Effect of the joint type on the bearing capacity of a multi–drum column under static load

The results of an experimental study on the effect of the joints between the blocks on the ultimate bearing capacity of a multi-drum column loaded to centric vertical force and horizontal force in the middle of its height are shown. The column is approximately 2.5 m high, with one hinge at the top and another hinge at the bottom. Four types of joints between the blocks were considered: a dry joint (column C-DJ) and joints with stone powder (column C-SPJ), lead (column C-PBJ), and epoxy (column C-EPJ). The applied vertical and horizontal forces, horizontal displacement, vertical strains, and horizontal circumferential strains in the middle of the column height, as well as shortening of the column, were measured. Under axial compression, ratios between the ultimate load bearing capacities of tested columns were C-EPJ: C-DJ: C-SPJ: C-PBJ = 1: 0.68: 0.59: 0.51. The bearing capacity of the tested columns with regard to the horizontal force depended on the level of the applied centric compression force. Columns with soft joints (C-PBJ, C-SPJ) had the largest shortening and the largest horizontal displacements for the equal forces.     

Plastic Hinge Length for Lightly Reinforced Rectangular Concrete Walls

This research investigates the plastic hinge length in lightly reinforced rectangular walls typically found in regions of low-to-moderate seismicity. Poor performance has been exhibited by lightly reinforced concrete walls in past earthquake events. A series of finite element analyses have been carried out which demonstrate that if the longitudinal reinforcement ratio in the wall is below a certain threshold value, there will not be sufficient reinforcement to cause secondary cracking, and instead fracture of the longitudinal reinforcement at a single crack could occur. A plastic hinge length equation has been derived based on the results from the numerical simulations.     

Optimal Spectral Acceleration-based Intensity Measure for Seismic Collapse Assessment of P-Delta Vulnerable Frame Structures

This study proposes an “optimal” spectral acceleration-based intensity measure (IM) to assess the collapse capacity of highly inelastic frame structures vulnerable to the P-delta effect. The IM is derived from the geometric mean of the spectral pseudo-acceleration over a certain period interval. The lower bound period of the averaging interval is related to the mode in which 95% of the effective modal mass is exceeded. The upper bound period is 1.6 times the fundamental period. This IM provides minimum, or close to the minimum, dispersion for frames with different fundamental periods of vibration, or number of stories.     

Force-Based Beam Finite Element (FE) for the Pushover Analysis of Masonry Buildings

A simplified approach for analyzing the nonlinear response of masonry buildings, based on the equivalent frame modeling procedure and on the nonlinear equivalent static analyses, is presented. A nonlinear beam finite element (FE) is formulated in the framework of a force-based approach, where the stress fields are expanded along the beam local axis, and introduced in a global displacement-based FE code. In order to model the nonlinear constitutive response of the masonry material, the lumped hinge approach is adopted and both flexural and shear plastic hinges are located at the two end nodes of the beam. A classical elastic-plastic constitutive relationship describes the nonlinear response of the hinges, the evolution of the plastic variables being governed by the Kuhn-Tucker and consistency conditions. An efficient element state determination procedure is implemented, which condenses the local deformation residual into the global residual vector, thus avoiding the need to perform the inner loops for computing the element nonlinear response. The comparison with some relevant experimental and real full-scale masonry walls is presented, obtaining a very good agreement with the available results, both in terms of global pushover curves and damage distributions.     

Long-term tropospheric and lower stratospheric ozone variations from ozonesonde observations

An analysis is presented of the long-term mean pressure latitude seasonal distribution of tropospheric and lower stratospheric ozone for the four seasons covering, in part, over 20 years of ozonesonde data. The observed patterns show minimum ozone mixing ratios in the equatorial and tropical troposphere except in regions where net photochemical production is dominant. In the middle and upper troposphere, and low stratosphere to 50 mb, ozone increases from the tropics to subpolar latitudes of both hemispheres. In mid stratosphere, the ozone mixing ratio is a maximum over the tropics. The observed vertical ozone gradient is small in the troposphere but increases rapidly above the tropopause. The seasonal variation at a typical mid latitude station (Hohenpeissenberg) shows a summer maximum in the low to middle troposphere, shifting to a winter-spring maximum in the upper troposphere and lower stratosphere and spring -summer maximum at 10 mb. The amplitude of the annual variation increases from a minimum in the tropics to a maximum in polar regions. Also, the amplitude increases with height at all latitudes up to about 30 mb where the phase of the annual variation changes abruptly. The phase of the annual variation is during spring in the boundary layer, summer in mid troposphere, and spring in the upper troposphere and lower stratosphere. The annual long-term ozone trends are significantly positive at about + 1.2% yr in mid troposphere (500 mb) and significantly negative at about − 0.6% yr¹ in the lower stratosphere(50mb)     

