924 resultados para Copper mines and mining
Resumo:
There has been a long standing desire to produce thick (up to 500 nm) cryo-sections of fully hydrated cells and tissue for high-resolution analysis in their natural state by cryo-transmission electron microscopy. Here, we present a method that can successfully produce sections (lamellas in FIB-SEM terminology) of fully hydrated, unstained cells from high-pressure frozen samples by focused ion beam (FIB) milling. The samples are therefore placed in thin copper tubes and vitrified by high-pressure freezing. For transfer, handling and subsequent milling, the tubes are placed in a novel connective device (ferrule) that protects the sample from devitrification and contamination and passes through all operation steps. A piezo driven sample positioning stage (cryo-nano-bench, CNB) with three degrees of freedom was additionally developed to enable accurate milling of frozen-hydrated lamellas. With the CNB, high-pressure frozen samples can be milled to produce either thin lamellas (<100 nm), for direct imaging by high-resolution cryo-TEM or thicker lamellas (300-500 nm) for cryo-electron tomography. The sample remains vitreous throughout the process by using the presented tools and methods. The results are an important step towards investigating larger cells and even tissue in there natural state which in the end will enable us to gain better insights into cellular processes.
Resumo:
The broad aim of biomedical science in the postgenomic era is to link genomic and phenotype information to allow deeper understanding of the processes leading from genomic changes to altered phenotype and disease. The EuroPhenome project (http://www.EuroPhenome.org) is a comprehensive resource for raw and annotated high-throughput phenotyping data arising from projects such as EUMODIC. EUMODIC is gathering data from the EMPReSSslim pipeline (http://www.empress.har.mrc.ac.uk/) which is performed on inbred mouse strains and knock-out lines arising from the EUCOMM project. The EuroPhenome interface allows the user to access the data via the phenotype or genotype. It also allows the user to access the data in a variety of ways, including graphical display, statistical analysis and access to the raw data via web services. The raw phenotyping data captured in EuroPhenome is annotated by an annotation pipeline which automatically identifies statistically different mutants from the appropriate baseline and assigns ontology terms for that specific test. Mutant phenotypes can be quickly identified using two EuroPhenome tools: PhenoMap, a graphical representation of statistically relevant phenotypes, and mining for a mutant using ontology terms. To assist with data definition and cross-database comparisons, phenotype data is annotated using combinations of terms from biological ontologies.
Resumo:
The compounds responsible for the colours and decorations in glass and glazed ceramics include: colouring agents (transition metal ions), pigments (micro-and nano-precipitates of compounds that either do not dissolve or recrystallize in the glassy matrix) and opacifiers (microcrystalline compounds with high light scattering capability). Their composition, structure and range of stability are highly dependent not only on the composition but also on the procedures followed to obtain them. Chemical composition of the colorants and crystallites may be obtained by means of SEM-EDX and WDX. Synchrotron Radiation micro-X-ray Diffraction has a small beam size adequate (10 to 50 microns footprint size) to obtain the structural information of crystalline compounds and high brilliance, optimal for determining the crystallites even when present in low amounts. In addition, in glass decorations the crystallites often appear forming thin layers (from 10 to 100 micrometers thick) and they show a depth dependent composition and crystal structure. Their nature and distribution across the glass/glazes decorations gives direct information on the technology of production and stability and may be related to the color and appearance. A selection of glass and glaze coloring agents and decorations are studied by means of SR-micro- XRD and SEM-EDX including: manganese brown, antimony yellow, red copper lusters and cobalt blue. The selection includes Medieval (Islamic, and Hispano Moresque) and renaissance tin glazed ceramics from the 10th to the 17th century AD.
