Unruly Representation: Materiality,indexicality and agency of the photographic trace

This article examines photographic representation as a material and indexical trace caused by photons reflected and/or emitted from the photographed objects. It argues that the contested idea of indexicality remains relevant to the photograph despite the digitalization of the photographic process. It also suggests that the trace works as an affordance which renders ambiguous the photographic representation as re-presentation. The material trace provides an anchorage point for the presence of the photographed objects. However, the very same presence destabilizes the photograph’s function as a representation and renders its status controversial. Therefore, the photograph both is and is not a representation. As a much-celebrated guarantee of photographic truth, the trace works, in fact, as an element of perpetual epistemological controversy and also as an affordance for philosophical, ontological and poetic analysis.     

Carbon nanotube micropillars trigger guided growth of complex human neural stem cells networks

Nano Research - New strategies for spatially controlled growth of human neurons may provide viable solutions to treat and recover peripheral or spinal cord injuries. While topography cues are known...     

Comparison of pulse responses of step-index fibres

Pulse responses of step-index fibres with V parameters lying between 2 and 40 are presented. The results are based on computations using the normal WKB, a modified WKB, the `weakly guiding? and the `exact? eigenvalue equations.     

Oxidation of accident tolerant fuel candidates

In this study, the oxidation of various accident tolerant fuel candidates produced under different conditions have been evaluated and compared relative to the reference standard – UO₂. The candidates considered in this study were UN, U₃Si₂, U₃Si₅, and a composite material composed of UN–U₃Si₂. With the spark plasma sintering (SPS) method, it was possible to fabricate samples of UN with varying porosity, as well as a high-density composite of UN–U₃Si₂?(10%). Using thermogravimetry in air, the oxidation behaviors of each material and the various microstructures of UN were assessed. These results reveal that it is possible to fabricate UN to very high densities using the SPS method, such that its resistance to oxidation can be improved compared to U₃Si₅ and UO₂, and compete favorably with the principal ATF candidates, U₃Si₂, which shows a particularly violent reaction under the conditions of this study, and the UN–U₃Si₂?(10%) composite.     

On TiN-particle fuel based helium-cooled transmutation systems

We have designed a sub-critical helium-cooled core with TiN-coated particle fuel, dedicated to the transmutation of minor actinides. The excellent neutronic properties of helium allows for a low plutonium fraction in the fuel, which yields a low reactivity swing, Δk = 2600 pcm, for a burnup of 31.2%. Further the neutron spectrum is hard, limiting the buildup of Cm and Cf. The high burnup combined with a minor actinide burning rate of 355 kg/GWth year makes the present design an attractive transmutation system.     

Supplemental safety? Exploring experienced safety in relation to other qualities of successful public spaces

ABSTRACT

Combining insights from the urban design and criminological literature, this paper explores the degree to which conviviality, feeling welcome, and feeling at home are related to peoples’ experiences of safety. A questionnaire was distributed on four squares in the city of Utrecht, the Netherlands. While participants valued the positive qualities of the squares differently, feeling safe was connected to a wider, positive evaluation of the quality of space and especially to feeling at home. By investing primarily in public spaces that are ‘homely’ or ‘domesticated’, a ‘supplemental safety’ might therefore be nurtured. This poses important insights for safety management.     

楼宇电梯配置和目标选层系统

楼宇内的电梯配置取决于上行高峰和运输能力的计算结果，以满足楼宇内运输流量的需求。基于上行，下行呼梯按钮的集选控制系统，考虑到电梯运输能力时上行高峰是最需要满足的交通工况。如果电梯可以满足上行高峰状况，电梯就具有足够的运输能力满足其他运行状况。使用安装在大厅的目标选层系统（DCS），在上行高峰的状况下，电梯的运输能力可以达到与下行高峰相近的水平。用于常规集选控制下的计算上行高峰往返行程时间的方程式是无效的。在本篇文章中，介绍了一种使用DCS控制系统来选配电梯的方法．使得电梯在任何运输状况下都提供良好的服务。     

Effects of silane and the lowering of pH on the properties of phenol–formaldehyde resol resins and resin coatings

Phenol–formaldehyde resol resins were modified by the addition of silane (3‐aminopropyltriethoxysilane) and the lowering of pH (formic acid). The effects of the modifications on the properties of the resins during storage were studied through comparison with the parent resins and by viscosity measurements, NMR spectroscopy, ultraviolet–visible spectroscopy, and differential scanning calorimetry. Resin coatings on paper were prepared to determine the influence of discoloration of the resin solution on the color of the cured resin. A decrease in the pH of the NaOH‐catalyzed resin solutions lightened the color of the solutions and corresponding coatings, whereas silane additions made the coatings slightly more yellow. The lowering of pH increased the viscosities and decreased the reactivities of the resin solutions compared with the unmodified reference resins during storage. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1933–1941, 2007