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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Extração em fase sólida magnética : nova abordagem na determinação de hidrocarbonetos policíclicos aromáticos (HPA) em água produzida por cromatografia líquida de alta eficiência / Magnetic solid phase extraction : new approach to determining polycyclic aromatic hydrocarbons (PAH) in water produced by high performance liquid chromatography

Caetano, Vinícius Crispim Lima de Barros 30 November 2017 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The oil and gas industry produces huge amounts of produced water (PW), a complex effluent. This product is one of the main constituents of polycyclic aromatic hydrocarbons (PAH), which exhibit high toxicity. Therefore, this study aims at developing and validating a method for determining PAH (Benz(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(a)pyrene, and Dibenzo (a,h)anthracene) in PW by using magnetic solid phase extraction (MSPE) and high-performance liquid chromatography with fluorescence detector. We synthesized three new adsorbents: FeCt (with ferric chloride and water rich in natural organic matter); FeCc (with ferric chloride, distilled water, and coconut husk), and FeSt (with ferric sulfate and water rich in natural organic matter). The x-ray diffraction and infrared spectroscopy confirmed obtaining the hybrid materials. The best extraction conditions were obtained by using ultrasonic cleaning as a mixing mechanism with time set to 2.5 minutes for adsorption and 2.5 minutes for desorption, using 10 mL of ethyl acetate as an extractor and 20 mg of hybrid FeSt; the values of PAH recovery varied from 84.3 to 92.3 %. The capacity of reusing the material was assessed and the results exhibited a great recovery with up to 4 cycles of adsorption/desorption. The methodology we propose was applied to two PW samples. The recovery values for samples PWW1 (produced water at well 1) enriched with 100μg L-1 were of 81 – 104%, without the presence of B(a)P standard. As for the PAH concentrations in the sample, they varied from 0.63 to 1.66 μg L-1 for PWW1 from 0.54 to 1.62 μg L-1 for PWW2 (produced water at well 2). The validation of the method was performed for the following parameters: linearity, which exhibits a correlation coefficient (r) above 0.9943 within the interval of 0.5 - 25 μg L-1 ; accuracy and precision, with recovery values between 98.2 – 108.9 %, and coefficient of variation 0.64 – 6.72 % for the concentration levels of 3.8 and 15 μg L-1 (n=3), respectively. LODs varied from 0.012 and 0.02 μg L-1 and LOQs, from 0.036 to 0.06 μg L-1. / A indústria de petróleo e gás produz grandes quantidades de água produzida (AP), que é um efluente complexo, sendo que um dos seus principais constituintes são os Hidrocarbonetos Policíclicos Aromáticos (HPA), os quais apresentam elevada toxicidade. Assim, o presente trabalho tem por objetivo desenvolver e validar um método de determinação de HPA (Benzo(a)Antraceno, Benzo(b)Fluoranteno, Benzo(k)Fluoranteno, Benzo(a)Pireno e Dibenzo(ah)Antraceno) em AP utilizando a extração em fase sólida magnética (MSPE) e cromatografia líquida de alta eficiência com detector de fluorescência. Foram sintetizados três novos adsorventes FeCt (com cloreto férrico e água com alto teor de MON), FeCc (com cloreto férrico, água destilada e bagaço de coco) e FeSt (com sulfato férrico e água com alto teor de MON). A difração de raios X e a espectroscopia de infravermelho confirmaram a obtenção dos materiais híbridos. As melhores condições de extração foram obtidas em banho de ultrassom como mecanismo de agitação, com tempo estipulado em 2,5 min para a adsorção e 2,5 min para a dessorção, utilizando 10 mL de acetato de etila como extrator e 20 mg do híbrido FeSt. Os valores de recuperação dos HPA variaram de 84,3 – 92,3 %. A capacidade de reutilização do material foi avaliada e os resultados apresentaram ótima recuperação com até 4 ciclos de adsorção/dessorção. A metodologia proposta foi aplicada em duas amostras de AP e os valores de recuperação para a amostra de APP1 (água produzida poço 1), enriquecida com 100 μg L-1, foram de 81 – 104 %, sem a presença do padrão do B(a)P, e a concentração dos HPA na amostra variou de 0,63 – 1,66 μg L-1 para o APP1, e de 0,54 – 1,62 μg L-1 para o APP2 (água produzida poço 2). A validação do método foi realizada para os parâmetros: linearidade, com o coeficiente de correlação (r) acima de 0,9943 no intervalo de 0,5 - 25 μg L-1; exatidão e precisão, com valores de recuperação entre 98,2 - 108,9 % e coeficiente de variação 0,64 - 6,72 % para os níveis de concentração 3, 8 e 15 μg L-1 (n=3), respectivamente. Os limites de detecção (LD) variaram entre 0,012 a 0,02 μg L-1 e os limites de quantificação (LQ) entre 0,036 a 0,06 μg L-1. / São Cristóvão, SE
192

