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Characterization of ginger and turmeric extracts
No full textIako su eterična ulja sastavni dio ljudske povijesti i kulture već dugi niz stoljeća, njihova raznolika svojstva i danas omogućavaju razvoj inovativnih proizvoda u raznim industrijskim granama, posebice u farmaceutskoj, prehrambenoj i kozmetičkoj industriji, Budući da u današnje vrijeme fokus na ekološki održive proizvode dobiva na zamahu, uloga eteričnih ulja time postaje još značajnija. Cilj ovog rada bio je provođenje kvantitativne i kvalitativne analize ekstrakata dobivenih iz rizoma biljaka Zingiber officinale i Curcuma longa te ispitivanje antimikrobne aktivnosti na bakterijama Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus i Escherichia coli, i kvascu Candida lipolytica. Provedena je karakterizacija pomoću tankoslojne kromatografije, plinske kromatografije s masenom spektrometrijom, infracrvene spektroskopije s Fourierovom transformacijom i UV/Vis spektrofotometrije. Navedenim metodama utvrđena je varijabilnost kemijskog sastava ovisno o metodi ekstrakcije, načinu sušenja i ekstrakcijskom otapalu. Disk difuzijskim testom ispitivana je antimikrobna aktivnost ekstrakata đumbira i kurkume. Utvrđeno je značajno inhibicijsko djelovanje ekstrakata kurkume na testirane mikroorganizme, dok su ekstrakti dobiveni iz đumbira demonstrirali značajno inhibicijsko djelovanje na bakteriju B. subtilis i kvasac C. lipolytica.While essential oils have been an integral part of human history and culture for centuries, their diverse properties continue to facilitate the development of innovative products across various industrial sectors, particularly in the pharmaceutical, food, and cosmetic industries. As the focus on ecologically sustainable products gains momentum, the role of essential oils becomes even more significant. The aim of this study was to conduct a quantitative and qualitative analysis of extracts obtained from the rhizomes of Zingiber officinale and Curcuma longa plants, as well as to investigate their antimicrobial activity against the bacteria Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and the yeast Candida lipolytica. Characterization was carried out using thin-layer chromatography, gas chromatography-mass spectrometry, Fourier-transform infrared spectroscopy, and UV/Vis spectrophotometry. Through these methods, the variability in chemical composition was determined, dependent on extraction method, drying technique, and solvent used for extraction. The antimicrobial activity of ginger and turmeric extracts was assessed using disk diffusion tests. A significant inhibitory effect of turmeric extracts on the tested microorganisms was observed, while extracts derived from ginger demonstrated substantial inhibitory activity against the bacterium B. subtilis and the yeast C. lipolytica
Measurement and modeling of dimensional changes of wood wool cement composite during drying and wetting cycles
No full textPromjena dimenzije drvocementnog kompozita koja se odvija pri sušenju i vlaženju istog, iznimno je bitna stavka zbog primjene drvocementnog kompozita. U ovom radu određivana je temperatura rosišta pri sobnim uvjetima da bi se utvrdila preciznost higrometra kod određivanja vlažnosti zraka, te je mjerena promjena dimenzije i mase drvocementog kompozita prije i poslije vlaženja i sušenja. Mjerenja su provedena u laboratoriju koristeći otporničku metodu određivanja temperature rosišta, sušionik i mikrometar. U eksperimentalnom dijelu ovoga rada konstruirana je aparatura za određivanje temperature rosišta na temelju otporničke metode određivanja temperature rosišta, tako što se preko optičkog senzora CNY70 pratila promjena otpora na detektoru senzora. Zatim su mjerene dimenzije i drvocementnog kompozita prilikom sušenja. Eksperimentalni podaci za određivanje temperature rosišta potvrdili su ispravnost aparature zbog izrazitog poklapanja rezultata relativne vlažnosti, RH s očitanim vrijednostima na higrometru. Kod ispitivanja promjena mase i dimenzija kompozita, podaci za praćenje promjene mase utočnjeni su prema modelu jednofaznog eksponencijalnog opadanja: y=A1*e^(-x/t1)+yo, te je uočljiva poveznica početnih dimenzija kompozita sa promjenom mase i količinom apsorbirane vlage. Dimenzijske promjene ovisne su o debljini drvocementnog kompozita, što ima utjecaj na njegova svojstva.The change in the dimensions of the wood-cement composite, which takes places during drying and wetting is an extremely important due to the application of the wood-cement composite. In this work, the dew point temperature was determined in order to establish the precision of the hygrometer in determining air humidity, and the change in the dimensions and mass of the wood-cement