically modified organisms is usually required. In general, the main challenges in this field could be summarized as follows: (a) the need for prospecting alternative sources of biomass that are not linked to the food chain; (b) the intensive use of green chemistry principles in our current industrial activities; (c) the development of mature technologies for the production of second and third generation biofuels; (d) the development of safe bioprocesses that are based on environmentally benign microorganisms; (e) the scale-up of potential technologies to a suitable demonstration scale; and (f) the full understanding of the technological and environmental implications of the food vs. fuel debate. On the basis of these, the main objective of this article is to stimulate the discussion and help the decision making regarding "energy security" issues and their challenges for modern society, in such a way to encourage the participation of the Brazilian Chemistry community in the design of a road map for a safer, sustainable and prosper future for our nation.

ARSÊNIO E ARROZ: TOXICIDADE, METABOLISMO E SEGURANÇA ALIMENTAR

Arsenic is considered a semimetal, and its wide distribution in the Earth's crust in different chemical forms, including organic and inorganic species, has a great deal of influence on the mechanisms of toxicity. Exposure to arsenic can be either through occupational practice (use of pesticides) or by the consumption of water and food containing the element. Rice is considered a fundamental constituent of the basic diet of Brazilians and is usually cultivated in flooded conditions. Such a plantation system results in an increased amount of As in the soil and hence a greater accumulation of As in the plant, which is highlighted by the inorganic species' classification as highly toxic. Besides the use of mitigation techniques to reduce the toxicological risk, monitoring the concentration of As and its chemical species in rice and rice products is required through the establishment of legislation in the area. Thus, some world organizations are conducting improved research to determine and establish acceptable concentrations of As and its chemical species in rice, e. g., in 2012, FDA researchers described a chemical speciation methodology for As in rice and rice products. Hence, the application of existing chemical speciation methods and the establishment of parameters for ensuring food security and exposure risk assessment deserve particular consideration.

EMISSÕES DE ÓXIDO NITROSO E METANO DO SOLO EM ÁREAS DE RECUPERAÇÃO DE PASTAGENS NA AMAZÔNIA MATOGROSSENSE

AbstractThis study evaluates the chemical processes responsible for the nitrous oxide (N2O) and methane (CH4) fluxes in the managed pasture (PM) and unmanaged pasture (PNM). In addition, the impact of nitrogen fertilization on the N2O and CH4 fluxes was assessed. The experiments were conducted on three farms in Alta Floresta city in the state of Mato Grosso. Both regular and intensive samples were collected from PM, PNM, and forest areas for each of the properties. The gases were sampled using static chambers in the morning. Higher N2O fluxes were recorded in the PMs, whereas the CH4 fluxes showed no influence of nitrogen fertilization in both regular and intensive samples. Low fertilizer levels resulted in low N2O emissions.

A FACTORIAL DESIGN APPLIED TO THE STUDY OF CHROMIUM TOXICITY ON THE GLUTATHIONE LEVELS OF Brachiaria brizantha AND Brachiaria ruziziensis SEEDLINGS

Chromium toxicity affects redox reactions within plant cells, generating detrimental reactive oxygen species. Glutathione is an antioxidant peptide and also a substrate for the production of phytochelatins, which are chelating peptides reported to mitigate Cr3+ toxicity in plants. In this study, Brachiaria brizantha (B. brizantha) and Brachiaria ruziziensis (B. ruziziensis) seedlings were evaluated for physiological responses and glutathione production following the addition of zero or 5 mg L-1 Cr3+ to the nutrient solution. Glutathione levels were determined by colorimetric analysis at 412 nm using 5,5'-dithio-bis(2-nitrobenzoic acid) as a chromophore reagent and recovery with glutathione reductase (with evaluations at days 10 and 20 of continuous growth). The assessments were carried out in a completely randomized design with 2 authentic replications, and arranged in a 23 factorial. Cr3+ caused an average increase of 0.76 mg g-1 in the initial glutathione content. However, by day 20 there was an average reduction of 3.63 mg g-1. Chromium-affected physiological detrimental responses, albeit detected in both species, were less-pronounced in B. ruziziensis, along with a much higher level of glutathione. This study indicates that B. ruziziensis has a greater tolerance for chromium toxicity than B. brizantha, and that glutathione is likely to be involved in the mitigation of chromium stress in B. ruziziensis.

