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Povzetek: (1–x)Pb(Fe0.5Nb0.5)O3–xBiFeO3 (PFN–100xBFO) ceramics exhibit versatile functional properties, from ferroelectric, relaxor to antiferroelectric behaviour, but have not yet been prepared as ceramic thick films, which are the key to miniaturization of electronic components. In this work, screen-printed thick films of PFN–30BFO were prepared on gold-coated alumina substrates and sintered at 800 °C, 850 °C and 930 °C. The impact of the sintering temperature on their properties was studied. The films annealed at 930 °C exhibited excessive electrical conductivity. In contrast, well developed polarization versus electric field hysteresis loops were observed in the films treated at 800 °C and 850 °C. The films annealed at 800 °C had the smallest grain size and dielectric permittivity values but achieved the highest dielectric breakdown strength. The findings of this study highlight the potential of PFN–30BFO screen-printed films, sintered at 800 °C, for use in miniaturized high-voltage electronic devices.
Ključne besede: thick films, electronic ceramics, sintering temperature
Objavljeno v DiRROS: 20.04.2026; Ogledov: 161; Prenosov: 100
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Povzetek: Frost hollows are areas where cold air pools frequently form due to relief, resulting in specific microclimatic conditions. The different microclimate also manifests itself in specific ecological conditions where only adapted plant communities develop. These unique areas are of high conservation impor-tance as they can provide suitable habitats for cold-adapted plant species that are not found in the surrounding landscape. Such microrefugia are known to maintain relict populations of some endemic species. It can be concluded that frost hollows are special areas in terms of both geodiversity and biodiversity. The chapter discusses the climatological and vege-tation characteristics of frost hollows from the Slovenian alpine areas.
Ključne besede: Mountain climate, topoclimate, temperature inversion, vegetation inversion, cold air pools, mountain species adaptation
Objavljeno v DiRROS: 05.03.2026; Ogledov: 229; Prenosov: 153
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Povzetek: Under simultaneous ambient temperature and postural stressors, integrated regional blood flow responses are required to maintain blood pressure and thermoregulatory homeostasis. The aim of the present study was to assess the effect of ambient temperature and body posture on regional regulation of microvascular blood flow, specifically in the arms and legs. Participants (N = 11) attended two sessions in which they experienced transient ambient conditions, in a climatic chamber. During each 60-min trial, ambient temperature increased from 15.7 (0.6) °C to 38.9 (0.6) °C followed by a linear decrease, and the participants were either standing or in a supine position throughout the trial; relative humidity in the chamber was maintained at 25.9 (6.6) %. Laser doppler flowmetry of the forearm (SkBFarm) and calf (SkBFcalf), and haemodynamic responses (heart rate, HR; stroke volume, SV; cardiac output, CO; blood pressure, BP), were measured continuously. Analyses of heart rate variability and wavelet transform were also conducted. SkBFarm increased significantly at higher ambient temperatures (p = 0.003), but not SkBFcalf. The standing posture caused lower overall SkBF in both regions throughout the protocol, regardless of temperature (p < 0.001). HR and BP were significantly elevated, and SV significantly lowered, in response to separate and combined effects of higher ambient temperatures and a standing position (all p < 0.05); CO remained unchanged. Mechanistic analyses identified greater sympathetic nerve activation, and higher calf myogenic activation at peak temperatures, in the standing condition. Mechanistically and functionally, arm vasculature responds to modulation from both thermoregulation and baroreceptor activity. The legs, meanwhile, are more sensitive to baroreflex regulatory mechanisms.
Ključne besede: blood flow, thermoregulation, baroreflex, vasomotor zone, ambient temperature, posture, neural control
Objavljeno v DiRROS: 04.02.2026; Ogledov: 563; Prenosov: 235
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Povzetek: The fan mussel Pinna nobilis is a bivalve endemic to the Mediterranean Sea that is listed as Critically Endangered on the IUCN Red List. Its decline is due to a disease that has led to mass mortalities throughout the Mediterranean. The Gulf of Trieste (northern Adriatic) used to harbour one of the densest populations of P. nobilis, but since 2019, it has also been affected by this disease. The aim of this work was to analyse the growth of P. nobilis in the Slovenian part of the Gulf, with 3 case studies: (1) in situ measurement of adults before the mass mortality event (MME), (2) in situ measurement of juveniles after the MME and (3) ex situ measurement of juveniles kept in the laboratory. The pre-MME growth rate was comparable to that in other areas of the Gulf. In the first years of life, the growth rate of P. nobilis is higher than the growth rate reported in the southern Adriatic, and comparable to the growth rate in the Spanish lagoons. This is probably related to the physico-chemical conditions and confirms the potential of the area for restoration actions. Captive growth of juveniles could be an effective conservation measure, although juveniles kept in the laboratory grow more slowly than those in the sea, probably because of their lower immune response. Temperature plays an ambivalent role, as it increases the growth rate but also triggers the parasites responsible for the MME, which is of concern, given the recent rise of seawater temperatures and heatwaves.
Ključne besede: fan mussel, model growth, temperature, conservation, northern Adriatic sea
Objavljeno v DiRROS: 23.12.2025; Ogledov: 410; Prenosov: 265
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Povzetek: : An integrated miniature electrochemical sensor (ES) that offers rapid, sensitive, and selective detection of chemical and biological contaminants in a variety of samples requires temperature control to work accurately. To address this, one approach is to locate temperature sensor (TS) next to the ES components. However, this integration poses a challenge as different firing processes are required for the sensor components and the TS. Commercially available thick-film materials for the realisation of TS are designed for screen printing on alumina and firing in air at 850 °C for 10 minutes. However, a key component of an ES, a carbon-based working electrode, must be fired in an oxygen-lean atmosphere. In this study, we investigated the influence of the firing atmosphere, i.e., air and argon, on the characteristics of thick-film resistors, including thickness, roughness, phase composition, resistivity, and temperature dependence. For the study, we used two commercially available thick-film pastes, NTC2114 and NTC2113, as TS with nominal sheet resistivities of 10 kΩ/sq and 1 kΩ/sq at 25 °C, respectively. Using X-ray powder diffraction analyses, we detected RuO2 and spinel phases in the samples heated at 850 °C in air. However, when the samples were fired in argon, we detect metallic ruthenium and alloys. As a result of these changes, the resistivity of the NTC2114 and NTC2113 increased significantly. However, despite these changes, the relative resistance and the coefficient of temperature sensitivity did not vary significantly, indicating the suitability of these materials as TS. These findings have important implications for the future integration of TS into various screen-printed ES systems, fostering the design and development of systems with enhanced accuracy and reliability in temperature measurements.
Ključne besede: NTC, thick film, screen printing, temperature sensors
Objavljeno v DiRROS: 23.10.2025; Ogledov: 543; Prenosov: 254
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