To see the other types of publications on this topic, follow the link: Reagant.
Dissertations / Theses on the topic 'Reagant'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Reagant.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Walters, Jennifer Caroll. "NITROGEN-LIGATED (POLY)CATIONIC IODINE(III) REAGENTS: PLATFORMS FOR REAGENT DEVELOPMENT AND DIVERSE HETEROCYCLIC SYNTHESES." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/558365.
Full textAbstract:
Chemistry<br>Ph.D.<br>Hypervalent iodine (HVI) reagents are easily accessed, highly tunable, mild, selective oxidants that are less toxic and more environmentally benign compared to their heavy metal counterparts. λ3-Iodanes, which possess an iodine center bound to one aryl substituent and two heteroatom ligands, have been the subject of recent interest due to their electrophilicity and hypernucleofugality. A central focus of the Wengryniuk laboratory has been the further development and application of a class of electrostatically activated (bis)cationic nitrogen-ligated HVI (N-HVI) reagents. N-HVIs feature datively bound heterocyclic ligands which results in dramatically enhanced electrophilicity and redox potentials. Despite being a highly tunable platform for reagent development, N-HVIs remain a relatively underexplored class of λ3-iodanes. This dissertation focuses on demonstrating N-HVI’s synthetic potential and developing novel variants to enhance their synthetic utility. Chapter 1 of this dissertation serves as a general background and introduction to nitrogen-ligated HVI reagents. Chapter 2 outlines our efforts in N-HVI library expansion, novel syntheses, and characterization. With a library of 33 novel N-HVIs in hand, ligand effects on N-HVI reactivity were analyzed via qualitative and quantitative methods. Chapter 3 describes our first synthetic application of N-HVIs in the development of novel oxidative rearrangements of simple and complex cyclic alcohols. This chapter describes the chemoselective ring expansion of 2° and 3° cyclic alcohols accessing medium-sized cyclic acetal products in good to excellent yields with applicability to Complexity-to-Diversity (CTD) efforts. Chapter 4 demonstrates our initial efforts toward the development of another synthetic method where the functionalized N-heterocyclic ligands of the N-HVIs can be regioselectivity incorporated into a molecule following N-HVI activation of an olefin. The pyridinium lactone salts formed from olefinic acids were isolated in excellent yields via simple trituration, supplying a synthetically useful functional handle that was easily derivatized via known methods. These four chapters summarize the current state of the research with nitrogen-ligated HVI salts, expand upon our initial publications to highlight the development of novel heterocyclic syntheses, and provide a useful guide to further explore the reactivity of these tunable reagents.<br>Temple University--Theses
2
Petersson, Maria Jenni. "Development of Phosphonium Anhydrides for the Synthesis of Heterocycles; Synthesis of Potential Inhibitors of Glycogen Phosphorylase." Thesis, Griffith University, 2009. http://hdl.handle.net/10072/367001.
Full textAbstract:
The use of several phosphonium anhydride reagents for the synthesis of a range of
heterocyclic compounds has been investigated.
The structure of a polymer-supported version of the Hendrickson ‘POP’ reagent,
prepared by the reaction of polymer-supported triphenylphosphine oxide (57) with
triflic anhydride, was established as an equilibrium mixture of polymer-supported
triphenylphosphine ditriflate 54 (δ 79.4 ppm) and polymer-supported phosphonium
anhydride 76 (δ 73.3 ppm). The 31P NMR chemical shift reported previously for 54
was shown to be incorrect.
β-Hydroxy amides 96 and 103 were treated with triphenylphosphonium anhydride
trifluoromethane sulfonate (38) or the cyclic analogue 53 to generate 2-oxazolines 92
and 104 under mild conditions. The reaction was optimised by examining the number
of equivalents of reagents 38, 53, or diisopropylethyl amine required to effect
cyclisation. The effects of altering the reaction temperature, reaction time,
concentration, solvent, and addition rate were also investigated. Use of trityl β-
hydroxy amide 114 led to a significantly improved yield of 2-oxazoline 92 (94%).
Reagent 53 offered significant advantages in purification of products and was used to
dehydrate a range of trityl amides to form simple oxazolines (92, 100, 104 and 125),
thiazolines (113 and 126), and a dihydro-1,3-oxazine (101), in high yield (85-99%),
as well as a tetrahydro-1,3-oxazepine (112, 31%).
A serendipitous discovery during the synthesis of thiazoline 113, led to the
development of the first reported procedure for selective reduction of bis-phosphine
oxides to bis-phosphine monoxides. The mono reduction was performed under
exceptionally mild conditions using triflic anhydride and a thiol. The procedure
appears to be general, at least for the reduction of bis-phosphine oxides of the type
93, 133, 134 and 135 and selected BINAP bis-phosphine oxides (128 and 142).
When the mild dehydrating reagent phosphonium anhydride 38, was used to cyclise
amino amides 56 and 144, the corresponding cyclic amidines 24 and 25 were
obtained, though in low yields (36% and 29%, respectively). In comparison, by trityl
protecting the amide precursors (56 and 144) and subsequently cyclising them with
reagent 38, 24 and 25, were obtained in dramatically improved yields (79% and 89%, respectively). The scope of the reaction was explored and a selection of amides and
trityl amides were synthesised and cyclised with reagent 38 to form simple
tetrahydropyrimidines and imidazolines in high yields (85-95%), as well as a
tetrahydrodiazepine 156 (51%).
A number of simple analogues of the natural products, hyphodermins A, B and D
were synthesised. Addition of a range of nucleophiles to anhydride 167 resulted in
regioselective ring opening at C1 of the anhydride, and amide, ester and thioester
derivatives 174–180 were obtained (60–99%). The increased electrophilic reactivity
of the C1 carbonyl group of anhydride 167 was supported by a competition
experiment with phthalic anhydride. Unexpected formation of lactams 184 and 186
from amides 180 and 179 was shown to proceed via the lactamols 185 and 186 and
could be controlled by the reaction conditions.
The 13 heterocycles and 14 Hyphodermin derivatives all obeyed Lipinskis ‘rule-offive’,
and the calculated physicochemical values were within desired limits. All
compounds were tested against Glycogen Phosphorylase a (GPa). Four phenyl and
benzyl substituted 2-oxo-hexahydro and tetrahydrobenzo[cd]indole carboxylic acids
were identified as novel inhibitors of GPa with apparent IC50 values in the range 0.8–
1.3 mM. All of the heterocycles synthesised displayed some inhibition of GPa, with
thiazoline 126 (IC50 value of 24.5 μM) being the most active compound identified.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Eskitis Institute for Cell and Molecular Therapies<br>Science, Environment, Engineering and Technology<br>Full Text
3
Jenkins, Ava W. (Ava Walker). "The Role of Neo-Aristotelian Invention in Selected Speeches of Ronald Reagan." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc500901/.
Full textAbstract:
Using the Aristotelian concept of artistic proof, this thesis analyzes nine televised speeches presented by President Reagan from February 1981 through April 1983. Reagan skillfully utilizes only two modes of rhetorical proof--ethos and pathos. However, his lack of logical proof has not lessened his effectiveness. This study reveals several reasons for Reagan's rhetorical effectiveness and success. For example, Reagan's strong ethical image and personality comfort his audience and encourage their trust. His weaknesses in logical argument are overlooked by his audience because of his high personal appeal. Furthermore, Reagan's use of pathos appeals makes Americans feel good about themselves and their country, helping him to maintain his popularity. Finally, Reagan's skillful use of the television medium has increased his effectiveness.
4
Fu, Yunyi Michael. "Development of a polymer-supported reagent for Trost-Lu isomerization reactions and reagents for Mitsunobu reactions." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B39793989.
Full text
5
Fu, Yunyi Michael, and 付運毅. "Development of a polymer-supported reagent for Trost-Lu isomerization reactions and reagents for Mitsunobu reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39793989.
Full text
6
Svensson, Fredrik. "Why did't Reagan invade Rhode Island instead? : En studie om Ronald Reagans motiv till att USA skulle intervenera på Grenada." Thesis, Högskolan Kristianstad, Sektionen för Lärarutbildning, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-7694.
Full textAbstract:
Studien behandlar de motiv den amerikanske presidenten Ronald Reagan fann till att USA skulle intervenera på Grenada, samt hur denna motivbild skapades. Som teori användes John J Mearsheimers offensiva realism och metoden tog sin utgångspunkt i Ernesto Laclau och Chantal Mouffes diskursanalys. Materialet som undersöktes bestod av texter och uttalanden med Reagan som avsändare. I analysen visade sig både motiv tillhörande den realistiska och liberala diskursen. Den liberala diskursen var dock underställd den realistiska, vilket visade på en hegemoni för den senare.
7
Sass, Daiane Cristina. "Síntese biomimética de Eremantolidos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-05042009-205309/.
Full textAbstract:
Neste trabalho foram desenvolvidos alguns estudos que tiveram como objetivo principal a transformação de furanoeliangolidos contendo a unidade -metileno--butirolactona em eremantolidos, através da reação de adição 1,4 de hidreto seguida de ciclização, realizada pelo reagente de Stryker [(Ph3PCuH)6].<br>In this work we describe our studies for the biomimetic transformation of furanoheliangolides into eremantholides using the Strykers reagent [(Ph3PCuH)6].
8
Saber, Aabed (Aabed Saud). "Manufacturability of lab on chip devices : reagent-filled reservoirs bonding process and its effect on reagents flow pattern." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/79315.
