University of Niš: Facta Universitatis (E-Journals) / Универзитет у Нишу
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ON THE SQUARE-INTEGRABLE SOLUTIONS OF SINGULAR IMPULSIVE DYNAMIC STURM-LIOUVILLE EQUATIONS
Get PDFIn this work, singular impulsive dynamic Sturm{Liouville equations are studied. Weyl’s famous classification was obtained for equations of this type. In this context, firstly, it is defined as the maximal operator that corresponding to the problem. Then, under impulsive conditions, we studied the square integrability of the solutions to the dynamic Sturm{Liouville problem. Weyl’s well-known limit-circle/limit-point situations were examined last
OCCUPATIONAL SAFETY AND HEALTH CHALLENGES IN SERBIAN CHEMICAL LABORATORIES: GAPS IN RISK ASSESSMENT, TRAINING, AND INSTITUTIONAL SUPPORT
Get PDFOccupational safety and health (OSH) are critical in chemical laboratories, where employees are routinely exposed to hazardous substances. Despite a comprehensive legal framework in Serbia, gaps remain in the implementation of protective measures, training, and institutional support. This study assessed awareness, training, and preparedness of laboratory employees in Serbia, focusing on risk assessment, chemical hazard monitoring, and institutional mechanisms. A cross-sectional survey was conducted in June–July 2024 using a structured online questionnaire. The sample included 101 permanently employed staff across universities, research institutes, and other laboratories where chemicals are used. Data were analyzed using descriptive statistics. Results revealed substantial shortcomings: over 70% of employees were unfamiliar with workplace risk assessments, and only 15.8% reported chemical hazard monitoring. Training participation was low, with just 15.8% attending regularly and one-third completing initial training. Specialized training was inadequate: 15.8% for SDS interpretation, 21.8% for PPE, 14.9% for decontamination, and 52.5% for first aid. While 58.4% acknowledged an OSH advisor, nearly one-third were unaware of such mechanisms. These findings indicate critical weaknesses in OSH implementation. Strengthening risk assessment transparency, expanding specialized training, introducing practical drills, and ensuring stricter legal compliance are essential to improving safety and aligning with international best practices
RAZVOJ PRVE NIŠKE GIMNAZIJE OD 1878. DO 1914. GODINE
No full textThe paper provides an overview of the development of the first gymnasium in Niš from its foundation in 1878 until 1914, that is, until the beginning of the First World War. For the realization of this work, both published and unpublished sources, as well as press and professional literature, were used. The paper includes the establishment of the first gymnasium in Niš and all the difficulties that affected its development, such as lack of space for teaching, an insufficient number of professors, lack of teaching and material resources and insufficient preparation of students for gymnasium enrollment. In addition, the paper also talks about the importance of the first gymnasium in Niš for the development of the urban population, as well as the city of Niš itself.Rad daje pregled razvoja prve gimnazije u Nišu od njenog osnivanja 1878. godine do 1914. godine, odnosno do početka Prvog svetskog rata. Za realizaciju ovog rada korišćeni su i objavljeni i neobjavljeni izvori, kao i štampa i stručna literatura. U radu se obrađuje osnivanje prve gimnazije u Nišu i sve teškoće koje su uticale na njen razvoj, poput nedostatka prostora za nastavu, nedovoljnog broja profesora, nedostatka nastavnih i materijalnih sredstava, kao i nedovoljne pripremljenosti učenika za upis u gimnaziju. Pored toga, rad govori i o značaju prve gimnazije u Nišu za razvoj građanskog sloja, kao i samog grada Niša
NUMERICAL MODELLING OF THE CROSSWIND INFLUENCE ON VEHICLE AERODYNAMICS IN HIGHWAY TRAFFIC CONDITIONS
