2021 - Repozytorium publikacji - Politechnika Gdańska

Pokaż publikacje z roku

Publikacje z roku 2021

Pokaż wszystkie

Opinia na temat celowości oraz zakresu rzeczowego remontu wytaczarko-frezarki płytowej typu FLF16/CNC. Ekspertyza techniczna opracowana na zlecenie ENEROMONTAŻ-PÓŁNOC GDYNIA S.A.
- Wojciech Blacharski
2021
Opracowana Opinia Jednostki Naukowej dotyczyła ciężkiej wytaczarko-frezarki płytowej typu FLF16/CNC ze sterowaniem CNC. Na podstawie przeprowadzonego w miejscu użytkowania tej obrabiarki audytu, dokonano oceny obecnego stanu maszyny oraz przeanalizowano przyczyny awarii, które zdarzały się w okresie jej eksploatacji. Zakres analizy przyczyn problemów eksploatacyjnych i stanów awaryjnych obejmował: - awarie zespołu elektrowrzeciona oraz układów hydraulicznych zawartych w tym zespole; - usterki głowicy przechylnej do elektrowrzeciona; - usterki w układach napędowych osi liniowych, w tym osi X (ruch liniowy stojaka w kierunku poziomym, osi Y (ruch liniowy suwaka w kierunku pionowym), osi Z (ruch liniowy belki wrzeciennika); - problemy ze zbyt dużymi błędami geometrycznymi ustawienia głównych zespołów obrabiarki i niedotrzymywaniem wymagań WOT; - usterki układów smarowania i hydrauliki; - problemy z układem sterowania. W opracowaniu określono zakres prac remontowych, które byłyby konieczne dla przywrócenia maszyny do jej stanu początkowego. Wskazano również na istotne ograniczenia możliwości obróbkowych wytaczarko frezarki FLF16/CNC w kontekście aktualnych potrzeb produkcyjnych firmy użytkującej tą maszynę. Opracowanie zawiera 25 stron, 1 rysunek i 10 fotografii.
Opioid Growth Factor and its Derivatives as Potential Non-toxic Multifunctional Anticancer and Analgesic Compounds
- Justyna Budka
- Szymon Kowalski
- Monika Chylińska
- Krystyna Dzierzbicka
- Iwona Inkielewicz-Stępniak
2021 Pełny tekst CURRENT MEDICINAL CHEMISTRY
In this paper, we review the structure-activity relationship of OGF and its analogues. We highlight also OGF derivatives with analgesic, immunomodulatory activity and the ability to penetrate the blood-brain barrier and may be used as safe agents enhancing chemotherapy efficacy and improving quality of life in cancer patients. The reviewed papers indicate that Met-enkephalin and its analogues are interesting candidates for the development of novel, non-toxic, and endowed with an analgesic activity anticancer drugs. More preclinical and clinical studies are needed to explore these opportunities.
Opłacalność zastosowania pompy ciepła w układach centralnego ogrzewania i ciepłej wody użytkowej
- Karol Olszewski
- Blanka Jakubowska
2021 Ciepłownictwo, Ogrzewnictwo, Wentylacja
W artykule przedstawiono problem opłacalności ekonomicznej stosowania pompy ciepła, w układach ciepłej wody użytkowej oraz centralnego ogrzewania. Zasadność zastosowania takich źródeł ciepła w tych instalacjach spowodowana jest ogólnoświatowymi kierunkami i stopniowym odchodzeniem od konwencjonalnych źródeł energii takich jak kotły olejowe lub gazowe. Przedmiotem artykułu był budynek jednorodzinny o powierzchni użytkowej ok. 145 m2, w którym instalacja c.o. oraz c.w.u. byłaby zasilana gruntową pompą ciepła. Do analizy przyjęto dwa warianty instalacji c.o., tj. dwururową grzejnikową z rozdziałem dolnym oraz ogrzewanie podłogowe. W przypadku instalacji ciepłej wody użytkowej przyjęto jeden wariant układu centralnego przygotowaniu c.w.u. i magazynowanej w zbiorniku znajdującym się wewnątrz obudowy pompy ciepła. Do analizy opłacalności użyto metodę prostego czasu zwrotu nakładów inwestycyjnych, w której pompa ciepła została porównana z konwencjonalnym źródłem ciepła.