Resumo:
La contaminació per nitrats de les aigües subterrànies és un dels problemes mediambientals i de salut pública que més afecten els nostres aqüífers. És per això que un dels eixos del nostre estudi és fer la màxima difusió de l’estat de la qualitat de l’aigua dels aqüífers de diferents àrees de Catalunya. En el present estudi es tracta la contaminació per nitrats a les aigües de 945 punts de mostreig (sobretot d’aigua procedent de pous, d’algunes mines i d’algunes fonts) de Catalunya, situats en 12 comarques diferents, totes elles amb algun o una gran part dels seus municipis englobats en una zona vulnerable. D’aquests punts de mostreig s’ha fet un recull de dades de la concentració de nitrats des de l’any 2003 fins el 2012 per tal d’estudiar-ne l’evolució i la incidència de la pluviometria, així com conèixer en quines comarques les variables externes: superfície agrària útil (SAU), explotacions agràries i cabana porcina i bovina poden haver incidit directament en la contaminació. També s’estudia fins a quin punt, aquest deteriorament, ha afectat la mineralització de l’aigua o afecta a llocs d’aigües més mineralitzades. A partir dels resultats obtinguts s’ha arribat a les conclusions que la concentració mitjana de nitrats a les aigües subterrànies en la majoria de comarques estudiades és elevada, superior als 50 mg/l que estableix la normativa vigent; que ha tendit a l’estabilitat en els últims deu anys; que afecta llocs d’aigües molt mineralitzades i que la pluviometria incideix notablement en la concentració de nitrats. S’ha observat que les variables externes superfície agrària útil (SAU), explotacions agràries i cabana porcina i bovina incideixen directament en la contaminació, excepte al Maresme. Finalment es presenten diferents usos alternatius als de l’aigua de consum per aquestes aigües contaminades amb nitrats i que han posat en pràctica diferents municipis de les comarques estudiades.
Resumo:
The purpose of this project is to develop an investment analysis model that integrates the capabilities of four types of analysis for use in evaluating interurban transportation system improvements. The project will also explore the use of new data warehousing and mining techniques to design the types of databases required for supporting such a comprehensive transportation model. The project consists of four phases. The first phase, which is documented in this report, involves development of the conceptual foundation for the model. Prior research is reviewed in Chapter 1, which is composed of three major sections providing demand modeling background information for passenger transportation, transportation of freight (manufactured products and supplies), and transportation of natural resources and agricultural commodities. Material from the literature on geographic information systems makes up Chapter 2. Database models for the national and regional economies and for the transportation and logistics network are conceptualized in Chapter 3. Demand forecasting of transportation service requirements is introduced in Chapter 4, with separate sections for passenger transportation, freight transportation, and transportation of natural resources and commodities. Characteristics and capacities of the different modes, modal choices, and route assignments are discussed in Chapter 5. Chapter 6 concludes with a general discussion of the economic impacts and feedback of multimodal transportation activities and facilities.
Resumo:
Airborne particles can come from a variety of sources and contain variable chemical constituents. Some particles are formed by natural processes, such as volcanoes, erosion, sea spray, and forest fires, while other are formed by anthropogenic processes, such as industrial- and motor vehicle-related combustion, road-related wear, and mining. In general, larger particles (those greater than 2.5 μm) are formed by mechanical processes, while those less than 2.5 μm are formed by combustion processes. The chemical composition of particles is highly influenced by the source: for combustion-related particles, factors such as temperature of combustion, fuel type, and presence of oxygen or other gases can also have a large impact on PM composition. These differences can often be observed at a regional level, such as the greater sulphate-composition of PM in regions that burn coal for electricity production (which contains sulphur) versus regions that do not. Most countries maintain air monitoring networks, and studies based on the resulting data are the most common basis for epidemiology studies on the health effects of PM. Data from these monitoring stations can be used to evaluate the relationship between community-level exposure to ambient particles and health outcomes (i.e., morbidity or mortality from various causes). Respiratory and cardiovascular outcomes are the most commonly assessed, although studies have also considered other related specific outcomes such as diabetes and congenital heart disease. The data on particle characteristics is usually not very detailed and most often includes some combination of PM2.5, PM10, sulphate, and NO2. Other descriptors that are less commonly found include particle number (ultrafine particles), metal components of PM, local traffic intensity, and EC/OC. Measures of association are usually reported per 10 μg/m3 or interquartile range increase in pollutant concentration. As the exposure data are taken from regional monitoring stations, the measurements are not representative of an individual's exposure. Particle size is an important descriptor for understanding where in the human respiratory system the particles will deposit: as a general rule, smaller particles penetrate to deeper regions of the lungs. Initial studies on the health effects of particulate matter focused on mass of the particles, including either all particles (often termed total suspended particulate or TSP) or PM10 (all particles with an aerodynamic diameter less than 10 μm). More recently, studies have considered both PM10 and PM2.5, with the latter corresponding more directly to combustion-related processes. UFPs are a dominant source of particles in terms of PNC, yet are negligible in terms of mass. Very few epidemiology studies have measured the effect of UFPs on health; however, the numbers of studies on this topic are increasing. In addition to size, chemical composition is of importance when understanding the toxicity of particles. Some studies consider the composition of particles in addition to mass; however this is not common, in part due the cost and labour involved in such analyses.
