44 research outputs found
HEAVY DISC HARROW TESTING WITH INTEGRATED TRANSPORT TRAIN FOR TRACTORS OF 80 - 100 HP
Heavy-disc harrow with integrated GDG-2.7M transport train is intended for carrying out the work of harrowing stubble on medium and heavy light soils located on lands with a maximum slope of 22 °, as well as for discussing bulky and dry plows, in the framework for the preparation of the germinating bed for sowing. Depending on the specificity of the work performed and the working conditions (plowing quality, humidity and soil type), the GDG-2.7M heavy disc harrow can also be used in aggregate with other ground grinding machines (soiled or adjustable harrows, staples or rollers). The paper presents the test methodology of the GDG-2.7M disc harrow
ETHODOLOGY FOR ESTIMATING FUEL CONSUMPTION AND PRODUCTION NORMS (WORKING CAPACITY) BY POWER CLASSES, DEPENDING ON THE AGRICULTURAL WORK IN HILLY AREAS
The paper presents the results of researches conducted for determining a frame methodology for estimating fuel consumption and production norms, at national level, depending on the existing power sources, their power classes correlated with the existing surfaces at farmers and the agricultural works that need to be conducted in hilly areas in Romania, for the works of ploughing, harrowing and preparing the seedbed with rotating harrows.
EXPERIMENTAL RESEARCH ON ENERGY AND OPERATING PARAMETERS OF THE TILLER M7.5 + REVERSIBLE PLOW PR1 AGGREGATE
This paper shows some information about the experimental research made todetermine the operating parameters of an aggregate which consists of a 7.5 hp tiller, symbolized M7,5 and a reversible plow with a band, symbolized PR1. The researches were carried out in real working conditions, the ultimate goal being to promote the marketing of the mentioned machine. To achieve optimal conditions for growing plants in general, and vegetables particularly in small farms and individual households, a good quality plowing it’s essential. This work can be realized with smaller equipment and addequate working capacities such as tillers in aggregate with technical working equipments, these being the ideal solution to meet the needs of small farmers
Study of pulsatile pressure-driven electroosmotic flows through an elliptic cylindrical microchannel with the Navier slip condition
This paper aims to study an unsteady electric field-driven and pulsatile pressure-driven flow of a Newtonian fluid in an elliptic cylindrical microchannel with Navier boundary wall slip. The governing equations of the slip flow and distributions of electric potential and charge densities are the modified Navier-Stokes equations, the Poisson equation and the Nernst-Planck equations, respectively. Analytical and numerical analyses based on the Mathieu and modified Mathieu equations are performed to investigate the interplaying effects of pulsatile pressure gradients and the slip lengths on the electroosmotic flow
Effects of Functional Groups and Ionization on the Structure of Alkanethiol-Coated Gold Nanoparticles
We
report classical atomistic molecular dynamics simulations of
alkanethiol-coated gold nanoparticles solvated in water and decane,
as well as at water/vapor interfaces. The structure of the coatings
is analyzed as a function of various functional end groups, including
amine and carboxyl groups in various ionization states. We study both
neutral and charged end groups for two different chain lengths (9
and 17 carbons). For the charged end groups, we simulated both mono-
and divalent counterions. For the longer alkanes, we find significant
local bundling of chains on the nanoparticle surface, which results
in highly asymmetric coatings. In general, the charged end groups
attenuate this effect by enhancing the water solubility of the nanoparticles.
On the basis of the coating structures and density profiles, we can
qualitatively infer the overall solubility of the nanoparticles. This
asymmetry in the alkanethiol coatings is likely to have a significant
effect on aggregation behavior. Our simulations elucidate the mechanism
by which modulating the end group charge state can be used to control
coating structure and therefore nanoparticle solubility and aggregation
behavior
Nonsmooth optimization over the (weakly or properly) Pareto set of a linear-quadratic multi-objective control problem: Explicit optimality conditions
We present explicit optimality conditions for a nonsmooth functional dened over the (properly or weakly) Pareto set associated with a multiobjective linear-quadratic control problem. This problem is very dicult even in anite dimensional setting, i.e. when, instead of a control problem, we deal with a mathematical programming problem. Amongst various applications, our problem may be considered as a response for a decision maker when he has to choose a solution over the solution set of the grand coalition p-player cooperative differential game