Avaliação da resina quelante chelex-100® na pré-concentração e da espectrometria de absorção atômica de alta resolução com fonte contínua e forno de grafite para a determinação de metais-traço em água produzida de alta salinidade

Freire, Aline Soares 14 April 2016 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-04-14T16:10:05Z No. of bitstreams: 1 Dissertação - Aline Soares Freire - FINAL.pdf: 4503064 bytes, checksum: 1e469a75225eda50cf3c49c6ab32c87a (MD5) / Made available in DSpace on 2016-04-14T16:10:05Z (GMT). No. of bitstreams: 1 Dissertação - Aline Soares Freire - FINAL.pdf: 4503064 bytes, checksum: 1e469a75225eda50cf3c49c6ab32c87a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / A análise de amostras hipersalinas ainda é um problema analítico a ser resolvido, tendo em vista que a presença de sais dissolvidos é fonte freqüente de interferências em espectrometria atômica. Atualmente, tem ocorrido um grande aumento da demanda para caracterização de águas de alta salinidade, como as águas produzidas, pelo fato de estas serem um dos maiores descartes da indústria de petróleo. Devido a isto, metodologias analíticas para sua caracterização têm sido amplamente desenvolvidas para a determinação de metais-traço em amostras salinas e dentre as técnicas analíticas destaca-se a Espectrometria de Absorção Atômica de Alta Resolução com Fonte Contínua, uma renovação da AAS convencional. Contudo, para a obtenção de resultados acurados, é imprescindível que se faça a remoção dos sais presentes nessas matrizes hipersalinas. Essa separação prévia pode ser realizada através do emprego de resinas qualantes, que pré-concentram o analito e permitem a remoção da matriz. Sendo assim, este trabalho visa à avaliação do uso da resina quelante comercial Chelex-100® na préconcentração de Co, Cu, Mn, Ni e Pb e posterior determinação destes por Espectrometria de Absorção Atômica de Alta Resolução com Fonte Contínua e Forno de Grafite (HR-CS GF AAS). A metodologia foi validada através do uso dos materiais de referência certificados para água do mar CASS-4, CASS-5 e NASS-5. Os limites de detecção obtidos, em μg L-1, foram de 0,006; 0,070; 0,024; 0,074; e 0,018 para Co, Cu, Mn, Ni e Pb, respectivamente. Amostras de água produzida oriundas de plataformas de petróleo offshore foram analisadas e os resultados mostraram que essas águas possuem baixas concentrações dos elementos determinados ou os mesmos não foram detectados. Os valores encontrados são muito inferiores aos limites preconizados pela legislação brasileira através da Resolução CONAMA 357/05 / The analysis of hypersaline samples is still an analytical problem to be solved, once the presence of dissolved salts is a frequent source of interferences in atomic spectrometry. Actually, there is a large increase in the interest in the caracterization of this kind of sample, as produced waters are one of the largest discharges of petroleum industry. Hence, analytical methodologies to produced water caracterization have been widely developed to trace metals determination in saline samples and among the analytical techniques, there is High Resolution Continuum Source Atomic Absorption Spectrometry, a renovation of conventional AAS. However, to obtain accurated results, it's necessary to remove the salts present in this high salinity matrices. This previous separation can be done employing a chelating resin, that preconcentrates the analyte(s) and allows matrix removal. In this way, the aim this work is to evaluate the use of chelating resin Chelex-100® to preconcentrate Co, Cu, Mn, Ni and Pb, for the later determination by High Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry (HR-CS GF AAS). The methodology was validated by the use of sewater certified reference materials CASS-4, CASS-5 e NASS-5. The detection limits in μg L-1, were 0,006; 0,070; 0,024; 0,074; and 0,018 for Co, Cu, Mn, Ni and Pb, respectively. Produced water samples from offshore petroleum platforms were analysed and results showed that this waters have low concentrations of these studied elements or could not be detected. Found values are much lower when compared to limits from Brazilian legislation, in this case CONAMA 357/05 Resolution
193

Koagulace neproteinové složky látek produkovaných fytoplanktonem / Coagulation of non-protein algal organic matter

