1,720,961 research outputs found
Cyclic behavior of the Drava sand in undrained conditions
No full textNa slabo graduiranom pijesku, uzorkovanog u rijeci Dravi, provedena su troosna ispitivanja cikličkog ponašanja u nedreniranim uvjetima. Svi pokusi provedeni su uz kontrolu vertikalne deformacije. Ispitani su utjecaji frekvencije 0.1 Hz i 0.05 Hz, relativne zbijenosti od 33%, 50% i 80% te efektivnog naprezanja od 100 kPa, 200 kPa i 400 kPa. Rezultati pokusa su potvrdili pretpostavku da je likvefakcija pijeska popraćena porastom pornih pritisaka koji su nastali uslijed velikih deformacija. Degradacija pijeska se očituje i smanjenjem nosivosti tla, padom vrijednosti sekantnog posmičnog modula, rastom prigušenja kroz cikluse smicanja te rastom parametra prigušenja. Također, pri malim deformacijama zabilježeno je ojačanje materijala prije degradacije.Undrained cyclic triaxial shear tests were conducted on poorly graded sand sampled from Drava river. All tests were performed using strain-control test method. Effects of two different loading frequencies (0.1 Hz and 0.05 Hz) were studies, as well as different relative densities (33%, 50% and 80%) and effective confining stresses (100 kPa, 200 kPa and 400 kPa). Obtained results confirmed the premise that liquefaction of sand is accompanied with the rise of the pore water pressure which is caused by large cyclic shear strains. Degradation of sand is manifested through reduction in bearing capacity, decreased values of the secant shear modulus, increased damping coefficient and increased damping parameter. Also, at lower amplitude shear strains material hardening was noticed prior to degradation
Preparation of Rock Specimens for Laboratory Testing
No full textStijena je inženjerski materijal koji ima široku upotrebu u građevinarstvu, te je za njenu praktičnu primjenu potrebno poznavati njena svojstva. U ovom završnom radu je prikazan postupak pripreme uzoraka stijene za laboratorijska ispitivanja prema normi koju preporuča American Society of the International Association for Testing and Materials (ASTM). Također su opisani i standardi koje propisuju The International Society for Rock Mechanics (ISRM) i European standard Eurocode 7. Obrađeno je ukupno pet uzoraka stijene uzetih sa lokacije Grohovo, na umirenom klizištu smještenom na jugozapadnoj padini doline Rječine. Priprema tih uzoraka uključivala je bušenje, rezanje i brušenje koje se izvelo pomoću laboratorijske opreme Građevinskog fakulteta u Rijeci. Obrađenim uzorcima je potom utvrđena sukladnost dimenzija s propisanim veličinama. Podaci dobiveni verificiranjem prikazani su tablično i grafički pomoću računalnih programa Grapher i Excel.Rock is an engineering material widely used in construction, so understanding its behavior is necessary for practical application. This paper presents the procedure for rock specimen preparation for laboratory testing in accordance with standard practices suggested by The American Society of the International Association for Testing and Materials (ASTM). Methods suggested by the International Society for Rock Mechanics (ISRM) and European standard Eurocode 7 are also described in this thesis. For the purpose of this work a total of five specimens from location Grohovo, were taken at a dormant landslide on the south-western slope of the Rječina Valley. The preparation of these samples included drilling, cutting and grinding the rock core, using equipment from the Geotechnical Laboratory at the Faculty of Civil Engineering Rijeka. After that it was determined whether the prepared rock specimens meet dimensional tolerances in accordance with ASTM D4543. Shape and dimensional tolerance data are presented in table and graphic format, using Grapher and Excel software
Numerical Model for Identification of Fiber-Reinforced Concrete Parameters from the Crack-Mouth Opening Displacement
No full textDetermining material parameters is crucial for understanding their physical properties, improving the design process, and optimizing costs. Due to the challenges of measuring parameters in fibre-reinforced concrete, numerical models and inverse analysis are employed for parameter identification. Laboratory tests, including bending and compressive strength tests, were conducted on concrete samples, recording three parameters: vertical displacement, crack mouth opening displacement, and applied force. The laboratory test results served as a reference for developing a numerical model of micro-reinforced concrete, which generated simulated data used as input for an inverse model based on the LevenbergMarquardt method. Model verification involved comparing the results with the data obtained from the laboratory tests
Zajednički temelji 2025: zbornik radova 11. skupa mladih istraživača iz područja građevinarstva i srodnih tehničkih znanosti, 9. – 12. srpnja 2025., Rijeka
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Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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