Earthquake Resilience of Reinforced Concrete Structural Walls with Replaceable “Fuses”

The concept of providing a fuse in a structural system has been both developed and investigated over the past few years (e.g., the use of replaceable links in eccentrically braced frames or the use of replaceable links in the new San Francisco-Oakland Bay Bridge). This paper presents a new coupling beam with a creative fuse installed in the mid-span of a steel-concrete composite beam via an end plate and high-strength bolts. First, a practical design methodology of a replaceable coupling beam is presented. Next, the seismic behavior of the proposed fuse is tested and evaluated, and two structural wall specimens with or without a fuse are designed and fabricated according to the proposed design methods. The two specimens possess similar shear capacities under large-scale cyclic loading, and the walls of the two specimens show similar failure modes; however, the new walls exhibit slightly lower levels of damage than the conventional walls. In particular, the inelastic deformation and damage of replaceable coupling beams are mainly concentrated in the fuse, whereas the non-yield segment and the beam-wall pier interfaces remain nearly intact and produce only slight damage, which is beneficial regarding the replacement of the fuse in post-earthquake events.     

Preliminary archaeoentomological analyses of permafrost-preserved cultural layers from the pre-contact Yup'ik Eskimo site of Nunalleq,Alaska: Implications,potential and methodological considerations

At Nunalleq, a pre-contact Yup'ik Eskimo village site in Alaska (14th–17th century AD), abundant insect remains from highly organic substrates preserved within permafrost offer a unique opportunity to investigate past ecological and living conditions. This paper presents the preliminary results obtained from the analysis of two samples collected from floor layers in sod houses. The numerous and diverse insect remains highlight the exciting potential of archaeoentomology for reconstructing past ecological conditions, resource exploitation and the use of space at northern hunter–gatherer sites and have permitted the development of a strategy for the future collection of archaeoentomological data at permafrost-preserved sites in Alaska and elsewhere.     

南诏大理国金属佛像制作工艺初探

为研究南诏大理国金属佛像的制作工艺,对部分金属佛像进行了科学分析,表明制作各种铜佛像时,主要使用失蜡铸造工艺,已使用多种金属元素作为材质,阿嵯耶观音像和其他铜像是以含砷的铜合金为特征,金质佛像的材质主要用金银合金,铸造小铜佛像则采用复杂的合金成分配比。根据铭文和绘画资料分析,这些金属佛像主要是大理本地的工匠制作。     

固定和浮放条件下文物展柜动力响应分析与试验研究

目前对文物保护的研究主要以试验为主,本研究试图用数值方法分析文物展柜的动力学特性,以解决试验分析方法所导致的缺陷。为此,对固定和浮放两种不同边界条件的文物展柜进行地震作用和简谐激励下的动力响应分析,给出了展柜展台面处的加速度动力放大系数(简称放大系数)上限值。以某博物馆展柜为原型,按1∶1/0.39进行缩尺振动试验,得出两种边界条件下展柜展台面处的放大系数。对试验展柜建立有限元模型,通过与试验对比,验证模型及分析方法的正确性。然后,建立展柜模型的有限元模型,对5种尺寸的展柜进行了动力响应分析,并考虑激励幅值、激励频率等对放大系数的影响。分析结果有助于指导文物的防震保护工作。     

Blank Concerns: Issues of Skill and Consistency in the Replication of Scottish Later Mesolithic Blades

Skill is central to the identification of the individual within lithic analysis. Modern replication tends to focus on the proficient flintknapper, and emphasises complex, technically demanding implements and high quality raw materials. Yet, acquiring lithic skill is a universal process that manifests itself in various ways depending on technological strategy and raw material. This paper presents the results of a programme of experimental replication that explores notions of consistency and identity. Based on Mesolithic blade technology, using direct percussion reduction and variable pebble resources, it compares knappers with different experience and identifies some salient parameters of individual performance.     

