1,195 research outputs found
Moving from a Product-Based Economy to a Service-Based Economy for a More Sustainable Future
Traditionally, economic growth and prosperity have been linked with the availability, production and distribution of tangible goods as well as the ability of consumers to acquire such goods. Early evidence regarding this connection dates back to Adam Smith's Wealth of Nations (1776), in which any activity not resulting in the production of a tangible good is characterized as unproductive of any value." Since then, this coupling of economic value and material production has been prevalent in both developed and developing economies throughout the world. One unintended consequence of this coupling has been the exponential increase in the amount of solid waste being generated. The reason is that any production and consumption of material goods eventually generates the equivalent amount of (or even more) waste. Exacerbating this problem is the fact that, with today's manufacturing and supply chain management technologies, it has become cheaper to dispose and replace most products rather than to repair and reuse them. This has given rise to what some call a disposable society." To put things in perspective: In 2012 households in the U.K. generated approximately 22 thousand tons of waste, which amounted to 411 kg of waste generated per person (Department for Environment, Food & Rural Affairs, 2015). During the same time period, households in the U.S. generated 251 million tons of waste, which is equivalent to a person generating approximately 2 kg of waste every day (U.S. Environmental Protection Agency, 2012). Out of these 251 million tons of total waste generated, approximately 20% of the discarded items were categorized as durable goods. The disposal of durable goods is particularly worrisome because they are typically produced using material from non- renewable resources such as iron, minerals, and petroleum-based raw materials
On the Change of the Inner Boundary of an Optically Thick Accretion Disk around White Dwarfs Using the Dwarf Nova SS Cyg as an Example
We present the results of our studies of the aperiodic optical flux
variability for SS Cyg, an accreting binary systemwith a white dwarf. The main
set of observational data presented here was obtained with the ANDOR/iXon
DU-888 photometer mounted on the RTT-150 telescope, which allowed a record(for
CCD photometers) time resolution up to 8 ms to be achieved. The power spectra
of the source's flux variability have revealed that the aperiodic variability
contains information about the inner boundary of the optically thick flow in
the binary system. We show that the inner boundary of the optically thick
accretion disk comes close to the white dwarf surface at the maximum of the
source's bolometric light curve, i.e., at the peak of the instantaneous
accretion rate onto the white dwarf, while the optically thick accretion disk
is truncated at distances 8.5e9 cm ~10 R_{WD} in the low state. We suggest that
the location of the inner boundary of the accretion disk in the binary can be
traced by studying the parameters of the power spectra for accreting white
dwarfs. In particular, this allows the mass of the accreting object to be
estimated.Comment: 9 pages, 7 figures, Published in Astronomy Letter
Learning Mechanics and Game Mechanics Under the Perspective of Self-Determination Theory to Foster Motivation in Digital Game Based Learning
Background: Using digital games for educational purposes has been associated
with higher levels of motivation among learners of different educational
levels. However, the underlying psychological factors involved in digital game
based learning (DGBL) have been rarely analyzed considering self-determination
theory (SDT, Ryan \& Deci, 2000b); the relation of SDT with the flow experience
(Csikszentmihalyi, 1990) has neither been evaluated in the context of DGBL
The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour
Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect
A Search for Mid-Infrared Molecular Hydrogen Emission from Protoplanetary Disks
We observed the Herbig Ae/Be stars UX Ori, HD 34282, HD 100453, HD 101412, HD
104237 and HD 142666, and the T Tauri star HD 319139 and searched for H2 0-0
S(2) emission at 12.278 micron and H2 0-0 S(1) emission at 17.035 micron with
VISIR, ESO-VLT's high-resolution MIR spectrograph. None of the sources present
evidence for H2 emission. Stringent 3sigma upper limits to the integrated line
fluxes and the mass of optically thin warm gas in the disks are derived. The
disks contain less than a few tenths of Jupiter mass of optically thin H2 gas
at 150 K at most, and less than a few Earth masses of optically thin H2 gas at
300 K and higher temperatures. We compare our results to a Chiang and Goldreich
(1997, CG97) two-layer disk model. The upper limits to the disk's optically
thin warm gas mass are smaller than the amount of warm gas in the interior
layer of the disk, but they are much larger than the amount of molecular gas in
the surface layer. We present a calculation of the expected thermal H2 emission
from optically thick disks, assuming a CG97 disk structure, a gas-to-dust ratio
of 100 and Tgas = Tdust. The expected H2 thermal emission fluxes from typical
disks around Herbig Ae/Be stars (10^-16 to 10^-17 erg/s/cm2 at 140 pc) are much
lower than the detection limits of our observations (5*10^-15 erg/s/cm2). H2
emission levels are very sensitive to departures from the thermal coupling
between the molecular gas and dust. Additional sources of heating of gas in the
disk's surface layer could have a major impact on the expected H2 disk
emission. In the observed sources the molecular gas and dust in the surface
layer have not significantly departed from thermal coupling (Tgas/Tdust< 2) and
that the gas-to-dust ratio in the surface layer is very likely lower than 1000.Comment: 16 pages, 9 figures, accepted by A&A. v2: typo in footnote **
corrected, v3: corrections of the A&A language editor included, typo in title
of Fig. 1. correcte
W51 IRS 2: A Massive Jet Emerging from a Molecular Cloud into an H II Region
We have mapped [Ne II] (12.8um) and [S IV] (10.5um) emission from W51 IRS 2
with TEXES on Gemini North, and we compare these data to VLA free-free
observations and VLT near-infrared images. With 0.5" spatial and 4 km/s
spectral resolution we are able to separate the ionized gas into several
components: an extended H II region on the front surface of the molecular
cloud, several embedded compact H II regions, and a streamer of high velocity
gas. We interpret the high velocity streamer as a precessing or fan-like jet,
which has emerged from the molecular cloud into an OB star cluster where it is
being ionized.Comment: 3 pages, 4 figures, 2 movie
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Lamination of the Outer Plexiform Layer in Optic Atrophy Caused by Dominant WFS1 Mutations.
