No description available.

No description available.

This thesis is a multi-disciplinary survey of the Central Jordan Valley during the Late Bronze Age (1500-1200 BC) illustrated with an abundant use of maps and tables. The purpose is to determine how the Jordan Valley functioned as an economic unit during the Late Bronze Age. This thesis surveys the geographical, historical and archaeological records related to the Jordan Valley during the Late Bronze Age. A chapter is devoted to each field, geography (physical and human), history (Egyptian and Hebrew Bible) and archaeology. The data from each discipline is used to individually answer two questions: 1) was the Jordan Valley a single geographic/economic unit in the Late Bronze Age? 2) to what extent was the Jordan Valley integrated/interacting with the east-west highlands and the larger region in the Late Bronze Age? The primary objectives are to 1) explore and model a historical geographic hermeneutic for understanding the human experience of the Ancient Near East; and 2) lay a foundation for understanding the role of the Jordan Valley in affecting the Biblical periods of the Israelite monarchy to the Roman period.The answers from each chapter are then synthesized into a single geographic historical archaeological picture of the Central Jordan Valley during the Late Bronze Age. The Central Jordan Valley was divided into two sections: a fertile, populated, well connected north-central section and an isolated, sparsely populated southern section with limited agricultural zones. Trade with and between the eastern and western highlands is well represented by artifactual parallels in and through the Jordan Valley, the north-central section on a regional and international scale and the southern section on a more local scale. The thesis concludes that there are more artifactual points of connection between the Jordan Valley and the eastern highlands than with the western highlands. An ‘early conquest’ model of the Hebrew Bible is plausible within the historical records of the Egyptian 18th and 19th Dynasties and the geographical and archaeological records of the Jordan Valley during the Late Bronze Age. / Old Testament & Ancient Near Eastern Studies

In 2014, Gauteng Education MEC announced the “Big Switch On” project in which he envisaged paperless classrooms in Gauteng schools over the next three years. He also said that this would see digital media such as iPads and other electronic Tablets replacing textbooks and stationery. He had a vision that the chalkboard would disappear and projectors would take their place. When the MEC for Education introduced the Big Switch On project, he emphasised the positive effects that paperless classrooms will have on the learners. Education authorities were concerned about and wanted to improve the quality of learning and teaching for disadvantaged learners. However, the MEC for Education failed to highlight the possible impact that paperless classrooms will have on educators. It is important that educators are given an opportunity to provide input with regard to the implementation of paperless classrooms. This study will focus on the perceived stress experienced by teachers in Gauteng, whose schools have been part of the Big Switch On project and have had to mandatorily include the use of digital tablets in their classrooms. This study sought to investigate the influence of digital media use in classrooms on teacher stress in Gauteng schools. It is important to conduct a contextual study that explores the perceived stress factors experienced by teachers in the Gauteng schools that were selected in the Big Switch On project. The research from other contexts can only provide general frameworks regarding the constructs involved. It cannot replace the research conducted specifically for the Big Switch On project. The purpose of this study is threefold. Firstly, the Big Switch On project has been introduced in 2015 in seven Gauteng schools, and was expanded to 375 schools in the following two years. For many schools, this is a first time, thereby rendering it a scarcely researched topic. The implications and effects of the project have yet to be considered. Secondly, it is often assumed that the use of digital tablets in the classroom makes teachers lives easier and reduces their workload. The research that will be undertaken will address this question scientifically to make reliable and valid conclusions that go beyond assumptions. Thirdly, related research has indicated barriers and challenges to the implementation