On the possibility of calibrating urban storm-water drainage models using gauge-based adjusted radar rainfall estimates

Traditionally, urban storm water drainage models have been calibrated using only raingauge data, which may result in overly conservative models due to the lack of spatial description of rainfall. With the advent of weather radars, radar rainfall estimates with higher temporal and spatial resolution have become increasingly available and have started to be used operationally for urban storm water model calibration and real time operation. Nonetheless, the insufficient accuracy of radar rainfall estimates has proven problematic and has hindered its widespread practical use. This work explores the possibility of improving the applicability of radar rainfall estimates to the calibration of urban storm-water drainage models by employing gauge-based radar rainfall adjustment techniques. Four different types of rainfall estimates were used as input to the recently verified urban storm water drainage models of the Beddington catchment in South London; these included: raingauge, block-kriged raingauge, radar (UK Met Office Nimrod) and the adjusted (or merged) radar rainfall estimates. The performance of the simulated flow and water depths was assessed using measurements from 78 gauges. Results suggest that a better calibration could be achieved by using the block-kriged raingauge and the adjusted radar estimates as input, as compared to using only radar or raingauge estimates

A simplified analytical approach to calculation of the electromagnetic behavior of left-handed metamaterials with a graded refractive index profile

We investigated the spectral properties of a new class of nanostructured artificial composite materials with tailored electromagnetic response, i.e. negative refractive index materials, also known as "left-handed" metamaterials. We analyzed structures incorporating both ordinary positive index media and negative refractive index metamaterials where the interface may be graded to an arbitrary degree. Utilizing a modified version of the Rosen-Morse function, we derived analytical expressions for the field intensity and spectral reflection and transmission through a graded interface between positive and negative index materials. We compared our results to numerical solutions obtained using the transfer matrix technique.

A milestone in the era of esports: The Olympics through the lens of virtual reality

Whether the International Olympic Committee (IOC) ever includes electronic sports (esports) in the official program of the Olympic Games, the popularity of competitive gaming continues to grow—sports present a modern audience powerhouse the world cannot fail to notice. By the end of 2025, the number of viewers in esports is expected to reach 640.8 million and revenue growth of 1,866.2 billion U.S. dollars (Gough, 2022). Over 170 colleges in the United States have established varsity esports teams and offer esports players' educational opportunities, including partial or full scholarships (Lyman, 2022). Esports has also found its place in schools, largely influencing the youth (Rothwell and Shaffer, 2019). Additionally, numerous NBA teams have entered the esports race, and even Usain Bolt owns an esports team (Gardner, 2022), perhaps better illustrating esports' global prevalence. In 2021, the IOC took a step closer to the digital world, creating the Olympic Virtual Series (OVS). The main objective was to promote the development of virtual sports games and engage with the gaming communities worldwide. The OVS consisted of five different games: baseball (Powerful Pro Baseball 2020), cycling (Zwift), rowing (World rowing, using a rowing machine), sailing (Virtual Regatta), and motor racing (Gran Turismo). The IOC fused traditional elements of sport physicality and video games to uniquely incorporate physical activity (PA) to new audiences, connecting “e” and sports through the Olympic Movement (Palaar, 2021). Opposingly, the 2022 Asian Games (postponed to 2023 due to COVID-19) in Hangzhou will be the first official continental competition to include eight esports games played on computers, consoles, and even smartphone devices (Daniels, 2021). While these actions by the IOC certainly took cognizance of esports and presented it to a world audience, none of the included games utilized virtual reality (VR) technology. Compared to the vast library of traditional esports games (e.g., Dota 2, League of Legends, Apex, CS:GO), VR games have a small selection of titles—which has affected the global VR prevalence in the gaming world. However, an excellent example is the VR game Onward, which (according to players) brought new features and a higher skill ceiling than traditional games, in addition to the physical embodiment and “immersiveness” for players (Turkay et al., 2021). VR is defined as an immersive and multisensory experience for the user, with the support of multimedia components such as VR headset and body tracking sensors (Gigante, 1993). As opposed to the 360° VR, which relies on the video recorded by the actual camera and then implemented into the system—this gives users a more realistic view and experience. However, both rely on the physical headset device with or without motion controllers. VR and the gaming industry joint became more evident as VR became a globally more available technology (e.g., Oculus Rift, HTC Vive, PlayStation) on the market. While the VR player base is not as big as Dota 2 or CS:GO, VR esports have a promising future with exponential growth, forecasted to reach 2.4 billion U.S dollars by 2024 (Clement, 2022). Besides games, VR technology has wide application in the rehabilitation of specific populations, psychology, psychiatry, education, and even sports performance (Lange et al., 2010; Salem and Elokda, 2014; Izard et al., 2018; Michalski et al., 2019; Park et al., 2019; Kaplan et al., 2021; Lee et al., 2021)

