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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.
21

Plan de emprendimiento en base a Gomitas con complementos alimenticios, Lima 2020

Diaz Ramirez, Gustavo Adrian, Galarza Davila, Diego Andre, López Chacaltana, Joana Lilian, Salomón Lapel, Gustavo Fabrizio, Solis Fuentes-Rivera, Flavia 30 November 2020 (has links)
En este proyecto se planteó una idea de negocio evaluando la viabilidad comercial y financiera aplicando todos los recursos y aprendizajes a lo largo de la carrera universitaria. Primero hemos identificado el problema, el cual existe poca oferta de complementos alimenticios en forma de golosinas saludables en el mercado peruano, el sabor no tan agradable con exceso de saborizantes, altos en químicos y los elevados precios que no motivan a las personas a adquirirlos. Por ello, analizando las tendencias de complementos alimenticios, la oferta y la demanda mediante estudios primarios y secundarios. Nuestro público objetivo seleccionado son ciudadanos de Lima Metropolitana Moderna entre 18 y 55 años de los Niveles Socioeconómicos A y B que usan complementos alimenticios. Por ello, creamos Junglamitas, el cual es un complemento alimenticio en forma de gomitas hecho a base de 100% fruta natural, orgánica y exótica de la Selva Peruana. El producto cuenta con tres presentaciones distintas: Gomitas de Aguaje con colágeno, para obtener un gran beneficio para la piel , Gomitas de Camu Camu con B12 para el sistema inmunitario y brindar energía, Gomitas de Aguaymanto y magnesio para aliviar la ansiedad y combatir el estrés. Para poner en marcha el proyecto, hemos desarrollado experimentos que validen el modelo de negocio, una proyección de ventas del producto, un desarrollo de un plan estratégico, de operaciones, de Recursos Humanos, de marketing, de Responsabilidad Social Empresarial y Financiero concluyendo que el negocio es rentable y escalable. / In this project, a business idea was proposed evaluating the commercial and financial viability applying all the resources and learning throughout the university career. First we have identified the problem, which there is little supply of food supplements in the form of healthy sweets in the Peruvian market, the not so pleasant taste with excess flavorings, high in chemicals and the high prices that do not motivate people to buy them. Therefore, analyzing the trends of food supplements, supply and demand through primary and secondary studies. Our target audience are citizens of Modern Metropolitan Lima From the NSE A and B between 18 and 55 years old who use nutritional supplements. For this reason, we created Junglamitas, which is a food supplement in the form of gummies made from 100% natural, organic and exotic fruit from the Peruvian Jungle. The product has three different presentations: Aguaje Gummies with collagen to obtain a great benefit for the skin and hair, Camu Camu Gummies with B12 for the immune system and provide energy, Aguaymanto and magnesium Gummies to relieve anxiety and combat stress. To start the project, we have developed experiments that validate the business model, a projection of product sales, a development of a strategic plan, operations, Human Resources, marketing, Corporate Social Responsibility and Financial, concluding that the business is profitable and scalable. / Trabajo de investigación
22

Multiple Ingredient Dietary Supplement and Protective Effects in Gamma Irradiated Mice

Monster, Kathleen 11 1900 (has links)
Cognitive impairment, “Chemofog”, has been well established as a negative outcome of otherwise successful medical radiation treatments. Mitigation of this negative feature would dramatically increase quality of life for those recovering from cancer treatment. There is currently no known intervention to protect or restore cognitive function of patients undergoing radiation treatments. Development of a multiple ingredient dietary supplement (MDS) is meant to offer a non-invasive therapy to help mitigate risk and decrease damage to individuals. The MDS was originally designed to off-set 5 key mechanisms associated with aging including oxidative damage, inflammation, impaired glucose metabolism, mitochondrial dysfunction and membrane deterioration. Radiation damage shares many of the same deficiencies that develop with age and supplementation with MDS would impact many of the same pathways. Changes in cytokine profile (inflammation markers), and biomarkers of behavioural functions, sensory functions, and oxidative damage provide preliminary evidence of MDS impacts. / Thesis / Bachelor of Science (BSc) / Cognitive impairment, “Chemofog”, has been well established as a negative outcome of otherwise successful medical radiation treatments. Mitigation of this negative feature would dramatically increase quality of life for those recovering from cancer treatment. There is currently no known intervention to protect or restore cognitive function of patients undergoing radiation treatments. Development of a multiple ingredient dietary supplement (MDS) is meant to offer a non-invasive therapy to help mitigate risk and decrease damage to individuals. The MDS was originally designed to off-set 5 key mechanisms associated with aging including oxidative damage, inflammation, impaired glucose metabolism, mitochondrial dysfunction and membrane deterioration. Radiation damage shares many of the same deficiencies that develop with age and supplementation with MDS would impact many of the same pathways.
23

