Heavy metals like cadmium (Cd) and lead (Pb) are pollutants that are toxic, difficult to decompose and accumulate in biota. One of the biota that lives in the waters is mullet fish. This fish is demersal, has a relatively long life period, has a specific tolerance to the aquatic environment and highly consumable in Indonesia. Therefore need to know the metal content of Cd and Pb in water, sediments and mullet fish and their relationship in Indonesia. The study used a survey method with purposive random sampling at four stations, three replications. The study was conducted from June to November 2019. Analysis of data was descriptive, F-test and correlation. The results showed that the heavy metal content of Cd and Pb between stations in the water media, sediment and in mullet fish there was a significant difference. The highest Cd and Pb were showed in station III, coming from the oil industry, domestic waste and transportation activities. The heavy metal content of Cd and Pb in water, sediment and mullet fish (Planiliza subviridis) in the Donan River, Cilacap shows results exceeding the allowed threshold and danger to human health.

Various experiences related to research work, including the less successful ones, are all part of the research process. Awareness of their existence allows to draw conclusions from one’s mistakes and a more responsibly design of a research. This article aims to understand the traps a researcher, exploring intellectual disability, may fall into. As a result of search and reflection, three kinds of traps can be listed: resistance — submission, norm — pathology, correctness — negligence.

The physical phenomena occurring in sound-absorbing and insulating enclosures are subject of the present paper. These phenomena are: absorption in air and by the sound-absorbing material covering the walls and the coincidence effect. The absorption in the air can be neglected in small size enclosures for low ultrasonic frequencies (20-30 kHz). The coincidence plays a role in decrease of the sound insulation, however the main role play the leaks. The boards made of ceramic fibers have been chosen as the optimal sound-absorbing material. They are dense and have deeply porous structures. The enclosure for insulation of 20-kHz noise produced by a welding machine has been designed and manufactured, and reductions of 25 dB of peak and Leq levels have been achieved.

The interview provides a record of a conversation held during the XXIII International Congress of Historical Sciences in Poznan, with late antiquity scholar and epigraphic specialist Ignazio Tantillo (professor at the Università di Napoli “L’Orientale”). The conversation revolves around the matter of understanding the peculiarities of Late Antiquity in terms of an autonomous period in history, the temporal and spatial framework of which remains the subject of deliberations to this day. In the article, Ignazio Tantillo discusses the role of new challenges and hopes for scholars of Late Antiquity in the coming decades. The conversation also includes a reflection upon the nature of the historian's involvement in the public sphere, the (paradigm of public history), especially in the context of the “cancel culture” phenomenon.