Formation of hydrogarnets: Calcium hydroxide attack on clays and feldspars

The reaction of calcium hydroxide with sericite, with shale and with a few igneous rocks gives hydrogarnets, hydrated calcium silicates and free alkalies. In the experiments described, slurries of the hydroxide and the starting materials were boiled (95 °C). Hydrothermal treatment was carried out at 1 MPa and at 2 MPa. The full significance of the findings is unknown but the possible unfavourable influence of these reactions on the durability of concrete is considered.     

Transport properties of two-dimensional hole gas in a Ge1? x Si x /Ge/Ge1? x Si x quantum well in the vicinity of metal-insulator transition

Observation of a low-temperature transition from metallic (∂ρ/∂T > 0) to insulator (∂ρ/∂T < 0) behavior of resistivity ρ(T) induced by a perpendicular magnetic field B is reported for a two-dimensional (2D) hole system confined within Ge layers of a p-Ge_1−x Si _x /Ge/Ge_1−x Si _x heterostructure. The essential feature of this system is that it is described by the Luttinger Hamilton with the g-factor highly anisotropic for orientations of magnetic field perpendicular and parallel to the 2D plane (g _⊺ ≫ g _‖). The positive magnetoresistance revealed scales as a function of B/T. We attribute this finding to suppression of the triplet channel of electron-electron (hole-hole) interaction due to Zeeman splitting in the hole spectrum. The text was submitted by the authors in English.     

Re-using users: co-create and co-evaluate

Although user participation has become a standard ingredient of modern product design, in most cases users participate only for a moment, e.g. one afternoon. In this poster we report a case where we had users, who had participated in a generative study, return after 4 months to evaluate the resulting concept design. Our experience in this study suggests that the ‘returning participants’ had retained the sensitivity for the product context that was built up during the first study. This paper is part of the 3AD design colloquium creative connections.     

Detecting threat-related intentional actions of others: Effects of image quality, response mode, and target cuing on vigilance.

Three experiments examined the vigilance performance of participants watching videos depicting intentional actions of an individual’s hand reaching for and grasping an object—involving transporting or using either a gun or a hairdryer—in order to detect infrequent threat-related actions. Participants indicated detection of target actions either manually or by withholding response. They also rated their subjective mental workload before and after each vigilance task. Irrespective of response mode, the detection rate of intentional threats declined over time on task and subjective workload increased, but only under visually degraded viewing conditions. This vigilance decrement was attenuated by temporal cues that were 75% valid in predicting a subsequent target action and eliminated with 100% valid cues. The findings indicate that detection of biological motion targets, and threat-related intentional actions in particular, although not attention sensitive under normal viewing conditions, is subject to vigilance decrement under degraded viewing conditions. The results are compatible with the view that the decrement in detecting threat-related intentional actions reflects increasing failure of attention allocation processes over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multimodal Fused Deep Learning Networks for Domain Specific Image Similarity Search

The exponential increase in data over the past few years, particularly in images, has led to more complex content since visual representation became the new norm. E-commerce and similar platforms maintain large image catalogues of their products. In image databases, searching and retrieving similar images is still a challenge, even though several image retrieval techniques have been proposed over the decade. Most of these techniques work well when querying general image databases. However, they often fail in domain-specific image databases, especially for datasets with low intraclass variance. This paper proposes a domain-specific image similarity search engine based on a fused deep learning network. The network is comprised of an improved object localization module, a classification module to narrow down search options and finally a feature extraction and similarity calculation module. The network features both an offline stage for indexing the dataset and an online stage for querying. The dataset used to evaluate the performance of the proposed network is a custom domain-specific dataset related to cosmetics packaging gathered from various online platforms. The proposed method addresses the intraclass variance problem with more precise object localization and the introduction of top result reranking based on object contours. Finally, quantitative and qualitative experiment results are presented, showing improved image similarity search performance.     

