1. The ǂcircular economy : the ǂbutterfly diagram, systems theory and the economic pluriverseKeith R. Skene, Andreea Oarga-Mulec, 2024, original scientific article Keywords: earth system, non-linearity, emergence, regeneration, resilience, restoration, supply chain network Published in RUNG: 12.08.2024; Views: 646; Downloads: 2 Full text (758,34 KB) This document has many files! More... |
2. Morphogenesis of the Postojna Basin karst periphery : dissertationAstrid Švara, 2023, doctoral dissertation Abstract: This thesis represents a karstological study on the drainage of the Postojna Basin. It focuses on a multidisciplinary approach, based on fieldwork, computer analyses and dating. The northern study area has the highest: doline density of 108 dolines/km2, number of contact karst features (i.e. 9), and number of collapse dolines (i.e. 19). It has three catchments. The Lokva cuts into the flysch ridges and sinks in the Predjama Cave System at the lowest point of the basin (i.e. 474 m a.s.l.). Between 37 selected caves, 14 were longer than 150 m. The Predjama Cave System was developed in 3 levels and the Postojna Cave System was developed in 2 levels. The vertical passages connecting them are deepest in the Predjama cave, where the vadose zone is up to 250 m deep. By the favourable ponor steepheads and 140 m deep vadose passages, the Hrušica Plateau shows a major uplift phase. The Postojna Cave System, Risovec blind valley and 17 collapse dolines indicate significant past hydrological changes. First, Nanoščica formed the Risovec blind valley, followed by Otoška jama, Tartarus, Male jame, and Artificial tunnel toward E/NE, forming the Vodni dol. At the same time, the ponor of Pivka shifted in the Postojnska jama (at present “Stara jama”), flowing towards N, forming Jeršanove doline. The successive subsidence of the erosional base and the Postojna karst uplift redirected the Nanoščica in Pivka. Now they sink into active parts of the Postojna cave at 511 m a.s.l. The eastern study area has the Unroofed cave Kriva dolina as a former ponor of Pivka. At present the area has springs and favourable (sub)vertical passages. The southern study area has the highest variety of contact karst features (i.e. 5). The Prestranški ravnik represents an aquifer with ponors and springs. It is separated from the Slavinski ravnik, by a flysch belt. In the southern study area, 10 caves were longer than 150 m among 49 selected caves. The Loza Cave System, a case study in Slavinski ravnik, is developed in 3 epiphreatic levels that followed two phases of tectonic uplift with a successive formation of diversion routes through 30-40 m deep vadose passages. The oldest upper cave level has sediments from at least the Gilbert Chron with CW rotations. U-Th dates from speleothems prove vadose speleogenesis before the cave ceiling denudation and collapse from 210 ka to 550 ka (≤1.2 Ma). The middle cave level has epiphreatic sediments at least in the Gauss Chron (i.e. 2.59-3.59 Ma) and reveals 35-38° CCW rotations. The allogenic sediments in the lower cave level show Brunhes and Matuyama Chrons (i.e. <0.78-2.58 Ma). We generally discussed ponor steepheads that develop on steepest slopes on the thrust/fault contact, while blind valleys and border depressions develop on normal stratigraphic contact with mildest slopes. The speleogenesis was mainly driven by relatively quick tectonic uplift, followed by vadose speleogenesis, with intermediate speleogenesis in the epiphreatic zone. Speleogenesis and contact karst features follow the subsidence of the water table, evidenced by cave levels, and active and relict features. Allogenic sediments are followed by speleothems as shift of caves between hydrological zones. The sequence of events repeated 2-3 times. The main local source of allogenic sediments is in the Postojna Basin, represented by the erosion of flysch rocks and alluvium. The mineralogical composition between catchments is similar with no significant change. The regional compressional-tectonic regime has significantly influenced the changes in the drainage of the Postojna Basin during the last 7 Ma, with different uplifts and drop of the karst water table. The major uplift was reflected by the change in the Nanoščica course from the Slavinski ravnik to the Postojna karst from S to N, presumably between 3.59 Ma and >1.77 Ma and represented the last important general shift in the drainage of the Postojna Basin. Keywords: karst, contact karst, regional tectonic uplift, cave levels, shift from epiphreatic to vadose speleogenesis, Loza Cave System, Postojna drainage basin Published in RUNG: 05.12.2023; Views: 1528; Downloads: 70 Full text (29,89 MB) |
3. Simulation cases of advanced driver-assistance systemsOliver Angelov, 2023, undergraduate thesis Abstract: In the bachelor’s thesis, advanced driver-assistance systems are discussed and explained. The focus of the explanation is placed on two specific systems, the anti-lock braking system and the automatic transmission system. To provide a deeper understanding of these systems, simulations were created using the computer program. Computer simulation is explained and the types of computer simulation are discussed. Programs used for computer simulation are presented and explained. The program used for computer simulation in this bachelor’s thesis is Scicos, and the visual and interactive representation of the anti-lock braking system and the automatic transmission system is made. For the anti-lock braking system, the simulation scheme is divided into models representing various components of the system, such as the vehicle, wheel, slip, friction, and control. Each of these models interacts with one another to replicate the functioning of the anti-lock braking system. Similarly, for the automatic transmission system, the simulation scheme is divided into models representing the driver and environment, engine, transmission, vehicle, and controller. These models interact to simulate the operation of the automatic transmission system. The thesis presents the results from the simulation of these two systems to analyze the difference in using the systems in different driving scenarios. The effect of the advanced driver-assistance systems in the vehicles is also showcased. Keywords: Advanced driver-assistance systems, computer simulation, Scicos, anti-lock braking system, automatic transmission system. Published in RUNG: 03.10.2023; Views: 1759; Downloads: 17 Full text (3,04 MB) |
