Prediction of the Strength of Oakwood Adhesive Joints Bonded with Thermoplastic Polyvinyl Acetate Adhesives

Among the several kinds of thermoplastic adhesives, structured and non-structured polyvinyl acetate (PVA) adhesives have a rather wide application and are used currently for forming adhesive joints from different wood species, especially oakwood. To ensure proper conditions of oakwood adhesive joints use, it is important to have fast and accurate methods of predicting their strength and durability. The strength changes of the oakwood adhesive joints bonded with structured and non-structured PVA adhesives have been investigated by conducting long-term experiments.

Influence of Accumulated Damage on the Experimental Resource of the Boiler Unit Drum of the Thermal Power Plant

Goal of the work is to develop a methodology for researching the possibility of further exploitation of drums of boiler units of thermal power plants after exhausting their park resource. Significance.

Effect of Borosilicate Glass Wastes and Synthetic Silica on Cement Products Properties

This paper presents the findings of research study on the effect of borosilicate glass wastes on properties of cement paste and mortar. The borosilicate glass contains three times less alkali than soda-lime glass and about 12 % of boron oxide, so pozzolanic activity of borosilicate glass is three times higher compared to soda-lime glass. In order to increase the pozzolanic activity of glass precipitated synthetic silica was used. Mathematical models were used in order to test the effect of synthetic silica on pozzolanic activity of borosilicate glass.

Modeling of “combined cutter - cone” connection in tricone drill bits

A theoretical analysis of the stiffness of the “cutter-cone” connection was performed. In the article the character and magnitude of the tension at the contact of "cutter-cone" are investigated. An analysis of the surface of the openings for carbide inserts revealed traces of plastic deformation and fretting wear.

Іnfluence of Fatigue Crack Growth Resistance Characteristics of Wheel Steels With Nitride Strengthening on Their Damage Resistance Under Contact Fatigue

The relationship between spalling formation on model wheels tread surface and cyclic fracture toughness of steels with nitride strengthening is study. It is shown that the nitride strengthening of wheel steels has a positive influence on damage resistance of surface rolling of model wheels. To improve the serviceability of wheel steels with nitride strengthening indicated the need to optimize their chemical composition providing content of carbon in the range of 0.50...0.55 %, vanadium — 0.08...0.12 % and nitrogen — 0,008...0,015 %.

Interrelated processes of local electric field amplification in solid dielectrics, contributing to their degradation

The complex processes of local disturbance of an electric field, as well as the amplification of electrical strength and mechanical and thermal intensities in the solid dielectric, depending on the configuration of its conducting micro-inclusions are described.

Технологічні особливості отримання пористих матеріалів на основі уламків скла та природної сировини

Розроблено шихтові склади силікатних мас системи скло – глина – цеоліт –
органічна водорозчинна добавка. Проведено випал зразків за швидкісним режимом за
температури 850–1000 °С з витримкою за максимальної температури 20, 25, 30 хв.
Досліджено вплив вмісту органічної добавки на міцнісні показники сформованих
гранул та її роль на процес поризування. Досліджено вплив часу витримки за
температури 1000 °С на формування пористої структури досліджуваних зразків.