Full textAbstract:
Thesis (M. Eng. in Manufacturing)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2013.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 71-73).<br>In its lab-on-a-chip product, Daktari Diagnostics utilizes "reagent-filled reservoirs" as a means of storing and delivering the liquid reagent. During the clinical trials of the product, undesired reagent flow patterns (namely, flow anomaly 1 & flow anomaly 2) were noticed. This work focused on optimizing the bonding process of the reagent-filled reservoirs to the backbone. Also, the relationship between the bonding process parameters and the reagent flow pattern was studied in depth. To achieve the objective of this thesis, an experiment was designed in which independent variables were the heat sealing parameters (x, y, z) and accelerated aging and the dependent variables were bond strength and the reagent flow pattern. Experiments showed that optimal Heat Sealing parameters are: parameter x = 4.5, parameter y = 110 and parameter z = 1.5. At the optimal settings of bonding process, the highest bond strength was attained and the reagent flow improved considerably but flow anomalies were not completely resolved. Also, results showed that accelerated aging affected the bond strength negatively. Accelerated aging also affected the flow pattern negatively, but this effect was not statistically significant.<br>by Aabed Saber.<br>M.Eng.in Manufacturing
9
Policarpo, Nara Angélica. "Tratamento de solos contaminados com bifenilas policloradas (PCBs)." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-15092008-140303/.
Full textAbstract:
Devido à alta toxicidade, a produção e comercialização dos PCBs (Polychlorinated Biphenyls - Bifenilas Policloradas) estão proibidas no mundo todo. Esses compostos foram utilizados principalmente como base de misturas comerciais em óleos dielétricos para transformadores e capacitores. Hoje existem diversas áreas contaminadas com essas substâncias que são de difícil degradação ocasionada pela sua elevada estabilidade térmica e química. Há diversos estudos sobre diferentes técnicas de tratamento de áreas contaminadas por PCBs. A técnica proposta nesse trabalho foi a de oxidação química através do reagente de Fenton. Para isso, foi simulado em laboratório experimentos de tratamento de solo contaminados artificialmente por ascarel (mistura comercial de PCBs). A oxidação foi realizada segundo a técnica do planejamento experimental fatorial de dois níveis e duas variáveis. Manteve-se constante a concentração do contaminante - em torno de 6000 mg de PCB/ kg de solo - e variou-se a concentração de Fe2+ (0,04 a 0,1 mol/L) e H2O2 (2,07 a 4,15 mol/L). Os ensaios foram realizados ainda nos seguintes tempos de reação: 0, 5, 24 e 48 horas. A análise dos dados foi realizada através de cromatografia gasosa acoplada a um espectrômetro de massa - GC/MS. Dos resultados, concluiu-se que o experimento cuja concentração do reagente de Fenton era 4,15 mol/L de H2O2 e 0,04 mol/L de Fe2+, apresentou melhor percentual de remoção, em torno de 76% para o pentaclorobifenila, 67% para o hexaclorobifenila e 72% para o heptaclorobifenila. Além disso, observou-se que, dentro da região experimental estudada, o efeito da concentração de íons ferrosos foi mais significativo do que o causado pela concentração de peróxido de hidrogênio e que o mesmo tem um efeito negativo pois aumentando a concentração dos íons ferrosos diminui-se a remoção dos contaminantes.<br>Production and trading of polychlorinated biphenyls (PCBs) are prohibited at whole world due to their high toxicity. They were used mainly as dielectric oils for transformers and capacitors. Recently there are many contaminated areas with these compounds. The high thermic and chemistry stability of PCBs are responsible for their hard degradation. Many studies have been conducted about several techniques of soil remediation. The main purpose of this research is to study chemical oxidation using Fenton\'s reagent to soils treatment. It was simulated in laboratory experiments of soil treatment which was artificially contaminated with Ascarel (PCBs commercial mixture). Process oxidation was made according to factorial experimental planning technique of two levels and two variables (22). The contaminant concentration was constant - 6000 mg PCB/ kg soil - and it was varied the Fe2+ concentration (0,04 mol/L to 0,10 mol/L) and H2O2 concentration (2,07 mol/L to 4,15 mol/L). The times reaction of experiments were: 0, 5, 24 and 48 hours. It was used gas chromatography coupled with mass spectrometer - GC/MS. The better result shown removal rate of 76% to pentachlorobiphenyl, 67% to hexachlorobiphenyl and 72% to heptachlorobiphenyl, experimental conditions were Fe2+ concentration of 0,04 mol/L and H2O2 concentration of 4,15 mol/L. Besides it was observed that studied region the concentration effect of ferrous ions was more significant than concentration effect of hydrogen peroxide. The concentration effect of ferrous ions was negative on system because removal rate of contaminants decreases when [Fe2+] increases.
10
Fazzio, Araceli Laranjeira. "Tratabilidade de lixiviado de aterro sanitário por reagente de Fenton consorciado com esgoto sanitário em biofiltro aerado submerso." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-27082014-100630/.
Full textAbstract:
A disposição ambientalmente adequada dos resíduos sólidos em aterros sanitários requer atenção ao tratamento do lixiviado gerado, que atualmente representa um desafio aos engenheiros, técnicos e pesquisadores da área. Esse trabalho avalia a tratabilidade do lixiviado pelo processo oxidativo avançado Reagente de Fenton, seguido por tratamento consorciado com esgoto sanitário em biofiltro aerado submerso. Os ensaios com Reagente de Fenton foram realizados em escala de bancada, com tempo de duração de 70 min por batelada; constatou-se que a razão mássica mais eficiente em termos de remoção de DQO do lixiviado bruto foi de 2:1 (H2O2:Fe II). Os resultados mostraram que esse tratamento reduziu, em média, 62% da DQO do lixiviado bruto. Entretanto, houve acréscimo do teor de sólidos no efluente e formação de lodo. Quanto ao tratamento consorciado com esgoto sanitário, foram utilizados dois biofiltros aerados submersos - reator controle (R1) e reator R2, que recebia 2% de lixiviado tratado por reagente de Fenton - com vazões de 330 mL/h e 450 mL/h, respectivamente, ambos com tempo de detenção hidráulica de 12 h. No período monitorado e considerando as eficiências médias de remoção de DQO de 75% e 70% e de DBO de 95% e 88% nos reatores R1 e R2, respectivamente, não foi possível concluir se houve tratamento do lixiviado ou apenas diluição. Entretanto, foi observado que a adição de lixiviado comprometeu a eficiência de remoção de matéria orgânica na forma de COD, no biofiltro R2.<br>The environmentally sound disposal of solid waste in landfills requires attention to the treatment of the leachate generated, which currently represents a challenge to the engineers, technicians and researchers. This research assesses the treatability of leachate by advanced oxidation process Fenton\'s reagent, followed by combined treatment with sewage submerged aerated biofilters. Assays with Fenton\'s reagent were performed in a bench scale, with a duration of 70 min per batch, it was found that the most efficient weight ratio in terms of COD removal of crude leachate was 2:1 (H2O2:Fe II). Results shows that treatment decreased on average 62% of the COD of the crude leachate. However, there was an increase of solids in the effluent and sludge formation. As for combination with sewage treatment, two submerged aerated biofilters were used - control reactor (R1) and R2 reactor, which received 2% of treated leachate by Fenton\'s reagent - with flows of 330 mL/h and 450 mL/h, respectively, both with a hydraulic retention time of 12 h. In the monitored period and considering the average COD removal efficiencies of 75% and 70% of BOD and 95% and 88% in the reactors R1 and R2, respectively, it was not possible to conclude whether there was treatment of leachate or just dilution. However, it was observed that the addition of leachate compromised the efficiency of removal of organic material in the form of COD in the biofilter R2.
11
Araújo, Eny Sá de. "Fita reagente no diagnóstico de peritonite em pacientes submetidos a diálise peritoneal." Universidade Federal de Sergipe, 2009. https://ri.ufs.br/handle/riufs/3678.
Full textAbstract:
Rapid diagnosis of peritonitis remains a significant goal in the management of peritoneal dialysis patients. Several attempts to use leukocytes esterase strips to diagnose peritonitis have been described. This study evaluated the usefulness of
Multistix® 10 SG, a urine reagent strip, for diagnosis of peritonitis in peritoneal dialysis patients. Reference standard for peritonitis diagnosis was International Society Peritoneal Dialysis ISPD criteria. A hundred-fifty-two peritoneal effluents were obtained from 96 patients maintained on peritoneal dialysis program, in a single renal replacement therapy center. There were 28 suspected patient specimens and 124 asymptomatic one. White cell count, culture and gram stain were obtained from 28 suspected patient specimens and from 35 asymptomatic one. In 89 asymptomatic
patient specimens were obtained only white cell count. Reagent strip was used in all specimens. Prevalence of peritonitis in this sample was 18,41 %. Sensibility, specificity, positive predictive value and negative predictive value of the reagent strip for the diagnosis of peritonitis was 92,86 %, 100 %, 100 % and 98,41 %, respectively. Multistix® 10 SG reagent strip is a sensitive, specific and rapid tool for
the diagnosis of peritonitis in peritoneal dialysis patients. Widespread use in peritoneal dialysis would aid in the early recognition and treatment of peritonitis.<br>O diagnóstico rápido de peritonite continua sendo uma meta importante no manejo de pacientes em diálise peritoneal. Diversas tentativas de utilizar fitas reagentes para esterase leucocitária no diagnóstico de peritonite já foram descritas.