Resumo:
Diplomityössä on tarkasteltu kunnissa myönnettyjen ympäristölupien myöntämiskriteereitä ja niiden yhtenäistämismahdollisuuksia eläinsuojien, polttonesteiden jakeluasemien sekä kivenlouhimokokonaisuuksien osalta. Työssä tutkittiin ympäristönsuojelulain (86/2000) mukaisialupapäätöksiä viidestä kunnasta. Lupapäätöksissä havaittiin eroja kuntien välillä kaikkien lupakokonaisuuksien osalta. Pääasiassa erot kohdistuivat ympäristölautakunnan antamiin lupamääräyksiin. Lupien myöntämiskriteereiden yhtenäistäminen kuntatasolla vaatii aikaa ja resursseja, mutta ei ole mahdotonta. Yhtenäistämiskeinoja ovat kunnan sisäinen muistilista, korkeimman hallinto-oikeuden ratkaisulinjan tulkitseminen, ympäristönsuojelulain tulkinnan syventämien, alueellisten ympäristökeskusten taitojen hyödyntäminen sekä kuntien välinenyhteistyö. Kutakin yhtenäistämiskeinoa voi käyttää itsenäisenä keinona, mutta tehokkaampi tulos saada yhdistämällä kaikki viisi keinoa. Keinojen yhtenäistäminen on paras toteuttaa kunnan ympäristötarkastajien koulutuksella.
Resumo:
One critical factor for success in characterizing metals polluting mining environments so as to be able to eliminate them and subsequently recover these areas depends upon a speedy and correct response in the analysis of samples. Rapid, simultaneous, multi-element analysis can be undertaken using X-ray fluorescence spectrometry, a versatile, non-destructive analytical technique commonly employed to identify both major and minor elements in samples related to environmental studies. An additional advantage of this technique is the possibility of conducting the analysis directly on solid samples, which is extremely convenient when dealing with environmental samples that are difficult to dissolve, such as soils, sediments and mining wastes. Moreover, in recent years the development of spectrometers equipped with digital-signal processors combined with enlarged X-ray production, using better designs for excitation-detection, has contributed to an improvement in instrumental sensitivity, thus allowing us to detect important polluting elements such as Cd and Pb at trace levels. In this paper the authors describe, on the basis of their own experience, some interesting applications of XRF spectrometry for the analysis of several types of environmental samples related to the study of the dispersion of metals within mining environments: (A) analysis of mining wastes, soils and sediments; (B) analysis of samples of vegetation used as bioindicators or related to phytoremediation studies; and (C) analysis of water samples related to mining operations
Resumo:
Työn teoriaosassa käydään läpi kuparisulaton prosessi pääpiirteittäin, jonka jälkeen siirrytään lämmönsiirron teoriaan. Lämpö siirtyy kolmella penis mekanismilla: johtumalla, säteilemällä ja konvektiolla. Naiden ilmiöiden vaikutusta kupariliekkisulatusuunin eri osissa tapahtuviin lämpöhäviöihin on käyty läpi. Lisaksi työstä löytyy kupariliekkisulatusuunin lämpö- ja ainetase sekä erilaisten lämpötilanmittauslaitteiden vertailua sekä mitä tulee ottaa huomioon lämpötiloja mitatessa. Työn kokeellisessa osassa esitellään lämpötilanmittausten perusteella lasketut kupariliekkisulatusuunin eri osien lämpöhäviöiden suuruudet mittauskampanjan ajalta. Saatuja tuloksia on vertailtu kirjallisuudesta löydettyihin aikaisempiin arvoihin. Uunin keskimääräiseksi kokonaislämpöhäviöksi saatiin 9,8 MW mittauskampanjan ajalle. Lisäksi on vertailtu uunin erilaisten ajoarvojen, kuten rikaste-, lentopöly-, murska-, ja kuonarikastesyötön suuruuden sekä öljyn syötön ja rikasteseoksen vaihtumisen vaikutusta lämpöhäviöihin sekä mietitty muita mahdollisia syitä lämpöhäviöiden vaihtelulle.
