1731. Zagotavljanje kakovosti pri razvijanju mamogramovLucijan Miklavčič, 2001, objavljeni znanstveni prispevek na konferenci Povzetek: Ekipa, ki se ukvarja z zagotavljanjem kakovosti na področju radiologije, posebno pa v mamografiji, mora dobro poznati uporabo senzitometra in denzitometra za spremljanje učinkovitosti razvijanja filmov. Prispevek uvaja bralca v osnove, ki so nujne za razumevanje programa zagotavljanja kakovosti in spremljanja parametrov učinkovitosti pri razvijanju mamografskih filmov.
Objavljeno v DiRROS: 30.11.2023; Ogledov: 252; Prenosov: 64
 Celotno besedilo (404,12 KB) |
1732. Klinična presoja kakovosti mamogramovMiljeva Rener, Kristijana Hertl, Franc Guna, 2001, objavljeni znanstveni prispevek na konferenci Povzetek: Kakovosten mamogram prikaže kar največ tkiva dojke, je primerno eksponiran, kontrasten, ni neoster, je brez artefaktov in je narejen s sprejemljivo ekspozicijsko dozo. Končni videz mamograma je skupek raznih dejavnikov, od katerih so najpomembnejši sodobna mamografska naprava z optimalno naravnano fotocelico in s sodobnim priborom; posebna pozornost velja postopku razvijanja. Dobro usposobljeno, posebej za to delo izobraženo osebje mora nenehno vzdrževati visoko kakovost, to pa pripomore k čim manjšemu številu zgrešenih in zapoznelih diagnoz.
Objavljeno v DiRROS: 30.11.2023; Ogledov: 256; Prenosov: 70
Celotno besedilo (810,89 KB) |
1733. Tehnologija mamografijLucijan Miklavčič, 2001, objavljeni znanstveni prispevek na konferenci Povzetek: Mamografija je specialna radiografska preiskava katere namen je diagnostika karcinoma dojke. S tehnične plati mora zagotoviti dobro kontrastno ločljivost sprememb v mehkih tkivih, dobro prostorsko ločljivost mikrokalcinacij in kontur nasploh (robovi, spikule); to dosežemo kadar je radiografski šum dovoljnizek, da v sliki ne zabriše teh podrobnosti morfološke vsebine.
Objavljeno v DiRROS: 30.11.2023; Ogledov: 278; Prenosov: 85
Celotno besedilo (318,02 KB) |
1734. |
1735. More losses than gains? : Distribution models predict species-specific shifts in climatic suitability for European beech forest herbs under climate changeJanez Kermavnar, Lado Kutnar, Aleksander Marinšek, 2023, izvirni znanstveni članek Povzetek: Introduction: Herbaceous plant species constitute an essential element of the flora of European beech (Fagus sylvatica) forests. There is increasing evidence that rapidly changing climate is likely to modify the spatial distribution of plant species. However, we lack understanding of the impact that climate change might have on beech forest herbs across the European continent. We investigated the possible effects of predicted increasing rates of global warming and altered precipitation regimes on 71 forest herbs closely associated with beech forests, but with varying biogeographic and climatic niche attributes. Methods: By using a total of 394,502 occurrence records and an ensemble of species distribution models (SDMs), we quantified the potential current distribution and future (2061-2080) range shifts in climatic suitability (expressed as occurrence probability, OP) according to two climate change scenarios (moderate SSP2-4.5 and severe SSP5-8.5). Results: Overall, precipitation of the warmest quarter and temperature seasonality were the most influential predictors in shaping current distribution patterns. For SSP5-8.5 scenario, all studied species experienced significant reductions (52.9% on average) in the total size of highly suitable areas (OP >0.75). However, the magnitude and directions of changes in the climatic suitability were highly species-specific; few species might even increase OP in the future, particularly in case of SSP2-4.5 scenario. The SDMs revealed the most substantial decline of climatic suitability at the trailing edges in southern Europe. We found that climatic suitability is predicted to show unidirectional northward shift and to move toward higher elevations. The gain/loss ratio was generally higher for narrow-ranged species compared to widespread taxa. Discussion: Our findings are contextualized with regards to potential confounding factors (dispersal limitation, microclimatic buffering) that may mitigate or accelerate climate change impacts. Given the low long-distance migration ability, many beech forest herbs are unlikely to track the velocity with which macroclimatic isotherms are moving toward higher latitudes, making this species group particularly vulnerable to climate change.