四川地区潮湿气候环境下的馆藏陶瓷器文物的保护与修复

馆藏陶、瓷器文物的保护与修复,是文物保护与修复工作之一。由于各种原因,长期以来,全国从事陶、瓷器文物保护与修复的专业技术人员并不多,四川省博物馆在馆藏陶、瓷器文物的保护与修复工作中积累了一定的经验,因地制宜,探索出一套适合在四川地区潮湿气候环境下进行馆藏陶、瓷器文物的保护与修复的经验,以及如何正确选用保护材料和具体实施的方法与步骤。     

Plant processing strategies and their affect upon starch grain survival when rendering Peltandra virginica (L.) Kunth,Araceae edible

There is a long history of human interaction with plants of the Aroideae subfamily (Araceae). Despite these plants' chemical defenses against animal and vegetal predation, humans have targeted their starchy corms, tubers and rhizomes for dietary purposes. In the Eastern Woodlands of North America, early Europeans described the Native population as utilizing the highly acridic Peltandra virginica (arrow arum) for subsistence needs. In order to render this resource edible, however, the acridic principle first needs to be eliminated. Our study investigates the affect these processing activities have on the integrity of arrow arum starch grains. Findings from this study demonstrate that environmental variables specific to individual processing procedures may be more influential on starch grain survival than simply the temperatures reached during cooking.     

Remains of the day-preservation of organic micro-residues on stone tools

Here I report on the decay processes of microscopic organic residues left on stone tool surfaces after their use. Residue analysis on ancient stone tools facilitates reconstruction of past activities. This study enables predictions about the circumstances under which ancient residues preserve. Experimental tool sets with modern residues were buried for a year in separate deposits at Sterkfontein, Sibudu (South Africa) and Zelhem (the Netherlands) whose pH and geomorphology varied, they were then analysed using light microscopy. Biological weathering mainly causes residue decay. In unstable environments rich in microbes and micro-organisms, residues decay quickly. From an archaeological perspective this means that sites that are stable, desiccated, waterlogged, extremely acidic or alkaline and extremely cold or hot sites. Different residue types have different preservation optima and this may lead to a preservation and perhaps interpretation bias. The preliminary predictive models presented in this paper could aid in the considered selection of sites and samples.     

How flakes shatter: a critical evaluation of quartz fracture analysis

Despite its worldwide use as a stone tool raw material, quartz is known to be a difficult material for archaeologists. The main reason for this is the tendency of quartz flakes to fragment during detachment, which complicates the use of traditional lithic analyses. In this article we present an experimental study of quartz flake fragmentation. We evaluate the method called fracture analysis that has been developed and used explicitly for the study of quartz assemblages. The method assumes high predictability of quartz flake fragmentation, but our experiments show that there is significant variation in fragmentation that fracture analysis does not take into account. Our results indicate that this variation is partly explained by indenter hardness, the relative thickness of the detached flake, as well as individual knapper-related factors. These results undermine the applicability of quartz fracture analysis in its current form. In addition, we discuss the effects of flake fragmentation on the technological organisation of prehistoric quartz users and suggest that it has affected reduction strategies as well as blank and tool dimensions. We also suggest that there should be mobility-related differences in archaeological assemblages in terms of the quality of the quartz raw material and that the curation of quartz should be low in relation to better quality raw materials used parallel with it.     

New experimental data on the distance of sling projectiles

The range of stones cast by slings used in the past is debated. In the Central Andes, slings are asserted to be important weapons of prehispanic war, and have been recovered archaeologically. Rolled river cobbles and stones presumed to be slingstones found at fortified hilltop archaeological sites are presented as evidence that slings were used at these fortifications. Yet sling use has not been adequately tested at hillforts. Experiments conducted in Europe by a novice slinger have attempted to illuminate the range of sling cast stones at ancient hillforts. Data acquired from native slingers is necessary to more accurately assess distances achieved by projectiles launched by slings. We present data from sling experiments carried out in Puno, Perú among Quechua-speaking herders who are experienced slingers. The results demonstrate that a prior model of the maximum theoretical distance of sling cast stones underestimates their range. Results also show significant differences in the use of slings by men and women, and by different age groups. These new data permit a better approximation of warfare that has bearing on our interpretation of fortified sites.