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Vegetarian diet : bachelor thesis
No full textDanas se ljudi pitaju kada su se pojavili prvi vegetarijanci i kada su nastali prvi pisani doku- menti o vegetarijanstvu. Vegetarijanstvo je bilo značajno i kroz prošlost tj. u Staroj Grčkoj kada je živio Pitagora koji je vjerovao u reinkarnaciji. Danas sve više i više ljudi prelazi na Pigorejski način života. Ve- getarijanci su poznati po tome što ne jedu meso, ali danas se sve više postavlja pitanje „Je li vegetarijanci jedu jaja, ribu, mlijeko i mliječne proizvode?“ Postoji više vrsta vegetarijanca. Imamo one koji jedu jaja i mliječne proizvode i ribu (ovolakto-vegetarijanci), zatim one koji jedu mliječne proizvode, ali ne i jaja (lakto-vegetarijanci) i oni koji se smatraju čistim vegetarijancima jer ne jedu meso, ribu, mlijeko, mliječne proizvode i jaja (vegani). Vegetarijanska prehrana ima dobar utjecaj na ljudski organizam, tako što smanjuje nastanak kardiovaskularnih bolesti, karcinoma, ali zato vegetarijanci u odnosu na svejede imaju manjak određenih nutrijenata u organizmu. . Cilj završnog rada je bio da ljude bolje upoznamo sa vegetarijanskom prehranom, djelovanje vegetarijanske prehrane na organizam, upoznat ih sa različitim vrsta vege-tarijanaca kao i sa oznakom na vegetarijanskim proizvodima. U sklopu završnog rada prove- dena je anketa pod nazivom „Vegetarijanstvo“ kako bi se dao uvid u poznavanje pojma „vegetarijanstvo“ te stav ispitanika o vegetarijanskoj prehrani.Today, people wonder when the first vegetarians appeard and when were the first written docu- ments about vegetarians created. Vegetarianism was also significant throught the past, in Aciant Greece when Pythagoras lived, who believed in reincarnation. Today, more and more people are switching to the Pythagorean way of life. Vegetarians are known for not eating meat, but today the question „Do vegetari- ans eat eggs, fish, milk and dairy products“ is increasingly being asked. There are several types of vegeta- rians. We have those who eat eggs, dairy products and fish (ovo-lacto-vegetarians), then those who eat dairy products but not eggs (lacto-vegetarians) and those who are considered pure vegetarians because they do not eat meat, fish, milk, dairy products and eggs (vegan). A vegetarian diet has a good effect on the human body, as it reduces the occurrence of cardiovascular diseases and cancer, but that's why vegeta- rians, compared to omnivores, lack certain nutrients in the body. The goal of the final paper was to make people better acquainted with the vegetarian diet, the effect of the vegetarian diet on the body, to familia- rize them with different types of vegetarians, as well as with the label on vegetarian products. As part of the final paper, a survey called "Vegetarianism" was conducted in order to provide an in-sight into the knowledge of the term "vegetarianism" and the respondents' attitude towards vegetarian diet
Coordination complexes of transitional metals: Synthesis, spectroscopic and electrochemical research coordination complexes of cobalt(II) : bachelor thesis
No full textKoordinacijski kompleksi su skupina spojeva, koja privlači sve veći interes zbog svojih strukturnih karakteristika, iz kojih proizlazi široka upotreba u svim sferama života i industrije: farmacija, senzorska tehnologija, ioniski-izmjenjivači, katalizatori. Kobalt zbog svojih iznimnih osobina je često korišten u sintezi koordinacijskih kompleksa kao središnji atom/ion, odnosno kao koordinacijski centar. U tipičnom Co-kompleksu, metalni je ion vezan za nekoliko donorskih atoma, koji mogu biti isti ili različiti i jednostruko ili višestruko vezani. Fokus ovog rada bio je hidrotermalna sinteza i karakterizacija koordinacijskih kompleksa metala d-bloka, kompleksa kobalta(II) s 6-hidroksonikotinskom kiselinom i 4,4’-bipiridinom kao ligandima. Priređeni kompleks karakteriziran je infracrvenom spektroskopijom s Fourierovim transformacijama, pretražnom elektronskom mikroskopijom i eletrokemijskim metodama. Elektrokemijska karakterizacija je imala za cilj proučiti stabilnost kompleksa i istražiti