Get PDFThis study presents an efficient numerical model for evaluating the impact of crosswinds on vehicle aerodynamics using ANSYS Fluid Flow. It offers valuable insights into the qualitative behavior of vehicles under typical highway traffic conditions. The analysis explores airflow distribution when a car overtakes a truck at approximately 100 km/h, considering weak, moderate, and strong lateral winds. A detailed examination of the overtaking phases, with vehicles positioned in three distinct configurations, reveals significant aerodynamic interactions. These interactions influence vehicle handling and stability, as reflected in variations in velocity and pressure distributions, increased drag coefficients for the truck under stronger lateral winds, and significant fluctuations in the car’s drag coefficients based on its position relative to the truck. Additionally, Reynolds numbers indicate a transition to turbulent flow. This paper provides an in-depth analysis and discussion of these findings
KONCEPT OSEĆANJA U KREATIVNOM PROCESU PREMA TEODORU DE VIZEVI: OD KANTA DO LAVA TOLSTOJA I RIČARDA VAGNERA
No full textL’article examine les origines des points de vue esthétiques de Théodore de Wyzewa, critique et traducteur français, et brillant représentant de l’idéalisme subjectif. L’accent est mis sur l’influence des idées de Kant et de Tolstoï sur le concept du sentiment dans l’interprétation de Wyzewa.Članak ispituje poreklo estetskih pogleda Teodora de Vizeve, francuskog kritičara i prevodioca, i blistavog predstavnika subjektivnog idealizma. Akcenat je stavljen na uticaj Kantovih i Tolstojevih ideja na koncept osećanja u Vizevinoj interpretaciji
COMPARATIVE CHEMICAL ANALYSIS OF ORIGANUM MAJORANA ESSENTIAL OILS FROM SERBIA AND EGYPT
Get PDFThe chemical composition of commercial marjoram (Origanum majorana) essential oils sourced from Serbia and Egypt was investigated using GC and GC-MS. The major volatile compounds in both oils were terpinen-4-ol and γ-terpinene, constituting over a third of the oils based on GC peak areas. However, there were significant differences between the two oils in terms of their cis- and trans-sabinene hydrate content, which are commercially important monoterpenes. The Egyptian oil contained 12.1% trans-sabinene hydrate and 3.5% cis-sabinene hydrate, while the Serbian oil contained a total of 7.3% cis- and trans-sabinene hydrates in a 1:1.7 ratio
INTEGRATING DEEP LEARNING FOR AUTOMATED DETECTION OF NEGATIVE HOTEL REVIEWS
Get PDFThis paper presents an automated deep learning framework for detecting and classifying negative hotel reviews, integrating both textual and numerical inputs. The model utilizes a Fully Connected Feedforward Neural Network (FCNN) to capture complex global relationships and non-linear patterns in the data, ensuring accurate classification of negative reviews. Experimental results show that the model achieves an accuracy of 90.1% and precision of 88.6%. These results demonstrate the model's effectiveness in processing large-scale datasets, outperforming traditional methods in terms of classification performance. By automating the detection of negative reviews, our approach offers a scalable solution for the hospitality industry to enhance both operational efficiency and customer satisfaction
RULED SURFACES WITH CONSTANT CURVATURES IN A STRICT WALKER 3-MANIFOLD
Get PDFIn this paper, we give explicit descriptions for a family of ruled surfaces in a strict Walker 3-manifold with constant Gaussian or mean curvature according to the causal character of the surfaces (timelike, spacelike, and lightlike). For each causal character of the considered family of ruled surface, we start with the constant Gaussian curvature case and we end with the constant mean curvature situation
NOTE ON POINTWISE QUASI BI-SLANT SUBMERSIONS IN COMPLEX GEOMETRY
Get PDFIn this article, we acquaint with the notion of pointwise quasi bi-slant (PQBS, in brief) submersions in complex geometry. We present the concept of pointwise quasi bi-slant submersions from almost Hermitian manifolds onto Riemannian manifolds as a generalization of pointwise hemi-slant submersions and pointwise semislant submersions and specially, we study such submersions from K¨ahler manifolds onto Riemannian manifolds. We explore the geometry of leaves of distribution which are involved in discussed submersions and furnish with a characterization theorem for pointwise quasi bi-slant submersions with totally umbilical fibers
GEOMETRIC STRUCTURES ON THE CROSS SECTION IN THE TANGENT BUNDLE
Get PDFOur goal is to investigate the Lie derivative in the tangent bundle TM with regard to the complete and vertical lifts of almost para-contact structures by using partial differential equations. We study certain theorems about vector fields inTM that are almost analytic. Additionally, the complete lift of an almost product structure in TM is examined along the cross section