Nesse estudo, foi avaliada a utilidade da fita reagente de urina Multistix® 10 SG para o diagnóstico de peritonite em pacientes submetidos a diálise peritoneal. O padrão de
referência para o diagnóstico de peritonite considerado foram os critérios diagnósticos da ISPD International Society of Peritoneal Dialysis.Foram estudados 152 efluentes peritoneais obtidos de 96 pacientes mantidos em programa crônico de
diálise peritoneal nas modalidades DPAC diálise peritoneal ambulatorial contínua, DPA diálise peritoneal automática e DPI diálise peritoneal intermitente, em um único centro de terapia renal substitutiva. A distribuição das coletas correspondeu a 28 casos sintomáticos e 124 casos assintomáticos. Das 28 coletas de pacientes sintomáticos de peritonite foram analisados citometria, pesquisa direta com
coloração de Gram e cultura. Das 124 coletas em pacientes assintomáticos, em 35 coletas foram analisadas citometria, pesquisa direta com coloração de Gram e cultura e em 89 coletas, foram analisadas somente citometria. Em todas as coletas foi realizado o teste com a fita reagente de urina. Segundo os critérios da ISPD, a prevalência de peritonite na amostra foi 18,41 % (28/152). Os resultados de sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo da fita reagente de urina para o diagnóstico de peritonite foram, respectivamente, 92,86 %, 100 %, 100 % e 98,41 %. A fita reagente de urina Multistix® 10 SG é uma
ferramenta sensível, específica e rápida para o diagnóstico de peritonite em pacientes em diálise peritoneal. A sua utilização ajudaria no reconhecimento rápido da peritonite e em seu pronto tratamento.
12
Louro, André de Souza. "Remediação de solos e lençóis freáticos em postos de gasolina via processo de fenton: estudo de caso." Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3773.
Full textAbstract:
Alguns cientistas ambientais prevêem que a poluição dos solos será um dos maiores legados com grandes impactos para as gerações futuras, pois atualmente ainda existe desconhecimento das fontes poluidoras e da sua extensão. O Brasil, devido a sua extensão territorial, suas bacias hidrográficas, número de postos de abastecimentos e controles ambientais ainda ineficazes, está muito exposto a esse tipo de poluição. Atualmente, há no Brasil mais de 34.300 postos de combustíveis, com volume de 65.000.000 m3 de gasolina e diesel consumidos anualmente, conforme dados da Agência Nacional do Petróleo Gás Natural e Biocombustíveis , ANP, em 2008. Sendo assim, a exposição e contaminação dos solos e dos lençóis freáticos com constituintes aromáticos do diesel e gasolina torna-se um sério problema ambiental. Dentro deste grupo, encontram-se o benzeno, tolueno, xileno, conhecido como BTEX e os hidrocarbonetos policíclicos aromáticos, conhecido como PAH.
Este trabalho tem como objetivo estudar a remediação in-situ de um posto de combustíveis na região do ABC Paulista, no Estado de São Paulo. Aplicando-se a técnica de Processo Oxidativo Avançado via reagente de Fenton (H2O2 + Fe2+ → Fe3+ + OH- + OH . ), o radical hidroxila gerado mineraliza compostos aromáticos, decompondo-os definitivamente. Amostras de água do posto em estudo apresentavam elevados teores de BTEX e PAH, 2,58 mg.L-1 e 0,298 mg.L-1 respectivamente, estando em níveis não tolerados pelo órgão ambiental paulista CETESB sendo necessária a intervenção para tratamento da área. Com os níveis de poluentes e o perfil hidrogeológico identificados, a remediação foi iniciada com injeções no solo de peróxido de hidrogênio a 8%v.v, FeSO4 a 0,40 mg.L-1 e solução à base de NPK (nitrogênio, fósforo e nitrogênio) a 100 mg.L-1 como nutrientes para os microorganismos do solo. Estes valores são provenientes de experimentos anteriores e tratamentos já realizados. Foram conduzidas campanhas de injeção trimestrais com 100 litros desta solução completa como reagente , e medições trimestrais de BTEX, PAH e outros parâmetros de controle, que foram indicando o sucesso do tratamento. Após 18 meses o local foi considerado tratado pelo órgão ambiental, onde monitoramentos semestrais estão em continuidade para garantir o resultado do tratamento e das ações corretivas. Assim, o estudo real da remediação de solos contaminados com os poluentes orgânicos via processo de Fenton, com concentração de H2O2 a 8%v/v, e FeSO4 a 0,40 mg.L-1 demonstrou-se uma técnica de sucesso. O entendimento dos resultados da remediação, mesmo sujeitos aos fenômenos naturais, como intempéries e chuvas, é uma experiência grande, pois por mais reais que simulações em laboratório possam ser, é muito difícil incluir nestes sistemas, as variações que um tratamento real está exposto<br>Some environmental scientists foresee that soil pollution would be one of the biggest legates to the next human generation, because nowadays there is not enough knowledge about all impacts and origins of such source of pollution. From inadequate batteries disposal to leakage of gasoline underground storage tanks, the range of sources of soil and groundwater pollution is immense. The Brazilian territory and its groundwater are greatly exposed to such contamination, also due to lack of environmental controls and government actions. Luckily, there are available some soil remediation technologies and good literature and previous researches. Nowadays, there are in Brazil around 34,300 gas stations all over the country, and a volume of 65,000,000 m3 of gasoline and diesel consumed annually, according to the National Petroleum Agency (ANP) in 2008. The probability to occur a soil and groundwater contamination is high and accurate processes are needed to quickly stop the underground contamined plume with BTEX (benzene, toluene, ethyl benzene and xylenes), found in gasoline and combustion byproducts and the wellness to people and other organisms.
This work has the intention to elucidate an in-situ soil and groundwater remediation process. The site treated was a gas station located in São Paulo state, responsible for almost 60% of gas stations in Brazil. Application of the Advanced Oxidation Process, using Fenton reaction (H2O2 + Fe2+ → Fe3+ + OH- + OH . ), which is a process that deliver into soil-water contamined systems, the hydroxyl radical in order to break undesired aromatic compounds. Water samples from the gas station in study, presented prohibited levels of BTEX and PAH according to the CETESB São Paulo Environmental Company which reason started the soil remediation and the area intervention. After understood of hydro-geological characteristics and the level of pollutants, the Fenton process started with well injections containing hydrogen peroxide ( 8% v/v), iron (II) salts (0,4 mg/L) and NPK based nutrients. At quarterly injections with 100 liters each, the further monitoring of BTEX, PAH and other control parameters, indicated the success of the treatment. After 18 months, the site was considered as remediated. Periodically sampling at each 6 months guarantee that the corrective actions kept successful. Based on that, the in-loco study about remediation of contaminated soils, with organic pollutants presents a great experience, and the Fenton reaction demonstrated a technique of outstanding success. The understand of real and in-situ results, even subjected to rain and other natural phenomena, gives expertise to treat real sites and help the society to stop such contamination. Moreover than laboratory simulation, the real remediation gives a complete snapshot about the Fentons reaction at the soil
13
Silva, Aluízio Gonçalves da. "Avaliação do pH de oxidação do processo fenton na remoção de microcistina-LR de água de abastecimento." Universidade Estadual da Paraíba, 2015. http://tede.bc.uepb.edu.br/tede/jspui/handle/tede/2290.
Full textAbstract:
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-04-27T14:30:56Z
No. of bitstreams: 1
PDF - Aluízio Gonçalves da Silva.pdf: 2861910 bytes, checksum: fec467664bbab2d62bb600299f8e0d10 (MD5)<br>Made available in DSpace on 2016-04-27T14:30:56Z (GMT). No. of bitstreams: 1
PDF - Aluízio Gonçalves da Silva.pdf: 2861910 bytes, checksum: fec467664bbab2d62bb600299f8e0d10 (MD5)
Previous issue date: 2015-11-24<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>Algal blooms and toxic cyanobacteria in fountains intended for human supply has been reported in many countries in recent decades due to impacts and human actions in the most diverse ecosystems on the planet. The presence of lineages of cyanobacteria producing cyanotoxins has negative effects on water bodies in particular in the intendend to the public supply due to the harmful effect of these substances on human health and animals. In general, cyanotoxins are not removed by conventional purifying water technologies. This study aimed to evaluate the efficiency of advanced oxidation process with the Fenton reagent in the oxidation of microcystin-LR water for public supply using conventional treatment steps coagulation, flocculation and sedimentation. The study water was prepared by adding the lysed cell cultivation Microcystis aeruginosa dechlorinated with potable water. Oxidation steps were performed, coagulation, flocculation and sedimentation JarTest programmed with rapid mixing -1 time of 10 s, rapid mixing gradient of 1000 s , flocculation time 20 min, flocculation gradient -1 -1 30 s and sedimentation velocity 1,4 cm.min . Different pH ranges were tested (2,0, 4,5 and + 7,0) and different concentrations of the Fenton reagent in the proportion of 1/3 H2O/Fe . The obtained results showed the oxidation of microcystin-LR in the treatments with pH 2,0; 4,5; and 7,0. By scanning the ions in the mass spectrometer it was possible to identify the peaks of mass/charge (m/z) fragments of enabling confirmation of oxidation by the presence of oxidation by products. Furthermore, after sedimentation the Fenton reagent enables significant removal being treatment T2 in time of 15 minutes the best for include percentage removal of turbidity 0,07 uT, true color 2,61 uH, COD 7,7 mg.L and MC-LR 0,07 μg.L.<br>Florações de algas e cianobactérias tóxicas em mananciais destinados ao abastecimento humano tem sido relatado em vários países nas últimas décadas devido aos impactos e ações do homem nos mais diversos ecossistemas do planeta. A presença de linhagens de cianobactérias produtoras de cianotoxinas tem efeitos negativo nos corpos hídricos em particular nos destinados ao abastecimento público devido ao efeito nocivo dessas substâncias à saúde humana e de animais. Em geral as cianotoxinas não são removidas pelas tecnologias convencionais de potabilização de água. O presente trabalho buscou avaliar a eficiência do processo de oxidação avançada com o reagente Fenton na oxidação da microcistina-LR de água destinada ao abastecimento público utilizando as etapas de tratamento convencional de coagulação, floculação e sedimentação. A água de estudo foi preparada com adição de cultivo de células lisadas de Microcystis aeruginosa com água potável desclorada. Foram realizadas as etapas de oxidação, coagulação, floculação e sedimentação em JarTest programado com tempo de -1 mistura rápida de 10 s, gradiente de mistura rápida 1000 s , tempo de floculação 20 min, -1 -1 gradiente de floculação 30 s e velocidade de sedimentação de 1,4 cm.min . Foram testados diferentes faixas de pH (2,0, 4,5, e 7,0) e diferentes concentrações do reagente Fenton na 2+ proporção de 1/3 de H2O/Fe . Os resultados obtidos mostraram a oxidação da microcistina-LR nos tratamentos com pH 2,0; 4,5; e 7,0. Através da varredura dos íons no espetrômetro de massas foi possível identificar os picos de massa/carga (m/z) dos fragmentos possibilitando a confirmação da oxidação através da presença dos subprodutos da oxidação. Além disso, após a sedimentação o reagente Fenton possibilitou a remoção significativa sendo tratamento T2 no tempo de 15 minutos o melhor por abrangir percentuais de remoção de turbidez 0,07 uT, cor verdadeira 2,61 uH, COD 7,7 mg.L e MC-LR 0,07 µg.L.