4. The Monitoring, Logging, and Alarm system for the Cherenkov Telescope ArrayAlessandro Costa, Saptashwa Bhattacharyya, Barbara MARČUN, Judit Pérez Romero, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, published scientific conference contribution Abstract: We present the current development of the Monitoring, Logging and Alarm subsystems in the framework of the Array Control and Data Acquisition System (ACADA) for the Cherenkov Tele-scope Array (CTA). The Monitoring System (MON) is the subsystem responsible for monitoring and logging the overall array (at each of the CTA sites) through the acquisition of monitoring and logging information from the array elements. The MON allows us to perform a systematic approach to fault detection and diagnosis supporting corrective and predictive maintenance to minimize the downtime of the system. We present a unified tool for monitoring data items from the telescopes and other devices deployed at the CTA array sites. Data are immediately available for the operator interface and quick-look quality checks and stored for later detailed inspection. The Array Alarm System (AAS) is the subsystem that provides the service that gathers, filters, exposes, and persists alarms raised by both the ACADA processes and the array elements su-pervised by the ACADA system. It collects alarms from the telescopes, the array calibration, the environmental monitoring instruments and the ACADA systems. The AAS sub-system also creates new alarms based on the analysis and correlation of the system software logs and the status of the system hardware providing the filter mechanisms for all the alarms. Data from the alarm system are then sent to the operator via the human-machine interface. Keywords: Cherenkov Telescope Array, Array Control and Data Acquisition System, Monitoring System, Array Alarm System Published in RUNG: 18.09.2023; Views: 1181; Downloads: 5 Full text (936,81 KB) This document has many files! More... |
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6. DESIGN AND IMPLEMENTATION OF THE SUPERVISORY MODULE AS PART OF A SYSTEM FOR CONDITION MONITORING AND CONTROL OF SOLID OXIDE ELECTROLYSIS CELL SYSTEMSAmina Uglješa, 2023, master's thesis Abstract: Hydrogen is playing an important role in many sectors of modern economy (green vehicles, energy conversion and storage in electrical grids, processing industry). Solid oxide electrolysis cell (SOEC) is an emerging technology for the production of hydrogen from steam and electrical energy as well as for renewable energies storage. Unfortunately, operating at high current and electrical transients cause degradation that leads to premature end of life. A remedy is to implement a hardware module capable to perform online condition monitoring and optimization of SOEC systems resulting in improved overall performance and extended lifetime. That is expected to significantly expand their deployment on the market.
However, very little has been done so far. The H2020 project REACTT seems to be one of the first attempts to build an embedded system for monitoring, diagnosis, prognostics, and control (MDPC) for SOEC system. The underlying master's thesis contributes to the REACTT project in the segment related to the supervision of different modules of the MDPC system. The supervisor module is aimed to orchestrate the operation of various functional modules (agents) such as data acquisition, system optimization, diagnosis, prognostics, and mitigation. The thesis focuses on the design of the supervisor module and its implementation on a control platform based on Raspberry Pi 4. The main contributions of the thesis are twofold. First, the dynamic operation of the supervisor modelled by using the state transition diagram (STD). Second, the code for implementation of the supervisor on the target platform done in Python in a way that complies with the requirements imposed in the project. Keywords: supervisor, module, agent, method, solid oxide electrolysis cell system, diagnosis, prognostics, real-time optimization, Python programming, state transition diagram Published in RUNG: 20.06.2023; Views: 1716; Downloads: 25 Full text (2,94 MB) |
7. Recent progress and applications of thermal lens spectrometry and photothermal beam deflection techniques in environmental sensingMladen Franko, Leja Goljat, Mingqiang Liu, Hanna Budasheva, Mojca Žorž, Dorota Korte, 2023, original scientific article Abstract: This paper presents recent development and applications of thermal lens microscopy (TLM) and beam deflection spectrometry (BDS) for the analysis of water samples and sea ice. Coupling of TLM detection to a microfluidic system for flow injection analysis (µFIA) enables the detection of microcystin-LR in waters with a four samples/min throughput (in triplicate injections) and provides an LOD of 0.08 µg/L which is 12-times lower than the MCL for microcystin-LR in water. µFIA-TLM was also applied for the determination of total Fe and Fe(II) in 3 µL samples of synthetic cloudwater.