The Determinants for Chinese Consumers’ Intention to Use Soy-based Dietary Supplements: An Application of The Theory of Planned Behavior

Ren, Jing 26 June 2009 (has links)
No description available.
24

Utilisation des suppléments alimentaires chez les athlètes d’élite québécois

Fréchette, Martin 04 1900 (has links)
Ce projet découle du Canadian Sport Centre Dietary Study qui avait pour objectif d’évaluer les habitudes de consommation de suppléments alimentaires chez les athlètes canadiens et de déterminer si des différences régionales existaient. Un nombre de sujets était prédéterminé pour chaque province en considération du nombre d’athlètes identifiés comme Excellence, Élite ou Relève par les Centres d’entraînement nationaux et les organismes gouvernementaux. Pour ce mémoire, seules les données associées aux athlètes du Québec ont été considérées. Quarante-trois athlètes ont répondu à un questionnaire sur l’utilisation des suppléments alimentaires, 71 ont fourni un journal alimentaire de trois jours et 42 parmi ces derniers ont remis les deux documents. La prévalence d’utilisation des suppléments alimentaires était de 90,7%. Les utilisateurs consommaient en moyenne 3,35 produits différents, particulièrement des boissons énergétiques (48,8%), des multivitamines-minéraux (37,2%), des produits de santé naturels (37,2%) et des suppléments de protéines en poudre (34,9%). Les athlètes souhaitaient maintenir leur santé (27,9%) et améliorer leur niveau d’énergie (27,9%) ou leur récupération (25,6%). Les sources d’information citées étaient les entraîneurs physiques (25,6%), la famille ou les amis (16,3%) et les coéquipiers (16,3%). Les sujets se procuraient ces produits dans les épiceries (16,3%), les pharmacies (14,0%) et les magasins spécialisés (9,3%). Soixante-dix pour cent des sujets croyaient que l’arrêt de l’utilisation des suppléments alimentaires n’aurait aucun impact sur leurs performances ou ne savaient pas comment cela les influencerait. Ils démontraient un vif intérêt au sujet de l’efficacité (69,8%), la légalité (55,8%) et la sécurité (53,5%) de ces produits. Des sujets qui utilisaient un supplément de protéines, 81% présentaient un apport alimentaire supérieur à leurs besoins. L’utilisation de suppléments de multivitaminesminéraux permettait de combler l’apport insuffisant en calcium et en folate, mais pas en potassium. Nos résultats soulignent que ces utilisateurs présentaient des apports dépassant l’apport maximal tolérable pour le sodium, le magnésium, la niacine, le folate, la vitamine A et le fer. Nous pouvons donc conclure que ces deux types de suppléments alimentaires n’étaient pas utilisés d’une façon pertinente. / This project derives from the Canadian Sport Centre Dietary Study. The purpose of this global research project consisted in studying the consumption habits of Canadians elite athletes towards dietary supplements and evaluating if regional differences could be identified. The number of subjects needed for each province was calculated from the number of athletes identified as Excellence, Elite or Releve by the Canadian Sports Centres and governmental organisms. Only subjects from Québec had been considered for this research work. Forty three subjects completed the questionnaire on dietary supplement consumption habits, 71 filled a three day food diary and 42 of them returned both documents. Results showed that dietary supplements were used by 90.7% of our sample. Users were consuming an average of 3.35 different types of dietary supplements, mostly sports drinks (48.8%), multivitamins-minerals (37.2%) and protein powders (34.5%). Reasons behind the use of supplements were: to stay healthy (27.9%), to raise energy level (27.9%) and to accelerate recovery (25.6%). Athletes were getting their information from physical trainers (25.6%), family members or friends (16.3%) and teammates (16.3%). Dietary supplements were bought in grocery stores (16.3%), drug stores (14.0%) and specialised stores (9.3%). Seventy percent of our sample thought that stopping the use of dietary supplement would have no impact on their performance level or had no idea of the impact it could have. Nevertheless, participants showed a clear interest concerning the efficiency (69.8%), legality (55.8%) and safety (53.5%) of dietary supplements. Eighty one percent of the subjects who were using protein supplements had dietary intakes above their needs for that nutrient. The use of multivitamin-mineral supplements compensated for inadequate intakes in calcium and folic acid, but not in potassium. This investigation showed that multivitamin-mineral users had dietary intakes above the Upper Intake Levels for sodium, magnesium, niacin, folic acid, vitamin A and iron. From these results, we can conclude, in this athlete population, that protein and multivitamin-mineral supplements were not required or used adequately.
25

