scholarly journals A Context-Appropriate Approach to Marine 14C Calibration: Δr and Bayesian Framework for the Nuvuk Cemetery, Point Barrow, Alaska

Radiocarbon ◽  
2019 ◽  
Vol 61 (03) ◽  
pp. 733-747 ◽  
Author(s):  
Anthony M Krus ◽  
Anne M Jensen ◽  
W Derek Hamilton ◽  
Kerry Sayle
Keyword(s):  
Human Populations ◽  
Weighted Mean ◽  
New Approach ◽  
Local Correction ◽  
Severe Erosion ◽  
Local Deviation ◽  
Alaskan Arctic ◽  
Best Fit ◽  
Global Surface

ABSTRACTThis study provides an assessment of the temporal changes in ΔR, which is the local deviation from the global surface water marine reservoir effect (MRE), in the Point Barrow area of the Alaskan Arctic, a coastal archaeological area that has experienced severe erosion accelerated by global warming. A total of 26 samples were submitted for radiocarbon (14C) dating from eight secure Thule (AD 1000–1750) archaeological contexts, and specifically from archaeological features with paired processed seal and caribou bones that had been frozenin situ. This new approach towards ΔR estimation provides a best-fit local correction for the14C dating of human populations by focusing on the marine mammal (seals) predominantly consumed by the Thule (Coltrain et al. 2016). The weighted-mean ΔR value on these pairs is 450 ± 84 yr, which is about 50 years less than the weighted-mean (506 ± 69 yr) for the Point Barrow area calculated through14C measurements from four known-age bivalves collected in AD 1913 (McNeely et al. 2006). The effects of using this new ΔR value for calibration was assessed through the Bayesian chronological modeling of 5414C measurements from samples of human skeletons interred in the Nuvuk cemetery at Point Barrow, the largest ancient cemetery in northwest Alaska and traditionally thought to date to the Thule and earlier Birnirk (AD 500–1000) periods.

scholarly journals Neuroimmune Response Mediated by Cytokines in Natural Scrapie after Chronic Dexamethasone Treatment

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Isabel M. Guijarro ◽  
Moisés Garcés ◽  
Pol Andrés-Benito ◽  
Belén Marín ◽  
Alicia Otero ◽  
...  
Keyword(s):  
Prion Diseases ◽  
Global Approach ◽  
Profile Data ◽  
Dexamethasone Treatment ◽  
New Approach ◽  
Complex Interactions ◽  
Natural Scrapie ◽  
Anti Inflammatory

The actual role of prion protein-induced glial activation and subsequent cytokine secretion during prion diseases is still incompletely understood. The overall aim of this study is to assess the effect of an anti-inflammatory treatment with dexamethasone on different cytokines released by neuroglial cells that are potentially related to neuroinflammation in natural scrapie. This study emphasizes the complex interactions existent among several pleiotropic neuromodulator peptides and provides a global approach to clarify neuroinflammatory processes in prion diseases. Additionally, an impairment of communication between microglial and astroglial populations mediated by cytokines, mainly IL-1, is suggested. The main novelty of this study is that it is the first one assessing in situ neuroinflammatory activity in relation to chronic anti-inflammatory therapy, gaining relevance because it is based on a natural model. The cytokine profile data would suggest the activation of some neurotoxicity-associated route. Consequently, targeting such a pathway might be a new approach to modify the damaging effects of neuroinflammation.

scholarly journals An Unconventional Field Mapping Application: A Complete Opensource Workflow Solution Applied to Lithological Mapping of the Coatings of Cultural Heritage

2021 ◽  
Vol 10 (6) ◽  
pp. 357
Author(s):  
Niccolò Iandelli ◽  
Massimo Coli ◽  
Tessa Donigaglia ◽  
Anna Livia Ciuffreda
Keyword(s):  
Cultural Heritage ◽  
Coating Materials ◽  
Historical Building ◽  
New Approach ◽  
Photo Interpretation ◽  
Organization Management ◽  
Field Mapping ◽  
Lithological Mapping ◽  
Entire Amount