Ključne besede: species distribution modelling, global warming, range shift, climatic niche, biogeography, Europe
Objavljeno v DiRROS: 29.11.2023; Ogledov: 392; Prenosov: 204
Celotno besedilo (8,49 MB)
Gradivo ima več datotek! Več... |
1736. 1. Šola maligne utesnitve hrbtenjače : [strokovno srečanje]2023, ni določena Povzetek: Izidi zdravljenja maligne utesnitve hrbtenjače (MUH) v Sloveniji trenutno niso najboljši. Obravnava bolnikov je kompleksna, multidisciplinarna in večnivojska. Takoj ko bolnik zazna znake MUH, mora stanje prepoznati zdravnik družinske medicine, hitro ukrepati ter ga napotiti na nevrološki pregled oziroma k lečečemu onkologu. Namen 1. Šole maligne utesnitve hrbtenjače je, da se zdravniki, ki sodelujemo pri prepoznavi in zdravljenju MUH pogovorimo o trenutnem stanju obravnave in vseh dilemah, ki jih imamo.
Ključne besede: maligna utesnitev
Objavljeno v DiRROS: 29.11.2023; Ogledov: 384; Prenosov: 189
Celotno besedilo (2,46 MB)
Gradivo ima več datotek! Več... |
1737. Experimental investigation of the axial strength of glued-in rods in cross laminated timberBoris Azinović, Erik Serrano, Miha Kramar, Tomaž Pazlar, 2018, izvirni znanstveni članek Povzetek: This paper presents results from an experimental assessment of glued-in rods in cross laminated timber (CLT). For the purposes of the study more than 60 pull-pull tests were performed, where the specimens varied in terms of bonded-in length (from 80 to 400 mm), rod diameter (16-24 mm) and rod-to-grain angle (parallel and perpendicular). Several different failure modes that are not common for other applications of glued-in rods (e.g., a failure between CLT layers) were obtained for the analysed CLT specimens. It was found that these failure mechanisms can substantially influence the obtained ultimate tension loads. At the end, the experimental results were compared with empirical and semi-empirical equations for estimating the pull-out strength of glued-in rods in structural timber and glulam. The comparison showed that most of the existing equations overestimate the ultimate tension loads for specimens with the rod parallel to the grain and underestimate the ultimate tension load for specimens with the rod perpendicular to the grain. The results vary because the possible CLT failure modes were not included in previous studies. Further studies are proposed to improve the equations for glued-in rods in CLT.
Ključne besede: glued-in rods, cross laminated timber (CLT), pull-pull experiment, glued-in length, rod-to-grain angle, failure mechanisms in CLT
Objavljeno v DiRROS: 29.11.2023; Ogledov: 316; Prenosov: 248
Celotno besedilo (4,13 MB)
Gradivo ima več datotek! Več... |
1738. Structural health monitoring for performance assessment of bridges under flooding and seismic actionsLuke J. Prendergast, Maria P. Limongelli, Naida Ademovic, Andrej Anžlin, Gavin Kenneth, Mariano Zanini, 2018, izvirni znanstveni članek Povzetek: Bridges can be subjected to damaging environmental actions due to flooding and seismic hazards. Flood actions that result in scour are a leading cause of bridge failure, while seismic actions that induce lateral forces may lead to high ductility demand that exceeds pier capacity. When combined, seismic actions and scour can lead to effects that depend on the governing scour condition affecting a bridge. Loss of stiffness under scour can reduce the ductility capacity of a bridge but can also lead to an increase in flexibility that may reduce seismic inertial forces. Conversely, increased flexibility can lead to deck collapse due to support loss, so there exists some uncertainty about the combined effect of both phenomena. A necessary step towards the performance assessment of bridges under flooding and seismic actions is to calibrate numerical models that can reproduce structural responses under different actions. A further step is verifying the achievement of performance goals defined by codes. Structural health monitoring (SHM) techniques allow the computation of performance parameters that are useful for calibrating numerical models and performing direct checks of performance goal compliance. In this paper, various strategies employed to monitor bridge health against scour and seismic actions are discussed, with a particular focus on vibration-based damage identification methods.