Lukeš, Jan January 2017 (has links)
The diploma thesis deals with characterizing properties of non-proteinaceous cellular organic matter (COM) of green alga Chlorella vulgaris in connection with its coagulation using aluminium sulphate and polyaluminiumchloride. As a part of this work, interaction mechanisms were also studied. It has been found out that non-proteinaceous COM of Chlorella vulgaris is made up by saccharides (25 % DOCNP, 21 % of dry biomass of non- protein matter) and other unspecified non-protein substances. It has been found out by fractionation of molecular weights that non-protein COM is formed primarily by substances with MW < 3 kDa and substances with MW > 100 kDa. Coagulation by aluminium sulphate taken place in interval pH 5 - 8,5 and coagulation by polyaluminiumchlorid taken place in interval pH 7 - 10 depending on coagulation agent dose. The maximum DOC removals were 17 - 22 % depending on selected coagulation agent, on its dose and pH. Polyaluminiumchloride showed higher DOC removal rates than aluminium sulphate. The highest effectiveness of coagulation was in the area of neutral pH for both agents. In all the coagulation tests the values of residual concentrations of aluminium were higher than the hygienic limit for drinking water (0.2 mg.L-1 ). Primarily high-molecular matter was removed by coagulation and...
194

Uklanjanje metala iz vode primenom stabilisanog i „zelenom“ sintezom produkovanog nano gvožđa (0) / Removal of metals from water using stabilized and “green” method produced nano iron (0)