The LODs were found to be 100 nM for Fe(II) and 70 nM for total Fe. The application of µFIA-TLM for the determination of ammonium in water resulted in an LOD of 2.3 µM for injection of a 5 µL sample and TLM detection in a 100 µm deep microfluidic channel. For the determination of iron
species in sea ice, the BDS was coupled to a diffusive gradient in the thin film technique (DGT). The 2D distribution of Fe(II) and total Fe on DGT gels provided by the BDS (LOD of 50 nM) reflected the distribution of Fe species in sea ice put in contact with DGT gels. Keywords: thermal lens microscopy, beam deflection spectrometry, microfluidic system, microcystin-LR detection, iron species determination, ammonium detection Published in RUNG: 03.01.2023; Views: 2341; Downloads: 32 Full text (2,90 MB) This document has many files! More... |
8. Monitoring the success of the performance of a travel agency with the Power BI tool : diploma thesisRiste Ristov, 2022, undergraduate thesis Abstract: In today’s times, when digitalisation is advancing in all areas, travel agencies need to follow trends to optimise their work as much as possible and stay competitive. Business information systems provide a more detailed insight into business processes and their operation, which helps monitor progress and adapt to possible changes to achieve the best results in the business world. Travel agencies need a quality business information system that helps employees shift from using basic office tools to more modern and effective systems for reporting and monitoring work performance. Data is the basis on which agencies adjust, optimise and build their business. Data is available in huge quantities and a variety of formats. Raw data that is not organised into a meaningful whole cannot bring added value to the company. The thesis aims to use Power BI as a tool for editing and integrating databases in travel agencies, as well as their visualisation and display, which is understandable for the user. With the help of the tool, we will create a report which will help the travel agency improve its business and make critical decisions that are critical for success. Keywords: Travel agency, business information system, data, database, Power BI, visualisation Published in RUNG: 30.09.2022; Views: 2562; Downloads: 78 Full text (1,26 MB) This document has many files! More... |
9. Two-year-long high-time-resolution apportionment of primary and secondary carbonaceous aerosols in the Los Angeles Basin using an advanced total carbon–black carbon (TC-BC([lambda])) methodMatic Ivančič, Asta Gregorič, Gašper Lavrič Palancsai, Bálint Alföldy, Irena Ježek, Sina Hasheminassab, Payam Pakbin, Faraz Ahangar, Mohammad Sowlat, Steven Boddeker, Martin Rigler, 2022, original scientific article Keywords: carbonaceous aerosols, black carbon, brown carbon, Carbonaceous Aerosol Speciation System Published in RUNG: 04.08.2022; Views: 2100; Downloads: 9 Link to full text This document has many files! More... |
10. Soot effected sample entropy minimization in nanofluid for thermal system design : a thermal lens studyMohanachandran Nair Sindhu Swapna, Vimal Raj, K. Satheesh Kumar, Sankaranarayana Iyer Sankararaman, 2020, original scientific article Abstract: The present work suggests a method of improving the thermal system efficiency, through entropy minimisation,
and unveils the mechanism involved by analysing the molecular/particle dynamics in soot nanofluids (SNFs)
using the time series, power spectrum, and wavelet analyses of the thermal lens signal (TLS). The photothermal
energy deposition in the SNF lowers the refractive index due to the temperature rise. It triggers the particle dynamics that are investigated by segmenting the TLS and analysing the refractive index, phase portrait, fractal dimension (D), Hurst exponent (H), and sample entropy (SampEn). The wavelet analysis gives information about
the relation between the entropy and the frequency components. When the phase portrait analysis reflects the
complex dynamics from region 1 to 2 for all the samples, the SampEn analysis supports it. The decreasing
value of D (from 1.59 of the base fluid to 1.55 and 1.52) and the SampEn (from 1.11 of the base fluid to 0.385
and 0.699) with the incorporation of diesel and camphor soot, indicate its ability to lower the complexity, randomness, and entropy. The increase of SampEn with photothermal energy deposition suggests its relation to
the thermodynamic entropy (S). The lowering of thermal diffusivity value of the base fluid from
1.4 × 10−7 m2/s to 1.1 × 10−7 and 0.5 × 10−7 m2
/s upon diesel and camphor soot incorporation suggests the
heat-trapping and reduced molecular dynamics in heat dissipation. Keywords: soot, entropy, thermal system, photothermal, time series, nanofluid, fractal Published in RUNG: 30.06.2022; Views: 1925; Downloads: 0 This document has many files! More... |