The subject of this article are the Egyptian inspirations in the graphic works of Ewa Siedlecka-Kotula, an artist living and working in Kraków in the second half of the 19th century. During the period from May 1948 until June 1949 she resided in Cairo, a productive period which came to fruition in the form of a special cycle of linocuts, executed in 1969 and based on earlier sketches. The series comprises of the following works: “Kobiety/Women”, “Woda/Water”, “Ryż/Rice”, “Tkacze/Weavers”, “Pasterka/ Female shepherd”, and “Barany/Rams”, depicting contemporary Egyptians and their typical, everyday tasks. During her stay in Egypt the artist also designed the exhibition graphics for the 16th Agricultural and Industrial Exhibition in Cairo. Her works were put on display at an individual exhibition (December 1948). She also participated in the exhibitions entitled “Le salon des femmes-artistes” in Cairo Women’s Club (March 1949) and “France-Égypte” in the Museum of Modern Art in Cairo (May 1949). Ewa Siedlecka-Kotula’s works met with much interest at that time. Unfortunately, references to antiquity are very scarce in her art, and include only a watercolour showing an Egyptian peasant by a shaduf (fig. 1), and a drawing of a female offering-bringer figurine from the tomb of Nakhti, overseer of the seal, in Asyut (early 12th dynasty, around 1900 BC). The latter drawing was perhaps made in the Egyptian Museum in Cairo, and most likely represents a statuette whose current fate remains unknown, which would make this drawing an exceptional record.
The paper presents the results of research on the modification of the face geometry of the refill friction stir spot welding tool sleeve for welding thin aluminum sheets with an Alclad and an oxide anode coating. The analysis of the impact of such modification on the process perform (tool motion parameters, temperature) and microstructure as well as mechanical strength of the lap joints were analyzed. The tests were carried out using aluminum alloy 2024-T3 sheets with thickness 1.27 mm. For comparative purposes, joints were also made using plates without an Alclad and without anodized coating with using unmodified tool and modified tools with developed 3 variants of face geometry. The samples with the joint were subjected to metallographic and strength tests. It has been shown that the use of modified geometry has a decisive influence on the performance of the process and the effect of softening and mixing of materials in the zone of point connection.
The paper presents the results of theoretical analysis and experimental research on the material’s influence and tool geometry on the welding speed and mechanical strength of Al 2024 thin sheet metal joints. To make the joints, tungsten carbide and ceramics tools with a smooth and modified surface of the shoulder were used. The choice of the geometrical parameters of the tool was adjusted to the thickness of the joined sheet. During welding, the values of axial and radial force were recorded to determine the stability of the process. The quality of the joint was examined and evaluated on the basis of visual analysis of the surface and cross-sections of the joint area and the parent material, and subjected to mechanical strength tests. The test results indicate that both the geometry of the tool shoulder and the tool material have a decisive influence on the quality of the joint and the welding speed, making it possible to shorten the duration of the entire process.
Lichens of relict penguin colonies and sites affected by active penguin colonies were investigated in Victoria Land, Ross Sea sector, continental Antarctica. A total of 17 coastal sites, seven in northern and ten in southern Victoria Land, have been investigated across 7 ° of latitude from 71 ° to 78 ° S. Altogether 40 taxa of lichens have been identified. Four of the recorded species are new to the Antarctic – Caloplaca erecta , C. soropelta , C. tominii and Physcia tenella ; two species are new to the Victoria Land area – Lecania nylanderiana and Lecanora polytropa . The first lichen records from Beaufort Island are also provided. Data presented here expand the knowledge on the occurrence, diversity and distribution of Victoria Land lichens.
Recently, a new class of ceramic foams with porosity levels up to 90% has been developed as a result of the association of the gelcasting process and aeration of the ceramic suspension. This paper presents and discusses original results advertising sound absorbing capabilities of such foams. The authors man- ufactured three types of alumina foams in order to investigate three porosity levels, namely: 72, 88, and 90%. The microstructure of foams was examined and typical dimensions and average sizes of cells (pores) and cell-linking windows were found for each porosity case. Then, the acoustic absorption coefficient was measured in a wide frequency range for several samples of various thickness cut out from the foams. The results were discussed and compared with the acoustic absorption of typical polyurethane foams proving that the alumina foams with high porosity of 88-90% have excellent sound absorbing properties competitive with the quality of sound absorbing PU foams of higher porosity.