Utilisation des suppléments alimentaires chez les athlètes d’élite québécois

Fréchette, Martin 04 1900 (has links)
Ce projet découle du Canadian Sport Centre Dietary Study qui avait pour objectif d’évaluer les habitudes de consommation de suppléments alimentaires chez les athlètes canadiens et de déterminer si des différences régionales existaient. Un nombre de sujets était prédéterminé pour chaque province en considération du nombre d’athlètes identifiés comme Excellence, Élite ou Relève par les Centres d’entraînement nationaux et les organismes gouvernementaux. Pour ce mémoire, seules les données associées aux athlètes du Québec ont été considérées. Quarante-trois athlètes ont répondu à un questionnaire sur l’utilisation des suppléments alimentaires, 71 ont fourni un journal alimentaire de trois jours et 42 parmi ces derniers ont remis les deux documents. La prévalence d’utilisation des suppléments alimentaires était de 90,7%. Les utilisateurs consommaient en moyenne 3,35 produits différents, particulièrement des boissons énergétiques (48,8%), des multivitamines-minéraux (37,2%), des produits de santé naturels (37,2%) et des suppléments de protéines en poudre (34,9%). Les athlètes souhaitaient maintenir leur santé (27,9%) et améliorer leur niveau d’énergie (27,9%) ou leur récupération (25,6%). Les sources d’information citées étaient les entraîneurs physiques (25,6%), la famille ou les amis (16,3%) et les coéquipiers (16,3%). Les sujets se procuraient ces produits dans les épiceries (16,3%), les pharmacies (14,0%) et les magasins spécialisés (9,3%). Soixante-dix pour cent des sujets croyaient que l’arrêt de l’utilisation des suppléments alimentaires n’aurait aucun impact sur leurs performances ou ne savaient pas comment cela les influencerait. Ils démontraient un vif intérêt au sujet de l’efficacité (69,8%), la légalité (55,8%) et la sécurité (53,5%) de ces produits. Des sujets qui utilisaient un supplément de protéines, 81% présentaient un apport alimentaire supérieur à leurs besoins. L’utilisation de suppléments de multivitaminesminéraux permettait de combler l’apport insuffisant en calcium et en folate, mais pas en potassium. Nos résultats soulignent que ces utilisateurs présentaient des apports dépassant l’apport maximal tolérable pour le sodium, le magnésium, la niacine, le folate, la vitamine A et le fer. Nous pouvons donc conclure que ces deux types de suppléments alimentaires n’étaient pas utilisés d’une façon pertinente. / This project derives from the Canadian Sport Centre Dietary Study. The purpose of this global research project consisted in studying the consumption habits of Canadians elite athletes towards dietary supplements and evaluating if regional differences could be identified. The number of subjects needed for each province was calculated from the number of athletes identified as Excellence, Elite or Releve by the Canadian Sports Centres and governmental organisms. Only subjects from Québec had been considered for this research work. Forty three subjects completed the questionnaire on dietary supplement consumption habits, 71 filled a three day food diary and 42 of them returned both documents. Results showed that dietary supplements were used by 90.7% of our sample. Users were consuming an average of 3.35 different types of dietary supplements, mostly sports drinks (48.8%), multivitamins-minerals (37.2%) and protein powders (34.5%). Reasons behind the use of supplements were: to stay healthy (27.9%), to raise energy level (27.9%) and to accelerate recovery (25.6%). Athletes were getting their information from physical trainers (25.6%), family members or friends (16.3%) and teammates (16.3%). Dietary supplements were bought in grocery stores (16.3%), drug stores (14.0%) and specialised stores (9.3%). Seventy percent of our sample thought that stopping the use of dietary supplement would have no impact on their performance level or had no idea of the impact it could have. Nevertheless, participants showed a clear interest concerning the efficiency (69.8%), legality (55.8%) and safety (53.5%) of dietary supplements. Eighty one percent of the subjects who were using protein supplements had dietary intakes above their needs for that nutrient. The use of multivitamin-mineral supplements compensated for inadequate intakes in calcium and folic acid, but not in potassium. This investigation showed that multivitamin-mineral users had dietary intakes above the Upper Intake Levels for sodium, magnesium, niacin, folic acid, vitamin A and iron. From these results, we can conclude, in this athlete population, that protein and multivitamin-mineral supplements were not required or used adequately.
26