potencijalne primjene u katalitičkoj oksidaciji metanola. Na temelju IR spektra i riješenih struktura jednodimenzijskih polimera {[C 10 H 16 CoN 2 O 4 ](C 6 H 4 NO 3 ) 2 ·2H 2 O} n odnosno {[Co(4,4’-bpy)(H 2 O) 4 ](6-Onic) 2 ×2H 2 O} n pretpostavka je kako visoko oksidativne vrste prisutne u ovakvim materijalima, Co(II)/Co(III) predstavljaju katalitički aktivan centar. Rezultati istraživanja su pokazali kako elektroda modificirana s Co-kompleksom pokazuje slabu katalitičku aktivnost prema metanolu, uslijed nestabilnosti kompleksa tijekom redoks-reakcije s metanolom.Coordination complexes are a relatively new group of compounds, which attracts increasing interest due to their structural characteristics, which result in wide use in all spheres of life and industry: pharmacy, sensor technology, ion-exchangers, catalysts. Due to its exceptional properties, cobalt is often used in the synthesis of coordination complexes as a central atom/ion, or as a coordination center. In a typical Co- complex, the metal ion is bound to several donor atoms, which may be the same or different and singly or multiply bonded. The focus of this work was on the hydrothermal synthesis and characterization of d-block metal coordination complexes, cobalt(II) complexes with 6-hydroxynicotinic acid and 4,4'-bipyridine as ligands. The prepared complexes were characterized by infrared spectroscopy with Fourier transformation, scanning electron microscopy and electrochemical methods. The electrochemical characterization was used to study the stability of the complex and to explore potential applications in the catalytic oxidation of methanol. Based on the IR spectrum and the structures of the one-dimensional polymers {[C 10 H 16 CoN 2 O 4 ](C 6 H 4 NO 3 ) 2 ·2H 2 O} n or {[Co(4,4’-bpy)(H 2 O) 4 ](6-Onic) 2 ×2H 2 O} n , the strongly oxidizing species present in these materials, Co(II)/Co(III), has potential to act as a catalytically active site. The research results showed that the electrode modified with Co-complex shows a weaker catalytic activity towards methanol, due to the instability of the complex during the redox reaction with methanol
Determination of limonene in grapefruit, mandarine and celery essential oils : bachelor thesis
No full textLimonen je predstavnik monoterpenskih ugljikovodika sadržan u eteričnim uljima mnogih citrusa kao njihova glavna okosnica. Zbog izrazitih biokemijskih svojstava, limonen je jaki antioksidans, sastojak je kozmetičkih pripravaka te ostalih sredstava kao što su insekticidi, fungicidi i sl. Ovim radom razvijena je metoda pogodna za određivanje, kako kvalitativno, tako i kvantitativno monoterpena limonena uz korištenje plinske kromatografije uz kvadrupolni analizator masa te su potom određene koncentracije sastojka limonena unutar eteričnih ulja celera, mandarine i grejpa, sve to uz korištenje iste metode. Identificirani su i okarakterizirani specifični prijelazi korištenjem MRM načina snimanja standarda limonena. Pritom je konstruirana krivulja umjeravanja na temelju najpogodnijih specifičnih reakcija prijelaza određenih na temelju optimizacije energije sraza s dušikom za svaki izabrani prijelaz. Koncentracijski raspon korišten za konstruiranje krivulje umjeravanja iznosi 50-2000 µg mL -1 . Analizom realnog uzorka, konkretno eteričnog ulja celera, mandarine i grejpa, određene su koncentracije analita, limonena unutar tih „smjesa“.Limonene is a representative of monoterpene hydrocarbon contained in the essential oils of many citrus fruits as their main component. Due to its distinct biochemical properties, limonene is a strong antioxidant, an ingredient in cosmetics and other product such as insecticides, fungicides, etc. In this thesis a method was developed for qualitative and quantitative determination of monoterpene limonene using gas chromatography with a quadrupole mass analyzer. The concentrations of limonene in the essential oils of celery, grapefruit and mandarine were all determinated using the same method. Specific transitions were identified and characterized using the MRM scanning mode of the limonene standard. A calibration curve was constructed on the basis of the most suitable specific reactions/transiotions which were chosen based on the optimisation of the collision energy with nitrogen for each chosen transition. The concentration range used to construct the calibration curve was 50-2000 µg mL -1 . By analysing a real sample, specifically essential oil of celery, mandarin and grapefruit, the concentrations of limonene were determined
