New geometry and technology of face-gear forming with circle line of teeth on CNC milling machine

Different types of geometric models of face-gear with circle line of teeth have been shown in the paper. Generation of a new geometrical of a face-gear is performed on CNC milling machine. The basic direction of the development geometrical of a face-gear and technology is in the search of new trends and methods focused on improving the quality of products, shortening the production cycles, their mechanizations, automation and implementation of a high-precision technology

Nova geometrija i tehnologija oblikovanja hipoidnih zupčanika na CNC glodalici

Different types of geometric models of face-gear with circle line of teeth have been shown in the paper. Generation of a new geometrical of a face-gear is performed on CNC milling machine. The basic direction of the development geometrical of a face-gear and technology is in the search of new trends and methods focused on improving the quality of products, shortening the production cycles, their mechanizations, automation and implementation of a high-precision technology.Različiti tipovi geometrijskih modela hipoidnih zupčanika su prikazani u radu. Izrada novog geometrijskog oblika zupčanika je provedena na CNC glodalici. Temeljni smjer razvoja geometrijskih oblika zupčanika i tehnologije izrade je u traženju novih trendova i metoda za unaprjeđenje kvalitete proizvoda, skraćenja trajanja proizvodnog ciklusa, njegova mehanizacija, automatizacija iimplementacija visokoprecizne tehnologije

The Mossbauer spectroscopy studies of retained austenite

Purpose: of this paper: This paper completes the knowledge concerning the mechanisms of destabilization and properties of retained austenite. Investigations were performed on 120MnCrMoV8-6-4-2 steel, which was designed in 1998, in Phase Transformations Research Group of Department of Physical and Powder Metallurgy at the Faculty of Metals Engineering and Industrial Computer Science at AGH University of Science and Technology in Krakow. Design/methodology/approach: The samples of investigated steel were austenitized at the temperature of 900ºC and hardened in oil. Next, three from four samples were tempered. Tempering consisted of heating the samples up to chosen temperatures with a heating rate of 0.05ºC/s and, after reaching desired temperature, fast cooling. CEMS technique was applied for Mössbauer studies. Findings: Stabilized by heating up to 80ºC retained austenite, in the result of mechanical destabilization, transforms into low-temperature tempered martensite, with the structure of low bainite (into the structural constituent in which ε carbide exists). Research limitations/implications: The influence of the temperature, up to which the samples were heated during tempering, on the mechanical stability of retained austenite and on the products of its transformation, was determined. Practical implications: Changes occuring in retained austenite during tempering of steel of high hardenability (hardness), developed for potential applications on tools of enhanced wear resistance, were described. Originality/value: Mössbauer spectroscopy was applied not only for qantitative analysis of retained austenite, but also to analyze the values of quadrupole splitting and isomeric shift, what resulted in significant conclusions concerning the changes in its chemical composition, microstructure, and the level of stresses being present in it

Mjerenje ravnosti dugačkih strojnih vodilica

This paper shows the guideway types of large machines and describes problems with their straightness measurement. A short description of straightness measurement methods and the results of investigation in straightness of 10 meter long guideways of a CNC machine by means of the XL-10 Renishaw interferometer are also presented.Rad prikazuje tipove vodilica velikih strojeva i opisuje probleme mjerenja njihove ravnosti. Dat je također i opis metoda mjerenja ravnosti, te rezultati ispitivanja ravnosti 10 metarskih vodilica CNC stroja pomoću XJ-10 Renishawovog interferometra

Bridging senses of place and mobilities scholarships to inform social-ecological systems governance:A research agenda

Uncertainty and change are increasingly commonplace as communities respond to impacts of social-ecological change including climate change, and dangerous levels of pollution. Given the extent of these crises, new approaches are needed to support responses. Here we identify challenges and discuss insights that the nexus of Senses of place (SoP) and mobilities research offers in navigating such uncertainty. We conducted a two-round Delphi, followed by a workshop, and collaborative writing process with a global network of researchers with expertise in either or both SoP and mobilities research. Participants identified five challenges at the place-mobility nexus that emerge when a social-ecological system is disrupted. We use the 2022 Odra River fish die-off to exemplify the identified challenges: 1) accounting for power dynamics, inequalities and motility; 2) doing justice to more-than human actors; 3) integrating multiple and sometimes nested spatial scales; 4) considering temporalities of place and mobilities, and 5) embracing multisensoriality. To address these challenges, we recommend drawing on diverse methods and knowledge co-creation processes that combine more-than-human perspectives, multisensoriality, and engage in the dynamic relations between places to understand people-place disruptions in the face of socio-spatial precarity. Addressing such knowledge gaps requires stronger collaboration of mobilities and place researchers.</p