composite before and after drying and wetting process. The measurements were carried out in the laboratory using the resistance method for determining the dew point temperature, the dryer and a micrometar. In the experimental part, an apparatus for determining the dew point temperature was constructed based on the resistive method of determining the dew point temperature, by monitoring the resistance change on the sensor detector via the CNY 70 optical sensor. Then the dimensions and mass of the wood-cement composite were measured during drying process. Eksperimental data for determining the dew point temperature confirmed the precision of the apparatus due to the remarkable accuracy in results of relative humidity in comparison to the values detected by the hygrometer. When testing the changes in mass and dimensions of the composite, the dana for monitoring the change in mass were modeled according to one-phase exponential decay model: y=A1*e^(-x/t1)+yo, and there is a noticable link between the initial dimnesions of the composite and the change of mass and amount of absorbed moisture. Dimensional changes are depend on the thickness of the wood-cement composite, which has an impact on its properties
Synthesis and characterisation of Prussian blue nanoparticles
No full textAnalitički uređaji koji imaju sposobnost pretvorbe kemijske informacije u koristan i mjerljiv signal nazivaju se kemijski senzori. Kada takav uređaj uslijed interakcije s analitom bilježi promjenu određenih optičkih svojstava, tada se on klasificira kao optički kemijski senzor. U novije doba sve se više teži implementaciji bioloških i ekološki prihvatljivih materijala u svim životnim sferama, pa tako i u senzorskoj tehnologiji. Trenutno su na tržištu posebno zanimljivi materijali kao što su papir i tekstil. Osim prirodnih materijala, u sferi interesa pri razvoju novih tehnologija pojavila se i nanotehnologija. Naime, nanoobjekti kao što su nanožice, nanocjevčice i nanočestice otvaraju brojne nove mogućnosti svojim specifičnim svojstvima koja se razlikuju od onih na makro razini. Često prisutna mana prilikom primjene nanočestica jest njihova toksičnost i bioakumulacija. Jedna od posebnosti nanočestica berlinskog modrila jest njihova netoksičnost što značajno proširuje spektar njihove primjene. U ovom radu cilj je bio objediniti materijal biološkog porijekla (papir) sa nanotehnologijom (nanočestice berlinskog modrila) te ispitati njihov potencijal za razvoj optičkih kemijskih senzora. Nanočestice berlinskog modrila uspješno su sintetizirane metodom fotoredukcije in-situ, odnosno uranjanjem papirnih traka u sinteznu otopinu i izlaganjem UV zračenju. Ispitan je utjecaj različitih parametara na sintezu berlinskog modrila: vrijeme izlaganja UV zračenju, ispiranje različitim reagensima, koncentracija sintezne otopine, omjer reaktanata te utjecaj pH u svrhu istraživanja mogućnosti primjene berlinskog modrila kao optičkog senzora. Također je dodatno ispitana reverzibilnost i stabilnost papirnih traka pri različitim pH vrijednostima. Optička karakterizacija otopina i papirnih traka provedena je metodama apsorpcijske i reflektancijske spektroskopije u UV–Vis–NIR području. Zaključeno je kako nanočestice berlinskog modrila mijenjaju boju prilikom kontakta s puferskim otopinama različitog pH te da je područje ponovljivosti rezultata tj. raspon djelovanja takvog senzora od pH = 5 do pH = 8.Analytical devices that have the ability to convert chemical information into a valuable and measurable signal are called chemical sensors. When such a device records a change in specific optical properties as a result of interaction with the analyte, then it is classified as an optical chemical sensor. In recent times, there has been an increasing effort to implement biological and ecologically acceptable materials in all spheres of life, including sensor technology. Currently, particularly interesting materials on the market are paper and textiles. In addition to natural materials, nanotechnology is in the sphere of interest in the development of new technologies. Nano-objects such as nanowires, nanotubes and nanoparticles unlock numerous new possibilities with their specific properties that differ from those at the macro level. A frequently present drawback when using nanoparticles is their toxicity and bioaccumulation. One of the unique features of Prussian blue nanoparticles is their non-toxicity, which significantly expands the spectrum of their application. In this work, the goal was to combine a material of biological origin (paper) with nanotechnology (Prussian blue nanoparticles) to create an optical pH sensor. Nanoparticles of Prussian blue were successfully synthesized by photoreduction in situ by immersing paper strips in the