of digital tablets in the classroom. The research will address these barriers and make recommendations regarding future implementation of digital tablets in the classroom. In this qualitative study, I chose a multi-site case study with purposeful, convenience sampling. Two secondary schools that were part of the Big Switch On project were selected. The classrooms in the schools had smartboards, the teachers were given laptops and learners were given tablets. Furthermore, a lot of money was spent on the upgrade of the infra-structure of the schools. These schools were chosen as sites to study the influence of digital media use in the classroom on teacher stress. I chose to interview all levels of teachers and principals, which would allow me to make comparisons as well as provide me with data from which I would be able to reflect on my own practices. I chose to gather data by means of semi-structured face to face interviews. The data revealed that teachers were not part of the decision-making process to introduce digital media in the classroom. Although teachers cited benefits, they felt that the challenges were frustrating with the implementation of digital media in the classroom. Teachers expressed that the initial workload increased but felt that it would decrease over time. Whilst teachers felt that the quality of teaching has improved, they indicated that the quality of learning has deteriorated because learners use the tablets for off-task behaviour. Teachers made recommendations that mirrored the recommendations from the literature and if these concerns are addressed, it would make the implementation of digital media in the classroom more effective and at the same time empower teachers. In order to address school effectiveness, one needs optimum levels of commitment and performance from teachers. Therefore, it is important to emphasize any notion affecting the performance capability of teachers and learners and to create stress free working conditions. It is with this in mind that the study was conducted. / Educational Leadership and Management / M. Ed. (Educational Leadership and Management)

This thesis is a multi-disciplinary survey of the Central Jordan Valley during the Late Bronze Age (1500-1200 BC) illustrated with an abundant use of maps and tables. The purpose is to determine how the Jordan Valley functioned as an economic unit during the Late Bronze Age. This thesis surveys the geographical, historical and archaeological records related to the Jordan Valley during the Late Bronze Age. A chapter is devoted to each field, geography (physical and human), history (Egyptian and Hebrew Bible) and archaeology. The data from each discipline is used to individually answer two questions: 1) was the Jordan Valley a single geographic/economic unit in the Late Bronze Age? 2) to what extent was the Jordan Valley integrated/interacting with the east-west highlands and the larger region in the Late Bronze Age? The primary objectives are to 1) explore and model a historical geographic hermeneutic for understanding the human experience of the Ancient Near East; and 2) lay a foundation for understanding the role of the Jordan Valley in affecting the Biblical periods of the Israelite monarchy to the Roman period.The answers from each chapter are then synthesized into a single geographic historical archaeological picture of the Central Jordan Valley during the Late Bronze Age. The Central Jordan Valley was divided into two sections: a fertile, populated, well connected north-central section and an isolated, sparsely populated southern section with limited agricultural zones. Trade with and between the eastern and western highlands is well represented by artifactual parallels in and through the Jordan Valley, the north-central section on a regional and international scale and the southern section on a more local scale. The thesis concludes that there are more artifactual points of connection between the Jordan Valley and the eastern highlands than with the western highlands. An ‘early conquest’ model of the Hebrew Bible is plausible within the historical records of the Egyptian 18th and 19th Dynasties and the geographical and archaeological records of the Jordan Valley during the Late Bronze Age. / Biblical and Ancient Studies

