15,466 research outputs found
Model Predictions for Neutrino Oscillation Parameters
We have surveyed leptonic and grand unified models of neutrino masses and
mixings in the literature which are still viable and give numerical predictions
for the reactor angle, . The results are of considerable interest
in anticipation of the next generation reactor experiments and the possible
future need for neutrino factories. Of the 63 models considered which were
published or posted on the Archive before June 2006, half predict values of
\sin^2 2\theta_{13} \gsim 0.015, which should yield positive signals for
disappearance in the reactor experiments planned for the near
future. Depending upon the outcome of those experiments, half of the models can
be eliminated on the basis of the presence or absence of such an observed
disappearance signal.Comment: 23 pages including 3 figures; published versio
Adaptation to Climate Change: Land Use and Livestock Management Change in the U.S.
Replaced with revised version of paper 01/26/11Climate Change, Stocking Rate, Land Use, Livestock Management, Environmental Economics and Policy, Land Economics/Use, Livestock Production/Industries,
Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells
The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic
Challenges of Primary Frequency Control and Benefits of Primary Frequency Response Support from Electric Vehicles
As the integration of wind generation displaces conventional plants, system inertia provided by rotating mass declines, causing concerns over system frequency stability. This paper implements an advanced stochastic scheduling model with inertia-dependent fast frequency response requirements to investigate the challenges on the primary frequency control in the future Great Britain electricity system. The results suggest that the required volume and the associated cost of primary frequency response increase significantly along with the increased capacity of wind plants. Alternative measures (e.g. electric vehicles) have been proposed to alleviate these concerns. Therefore, this paper also analyses the benefits of primary frequency response support from electric vehicles in reducing system operation cost, wind curtailment and carbon emissions
CLIMATE CHANGE INFLUENCES ON THE RISK OF AVIAN INFLUENZA OUTBREAKS AND ASSOCIATED ECONOMIC LOSS
This paper examines the effect that climate has on Avian Influenza outbreak probability. The statistical analysis shows across a broad region the probability of an outbreak declines by 0.22% when the temperature rises 1 Celsius degree and increases by 0.34% when precipitation increases by 1millimeter. These results indicate that the realized climate change of the last 20 years not only has been a factor behind recent HPAI outbreaks, but that climate change is likely to play an even greater role in the future. The statistical results indicate that overall, the risk of an AI outbreak has been increased by 51% under past climate change and 3-4% under future climate change. An economic evaluation shows the increased probability of outbreaks has caused damages of about 29 million in the United States due to past climate change. In the year of 2011-2030, for countries with a high proportion of chicken production, economic loss could reach 146 million in China and 18 million in the United Sates.Climate change, Avian Influenza outbreaks, GDP loss, Environmental Economics and Policy, Research Methods/ Statistical Methods,
Ready for the Flipped Classroom? Preliminary Experiences of The New Approach In Teaching Economics to Non-Major Students
The flipped classroom is an innovative educational model that has attracted more attention recently. In the flipped
classroom, course content is delivered via online videos and/or pre-recorded lectures that can be watched by students at home. It can free up the class time that lecturers are able to devote for learner-centered activities such as problem solving and active learning. This research is motivated by the flipping model with an aim to engage students’ learning outside of the classroom as well as respond to the challenges of teaching economics to non-economics majors, which reflect difficulties in delivering all the materials given the limited time period of a class. An online tool called “EDpuzzle” is introduced to facilitate flipping the class. After four-week trial of partially flipping the classroom, we surveyed 170 students from three economics modules to gather their feedback in order to explore the possibility and potential to adopt the flipped classroom strategy at a wider scale. Our pilot analysis indicates that technologies, like EDpuzzle, can help lecturers to deliver the course content through videos and monitor the class, but more effort is needed to motivate and encourage students to participate and prepare. In addition, flipping a class also involves design
of various types of activities, including in-class and out-of-class, which are all vital for an effective flipped classroom. Therefore, our study calls for further research on how to design, implement and evaluate the flipped classroom in economics teachin
Passive faraday mirror attack in practical two-way quantum key distribution system
The faraday mirror (FM) plays a very important role in maintaining the
stability of two way plug-and-play quantum key distribution (QKD) system.
However, the practical FM is imperfect, which will not only introduce
additional quantum bit error rate (QBER) but also leave a loophole for Eve to
spy the secret key. In this paper, we propose a passive faraday mirror attack
in two way QKD system based on the imperfection of FM. Our analysis shows that,
if the FM is imperfect, the dimension of Hilbert space spanned by the four
states sent by Alice is three instead of two. Thus Eve can distinguish these
states with a set of POVM operators belonging to three dimension space, which
will reduce the QBER induced by her attack. Furthermore, a relationship between
the degree of the imperfection of FM and the transmittance of the practical QKD
system is obtained. The results show that, the probability that Eve loads her
attack successfully depends on the degree of the imperfection of FM rapidly,
but the QBER induced by Eve's attack changes with the degree of the
imperfection of FM slightly
Evaluating the demand for aquaculture insurance: An investigation of fish farmers' willingness to pay in central coastal areas in China
Despite the remarkable development in its fishery sector, the penetration rate of fishery insurance in China is considerably low. This paper examines the key factors that contribute to the poor performance of fishery insurance, in particular aquaculture insurance, in China. The double-bounded dichotomous choice contingent valuation method (DB DCCVM) is used to investigate fish farmers’ willingness to pay (WTP) for an insurance program, based on a survey of 1280 fish farmers in three coastal cities in China. The results indicate that fish farmers’ decisions on adoption of an insurance scheme depend on various factors, among which magnitude of loss, fish farmers’ awareness toward insurance and their education all have a positive impact. However, income and farming years are more likely to have a negative effect. In addition, the mean WTP for aquaculture insurance is estimated to be CNY 579 (US$ 90.05) 2 per household, which is equivalent to 1.5% of fish farmers' mean annual income. These results provide several policy implications for not only the Chinese government but also researchers as well as insurance companies
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