FOLIAR ANALYSES OF SAMPLES FROM INTENSIVE MONITORING PLOTS AND INTER-LABORATORY TESTING WITHIN THE FRAMEWORK OF ICP FORESTS PROGRAMME

U sklopu Me|unarodnog programa za procjenu i praćenje utjecaja zračnog onečišćenja na šume ( ICP Forests ) u Hrvatskoj se na sedam ploha intenzivnog motrenja (Razina II) s karakterističnih šumskih zajednica provode istraživanja i kemijske analize biljnog materijala. Kako bi se mogla pratiti pouzdanost primijenjenih metoda u laboratorijskim analizama, osiguranja kvalitete rada i nova saznanja na području analitičkih metoda primjenjivih za analizu biljnog materijala Forest Foliar Co-ordinating Centre u Beču organizira svake godine Interlaboratorijska ispitivanja na uzorcima pripremljenim u laboratorijima zemalja koje su uključene u ICP Forests program. Šumarski institut Jastrebarsko 2004. godine pripremio je lišće obične bukve kao referentni uzorak za sve europske laboratorije. Uzorci su analizirani na obavezne elemente: sumpor, dušik, fosfor, kalij, kalcij i magnezij, te neobavezne elemente: cink, mangan, željezo i ugljik. Dobiveni rezultati govore o dobroj kvaliteti laboratorija Šumarskog instituta Jastrebarsko. Takva ispitivanja u skladu su sa zahtjevima internacionalnih standarada, a omogućuju i provjeru nove metode uvedene u laboratorijska ispitivanja. U kemijskom laboratoriju šumarskog instituta Jastrebarsko ispitivana je nova metoda određivanja dušika na elementarnom analizatoru CNS 2000 i rezultati su provjereni u interlaboratorijskim istraživanjima koja su potvrdila opravdanost metode.Within the framework of International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests), research and chemical analyses of plant material has been carried out in Croatia on seven intensive monitoring plots (Level II) with typical forest communities. In order to monitor the reliability of methods of laboratory analyses, as well as to ensure operational quality of analytical methods that can be applied in plant material analysis, Forest Foliar Co–ordinating Centre in Vienna organizes each year Inter-laboratory testing on samples prepared in laboratories of countries taking part in ICP Forests. In 2004, Forest Research Institute, Jastrebarsko prepared leaves of common beech as reference sample for all European laboratories. Samples were tested for the following required elements: sulphur, nitrogen, phosphorous, potassium, calcium and magnesium, and the following optional elements: zinc, manganese, iron and carbon. Obtained results are evidence of high quality of performance of the laboratory of Forest Research Institute in Jastrebarsko. This type of laboratory testing is in line with the requirements of international standards and facilitate testing of new methods introduced into laboratory procedure. New method of determining nitrogen on elementary analyser CNS 2000 was tested in chemical laboratory of the Forest Research Institute, Jastrebarsko and the results have been checked by inter-laboratory testing, which confirmed the validity of the method

FOLIAR ANALYSES OF SAMPLES FROM INTENSIVE MONITORING PLOTS AND INTER-LABORATORY TESTING WITHIN THE FRAMEWORK OF ICP FORESTS PROGRAMME