Complex Dietary Interventions to Slow Rates of Aging

Aksenov, Vadim 01 September 2014 (has links)
<p>Aging erodes motivation, cognition, sensory modalities and physical capacities, effectively depleting quality of life. Declining sensory, cognitive and motor function are reliable biomarkers of aging and mortality risk. These declines are associated with dysregulation of systemic and cellular processes. We developed a complex dietary supplement (DSP) designed to ameliorate five mechanisms of aging (oxidative processes, inflammation, mitochondrial function, insulin resistance and membrane integrity). Remarkably, normal mice fed the DSP retained youthful functionality into old ages, reflecting slower aging rates. Marked improvements in motor function, memory capacity, spatial learning, muscle strength, visual acuity, olfaction, fecundity and important behavioral functions were observed in aging supplemented mice. Conversely, untreated control animals showed age-related declines in all of the above. Functional improvements were associated with reduced oxidative damage, elevated mitochondrial activity, positive cellular energy balance, improved glucose tolerance, boosted neurotransmitters, greater synaptic density and higher neuronal numbers throughout the brain. A 30% reduction in cancer rates was also documented for DSP treated p53+/- mice. The vast functional benefits greatly exceed the modest longevity extension (11%) in normal supplemented mice. For aging humans, maintaining functionality and performance into later years may provide greater socioeconomic and health benefits than simply prolonging lifespan. Implications of these findings extend to common age-related pathologies including dementia and neurodegenerative diseases, diabetes, cancer, sarcopenia and age-related macular degeneration. Although identifying the role of specific ingredients remains outstanding, results provide proof of principle that complex dietary cocktails can powerfully ameliorate biomarkers of aging and modulate mechanisms considered ultimate goals for aging interventions.</p> / Doctor of Philosophy (PhD)
27

Voltametrijske metode zasnovane na ugljeničnim elektrodama modifikovane kompozitima na bazi višezidnih ugljeničnih nanocevi i čestica bizmuta ili antimona za određivanje odabranih ciljnih analita / Voltammetric methods based on carbon electrodes modified with multi walled carbon nanotubes and bismuth and antimony particles based composites for determination of selected target analytes

