Radiocarbon dating is essential for establishing robust chronologies in archaeological and paleoenvironmental contexts spanning the last 55,000 years. Pottery, pervasive in the archaeological record, offers a crucial framework for dating human activity during the Holocene. Traditionally, radiocarbon dating of pottery has relied on targeting carbonaceous inclusions such as organic temper or measuring stratigraphically associated materials like bone and charcoal. Inaccuracies can arise, however, if the targeted fraction does not reflect the timing of vessel use or if stratigraphic associations are uncertain. An alternative involves radiocarbon dating of lipid residues, particularly fatty acids absorbed into the ceramic matrix during the processing and storage of plant and animal-derived resources. This approach holds promise for delivering highly accurate measurements directly correlating to vessel use. At the Oxford Radiocarbon Accelerator Unit, efforts have been made to develop this methodology through compound-specific radiocarbon dating of pottery, employing a gas chromatography (GC)-preparative fraction collector (PFC) approach. Here, we describe the protocol and present preliminary findings, including analyses conducted on pottery samples sourced from an archaeological site with an established chronology.
The hull of a linear code 𝒞 is the intersection of 𝒞 with its dual code. We present and analyze the sequence of numbers of linear codes with increasing hull dimension but the same length n and dimension k. We also present classification results for binary and ternary linear codes with trivial hulls (LCD and self-orthogonal) for some values of the length n and dimension k, comparing the obtained numbers with the number of all linear codes for the same n and k.
The object of study in the present paper is a class of null curves in Lorentzian hypersurfaces M of a 5-dimensional cosymplectic B-metric manifold M-, which are Legendre curves in the ambient manifold. We construct a basis along the examined curves through the almost contact B-metric structure of M- and the induced objects in M. By using this basis, we prove that there exists a unique Cartan frame for the curves belonging to the investigated class. We show that if the Lorentzian hypersurface M is totally geodesic (resp. totally umbilical), then the curve is geodesic (resp. non-geodesic). Special attention is paid to the case when M is totally umbilical. We obtain that if M is an extrinsic sphere, then the studied curves are helices. We construct an example of a helix belonging to the considered class of null curves in a 4-dimensional anti-de Sitter space H-1(4), which is a Lorentzian hypersurface of R-2(5), endowed with a cosymplectic B-metric structure.
Developing economical and scalable electrode materials continues to be a significant issue for asymmetric supercapacitors that integrate high energy and power densities. In this study, a ZnCo2S4/multiwalled carbon nanotube (ZCS/MWCNT) composite was synthesized through a simple two-step route involving a solvothermal process followed by physical integration. The incorporation of conductive MWCNTs effectively enhanced electron transport and structural stability of the ZCS matrix. The optimized ZCS/MWCNT electrode delivered a gravimetric specific capacity of 1388 C/g at 1 A/g, outperforming pristine ZCS (1079 C/g at 1 A/g) due to improved charge transfer and accessible active sites. The ZCS/MWCNT//AC device operated within the stable potential window 0-1.5 V, delivers a gravimetric specific capacitance of 73.3 F/g, a gravimetric energy density of 45.83 Wh/kg at a gravimetric power density of 1500 W/kg and an arial energy density of 0.0906 & micro;Wh/cm(2) at an arial power density of 2.96 & micro;W/cm(2) with similar to 70% capacitance retention at 5 A/g after 10,000 cycles. To further demonstrate its application in real time, the ZCS/MWCNT//AC device was used as a power source for operating a light sensor. This work highlights the effectiveness of a facile hybridization strategy in promoting electrochemical reversibility and structural robustness of bimetallic sulfide based pseudocapacitive electrodes for practical energy storage applications.
Review of the Monograph Entitled Website Optimization and Usability— Methodologies, Principles, and Strategies. Author: Juliana Dochkova-Todorova. I&B Publishing House, 2025, 131 p.,
