223 research outputs found
Supportive methods for assessing effective porosity and regulating karst aquifers
Regulation of a karst aquifer implies engineering interventions designed to control its flow and manage its water reserves. One of the most important prerequisites for the feasibility and sucĀcess of regulation projects is proper assessment of aquifer efĀfective porosity (storativity) and accumulated groundwater reserves. This paper is focused on several specific methods whichcan contribute to a reliable assessment of the size and volume of effective storage in karst: cave diving survey, camera logging of cavities, stochastic analysis of discharge regime and 3D modelling of karst interior. The application of these methĀods on selected test sites in Montenegro, Algeria and Serbia are described. These methods were applied as part of the researchprogramme conducted in the catchment of Mlava Spring, the largest spring in the Carpathian karst of Serbia. The results obĀtained by the stochastic analyses of the springās discharge reĀgime, as well as siphon diving of the spring and 3D modelling for reconstruction of conduits networks in karst interior are particularly important
Beogradski inventar za procenu liÄnosti adolescenata kao most izmeÄu procene liÄnosti dece i odraslih
Personality inventories for assessment and study temperament and character of adolescents, an age critical for the finalisation of both normal and pathological mental development, have not been specifically developed. In this paper, we introduce a new personality inventory based on Cloninger's Psychobiological model of personality to assess adolescents from 14 to 18 years of age (the Belgrade Adolescent Personality Inventory - BAPI), which bridges the gap between personality assessment in children and adults. The BAPI is a 46-item Likert scale inventory derived from previous studies using the TCI and JTCI on the Serbian sample. The psychometric properties of the BAPI were tested on the sample of 535 secondary school students in Serbia, aged 15 to 16. In order to assess the fit of the model, the Confirmatory factor analysis (CFA) was performed. The differences between sexes were analysed by MANOVA, while the Latent class analysis (LCA) was applied in order to identify different adaptation profiles among adolescents. The BAPI scales had a satisfactory internal consistency (.66 - .80.) considering the small number of items (5-6) in each scale. The confirmatory factor analysis (CFA) generally supported the main dimensions of temperament and character, as postulated by Cloninger. The only exception was Novelty Seeking, which best fitted a two-factor solution, Explorative curiosity and Impulsivity, separating the 'good' (curious, inquisitive, creative) and 'bad' (impulsive, impatient, disorderly) facets of this trait. Such polarity of Novelty Seeking could be specific for personality development and behaviour disorders in adolescence. The LCA differentiated the personality profiles of well-adapted adolescents from those at risk for maladaptation that manifested low character traits, lack of Persistence and high Novelty seeking Impulsivity subscale. The results support the construct validity of the BAPI and thus provide the basis for its practical application in personality assessment of adolescents and contribute to the theoretical understanding of personality structure and the risk of psychopathology in adolescence.S obzirom da postoji nedostatak namenski konstruisanih inventara za procenu i prouÄavanje liÄnosti adolescenata koji su u uzrastu kljuÄnom za zavrÅ”etak kako normalnog, tako i patoloÅ”kog mentalnog razvoja, u radu je predstavljen novi inventar liÄnosti zasnovan na Klonindžerovom PsihobioloÅ”kom modelu liÄnosti. Beogradski Inventar LiÄnosti Adolescenata (BILA) koristi se za procenu adolescenata uzrasta od 14 do 18 godina i trebalo