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Application of municipal biosolids to agricultural soil can improve soil quality and improve crop yields. However, runoff or tile leachate from biosolids‐applied fields may contribute to localized eutrophication of surface water. A laboratory experiment was conducted to determine loss potential of nutrients from soils amended with two different biosolids (anaerobically digested and chemically stabilized) relative to loss from a reference soil and to determine response in freshwater microcosms to nutrients lost from soils. Total phosphorus (TP) and total nitrogen (TN) were measured in runoff, and equivalent amounts were added to reference microcosms to determine if aquatic systems would respond similarly to TN and TP loading in bioavailable forms (PO43−, NH4+, NO3−) simulating loading related to inorganic fertilizer application. Nutrient concentrations (TP, TN, PO43−, NH4+, NO3−, and organic P and N) were similar in the runoff from the two biosolids‐amended soils and higher than those in the runoff from the reference soil. Runoff from biosolids‐amended soils stimulated algal growth and production (chlorophyll a and dissolved oxygen) relative to runoff from reference soil, but the response was weaker than in microcosms receiving equivalent amounts of inorganic N and P. Nutrient runoff from land‐applied biosolids does have potential to increase algal production in receiving waters; however, this experiment suggests receiving waters may absorb a single large nutrient loading event associated with runoff from biosolids‐amended soil without substantial impact. Moreover, the response to N and P in biosolids versus inorganic nutrient additions suggests biosolids may contribute relatively less to eutrophication than inorganic fertilizers, assuming equivalent TN and TP loading to aquatic systems.

Teeth profiles have an important role in the efficient transformation of motion in the precessional transmissions. Multiple precessional gear theory, previously developed, did not take into consideration the influence of the diagram error of the linking mechanism in the processing device for gear wheel on the teeth profile. Functioning under the multiplication regime, these errors have major influence, which can lead to instant blocking of gear and to power losses. With this purpose, a thorough analysis was conducted on the motion development mechanism under multiplication, and on the teeth profile error generating source. On the basis of fundamental theory of multiple precessional gear, previously developed, a new gear with modified teeth profile and the technology for its industrial manufacturing was proposed and patented. The elaboration of the mathematic model of the modified teeth profile is based integrally on the mathematic model of teeth profile, previously developed by the authors. With this purpose it is necessary to present the detailed description of teeth profile without modification and, then, to present of the description of modified profile peculiarities.

The majority planetary precessional transmissions diagrams developed previously operate efficiently in reducer's regime. Teeth profiles have an important role in the efficient transformation of motion in the precessional transmissions that operate as multipliers. Multiple precessional gear theory, previously developed, did not take into consideration the influence of the diagram error of the linking mechanism in the processing device for gear wheel on the teeth profile. Functioning under the multiplication regime, the errors of the linking mechanism have major influence, which can lead to instant blocking of gear and to power losses. With this purpose, a thorough analysis was conducted on the motion development mechanism under multiplication, and on the teeth profile error generating source. This paper describes also the precessional transmission diagrams operate efficiently in multiplier's regime, and cinetostatic analysis of precessional multipliers.

The paper presents a method for obtaining the teeth of the precessional gear by plastic deformation. There are analyzed the basic problems that must be resolved to apply this process: determination of dimensions of initial workpiece; choosing the correct machining regime; determination of necessary forces for material deformation for dimensioning of mechanisms used in machine-tool. The aim is obtaining of precessional gear wheel teeth, still from workpiece to ensure a minimum cost of machining and to improve operating conditions by providing a continuous material fibrillation.

A variety of materials are used in the manufacture of gearwheels. These materials satisfy various working conditions for gears. Such gears are made of metallic materials - ferrous, non-ferrous and from plastic materials. Among ferrous materials the following are used: irons; cast, forged and rolled steels; among non-ferrous materials the following are used: bronze, aluminium alloys, brass, etc., and of plastics the following are used: textolite, polyamide, polyacetal. In the practice of exploitation and in the process of special research it was established that the permissible load, according to teeth contact resistance, is generally determined by the hardness of the material. The highest hardness and respectively, the smallest sizes and reduced mass of the transmission can be obtained in the manufacture of steel gears via thermal treatment. It is obvious that by plastic deformation at cold it cannot be obtained gearwheels with complicated configuration as deformed plastic metal will form cracks caused by low plasticity. To improve processability by plastic deformation the mouldings for gearwheels are heated. With increasing the heating temperature, plasticity increases and resistance to deformation decreases.

The multiplier is an indispensable part of the micro hydropower plant and high power wind turbine. It helps to increase rotor low speeds limited by the water flow small velocity and by the relative big placement diameter of the blades that participate in the energy conversion. For example, the microhydrostation rotor's speed is (2 - 3) min'1 for water flow velocity V= (1...1,6) m/s and for blade placement diameter D = 4 m. Diversity of requirements forwarded by the beneficiaries of mechanical transmissions consists, in particular, in increasing reliability, efficiency and lifting capacity, and in reducing the mass and dimensions. It becomes more and more difficult to satisfy the mentioned demands by partial updating of traditional transmissions. The target problem can be solved with special effects by developing new types of multipliers based on precessional planetary transmissions with multiple gear, that were developed by the authors. Absolute multiplicity of precessional gear (up to 100% pairs of teeth simultaneously involved in gearing, compared to 5%-7% - in classical gearings) provides increased lifting capacity and small mass and dimensions. To mention that until now precessional planetary transmissions have been researched and applied mainly in reducers. Therefore it was necessary to carry out theoretical research to determine the geometrical parameters of the precessional gear that operates in multiplier mode. Also, it was necessary to develop new conceptual diagrams of precessional transmissions that function under multiplier regime. The majority of precessional planetary transmissions diagrams developed previously operate efficiently in reducer's regime. Depending on the structural diagram, precessional transmissions fall into two main types - K-H-V and 2K-H, from which a wide range of constructive solutions with wide kinematical and functional options that operate in multiplier regime.