2014 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2014

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Comparative model tests of SDP and CFA pile groups in non-cohesive soil
- Adam Krasiński
- Tomasz Kusio
2014 Pełny tekst Studia Geotechnica et Mechanica
The research topic relates to the subject of deep foundations supported on continuous flight auger (CFA) piles and screw displacement piles (SDP). The authors have decided to conduct model tests of foundations supported on the group of piles mentioned above and also the tests of the same piles working alone. The tests are ongoing in Geotechnical Laboratory of Gdańsk University of Technology. The description of test procedure, interpretation and analysis of the preliminary testing series results are presented in the paper.
Comparison of Average Energy Slope Estimation Formulas for One-dimensional Steady Gradually Varied Flow
- Wojciech Artichowicz
- Patrycja Mikos-Studnicka
2014 Pełny tekst Archives of Hydro-Engineering and Environmental Mechanics
To find the steady flow water surface profile, it is possible to use Bernoulli’s equation, which is a discrete form of the differential energy equation. Such an approach requires the average energy slope between cross-sections to be estimated. In the literature, many methods are proposed for estimating the average energy slope in this case, such as the arithmetic mean, resulting in the standard step method, the harmonic mean and the geometric mean. Also hydraulic averaging by means of conveyance is commonly used. In this study, water surface profiles numerically computed using different formulas for expressing the average slope were compared with exact analytical solutions of the differential energy equation. Maximum relative and mean square errors between numerical and analytical solutions were used as measures of the quality of numerical models. Experiments showed that all methods gave solutions useful for practical engineering purposes. For every method, the numerical solution was very close to the analytical one. However, from the numerical viewpoint, the differences between the methods were significant, as the errors differed up to two orders of magnitude.
COMPARISON OF BLOOD PRESSURE PREDICTION METHODS
- Artur Poliński
- Mariusz Kaczmarek
- Jerzy Wtorek
- Jacek Kot
2014
In the paper dierent approaches of predicting blood pressure values are presented. Basically, two methods and theirs modifications are considered. In total, seven algorithms have been examined. Tests have been conducted using both synthetic and clinical data. From our study it follows that none of the examined methods is superior to other.
Comparison of buckling resistance of columns modelled by beam and shell elements using non-linear analysis
- Łukasz Żmuda-Trzebiatowski
2014
The aim of the paper is to investigate the stability process in the axially compressed columns modelled by beam and shell elements using static and dynamic finite element analysis by taking both the geometric and material non-linearity into account. The perfect columns and columns with geometric imperfections were analysed. The differences between the results of static and dynamic analyses in shell and beam models were discussed.
Comparison of different types of electronic nose instruments for evaluation of odour nuisance from landfill
- Jacek Gębicki
- Tomasz Dymerski
- Jacek Namieśnik
2014
The paper presents and compares the results of investigation on classification of atmospheric air samples collected in a vicinity of municipal landfill with respect to their odour nuisance. The research was conducted using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type – HERACLES II. The prototype was equipped with six semiconductor sensors of TGS type. Classification of the air samples with respect to the place of collection relative to the landfill was performed using quadratic discriminant function (QDA) supported with cross-validation method. More than 80% of the samples were correctly classified employing the analysis with HERACLES II. The prototype of electronic nose provided correct classification of 50% of the samples.
COMPARISON OF HEAT TRANSFER CHARACTERISTICS IN SURFACE COOLING WITH BOILING MICROJETS OF WATER, ETHANOL AND HFE7100
- Dariusz Mikielewicz
- Tomasz Muszyński
2014
The basis of microjet technology is to produce laminar jets which when impinging the surface have a very high kinetic energy at the stagnation point. Boundary layer is not formed in those conditions, while the area of film cooling has a very high turbulence resulting from a very high heat transfer coefficient. Applied technology of jet production can result with the size of jets ranging from 20 to 500μm in breadth and 20 to 100μm in width. Presented data are used in order to validate authors own semi-empirical model of surface cooling by evaporating microjet impingement in the stagnation point. Main objective of this paper was to investigate the physical phenomena occurring on solid surfaces upon impingement of the single microjet in case of three fluids. Intense heat transfer in the impact zone of microjet has been examined and described with precise measurements of thermal and flow conditions of microjets. Reported tests were conducted under steady state conditions for surface cooling by single microjet producing an evaporating film. Obtained database of experimental data with analytical solutions and numerical computer simulation allows the rational design and calculation of microjet modules and optimum performance of these modules for various industrial applications.