<p>Cilj&nbsp; ove&nbsp; doktorske&nbsp; disertacije&nbsp; je&nbsp; bio&nbsp; razvoj&nbsp; brzih&nbsp; i&nbsp; pouzdanih&nbsp; voltametrijskih&nbsp; metoda zasnovanih na primeni jednostavnih i savremenih elektroda/senzora na bazi ugljeničnih materijala (ugljenične&nbsp; paste&nbsp; napravljene&nbsp; od&nbsp; grafitnog&nbsp; praha&nbsp; i&nbsp; parafinskog&nbsp; ulja&nbsp; i&nbsp; &scaron;tampanih&nbsp; ugljeničnih elektroda)&nbsp; za&nbsp; određivanje&nbsp; H ₂O₂u&nbsp; odabranim&nbsp; složenim&nbsp; model&nbsp; i&nbsp; realnim&nbsp; uzorcima.&nbsp; U&nbsp; tu&nbsp; svrhu, ispitana je primenljivost različitih radnih elektroda. Amperometrijska&nbsp; metoda&nbsp; zasnovana&nbsp; na&nbsp; elektrodi&nbsp; od&nbsp; ugljenične&nbsp; paste&nbsp; (CPE)&nbsp; zapreminski modifikovane&nbsp; sa&nbsp; 5%&nbsp; (m:m)&nbsp; MnO2 je,&nbsp; pri&nbsp; optimizovanim&nbsp; uslovima&nbsp; i&nbsp; pri&nbsp; radnom&nbsp; potencijalu&nbsp; od 0,40 V&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; zasićenu&nbsp; kalomelovu&nbsp; elektrodu&nbsp; (ZKE)&nbsp; u&nbsp; fosfatnom&nbsp; puferu&nbsp; pH&nbsp; 7,50&nbsp; kao pomoćnom elektrolitu, omogućila kvantifikaciju H ₂O₂ u opsegu koncentracija od 1,4 do 65 &micro;g mL -1 sa&nbsp; relativnom&nbsp; standardnom&nbsp; devijacijom&nbsp; (RSD)&nbsp; manjom&nbsp; od&nbsp; 10%.&nbsp; Ova&nbsp; metoda&nbsp; je&nbsp; primenjena&nbsp; za određivanje sadržaja H ₂O₂u uzorcima podzemne vode iz centralnog Banata (Pokrajina Vojvodina, Srbija)&nbsp; tretirane&nbsp; Fentonovim&nbsp; (Fe²⁺ i&nbsp; H ₂O₂ )&nbsp; i&nbsp; Fentonu-sličnim&nbsp; (Fe ³⁺ i&nbsp; H ₂O₂ )&nbsp; reagensima&nbsp; u&nbsp; cilju uklanjanja&nbsp; prirodnih&nbsp; organskih&nbsp; materija&nbsp; (POM)&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; kori&scaron;ćene&nbsp; različite&nbsp; početne koncentracije&nbsp; gvožđa&nbsp; i&nbsp; različiti&nbsp; odnosi&nbsp; molarnih&nbsp; koncentracija&nbsp; gvožđa&nbsp; i&nbsp; H ₂O₂ .&nbsp; Utvrđeno&nbsp; je&nbsp; da oksidaciono&nbsp; stanje&nbsp; gvožđe&nbsp; (Fe²⁺ ili&nbsp; Fe ³⁺)&nbsp; i&nbsp; molarni&nbsp; odnos&nbsp; jona&nbsp; Fe&nbsp; i&nbsp; H₂O₂ utiču&nbsp; na&nbsp; stepen potro&scaron;nje/razgradnje&nbsp; H₂O₂<br />u&nbsp; podzemnoj&nbsp; vodi&nbsp; sa&nbsp; visokim&nbsp; sadržajem&nbsp; POM.&nbsp; Takođe,&nbsp; u&nbsp; slučaju Fentonu-sličnog&nbsp; procesa,&nbsp; za&nbsp; sve&nbsp; početne&nbsp; koncentracije&nbsp; Fe ³⁺ i&nbsp; H ₂O_{2 ,}&nbsp; signifikantna&nbsp; količina&nbsp; H ₂O₂ostaje&nbsp; neiskori&scaron;ćena,&nbsp; &scaron;to&nbsp; ukazuje&nbsp; na&nbsp; nižu&nbsp; efikasnost&nbsp; ovakvog&nbsp; sistema u&nbsp; poređenju&nbsp; sa&nbsp; Fentonovim procesom.&Scaron;tampana&nbsp; ugljenična&nbsp; elektroda&nbsp; (SPCE)&nbsp; zapreminski&nbsp; modifikovana&nbsp; sa&nbsp; MnO 2 kao medijatorom&nbsp; je&nbsp; primenjena&nbsp; za&nbsp; određivanje&nbsp; sadržaja&nbsp; H₂O₂ u&nbsp; toku&nbsp; Fentonovog&nbsp; (Fe ²⁺ ,&nbsp; H₂O₂ )&nbsp; i vidljivom&nbsp; svetlo&scaron;ću&nbsp; potpomognutog&nbsp; foto-Fentonovog&nbsp; (Fe²⁺,&nbsp; H ₂O₂,&nbsp; h&nu;)&nbsp; procesa&nbsp; uklanjanja neonikotinoidnog&nbsp; insekticida&nbsp; acetamiprida&nbsp; (ACT).&nbsp; Pri&nbsp; optimizovanim&nbsp; uslovima&nbsp; (radni&nbsp; potencijal 0,40&nbsp; V&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; ZKE,&nbsp; fosfatni&nbsp; pufer&nbsp; pH&nbsp; 7,50&nbsp; kao&nbsp; pomoćni&nbsp; elektrolit)&nbsp; amperometrijskog određivanja&nbsp; H ₂O₂ ,&nbsp; postignuta&nbsp; je&nbsp; linearnost&nbsp; u&nbsp; opsegu&nbsp; koncentracija&nbsp; 0,01&ndash;1,24&nbsp; mmol&nbsp; L-1(0,34&ndash; 42,2 &micro;g mL -1<br />) i vrednost RSD nije prelazila 4,2%. U ispitivanimuzorcima (nakon odgovarajućeg<br />pode&scaron;avanja pH vrednosti od 2,8 do 7,5 odmah nakon&nbsp; uzorkovanja radi stopiranja ili maksimalnog usporavanja&nbsp; procesa&nbsp; oksidacije,&nbsp; filtriranja,&nbsp; zamrzavanja&nbsp; i&nbsp; odmrzavanja&nbsp; neposredno&nbsp; pre&nbsp; merenja) sadržaj&nbsp; H ₂O₂ je&nbsp; određen&nbsp; metodom&nbsp; standardnog&nbsp; dodatka&nbsp; analiziranjem&nbsp; odgovarajućih amperometrijskih&nbsp; krivi.&nbsp; Paralelna&nbsp; HPLC-DAD&nbsp; merenja&nbsp; su&nbsp; vr&scaron;ena&nbsp; u&nbsp; cilju&nbsp; praćenja koncentracije/uklanjanja ACT. U slučaju foto-Fentonovog procesa (početne koncentracije 0,31; 2,0 i 3,0 mmol L -1 (70,0; 111,7 i 102,1 &micro;g mL -1 ) za ACT, Fe<br />²⁺ i H ₂O₂, redom) nakon 10 min H ₂O₂je izreagovao, a može se smatrati da je ACT uklonjen nakon 5 min. U toku Fentonovog procesa ACT je&nbsp; uklonjen&nbsp; nakon&nbsp; 20&nbsp; min&nbsp; tretmana&nbsp; i&nbsp; oko&nbsp; 10%&nbsp; početne&nbsp; koncentracije&nbsp; H ₂O₂ je&nbsp; ostalo&nbsp; u&nbsp; sistemu<br />neiskori&scaron;ćeno.CPE&nbsp; je&nbsp; povr&scaron;inski&nbsp; modifikovane&nbsp; kompozitom&nbsp; na&nbsp; bazi&nbsp; nanočestica&nbsp; Pt&nbsp; (&lt;&nbsp; 5&nbsp; nm)&nbsp; i grafitizovanog&nbsp; ugljenika&nbsp; (Pt-C,&nbsp; 10%&nbsp; Pt&nbsp; na&nbsp; Vulkanu&nbsp; XC72)&nbsp;&nbsp; etodom&nbsp; nano&scaron;enja&nbsp; kapi. Nemodifikovana&nbsp; CPE&nbsp; i&nbsp; modifikovana&nbsp; (Pt-C/CPE)&nbsp; su&nbsp;&nbsp; okarakterisane&nbsp; primenom&nbsp; SEM/EDS&nbsp; i&nbsp; CV merenja.