U sklopu Me|unarodnog programa za procjenu i praćenje utjecaja zračnog onečišćenja na šume ( ICP Forests ) u Hrvatskoj se na sedam ploha intenzivnog motrenja (Razina II) s karakterističnih šumskih zajednica provode istraživanja i kemijske analize biljnog materijala. Kako bi se mogla pratiti pouzdanost primijenjenih metoda u laboratorijskim analizama, osiguranja kvalitete rada i nova saznanja na području analitičkih metoda primjenjivih za analizu biljnog materijala Forest Foliar Co-ordinating Centre u Beču organizira svake godine Interlaboratorijska ispitivanja na uzorcima pripremljenim u laboratorijima zemalja koje su uključene u ICP Forests program. Šumarski institut Jastrebarsko 2004. godine pripremio je lišće obične bukve kao referentni uzorak za sve europske laboratorije. Uzorci su analizirani na obavezne elemente: sumpor, dušik, fosfor, kalij, kalcij i magnezij, te neobavezne elemente: cink, mangan, željezo i ugljik. Dobiveni rezultati govore o dobroj kvaliteti laboratorija Šumarskog instituta Jastrebarsko. Takva ispitivanja u skladu su sa zahtjevima internacionalnih standarada, a omogućuju i provjeru nove metode uvedene u laboratorijska ispitivanja. U kemijskom laboratoriju šumarskog instituta Jastrebarsko ispitivana je nova metoda određivanja dušika na elementarnom analizatoru CNS 2000 i rezultati su provjereni u interlaboratorijskim istraživanjima koja su potvrdila opravdanost metode.Within the framework of International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests), research and chemical analyses of plant material has been carried out in Croatia on seven intensive monitoring plots (Level II) with typical forest communities. In order to monitor the reliability of methods of laboratory analyses, as well as to ensure operational quality of analytical methods that can be applied in plant material analysis, Forest Foliar Co–ordinating Centre in Vienna organizes each year Inter-laboratory testing on samples prepared in laboratories of countries taking part in ICP Forests. In 2004, Forest Research Institute, Jastrebarsko prepared leaves of common beech as reference sample for all European laboratories. Samples were tested for the following required elements: sulphur, nitrogen, phosphorous, potassium, calcium and magnesium, and the following optional elements: zinc, manganese, iron and carbon. Obtained results are evidence of high quality of performance of the laboratory of Forest Research Institute in Jastrebarsko. This type of laboratory testing is in line with the requirements of international standards and facilitate testing of new methods introduced into laboratory procedure. New method of determining nitrogen on elementary analyser CNS 2000 was tested in chemical laboratory of the Forest Research Institute, Jastrebarsko and the results have been checked by inter-laboratory testing, which confirmed the validity of the method

The impact of stuttering on the quality of life in adults who stutter

Mucanje je poremećaj tečnosti govora koji predstavlja složeni multidimenzionalni sindrom te može imati negativan utjecaj na kvalitetu života odraslih osoba koje mucaju. Mucanje tako može utjecati na različite sfere života pojedinca, poput školskog, radnog, društvenog i svakodnevnog funkcioniranja osobe koja muca. Cilj ovog istraživanja jest utvrditi kakav utjecaj ima mucanje na cjelokupno društveno, akademsko, poslovno i obiteljsko funkcioniranje odraslih osoba koje mucaju u Hrvatskoj te na koji se način te osobe nose s preprekama uzrokovanim mucanjem u svakodnevnim komunikacijskim situacijama. Isto tako, svrha je rada ujedno i prikazati moguće razlike u odgovorima ispitanika s obzirom na spol i jakost mucanja. Za potrebe ovoga rada vlastoručno je kreiran Upitnik za samoprocjenu kvalitete života odraslih osoba koje mucaju čije su čestice podijeljene prema pojedinim aspektima života koji su u sklopu ovog istraživanja ispitani. U istraživanju je sudjelovalo 40 odraslih osoba koje mucaju u dobi od 18 do 43 godine koje su elektronički ispunjavale navedeni upitnik. Rezultati istraživanja pokazali su kako mucanje ima negativan utjecaj na školske aktivnosti osoba koje mucaju, kao i na sudjelovanje u svakodnevnim komunikacijskim situacijama. Utjecaj mucanja na izbor zanimanja i zaposlenje nije se pokazao razmjerno velikim i negativnim da bi ga se uzelo u obzir. Isto tako, može se reći da mucanje negativno utječe na neke aspekte društvenog funkcioniranja osoba koje mucaju, dok primjerice na ljubavni život ne utječe. Nadalje, na nekim se stavovima dokazala statistički značajna razlika između razmišljanja muškaraca i žena. Pokazalo se da mucanje u određenim aspektima ženama predstavlja veći problem. Skupine s blagim, umjerenim, jakim i ozbiljnim mucanjem statistički su se značajno razlikovale na određenim stavovima. Kod skupina ispitanika s jakim i ozbiljnim mucanjem uočava se razmjerno veći utjecaj mucanja na kvalitetu života. Iako su potrebna daljnja istraživanja ovog područja kako bi se rasvijetlila dubina utjecaja mucanja na kvalitetu života odraslih osoba koje mucaju, podatci ovog istraživanja mogu pomoći logopedima u terapijskom radu s osobama koje mucaju i stvaranju terapijskih planova, a s ciljem poboljšanja njihove kvalitete života.The impact of stuttering on the quality of life in adults who stutter Stuttering is a speech fluency disorder and it represents a complex multidimensional syndrome which can have a rather negative impact on the quality of life in adults who stutter. It can have multiple effects on different aspects of individual’s life: school life, work life, social functioning and participation in everyday communication activities. The aim of this study was to examine the impact stuttering has on social, educational, occupational and family functioning in adults who stutter in Croatia and to determine the way in which those individuals deal with difficulties they meet in everyday communication situations and in daily interactions. Also, the purpose of this research was to examine possible differences in opinions of adults who stutter regarding two variables: gender and stuttering severity. For the purposes of this paper a questionnaire was made whose particles were divided into four different units regarding the aspects of life which were examined in this research. Participants were 40 adults who stutter with age ranging from 18 to 43 years. The questionnaire was fulfilled electronically. The results of this study indicate that stuttering has a rather negative impact on school activities and participation in daily social communication situations in adults who stutter. Their stuttering was not perceived to adversely influence occupational choice and employment possibilities. It can also be said that stuttering negatively influences specific aspects of social relationships and interactions, while it does not adversely affects love life of adults who stutter. Furthermore, the results showed a statistically significant difference in some opinions regarding gender and stuttering severity. Female participants and adults with more severe stuttering felt that stuttering in some ways affected their quality of life more than others. Although further research is needed to brighten up the depths of stuttering’s impact on quality of life in adults who stutter, the findings of this study can help speech and language pathologists in clinical management of stuttering and to create helpful therapy plans to improve the quality of life in adults who stutter