Comparison of High Performance Liquid Chromatography Methods with Different Detectors for Determination of Steroid Hormones in Aqueous Matrices
- Katarzyna Kozłowska-Tylingo
- Piotr Konieczka
- Ewelina Gustaw
- Andrzej Wasik
- Jacek Namieśnik
2014 ANALYTICAL LETTERS
This paper presents the development and comparison of procedures for the qualitative and quantitative determination of five estrogenic compounds (17-a-ethynylestradiol, estrone, estradiol, estriol, and progesterone) in drinking water and wastewater samples. Five extraction columns and two disks were tested for their efficiency. The C18 columns were superior on the basis of cost for solid phase extraction of drinking water or sewage. However, the best recoveries were achieved using extraction disks. High-performance liquid chromatography with diode array, fluorescence, and tandem mass spectrometry detectors were compared for selectivity, repeatability, and linearity of response. Solid phase extraction with high-performance liquid chromatography and tandem mass spectrometry was the most sensitive, efficient, and precise for the determination of hormones in drinking water and wastewater. This method satisfied analytical validation criteria and was characterized by a low limit of detection at the pg-ng/L level. The study also considered challenges that emerged for steroidal hormone determination in aqueous samples.
COMPARISON OF INFINITE ELEMENT MODELS
- Arkadiusz Żak
- Magdalena Palacz
- Marek Krawczuk
- Łukasz Doliński
- Łukasz Skarbek
2014
The main objective of this paper is to show the comparison of two models of inﬁnite ab- sorbing layer with increasing damping in numerical investigations of elastic wave prop- agation in unbounded structures. This has been achieved by the Authors by a careful in- vestigation of two different engineering structures characterised by gradually increasing geometrical and mathematical description complexities. The analysis included propaga- tion of longitudinal elastic waves in a 1-D half-inﬁnite isotropic rod, modelled according to the classical 1-mode theory of rods as well as propagation of coupled shear and ﬂexural elastic waves in a 1-D half-inﬁnite isotropic beam modelled according to the Timoshenko beam theory. The comparison of both models has been not only presented by the Authors, but also advantages and disadvantages of both of them have been discussed.
Comparison of new position estimation algorithm for indoor environment
- Agnieszka Czapiewska
- Jarosław Sadowski
2014
In the paper a new position estimation algorithm based on distance measurements is presented. This algorithm is dedicated for indoor environments. In the paper the new algorithm is compared with Chan algorithm. For the comparison were used real measurements conducted inside a building.
Comparison of Quality Evaluation of Agricultural Distillates Using Prototype of Electronic Nose and Fast/Flash GC
- Tomasz Dymerski
- Jacek Gębicki
- Jacek Namieśnik
2014 CHEMICAL ENGINEERING TRANSACTIONS
The paper presents the results of investigation on quality evaluation of agricultural distillates using a prototype of electronic nose instrument and a commercial electronic nose of Fast/Flash GC type – HERACLES II. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co.. In case of the prototype volatile fraction of the agricultural distillate was prepared via barbotage process. HERACLES II analysed the headspace fraction. Classification of the samples into particular quality classes was performed using linear discriminant function supported with cross-validation method. Almost 100 % correct classification of agricultural distillate was observed for the analyses with HERACLES II. The prototype of electronic nose provided correct classification of 70 % of the samples.
Comparison of road and laboratory measurements of tyre/road noise
- Beata Świeczko-Żurek
- Jerzy Ejsmont
- Grzegorz Ronowski
- Stanisław Taryma
2014
Tyre/road noise is one of the major environmental problems related to road traffic. There are several measuring methods of tyre/road noise that may be carried out on the road (for example Coast-down and Close Proximity Method) or in the laboratory (Drum Method). Road measurements are preferred for evaluations of pavement properties while laboratory methods are mostly used to evaluate tyres. One of the biggest problems associated with laboratory methods is to ascertain that tyre interfaces with pavement that has texture, porosity and mechanical impedance the same as with the real road surface. The paper presents results of tests performed by the Close Proximity Method (with test trailer Tiresonic Mk.4) and drum method where very similar or exactly the same surfaces are used. The reported measuring program includes tests performed on an innovative poroelastic road surface called PERS.