&nbsp; Pt-C/CPE&nbsp; je&nbsp; pokazala&nbsp; izuzetne&nbsp; elektrokatalitičke&nbsp; osobine&nbsp; u&nbsp; pogledu&nbsp; elektrohemijskeredoks&nbsp; reakcije&nbsp; H<br />₂O₂ u&nbsp; poređenju&nbsp; sa&nbsp; nemodifikovanom&nbsp; CPE&nbsp; u&nbsp; fosfatnom&nbsp; puferu&nbsp; (0,1 mol&nbsp; L -1 ;<br />pH 7,50),&nbsp; a&nbsp; takođe&nbsp; i&nbsp; u&nbsp; acetatnom&nbsp; puferu&nbsp; (0,1&nbsp; mol&nbsp; L -1 ;&nbsp; pH&nbsp; 4,50)&nbsp; kao&nbsp;&nbsp; pomoćnim&nbsp; elektrolitima. Prilikom&nbsp; amperometrijskog&nbsp; određivanja&nbsp; H ₂O₂ primenom&nbsp; Pt-C/CPE&nbsp; u&nbsp; model&nbsp; sistemima, zadovoljavajuća linearnost je postignuta u koncentracionom opseguH₂O₂od 0,15 do 1,45 &micro;g mL -1 ,dok su vrednosti GO iznosile 0,06 &micro;g mL -1 (pH 7,50, radni potencijal 0,20 V) i 0,10 &micro;g mL -1 (pH<br />4,50,&nbsp; radni&nbsp; potencijal&nbsp; 0,50&nbsp; V).&nbsp; Optimizovane&nbsp; analitičke&nbsp; metode&nbsp; su&nbsp; primenjene&nbsp; za&nbsp; određivanje sadržaja H ₂O₂ u komercijalno dostupnim proizvodima za ličnu negu: rastvoru za dezinfekciju (pH 7,50)&nbsp; i&nbsp; rastvoru&nbsp; za&nbsp; či&scaron;ćenje&nbsp; kontaktnih&nbsp; sočiva&nbsp; (pH&nbsp; 4,50).&nbsp; Amperometrijski&nbsp; dobijeni&nbsp; rezultati&nbsp; su&nbsp; u dobrom&nbsp; slaganju&nbsp; sa&nbsp; rezultatima&nbsp; dobijenim&nbsp; primenom&nbsp; tradicionalne&nbsp; spektrofotometrijske&nbsp; metode bazirane&nbsp; na&nbsp; titanijum-sulfatu&nbsp; kao&nbsp; reagensu&nbsp; sa&nbsp; određenim&nbsp; koncentracijama&nbsp; 2,91%&nbsp; i&nbsp; 2,94%&nbsp; za<br />dezinfekcioni rastvor i 3,04% i 3,17% za rastvor zakontaktna sočiva, redom. RSD je bila manja od 2%.&nbsp; Postignuti&nbsp; rezultati&nbsp; su&nbsp; u&nbsp; dobrom&nbsp; slaganju&nbsp; sa&nbsp; sadržajem&nbsp; H<br />₂O₂deklarisanim&nbsp; od&nbsp; strane proizvođača (3%) u oba ispitivana uzorka. Pt-C/CPE je takođe testirana za praćenje koncentracije H₂O₂ u rastvoru za kontaktna sočiva u toku procesa njegove neutralizacije/razgradnje. Nakon 6 h procesa neutralizacije, 24,68&nbsp; &micro;g mL -1 je bila određena koncentracija H ₂O_{2 ,} &scaron;to je ispod dozvoljene<br />H₂O₂koncentracije u rastvoru za kontaktna sočiva imajući u vidu granicu koja izaziva iritaciju oka. CPE&nbsp; je&nbsp; povr&scaron;inski&nbsp; modifikovana&nbsp; vi&scaron;ezidnim&nbsp; ugljeničnim&nbsp; nanocevima&nbsp; (MWCNT)&nbsp; i kompozitima MnO 2 -MWCNT ili Pt-MWCNT metodom nano&scaron;enja kapi radi pripreme jednostavnih, osetljivih i pouzdanih voltametrijskih senzora za&nbsp; određivanje H ₂O₂u odabranom uzorku. Rezultati SEM/EDS&nbsp; analize&nbsp; kompozitnih&nbsp; materijala&nbsp; su&nbsp; potvrdili da&nbsp; su&nbsp; medijatori,&nbsp; čestice&nbsp; MnO 2 i&nbsp; Pt, nasumično&nbsp; raspoređeni na povr&scaron;ini MWCNT i zastupljeni sa blizu 5% (m:m) u kompozitu izraženo<br />preko Mn i Pt. CV merenja su vr&scaron;ena sa pripremljenim radnim elektrodama u acetatnom (pH 4,50), fosfatnom&nbsp; (pH&nbsp; 7,50)&nbsp; i&nbsp; boratnom&nbsp; (pH&nbsp; 9,18)&nbsp; puferu&nbsp; kako&nbsp; bi&nbsp; se&nbsp; okarakterisalo&nbsp; osnovno elektrohemijsko&nbsp; pona&scaron;anje&nbsp; H ₂O₂i&nbsp; odabrali&nbsp; pogodni&nbsp; radni&nbsp; potencijali&nbsp; za&nbsp; amperometrijsko određivanje ovog ciljnog analita. Pt- WCNT/CPE je primenljiva za rad kako u fosfatnom puferu pH&nbsp; 7,50&nbsp; tako&nbsp; i&nbsp; u&nbsp; acetatnom&nbsp; puferu&nbsp; pH&nbsp; 4,50&nbsp; V&nbsp; kako&nbsp; pri&nbsp; negativnim&nbsp; tako&nbsp; i&nbsp; pri&nbsp; pozitivnim&nbsp; radnim<br />potencijalima, pri&nbsp; čemu su vrednosti RSD uglavnom ispod 2,5%. U slučaju MnO 2<br />-MWCNT/CPE, na&nbsp; potencijalu&nbsp; 0,30&nbsp; V&nbsp; i&nbsp; vi&scaron;im&nbsp; vrednostima,&nbsp; oksidacioni&nbsp; signali&nbsp; H<br />₂O₂ su&nbsp; signifikantni&nbsp; u&nbsp; blago alkalnoj sredini (pH 7,50), pri pH 4,50 ova elektroda pokazuje nezadovoljavajuće pona&scaron;anje, dok&nbsp; pri pH 9,18 ima prihvatljive performanse. Granice određivanja (GO) su bile u oblasti &micro;g mL -1 . H ₂O₂ je&nbsp; određen&nbsp; u&nbsp; spajkovanom&nbsp; uzorku&nbsp; mleka&nbsp; metodom&nbsp; standardnog&nbsp; dodatka&nbsp; nakon&nbsp; odgovarajuće pripreme&nbsp; uzorka&nbsp; (pH&nbsp; pode&scaron;avanje&nbsp; i&nbsp; centrifugiranje)&nbsp; i&nbsp; primenom&nbsp; optimizovane&nbsp; amperometrijske procedure (acetatni pufer pH 4,50, radni&nbsp; potencijal-0,75 V) koristeći Pt-MWCNT/CPE kao radnu elektrodu. RSD za tri&nbsp; ponovljena merenja je iznosila 2,5%, dok je prinos metode bio ne&scaron;to veći od 71%.