Sauropod (Saurischia: Dinosauria) material from the Early Cretaceous Griman Creek Formation of the Surat Basin,Queensland, Australia

An isolated ischium and possible neural arch recovered from the lower–middle Albian Griman Creek Formation near Surat, are the only sauropod postcranial elements from that unit in Queensland. This is the southernmost occurrence of sauropod post-cranial remains in eastern Australia. Comparison with other sauropod remains suggests that the ischium might represent an indeterminate titanosaur that is different from taxa previously named from Australia.     

Tooth Wear Related to Marine Foraging,Agro‐Pastoralism and the Formative Transition on the Northern Chilean Coast

Occlusal surface wear scores were examined in a sample of 200 Formative period (1500 bc–ad 500) skeletons from the lower Azapa Valley in northwest Chile. Wear rate and plane (angle) were additionally evaluated using a subsample of paired first and second mandibular molars. The Formative period represents the transition from marine foraging to agro‐pastoral dependence in the region, and differences in oral pathology indicate that diet varied by site location (coast vs valley interior) but not by archaeological phase (early vs late). We predicted that occlusal wear would demonstrate similar patterns, resulting from differences in food consistency, and therefore hypothesised that in coastal groups consuming greater quantities of foraged foods, occlusal surfaces should wear faster and exhibit flat molar wear, whereas among valley interior groups consuming greater quantities of agro‐pastoral products, these should wear slower but exhibit more angled molar wear. Heavier posterior tooth wear was identified among coastal residents, but rate and angle of molar occlusal attrition did not differ significantly by location. Heavier overall wear and a steeper molar wear plane were identified during the early phase indicating that food consistency varied somewhat over the course of the Formative period. Overall, the results indicate that, although limited differences in tooth wear exist by site location, wear varied more over time likely reflecting a gradual transition from foraging to agro‐pastoral dependence in the lower Azapa Valley. Although oral health indicators point to differences in dietary investment by location, maintenance of a mixed subsistence economy likely sustained a comparative consistency of foodstuffs. Copyright © 2011 John Wiley & Sons, Ltd.     

Probing the reds and blues: Sectionalism and voter location in the 2000 and 2004 U. S. presidential elections

The election outcomes of a place hinge largely on what is within its political boundaries: economic, social, cultural, and other compositional factors facing voters. Yet, it is also important to investigate geographic context, both within and between places. This study presents renewed emphasis on two geographic factors that relate to electoral outcomes while controlling for compositional attributes: sectional distinctions and population density. Within different regions of the United States and across different locations (urban, suburban, and rural residents), there exist notable differences in presidential voting. Using survey and county-level data on the 2000 and 2004 U.S. presidential elections, this study evaluates the partisan preferences of voters from a regional perspective, and from a density perspective. The findings demonstrate independent relationships between section and voting, and location and voting. A major consequence of the distinctiveness of section and location in the face of migration effects (as noted by others) is the increased spatial polarization of the electorate's political preferences in these recent presidential contests.     

Evaluation of Structure from Motion Software to Create 3D Models of Late Nineteenth Century Great Lakes Shipwrecks Using Archived Diver-Acquired Video Surveys

Here we demonstrate the ability to use archived video surveys to create photorealistic 3D models of submerged archeological sites. We created 3D models of two nineteenth century Great Lakes shipwrecks using diver-acquired video surveys and Structure from Motion (SfM) software. Models were georeferenced using archived hand survey data. Comparison of hand survey measurements and digital measurements made using the models demonstrate that spatial analysis produces results with reasonable accuracy when wreck maps are available. Error associated with digital measurements displayed an inverse relationship to object size. Measurement error ranged from a maximum of 18 % (on 0.37 m object) and a minimum of 0.56 % (on a 4.21 m object). Our results demonstrate SfM can generate models of large maritime archaeological sites that for research, education and outreach purposes. Where site maps are available, these 3D models can be georeferenced to allow additional spatial analysis long after on-site data collection.     