Poguberović Sofija 04 July 2016 (has links)
<p>Predmet izučavanja ove disertacije je ispitivanje mogućnosti&nbsp; primene stabilisanog nano Fe(0)&nbsp; i &bdquo;zelenom&ldquo; sintezom produkovanog nano&nbsp; Fe(0)&nbsp; u uklanjanju Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II) i As(III)&nbsp; iz vode.&nbsp; Sinteza nano Fe(0) za stabilizaciju izvr&scaron;ena je konvencionalnom metodom&nbsp; redukcije gvožđa sa natrijum borhidridom&nbsp; u prisustvu materijala za stabilizaciju: kaolinita,&nbsp; bentonita i karboksimetil celuloze. Za &bdquo;zelenu&rdquo; sintezu nano Fe(0) kori&scaron;ćeno je li&scaron;će drveća: hrasta, duda i vi&scaron;nje.&nbsp; Karakterizacija&nbsp; dobijenih nanomaterijala izvr&scaron;ena je transmisionom i skenirajućom elektronskom mikroskopijom. Rezultati karakterizacije su pokazali da se tokom sinteze nano Fe(0) natrijum borhidridom i stabilizacije kaolinitom, bentonitom i karboksimetil celulozom, formiraju nano čestice Fe(0) veličine 20 do 90 nm, dok su veličine čestica nano Fe(0) sintetisanih &bdquo;zelenom&ldquo; metodom iznosile 10-30 nm i okarakterisane su kao nano čestice sfernog oblika, različitih veličina bez značajane aglomeracije.&nbsp; Primena nano&nbsp;Fe(0) na efikasnost&nbsp; uklanjanja metala iz vode ispitivana je pri različitim uslovima:&nbsp; uticaju doze nanomaterijala, početne koncentracije&nbsp; metala, pH vrednosti rastvora i kontaktnog vremena.&nbsp; Dobijeni rezultati prilikom ispitivanja uticaja&nbsp; doze nanomaterijala&nbsp; na efikasnosti uklanjanja odabranih metala iz vode primenom stabilisanih i &bdquo;zelenih&ldquo; nanomaterijala&nbsp; pokazali&nbsp; su&nbsp; da se povećanjem doze nanomaterijala&nbsp; povećava efikasnost uklanjanja.&nbsp; Prilikom primene stabilisanih nanomaterijala, koncentracije 14.00 gFe(0)/l,&nbsp; postignute&nbsp; su visoke efikasnosti uklanjanja, već pri dozama od&nbsp; 2 ml, dok je efikasnost uklanjanja primenom&nbsp; &bdquo;zelenih&ldquo; nanomaterijala koncentracije 1,395 gFe(0)/l bila niža. Prilikom ispitivanja uticaja pH vrednosti na uklanjanje metala iz vode primenom ispitivanih nanomaterijala, određeni &nbsp;su optimalni opsezi pH vrednosti pri kojima se postiže najveća adsorpcija metala&nbsp; na ispitivanim nanomaterijalima.&nbsp; Veza između metala&nbsp; i&nbsp; ispitivanih nanomaterijala obja&scaron;njena je modelovanjem Langmuir-ove i Freunlich-ove&nbsp; adsorpcione izoterme. Veće adsorpcione kapacitete prilikom adsorpcije svih ispitivanih metala pokazali su nanomaterijali produkovani &bdquo;zelenom&ldquo; sintezom u odnosu na stabilisane nanomaterijale, &scaron;to je povezano sa veličinom čestica, tj. manje nanočestice nanomaterijala produkovanih &bdquo;zelenom&rdquo; sintezom imaju veću&nbsp; specifičnu povr&scaron;inu i samim tim mogu&nbsp; ponuditi&nbsp; vi&scaron;e reaktivnih mesta, veću reaktivnost i bolju disperziju. Ispitivanje kinetike adsorcije&nbsp; Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II) i As(III) na ispitivanim stabilisanim i &bdquo;zelenom&ldquo; sintezom produkovanim nanomaterijalima pokazalo je veoma brzu reakciju adsorpcije metala na ispitivanim&nbsp;nanomaterijalima i&nbsp; bolje slaganje eksperimentalno dobijenih podataka sa pseudo-drugim kinetičkim modelom.&nbsp; Rezultati dobijeni u ovom&nbsp; istraživanju omogućiće procenu&nbsp; primene nano Fe(0) za uklanjanje metala iz vode, posebno adsorpciju metala iz vode kao i odabir najefikasnijeg i najekonomičnijeg adsorbensa za uklanjanje različitih metala iz vode.</p> / <p>This work is concerned with exploring the possibility&nbsp; of&nbsp; application of&nbsp; stabilized nano Fe(0)&nbsp; and nano Fe (0) produced by &ldquo;green&rdquo; synthesis&nbsp; in the&nbsp; removal&nbsp; of Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II)&nbsp; and&nbsp; As(III)&nbsp; from&nbsp; the&nbsp; water.&nbsp; Synthesis of nano Fe(0) for the stabilization is carried out according to conventional method of iron reduction with sodium borohydride in the presence of a material for stabilization: kaolinite, bentonite and carboxymethyl cellulose. Leaves of oak, mulberry and cherry trees used for&nbsp; &ldquo;green&rdquo;&nbsp; synthesis of nano Fe(0). Characterization of nanomaterials&nbsp; was performed by transmission and scanning electron microscopy.&nbsp; The&nbsp; characterization&nbsp; results&nbsp; have shown that during the synthesis and stabilization of nano Fe (0) process formed nanoparticles with size from 20 to 90 nm, while the nano Fe (0) particles synthesized by &quot;green&quot; method were within the&nbsp; size of&nbsp; 10-30 nm and characterized as spherical nanoparticles with&nbsp; various sizes without significant agglomeration.&nbsp; Application of nano Fe (0) on the&nbsp; removal&nbsp; efficiency of&nbsp; metals from water was studied under different conditions: the influence of&nbsp; nanomaterials&nbsp; dose, the initial metal concentrations, pH value of the solution&nbsp; and the contact time. The results obtained during the examination of the impact of nanomaterial&nbsp; dose&nbsp; on the&nbsp; removal&nbsp; efficiency&nbsp; of selected metals from water&nbsp; have shown that increasing&nbsp; of nanomaterial&nbsp; dose increases removal efficiency. High removal efficiency is achieved when used&nbsp; 2 ml of stabilized nanomaterials, concentration of 14.00 gFe(0)/L, while when &quot;green&quot; nanomaterials,&nbsp; concentration&nbsp; of&nbsp; 1,395&nbsp; gFe(0)/L,&nbsp; were&nbsp; used&nbsp; the removal efficiency&nbsp; was&nbsp; lower.&nbsp; The optimal ranges of pH values&nbsp; at which&nbsp; the tested&nbsp; nanomaterials&nbsp; reach the maximum adsorption of metals&nbsp; were obtained, during the examination of&nbsp; the influence of pH value on removal of metals from water by using the tested nanomaterials&nbsp; The&nbsp; relation&nbsp; between&nbsp; the metals&nbsp; and tested&nbsp;&nbsp; nanomaterials is explained by modeling&nbsp; of&nbsp; Langmuir&#39;s and Freunlich&#39;s adsorption isotherm.&nbsp; Nanomaterials&nbsp; produced&nbsp; by&nbsp; &quot;green&quot; synthesis&nbsp; showed higher&nbsp; adsorption capacity&nbsp; than&nbsp; stabilized&nbsp; nanomaterials, which is related&nbsp; with particle size, i.e. the&nbsp; nanoparticles&nbsp; produced by&nbsp; &quot;green&quot; synthesis&nbsp; have&nbsp; less particles, higher specific surface area and therefore can offer more reactive sites, greater reactivity and better dispersion. Kinetics&nbsp; tests&nbsp; showed a very fast adsorption of metal&nbsp; on&nbsp; the tested nanomaterials and better agreement with the experimental data to&nbsp; second&nbsp; pseudo-kinetic model.&nbsp; The results obtained in this study will enable the assessment of the application of nano&nbsp; Fe (0) for the removal of metals from water, especially for the adsorption of metals from water as well as the selection of the most&nbsp; efficient and most economical of the adsorbent for the removal of various metals from water.</p>
195

