LABORATORY METHODS OF RESEARCH OF ADHESIVE SYSTEMS

1UKRAINIAN MEDICAL STOMATOLOGICAL ACADEMY, POLTAVA, UKRAINE 2 ABSTRACT The aim of out research was to determine the effectiveness of the sealing property of adhesive systems V and VII generations by studying the depth of curing, water absorption and water solubility of their samples. Materials and methods: The study was performed according to ISO / TS 11405: 2015 at the Central Factory Laboratory of JSC “CTOMA”, Kharkiv, Ukraine, Certificate of Attestation No. 100-062 / 2015 dated 03/04/2015. For the study we used specially prepared laboratory samples which were made in the form of plates from adhesive system “DC Adhesive NF” (Dental Central) of V generation “Single bond Universal” (3M ESPE) of VII generation. А monitor and analyze the results obtained used micrometer MK-25, №4694, №03 / 5321 from 08/18/17; caliper SC-1, No. 267447, No. 03/5322 from 08/18/17; scales AP 210, №112144137, №87027 / 9 from 24.11.2017 Results: According to the results of the investigation the following results were obtained: 1) the average curing depth of V and VII generation of adhesive systems was 4.08mm and 3.51mm respectively at the rate of 2mm; 2) average water absorption: 45.97 μg/mm3 and 30.89 μg/mm3 for V and VII generations respectively; 3) the average water solubility was 6.94 μg / mm3 and 4.17 μg / mm3, respectively. Conclusions: According to the results of our laboratory studies, it can be concluded that adhesive systems of V and VII generations can be used for restoration of lesions of tooth hard tissued. Along with this, it can be recommended to use V generation adhesives in closed defects where direct polymerization should be performed and oral fluid access is minimal. Adhesive sysyems of VII generation can be recommended in such cases as: opened restorations, pregingival areas of teeth, cases where a permanent contact of restorations with oral fluid be found along with the cases of autonomic application of adhesive system.

Rational redistribution of waste of resources. Manufacturing of equipment for cutting machine

Almost all metal at OJSC «Byelorussian Steel Works» – management company of holding «Belarusian Metallurgical Company» includes today a mandatory physical-mechanical tests which allow to estimate the parameters of the raw materials, to know the reasons for loss of strength and determine operational characteristics. In the Central Factory Laboratory (CFL), laboratory of physical and mechanical tests (LPMT) for the preparation of samples of reinforcement equipment is used of knives in the cutting machine SIMA GEL-30 for cutting rebar from the mill 320 rolling shop № 1 with a diameter from 6 to 24 mm. In the drop-hummer shop annually discards off for scrap waste up to 50 knives. Hydraulic shears of drop-hummer shop used knives set of production of OJSC «Kobrin tool plant «SITOMO», made of steel grade 30ХСНВФА, according to the TU14-1-4461. The staff of the Central laboratory LFMI proposed to use waste knives drop-hummer shop for the manufacture of knives for the chopping of the machine SIMA GEL-30. On the basis of the conducted researches the technological scheme was developed for production of knives for the chopping of the machine SIMA GEL-30 cold cutting of reinforcing bar mill 320 the rolling shop № 1.

THE ORGANIZATION OF INTERLABORATORY COLLATING TESTS IN THE CENTRAL FACTORY LABORATORY OF THE OJSC «BSW – MANAGEMENT COMPANY OF HOLDING «BMC»

The testing laboratory is obliged to plan and realize the actions guaranteeing quality of the carried-out tests. The main directions of this work are:• participation in programs of check of qualification (interlaboratory collating tests (ICT); • application of standard samples; • retests, encoded tests, check by other test method; • statistical control methods.But at the same time it is necessary to use and analyze all sources allowing to estimate quality of the carried-out tests. Such sources could be responses of consumers of production; tests, the procedures of certification of production which are carried out in independent laboratory when carrying out; the ICT organized by both the consumer, and testing laboratory.

External quality control of chemical-analytical units of refractory enterprises in 2016

External quality control of the chemical-analytical departments of the central factory laboratories was carried out: PJSC Krasnoarmeysky Dinas Factory, PJSC Chasovoyarsk Refractory Plant, PJSC Velikoanadol Refinery Plant. During the chemical analysis of samples of refractories of the listed enterprises, the analysis methods, equipment and materials described in DSTU 3305(3, 4, 5)—96 (GOST 2642.(3, 4, 5)—97) — gravimetric (SiO2), complexometric (Al2O3), photometric (Fe2O3). As a result of the work carried out, conclusions were drawn up in which the quality of the work of the chemical analytical units of the central factory laboratories of the PJSC “Krasnoarmeysky Dinas Factory”, PJSC “Chasovoyarsk Refractory Plant”, and PJSC “VELIKOANADOL REFRACTORY PLANT” was considered satisfactory.

A New Model for Biologic Constructs: Biotensegrity

Present biologic models envision organisms behave like the character ‘Topsy’ in Gone with the Wind; they “just grew.” Modeled of Lego©-like components, the individual structures are linked together as if they are automobile parts that are manufactured at different plants and assembled at some central factory. For the most part, hexahedral finite element meshes are used to model structures. When tetrahedral modeling is used, no account is made of the different mechanical properties that are inherent in triangulated structures, (trusses), that make the structures behave very differently than hexahedral-based models.