In For various pipe manufacturing processes, information on the pipe circumferential strain and stress state is needed (e.g. in the oil industry, the process of manufacturing seamless pipes with a ...conical shaft). This study's objective is to create a method for analyzing the strain and stress behavior of a pipe ring tensile specimen (PRTS) in the hoop direction. The potential for the creation of a PRTS is indicated by the absence of official standardized testing procedures. The use of the digital image correlation approach to test plastic PRTS is discussed in the paper. A steel instrument with two D blocks that has been particularly constructed is used to test PRTS. Over two D-shaped mandrels that are fixed to a tensile tool and a tensile testing machine, a 3D- printed PRTS is inserted. Three-dimensional Digital image correlation (3D DIC) method was used to record the strain evolution in the gage length of the specimens. All of the specimens are 3D scanned to verify the geometry of the cross-section of the PRTS following fracture. Five single PRTS were examined for the study. The results demonstrate that the DIC system, 3D printer, and scanner approach are efficient tools for characterizing the mechanical properties of pipes by mapping complete strain fields in steel PRTS.
Savremeni autori produbljuju uvide o kreativnom procesu ispitujući homospacijalno mišljenje zasnovano na ukrštanju udaljenih asocijacija koje su suprotstavljene u razvoju novih ideja. Upitno je da li ...se ukrštanje zasniva isključivo na pret-postavkama semiotičke raznorodnosti, ili pak emocije imaju izvesnu ulogu u povezivanju različitih asocijacija. Cilj ovog istraživanja je ispitati razlike između sadržaja koji izazivaju kongruentne i nekongruentne emocionalne doživljaje u pogle-du njihovog delovanja na kreativnu produkciju. Stepen kon-gruentnosti emocionalnog doživljaja kontrolisan je na dimen-zijama valence i pobuđenosti. U eksperimentu su učestvovali studenti dramskih umetnosti (N = 32), a za vizuelnu stimu-laciju korišćena je IAPS baza (International Affective Picture System): Ukrštanjem 32 fotografije napravljeno je 56 super-poniranih vizuelnih kompozicija u kojima su vrednosti valence i pobuđenosti sistematski varirane, tako da se uzorak sastojao od kompozicija izrazitog, umerenog i odsutnog kontrasta kako na dimenziji valence tako i pobuđenosti, kao i kompozicija koje su u potpunosti neutralne jer imaju srednje vrednosti na obe dimenzije. Nakon izlaganja od studenata je traženo da za svaku kompoziciju smisle kreativan naslov, dok je kreativnost merena pomoću koeficijenata zasnovanih na proceni original-nosti i intencionalnosti odgovora. Analizom varijanse potvrđen je efekat kontrasta na dimenziji valence, ali ne i pobuđenosti. Kontrast valence pozitivno je koreliran sa kreativnošću i može biti njen prediktor. Rezultati proširuju uvide o homospacijalnom mišljenja i delimično mogu biti objašnjeni psihodinamskim konceptom reparacije, potvrđujući pritom značajnu ulogu am-bivalencije u generativnim procesima.
U radu su testirane validnost i pouzdanost novog načina merenja kreativnosti produkta, putem konstruisanja koeficijenata izuzetnosti i kreativnosti. Proverena je preciznost merenja, kao i opravdanost ...primene koeficijenata u proceni likovnih produkata, uz poređenje sa rezultatima izvedenim iz konsenzualne tehnike procene (CAT). Postupak konstrukcije obuhvata dva koraka: 1) kategorizaciju kreativnih produkata po sličnosti, uz proveru njihove intencionalnosti, nakon čega sledi 2) izračunavanje koeficijenata izuzetnosti kao mere originalnosti pojedinačnih odgovora (količnika broja 1 i broja ispitanika koji su dali isti odgovor), i koeficijenta kreativnosti (količnika dobijenih i mogućih odgovora na nivou varijable). Validnost i pouzdanost koeficijenata izuzetnosti testirane su uz učešće 53 studenta, podeljenih u dva poduzorka: umetnička i opšta studentska populacija. Svaki student je imao zadatak da na osnovu apstraktnog stimulusa napravi svoj crtež. Potom je kreativnost njihovih crteža izmerena koeficijentima, kao i konsenzualnom tehnikom procene (Consensual Assessment Technique - CAT). Razlike u kreativnosti između umetničke i opšte studentske populacije ukazuju na diskriminativnost i kriterijumsku validnost koeficijenata. Pozitivna i statistički značajna korelacija između ekspertskih procena i koeficijenata govori u prilog konvergentne validnosti. Nalazi sugerišu da konstruisani koeficijenti omogućuju precizno i objektivno procenjivanje likovnih produkata podjednako kao i CAT, pritom su daleko dostupniji u uslovima ograničenih resursa, te se primena već sada čini opravdanom.
The paper presents the technical solution of the main sewer collector on the Herceg Novi Riviera, which was built from 2008 to 2019, as a gravity-pushing pipeline. It is located in the trunk of the ...coastal road-pedestrian road, with 11 pumping stations, connected in a row. The collector is connected to the Herceg Novi sewage system through a wastewater treatment plant, located in the central part of the municipality, in Meljine. It is presented through technical problems that are reflected in its functionality.
The majority of manufacturers of polymer filaments for FDM technology rely their datasheets only on tensile tests, so their documentation usually lacks any data concerning fracture mechanics ...parameters. Having in mind the importance of fracture mechanics parameters in material design and application e.g., plane-strain fracture toughness, and the fact that it can be measured using only standard tensile grips, or three-point bending test fixture on a regular tensile testing machine, this practice offers vital information for AM components carrying the load. Anyhow, it is not always a simple task to satisfy all requirements of the standard for plane-strain fracture toughness assessment of plastic materials (ASTM D5045-14), as in the case of FDM technology due to many printing parameters that not only influence fracture toughness results, but also can question the eligibility of test results if crack propagation deviates from the expected path or if the specimens don’t meet the size criterion necessary for achieving the plane-strain condition. These problems are tackled in this research on PLA polymer, a material widely used in FDM technology. For this research SENB specimens are prepared according to ASTM D5045-14 standard and tested on tensile testing machine using three-point bending test fixture.