synthesis solution and exposing them to UV radiation. The influence of various parameters on the synthesis of Prussian blue was tested: exposure time to UV radiation, washing with different reagents, concentration of the synthesis solution, ratio of reactants and the influence of pH to investigate the possibility of using Prussian blue as an optical sensor. The reversibility and stability of the paper strips at different pH values were also additionally tested. The optical characterization of the paper strips was carried out by measuring the reflectance. It was concluded that Prussian blue nanoparticles change colour when in contact with buffer solutions of different pH and that the pH working range is between 5 and 8
In-situ formation of reference membrane for solid state electrodes
No full textOsnovni cilj ovog rada je formiranje referentne Ag|AgCl membrane temeljene na poli(vinil-butiralu) za čvrstofazne elektrode. Opisana je priprava te nanošenje referentne i zaštitne membrane na ispisane elektrode. Nakon sušenja i kondicioniranja, provedeno je potenciometrijsko mjerenje pripremljenih elektroda u širokom rasponu koncentracija
od 10^-6 do 10^-1 mol/dm^3 u standardnim otopinama KCl, Na2SO4, NaNO3 te CaCl2. Najbolje rezultate pokazala je čvrstofazna elektroda u otopini Na2SO4. Pripremljene elektrode ispitane su u postupku baždarenja komercijalne natrijeve ion-selektivne elektrode, a rezultati su prikazani grafički. Također, provedena je i ciklička voltametrija kako bi se usporedila pripremljena čvrstofazna referentna elektroda s klasičnom Ag|AgCl elektrodom.The aim of this work is to form reference Ag|AgCl membrane based on poly(vinyl-butyral) for solid-state electrodes. The preparation and application of the reference and protective membrane to the printed electrodes is described. After drying and conditioning, potentiometric measurement of the prepared electrodes was performed in a wide range of concentrations from 10^-6 to 10^-1 mol/dm^3 in standard solutions of KCl, Na2SO4, NaNO3 and CaCl2. The solid-state electrode in Na2SO4 standard solution shows the best results. The prepared electrodes were tested in the calibration process of a commercial sodium ion-selective electrode, and the results are presented graphically. Also, cyclic voltammetry was performed to compare the prepared solid-state reference electrode with the classic Ag|AgCl electrode
Evaluation of methods for extraction of piperine from different types of pepper
No full textEkstrakcija je jedan od dobro znanih separacijskih procesa, a od njezinih začetaka kada je predstavljala samo jednostavno miješanja uzorka i otapala proces je do danas znatno napredovao. Težilo se pronaći metodu koja je ekonomična, ne dugotrajna, a učinkovita, stoga su razvijene brojne metode ekstrakcije. Jedna od primjena je ekstrakcija iz biljnog materijala koji u sebi sadrži vrijedne sastojke, a primjer takvog ekstrakta je piperin dobiven iz papra. U ovom radu provedene su četiri metode ekstrakcije (ekstrakcija otapalom, Soxhlet ekstrakcija, ekstrakcija potpomognuta ultrazvukom i ekstrakcija potpomognuta mikrovalovima) na četirima paprima (crni, bijeli, zeleni i voatsiperifery papar) korištenjem etanola kao otapala. Ekstrakcije su se izvodile pri različitim temperaturama i korištenjem različitih veličina čestica papra. Cilj rada bio je usporediti metode po svom djelovanju na proces, odnosno utvrditi utjecaj temperature i veličine čestica na učinkovitost ekstrakcije. Soxhlet ekstrakcijom i UV/Vis spektroskopijom utvrđeno je da najviše piperina ima u zelenom, a najmanje u voatsiperifery papru. Rezultati su pokazali da procesu ekstrakcije pogoduje povišenje temperature i smanjenje veličine čestica. Najučinkovitijom metodom pokazala se ekstrakcija otapalom na magnetskoj miješalici.Extraction is one of well-known separation processes, which has developed profoundly from its starts when it presented just a simple mixing of a sample and a solvent. The aim of scientists was to find extraction method that is economical, short-lasting, and efficient,
so a numerous methods have been invented. One of application of the process is extraction of plant material which consists of valuable ingredients, such as is piperine obtained from pepper. In this paper four extraction methods have been conducted (solvent extraction, Soxhlet extraction, ultrasound assisted extraction and microwave assisted extraction) using four different types of pepper (black, white, green and voatsiperifery pepper) and ethanol as solvent. Extractions were executed under different temperatures and using different peppercorn particle size. The goal of the paper was to compare the methods by their effect on the process, and determine the impact of temperature and particle size on extraction.
