Spectroscopic methods for the analysis of celadonite and glauconite in Roman green wall paintings

One set of samples from wall paintings of the X^th Regio of Italy containing green colours was analysed exploiting different spectroscopic techniques, aiming to identify the pigments used. The possibility to distinguish between glauconite and celadonite, the most common green pigments used in such paintings, was of particular interest. Samples of celadonite from Monte Baldo and glauconite from Belgium were considered as standard materials for comparison. The results obtained using FTIR, EDS, AAS, Colorimetry, Raman and EPR spectroscopies were compared for the identification of the green pigments.     

Pore structure of historic and repair Roman cement mortars to establish their compatibility

Mercury porosimetry was applied to the study of pore structure of the historic Roman cement mortars representative of different locations in Europe and time periods as well as different application techniques from architectural castings to in situ formed renders and profiles. Three categories of pores were found to coexist in the mortars. The finest pores, with diameters below 0.1 μm, are present within the hardened aged Roman cement matrix. The larger ‘air’ pores, with diameters between 0.2–2 μm, are due to the evaporation of the excess unbound water and restricted hydration. Pores larger than 2 μm are rare and, in general, can be related to microcracking induced by shrinkage drying and mortar weathering. The mortars have rarely been found to develop a dense fine-porous microstructure characteristic of the ideal conditions of moist-curing; massive architectural castings being the only exception identified. The presence of larger ‘air’ pores was, in turn, almost universally observed. The investigations of the freshly prepared Roman cement mortars have revealed that the restricted hydration could be due to the exposure of the freshly laid surface to dry real-world external environments, a high water-to-cement ratio in the original mortars, or the drawing of water from the stucco mass due to insufficient pre-wetting of the porous masonry. The insufficient reactivity of historic cements, resulting from a high content of over-burned, non-reactive cement components or coarseness of the cement grains, could be another reason for yielding poorly hydrated mortars in the past. In general, Roman cement stuccoes are in an excellent state of preservation in spite of their usual exposure to polluted urban environments for more than a century. Therefore, the coexistence of Roman cement mortars of widely different pore structures has not brought about any problems of incompatibility which field observations could reveal. The Roman cement repair materials have been found to develop pore structures similar to those of historic mortars. Therefore, they are in broad terms compatible with historic masonry or stuccoes. However, the porosity and strength of the repair materials can be controlled by a careful manipulation of the water-to-cement ratio of the mix to adapt them better to the properties of the host material.     

Comfort,Class and Climate Change: The Rise of Glass in Late Medieval and Early Modern Domestic Architecture

ABSTRACT

In the modern world, glass windows are considered an indispensable element of the built environment. Throughout premodern times, however, glass was not universally used in European architecture. This article argues that the rise of glass in Western architecture was neither an inevitable nor a linear process, but rather a response to certain social, cultural and environmental factors that gained increasing relevance from the late medieval period onwards. In other words, glass windows are a cultural convention, reflecting some of the wide-ranging and transformative challenges that Europeans faced in the late medieval and early modern period.     

Knots in the Fourth Dimension

ABSTRACT

The article analyses a debate that preoccupied the Russian press in the winter of 1878/9. Writers, journalists and scientists discussed whether mathematics could explain spiritualist séance phenomena. At its core, this was an assessment of social change and a debate about the ambiguity of modern life. While spiritualists hoped to bridge the divide between science and religion, subjectivity and objectivity, their opponents feared that séance phenomena and modern mathematics undermined a rationalist world-view that was endowed with reliability and universal truth. That no agreement could be reached indicates that the post-reform public sphere had become truly pluralist and modern.     

Fiḍḍa l-Nūbiyya: The Woman and her Role in Early Shīՙite History

The purpose of the present study is to analyse the role played by an important female figure in early Shī?ite history. The person in question is Fi[ddot][ddot]a l-Nūbiyya, the servant-girl of Fā ?ima, the Prophet's daughter. After a long period of neglect by scholars, who have focused on what to their mind were figures of greater import, we shall here attempt to describe the role played by Fi[ddot][ddot]a in early Shī?ite history by way of analysing her biography and her close relations with Fā ?ima and members of the latter's family (?Alī, [Hdot]asan and [Hdot]usayn). We shall further describe what has been reported of Fi[ddot][ddot]a's personality, her family, her admiration for the Prophet's family, Qur?ānic verses which supposedly mention her, and the great respect in which she was held by Fā ?ima's family.     

浅析竞技散打运动的早期身体素质训练

文章运用了文献资料法、观察法、数理统计等研究方法,对竞技散打运动中竞技能力的发展作了概要的评述,通过查阅大量的书籍和论文,概括出了竞技散打运动的竞赛与训练中对身体素质的基本要求,以及儿童少年各项身体素质发展敏感期的图表,反思了竞技散打运动训练所存在的问题,指出竞技散打训练中儿童少年早期身体素质训练应以竞技散打技术体系的训练为主,以各种各样的身体练习手段为辅,使各项身体素质得到最佳发展,以为后续训练提供更多的发展空间。     

美国珀尔修斯数字图书馆——探索古文明的窗口

美国珀尔修斯数字图书馆（Perseus Digital Library,PDL）是一个以收藏古希腊罗与时期古典文献资料为主的人文科学研究型数字图书馆,旨在完善人类文明记录,包括语言资源、物质工艺品、历史空间等,让人文科学尽可能智能地被不同语言和文化环境的人们所接受。文章重点从资源组织、技术特征、界面设计、服务特点、评价和建议等方面对珀尔修斯数字图书馆做了评述。     

论理性主义与希腊罗马史学观念之嬗变

古希腊的理性主义世界观和方法论对希腊罗马的历史观产生了重要影响,实质主义和形而上学的方法论是这一历史观的突出特征。西方史学家在希腊罗马时代就把历史看做是具有理性的实践活动,排斥否定神灵对人事的影响,从而树立起人文主义的历史观。希腊哲学是基督教思想的来源之一,与基督教史学也有着密切联系。西方近现代史学最突出的特征就在于打破理性主义哲学对历史学的桎梏,并努力用辩证的方法将史论两者有机地统一起来。     

基于现金流的财务危机预警

本文主要从现金流的角度出发,以财务危机为研究对象,主要研究企业财务危机的防范和预警问题。本文分析了企业发生财务危机时现金流的反映,探讨了如何准确把握现金流相关指标来进行财务预警,并针对现金流的管理提出了一些建议。