故宫中和殿某中金檩断裂分析

勘查发现,故宫中和殿明间某中金檩在与上部爬梁相交位置出现局部断裂,造成下部中金枋产生较大挠度.为探明该中金檩产生断裂的原因,采取理论计算与数值模拟相结合的方法,对中金檩、中金枋体系进行了分析.基于榫卯连接边界条件的特征,分别考虑中金檩与中金枋叠合、中金檩与中金枋分离、中金檩完全断裂等三种工况,建立了中金檩-枋体系的受力模型,进行了静力分析,获得了中金檩、中金枋的变形及内力分布特征,讨论了中金檩断裂破坏的影响因素.结果表明:由于中金檩在爬梁作用位置截面削弱,造成中金檩自身拉、压、弯承载力不足,从而导致中金檩产生断裂;中金檩与中金枋分离条件下,中金檩断裂造成的中金枋内力增加,且比檩枋叠合条件更明显;中金檩完全断裂后,将造成中金枋内力及变形剧增,威胁中金枋安全.因此,对中金檩采取及时有效的加固措施极其重要.研究结果将为中金枋采取加固措施提供理论参考.     

Finials on stone flakes

When a conchoidal flake is detached from a stone the fracture can either terminate at a small angle to the stone's surface, creating a feather flake, or turn to end at rightangles, creating a hinge or step flake. If a crack turns towards the surface of the stone its path is unstable, and the crack often turns once again, to propagate parallel to the surface of the stone and form a retroflexion or an inflexion on the end of the flake. The retroflexion on the end of a hinge termination has long been recognized, but the inflexion, and its combination with a retroflexion to form a pseudo-bifurcation, has not. Recognition of these finials is important in use-wear analysis for the accurate identification of the various flake scar types and the determination of stone tool function.     

Performance of Wall to Diaphragm Anchors for Use in Seismic Upgrade of Heritage Masonry Buildings

Performance of wall to diaphragm (WD) anchors in heritage unreinforced masonry (URM) buildings during the recent New Zealand earthquake series is commented on, detailing typical failure modes. Current building code provisions for the design of masonry anchors are discussed and overview of an associated experimental program investigating the effectiveness of a relatively new type of retrofit WD anchors is presented. A total of 40 anchors were tested for pull out capacity (POC), of which 30 were installed in salvaged heritage material assemblages and 10 were tested in-situ at a heritage URM building. The POC of anchors ranged from 13.01 kN to 23.12 kN when installed in a heritage URM wall and between 9.54 kN and 12.16 kN when driven from side into two consecutive floor joists of a heritage timber diaphragm. Investigated also were the effects of embedment length, installation quality, anchor location, condition of masonry, and condition of substrate materials on anchor performance.     

Überlieferungs- und Verständnisprobleme im medizinischen Latein des frühen Mittelalters

In most instances, knowledge is passed on through the medium of language. The author tries to demonstrate to what extent the Latin present in early medieval Latin medical treatises failed to fulfill its role as an efficient medium of communication, which factors may account for this failure and how scholars in the middle ages strove to restore sense in texts in various stages of corruption, an attempt that was bound to be unsuccessful in many cases owing to a lack of reliable dictionaries.     

上海中央游憩区特征及发展对策研究

中央游憩区是城市功能的重要组成部分。上海中央游憩区具有空间区位中心、市场区位核心、交通集散枢纽和产业布局重心的特征。针对上海中央游憩区在以城市产业调整、城市功能重组为主的新一轮城市发展中遇到的诸多挑战,本文提出了相应的对策和思路。     

巴中石窟龛窟形制及相关内容

巴中石窟分为隋、初唐,盛唐,中晚唐,宋至民国四个时期.巴中石窟的龛窟多为双重龛,外龛呈长方形,内龛有素面圆拱形龛、带纹饰龛楣的圆拱龛、佛帐龛三种形式.外方、内二重檐的佛帐龛存在于巴中石窟各个时期.盛唐时期巴中石窟精美的佛帐形窟龛与精湛造像相结合,形成了巴中石窟独有的艺术风格,被专家学者誉为——“巴中样式”.     

