Efekti HS-3 i HS-6 na kardiovaskularne promene izazvane somanom u pacova

The effects of HS-3 and HS-6 on cardiovascular changes due to poisoning with the LD50 of soman were studied in anaesthetized rats. Both HS-3 and HS-6 were found to antagonize the changes in arterial blood pressure and heart rate. HS-3 was more effective than HS-6 in neutralizing the changes in cardiovascular performance induced by the central action of soman. The two oximes produced an antagonistic effect on some abnormalities in the electrocardiogram caused by soman. The primary haemodynamic effect of soman and its antidotes reflected itself on peripheral vascular resistance, the alteration in cardiac output being secondary, in the course of the homeostatic control of arterial pressure.Dejstvo HS-3 i HS-6 na kardiovaskularne promene izazvane sa LD50 somana ispitivana je u anestetisanih, veštački ventilisanih pacova. Rezultati ovih istraživanja upućuju na to da i HS-3 i HS-6 smanjuju pramene arterijskih pritisaka u pacova tretiranih somanom te da je HS-3 efikasniji od HS-6 u neutralisanju promena u funkciji kardiovaskularnog sistema koje su izazvane centralnim dejstvom somana. HS-3 i HS-6 pokazuju antagonistički efekat na neke poremećaje u EKG-u do kojih dolazi kod trovanja somanom. Primarni hemodinamski efekat somana i njegovih antidota je na perifernom sudovnom otporu, dok su promene u minutnom volumenu srca sekundarne i deo su homeostatske kontrole krvnog pritiska

The influence of service solutions on longitudinal and circumferential tensile properties of glass-polyester composite pipes

Traditionally used metals and alloys as constructive materials in process equipment can nowadays be successfully replaced in many cases by non-metallic composite materials. The influence of service solutions on the state of stress and tensile properties in longitudinal and circumferential direction of glass-polyester pipes is studied in this paper. These analyses are of great importance for the use of examined pipes in chemical industry. The pipes were produced by Corporation “Poliester” Priboj. The influence of two solutions, methanol and ammonia, was studied. The samples were treated in solutions for three, seven and ten days. After that, the samples were subjected to tensile testing by the standard procedure. The stresses and strengths were determined in longitudinal direction (testing on flat test specimens) and in circumferential direction (ring test). The analysis of test results, according to the type of solution and period of exposure, was done in comparison with the results obtained by virgin pipes testing (without the influence of the solution). Micromechanical analysis on broken samples helped to determine the influence of the solution on the structure of composite pipe and to find out the models and mechanisms which produced decrease of strength.Композиційні матеріали – перспективні замінники металів та сплавів, які традиційно використовують для виготовлення технологічного обладнання хімічної промисловості. Вивчено вплив розчинів метанолу та аміаку на напруження та механічні властивості склополіефірних труб за їх розтягу в поздовжньому та круговому напрямках. Плоскі та кільцеподібні зразки вирізали із труб та випробовували на розтяг за стандартною методикою. Одержані результати порівнювали з даними для труб у вихідному стані. За допомогою мікромеханічного аналізу зруйнованих зразків встановлено характер впливу розчинів на структуру композиційної труби. Розкрито особливості механізму зниження її міцності.Композиционные материалы – перспективные заменители металлов и сплавов, которые традиционно используют для изготовления технологического оборудования химической промышленности. Изучено влияние растворов метанола и аммиака на напряжение и механические свойства стеклополиэфирных труб при их растяжении в продольном и круговом направлениях. Плоские и кольцевидные образцы вырезали из труб и испытывали на растяжение по стандартной методике. Полученные результаты сравнивали с данными для труб в исходном состоянии. С помощью микромеханического анализа разрушенных образцов установлен характер влияния растворов на структуру композиционной трубы. Раскрыты особенности механизма снижения ее прочности

