The Effects of Total Dissolved Solids on Locomotory Behavior and Body Weight of Streamside Salamanders, and a Baseline Survey of Salamander Diversity and Abundance

Increased levels of total dissolved solids (TDS) in stream habitats are of concern due to salinity as well as the presence of potentially toxic ions. Natural gas drilling in the Marcellus shale could increase TDS in nearby streams. This thesis investigated the effects of water with elevated TDS on the locomotory activity and body weight of the streamside salamander Desmognathus ochrophaeus. Salamanders were exposed to water collected from streams in southwest Pennsylvania with elevated TDS as well as synthetic ion solutions that mimicked the ionic composition found in streams. Chronic, but not acute exposure to solutions of 1000 ppm TDS caused significant differences in weight loss and locomotory activity, although the effect depended on the exact ion composition of the dissolved solids. Finally, field surveys of salamander abundance were completed on two streams to provide baseline data with which to track population changes should the TDS in the streams increase

Design Optimization of Slider-Crank Mechanisms Subject to Coulomb Bearing Friction

Optimization techniques are applied to the design of slider-crank mechanisms operating as single acting compressors subject to Coulomb bear ing friction. The dynamic force analysis is performed by the solution of a set of nonlinear equations in dimensionless form. The optimization re sults presented are for various cases of inertia, friction, and external loading. The optimization procedure developed minimizes a weighted sum of the input work and bearing shear stress by adjusting the mechanism\u27s dimensions. The independent dimensions that are varied are the connecting rod length, the offset, and the three bearing radii. The results of the optimization are different optimum slider-crank linkage configurations, where each link age minimizes a different level of the work-stress combination. This optimization procedure can be useful in the design of slider- crank mechanisms employed in compressors. Further, the method can be ex panded to other mechanism types and loading forms

Exposure of farm workers to electromagnetic radiation from cellular network radio base stations situated on rural agricultural land

The electromagnetic field (EMF) levels generated by mobile telephone radio base stations (RBS) situated on rural-agricultural lands were assessed in order to evaluate the exposure of farm workers in the surrounding area. The expected EMF at various distances from a mobile telephone RBS was calculated using an ad hoc numerical forecast model. Subsequently, the electric fields around some RBS on agricultural lands were measured, in order to obtain a good approximation of the effective conditions at the investigated sites. The viability of this study was tested according to the Italian Regulations concerning general and occupational public exposure to time-varying EMFs. The calculated E-field values were obtained with the RBS working constantly at full power, but during the in situ measurements the actual power emitted by RBS antennas was lower than the maximum level, and the E-field values actually registered were much lower than the calculated values

Hierarchization of the Italian region on the strength of the agricultural mechanization through clustering analysis

The aim of this paper has been to study the organization of the Italian agricultural enterprises through a cluster analysis. Starting from statistical data, the Italian Regions were then classified into homogeneous groups in proportion with the size of the farms, their agricultural mechanization level and the manpower employment. The suitability of this arrangement was supported by the variability among the groups, which was greater than that within the groups. Generally each group is formed both by adjacent and non-adjacent Regions and also by Regions geographically distant. A concise but clear picture pertaining the different structure of Italian farms were was pointed out

The theory of sifting the soil mass when cleaning potatoes on a spiral separator

The removal of soil and impurities is an important problem when harvesting potatoes. and the main reason for this problem is due to the modalities employed to carry out the potatoes mechanical harvesting. The equipments currently implemented on potato harvesters do not always allow to obtain high levels of soil and impurities separation, mainly due to the gluing of the moist soil to the surfaces of the separating organs. The authors have developed a spiral separator of soil clods from potatoes heaps, patented in Ukraine. The purpose of this paper has been to analyze the theory of sifting the soil mass when a spiral separator is used. A mathematical model of the motion of an elementary body along the spiral surface of a potato heap separator has been built. The numerical solution of the model has highlighted that the lowest angular speed (10 rad s-1) of the cleaning rollers allows the greatest amount of sifted soil mass. Field tests carried out confirmed that the developed spiral separator is able to perform the task achieving meaningful values of the efficiency of separation and heap purity. Further field and laboratory tests will be executed in order to improve the set up mathematical model