FATIGUE ASSESSMENT OF SHIP SUPERSTRUCTURE AT EXPANSION JOINT

Despite the long history of application of subdivided superstructures and deckhouses, and efforts of ship designers and researchers a sensible solution in design of reliable details at the cut endings was not found yet. It may be explained as consequence of controversial requirements in design of the cut endings. Fatigue design of the superstructure details is addressed to solution of the problem. Presented is an example of fatigue design of the cut ending in a fast ship superstructure based on application of modified «Strain-Life» criterion for fatigue and subsequent approach which utilizes Neuber’s formula and material cyclic properties. To realize the approach a procedure of the long-term stress distribution transformation to the block-type format is developed. Efficiency of the developed technique is illustrated by comparing the results with those of application standard S-N criteria based techniques. The results of analysis allowed selection of the expansion joint detail of the superstructure geometry and construction procedure providing necessary reliability.

Changes in Electrical Conductance of Polymer Composites Melts Due to Carbon Nanofiller Particles Migration

In this work, the results of investigation of the effect of polymer composite melts electrical conductance increase with time are presented. The conductance time dependencies were obtained for composites based on polypropylene filled with carbon nanoparticles of different types. The dependencies were analyzed to demonstrate the possibility of correlation of the conductance kinetics with different composite parameters, such as the filler geometry. Additional studies were carried out, such as electron microscopy study, conductance measurements after consecutive surface layer removal, and composite melt conductance measurements using a three-electrode scheme. The results showed that the increased electrical conductance of the composite materials can be attributed to the formation of an enriched with the filler particles surface layer, which happens during the stay of the composite in a melt state. Analysis of the experimental data, along with the results of numerical modeling, allowed to suggest a possible filler distribution transformation scheme. The physical premises behind the investigated effect are discussed.

STUDY ON ENERGY AND PROTEIN DISTRIBUTION FOR EGG MASS PRODUCTION IN GUINEA FOWLS LAYERS USING THE SYSTEM ‘CLARCS OF DISTRIBUTION/TRANSFORMATION’

Aim: To introduce and calculate the energy and crude protein distribution from fodder to the edible part of the egg mass. New indexes “Clarc of energy distribution (CED)” and “Clarc of protein transformation (CPT)” were introduced. Methods: The “Clarc’s” were calculated by using the following formula: CED = Total energy content in the yolk, albumen, mélange/Total metabolizable energy intake for 1 kg yolk, albumen, mélange; CPT = Total (crude) protein content in yolk, albumen, mélange/Total (crude) protein intake for 1 kg yolk, albumen, mélange. Results: CDE to the yolk, albumen, mélange – 0.1492, 0.0399 and 0.1891 respectively; CPT to the yolk, albumen, mélange – 0.1041, 0.113, 0.2771 respectively.