Logo

Publikacije (45381)

Nazad
Husein Rošić, Aldin Bjelić, Atif Hodžić, Miran Merhar

It is known from theory and practice that the workability of wood depends on structural parameters that are closely related to the physical, mechanical and chemical properties of the type of wood itself, and disturbance parameters that refer to the technological and geometric parameters determined by the specific processing regime. That machinability, in addition to the mechanical output sizes, is often expressed by the quality, that is, the roughness of the processed surface. By defining a mathematical model in the process of planing solid wood in which the input sizes are processing parameters: wood density (ρ), feed rate (m/min) and number of cutting spirals (z), and the spilled sizes are praamters of roughness of the treated surface (Ra and Rz), and by applying optimization methods, optimal solutions for the process of planing solid wood on planer machines will be determined, so that the obtained Yoptim model will aim to improve the workability of solid wood, specifically its roughness of the processed surface.

Abstract Tourist boards, through their social activities, can make a tourist destination, tourist attractions and tourist products attractive, unique, and special. Through relevant scientific knowledge, using the tools and techniques of destination management as well as modern forms of communication, tourist boards can make the entire area of a tourist destination very interesting and desirable for tourist visits throughout the year by promoting the specificity, authenticity and originality of the tourist offer and tourist products. Keywords: tourist board; tourism promotion through sports and sports recreation competitions; tourism promotion through social networks, tourism

Abstract In the dynamic field of power systems, integrating distributed generation (DG) sources like solar photovoltaic (PV) plants is crucial for enhancing reliability and fostering sustainability. However, this integration poses voltage profile management challenges in electrical grids. This study investigates voltage profile optimization in Bosnia and Herzegovina’s Gračanica network, focusing on a medium voltage feeder with 68 buses. Using DIgSILENT PowerFactory software, six scenarios with different configurations of solar plants are analyzed for their impact on voltage profiles and power losses. Results show that while DG integration offers benefits, incorrect sizing or placement can increase power losses. Optimal DG benefits are linked to specific sizes and locations. This research emphasizes the need for balancing PV generation with load demands and provides insights for optimal PV plant size and output to minimize negative impacts. These findings aid energy planners and policymakers in implementing distributed solar PV in medium voltage networks.

Nadina Grebović-Lendo, Vahid Piralić

Open access implies the idea of scientific information dissemination over the Internet that is free to the end user. The higher education and university libraries’ mission is to connect people and information, and the goals of open access help librarians respond to users' information queries more quickly. This paper presents the basic concepts of open access with an emphasis on creating an open access journal through ten steps. The open access portal at the University of Sarajevo is also presented within the paper, as well.

Mario Ostojić, A. Bosovic

Abstract Voltage unbalance is common issue encountered in low voltage distribution networks, caused by uneven allocation of single-phase customers among phases. This paper analyses part of real low voltage distribution network in Bosnia and Herzegovina. The impact of single-phase customers and single-phase connected micro photovoltaic power plants (MPPP-s) were analysed. To reduce unbalance and improve voltage profiles, Phase Balance Optimization toolbox in DIgSILENT PowerFactory software was performed in six scenarios with different distribution of customers and different percentage of penetration of MPPS-s. The aim was to find method with least number of changes in customer and photovoltaic phase connection that fits within defined limits of voltage variations and voltage unbalance of European standard for power quality (EN 50160). Conclusion is that MPPP-s cause voltage increases in the network, as well as an increase in voltage unbalance, but these effects can be mitigated by proper distribution of customer loads and MPPS-s among phases.

E. Mušeljić, K. Roppert, L. Domenig, Alice Reinbacher Köstinger, M. Kaltenbacher

This paper is about the parameter identification of an energy based hysteresis model from measurements by employing automatic differentiation and neural networks. We first introduce the energy based hysteresis model and the parameters which are to be identified. Then we show how the model can benefit from automatic differentiation. After that we incorporate a parametrization of the energy based hysteresis model via distribution functions and identify the parameters of the distribution function. Then, the hysteresis model is sampled and the generated datasets are used to train neural networks to predict the hysteresis parameters. The described methods are tested and verified on synthetic as well as measurement data.