By using UV spectroscopy results of Soxhlet extraction, it was determined that content of piperine is the highest in green pepper, and the lowest in voatsiperifery pepper. Results have shown that the rise of temperature and decrease of particle size enhance the efficiency of extraction. The most efficient extraction is solvent extraction performed by using magnetic stirrer
Biodegradation of antivirals
No full textPosljednjih godina bilježi se porast uporabe antivirusnih lijekova pa samim time raste i kontinuirana pojava i postojanost navedenih u otpadnim vodama. Temeljni cilj ovog rada usmjeren je prema prikazu područja mogućnosti biološke razgradnje antivirotika, odnosno procjeni različitih metoda uklanjanja konvencionalnim metodama kao što su biološke, kemijske metode i fizikalno-kemijski postupci kao što je membranski bioreaktor.In recent years, there has been an increase in the use of antiviral drugs, which means that the continuous occurrence and persistence of the above-mentioned drugs in wastewater is also increasing. The main goal of this work is directed towards the presentation of the area of possibility of biological degradation of antivirals, the evaluation of different methods of removal by conventional methods such as biological, chemical methods and physico-chemical procedures such as a membrane bioreactor
Machine learning models in material engineering
No full textSvaki dan ljudi udahnu oko dvadeset tisuća puta, što bi iznosilo otprilike trinaest do petnaest tisuća litara zraka. Dakle, neminovno je zaključiti da je glavna komponenta života na Zemlji onda svakako zrak. Kao glavna komponenta, neophodan je za opstanak svih živih bića. Zrak je dakle mješavina plinova i to prvenstveno dušika i kisika, a zatim ugljikova dioksida, argona, neona, vodika i drugih. S obzirom na količinu zraka koju ljudi dnevno udišu važno je voditi računa o kvaliteti zraka koji se udiše. Bilo kakvo onečišćenje u zraku utječe na zdravlje ljudi, pravilan rad i aktivnost tijela, cirkulaciju krvi, pravilan rad mozga, a samim tim i na kvalitetu života. Velik je broj parametara koji utječu na onečišćenje zraka. Međutim, većina čestica i plinova koji utječu na kvalitetu zraka nastaju ljudskim djelovanjem i uglavnom potječu iz urbanih i industrijskih područja. Tako primjerice, veliki gradovi poput Pekinga ili Delhija zbog velike naseljenosti i industrijalizacije imaju problem s tamnim smogom. Koncentracija onečišćujućih tvari u zraku zajedno sa povezanim zdravstvenim rizicima mogu se prikazati indeksom kvalitete zraka, AQI. Indeks kvalitete zraka može se odrediti „ručno“ mjerenjem utjecaja pojedinih parametara; temperature, tlaka, vidljivosti i slično te sumiranjem njihovih utjecaja. Ali, kako bi se brže i jednostavnije odredio utjecaj pojedinih parametara na AQI moguća je primjena algoritama strojnog učenja uz korištenje nekog od dostupnih programskih jezika. Dakle, cilj ovog rada jest primjenom algoritama strojnog učenja i programskog jezika R pronaći model koji najbolje predviđa indeks kvalitete zraka te usporediti mjerne vrijednosti indeksa kvalitete zraka s vrijednostima dobivenim predikcijom.Every day, people breathe in about twenty thousand times, which would amount to approximately thirteen to fifteen thousand liters of air. Therefore, it is inevitable to conclude that the main component of life on Earth is air. As the main component, it is necessary for the survival of all living beings. Air is a mixture of gases, primarily nitrogen and oxygen, followed by carbon dioxide, argon, neon, hydrogen, and others. Considering the amount of air that people breathe in daily, it is important to take care of the quality of air that is inhaled. Any air pollution affects human health, proper body work and activity, blood circulation, proper brain work, and therefore the quality of life. There are a large number of parameters that influence air pollution. However, most of the particles and gases that affect air quality are human-made and mainly originate from urban and industrial areas. For example, large cities such as Beijing or Delhi have a problem with dark