<br />Kompozitni materijali koji se sastoje od MWCNT i&nbsp; čestica na bazi Pd (Pd-MWCNT) ili Pt (Pt-MWCNT) su primenjeni za pripremu zapreminski modifikovanih SPCE (Pd-MWCNT-SPCE i Pt-MWCNT-SPCE)&nbsp; i&nbsp; povr&scaron;inski&nbsp; modifikovane&nbsp; SPCE&nbsp; (Pd-MWCNT/SPCE).&nbsp; Ove&nbsp; elektrode,&nbsp; kao&nbsp; i nemodifikovana&nbsp; SPCE&nbsp; i&nbsp; MWCNT-SPCE,&nbsp; su&nbsp; okarakterisane primenom&nbsp; CV&nbsp; i&nbsp; amperometrije&nbsp; u fosfatnom puferu pH 7,50 radi određivanja H ₂O₂ . Pd-MWCNT-SPCE i Pd-MWCNT/SPCE su se pokazale&nbsp; pogodnim&nbsp; za&nbsp; određivanje&nbsp; H ₂O₂ na&nbsp; radnim&nbsp; potencijalima&nbsp; između&nbsp; -0,50&nbsp; i&nbsp; 0,50&nbsp; V,&nbsp; a&nbsp; PtMWCNT-SPCE na ispitivanim radnim potencijalima od -0,80 do 0,70 V. Ove&nbsp; elektrode su zatim modifikovane&nbsp; enzimom&nbsp; glukoza&nbsp; oksidazom&nbsp; (GOx)&nbsp; metodom&nbsp; nano&scaron;enja&nbsp; kapi&nbsp; rastvora&nbsp; GOx&nbsp; i Nafion &reg; -a&nbsp; na&nbsp; njihovu&nbsp; povr&scaron;inu,&nbsp; pri&nbsp; čemu&nbsp; je&nbsp; optimizovana&nbsp; količina&nbsp; nanetog&nbsp; biofilma.&nbsp; GOx/PdMWCNT-SPCE&nbsp; je&nbsp; pokazala&nbsp; bolje&nbsp; analitičke&nbsp; performanse&nbsp; za&nbsp; određivanje&nbsp; glukoze&nbsp; u&nbsp; poređenju&nbsp; sa GOx/Pd- WCNT/SPCE.&nbsp; Kao&nbsp; optimalan&nbsp; radni&nbsp; potencijal&nbsp; GOx/Pd-MWCNT-SPCE&nbsp; je&nbsp; odabrana<br />vrednost&nbsp; potencijala&nbsp; -0,40&nbsp; V&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; ZKE,&nbsp; sa&nbsp; zadovoljavajućom&nbsp; linearno&scaron;ću&nbsp; u&nbsp; ispitivanom opsegu&nbsp; koncentracija&nbsp; glukoze&nbsp; od&nbsp; 0,16&nbsp; do&nbsp; 0,97&nbsp; mmol&nbsp; L -1 (od&nbsp; 29,1&nbsp; do&nbsp; 174&nbsp; &micro;g&nbsp; mL -1),&nbsp; dok&nbsp; je&nbsp; GO iznosila 0,14 mmol L -1 (25 &micro;g mL<br />-1 ). Optimizovana metoda zasnovana na GOx/Pd-MWCNT-SPCE je&nbsp; uspe&scaron;no&nbsp; primenjena&nbsp; za&nbsp; određivanje&nbsp; glukoze&nbsp; u&nbsp; uzorku&nbsp; livadskog&nbsp; meda.&nbsp; Dobijeni&nbsp; rezultati&nbsp; su&nbsp; u dobroj&nbsp; saglasnosti&nbsp; sa&nbsp; onima&nbsp; dobijenim&nbsp; primenom&nbsp; komercijalno&nbsp; dostupnog&nbsp; aparata&nbsp; za&nbsp; merenje glukoze. Pogodan radni potencijal za GOx/Pt-MWCNT-SPCE je bio -0,50 V u odnosu na ZKE, pri čemu je zadovoljavajuća linearnost postignuta u ispitivanom opsegu koncentracija glukoze od 65,8 do 260,6 &micro;g mL -1 , sa GO 35 &micro;g mL -1 . Optimizovana metoda zasnovana na GOx/Pt-MWCNT-SPCE je&nbsp; uspe&scaron;no&nbsp; primenjena&nbsp; za&nbsp; određivanje&nbsp; glukoze&nbsp; u&nbsp; u&nbsp; uzorku&nbsp; belog&nbsp; grožđa&nbsp; i&nbsp; uzorku&nbsp; tableta (Traubenzucker-bonbons),&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; dobijeni&nbsp; rezultati&nbsp; u&nbsp; dobroj&nbsp; saglasnosti&nbsp; sa&nbsp; rezultatima dobijenim primenom Accu-Chek aparata.<br />Na&nbsp; osnovu&nbsp; dobijenih&nbsp; rezultata&nbsp; može&nbsp; se&nbsp; zaključiti&nbsp; da&nbsp; su&nbsp; razvijene&nbsp; analitičke&nbsp; metode&nbsp; pre svega jednostavne, pouzdane i pogodne za dobijanje brzih informacija o sadržaju H ₂O₂ u različitim tipovima&nbsp; uzoraka.&nbsp; Svakako&nbsp; odabir&nbsp; pogodne&nbsp; radne&nbsp; elektrode,&nbsp; kao&nbsp; i&nbsp; optimizacija&nbsp; eksperimentalnih uslova su ključni faktori za uspe&scaron;no određivanje H ₂O₂</p> / null / <p>The aim of this doctoral dissertation was the development of fast and reliable voltammetric methods&nbsp; based&nbsp; on&nbsp; the&nbsp; application&nbsp; of&nbsp; simple&nbsp; and&nbsp; contemporary&nbsp; electrodes/sensors&nbsp; based&nbsp; on carbonaceous materials (carbon paste made of graphite powder and paraffin oil and screen printed carbon electrodes) for the determination of H <span id="cke_bm_571S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_571E" style="display: none;">&nbsp;</span>O₂ in the selected complex model and real samples.For this purpose, applicability of different working electrodes was investigated.The&nbsp; amperometric&nbsp; method&nbsp; based&nbsp; on&nbsp; carbon&nbsp; paste&nbsp; electrode&nbsp; (CPE)&nbsp; bulk- modified&nbsp; &nbsp;&nbsp; with 5% (m:m) MnO 2 , under optimized conditions, with a working potential of 0.40 V vs. the saturated