Towards the Ultimate Scanning Electron Microscope

An analysis of all the factors which contribute to the electron probe size in a scanning electron microscope and of the correct method of combining those effects to give optimum performance. Assuming perfect specimen preparation the only other factors are the non-local nature of the basic electron interactions and the nature of the display system

‘Uncle Tom was there, in crockery’: Material Culture and a Victorian Working-class Childhood

British archaeologists have long recognised the potential for the archaeology of working-class neighbourhoods to illuminate communities that typically left few direct traces of their own in the written record. They have also emphasised that the diversity of material culture from such sites provides alternative perspectives to the textual evidence, which is often moralising and condemnatory. Drawing on a case-study from Sheffield in Yorkshire, England, this paper explores what material culture can reveal about working-class childhoods. It argues that childhood was depicted and experienced at the intersections of the chapel, mine and pub, and that competing conceptions of childhood and family were pivotal to the struggle for working-class identity

‘Uncle Tom was there, in crockery’: Material Culture and a Victorian Working-class Childhood

British archaeologists have long recognised the potential for the archaeology of working-class neighbourhoods to illuminate communities that typically left few direct traces of their own in the written record. They have also emphasised that the diversity of material culture from such sites provides alternative perspectives to the textual evidence, which is often moralising and condemnatory. Drawing on a case-study from Sheffield in Yorkshire, England, this paper explores what material culture can reveal about working-class childhoods. It argues that childhood was depicted and experienced at the intersections of the chapel, mine and pub, and that competing conceptions of childhood and family were pivotal to the struggle for working-class identity

A sub-cm micromachined electron microscope

A new approach for fabricating macroscopic (approximately 10x10x10 mm(exp 3)) structures with micron accuracy has been developed. This approach combines the precision of semiconductor processing and fiber optic technologies. A (100) silicon wafer is anisotropically etched to create four orthogonal v-grooves and an aperture on each 10x12 mm die. Precision 308 micron optical fibers are sandwiched between the die to align the v-grooves. The fiber is then anodically bonded to the die above and below it. This procedure is repeated to create thick structures and a stack of 5 or 6 die will be used to create a miniature scanning electron microscope (MSEM). Two die in the structure will have a segmented electrode to deflect the beam and correct for astigmatism. The entire structure is UHV compatible. The performance of an SEM improves as its length is reduced and a sub-cm 2 keV MSEM with a field emission source should have approximately 1 nm resolution. A low voltage high resolution MSEM would be useful for the examination of biological specimens and semiconductors with a minimum of damage. The first MSEM will be tested with existing 6 micron thermionic sources. In the future a micromachined field emission source will be used. The stacking technology presented in this paper can produce an array of MSEMs 1 to 30 mm in length with a 1 mm or larger period. A key question being addressed by this research is the optimum size for a low voltage MSEM which will be determined by the required spatial resolution, field of view, and working distance

Observation of nonhexagonal superlattices in high-stage cesium intercalated graphite

Using a scanning transmission electron microscope with an electron beam size of ∼800 Å, we have found that unsaturated cesium intercalated graphite at 98±2 K exhibits multiple structural phases with a typical domain size of ∼1 μm. Electron diffraction patterns from individual structural islands were studied, and the p(2×2), p(3√×2), and p(3√×13−−√) in-plane superlattices were identified

The Ties That Bind: Materiality, Identity, and the Life Course in the “Things” Families Keep

Using an interdisciplinary research methodology across three archaeological and historical case studies, this article explores “family archives.” Four themes illustrate how objects held in family archives, curation practices, and intergenerational narratives reinforce a family’s sense of itself: people–object interactions, gender, socialization and identity formation, and the “life course.” These themes provide a framework for professional archivists to assist communities and individuals working with their own family archives. We argue that the family archive, broadly defined, encourages a more egalitarian approach to history. We suggest a multiperiod analysis draws attention to historical forms of knowledge and meaning-making practices over time

Wingless and intermorphic males in the ant Cardiocondyla venustula

The ant genus Cardiocondyla is characterized by a pronounced male diphenism with wingless fighter males and winged disperser males. Winged males have been lost convergently in at least two species-rich clades. Here, we describe the morphological variability of males of C. venustula from uThukela valley, South Africa. Winged males appear to be absent from this species. However, in addition to wingless (“ergatoid”) males with widely fused thoracic sutures and without ocelli, “intermorphic” males exist that combine the typical morphology of wingless males with characteristics of winged males, e.g., more pronounced thoracic sutures, rudimentary ocelli, and vestigial wings. Similar “intermorphic” males have previously been described from one of several genetically distinct lineages of the Southeast Asian “C. kagutsuchi” complex (Yamauchi et al., 2005). To determine whether male morphology is associated with distinct clades also in C. venustula, we sequenced a 631 bp fragment of mitochondrial DNA of workers from 13 colonies. We found six haplotypes with a sequence variation of up to 5.7%. Intermorphic and wingless males did not appear to be associated with a particular of these lineages and within colonies showed the same sequence. Interestingly, two colonies contained workers with different haplotypes, suggesting the occasional migration of queens and / or workers between colonies.Financial support came from Deutsche Forschungsgemeinschaft (He 1623/32 and He 1623/34).http://www.springerlink.com/content/101198/?p=d05a2cfd29ea4cf1b64b48ed3302b001&pi=906hb2013ab201

The significance of 'the visit' in an English category-B prison: Views from prisoners, prisoners' families and prison staff

A number of claims have been made regarding the importance of prisoners staying in touch with their family through prison visits, firstly from a humanitarian perspective of enabling family members to see each other, but also regarding the impact of maintaining family ties for successful rehabilitation, reintegration into society and reduced re-offending. This growing evidence base has resulted in increased support by the Prison Service for encouraging the family unit to remain intact during a prisoner’s incarceration. Despite its importance however, there has been a distinct lack of research examining the dynamics of families visiting relatives in prison. This paper explores perceptions of the same event – the visit – from the families’, prisoners’ and prison staffs' viewpoints in a category-B local prison in England. Qualitative data was collected with 30 prisoners’ families, 16 prisoners and 14 prison staff, as part of a broader evaluation of the visitors’ centre. The findings suggest that the three parties frame their perspective of visiting very differently. Prisoners’ families often see visits as an emotional minefield fraught with practical difficulties. Prisoners can view the visit as the highlight of their time in prison and often have many complaints about how visits are handled. Finally, prison staff see visits as potential security breaches and a major organisational operation. The paper addresses the current gap in our understanding of the prison visit and has implications for the Prison Service and wider social policy