93 research outputs found
Affective role of the teacher: the conceptualization and empirical validation of the construct.
Interesovanje istraživača za ulogu emocija u nastavi je novijeg datuma. U klasifikaciji nastavničkih uloga koju su dali Ivić i saradnici (2003) navodi se uloga nastavnika kao partnera u afektivnoj interakciji kao jedna od profesionalnih uloga nastavnika, ova uloga nije elaborirana, te samim tim ne postoje precizno definisana očekivana ponašanja nastavnika koja bi proizilazila iz ove njegove uloge.
Predmet istraživanja je konceptualizacija (definicija i klasifikacija) i empirijska provera konstrukta afektivna uloga nastavnika...Research interest into the role emotions play in the teaching process is rather recent. In the classification of teachers’ roles provided by Ivić et al. (2003) one of the roles is teachers’ role as a partner in affective interaction with pupils. As one of the professional roles of the teacher, this role is not elaborated upon, and thus there are no precisely defined expected forms of teacher behavior which would stem from his role.
The subject matter of this study is the conceptualization (definition and classification) and empirical validation of the construct of the affective role of the teacher..
Multielement determination using inductively coupled plasma optical emission spectrometry for metal characterization of water from artesian wells in Semberija region: Multivariate analysis of data
The concentrations of fifteen metals (Mg, Na, Ca, K, Se, Zn, Mn, Fe, Pb, Cr,
Cu, Cd, Sb, Ni, Co) were determined in water from ten artesian wells (AW) in
Semberija to obtain a general metal profile of water in this region.
Principal components analysis (PCA) was used in this classification. Using
principal component analysis two factors controlling the metal variability
were obtained, which accounted for nearly 71.5% of the total variance.
Natural (lithogenic) factor is represented by PC1, while anthropogenic factor
is represented by PC2. PC1 with high contribution of Mn, Mg, Na, K, Ca, Zn
and Se accounting for 41.84% of the total variance, while PC2 exhibits high
loading for Cd, Ni, Sb, Cr and Pb (29.66%). Three general areas (clusters)
with different metal characteristics were detected. Water from artesian wells
in first cluster (AW1, AW2, AW3, AW4, AW5 and AW6) had much higher metal
concentration compared with those in the second (AW7, AW8 and AW9) and third
cluster (AW10). That is as a result of anthropogenic inputs. Also, the
analysis of water demonstrated slightly elevated values for Mn
(concentrations up to 0.176 mg/L), while concentrations of the other
investigated elements are below the values recommended by the World Health
Organization (WHO) and the United States Environmental Protection Agency (US
EPA). [Projekat Ministarstva nauke Republike Srbije, br. 172047
On some new pre-orders defined by weighted Drazin inverses
In this paper, we investigate new binary relations defined on the set of rectangular complex matrices based on the weighted Drazin inverse and give some characterizations of them. These relations become pre-orders and improve the results found by the authors in Hernandez et al. (2013) as well as extend those known for square matrices. On the other hand, some new weighted partial orders are also defined and characterized. The advantages of these new relations compared to the ones considered in the mentioned paper are also pointed out.N. Thome was partially supported by Ministerio de Economia y Competitividad of Spain (Grant DGI MTM2013-43678-P and Red de Excelencia MTM2015-68805-REDT).Hernández, AE.; Lattanzi, MB.; Thome Coppo, NJ. (2016). On some new pre-orders defined by weighted Drazin inverses. Applied Mathematics and Computation. 282:108-116. https://doi.org/10.1016/j.amc.2016.01.055S10811628
Characterizing the diffuse continuum excitations in the classical spin liquid -YMnO
We extend previous inelastic neutron scattering results on the geometrically
frustrated antiferromagnet hexagonal-YMnO, which has been suggested to
belong to the class of classical spin liquids. We extend the energy transfer
coverage of the diffuse signal up to 6.9 meV within a wide temperature range
around the ordering temperature, . The two distinct diffuse
signals in the a-b plane, the signal localized at ' and the scattering
