scholarly journals Personal adornments from the Eneolithic necropolis of Chirnogi-Suvita Iorgulescu (Romania):

2019 ◽  
Vol 46 ◽  
pp. 398-413
Author(s):  
Monica Margarit ◽  
Madalina Dimache

The Necropolis of Chirnogi – Suvita Iorgulescu (Calarasi county) was located on the high terrace of the Danube and was investigated by Done Serba˘nescu (in 1989) by means of the archaeological excavations carried out for the construction of the Danube-Bucharest Channel. For this study, we analysed the archaeological assemblage preserved in the Museum of Gumelnita civilization from Oltenita (Calarasi county) coming from 10 graves, out of a total of 58, which are attributed to the Gumelnita culture (the second half of the 5th millennium BC). The personal adornments are mainly bracelets made of Spondylus valve (16 specimens) which appear in most of the graves, along with an equal number of perforated plates made of Sus scrofa canine, this time the pieces being grouped into two graves. The funeral inventory is complemented by small cylindrical, tubular or biconvex beads, made of various raw materials: Spondylus valve, bone, malachite, cooper and green slate. At the technical level, attention is drawn towards the technological transformation scheme of the raw material, which is extremely uniform for the two main categories of ornaments. Also, the analysed pieces showed different degrees of use-wear, demonstrating on the one hand that they were worn before the deposition in graves, and on the other that the accumulationof these items took place over time.

2019 ◽  
Vol 46 ◽  
pp. 398-413
Author(s):  
Monica Margarit ◽  
Madalina Dimache

The Necropolis of Chirnogi – Suvita Iorgulescu (Calarasi county) was located on the high terrace of the Danube and was investigated by Done Serba˘nescu (in 1989) by means of the archaeological excavations carried out for the construction of the Danube-Bucharest Channel. For this study, we analysed the archaeological assemblage preserved in the Museum of Gumelnita civilization from Oltenita (Calarasi county) coming from 10 graves, out of a total of 58, which are attributed to the Gumelnita culture (the second half of the 5th millennium BC). The personal adornments are mainly bracelets made of Spondylus valve (16 specimens) which appear in most of the graves, along with an equal number of perforated plates made of Sus scrofa canine, this time the pieces being grouped into two graves. The funeral inventory is complemented by small cylindrical, tubular or biconvex beads, made of various raw materials: Spondylus valve, bone, malachite, cooper and green slate. At the technical level, attention is drawn towards the technological transformation scheme of the raw material, which is extremely uniform for the two main categories of ornaments. Also, the analysed pieces showed different degrees of use-wear, demonstrating on the one hand that they were worn before the deposition in graves, and on the other that the accumulationof these items took place over time.


Author(s):  
K. Shevchenko ◽  
A. Grigorov ◽  
I. Sinkevich

In order to improve the performance properties, in particular viscosity-temperature, of boiler fuel, it is proposed to combine them with narrow fuel fractions obtained by thermal destruction of secondary polymer raw materials (low pressure polyethylene and polypropylene). When compounding grade 100 fuel oil with narrow fuel fractions, the values ​​of density are reduced to 865 (873) kg / m3, conditional viscosity to 2.50 (2.63) deg. um., pour point up to 8 (13) °C), sulfur content up to 0.17 wt%. and the lower heat of combustion increases to 43606 (43850) kJ / kg. At the same time, there is a gradual decrease in the value of the flash point to 114 (127) °C. This reduction is a negative point, which leads to increased fire safety of fuel oil during its use, storage, pumping and transport. However, the values of the flash point, according to the requirements of regulatory documentation, are within acceptable limits. That is, the value of this indicator can limit the content of fuel oil in narrow fuel fractions. It is determined that the rational concentration of narrow fuel fractions in the composition of fuel oil grade 100, is within 30% of the mass. Within these limits, there is a permissible decrease in flash point values – an indicator that characterizes the fire hazard of fuel oil during its use, storage, pumping and transportation against the background of improving other performance properties of fuel oil. The production of the proposed compound boiler fuel on the one hand allows to expand the raw material base of the process by involving in the production process secondary polymer raw materials – solid waste subject to mandatory disposal, on the other – to meet existing demand for boiler fuel by increasing its production.


2020 ◽  
Vol 5 (2) ◽  
pp. 67-99
Author(s):  
Aleksandr Kolesnik ◽  
◽  
Aleksandr Otcherednoy ◽  
Kseniia Stepanova ◽  
Aleksei Danilchenko ◽  
...  

