Impacts of Water Supply Changes on the Rice Market of Lao PDR: Stochastic Analysis of Supply and Demand Model

Laotian rice producers in upland areas experience highly fluctuating yields and production and producers in wet season rice areas in the southern region face high price risk. This paper examines the exposure to risk of producers in both regions facing changes in water supplies. A supply and demand model of rice in Laos, considering water supply changes, is developed and stochastic elements are added to the model to represent uncertainty in climatic variables. Furthermore, the risks associated with price and production fluctuation are evaluated by using the differences between market and certainty equivalent prices. The results show that the coefficient of variation of production is higher in upland rice than wet and dry season rice, i.e., 0.3226, and if the fluctuation of water supply increases 20%, the coefficient of variation of production will increase about 20% for all type of rice cultivation. In the case of expanding water supply fluctuations, potentially due to climatic change, the price risk of wet season rice will increase from 48.5 kip to 150.8 kip while that of upland and dry season rice will increase from 66.4 kip to 94.9 kip and 14.3 kip to 20.5 kip respectively. Examining provincial price risk of wet season rice, the differences between market and certainty equivalent prices are 56.3 kip and 33.9 kip in Champasack and Attapeu provinces. The regions or provinces which suffer highly fluctuating production and price risk may need to consider alternative water management and harvesting methods.water supply change, rice supply and demand model, stochastic model, Lao PDR, Q11, Q25, Crop Production/Industries, Resource /Energy Economics and Policy,

183 GHz H2_2O maser emission around the low-mass protostar Serpens SMM1

We report the first interferomteric detection of 183 GHz water emission in the low-mass protostar Serpens SMM1 using the Submillimeter Array with a resolution of 3$"$ and rms of $\sim$7 Jy in a 3 km s$^{-1}$ bin. Due to the small size and high brightnessof more than 240 Jy/beam, it appears to be maser emission. In total three maser spots were detected out to $\sim$ 700 AU from the central protostar, lying along the red-shifted outflow axis, outside the circumstellar disk but within the envelope region as evidenced by the continuum measurements. Two of the maser spots appear to be blue-shifted by about 1 to 2 km s$^{-1}$. No extended or compact thermal emission from a passively heated protostellar envelope was detected with a limit of 7 Jy (16 K), in agreement with recent modelling efforts. We propose that the maser spots originate within the cavity walls due to the interaction of the outflow jet with the surrounding protostellar envelope. Hydrodynamical models predict that such regions can be dense and warm enough to invert the 183 GHz water transition.Comment: Accepted for ApJ letters, 2 figure

Dressed-State Approach to Population Trapping in the Jaynes-Cummings Model

The phenomenon of atomic population trapping in the Jaynes-Cummings Model is analysed from a dressed-state point of view. A general condition for the occurrence of partial or total trapping from an arbitrary, pure initial atom-field state is obtained in the form of a bound to the variation of the atomic inversion. More generally, it is found that in the presence of initial atomic or atom-field coherence the population dynamics is governed not by the field's initial photon distribution, but by a `weighted dressedness' distribution characterising the joint atom-field state. In particular, individual revivals in the inversion can be analytically described to good approximation in terms of that distribution, even in the limit of large population trapping. This result is obtained through a generalisation of the Poisson Summation Formula method for analytical description of revivals developed by Fleischhauer and Schleich [Phys. Rev. A {\bf 47}, 4258 (1993)].Comment: 24 pages, 5 figures, to appear in J. Mod. Op

High Resolution Observations of the Massive Protostar in IRAS18566+0408

We report 3 mm continuum, CH3CN(5-4) and 13CS(2-1) line observations with CARMA, in conjunction with 6 and 1.3 cm continuum VLA data, and 12 and 25 micron broadband data from the Subaru Telescope toward the massive proto-star IRAS18566+0408. The VLA data resolve the ionized jet into 4 components aligned in the E-W direction. Radio components A, C, and D have flat cm SEDs indicative of optically thin emission from ionized gas, and component B has a spectral index alpha = 1.0, and a decreasing size with frequency proportional to frequency to the -0.5 power. Emission from the CARMA 3 mm continuum, and from the 13CS(2-1), and CH3CN(5-4) spectral lines is compact (i.e. < 6700 AU), and peaks near the position of VLA cm source, component B. Analysis of these lines indicates hot, and dense molecular gas, typical for HMCs. Our Subaru telescope observations detect a single compact source, coincident with radio component B, demonstrating that most of the energy in IRAS18566+0408 originates from a region of size < 2400 AU. We also present UKIRT near-infrared archival data for IRAS18566+0408 which show extended K-band emission along the jet direction. We detect an E-W velocity shift of about 10 km/sec over the HMC in the CH3CN lines possibly tracing the interface of the ionized jet with the surrounding core gas. Our data demonstrate the presence of an ionized jet at the base of the molecular outflow, and support the hypothesis that massive protostars with O-type luminosity form with a mechanism similar to lower mass stars

