The aim of the present study was to evaluate the effect of one of the most important foliar diseases, powdery mildew, on the leaf physiological traits of Quercus robur L. using chlorophyll a fluorescence parameters in combination with parameters of leaf gas exchange. For this purpose, greenhouse semi-controlled experiment was conducted with 25 one-year-old seedlings kept in optimal conditions, and the same number of seedlings infected with the mentioned pathogen. Measurements were carried out when the coverage of epiphytic micelia visually reached more than 75% of the surface of leaves in the infected seedlings. The results of gas exchange measurement showed that Erysiphe alphitoides (Griffon and Maubl.) U. Braun and S. Takam caused a significant reduction of net photosynthesis (A) and a significant increase in substomatal CO2 concentration (Ci). Furthermore, considering the fast kinetics of chlorophyll a fluorescence, all of the observes parameters were significantly affected by oak powdery mildew. On the other hand, pulse amplitude modulated fluorescence parameters were mildly affected, with only minimal (Fo?) and maximal (Fm?) fluorescence of dark adopted leaves showing significant difference. This study presented the possibility of usage and the effectiveness of chlorophyll a fluorescence parameters in detection the severe stress conditions, on the example of leaves infected with oak powdery mildew over 75%. Some additional studies should be conducted in the future to determine the possibility of usage and the effectiveness of the observed fluorescence parameters of fast kinetics in detection of mild and early stress.
This paper describes the analysis of steel reel shaft as drive shaft in a process of umbilical spooling of wire rope. There is a need to investigate shaft behaviour in the conditions of increasing workload. The aim is to investigate avoiding possible redesign or enabling redesign with minimal costs. Stress analysis has been carried out by using finite element analysis (FEA) and results are compared with the analytically calculated values. Finite element analysis has been carried out using maximum stress criteria and the area of potential failure is found. The main objective of this paper is to find balance in results between "design by rule" and "design by analysis". Design by rule provides rules on how to design a steel reel shaft using analytical equations and other strict rules from design elements. Design by analysis provides rules on using numerical analysis, typically finite element analysis to design a steel reel shaft. The steel reel shaft has been geometrically modelled using SolidWorks. To check all stresses, linear static analysis is done using DSS Simulation and Ansys.
O plakatu kao sredstvu komunikacije Vrijeme u kojem živimo potpuno je usaglaseno sa novim medijima vizuelnih komunikacija u koje se nedvosmisleno ubraja i plakat, sa svojom apsolutno prijemcivom i likovno pretpostavljenom formom, koja prati, osluskuje, provocira, uzbuđuje, obavjestava i uvodi u kompleksan svijet likovnosti i dizajna. Brojni teoreticari, istoricari i umjetnici raznih profila su se bavili njegovom pojavom i analizom, te predlaganjem raznih mogucnosti definisanja samog pojma plakata i plakatske umjetnosti, pa najcesce nailazimo na informacije o plakatu kao umoženoj obavijesti koja se postavlja na javnim mjestima (moguce od rijeci plak -mrljica ili krpica)? U engleskom jeziku se koristi termin poster (prihvaceno i u nasem jeziku kao doslovni prevod), ili posted up (objavljeno, u smislu postavljanja na javno mjesto). U francuskom jeziku se koristi the World Biennial of Student Poster -A Case Study Abstract: The paper World Biennial of Student Poster -A Case Study aims to show the complex structure of the poster as an art form in a historico-analytical and content-wise manner. Viewing the poster in the light of the progressive technological and innovative possibilities of modern information technologies, constantly requires challenging of the scopes and justification of the existence of a "classic" poster. Its role in contemporary society has been analyzed through various forms of manifestation in the spheres of art and modern design. Insufficiently paid attention to the essence of artistic expression through the poster, which has historically been marginalized in relation to classical painting, has positively changed over time, and through the apostrofing of the strength and the range the poster reaches, it has pointed to the significant changes in the society that this type of communication has achieved. In this paper, a prominent event of the Academy of Arts in Novi Sad, the World Biennial of Student Poster, was selected for the case study, and through the analysis of eight exhibitions of the Biennial, its role since 2004 has been evaluated with an obvious improvement in pedagogical and creative work on the poster.
Nanocomposites (HAp/iron oxide), made of hydroxyapatite (HAp) and ferrimagnetic iron oxide, were synthesized by high-energy ball milling a mixture consisting of iron oxide nanoparticles and the starting materials used for the HAp synthesis: calcium hydrogen phosphate anhydrous (CaHPO4), and calcium hydroxide (Ca(OH)2). Two HAp/iron oxide samples with the magnetic phase content of 12 and 30 wt.% were prepared and their microstructure, morphology and magnetic properties were analysed by X-ray diffraction and transmission electron microscopy. Furthermore, the measurement of particle size distribution was performed by laser scattering, and temperature/field dependence on magnetization was determined. X-ray diffraction data confirmed the formation of two-phased samples (HAp and spinel iron oxide) without the presence of any other parasite phase. The shape of particles was nearly spherical in both samples, ranging from only a few to several tens of nanometres in diameter. These particles formed agglomerates with the most common value of the number-based particle size distribution of 380 and 310 nm for the sample with 12 and 30wt.% of iron oxide, respectively. Magnetization data showed that both HAp/iron oxide composites had superparamagnetic behaviour at room temperature.