Creating an African Riviera: Revisiting the Impact of the Victoria and Alfred Waterfront Development in Cape Town

The use of leisure and tourism to re-image and redevelop cities has been interpreted as a mechanism for attracting capital and people. In a period of intense inter-place competition and urban entrepreneurialism, whole built environments become centerpieces of urban spectacle and display. Waterfront developments have become emblematic in this regard. Over the past two decades the redevelopment of the Victoria and Alfred Waterfront (V&AW) in Cape Town has been transformed from ‘port’ to ‘playground’ and is internationally acknowledged as one of the most successful of these developments. This redevelopment has, as has been the case with numerous other waterfront developments, not been uncontroversial. New tensions and conflicts have arisen over the use, meaning, and ownership of this space. The acquisition of the waterfront by a consortium of London- and Dubai-based property developers in 2006 has renewed concerns about the ‘plasticization’ of the waterfront and signals the symbolic start of a new phase in this waterfront’s development trajectory. The paper tracks the development of the V&AW since its inception in the late 1980s and argues that general critiques of waterfront developments sit uneasily in the Cape Town context. It is also suggested that these developments can fulfil a very significant and positive role for developing world cities.     

Fluorescence lifetime standards for time and frequency domain fluorescence spectroscopy

A series of fluorophores with single-exponential fluorescence decays in liquid solution at 20 degrees C were measured independently by nine laboratories using single-photon timing and multifrequency phase and modulation fluorometry instruments with lasers as excitation source. The dyes that can serve as fluorescence lifetime standards for time-domain and frequency-domain measurements are all commercially available, are photostable under the conditions of the measurements, and are soluble in solvents of spectroscopic quality (methanol, cyclohexane, water). These lifetime standards are anthracene, 9-cyanoanthracene, 9,10-diphenylanthracene, N-methylcarbazole, coumarin 153, erythrosin B, N-acetyl-l-tryptophanamide, 1,4-bis(5-phenyloxazol-2-yl)benzene, 2,5-diphenyloxazole, rhodamine B, rubrene, N-(3-sulfopropyl)acridinium, and 1,4-diphenylbenzene. At 20 degrees C, the fluorescence lifetimes vary from 89 ps to 31.2 ns, depending on fluorescent dye and solvent, which is a useful range for modern pico- and nanosecond time-domain or mega- to gigahertz frequency-domain instrumentation. The decay times are independent of the excitation and emission wavelengths. Dependent on the structure of the dye and the solvent, the excitation wavelengths used range from 284 to 575 nm, the emission from 330 to 630 nm. These lifetime standards may be used to either calibrate or test the resolution of time- and frequency-domain instrumentation or as reference compounds to eliminate the color effect in photomultiplier tubes. Statistical analyses by means of two-sample charts indicate that there is no laboratory bias in the lifetime determinations. Moreover, statistical tests show that there is an excellent correlation between the lifetimes estimated by the time-domain and frequency-domain fluorometries. Comprehensive tables compiling the results for 20 (fluorescence lifetime standard/solvent) combinations are given.     

Shopping Versus Growing: Food Acquisition Habits of Dutch Urban Gardeners

In this article, we explore how urban food growing gets interwoven with other areas of life and show how this differs between people actively engaged in gardening and people not or only limitedly involved. We compare four urban food-growing initiatives: two allotments and two Alternative Food Networks (AFNs); the AFNs do not require active participation. Using the theory of practice, we show that allotment gardeners are mainly involved in the practice of gardening. Having responsibility over a garden stimulates them to perform the gardening practice, turning it into a routine that has its place in everyday life. As a result, the harvest is easily integrated in the daily meal. Members of the AFNs studied engage in the practice of shopping. These AFNs therefore remain in competition with more convenient food acquisition venues such as supermarkets and members have difficulty eating from them regularly. We conclude that whether members are involved in shopping or growing impacts the degree to which they manage to eat urban-grown food. This also implies that motivations to change the current food system “only go so far”; such motivations are embedded in the context of everyday life, in which routines may forego conscious choices.