14
Norris, Patrick B. "Ronald Reagan Rain." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/830.
Full textAbstract:
RONALD REAGAN RAIN is a collection of poems that explore the wildness and terror lurking beneath the surface of contemporary suburban landscapes in a largely imagined America. Images of menacing policemen, bears, fast food restaurants, and dead film stars appear as substantive figures that embody loss and a preoccupation with aging, money woes, and a failed national confidence. Influenced by Russel Edson and Georg Trakl, poets whose work is characterized by Hermeticism and Expressionism, the poems in RONALD REAGAN RAIN suggest a similar dual need for autonomy and compromise in both highly charged poetic fragments and longer prose passages that examine issues of civil and personal estrangement as the outside world calls for constant introspection and reassessments of identity.
15
Bolien, David. "Reagent-free flow chemistry." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/362746/.
Full textAbstract:
A range of flow chemistries unified by the overlapping concepts of Reagentless Synthesis and Reactive Intermediate Trapping were developed. Thermochemically-promoted transformations for the generation and trapping of reactive intermediates, such as ketenes and N-acyliminium species, are reported. A particular emphasis was given to acquire kinetic data by means of in-situ spectroscopy techniques. Photochemistry is another ‘reagentless’ technique that is much less used in organic synthesis than might be expected from its capabilities. Flow chemistry provides a timely opportunity to develop ‘user friendly’ photochemical flow reactors and validate the equipment on selected photochemical reactions. Organometallic compounds impose particular challenges when handled in flow. Homogeneous or immobilised cobalt reagents were tested in combination with commercial flow equipment. Flow syntheses of selected piano stool iron complexes are also presented. Finally mixing properties of simple-shaped commercial flow mixers were assessed due to their critical role in commercial flow platforms. A mixing test was developed and compared against established procedures.
16
Horňák, Jakub. "Zahraničná politika Ronalda Reagana." Master's thesis, Vysoká škola ekonomická v Praze, 2017. http://www.nusl.cz/ntk/nusl-360116.
Full textAbstract:
Even though the Cold War ended almost 30 years ago, it has been one the most discussed phenomenon not only among IR scholars but also within the public. The whole Cold War discourse addresses many controversial question and who ended the Cold War is one of these questions. Basically, there are two schools of thought, one of which gives the credit to General Secretary of the Communist Party of the Soviet Union Mikhail Gorbachev and his reform policies. The second one perceives the US President Ronald Reagan and his unapologetic foreign policy as the most decisive factor in the End of the Cold War. By employing the methodology of analysis, this thesis aims to assess the impact of Ronald Reagan and his foreign policy on the End of the Cold War. This thesis tests the hypothesis that Ronald Reagan and his foreign policy were the most decisive factor in the End of the Cold War.
17
Winter, Stephen B. D. "A new silyl-cuprate reagent." Thesis, University of Cambridge, 1995. https://www.repository.cam.ac.uk/handle/1810/272799.
Full text
18
Babcock, Jennifer L. "A Tale of Two Women: The Journalistic Narrative of Nancy Reagan." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/BabcockJL2007.pdf.
Full text
19
Oswald, John Francis. "The mechanism of Grignard reagent formation." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/27140.
Full text
20
Russell, Rebecca Lee. "The Impact of President Reagan's Foreign Policy Efforts in Chile and Nicaragua." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/34424.
Full textAbstract:
This thesis explores whether President Ronald Reagan's policies on Chile and Nicaragua met his intended goals of promoting the spread of liberal democracy and countering Soviet influence in the region. Using a case studies approach to analyze Reagan's foreign policies in Chile and Nicaragua, the thesis seeks to inform conclusions about his success and failure in U.S. foreign policy in Latin America. The study examined whether Reagan achieved success in these two countries by using the key tenets of the Reagan Doctrine, the principal expression of the campaign to gain public support for the strengthening of governments and anti-government forces on the side of free democratic capitalism and the weakening of governments and anti-government forces on the side of Marxist-Leninism. The tenets of the Reagan Doctrine include: regimes that were not aligned with communism; national economies that did not rely upon the Soviet Union and that had open trade with the U.S. and stronger private sectors; and regimes that cooperated with the U.S. government. This thesis is both relevant and timely as U.S. presidents continue to involve themselves in the affairs of other nations. It seeks to contribute to the ongoing debate on the necessity and practicality of influencing affairs in countries around the world so that they will align themselves politically and ideologically with the United States and to provide lessons for future U.S. presidents as they create their own foreign policy agendas.<br>Master of Arts
21
Cavalcanti, Alessandro Sampaio. "Estudo da aplicação de foto-fenton solar como tratamento de chorume proveniente do aterro sanitário de Cachoeira Paulista-SP." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/97/97137/tde-08102013-100019/.
Full textAbstract:
O chorume in natura utilizado foi proveniente do aterro sanitário da cidade de Cachoeira Paulista no interior do estado de São Paulo. Possui baixa razão de biodegradabilidade (DBO/DQO = 0,094) evidenciado principalmente através das análises de caracterização dos parâmetros COT (618,1 mg C/L), DQO (4345,88 mg O2/L) e DBO5 (409,7 mg O2/L) que estão acima do limite permitido pela legislação. Em função disso, os processos oxidativos avançados (POA´s) surgem como alternativa para o seu pré-tratamento. O foco principal desse trabalho foi utilizar a aplicação da fotocatálise homogênea, empregando concomitantemente a luz solar com o reagente Fenton (H2O2 + Fe2+) num reator aberto com volume constante da amostra (3L) em sistema semi-batelada para verificar a eficiência do processo na remoção da carga orgânica. O reator solar possui um suporte de madeira que está direcionado ao Equador com um ângulo de inclinação de 23º, com uma placa metálica sem pigmentação denominada branco, numa vazão constante (13 L / min) em períodos com maior intensidade de radiação UV e monitorados pelo radiômetro. Após o ajuste do chorume de acordo com a planilha experimental, o volume do reagente Ferro (0,82 mol) foi adicionado totalmente no início da reação e o peróxido de hidrogênio (30% m/v) durante 30 min do tempo total de 1 hora, através de uma bureta dosadora, de maneira controlada que o peróxido de hidrogênio fosse consumido integralmente na reação de degradação, aumentando assim sua eficiência. O chorume tratado foi bombeado até a parte superior da placa, percolando-a uniformemente enquanto recebia a radiação solar sobre a placa. O processo fotocatalítico foi otimizado por um planejamento fatorial (23) com duplicata e triplicata no ponto central contendo 19 experimentos com variáveis de entrada: pH (3, 3,5 e 4) , quantidade de [H2O2] ( 73,2 g , 85,4 g e 97,6 g ) e quantidade de [Fe2+ ] (4,0 g , 5,0 g e 6,0 g ). As variáveis respostas do processo utilizadas foram: eficiência de remoção de COT (Carbono Orgânico Total) e DQO (Demanda Química de Oxigênio). As maiores reduções percentuais de DQO e COT, respectivamente, 89,19% e 86,12%, além do aumento de sua biodegradabilidade para 0,55 com um custo de R$ 0,3558 / 3L. Desta forma, o processo fotocatalítico mostrou grande viabilidade técnica e econômica em relação à degradação da carga orgânica de chorume.<br>The leachate used was fresh from the landfill of the city of Cachoeira Paulista in the state of São Paulo. Has a low ratio of biodegradability (BOD / COD = 0.094) demonstrated mainly through the analysis parameters characterizing the TOC (618,1 mg C / l) COD (mg O2 4345,88 / L) and BOD5 (mg O2 409,7 / L) that are above the limit allowed by law. As a result, the advanced oxidation processes (AOP\'s) are an alternative to their pre-treatment. The main focus of this work was to use the application of photocatalysis homogeneous, employing concurrently sunlight with Fenton\'s reagent (H2O2 + Fe2+) in an open reactor with constant volume of sample (3L) in the semi-batch to verify the efficiency of the process in removal of organic matter. The solar reactor has a wooden support that is directed to the equator with a tilt angle of 23 º, with a metal plate without pigmentation called white, a constant flow rate (13 L / min) in periods with higher UV intensity and monitored by radiometer. After adjusting the leachate according to the experimental sheet, the volume of reagent iron (0,82 mol) was added entirely at the beginning of the reaction and hydrogen peroxide (30% w / v) for 30 min to 1 hour total time through a dosing burette so controlled that the hydrogen peroxide was consumed entirely in the degradation reaction, thus increasing its efficiency. The treated leachate was pumped to the top of the plate evenly percolating while receiving the solar radiation on the plate. The photocatalytic process was optimized by a factorial design (23) with duplicate and triplicate center point experiments containing 19 input variables: pH (3, 3,5 and 4), the amount of [H2O2] (73,2 g, 85,4 g 97,6 g) and the amount of [Fe 2+] (4,0 g, 5,0 g and 6,0 g). The response variables of the process were: removal efficiency of TOC (Total Organic Carbon) and COD (Chemical Oxygen Demand). The largest percentage reductions of COD and TOC, respectively, 89,19% and 86,12%, besides increasing its biodegradability to 0,55 at a cost of R $ 0,3558 / 3L. Thus, the photocatalytic process showed great technical and economic feasibility in relation to the degradation of the organic leachate.
