scholarly journals A new Pre-Pottery Neolithic site in Southeastern Turkey: Ayanlar Höyük (Gre Hut)

2018 ◽  
Vol 44 ◽  
pp. 360-367
Author(s):  
Bahattin Celik
Keyword(s):  
Surface Area ◽  
Large Scale ◽  
Neolithic Period ◽  
Neolithic Site ◽  
Surface Survey

Ayanlar Höyük (Gre Hut), located 30km west of Şanlıurfa, was discovered during surface surveys conducted in 2013. Ayanlar Höyük dated to the Pre-Pottery Neolithic Period, is a large- scale mound like Göbekli Tepe and Karahan Tepe, covering an overall surface area of 14 hectares. It was learned recently that three artefacts dated to the Pre-Pottery Neolithic period which are held by Şanlıurfa Museum were brought from Ayanlar Höyük. The artefacts in Şanlıurfa Museum and the finds recovered from Ayanlar Höyük during a surface survey have been identified as having characteristics similar to those from Körtik Tepe, Göbekli Tepe, Nevali Çori and Karahan Tepe. Con­sequently, Ayanlar Höyük should be dated between the early Pre-Pottery Neolithic Period B (EPPNB) and the mid-Pre-Pottery Neolithic Period B (MPPNB).

scholarly journals A new Pre-Pottery Neolithic site in Southeastern Turkey: Ayanlar Höyük (Gre Hut)

10.4312/dp.22 ◽  
2018 ◽  
Vol 44 ◽  
pp. 360
Author(s):  
Bahattin Celik
Keyword(s):  
Surface Area ◽  
Large Scale ◽  
Neolithic Period ◽  
Neolithic Site ◽  
Surface Survey

Ayanlar Höyük (Gre Hut), located 30km west of Şanlıurfa, was discovered during surface surveys conducted in 2013. Ayanlar Höyük dated to the Pre-Pottery Neolithic Period, is a large- scale mound like Göbekli Tepe and Karahan Tepe, covering an overall surface area of 14 hectares. It was learned recently that three artefacts dated to the Pre-Pottery Neolithic period which are held by Şanlıurfa Museum were brought from Ayanlar Höyük. The artefacts in Şanlıurfa Museum and the finds recovered from Ayanlar Höyük during a surface survey have been identified as having characteristics similar to those from Körtik Tepe, Göbekli Tepe, Nevali Çori and Karahan Tepe. Con­sequently, Ayanlar Höyük should be dated between the early Pre-Pottery Neolithic Period B (EPPNB) and the mid-Pre-Pottery Neolithic Period B (MPPNB).

The entrainment interface

1972 ◽  
Vol 51 (1) ◽  
pp. 97-118 ◽  
Author(s):  
O. M. Phillips
Keyword(s):  
Velocity Field ◽  
Turbulent Flow ◽  
Surface Area ◽  
Large Scale ◽  
Positive Curvature ◽  
Lagrangian Description ◽  
Eulerian Description ◽  
Entrainment Process ◽  
Necessary And Sufficient ◽  
Small Disturbances

A theory is developed to describe the evolution of the entrainment interface in turbulent flow, in which the surface is convoluted by the large-scale eddies of the motion and at the same time advances relative to the fluid as a result of the micro-scale entrainment process. A pseudo-Lagrangian description of the process indicates that the interface is characterized by the appearance of ‘billows’ of negative curvature, over which surface area is, on average, being generated, separated by re-entrant wedges (lines of very large positive curvature) where surface area is consumed. An alternative Eulerian description allows calculation of the development of the interfacial configuration when the velocity field is prescribed. Several examples are considered in which the prescribed velocity field in the z direction is of the general form w = Wf(x – Ut), where the maximum value of the function f is unity. These indicate the importance of leading points on the surface which are such that small disturbances in the vicinity will move away from the point in all directions. The necessary and sufficient condition for the existence of one or more leading points on the surface is that U [les ] V, the speed of advance of an element of the surface relative to the fluid element at the same point. The existence of leading points is accompanied by the appearance of line discontinuities in the surface slope re-entrant wedges, In these circumstances, the overall speed of advance of the convoluted surface is found to be W + (V2 – U2)½, where W is the maximum outwards velocity in the region; this result is independent of the distribution f.When the speed U with which an ‘eddy’ moves relative to the outside fluid is greater than the speed of advance V of an element of the front, the interface develops neither leading points nor discontinuities in slope; the amplitude of the surface convolutions and the overall entrainment speed are both reduced greatly. In a turbulent flow, therefore, the large-scale motions influencing entrainment are primarily those that move slowly relative to the outside fluid (with relative speed less than V). The experimental results of Kovasznay, Kibens & Blackwelder (1970) are reviewed in the light of these conclusions. It appears that in their experiments the entrainment speed V is of the order fifteen times the Kolmogorov velocity, the large constant of proportionality being apparently the result of augmentation by micro-convolutions of the interface associated with small and meso-scale eddies of the turbulence.

