45,295 research outputs found
Precise time and time interval data handling and reduction
In the past year, the increase in Precise Time And Time Interval data to be reduced to the U.S. Naval Observatory Master Clock and the requirement for its quick dissemination has necessitated development of more efficient methods of data handling and reduction. An outline of the data involved and of the Time Service computerization of these functions is presented
Mission and spacecraft support functions of the Materials Engineering Branch: A space oriented technology resource
The capabilities of the Materials Engineering Branch (MEB) of the Goddard Space Flight Center, Greenbelt, Maryland, are surveyed. The specific functions of spacecraft materials review, materials processing and information dissemination, and laboratory support, are outlined in the Activity Report. Further detail is provided by case histories of laboratory satellite support and equipment. Project support statistics are shown, and complete listings of MEB publications, patents, and tech briefs are included. MEB staff, and their respective discipline areas and spacecraft liaison associations, are listed
Inelastic neutron scattering signal from deconfined spinons in a fractionalized antiferromagnet
We calculate the contribution of deconfined spinons to inelastic neutron
scattering (INS) in the fractionalized antiferromagnet (AF*), introduced
elsewhere. We find that the presence of free spin-1/2 charge-less excitations
leads to a continuum INS signal above the Neel gap. This signal is found above
and in addition to the usual spin-1 magnon signal, which to lowest order is the
same as in the more conventional confined antiferromagnet. We calculate the
relative weights of these two signals and find that the spinons contribute to
the longitudinal response, where the magnon signal is absent to lowest order.
Possible higher-order effects of interactions between magnons and spinons in
the AF* phase are also discussed.Comment: 9 page
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The joy of vacuuming? How the user experience affects vacuum cleaner longevity
An apparent reduction in the average lifetime of vacuum cleaners is explored in this paper in relation to their perceived usability and increasingly frequent product replacement. Motivations for product disposal combine perceived and real product failure with a perceived or real improved product offer. From an historical perspective, vacuum cleaners typify this pattern, continually offering a ‘cheaper and improved’ product. Vacuum cleaner manufacturers reinvigorate the sense of satisfaction and revulsion associated with extracting dirt from our homes through new performance focused product development. For example, increased motor power, filtration, bag-less machines and clear bin compartments have all acted as sales drivers, whilst cost effective materials and offshore and more efficient manufacturing have reduced purchase prices. The latter, cost-driven, processes can create machines that are more likely to be functionally and aesthetically damaged in use, reinforcing the trend for faster replacement. The market appears likely to continue to focus on improved user experience, with growth in market share for lighter weight cordless battery powered machines posing the risk of an increased environmental burden. Drawing from qualitative and quantitative research undertaken for a study for Defra, we explore the user’s relationship to the product, investigating the frustrations and joys of vacuum cleaner use and ownership. The findings illustrate that the revulsion and attraction of cleaning, as well as the tedium and satisfaction fostered by the product, have direct implications for vacuum cleaner longevity
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The relationship between ideas about cleanliness and actions that affect product longevity
As Mary Douglas famously put it, ‘where there is dirt there is system’ (1991 (1966): 35). She was concerned particularly with the cultural systems that determine the ideas about dirt that motivate and constrain people’s actions with material objects. This paper assumes that such motivations and constraints may affect consumers’ willingness to keep or to dispose of their possessions, and therefore have an impact on product longevity. It reports on ongoing empirical research using product analysis, ethnographic interviews, a questionnaire and student design work into the possibility of increasing the longevity of vacuum cleaners by design interventions. Because its object of study is a cleaning product used in everyday cleaning practices, the research naturally connects with Douglas’ ideas as well as more recent work such as Dant 2003 that focuses on how people deal practically with the materiality of dirt, not determined by cultural categories. This paper builds on Vaussard et al.’s (2014) classification of individuals by their degree of concern for keeping their house clean, into ‘Spartan’, ‘Minimalistic’, ‘Caring’ and ‘Committed’ cleaners and their implications for vacuum cleaner replacement. Introducing a short history of concern about dirt since germ theory, it considers whether the desire for a more up to date/efficient/powerful/good looking/clean/shiny machine may accelerate replacement. It finally considers whether a design that ‘ages gracefully’ might have a longer life-span, either as a personal possession or as part of a service system
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What is broken? Expected lifetime, perception of brokenness and attitude towards maintenance and repair
This paper addresses the discrepancy between the expected and actual lifetimes of vacuum cleaners considering perceived ‘brokenness’ as a driver for replacement. Among electrical products, vacuum cleaners have a high rate of domestic ownership in the UK. They also embody large quantities of greenhouse gases which could be reduced by increasing their longevity and resource efficiency (Schreiber et al., 2012). A focus on energy efficiency has only shown limited or even negative results, therefore to meet recent European Union regulations on durability requirements a focus on product longevity is needed. Around one half of new vacuum cleaner purchasers replace one less than 5 years old, below the expected lifespan, with perceived breakage, poor performance and unreliability as the major reasons for replacement. Their relative simplicity could allow vacuum cleaners to last for significantly longer. The nature of the common causes of failure is known, including stretched cords or blockages, and WRAP has developed guidelines for product improvements. However, many working or repairable machines are disposed of because they are perceived to be ‘irremediably’ broken
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