It looks as if it was frozen lava, but it is a by-product of metal smelting. If left piled up, it may have a strong negative impact on the environment. But when reused in a smart way, it can actually bring many benefits.

An important discovery has been made at Targowisko in southern Poland, where ancient bog-oak trunks with well-preserved remains of great capricorn beetle galleries were found in old sediments of the Raba River. Traces of these insects in fossilized or partially fossilized wood provide valuable information, helping us interpret the ancient environment and climate.

Prof. Monika Kaczmarek from the PAS Institute of Animal Reproduction and Food Research discusses the impact of nutrition and environment on human and animal development.

Professor Krzysztof Spalik, Chairman of the PAS Committee for Environmental and Evolutionary Biology, tells us why the Białowieża Forest should be allowed to renew itself on its own.

Prof. Andreas Böhn, a fellow of the Polish Institute of Advanced Studies (PIASt), explains why we love Polaroids and wonders if our refrigerators will be soon buying milk for us.

The quarry in Lubiechowa has been attracting mineralogists as well as amateur rock-collectors for years. What undiscovered secrets does it still hold?

I n this second interview in our series with scientist-couples who are partners both at work and in life, we talk to Joanna Sułkowska and Piotr Sułkowski about science as discussed on morning talk shows as well as the need for understanding and keeping distance.

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.

Astronomers who work during daylight hours focus on observing sunspots. Why are they keeping a close eye on them right now in particular?

How does breathing polluted air affect us? What broader impact does it have on our health?

Can the fight against smog be won? Can new technologies become our allies in this struggle?

Prof. Katarzyna Biernacka from the Warsaw Institute of Cardiology explains sudden cardiac arrest and how to protect against it.

The process of authenticating artworks, whether musical, painting or architectural, is constantly changing. And sometimes it is influenced by ideology.

We talk to Prof. Maria Gołębiewska from the PAS Institute of Philosophy and Sociology about performatics.

Dr. Krzysztof Fic of the Poznań University of Technology discusses energy storage, aesthetic medicine’s quest for immortality, and how much time goes into being a scientist.

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.

What is smog, what does it consist of, and where does it come from? How badly polluted is the air in Poland in relation to other countries in Europe?

The “Oceania” never sleeps. Her crew work 24 hours per day, and after they disembark they will remember their time aboard for years to come – perhaps forever.

The obsession with success in science comes at a price. The highest price is a fear of taking risks.

Dr. Piotr Achinger of the PAS Institute of Mathematics talks about the job of a mathematician and the importance of basic research – explaining why some projects are like snakes, but others are like octopuses.

To examine the correlation of driver visual behaviors and subjective levels of fatigue, a total of 36 commercial drivers were invited to participate in 2-h, 3-h, and 4-h naturalistic driving tests during which their eye fixation, saccade, blinking variables, and self-awareness of their fatigue levels were recorded. Then, one-way ANOVA was applied to analyze the variations of each variable among different age groups over varying time periods. The statistical analysis revealed that driving duration had a significant effect on the variation of visual behaviors and feelings of fatigue. After 2h of driving, only the average closure duration value and subjective level of fatigue had an increase of one-fifth or more. After 4h of driving, however, all these variables had a significant change except for the number of saccades and pupil diameter measurements. Particularly, driver saccadic eye movement was more sensitive to driving fatigue, and the elderly were more likely to be affected by the duration of the drive. Finally, a predictor of driver fatigue was determined to detect the real-time level of fatigue and alert at the critical moment.

Elaborating composites containing waste materials requires study of basic mechanical properties and assessment of their structure quality. The subject of investigation was PPC concrete where aggregate was substituted with PET remaining after beverages bottles grinding. Substitution was done up to 25% (by volume). Waste material was fractioned and applied in various granulations. The main goal was to indicate the influence of such modification on the composite mechanical properties and to examine composite structure quality at macro level. Since PET and quartz differ greatly in density, to perform such examination it was possible to apply the nondestructive ultrasonic method, one of the most common NDT techniques used in material science and industry. The paper presents the effects of substitution of quartz with PET on ultrasonic wave propagation in PCC. The ultrasonic test results (measurements of wave velocity) compared with results of destructive tests (flexural and compressive strength) showed great correlation.

This paper deals with a Continuous Stiffness Degradation (CSD) version of advanced analysis of braced steel framing. It is based on the gradual stiffness degradation concept of frame and truss members. A novelty of the approach presented herein is related to the introduction of the bracing member response in the whole range of its behaviour in tension and compression, including the post-limit range. The validation of the proposed advanced analysis is performed for braced framework with rolled angle section braces. The validation of the brace force-deformation model has been presented in the author’s earlier publication. The basis for the presented CSD advanced analysis is briefly summarized and its difference with regard to the Refined Plastic Hinge (RPH) version of advanced analysis is emphasized. Experimental investigations dealing with tests on portal braced sub-frame specimens are referred to briefly. Results of the experimental investigations are presented in the form of a frame global response and they are used for the validation of the developed computational model.

Shear connectors are designed in steel-concrete composite construction to transmit the longitudinal shear, to prevent separation of steel and concrete slabs, and also to increase the structural efficiency of the whole system. In this study, the performances of different types of shear connectors in steel-concrete composite specimens are evaluated by conducting push-out tests under monotonic loading conditions. An ISMB 200 @ 25.4 kg/m universal steel beam measuring 400 mm and a reinforced cement concrete slab measuring 300 mm with a breadth of 200 mm and a thickness of 200 mm reinforced with 8 mm diameter steel rods are used for the experimental study. The results reveal that the load-slip relationships for various types of shear connectors and failure mechanisms are obtained to identify those shear connectors which are more relevant to the steel – concrete composite members.