At the Kielce University of Technology a new concept of accurate measurements of sphericity deviations of machine parts has been developed. The concept is based upon measurement of roundness profiles in many clearly defined cross-sections of the workpiece. Measurements are performed with the use of typical radial measuring instrument equipped with a unit allowing accurate positioning of the ball. The developed concept required finding a solution to numerous problems relating to the principle of the radial measurement. One of the problems to be solved was matching of measured roundness profiles. The paper presents an outline of the developed concept of sphericity measurement, a mathematical model of profile matching and results of the verification of the model.
The aim of this research was to assess the content and composition of the pollutants emitted by domestic central heating boilers equipped with an automatic underfeed fuel delivery system for the combustion chamber. The comparative research was conducted. It concerned fuel properties, flue gas parameters, contents of dust (fl y ash) and gaseous substances polluting the air in the flue gases emitted from a domestic CH boiler burning bituminous coal, pellets from coniferous wood, cereal straw, miscanthus, and sunflower husks, coniferous tree bark, and oats and barley grain. The emission factors for dust and gaseous air pollutants were established as they are helpful to assess the contribution of such boilers in the atmospheric air pollution. When assessing the researched boiler, it was found out that despite the development in design and construction, flue gases contained fly ash with a significant EC content, which affected the air quality.
Distillation boundaries originate from saddle azeotropes, dividing the composition space into distillation regions. In heterogeneous mixtures distilled in packed columns, distillation regions overlap. The common area of distillation regions is parametrically sensitive, and it determines the possibilities of crossing (at a finite reflux) the distillation boundaries defined for a total reflux or reboil ratio. This work is an extended research of the paper (Królikowski et al., 2011) conducted to scrutinize whether the distillation regions overlapped in heteroazeotropic systems distilled in staged columns. Presented studies were performed by finding such composition points of the products, for which the rectifying profiles of staged columns were ended in different distillation regions. Calculations were executed for the heterogeneous mixture classified under Serafimov's topological class as 3.1-2: ethanol - benzene - water. Distillation regions for staged columns were found to overlap each other in the heterogeneous systems. As a result, their common part was parametrically sensitive.
The article presents results of comparative tests performed to verify the conformity of geometric deviation measurements of a crankshaft carried out at a test bed equipped with a system of elastic support with measurements adopted as reference values. A number of simulation tests were carried out with varied shaft support conditions using the proposed measuring system. The selection criteria were established for support parameters. Meeting these criteria guarantees that shaft elastic deflections and strains are eliminated. Consequently, such strains will not affect the estimation of geometrical deviations of the measured object. The comparative evaluation measurement of roundness profiles and values of roundness deviations of main crankshaft bearing journals of a marine medium speed engine was performed using a correlation calculus. The results have revealed high conformity of both determined roundness deviation values and measured profiles compared to the reference ones.
The article presents youth expectations towards:
– school, presented by the competences of the eighteen-year-old,
– the world, reflecting the concept of one’s own identity,
– oneself expressing the condition measured by satisfaction with oneself.
The summary tries to answer the question: can the expectations be fulfilled?
Studies in human medicine have shown that in addition to affecting the reproductive system, the hormone estrogen also has cardioprotective effects. The present study hypothesized that ovariohysterectomized (OVH) dogs would have a higher incidence of cardiac dysfunction and impairment of lipid profiles compared to intact female dogs. Thirty healthy female dogs were divided into two groups, 15 intact female dogs and 15 OVH dogs. All the dogs underwent a physical examination, including investigation of physical parameters, blood collection for lipid profile measurement, thoracic radiography, electrocardiography and echocardiography. Physical examination parameters, electrocardiographic parameters, heart size and cardiac function in OVH dogs were not different when compared to intact female dogs. However, in the OVH dogs, triglyceride and very-low-density lipoprotein levels were increased, while high-density lipoprotein was significantly decreased compared to the intact female dogs (P<0.05). Differences between the groups in total cholesterol and low-density lipoprotein did not reach statistical signi- ficance. We concluded that estrogen deprivation in dogs can induce lipid profile impairment but not cardiac performance impairment 1 year after an ovariohysterectomy.
The following analysis investigates selected properties of the language of the tweets used in the interaction with consumers on English and Polish brand profiles. The analysis examines the structure of tweets, word frequency, as well as the frequency of informal and non-standard language items, language mistakes, the use of emoticons and hashtags. The study contrasts the language used by English and Polish representatives and reveals a number of similarities and differences between the corpora. What the corpora share is a high frequency of conventional politeness acts and language structures reflecting a customer-oriented tone of the interaction. Differences are observed in the frequency and use of informal and non-standard structures, emoticons and hashtags, as well as in the structure and complexity of the tweets. The study indicates a lower formulaicity and a greater individualization of the interaction on the Polish profiles.
In this study the quality of total RNA, isolated from fresh spermatozoa, was compared between boars with good and poor semen freezability (GSF and PSF, respectively). Semen from 3 boars with GSF exhibited significantly higher total motility, mitochondrial function, plasma membrane integrity and reduced lipid peroxidation compared with 3 boars with PSF after cryo- preservation. There were variations in the quality of RNA isolated from spermatozoa of boars with GSF and PSF. Boars with GSF exhibited mainly full-length, intact RNA, whereas substantial amounts of degraded RNA were detected in spermatozoa from boars with PSF. Further under- standing of the biological relevance of RNAs in sperm function is critical to improve the freezabil- ity of boar semen.
This paper explores the influence of linear gear tip relief modification on power transmission efficiency. In real time applications gears experience transmission error (TE) during operation which increases noise and vibration and also results in increased tooth profile deformation during operation of the gear. By providing tip relief profile modification this TE can be decreased. Using MATLAB for computation and ANSYS for the simulation of deformation, stress, strain, life, and factor of safety results for the gear assemblies are obtained. Deformation results are used for the computation change in power transmission efficiency followed by the modal and harmonic analysis of the gears and gear assemblies to determine change in the first mode of natural frequency.
