Neutron activation analysis of stone from the Chadron Formation and a Clovis Site on the Great Plains

Cryptocrystalline silicates from the Chadron Formation were widely used by prehistoric human groups in the Great Plains of North America. There are two documented quarry areas: Flattop Butte in Colorado and the White River Badlands of South Dakota. Cryptocrystalline silicates from these sources are visually indistinguishable, making it difficult to determine the sources of artefacts found at archaeological sites. In this investigation, neutron activation analysis is used to distinguish the two sources. This technique also identifies lithic material from the Clovis-age Eckles site in Kansas as being from Flattop Butte.     

胶东青铜器科学分析

本文通过考古实物的科学分析,认为早在西周时期胶东青铜技术便发展到了一定水平,战国后便发展到了较为成熟的阶段,大约自西周始,胶东青铜技术与中原便是大体同步发展了的.文章最后还将胶东青铜合金成分与《考工记·六齐》作了比较,并提出了“六齐”既不是生产经验的总结,也不是指导生产实践的工艺规范,而是一种试验资料的反映和归纳的观点。     

When leadership traits meet historic success: Hassan Rouhani and the nuclear deal of 2015

This study aims to show how dispositional characters of political leaders are affected by situational developments during the time‐in‐office. Although newly emerging literature of leadership traits demonstrate that significant events alter leaders’ traits, they mainly focus on the measurement of shocking events on dispositional features, leaving the effect of achievements underexplored. The Iranian nuclear deal of 2015 is one of the most significant successes in the last decade of world politics. Gambling his political career on nuclear talks by promising the Iranian people to solve Iran's decades‐long isolation, President Hassan Rouhani played a momentous role in negotiating the deal. The Joint Comprehensive Plan of Action (JCPOA) was globally recognized as a success of Rouhani's leadership. Using the Leadership Trait Analysis (LTA), this article will show the role of Rouhani's personality in the realization of the historic nuclear deal and measure the effect of such a success on Rouhani's leadership traits.     

Galilei als Methodologe

Galileo did not develop a systematic methodology but rather a methodical form which represents an essential part of the development of modern scientific thought. Keywords to the methodical form of Galileo's thought are: 1) The geometrization of the sciences (‘mathematization of nature’) - this refers especially to the explication of the methodological priority of a theory of measurement. 2) Argomento ex suppositione, that is, the coupling of the originally proof-theoretical distinction between analysis and synthesis to elements of a methodology of empirical science. 3) The axiomatic structure of mechanics that corresponds to the modern semantic theory conception and to constructivist conceptions of the philosophy of science. 4) A constructive (or instrumental) concept of experience, which replaces the Aristotelian concept of a phenomenal experience in the construction of physics.     

X-ray fluorescence analysis of late Roman and Sassanian silver plate

About 200 analyses have been made on late Roman and Sassanian silver objects using energy-dispersive X-ray fluorescence. This has shown that the main feature of the composition of the silver throughout the period and across the geographical area studied was towards high fineness (average silver percentage about 95%). Compositional differences are found between Roman and Sassanian silversmiths' products for the elements copper and lead. Much of the material analysed came from hoards, and using a statistical technique on the analytical data (Discriminant Analysis) broad compositional differences between hoards were found to emerge. The use of different compositions of silver for different joined parts of a single object are discussed.     

The Evolution of the Vitruvian Recipes over 500 Years of Floor‐Making Techniques: The Case Studies of the Domus delle Bestie Ferite and the Domus di Tito Macro (Aquileia,Italy)

The paper reports the results of a research project aimed at the characterization of the floor bedding mortars of two Roman houses in Aquileia (north‐eastern Italy), the Domus delle Bestie Ferite and the Domus di Tito Macro. Seventy floor bedding mortars of the two domus were selected and almost half were fully minero‐petrographically characterized by means of optical microscopy operated in transmitted light (OM‐TL), X‐ray powder diffraction analyses coupled with quantitative phase analysis by means of the Rietveld method (XRPD‐QPA) and scanning electron microscopy with EDS microanalysis (SEM–EDS). The results indicate an evolution of the mortar preparation techniques over time in the mosaic of both houses. The materials are compared to the traditional Roman recipes for specific construction techniques.     

A High-Performance Quadrilateral Flat Shell Element for Seismic Collapse Simulation of Tall Buildings and Its Implementation in OpenSees

Shear walls are important lateral force-resistant components of tall buildings. Hence, a reliable numerical model that can accurately represent the mechanical characteristics and large deformations of shear walls is critical for realistic collapse simulation of tall buildings. Based on the theory of generalized conforming element, a high-performance quadrilateral flat shell element, NLDKGQ, accounting for the large deformation using the updated Lagrangian formulation, is proposed herein and implemented in OpenSees. The reliability of NLDKGQ is validated using classical benchmark problems and reinforced concrete specimens. In addition, its capability in simulating the collapse of a tall building is also demonstrated.     

Seismic vulnerability assessment and fragility analysis of stone masonry monastic temples in Sikkim Himalayas

Buddhist monasteries in Sikkim Himalayas constitute important religious and architectural heritage. These random rubble (RR) stone masonry structures located in high seismically active regions of the Himalayas have suffered varied degrees of damages in the past earthquakes. The study presents seismic vulnerability assessment of four archetypal monastic temples using finite element (FE) analyses. Linear and nonlinear analyses of these structures were conducted in Abaqus FE environment. These analyses identified the damage prone areas of the structures and provided load-deformation behavior under lateral loads. Fragility analyses indicate a high probability of collapse for the specified design level earthquake of the region. The study shows that performance of the structure can be enhanced by improving the strength and stiffness of the stone masonry walls.     

DEM Algorithm for Progressive Collapse Simulation of Single-Layer Reticulated Domes under Multi-Support Excitation

In this paper, the Member Discrete Element Method (MDEM) is modified and perfected for three aspects: the algorithm itself, loading and computational efficiency, and to accurately and quantitatively simulate the progressive collapse for large-span spatial steel structures. In addition, the corresponding computational programs are compiled. First, from the perspective of the method, a meshing principle for discrete element models is determined, a treatment for material nonlinearity and strain rate effect is proposed, and a damping model is established. Next, the Displacement Method is introduced to determine the multi-support excitation for the MDEM, and then motion equations of particles under multi-support excitation are derived. On this basis, the specific process of gravitational field loading is presented. Furthermore, parallel implementation strategies for the MDEM based on OpenMP are constructed. Finally, the collapse simulation of a 1/3.5-scaled single-layer reticulated dome shaking table test model under multi-support excitation is carried out. The comparison demonstrates that the ultimate load and failure mode as well as the complete collapse time of the numerical results are consistent with the experimentally measured responses, and the configuration variations from member buckling and local depression until collapse failure are fully captured. Moreover, the displacement time-history curves obtained using MDEM are almost identical to the experimental measurements, and there is a nuance only in the amplitude. It is verified that MDEM is capable of precisely addressing the collapse failure for large-span spatial steel structures. Additionally, the failure mechanism for structures of this type is naturally revealed.