8,482 research outputs found
Large scale CMB anomalies from thawing cosmic strings
Cosmic strings formed during inflation are expected to be either diluted over
super-Hubble distances, i.e., invisible today, or to have crossed our past
light cone very recently. We discuss the latter situation in which a few
strings imprint their signature in the Cosmic Microwave Background (CMB)
Anisotropies after recombination. Being almost frozen in the Hubble flow, these
strings are quasi static and evade almost all of the previously derived
constraints on their tension while being able to source large scale
anisotropies in the CMB sky. Using a local variance estimator on thousand of
numerically simulated Nambu-Goto all sky maps, we compute the expected signal
and show that it can mimic a dipole modulation at large angular scales while
being negligible at small angles. Interestingly, such a scenario generically
produces one cold spot from the thawing of a cosmic string loop. Mixed with
anisotropies of inflationary origin, we find that a few strings of tension GU =
O(1) x 10^(-6) match the amplitude of the dipole modulation reported in the
Planck satellite measurements and could be at the origin of other large scale
anomalies.Comment: 23 pages, 11 figures, uses jcappub. References added, matches
published versio
Risks, ex-ante actions, and public assistance: Impacts of natural disasters on child schooling in Bangladesh, Ethiopia, and Malawi
"This paper uses panel data from Bangladesh, Ethiopia, and Malawi to examine the impacts of natural disasters on schooling investments, with a particular focus on the roles of ex-ante actions and ex-post responses. We find that the importance of ex-ante actions depends on disaster risks and the likelihood of public assistance, potentially creating substitution between the two actions. We find that higher future probabilities of disaster increase the likelihood of agents holding more human capital and/or livestock relative to land; this asset-portfolio effect is significant in disaster-prone areas. Our empirical results support the roles of both ex-ante and ex-post (public assistance) responses in coping with disasters, but we see interesting variations across countries. In Ethiopia, public assistance plays a more important role than ex-ante actions in mitigating the impact of shocks on child schooling. In contrast, Malawi households rely more on private ex-ante actions than on public assistance. The Bangladesh example shows that active roles are played by both ex-ante and ex-post actions. These observations are consistent with our findings on the relationship between ex-ante actions and disaster risks. Our results also show that among ex-ante actions, human capital accumulated in the household prior to disasters helps mitigate the negative effects of a disaster in both the short and long runs." from authors' abstractNatural disasters, Ex-ante actions, Ex-post responses, Human capital investment, Poverty reduction, Social protection, Gender, Childcare and work,
Natural disasters, self-Insurance, and human capital investment: Evidence from Bangladesh, Ethiopia, and Malawi
"This paper uses panel data from Bangladesh, Ethiopia, and Malawi to examine the impacts of disasters on dynamic human capital production. Our empirical results show that accumulation of biological human capital prior to a disaster helps children maintain investments during the post-disaster period. Biological human capital formed in early childhood (for example, good long-term nutritional status) helps insure resilience to disasters by protecting schooling investments and outcomes, even though disasters have negative impacts on the actual investments (for example, by destroying schools). In Bangladesh, children with more biological human capital are less adversely affected by flood, and the rate of investment increases with the initial human capital stock during the post-disaster recovery process. In Ethiopia and Malawi, where droughts are relatively frequent, repeated drought exposure reduces schooling investments in some cases, with larger negative impacts seen among children who embody less biological human capital. Asset holdings prior to disaster (especially intellectual human capital stock in the household) also help maintain schooling investments to at least the same degree as the stock of human capital accumulated in the children prior to the disaster. Our results suggest that as the frequency of natural disasters increases due to global warming, the insurance value of investments in child nutrition will increase. Public investments in child nutrition therefore have the potential to effectively protect long-term human capital formation among children who are vulnerable to natural disasters." from authors' abstractDisasters, Human capital, Nutrition, Schooling, Self-insurance, Poverty reduction, Social protection, Shocks, Asset dynamics, Education,
Electrochemical synthesis and properties of CoO2, the x = 0 phase of the AxCoO2 systems (A = Li, Na)
Single-phase bulk samples of the "exotic" CoO2, the x = 0 phase of the AxCoO2
systems (A = Li, Na), were successfully synthesized through electrochemical
de-intercalation of Li from pristine LiCoO2 samples. The samples of pure CoO2
were found to be essentially oxygen stoichiometric and possess a hexagonal
structure consisting of stacked triangular-lattice CoO2 layers only. The
magnetism of CoO2 is featured with a temperature-independent susceptibility of
the magnitude of 10-3 emu/mol Oe, being essentially identical to that of a
Li-doped phase, Li0.12CoO2. It is most likely that the CoO2 phase is a
Pauli-paramagnetic metal with itinerant electrons.Comment: 12 pages, 3 figure
Hub loads analysis of the SA349/2 helicopter
The forces and moments at the rotor hub of an Aerospatiale SA349/2 helicopter were investigated. The study included three main topics. First, measured hub forces and moments for a range of level flight conditions (mu = 0.14 to 0.37) were compared with predictions from a comprehensive rotorcraft analysis to examine the influence of the wake model on the correlations. Second, the effect of changing the blade mass distribution and blade chordwise center of gravity location on the 3/rev nonrotating frame hub loads was studied for a high-speed flight condition (mu = 0.37). Third, the use of higher harmonic control to reduce nonrotating frame 3/rev hub shear forces was investigated. The last two topics were theoretical studies only
Craft, design and nostalgia in modern Japan: the case of sushi
"This edited book focuses on the organization and meaning of craft work in contemporary society. It considers the relationship between craft and place and how this enables the construction of a meaningful relationship with objects of production and consumption. The book explores the significance of raw materials, the relationship between the body, the crafted object and the mind, and the importance of skill, knowledge and learning in the making process. Through this, it raises important questions about the role of craft in facing future challenges by challenging the logic of globalized production and consumption.
The Organization of Craft Work encompasses international analyses from the United States, France, Italy, Australia, Canada, the UK and Japan involving a diverse range of sectors, including brewing, food and wine production, clothing and shoe making, and perfumery. The book will be of interest to students and academic researchers in organization studies, marketing and consumer behaviour, business ethics, entrepreneurship, sociology of work, human resource management, cultural studies, geography, and fashion and design. In addition, the book will be of interest to practitioners and organizations with an interest in the development and promotion of craft work.
Bias Voltage and Temperature Dependence of Hot Electron Magnetotransport
We present a qualitative model study of energy and temperature dependence of
hot electron magnetotransport. This model calculations are based on a simple
argument that the inelastic scattering strength of hot electrons is strongly
spin and energy dependent in the ferromagnets. Since there is no clear
experimental data to compare with this model calculations, we are not able to
extract clear physics from this model calculations. However, interestingly this
calculations display that the magnetocurrent increases with bias voltage
showing high magnetocurrent if spin dependent imaginary part of proper self
energy effect has a substantial contribution to the hot electron
magnetotransport. Along with that, the hot electron magnetotransport is
strongly influence by the hot electron spin polarization at finite
temperatures
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