Uvod: Biotin, vitamin H ili vitamin B7, je topiv u vodi i neophodan je za reakcije karboksilacije, glukoneogenezu i metabolizam aminokiselina. Preporučena doza za odrasle je 0,03-0,06 mg/dan. Terapija visokim dozama biotina medicinski je indicirana za urođene pogreške metabolizma (nedostatak biotinidaze) i određene oblike alopecije, obično u dozama 5-10 mg/dan. U kliničkom ispitivanju je primjena biotina u dozi od 300 mg/dan kao tretman za progresivnu multiplu sklerozu. Materijal i metode: Streptavidin i manjim dijelom avidin nekovalentno se vežu za biotin s posebno jakim afinitetom, a trajnost te interakcije iskorištava se u laboratorijskim tehnikama kao što su western blot, protočna citometrija, imunohistokemija i imunohemijski testovi. Prema trenutačnim istraživanjima, poznato je da biotin uzrokuje interferencije u imunohemijskim testovima. Biotin ima sposobnost vezanja na različite molekule (biotinilacija) uz minimalne promjene u funkcionalnih ili antigenskih svojstava. Interferencije sa biotinom uključuju brojne imunohemijske testove kao što su proteini i steroidni hormoni, tumorski markeri, mikronutrijenti i lijekovi. Rezultati: Biotin može lažno povećati ili smanjiti rezultate u kompetitivnome i nekompetitivnome “sendvič” imunohemijskom testu. Niža povećanja vrijednosti obično se čine manje značajnima u usporedbi s visokim odstupanjima kod povišenih koncentracija biotina, ali mogu biti od terapijske i dijagnostičke važnosti. Osobito za procjenu hormona štitnjače (T3, T4, fT3, fT4), steroidnih hormona (kortizol, progesteron, testosteron i estradiol) kao i vitamina B12 i folne kiseline u slučaju postojeće interferencije biotina teško će se razlikovati deficit, referentna vrijednost odnosno povećanje. Interferencija sa biotinom mogla bi se ukloniti sa serijskim razblaženjem uzorka, ponavljanjem analize na drugoj metodi koja ne koristi biotin, utvrđivanjem koncentracije biotina i uklanjanjem biotina prije nego što se uzorak testira. Zaključak: Preporuka je da pacijent prestane sa terapijom biotina 3 dana prije uzorkovanja krvi odnosno 14 dana ako se koriste visoke doze biotina.

Introduction: Laboratory professionals (LP) are exposed to various hazards in the workplace, whose direct and/or cumulative effects can lead to the development of health disorders of varying severity. Our study aims to assess the level of occupational risk in biomedical laboratories. Subjects and methods: A cross-sectional study was conducted between November 2020 and February 2021. The study included LP of all profiles in Europe, and the territorial affiliation of the respondents formed the basis for the formation of the groups studied. A validated questionnaire used for data collection was distributed online through the networks of professional associations. Based on the type of agent, frequency of exposure, characteristics of the workplace and work process, and individual factors, an occupational risk assessment matrix was created in categories ranging from low to very high. Descriptive and inferential statistical methods with a statistical significance threshold of 5% (p ≤ 0.05) were used for the statistical analysis. Results: Significant differences in risk categorization were found between the groups studied (p < 0.001). Overall, 81.2% of LP in the European Union fall into the medium risk category, while more than half (52.1%) of LP and 1.7% of LP in Bosnia and Herzegovina fall into the high and very high risk categories. Higher education, service longer than 21 years, public sector, and biochemistry laboratory were identified as predictors of high risk, while predictors of very high risk were higher education, service of 21 to 30 years, public sector, and histopathology and molecular laboratories. Conclusions: Lack of equipment, organizational issues and working conditions were identified as weak points that directly correlate with risk levels in biomedical laboratory workplaces. Additional efforts to control exposure in biomedical laboratories are needed to maintain the health of LP.