This paper investigates the life cycle profiles of income and consumption and relative income mobility in Poland – a transition economy facing rapid structural economic and social changes. According to my results, and in line with the empirical evidence for advanced economies, the age-profiles of average income and consumption in Poland exhibit a hump. The inequality of income over the life cycle is found to flatten relatively quickly in Poland, which contrasts with the approximately linear shape observed in the US. When individual income process is fitted to match the Polish inequality profile, it exhibits less persistence than in the US. Past earnings turn out to affect current income more strongly for the group of more educated individuals. Moreover, and in contrast to the permanent income hypothesis as well as findings for other economies, no evidence of an increase in consumption inequality for households older than 30 years is found. Finally, the obtained estimates of relative income mobility in Poland are higher than those for developed countries.
The impacts of long-term polycyclic aromatic hydrocarbons (PAHs) and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs) analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni), moisture and conductivity than by PAHs.
The velocity field around the standard Rushton turbine was investigated by the Laser Doppler Anemometry (LDA) and Particle Image Velocimetry (PIV) measurements. The mean ensembleaveraged velocity profiles and root mean square values of fluctuations were evaluated at two different regions. The first one was in the discharge stream in the radial direction from the impeller where the radial flow is dominant and it is commonly modelled as a swirling turbulent jet. The validity range of the turbulent jet model was studied. The second evaluated region is under the impeller where flow seems to be at first sight rather rigorous but obtained results show nonnegligible values of fluctuation velocity.
The herein paper contains the results of investigations on a new type of cellulose blend used for the manufacture of profiles applied in the
process of making gating systems in the foundry industry. A standard cellulose profile was subjected to an experiment. During the
experiment the profile was filled with a liquid cast iron and at the same time the temperatures of the liquid metal crystallizing inside the
profile were measured as well as the temperature of the outer layer of the profile was controlled. Further, the microstructure of the cast
iron, which crystallized out inside the cellulose profile, was analysed and the cellulose, thermally degraded after the experiment, was
verified with the use of the chemical analysis method. Moreover, a quality analysis of the original as well as the degraded cellulose profile
was run with the use of the FTIR infrared spectroscopy. The presented results revealed that the cellulose blend is aluminium silicate
enriched and contains organic binder additives. The cast iron, which crystallized out, tended to have an equilibrium pearlitic structure with
the release of graphite and carbides. The generation of disequilibrium ausferrite phases was also observed in the structure.
Root-knot nematodes, genus Meloidogyne, are among the most plant damaging pathogens worldwide. The action of natural products against plant pathogens has been investigated to assess their effectiveness in the control of diseases. Thus, the present study aimed to evaluate the phytochemistry potential of the Ficus species for the control of Meloidogyne javanica. In vitro inhibitory activity assays were performed with crude ethanolic extracts of leaves and branches from 10 Ficus species. Among these, Ficus carica extracts exhibited strong paralysis activity against second stage juveniles (J2) (EC50 = 134.90 μg ∙ ml–1), after 72 hours. In addition, high efficacy was observed in egg-hatching inhibition at different embryonic stages. Microscopy analysis revealed severe morphological alterations in the nematode tissues at the J2 stage, as well as immotility of juveniles released from eggs in the presence of F. carica extracts. The efficacy of the treatments for the other species was very low. These differences were supported by the variation in the compound classes, mainly for alkaloids and metabolite profiles by Gas Chromatography/Mass Spectrometry (GC/MS) when F. carica was compared with the other species. The results indicated that F. carica is a promising source for the isolation and identification of molecules capable of acting in the control of M. javanica.
The ground source of drinking water for the village of Skalice nad Svitavou is located 35 km North of Brno (Czech Republic). An evaluation of developments in selected indicators of water quality in this groundwater source in the period 2013–2017 was the essence of this work. The data was provided by Vodárenská akciová společnost, a.s., i.e. the operator. At the same time, annual monitoring of water quality in the Úmoří stream, which flows through the catchment area and can affect the quality of groundwater, was carried out. Water samples were collected in 2017–2018 from 6 profiles on the Úmoří stream and its two tributaries. Raw water from the groundwater source does not meet the requirements for drinking water in some indicators and needs to be treated. Monitoring of surface water shows that the most problematic indicator is total phosphorus, the concentration of which exceeded limit values on all sampling profiles. The highest values were found in the tributaries, where total phosphorus concentrations exceeded 10 mg∙dm–3. There are 12 municipalities in the area of interest, only two of which have their own sewage treatment plant. It is clear from the results that wastewater in some municipalities is discharged directly into the recipient and is the cause of above-limit concentrations of both phosphorus and nitrogen. Intensively used agricultural land is another major source of pollution. Based on an analysis of sources of pollution, corrective measures have been proposed to improve the quality of surface and groundwater in the area.
The behaviour of energy levels and optical spectra of a charged particle (electron or hole) confined within a potential well of ellipsoidal shape is investigated as a function of the shape-anisotropy parameter. If two energy levels of the same symmetry intersect in a perturbation-theory approximation, they move apart on direct diagonalization of the appropriate Hamiltonian. The intersection of the energy levels leads to a discontinuity of the corresponding dipole-moment matrix element. The discontinuity of matrix elements is not reflected in the behaviour of transition probabilities which are continuous functions of the shape-anisotropy parameter. The profiles of a spectral line emitted or absorbed by an ensemble of ellipsoidally shaped nanoparticles with a Gaussian distribution of size are calculated and discussed.