Ključne besede: scour, seismic, damage, hazard, vibration-based methods
Objavljeno v DiRROS: 29.11.2023; Ogledov: 345; Prenosov: 173
Celotno besedilo (2,18 MB)
Gradivo ima več datotek! Več... |
1739. Condition assessment of roadway bridges: from performance parameters to performance goalsMaria P. Limongelli, Eleni Chatzi, Andrej Anžlin, 2018, izvirni znanstveni članek Povzetek: Deterioration of bridges due to ageing and higher demands, induced by increased traffic load, require the development of effective maintenance policies and intervention strategies. Such concern should be aimed at ensuring the required levels of safety, while optimally managing the limited economic resources. This approach requires a transversal advance; from the element level, through the system level, all the way to the network level. At the same time intervention prioritisation based on the importance of the system (bridge) inside the network (e.g. highway), or of the single structural element inside the bridge is dependent. The first step in bridge condition assessment is the verification of safety and reliability requirements that is carried out using the traditional prescriptive (deterministic) approach or the current performance-based (probabilistic) approach. A critical issue for efficient management of infrastructures lies in the available knowledge on condition and performance of bridge asset. This information is obtained using a collection of significant Performance Parameters at one or more of the three levels (element, system, and network). Traditional techniques for estimation of Performance Parameters rely on already established visual inspection. However, a more reliable description of the system performance is obtained through Non-Destructive Testing and Structural Health Monitoring. Condition assessment essentially pertains to the check of compliance with Performance Goals and requires the definition and computation of Performance Indicators. They are calculated directly from Performance Parameters or from physical models calibrated using the Performance Parameters collected on the structure. Paper overviews the steps to bridge condition assessment regarding safety and reliability.
Ključne besede: bridge, reliability, safety, condition assessment, performance goals, performance parameters
Objavljeno v DiRROS: 29.11.2023; Ogledov: 324; Prenosov: 165
Celotno besedilo (487,92 KB)
Gradivo ima več datotek! Več... |
1740. Cost-benefit analysis of fire protection in buildings : application of a present net value approachThomas Gernay, Shuna Ni, David Unobe, Andrea Lucherini, Ranjit Kumar Chaudhary, Ruben Van Coile, 2023, izvirni znanstveni članek Povzetek: In fire safety engineering, cost–benefit analysis provides a systematic method to assess whether the projected benefits from a fire safety measure outweigh its costs. However, there remains a wide discrepancy between methods used in the field for cost–benefit analysis, as well as a lack of quantitative data on the costs and economic impact of fire protection in buildings. In a recent research project, a reference methodology was proposed based on Present Net Value evaluation and on a combination of specialized construction database, fire statistics, and numerical modeling for estimation of the cost components. This paper presents the application of the methodology to four case studies. The case studies allow describing the methodology, the collection of data, fire statistics, and loss estimation, as well as illustrating how the methodology can support decision-making when multiple alternatives are compared. Under the assumptions adopted for the single-family house and the residential timber building case studies, it is found that for every 1\$, invested in sprinklers, \$1.06 is saved. This benefit–cost ratio increases with increasing valuation of indirect losses and statistical value of life. Sensitivity analyses are provided to explore the robustness of the investment recommendations. The results of evaluations, adapted from the presented case studies with project-specific inputs, can support decision making for policy makers, insurance companies, and individual building owners.
Ključne besede: fire safety, cost-benefit analysis, fire protection, fire statistics, sprinklers, compartmentation
Objavljeno v DiRROS: 29.11.2023; Ogledov: 422; Prenosov: 104
Celotno besedilo (758,66 KB)
Gradivo ima več datotek! Več... |