Petrović Sandra 12 September 2019 (has links)
<p>Cilj ove doktorske disertacija&nbsp; bio je razvoj&nbsp; novih, osetljivih, selektivnih i ekonomski<br />isplativih&nbsp; voltametrijskih&nbsp; radnih&nbsp; elektroda&nbsp; za&nbsp; praćenje&nbsp; odabranih&nbsp; analita&nbsp; kako&nbsp; u<br />laboratorijskim tako i pri terenskim uslovima.&nbsp; Ispitivana je&nbsp; mogućnost primene&nbsp; ovih&nbsp; radnih&nbsp; elektroda&nbsp; primenom&nbsp; voltametrijskih&nbsp; metoda&nbsp; kako&nbsp; u&nbsp; model&nbsp; rastvorima&nbsp; tako&nbsp; i&nbsp; u&nbsp; pojedinim realnim sistemima. SW-ASV&nbsp; zasnovana&nbsp; na&nbsp; elektrodama&nbsp; od&nbsp; staklastog&nbsp; ugljenika&nbsp; povr&scaron;inski modifikovanim&nbsp; Bi-MWCNT&nbsp; i&nbsp; BiOCl-MWCNT&nbsp; je&nbsp; primenjena&nbsp; za&nbsp; određivanje&nbsp; jona&nbsp; Pb(II)&nbsp; i Cd(II)&nbsp; pri&nbsp; optimizovanim&nbsp; uslovima&nbsp; merenja.&nbsp; Određivanje&nbsp; ciljnih&nbsp; jona&nbsp; vr&scaron;eno&nbsp; je&nbsp; pri&nbsp; radnom potencijalu&nbsp; od&nbsp; -1,2&nbsp; V&nbsp; (izmeren&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; zasićenu&nbsp; kalomelovu&nbsp; elektrodu)&nbsp; i&nbsp; vremenu<br />elektrodepozicije jona&nbsp; od 120 s. Sva merenja su izvr&scaron;ena u rastvoru acetatnog pufera čija je pH-vrednost iznosila&nbsp; 4,0. Primenjeni koncentracioni opseg ciljnih analita iznosio je&nbsp; od 5 do 50&nbsp; &mu;g&nbsp; dm <sup>-3</sup> .&nbsp; Primenom&nbsp; ovog&nbsp; tipa&nbsp; elektrode&nbsp; dobijene&nbsp; su&nbsp; vrednosti&nbsp; granice&nbsp; detekcije&nbsp; za&nbsp; jone Pb(II) i Cd(II) 0,57&nbsp; &mu;g dm <sup>-3 </sup>i 1,2 &mu;g dm<sup>-3</sup> , redom. Dobijena RSD iznosila je manje od 10% za oba&nbsp; jona.&nbsp; Ova&nbsp; metoda&nbsp; je&nbsp; primenjena&nbsp; i&nbsp; za&nbsp; određivanje&nbsp; ciljnih&nbsp; jona&nbsp; u&nbsp; realnom&nbsp; uzorku&nbsp; porne vode&nbsp; sedimenta&nbsp; a&nbsp; rezultati&nbsp; dobijeni&nbsp; optimizovanom&nbsp; voltametrijskom&nbsp; metodom&nbsp; su&nbsp; u&nbsp; dobroj saglasnosti sa rezultatima koji su dobijeni primenom komparativne GFAAS metode. Bizmut oksihlorid-vi&scaron;ezidne ugljenične nanocevi kompozitni materijal je primenjen za povr&scaron;insko&nbsp; modifikovanje&nbsp; elektrode&nbsp; od&nbsp; staklastog&nbsp; ugljenika&nbsp; za&nbsp; brzo&nbsp; i&nbsp; jednostavno voltametrijsko&nbsp; određivanje&nbsp; tragova&nbsp; Zn(II)-jona&nbsp; primenom&nbsp; SW-ASV&nbsp; metode.&nbsp; BiOClMWCNT/GCE je pokazala linearan analitički odgovor u&nbsp; osegu koncentracija od&nbsp; 2,50 do&nbsp; 80,0 &mu;g&nbsp; dm <sup>-3 </sup>sa dobijenom vredno&scaron;ću GD 0,75 &mu;g&nbsp; dm<sup>-3 </sup>pri akumulacionom vremenu od&nbsp; 120 s&nbsp; i potencijalu&nbsp; elektrodepozicije&nbsp; -1,40&nbsp; V&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; ZKE.&nbsp; Merenja&nbsp; su&nbsp; vr&scaron;ena&nbsp; u&nbsp; acetatnom puferu pH 4,5. Dobijena RSD iznosila je 4,8 %. Upoređene su performanse novodizajnirane BiOCl-MWCNT/GCE elektrode&nbsp; i&nbsp; tradicionalne elektrode na bazi bizmut filma (BiF/GCE), MWCNT/GCE,&nbsp; BiF-MWCNT/GCE&nbsp; i&nbsp; nemodifikovane&nbsp; GC&nbsp; elektrode.&nbsp; Novodizajnirana elektroda je primenjena za&nbsp; detekciju&nbsp; i određivanje&nbsp; Zn(II)-jona&nbsp; u realnim&nbsp; uzorcima kao &scaron;to su<br />dijetetski&nbsp; suplement&nbsp; i&nbsp; pekarski&nbsp; kvasac.