Dosadašnja istraživanja djelomično potvrđuju psihodinamske pretpostavke da neugodni i novi sadržaji mogu poticajno djelovati na kreativnost. Upitno je, međutim, na koji način bliskost sadržaja, ...pojedine dimenzije emocionalnog doživljaja, i kvalitete emocija djeluju na produkciju izrazito kreativnih osoba i pokazuju li oni izvjesne specifičnosti tijekom generativnih procesa. U ovom istraživanju ispituje se stupanj i vrsta povezanosti između kreativnosti odgovora i kvalitete emocija (radosti, žalosti, straha, srdžbe, iznenađenja i gađenja), dimenzija emocionalnog doživljaja (valencije i uzbuđenosti) i bliskosti sadržaja kod različitih studentskih populacija. Eksperiment je izveden uz sudjelovanje 59 studenata, a za vizualnu stimulaciju je izabrano 40 fotografija, tako da su vrijednosti dimenzija i kvalitete emocionalnog doživljaja sustavno varirane. Od ispitanika je traženo da ocijene koliko im je blizak sadržaj fotografija, a zatim da smisle najkreativniji naslov za svaku od njih. Kreativnost naslova je mjerena putem koeficijenata kreativnosti i izuzetnosti baziranih na statističkoj procjeni originalnosti. Rezultati potvrđuju umjerenu negativnu povezanost kreativnosti s valencijom, s bliskošću sadržaja i s radošću, zatim umjerenu pozitivnu povezanost kreativnosti s uzbuđenošću, žalošću, strahom, srdžbom, iznenađenjem i gađenjem, kao i specifičnosti kreativnog procesa studenata umjetnosti, kod kojih novina i iznenađenje preuzimaju primat pred drugim dimenzijama i kvalitetama emocionalnog doživljaja. Ključne riječi: kreativnost, primarne emocije, bliskost sadržaja, dimenzije emocionalnog doživljaja, umjetnička produkcija
Intoduction. Water polo is team, contact sport played in the swimming pool with a ball. It is characterized by dynamism, specific type of swimming in all directions, changing body position in the ...water, ball handling, passing and shooting at the goal and by unpredictable situations in the defense and attack phase. Game-related statistics are an integral part of water polo match analyses. They enable a special insight into reasons for winning or losing by comparing specific game parameters. The aim of this research is to determine the relationship between the technical and tactical parameters in regards to the results of the preliminary and final matches of the Champions League in water polo in the 2021 season. In view of that, the research also aims to clarify the relationship between the winning and losing teams in the preliminary and final stages of the competition. Methods. The sample used includes the analysis of 56 water polo games played within 14 rounds of the preliminary part of the league, and 12 games of the final F8 tournament in Belgrade. A total of 32 technical and tactical variables related to defense and attack were analyzed. They were obtained from the official statistical match reports. Results. Based on the descriptive statistic, manova and canonical discriminant analyses of water polo segments, seven variables from the model were found to be significant for winning a match in the Champions League of the 2020/21 season (total shot score, total shot %, extra player goal %, blocked shots, counterattack score, counterattack shoot and sprint), while the leading parameters were blocked shots and 20second player exclusion in the center position. Conclusion. In this research, we determined that the outcome of a match can be scientifically explained with 91.9% accuracy, based on technical and tactical indicators.
The goal of this study was to define the population parameters of the body fat percentage of residents of the Republic of Serbia. The sample was a total of 8145 respondents, of which 3051 (37.5%) ...were women with an average age of 32.0 ± 9.8 years, and the rest of 5094 (62.5%) were men with an average age of 32.9 ± 11.3 years. The average value of PBF for the women subsample was 28.46 ± 9.19% and 18.00 ± 7.98% for the men subsample. The results of factorial variance analysis have shown that there is a statistically significant difference (p<0.001) of PBF values regarding sex (F=1243.719) and respondent's age (F=508.469) as well as the interaction of factors "age" and "sex" (F=22.593). The regression analysis has shown that age explains 82.09% of variance regarding the age function for women and 85.08% of variance regarding the age function for men, taking into consideration that the function that best describes the variance PBF for women is linear and polynomial for men. Both sex and age are determined as factors that influence over-increasing the values of PBF, while the most critical groups where PBF crosses critical values are the groups of women over 50 years of age (the average prevalence of overweight and obese is 37.81% and 23.89% respectively) and men over 60 years of age (the average prevalence of overweight and obese is 25.48% and 38.36% respectively).
High demand for part customization shifts industries toward AM technologies. Part customization in high-volume manufacturing is developed to its limits, whereas low-volume production using AM is ...still economically unjustified. FDM technology is quite common in low-volume AM production, but the main issue is poor printing parameter optimization which may result in insufficient final part quality. The subject of this paper is the experimental determination of the optimal parameters for the PLA polymer FDM parts, focusing on nozzle temperature and printing speed. Part geometry and mechanical properties are evaluated for the temperature range of 170–210 °C and speeds of 40, 80, and 120 mm/min. Roughness measurements for part geometrical accuracy assessment and tensile tests for mechanical property estimation have shown the clear advantage of 190 °C and 40 mm/min over the other parameter combinations. However, for higher FDM process productivity 80 mm/min speed may also be considered with 190 °C.
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