Mine blast vibration response spectrum for structural vulnerability assessment: case study of heritage masonry buildings

Ground-borne vibrations induced by mine blasting are typically of low amplitudes, which are not considered a major concern for modern engineered structures. However, historic structures are often considered more vulnerable due to inadequate knowledge regarding the state of construction materials and structural response. Specifically, the construction materials used might be fragile or have deteriorated to a stage that could be vulnerable to such vibrations. Simplistic rule based on peak ground motion parameter has been adopted worldwide for safety assessment, while the frequency characteristics of vibrations are not taken into account. Further, there is very limited study on response of heritage structures to near-field blasting. This article presents a practical structural vulnerability assessment method for mine blast-induced vibrations. In particular, a design response spectrum model is proposed based on close range measurements of nearby mine blasting, which is compared with an existing design spectrum model for far-field mine blasts and a typical design spectrum model for earthquake actions. The method is illustrated through a case study of heritage masonry buildings in Australia. The unique blast data presented and the generalized methodology would be useful to both structural engineers and blast engineers in considering potential effects of blasting on heritage structures.     

Plant microfossils in human dental calculus from Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq

Samples of dental calculus were taken from 11 human individuals buried at Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq. All of them represented the time span of ca. 9100–8600 bp. In total, 95 microfossils were retrieved from these samples, including 70 phytoliths, 9 starch granules or clusters of starch, 3 pollens, and 1 xylem fragment. Most microfossils could be attributed to C₃ cool season cereals, most likely wheat and barley, which is consistent with previous knowledge about the composition of crops in early farming communities living in the Fertile Crescent. In addition, three phytoliths and one starch granule typical of C₄ warm season grasses were recovered including one subangular and faceted starch granule, which might derive from a native grass, but is not diagnostic of any genus. Prior to assigning diagnostic status to this starch, exhaustive reference work on native grass seeds is necessary. The presence of one Phragmites phytolith suggests non-alimentary processing of reeds using teeth or perhaps using the stem of this grass as a toothbrush or toothpick.     

Ethics and Entrepreneurship

An important criticism of public entrepreneurship has been that Us precepts and practices are not consonant with democratic values. This paper examines the meaning of entrepreneurship as defined in bath the public and private sectors, suggesting that some attributes of entrepreneurs that commonly are deemed undesirable–egotism, selfishness, waywardness, domination, and opportunism–actually are functional for entrepreneurial activity. This is because entrepreneurship plays an essential role in addressing a particular type of policy problems (here called "anarchic")–those where goals are ambiguous or conflicting and where the means to achieve them are unknown or uncertain. Finally, methods are suggested for encouraging ethical entrepreneurship, whether undertaken in an anarchic setting or within an organizational matrix that is communitarian or bureaucratic.     

Life in the Swahili town house reveals the symbolic meaning of spaces and artefact assemblages

Swahili ethnographic information was used to interpret eighteenth-century coral house excavations in Lamu, Kenya. The author was especially interested in learning the symbolic or social meaning of durable objects that were found in archaeological assemblages. It was learned that many of the artefacts found in the excavations are related to rituals performed in Swahili houses. The spaces within the house are ranked and used to teach social position. Features of coral houses, animal remains, infant burials, shells, ceramics, and beads can be shown to have symbolic meaning within the Swahili context.

---

Résumé L'auteur a utilisé des informations ethnographiques souahélies afin d'interpréter les fouilles de maisons en corail du 18e siècle à Lamu, Kenya. Elle s'intéressait surtout à connaître la signification symbolique ou sociale des objets non-périssables trouvés dans les assemblages archéologiques. Elle a appris que beaucoup des artefacts trouvés pendant les fouilles sont à rattacher aux rituels célébrés dans les maisons souahélies. Les espaces à l'intérieur de la maison sont classés et utilisés afin de montrer la position sociale. On peut démontrer que certaines particularités des maisons en corail, les restes de faune, les inhumations de tous petits enfants, la céramique et les grains de collier ont des significations symboliques dans leur contexte souahéli.

     

Book reviews

English Maps: A History. By Catherine Delano‐Smith and Roger J. P. Kain. London: The British library, 1999. Toronto: University of Toronto Press, 1999. ISBN 0 7123 4609 0 (cloth); 0 7123 4660 0 (paper). Pp. xiv, 320, illus., col. plates. STG£25.00 (cloth).

Abraham Ortelius and the First Atlas: Essays Commemorating the Quadricentennial of his Death, 1598–1998. Edited by Marcel van den Broecke, Peter van der Krogt and Peter Meurer. Utrecht: HES Publishers, 1998. ISBN 90 6194 388 4. Pp. 430, illus.,. 19 col. plates. DFL371.00(cloth).

A Biographical Index of East India Company Maritime Service Officers 1600–1834. By Anthony Farrington. London: The British Library, 1999. ISBN 0 7123 4647 3. Pp. 886. STG£85.00 (cloth).

Catalogue of East India Company Ships’ Journals and Logs 1600–1834. By Anthony Farrington. London: The British Library, 1999. ISBN 0 7123 4646 5. Pp. 789. STG£85.00 (doth).

Ordnance Survey Small‐Scale Maps: Indexes: 1801–1998. By Roger Hellyer. Kerry, Newtown, Montgomeryshire: David Archer, 1999. ISBN 0951757954. Pp. xxiv, 264, illus. STG£35.00 (cloth). [David Archer, Kerry, Wales SY16 . 4PD.]     

‘The final decision is with the patient’: reproductive modernity and preferences for non-hormonal and non-biomedical contraceptives among postpartum middle class women in Yogyakarta,Indonesia

In Indonesia fertility has plateaued for more than a decade. Over the same period Indonesian women have increasingly accessed contraception via the private sector. Our qualitative inquiry into the contraceptive preferences of middle class women in urban Yogyakarta revealed limited interest in and intent to use biomedical and hormonal contraceptive methods. Women’s justifications for their contraceptive choices were complex and manifold: most had concerns about safety and the side effects associated with hormonal and biomedical contraceptives; others were ideologically opposed to fertility control. We conclude that contraceptive choices were an embodiment of women’s reproductive modernity, which in turn underpinned their reproductive agency. We also problematise the extent to which women’s contraceptive choices were comprehensively informed. Women’s reproductive modernity was shaped by their socioeconomic status; access to modern communication technologies; understandings of their right to health and contraceptive choice; pious yet pragmatic religious identities; and negotiations within their marital relationships.