A Variable Approach-Angle Moldboard Plow

A moldboard plow was modified such that the ap-proach-angle of the bottoms could be varied and held at a given angle by a hydraulic cylinder. Field tests of this plow verified that good plowing performance could be obtained at high travel speeds when the bottoms were operated at an approach-angle less than the design approach-angle

Method and apparatus for controlling the approach angle of a plow unit in response to speed variations

A moldboard plow implement includes an elongated tool bar and several moldboard plow units, each plow unit including a plow bottom and a plow bottom support frame connected to the tool bar for pivotal movement about a pivot axis situated in vertical alignment with the point of the respective plow bottom. The plow units are pivotally moved in unison in response to the plowing speed to maintain the specific plow resistance constant for all tractor speeds

Cluster model of polarization upon reflection from metallic surfaces

Polarization of light due to metallic reflection is at best only partially explained by current models. A new model is proposed to account for this phenomenon involving "native clusters". These clusters are assumed to be an integral part of metallic bulk surfaces and to manifest their dielectric properties in the visible region. As index of refraction may be computed based on a pseudo-Brewster angle, that angle of incidence where the minimum perpendicular reflectance occurs. Next the model identifies the cluster-to-bulk surface area ratio of the material and formulates the contribution of reflection from these areas by utilizing the Fresnel equations. Reflectance from the remainder, the bulk-surface area, is computed by applying conventional metallic reflection techniques. By combining the two contributions of reflectance for angles of incidence from 0 to 90 degrees, reflectance curves are generated for gold, silver, nickel and aluminum. These calculations assume a wide-band radiating source of light. Although the magnitude of reflectance for the model showed some variance over the range of angles of incidence (within 10%), the curves are similar in shape. The minimum perpendicular reflectance and grazing angles in incidence are consistent with experimental findings. The computer surface ratio for each metal varies indirectly with the metals' normal reflectance value, as expected from the model. Spectral information on the complex index of refraction is included to infer probable cluster size.http://archive.org/details/clustermodelofpo00baldLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Editorial: Vision zero: the safe system approach and traffic safety culture

According to the World Health Organization, in 2018, traffic crashes killed over 1.35 million people (WHO, 2018). While some nations have seen declining trends in traffic fatalities post-COVID-19, for many nations, especially the United States, traffic fatalities continue to grow at an alarming rate. This rise is especially problematic for the most vulnerable, as pedestrians and bicyclists continue to be killed at disproportionate rates in many countries (ITF, 2022). Thus, for much of the world, a new traffic safety management paradigm is needed