Uvod: Heterogena priroda akutne mijeloične leukemije (AML) iziskuje primjenu specifičnih i pouzdanih laboratorijskih testova pri postavljanju dijagnoze. Istraživanja ukazuju na određene nedostatke konvencionalnih morfoloških i imunofenotipskih metoda, ali i potrebu za imple-mentacijom kompleksnog dijagnostičkog algoritma koji uz navedene metode inkorporira citogenetičke i molekularno-genetičke analize u integrirani dijagnostički pristup. Cilj: Predstaviti prednosti i nedostatke integriranog dijagnostičkog pristupa u dijagnostici akutne mijeloične leukemije. Metode: Za potrebe neeksperimentalnog kvalitativnog istraživanja, pretražene su relevantne baze podataka (PubMed, Scopus i Web of Science). Pretraga baza u širem opsegu provedena je uz pomoć ključnih riječi acute myeloid leukemia, cytomorphology, flow cytometry, cytogenetic abnormalities i molecular diagnostics. Za konačnu analizu, odabrani su naučni radovi koji zadovoljavaju kriterije relevantnosti i povezanosti s postavljenim ciljem i temom istraživanja. Rezultati: Integracija dijagnostičkih modaliteta u AML predstavlja veliki izazov zbog kontinuriane složenosti i opterećenja za zdravstvene profesionalce. Kao značajne prednosti izdvajaju se mogućnost umrežavanja rezultata različitih dijagnostičkih modaliteta, te detekcija nespecifičnih i izazovnih slučajeva AML. Prijavljeni nedostaci se odnose na potrebu za jedinstvenim protokolima, nepredvidiv turnaround time, validaciju i potrebu za visoko specija-liziranim osobljem. Danas se sve više pažnje pridaje AI (engl. artifical intelligence) i njenoj sposobnosti da obradi podatke s ciljem pružanja brzih i preciznih dijagnostičkih i prognostičkih informacija što predstavlja obećavajući koncept u AML-u. Usvajanje ove paradigme znatno bi olakšalo trenutne pristupe i unaprijedilo koncept zdravstvene zaštite. Zaključak: Integrirani dijagnostički pristup ima za cilj poboljšati kvalitet pojedinačnih metoda primjenom dosadašnjih saznanja i paralelnim testiranjem novih mogućnosti. S razvojem precizne medicine, ovaj dijagnostički model će u budućnosti dobiti dodatni značaj. Neovisno od utvrđenih prednosti i nedostatka, dostupna istraživanja ukazuju na nužnost dodatnih napora i primjenu AI za uspostavljanje standardiziranog integriranog pristupa na globalnom nivou.

S. Obradović, B. Džudović, P. Pruszczyk, I. Djuric, B. Subotic, J. Matijašević, M. Benic, S. Šalinger et al.

Amel Durakovic, C. Skordis

The Aether-Scalar-Tensor (AeST) theory is an extension of General Relativity (GR) which can support Modified Newtonian Dynamics (MOND) behaviour in its static weak-field limit, and cosmological evolution resembling ΛCDM. We consider static spherically symmetric weak-field solutions in this theory and show that the resulting equations can be reduced to a single equation for the gravitational potential. The reduced equation has apparent isolated singularities at the zeros of the derivative of the potential and we show how these are removed by evolving, instead, the canonical momentum of the corresponding Hamiltonian system that we find. We construct solutions in three cases: (i) in vacuum outside a bounded spherical object, (ii) within an extended prescribed source, and (iii) for an isothermal gas in hydrostatic equilibrium, serving as a simplified model for galaxy clusters. We show that the oscillatory regime that follows the Newtonian and MOND regimes, obtained in previous works in the vacuum case, also persists for isothermal spheres, and we show that the gas density profiles in AeST can become more compressed than their Newtonian or MOND counterparts. We construct the Radial Acceleration Relation (RAR) in AeST for isothermal spheres and find that it can display a peak, an enhancement with respect to the MOND RAR, at an acceleration range determined by the value of the AeST weak-field mass parameter, the mass of the system and the boundary value of the gravitational potential. For lower accelerations, the AeST RAR drops below the MOND expectation, as if there is a negative mass density. Similar observational features of the galaxy cluster RAR have been reported. This illustrates the potential of AeST to address the shortcomings of MOND in galaxy clusters, but a full quantitative comparison with observations will require going beyond the isothermal case.

Amir Ćoralić, Anel Maslo, Mirza Manjgo, Vesna Raspudić, M. Manjgo, T. Vuherer

Polymers and polymer composite materials, due to their properties, are becoming increasingly important materials in industry. They are used in a wide range of applications in space and aerospace, aviation, marine and automotive industry, as well as in production of sports equipment, household appliances, medical equipment, etc. They are expected to withstand loads during their lifetime, which requires predicting the reliability of structural elements, i.e. knowledge of material properties. To achieve better properties, polymer materials are reinforced with different percentages of fibre-reinforced materials, including glass fibres. The paper presents the results of experimental determination of the mechanical properties of injection moulded PA6 polymer reinforced with 30% glass fibres, determined by tensile and impact tests.

Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!

Pretplatite se na novosti o BH Akademskom Imeniku

Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo

Saznaj više