Comparison of selected algorithms for scheduling workflow applications with dynamically changing service availability
- Paweł Czarnul
2014 Journal of Zhejiang University-SCIENCE C-Computers & Electronics
This paper compares the quality and execution times of several algorithms for scheduling service based workflow applications with changeable service availability and parameters. A workflow is defined as an acyclic directed graph with nodes corresponding to tasks and edges to dependencies between tasks. For each task, one out of several available services needs to be chosen and scheduled to minimize the workflow execution time and keep the cost of service within the budget. During the execution of a workflow, some services may become unavailable, new ones may appear, and costs and execution times may change with a certain probability. Rescheduling is needed to obtain a better schedule. A solution is proposed on how integer linear programming can be used to solve this problem to obtain optimal solutions for smaller problems or suboptimal solutions for larger ones. It is compared side-by-side with GAIN, divide-and-conquer, and genetic algorithms for various probabilities of service unavailability or change in service parameters. The algorithms are implemented and subsequently tested in a real BeesyCluster environment.
Comparison of Single and Multi-Population Evolutionary Algorithm for Path Planning in Navigation Situation
- Łukasz Kuczkowski
- Roman Śmierzchalski
2014 Solid State Phenomena
In this paper a comparison of single and multi-population evolutionary algorithm is presented. Tested algorithms are used to determine close to optimal ship paths in collision avoidance situation. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of single-population and multi-population evolutionary algorithm is described. Using presented algorithms the simulations on three close to real sea environments were performed. Regardless of the test situation constant time simulation was maintained. Obtained results are presented in graphical form (sequences of successive stages of the simulation) and in form of table in which the values of fitness function for best individual in each simulation were compared. Undertaken research allow to select evolutionary algorithm that, assuming constant simulation time, will determine a better path in close to real collision avoidance situation at sea.
Comparison of the content of phenolic compounds and antioxidant activity of white, red and black currants (Ribes sp.) extracts
- Izabela Koss-Mikołajczyk
- Barbara Kusznierewicz
- Agnieszka Bartoszek-Pączkowska
2014 Camera Separatoria
The aim of this study was to compare the content of antioxidant compounds and the antioxidant activity of extracts from white, red and black currants (Ribes sp.). The chemical properties verified included determinations of anthocyanins and other phenols by HPLC-DAD-MS, total antioxidant activity by standard spectrophotometric tests (ABTS, DPPH and FCR), and profiles of antioxidants by TLC with visualization reagents (ABTS, DPPH, FC) and post- column derivatization with ABTS reagent. The results obtained showed that the studied varieties of Ribes sp. differed mostly in the content of anthocyanins and hence in antioxidant activity. The highest content of phenolic compounds, as well as the highest antioxidant activity exhibited black currant extract, followed by red currant extract and white variety.
COMPARISON OF THE CONVENTIONAL AND ALTERNATIVE GRANULAR MATERIALS FOR DUAL-MEDIA FILTRATION OF GROUNDWATER: PILOT PLANT TESTING
- Jakub Drewnowski
2014
Nowadays, occurrence of abnormal mineral or organic natural (geogenic) compounds concentrations, in ground and infiltration water, but also quite often in surface waters, is now a common problem encountered in Poland, Europe and many other countries throughout the world. The most concern is usually paid on the removal of iron (Fe) and manganese (Mn) as well as anthropogenic compounds (in particular referring to the organic compounds such as nitrogen) associated with human activity. From the 19th century, the main filter media used in rapid gravity filtration have been silica sand and anthracite coal. Sand still remains the preferred filter medium in the lower layer with typically anthracite coal used in the upper layer. This dominance is due to its low cost, availability and extensive experience in water treatment applications, which has led to dependable and predictable performance. Over recent years multi-media filters have become the typical filter arrangement. Furthermore, granular filters can be made of a variety of natural materials. Depending on the origin of these materials they can have very different shapes, sizes and compositions. Granular filter media must satisfy various specifications before they can be considered for applications. These include grain size, grain surface condition, density, particle porosity, solubility, durability, settling rate (Mörgeli and Ives, 1979; Trussell et al., 1980). The aim of this study was to assess and compare the efficiency of the alternative Filtralite MonoMulti with a conventional dual-media filter beds consisting of anthracite coal on top of a silica sand layer. Media with the trade name “Filtralite” are processed (expanded) clay products with high porosity and quite rough grain surfaces. To perform a reliable comparison of the two different media filters, two pilot filter columns operated in parallel with the similar feed water and under iqual conditions were used. The pilot plant, constructed and installed in a „Gdańsk – Lipce” Water Treatment Plant (WTP) in northern Poland, provided the experimental database for comparative study of water quality parameters using conventional vs. alternative granular materials to improve the groundwater treatment process by dual-media filtration.