22
Mendes, Paulo Ricardo Amador. "Integração de processos físico-químicos e oxidativos avançados no tratamento de efluentes da indústria de laticínios." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/97/97137/tde-24072014-154502/.
Full textAbstract:
Por meio das mudanças de paradigmas relacionados à gestão ambiental e elevação dos custos de lançamento de efluente, captação e tratamento de água, as indústrias passam por processos de inovação que resultam em melhor utilização dos recursos e maior diminuição dos custos. Além disso, as empresas estão sujeitas a maiores exigências quanto à legislação ambiental vigente impulsionando-as a implantar sistemas de reúso de efluentes. Apesar de representar uma importante atividade econômica, a indústria de laticínios é responsável pela geração de efluentes líquidos com alto potencial poluidor. O presente trabalho teve como objetivo a redução de contaminantes e melhoria da biodegradabilidade de efluentes de laticínios utilizando tratamentos combinados, em destaque, coagulação/floculação, processos com membranas e oxidação/redução química fotocatalítica. Os efluentes foram provenientes de uma indústria da região, oriundos da etapa de nanofiltração do soro ultrafiltrado. Eles foram divididos em duas correntes, denominadas de concentrado de nanofiltração (corrente 1) e permeado de nanofiltração (corrente 2). Para o tratamento da corrente 1 foi proposto inicialmente coagulação/floculação utilizando diferentes agentes coagulantes naturais (quitosana, derivado de tanino e extrato de moringa), seguido do uso de processos com membranas do tipo microfiltração (0,40 ?m em polieterimida) e ultrafiltração (50 kDa em polietersulfona). Para a corrente 2 foi proposto a utilização de Processos Oxidativos e Redutivos Avançados. Em todas as etapas foi utilizada a Metodologia da Superfície de Resposta para identificação das condições otimizadas. Para o tratamento de coagulação/floculação da corrente 1 foram avaliadas as influências do pH, dos coagulantes naturais e da agitação sobre as variáveis resposta reduções de carbono orgânico total (COT), demanda química de oxigênio (DQO) e turbidez. Na condição indicada como ótima foram alcançadas reduções de 18,3% de COT, 12,7% de DQO e 19,6% de turbidez. A partir da condição otimizada a corrente 1 foi submetida aos processos com membranas, sendo selecionada a microfiltração como melhor tratamento. O uso dessas membranas possibilitou reduções de 1,25% em COT, 5,21% em DQO e 87,4% em turbidez. A combinação destas tecnologias possibilitou a eliminação de 20,1%, 18,0%, 89,8% em COT, DQO e turbidez, respectivamente. Para o tratamento da corrente 2 foram utilizados diferentes tipos de processos oxidativos avançados sendo eles, foto-Fenton (íons ferrosos) e foto-Fenton avançado (uso de ferro metálico). Nestes casos foram avaliadas a influência das concentrações de peróxido de hidrogênio e íon ferroso e ferro metálico considerando como variáveis resposta reduções de COT e DQO. Os resultados otimizados obtidos para o POA foto-Fenton permitiram reduções de 89,9% em COT e 50,8% em DQO, enquanto os resultados otimizados para POA foto-Fenton avançado foram reduções de 74,9% de COT e 41,0% de DQO.<br>Through the paradigm changes related to environmental management and rising costs of effluent discharge, water abstraction and treatment, industries undergo innovation processes that result in better use of resources and greater reduction in costs. Moreover, companies are submitted to greater requirements regarding environmental regulations driving them to deploy reuse of wastewater systems. Despite representing an important economic activity, the dairy industry is responsible for producing wastewater with high pollution potential. The present work was carried out in order to reduce contaminants and improve the biodegradability of dairy effluent by using an hybrid wastewater treatment based on coagulation/flocculation, membrane process and photocatalytic chemical oxidation/reduction. The effluents came from a regional industry and originating from the nanofiltration step of an ultrafiltrate whey. They were divided into two streams, called nanofiltration concentrate (stream 1) and nanofiltration permeate (stream 2). For the treatment of stream 1 was initially proposed coagulation/flocculation using different natural coagulant agents (chitosan, derivative tannin and moringa extract), followed by membrane processes type of microfiltration (0.40 ?m in polyetherimide) and ultrafiltration (50 kDa in polyethersulfone). For the stream 2 Advanced Oxidation and Reductive Processes were performed. In all steps of the work Response Surface Methodology was used to identify the optimum conditions. For the coagulation/flocculation treatment, the influence of the pH, natural coagulants and agitation were evaluated on the response variables total organic carbon (TOC), chemical oxygen demand (COD) and turbidity reductions. The optimized results reduced of 18.3% TOC, 12.7% COD and 19.6% turbidity. From the indicated condition stream 1 was submitted to membrane processes, being selected the microfiltration as the best treatment. The use of theses membranes provided 1.25% TOC, 5.21% COD and 87.4% turbidity reductions. The combination of these technologies has enabled the elimination of 20.1%, 18.0%, 89.8% in TOC, COD and turbidity, respectively. For the treatment of the stream 2 different types of Advanced Oxidation Processes were used being them, photo-Fenton (ferrous ions) and advanced photo-Fenton (metallic iron). In this cases the influence of the hydrogen peroxide, ferrous ion and metallic iron concentrations were evaluated, considering as response variables TOC and COD reductions. The optimized results for the photo-Fenton AOP allowed 89.9% TOC and 50.8% COD reductions, while the results optimized for advanced photo-Fenton AOP were 74.9% TOC and 41.0% COD reductions.
23
Lugon, Marcelo di Marcello Valladão. "Determinação de Sn(II) por polarografia: aplicação no controle de qualidade de reagentes liofilizados para radiodiagnóstico." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-10102011-141504/.
Full textAbstract:
Cloreto estanoso (SnCl2.2H2O) é o composto mais utilizado na redução do íon pertecnetato (TcO4-), obtido pela eluição do gerador, para a marcação de reagentes liofilizados para radiodiagnóstico. Estes reagentes liofilizados contêm um ligante, cloreto estanoso, e diferentes excipientes. Muitos métodos analíticos para a determinação de estanho não conseguem distinguir entre os íons estanoso (Sn(II)) e estânico (Sn(IV)) em soluções. Os dois métodos, descritos na literatura, para determinação seletiva de Sn(II) são análise titrimétrica e polarografia. O método mais confiável descrito para a quantificação do íon estanoso é a polarografia (voltametria) e pode ser utilizado para a determinação em concentrações de mg e g de Sn(II) e Sn(IV) (0,06-1,0 mg), com boa seletividade. Foi realizada análise titrimétrica, para quantificação de Sn(II), na matéria-prima e em 3 lotes consecutivos de 9 reagentes liofilizados produzidos pelo IPEN-CNEN/SP, utilizando-se sulfato cérico 0,1 mol L-1, diluído 10 vezes e iodo 0,05 mol L-1, diluído 10 vezes, como soluções titulantes. Polarografia por pulso diferencial foi utilizada com configuração convencional composta por três eletrodos: eletrodo de trabalho de gota de mercúrio, eletrodo referência de Ag/AgCl (saturado com KCl) e eletrodo auxiliar de platina. O intervalo de potencial analisado foi de -250 a -800 mV e o pico atribuído à redução de Sn(II) foi encontrado em -370 mV em eletrólito suporte de H2SO4 3 mol L-1 e, para Sn(IV), -470 mV, em eletrólito suporte de HCl 3 mol L-1. Para retirada do oxigênio da solução na cela polarográfica utilizou-se nitrogênio 5.0 por 5 minutos, antes e após cada introdução de amostra. Para determinação de Sn(IV) foi feita a oxidação do Sn(II), por adição de peróxido de hidrogênio, em 37 ± 5 ºC, por 5 minutos, seguida de purga com nitrogênio, e análise. A análise polarográfica desenvolvida mostrou-se adequada para a determinação de Sn(II), na presença de Sn(IV), e de estanho total nos kits radiofarmacêuticos estudados.<br>Stannous chloride (SnCl2.2H2O) is the major compound used for reduction of generator-derived 99mTc-pertechnetate in cold kits for on site preparation of 99mTc-radiopharmaceuticals. These cold kits usually contain a ligand, stannous chloride, and different additives. Various techniques were described for tin determination, but they cannot distinguish between stannous (Sn(II)) and stannic (Sn(IV)) ions in solutions. The two methods described in literature for selective determination of Sn(II) are polarography and mass analysis (redox-titration). Polarography is a good selective method in the mg range as well as in the g range for Sn(II) and Sn(IV) (0.06-1,0mg). Titrimetric analysis was performed for quantification of Sn(II) in Sn(II) reagents and in 3 consecutive lots of 9 radiopharmaceutical cold kits produced by IPEN-CNEN/SP, using Ce(SO4)2.4H2O 0.1 mol L-1, diluted 10 times and, I2 0.05 mol L-1, diluted 10, as a titrant solution. Differential pulse polarography was chosen with a conventional three-electrode configuration consisting of a static mercury drop electrode, an AgCl/Ag (saturated KCl) reference electrode and a platinum wire auxiliary electrode. The potential was swept from 250 to 800 mV and the current (A) was measured at 370 mV and 470 mV potentials for Sn(II) in H2SO4 3 mol L-1 and Sn(IV) in HCl 3 mol L-1, respectively. The supporting electrolytes were deaerated during 5 min with 5.0 nitrogen gas before and after each sample addition. For total tin determination the oxidation of tin (II) was carried out in the same vial, by adding H2O2 at 37 ± 5 ºC, for 5 min to quantify tin (IV). The developed polarographic method showed to be adequate to quantify tin (II), in the presence of tin (IV), in analyzed radiopharmaceutical cold kits.
