Exploratory studies of open-channel flow over boundaries of laterally varying roughness

An exploratory study was made of open-channel flow over beds consisting either entirely or partially of large granular roughness. Steady, uniform flow was established at various depths and velocities over two types of beds, one rough over the entire width of a laboratory flume, the other rough only over half the width and smooth over the other half. Friction factors were determined for these flows, and detailed velocity distributions were measured in three runs. The friction factors for the entirely rough beds compared closely with those predicted by the Karman-Prandtl equations, and the velocity distributions strongly suggested the existence of secondary circulation of the second kind. Analysis is offered to show that subdivision of the cross section of a turbulent flow by curves normal to the equal velocity curves does not result in hydraulically independent zones of flow, in that there will be turbulent interchange of the longitudinal component of momentum among such zones; other methods of subdivision are considered and none found to be completely satisfactory. The customary side-wall correction method is reviewed and found to have no explicit rational basis, and although it is recognized that the method gives reliable results in the situations to which it is usually applied, its application to widely different situations should be undertaken with caution. Suggestions for needed further research are offered

Delaboring Republicanism

This article criticizes radical labor republicanism on republican grounds. I show that its demand for universal workplace democracy via workers’ cooperatives conflicts with republican freedom along three different dimensions: first, freedom to choose an occupation…and not to choose one; second, freedom within the very cooperatives that workers are to democratically govern; and third, freedom within the newly proletarian state. In the conclusion, I ask whether these criticisms apply, at least in part, to the more modest, incrementalist strand of labor republicanism. To the extent that they do, delaboring republicanism might be the best response

A Kantian Defense of Self‐Ownership

Many scholars, including G. A. Cohen, Daniel Attas, and George Brenkert, have denied that a Kantian defense of self-ownership is possible. Kant's ostensible hostility to self-ownership can be resolved, however, upon reexamination of the Groundwork and the Metaphysics of Morals. Moreover, two novel Kantian defenses of self-ownership (narrowly construed) can be devised. The first shows that maxims of exploitation and paternalism that violate self-ownership cannot be universalized, as this leads to contradictions in conception. The second shows that physical coercion against rational agents involves a profound status wrong--namely, their treatment as children or animals--and that this system of differential status and treatment (including self-ownership rights for rational agents) can be morally justified by our capacity for autonomy

Kantian Personal Autonomy

Jeremy Waldron has recently raised the question of whether there is anything approximating the creative self-authorship of personal autonomy in the writings of Immanuel Kant. After considering the possibility that Kantian prudential reasoning might serve as a conception of personal autonomy, I argue that the elements of a more suitable conception can be found in Kant’s Tugendlehre, or “Doctrine of Virtue”—specifically, in the imperfect duties of self-perfection and the practical love of others. This discovery is important for at least three reasons: first, it elucidates the relationship among the various conceptions of autonomy employed by personal-autonomy theorists and contemporary Kantians; second, it brings to the surface previously unnoticed or undernoticed features of Kant’s moral theory; and third, it provides an essential line of defense against certain critiques of contemporary Kantian theories, especially that of John Rawls

On the limiting behaviour of augmented seasonal unit root tests

In a recent paper, Taylor (2003) has shown that the seasonal unit root tests of Dickey et al. (1984) [DHF] have non-degenerate limiting distributions for series which admit unit roots at any of the zero or seasonal frequencies. In this note we go a stage further and show that the standard practice of augmenting the DHF regression with lagged dependent variables alters the limiting distributions of the DHF statistics in the above scenario. Associated Monte Carlo evidence shows that this may either increase or decrease (possibly even below the nominal level) the rejection frequencies of the tests, relative to the unaugmented case.

ISSUES IN RISK/BENEFIT EVALUATION FOR PESTICIDE REGISTRATION

Agricultural and Food Policy,

CERTAINTY EQUIVALENCE FOR DETERMINATION OF OPTIMAL FERTILIZER APPLICATION RATES WITH CARRY-OVER

This note demonstrates that a certain class of stochastic problems for determination of optimal fertilizer application rates in the presence of fertilizer carry-over can be simplified to static, certainly equivalent problems. Conditions required for certainty equivalence to hold are: (1) fertilizer carry-over is agronomically equivalent to applied fertilizer; and (2) some addition of fertilizer is optimal in every decision period.Crop Production/Industries,