bi da premosti jaz izmeÄu procene liÄnosti kod dece i odraslih. Upitnik obuhvata 46 stavki Likertovog tipa i nastao je na osnovu prethodnih istraživanja u kojima su koriÅ”Äeni TCI i JTCI na uzorku naÅ”ih ispitanika. Psihometrijske karakteristike upitnika ispitane su na uzorku od 535 srednjoÅ”kolaca iz Srbije, starosti od 15 do 16 godina. Kako bi se utvrdila adekvatnost modela, uraÄena je konfirmatorna faktorska analiza. U cilju analize polnih razlika koriÅ”Äena je MANOVA, dok je analiza latentnih klasa primenjena kako bi se utvrdilo da li se mogu izdvojiti specifiÄni profil liÄnosti adolescenata iz uzorka iz opÅ”te populacije. Skale upitnika pokazale su zadovoljavajuÄu internu konzistenciju (.66 - .80), posebno imajuÄi u vidu mali broj stavki (5-6) u svakoj skali. Konfirmatorna faktorska analiza je naÄelno potvrdila glavne dimenzije temperamenta i karaktera onako kako ih je definisao Klonindžer. Jedini izuzetak je bio u sluÄaju Potrage za novinama, za koju je podesnije dvofaktorsko reÅ”enje. Potragu za novinama Äine Eksplorativna radoznalost i Impulsivnost koie razlikuju 'dobre' (znatiželjan, radoznao, kreativan) i 'loÅ”e' (impulsivan, nestrpljiv, haotiÄan) odlike ove dimenzije. Ovaj polaritet Potrage za novinama mogao bi da bude specifiÄan za razvoj liÄnosti i poremeÄaja u ponaÅ”anju tokom adolescencije. Analizom latentnih klasa utvrÄene su razlike izmeÄu profila liÄnosti dobro adaptiranih adolescenata i onih kod kojih postoji rizik za razvoj problema u ponaÅ”anju, a koji imaju nizak skor na crtama karaktera, niži stepen Perzistencije i poviÅ”enu Impulsivnost. Dobijeni rezultati potvrÄuju konstrukt validnost BILA upitnika i Å”to omoguÄava njegovu praktiÄnu primenu u proceni liÄnosti adolescenata, pružajuÄi doprinos teorijskom razumevanju strukture liÄnosti i rizika od psihopatologije u adolescenciji
Razlike u temperamentu i karakteru kod adolescenata sa raznim poremeÄajima ponaÅ”anja
Background/Aim. Adolescence is characterized both by a large developmental potential and by an increased risk for emergence of different forms of psychopathology. International classifications of mental disorders recognize the psychopathology of adolescence at the age of 15-18 through the categories of conduct disorders and some forms of addiction: chemical and non-chemical. The aim of this research was to analyse the personality structure among four groups of adolescents manifesting different types of conduct disorder based on Cloninger's Psychobiological theory of personality. Methods. The research sample consisted of 140 respondents at the age of 16-18, divided into five groups: 30 respondents manifesting socialized conduct disorder, 20 adolescents in conflict with the law, 30 respondents manifesting abuse of psychoactive substances, 30 respondents with the problem of the Internet addiction and 30 from general population. The Belgrade Adolescent Personality Inventory (BAPI) questionnaire was used for the purpose of assessment of personality. Multivariate analysis of variance (MANOVA), followed by univariate analysis of variance (ANOVA) was used to examine differences between the given groups of adolescents. Results. The results of MANOVA show differences in the personality structure among the groups, both in the dimensions of temperament, F (20,418.84) = 2.71, p lt 0.001, Wilks's lambda 0.67, and in the dimensions of character, F (12,344.24) = 3.27,p lt 0.001, Wilks's lambda is 0.75. Socialized conduct disorder is characterized by low self-directedness and average cooperativeness. Adolescents in conflict with the law have the lowest persistence, together with low self-directedness and cooperativeness. Adolescents abusing psychoactive substances have low harm avoidance and self-transcendence. Adolescents with Internet addiction are characterized by high novelty seeking (impulsivity and curiosity), low self-directedness and