&nbsp; Dobijeni&nbsp; rezultati&nbsp; su&nbsp; uporedivi&nbsp; sa&nbsp; deklarisanom vredno&scaron;ću&nbsp; u&nbsp; slučaju&nbsp; dijetetskog&nbsp; suplementa&nbsp; a&nbsp; u&nbsp; slučaju&nbsp; pekarskog&nbsp; kvasca&nbsp; sa&nbsp; rezultatima dobijenih komparativnom FAAS .<br />Elektroda od ugljenične paste je povr&scaron;inski modifikovana pripremljenim kompozitom<br />koji je&nbsp; izgrađen od vi&scaron;ezidnih ugljeničnih nanocevi i čestica&nbsp; Sb<sub>2</sub>O<sub>3.</sub>&nbsp; Kompozitni&nbsp; materijal&nbsp; je okarakterisan&nbsp; primenom&nbsp; TEM,&nbsp; EDS&nbsp; i&nbsp; XRD&nbsp; mernih&nbsp; tehnika.&nbsp; Sb<sub>2</sub>O<sub>3</sub>-MWCNT/CPE&nbsp; je okarakterisana primenom ciklične voltametrije a merenja su vr&scaron;ena u rastvoru hlorovodonične kiseline&nbsp; (pH&nbsp; 2,0).&nbsp; Primenom&nbsp; SW-ASV&nbsp; metode&nbsp; ova&nbsp; radna&nbsp; elektroda&nbsp; je&nbsp; upotrebljena&nbsp; za određivanje&nbsp; jona Pb(II) i Cd(II)&nbsp; u&nbsp; koncentracionom opsegu 2,0-40,0&nbsp; &mu;g&nbsp; dm&nbsp; <sup>-3 </sup>za&nbsp; Pb(II)-jon&nbsp; i 2,0-40,0&nbsp; &mu;g&nbsp; dm <sup>-3</sup> za&nbsp; Cd(II)-jon&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijene&nbsp; dobre&nbsp; linearne&nbsp; zavisnosti&nbsp; za&nbsp; oba&nbsp; ciljna jona.&nbsp; Optimalna&nbsp; procedura&nbsp; uključuje&nbsp; primenu&nbsp; Sb2O3-MWCNT/CPE&nbsp; u&nbsp; 0,01&nbsp; mol dm <sup>-3</sup><br />hlorovodoničnoj kiselini uz vreme elektrodepozicije jona iz rastvora od 120&nbsp; s&nbsp; na&nbsp; potencijaluod&nbsp; -1,2&nbsp; V,&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijene&nbsp; vrednosti&nbsp; za&nbsp; GD&nbsp; 1,1&nbsp; &mu;g&nbsp; dm <sup>-3</sup> Cd(II)&nbsp; i&nbsp; 1,6&nbsp; &mu;g&nbsp; dm <sup>-3</sup> Pb(II). Optimizovana&nbsp; metoda&nbsp; zasnovana&nbsp; na&nbsp; ovom&nbsp; tipu&nbsp; voltametrijskog&nbsp; senzora&nbsp; je&nbsp; uspe&scaron;no primenjena&nbsp; za&nbsp; određivanje&nbsp; jona&nbsp; Cd(II)&nbsp; u&nbsp; obogaćenom&nbsp; uzorku&nbsp; česmenske&nbsp; vode,&nbsp; gde&nbsp; su&nbsp; se dobijene vrednosti u&nbsp; saglasnosti sa očekivanom. Elektroda od ugljenične paste povr&scaron;inski je&nbsp; modifikovana primenom&nbsp; Sb<sub>2</sub>O<sub>3</sub>-MWCNT nanokompozitnog&nbsp; materijala&nbsp; i&nbsp; primenjena&nbsp; za&nbsp; direktno&nbsp; voltametrijsko&nbsp; određivanje imidakloprida&nbsp; u&nbsp; model&nbsp; rastvorima.&nbsp; U&nbsp; cilju&nbsp; postizanja&nbsp; &scaron;to&nbsp; boljih&nbsp; analitičkih&nbsp; performansi optimizovani su eksperimentalni uslovi merenja kao &scaron;to su pH-vrednost rastvora pomoćnog elektrolita&nbsp; i&nbsp; kondicioniranje&nbsp; povr&scaron;ine&nbsp; voltametrijskog&nbsp; senzora.&nbsp; Kao&nbsp; optimalna&nbsp; pH-vrednost pomoćnog elektolita (Britton-Robinsonovog pufera) odabrana je pH 7,0, a ponavljanje ciklusa cikliranja najmanje 4 puta povoljno utiče na stabilnost&nbsp; voltametrijskih signala. Optimizovana metoda primenjena je za SW direktno katodno određivanje imidakloprida u koncentracionom intervalu od 1,41 do 32,77 &mu;g cm <sup>-3</sup> uz dobijeni korelacioni faktor od 0,9995. Na osnovu dobijenih rezultata može se zaključiti da su razvijene analitičke metode pre svega&nbsp; osetljive,&nbsp; selektivne,&nbsp; reproduktivne&nbsp; i&nbsp;&nbsp; jednostavne&nbsp; &scaron;to&nbsp; omogućava&nbsp; njihovu&nbsp; primenu&nbsp; za veliki broj uzoraka.