PEDAGOŠKO ISTRAŽIVANJE – AUTOBIOGRAFSKA METODA

Istraživanje samog sebe kroz refleksiju omogućuje učitelju profesionalni rast. Stvaranje osobnog životnog puta (npr. rijeke života) potiče kritičko razmišljanje o vlastitoj praksi. Učiteljeva autobiografija također je usmjerena na vrednovanje i istraživanje sebe kao učenika i, naravno, kasnije kao učitelja. Kronološki zapis vašeg životnog puta može otkriti nedosljednosti u profesionalnom razvoju. Kroz ovaj pogled, učitelj može rasti osobno, profesionalno i društveno

PEDAGOŠKO ISTRAŽIVANJE – AUTOBIOGRAFSKA METODA

Istraživanje samog sebe kroz refleksiju omogućuje učitelju profesionalni rast. Stvaranje osobnog životnog puta (npr. rijeke života) potiče kritičko razmišljanje o vlastitoj praksi. Učiteljeva autobiografija također je usmjerena na vrednovanje i istraživanje sebe kao učenika i, naravno, kasnije kao učitelja. Kronološki zapis vašeg životnog puta može otkriti nedosljednosti u profesionalnom razvoju. Kroz ovaj pogled, učitelj može rasti osobno, profesionalno i društveno

Arable bryophytes from Northeastern Slovenia with new and interesting national records

We investigated the arable bryophyte flora in the Northeastern region of Slovenia. We found three new bryophyte taxa for Slovenia: Bryum violaceum, Dicranella staphylina and Hydrogonium consanguineum var. kurilense. The presence of the regionally extinct Ephemerum cohaerens was confirmed, and several other species from the National Red List of bryophytes were also recorded. A list of 25 bryophyte species growing on the studied arable fields is presented and commented on

Microtiter plate assay for phosphate using a europium–tetracycline complex as a sensitive luminescent probe

A new luminescent europium probe is presented for the determination of phosphate (P) in microtiter plate format. The assay is based on the quenching of the luminescence of the europium–tetracycline (EuTc) 1:1 complex by phosphate using a reagent concentration of 20.8 μmol/L. The probe is excited at 400 nm and displays a large Stokes’ shift of 210 nm. The emission maximum is located at 616 nm. The system works best at neutral pH 7 and is therefore suitable for phosphate determination in biological and biochemical systems. The linear range of the calibration plot is from 5 × 10−6 mol/L to 7.5 × 10−4 mol/L of phosphate, and the limit of detection is 3 μmol/L

Oxidation by-products of the C.I. Direct Blue 106 dye after ozonation

Oksidacijski nusprodukti bojila C.I. Direct Blue 106 nakon ozonizacije U radu je istražena oksidacija često upotrebljavanih oksazinskih direktnih bojila C.I. Direct Blue 106 (Direct Dye 106) u vodenim otopinama (600 mg L-1) pomoću ozona. VIS spekti su pokazali degradaciju oksazinskih skupina u početnoj strukturi Direct Dye 106. Oksidacijski nusprodukti, poput sulfata, nitrata, nitrita, kloridnih iona i spojeva fenola su identificirani pomoću MS-MS i LC-MS analiza. Provedena ispitivanja toksičnosti na dafnije (vodenbuhe) nakon ozonizacije otpadne vode koja je sadržala Direct dye 106 je potvrdio da nusprodukti nemaju toksične karakteristike.The oxidation of the often used oxazine direct dye C.I. Direct Blue 106 (Direct Dye 106) in an aqueous solution (600 mg L-1) by ozonation was investigated. VIS spectra showed degradation of the oxazine groups in the initial Direct Dye 106 structure. The oxidation by-products, such as sulphate, nitrate, nitrite, chloride ions and phenolic compounds, were identified by MS-MS and the LC-MS analyses. After ozonation the wastewater containing the Direct Dye 106 showed no toxic characteristics, according to Daphnia magna test (24 h- EC50 > 75%)

Synergistic chemo-enzymatic hydrolysis of poly(ethylene terephthalate) from textile waste

Due to the rising global environment protection awareness, recycling strategies that comply with the circular economy principles are needed. Polyesters are among the most used materials in the textile industry, therefore achieving a complete poly(ethylene terephthalate) (PET) hydrolysis in an environmentally-friendly way is a current challenge. In this work a chemo-enzymatic treatment was developed in order to recover the PET building blocks, namely terephthalic acid (TA) and ethylene glycol. To monitor the monomer and oligomer content in solid samples, a Fourier-Transformed Raman method was successfully developed. A shift of the free carboxylic groups (1,632 cm-1) of TA into the deprotonated state (1,604 and 1,398 cm-1) was observed and bands at 1,728 and 1,398 cm-1 were used to assess purity of TA after the chemo-enzymatic PET hydrolysis. The chemical treatment, performed under neutral conditions (T=250 °C, P=40 bar) led to conversion of PET into 85% TA and small oligomers. The latter were hydrolysed in a second step by using the Humicola insolens cutinase (HiC) yielding 97% pure TA, therefore comparable with the commercial synthesis grade TA (98%)

Synergistic chemo-enzymatic hydrolysis of poly(ethylene terephthalate) from textile waste

Due to the rising global environment protection awareness, recycling strategies that comply with the circular economy principles are needed. Polyesters are among the most used materials in the textile industry, therefore achieving a complete poly(ethylene terephthalate) (PET) hydrolysis in an environmentally-friendly way is a current challenge. In this work a chemo-enzymatic treatment was developed in order to recover the PET building blocks, namely terephthalic acid (TA) and ethylene glycol. To monitor the monomer and oligomer content in solid samples, a Fourier-Transformed Raman method was successfully developed. A shift of the free carboxylic groups (1,632 cm-1) of TA into the deprotonated state (1,604 and 1,398 cm-1) was observed and bands at 1,728 and 1,398 cm-1 were used to assess purity of TA after the chemo-enzymatic PET hydrolysis. The chemical treatment, performed under neutral conditions (T=250 °C, P=40 bar) led to conversion of PET into 85% TA and small oligomers. The latter were hydrolysed in a second step by using the Humicola insolens cutinase (HiC) yielding 97% pure TA, therefore comparable with the commercial synthesis grade TA (98%)

Wearable bio and chemical sensors

Chemical and biochemical sensors have experienced tremendous growth in the past decade due to advances in material chemistry combined with the emergence of digital communication technologies and wireless sensor networks (WSNs) [1]. The emergence of wearable chemical and biochemical sensors is a relatively new concept that poses unique challenges to the field of wearable sensing. This is because chemical sensors have a more complex mode of operation, compared to physical transducers, in that they must interact in some manner with specific molecular targets in the sample medium. To understand the challenges in developing wearable chemical and biochemical sensors the traits of these devices will be discussed in this introductory section. Following this the potential parameters of interest are presented and examples of wearable systems are discussed. A range of sampling techniques and methods of chemical sensing are presented along with integration issues and design challenges. Finally, some of the main application areas of this novel technology are discussed