Wasserstoffinduzierte Spannungsrisskorrosion: Ein Beitrag zur Beurteilung der Zuverlässigkeit von Spannbetonbrücken mit Hennigsdorfer Spannstahl

Wilhelm, Tobias 04 November 2014 (has links)
Bei dem Prozess einer Wasserstoffinduzierten Spannungsrisskorrosion (H-SpRK) handelt es sich um einen zeitabhängigen Vorgang, der zu einer Reduzierung der Duktilität und Widerstandskraft des Spannstahls führt und daraus resultierend ein sprödes und schlagartiges Versagen eines Spannbetonbauwerkes zur Folge haben kann. Der Prozess selbst und insbesondere auch die ihn beeinflussenden Parameter sind für die im Bauwesen verwendeten hochfesten Spannstähle älterer Produktion weitestgehend unerforscht. Die Relevanz für bestehende Bauwerke ist jedoch nicht zuletzt durch einzelne dokumentierte und untersuchte Schadensfälle nachgewiesen. Ziel der vorliegenden Arbeit war es, die zur Verfügung stehenden Bauwerksuntersuchungen aus den zurückliegenden ca. 10 Jahren statistisch zu analysieren und auszuwerten. Auf dieser Basis war ein Berechnungsmodell wahrscheinlichkeitstheoretischer Basis zu entwickeln, mit dem die Gefahr eines spröden Bauwerksversagens für das Gesamttragwerk beurteilt und hinsichtlich der Auswirkungen auf das einzuhaltende Sicherheitsniveau bewertet werden kann. Es wurden insgesamt 31 Bauwerksuntersuchungen statistisch ausgewertet und beurteilt. Die zur Verfügung stehenden Daten wurden analysiert und hinsichtlich der Prüfqualität sowie der Quantität der Proben bewertet. Dabei war festzustellen, dass aufgrund fehlender konkreter Vorgaben im Regelwerk eine sehr heterogene Datenbasis vorliegt. Nicht alle Untersuchungsergebnisse konnten in die weitere Auswertung einbezogen werden. Die in ausreichender Datenqualität und Datenumfang geeigneten Untersuchungen wurden hinsichtlich ihrer Relevanz für den Prozess einer H-SpRK analysiert und die Auswirkungen einzelner Parameter bewertet. Im Ergebnis der materialtechnischen Untersuchungen und statistischen Auswertung der Bauwerksuntersuchungen wurde ein Berechnungsmodell vorgestellt, das den gleichzeitigen Ausfall von Spannstahl in allen Bereichen des Bauwerkes berücksichtigt. Zusätzlich zum Standardverfahren des beschriebenen Vorgehens wird das Modell um den Ansatz eines korrelierten Spannstahlausfalls erweitert. Außerdem wird für Bauwerke mit einem statisch unbestimmten Anteil der Vorspannung sowie für Konstruktionen mit gestaffelter Spannstahlbewehrung die Anwendung des Verfahrens konkretisiert. Neben der Erstellung des Berechnungsmodells wurden Vorschläge zu Vorgaben für die Bauwerksprüfung vorgestellt. Dazu zählen insbesondere die Festlegung von Prüfintervallen sowie einheitliche Vorgaben zu den verwendeten Prüfmethoden und -verfahren. Bezüglich der Festlegung von Mindestumfängen von Proben wird zwischen bestehenden und auch weiter zu nutzenden Bauwerken einerseits sowie Probennahmen im Rahmen von Rückbaumaßnahmen unterschieden.
196

Sociala åtagande vid uppförandet av nyproducerat bostadsområde : i samarbete med Derome / Social commitment in the construction of newly produced residential area : in collaboration with Derome