Optical fiber aptasensor for label-free bacteria detection in small volumes
- Monika Janik
- Ewa Brzozowska
- Paula Czyszczoń
- Anna Celebańska
- Marcin Koba
- Andrzej Gamian
- Wojtek J. Bock
- Mateusz Śmietana
2021 SENSORS AND ACTUATORS B-CHEMICAL
Highly sensitive devices for fast bacteria detection are sought to be developed with the task of quantifying the worldwide problem of pathogenic bacteria and thus helping to take control over spreading bacterial infections. This work concerns a sensing solution based on microcavity in-line Mach-Zehnder interferometer (μIMZI) induced in an optical fiber. Such a device exhibits ultrahigh sensitivity to refractive index changes in the microcavity. We show that for well-adjusted chemical surface functionalization combined with highly specific low-molecular-weight bioreceptor the μIMZI can also be used for efficient label-free bacteria detection. The detection capability has been shown for peptide aptamers and pathogenic E. coli O157:H7 bacteria used as a bioreceptor and a target, respectively. We have found that the sensor is capable of detecting bacteria concen-trations as low as 10 colony-forming units per mL in a sample which volume may be as small as hundreds of picoliters. The selectivity of the synthesized peptides is additionally confirmed by Enzyme-Linked Immunosor-bent Assay (ELISA). Based on the presented performance, the μIMZI sensor is one of the most sensitive and lowest-analyte-volume label-free biosensors among fiber optical platforms to date
Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
- Piotr Srokosz
- Marcin Bujko
- Marta Bocheńska
- Rafał Ossowski
2021 Pełny tekst MEASUREMENT
In this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze the deformation within the small strain range (0.001–0.01%). Optical flow method variant by Ce Liu (2009) was used for motion estimation from series of images. This algorithm uses scale-invariant feature transform (SIFT) for image feature extraction and coarse-to-fine matching scheme for faster calculations. The results were validated with the Particle Image Velocimetry (PIV). The results show that the displacement distribution deviates from commonly assumed linearity. Moreover, the observed deformation mechanisms analysis suggest that the shear modulus G commonly determined through TS tests can be considerably overestimated.
Optical Spectroscopic Studies of Tetrahydrofuran Fragmentation Induced by Collisions with Dihydrogen Cations
- Tomasz Wąsowicz
- Bogusław Pranszke
2021 Pełny tekst ACTA PHYSICA POLONICA A
Collisions of dihydrogen cations with tetrahydrofuran molecules have been studied. Luminescence spectra and the emission functions of the excited products at projectile energies ranging from 8 to 1000 eV have been measured using collision-induced emission spectroscopy. The recorded spectra are dominated by the atomic lines of the hydrogen Balmer series, whose intensities decrease more quickly than derived by the quantum-theoretical principle. The spectra also exhibit weak molecular bands of vibrationally and rotationally excited diatomic CH fragments created in the A2D and B2S ectronic states. The collisional processes are identified and compared with the latest results on cation-induced fragmentation of tetrahydrofuran.
Optical-Fiber Microsphere-Based Temperature Sensors with ZnO ALD Coating—Comparative Study
- Paulina Listewnik
- Mikhael Bechelany
- Paweł Wierzba
- Małgorzata Szczerska
2021 Pełny tekst SENSORS
This study presents the microsphere-based fiber-optic sensor with the ZnO Atomic Layer Deposition coating thickness of 100 nm and 200 nm for temperature measurements. Metrological properties of the sensor were investigated over the temperature range from 100 °C to 300 °C, with a 10 °C step. The interferometric signal was used to monitor the integrity of the microsphere and its attachment to the connecting fiber. For the sensor with a 100 nm coating, a spectrum shift of the reflected signal and the optical power of the reflected signal were used to measure temperature, while only the optical power of the reflected signal was used in the sensor with a 200 nm coating. The R2 coefficient of the discussed sensors indicates a linear fit of over 0.99 to the obtained data. The sensitivity of the sensors, investigated in this study, equals 103.5 nW/°C and 19 pm/°C or 11.4 nW/°C for ZnO thickness of 200 nm and 100 nm, respectively.
OPTIMAL FARM SIZE AND EFFECTIVENESS OF AGRICULTURE IN THE EU: THE CASE OF WHEAT YIELDS
- Roman Skalicky
- Elżbieta Rogalska
- Michał Pietrzak
- Marek Zinecker
- Jana Meluzinova
2021 Pełny tekst Transformations in Business & Economics
The article concentrates on the relationship between the size of a farm and its efficiency in relation to wheat production in the European Union (EU). The issue is not new, however fundamental from the point of view of the agricultural policy, as the appropriate shape of the agrarian structure affects the economic rationality in agriculture and significantly improves the productivity. We analysed data for the period between 2004 to 2016 while using the Farm Accountancy Data Network. The fixed effects model was used to identify the explanatory variables for farm size and wheat yields. We calculate the yields per hectare as the ratio of the sum of input costs per hectare to the cost of producing a unit of yield per hectare. Using the 1st derivative, we then estimate the marginal cost of the inputs for each of the farm size categories. Our main conclusion is that with the growing size of a farm, there is a continuous increase in yields of wheat per hectare. This result is achieved by increasing the specific crop costs, a significant part of which are fertilizers and crop protection products, both with respect to the cultivated area and the production achieved. When evaluating the efficiency of production, the optimal size of the economic unit (according to the FADN categorization) is 5. Up to the size category 5, there is an increase in production with respect to the monetary value of production inputs. In the case of larger farms, the ratio is declining.