Multilevel converter modulation: implementation and analysis

Multilevel converters provide an attractive solution to bring the benefits of speed-controlled rotational movement to high-power applications. Therefore, multilevel inverters have attracted wide interest in both the academic community and in the industry for the past two decades. In this doctoral thesis, modulation methods suitable especially for series connected H-bridge multilevel inverters are discussed. A concept of duty cycle modulation is presented and its modification is proposed. These methods are compared with other well-known modulation schemes, such as space-vector pulse width modulation and carrier-based modulation schemes. The advantage of the modified duty-cycle modulation is its algorithmic simplicity. A similar mathematical formulation for the original duty cycle modulation is proposed. The modified duty cycle modulation is shown to produce well-formed phase-to-neutral voltages that have lower total harmonic distortion than the space-vector pulse width modulation and the duty cycle modulation. The space-vector-based solution and the duty cycle modulation, on the other hand, result in a better-quality line-to-line voltage and current waveform. The voltage of the DC links in the modules of the series-connected H-bridge inverter are shown to fluctuate while they are under load. The fluctuation causes inaccuracies in the voltage production, which may result in a failure of the flux estimator in the controller. An extension for upper-level modulation schemes, which changes the switching instants of the inverter so that the output voltage meets the reference voltage accurately regardless of the DC link voltages, is proposed. The method is shown to reduce the error to a very low level when a sufficient switching frequency is used. An appropriate way to organize the switching instants of the multilevel inverter is to make only one-level steps at a time. This causes restrictions on the dynamical features of the modulation schemes. The produced voltage vector cannot be rotated several tens of degrees in a single switching period without violating the above-mentioned one-level-step rule. The dynamical capabilities of multilevel inverters are analyzed in this doctoral thesis, and it is shown that the multilevel inverters are capable of operating even in dynamically demanding metal industry applications. In addition to the discussion on modulation schemes, an overvoltage in multilevel converter drives caused by cable reflection is addressed. The voltage reflection phenomenon in drives with long feeder cables causes premature insulation deterioration and also affects the commonmode voltage, which is one of the main reasons for bearing currents. Bearing currents, on the other hand, cause fluting in the bearings, which results in premature bearing failure. The reflection phenomenon is traditionally prevented by filtering, but in this thesis, a modulationbased filterless method to mitigate the overvoltage in multilevel drives is proposed. Moreover, the mitigation method can be implemented as an extension for upper-level modulation schemes. The method exploits the oscillations caused by two consecutive voltage edges so that the sum of the oscillations results in a mitigated peak of the overvoltage. The applicability of the method is verified by simulations together with experiments with a full-scale prototype.

Frequency converter protection against supply network phenomena

This master’s thesis is focused on power supply network disturbances and their effects on the frequency converter – one of the components of modern process crane electrical system. The most critical disturbance types, their causes and the effect they bring to crane electrical system was determined in this work. Variety of protective devices used for mitigation of disturbances is investigated. Device protection solutions for the frequency converter used in crane applications are presented. Analyses of the power supply requirements for frequency converter and various components of crane electrical system were carried out and as a result the crane power supply requirements list that guarantees normal crane operation was built. This list is to be included in crane projects for troubleshooting purposes in order to determine potentially dangerous network.

Luonnon kasvihuonekaasulähteiden ja -nielujen laskenta maakunnallisella tasolla

Kiihtyvän kasvihuoneilmiön aiheuttama maailmanlaajuinen ilmastonmuutos on yksi aikamme suurimmista haasteista. Kasvihuoneilmiön voimistuminen on ihmistoiminnan seurausta, mutta myös luonnon omat prosessit toimivat kasvihuonekaasujen lähteinä ja nieluina. Tässä työssä on selvitetty luonnon kasvihuonekaasulähteiden ja –nielujen määrää ja merkitystä maakunnallisella tasolla. Lisäksi työssä on esitetty maakunnallisia toimenpide-ehdotuksia kasvihuonekaasunielujen ylläpitämiseksi ja lisäämiseksi. Esimerkkinä työssä on käytetty Keski-Suomen maakuntaa ja laskenta on kohdistettu vuoteen 2008. Keski-Suomessa luonnon prosessit toimivat vuonna 2008 nettonieluna, jonka suuruus oli 1 813 701 tonnia hiilidioksidiekvivalenttia. Eniten kasvihuonekaasuja sitoi puusto 3 019 360 hiilidioksidiekvivalenttitonnin nielulla. Laskennassa huomioitiin hiilidioksidi, metaani ja dityppioksidi. Laskenta suoritettiin soveltuvilta osin kansallisen kasvihuonekaasuraportoinnin periaatteiden mukaisesti sekä tutkimuskirjallisuuteen perustuvien päästö- ja nielukertoimien avulla. Tämä työ osoittaa luonnon nielujen olevan tärkeässä roolissa ilmastonmuutoksen hillitsemisessä. Nielujen säilyttämiseen ja lisäämiseen tähtäävillä toimenpiteillä ilmakehän kasvihuonekaasupitoisuuksiin voidaan vaikuttaa kustannustehokkaasti sekä maailmanlaajuisella että alueellisella tasolla.