&nbsp; Merenjima u model i realnim rastvorima dokazana je mogućnost njihove primene&nbsp; u&nbsp;&nbsp; komplikovanim&nbsp; matriksima,&nbsp; pri&nbsp; različitim&nbsp; pH&nbsp; vredostima&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijeni<br />rezultati koji su u saglasnosti sa rezultatima primenjenih komparativnih metoda. Naravno, za dobijanje&nbsp; reprezentativnih&nbsp; rezultata&nbsp; neohodno&nbsp; je&nbsp; izvr&scaron;iti&nbsp; optimizaciju&nbsp; uslova&nbsp; merenja&nbsp; &scaron;to podrazumeva sam odabir supstrat-elektrode, odabir povr&scaron;inskog modifikatora i optimizaciju eksperimentalnih uslova merenja.</p> / <p>The&nbsp; aim of this&nbsp; Ph.D. thesis&nbsp; was the development of new, sensitive, selective and economically&nbsp; viable&nbsp; voltametric&nbsp; working&nbsp; electrode&nbsp; for&nbsp; continuous&nbsp; monitoring&nbsp; of&nbsp; different target&nbsp; analytes.&nbsp; The&nbsp; use&nbsp; of&nbsp; these&nbsp; advantaged&nbsp; working&nbsp; electrodes&nbsp; was&nbsp; investigated&nbsp; using voltametric methods both in model solutions and in certain real systems.SW-ASV&nbsp; based on glassy carbon&nbsp; electrode surface modified with&nbsp; Bi- MWCNT and BiOCl-MWCNT&nbsp; were&nbsp; applied&nbsp; for&nbsp; determination&nbsp; of&nbsp; Pb(II)&nbsp; and&nbsp; Cd(II)&nbsp; ions.&nbsp; Voltametric determination&nbsp; of&nbsp; Pb(II)&nbsp; and&nbsp; Cd(II)&nbsp; ions&nbsp; was&nbsp; performed&nbsp; at&nbsp; working&nbsp; potential&nbsp; of&nbsp; -1.2&nbsp; V (measured against the saturated calomel electrode) and time of electrodeposition of 120 s. All measurements were performed in acetate buffer solution pH 4.0. Concentration range of targetanalites were&nbsp; 5-50 &mu;g&nbsp; dm -3 . Using this type of electrode,&nbsp; obtained&nbsp; detection limits for&nbsp; Pb(II) and Cd(II) ions&nbsp; were&nbsp; 0.57&nbsp; &mu;g&nbsp; dm -3 and 1.2&nbsp; &mu;g&nbsp; dm -3 , respectively, with RSD lower than 10%.This&nbsp; method&nbsp; was&nbsp; applied&nbsp; for&nbsp; target&nbsp; ions&nbsp; determination&nbsp; in&nbsp; sediment&nbsp; pore&nbsp; water&nbsp; sample,&nbsp; and obtained results are comparable with those who are obtained using GFAAS method. Bismuth oxychloride-multiwalled carbon nanotubes composite material was applied for&nbsp; surface&nbsp; modification&nbsp; of&nbsp; the&nbsp; glass-carbon&nbsp; electrode&nbsp; for&nbsp; quick&nbsp; and&nbsp; simple&nbsp; voltametric determination&nbsp; of&nbsp; Zn(II)&nbsp; ions&nbsp; using&nbsp; the&nbsp; SW-ASV&nbsp; method.&nbsp; BiOCl-MWCNT/GCE&nbsp; showed&nbsp; a linear&nbsp; analytical&nbsp; response&nbsp; in&nbsp; a&nbsp;&nbsp; concentration&nbsp; from&nbsp; 2.50&nbsp; to&nbsp; 80.0&nbsp; &mu;g&nbsp; dm -3 with&nbsp; a&nbsp; value&nbsp; of detection limit 0.75 &mu;g dm -3 at a acumulation time of 120 s and an electrodeposition potential of&nbsp; -1.40 V vs. saturated&nbsp; calomel electrode.&nbsp; Measurements were carried out in acetate buffer pH 4.5. The obtained&nbsp; value of the RSD&nbsp; was&nbsp; 4.8%. The performance of the newly designed BiOCl-MWCNT/GCE&nbsp; electrode,&nbsp; traditional&nbsp; bismuth-based&nbsp; electrode&nbsp; (BiF/GCE), MWCNT/GCE,&nbsp; BiF-MWCNT/GCE&nbsp; and&nbsp; unmodified&nbsp; GC&nbsp; electrodes&nbsp; were&nbsp; compared.