Testing of the membrane response based on Ag2S:AgCl:PTFE=1:1:2 with the addition of magnetite nanoparticles : diploma thesis
No full textPotenciometrijska metoda se pokazala najučinkovitijom zbog jednostavnosti, praktičnosti te niske cijene, i upravo zbog toga je korištena u ovom radu. Korištene ion-selektivne elektrode pripremljene su od srebrovog sulfida, srebrovog klorida te politetrafluoretilen u omjeru 1:1:2 uz dodatak različitih omjera nanočestica magnetita. Metodom slijednog razrjeđivanja ispitan je odziv na srebrove ione u otopini srebrovog nitrata te odziv na kloridne ione u otopini natrijevog klorida. Selektivnost same metode je ispitana promjenom reakcijskih uvjeta kao što je pH otopine uzorka, te su se ispitivanja vršila pri tri različita pH=0, 1 i 2. Potenciometrijska mjerenja se vrše dok se ne postigne razlika potencijala manja od 1 mV između posljednja dva razrijeđena. Testiranje svake membrane se vrši tri puta a rezultati mjerenja su prikazani grafički.The potentiometric method proved to be the most effective due to its simplicity, practicality and low cost, and that is the reason why it is used in this work. The used ion-selective electrodes were prepared from silver sulfide, silver chloride and polytetrafluoroethylene in a ratio of 1:1:2 with the addition of different percentages of magnetite nanoparticles. The response to silver ions was tested in a silver nitrate solution and the response to chloride ions in a sodium chloride solution using a serial dilution method. The selectivity of this method was tested by changing the reaction conditions such as the pH of the sample solution, and the tests were performed at three different pH=0, 1 and 2. Potentiometric measurements are performed until a potential difference between last two dilutions is less than 1 mV. Each membrane is tested three times, and the measurement results are presented graphically
Synthesis and characterization of ZnO nanoparticles : bachelor thesis
No full textIstraţivanja u ovom radu usmjerena su na sintezu nanostrukturiranih ĉestica ZnO hidrotermalnom metodom te karakterizaciju istih. Kao izvor Zn 2+ iona korišten je cinkov(II)acetat dihidrat Zn(CH 3 COO) 2 ⋅ 2H 2 O, a kao otapalo apsolutni etanol uz dodatak NaOH. Za kontrolu rasta i oblika kristala korišten je sufraktant trietanolamin (TEA). Sinteze su provedene pri temperaturi T=55 ⁰ C u trajanju do 2 sata. Dobivene mlijeĉno bijele suspenzije su nakon termalne obrade centrifugirane, dekantirane i isprane ultraĉistom vodom, odnosno apsolutnim etanolom te je potom osušeni prah ZnO kalciniran na 400 ⁰ C. Pripravljeni uzorci su karakterizirani difrakcijom rendgenskih zraka na polikristalnim uzrocima (XRD), transmisijskom elektronskom mikroskopijom (TEM), pretraţnom elektronskom mikroskopijom (SEM/EDS), infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR) te je provedena i analiza distribucije veliĉine ĉestica. Prema rezultatima sintetizirani uzorci nanostrukturiranog ZnO štapićastog su oblika heksagonske vurcitne strukture.Research in this work is focused on synthesis of nanostructured ZnO particles using the hydrothermal method and their characterization. Zinc acetate dihydrate, Zn(CH 3 COO) 2 ·2H 2 O was used as a source of Zn 2+ ions, and absolute ethanol with the addition of NaOH was used as a solvent. The surfactant triethanolamine (TEA) was used to control crystal growth and shape. The syntheses were carried out at a temperature T=55 ⁰ C in duration up to 2 hours. The resulting milky white solutions were centrifuged, decanted, and washed with ultrapure water or absolute ethanol and then obtained powder of ZnO was dried and calcined at 400 ⁰ C. The samples were characterized by using X-ray diffraction on polycrystalline powder (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM/EDS), Fourier transform infrared spectroscopy (FT-IR). In addition, analysis of particle size distribution was performed. According to the results, the synthesized nanostructured ZnO rod-shaped samples have a hexagonal wurtzite structure