intensity connecting ' points over the M', are shown to be only weakly
energy dependent. In addition, an external magnetic field of up to 10.5 T
applied along c is shown to have no effect on the diffuse signal. In the
orthogonal scattering plane, the signals are shown to be dependent on l only
through the magnetic form factor, showing that the correlations are purely
two-dimensional, and supporting its origin to be the frustrated Mn
triangles. This result is corroborated by atomistic spin dynamics simulations
showing similar scattering vector and temperature behaviours. Lastly, data for
the spin wave scattering in the (h, 0, l) plane allow for a discussion of the
magnetic ground state where better agreement is found between the data and an
ordered structure of the or symmetry, albeit crystal
electric field arguments dismisses the as possibility
EFFECT OF STORAGE TEMPERATURE AND THERMAL PROCESSING ON CATECHINS, PROCYANIDINS AND TOTAL FLAVONOIDS STABILITY IN COMMERCIALLY AVAILABLE COCOA POWDERS
Storage stability of catechin, epicatechin, procyanidins B1-B4 and total flavonoids in cocoa powder samples was studied over the temperature range 4-35 ºC. Thermal stability of total flavonoids was studied over the temperature range 95-125 ºC. Total flavonoids concentration decreased as a function of time and the degradation was accelerated at higher temperatures: a half-life (t1/2) of total flavonoids was much shorter at room temperature than during cold storage. A first-order kinetic model fitted well to all the data. Temperature dependence of the degradation rate constants, described by the Arrhenius equation, was more pronounced during heating than during storage. In the temperature interval from 4 ºC to 35 ºC, the calculated activation energies (Ea) for catechin, epicatechin and procyanidins B1-B4 were 20.4 kJ/mol, 12.5 kJ/mol, 9.4 kJ/mol, 21.6 kJ/mol, 19.4 kJ/mol, 23.7 kJ/mol, respectively. UTICAJ TEMPERTURE ČUVANJA I ZAGREVANJA NA SADRŽAJ KATEHINA; PROCIJANIDINA I UKUPNIH FENOLA KOMERCIJALNIM UZORCIMA KAKAOA U PRAHUUticaj temperature čuvanja na stabilnost katehina, epikatehina, procijanidina B1-B4 i ukupnih flavonoida u uzorcima kakaoa u prahu praćen je u temperaturnom opsegu od 4 ºC do 35 ºC. Uticaj zagrevanja na sadržaj ukupnih flavonoida je praćen u temperaturnom opsegu od 95 ºC do 125 ºC. U toku skladištenja uzoraka je došlo do smanjenja u sadržaju ukupnih flavonoida. Pomenuta promena je bila izraženija na višim temperaturama: vreme polu-života (t1/2) ukupnih flavonoida u ispitivanom uzorku kakaoa u prahu bilo je kraće kada je on čuvan na sobnoj temperaturi nego kada je čuvan u frižideru. Promene u sadržaju flavonoida u ispitivanim uzorcima prate kinetiku prvog reda. Konstante brzine degradacije, izračunate pomoću Arenijusove jednačine, veće su tokom zagrevanja nego tokom čuvanja ispitivanih uzoraka na nižim temperaturama. Izračunate energije aktivacije (Ea) za katehin, epikatehin i procijanidine B1, B2, B3 i B4 u temperaturnom intevalu od 4 ºC do 35 ºC bile su: 20,4 kJ/mol, 12,5 kJ/mol, 9,4 kJ/mol, 21,6 kJ/mol, 19,4 kJ/mol i 23,7 kJ/mol. HIGHLIGHTS Storage stability of (epi)catechin, procyanidins B1-B4 and total flavonoids in cocoa powder samples was studied(temperature range 4-35 °C)The stability of the total flavonoids was studied over the temperature range 95-125 °CThe degradation of the total flavonoids was significantly accelerated at higher temperaturesTemperature dependence of the degradation rate constants was more pronounced during heating than during storag
Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options
Producción CientíficaPine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg
and O’ Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen to Southern Europe and its spread in Mediterranean region is alarming considering the immense
ecological and economic importance of pines in the region. Pines in forests and nurseries can be
infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants
for planting and in seeds, and results from recent studies have indicated that F. circinatum may also
spread through phoretic associations with certain insects. With this review, we aim to expand the
current understanding of the risk of insect-mediated spread of PPC in different parts of Europe.