calomel&nbsp; elect<span id="cke_bm_572E" style="display: none;">&nbsp;</span>rode&nbsp; (SCE)&nbsp; and&nbsp; a&nbsp; phosphate&nbsp; buffer&nbsp; solution&nbsp; (pH&nbsp; 7.50)&nbsp; as&nbsp; supporting&nbsp; electrolyte, enabled the quantitation of H <span id="cke_bm_577S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_577E" style="display: none;">&nbsp;</span>O₂in the concentration interval from 1.4 to 65 &micro;g mL &minus;1 with a relative standard deviation (RSD) of less than 10%. This meth<span id="cke_bm_578E" style="display: none;">&nbsp;</span>od was applied for the determination of the H<span id="cke_bm_583S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_583E" style="display: none;">&nbsp;</span>O₂consumption&nbsp; in&nbsp; samples&nbsp; of&nbsp; groundwater&nbsp; fro<span id="cke_bm_584E" style="display: none;">&nbsp;</span>m&nbsp; the&nbsp; Central&nbsp; Banat&nbsp; region&nbsp; (Province&nbsp; of Vojvodina, Serbia) treated by the Fenton (Fe ²⁺and H ₂O₂ ) and Fenton-&nbsp; like (Fe ³⁺and H ₂O₂ ) reagents to remove natural organic matter (NOM) at&nbsp; differentinitial concentrations of iron species, and of their molar ratios to the initial concentration of H₂O₂ . It was found that the form of Fe (Fe ²⁺ or Fe ³⁺ )and the molar&nbsp; ratio to H ₂O₂influenced the degree of the H₂O₂ decomposition in the groundwater with high NOM content. Besides, in the case of the Fenton-like process, for all initial doses of Fe ³⁺ and H<span id="cke_bm_604S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_604E" style="display: none;">&nbsp;</span>O₂, a sign<span id="cke_bm_605E" style="display: none;">&nbsp;</span>ificant amount of H<span id="cke_bm_610S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_610E" style="display: none;">&nbsp;</span>O₂ remained unused, whi<span id="cke_bm_611E" style="display: none;">&nbsp;</span>ch also indicates a lower efficiency of such system compared to the Fenton process. Screen&nbsp; printed&nbsp; carbon&nbsp; electrode&nbsp; (SPCE)&nbsp; bulk-modified&nbsp; with&nbsp; MnO&nbsp;₂ as&nbsp; a&nbsp; mediator&nbsp; was applied&nbsp; for&nbsp; amperometric&nbsp; determination&nbsp; of&nbsp; the&nbsp; H <span id="cke_bm_617S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_617E" style="display: none;">&nbsp;</span>O₂ content&nbsp; during&nbsp; the&nbsp; Fenton&nbsp; (Fe ²⁺ ,&nbsp; H <span id="cke_bm_624S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_624E" style="display: none;">&nbsp;</span>O₂)&nbsp; and <span id="cke_bm_625E" style="display: none;">&nbsp;</span>visible&nbsp; light-assisted<span id="cke_bm_618E" style="display: none;">&nbsp;</span>,&nbsp; photo-Fenton&nbsp; (Fe ^2+&nbsp; ,&nbsp; H <span id="cke_bm_631S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_631E" style="display: none;">&nbsp;</span>O₂ ,&nbsp; h&nu;)<span id="cke_bm_632E" style="display: none;">&nbsp;</span>&nbsp; based&nbsp; removal&nbsp; of&nbsp; neonicotinoid&nbsp; insecticide acetamiprid (ACT). Under&nbsp; optimized conditions (working potential of 0.40 V vs. SCE, phosphate buffer&nbsp; pH&nbsp; 7.50&nbsp; as&nbsp; supporting&nbsp; electrolyte)&nbsp; amperometric&nbsp; determination&nbsp; of&nbsp; H <span id="cke_bm_637S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_637E" style="display: none;">&nbsp;</span>O₂showed&nbsp; a&nbsp; linear dynamic range from 0.01 to 1.24 mmol L -1 (from 0.34 to 42.2 &micro;g mL -1) and the RSD did not exceed 4.2%. In the investigated samples (after appropriate pH adjustment from 2.8 to 7.5 instantly after the sampling<span id="cke_bm_638E" style="display: none;">&nbsp;</span> to stop or maximum decelerate the oxidation processes, filtering, and storage of the deep- frozen sample with defrosting immediately before the measurements) the H <span id="cke_bm_643S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_643E" style="display: none;">&nbsp;</span>O₂&nbsp; contents were determined by the standard addition method by analyzing the corresponding amperometric curves. Parallel HPLC-DAD measurements were performed to monito<span id="cke_bm_644E" style="display: none;">&nbsp;</span>r the concentration/removal of ACT. In the case of the photo- Fenton process (initial concentrations: 0.31; 2.0 and 3.0 mmol L -1 (70.0; 111.7 and 102.1 &micro;g mL -1 ) of ACT, Fe²⁺ and H <span id="cke_bm_650S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_650E" style="display: none;">&nbsp;</span>O₂, respec<span id="cke_bm_651E" style="display: none;">&nbsp;</span>tively) after 10 min of irradiation H <span id="cke_bm_656S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_656E" style="display: none;">&nbsp;</span>O₂ was&nbsp; consumed&nbsp; and&nbsp; it&nbsp; can&nbsp; be&nbsp; consi<span id="cke_bm_657E" style="display: none;">&nbsp;</span>dered&nbsp; that&nbsp; ACT&nbsp; was&nbsp; removed&nbsp; after&nbsp; 5&nbsp; min.