Facile and large-scale synthesis of poly(m-phenylenediamine) nanobelts with high surface area and superior dye adsorption ability

RSC Advances ◽  
2014 ◽  
Vol 4 (85) ◽  
pp. 45244-45250 ◽  
Author(s):  
Yun Meng ◽  
Liyuan Zhang ◽  
Liyuan Chai ◽  
Wanting Yu ◽  
Ting Wang ◽  
...  
Keyword(s):  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Dye Adsorption ◽  
High Adsorption ◽  
Adsorption Ability ◽  
Adsorption Performance ◽  
Large Scale Synthesis

PmPD nanobelts with high adsorption performance have been synthesized by using CTAP as oxidants.

Three-Dimensional MoS2/Graphene Hybrid Aerogel as Free-Standing, High-Performance Electrode for Supercapacitor

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050062
Author(s):  
Zhaolei Meng ◽  
Xiaojian He ◽  
Song Han ◽  
Zijian Hu
Keyword(s):  
Porous Structure ◽  
Surface Area ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Hydrothermal Process ◽  
Three Dimensional ◽  
Rate Capability ◽  
Free Standing ◽  
Hybrid Aerogel

Carbon materials are generally employed as supercapacitor electrodes due to their low- cost, high-chemical stability and environmental friendliness. However, the design of carbon structures with large surface area and controllable porous structure remains a daunt challenge. In this work, a three-dimensional (3D) hybrid aerogel with different contents of MoS2 nanosheets in 3D graphene aerogel (MoS2-GA) was synthesized through a facial hydrothermal process. The influences of MoS2 content on microstructure and subsequently on electrochemical properties of MoS2-GA are systematically investigated and an optimized mass ratio with MoS2: GA of 1:2 is chosen to achieve high mechanical robustness and outstanding electrochemical performance in the hybrid structure. Due to the large specific surface area, porous structure and continuous charge transfer network, such MoS2-GA electrodes exhibit high specific capacitance, good rate capability and excellent cyclic stability, showing great potential in large-scale and low-cost fabrication of high-performance supercapacitors.

scholarly journals Quantifying the Polygenic Architecture of the Human Cerebral Cortex: Extensive Genetic Overlap between Cortical Thickness and Surface Area

2020 ◽  
Vol 30 (10) ◽  
pp. 5597-5603 ◽  
Author(s):  
Dennis van der Meer ◽  
Oleksandr Frei ◽  
Tobias Kaufmann ◽  
Chi-Hua Chen ◽  
Wesley K Thompson ◽  
...  
Keyword(s):  
Surface Area ◽  
Cortical Thickness ◽  
Large Scale ◽  
Gaussian Mixture ◽  
Total Surface Area ◽  
Brain Morphology ◽  
Genetic Determinants ◽  
Genetic Predictors ◽  
Genetic Overlap ◽  
Causal Variants

Abstract The thickness of the cerebral cortical sheet and its surface area are highly heritable traits thought to have largely distinct polygenic architectures. Despite large-scale efforts, the majority of their genetic determinants remain unknown. Our ability to identify causal genetic variants can be improved by employing brain measures that better map onto the biology we seek to understand. Such measures may have fewer variants but with larger effects, that is, lower polygenicity and higher discoverability. Using Gaussian mixture modeling, we estimated the number of causal variants shared between mean cortical thickness and total surface area, as well as the polygenicity and discoverability of regional measures. We made use of UK Biobank data from 30 880 healthy White European individuals (mean age 64.3, standard deviation 7.5, 52.1% female). We found large genetic overlap between total surface area and mean thickness, sharing 4016 out of 7941 causal variants. Regional surface area was more discoverable (P = 2.6 × 10−6) and less polygenic (P = 0.004) than regional thickness measures. These findings may serve as a roadmap for improved future GWAS studies; knowledge of which measures are most discoverable may be used to boost identification of genetic predictors and thereby gain a better understanding of brain morphology.