The Masses and Evolutionary State of the Stars in the Dwarf Nova SS Cygni
The dwarf nova SS Cygni is a close binary star consisting of a K star transferring mass to a white dwarf by way of an accretion disk. We have obtained new spectroscopic observations of SS Cyg with the Hobby-Eberly Telescope (HET). Fits of synthetic spectra for Roche-lobe-filling stars to the absorption-line spectrum of the K star yield the amplitude of the K star's radial velocity curve and the mass ratio: K_{K} = 162.5 +/- 1.0 km/s and q= M_{K} /M_{wd} = 0.685 +/- 0.015. The fits also show that the accretion disk and white dwarf contribute a fraction f = 0.535 +/- 0.075 of the total flux at 5500 angstroms. Taking the weighted average of our results with previously published results obtained using similar techniques, we find = 163.7 +/- 0.7 km/s and = 0.683 +/- 0.012. The orbital light curve of SS Cyg shows an ellipsoidal variation diluted by light from the disk and white dwarf. From an analysis of the ellipsoidal variations we limit the orbital inclination to the range 45 deg. <= i <= 56 deg. The derived masses of the K star and white dwarf are M_{K} = 0.55 +/- 0.13 M_sun and M_{wd} = 0.81 +/- 0.19 M_sun, where the uncertainties are dominated by systematic errors in the orbital inclination. The K star in SS Cyg is 10% to 50% larger than an unevolved star with the same mass and thus does not follow the mass-radius relation for Zero-Age Main-Sequence stars; nor does it follow the ZAMS mass/spectral-type relation. Its mass and spectral type are, however, consistent with models in which the core hydrogen has been significantly depleted
Metaverse-Retail Service Quality: A Future Framework for Retail Service Quality in the 3D Internet
This paper argues that service quality in retailing in 3D Collaborative Virtual Environments (aka Metaverses) is distinct from service quality in the more familiar 2D mainly menu-driven web internet store (e-SQ). The study identifies and conceptualises the determinants of Metaverse Retailing service quality (MR-SQ) through a combination of focus groups and Critical Incident Technique. A set of four overarching determining elements of MR-SQ was revealed including customer service, product dimension, store dimension and 3D platform dimension. These incorporate some of the features found in 2D e-SQ but importantly the study indicated new characteristics, unique to MR-SQ. The CVE context presents opportunities for retailers in enhancing social experience, responsive service and creative co-production opportunities. It is within these gaps that respondents identified in 2D retailing that current CVEs and the future Web 3.0 hold appealing prospects for enhancing and producing creative and co-operative online retailing service quality (MR-SQ). The study provides a framework for guidance for retailers as well as for future research.
Summary Statement of Contribution:
The paper establishes new understanding of the determinants of Metaverse Retailing-Service Quality (MR-SQ). For virtual worlds in general and for service quality in particular, this study shows new MR-SQ dimensions, overlapping dimensions with different meanings to MR-SQ compares to e-SQ, and similar dimensions in both MR-SQ and e-SQ
Exploring the key drivers behind the adoption of mobile banking services
This research examines the main drivers behind the adoption of mobile banking, a concept that has revolutionized the day-to-day activities of humans. A review of relevant literature on the topic, leads us toward testing the following key hypotheses: consumers are adopting mobile banking due to the perceived usefulness and benefits associated with the concept; and consumers are adopting mobile banking due to technological advances meaning increased access to the mobile phone devices. We published an online questionnaire on Amazon Mechanical Turk to obtain responses from Internet users. A dominating proportion of participants highlighted how mobile banking is a concept that they adopted between three and 5 years ago, showing just how recently mobile banking took off. The results also showed a number of links between the study’s research hypotheses and the adoption of mobile banking. The overall result of the study shows online banking as a concept that is influenced by a number of both internal and external factors. No single factor plays a dominating force in pushing retail bankers to adopt mobile banking, with it instead being a culmination of numerous different factors. The recent introduction of mobile banking is made seemingly apparent, as is the increasing susceptibility to change in the near future. Subsequently, countless opportunities for further academic research are likely to arise
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