Resumo:
Työssä selvitettiin kuparielektrolyysissä syntyvän sivutuotteen, arseenitrioksidin, soveltuvuutta The New Boliden Kokkola Zinc Oy:n sinkkitehtaan liuospuhdistuksen koboltinpoistovaiheeseen. Nykyään sinkkitehtaalla käytetään puhdasta arseenitrioksidia koboltinpoiston apuaineena. Tällä hetkellä kuparielektrolyysin arseenista valmistetaan puunsuoja-aineita. Lainsäädäntö muuttuu siten että tulevaisuudessa kyseisten puunsuoja-aineiden käyttöä tullaan yhä rajoittamaan. Kun puunsuoja-aineiden kulutus vähenee, täytyy syntyvä arseeni varastoida jätealueelle ellei sille löydetä muuta käyttöä. Arseenin varastointitarve ei lisäänny jos kuparielektrolyysistä saatava arseeni voidaan hyödyntää sinkkitehtaalla. Kuparielektrolyysissä syntyvä arseenitrioksidi ei ole puhdasta. Työssä selvitettiin epäpuh-tauksien vaikutusta sinkkitehtaan liuospuhdistuksen koboltinpoistovaiheeseen. Kokeiden olosuhteet pyrittiin yhdenmukaistamaan sinkkitehtaan koboltinpoistovaiheessa vallitsevia olosuhteita vastaaviksi. Kokeissa käytetyillä arseeniliuosten eri epäpuhtaustasoilla ei havaittu olevan selkeää eroa liuospuhdistuskyvyssä. Koetulokset antavat viitteitä siitä, että koboltinpoistoprosessi on oletettua epäherkempi arseeniliuoksen epäpuhtauksien vaikutuksille. Kirjallisuudesta haettiin arseenitrioksidin valmistukseen ja puhdistamiseen liittyvää aineistoa. Valmistusmenetelminä tarkasteltiin valmistusta arseenimalmista ja kuparielektrolyytistä ja puhdistusmenetelminä uudelleenkiteytystä, jäädytys-sulatusprosessia ja ioninvaihtoa. Työssä puhdistettiin kuparielektrolyysin liuospuhdistuksessa syntyvää arseenitrioksidia. Puhdistuslaitteistosta tehtiin alustava prosessisuunnitelma.
Resumo:
The NaCl- KCl system as fused-salt solvent for leaching has shown to have some advantages over traditional solvents. In this work the solubility of copper, nickel and cobalt oxide in this system, as impurities in manganese concentrate, was studied. The euthetic mixture of NaCl - KCl at 700ºC was used at several fusion times and the dissolved metals were determined by Atomic Absorption Spectrometry. The results have shown that in these conditions only copper was solubilized.
Resumo:
Aquest projecte forma part d’un estudi sobre l’eliminació de metalls pesants utilitzant com aadsorbents residus d’indústries agroalimentàries, que des de fa uns quants anys està duent aterme el grup de Metalls i Medi Ambient (MiMA) del Departament d’Enginyeria Química,Agrària i Tecnologia Agroalimentària de la Universitat de Girona. L’objecte del treball és parametritzar un procés basat en marro de cafè que inclouetapes de reducció/adsorció i precipitació per al tractament d’aigües residuals quecontenen Cr(VI) i altres metalls. La parametrització permetrà conèixer en quinmoment s’ha assolit la reducció total del Cr(VI) en la primera etapa del tractament perpoder passar a una segona etapa d’eliminació de la resta dels metalls presents en solució
Resumo:
An on-line electrodissolution procedure implemented in a flow injection system for determination of copper, zinc and lead in brasses alloys by ICP-AES is described. Sample dissolution procedure was carried out by using a PTFE chamber and a DC power supply with constant current. Solid sample was attached to chamber as anode and a gold tubing coupled in the chamber was used as cathode. An electrolytic solution flowing through the gold tubing closed the electric circuit with sample, in order to provide condition for electric dissolution when the DC power supply was switched on. The best results were achieved by using a 1.5 mol l-1 nitric acid solution as electrolyte and a 2.5 A current intensity. The procedure presented a good performance characterized by a relative standard deviation better than < 5% (n=5) and a sample throughput of 180 determinations per hour for Cu, Zn and Pb. Results were in agreement with those obtained by conventional acid dissolution (99% confidence level).