Decoherence induced by a phase-damping reservoir

A phase damping reservoir composed by $N$-bosons coupled to a system of interest through a cross-Kerr interaction is proposed and its effects on quantum superpo sitions are investigated. By means of analytical calculations we show that: i-) the reservoir induces a Gaussian decay of quantum coherences, and ii-) the inher ent incommensurate character of the spectral distribution yields irreversibility . A state-independent decoherence time and a master equation are both derived an alytically. These results, which have been extended for the thermodynamic limit, show that nondissipative decoherence can be suitably contemplated within the EI D approach. Finally, it is shown that the same mechanism yielding decoherence ar e also responsible for inducing dynamical disentanglement.Comment: 8 pages, 3 figure

Microscopic and Macroscopic Signatures of Antiferromagnetic Domain Walls

Magnetotransport measurements on small single crystals of Cr, the elemental antiferromagnet, reveal the hysteretic thermodynamics of the domain structure. The temperature dependence of the transport coefficients is directly correlated with the real-space evolution of the domain configuration as recorded by x-ray microprobe imaging, revealing the effect of antiferromagnetic domain walls on electron transport. A single antiferromagnetic domain wall interface resistance is deduced to be of order $5\times10^{-5}\mathrm{\mu\Omega\cdot cm^{2}}$ at a temperature of 100 K.Comment: 3 color figure

A Monte Carlo Method for Modeling Thermal Damping: Beyond the Brownian-Motion Master Equation

The "standard" Brownian motion master equation, used to describe thermal damping, is not completely positive, and does not admit a Monte Carlo method, important in numerical simulations. To eliminate both these problems one must add a term that generates additional position diffusion. He we show that one can obtain a completely positive simple quantum Brownian motion, efficiently solvable, without any extra diffusion. This is achieved by using a stochastic Schroedinger equation (SSE), closely analogous to Langevin's equation, that has no equivalent Markovian master equation. Considering a specific example, we show that this SSE is sensitive to nonlinearities in situations in which the master equation is not, and may therefore be a better model of damping for nonlinear systems.Comment: 6 pages, revtex4. v2: numerical results for a nonlinear syste

Massive star-formation toward G28.87+0.07 (IRAS 18411-0338) investigated by means of maser kinematics and radio to infrared, continuum observations

We used the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to perform phase-referenced VLBI observations of the three most powerful maser transitions associated with the high-mass star-forming region G28.87+0.07: the 22.2 GHz H$_{2}$O, 6.7 GHz CH$_{3}$OH, and 1.665 GHz OH lines. We also performed VLA observations of the radio continuum emission at 1.3 and 3.6 cm and Subaru observations of the continuum emission at 24.5 $\mu$m. Two centimeter continuum sources are detected and one of them (named "HMC") is compact and placed at the center of the observed distribution of H$_{2}$O, CH$_{3}$OH and OH masers. The bipolar distribution of line-of-sight (l.o.s) velocities and the pattern of the proper motions suggest that the water masers are driven by a (proto)stellar jet interacting with the dense circumstellar gas. The same jet could both excite the centimeter continuum source named "HMC" (interpreted as free-free emission from shocked gas) and power the molecular outflow observed at larger scales -- although one cannot exclude that the free-free continuum is rather originating from a hypercompact \ion{H}{2} region. At 24.5 $\mu$m, we identify two objects separated along the north-south direction, whose absolute positions agree with those of the two VLA continuum sources. We establish that $\sim$90% of the luminosity of the region ($\sim$\times10^{5} L_\sun$) is coming from the radio source "HMC", which confirms the existence of an embedded massive young stellar object (MYSO) exciting the masers and possibly still undergoing heavy accretion from the surrounding envelope.Comment: Accepted for publication in Ap

Unconditional Bell-type state generation for spatially separate trapped ions

We propose a scheme for generation of maximally entangled states involving internal electronic degrees of freedom of two distant trapped ions, each of them located in a cavity. This is achieved by using a single flying atom to distribute entanglement. For certain specific interaction times, the proposed scheme leads to the non-probabilistic generation of a perfect Bell-type state. At the end of the protocol, the flying atom completely disentangles from the rest of the system, leaving both ions in a Bell-type state. Moreover, the scheme is insensitive to the cavity field state and cavity losses. We also address the situation in which dephasing and dissipation must be taken into account for the flying atom on its way from one cavity to the other, and discuss the applicability of the resulting noisy channel for performing quantum teleportation.Comment: 5 pages, 1 figure, detailed comments on the practical implementation of the scheme is added to replaced version, minor typos fixed, added references with comment