smog due to high population and industrialization. The concentration of pollutants in the air together with the associated health risks can be represented by the air quality index, AQI. The air quality index can be determined "manually" by measuring the influence of individual parameters; temperature, pressure, visibility, and similar but also summarizing their effects. But, to determine the influence of individual parameters on AQI more quickly and simply, the application of the machine learning algorithms combined with one of the available programming languages is possible. Therefore, the goal of this work is to find a model that best predicts the air quality index by applying machine learning algorithms and the R programming language and to compare the measured values of the air quality index with the values obtained by prediction
A review on sustainable starch-based hydrogels
No full textHidrogelovi su fizikalno ili kemijski umrežene makromolekule koje tvore trodimenzionalnu mrežu sposobnu zadržati vodu, bez raspadanja. Posjeduju dobra elastična svojstva, gotovo identična tkivu živog organizma. Široka uporaba hidrogelova na bazi škroba u industrijskim i ekološkim područjima primjene smatra se od primarne važnosti. Škrob pripada skupini polisaharida, izgrađen od jedinica glukoze koje su povezane u dva polimerna lanca- amilozu i amilopektin. Proizvodnja i uporaba škroba u svijetu u konstantnom je porastu zbog pozitivnih učinaka koji se ostvaruju njegovim dodavanjem pri proizvodnji različitih proizvoda. Polimliječna kiselina, PLA termoplastični je, biorazgradljiv polimer proizveden sintetski, polimerizacijom monomera mliječne kiseline ili dimera cikličkog laktida. Razgrađuje se hidrolizom osnovnih estera polimera. Ima brojne biomedicinske primjene, kao što su šavovi, stentovi, mediji za dijalizu i uređaji za isporuku lijekova. U ovom radu proveden je postupak umješavanja škroba u PLA matricu s ciljem priprave biorazgradljivih hidrogelova koji bi potencijalno imali primjenu kao matriksni sustavi za dostavu lijeka s produljenim oslobađanjem u farmaceutskoj industriji. Cilj je bio ispitati može li škrob koji je hidrofilan, a umješan u malim udjelima u PLA matricu potaknuti njeno jače bubrenje te posljedično ubrzati njenu kemijsku razgradnju kroz vrijeme. Eksperimentalni dio rada obuhvaćao je pripravu mješavina polilaktida s malim udjelom škroba (5-15 mas. %) i hidrogelova postupkom inverzije faza uzrokovane promjenom otapala N-metil pirolidona (NMP) (engl. solvent induced phase inversion). Provedena je karakterizacija hidrogelova koji su formirani u vodi te je praćen stupanj bubrenja kroz vremenski period od 14 dana. GPC (engl. Gel permeation chromatography) metodom je ispitano je li došlo do promjene molekulskih masa polilaktidne matrice kao posljedica hirdolitičke razgradnje. Iz rezultata dobivenih na temelju provedenih mjerenja vidljivo je da je najveći stupanj bubrenja postigao uzorak PLA+TPS/NMP (90:10).
Iz GPC rezultata ustanovljeno je da nije došlo do kemijske razgradnje polilaktidne matrice, neovisno o količini i o vrsti škroba koja je bila umiješana.Hydrogels are physically or chemically cross-linked macromolecules that form
a three-dimensional network capable of retaining water without disintegration. They have good elastic properties, almost identical to the tissue of a living organism. The widespread use of starch-based hydrogels in industrial and ecological fields of application is considered to be of primary importance. Starch belongs to the group of polysaccharides, built from glucose units connected in two polymer chains - amylose and amylopectin. The production and use of starch in the world is constantly increasing due to the positive effects achieved by its addition in the production of various products. Polylactic acid, PLA is a thermoplastic, biodegradable polymer produced synthetically, by polymerization of lactic acid monomers or cyclic lactide dimers. It is broken down by hydrolysis of basic polymer esters. It has numerous biomedical applications, such as sutures, stents, dialysis media, and drug delivery devices.