Extraction from curry plant (Helichrysum italicum) and impregnation of solid carries with the extract using supercritical carbon dioxide

Смиље (Helichrysum italicum (Roth) G. Don fil., Asteraceae) је медитеранска биљка, позната по својој традиционалној употреби у третману упалних процеса претежно на кожи и у дигестивном систему. Смиље представља вредан извор биолошки активних компонената, међу којима су најзаступљеније терпени и фенолна једињења. На основу прегледа литературних података може се закључити да екстракција помоћу наткритичног угљеник(IV)-оксида није довољно истражена у погледу хемијског састава и могућих примена добијених наткритичних екстраката. У овој дисертацији испитана је наткритична екстракција из смиља и, по први пут je наткритични екстракт смиља коришћен као активна супстанца за импрегнацију различитих чврстих носача у наткритичним условима...Curry plant (Helichrysum italicum (Roth) G. Don fil., Asteraceae) is Mediterranean plant, known for its traditional use in treatment of inflammatory processes mostly on skin and in the digestive system. This plant presents a valuable source of bioactive components, among which the most common are terpenes and phenolic compounds. According to available literature data, supercritical extraction with carbon dioxide from curry plant has not been investigated enough regarding chemical composition and possible uses of the supercritical extracts. In this dissertation, supercritical extraction from curry plant was investigated, and for the first time, supercritical extract of curry plant was used as an active component for impregnation of different solid carriers under supercritical conditions..

Fracture mechanics analysis of damaged turbine rotor discs using finite element method

This paper presents evaluation fracture mechanics parameters in low pressure turbine components. Critical locations such as keyway and dovetail area are experiencing stress concentration leading to crack initiation. Stress intensity factors were evaluated using the J-Integral approach available within ANSYS software code. The finite element method allowed the prediction of the point of crack initiation and the crack propagation using the orientations of the maximum principal stresses. Special attention in this investigation is focused to develop analytic expressions for stress intensity factors at critical location of low pres-sure steam turbine disc. [Projekat Ministarstva nauke Republike Srbije, br. I-174001 i br. TR-35045

Uvoz nerastova - kontrola semena i mogućnost reklamacije

Serbia is one of the countries with the continuous import of breeding sows and boars. Boars are usually imported at the age of 4 to 6 months, in the period when the quality of the breeding males cannot be determined due to sexual immaturity (prepubertal and pubertal age). In this paper, the method and results of semen quality control in 40 imported young boars are described, and also the method of documenting the cause for action claim. In the case of suspicious semen quality it is necesseary to perform at least 3 consecutive controls in one month intervals in order to establish a final estimation of quality and usability of semen. Of 40 imported boars, 4 boars (10%) were subject of complaint due to: azoospermia (1 boar), absence or reduction of total and progressive motility, present sperm agglutination (2 boars), and increased number of pathological forms of spermatozoa (78%, 1 boar). Increased proportion of sperm with unstable chromatin structure (SCSA test - 33.2% and 37.1%) was established in two boars. To initiate the complaint it is necessary to have a sales contract that provides possibility for the reclamation, recognized methods of semen quality control and trustful business relationship between all interested parties.Srbija se svrstava u red zemalja sa kontinuiranim uvozom priplodnih nazimica i nerastova. Nerastovi se uglavnom uvoze u dobi od 4 do 6 meseci, u periodu kada se kvalitet priplodnjaka ne može pouzdano utvrditi usled polne nezrelosti (prepubertetsko ili pubertetska dob nerastića). U ovom radu opisan je postupak i rezultati kontrole kvaliteta semena kod 40 mladih nerastova iz uvoza, kao i način dokumentovanja razloga za pokretanje postupka reklamacije. Kod sumnjivog kvaliteta semena potrebno je izvršiti najmanje 3 uzastopne kontrole u razmaku od po mesec dana, kako bi se donela konačna ocena o kvalitetu semena i upotrebljivosti nerasta za priplod. Od 40 uvezenih nerastova, 4 su reklamirana (10%) usled: azoospermije (1 nerast), odsustva ili smanjenje ukupne ili progresivne pokretljivosti, uz prisustvo aglutinacija spermatozoida (2 nerasta), i povećanog broja patoloških formi spermatozoida (78%; 1 nerast). Kod dva nerasta zabeležen je povećan udeo spermatozoida sa nestabilnom strukturom hromatina (SCSA test - 33,2% i 37,1%). Za pokretanje reklamacije neophodno je imati kupoprodajni ugovor koji predviđa mogućnost reklamacije, priznate metode kontrole semena kao i izgrađen poslovni odnos poverenja zainteresovanih strana