Large-scale and facile synthesis of a porous high-entropy alloy CrMnFeCoNi as an efficient catalyst

2020 ◽  
Vol 8 (35) ◽  
pp. 18318-18326 ◽  
Author(s):  
Hailong Peng ◽  
Yangcenzi Xie ◽  
Zicheng Xie ◽  
Yunfeng Wu ◽  
Wenkun Zhu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
High Entropy Alloy ◽  
Facile Synthesis ◽  
Efficient Catalyst ◽  
High Entropy

Porous high entropy alloy CrMnFeCoNi exhibited remarkable catalytic activity and stability toward p-nitrophenol hydrogenation. The enhanced catalytic performance not only resulted from the high surface area, but also from exposed high-index facets with terraces.

Study on Nano-Hydroxyapatite Assisted Preparing by Ionic Liquids

2014 ◽  
Vol 1015 ◽  
pp. 501-504 ◽  
Author(s):  
Yong Guang Bi ◽  
Xu Si Xu
Keyword(s):  
Grain Size ◽  
Ionic Liquids ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Large Scale ◽  
Preparation Method ◽  
Raw Material ◽  
Large Scale Preparation ◽  
Scale Preparation

Papers with Ca (NO3)2• 4H2O and (NH4)2HPO4as raw material, prepared by ionic liquids assisted nanoHAP, resulting hexagonal nanoHAP are crystal grain size are 10-20nm level, are smaller nanometer range ; specific surface area, the findings show that ionic liquids have the technology to promote the significance of the preparation method can provide a reference for large-scale preparation of biomedical nanomaterials.

scholarly journals An Empirical Parameterization of Heterogeneous Ice Nucleation for Multiple Chemical Species of Aerosol

2008 ◽  
Vol 65 (9) ◽  
pp. 2757-2783 ◽  
Author(s):  
Vaughan T. J. Phillips ◽  
Paul J. DeMott ◽  
Constantin Andronache
Keyword(s):  
Surface Area ◽  
Heterogeneous Nucleation ◽  
Large Scale ◽  
Water Saturation ◽  
Chemical Species ◽  
Spectral Width ◽  
Diffusion Chamber ◽  
Field Studies ◽  
Cloud Models ◽  
Multiple Species

Abstract A novel, flexible framework is proposed for parameterizing the heterogeneous nucleation of ice within clouds. It has empirically derived dependencies on the chemistry and surface area of multiple species of ice nucleus (IN) aerosols. Effects from variability in mean size, spectral width, and mass loading of aerosols are represented via their influences on surface area. The parameterization is intended for application in large-scale atmospheric and cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the cloud scale, and 2) concentrations of a variety of insoluble aerosol species. Observational data constraining the parameterization are principally from coincident field studies of IN activity and insoluble aerosol in the troposphere. The continuous flow diffusion chamber (CFDC) was deployed. Aerosol species are grouped by the parameterization into three basic types: dust and metallic compounds, inorganic black carbon, and insoluble organic aerosols. Further field observations inform the partitioning of measured IN concentrations among these basic groups of aerosol. The scarcity of heterogeneous nucleation, observed at humidities well below water saturation for warm subzero temperatures, is represented. Conventional and inside-out contact nucleation by IN is treated with a constant shift of their freezing temperatures. The empirical parameterization is described and compared with available field and laboratory observations and other schemes. Alternative schemes differ by up to five orders of magnitude in their freezing fractions (−30°C). New knowledge from future observational advances may be easily assimilated into the scheme’s framework. The essence of this versatile framework is the use of data concerning atmospheric IN sampled directly from the troposphere.

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