scholarly journals Chronological Modelling of the Chalcolithic Settlement Layers at Tell Yunatsite, Southern Bulgaria

2021 ◽  
Vol 48 ◽  
pp. 2-25
Author(s):  
Yavor Boyadzhiev ◽  
Kamen Boyadzhiev ◽  
Lennart Brandtstätter ◽  
Raiko Krauß
Keyword(s):  
Monte Carlo ◽  
Bayesian Statistics ◽  
Surface Area ◽  
Calibration Curve ◽  
Large Surface Area ◽  
Stratigraphic Sequence ◽  
Radiocarbon Dates ◽  
Chalcolithic Period ◽  
Small Test

This article publishes a new series of radiocarbon dates from Tell Yunatsite, Southern Bulgaria. Context-based excavations undertaken over a large surface area, as well as a small test trench, provided a long stratigraphic sequence (11 ‘building levels’) covering a large part of the Chalcolithic period in Thrace (5th millennium BCE). Bayesian statistics and Gaussian Monte Carlo Wiggle Matching were employed to achieve a fine chronology for the multilayered tell. Implications and problems on the application of the calibration curve for the Late and Final Chalcolithic in Bulgaria are also discussed.

High-resolution chronology for the Mesoamerican urban center of Teotihuacan derived from Bayesian statistics of radiocarbon and archaeological data

2009 ◽  
Vol 71 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Laura E. Beramendi-Orosco ◽  
Galia Gonzalez-Hernandez ◽  
Jaime Urrutia-Fucugauchi ◽  
Linda R. Manzanilla ◽  
Ana M. Soler-Arechalde ◽  
...  
Keyword(s):  
High Resolution ◽  
Bayesian Analysis ◽  
Bayesian Statistics ◽  
Calibration Curve ◽  
Bayesian Model ◽  
Archaeological Site ◽  
Urban Center ◽  
Radiocarbon Dates ◽  
Archaeological Data ◽  
Radiocarbon Data

AbstractA high-resolution 14C chronology for the Teopancazco archaeological site in the Teotihuacan urban center of Mesoamerica was generated by Bayesian analysis of 33 radiocarbon dates and detailed archaeological information related to occupation stratigraphy, pottery and archaeomagnetic dates. The calibrated intervals obtained using the Bayesian model are up to ca. 70% shorter than those obtained with individual calibrations. For some samples, this is a consequence of plateaus in the part of the calibration curve covered by the sample dates (2500 to 1450 14C yr BP). Effects of outliers are explored by comparing the results from a Bayesian model that incorporates radiocarbon data for two outlier samples with the same model excluding them. The effect of outliers was more significant than expected. Inclusion of radiocarbon dates from two altered contexts, 500 14C yr earlier than those for the first occupational phase, results in ages calculated by the model earlier than the archaeological records. The Bayesian chronology excluding these outliers separates the first two Teopancazco occupational phases and suggests that ending of the Xolalpan phase was around cal AD 550, 100 yr earlier than previously estimated and in accordance with previously reported archaeomagnetic dates from lime plasters for the same site.

scholarly journals Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽  
1997 ◽  
Vol 39 (1) ◽  
pp. 27-32 ◽  
Author(s):  
John C. Vogel ◽  
Joel Kronfeld
Keyword(s):  
South Africa ◽  
Magnetic Dipole ◽  
Satisfactory Agreement ◽  
Late Pleistocene ◽  
Calibration Curve ◽  
Dipole Field ◽  
Radiocarbon Dates ◽  
The Past ◽  
The Earth ◽  
Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

Functional Two-Dimensional Black Phosphorus Nanostructures towards Next-Generation Devices

2021 ◽  
Author(s):  
Mengke Wang ◽  
Jun Zhu ◽  
You Zi ◽  
Zheng-Guang Wu ◽  
Haiguo Hu ◽  
...  
Keyword(s):  
Surface Area ◽  
Biomedical Applications ◽  
Black Phosphorus ◽  
Large Surface Area ◽  
Two Dimensional ◽  
Next Generation

In recent years, two-dimensional (2D) black phosphorus (BP) has been widely applied in many fields, such as (opto)electronics, transistors, catalysis and biomedical applications due to its large surface area, tunable...

