The diaphragm wall and the open caisson represent two main competitive technologies used in the construction of underground objects. In modern times, diaphragm walls are primarily applied for large-size objects, with open caissons being preferred in the case of small-sized ones. Currently, objects of this type are designed mainly for sewage treatment plants and detention reservoirs. Their construction involves highly labour-intensive processes. During the execution of works unforeseen negative effects are observed to occur. During the underground objects construction the most common phenomena are: deviations from the vertical (tilt), sagging, sinking below the designed level, cracking, scratches or leakage through the wall. The purpose of the paper is to classify undesired risk factors emerging in the process of underground objects construction and selection of the optimal technological and material solution for municipal facilities. The implementation of this task involved the selection of Multi-Criteria Decision Making methods, taking into account the cause-effect rating, as the mathematical apparatus. The Ratio Estimation in Magnitudes or deciBells to Rate Alternatives which are Non-DominaTed (REMBRANDT) method was applied. The research proved that it is possible to analytically assess unforeseen risk factors conducive to emergency situations during the implementation of underground objects, using the REMBRANDT method.

Measurements of pollutants scavenged from air masses over southern Svalbard in summer precipitation are presented. Rainfall was sampled in July and August 2002 at Calypsobyen, Bellsund. Specific conductivity (SpC) and pH were measured and ion concentrations were determined by ion chromatography. Ions of marine origin were subtracted, assuming that all chlorides were of marine origin. The FLEXTRA trajectory model was applied to discover the sources of air masses arriving at Svalbard and track the paths of pollutant transport. Average (v/w) rainfall pH was 4.94, mean SpC amounted to 34.8 µS cm-1. Total dissolved solids concentration (TDS) ranged from 12.6 to 67 mg L-1, with ions of marine origin (Cl-, Na+, Mg2+) prevailing. Rains with the highest percentage of marine salts occurred with winds from the East at above average velocities. Non-sea salt (nss) sulphate concentrations ranged from 0.5 µeq L-1 to 23 µeq L-1, (v/w) average was 17 µeq L-1. Nitrate concentrations ranged from 0 to 24 µeq L-1. The highest concentrations of nss-SO42- and NO3- were measured on 25 August, when the highest rainfall occurred (27 mm) and pH was the lowest (4.65). Rainfall at Calypsobyen deposited 194 kg km-2 of acidifying anions and 263 kg km-2 of base cations over the recording period. The polluted air masses were mostly from northern and central Europe. Rainfalls scavenging air masses formed over Greenland and Norwegian Seas displayed similar concentrations, being probably polluted by SOx and NOx from ship emissions.

Population data are generally provided by state census organisations at the pre- defined census enumeration units. However, these datasets very are often required at user- defined spatial units that differ from the census output levels. A number of population estimation techniques have been developed to address these problems. This article is one of those attempts aimed at improving county level population estimates by using spatial disaggregation models with support of buildings characteristic, derived from national topographic database, and average area of a flat. The experimental gridded population surface was created for Opatów county, sparsely populated rural region located in Central Poland. The method relies on geolocation of population counts in buildings, taking into account the building volume and structural building type and then aggregation the people total in 1 km quadrilateral grid. The overall quality of population distribution surface expressed by the mean of RMSE equals 9 persons, and the MAE equals 0.01. We also discovered that nearly 20% of total county area is unpopulated and 80% of people lived on 33% of the county territory.

Selected scientific contacts of Jacek Hawranek and Jan Zygmunt with Professor Bogusław Wolniewicz in the period from the end of the 1980s to the beginning of the 21st century are presented in this essay. They concerned the algebraic aspects of the ontology of situations and from one moment – one only question that was posed by Wolniewicz in his note A question about join-semilattices (Bulletin of the Section of Logic, 19/3, 1990, pp. 108–108), and resulted in the Hawranek & Zygmunt paper Wokół pewnego zagadnienia z dziedziny półkrat górnych z jednością (“Some comments on a question about semilattices with unit”) (Acta Universitatis Wratislaviensis 1445, Logika 15 (1993), pp. 59–68) containing an answer to Wolniewicz’s question. The Hawranek & Zygmunt paper is reprinted below, and the essay might be also treated as a kind of an analytical and historical introduction to it. The story of contacts Wolniewicz – Hawranek & Zygmunt has been told with the help of the preserved correspondence between the three persons. In his letters Professor Wolniewicz appears as a passionate researcher, open to discussion, ready to share his research successes and difficulties with others.

Coal ash produced from thermal power plants as a substitute for conventional construction material has increased considerably in recent years. In the past, studies on partial replacement of soil were carried out with a single type of ash. Because of the insufficient evidence, limited research has been initiated on the productive usage of Fly and Bottom Ashes. This paper aims to study the properties of these materials and investigate their efficacy in road construction. Laboratory investigations were conducted to assess chemical and physical properties and mechanical performance to evaluate both ash types in pavement construction. The rutting factor is calculated for various combinations of coal ash materials with the addition of polypropylene fiber as a reinforcement in increments of 0.1% of its total weight with an aspect ratio of 200. The analytical tool ANSYS is used to validate the service life, vertical strain and quality of reinforced ash materials.