Исследование возможностей оценки состояния структуры металла трубопроводов, находившихся в эксплуатации, ультразвуковым методом

Results of the first stage of ultrasonic researches of structure of metal of pipelines of the thermal power stations which are taking place in operation are submitted. Metal of marks of steel was exposed to tests: 15Х1М1ФИ and the St. 20 with a various operating time (time of operation). Samples of metal were exposed metallographic to the analysis, on the basis of given which (medium-sized grains , dispersions of distribution lnD — σD) theoretical calculation of parameters OUSE of pulses of a bottom signal in metal is carried out. The quantitative data on influence of thickness of a layer of a contact liquid between the probe and object of the control on working frequencies 5,0, 7,5 and 10 MHz for various medium-sized values of a grain of metal are received. Examples of settlement and experimental pulses and spectra of signals for frequency 5 MHz are given.

Oleamide, a Bioactive Compound, Unwittingly Introduced into the Human Body through Some Plastic Food/Beverages and Medicine Containers

The purpose of the study was to investigate the migration of oleamide, a polymer lubricant, and a bioactive compound, from various plastic, marketed containers for food/beverages and medicines into polymer contact liquid. Methanol, food/medicine simulants or real samples were used to extract polymer leachables and extractables. Migrated oleamide into polymer contact liquids was determined by ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS). The concentration of oleamide in the extracts of medicinal and insulin syringes was 7351 ng mL−1 and 21,984 ng mL−1, respectively. The leachates of intravenous (i.v.) infusion bottle, medicinal and insulin syringes contained 17 ng mL−1, 12 ng mL−1 and 152 ng mL−1, respectively. Oleamide in the extracts of dummies ranged from 30 to 39 ng mL−1, while in the leachates of baby bottles, from 12 to 23 ng mL−1. Leachates of soft drink bottles contained from 6 to 15 ng mL−1 oleamide, milk bottles from 3 to 9 ng mL−1, liquid yogurt bottles 17 ng mL−1 and water bottles from 11 to 18 ng mL−1. Bottled real matrices of oil and milk contained oleamide in the range from 217 to 293 ng mL−1. Moreover, the source of migrated oleamide (e.g., containers, caps, other parts) was identified. Oleamide is listed in the current EU regulations without a specific migration limit. Accordingly, these values are considered of no concern, unless future toxicological studies prove the opposite.

MATHEMATICAL MODELING OF THE THERMODYNAMIC PROCESS GAS-STEAM BUBBLES

A mathematical model that considers the inertial oscillations and thermodynamic components bubbles in liquid heat exchange processes, heat transfer on the boundary bubbles. Research of the dynamic characteristics of gas-steam bubbles in various size was conducted. After the calculations its temperature, velocity, pressure steam environment inside the bubble in time, graphs bubbles size change graphs were built . It is established that each bubble size has its oscillation frequency. Calculated speed phase transients and found that it is in its maximum during the bubble oscillation. For thermodynamic properties of the surface of contact liquid and gaseous phases defined amount of solid phase formed. The research results can be applied to optimize various of technological processes related to the boil, swelling materials, and the formation of gas hydrates in a fluid cavitation.