scholarly journals New AMS dates from the Sub-Neolithic sites in the Southern Buh area (Ukraine) and problems in the Buh-Dnister Culture chronology

2019 ◽  
Vol 46 ◽  
pp. 216-245 ◽  
Author(s):  
Dmytro Haskevych ◽  
Eiko Endo ◽  
Dai Kunikita ◽  
Olexandr Yanevich

Ideas about the origin of the Buh-Dnister Culture under the influence of the Danube Early Neolithic were questioned by series of radiocarbon dates falling into the second half of the 7th millennium BC measured on bones at the Kyiv laboratory in 1998–2004. To start addressing this problem, 11 AMS dates on organic inclusions in the ceramic paste and charred residues on the surface of vessels were obtained at the Tokyo University laboratory. Apart from two heavily overestimated values, measured on samples with very low carbon content, they fall into the range of the 60th–46th century BC that correspond better to the primary views of this chronology. However, the issues of the time and direction of spreading of the first pottery in the region need further research.

2019 ◽  
Vol 46 ◽  
pp. 216-245
Author(s):  
Dmytro Haskevych ◽  
Eiko Endo ◽  
Dai Kunikita ◽  
Olexandr Yanevich

Ideas about the origin of the Buh-Dnister Culture under the influence of the Danube Early Neolithic were questioned by series of radiocarbon dates falling into the second half of the 7th millennium BC measured on bones at the Kyiv laboratory in 1998–2004. To start addressing this problem, 11 AMS dates on organic inclusions in the ceramic paste and charred residues on the surface of vessels were obtained at the Tokyo University laboratory. Apart from two heavily overestimated values, measured on samples with very low carbon content, they fall into the range of the 60th–46th century BC that correspond better to the primary views of this chronology. However, the issues of the time and direction of spreading of the first pottery in the region need further research.


1968 ◽  
Vol 33 (3) ◽  
pp. 363-366 ◽  
Author(s):  
R. E. Taylor ◽  
Rainer Berger

AbstractRadiocarbon determinations on a series of low-carbon-content ceramic and wattle-and-daub samples were made to determine the validity of radiocarbon dates based on these types of sample materials. Good agreement between radiocarbon dates obtained from the ceramic samples and from charcoal samples stratigraphically associated with the ceramics suggests that radiocarbon dates obtained on low-carbon-content ceramic materials are reliable if appropriate precautions are observed. The confidence which can be placed on radiocarbon dates obtained on wattle-and-daub sample materials is, at present, somewhat less secure. Problems in the use of these sample materials are discussed.


Alloy Digest ◽  
1984 ◽  
Vol 33 (2) ◽  

Abstract EASTERN STAINLESS Type 316L is a chromium-nickel-molybdenum steel with a very low carbon content (0.03 max.) Its general resistance to corrosion is similar to AISI Type 316 but, because of its low carbon content, it has superior resistance to the formation of harmful carbides that contribute to intergranular corrosion. Type 316L is used widely in many industries such as chemical, food, paper, textile, nuclear and oil. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-439. Producer or source: Eastern Stainless Steel Company.


Alloy Digest ◽  
1983 ◽  
Vol 32 (6) ◽  

Abstract EASTERN STAINLESS TYPE 304L is the basic 18-8 chromium-nickel austenitic stainless steel with a very low carbon content (0.03% max.). Its general resistance to corrosion is similar to AISI Type 304 but, because of its low carbon content, it has superior resistance to the formation of harmful carbides that indirectly contribute to intergranular corrosion. It is recommended for most articles of welded construction. Postweld annealing is not necessary. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-427. Producer or source: Eastern Stainless Steel Company.


2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Hadi Torkamani ◽  
Shahram Raygan ◽  
Carlos Garcia Mateo ◽  
Yahya Palizdar ◽  
Jafar Rassizadehghani ◽  
...  

AbstractIn this study, dual-phase (DP, ferrite + martensite) microstructures were obtained by performing intercritical heat treatments (IHT) at 750 and 800 °C followed by quenching. Decreasing the IHT temperature from 800 to 750 °C leads to: (i) a decrease in the volume fraction of austenite (martensite after quenching) from 0.68 to 0.36; (ii) ~ 100 °C decrease in martensite start temperature (Ms), mainly due to the higher carbon content of austenite and its smaller grains at 750 °C; (iii) a reduction in the block size of martensite from 1.9 to 1.2 μm as measured by EBSD. Having a higher carbon content and a finer block size, the localized microhardness of martensite islands increases from 380 HV (800 °C) to 504 HV (750 °C). Moreover, despite the different volume fractions of martensite obtained in DP microstructures, the hardness of the steels remained unchanged by changing the IHT temperature (~ 234 to 238 HV). Applying lower IHT temperature (lower fraction of martensite), the impact energy even decreased from 12 to 9 J due to the brittleness of the martensite phase. The results of the tensile tests indicate that by increasing the IHT temperature, the yield and ultimate tensile strengths of the DP steel increase from 493 to 770 MPa, and from 908 to 1080 MPa, respectively, while the total elongation decreases from 9.8 to 4.5%. In contrast to the normalized sample, formation of martensite in the DP steels could eliminate the yield point phenomenon in the tensile curves, as it generates free dislocations in adjacent ferrite.


2017 ◽  
Vol 740 ◽  
pp. 93-99
Author(s):  
Muhammad Hafizuddin Jumadin ◽  
Bulan Abdullah ◽  
Muhammad Hussain Ismail ◽  
Siti Khadijah Alias ◽  
Samsiah Ahmad

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).


Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 783-794 ◽  
Author(s):  
Natalia E Zaretskaya ◽  
Sönke Hartz ◽  
Thomas Terberger ◽  
Svetlana N Savchenko ◽  
Mikhail G Zhilin

Two well-known archaeological sites, the peat bogs of Shigir and Gorbunovo (Middle Urals, Russia), have been radiocarbon dated (61 conventional and accelerator mass spectrometry [AMS] dates from various natural and artifact samples). For the first time, a detailed chronology of Early to Late Mesolithic and Early Neolithic occupation for this region has been obtained, and a paleoenvironmental history reconstructed. Based on these results, we propose that the Mesolithic settlement of the Middle Urals region started in the early Holocene, at the same time as in central and eastern Europe.


2004 ◽  
Vol 7 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Jorge Otubo ◽  
Odair Doná Rigo ◽  
Carlos de Moura Neto ◽  
Michael Joseph Kaufman ◽  
Paulo Roberto Mei

1997 ◽  
Vol 467 ◽  
Author(s):  
F. C. Marques ◽  
J. Vilcarromero ◽  
F. L. Freire

ABSTRACTStructural and mechanical properties of hydrogenated amorphous germanium carbon (a-Ge1-xCx:H) alloys are presented. The films were prepared by the rf-co-sputtering technique using a graphite/germanium composed target. The carbon and germanium relative concentrations were determined by RBS, and the total hydrogen concentration by ERDA measurements. An increase in the optical gap was measured for low carbon content (0 < × < 0.15). For higher values of x the optical gap is almost constant. Infrared transmission absorption spectra show several absorption bands related to Ge-C stretching, C-Hn (n = 1,2,3) and Ge-H stretching and bending modes. The mechanical internal stress was strongly affected by the incorporation of carbon. The trends of the optical gap, refractive index, infrared absorption and mechanical stress as a function of the carbon content suggest that the high carbon concentration alloys have polymeric and/or graphite-like contribution in their structure.


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