The Sukhaya Mechetka site in the Lower Volga region being widely known due to the unique preservation of cultural remains, their clear geological position and a rich set of tools has long become a kind of icon of the Middle Paleolithic of Eastern Europe. Improtantly the site was excavated over a wide area (about 650 square meters). During the excavation an assemblage of stone items including more than 350 tools, cores and about 10,000 flint and quartzite flakes of various types was collected. The neogene flint and the paleogene quartzite were used as raw materials approximately equally. According to our observations almost all available and suitable for processing stone rocks that were carried to the site as nodules, blocks, fragments and flakes were intensively used. Raw materials were collected in the immediate vicinity of the site. The signals of raw materials shortage and significant depth of its processing were detected. The distribution of the products of flint and quartzite raw materials on the site is irregular. Primary knapping was carried out according to typical Middle Paleolithic technologies. A small series of stone hammers display specific patterns of their use-wear. The cores and the flakes produced with these hammers were found. The complete sequence of preparation and flaking from the pre-cores to the residual forms has been documented. The shortage of high-quality raw material resulted in extremely complete usage of the most cores. Additionally many residual forms have been used for making tools. The cores can be divided into radial, cuboid and Levallois samples.


2020 ◽  
Vol 15 (4) ◽  
pp. 174-185
Author(s):  
Elif Yılmaz ◽  
Sevda Altaş ◽  
Nildeniz Adman

Metalized yarns are produced by cutting the films in different thicknesses, metalized with aluminum on one or both sides, in a rectangular form in the desired dimensions and wrapping them on bobbins under a certain tension. Textile products made of these yarns are exposed to repetitive washings like most textile products; metal surfaces of metalized yarns are abraded over time, their bright appearance decreases or disappears. It is undesirable because it affects the lifetime of the final product. In the study, laminated films were produced by the lamination technique using different raw materials to produce metalized yarns with the improved fastness and mechanical properties. Laminated films were subjected to repetitive washings at different temperatures, and the effects of washings on the surface appearance of the films, lamination strength, and optical density properties were examined. As a result of the study, it was determined that repetitive washings reduce the lamination strength, the gloss property is affected by raw material type, the sample type, washing temperature, and the number of washing cycles affect the optical density.


1977 ◽  
Vol 50 (4) ◽  
pp. 835-841 ◽  
Author(s):  
R. W. Smith ◽  
V. L. Folt

Abstract Hevea brasiliensis or natural rubber (NR) has been used for over 500 years. Until World War II, it was the basic raw material of the rubber industry. Since that time, the use of synthetic polymers has steadily increased, but the importance of NR has not diminished. In fact, the future for the natural product is very promising since it is the one polymer that is obtainable without depleting fossil fuel raw materials. Natural rubber latex has been extensively studied by a variety of methods, especially the microscope. All of the early work with NR latex was conducted, of course, with the optical microscope. In the late 1940's the electron microscope began to be used, but at that time synthetic rubbers began to demand attention, and work on NR latex diminished. Perhaps investigators felt they knew all there was to know about the microscopical characteristics of this material. Indeed, some very fine work had been done and keen observations made with optical microscopes that could not even resolve all of the particles in a latex material. This paper deals with the electron microscopy of natural rubber latexes with particular attention to the proteinaceous layer on the particle and the fate of particles during varying stages of mastication. The critical technique used was to stain the proteinaceous layer of the latex particle with silver nitrate.


Author(s):  
Miloš R. Vasić ◽  
◽  
Milica V. Vasić ◽  

Drying has an enormous impact on the quality of final masonry clay elements. The accumulated knowledge about modeling the drying process, as well as the registered progress in computing the coupling between the heat and mass transfer during the last decade has reached the applicative industrial level. The available novel commercial drying solutions have dropped the drying cycle to 5 hours for hollow clay products and up to 9 hours for clay blocks of large size and weight. The ability to speed up the drying process also strongly depends on the properties of the raw materials. The decision on optimization of the existing dryer and its upgrade or investment in a novel drying facility must be experimentally validated. Results of the one-month monitoring and analysis of the production process in one Serbian brick factory including the material and energy balances are given in this paper. Based on the collected data, raw material limitations and costs of the novel dryer the existing tunnel dryer upgrade and the minimization of the "false" ambient air into the dryer are proposed.


2018 ◽  
Vol 56 ◽  
pp. 103-125
Author(s):  
Grzegorz Osipowicz ◽  
Piotr Chachlikowski ◽  
Justyna Orłowska ◽  
Zsolt Kasztovszky ◽  
Rafał Siuda ◽  
...  

