University of Niš: Facta Universitatis (E-Journals) / Универзитет у Нишу
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ANALYSIS OF THE IMPACT OF VALVE CHARACTERISTIC CURVE ON WATER HAMMER
Full text linkThere are various causes of water hammer, one of which is the control valve, a component found in most hydraulic systems. This paper examines the impact of inherent and installed control valve characteristics on hydraulic transient regimes. It is well known that guide vanes or nozzles are the primary flow control devices for hydro turbines, while the main turbine inlet valves are the secondary devices, and one of their tasks is to interrupt water supply to the turbine in case of failure of the primary regulators. Three typical inherent valve characteristic curves were selected and their installed characteristics were determined for two derivation pipeline diameters, after which three valve closure times were analyzed, starting from the nominal operating regime. Numerical analyses of unsteady flow regimes are used to obtain pressure distributions and max/min pressure envelopes during water hammer. In order to improve the system's characteristics in unsteady flow regimes, variable speed actuators were analyzed, new valve closing laws were designed, and possible performance improvements were quantified and proposed for practical engineering applications
THE SINGLE CUT-OFF CANNOT SEPARATE FASTING AND MEAN: HYPOGLYCEMIA, MID-RANGE GLYCEMIA AND HYPERGLYCEMIA IN AMI
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CUTANEOUS PENILE AND SCROTAL METASTASES FROM RECTAL ADENOCARCINOMA - CASE REPORT AND LITERATURE REVIEW
Full text linkPenile and scrotal metastases from rectal adenocarcinoma are rare and usually indicate advanced disease with poor prognosis. We report a 59-year-old male with locally advanced rectal cancer presenting with rectal bleeding. Imaging revealed a circumferential distal rectal tumor with extensive mesorectal, iliac, and inguinal lymphadenopathy. Elevated CEA and CA 19-9 were noted. The patient underwent neoadjuvant treatment. Twelve weeks later, multiple nodular and ulcerative lesions appeared on the penis, scrotum, inguinal region, and mons pubis. Skin biopsy confirmed metastatic rectal adenocarcinoma. Palliative colostomy was performed due to intestinal obstruction, but the patient died shortly after. Retrograde venous and lymphatic spread were likely mechanisms of metastasis. No standardized treatment exists; management is largely palliative. This case highlights an atypical and aggressive metastatic pattern of rectal adenocarcinoma. Awareness of cutaneous penoscrotal metastases is crucial, although the prognosis remains poor. Key words: rectal adenocarcinoma, penile metastasis, scrotal metastasis, surgery
IZVEŠTAVANJE O PARAOLIMPIJSKIM IGRAMA U TOKIJU KROZ FOTOGRAFIJE U SRPSKIM MEDIJIMA
No full textPhotos are an important tool when journalists want to tell the story of an event. One such example is the Paralympic Games, the largest elite sporting event for athletes with disabilities. The aim of this study is to analyze photos from the Serbian media during the Tokyo Paralympics in Tokyo. The research material consisted of Serbian daily media reporting during the Tokyo Paralympic Games, collected through the online platform PressReader. A conceptual analysis was used to analyze the photos by determining the presence and frequency of concepts in the photos. When reviewing selected Serbian daily newspapers, we found 41 photos depicting predominantly male persons, 28 photos showing a disability, that the athletes in the photos are predominantly of Serbian nationality, that only a few sports are shown, and that the focus was on athletes in wheelchairs. The results indicate that media coverage needs to be improved.TRANSLATE with x EnglishArabicHebrewPolishBulgarianHindiPortugueseCatalanHmong DawRomanianChinese SimplifiedHungarianRussianChinese TraditionalIndonesianSlovakCzechItalianSlovenianDanishJapaneseSpanishDutchKlingonSwedishEnglishKoreanThaiEstonianLatvianTurkishFinnishLithuanianUkrainianFrenchMalayUrduGermanMalteseVietnameseGreekNorwegianWelshHaitian CreolePersian // TRANSLATE with COPY THE URL BELOW Back EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster PortalBack//Fotografije su važan alat kada novinari žele da ispričaju priču o nekom događaju. Jedan takav primer su Paraolimpijske igre, najveći elitni sportski događaj za sportiste sa invaliditetom. Cilj ovog istraživanja jeste analiza fotografija srpskih medija tokom održavanja Paraolimpijskih igara u Tokiju. Materijal istraživanja činili su dnevni srpski mediji koji su izveštavali tokom Paraolimpijskih igara u Tokiju, prikupljeni preko onlajn platforme PressReader. Za analizu fotografija korišćena je konceptualna analiza, preko koje su se utvrđivali postojanje i učestalost pojmova na fotografijama. Pregledom izabranih srpskih dnevnih listova, pronašli smo 41 fotografiju, na koji se pretežno nalaze osobe muškog pola, invaliditet je vidljiv na 28 fotografija, sportisti na fotografijama su pretežno srpske nacionalnosti, prikazan je mali broj sportova uz potenciranje sportista u kolicima. Dobijeni rezultati sugerišu da je potrebno unapređivanje medijskog izveštavanja