24
Rossi, Samuel E. "Reagan, Rambo, and the Red Dawn." Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1180975486.
Full text
25
Marais, F., and S. Combrinck. "An Approach to Dealing with the Difficulties Undergraduate Chemistry Students Experience with Stoichiometry." South African Journal of Chemistry, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001499.
Full textAbstract:
Abstract
Chemistry for first year students has been identified by Tshwane University of Technology as one of the subjects with a low pass
rate. It is apparent that students often memorize formulae and definitions, without understanding the underlying concepts
required to work with abstract units of measure. We have found that the majority of students at this university are unable to
balance reaction equations satisfactorily. They are also unable to predict the reaction yield, or identify limiting reagents. It is
imperative that these and other related problems are overcome before any meaningful change to the high failure rate at first year
level will be realized. All conventional forms of lecture presentation failed to make any significant impact on the success rate.
Structured worksheets were developed and used, together with tactile models, to address the problems and the initial findings
showed a marked improvement. It was discovered that the students’ problems originated from their inability to understand the
meaning of subscripts and coefficients in chemical equations. The worksheets and the impact they have made on the students’
understanding of stoichiometry are shared in this paper.
26
Nie, Jing. "Landfill Leachate Treatment by Fenton's Reagent Oxidation." Thesis, University of Louisiana at Lafayette, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1585908.
Full textAbstract:
<p> Fenton's Reagent Oxidation can significantly enhance the COD removal efficiency of landfill leachate. The results presented in this thesis show that the maximum amount of COD that could be removed by Fenton's Reagent Oxidation was about 80% of the initial value. Such a maximum removal was achieved using reagent dosage of 300 mg/L of H<sub>2</sub>O<sub>2</sub>, 55.84 mg/L of Fe<sup> 2+</sup>, and a pH of 3 at 25°C. </p><p> A mechanistic model was developed based on the kinetic reactions. A coefficient α, representing the proportional constant between organic matter and COD was firstly introduced to this model. This model fit the data well. The modeling coefficients of α, [·OH] and <i>k</i><sub>7</sub> are 0.013mol <i>mg</i><sup>-1</sup>, 1.65×10<sup>-9</sup> <i> M</i> and 1.55×10<sup>-9</sup> <i>M</i><sup>-1 </sup><i>s</i><sup>-1</sup>, respectively. Hydroxyl radical concentration was calculated and the results confirm the pseudo steady state assumption. Response surface design and analysis results predicted that COD remaining can achieve the lowest value of 48 mg/L with the treatment conditions of a reaction time of 3.8 hours, a pH of 2.3, and a mass ratio of H<sub>2 </sub>O<sub>2</sub> to Fe<sup>2+</sup> of 38 at 60°C.</p>
27
Skinner, Christopher John. "Elemental fluorine as a valid synthetic reagent." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5141/.
Full textAbstract:
Chapter I Chapter I reviews the uses of elemental fluorine in selective organic synthesis and its use in the generation of selective electrophilic fluorinating agents. Chapter II Chapter II describes a systematic investigation into suitable solvents for the direct fluorination of deactivated aromatic systems. After highlighting 98% formic acid and 98 % sulphuric acid as excellent media for fluorinations, a number of other protonic acids were investigated. The work confirms the power of the resulting in situ fluorinating species is dependent on the pKa of the protonic acid. Chapter III Chapter III describes the use of elemental fluorine, in combination with strong acids, for the generation of powerful electrophilic halogenating agents derived for iodine, bromine and some interhalogens. The use of iodoaromatics in the incorporation of perfluoroalkyl groups into aromatics is also detailed. Chapter IV Chapter IV describes the use of elemental fluorine, in combination with iodine, for the direct fluorination of pyridines and quinoline in the 2- position. The use of elemental fluorine and an alcohol in the 2-alkoxylation of pyridine is also described. Investigation into a number of other potential nucleophiles for the 2- functionalisation of pyridines is also detailed. Chapter V-VII Experimental details relating to Chapters II-IV. Appendix One-Three Relevant (^1)H nmr, (^13)C nmr, (^19)Fnmr / IR data and mass spectra data.
28
Goon, Simon. "Applications of the Vilsmeier reagent in synthesis." Thesis, University of Sunderland, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245363.
Full text
29
Burns, Matthew. "Iterative reagent-controlled homologation of boronic esters." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658620.
Full textAbstract:
This thesis is concerned with developing a protocol for the reagent-controlled iterative homologation of boronic esters. Initial work focused on the synthesis of the highly enantioenriched Grignard reagent (5)-261 generated from sulfoxide (-)-anti-250 using a sulfoxide ligand exchange reaction. Grignard reagent (5)-261 has been successfully applied in the homologation of boronic esters 175 and (R)-176. However, it was found that Grignard reagent (5)-261 did not possess sufficiently high reactivity to homologate the sterically more hindered boronic ester 177. We therefore explored the use of highly enantioenriched Iithio derivatives as reagents for the homologation of boronic esters. Methods to generate Iithiated benzoates through a sulfoxide ligand exc~ange reaction proved fruitless as competing deprotonation occurred instead. A successful protocol was ultimately found in utilising the tin - lithium exchange reaction. A twostep procedure was developed that enabled the synthesis of either enantiomer of stannane 328 in 99.9 : 0.1 e.r.. Subjecting stannane 328 to a tin - lithium exchange generated Iithiated benzoate 272 which proved to be a highly effective reagent for the iterative homologation of boronic esters. Using Iithiated benzoate 272 we were able to rapidly construct molecules with ten contiguous stereocentres through an iterative homologation sequence. By choosing to use either (5)-272 or (R)-272 we have developed a system where any diastereoisomer can be synthesised. To demonstrate the potential of the methodology we have synthesised boronic esters 339,350 and 353. We have shown that by controlling. the configuration of the stereoecentres along a branched carbon chain we are able to control the conformation of the carbon backbone in the solid state. The alternating syn-anti diastereoisomer 350 causes the molecule to adopt a linear conformation in the solid state in order to minimise destabilising syn-pentane interactions. The all syn diastereoisomer, boronic ester 353 was successfully synthesised using our methodology. Additionally, we have shown that the crystalline derivative 355, adopts a helical conformation in the solid state, again to minimise destabilising syn-pentane interactions.
30
Streng, Emilia S. "Carbon dioxide as a reagent and solvent." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/42740/.
Full textAbstract:
The work described in this Thesis has been carried out within the Erasmus Mundus framework for Sustainable Industrial Chemistry (SINCHEM). The work concentrates on the possible utilisation of carbon dioxide as a solvent and as a starting material. Chapter 1 introduces carbon dioxide and its utilisation. In addition, the 12 Principles of CO2 Chemistry are presented, as well as continuous flow chemistry and self-optimising reactors. The relevant aspects of these reactors are discussed further in Chapter 2. The results of the research are presented in Chapters 3-6. A self-optimising reactor with FT-IR analysis was employed for the methylation of alcohols as explained in Chapter 3. Chapters 4-6 concentrate on N-alkylation reactions. In Chapter 4, the reactivity between aniline, tetrahydrofuran and dimethyl carbonate in supercritical carbon dioxide is discussed. This research led to the discovery of novel transformations. In Chapters 5 and 6, methanol was employed to methylate amines. A ruthenium triphosphate catalyst, which can produce methanol from carbon dioxide and hydrogen, was used to catalyse the reactions between methanol and aliphatic amines, as described in Chapter 5. Also the cyclisation and subsequent methylation of amino alcohols was studied. This reactivity is also the topic of Chapter 6, where γ-alumina was used as catalyst and supercritical carbon dioxide as solvent. Finally, Chapter 7 summarises the work described in this Thesis and evaluates the progress made towards achieving the aims that are introduced at the end of Chapter 1. One of these aims is to evaluate the work carried out in this Thesis according to the 12 principles of CO2 Chemistry. This evaluation is shown in Chapter 7.
31
Mishir, Qayum. "Enantioselective organocerium reagents." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366685.
Full text
32
Lallinger, Stefan. "Madison, Hamilton, and Reagan: The Limits of Executive Power in Foreign Policy and the Reagan Intervention in Nicaragua." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/1324.