Development of macroporous bioceramic materials based on multi-ion doped calcium-hydroxyapatite coated with chitosan

In recent years, scientists have been working on developing biocompatible materials that closely mimic the structure and properties of natural biological tissues for their application in hard tissue regeneration and controlled drug release. Human bones and teeth primarily consist of calcium-phosphate crystals with small amounts of various ions incorporated into their crystal structure. The aim of this study was to examine the possibility of processing macroporous bioceramic scaffolds based on calcium-hydroxyapatite (HAp) doped with magnesium (Mg), strontium (Sr) and fluorine (F) ions, subsequently coated with polymer chitosan. In this study, the doped HAp powder was synthesized by a hydrothermal process, and scaffolds were made using the sponge replica method, sintered and then coated with the chitosan. The influence of dopant ions and chitosan on the scaffold's microstructure, mechanical properties, bioactivity, cytotoxicity and drug release properties was examined. Energy dispersive spectroscopy confirmed that Mg and Sr are incorporated in all powder samples, while the presence of F was confirmed in samples synthesized with 1 and 2 mol.% F in the precursor solution. The phase composition of powders and scaffolds determined by X-ray analysis showed the presence of HAp and β-tricalcium phosphate phase (β-TCP) in scaffolds. In the compressive strength (CS) test, coated scaffolds showed significantly higher CS compared to uncoated scaffolds. Scanning electron microscopy was used to examine the morphology of nanostructured powders, microstructure, and the bioactivity of the scaffolds. The uncoated scaffolds showed satisfactory bioactivity after being immersed in simulated body fluid for 28 days, while lower bioactivity was observed in the coated scaffolds due to the slow degradation of chitosan. The synthesized scaffolds also demonstrated to have a positive impact on cell viability, even slightly stimulating the cell proliferation. Additionally, scaffolds were shown to successfully release drug. In concusion, the addition of ions and chitosan polymer significantly improved the properties of the obtained scaffolds, which indicates their potential application in tissue engineering and controlled drug release.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Synthesis and characterization of Co2+ doped TiO2 nanoparticles

Scrolled titania nanotubes were synthesized by a hydrothermal method using commercial TiO2 powder in proton-deficient aqueous systems. In presence of CoCl2 extended hydrothermal treatment of TiO2 nanotubes lead to formation Co2+ doped TiO2 nanoparticles. TEM and HRTEM measurement were used for determining the shape, dimension and structure of doped nanoaprticles. XRD confirmed anatase crystalline structure od Co2+ doped TiO2. The presence of Co2+ ions did not induce distortions of the overall anatase crystal structure of TiO2 matrix. The concentration of Co2+ ions was 1.5% compared with the amount of Ti4+ ions.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Ring tests as main parts of the quality assurance and control programme for the comparability of analytical data within the ICP Forests monitoring programme