the lowest cooperativeness. Conclusion. The results show that the dimensions of personality can play an important role in etiopathogenesis of various disorders in adolescents.Uvod/Cilj. Adolescenciju karakteriÅ”e veliki razvojni potencijal, ali i pojaÄani rizik od formiranja razliÄitih vidova psihopatologije. Psihopatologiju adolescencije uzrasta od 15 do 18 godina, meÄunarodne klasifikacije mentalnih poremeÄaja prepoznaju kroz kategorije poremeÄaja ponaÅ”anja i neke vidove bolesti zavisnosti: hemijskih i nehemijskih. Cilj istraživanja bio je da se na osnovu Klonindžerove psihobioloÅ”ke teorije liÄnosti analizira struktura liÄnosti kod Äetiri grupe adolescenata koji manifestuju razliÄite oblike poremeÄaja ponaÅ”anja. Metode. Uzorak istraživanja sastojao se od 140 ispitanika uzrasta od 16 do 18 godina, podeljenih u pet grupa: 30 ispitanika koji su manifestovali socijalizovani poremeÄaj ponaÅ”anja, 20 adolescenata sa poremeÄajem ponaÅ”anja u sukobu sa zakonom, 30 ispitanika sa problemom zloupotrebe psihoaktivnih supstanci, 30 ispitanika sa problemom zavisnosti od interneta i 30 ispitanika kontrolne grupe. Za procenu strukture liÄnosti koriÅ”Äen je upitnik Belgrade Adolescent Personality Inventory (BAPI). Razlike izmeÄu grupa adolescenata ispitane su multivarijatnom (MANOVA) i univarijatnom (ANOVA) analizom varijanse. Rezultati. Rezultati multivarijatne analize varijanse pokazuju da postoje razlike u strukturi liÄnosti izmeÄu svih grupa, kako na dimenzijama temperamenta, F(20,418.84) = 2.71,p lt 0.001, Vilksova lambda 0,67, tako i na dimenzijama karaktera, F (12,344.24) = 3,27, p lt 0,001, Vilksova lambda 0,75. Socijalizovani poremeÄaj ponaÅ”anja karakteriÅ”e niska samousmerenost, Ali proseÄna kooperativnost. Adolescenti u sukobu sa zakonom imaju najnižu perzistenciju, kao i nisku samousmerenost i kooperativnost. Adolescenti koji zloupotrebljavaju psihoaktivne supstance imaju nisko izbegavanje Å”tete i autotranscedenciju. Za adolescente sa internet zavisnoÅ”Äu karakteristiÄna je visoka potraga za novinama (impulsivnost i radoznalost), niska samousmerenost i najniža kooperativnost. ZakljuÄak. Rezultati ukazuju da dimenzije liÄnosti mogu igrati znaÄajnu ulogu u etiopatogenezi razliÄitih poremeÄaja adolescenata
History of chemistry in the pre-service chemistry teachers education
History of chemistry could be an important part of the curriculum for pre-service
chemistry teachersā education. This allows them the deeper understanding of nature
of science and scientific work, as well as to build a base for future planning the
contextual approaches through which their school students could learn about nature
of science. History of Chemistry is taught in the fourth year within the integrated
academic studies curriculum (300 ECTS) for chemistry teachersā education at the
Faculty of Chemistry University of Belgrade.
During the last three school years at the very beginning of the course of History of
Chemistry the estimation of the knowledge of some historical facts, such as the
scientific contribution of Robert Boyle, Henry Cavendish, Joseph Priestley, Antoine
Lavoisier, John Dalton, Jƶns Jacob Berzelius, Alessandro Volta, Michael Faraday was
conducted. These scientists were chosen according to the previous analysis of the
syllabuses of different secondary school and university chemistry and physics
subjects. In this way, we were able to examine whether students pay attention to the
work of scientists when they study various subjects from chemistry and physics
domain. In addition, we asked the students whether they read texts from the history
of science, what was the most important scientific discovery from their point of view,
who was the most significant scientist in their opinion, whether they had a role model
among scientists. Also, we asked students to describe an experiment that they knew
from the history of science.