Preparation and caracterization of PEO/APHIB-POSS/LiBOB solid polymer electrolytes : diploma thesis
No full textCilj ovog rada bila je priprava i karakterizacija čvrstih nanokompozitnih polimernih elektrolita koji se sastoje od polimerne matrice (poli(etilen-oksida) (PEO)), nanopunila (aminopropil hepta-izobutil poliedarskog oligomernog silseskvioksana (APHIB-POSS)) i soli (litij bis(oksalato)borata (LiBOB)). Nanokompozitni polimerni elektroliti pripremljeni su statičkom metodom interkalacije iz taljevine s različitim molarnim omjerima kisikovih atoma i litijevih iona (EO/Li) i različitim udjelima APHIB-POSS- a. Interakcije dodanog LiBOB-a i APHIB-POSS-a s polimernom matricom PEO-a analizirane su infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR) te potvrđene diferencijalnom pretražnom kalorimetrijom (DSC). Pritom je nađeno da Li sol ima puno veći utjecaj na smanjenje kristalne faze PEO-a u odnosu na nanopunilo. Rezultati istraživanja su pokazali da dodatak nanopunila APHIB- POSS-a fizičkim miješanjem s polimernom matricom PEO-a ne pokazuju znatan utjecaj na snižavanje kristalnosti PEO-a kao u slučaju kemijskog povezivanja molekule POSS-a s polimernom makromolekulom. Termogravimetrijska analiza (TG) je provedena u svrhu ispitivanja toplinske stabilnosti te je pokazala smanjenje toplinske stabilnosti pripremljenih uzoraka u usporedbi s čistim PEO. Međutim, polimerni nanokompozitni elektroliti ostaju dovoljno toplinski stabilni za njihovu primjenu u elektrokemijskim uređajima.The aim of this work was the preparation and characterization of solid nanocomposite polymer electrolytes consisting of a polymer matrix (poly(ethylene oxide) (PEO)), nanofiller (aminopropyl hepta- isobutyl polyhedral oligomeric silsesquioxane (APHIB-POSS)) and salt (lithium bis(oxalate )borate (LiBOB)). Nanocomposite polymer electrolytes were prepared by static melt intercalation method with different molar ratios of oxygen atoms and lithium ions (EO/Li) and different proportions of APHIB-POSS. The interactions of the added LiBOB and APHIB-POSS with the PEO polymer matrix were analyzed by Fourier transform infrared spectroscopy (FT-IR) and confirmed by differential scanning calorimetry (DSC). It was found that Li salt has a much greater influence on the reduction of the crystalline phase of PEO compared to the nanofiller. The results of the research showed that the addition of APHIB-POSS nanofillers by physical mixing with the PEO polymer matrix does not show a significant impact on reducing the PEO crystallinity as in the case of the chemical connection of the POSS molecule with the polymer macromolecule. Thermogravimetric analysis (TG) was carried out for the purpose of testing thermal stability and has showed a decrease in the thermal stability of the prepared samples compared to pure PEO. However, polymer nanocomposite electrolytes remain thermally stable enough for their application in electrochemical devices
Effect of the fulvic acids on zinc ions biding on natural zeolite : bachelor thesis
No full textU radu je ispitano vezanje cinkovih iona iz vodenih otopina različite početne koncentracije na prirodnom zeolitu klinoptiolitu u prisustvu organske tvari. Organska tvar je simulirana dodatkom vodene otopine trgovačkog naziva Fertireg ® koja na tržištu ima funkciju organski proizvedenog gnojiva. Otopina Fertireg ® je u eksperimentu pripremljena razrijeđivanjem s ultračistom vodom do koncentracija 3% i 0,12%. Miješanjem otopine cinkovih iona s otopinom Fertireg ® nije utvrđeno nastajanje taloga cinkovog hidroksida i formiranje kompleksa koji bi ometali određivanje koncentracije cinka. Vezanje cinkovih iona na zeolitu bez prisustva otopine Fertireg ® je vrlo blisko vrijednosti u prisustvu otopine Fertireg ® različitih koncentracija. Može se zaključiti da