Model of "pump aggregate - pipeline" system with controled driving match on diagnostic requirements

Przedmiotem pracy jest konstrukcja modelu systemu "zespół pompowy - przewód" składającego się z przemiennika częstotliwości, silnika napędowego, pompy oraz rurociągu. Idea pracy systemu opiera się na stabilizacji ciśnienia tłoczenia wody w rurociągu poprzez częstotliwościową regulację prędkości silnika napędzającego pompę tłoczącą. W pracy przedstawiono topologię systemu oraz jego opis analityczny, który zostanie wykorzystany jako model diagnostyczny w dalszych badaniach. Układ opisano wykorzystując modelowanie matematyczne, modelowanie neuronowe oraz charakterystyki statyczne. Szczególną uwagę zwrócono na dobór modelu neuronowego - porównując uzyskane z niego wyniki z danymi pomiarowymi.The aim of the paper is construction of "pump aggregate - pipeline" system model consists of frequency converter, driving motor, pumps and pipeline. Idea of system's work is based on pressure stabilization in pipeline through frequency control of speed of motor which drives the pump. The paper presents the topology of analysed system and its analytical description which will be taken advantage as diagnostic model in farthest research. The system is described through using mathematical modeling, neuron modeling and static characteristics. There was payed the special attention on selection of neuron model comparing received results to measuring data

Computer simulations of pumps drive system during additional induction motor connecting

The problem of suitable water pump drive system selection step forward in many water pump stations. It should be a compromise among the price of drive and the best technical parameters. The most imortant technical parameter for water receiver is pressure. It should be constant. The paper presents results of computer simulations of pump drive system during adding the second induction motor supply from power network. There is shown the matemathical model of PWM inverter, induction motor and the characteristic of pump. The pump drive system consists of two induction motors - one supply from PWM inverter, the second from power network. The second induction motor is connected when demand for water is higher than delivery of a pump fed by the controled motor

Diurnal and seasonal DOC and POC variability in the land-locked sea

Organic matter is a minor yet important component of the marine environment. The aim of this study was to investigate the diurnal and seasonal changes in dissolved and particulate organic carbon (DOC and POC, respectively). Thus, DOC and POC as well as chlorophyll a (Chl a), δ13C, NO3−, NO2−, NH4+, PO43−, salinity, pH, and temperature were regularly measured in samples collected for 24 h (2-h resolution) in the Gdańsk Deep (54°44.730′N, 19°08.531′E) at three water depths (1, 10, and 40 m) during sampling campaigns in 2011 (May), 2014 (May), and 2015 (January, March, May, July, September, November). Seasonal variations in DOC and POC followed the seasonality of Chl a (proportional trend) and nutrients (reverse trend) concentrations. Diurnal oscillations were detected in six out of the eight measurement series. The strongest diurnal variability in both POC and DOC occurred in May 2011 and March 2015, when phytoplankton activity was highest (high Chl a). The surprisingly low δ13C values (range: −28‰ to −24‰) measured over the course of the study revealed the gaps in our knowledge of the isotopic characteristics of terrestrial- vs. marine-derived particulate organic matter

Tarcie i zużycie z nanocząstkami WS2 w warunkach smarowania mieszanego i granicznego

The mixture of Inorganic Fullerene-like (IF) WS2 and Graphene-like nanoparticles were tested under mixed and boundary lubrication in air. The mixture of nanoparticles was synthesized by chemical vapor condensation (CVC) by the pyrolysis of W(CO)6 carbonyls. The synthesized nanoparticles were not found to give an ultra-low friction coefficient compared to hexagonal 2H-WS2 nanoparticles made by special rolling-milling technique. However, under the conditions of our experiments using contact loads of 300-900N and sliding velocity 0.44m/sec it is found that all nanoparticles can dramatically improve the anti-wear properties of the base oil. Additionally, an unusual friction behavior was found for nanoparticle suspension applied in step-load tests. A sharp drop of friction coefficient (up to 0.015) was registered at the normal load increase while usually friction coefficient sharp increase (up to 0.025) occurs for oil lubrication case. The nanoparticles and the interface were investigated using High Resolution TEM, SEM, XRD and surface analyses (XPS) on the wear tracks. The WS2 graphene-like nanoparticles were found to present in amorphous-crystalline mixture. The WS2 films were generated at the interface. Shear-induced reorientation of the graphene-like nanoparticles at the increase of contact stress assured low friction and unusual friction behaviour as compared to those of oil lubrication.Badano mieszaninę nieorganicznych cząstek fullerenopodobnych (IF) WS2 i grafenopodobnych w warunkach smarowania mieszanego i granicznego w powietrzu. Mieszaninę nanocząstek syntetyzowano w drodze skraplania pary chemicznej (CVC) przez pirolizę karbonylów W(CO)6. Nie stwierdzono, by zsyntetyzowane nanocząstki dawały bardzo niski współczynnik tarcia w porównaniu z sześciokątnymi nanocząstkami 2H-WS2 sporządzonymi specjalną techniką walcowania-mielenia. Jednakże, w warunkach naszych doświadczeń z zastosowaniem obciążeń stykowych 300-900 N i prędkości poślizgu 0,44 m/sek okazuje się, że wszystkie nanocząstki mogą znacznie poprawić przeciwzużyciowe własności oleju bazowego. Ponadto, stwierdzono niezwykłe zachowanie tarciowe dla zawiesiny nanocząstek stosowanej w próbach obciążania krokowego. Duży spadek współczynnika tarcia (do 0,015) zanotowano przy normalnym wzroście obciążenia, gdy tymczasem w przypadku smarowania olejem zwykle zdarza się duży wzrost współczynnika tarcia (do 0,025). Nanocząstki i powierzchnię styku poddano badaniu za pomocą TEM, SEM, XRD o wysokiej rozdzielczości i w drodze analizy powierzchniowej (XPS) na śladach zużycia. Stwierdzono obecność grafenopodobnych nanocząstek WS2 w mieszaninie amorficzno-krystalicznej. Na powierzchni styku tworzyły się filmy WS2. Spowodowana ścinaniem reorientacja nanocząstek grafenopodobnych przy wzroście naprężenia stykowego zapewniła niskie tarcie i niezwykłe zachowanie tarciowe w porównaniu ze smarowaniem olejowym

