Microclimates of Urban Reproduction: The Limits of Automating Environmental Control

Enclosed, controlled environments, stretching from sites of luxury consumption to urban food production, are proliferating in cities around the world, utilising increasingly advanced techniques for (re)creating and optimising microclimatic conditions for different purposes. However, the role of automated control systems—to filter, reprocess and reassemble atmospheric and metabolic flows with growing precision—remains under-researched. In this article, we explore the phenomenon of automated environmental control at three sites in the UK city of Sheffield: a botanical glasshouse, a luxury hotel and a university plant growth research lab. In doing so, we first show how controlled environments are constituted through specific relations between the inside and outside, which are embedded in inherently political urban contexts and processes. Second, we identify the technical and ecological tensions and limits of indoor environmental control at each site which limit the scope of automation, and the considerable amount of hidden labour and energy required to maintain and restabilise desired conditions. Drawing on these more established examples of ecological interiorisation in a key moment of transition, we raise urgent questions for critical urban and environmental geographers about the possible futures of controlled environments, their practical or selective scalability, and who and what will be left “outside”, when they are emerging as a strategic form of urban adaptation and immunisation in the face of converging ecological pressures.     

近代朝鲜华侨制造业研究——以铸造业为中心

以朝鲜殖民地时期华侨制造业中最具代表性的铸造业作为研究对象,对华侨铸造工厂诞生的背景、同乡网络及其生产体制进行了阐述;分析了华侨制造业在朝鲜烧锅制造领域里取得垄断性地位的原因,一是华侨铸造工厂里中国劳动者较低的工资及技术开发的进行;二是全国的华侨铸造工厂形成了以河北省交河县为中心的同乡网络并进行协力合作。中日战争爆发后,日本政府谋求战时经济的强化,朝鲜总督府也加强了战时统治经济,生铁原料的配给发生困难,华侨铸造工厂因而纷纷倒闭,走向衰退。     

Reinforcement of the 18th Century Buttresses of Maniace Castle: Design and Execution

ABSTRACT

Maniace Castle, built on Ortygia island in Siracusa (Italy) in the first half of the 13th century and hosting a magnificent hypostyle hall (the Salone), a square area covered by 25 cross vaults supported by columns, was severely damaged by the 1693 earthquake and the explosion of the ammunition dump in 1704. The buttresses, built immediately afterward to counteract the thrust of the 10 surviving vaults, did not guarantee adequate seismic safety so that a metal scaffolding was installed in 2001 to prevent an overturning mechanism. This article discusses the design and execution of an external pre-stressing steel system to increase existing buttress strength and the seismic capacity of the Salone, starting with historical and constructional analyses and dealing with both analytical and technical aspects. The monitoring system installed to detect structural response during and after the working execution is shown, along with some of the data acquired so far.     

CONCEPT AND DEVELOPMENT OF HYBRID SOLUTIONS FOR SEISMIC RESISTANT BRIDGE SYSTEMS

The development of alternative solutions for precast concrete buildings based on jointed ductile connections has introduced innovative concepts in the design of lateral-load resisting frame and wall systems. Particularly efficient is the hybrid system, where precast elements are connected via post-tensioning techniques and self-centring and energy dissipating properties are adequately combined to achieve the target maximum displacement with negligible residual displacements. In this contribution, the concept of hybrid system is extended to bridges as a viable and efficient solution for an improved seismic performance when compared with monolithic counterparts. Critical discussion on the cyclic behaviour of hybrid systems, highlighting the most significant parameters governing the response, is carried out.

The concept of a flexible seismic design (displacement-based) of hybrid bridge piers and systems is proposed and its reliability confirmed by quasi-static cyclic (push-pull) and nonlinear time-history analyses based on lumped plasticity numerical models.     

解放战争时期妇女职业状况考察

1945—1949年．随着解放战争的进行。中国职业妇女状况发生了较大变化：在国民党统治区,由于国民党独裁统治的加强和财政经济的崩溃,妇女就业机会、职业环境和生活待遇不仅没有得到较好改善．反而恶化,导致了广大职业妇女的普遍反抗：在共产党解放区．伴随解放区的扩大．农妇获得了土地所有权,成了纺织运动的主力。以女工为代表的女职工也得到了广泛的职业平等权．从而展示了中国职业妇女解放的道路。     

Shaking Table Test of the Taiwanese Traditional Dieh-Dou Timber Frame

This article attempts to explore the dynamic behavior of traditional Dieh-Dou timber structure under different combinations of structural forms and vertical loads. Using time-history record (TCU 084) from the Chi-Chi earthquake, two semi full-scale specimens (Symmetric and Asymmetric) were tested. Results showed that the Symmetric specimen tends to be damaged more easily and faster than the Asymmetric one. Damage pattern generally begins from the bottom Dou members and subsequently spreading upwards to the upper Dou, horizontal Gong members, and adjoining Shu members. Friction force between the contact surfaces is crucial towards the maintenance of overall structure. Increase vertical loadings have significant effect on the natural frequencies and global stiffness of the structure. Using the Single-Degree-Of-Freedom (SDOF) system, the derived stiffness is generally in good agreement with the dynamic results of both forms. This study suggests that the effects of increasing vertical loadings should be taken into consideration for future evaluation.     

Dynamic One-Sided Out-Of-Plane Behavior of Unreinforced-Masonry Wall Restrained by Elasto-Plastic Tie-Rods

Past earthquakes have shown the high vulnerability of existing masonry buildings, particularly to out-of-plane local collapse mechanisms. Such mechanisms can be prevented if façades are restrained by tie rods improving the connections to perpendiculars walls. Whereas in the past only static models have been proposed, herein the nonlinear equation of motion of a monolithic wall restrained by a tie rod is presented. The façade, resting on a foundation and adjacent to transverse walls, rotates only around one base pivot and has one degree of freedom. Its thickness is explicitly accounted for and the tie rod is modeled as a linear elastic—perfectly plastic spring, with limited displacement capacity. The model is used to investigate the response to variations of wall geometry (height/thickness ratio, thickness), tie rod features (vertical position, length, prestress level), and material characteristics (elastic modulus, ultimate elongation, yield strength) typical of historical iron. The most relevant parameter is the steel strength, whereas other characteristics play minor roles allowing to recommend reduced values for pre-tensioning forces. The force-based procedure customary in Italy for tie design is reasonably safe and involves protection also against collapse, although probably not enough as desirable.