This study explores the universal symbolic functions of circular and spherical forms in wedding and funeral ceremonies across world cultures using a multidisciplinary approach. The article analyzes how these forms are structured during key transitional stages of human life, based on van Gennep's rites of passage, Turner's liminality theory, and Jung's archetypes theory. In wedding ceremonies, circular dances, table arrangements, rings, and other symbols embody unity, eternity, and harmony. Azerbaijani traditions such as fastening a silver belt and red ribbon are of particular interest. In funeral rituals, circular forms express the transformation of the soul, continuity, and the idea of eternity. Prayer circles, candle rings, and motifs on tombstones carry similar symbolic meanings across different cultures. The research demonstrates that these forms are not merely aesthetic elements but universal symbols with social, psychological, and spiritual functions. In the modern era, traditional symbolism continues to persist in new forms—in virtual spaces, digital platforms, and contemporary memorial designs. Circular and spherical forms serve as visual expressions of human connection with the cosmos, earth, and the divine. The study's findings highlight the profound psychological and ontological significance of these forms, transcending not only cultural boundaries but also time. Future research directions include digital anthropology, neuroanthropology, and ecological anthropology.

This study comprehensively investigates the effect of volcanic trass (tuff) on the fundamental properties of Portland cement–based dry construction mixes. X-ray phase analysis revealed a high content (81%) of the active glassy phase in its composition, confirming its high pozzolanic potential. The research demonstrated that replacing 10–15% of the quartz sand by weight in the mix with finely ground trass significantly improves the technological properties of the material. In particular, the workable life (setting time) of the mortar increased from 8 to 11 hours, and its plasticity was enhanced. The results of mechanical tests indicate that although the addition of trass leads to a certain reduction in the strength of the hardened mortar at the early stage (7 days), these values are restored after 28 days of curing or even exceeded when an optimal content (15%) is used. This behavior is associated with the gradual development of pozzolanic reactions and the formation of additional calcium silicate hydrate (C–S–H) phases due to the binding of free calcium hydroxide (Ca(OH)₂). One of the most significant positive effects of trass is a 22–26% increase in adhesion strength to the surfaces of various construction materials (concrete, ceramics, and natural stone). In addition, the moisture-regulating capacity of the material increases substantially: at a relative humidity of 90%, the sorption moisture content rises from 1.5% to 3.2% (approximately twofold). This enables the effective use of the developed mortar in high-humidity environments, such as bathrooms and basements. Consequently, the use of Kemerli trass at a content of 10–15% as a pozzolanic additive replacing quartz sand in dry construction mixes is recommended. This not only provides improved workability and high adhesion properties but also makes the mortar a promising functional material for applications under humid conditions.

This article investigates the universal role of circular and spherical forms in domestic culture through a comprehensive analysis of their physical, cultural, psychological, and philosophical aspects. The research demonstrates that the dominance of these forms is not accidental but stems from energy efficiency related to the physical principles of isoperimetry and surface tension, ergonomic advantages compatible with human biomechanics, and a deep psychological need associated with Carl Jung's "Self" archetype. Conducted using comparative analysis, the study identifies functional, technological, and symbolic similarities of circular forms across African, Asian, European, American, and Oceanian cultures. Particular attention is paid to the cultures of Azerbaijan and other Turkic peoples, where manifestations of circularity as a profound cultural code are analyzed through elements such as the yurt, tandir, sac, armudu glass (pear-shaped glass), and copperware. The article demonstrates how traditional forms are transformed in modern design and technology (Apple Park, smartwatches, user interfaces), confirming the continuing fundamental importance of the circle in human material and spiritual life. Consequently, the circle and sphere are not merely geometric figures but also a unified language of nature, the human psyche, and culture.

This study is devoted to the experimental and analytical investigation of the mechanism underlying the formation of the ‘black crackle’ decorative effect on the surface of ceramic glaze, which arises as a result of the thermochemical transformation of a bio-derived organic precursor under oxygen-limited conditions. The aim of the study was to assess the influence of the thermal conversion products of the bio-precursor on the phase composition, microstructure, local distribution of elements and optical properties of the ceramic glaze, as well as to establish the mechanism underlying the formation of the decorative effect. The experimental programme was initially planned using the Taguchi approach; however, the processing conditions were subsequently adjusted based on preliminary experimental observations. The resulting samples were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray analysis (SEM–EDS), and spectrophotometric measurements using the CIELAB system. The results of X-ray diffraction analysis (XRD) showed that the decoration process did not lead to any significant change in the composition of the main crystalline phase of the glaze. FTIR spectroscopic analysis revealed chemical changes consistent with the thermal transformation of the bio-derived precursor. SEM–EDS observations revealed local differences in the detected carbon signal at selected microzones of the craquelure network; however, carbon coating and the limited number of measurement points prevent the distribution of precursor-derived carbonaceous material from being established directly. Spectrophotometric results confirmed a reduction in brightness and an increase in the total color difference in the decorated samples. Taken together, the results indicate that the black crackle decorative effect is associated with optical changes in the glazed surface rather than a detectable change in the main crystalline phase composition of the glaze. The possible contribution of carbon-rich thermally transformed material in selected crack regions remains a proposed mechanism requiring further verification. The proposed approach opens up new scientific and technological prospects for the use of bio-waste as a functional precursor in the decoration of ceramic surfaces.

This study is devoted to the experimental and analytical investigation of the mechanism underlying the formation of the ‘black crackle’ decorative effect on the surface of ceramic glaze, which arises as a result of the thermochemical transformation of a bio-derived organic precursor under reducing conditions. The aim of the study was to assess the influence of the thermal conversion products of the bio-precursor on the phase composition, microstructure, local distribution of elements and optical properties of the ceramic glaze, as well as to establish the mechanism underlying the formation of the decorative effect. The experimental programme covered various combinations of temperature, storage time and the amount of bioprecursor, using the Taguchi method. The resulting samples were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray analysis (SEM–EDS), and spectrophotometric measurements using the CIELAB system. The results of X-ray diffraction analysis (XRD) showed that the decoration process did not lead to any significant change in the composition of the main crystalline phase of the glaze. FTIR spectroscopic analysis revealed chemical changes consistent with carbonization resulting from the thermal degradation of the bioprecursor. SEM-EDS observations showed that the carbonized products are distributed unevenly across the entire surface and are mainly localized in individual microzones of the craquelure network. Spectrophotometric results confirmed a reduction in brightness and an increase in the total color difference in the decorated samples. An integrated analysis of the results showed that the black crackle decorative effect is formed not through the formation of a new crystalline phase, but through the local accumulation of carbonized products in specific areas of the crackle network—products formed as a result of the thermochemical transformation of the bio-precursor under reducing conditions—and the optical contrast created thereby. The proposed approach opens up new scientific and technological prospects for the use of bio-waste as a functional precursor in the decoration of ceramic surfaces.