Analiza primenjenih biosigurnosnih mera u proizvodnji sperme nerastova

This paper gives a detailed analysis of the applied biosecurity measures in the production of boar sperm at a swine reproduction center. Biosecurity indicators (existence of a written biosecurity plan, isolation, introduction of newly acquired animals into the herd, herd health, assessment of the personnel attitude towards equipment, traffic control, attitude towards visitors, feeding and watering control, manure management, disposal of dead animal carcasses, attitude towards other animals, rodents and birds control, sanitation) were viewed and evaluated by rating scale: (5) - excellent, (4) - very good, (3) - good, (2) - sufficient, (1) - insufficient, there are resources for improvement (0) - insufficient, with no resources for improvement. Obtained data were analyzed in the SWOT process, taking into account all the strengths, weaknesses, threats and opportunities for improving the biosecurity level. The situation in the center is rated as very good, with an average rating of 4.15. However, one disadvantage is serious and related to the boar facilities isolation possibilities, taking into account their location and the presence of two types of male breeding animals (boars and bulls) in the same location. Newly acquired breeding animals are purchased from various sources, but with a rigorous regime of control and not at the same time.U radu je detaljno analizirana primena biosigurnosnih mera u proizvodnji sperme nerastova u jednom centru za veštačko osemenjavanje svinja. Sagledani su i procenjeni svi indikatori biosigurnosti (postojanje pisanog plana biosigurnosti, izolacija, uvođenje novonabavljenih životinja u zapat, zdravstveni status zapata, ocena odnosa osoblja prema opremi, kontrola kretanja i prometa, odnos prema posetiocima, kontrola ishrane i vodosnabdevanja, izđubravanje, uklanjanje leševa uginulih životinja, odnos prema drugim životinjama na farmi, kontrola populacija glodara i ptica, sanitacija), i ocenjeni prema skali ocena: (5) - odličan, (4) - vrlo dobar, (3) - dobar, (2) - dovoljan, (1) - nedovoljan, ima resursa za poboljšanje, (0) nedovoljan, nema resursa za poboljšanje. U razmatranju rezultata primenjena je SWOT analiza i utvrđene prednosti, nedostaci, rizici i mogućnosti za podizanje nivoa biosigurnosti. Stanje u centru je ocenjeno kao vrlo dobro, uz prosečnu ocenu 4,15. Međutim, jedan nedostatak je veoma ozbiljan i odnosi se na mogućnost izolacije objekata, uzimajući u obzir njegovu lokaciju i prisustvo dve vrste muških priplodnih životinja (nerastova i bikova) na istoj lokaciji. Nove priplodne životinje se nabavljaju iz različitih izvora, ali uz rigorozan režim kontrole i ne u isto vreme. Svakako, izmeštanje objekata za držanje priplodnih nerastova na drugu bezbednu lokaciju predstavlja složen ali prioritetan zadatak, kojim bi se otklonile brojne pretnje po proizvodnju sperme