otopina Fertireg ® ima blagi utjecaj na vezanje cinka na zeolitu te u praksi može utjecati na postupak remedijacije u okolišu.The binding of zinc ions from aqueous solutions of different initial concentrations onto natural zeolite clinoptiolite in the presence of organic matter has been examined. An organic matter is simulated by adding of the Fertireg ® organic fertilizer. Experiments are performed in aqueous solutions of the Fertireg ® prepared with ultrapure water in concentrations of 3% and 0.12% respectively. In the solutions of the zinc ions with the Fertireg ® are not observed formation of zinc hydroxide formations and complexes which could affect determining of the zinc ions concentrations. Binding of the zinc ions on the zeolite in suspensions without Fertireg ® solutions has shown very similar values compared to suspensions with Fertireg ® solutions of different concentrations. It can be concluded that Fertireg ® solution slightly affect zinc ions binding onto zeolite and could affect remediation procedure into environment
Binding of zinc ions onto zeolite in the presence of Humistar r soution of different concentrations and pH values : diploma thesis
No full textU ovome radu ispitano je vezanje iona cinka na prirodnom zeolitu klinoptolitu u prisutnosti otopine Humistar ® različitih početnih koncentracija i pH vrijednosti. Humistar ® je komercijalni naziv za proizvod tvrtke Trade Corporation International S.A. koji ima veliki udio huminskih kiselina i organskih spojeva te simulira organske tvari koje se prirodno nalaze u tlu. Ispitivanje ponašanja cinkovih iona u otopini huminske kiseline ne ukazuje na formiranje metalno-organskih kompleksa i ne dolazi do taloženja cinkovog hidroksida. Dodatak Humistar ® preparata ne utječe značajno na stupanj vezanja i količinu vezanog cinka po gramu zeolita. Rezultati pokazuju blago povećanje uklanjanja u kiselom mediju u odnosu na kontrolnu otopinu.In this work, the binding of zinc ions on the natural zeolite clinoptolite in the presence of Humistar ® solutions of different initial concentrations and pH values have been examined. Humistar ® is a commercial name for a product of Trade Corporation International S.A. which has a large content of humic acids and organic compounds and simulates organic substances naturally present in the soil. Examination of the behavior of zinc ions in the humic acid solution does not indicate the formation of metal-organic complexes and precipitation of zinc in form of zinc hydroxide. The binding of zinc ions on zeolite in Humistar ® solutions indicates that the addition of Humistar ® does not significantly affect removal efficiency and the amount of zinc bound per gram of zeolite. Overall removal of zinc ions is slightly increased in the acidic medium
Grape marc spirit production and analysis : master thesis
No full textProizvodnja komovice zauzima važno mjesto u proizvodnji jakih alkoholnih i alkoholnih pića. Komovica je jedna od najzastupljenijih vrsta rakija koje se proizvode u Hrvatskoj, a posebice u Dalmatinskoj zagori. Također, ona se koristi kao najčešća osnova za proizvodnju ostalih vrsta rakija i likera. Vrlo je važno da cijeli tehnološki proces proizvodnje komovice bude ispravno proveden, počevši od odabira grožđa, provođenja fermentacije i naposljetku same destilacije prefermentirane komine grožđa iz koje se dobiva komovica. Kako bi se komovica mogla plasirati na tržište trebaju biti zadovoljeni određeni fizikalno- kemijski parametri kvalitete propisani Pravilnikom o jakim alkoholnim i alkoholnim pićima. U ovom diplomskom radu opisan je tradicionalni tehnološki proces proizvodnje komovice te su urađene osnovne analize (pH, ukupna kiselost, alkoholna jakost i hlapljive komponente) pet uzoraka komovice koje su proizvedene prema opisanom postupku.The production of grape marc spirit occupies an important place in the production of spirits and alcoholic beverages. Grape marc spirit is the most common type of brandy produced in Croatia, especially in the Dalmatian hinterland. Also, it is mainly used as the basis for the production of other brandies and liqueurs. Therefore, it