Bridging senses of place and mobilities scholarships to inform social-ecological systems governance:A research agenda

Uncertainty and change are increasingly commonplace as communities respond to impacts of social-ecological change including climate change, and dangerous levels of pollution. Given the extent of these crises, new approaches are needed to support responses. Here we identify challenges and discuss insights that the nexus of Senses of place (SoP) and mobilities research offers in navigating such uncertainty. We conducted a two-round Delphi, followed by a workshop, and collaborative writing process with a global network of researchers with expertise in either or both SoP and mobilities research. Participants identified five challenges at the place-mobility nexus that emerge when a social-ecological system is disrupted. We use the 2022 Odra River fish die-off to exemplify the identified challenges: 1) accounting for power dynamics, inequalities and motility; 2) doing justice to more-than human actors; 3) integrating multiple and sometimes nested spatial scales; 4) considering temporalities of place and mobilities, and 5) embracing multisensoriality. To address these challenges, we recommend drawing on diverse methods and knowledge co-creation processes that combine more-than-human perspectives, multisensoriality, and engage in the dynamic relations between places to understand people-place disruptions in the face of socio-spatial precarity. Addressing such knowledge gaps requires stronger collaboration of mobilities and place researchers.</p

Short-circuit duration and dynamic forces in central section of substation

Presented topic is the continuation of investigations concerning the estimation of short-circuit duration when computing the short-circuit effects using probabilistic methods. In the paper, an expanded model of distribution substation for simulation-based analysis of the short-circuit conditions and dynamic effects in the central section of bus-bar is presented. In the model, the operation of protections in the transformer bay has also been considered. The results of simulations aiming to assess the frequency of occurrence of the defined values of short-circuit current, short-circuit duration and dynamic forces are reported. Also, the question: “How the transformer’s protections involved in simulation affect the simulated short-circuit conditions?” has been answered. Computations have been carried out for four different EAZ system configurations

Probabilistic assessment of the short-circuit duration on the 220 kV transmission line basing on simulation analysis

In the paper, the problem of defining the short circuit duration time for the short-circuit effect calculations, especially thermal and electromagnetic ones, has been discussed. In author’s opinion, the results of probabilistic research could be helpful when resolving the problem. Therefore, a tailored simulation model based on the analysis of the protections and circuit breakers operation during the transmission lines fault clearance has been developed. Due to the results of simulation study, the found values of the fault duration time could be related to the expected risk of their exceeding depending on both the protection system configuration and the type of the circuit breakers applied

Factors affecting short-circuit duration values being determined during analysis of dynamic forces in distribution substation

Artykuł dotyczy zagadnienia określania wartości czasu trwania zwarcia podczas obliczania skutków dynamicznych w rozdzielniach najwyższych napięć z przewodami giętkimi metodą statystyczno-probabilistyczną. Do realizacji zadania opracowano model symulacyjny, którego ważnym elementem jest model czasu trwania zwarcia. Wykorzystując opracowaną metodę określania wartości czasu trwania zwarcia dla potrzeb obliczeń dynamicznych sił w rozdzielniach elektroenergetycznych opartą na kryterium ryzyka, zbadano wpływ parametrów przęsła, konfiguracji EAZ oraz awaryjności wyłączników i zabezpieczeń na rezultaty prowadzonych badań.The paper refers to the finding of the short-circuit duration values when computing the dynamic effects in the EHV distribution substations with flexible conductors using statistical-probabilistic method. A dedicated simulation model comprising an important element i.e. a short-circuit duration model has been developed. Using the elaborated risk criterion-based method of determination of the short-circuit duration values when computing the dynamic forces in the distribution substations, the influence of the span parameters, EAZ configuration and failure rate of the circuit-breakers and protections on the results of the conducted investigations has been discussed