Through the joint action of a multinational researcher team, we collate the existing information about
the insect species spectrum in different biogeographic conditions and scrutinize the potential of
these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of
environmental factors and forest management in this context. We present evidence for the existence of
a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including
several common beetle species. In many parts of Europe, temperatures are projected to rise, which
may promote the activity of several insect species, supporting multivoltinism and thus, further
amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM)
solutions that comply with forest management practices need to be developed to reduce this risk.
We recommend careful monitoring of insect populations as the basis for successful IPM. Improved
understanding of environmental control of the interaction between insects, the pathogen, and host
trees is needed in order to support development of bio-rational strategies to safeguard European pine
trees and forests against F. circinatum in future.European Cooperation in Science and Technology (COST Action FP1406 PINESTRENGTH)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Portuguese Foundation for Science and Technology (contract IF/00471/2013/CP1203/CT0001)Russian Foundation for Basic Research (grant 17-04-01486)Saint Petersburg State Polytechnical University (project 2019-0420
A guided tour of asynchronous cellular automata
Research on asynchronous cellular automata has received a great amount of
attention these last years and has turned to a thriving field. We survey the
recent research that has been carried out on this topic and present a wide
state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat
Electronic structure of silver-bismuth iodide rudorffite nanomaterials studied by synchrotron radiation soft X-ray photoemission spectroscopy
Silver-bismuth iodide (Ag-Bi-I) rudorffites are chemically stable and non-toxic materials that can act as a possible replacement for methylammonium lead halide perovskites in optoelectronic devices. In this report we will present innovative routes for fabrication of AgBi-I nanomaterials, as well as the results of the investigation of the electronic structure of isolated Ag-Bi-I nanoparticles by soft X-ray aerosol photoemission spectroscopy [1, 2]. Aerosol photoemission spectroscopy allows studies of the electronic structure of submicrometer particles that are free from the influence of a substrate or solvent [1-5]. In this approach the aerosol particles can be produced directly from a solution or a colloidal dispersion, which opens a possibility for investigation of a variety of nanosystems that can be produced by wet chemistry methods. This technique relies on the interaction of focused beam of isolated particles with ionizing radiation under high vacuum conditions. In addition, by using tunable synchrotron radiation as an excitation source it is possible to obtain highresolution photoelectron spectra in the investigated photoelectron energy range.X Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 26-27, 2022; Belgrad
The star partial order and the eigenprojection at 0 on EP matrices
[EN] The space of n x n complex matrices with the star partial order is considered in the first part of this paper. The class of EP matrices is analyzed and several properties related to this order are given. In addition, some information about predecessors and successors of a given EP matrix is obtained. The second part is dedicated to the study of some properties that relate the eigenprojection at 0 with the star and sharp partial orders. 2012 Elsevier Inc. All rights reserved.This paper was partially supported by Ministry of Education of Argentina (PPUA, Grant Resol. 228, SPU, 14-15-222) and by Universidad Nacional de La Pampa, Facultad de Ingenieria (Grant Resol. No 049/11).Hernández, AE.; Lattanzi, MB.; Thome, N.; Urquiza, F. (2012). The star partial order and the eigenprojection at 0 on EP matrices. Applied Mathematics and Computation. 218(21):10669-10678. https://doi.org/10.1016/J.AMC.2012.04.034S10669106782182
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