Full textAbstract:
The distribution of power between the executive branch and the legislative branch in the realm of foreign policy is a delicate balance and one that has been debated since the Founding Fathers met in Philadelphia in the summer of 1787. The debate has gotten no less intense and no less crucial in the modern, nuclear age, and it remains unresolved. The Reagan administration's foray into Nicaragua during the 1980's and its confrontations with Congress during that time period illuminate the complexities of the power-sharing arrangement in foreign policy and offer the ideal case study of executive-legislative war power. The lessons to be drawn from America's involvement in Nicaragua are that the expanded Presidential power in the realm of foreign policy are necessary for the safety of the country in today's world, but dangerous without the vigorous oversight and ultimate check by Congress.
33
Ikched, Abdellah. "La politique économique du président Ronald Reagan." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR10027.
Full textAbstract:
L’élection de R. Reagan a la présidence des États-Unis d'Amérique a constitué un grand tournant non seulement pour la politique de ce pays qui constitue la première puissance économique mondiale, mais aussi dans l'évolution des conceptions et des pratiques de la politique économique. Même si la présidence de R. Reagan n'est pas encore achevée, son terme normale se situant fin 1988, les principales reformes économiques sont à présent réalisées et l'expérience a déjà une durée de six ans. Dans ces conditions, il parait utile et possible d'établir un premier bilan de cette nouvelle stratégie économique. A cet égard, on peut dire que même si les prévisions des "supply-siders" ne sont pas toutes confirmées les résultats obtenus sont loin d'être négligeables puisque sur le plan macro-économique, la reprise de l'économie américaine est l'une des plus fortes que l'on ait observées depuis la guerre; et sur le plan microéconomique, la dérèglementation et les allégements fiscaux ont été bénéfiques aux entreprises qui ont réussi a restructurer leurs finances accroitre leurs investissements et leur emploi tout en améliorant leur marge bénéficiaire<br>Ronald Reagan's election to the presidency of the united states of America has been a big turning not only for the policy of this country which is the first world economic power, but in the conception's evolution and economic policy's practices too. Even if the Reagan’s presidency is not yet over, his term is fixed at the end of 1988, the main economic reforms are currently realized and the experience is six years old. Under those circumstances, it seems useful ad possible to draw up a first balance sheet of this new economic strategy. For that matter, we can say that even if the supply-sider's previsions are not all made certain, the results are positively undeniable. In fact, from the macro-economical point of view, the recovery of U. S. Economy is one of the most important since the war. And, in terms of micro-economy, deregulation and tax cuts have been beneficent for American corporates which successfully restructurated their finances, increased both investments and employment although they improved their margin of profit
34
Bayliss, M. A. J. "Fluorescent derivatising reagents for hydroxyl groups." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304787.
Full text
35
Sampson, David Francis John. "Boron linkers and immobilised boraines for solid phase chemistry." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250052.
Full text
36
Buswell, M. "Reactions of the dimethylphenylsilyllithium reagent with tertiary amides." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597162.
Full textAbstract:
Chapter one describes the known reactions of simple, <I>N,N</I>-dimethylamides with phenyldimethylsilyllithium, which give acylsilanes, enediamines or α-silylamines, depending upon the stoichiometry and reaction conditions. This thesis describes five investigations into the scope of these reactions with other amides. Chapter two describes reactions of the acyclic <I>N</I>-phenyl amides A1, which gave the corresponding disilylalcohol A3, presumably by way of the acylsilane A2. (Fig. 1359A). Chapter three describes reactions of <I>N,N</I>-dimethylthioamides A4 with phenyldimethylsilyllithium, which gave enethiols A6 (the more stale tautomer of the thioacylsilane A5). This route is comparable to the known method, which effectively reverses the order of these two steps. (Fig. 1359B). Chapter four describes the synthesis of the silapiperidine protected amides A7 designed to have a protecting group on nitrogen. Reaction wtih the dimethylphenylsilyllithium reagent gave the enediamine A9 and the α-silylamine A8, but the protecting group could not be removed. (Fig. 1359C). Chapter five describes the reactions of <I>N</I>-phenyl-2-pyrrolidinone A10 with phenyldimethylsilyllithium under a variety of conditions giving the products A11 to A17. These represent some remarkable transformations. The stereochemistry of the two tetracyclic dimers A11 and A12 was confirmed by obtaining an X-ray crystal structure. Some aspects of the reaction pathways have been investigated. (Fig. 1359D). Chapter six describes the reactions of some lactams and amides with the phenyldimethylsilyllithium reagent; 1-phenyl-azetidin-2-one, 1-phenyl-piperidin-2-one, 1,3-dimethyl-1,3-dihydro-benzoimidazol-2-one and 1-methylpyridin-2-one.
37
Sonmez, Hakan. "Reagent usage optimization In high volume diagnostics testing." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/117968.
Full textAbstract:
Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, 2018.<br>Thesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, in conjunction with the Leaders for Global Operations Program at MIT, 2018.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (page 67).<br>Company X provides healthcare diagnostics testing services. The company competes in the market by providing cost effective, short turn-around-time (TAT) solutions and a large variety of test selections. Reducing operating costs is a major area of ongoing improvement for Company X, and this effort includes reducing reagent costs in high volume diagnostics platforms across the nation. The objective of this thesis is to identify the major causes of reagent waste, and reduce unnecessary reagent consumption on a specific high volume testing platform which can test multiple different assays. The project targeted finding measures to mitigate reagent waste which can be employed in all sites. The current state analysis identified quality control testing that exceeded regulatory requirements and minimum standards defined in the SOPs and unoptimized distribution of assays to instruments as causes of unnecessary reagent consumption. The analysis also identified patient tests repeated due to mechanical errors in the instruments as another cause of reagent waste. Countermeasures are developed to mitigate these issues. In order to reduce reagent consumption due to superfluous quality control testing, a workflow study is conducted. The workflow study targets the minimization of quality control testing and instrument calibrations by optimizing the load distribution over similar instruments within a laboratory site. The optimal distribution of patient test volumes to instruments is modeled and solved as a linear programming problem. In addition to workflow optimization, process standardization and preventive maintenance strategies are explored.<br>by Hakan Sonmez.<br>M.B.A.<br>S.M.
38
Abd-Rahman, Noorsaadah. "A search for a new silyl-cuprate reagent." Thesis, University of Cambridge, 1990. https://www.repository.cam.ac.uk/handle/1810/272738.
Full text
39
Rojas, Anthony J. (Anthony Jose). "Palladium reagents for bioconjugation." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120905.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2018.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>physicochemical properties in comparison to their linear counterparts. Here we detail a method for a divergent macrocyclization of unprotected peptides by crosslinking two cysteine residues with bis-palladium organometallic reagents. These synthetic intermediates are prepared in a single step from commercially available aryl bis-halides. Two bioactive linear peptides with cysteine residues at i, i + 4 and i, i + 7 positions, respectively, were cyclised to introduce a diverse array of aryl and bi-aryl linkers. These two series of macrocyclic peptides displayed similar linker-dependent lipophilicity, phospholipid affinity, and unique volume of distributions. Additionally, one of the bioactive peptides showed target binding affinity that was predominantly affected by the length of the linker. Collectively, this divergent strategy allowed rapid and convenient access to various aryl linkers, enabling the systematic evaluation of the effect of appending unit on the medicinal properties of macrocyclic peptides. Chapter 2: We report the use of a sulfonated biarylphosphine ligand (sSPhos) to promote the chemoselective modification of cysteine containing proteins and peptides with palladium reagents in aqueous medium. The use of sSPhos allowed for the isolation of several air-stable and water-soluble mono- and bis-palladium reagents, which were used in an improved protocol for the rapid S-arylation of cysteines under benign and physiologically relevant conditions. The cosolvent-free aqueous conditions were applied to the conjugation of a variety of biomolecules with affinity tags, heterocycles, fluorophores, and functional handles. Additionally, bispalladium reagents were used to perform macrocyclization of peptides bearing two cysteine residues. Chapter 3: The synthesis of palladium oxidative addition complexes of unprotected peptides is described. Incorporation of 4-halophenylalanine into a peptide during solid phase peptide synthesis allows for subsequent oxidative addition at this position of the unprotected peptide upon treatment with a palladium precursor and suitable ligand. The resulting palladium-peptide complexes are solid, storable, water-soluble, and easily purified via high-performance liquid chromatography. These complexes react rapidly with thiols at low micromolar concentrations in an aqueous buffer, offering an efficient method for bioconjugation. Using this strategy, peptides can be rapidly functionalized with small molecules to prepare modified aryl thioether sidechains. Additionally, peptide-peptide and peptide-protein ligations are demonstrated under dilute aqueous conditions.<br>by Anthony J. Rojas.<br>Ph. D.
40
Herman, Mark A. "A historical-rhetorical analysis of the 1980/1984 campaign rhetoric of Ronald Reagan /." View online, 1990. http://repository.eiu.edu/theses/docs/32211998880613.pdf.
Full text
41
Muller, Craig. "In Reagan's backyard : an examination of the condition of liberalism in California in the early 1980s /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0073.
Full text
42
Richardson, Robert Gregory. "US foreign policy ideology & the Reagan administration /." Title page, contents and introduction only, 2002. http://web4.library.adelaide.edu.au/theses/09AR/09arr521.pdf.
Full text
43
Johnson, Roger James. "Ronald Reagan and the mythology of American history." Thesis, University of Sussex, 2010. http://sro.sussex.ac.uk/id/eprint/2354/.