Trulsson, Patricia January 2020 (has links)
Alla kommuner och städer i Sverige måste börja arbeta mot en hållbar stadsutveckling för att bland annat lösa problemen med den bostadsbrist som råder men också för att skapa platser för befolkningen att trivas i. Regeringens ambition om den hållbara stadsutvecklingen är att Sveriges kommuner och städer ska bli mer gröna, hälsosamma, inkluderande och klimatsmarta. Kommunerna har planmonopol som styr den fysiska planeringen och därigenom styr även hur bostadsbyggandet ska gå till, till exempel genom kommunala markanvisningar där kommunen ställer krav på hur byggnationen av en markbit får gå till. Kraven omfattar hållbarhetens tre dimensioner där fokus tenderar till att ligga mer på den ekologiska och ekonomiska hållbarheten. Dock börjar allt fler kommuner ställa mer krav på sociala åtagande vid kommunala markanvisningar och vid uppförandet av nyproducerade bostadsområden. Den här studien är i samarbete med Derome och utgår därmed utifrån Derome som exploatör vid kommunala markanvisningar. Studien ska svara mot den problematik som Derome upplever i deras arbete med sociala åtagande vid bland annat kommunala markanvisningar. Studien utgår därmed från markanvisningsprocessen där Derome är exploatör. Studien ska ge en ökad kunskap om vad social hållbarhet är och hur det kopplas samman med byggandet av ett nytt bostadsområde. Målet är att ta reda på hur Derome arbetar med sociala åtagande idag (2020), vad för krav som en kommun ställer på sociala åtagande och hur en arkitekt arbetar med socialt hållbara bostadsområden. Studien tar även upp hur samarbetet mellan de olika aktörerna ser ut vid kommunala markanvisningar. Studien är inspirerat av en intressentdialog enligt GRI som har genomförts med Deromes interna respektive externa intressenter i form av intervjuer. Studien utgår även från hållbarhetsredovisningens sociala åtagande och ett företags samhällsansvar, CSR. Deromes problematik framgår tydligt i studien där Derome har behövt en plan och hjälp med att komma loss i deras arbete med sociala åtagande vid uppförandet av nyproducerade bostadsområden. Resultatet är svaret mot problematiken som tydliggörs i förslaget vilket kommer att kunna fungera som en vägledning i Deromes arbete framöver. Förslaget har bland annat tagit fram hur ett socialt hållbart bostadsområde definieras och det är genom: att möta livets olika faser, skapa en blandning, skapa trygga och säkra boendemiljöer, skapa attraktiva platser där människor möter varandra, skapa en tillgänglig och stark mobilitet, främja fysisk aktivitet, ta tillvara på kulturvärden och vara ett område där alla ha råd att bo i. Det framkommer även tydligt att Derome behöver skapa förutsättningar för social hållbarhet i sina bostadsområden redan tidigt i planeringsprocessen, innan och/ eller under detaljplaneringen. Det är dock viktigt att understryka vikten av att ett bostadsområde aldrigiiblir socialt hållbart om inte den sociala närvaron tas i beaktning i förvaltningen och under dess livslängd. / All municipalities and cities in Sweden must start working towards sustainable urban development in order to, among other things, come to terms with the housing shortage prevailing but also to create places for the population to thrive in. The government's ambition for sustainable urban development is that Sweden's municipalities and cities should become more greener, healthier, inclusive and climate smart. The municipality has a planning monopoly that controls the physical planning and thereby also controls how housing construction should go. Therefore, the municipality makes demands on how the construction of a piece of land may go. The requirements cover the three dimensions of sustainability where the focus tends to be more on ecological and economic sustainability. However, the municipality is beginning to make more and more demands on social commitments in the construction of newly produced residential areas. This study is in collaboration with Derome and is therefore based on Derome as an operator for municipal land directions. The study will answer the problems that Derome experiences in their work with social commitment at municipal land directions. The work is based on the land allocation process where Derome is an operator. The study will provide an increased knowledge of what social sustainability is and how it is linked to the construction of a new residential area. The goal is to find out how Derome works with social commitments today (2020), what requirements a municipality places on social commitments and how an architect works with socially sustainable housing areas. The study also addresses how the cooperation between the various actors looks at municipal land directions. The study is inspired by a GRI stakeholder dialogue conducted with Derome's internal and external stakeholders, respectively. The study also starts from the sustainability report's social commitment and a corporate social responsibility, CSR. Derome's problems are clear in the study where Derome has the need for a plan and help to get rid of their work with social commitment in the construction of newly produced residential areas. The result is the answer to the problem that is clarified in the proposal, which will serve as a guide in Derome's work going forward. The proposal has, among other things, developed how a socially sustainable housing area is defined and it is through: meeting life's different phases, mixing, security, meeting places, mobility, promoting physical activity, cultural values and that everyone should be able to afford to live in the area. It also emerges that Derome needs to create conditions for social sustainability in its residential areas early in the planning process, before and/ or during the detailed planning. However, it is important to emphasize the importance of a residential area never being socially sustainable unless the social presence is taken into account in the administration and during its life.
197

Vznik organických molekul iniciovaný procesy o vysoké hustotě energie v planetárních atmosférách / Formation of organics molecules initiated by high-power density energy events in planetary atmospheres