COMPARISON OF TWO MODELS OF CONDENSATION
- Sebastian Kornet
- Janusz Badur
2014
In the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages. At least last two stages of this part of turbines operate in two –phase region. The liquid phase in this region in mainly created in the process of homogeneous and heterogeneous condensation. Several observations confirm however, that condensation often occurs earlier than it is predicted by theory i.e. before the Wilson line. It is because the nucleation can start at some soluble and insoluble impurities, particle of dust, chemical compounds or corrosion products. In the present paper we have focused on the prediction of the spontaneous condensation in wet steam flow. Two main types of non-equilibrium condensation models are considered and compared. These are: the single continuum approach and eulerian-eulerian multi-phase approach.
Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
- Dariusz Mikielewicz
- Rafał Andrzejczyk
- Blanka Jakubowska
- Jarosław Mikielewicz
2014 Pełny tekst Archives of Thermodynamics
In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation of the so called blowing parameter. The shear stress between vapor phase and liquid phase is generally a function of non-isothermal effects. The mechanism of modification of shear stresses at the vapor-liquid interface has been presented in detail. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also a different influence of heat flux on the modification of shear stress in the bubbly flow structure, where it affects bubble nucleation. In that case the effect of applied heat flux is considered. As a result a modified form of the two-phase flow multiplier is obtained, in which the non-adiabatic effect is clearly pronounced.
Compatibilization of polymeric composition filled with ground tire rubber – short review
- Magdalena Formela
- Józef Haponiuk
- Lidia Jasińska-Walc
- Krzysztof Formela
2014 Pełny tekst Chemistry & Chemical Technology
Waste rubber is recognized as valuable materials resource and searching for new recycling methods is the main activity of many research institutions and companies. At the turn of the last years only few scientific papers about foamed polymer compositions filled with ground tire rubber were published. In paper review about progress in compatibilization and foaming of polymeric compositions filled with ground tire rubber.
Competitiveness of the Visegrad Countries - Paths for Competitiveness Growth
- Nelly Daszkiewicz
- Magdalena Olczyk
2014
The article includes two objectives: 1) to determine competitiveness of V4 countries in terms of 12 pillars of competitiveness used by The Global Competitiveness Report of the WEF, 2) to propose taxonomic method to appoint a path of competitiveness growth of economies.
COMPOSITE FOOTBRIDGE - SYNERGY EFFECT IN COOPERATION BETWEEN UNIVERSITIES AND INDUSTRY
- Mikołaj Miśkiewicz
- Romanika Okraszewska
- Łukasz Pyrzowski
2014
Paper presents conditions of science and industry cooperation in Poland (restrictions, barriers, good practice). A key role in initiation of collaboration between units has financial support. What is also important, it is much easier to create innovative solutions on the base of combining the potential of individuals. That is why many countries all over the world look for innovative solutions using budget funds to support grants programs. The governments are aware that nowadays innovations are the engine of development. As a case study, the cooperation under a grant “Fobridge” is described. Here two universities and a private company joined their forces to design, build and test a shell composite footbridge. The goal was to create a structure which would be safe, cheap, widely available and constructed on the base of sustainable development rules. Combined advantages of each entity allowed to design the concept structure which will be constructed in near future and finally will hopefully change in a product available all over the world. It was possible because only the best advantages were taken from every consortium partner.