&nbsp; During&nbsp; the&nbsp; Fenton process ACT was removed after 20 min of treatment and around 10% of the initial concentration of the H 2O2 remained still unused.<br />CPE&nbsp; was&nbsp; surface&nbsp; modified&nbsp; with&nbsp; a&nbsp; composite&nbsp; of&nbsp; Pt&nbsp; nanoparticles&nbsp; (&lt;&nbsp; 5&nbsp; nm)&nbsp; on&nbsp; graphitized carbon (Pt-C, 10% Pt on Vulcan XC72) by simply dropcoating method. The unmodified CPE and the&nbsp; modified&nbsp; one&nbsp; (Pt-C/CPE)&nbsp; were&nbsp; characterized&nbsp; by&nbsp;&nbsp; EM/EDS&nbsp; and&nbsp; CV&nbsp; measurements.&nbsp; The&nbsp; PtC/CPE showed remarkable electrocatalytic propertiestoward the electrochemical redox reaction of H<span id="cke_bm_662S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_662E" style="display: none;">&nbsp;</span>O₂ compared to&nbsp; modified CPE in phosphate buffer (0.1 mol L -1 ; pH 7.50), as well in acetatebuffer&nbsp; (0.1 mol&nbsp; L -1 ; pH .50) supporting&nbsp; electrolytes. Amperometry of&nbsp; H2O2 in the concentration range from 0.15 to 1.45 &micro;g mL -1 with the Pt-C/CPE showed acceptable linearity, while the obtained values of LOQs were 0.06 &micro;g mL -1&nbsp; (pH 7.50, working potential 0.20 V) and 0.10 &micro;g mL -1 (pH 4<span id="cke_bm_663E" style="display: none;">&nbsp;</span>.50, working potential 0.50 V). The proposed analytical&nbsp; methods were applied to the determination of the H 2O2 content in commercially available personal care products; i.e., disinfection (pH 7.50) and contact lens cleaning solutions (pH 4.50). The obtained amperometric results are in good agreement with those measured by traditional titanium sulfatereagent based spectrophotometric method with determined concentrations as 2.91% and 2.94%&nbsp; for the disinfection product, and 3.04% and 3.17% for the contact lens solution, respectively. RSD was lower than 2%. The obtained results are in a good agreement with the amounts of the H<span id="cke_bm_668S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_668E" style="display: none;">&nbsp;</span>O₂declared by producers (3%) in the both investigated samples. The Pt-C/CPE was also tested for monitoring of the H<span id="cke_bm_674S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_674E" style="display: none;">&nbsp;</span>O₂ residual concentration in contact lens&nbsp; solution&nbsp; during&nbsp; its&nbsp; neutralization/decomposition&nbsp; rocess.&nbsp; At&nbsp; 6&nbsp; h&nbsp; of<span id="cke_bm_675E" style="display: none;">&nbsp;</span>&nbsp; neutralization&nbsp; treatment 24.68 &micro;g mL -1 of the H <span id="cke_bm_680S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_680E" style="display: none;">&nbsp;</span>O₂was&nbsp; determined which is almost half of the allowedH2<span id="cke_bm_681E" style="display: none;">&nbsp;</span>O2 concentration in the case of the contact lens solution concerningthe limit of eye irritation. CPE&nbsp; was&nbsp; surface&nbsp;&nbsp; modified&nbsp; with&nbsp; multiwalled&nbsp; carbon&nbsp; nanotubes&nbsp; (MWCNT)&nbsp; and&nbsp; with composites of MnO₂-MWCNT or Pt-MWCNT by drop coating method to prepare simply, sensitive and reliable volta<span id="cke_bm_669E" style="display: none;">&nbsp;</span>mmetric sensors for the determination of H <span id="cke_bm_687S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_687E" style="display: none;">&nbsp;</span>O₂in selected sample. The results of the&nbsp; SEM/<span id="cke_bm_688E" style="display: none;">&nbsp;</span>EDS&nbsp; analysis&nbsp; of&nbsp; composite&nbsp; materials&nbsp; have&nbsp; confirmed&nbsp; that&nbsp; the&nbsp; mediators,&nbsp; MnO ₂ and&nbsp; Pt&nbsp; articles, are randomly distributed on the surface of MWCNT and represent nearly 5% (m:m) of the composite expressed as Mn and Pt. CV measurements were performed&nbsp; with prepared electrodes in acetate&nbsp; (pH&nbsp; 4.50),&nbsp; phosphate&nbsp; (pH&nbsp; 7.50)&nbsp; and&nbsp; borate&nbsp; (pH&nbsp; 9.18)&nbsp; buffers&nbsp; to&nbsp; characterize&nbsp; the&nbsp; basic electrochemical&nbsp; behavior&nbsp; of&nbsp; H <span id="cke_bm_694S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_694E" style="display: none;">&nbsp;</span>O₂ and&nbsp; to&nbsp; select&nbsp; the&nbsp; working&nbsp; potentials&nbsp; suitable&nbsp; for&nbsp; amperometric determination&nbsp; of&nbsp; this&nbsp; target&nbsp; analyte.