The conservation of a primary importance historical building requires organization, management, continuous updating, comparison, and visualization of a large amount of data of different nature and origin. In relation to these aspects the use of a GIS brings various advantages including single and univocal management of the entire amount of existing data in a relational, dynamic, updatable and queryable way. The integration of a mobile solution permits the updating of the dataset and checking on site all information. The workflow presented uses opensource solutions, desktop and mobile, which allows the creation of an unconventional lithological Field Mapping activity: starting from photo interpretation and in situ survey, all the coating materials (stone, etc.) of some monuments of primary historical and cultural interest have been mapped (i.e., Duomo di Firenze, Duomo di Prato). The product can be considered as a lithological cartography, vertically oriented, processed by field surveys, geognostic surveys and photo interpretation. All combined to create a “lithological” mapping of the coatings of the various monuments; the advantage is a new approach for conservation and restoration of Cultural Heritage. The proposed workflow involves a mobile solution, opensource, that allows the verification and management of the database in the field.

scholarly journals Non-dispersive UV Absorption Spectroscopy: A Promising New Approach for in-situ Detection of Sulfur Dioxide

2019 ◽  
Vol 7 ◽  
Author(s):  
Jan-Lukas Tirpitz ◽  
Denis Pöhler ◽  
Nicole Bobrowski ◽  
Bruce Christenson ◽  
Julian Rüdiger ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Absorption Spectroscopy ◽  
Uv Absorption ◽  
New Approach ◽  
Uv Absorption Spectroscopy ◽  
In Situ Detection

A new approach to arylhydrazides via the reaction of the Mitsunobu reagent with arynes: further application to access diverse nitrogen-containing heterocycles in one pot

2017 ◽  
Vol 4 (8) ◽  
pp. 1636-1639 ◽  
Author(s):  
Bin Cheng ◽  
Bian Bao ◽  
Yanhe Chen ◽  
Ning Wang ◽  
Yun Li ◽  
...  
Keyword(s):  
One Pot ◽  
New Approach ◽  
Mild Conditions ◽  
Highly Active ◽  
Active Intermediates

A new route to arylhydrazides involving the reaction of two highly active intermediates, the 1,3-zwitterion generated in situ from the Mitsunobu reagent and arynes, under mild conditions has been developed.

scholarly journals Multi-source SO<sub>2</sub> emissions retrievals and consistency of satellite and surface measurements with reported emissions

2017 ◽  
Author(s):  
Vitali Fioletov ◽  
Chris A. McLinden ◽  
Shailesh K. Kharol ◽  
Nickolay A. Krotkov ◽  
Can Li ◽  
...  
Keyword(s):  
Point Source ◽  
Single Point ◽  
Control Measures ◽  
Ozone Monitoring Instrument ◽  
So2 Emissions ◽  
Vertical Column ◽  
Wind Speeds ◽  
Surface Measurements ◽  
Best Fit

Abstract. Reported sulfur dioxide (SO2) emissions from U.S. and Canadian sources have declined dramatically since the 1990s as a result of emissions control measures. Observations from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and ground-based in-situ measurements are examined to verify whether the observed changes from SO2 abundance measurements are quantitatively consistent with the reported changes in emissions. To make this connection, a new method to link SO2 emissions and satellite SO2 measurements was developed. The method is based on fitting satellite SO2 vertical column densities (VCDs) to a set of functions of OMI pixel coordinates and wind speeds, where each function represents a statistical model of a plume from a single point source. The concept is first demonstrated using sources in North America, and then applied to Europe. The correlation coefficient between OMI-measured VCDs (with a local bias removed) and SO2 VCDs derived here using reported emissions for 1° by 1° gridded data is 0.91 and the best-fit line has a slope near unity, confirming a very good agreement between observed SO2 VCDs and reported emissions. Having demonstrated their consistency, seasonal and annual mean SO2 VCD distributions are calculated, based on reported point-source emissions for the period 1980–2015, as would have been seen by OMI. This consistency is further substantiated as the emissions-derived VCDs also show a high correlation with annual mean SO2 surface concentrations at 50 regional monitoring stations.

scholarly journals Imaging the Polymorphic Transformation in a Single Cu6Sn5 Grain in a Solder Joint

