Insecta Mundi: procedures, production, and publication

This article outlines changes in procedures and production policies for the journal Insecta Mundi. Background data and discussions leading to these necessary changes are explained. Updated instructions for authors are presented. A full current version of author instructions will be posted on the latest Center for Systematic Entomology URL

ANALYSIS OF THE U.S. COMMODITY LOAN PROGRAM WITH MARKETING LOAN PROVISIONS

Over the next several years, crop prices are projected to be below to slightly above commodity loan rates. As a result, marketing loan benefits to farmers, in the form of loan deficiency payments and marketing loan gains from the commodity loan program, are likely to continue to be sizeable. The level of realized per-unit revenues facilitated by marketing loans exceeds commodity loan rates, thereby raising expected net returns to farmers. Model simulations show that the loan program can raise total acreage planted to major field crops, generally increasing levels of domestic use and exports while lowering crop prices. Cross-commodity effects of supply response to relative returns (including marketing loan benefits), however, result in acreage shifts among competing crops, which can lead to reductions in plantings of some crops in some years. Most impacts occur in the years when there are marketing loan benefits, with little effect in subsequent years when prices rise high enough to eliminate marketing loan benefits. The livestock sector benefits from these outcomes because of generally lower feed costs.Commodity loans, marketing loans, nonrecourse loans, loan deficiency payments, price support, commodity programs, Agricultural Finance,

Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.

The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000 shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5–13.5 mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1–4.4 mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation

Experimental Measurements of Store Separation Using Dry Ice Models in a Subsonic Flow

Testing free-drop store separation from a cavity in wind tunnels proves a difficult task because the models are typically destroyed during the test. Furthermore, there is potential for damage to wind tunnel components. Prior work has shown that small dry ice models released within the test section do not cause damage to the AFIT pressure-vacuum wind tunnel components or vacuum chamber. Rather, the dry ice models break apart and sublimate harmlessly into gaseous carbon dioxide. Therefore, this study was undertaken to determine whether dry ice models might prove useful in free-drop store separation testing. A generic aircraft cavity was constructed for testing in the AFIT low speed wind tunnel. Stores were formed by directly injecting pressurized liquid carbon dioxide into a mold. The store geometry used is a circular cylinder with spherical nosecone, with 1.0-inch diameter by 1.8 inches in length. Three 5mW lasers fitted with pattern generating optics were mounted on the wind tunnel sting to illuminate the store and cavity. Three high-speed cameras recorded each test at 700 frames per second and the models were tracked using laser dot projection photogrammetry. Experiments were conducted at nominal freestream velocities of 0, 50, and 100 mph

A physical model for seismic noise generation from sediment transport in rivers

Measuring sediment flux in rivers remains a significant problem in studies of landscape evolution. Recent studies suggest that observations of seismic noise near rivers can help provide such measurements, but the lack of models linking observed seismic quantities to sediment flux has prevented the method from being used. Here, we develop a forward model to describe the seismic noise induced by the transport of sediment in rivers. The model provides an expression for the power spectral density (PSD) of the Rayleigh waves generated by impulsive impacts from saltating particles which scales linearly with the number of particles of a given size and the square of the linear momentum. After incorporating expressions for the impact velocity and rate of impacts for fluvially transported sediment, we observe that the seismic noise PSD is strongly dependent on the sediment size, such that good constraints on grain size distribution are needed for reliable estimates of sediment flux based on seismic noise observations. The model predictions for the PSD are consistent with recent measurements and, based on these data, a first attempt at inverting seismic noise for the sediment flux is provided

Kinematics and control algorithm development and simulation for a redundant two-arm robotic manipulator system

An efficient approach to cartesian motion and force control of a 7 degree of freedom (DOF) manipulator is presented. It is based on extending the active stiffness controller to the 7 DOF case in general and use of an efficient version of the gradient projection technique for solving the inverse kinematics problem. Cooperative control is achieved through appropriate configuration of individual manipulator controllers. In addition, other aspects of trajectory generation using standard techniques are integrated into the controller. The method is then applied to a specific manipulator of interest (Robotics Research T-710). Simulation of the kinematics, dynamics, and control are provided in the context of several scenarios: one pertaining to a noncontact pick and place operation; one relating to contour following where contact is made between the manipulator and environment; and one pertaining to cooperative control

High mobility n-channel organic field-effect transistors based on soluble C60 and C70 fullerene derivatives

We report on n-channel organic field-effect transistors (OFETs) based on the solution processable methanofullerenes [6,6]-phenyl-C61-butyric acid ester ([60]PCBM) and [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM). Despite the fact that both derivatives form glassy films when processed from solution, their electron mobilities are high and on the order of 0.21 cm2/V s and 0.1 cm2/V s, for [60]PCBM and [70]PCBM, respectively. Although the derived mobility of [60]PCBM is comparable to the best values reported in the literature, the electron mobility of [70]PCBM is the highest value reported to date for any C70 based molecule. We note that this is the only report in which C60 and C70 methanofullerenes exhibit comparable electron mobilities. The present findings could have significant implications in the area of large-area organic electronics and organic photovoltaics where C60 derivatives have so far been the most widely used electron acceptor materials.