Full textAbstract:
The concept of myth has been central to the interpretation of President Ronald Reagan. This is a complex and ambiguous association. Myth is variously defined, referring to fable and falsehood as well as symbolic narratives of memory and identity. It is also variously applied, to Reagan's character, ideology, communication and legacy. Reagan's relationship to American mythology has been incompletely defined, and is in need of a synthesis which shows the connections between its different facets and processes, while identifying the problems of such an approach. Analysing the extensive literature on Reagan, using his public papers and published writings, and based on original research at the Reagan Presidential Library and at Stanford University, this thesis considers the presence and functions of American myth in Reagan's presidency in five distinct ways. Firstly, I look at the mythic narratives of Reagan's life in his biography. Secondly, I define his own perception of American history. Thirdly, I describe his distinctive, but constrained engagements with national commemoration. Fourthly, I explore the politicised historical interpretations of two central events of his presidency, the end of the Cold War, and the Iran/Contra affair. Lastly, I examine how his presidential library works to define his varied meaning in American history and mythology. The thesis concludes by surveying Reagan's meaning in twenty-first century America, and the tension between his national and partisan symbolism. Reagan built a reputation on his successful appeals to American myth, memory and identity and maintains a charged and contested symbolism. This association and this success have become the definitive factor of his image as his own mythology emerges in American national culture.
44
Hill, Ronald Bryant. "Missing in America homelessness during the Reagan revolution /." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3034548.
Full text
45
Carvalho, Gracielle Mayra Rodrigues. "Avaliação do tratamento de efluente farmacêutico endoparasiticida por processos Fenton e Foto-Fenton." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/97/97137/tde-24032015-153633/.
Full textAbstract:
A ocorrência de fármacos no meio ambiente tem se tornado um assunto de interesse nos últimos anos. A preocupação com a presença de produtos farmacêuticos decorre de sua persistência química, resistência microbiana, e efeitos sinérgicos, que levam às implicações toxicológicas. O objetivo deste trabalho foi avaliar o tratamento do efluente farmacêutico endoparasiticida. Para isso, os processos Fenton e Foto-Fenton foram usados para se obter a redução da carga orgânica do efluente em questão. Para a caracterização analítica do efluente farmacêutico in natura e tratado foram empregados métodos estabelecidos e otimizados, tais como DQO, COT, DBO5, Ferro, Sólidos (ST, STF, STV), fenol e análise de elementos via absorção atômica. Por meio de dois arranjos ortogonais - Taguchi L9 e Taguchi L16 - os parâmetros de melhor eficiência para o tratamento por Fenton e Foto-Fenton foram determinados. A matriz L9 foi utilizada para estudo exploratório dos fatores mais importantes na redução percentual da DQO. Este estudo mostrou que a condição experimental na qual se observou a maior porcentagem de redução de DQO (da ordem de 86,2 %) no efluente farmacêutico foi o experimento com reagente Fenton igual a 31,7g H2O2 e 2,2 g Fe2+, sem radiação ultravioleta, pH igual a 3,0 e temperatura de 30 °C. Já com a matriz L16 foram determinados os melhores experimentos, tendo como fatores resposta o percentual de redução do COT e percentual de degradação dos princípios ativos Fenbendazol e Triclabendazol. Portanto, a melhor configuração dos fatores foi Temperatura de 20°C, massa de H2O2 igual a 30 g, massa de Fe2+ igual a 2,5 g, pH igual a 3,0 e potência de radiação ultravioleta de 28 W, ou seja, a configuração que apresentou as maiores porcentagens de redução do COT (da ordem de 73,6%), degradação do Fenbendazol (da ordem de 77,8 %) e degradação do Triclabendazol (da ordem de 91,5 %).<br>The occurence of the drugs in the environment has become a subject of interest in the latest years. The concern with the presence of pharmaceutical products comes from its chemical persistence, microbial resistence and synergistic effects which lead to toxicological implications. The objective of this work was to evaluate of the treatment of endoparasiticide pharmaceutical effluent. For that, the photo-Fenton and Fenton were used for achieving the reduction of the organic load of the effluent in question. For the analytical characterization of pharmaceutical effluent in natura and treated were employed methods established and optimized such as DQO, COT, TOC, DBO5, Iron, Solid ( ST, STV, STF), phenol and element analysis via atomic absorption. By means of two orthogonal arrangements - Taguchi L9 and L16 - parameters of better efficiency in the treatment by Photo-Fenton and Fenton were determined. The L9 matrix was used for exploratory study of the most important factors in reducing the percentage of DQO. This study showed that the experimental condition, in which it was observed the highest percentage reduction of DQO (approximately 86.2%) in the pharmacist effluent, was the experiment with Fenton\'s reagent equal to 31,7g H2O2 e 2,2 g Fe2+, without ultraviolet radiation, pH equal to 3.0 and a temperature of 30 ° C. With the L16 matrix were determined as the best experiment with response factors the percentage reduction of COT and percentage of degradation of the active Fenbendazole and Triclabendazole. Therefore, the best configuration of the factors was 20 º C, H2O2 mass equal to 30g, Fe2 + mass of 2.5 g, and pH equal to 3.0 and power of 28W ultraviolet radiation, in other words the configuration that had the greatest percentage reduction of COT ( the order of 73.6%), Fenbendazole degradation (the order of 77.8%) and degradation Triclabendazole (the order of 91.5%).
46
Xie, Ting 1971. "Heavy metal removal from soil by complexing reagents with recycling of complexing reagents." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30838.
Full textAbstract:
Heavy metals in the environment are a source of some concern because of their potential reactivity, toxicity, and mobility in the soil. Soil contamination by metals is placing human and environmental health at risk through possible contamination of food chain.<br>Soil washing can be used to remove metals from the soil. Chemical treatment involves the addition of extraction agents that react with the contaminant and leach it from the soil. The liquid, containing the contaminants, is separated from the soil resulting in a clean solid phase. Six chelating reagents, EDTA, Citric acid, ADA, DTPA, SCMC, and DPTA, were employed to determine the relative extraction efficiencies of the six chelating reagents for the target metals. Recycling of chelating reagent was the main interest of this study. The experiments were divided into four parts: (1) preliminary studies on the preparation and characterization of soil that included grinding, sieving, soil texture measurements, total metals content post digestion and the distribution of metals in different soil fractions as well as (2) a comparison of the extraction efficiencies of six chelating reagents toward Cu, Pb, Zn, Fe, and Mn. Additionally, the chelating reagent was liberated and recycled by treatment of the metal-complexes with disodium diethyl dithiocarbomate (DEDTC). Additionally, supercritical CO2 was used to extract metal-DEDTC complexes using various surfactants to maintain the metal-DEDTC complexes in suspension. Finally, (4) magnesium metal was evaluated as an alternative method for liberating the water-soluble chelating reagent from the complex so as to be able to recycle this reagent as well.<br>The different approaches were promising in terms of recycling the chelating reagents that suggests a means of optimizing the experimental conditions in future applications.
47
Stow, Jason P. "Chemical remediation of PCB contaminated soils using Fenton's reagent." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22781.pdf.
Full text
48
van, Kleef Eduard Hendrik. "Optical preparation of reagent states in molecular dynamics investigations." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357947.
Full text
49
Whittaker, David Thomas Edward. "Dimanganese decacarbonyl : a new reagent for radical organic synthesis." Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341094.
Full text
50
Gobel, Amy Rose. "Reducing reagent waste through process improvement and preventive maintenance." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111273.
Full textAbstract:
Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, 2017.<br>Thesis: S.M. in Engineering Systems, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, in conjunction with the Leaders for Global Operations Program at MIT, 2017.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (page 91).<br>Quest Diagnostics has committed to reducing operating expenses by $1.3B between 2012 and 2017. A portion of the cost-saving initiative focuses on reagents - expensive liquids that are combined with patient samples to detect compounds of interest. This project aims to reduce reagent waste for high-volume diagnostic tests run on an instrument platform that generates a relatively high amount of reagent waste. Waste, in this context, means any reagent that does not generate unique patient results. Therefore critical components of the quality system, such as quality control and calibration tests, are designated waste even though they are a necessary expenditure. Quality control (QC) samples and mechanical errors accounted for 5.2% and 4.4%, respectively, of all reagent usage prior to the start of the project. Mechanical errors occur when the diagnostic testing platform encounters something unexpected, such as debris or a reading that indicates insufficient sample volume, which interrupts sample processing. The instrument jettisons this test and attempts to repeat the assay. Initial discussions with laboratory representatives revealed differing interpretations of quality control requirements. All sites using the platform of interest were then surveyed to gauge the extent of variation. All sites met quality control requirements but several exceeded them. The most pertinent variations are listed below. 1. Frequency: Several sites ran control samples more often than established in Standard Operating Procedure (SOP) requirements, increasing total QC usage by over 70%. 2. Container size: The choice of container determines the amount of "dead volume", material that the instrument cannot access and must be discarded. Some sites used containers with 12.8 times the dead volume required in the smallest option. 3. Reuse policy: Some labs reuse containers of quality control materials across multiple batches. Reusing QC material further reduces the amount of dead volume discarded, but using new QC materials eliminates the possibility of evaporation between batches. An interdisciplinary team of experts tasked with maintaining the SOPs has reviewed these results and will clarify the appropriate SOP interpretation to unify practices across laboratories. In order to understand mechanical errors, I observed routine maintenance at four sites and found that business units did not consistently share best practices. Collaborating with vendor representatives and operators, I launched an Autonomous Maintenance (AM) pilot program in order to develop training materials capturing institutional knowledge and to test additional maintenance procedures. The AM activities generated 29 training documents, which were added to a national database of competency training materials. All operators certified to operate the testing platform will be required to review and pass comprehension quizzes on the training materials. As the Marlborough site continues to develop improvements to the maintenance procedures, these changes will be shared with the vendor and incorporated into training documents.<br>by Amy Rose Gobel.<br>M.B.A.<br>S.M. in Engineering Systems