Rocking of a rigid block freestanding on a flat pedestal

The seismic protection of objects contained within museums is a topic of great interest, especially with reference to how they are displayed or stored. This problem is the same as that of a large class of non-structural components, such as mechanical and electrical hospital and laboratory equipment that could lose their functionality because of earthquakes. Statues and ceramics simply supported on the floor represent a significant set of case. In some cases, like the Bronzes of Riace, isolation systems have been developed. However, in general museum exhibits are not equipped with devices capable of mitigating the oscillations induced by possible earthquakes. The case study of a marble statue placed on a freestanding squat rigid pedestal is examined. The system of algebraic differential equations governing the problem has been derived and included in an ad-hoc numerical procedure. It is shown that the insertion of a squat rigid body with low frictional resistance at the lower interface with the floor, and high frictional resistance at the upper interface with the artifact significantly reduces the amplitude of the rocking response. As a result the artifact rocks without sliding on the rigid base that slides without rocking with respect to the floor. The numerical analysis performed can be a tool to help in the choice of the optimal friction values in the surfaces of the flat block, designed as a simple isolation system.     

水平支座上独立式刚性块的摆动模型（英文）

目的:本研究集中探讨水平支座上独立放置简单叠合的双刚性块的动力学行为,旨在通过构建并求解合适的动力学数值模型以助于设计可广泛适用于博物馆、实验室和医院的保护小型艺术品或装置的隔振系统。创新点:1.研究对象为两个叠合在一起的刚性块,较以往同类问题中的单一刚性块,更具现实意义;2.同时研究了刚性块的摆动和滑动两类运动模式。方法:1.基于达朗贝尔原理构建摆动控制方程,分析单刚体情形下的摆动并利用数值手段描述其滑动状态;2.在分析单刚体的基础上构建双刚体控制方程组并对其进行数值求解。结论:1.通过研究大理石雕塑置于蹲式刚性基底上且基底独立放置在移动地面上的情形发现,相比于滑动,雕塑自身的摆动是造成其损坏的主要原因;2.在某些情况下,刚体表面延迟的存在可以避免细长刚性块的翻转,尤其是对于那些细长的摇摆块体以及上部块体质量增加的情形;3.本文提出的数值分析可以成为优化简易隔振系统的一个有效工具。     

Ways of (Not) Seeing Guns: Presence and Absence at the Cody Firearms Museum

Boasting over 6000 objects, including replicas of a western hardware store, a frontier stage stop, and a late nineteenth-century industrial factory, the Cody Firearms Museum, located at the Buffalo Bill Historical Center in Cody, Wyoming, is “the largest and most important collection of American firearms in the world.” 1 1. Treasures from Our West (Cody, WY: Buffalo Bill Historical Center, 1992), 44. The museum, which creates a decidedly visual space through its near-exclusive engagement with looking, employs an aesthetic of domestication and sterility to frame firearms for museumgoers. Even as it transforms guns into inert objects of visual pleasure, the museum cannot fully erase the history of violence and colonial conquering in which guns played a starring role. The museum's rhetorical effectivity/affectivity, then, turns upon the unique play of presence and absence.     

Part-Time Faculty Involvement in Decision-Making

Drawing from a survey of 1,239 part-time community college faculty, this analysis investigates their views about being involved in departmental and campus-wide decision-making. The adjuncts had somewhat of a voice in instructional decisions pertaining to their area of expertise, but virtually no involvement in personnel or broader organizational matters. In all domains, they expressed desire to have a stronger voice. However, they also noted barriers to inclusion of part-time faculty in decision-making, including schedule constraints, compensation, and respect from their full-time counterparts.     

Developmental tasks and well-being in adolescent elite athletes in comparison with recreational/non-athletes

Young elite athletes (EA) have to solve the same developmental tasks (DTs) as non-athletes, even though they spend a lot of time with their sports and have to solve certain sports-related DTs in addition [Ohlert & Kleinert (2014). Entwicklungsaufgaben jugendlicher Elite-Handballerinnen und –Handballer [Developmental tasks in adolescent elite handball players]. Zeitschrift für Sportpsychologie, 21(4), 161–172. doi:10.1026/1612-5010/a000129]. The aim of this study was to find out if this situation leads to a shortfall in certain DTs and, furthermore, to a reduced well-being in adolescent EA. In total, 185 EA participated in the survey together with 166 recreational/non-athletes (RA). Participants were between 16 and 19 years old (69% female) and answered questions regarding the relevance of different DTs, their actual progression, satisfaction with their actual progression, and the WHO-5 measure for well-being. Compared to the RA group, the EA group reported a different relevance for some DTs. No significant differences were found between the two groups in progression or satisfaction with progression. The stepwise multiple regression resulted in two significant predictors for well-being in EA: satisfaction with progression in the DTs “to find oneself” and “circle of friends”. For RA, the analysis revealed only satisfaction with progression in “circle of friends” as a significant predictor. Implications are that, at least for this age group, problems with DTs were not detected for the adolescent EA. However, if satisfaction with the own progression in certain DTs is low, well-being will also be reduced.