Nutrient deficiencies affecting peanut production in soils of northeast Thailand

Peanut is widely grown in the rainy season on upland soils (mostly Paleustults) in northeast Thailand. The nutrient status of these soils for peanut production has not been adequately assessed. Response to phosphorus, potassium, sulfur, and copper on a range of soil types of this region have been obtained in pot trials using pasture legumes (Wilaipon 1976). The present experiments were set up to identify nutrient deficiencies which could limit yield and kernel quality of peanut on an Oxic Paleustult (Khorat series)

A Finitely Convergent Duality Theory for Zero-One Integer Programming

Given an integer programming problem, a constructive procedure is presented for generating a finite sequence of increasingly stronger dual problems to the given problem. The last dual problem in the sequence yields an optimal solution to the given integer programming problem. It is shown that this dual problem approximates the convex hull of the feasible integer solutions in a neighborhood of the optimal solution it finds. The theory is applicable to any bounded integer programming problem with rational data

Nuclear Reactor Refueling Optimization

In a 1971 paper, Suzuki and Kiyose give a model for light water moderated atomic reactor refueling optimization. Specifically, they present a linear programming formulation for minimizing the number of fresh fuel assemblies required by a reactor over a finite planning horizon subject to power generation and safety requirements and reactor design specifications. The optimal refueling policies found by Suzuki and Kiyose were useful in reducing the fresh fuel required, but two difficulties were encountered. First, the optimal linear programming solutions included small fractional numbers of fresh fuel assemblies which were difficult to round off. The second difficulty was that their formulation had approximately 165H constraints where H is the length of the planning horizon. The problems solved had H=10, but it was desired to analyze the problem for longer planning horizons of 20 to 30 stages without solving prohibitively large mathematical programming problems. In this paper, we give a reformulation of the reactor refueling optimization problem that consists of approximately 15H constraints and a large number of columns. This reformulation is required because the state-of-the-art of integer programming does not usually permit the solution of integer programs with thousands or even many hundreds of constraints. Moreover, the reformulation should permit the linear programming approximation to be more easily solved, at least approximately. Finally, the reformulation identifies and analyzes explicitly the fundamental activity in refueling optimization; namely, the introduction, degradation and removal of fuel assemblies. This should make it easier to modify the model to take into account additional features of the problem such as a cost for moving an assembly from one location to another

Staying in the science stream: patterns of participation in A-level science subjects in the UK.

This paper describes patterns of participation and attainment in A-level physics, chemistry and biology from 1961 to 2009. The A-level has long been seen as an important gateway qualification for higher level study, particularly in the sciences. This long term overview examines how recruitment to these three subjects has changed in the context of numerous policies and initiatives that seek to retain more young people in the sciences. The results show that recruitment to the pure sciences has stagnated, general trends have hardly varied and the track record of government policy in influencing change is not strong. There is no evidence for increasing achievement gaps between the sexes at A-level and even national policy requiring that all young people study science up to the age of 16 appears to have had little impact on recruitment at this leve

Optimal States for Bell inequality Violations using Quadrature Phase Homodyne Measurements

We identify what ideal correlated photon number states are to required to maximize the discrepancy between local realism and quantum mechanics when a quadrature homodyne phase measurement is used. Various Bell inequality tests are considered.Comment: 6 pages, 5 Figure

Non-local Realistic Theories and the Scope of the Bell Theorem

According to a widespread view, the Bell theorem establishes the untenability of so-called 'local realism'. On the basis of this view, recent proposals by Leggett, Zeilinger and others have been developed according to which it can be proved that even some non-local realistic theories have to be ruled out. As a consequence, within this view the Bell theorem allows one to establish that no reasonable form of realism, be it local or non-local, can be made compatible with the (experimentally tested) predictions of quantum mechanics. In the present paper it is argued that the Bell theorem has demonstrably nothing to do with the 'realism' as defined by these authors and that, as a consequence, their conclusions about the foundational significance of the Bell theorem are unjustified.Comment: Forthcoming in Foundations of Physic

Qubits from Number States and Bell Inequalities for Number Measurements

Bell inequalities for number measurements are derived via the observation that the bits of the number indexing a number state are proper qubits. Violations of these inequalities are obtained from the output state of the nondegenerate optical parametric amplifier.Comment: revtex4, 7 pages, v2: results identical but extended presentation, v3: published versio

Characterization of Binary Constraint System Games

We consider a class of nonlocal games that are related to binary constraint systems (BCSs) in a manner similar to the games implicit in the work of Mermin [N.D. Mermin, "Simple unified form for the major no-hidden-variables theorems," Phys. Rev. Lett., 65(27):3373-3376, 1990], but generalized to n binary variables and m constraints. We show that, whenever there is a perfect entangled protocol for such a game, there exists a set of binary observables with commutations and products similar to those exhibited by Mermin. We also show how to derive upper bounds strictly below 1 for the the maximum entangled success probability of some BCS games. These results are partial progress towards a larger project to determine the computational complexity of deciding whether a given instance of a BCS game admits a perfect entangled strategy or not.Comment: Revised version corrects an error in the previous version of the proof of Theorem 1 that arises in the case of POVM measurement

Does quantum nonlocality irremediably conflict with Special Relativity?

We reconsider the problem of the compatibility of quantum nonlocality and the requests for a relativistically invariant theoretical scheme. We begin by discussing a recent important paper by T. Norsen [arXiv:0808.2178] on this problem and we enlarge our considerations to give a general picture of the conceptually relevant issue to which this paper is devoted.Comment: 18 pages, 1 figur

Two qubits of a W state violate Bell's inequality beyond Cirel'son's bound

It is shown that the correlations between two qubits selected from a trio prepared in a W state violate the Clauser-Horne-Shimony-Holt inequality more than the correlations between two qubits in any quantum state. Such a violation beyond Cirel'son's bound is smaller than the one achieved by two qubits selected from a trio in a Greenberger-Horne-Zeilinger state [A. Cabello, Phys. Rev. Lett. 88, 060403 (2002)]. However, it has the advantage that all local observers can know from their own measurements whether their qubits belongs or not to the selected pair.Comment: REVTeX4, 5 page