Kamas, Michal January 2010 (has links)
The focused laser beam delivered by the high-power laser system PALS was used for laboratory simulation of high-energy-density events in a planetary atmosphere. Several model gas mixtures were prepared to mimic the mildly reducing early Earth's atmosphere (CO-N2-H2O) as well as the atmosphere of Saturn's moon Titan and the strongly reducing early Earth's atmosphere (CH4-N2-H2O). In situ investigation of transient species generated by the laser-induced dielectric breakdown in the gaseous mixtures was performed by optical emission spectroscopy (OES). Final products of laser-plasma initiated chemical reactions were identified and determined by advanced mass-spectrometry (SIFT-MS) and absorption FT-IR spectroscopy. High-power laser system SOFIA was utilized to simulate in our laboratory a high-velocity impact into the icy satellites of the outer planets of the Solar system. OES was engaged in probing the plasmas produced by the SOFIA beam focused on ice surfaces (water, methanol, formamide), while final products were analyzed by means of gas chromatography (GC/MS) and mass-spectrometry (SIFT-MS).
198

Production of filamentous fungal biomass on waste-derived volatile fatty acids for ruminant feed supplementation and it's in vitro digestion analysis

Bouzarjomehr, Mohammadali January 2022 (has links)
Single cell proteins such as that of edible filamentous fungal biomass are considered as a promising sustainable source of animal feed supplementation. Filamentous fungi can be cultivated on different organic substrates including volatile fatty acids (VFAs) such as acetic, propionic, and butyric acids. These VFAs can be generated through the famous waste valorisation approach of anaerobic digestion (AD) as intermediate metabolites. This project investigates a sustainable approach for the production of animal feed supplementation through cultivation of fungal biomass on waste derived VFAs along with the in vitro analysis of fungal biomass digestibility as ruminant feed. In this regard, optimum conditions for the production of Aspergillus oryzae biomass on different VFAs effluents derived from anaerobic digestion process of food waste plus chicken manure (FWCKM) and potato protein liquor (PPL) at different pH, nitrogen sources, and feed mixture was studied. Accordingly, analyses showed that PPL has the highest biomass yield with 0.4 (g biomass/g consumed VFAs) based on the volatile solids (VS) by adjusting pH to 6.2. Furthermore, the digestibility of the produced fungal biomass is analysed by using three different in vitro digestion methods including Tilley and Terry (TT) method, Gas Production Method (GPM), and Nylon Bag Method (NBM) and the results are compared with the conventional feed (silage and rapeseed meal). Results obtained from different digestibility methods illustrate that different A. oryzae fungal biomass had approximately 10-15 % higher dry matter digestibility fraction compared to silage and rapeseed meal (reference feeds). Hence, these results revealed that A. oryzae fungal biomass can grow on VFAs effluents and produce protein-rich fungal biomass while this biomass has better digestibility compared to conventional feeds and confirmed the initial hypothesis of the study.
199

Evaluating Leachability of Residual Solids Generated from Unconventional Shale Gas Production Operations in Marcellus Shale

Sharma, Shekar 17 September 2014 (has links)
Hydraulic fracturing operations utilized for shale gas production result in the generation of a large volume of flowback and produced water that contain suspended material, salts, hydrocarbons, metals, chemical additives, and naturally-occurring radioactive material. The water is impounded at drilling sites or treated off-site, resulting in significant generation of residual solids. These are either buried on site or are disposed in lined landfills. The objective of this study was to determine the levels of heavy metals and other elements of concern that will leach from these residual solids when placed in typical disposal environments. For this purpose, laboratory leaching experiments were employed wherein representative samples were brought into contact with a liquid to determine the constituents that would be leached by the liquid and potentially released into the environment. The samples used included sludge resulting from the physicochemical treatment of process water (TS), sludge solidified with cement kiln dust (SS), raw solids obtained by gravity separation of process water (RS), and drilling mud (DM). The samples were subjected to both single extraction (i.e. Shake Extraction Test, SET) and multiple extraction (i.e. Immersion Test, IT) leaching tests. For the shake extraction test, samples were mixed with a specific amount of leaching solution without renewal over a short time period. In the immersion test, samples were immersed in a specific amount of leaching solution that was periodically renewed over a longer period of time. For both these tests, analyses were performed on the filtered eluate. The tests were performed as per standards with modifications. Distilled de-ionized water, synthetic acid rain (pH ~ 4.2), weak acetic acid (pH ~ 2.88), and synthetic landfill leachate were used as leaching solutions to mimic specific disposal environments. Alkali metals (Li, K, Na), alkaline earth metals (Ba, Ca, Mg, Sr) and a halide (Br), which are typically associated with Marcellus shale and produced waters, leached at high concentrations from most of the residual solids sample. The SS sample, due to its stabilization with CKD, had a lower extraction efficiency as compared to the unconsolidated TS and RS samples. In EF 2.9 and EF SLL, the leaching took place under acidic conditions, while for EF DDI and EF 4.2, the leaching occurred in alkaline conditions. EF 2.9 and EF SLL were determined to be the most aggressive leaching solutions, causing the maximum solubility of most inorganic elements. Thus, high amounts of most EOCs may leach from these residual solids in MSW landfills disposed under co-disposal conditions. Agitation, pH and composition of the leaching solution were determined to be important variables in evaluating the leaching potential of a sample. The results of this study should help with the design of further research experiments being undertaken to develop environmentally responsible management/disposal strategies for these residual solids and also prove useful for regulatory authorities in their efforts to develop specific guidelines for the disposal of residuals from shale gas production operations. / Master of Science
200