201

Valorisation of Waste Wood Biomass as Biosorbent for the Removal of Synthetic Dye Methylene Blue from Aqueous Solutions

Background and Purpose: Wood and wood processing industries are generators of a substantial amount of waste wood biomass, such as wood chips, shavings and sawdust. Such waste is often unused and its disposal can be a serious environmental problem. Different lignocellulosic waste materials have been successfully used as low-cost adsorbents (biosorbents) for the removal of synthetic dyes, as well as other contaminants, from wastewater. The aim of this study was to valorise the waste wood biomass of ten tree species, out of which seven are the most represented species of the Croatian growing stock, as biosorbents for the removal of synthetic dye methylene blue (MB) from model solutions. Materials and Methods: The waste wood biomasses (shavings or sawdust) of ten tree species, namely common beech, pedunculate oak, sessile oak, common hornbeam, narrow-leafed ash, poplar, European silver fir, Norway spruce, European larch and Douglas fir, were dried and milled prior to characterisation and adsorption experiments. Characterisation of the biosorbents was performed by chemical analysis and Fourier transform Fourier transform infrared spectroscopy (FTIR). Upon characterisation, batch adsorption experiments were conducted in order to survey waste wood biomass as potential adsorbents for the removal of synthetic dye MB. The colour removal was monitored spectrophotometrically at predetermined time intervals. Further adsorption experiments were performed using poplar sawdust. The effects of contact time, biosorbent concentration, initial dye concentration, and pH on the adsorption process were investigated. The experimental data obtained by batch adsorption experiments were analysed using adsorption isotherm models (Freundlich and Langmuir). Results: All the tested biosorbents were found to be very effective for the removal of MB from model dye solution, achieving high removal percentages ranging from 93.25 to 98.50%. Poplar sawdust proved to be the most effective. It was shown that MB adsorption process onto poplar sawdust could be interpreted in terms of Langmuir and Freundlich adsorption isotherm models. Conclusions: Taken together, these results suggest that waste wood biomass has the potential to be used as a low-cost biosorbent for MB removal from aqueous solutions

Crown volume in forest stands of pedunculate oak and common hornbeam

Background and Purpose: The structure of the crown volume in a forest stand is one of the main factors that drive the growth and development of trees. It changes dynamically with the age of the forest stand and according to the management activities and natural disturbances that remove trees from the stand. The aim of this article is to analyse crown volume structure in relation to the stand age and diameter at breast height (DBH) of pedunculate oak and common hornbeam trees in one of the most important forest types in Croatia. Materials and Methods: Data for the research were collected from a set of 47 permanent sample plots established as a chronosequence over the distribution range of pedunculate oak and common hornbeam forests in Croatia. The combined area of all the plots amounted to 33.45 ha. Trees were measured for DBH, total height and height to crown base, and a detailed map of crown projection areas was made for each plot. In total, the crowns of 1,609 pedunculate oak trees and 1,979 common hornbeam trees were measured. Crown volumeswere calculated for each tree, the trees were pooled into age classes of 20 years, and analyses were carried out per tree species, per age class. A nonlinear regression with an exponential function of crown volume was performed to establish the relationship between the crown volume and DBH in each age class. Results and Discussion: Up to a stand age of 40 years, crowns of pedunculate oak dominate in the canopy layer (66%), after which crowns of common hornbeam trees assume dominance. Coefficients of determination for the regression lines for pedunculate oak crowns are higher than the coefficients for common hornbeam. In all age classes, they are higher than 0.50, except for the first age class for common hornbeam and the seventh age class for pedunculate oak. The shape of the regression lines of pedunculate oak crown volume shift more to the right side of the diameter range as the stand matures, while those of common hornbeam are more static and form a bundle of lines. Conclusions: Results indicate that the relationship between the crown volume of pedunculate oak and common hornbeam trees and DBH can be described by a nonlinear regression model with an exponential function. Further research is needed to assess the possibilities of integrating the obtained regression models into simulators of forest growth and development