17,861 research outputs found
Distributed sensing devices for monitoring marine environment
The lack of affordable, self-sustaining platforms for monitoring marine water quality means that measurements are done primarily through grab sampling at a limited number of locations and time, followed by analysis back at a centralised facility. This has resulted in huge gaps in our knowledge of water quality. This project aims to develop platforms capable of remote sampling and analysis over extended periods of time. This would provide the building blocks for establishing an 'environmental nervous system' comprised of many distributed sensing devices that share their data in near real-time on the web. The envisaged 'environmental nervous system’ allows marine environment to be closely monitored, enabling the early detection of pollution events to minimise the danger to people and contamination of distribution systems
Impact of Direct Income Payments on Productive Efficiency of Korean Rice Farms
This paper examines the impact of direct income payments on productive efficiency of Korean rice farms, using farm-level cross sectional data in 2006. For representation of efficiency and its determinants, this paper uses a model that estimates the deviations of farms from a translog distance function and the determinants of these deviations. This paper especially estimates a stochastic frontier production function to explain deviations from best-practice productivity with a two-part error term including statistical noise from measurement error and technical inefficiency arising from farms not reaching the production frontier boundary. The empirical evidence finds that farms that get a higher share of direct payments in farm revenue are less efficient than others. This inefficiency is reduced by increases in farm size. Another result indicates that farms received greater direct payments on aggregate are more efficient than other farms since fixed payment, one part of rice direct payment, is tied to the amount of a farm's cropland that has been enrolled in programs, as well as yield histories.direct income payments, productive efficiency, stochastic frontier production function, Korea, Agribusiness, Agricultural and Food Policy, Crop Production/Industries,
Parity-violating coupling constant from the flavor-conserving effective weak chiral Lagrangian
We investigate the parity-violating pion-nucleon-nucleon coupling constant
, based on the chiral quark-soliton model. We employ an effective
weak Hamiltonian that takes into account the next-to-leading order corrections
from QCD to the weak interactions at the quark level. Using the gradient
expansion, we derive the leading-order effective weak chiral Lagrangian with
the low-energy constants determined. The effective weak chiral Lagrangian is
incorporated in the chiral quark-soliton model to calculate the
parity-violating constant . We obtain a value of about
at the leading order. The corrections from the next-to-leading order
reduce the leading order result by about 20~\%.Comment: 12 page
Lattice-coupled Antiferromagnet on Frustrated Lattices
Lattice-coupled antiferromagnetic spin model is analyzed for a number of
frustrated lattices: triangular, Kagome, and pyrochlore. In triangular and
Kagome lattices where ground state spins are locally ordered, the spin-lattice
interaction does not lead to a static deformation of the lattice. In the
pyrochlore structure, spin-lattice coupling supports a picture of the hexagon
spin cluster proposed in the recent experiment[S. H. Lee et al. Nature, 418,
856 (2002)]. Through spin-lattice interaction a uniform contraction of the
individual hexagons in the pyrochlore lattice can take place and reduce the
exchange energy. Residual hexagon-hexagon interaction takes the form of a
3-states Potts model where the preferred directions of the spin-loop directors
for nearby hexagons are mutually orthogonal
Development of optical sensing system for detection of Fe ions using conductive polymer actuator based microfluidic pump
In this paper, we present a novel microfluidic optical
sensing system by combining a low-power conductive polymer
-based microfluidic pump and a microfluidic chip integrated
with an optical sensor. A self priming microfluidic pump is
developed using a polypyrrole. A microfluidic chip- optical
detector module that contained an optical cuvette with LED
and photo-diode optical sensing module was fabricated.
Integration of the micro pump and the microfluidic chips
complete the sensing system. The pump performance and its
application in chemical analysis have been demonstrated in the
detection of Fe ions
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