Fake Mass-Produced Advertisements Detection on Global Online Adult Service Websites / Detektering av Falska Massproducerade Annonser på Globala Webbplatser som Erbjuder Eskorttjänster

Pokropek, Ernest January 2023 (has links)
A significant amount of sex trafficking victims are being advertised on online adult services, which are currently being flooded with spam. Investigators rely on online adult services to track cases of sex trafficking; however, the ever-increasing volume of spam poses a mounting challenge, making their task progressively more difficult. This thesis presents a machine learning-based approach for detecting fake mass-produced advertisements on global online adult service websites. The objective is to aid investigators in tracking sex trafficking by developing a robust spam classifier that minimizes false positives on genuine ads while effectively identifying mass-produced spam. This objective is of utmost importance as it allows for filtering out spam effectively while ensuring that genuine ads are not mistakenly labeled as spam, ensuring their inclusion in crucial investigations. The research involved cleaning advertisement text, generating text embeddings using sentence-BERT, clustering them with DBSCAN, and feature engineering for classification using a random forest classifier. A dataset of two million advertisements was utilized for training and evaluation. The study successfully achieved the crucial goal of minimizing false positives, ensuring that genuine ads are not misclassified as spam. By employing innovative techniques and carefully engineered features, the classifier demonstrates a high level of recall in distinguishing mass-produced spam from authentic ads. Furthermore, the investigation identified key markers of mass-produced spam, such as geographical spread and frequent use of profane language. This research fills a significant research gap, as no previous attempts had been made to classify spam on these websites. The findings not only contribute to the field of machine learning but also provide a comprehensive overview of fraudulent advertisement features, making sex trafficking investigations more efficient. Equipping investigators with a reliable tool to navigate the vast amount of data associated with global online adult service websites, this work plays a crucial role in combating sex trafficking and ensuring the integrity of the investigative process. / En betydande mängd offer för sexhandel annonseras ut på webbplatser som erbjuder eskorttjänster på nätet, som för närvarande översvämmas av skräppost. Poliser använder sig av webbplatser som erbjuder eskorttjänster för att spåra fall av sexhandel, men den ständigt ökande mängden skräppost utgör en allt större utmaning och gör deras uppgift allt svårare. Denna avhandling presenterar en maskininlärningsbaserad metod för att upptäcka falska massproducerade annonser på globala webbplatser som erbjuder eskorttjänster. Målet är att hjälpa poliser att spåra sexhandel genom att utveckla en robust spamklassificerare som minimerar risken att kategorisera äkta annonser som spam, samtidigt som den effektivt identifierar massproducerad spam. Detta mål är av yttersta vikt eftersom det möjliggör effektiv filtrering av skräppost samtidigt som det säkerställer att äkta annonser inte felaktigt märks som skräppost, vilket säkerställer att de inkluderas i viktiga utredningar. Arbetet omfattade tvättning av annonstexterna, generering av ordvektorer med hjälp av sentence-BERT, klustring av vektorerna med hjälp av DBSCAN och definition av särdrag för den klassificering som sedan utfördes med hjälp av en random forest-klassificerare. Ett dataset med två miljoner annonser användes för träning och utvärdering. Studien lyckades uppnå det viktiga målet att minimera falska positiva resultat, vilket säkerställer att äkta annonser inte felklassificeras som skräppost. Tack vare innovativa tekniker och noggrant utformade särdrag uppvisar klassificeraren hög täckning (recall) när det gäller att skilja massproducerad skräppost från autentiska annonser. Dessutom identifierade undersökningen viktiga kännetecken för massproducerad skräppost, såsom geografisk spridning och frekvent användning av grova ord. Denna forskning fyller en betydande forskningslucka, eftersom inga tidigare försök hade gjorts för att klassificera skräppost på dessa webbplatser. Resultaten bidrar inte bara till området maskininlärning utan ger också insikter om bedrägliga annonser, vilket gör utredningar av sexhandel mer effektiva. Genom att förse utredare med ett tillförlitligt verktyg för att navigera i den enorma mängd data som är kopplad till globala webbplatser som erbjuder eskorttjänster spelar detta arbete en avgörande roll i kampen mot sexhandel.

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