The aim of the article is to present the results of a multifaceted analysis of a collection of non-flint stone artefacts obtained during excavations of the complex of Late Palaeolithic camps at site 17 in Nowogród, Golub-Dobrzyń district. It included an obsidian artefact and objects made of crystalline rocks (quartzite, quartzite sandstone, quartz, coarse sandstone and diorite), which were created as a result of knapping the raw material using techniques similar or identical to those used during the processing of flint. The results of petrographic analysis confirmed that these raw materials had come from natural resources located near the site. Most of the analysed artefacts are represented by large flakes. In addition, one chip and two tools, a multiple burin and a pebble tool, were distinguished. Use-wear analysis showed signs of use on two artefacts, including the pebble tool. The obsidian artefact is currently the northernmost Late Palaeolithic find of this type. In order to determine the geological source of the raw material, the artefact was subjected to PGAA and XRF analysis. PGAA analysis confirmed that the obsidian originated from a source in northern Slovakia (Carpathian 1 type), probably from the Cejkov or Kašov deposits, Trebišov district. The article also describes a rock crystal and a probable concretion of quartz of this type originating from site 6 in Ludowice, Wąbrzeźno district


1940 ◽  
Vol 13 (3) ◽  
pp. 533-538
Author(s):  
Aristid V. Grosse ◽  
Jacque C. Morrell ◽  
Julian M. Mavity

Abstract Aside from the scientific value of the method described here for the catalytic dehydrogenation of monoölefins to diolefins, the present contribution has an important industrial, commercial, and military value, viz., as an economic source of raw material for synthetic rubber. The production of butenes from butanes and pentenes from pentanes has already been described. The present paper, showing the production of butadiene from butenes and isoprene from pentenes, is the connecting link between the billions of cubic feet of butanes present in natural and cracked gases and of butenes present in the latter, and the billions of gallons of pentanes available in natural gasoline and crude oil on the one hand, and the production of synthetic rubber from these raw materials on the other. The basic raw materials for the production of synthetic rubber therefore now include our tremendous resources of hydrocarbon oils, hydrocarbon gases, and coal to produce synthetic hydrocarbons, if and when our petroleum resources become exhausted. The production of synthetic rubber from butadiene and isoprene is well known. Wallach exposed isoprene to light and produced synthetic rubber. Matthews and Harries independently used metallic sodium to polymerize isoprene to rubber. Similar work has also been done bv others.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5512
Author(s):  
Leonel J.R. Nunes ◽  
Jorge T. Pereira da Costa ◽  
Radu Godina ◽  
João C.O. Matias ◽  
João P.S. Catalão

The biomass industry is growing due to the current search for greener and more sustainable alternatives to fossil energy sources. However, this industry, due to its singularity, presents several challenges and disadvantages related to the transportation of raw materials, with the large volumes that are usually involved. This project aimed to address this internal logistics situation in torrefied biomass pellets production with two different biomass storage parks, located in Portugal. The main park receives raw material coming directly from the source and stores it in large amounts as a backup and strategic storage park. The second park, with smaller dimensions, precedes the production unit and must be stocked daily. Therefore, a fleet of transport units with self-unloading cranes is required to help to unload the biomass at the main park and transport the raw material from this park to the one preceding the production unit. Thus, the main goal was to determine the dimensions of the fleet used in internal transportation operations to minimize the idle time of the transport units using a methodology already in use in the mining and quarrying industry. This methodology was analyzed and adapted to the situation presented here. The implementation of this study allows the elimination of unnecessary costs in an industry where the profit margins are low.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Karin M. Frei

In the last two decades, measurements of strontium (Sr) isotopes in archaeological bone tissues/skeletons have shown to be an effective technique for the characterisation of human and animal mobility in prehistory. More recently, this tracing system is also being applied to the investigation of archaeological textile’s provenance. The importance of ancient textiles has been often underestimated, however research of archaeological textiles is currently experiencing an extremely increasing interest as the development of new methodologies, conducting experimental studies and lancing of new projects are providing an unreached amount of new information, knowledge and impressive data sets which together build the basis of novel thinking and interpretations. This manuscript aims at summarising two of the most recently developed methods that focus on the extraction of Sr from ancient non-dyed and organic-dyed wool threads from archaeological textiles in an attempt to identify if the raw materials are local or non-local to the sites. In particular, this study presents two case studies which rely on the use of these chemical protocols. The first example deals with a wool/fur sample from a modern Greenlandic Musk ox. The purpose of this study is to characterise wool from an exotic animal on the one side, and to try to establish a link between this wool and a geologically-seen ancient and very special terrain (Archaean basement rocks from the Kangerlussuaq area of Western Greenland) on which this musk ox was grazing. Our interest was focused on whether the bioavailable Sr fraction from this terrain impacted on the composition of the wool from the animal. The second case study deals with three thread samples from four ancient wool textile pieces recovered from one and the same pre-Roman Iron Age peat bog site at Krogens Mølle (Denmark). Some of these textiles have proven to be dyed with organic dyestuffs. This study therefore aimed at applying a novel pre-cleaning methodology developed for dyed (by organic dyestuffs) wool threads from ancient textiles. The outcome of these two particular studies revealed both the potential of these novel methodologies for retrieving the original Sr isotope signature of the raw material wool, and their limitations.


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