94 research outputs found
High order vibration modes of glass embedded AgAu nanoparticles
High resolution low frequency Raman scattering measurements from embedded
AgAu nanoparticles unveil efficient scattering by harmonics of both the
quadrupolar and the spherical modes. Comparing the experimental data with
theoretical calculations that account for both the embedding medium and the
resonant Raman process enables a very complete description of the observed
multiple components in terms of harmonics of both the quadrupolar and spherical
modes, with a dominating Raman response from the former ones. It is found that
only selected harmonics of the quadrupolar mode contribute significantly to the
Raman spectra in agreement with earlier theoretical predictions.Comment: 11 pages, 4 figure
When Universal Access does not go to plan: Lessons to be learned
While the theory of designing for Universal Access is increasingly understood, there remain persistent issues over realising products and systems that meet the goal of being accessible and usable by the broadest possible set of users. Clearly products or service that are designed without even considering the needs of the wider user base are implicitly going to struggle to be universally accessible. However, even products that have been designed knowing that they are to be used by broad user bases frequently still struggle to achieve the ambition of being universally accessible. This paper examines a number of such products that did not achieve, at least initially, the desired level of universal accessibility. Principal recommendations from each case study are presented to provide a guide to common issues to be avoided
Effects of pretreatments of Napier Grass with deionized water, sulfuric acid and sodium hydroxide on pyrolysis oil characteristics
The depletion of fossil fuel reserves has led to
increasing interest in liquid bio-fuel from renewable biomass. Biomass is a complex organic material consisting of
different degrees of cellulose, hemicellulose, lignin,
extractives and minerals. Some of the mineral elements
tend to retard conversions, yield and selectivity during
pyrolysis processing. This study is focused on the extraction of mineral retardants from Napier grass using deionized water, dilute sodium hydroxide and sulfuric acid and subsequent pyrolysis in a fixed bed reactor. The raw biomass was characterized before and after each pretreatment
following standard procedure. Pyrolysis study was conducted
in a fixed bed reactor at 600 o�C, 30 �C/min and 30 mL/min N2 flow. Pyrolysis oil (bio-oil) collected was analyzed using standard analytic techniques. The bio-oil yield and characteristics from each pretreated sample were compared with oil from the non-pretreated sample. Bio-oil
yield from the raw sample was 32.06 wt% compared to
38.71, 33.28 and 29.27 wt% oil yield recorded from the
sample pretreated with sulfuric acid, deionized water and
sodium hydroxide respectively. GC–MS analysis of the oil
samples revealed that the oil from all the pretreated biomass had more value added chemicals and less ketones and
aldehydes. Pretreatment with neutral solvent generated
valuable leachate, showed significant impact on the ash
extraction, pyrolysis oil yield, and its composition and
therefore can be regarded as more appropriate for thermochemical conversion of Napier grass
Seven HCI Grand Challenges
This article aims to investigate the Grand Challenges which arise in the current and emerging landscape of rapid technological evolution towards more intelligent interactive technologies, coupled with increased and widened societal needs, as well as individual and collective expectations that HCI, as a discipline, is called upon to address. A perspective oriented to humane and social values is adopted, formulating the challenges in terms of the impact of emerging intelligent interactive technologies on human life both at the individual and societal levels. Seven Grand Challenges are identified and presented in this article: Human-Technology Symbiosis; Human-Environment Interactions; Ethics, Privacy and Security; Well-being, Health and Eudaimonia; Accessibility and Universal Access; Learning and Creativity; and Social Organization and Democracy. Although not exhaustive, they summarize the views and research priorities of an international interdisciplinary group of experts, reflecting different scientific perspectives, methodological approaches and application domains. Each identified Grand Challenge is analyzed in terms of: concept and problem definition; main research issues involved and state of the art; and associated emerging requirements
Reviving calm technology in the e-tourism context
Tourism industry practitioners should understand the controversial nature of the information and communication technology (ICT) proliferation to ensure the ICT solutions do not consume too much of their attention, thus jeopardizing consumer enjoyment of tourism services. The concept of calm technology or calm design serves this purpose. Calm design suggests that technology should quietly recede in the background and come into play with users when and if required, thus delivering and/or enhancing a desired experience. Although this concept is of relevance to e-tourism, until recently, it has never been considered within. This is where this paper contributes to knowledge as, for the first time, it introduces calm design into the e-tourism context and critically evaluates the determinants of its broader adoption within the tourism industry. It positions calm design within the e-tourism realm, discusses its implications for customer service management, supply chain management and destination management, and discloses opportunities for future research
Six Human-Centered Artificial Intelligence Grand Challenges
Widespread adoption of artificial intelligence (AI) technologies is substantially affecting the human condition in ways that are not yet well understood. Negative unintended consequences abound including the perpetuation and exacerbation of societal inequalities and divisions via algorithmic decision making. We present six grand challenges for the scientific community to create AI technologies that are human-centered, that is, ethical, fair, and enhance the human condition. These grand challenges are the result of an international collaboration across academia, industry and government and represent the consensus views of a group of 26 experts in the field of human-centered artificial intelligence (HCAI). In essence, these challenges advocate for a human-centered approach to AI that (1) is centered in human well-being, (2) is designed responsibly, (3) respects privacy, (4) follows human-centered design principles, (5) is subject to appropriate governance and oversight, and (6) interacts with individuals while respecting human’s cognitive capacities. We hope that these challenges and their associated research directions serve as a call for action to conduct research and development in AI that serves as a force multiplier towards more fair, equitable and sustainable societies
Adaptive model-driven user interface development systems
Adaptive user interfaces (UIs) were introduced to address some of the usability problems that plague many software applications. Model-driven engineering formed the basis for most of the systems targeting the development of such UIs. An overview of these systems is presented and a set of criteria is established to evaluate the strengths and shortcomings of the state-of-the-art, which is categorized under architectures, techniques, and tools. A summary of the evaluation is presented in tables that visually illustrate the fulfillment of each criterion by each system. The evaluation identified several gaps in the existing art and highlighted the areas of promising improvement
Tell me where you've lived, and I'll tell you what you like: adapting interfaces to cultural preferences
Mechanisms underlying the effectiveness of the adjustable gastric band—Insights from a rodent model
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