1,041 research outputs found
Water resources planning using integrated systems of marketable water rights and reservoir design and operation
The needs and the approaches for developing (1) efficient methods for the allocation of water resources and (2) efficient planning tools for the design and operation of storage facilities and other water supply enhancement techniques, are often interrelated, and should be addressed in a coordinated fashion. Recent studies have shown that the marketable water permits system holds some attractive features as a vehicle for allocating water supplies. In this study, management techniques to integrate marketable water rights systems with systems for the design and operation of a single reservoir are developed. Three kinds of rights may be found in such integrated systems. They are natural flowing water rights, release rights, and storage rights, which are contingent on possession of permits. Auctions of these rights or other market transactions may be helpful to the design and operation of the reservoir by providing useful information about the users' demand and benefit functions. In order to assess the efficiency of these policies, their operations are simulated using economic data based on corn irrigation. These programs are then compared to some other methods of water allocation and reservoir operation. Results of the study show that high efficiency may be attained by these integrated systems. As in many other water resources and reservoir management systems, the efficiencies attained are, in part, dependent on how well the future is predicted. A highly sophisticated storage management policy is likely to generate higher efficiency than simple ones, but only if the release decisions are carefully determined. Restrictions on spot trading would also prevent some of the efficiency from being captured. When the integrated system is operated and managed by a profit-seeking private enterprise, some degree of supervision from the authority may be required to prevent the problem of supply curtailment (i.e., undersizing of the reservoir), caused by a potentially larger profit at a smaller reservoir size.U.S. Geological SurveyU.S. Department of the InteriorOpe
Alternative structures for water rights markets: Overview and hypothetical case study
The design of systems of marketable permits for water consumption from natural watercourses is examined through a qualitative overview and a quantitative quasi-empirical, quasi-hypothetical case study. For the work reported upon here, the most important considerations are those associated with: 1) uncertainty of future streamflows and economic conditions, 2) locational issues, and 3) efficient and effective functioning of the markets. Particular attention is given to the problem of implementing marketable rights systems in regions presently following the riparian doctrine. In these regions the most important design decisions include: the basis of definition of permits, the means for initially distributing them, the type of market mechanism used for their transfer after they are issued, and the restrictions placed on their use and transfer. These design decisions are examined here with respect to program objectives including: economic efficiency, equity, ease of administration and implementation, and maintenance of instream flows. Alternative approaches to the design problems are discussed and trade-offs implied by the decisions are identified. The efficiency of two marketable water rights systems in a lentic (lake-like) structure is assessed quantitatively for a case study based on hypothetical irrigation water use. Water rights markets are simulated on the bases of no foresight and perfect foresight on the parts of users, and the economic outcomes of these markets are evaluated from both ex ante and ex post perspectives. The market outcomes are compared to the optimal (efficient) scheme and to two alternative non-market policies. Distributional aspects of markets are examined on the basis of individual financial gain to the users. Simulation results show that higher efficiency is obtained for the two market systems than for the non-market policies and that the market systems recoup about 95% of the economic value of the optimal distribution. The results suggest that most of the 5% efficiency loss should be attributed to the restrictions imposed by the definition of the rights, rather than the users' inability to predict future events.U.S. Department of the InteriorU.S. Geological SurveyOpe
Generating alternative solutions for dynamic programming models of water resources problems
A technique is presented to generate alternatives that are different from each other, but good with respect to modeled objectives, for problems that can be modeled by dynamic programming. The technique is compared to other possible approaches, and relevant concepts of difference among alternatives are discussed. Application to a floodplain management model shows that the technique can produce sets of different alternatives for water resources problems.U.S. Geological SurveyU.S. Department of the InteriorOpe
Orexin and Circadian Influences in Sleep and Psychiatric Disorders: A Review of Experimental and Computational Modelling Studies
Stabilisation of single longitudinal mode operation in a Q-switched Nd:YAG laser
Detection of the reflected laser beam power from the mode-selecting etalon in a prelase-Q-switched laser provides an indicator of mode-frequency drifts. The detected signal can be used to control a piezo-mounted resonator mirror, thus correcting the drift and providing a means for maintaining single longitudinal mode operation on every shot
Nuclear shell-model calculations for 6Li and 14N with different NN potentials
Two ``phase-shift equivalent'' local NN potentials with different
parametrizations, Reid93 and NijmII, which were found to give nearly identical
results for the triton by Friar et al, are shown to yield remarkably similar
results for 6Li and 14N in a (0+2)hw no-core space shell-model calculation. The
results are compared with those for the widely used Hamada-Johnson hard-core
and the original Reid soft-core potentials, which have larger deuteron D-state
percentages. The strong correlation between the tensor strength and the nuclear
binding energy is confirmed. However, many nuclear-structure properties seem to
be rather insensitive to the details of the NN potential and, therefore, cannot
be used to test various NN potentials. (Submitted to Phys. Rev. C on Nov. 9,
1993 as a Brief Report.)Comment: 12 text pages and 1 figure (Figure available upon request),
University of Arizona Physics Preprint (Number not yet assigned
Effect of Aging on the Reversibility of Pu(IV) Sorption to Goethite
Designing safe remediation and disposal strategies for plutonium (Pu) requires understanding the sorption affinity of Pu for soil minerals. Sorption of Pu(IV) was examined with respect to aging for a goethite system using batch sorption experiments. Sorption of Pu(IV) to iron oxides has been observed to be strong, rapid, and possibly irreversible or hysteretic. These observations may be explained by aging, a surface chemical process happening after initial sorption which causes a change in contaminant surface speciation over time. Measurements of Pu(IV) sorption are often complicated by oxidative leaching of Pu(IV) as Pu(V). Desferrioxamine B (DFOB) is a complexant capable of competing with the proposed strong surface complexes. Additionally, DFOB minimizes oxidative leaching by forming strong Pu(IV)-DFOB complexes, thereby stabilizing Pu(IV) as the dominant aqueous oxidation state. Pu(IV) was reacted in suspensions of 0.1g/L goethite and 10mM NaCl spanning pH 4–7 for various lengths of time (1,6,15,34 and 116 days). Supernatant was replaced with a 1.7µM DFOB solution and, after 34 more days, analyzed for aqueous Pu by liquid scintillation counting. Modeling sorption curves in FITEQL yielded logK values which increased from 0.078 to 0.953 over 116 days, indicating Pu(IV) sorption onto goethite becomes less reversible with aging
A New Transport Regime in the Quantum Hall Effect
This paper describes an experimental identification and characterization of a
new low temperature transport regime near the quantum Hall-to-insulator
transition. In this regime, a wide range of transport data are compactly
described by a simple phenomenological form which, on the one hand, is
inconsistent with either quantum Hall or insulating behavior and, on the other
hand, is also clearly at odds with a quantum-critical, or scaling, description.
We are unable to determine whether this new regime represents a clearly defined
state or is a consequence of finite temperature and sample-size measurements.Comment: Revtex, 3 pages, 2 figure
The Nature of the Hall Insulator
We have conducted an experimental study of the linear transport properties of
the magnetic-field induced insulating phase which terminates the quantum Hall
(QH) series in two dimensional electron systems. We found that a direct and
simple relation exists between measurements of the longitudinal resistivity,
, in this insulating phase and in the neighboring QH phase. In
addition, we find that the Hall resistivity, , can be quantized in
the insulating phase. Our results indicate that a close relation exists between
the conduction mechanism in the insulator and in the QH liquid.Comment: RevTeX, 4 pages, 4 figure
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