Seasonal-dependent variations in metabolic status of spermatozoa and antioxidant enzyme activity in the reproductive tract fluids of wild boar/domestic pig hybrids

This study investigated seasonal changes in the metabolic performance of spermatozoa and activity of the antioxidant enzymes in the seminal plasma of three wild boar/domestic pigs (aged 1.5 to 2.5 years) and the activity of the antioxidant enzymes in fluids of the cauda epididymidis and vesicular glands from 16 wild boar/domestic pig hybrids (aged 1 to 3 years). Parameters of the sperm metabolic activity, such as total motility, mitochondrial functions, and measurements of oxygen uptake, ATP content and L-lactate production, were analyzed during the spring-summer and autumn-winter periods. Besides these sperm metabolic parameters, the sperm membrane integrity was also assessed. Total protein content and activity of the antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured in the reproductive tract fluids. There were no marked significant differences (P > 0.05) between the seasonal periods in terms of sperm motility, mitochondrial function and oxygen uptake; however, spermatozoa collected during the autumn-winter period exhibited higher (P < 0.05) ATP content and L-lactate production than those harvested during the spring-summer period. It was found that the vesicular gland fluid exhibited a higher level of SOD activity during the spring-summer period compared with the autumn-winter period. Furthermore, CAT activity in the seminal plasma and vesicular gland fluid was greater during the autumn-winter. Total protein content was significantly higher in the vesicular gland fluid, whereas the cauda epididymidal fluid exhibited greater SOD and GPx activities, irrespective of the seasonal period. The findings of this study confirmed seasonal-related differences in the metabolic performance of spermatozoa and activity of antioxidant enzymes of the reproductive tract of the boar/domestic pig hybrids

Effect of boar ejaculate fraction, extender type and time of storage on quality of spermatozoa

The aim of this study was to investigate the effect the sperm-rich fraction (F1) and the post-F1 fraction (F2) on the quality of boar spermatozoa stored in a liquid state. Ejaculates were collected from three Polish Landrace boars. Each ejaculate fraction was diluted with BTS short-term extender and Safe-Cell Plus (SCP) long-term extender and stored for seven days (D1-D7) at 17°C. Analyses included sperm motility parameters, normal apical ridge (NAR) acrosomes and plasma membrane integrity (PMI). Prior to the dilution of fractions, marked changes (p<0.05) were noted between F1 and F2 in progressive motility (PMOT), velocity average pathway (VAP) and velocity straight line (VCL). After the ejaculate was diluted, the type of fraction and type of extender significantly affected (p<0.05) PMOT, being markedly higher (p<0.05) for F1 extended in BTS. No marked changes (p<0.05) were observed between F1 and F2 extended in SCP for any of the analyzed sperm quality parameters during seven days of storage. Significantly higher (p<0.05) values of sperm quality parameters were noted in F1 compared with F2 for BTS on D7 of storage. The results of the four-way ANOVA analysis indicate that boar, fraction of ejaculate, extender type and day of storage had significant effects on the quality of boar stored spermatozoa. The F1 was characterised by higher quality of spermatozoa during storage in comparison with F2 in the short-term extender. Using the long-term extender containing the proteins allowed for a better application of F2, which could be important for the pig industry