In this work, the process of mixing starch into the PLA matrix was carried out with the aim of preparing biodegradable hydrogels that could potentially be used as matrix systems for the delivery of drugs with prolonged release in the pharmaceutical industry. The aim was to test whether starch, which is hydrophilic and mixed in small proportions in the PLA matrix, can stimulate its stronger swelling and consequently accelerate its chemical decomposition over time. The experimental part of the work included the preparation of mixtures of polylactide with a small proportion of starch (5-15 wt. %) and hydrogels by the process of phase inversion caused by the change of solvent N-methyl pyrrolidone (NMP) (solvent induced phase inversion). Hydrogels formed in water were characterized and the degree of swelling was monitored over a period of 30 days. The GPC (Gel permeation chromatography) method was used to determine whether there was a change in the molecular weight of the polylactide matrix as a result of hydrolytic decomposition. From the results obtained on the basis of the measurements, it is evident that the highest degree of swelling was achieved by the sample PLA+TPS/NMP (90:10). From the GPC results, it was established that there was no chemical degradation of the polylactide matrix, regardless of the amount and type of starch that was mixed
Preparation and application of natural dyes
No full textBojila se mogu podijeliti u dvije glavne kategorije, prirodna i sintetska. Tirska ljubičasta, karmin, bojadisarski broć i indigo neka su od najjpoznatijih i najstarijih prirodnih bojila. Prirodna bojila koristile su najranije civilizacije. Dokazi o korištenju nalaze se u špiljama, drevnim naseljima i grobnicama. Prirodna bojila moguće je podijeliti na više načina, a česte su podjele prema kemijskoj strukturi, izvoru proizvodnje te metodama primjene na tekstilu. Najčešće se koriste za bojenje tekstila, hrane, kozmetike, u farmaceutskoj industriji te umjetnosti. Do 1856. g. koristila su se samo prirodna bojila, a te je godine W. H. Perkin slučajno pripremio mauvein, prvo sintetsko bojilo koje je bilo put razvoju mnogih drugih sintetskih bojila. Neka sintetska bojila predstavljaju opasnost za okoliš i ljude, stoga se u posljednjih nekoliko godina pojavilo ponovno zanimanje za korištenje ekološki prihvatljivijih i zdravijih bojila. Također, čimbenik koji potiče upotrebu prirodnih bojila želja je kupaca za jedinstvenim proizvodima. U eksperimentalnom dijelu ovog rada pripremljeno je jedanaest bojila iz biljnih izvora i gljiva (crveni kupus, cikla, špinat, avokado, vrganji, lisičarke, trubice, žuti luk, ljubičasti luk, borovnice i kurkuma), a korištena su za bojenje materijala pamuka i vune. Da bi se ispitale različite mogućnosti bojenja, otopine su razdijeljene u staklene bočice. Za promjenu pH vrijednosti i dobivanje različitih boja korišteni su modifikatori. Kako bi se provjerilo vezivanje bojila za tkaninu, pojedine su bočice sadržavale samo čisto bojilo, a druge i sredstvo na vezivanje. Također, kako bi se ispitao utjecaj vremena bojenja i temperature na konačan produkt, vlakna su držana u pripremljenim bočicama s otopinama najprije oko jedan sat, pri temperaturi oko 80 °C te tri dana na temperaturi oko 8 °C.Dyes can be divided into two main categories: natural and synthetic. Tyrian violet, carmine, madder and indigo are some of the best known and oldest natural dyes. Natural dyes were used by the earliest civilizations. Evidence of their use can be found in caves, ancient settlements and tombs. Natural dyes can be categorised in several ways, often according to their chemical structure, their source of manufacture, and their methods of application to textiles. They are most commonly used for dyeing textiles, food, cosmetics, in the pharmaceutical industry, and in the arts. Until 1856, only natural dyes were used. In that year, W. H. Perkin accidentally produced mauveine, the first synthetic dye, which paved the way for the development of many other synthetic dyes. Some synthetic dyes pose a danger to the environment and humans, so in recent years there has been a renewed interest in using more environmentally friendly and healthier dyes. In the experimental part of this work, eleven dyes were prepared from plant sources and mushrooms (red cabbage, beets, spinach, avocados, porcini mushrooms, chanterelles, tubers, yellow onions, purple onions, blueberries, and turmeric) and used to dye cotton and wool materials. To test the different dyeing options, the solutions were divided into glass vials. Modifiers were used to change the pH and obtain different colours. To test the binding of the dye to the fabric, some bottles contained only pure dye, while others contained a binder. To study the effects of dyeing time and temperature on the final product, the fibres were stored in the prepared vials containing the solutions first at a temperature of 80 °C for one hour and then at a temperature of about 8 °C for three days
Preparation and characterization of new indole derivatives as potential antifungal agents
No full textCilj ovog rada je fukcionalizirati i spektroskopski okarakterizirati nove indolske derivate. Sinteze novih produkata provedene su Wittigovom reakcijom, aldolnom kondenzacijom, redukcijom i Williamsovom sintezom etera, pri čemu su se sve rekcije, osim aldolne kondenzacije, pokazale uspješnima.The aim of this work is to functionalize and spectroscopically characterize new indole derivatives. Syntheses of new products were carried out by Wittig reaction, aldol condensation, reduction and Williams ether synthesis, where all reactions, except aldol condensation, proved to be successful