&nbsp; The&nbsp; Pt-MWCNT/CPE&nbsp; performs&nbsp; well&nbsp; in&nbsp; phosphate&nbsp; buffer pH .50 and acetate buffer solution pH 4.50 in the&nbsp; negative as well as in the positive polarization range with RSD mainly lower than 2.5%. In case of MnO₂-MWCNT/CPE at <span id="cke_bm_695E" style="display: none;">&nbsp;</span>0.30 V and above the H<span id="cke_bm_701S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_701E" style="display: none;">&nbsp;</span>O₂oxidation signal is rem<span id="cke_bm_702E" style="display: none;">&nbsp;</span>arkable in slightly alkaline media (pH 7.50), at pH 4.50 this electrode showed poor behavior and at pH 9.18 offered acceptable performance. LOQs were in the &micro;g mL -1 concentration&nbsp; range.&nbsp; H<span id="cke_bm_707S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_707E" style="display: none;">&nbsp;</span>O₂was&nbsp; determined&nbsp; in&nbsp; a&nbsp; spiked&nbsp; milk&nbsp; sample&nbsp; by&nbsp; standard addition&nbsp; method after&nbsp; appropriate&nbsp; sample&nbsp; preparation&nbsp; (pH&nbsp; adjustment and&nbsp; centrifugation)&nbsp; and&nbsp; using&nbsp; optimized amperometric p<span id="cke_bm_708E" style="display: none;">&nbsp;</span>rocedure (acetate buffer pH 4.50, working potential -0.75 V) by Pt-MWCNT/CPE as a working electrode. RSD for three repeated measurements was 2.5%, while the recovery of the method was a bit higher than 71%. The&nbsp; composite&nbsp; materials&nbsp; consisting&nbsp; of&nbsp; MWCNT&nbsp; and&nbsp; Pd&nbsp; (Pd-MWCNT)&nbsp; or&nbsp; Pt&nbsp; containing particles&nbsp; (Pt-WCNT)&nbsp; were&nbsp; applied&nbsp; to&nbsp; the&nbsp; preparation&nbsp; of&nbsp; bulk- modified&nbsp; SPCEs&nbsp; (Pd-MWCNTSPCE and Pt-MWCNT-SPCE) and surface modifiedSPCE (Pd- MWCNT/SPCE). These electrodes, as well as unmodified SPCE and MWCNT-SPCE,&nbsp; were characterized by CV and&nbsp; amperometry&nbsp; in phosphate&nbsp; buffer&nbsp; solution&nbsp; of&nbsp; pH&nbsp; 7.50&nbsp; for&nbsp; the&nbsp; H<span id="cke_bm_713S" style="display: none;">&nbsp;</span>₂<span id="cke_bm_713E" style="display: none;">&nbsp;</span>O₂determination.&nbsp; Pd-MWCNT-SPCE&nbsp; and&nbsp; PdMWCNT/SPCEare convenient for the etermination of H 2O2 at working potentials from -0.50 to 0.50 V, and Pt-MWCNT-SPCE at investigated working potentials in the range from -0.80 to 0.70 V. These electrodes were then modified with glucose&nbsp; oxidase (GOx) by drop coating a solution of GOxand Nafion &reg; on their surface, whereby the applied amount of biococktail was optimized. GOx/PdMWCNT-SPCE&nbsp; showed&nbsp; better&nbsp; analytical&nbsp; performance&nbsp; for&nbsp; glucose&nbsp; determination&nbsp; in&nbsp; comparison with&nbsp; GOx/Pd-MWCNT/SPCE.&nbsp; The&nbsp; optimal&nbsp; working&nbsp; potential&nbsp; for&nbsp; GOx/Pd-MWCNT- SPCE&nbsp; was -0.40 V vs. SCE and <span id="cke_bm_714E" style="display: none;">&nbsp;</span>satisfactory linearity was obtained in the investigated glucose concentration range from 0.16 to 0.97 mmol L -1 (from 29.1 to 174&nbsp; &micro;g mL -1 ), hile the LOQ was 0.14 mmol L -1 (25 &micro;g mL -1 ). The optimized method based on GOx/Pd-MWCNT-SPCE was successfully applied to the determination of glucose in multifloral honey sample.&nbsp; The results are in a good agreement with those&nbsp; obtained by commercially available equipment for determination of glucose. Optimal working potential&nbsp; for&nbsp; GOx/Pt-MWCNT-SPCE&nbsp; was&nbsp; -0.50&nbsp; V&nbsp; vs.&nbsp; SCE,&nbsp; and&nbsp; the&nbsp;&nbsp; satisfactory&nbsp; linearity&nbsp; was obtained in the investigated concentration range ofglucose from 65.8 to 260.6&nbsp; &micro;g mL -1 , with LOQ of 35&nbsp; &micro;g mL -1 . The optimized method based on GOx/Pt- MWCNT-SPCE was successfully applied for determination of glucose in white grape and glucose tablets (Traubenzucker-bonbons) samples, whereby&nbsp; the&nbsp; obtained&nbsp; results&nbsp; were&nbsp; in&nbsp; a&nbsp; good&nbsp; agreement&nbsp; with&nbsp; the&nbsp; results&nbsp; obtained&nbsp; by&nbsp; Accu-Chek device. Based on the results, the developed analytical methods are first of all simple, reliable and suitable&nbsp; for&nbsp; obtaining&nbsp; fast&nbsp; information&nbsp; about&nbsp; the&nbsp; content&nbsp; of&nbsp; H ₂O₂ in&nbsp; different&nbsp; types&nbsp; of&nbsp; samples. Certainly the selection of a suitable working electrode, as well as the optimization of experimental conditions are key factors for the successful determination of H₂O₂.</p>