The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

Fossilized bones help scientists not only identify the age of rocks, but also to determine the ancient environment and climate in which ancient humans and animals once lived. One just needs to know the right methods to use.

Loess is an important component of cave deposits. Loess and loess-like strata in caves and rock shelters may serve as stratigraphic correlative units and paleoclimate indicators. For the Polish Jura (southern Poland), one of the key regions of cave deposits studies in Europe, the published information concerning the stratigraphic importance of loess is limited to the sequences from around the Last Glacial Maximum (LGM). In this paper, a review of the archival data about loess deposits situated below the LGM strata in caves and rock shelters of the Polish Jura is presented. The paper discusses the occurrence, lithology, stratigraphy, chronology and paleoecology of the pre-LGM cave loess. The most important sites of the pre-LGM cave loess in the region include: Biśnik Cave, Nietoperzowa Cave, Mamutowa Cave, and Ciemna Cave (only the outer zones). The loess strata in these sites correlate with cold Marine Isotope Stages (MIS): mid-3, 4, 5b–d, 6, and possibly 10. They represent all the main facies of cave loess: typical eolian loess, colluviated loess-like deposits, loess with bedrock debris, and loams of complex grain-size composition but with the predominance of a loess component. Stratigraphic correlations with loess-paleosol sequences are proposed.

Analysis of weathering parameters of bones from cave deposits is presented as a useful tool of palaeoenvironmental reconstruction. As an example, we studied profiles of sediments in two Palaeolithic sites: Nietoperzowa Cave and Deszczowa Cave. Our studies included histological and EDS analyses of bone remnants found in these profiles. This method allowed us to reconstruct the changes of palaeotemperature and palaeohumidity, and finally the climatostratigraphy of sediments. The results presented here put a new light onto the stratigraphy of Deszczowa Cave's filling. In particular, besides the Vistulian sediments (MIS 2-5d), we confirmed the presence oflayers formed during the Penultimate Glaciation (MIS 6) and Eemian Interglacial (MIS 5e).

An important source of palaeoecological and palaeoenvironmental information is intra-specimen variability of isotopic composition of mammal tooth enamel. It reflects seasonal or behavioral changes in diet and climate occurring during a life of the animal. While well-known in ungulates, in carnivorans this variability is poorly recognized. However, carnivoran remains are amongst the most numerous in the Pleistocene fossil record of terrestrial mammals, so their isotopic signature should be of particular interest. The aim of the study was to verify if enamel of a fossil cave hyena (Crocuta crocuta spelaea) and a cave bear (Ursus ingressus) records any regular inter- or intra-tooth isotopic variability. We examined intra-individual variability of δ13C and δ18O values in permanent cheek teeth enamel of fossil cave hyena and cave bear from the site of the Perspektywiczna Cave (southern Poland). We conclude that the isotopic variability of the cave hyena is low, possibly because enamel mineralization took place when the animals still relied on a uniform milk diet. Only the lowermost parts of P3 and P4 enamel record a shift toward an adult diet. In the case of the cave bear, the sequence of enamel formation records periodic isotopic changes, possibly correlating with the first seasons of the animal life.

Bisnik Cave is an important site of Middle Palaeolithic, with the longest sequence of Neanderthal settlement phases in Central Europe. In the previous studies of the Bisnik sediments, different elements of palaeoenvironment in the periods of Neanderthal occupation have been recognised, except of palaeovegetation, which could not be derived because of lack of preserved plant micro- or macrofossils. The current work is an attempt to reconstruct palaeovegetation in vicinity of the Bisnik Cave, using analysis of composition of plant-derived n-alkanes, preserved in sediments. In our study, we analyzed one sample from each of the sediment's layers 11 - 19c (early Late Pleistocene and late Middle Pleistocene). Abundant n-alkanes (mostly n-C27, n-C29 and n-C31) were found in all the sampled layers except for the layers 12, 16 and 19d, showing no alkanes at all. There is clear diversification of n-alkanes composition and cpr (carbon preference index) values between layers. Analysis of this composition, allows us to claim that the layers 11 and 14 were accumulated when the cave's vicinity was covered by dense coniferous forests, hence upon warm climate. The layers 19, 19a lower, 19b and 19c, presumably originated during cold periods when open woodlands or grasslands dominated. The other analyzed layers could be counected with intermediate vegetation in form of open woodland. However, not all of the achieved results stay in compliance with the actual stratigraphy, established basing on lithological data and palaeoecology offossil fauna, and we hope that explanation of this discrepancy would be possible after more extensive studies of molecular fossils are done.