Investigating Global and Local Categorical Map Configuration Comparisons Based on Coincidence Matrices

The simple and intuitive nature of the coincidence matrix has not only made it the current "gold standard" for accuracy assessment (based on a sample of map pixels), but also a common tool for describing difference between two categorical maps (when all pixels are enumerated). It is this latter case of map comparison that this article explores. Coincidence matrices, although providing significant information regarding thematic agreement between two categorical maps (composition), can lack significantly in terms of conveying information about differences or similarities in the spatial arrangement (configuration) of those map categories in geographic space. This article introduces means for distilling the available configuration information from a coincidence matrix while demonstrating some simple categorical map comparisons. Specifically, while the coincidence matrix summarizes per-pixel compositional persistence or change, the introduced technique further quantifies the global and local configurational uncertainty between compared maps. I demonstrate how this quantification of configurational uncertainty can be used to gauge which thematic mismatch types are most significant and how to measure/present local configurational uncertainty in a spatial context. Implementation is through a straightforward mathematical algorithm in R that is illustrated by several examples.     

基于改进灰关联分析的设施选址评价

本文在运用灰关联分析法评价成本因素与非成本因素综合存在的设施选址问题的基础上,运用改进的灰关联分析,引入向量夹角余弦确定权重的方法对影响选址的各项指标进行了权重分析,并通过优、劣关联度确定综合关联度,综合关联度最大者为最优方案。     

ON THE RESOLUTION OF H/V MEASUREMENTS TO DETERMINE SEDIMENT THICKNESS,A CASE STUDY ACROSS A NORMAL FAULT IN THE LOWER RHINE EMBAYMENT,GERMANY

In recent years, H/V measurements have been increasingly used to map the thickness of sediment fill in sedimentary basins in the context of seismic hazard assessment. This parameter is believed to be an important proxy for the site effects in sedimentary basins (e.g. in the Los Angeles basin). Here we present the results of a test using this approach across an active normal fault in a structurally well known situation. Measurements on a 50 km long profile with 1 km station spacing clearly show a change in the frequency of the fundamental peak of H/V ratios with increasing thickness of the sediment layer in the eastern part of the Lower Rhine Embayment. Subsequently, a section of 10 km length across the Erft-Sprung system, a normal fault with ca. 750 m vertical offset, was measured with a station distance of 100 m. Frequencies of the first and second peaks and the first trough in the H/V spectra are used in a simple resonance model to estimate depths of the bedrock. While the frequency of the first peak shows a large scatter for sediment depths larger than ca. 500 m, the frequency of the first trough follows the changing thickness of the sediments across the fault. The lateral resolution is in the range of the station distance of 100 m. A power law for the depth dependence of the S-wave velocity derived from down hole measurements in an earlier study [Budny, 1984] and power laws inverted from dispersion analysis of micro array measurements [Scherbaum et aL, 2002] agree with the results from the H/V ratios of this study.     

Programming Models for Facility Dispersion: The p-Dispersion and Maxisum Dispersion Problems

The p-dispersion problem is to locate p facilities on a network so that the minimum separation distance between any pair of open facilities is maximized. This problem is applicable to facilities that pose a threat to each other and to systems of retail or service franchises. In both of these applications, facilities should be as far away from the closest other facility as possible. A mixed-integer program is formulated that relies on reversing the value of the 0–1 location variables in the distance constraints so that only the distance between pairs of open facilities constrain the maximization. A related problem, the maxisum dispersion problem, which aims to maximize the average separation distance between open facilities, is also formulated and solved. Computational results for both models for locating 5 and 10 facilities on a network of 25 nodes are presented, along with a multicriteria approach combining the dispersion and maxisum problems. The p -dispersion problem has a weak duality relationship with the (p-1)-center problem in that one-half the maximin distance in the p-dispersion problem is a lower bound for the minimax distance in the center problem for (p-1) facilities. Since the p-center problem is often solved via a series of set-covering problems, the p-dispersion problem may prove useful for finding a starting distance for the series of covering problems.