Low-temperature tension properties of glass-epoxy composite materials

Predmet i cilj ispitivanja prikazanih u ovom radu predstavlja određivanje zatezne čvrstoće (Rm) i modula elastičnosti (EJ staklo-epoksi kompozitnih materijala ispitivanjem na zatezanje na dve različite temperature (t=20°S i t=-50°S). Ispitivanja su izvedena prema standardu na staklo-epoksi kompozitnom materijalu različitih struktura (dve specifične težine ojačanja 210 g/m2H 550 g/m2) i orijentacija ojačanja (0°/90° i ±45°). Doprinos predstavlja i mikromehanička analiza na prelomnim površinama izvedena na stereo i elektronskom mikroskopu kojom se došlo do stvarnih modela nastanka i razvoja oštećenja pri izvedenim ispitivanjima.The aim of this paper was to present the determination of tensile strength Rm and modulus of elasticity Et of glass-epoxy composites at two different temperatures (at room temperature t=20°C, and at t =-50°C). Standard mechanical testing was carried out on glass woven-epoxy composite material with different structures (two specific weights of reinforcement, 210 g/m2 and 550 g/m2) and orientations (0°/90° and ±45°). Micromechanical analysis of failure was performed on a stereo microscope and SEM in order to determine real models and mechanisms of crack

Structural, Mechanical, and Barrier Properties of the Polyvinylidene Fluoride-Bacterial Nanocellulose-Based Hybrid Composite

This study presents an analysis of films which consist of two layers; one layer is PVDF as the matrix, along with fillers BaTiO3 (BT), and the second is one bacterial nanocellulose (BNC) filled with Fe3O4. The mass fraction of BT in PVDF was 5%, and the samples were differentiated based on the duration of the mechanical activation of BT. This innovative PVDF laminate polymer with environmentally friendly fillers aligns with the concept of circular usage, resulting in a reduction in plastic content and potential improvement of the piezoelectric properties of the entire composite. This work presents new, multifunctional “green” packaging materials that potentially could be a good alternative to specific popular materials used for this purpose. The synthesis of the films was carried out using the hot press method. Tensile tests, water vapor permeability examination, and structural analyses using SEM-EDS and FTIR have been conducted. The sample PVDF/BT20/BNC/Fe3O4 exhibited the best barrier properties (impermeability to water vapor), while the highest tensile strength and toughness were exhibited by the PVDF/BT5/BNC/Fe3O4 sample

Efekti HS-3 i HS-6 na kardiovaskularne promene izazvane somanom u pacova

The effects of HS-3 and HS-6 on cardiovascular changes due to poisoning with the LD50 of soman were studied in anaesthetized rats. Both HS-3 and HS-6 were found to antagonize the changes in arterial blood pressure and heart rate. HS-3 was more effective than HS-6 in neutralizing the changes in cardiovascular performance induced by the central action of soman. The two oximes produced an antagonistic effect on some abnormalities in the electrocardiogram caused by soman. The primary haemodynamic effect of soman and its antidotes reflected itself on peripheral vascular resistance, the alteration in cardiac output being secondary, in the course of the homeostatic control of arterial pressure.Dejstvo HS-3 i HS-6 na kardiovaskularne promene izazvane sa LD50 somana ispitivana je u anestetisanih, veštački ventilisanih pacova. Rezultati ovih istraživanja upućuju na to da i HS-3 i HS-6 smanjuju pramene arterijskih pritisaka u pacova tretiranih somanom te da je HS-3 efikasniji od HS-6 u neutralisanju promena u funkciji kardiovaskularnog sistema koje su izazvane centralnim dejstvom somana. HS-3 i HS-6 pokazuju antagonistički efekat na neke poremećaje u EKG-u do kojih dolazi kod trovanja somanom. Primarni hemodinamski efekat somana i njegovih antidota je na perifernom sudovnom otporu, dok su promene u minutnom volumenu srca sekundarne i deo su homeostatske kontrole krvnog pritiska

The interlaminar strength of the glass fiber polyester composite

The paper outlines the method and the results of the experimental investigation of interlaminar strength of glass fibre reinforced polyester composites, with the aim of determining the influence that the structure, a reinforcement type and a sort of resin exert upon the interlaminar strength. The tested specimens were fabricated under different formation conditions, namely in eight composition patterns and with three sorts of resin used for polymerization

Far infrared study of some rare earth impurities crystals of Pb1-xSnx alloys

Single crystal samples of Pb0.9Sn0.1Te doped with Yb, Sm or Gd were produced using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for highly polished samples with various impurity concentration (between 0.2 at% and 1 at%). The experimental diagrams were numerically analyzed using a fitting procedure based on the plasma-phonon interaction model and the optical parameters were determined. The application of lead-tin tellurides doped with rare earth elements for infrared astronomy has been discussed