Selection of the implant thread pitch for optimal biomechanical properties: A three-dimensional finite element analysis

In this paper, effects of the implant thread pitch on the maximum Von Mises stresses were evaluated in jaw bones and implant–abutment complex by a finite element method. The thread pitch ranged from 0.5 mm to 1.6 mm. Results suggested that under axial load, the maximum equivalent stresses in cortical bone, cancellous bone and implant–abutment complex decreased by 6.7%, 55.2% and 22.3%, respectively with the variation of thread pitch; and under buccolingual load, 2.7%, 22.4% and 13.0%, respectively. When thread pitch exceeded 0.8 mm, minimum stresses were obtained. Data indicated that cancellous bone was more sensitive to thread pitch than cortical bone did; thread pitch played a great role in protecting dental implant under axial load than under buccolingual load; and thread pitch exceeding 0.8 mm were optimal selection for a screwed implant by biomechanical consideration.     

Infrastructuring for Cultural Commons

In this paper we reflect on our involvement in the design and development of two information systems: Fusion and EUscreen. Both are infrastructural initiatives aimed at contributing, from different angles, to wider public access to and appropriation of the European digital cultural heritage. Our analysis is founded on the notions of an installed base and gateway in information infrastructure development. We situate our co-design activities and infrastructuring strategies in relation to a broader interest in advocating not only the preservation of and access to digital cultural heritage, but, more importantly, enabling collaboration, to support the emerging practices of diverse user groups, and to contribute to cultural commons.     

Balancing User Priorities for Sustainability versus Security

In these times of global change, many facility emphases are competing for limited resources. Competing factors include, but are not limited to, sustainable design or green buildings; security, hardening or force protection; accessibility; historic preservation; aesthetics; and functionality. Yet, unlimited resources are seldom, if ever, available to fulfill all of these competing requirements in private or public construction. The Georgia Institute of Technology designed a decision matrix to allow owners and planners to balance these competing requirements on a project-by-project basis and to document the rationale.     

红花檵木仿生古桩景快速成型技术

红花檵木作为一种彩色叶植物广泛应用于园林造景当中,目前在园林景观建设中红花檵木主要以低矮灌木的形式存在,由于其景观应用形式的单一化,严重制约了红花檵木生态、景观、经济价值的充分发挥以及相关行业的进一步发展。文章从红花檵木的生态、生理习性为理论基础出发,通过对两种红花檵木仿生古桩景制作材料及方法的介绍,公开了一种红花檵木古桩景快速成型园林景观应用的新形式、新方法,达到丰富红花檵木景观应用形式,提升其生态、景观价值的目的。同时应用形式的多样化,能促进红花檵木相关上下游产业的发展,为红花檵木景观产业注入新的活力。     

烟台海昌渔人码头穹幕影院建筑声学设计

穹幕影院位于烟台海昌渔人码头鲸鲨馆内,影院内建筑面积约为300 m2,内设一穹形投影天幕,是一座以放映海底世界动画为主的专业影院.影院观众最大容量为80人,不设座椅,观众站立观看.简单介绍了该影院的建声设计指标、设计思路以及采取的声学措施,以供大家参考.     

某石灰岩矿中深孔爆破参数优化研究

针对某石灰岩矿劳动强度大、生产效率低、安全条件差的开采现状,应用中深孔房柱法,借鉴露天台阶爆破参数设计及优化方法,通过正交试验法对抵抗线、孔排距、堵塞长度等3个影响爆破效果主要因素进行优选,并进行了爆破震动测试．确定了合理的中深孔凿岩爆破参数,降低了爆破大块率,改善了爆破效果,降低了矿山成本．     

Contractors’ Views of the Potential Causes of Inconsistencies between Design and Construction in Saudi Arabia

The study identifies the causes of inconsistencies between the design and construction of large building projects. To achieve the study objectives, a questionnaire survey was carried out to collect information on potential causes of inconsistencies at the project design and construction interface. Responses from 27 contractors were analyzed. The results suggest that the involvement of designer as consultant, communication gap between constructor and designer, insufficient working drawing details, lack of coordination between parties, lack of human resources in design firm, lack of designer’s knowledge of available materials and equipment, and incomplete plans and specifications were considered as the most important causes of the project design and construction interface inconsistencies. On the other hand, project management as a professional service, weather conditions, nationalities of participants, involvement of the contractor in design conceptual phase, unforeseen problems, involvement of the contractor in design development phase, and government regulations were the least important causes of inconsistencies between professionals at the project design and construction interface in large building projects.     

Development of Boundary Structures for Complex-Shaped Buildings

Over the past few years, the field of architecture has witnessed revolutionary changes in design. The recent completions of Frank O. Gehry’s projects brought unprecedented attention to complex-shaped, nonconventional design. In following these latest trends, the author has been drawn to the issue concerning the structural systems currently being adopted in realizing these complicated designs. It is perhaps inevitable that the traditional structural systems, comprised of structural elements suitable for use in conventional linear shapes, face tremendous challenges and limitations in building such complicated designs. In this context, this research consists of proposing a new alternative by employing “boundary structures with continuously changing curvature,” which follow the complex-curved envelope surface, as well as fabricating an experimental model made of polymer composite materials with computer-aided design/computer-aided engineering/computer-aided manufacturing technologies. Consequently, the study aims at offering architects unprecedented freedom in design and a new paradigm for realizing their creative ideas.     

Thermal Probe Technology for Buildings: Transition from Laboratory to Field Measurements

This paper reports the results of an investigation into the transfer of thermal probe measurement technology from laboratory use to actual buildings in order to undertake the in situ determination of thermal material properties. The imperative reasons for using in situ measurements are (1) the impact of moisture content on thermal properties; (2) the possible wide range of variation of properties across most materials used in construction; and (3) the lack of data for new and innovative materials. Thermal probe technology offers the prospect of taking building specific data, addressing these issues. Based on commercially available thermal probes a portable measurement kit and accompanying measurement procedure have been developed. Three case study buildings, each having different materials, have been studied to ascertain whether or not the technique can be transferred to relatively uncontrolled environments and remain capable of achieving a precision that is similar to an ASTM standard that can be related to thermal conductivity measurements of building materials. The results show that this is indeed the case, and that the use of thermal probe technology may yield thermal properties that vary significantly from the laboratory values currently used in building thermal engineering calculations.     

Redesigning China’s superblock neighbourhoods: policies,opportunities and challenges

In February 2016, China’s State Council released a set of guidelines representing a change in the country’s approach toward neighbourhood design: to move away from superblock neighbourhoods and create a finer network of urban blocks and streets. The paper traces the circumstances that prompted this change, drawing on a comparative review of international literature and practice, and explores the opportunities and challenges for urban design. While modifications of the superblock are somewhat overdue, this current mode of organization should not be entirely abandoned. The suggestions and overall blueprint warrant a more circumspect approach and should be adopted with discretion.