The obtained results showed that students, future chemistry teachers, have
developed certain attitudes about chemistry as a science, but they possess little
knowledge about the scientific work of scientists. These findings are later useful for
the lessons and workshops planning within the course of history of chemistry
Crane operators' anthropomeasures factors identification
Cilj ovog rada je primena metode zasnovane na viÅ”evarijantnoj statistiÄkoj tehnici u cilju odreÄivanja kritiÄnih dimenzija kabine krana, sa maksimalnom ergonomskom prilagoÄenoÅ”Äu radi smeÅ”taja Å”to Å”ireg opsega populacije i veÄe bezbednosti rada. KoriÅ”Äena je viÅ”evarijantna tehnika - faktorska analiza. Rezultati ovog istraživanja sprovedenog na uzorku 83 operatora pokazuju da se faktorskom analizom veÄi broj faktora rasporeÄuje u trodimenzionalnom prostoru. Rezultati ovog rada omoguÄavaju projektantima reÅ”avanje dilema, a zahvaljujuÄi rezultatima ovog rada mogu se projektovati kabine krana sa manje stresnim položajem operatera i poveÄanom produktivnosti i bezbednosti.Purpose of this paper is application of method based on multivariate statistical technique in order to determine critical dimensions of the crane cabin, which would maximize adjustability and ergonomics of the product, resulting in accommodation of wider range of the population and greater safety while operating. Multivariate statistical technique used for this purpose is factor analysis. Results of this research, conducted on a sample consisted of 83 crane cabin operators, showed that while designing a working space critical anthropomeasures take three-dimensional space, while their influence contributions in each dimension are determined with factor analysis. Results of this work are expected to be useful for industry in a way such that crane cabins' designers can troubleshoot the dilemmas they encounter in their job. Using findings of this survey might lead to new designs of cabins that will offer less strenuous postures of operator, which consequently will improve productivity and safety
The programme for professional development of chemistry teachersā assessment competency
The aim of this paper is to investigate the effects of the programme for professional development of chemistry teachers on their competencies for conducting formative and summative assessment in chemistry teaching. The programme participants were 30 chemistry teachers from primary and secondary schools. Data were collected using a questionnaire at the beginning and at the end of the programme implementation. The programme included four workshops with the same structure: the introduction, group work and the discussion of the results obtained through group work. The workshops focused on: i) the assessment as a support for chemistry learning; ii) the harmonization of teaching and learning activities, formative and summative assessment, feedback from formative assessment and the criteria used to evaluate students in summative assessment; iii) the evaluation of the validity of tasks used for formative and summative assessment according to the curricula aims and the educational standards; iv) designing tasks for monitoring studentsā progress towards certain educational standards. Teachersā responses show the impact of the programme for the development of their competencies for assessment, particularly regarding formative and summative assessment and designing various kinds of assessment in accordance with the achievement standards
Crane operators' anthropomeasures factors identification
Cilj ovog rada je primena metode zasnovane na viÅ”evarijantnoj statistiÄkoj tehnici u cilju odreÄivanja kritiÄnih dimenzija kabine krana, sa maksimalnom ergonomskom prilagoÄenoÅ”Äu radi smeÅ”taja Å”to Å”ireg opsega populacije i veÄe bezbednosti rada. KoriÅ”Äena je viÅ”evarijantna tehnika - faktorska analiza. Rezultati ovog istraživanja sprovedenog na uzorku 83 operatora pokazuju da se faktorskom analizom veÄi broj faktora rasporeÄuje u trodimenzionalnom prostoru. Rezultati ovog rada omoguÄavaju projektantima reÅ”avanje dilema, a zahvaljujuÄi rezultatima ovog rada mogu se projektovati kabine krana sa manje stresnim položajem operatera i poveÄanom produktivnosti i bezbednosti.Purpose of this paper is application of method based on multivariate statistical technique in order to determine critical dimensions of the crane cabin, which would maximize adjustability and ergonomics of the product, resulting in accommodation of wider range of the population and greater safety while operating. Multivariate statistical technique used for this purpose is factor analysis. Results of this research, conducted on a sample consisted of 83 crane cabin operators, showed that while designing a working space critical anthropomeasures take three-dimensional space, while their influence contributions in each dimension are determined with factor analysis. Results of this work are expected to be useful for industry in a way such that crane cabins' designers can troubleshoot the dilemmas they encounter in their job. Using findings of this survey might lead to new designs of cabins that will offer less strenuous postures of operator, which consequently will improve productivity and safety