Resumo:
Diplomityön tarkoituksena oli tutkia ja kehittää menetelmä arvometallien kuten kuparin, sinkin, koboltin ja nikkelin talteenottoon metallikloridiliuoksesta. Tavoitteena oli valita taloudellisin ja ympäristöystävällisin menetelmä, jolla saadaan nämä arvometallit myyntituotteiksi. Lisäksi puhdistetun prosessiveden tuli täyttää asetetut tavoitteet. Kirjallisuustyön perusteella laskettiin viidelle eri prosessivaihtoehdolle ainetaseet HSC Sim 6.0 ohjelmalla, joka on HSC Chemistry-pohjainen prosessien simulointi- ja mallinnusohjelma. Kaikissa vaihtoehdoissa oli ensimmäisenä prosessiosana kuparin, sinkin, koboltin ja nikkelin sulfidisaostus ja sakan pesu. Sulfidisaostusta seurasi vaihtoehtoisesti joko 1) hapetus hapella ja hydroksidisaostus, 2) hapetus vetyperoksidilla ja hydroksidisaostus, 3) pelkkä hydroksidisaostus, 4) hapetus SO2/O2-kaasuseoksella ja hydroksidisaostus tai 5) karbonaattisaostus. Taselaskennan perusteella valittiin kokeelliseen osaan tutkittavat prosessivaihtoehdot, jotka olivat sulfidisaostus, hydroksidisaostus, SO2/O2- hapetus ja hydroksidisaostus sekä karbonaattisaostus. Kokeissa arvometallit saatiin talteenotettua sulfidisaostuksella selektiivisimmin lämpötilassa 55 °C ja pH:ssa 4. Näissä olosuhteissa reagenssin kulutus verrattaessa muihin tehtyihin sulfidisaostuksiin oli pienin. Sakka laskeutui ja suotautui hyvin. Loppusakan sisältämien metallien (kupari, sinkki ja koboltti) pitoisuudet olivat korkeimmat. Myös nikkelin määrä oli suuri. Mangaani ja rauta saatiin talteenotettua selektiivisimmin karbonaattisaostuksella lämpötilassa 65 °C. Sakka sisälsi eniten mangaania. Sakka laskeutui ja suotautui hyvin. Tällä menetelmällä puhdistetun prosessiveden laatu täytti asetetut tavoitteet.
Resumo:
Tetrahydroborate complexes of copper (I) with bidentate phosphines, [Cu(eta²-BH4)(dppm)] (1), [Cu(eta²-BH4)(dppe)] (2), [Cu(eta²-BH4)(cis-dppet)] (3) and [Cu(eta²-BH4)(dppb)] (4) (dppm = bis(diphenylphosphino)methane; dppe = 1,2-bis(diphenylphosphino) ethane; cis-dppet = 1,2-cis(diphenylphosphino)ethene; dppb = 1,4-bis(diphenylphosphino)butane) were prepared and characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR data for 1-4 showed bands typical of a bidentate coordination of BH4 group to the copper atom and the 31P{¹H} NMR spectra indicated that the phosphorous atoms are chelating the metal centre. The thermal behavior of the compounds was investigated and suggested that their thermal stability is influenced by the phosphines. Their thermal stability decreased as follows: [Cu(eta²-BH4)(dppe)] (2) > [Cu(eta²-BH4)(dppm)] (1) > [Cu(eta²-BH4)(dppb)] (4) > [Cu(eta²-BH4)(cis-dppet)] (3). According to thermal analysis and X-ray diffraction patterns all compounds decomposed giving Cu(BO2)2, CuO, CuO2 and Cu as final products.