The Relationship between Classroom Distractions and Off-Task Students

This study focuses on the prevalence of classroom distractions in elementary education candidates’ field experiences. Classroom disturbances challenge students’ ability to focus on, and process the information that is being taught (Frisby, et al. 2018). Disturbances can occur for a variety of reasons. Intentional distractions, or anti-citizenship behaviors are classroom disturbances that are created by students with the goal of distracting others (Myers, et al. 2015). Classroom disturbances can also be unintentional, yet still equally distracting. Throughout the duration of this research, the candidates have conducted observations and research in a variety of grade levels. In this paper, the candidates will compare and contrast their findings from each segment of time spent in the field, including COVID-19 data. From this comparison, the candidates will make note of similarities and their relevant significance from the research. The insights gleaned from this study have implications for all elementary teachers. By limiting the possible sources of distraction, teachers can more readily improve students’ focus, attention, and their overall engagement

Influence of exciton spin relaxation on the photoluminescence spectra of semimagnetic quantum dots

We present a comprehensive experimental and theoretical studies of photoluminescence of single CdMnTe quantum dots with Mn content x ranging from 0.01 to 0.2. We distinguish three stages of the equilibration of the exciton-Mn ion spin system and show that the intermediate stage, in which the exciton spin is relaxed, while the total equilibrium is not attained, gives rise to a specific asymmetric shape of the photoluminescence spectrum. From an excellent agreement between the measured and calculated spectra we are able to evaluate the exciton localization volume, number of paramagnetic Mn ions, and their temperature for each particular dot. We discuss the values of these parameters and compare them with results of other experiments. Furthermore, we analyze the dependence of average Zeeman shifts and transition linewidths on the Mn content and point out specific processes, which control these values at particular Mn concentrations.Comment: submitted to Phys. Rev.

Analiza nastanka grešaka u zasićenim kompozitnim metalima u lijevanom stanju

In research into the porosity of casts from metal saturated composites there is a need to identify the pores. Problems encountered here are connected with the following: - the difficulty in differentiating the pores from other structure components of materials, - the necessity of differentiating the porosity types resulting from non-saturation, gas occlusion and gas emission during coagulation and contraction of the matrix. The report presents research results conducted to identify the pores by means of computer image analysis with the application of an analyzing scanning computer.U istraživanju poroznosti na ljevovima metala od zasićenih kompozita postoji nužnost određivanja poroznosti. Prolemi koji se ovdje susreću su povezani sa slijedećim: - teškoćama u razlikovanju pora od drugih strukturnih sastavnica materijala; - potreba za razlikovanjem vrsta poroznosti zbog nezasićenosti plinske poroznosti i emisijom plinova tijekom zgrušavanja i stezanja matrice. Izvješće predstavlja rezultate istraživanja provedenog radi određivanja pora kompjutorske analize slike uz primjenu kompjutorskog skenera za provođenje analize

Magnetic polaron formation and exciton spin relaxation in single CdMnTe quantum dots

We study the formation dynamics of a spontaneous ferromagnetic order in single self-assembled CdMnTe quantum dots. By measuring time-resolved photoluminescence, we determine the formation times for QDs with Mn ion contents x varying from 0.01 to 0.2. At low x these times are orders of magnitude longer than exciton spin relaxation times evaluated from the decay of photoluminescence circular polarization. This allows us to conclude that the direction of the spontaneous magnetization is determined by a momentary Mn spin fluctuation rather than resulting from an optical orientation. At higher x, the formation times are of the same order of magnitude as found in previous studies on higher dimensional systems. We also find that the exciton spin relaxation accelerates with increasing Mn concentration.Comment: sent to Physical Review

Spectroscopy of Indirect Excitons in Vertically Stacked CdTe Quantum Dot Structures

We show that by means of an electric field we can tune the energy levels in vertical quantum dot pairs and study transitions related to recombination of direct and indirect excitons. With decreasing the reverse bias, we observe both the blue-and red-shifted indirect exciton transitions. Based on the band profile of our device, we conclude that the former corresponds to the recombination of the electron and hole localized in the top and the bottom dot, respectively and the latter is related to the recombination of the electron and hole localized in the bottom and the top dot, respectively

Espon-Interstrat. Espon in Integrated Territorial Strategies.

The INTERSTRAT project’s overall aim is “to encourage and facilitate the use of ESPON 2013 Programme findings in the creation and monitoring of Integrated Territorial Development Strategies (ITDS) and to support transnational learning about the actual and potential contribution of ESPON to integrated policy-making.” We defined integrated territorial development as ‘the process of shaping economic, social and environmental change through spatially sensitive policies and programmes’