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2229 ◽  
Author(s):  
Flora Somidin ◽  
Hiroshi Maeno ◽  
Xuan Tran ◽  
Stuart D. McDonald ◽  
Mohd Mohd Salleh ◽  
...  
Keyword(s):  
Solder Joint ◽  
Polymorphic Transformation ◽  
Structural Evolution ◽  
Real Space ◽  
Transformation Behavior ◽  
New Approach ◽  
Transmission Electron ◽  
Contrast Pattern ◽  
In Situ Observations

In-situ observations of the polymorphic transformation in a single targeted Cu6Sn5 grain constrained between Sn-0.7 wt % Cu solder and Cu-Cu3Sn phases and the associated structural evolution during a solid-state thermal cycle were achieved via a high-voltage transmission electron microscope (HV-TEM) technique. Here, we show that the monoclinic η′-Cu6Sn5 superlattice reflections appear in the hexagonal η-Cu6Sn5 diffraction pattern upon cooling to isothermal 140 °C from 210 °C. The in-situ real space imaging shows that the η′-Cu6Sn5 contrast pattern is initiated at the grain boundary. This method demonstrates a new approach for further understanding the polymorphic transformation behavior on a real solder joint.

Experimental Validation of an Identification Procedure of Soil Profile Characteristics from Free Field Acceleration Records

2012 ◽  
Vol 3 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Z. Harichane ◽  
H. Afra ◽  
R. Bahar
Keyword(s):  
Soil Profile ◽  
Damping Ratio ◽  
Linear Optimization ◽  
Free Field ◽  
Unit Weight ◽  
New Approach ◽  
Theoretical Function ◽  
Minimization Technique ◽  
Profile Characteristics

In this paper, a new approach for soil profile characterization is validated. The soil characteristics are calculated by fitting the theoretical amplification functions to those obtained experimentally. The identified characteristics have been observed to agree well with those obtained by in situ and laboratory tests. This new approach uses system identification theory and free field records. It is based on formulation of theoretical soil amplification function for two sites in terms of the different parameters of the soil profile layers (thickness, damping ratio, shear wave velocity and unit weight). The theoretical function is smoothed according to the experimental data (spectral ratios) by means of the least squares minimization technique. The function parameters are determined by solving, numerically, a non linear optimization problem. In this approach, soil profile characteristics of two sites can be identified simultaneously, from only a single soil acceleration record at free surface of each site without need of bedrock or outcropping acceleration records. Strong ground motions data recorded during the Boumerdes earthquake (Algeria) of May 21, 2003, are used for the validation.

scholarly journals Interfacial Adhesion and Mechanical Properties of PET Fabric/PVC Composites Enhanced by SiO2/Tributyl Citrate Hybrid Sizing

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 898
Author(s):  
Dandan Pu ◽  
Fuyao Liu ◽  
Yubing Dong ◽  
Qingqing Ni ◽  
Yaqin Fu
Keyword(s):  
Interfacial Adhesion ◽  
Ethylene Terephthalate ◽  
Sio2 Nanoparticles ◽  
New Approach ◽  
Pet Fabric ◽  
Poly Ethylene Terephthalate ◽  
Wide Range ◽  
Peeling Strength ◽  
Poly Ethylene

Poly(ethylene terephthalate) (PET) fabric-reinforced polyvinyl chloride (PVC) composites have a wide range of applications, but the interface bonding of PET fabric/PVC composites has remained a challenge. In this work, a new in-situ SiO2/tributyl citrate sizing agent was synthesized according to the principle of “similar compatibility.” The developed sizing agent was used as a PET surface modifier to enhance the interfacial performance of PET fabric/PVC composites. The morphology and structure of the PET filaments, the wettability and tensile properties of the PET fabric, the interfacial adhesion, and the tensile and tearing properties of the PET fabric/PVC composites were investigated. Experimental results showed that many SiO2 nanoparticles were scattered on the surface of the modified PET filaments. Moreover, the surface roughness of the modified PET filaments remarkably increased in comparison with that of the untreated PET filaments. The contact angle of the modified PET filaments was also smaller than that of the untreated ones. The peeling strength of the modified PET fabrics/PVC composites was 0.663 N/mm, which increased by 62.50% in comparison with the peeling strength of the untreated ones (0.408 N/mm). This work provides a new approach to the surface modification of PET and improves the properties of PET fabric/PVC composites.

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