Mineralogical characteristics of slag (from the Flotation plant of RTB Bor) granulated in the laboratory conditions
A sample of slag from the Flotation Bor, RTB Bor, was mineralogical tested after granulation in the laboratory conditions. Minerals contained in the sample of granulated slag are: fayalite and ferrite that form the basis with rarely sprayed fine particles of magnetite, pyrite, chalcopyrite, bornite, copper matte and elemental - native copper [6, 7]. Granulation of slag was conducted in the laboratory conditions on the device specially designed for this purpose
History of chemistry in chemistry education ā chemistry teachers attitudes
Ideja o ukljuÄivanju istorije i filozofije nauke u kurikulume prirodnih nauka promoviÅ”e se
decenijama. Primena istorije i filozofije nauke u nastavi/uÄenju pririodnih nauka
okarakterisana je kao dobar naÄin za poboljÅ”anje nauÄne pismenosti uÄenika. Neke od
prepreka za takav pristup u nastavnoj praksi su: perspektive nastavnika, njihova uverenja,
razumevanje glavnih ideja i ciljeva nastave/uÄenja, kao i epistemoloÅ”ka shvatanja.1 U
istraživanju, u kome je uÄestvovalo 272 nastavnika hemije osnovnih Å”kola u Srbiji, putem
upitnika ispitani su: stavovi nastavnika o sadržajima iz istorije hemije i efektima primene tih
sadržaja u nastavi na uÄeniÄko razumevanje hemije, naÄini kako nastavnici prezentuju nauku
uÄenicima, uÄestalost primenjivanja metoda nastave/uÄenja i aktivnosti koje podstiÄu razvoj
nauÄnog rezonovanja kod uÄenika. Ispitano je i da li su nastavnici tokom inicijalnog
obrazovanja uÄili sadržaje iz istorije i filozofije nauke i da li imaju uzore meÄu nauÄnicima.
Na osnovu dobijenih rezultata može se zakljuÄiti da nastavnici uviÄaju potencijal sadržaja iz
istorije hemije za bolje razumevanje hemije, ali da takve sadržaje u praksi nedovoljno
primenjuju. Rezultati istraživanja ukazuju i na nedostatak kurseva iz istorije i filozofije
nauke u toku inicijalnog obrazovanja nastavnika.The idea of involving the history and philosophy of science in the science curricula has been
promoting for decades. The involving of the history and philosophy of science in the science
classes is characterized as a good way to improve scientific literacy of students. Some of
obstacles for this approach in teaching practice are: the perspectives of teachers, their
beliefs, understanding of the main ideas and goals of teaching/learning and epistemological
understanding.1
In the research with 272 chemistry teachers from primary schools in Serbia,
questionnaire was used to examine: the attitudes of teachers about the contents of the
history of chemistry and about the effects of application these contents in teaching practice
on studentās understanding of chemistry, the ways in which teachers present science to
students, the frequency of application teaching/learning methods and activities that
encourage the development of scientific reasoning of students. Also, we examined whether
the teachers learned the contents of the history of chemistry and philosophy of science
during their initial education and their personal preferences about scientists. Based on the
results it can be concluded that teachers recognize the potential of the history of chemistry
content for better studentās understanding of chemistry. However, they donāt apply these
contents in practice enough. The results indicate the lack of courses in the history and
philosophy of science during initial education of chemistry teacher
History of Chemistry as a Part of Assessment of Students' Understanding of the Law of Conservation of Mass
The aim of this research was to explore students' ideas about chemical reactions and difficulties in understanding the law of conservation of mass in such reactions by using an approach that started from presentations of scientists' work associated with the law. The developed test items relied on: 1) the historical contents that illustrate the experimental work of three scientists (Lavoisier, Landolt and Lomonosov); 2) the description of school experiments and 3) real life situation. In this way, students would have an opportunity to show understanding of the law of conservation of mass in two contexts, one based on the stories from the history of chemistry and the other contemporary, based on school laboratory experiments and real life situation. Students of different ages were selected for the research: the seventh and the eighth grade of primary school (age 13-14), and the second year of grammar school (age 16). The research involved a total of 301 students. The results indicated that students' difficulties were mostly associated with the predictions and explanations of mass changes in open reaction systems in which a gas was a reactant than with the reactions in which a gas was a product
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