Iskanje po katalogu digitalne knjižnice

Opis: Working memory is important for a number of higher cognitive functions such as problem solving, reasoning, reading and language comprehension. Moreover, working memory measures are significantly correlated with measures of intellectual abilities. Investigating the neural basis of working memory provides the opportunity to gain a deeper understanding of individual differences in general cognitive ability. This thesis aimed to elucidate the roles of brain oscillations in working memory, with a particular focus on theta and gamma frequency bands. Two techniques were employed that are best suited for the non-invasive study of brain oscillations: scalp recorded EEG and transcranial alternating current stimulation (tACS). In the first step, correlational studies were conducted followed by neuromodulatory studies in the next step. The results showed that individuals with high working memory capacity, contrasted against individuals with low working memory capacity, display stronger alpha and gamma band desynchronisation and increased coherence in the theta frequency band between fronto- parietal areas during maintenance and between frontal brain areas during retrieval. The results further demonstrated that interactions between theta and gamma frequency bands are related to individual differences in working memory capacity. The neuromodulatory studies showed that theta tACS applied over parietal brain areas can be used to enhance performance on working memory tasks, thereby providing support for the causal role of theta band oscillations in working memory.
Ključne besede: working memory, brain oscillations, capacity, electroencephalograpy, tACS, theta, gamma
Objavljeno v DKUM: 28.07.2017; Ogledov: 1590; Prenosov: 172
Celotno besedilo (3,46 MB)

Opis: This work presents the results of the microstructure observation of six different types of NiTi orthodontic wires by using Transmission Electron Microscopy (TEM). Within these analyses the chemical compositions of each wire were observed in different places by applying the EDS detector. Namely, the chemical composition in the orthodontic wires is very important because it shows the dependence between the phase temperatures and mechanical properties. Micro- structure observations showed that orthodontic wires consist of nano-sized grains containing precipitates of Ti2Ni and/or TiC. The first precipitated Ti2Ni are rich in Ti, while the precipitated TiC is rich in C. Further investigation showed that there was a difference in average grain size in the NiTi matrix. The sizes of grains in orthodontic wires are in the range from approximately 50 to 160 nm and the sizes of precipitate are in the range from 0,3 μm to 5 μm.
Ključne besede: orthodontic wires, nickel-titanium orthodontic wire, NiTi wire, shape memory alloys, SMA wires, microstructure, transmission electron microscopy, TEM, average grain size
Objavljeno v DKUM: 03.07.2017; Ogledov: 1015; Prenosov: 110
Celotno besedilo (869,15 KB)
Gradivo ima več datotek! Več...

Opis: Suggestopedia is a teaching method, originally developed by psychiatrist Dr. Georgi Lozanov, the foundations of which are built upon the knowledge of psychology, neurology and linguistics. By combining the knowledge of suggestology, medical facts and well-established psychological effects, Lozanov attempted to reconcile various aspects of this knowledge by their systematic and strategic integration. This has been achieved by using suggestion as a common denominator, and creating the carefully coordinated “set-up” (preparation of the classroom and the students) which would then make tapping into the “hidden reserves” of our brain possible. Lozanov argues that these reserve capacities, although present, are normally more or less inhibited by parasitic conscious and subconscious thought processes, which he calls barriers, and that it is critical to discard or override, i.e. de-suggest them, and then suggest new standards prior to any language teaching. Hence, this involves the process of suggesting as well as the process of de-suggesting, i.e. erasing negative ideas by setting and anchoring positive ones. In every-day life, language (mother tongue or foreign language) is by far more dependent on subconscious processes (automaticity) than on conscious ones. In fact, it is believed that about 95% of the language acquisition happens by employing these subconscious mechanisms. And this is believed to give us fluency and grammatical accuracy at the same time. Since it makes sense that the acquisition of knowledge should follow the principle of economy and efficiency, and, at the same time, should have a solid scientific support, the fact that suggestopedia, in addition to employing various types of suggestions, also makes use of almost all known beneficial psychological effects found in humans makes this method rather scientifically plausible. In Slovenian elementary schools suggestopedia did not establish itself either as the principal or alternative teaching method. One definitive reason for this situation is that the method is almost unknown. The other reason lies in the lack of appropriate (suggestopedic) teacher training which is mainly due to the first reason. In terms of suggestopedia being applied as an alternative teaching method in Slovenian elementary schools, although a fair amount of mistrust towards the effectiveness of the method has been revealed, the general attitude of the teachers toward suggestopedia, nevertheless, is not negative or reluctive, but rather positive and embracive, and there is a general consensus that suggestopedia is an acceptable alternative to the standard way of teaching.
Ključne besede: Suggestopedia, Superlearning, memory enhancement, language acquisition, neurons, episodic memory, semantic memory
Objavljeno v DKUM: 25.11.2016; Ogledov: 2004; Prenosov: 77
Celotno besedilo (20,69 MB)

Opis: The aim of this paper was to analyse the characteristic properties of six different, commercially available nickel-titaniumorthodontic wires with a diameter of 0.305 mm (0.014"). The characteristic properties were determined by usingsemi-quantitative EDX analyses, DSC analyses for a determination of the phase temperatures, and a tensile test to obtain themechanical properties of the wires. The investigation of the chemical composition showed an equiatomic NiTi alloy. Analysesof phase temperatures showed that the nickel-titanium orthodontic wires were, in an austenitic microstructure, exhibiting asuperelastic effect in the oral environment. The uniaxial tensile stressstrain curves showed different values for the beginningand the end of the transformation range during the loading.
Ključne besede: shape-memory alloy, phase transformation, thermal analysis, tensile test
Objavljeno v DKUM: 21.12.2015; Ogledov: 1090; Prenosov: 93
Celotno besedilo (429,57 KB)
Gradivo ima več datotek! Več...

Opis: The main aim of this thesis was to examine verbal working memory in native and foreign language. In the theoretical part we mainly focused on the Baddeley’s (2002) multicomponent model of working memory. We also reviewed several studies that had aims similar to ours. Finally, we briefly discussed the importance of working memory for scholastic attainment and effectiveness of working memory training. For the empirical part, two versions of an experiment were designed. One version was in Slovene and the other in English. We tested verbal working memory of 76 participants which we divided into four groups. Two groups were tested in their native (Slovene) language, and two in foreign (English) language. The experiment consisted of twelve word sequences, each containing five words. English words were matched with their Slovene equivalents in meaning, frequency and number of syllables. The participants had to recall each word in a sequence in order in which it appeared. The groups were matched for age and level of education, but differed in language proficiency. Results of the experiments strongly support the view that verbal working memory interacts with language proficiency and that it is superior in native language. Furthermore, similar phenomena showed in both languages, suggesting universal nature of verbal working memory.
Ključne besede: working memory, verbal working memory, foreign language, native language, language proficiency
Objavljeno v DKUM: 07.10.2013; Ogledov: 1912; Prenosov: 217
Celotno besedilo (1,37 MB)