EVALUATION OF SERUM PERIOSTIN AND PIIINP AS BIOMARKERS OF RENAL FIBROSIS AND FUNCTION DECLINE IN RENAL TRANSPLANT PATIENTS
Full text linkThis study aimed to evaluate the potential of serum periostin and N-terminal propeptide of type III procollagen (PIIINP) as biomarkers for predicting renal fibrosis and functional decline in renal transplant patients. We conducted a two-visit observational study among 86 renal allograft patients, reduced to 35 at the two-year follow-up due to the COVID-19 pandemic. Blood samples were collected at baseline and follow-up, while urine samples were collected only at follow-up. Serum levels of PIIINP and periostin were measured using ELISA kits, and various renal function parameters were assessed. Serum PIIINP levels showed a significant decrease over two years (p<0.001, Wilcoxon test), while periostin levels significantly increased (p<0.001, Wilcoxon test). These changes correlated with declines in renal function, as indicated by decreased serum albumin and creatinine clearance levels, and increased serum creatinine levels. Significant correlations were found between changes in PIIINP and creatinine clearance (Spearman coefficient = 0.352, p<0.05), as well as between changes in periostin and creatinine clearance (Spearman coefficient = 0.626, p<0.001). Our findings suggest that serum periostin and PIIINP levels are valuable biomarkers for assessing renal fibrosis and functional decline in renal transplant patients. These biomarkers may provide insights into disease progression and guide therapeutic interventions.
EFEKAT RELATIVNE STAROSTI U SRPSKOM FUDBALU
No full textThe aim of this research was to examine the presence of Relative Age Effect (RAE) among professional football players in Serbia. The presence of RAE is reflected through the unequal distribution that favors players born closer to the selection cutoff date. The total sample included 913 professional football players in Serbia during the 2022/2023 season. A chi-square test (χ2) was used to determine differences in the distribution of players birthdays by quarters and post-hoc z-test with Bonferroni correction were applied for pairwise comparison between quarters. The results for the total sample indicate statistically significant differences in player representation (χ2 = 16.17, p = .001, ES = .078). The presence of the RAE was confirmed in the Serbian First League (χ2 = 15.94, p = .001, ES = .069), but not in the Super League (χ2 = 5.49, p = .139, ES = .063). No significant differences were found in the distribution of players from teams competing in the play OFF (χ2 = 5.53, p = .137, ES = .061) or play OUT (χ2 = 2.15, p = .543, ES = .034). Nevertheless, descriptive statistics show the highest representation of player born in Q1 in both groups. The results of this study confirm the presence of RAE among professional football players in Serbia; however RAE does not appear to be a factor that significantly affects team standings at the senior competition level. To mitigate the adverse effects of this phenomenon, it is necessary to modify talent identification strategies in Serbia.Cilj ovog istraživanja bio je da se ispita prisustvo efekta relativne starosti (RAE) kod profesionalnih fudbalera u Srbiji. Prisustvo RAE se ogleda kroz nejednaku raspodelu fudbalera koja favorizuje igrače rođene bliže početnom datumu u selektiranju. Ukupan uzorak je predstavljalo 913 profesionalnih igrača koji su nastupali u Srbiji tokom sezone 2022/2023. Hi-kvadrat test je korišćen za utvrđivanje razlika u distribuciji rođendana igrača po kvartalima, a post-hoc analiza z-test sa Bonferoni korekcijom je primenjena za poređenje između kvartala. Rezultati za ukupan uzorak pokazuju statistički značajne razlike prema zastupljenosti igrača po kvartalima (χ2 = 16.17, p = .001, ES = .078). Prisustvo fenomena RAE je potvrđeno u Prvoj ligi Srbije (χ2 = 15.94, p = .001, ES = .069), ali ne i u Super Ligi (χ2 = 5.49, p = .139, ES = .063). Nisu utvrđene značajne razlike u distribuciji igrača koji su igrali u play off (χ2 = 5.53, p = .137, ES = .061) kao i play out delu takmičenja (χ2 = 2.15, p = .543, ES = .034). Ipak, deskriptivna statistika pokazuje najveću zastupljenost igrača rođenih u Q1 za obe grupe. Rezultati ovog istraživanja potvrđuju prisustvo RAE kod profesionalnih fudbalera u Srbiji, ali ukazuju na to da RAE nije faktor koji značajno utiče na plasman timova u seniorskoj konkurenciji. Kako bi se ublažili nepovoljni efekti ovog fenomena neophodno je modifikovati strategiju identifikacije talentovanih igrača u Srbiji