&nbsp; The applied electrode shows very good electroanalytic properties when determining this target ion. Obtained results are in good agreement with declared value in case of dietetic suplement, and in the brewer&rsquo;s yeast sample results were comparable with FAAS results. Carbon&nbsp; paste&nbsp; electrode&nbsp; surface&nbsp; modified&nbsp; with&nbsp; new&nbsp; composite&nbsp; material&nbsp; based&nbsp; on multiwalled carbon nanotubes and&nbsp; Sb2O3&nbsp; particles. The composite is characterized by TEM, EDS and&nbsp; XRD measurment. Sb2O3- MWCNT/CPE was characterized by cyclic voltammetry and measurements were carried out in a&nbsp; hydrochloric acid&nbsp; solution&nbsp; (pH 2.0). Using the SWASV&nbsp; method,&nbsp; this&nbsp; working&nbsp; electrode&nbsp; was&nbsp; used&nbsp; to&nbsp; determine&nbsp; Pb(II),&nbsp; Cd(II)&nbsp; ions&nbsp; in&nbsp; the concentration range&nbsp; from&nbsp; 2.0&nbsp; to 40.0&nbsp; &mu;g dm -3 for Pb(II) and 2.0-40.0&nbsp; &mu;g dm -3 for Cd(II) ions. Newly&nbsp; designed&nbsp; sensor&nbsp; showed&nbsp; good&nbsp; linear&nbsp; dependences&nbsp; for&nbsp; both&nbsp; target&nbsp; ions.&nbsp; The&nbsp; most optimal&nbsp; procedure&nbsp; involving&nbsp; application&nbsp; of&nbsp; Sb2O3-MWCNT/CPE&nbsp; in&nbsp;&nbsp; .01&nbsp; mol&nbsp; dm -3 hydrochloric&nbsp; acid,&nbsp; with&nbsp; electroposition&nbsp; time&nbsp; of&nbsp; target&nbsp; ions&nbsp; 120&nbsp; s&nbsp; at&nbsp; a&nbsp; electrodeposition potential&nbsp; of&nbsp; -1.2&nbsp; V.&nbsp; Obtained&nbsp;&nbsp; values&nbsp; of&nbsp;&nbsp;&nbsp; LOD&nbsp; 1,1&nbsp; &mu;g&nbsp; dm -3 for&nbsp; Cd(II)&nbsp; and&nbsp; for&nbsp; 1,6&nbsp; &mu;g&nbsp; dm -3 Pb(II)&nbsp; ions.&nbsp; An&nbsp; optimized&nbsp; method&nbsp; based&nbsp; on&nbsp; this&nbsp; type&nbsp; of&nbsp; voltametric&nbsp; sensor&nbsp; has&nbsp; been successfully&nbsp; applied&nbsp; for&nbsp; determination&nbsp; of&nbsp; Cd(II)&nbsp; ion&nbsp; in&nbsp; a&nbsp; spiked&nbsp; tap&nbsp; water&nbsp; sample.&nbsp; Results obtained during this measurment were in tune with expected results. CPE&nbsp; was&nbsp; surface&nbsp; modified&nbsp; using&nbsp; Sb2O3-MWCNT&nbsp; nanocomposite&nbsp; material&nbsp; and tested&nbsp; for&nbsp; direct&nbsp; voltametric&nbsp; determination&nbsp; of&nbsp; imidacloprid&nbsp; in&nbsp; model&nbsp; solutions.&nbsp; In&nbsp; order&nbsp; to achieve the best analytical performance, experimental conditions of measurement such as the pH value of the supporting electrolyte and conditioning of the voltametric sensor surface havebeen&nbsp; optimized.&nbsp; As&nbsp; an&nbsp; optimum&nbsp; pH&nbsp; value&nbsp; of&nbsp; the&nbsp; supporting&nbsp; electrolyte&nbsp; (Britton-Robinson buffer), a pH 7.0 was selected, and the repeating cycles of the cycling process at least 4 times favorably&nbsp; influenced&nbsp; the&nbsp; stability&nbsp; of&nbsp; the&nbsp; voltametric&nbsp; signals.&nbsp; The&nbsp; optimized&nbsp; method&nbsp; was applied for the SW direct cathodic determination&nbsp; of&nbsp; imidacloprid in the concentration range from 1.41 to 32.77 &mu;g cm -3&nbsp; with obtained correlation factor of 0.9995. Based on results it can be concluded that developed analytical methods are sensitive, selective, reproducibile and simple, which can enable their application for various number of samples. Measurements in the model and real solutions have demonstrated the possibility of their&nbsp; application&nbsp; in&nbsp; complicated&nbsp; matrices,&nbsp; at&nbsp; different&nbsp; pH,&nbsp; whereby&nbsp; obtained&nbsp; results&nbsp; are&nbsp; in accordance&nbsp; with&nbsp; the&nbsp; results&nbsp; of&nbsp; the&nbsp; applied&nbsp; comparative&nbsp; methods.&nbsp; For&nbsp; obtainig&nbsp; of representative&nbsp; results&nbsp; it&nbsp; is&nbsp; necessary&nbsp; to&nbsp; optimize&nbsp; conditions&nbsp; of&nbsp; measurment&nbsp; which&nbsp; include: selection of substrat electrode, surface modifier and optimization of experimental condition.</p>

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