Research on metallic chalcogen-functionalized monolayer-puckered V2CX2 (X = S, Se, and Te) as promising Li-ion battery anode materials

2021 ◽  
Author(s):  
Chunmei Tang ◽  
Xiaoxu Wang ◽  
Shengli Zhang
Keyword(s):  
Surface Area ◽  
Anode Materials ◽  
Large Surface Area ◽  
Two Dimensional ◽  
Li Ion Batteries ◽  
Li Ion Battery ◽  
Li Ion ◽  
Battery Anode

Two-dimensional MXene nanomaterials are promising anode materials for Li-ion batteries (LIBs) due to their excellent conductivity, large surface area, and high Li capability.

scholarly journals Strategic use of nanotechnology in drug targeting and its consequences on human health: A focused review

2019 ◽  
Vol 11 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Anand Maurya ◽  
Anurag Kumar Singh ◽  
Gaurav Mishra ◽  
Komal Kumari ◽  
Arati Rai ◽  
...  
Keyword(s):  
Human Health ◽  
Surface Area ◽  
Medical Diagnosis ◽  
Drug Targeting ◽  
Pharmaceutical Market ◽  
Large Surface Area ◽  
Mass Ratio ◽  
Disease Therapy ◽  
Significant Interest ◽  
Medical Benefits

Since the development of first lipid-based nanocarrier system, about 15% of the present pharmaceutical market uses nanomedicines to achieve medical benefits. Nanotechnology is an advanced area to meliorate the delivery of compounds for improved medical diagnosis and curing disease. Nanomedicines are gaining significant interest due to the ultra small size and large surface area to mass ratio. In this review, we discuss the potential of nanotechnology in delivering of active moieties for the disease therapy including their toxicity evidences. This communication will help the formulation scientists in understanding and exploring the new aspects of nanotechnology in the field of nanomedicine.

Synthesis of functional hollow WS2 particles with large surface area for Near-Infrared (NIR) triggered drug delivery

2021 ◽  
Vol 875 ◽  
pp. 160034
Author(s):  
Na Liu ◽  
Fan Fan ◽  
Wei Xu ◽  
Hao Zhang ◽  
Qi Zhou ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Surface Area ◽  
Near Infrared ◽  
Large Surface Area

Accelerating ion diffusion with unique three-dimensionally interconnected nanopores for self-membrane high-performance pseudocapacitors

Nanoscale ◽  
2017 ◽  
Vol 9 (46) ◽  
pp. 18311-18317 ◽  
Author(s):  
Yuan Gao ◽  
Yuanjing Lin ◽  
Zehua Peng ◽  
Qingfeng Zhou ◽  
Zhiyong Fan
Keyword(s):  
Aspect Ratio ◽  
Surface Area ◽  
Structural Stability ◽  
High Aspect Ratio ◽  
High Performance ◽  
Three Dimensional ◽  
Rate Capability ◽  
Large Surface Area ◽  
Nanoporous Structure ◽  
Ion Diffusion

Three-dimensional interconnected nanoporous structure (3-D INPOS) possesses high aspect ratio, large surface area, as well as good structural stability. Profiting from its unique interconnected architecture, the 3-D INPOS pseudocapacitor achieves a largely enhanced capacitance and rate capability.

Transport of Ions and Molecules in Nanofluidic Devices

2008 ◽  
Author(s):  
Rohit Karnik ◽  
Chuanhua Duan ◽  
Kenneth Castelino ◽  
Rong Fan ◽  
Peidong Yang ◽  
...  
Keyword(s):  
Surface Charge ◽  
Surface Area ◽  
Field Effect ◽  
Electrostatic Interactions ◽  
Surface Reactions ◽  
Molecular Transport ◽  
Large Surface Area ◽  
Ionic Concentrations ◽  
Nanofluidic Devices ◽  
Transport Of Ions

Interesting transport phenomena arise when fluids are confined to nanoscale dimensions in the range of 1–100 nm. We examine three distinct effects that influence ionic and molecular transport as the size of fluidic channels is decreased to the nanoscale. First, the length scale of electrostatic interactions in aqueous solutions becomes comparable to nanochannel size and the number of surface charges becomes comparable to the number of ions in the channel. Second, the size of the channel becomes comparable to the size of biomolecules such as proteins and DNA. Third, large surface area-to-volume ratios result in rapid rates of surface reactions and can dramatically affect transport of molecules through the channel. These phenomena enable us to control transport of ions and molecules in unique ways that are not possible in larger channels. Electrostatic interactions enable local control of ionic concentrations and transport inside nanochannels through field effect in a nanofluidic transistor, which is analogous to the metal-oxide-semiconductor field effect transistor. Furthermore, by controlling surface charge in nanochannels, it is possible to create a nanofluidic diode that rectifies ionic transport through the channel. Biological binding events result in partial blockage of the channel, and can thus be sensed by a decrease in nanochannel conductance. At low ionic concentrations, the effect of biomolecular charge is dominant and it can lead to an increase in conductance. Surface reactions can also be used to control transport of molecules though the channel due to the large surface area-to-volume ratios. Rapid surface reactions enable a new technique of diffusion-limited patterning (DLP), which is useful for patterning of biomolecules and surface charge in nanochannels. These examples illustrate how electrostatic interactions, biomolecular size, and surface reactions can be used for controlling ionic and molecular transport through nanochannels. These phenomena may be useful for operations such as analyte focusing, pH and ionic concentration control, and biosensing in micro- and nanofluidic devices.

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