OCCUPATIONAL HEALTH AND SAFETY CULTURE IN SERBIA: A SEVEN-DIMENSION ASSESSMENT
Full text linkOccupational health and safety (OHS) culture is central to decent work (Sustainable Development Goal (SDG) 8.8) and a key lever of organisational resilience. This paper assesses OHS culture in Serbia using a cross-sectional survey structured around seven dimensions: vision, credibility, collaboration, feedback and recognition, responsibility, communication, and action orientation. Responses are summarised at dimension levels and interpreted against a desired, improvement-oriented state embedded in the instrument. The analysis highlights uneven maturity across dimensions and identifies concrete opportunities to strengthen day-to-day safety practices and learning routines. In light of these gaps, a prioritised improvement pathway for organisations is proposed: (i) making leadership commitment visible and credible; (ii) institutionalising joint problem-solving and open communication; (iii) systematising feedback and recognition to reinforce desired behaviours; and (iv) introducing a set of leading indicators to guide continuous improvement. The study provides a multi-dimensional baseline for Serbia and a clear set of actionable pathways for practitioners and policymakers seeking to enhance workplace well-being and resilience while advancing the decent-work agenda
MQTT ENABLED DEVICE FOR INDUSTRIAL ENVIRONMENT AND SMART CITY
Full text linkAn enormous range of industries is covered by the Industrial Internet of Things (IIoT). IIoT covers any device or system with sensors connected to a GSM/GPRS module or network and gathering/sharing data. Any device in the industry can consist of a low-cost sensor connected to a network, allowing them to be monitored and tracked, sharing data on their status, and communicating with other devices. It means identifying possible problems fast, which leads to cost-effective processes. It can be scaled from a single device up to massive platform distribution of embedded technologies and cloud systems connected in real-time. With all that, numerous communication protocols allow devices and servers to communicate with each other in a more interconnected way. This research provides using the MQTT protocol for communication between the GSM/GPRS module and the cloud system. The system is made of PIC18F46K22 microcontroller, GSM/GPRS module RS485 serial communication, and DHT11 temperature sensor. The data are being sent to the ThingSpeak server and environmental parameters are being measured for a certain period of time
A COMPREHENSIVE FRAMEWORK FOR OCCUPATIONAL HEALTH AND SAFETY PERFORMANCE EVALUATION
Full text linkOccupational health and safety (OHS) is not a phenomenon of the modern era but rather a field with deep historical roots and continuous development through several distinct phases. According to the European Agency for Safety and Health at Work (EU-OSHA), the social cost of work-related injuries and diseases amounts to 3.9% of global GDP and 3.3% of EU GDP, while the loss of GDP in the European Union is the lowest among all regions, according to the World Health Organization (WHO). In these challenging times, when the world of work is undergoing rapid technological and organizational transformations, the evaluation of OHS performance is becoming increasingly significant. Systematic monitoring of various performance indicators at different organizational levels enables the assessment of both proactive and reactive aspects of occupational safety and health. This paper reviews recent scientific literature and relevant international standards, particularly ISO 45004:2024, which provides guidelines for the evaluation of OHS performance. The analysis emphasizes the importance of combining quantitative and qualitative indicators, applying both leading and lagging measures, and fostering a positive safety culture as a foundation for continuous improvement. The paper presents current perspectives on how to achieve effective evaluation of OHS performance through the integration of standardized methods, management commitment, and a mature organizational safety culture - key factors in enhancing both worker protection and organizational resilience
ON hα-IRRESOLUTE TOPOLOGICAL VECTOR SPACES
Full text link In this paper, we defined and investigated a generalized type of topological vector space known as -irresolute topological vector spaces by using the notion of -open sets, which was given by Abdullah et al. \cite{8} in 2022. We explore and investigate several properties and characterizations of this new notion of -irresolute topological vector space. Also we give the several characterizations of -compact space and -Hausdorff space. Furthermore, we show that an -irresolute topological vector space is -hausdorff iff one-point set in is -closed in