is very important that the entire technological process of grape marc spirit production is carried out correctly, starting with the selection of grapes, fermentation and finally the distillation of the grape pomace from which the grape marc spirit is obtained. In order to place grape marc spirit on the market, certain physico-chemical quality parameters prescribed by the Ordinance on strong alcoholic and alcoholic beverages must be met. This diploma thesis describes the traditional technological process of grape marc spirit production and performed basic analyses (pH, total acidity, alcohol strength and volatile components) of five samples produced according to the described procedure
Preparation and characterization of PEO/PEG-POSS/LiBOB nanocomposits : master thesis
No full textU ovom radu istraţivana je mogućnost modifikacije poli(etilen-oksida) (PEO) s poli(etilen-glikol) poliedarskim oligomernim silseskvioksanom (PEG-POSS) u svrhu smanjenja kristalne faze polimera, odnosno poboljšanja njegove ionske provodnosti. U tu svrhu pripravljeni su uzorci u kojima je PEO modificiran s 5 %, 10 % i 15 % PEG-POSS-a te uzorci u koje je još dodana i sol litijev bis(oksalat) borat (LiBOB) u omjeru kisika iz PEO-a i litija iz soli 8:1. Uzorci su pripravljeni dinamiĉkom metodom iz taljevine u dvopuţnom ekstruderu, koja osigurava dobru dispergiranost punila i soli u polimernoj matrici, te su dobiveni rezultati usporeĊeni s rezultatima istraţivanja ovih uzoraka pripravljenih miješanjem iz taljevine statiĉkom metodom. NaĊeno je da dodatak PEG-POSS-a ne utjeĉe znaĉajno na temperature faznih prijelaza PEO-a, kao ni na udio kristalne faze. PEG-POSS ne utjeĉe na toplinsku stabilnost PEO-a. Stoga se ovakvi rezultati ne pripisuju lošoj dispergiranosti punila, što se pretpostavljalo kod statiĉke priprave uzoraka, već se zakljuĉuje da PEG-POSS ne utjeĉe ni na toplinska svojstava PEO-a niti na formiranje kristalne faze PEO-a. TakoĊer je naĊeno da sol LiBOB potpuno narušava kristalnu fazu PEO-a te da povećava temperaturu poĉetka razgradnje PEO-a za 13 °C, dok vrijednost staklišta povećava za desetak stupnjeva. Ipak, rezultati elektrokemijske impedancijske spektroskopije pokazuju da dodatak PEG-POSS-a ima utjecaja na ionsku provodnost. Uzorak kojem je dodano 15 % PEG-POSS-a i Li sol pokazuje najveću vrijednosti ionske provodnosti.In this work, the possibility of modifying poly(ethylene oxide) (PEO) with poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG-POSS) was investigated for the purpose of reducing the crystalline phase of the polymer or improving his ionic conductivity. For this purpose, samples were prepared in which PEO was modified with 5, 10 and 15 % PEO-POSS and samples in which lithium bis(oxalate) borate salt was also added in the ratio of oxygen from PEO and lithium from salt 8:1. The samples were prepared by the dynamic method from the melt in a twin screw extruder, which ensures good dispersion of the filler and salt in polymer matrix, and the obtained results were compared with the results of the research of these samples prepared by mixing from the melt using the static method. It was found that the addition of PEG-POSS does not significantly affect the phase transition temperatures of PEO, as well as the proportion of the crystalline phase. PEG-POSS does not affect the thermal stability of PEO. Therefore, these results are not attributed to the poor dispersibility of the filler, which was assumed in the static preparation of the samples, but it is concluded that PEG-POSS does not affect either the thermal properties of PEO or the formation of the crystalline phase of PEO. It was also found that the LiBOB salt completely destroys the crystalline phase of PEO and that it increases the temperature of the beginning of PEO decomposition by 13 °C, while the value of the glass transition increases by ten degrees. Nevertheless, the results of electrochemical impedance spectroscopy show that the addition of PEG-POSS has an effect on ionic conductivity. The sample to which 15% of PEG-POSS and Li salt were added shows the highest values of ionic conductivity