The effects of pigments on the photostability of polyethylene

The affect of carbon black and various colourizing pigments on the ultraviolet (UV) stability of high and low density polyethylene (HDPE and LDPE) was determined using a novel method for the analysis of oxygen uptake profiles. Samples were exposed to 0.27 Wm⁻² (measured at 340 nm) UV irrdiation at 25.0±0.1° C in air at 1.0 atm. The usefulness of this method of assessment of UV stability is demonstrated. The method also enables the rapid collection of data that enable the comparison of the relative photostabilities of experimental and commercial formulations containing pigments and stabilizing additives. The results show that carbon black is an effective UV screening agent for HDPE when added at levels as low as 0.05% (wt/wt) and that increased photoprotection is achieved with increasing concentration of carbon black, up to 5% (wt/wt), above which there is no further significant increase in photostability. LDPE containing ultramarine blue pigment (Na₇Al₆Si₆O₂₄S₃) exhibits relatively poor photostability, whereas ferric oxide (Fe₂O₃) and chrome orange (PbCrO₄.PbO) pigments are better photostabilizers for this material. Cadmium sulphide (CdS) was found to photosensitize LDPE. A compound containing 0.10% (wt/wt) carbon black, 0.12% (wt/wt) titanium dioxide (TiO₂) and 1.78% (wt/wt) phthalocyanine green (C₃₃H₂N₈Cl₁₄Cu) is an effective formulation for the stabilization of LDPE. Formulations of LDPE containing ultramarine blue-TiO₂ or ferric oxidecarbon black combinations absorb heat on exposure and this may affect their photostability.     

Image auto-annotation with automatic selection of the annotation length

Developing a satisfactory and effective method for auto-annotating images that works under general conditions is a challenging task. The advantages of such a system would be manifold: it can be used to annotate existing, large databases of images, rendering them accessible to text search engines; or it can be used as core for image retrieval based on a query image’s visual content. Manual annotation of images is a difficult, tedious and time consuming task. Furthermore, manual annotations tend to show great inter-person variance: considering an image, the opinions about what elements are significant and deserve an annotation vary strongly. The latter poses a problem for the evaluation of an automatic method, as an annotation’s correctness is greatly subjective. In this paper we present an automatic method for annotating images, which addresses one of the existing methods’ major limitation, namely a fixed annotation length. The proposed method, PATSI, automatically chooses the resulting annotation’s length for each query image. It is held as simple as possible and a build-in parameter optimization procedure renders PATSI de-facto parameter free. Finally, PATSI is evaluated on standard datasets, outperforming various state-of-the-art methods.     

Context-dependent software solutions to handle video synchronization and delay in collaborative live mobile video production

The advent of modern mobile phones, 3G networks, and live video streaming has made it possible to broadcast live video from mobile devices. This is now giving rise to a new class of applications which enable mobile collaborative live video production, in which groups of amateurs work together to provide a rich broadcast of events. We focus on new and expected synchronization problems that arise in these more complex systems when broadcasting live events because of the delays that often occur in streaming over internet and mobile networks. The problem has been investigated by acquiring initial user feedback, as well as conducting technical delay measurements of two examples of such systems and relating them to existing literature. We identified two types of technical problems which affect the mixing of the streams, namely the difference in delay in multiple streams, a.k.a. asynchrony among streams, and the delay between the event itself and its presentation in the mixer. These problems affect the mixing in various ways depending on whether or not the director has visual access to the unmediated event. This knowledge has then been used to inform the conceptualization of identifiable ways of handling delays and synchronization. We suggest the introduction of a software feature providing context-dependent delay, in which these requirements can be balanced differently to fit specific contexts of use. We specifically address the different types of mixing which occurs when the director, or mixer, only has access to the topic through the mobile media (“out of view”), as well as mixing in a context in which the topic also is physically present (“in-view”) in front of the mixer.     

A decision support system for environmental effects monitoring

The Environmental Effects Monitoring (EEM) Statistical Assessment Tool (SAT) Decision Support System (DSS) has been developed to provide a user-friendly data analysis, display and decision support tool for Canada's federal environmental effects monitoring program for the pulp and paper and mining industries. The target users include industries, consultants, regional EEM coordinators, National EEM Office and scientists involved in EEM-related research. The tool allows the assessment of the effects of effluent from industrial or other sources on fish and benthic populations. Effect endpoints, which are used as indicators of potentially important effluent effects, are measured at effluent-exposed sites and are compared statistically to measures at reference sites, in order to determine if changes have occurred and the magnitude of the changes. The main driver of the EEM-SAT DSS is its rule-based expert system. The results are used in assessing the adequacy of existing regulations for protecting aquatic environments.     

Multiphase microstructure in steel bars produced by dieless drawing

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ?_max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ?_max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ?_max ≈ 900–1000°C and a finale cooling rate of about 20 K/s.     

Theoretical and experimental investigations into dieless drawing

Some experimental and theoretical results are presented for the dieless drawing method. Because of the absence of a rigid die considerable flexibility is reached by this method. For example it is possible to achieve very high strains in one pass. Unlike in conventional drawing it is possible to produce parts with variable cross‐sections along the length by varying the drawing velocity appropriately. This is demonstrated theoretically and experimentally. To model this process a simple one‐dimensional disk model is suggested. The resultant temperature distribution is compared with previous calculations.     

Beckmann's Studio Computers Specified for Early Computer Art

When the pioneers of computer art started to produce their works by programming mainframes, using plotters for output, the Austrian sculptor Otto Beckmann took a different path. He used a special computer constructed by his son Oskar Beckmann. This article describes the technical context of early computer art, Beckmann's interdisciplinary team ars intermedia, and the development of nonconventional studio computers.     

Farbmessungen auf dem Gebiete der Lebensmitteluntersuchung

Ohne Zusammenfassungbedeutet mit Abbildungen.