Delays in Construction Projects: Causes and Mitigation

During execution of construction projects, the works proceed at a slower pace than planned, and delays frequently appear. Their appearance leads to additional cost generation, conflicts among project participants and, in worst-case scenario, litigation. The presented study uses online survey as the research tool in order to determine the current level of use of time management techniques and tools in Slovenian construction industry. The obtained results show that the construction companies could use the available contemporary time management tools in larger extent, as well as more efficiently in order to manage their projects more efficiently

Fanny Copeland and the geographical imagination

Raised in Scotland, married and divorced in the English south, an adopted Slovene, Fanny Copeland (1872 – 1970) occupied the intersection of a number of complex spatial and temporal conjunctures. A Slavophile, she played a part in the formation of what subsequently became the Kingdom of Yugoslavia that emerged from the First World War. Living in Ljubljana, she facilitated the first ‘foreign visit’ (in 1932) of the newly formed Le Play Society (a precursor of the Institute of British Geographers) and guided its studies of Solčava (a then ‘remote’ Alpine valley system) which, led by Dudley Stamp and commended by Halford Mackinder, were subsequently hailed as a model for regional studies elsewhere. Arrested by the Gestapo and interned in Italy during the Second World War, she eventually returned to a socialist Yugoslavia, a celebrated figure. An accomplished musician, linguist, and mountaineer, she became an authority on (and populist for) the Julian Alps and was instrumental in the establishment of the Triglav National Park. Copeland’s role as participant observer (and protagonist) enriches our understanding of the particularities of her time and place and illuminates some inter-war relationships within G/geography, inside and outside the academy, suggesting their relative autonomy in the production of geographical knowledge

Multiple-criteria decision support system in highway infrastructure management

Highway infrastructure represents a significant part of the public assets, and through its lifetime, is exposed to various deterioration processes leading to the depreciation of its value. It is therefore of vital importance to manage these assets aiming to reduce the loss of their value with time to a minimum. A typical task of road managers is making decisions related to maintenance, repair and rehabilitation based on data regarding the existing condition, risk of its use, life cycle costs and age. Road infrastructure is complex, and therefore the optimal choice of planned interventions is a delicate task often left to the road managers’ subjective judgment. The main goal of research work presented in the paper is the development of a multiple criteria decision support system to determine the priority ranking of asset rehabilitation projects. Results are presented for a selected case study that consists of 27 overpasses for a highway section. The data on the condition of crossovers obtained by regular inspection along their contribution to a structured database are essential. The selection of the set of asset rehabilitation projects is carried out by using the developed decision support system that includes the budget constraint option. The selected set of asset maintenance/rehabilitation projects meets best the pre-defined combination of several criteria and therefore yields the maximized overall benefit. The results showing the selection criteria employed in the decision process and relative importance are crucial in obtaining the targeted goals. The selected criteria should therefore reflect the needs of the users and the actual conditions related to the assets

3D laser ablation-ICP-mass spectrometry mapping for the study of surface layer phenomena - a case study for weathered glass

In this work, a multi-elemental 3D laser ablation-ICP-mass spectrometry mapping procedure for highresolution depth information retrieval to investigate surface layer phenomena is presented. The procedure is based on laser drilling on a virtual grid on the surface, followed by extraction of depth maps along the z-axis (for each element monitored). Using a burst of 50 laser pulses at 1 Hz on each point of the grid, a penetration rate of ca. 150 nm per pulse (in glass) was obtained and a lateral resolution in the order of the laser beam diameter. By ultrafast ICP-MS monitoring of individual ablation pulses (58 ms for a set of 19 elements) using a laser ablation cell with fast signal washout (less than 0.5 s for whole laser pulse), the corresponding peak areas could be consistently integrated, resulting in spatial elemental data associated with individual pulses. The usual laser drilling limitations such as pulse mixing and signal tailing are avoided with this approach. After manipulation of the spatial elemental datasets and quantification, stacks of 50 2D depth maps (for each element monitored) were produced which could be visualized as volume images or time-lapse movies. As a proof of concept, this approach was successfully used to investigate the degradation mechanisms of a medieval, weathered glass artifact by colocalization analysis of selected cross-sectional 2D elemental images in arbitrary planes of the volume images. It was shown that degradation must have started as a result of dealkalinization leading to depletion of alkalis/earth alkalis in glass surface layers and enrichment of network formers (Si and Al), and subsequent worsening by cracking and formation of corrosion pits and so-called spatiotemporal Liesegang rings indicative of radial leaching