Paper monitors seasonal dynamics of heavy metals bioaccumulation (Fe, Mn, Cu, Zn and Pb) of emerged plant Phragmites australis (Cav.) Trin. ex Steud. on two localities (Necik and Sinjak) in the area of Bardača fishpond (BiH-Republic of Srpska). Dynamics of heavy metals bioaccumulation varied depending on sampling period, locality and plant organ. Concentration, transfer (transport) and accumulation of metals from sediment to rhizome above ground plant part was evaluated based on biological concentration factor (BCF), translocation ability (TA) and bioaccumulation factor (BAC). The highest average BCF value in researched species was determined for Fe (0.87) and the lowest for Zn (0.18). Bioaccumulation coefficient was the highest for Mn (0.82) and the lowest for Fe (0.20) whereas TA was the highest for Zn (2.28) and Mn (2.70). For Fe, it was significantly lower (0.24). Based on values for BCF, TA and BAC, Phragmites australis (Cav.) Trin. ex Steud. could be identified as accumulator for Mn and indicator for metals Fe, Zn and Cu and it has good potential for application in phytoremediation techniques, especially in phytostabilization and phytoextraction of polluted land. Considering the fact that higher degree of bioaccumulation was recorded in the period at the end of season, we could take this period as a signal for their removal from water ecosystems.
The objective of the study was to explore the barriers or the reasons behind the insufficient use of Web 2.0 technology in companies. The empirical research was conducted among managers in companies in Bosnia and Herzegovina during 2015. The results indicate that managers see information technology infrastructure (department size, technology implementation costs) and computer illiteracy as the main barriers to intensified use of Web 2.0 technology in business. The least relevant obstacles are related to the lack of support from, and the inability to protect the data privacy and integrity in an adequate manner. The results indicate that significant efforts to promote the benefits that Web 2.0 technology brings to the business are needed, which would, in turn, significantly affect the perception of their disadvantages.
Over the last few decades, researchers put efforts to improve intelligent tutoring systems' abilities with the aim to get them as close as possible to the ultimate goal of one-to-one tutoring. CoLaB Tutor and AC-ware Tutor are intelligent tutoring systems based on conceptual knowledge learning and are notable due to the fact they are relatively easy to generalize to multiple knowledge domains. CoLaB Tutor's forte lies in teacher-learner communication in controlled natural language, while AC-ware Tutor focuses on the automatic and dynamic generation of adaptive courseware. In order to compare various intelligent tutoring system supported education environments, in this chapter, the authors summarize several empirical evaluations of CoLaB Tutor and AC-ware Tutor. The results of intelligent tutoring systems' effectiveness in these environments offer the possibility to observe the specific intelligent tutoring system across various education levels, as well as to compare the intelligent tutoring systems' supported education environments.
Mastitis is one of the most important diseases in dairy cow farms and one of the most common cause for antibiotic treatment. Aims of this study were: to investigate frequency and trends of clinical mastitis in cows on a large dairy farm, describe clinical characteristics of mastitis and investigate causative infectious agents in selected cases alongside antimicrobial resistance. In our study we used farm records for clinical mastitis recorded for period 2016 and 2017. We also used results of the regular on farm testing of the somatic cell count for 2017. Samples of milk from all clinical mastitis cases were taken during November and December 2017 in order to investigate causative agents and their antimicrobial resistance. Occurrence of clinical mastitis was 205 cases (47.7%) in 2017 compared to 93 cases (29.7%) recorded in 2016. In 2017 reoccurrence of clinical mastitis in same animal was recorded for 93 cows (45.4%). In 2016 reoccurrence of clinical mastitis in same animal was recoded for 49 cows (29.7%). Average course of clinical mastitis in 2016 was 3 days, while in 2017 4.5 days (continuous days of recording a case in farm records). Somatic cell count in more than half of tested animals was higher than 200.000 SC/ml according to the measurements from February and July 2017 (number of cows tested 236 and 169, respectively). Out of 23 milk samples, 20 had bacteriological growth. In 9 samples we identified S.aureus, in 6 streptococcus spp., in 4 coagulase negative staphylococci (CNS) and one sample contained E.coli. Most common resistance was found for lincomycin-spectinomycin (100%) gentamicin (92%), followed by cefquinome (65%), linkomycin (53%) and erythromycin (47%). Isolates of S.aureus were resistant on the largest number of investigated antibiotics.
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