Optimal Rotating Receiver Angles Estimation for Multicoil Dynamic Wireless Power Transfer
- Bohdan Pakhaliuk
- Viktor Shevchenko
- Jan Mućko
- Oleksandr Husev
- Mykola Lukianov
- Piotr Kołodziejek
- Natalia Strzelecka
- Ryszard Strzelecki
2021 Pełny tekst ENERGIES
This study proposed an approach to dynamic wireless charging that uses a rotating receiver coil. Our simulation study focused on the verification of a novel way of increasing the coupling coefficient and power transfer stability by following the flux of the transmitting coils. To obtain the highest possible coupling by means of the FEM analysis, we studied the optimization of the trajectory of the angular velocity of the rotating receiver. The coupling coefficient trajectories that were obtained were simulated by means of the state space model with three transmitters. Our comprehensive analysis showed that the proposed approach of wireless power transmission enabled a 40% increase in the usage of track space
Optimisation and field assessment of poroelastic wearing course bond quality
- Piotr Jaskuła
- Dawid Ryś
- Cezary Szydłowski
- Marcin Stienss
- Łukasz Mejłun
- Mariusz Jaczewski
- Grzegorz Ronowski
2021 Pełny tekst Road Materials and Pavement Design
Compared to typical asphalt mixtures, poroelastic mixtures are characterised by high porosity and high flexibility, which are desirable for traffic noise reduction. However, the same properties increase the risk of debonding from the lower layer, which is a significant source of premature damage. The study investigates which of the factors – tack coat agent, type and texture of the lower layer – have the greatest impact on interlayer bonding quality. From 27 variants of interface bond techniques investigated in laboratory, 8 were selected and constructed on two full-scale test sections. Monotonic direct shear loading and cyclic direct shear loading tests with normal force were used for this purpose. The tests indicated that softer bitumen used for the tack coat and the milled texture of the lower layer improves bond quality. However the appropriate laying compaction has the major influence. Poroelastic mixtures are much more sensitive to technological imperfections than standard asphalt mixtures.
Optimization of carbamazepine photodegradation on defective TiO2-based magnetic photocatalyst
- Szymon Dudziak
- Zuzanna Bielan
- Paweł Kubica
- Anna Zielińska-Jurek
2021 Pełny tekst Journal of Environmental Chemical Engineering
In this work, carbamazepine (CBZ) degradation over defective Fe3O4@SiO2/d-TiO2/Pt photocatalyst was studied. Within the titania structure, Ti vacancies and Pt nanoparticles were introduced to enhance the photocatalyst’s light absorption and influence charge carriers’ mobility. For the carbamazepine degradation, process parameters, e.g., temperature, flux intensity, photocatalyst loading, aeration, pH, and addition of H2O2, were optimized for 4 or 5 different levels, with the quadratic model including 2-factor interactions determined to analyze the effect of these parameters. Carbamazepine presence and by-product formation were monitored using the HPLC-DAD system together with additional HPLC-TOFMS analysis for further identification of created compounds. Acridine was selected as an additional factor, indicating differences in the performed process of photolysis and photocatalytic CBZ degradation. Pure TiO2 exhibited the highest efficiency of CBZ degradation under alkaline conditions, while the performed optimization shows that a combination of H+ and H2O2 addition is crucial to achieve high CBZ removal and its mineralization in the presence of Fe3O4@SiO2/d-TiO2/Pt photocatalyst. The obtained results were discussed concerning photocatalyst structure, generation of reactive oxygen species inside H+/H2O2/photocatalyst system, and the possible effect of introduced Ti vacancies. In terms of reusability, the performance of Fe3O4@SiO2/d-TiO2/Pt photocatalyst was stable after 8 subsequent cycles of carbamazepine degradation.
Optimization of Data Assignment for Parallel Processing in a Hybrid Heterogeneous Environment Using Integer Linear Programming
- Tomasz Boiński
- Paweł Czarnul
2021 Pełny tekst COMPUTER JOURNAL
In the paper we investigate a practical approach to application of integer linear programming for optimization of data assignment to compute units in a multi-level heterogeneous environment with various compute devices, including CPUs, GPUs and Intel Xeon Phis. The model considers an application that processes a large number of data chunks in parallel on various compute units and takes into account computations, communication including bandwidths and latencies, partitioning, merging, initialization, overhead for computational kernel launch and cleanup. We show that theoretical results from our model are close to real results as differences do not exceed 5% for larger data sizes, with up to 16.7% for smaller data sizes. For an exemplary workload based on solving systems of equations of various sizes with various compute-to-communication ratios we demonstrate that using an integer linear programming solver (lp_solve) with timeouts allows to obtain significantly better total (solver+application) run times than runs without timeouts, also significantly better than arbitrary chosen ones. We show that OpenCL 1.2’s device fission allows to obtain better performance in heterogeneous CPU+GPU environments compared to the GPU-only and the default CPU+GPU configuration, where a whole device is assigned for computations leaving no resources for GPU management.
Optimization of the Aeration Strategies in a Deammonification Sequencing Batch Reactor for Efficient Nitrogen Removal and Mitigation of N2O Production
- Hussein Al-Hazmi
- Lu Xi
- Joanna Majtacz
- Przemysław Kowal
- Li Xie
- Jacek Mąkinia
2021 Pełny tekst ENVIRONMENTAL SCIENCE & TECHNOLOGY
In deammonification systems, nitrite-oxidizing bacteria (NOB) suppression and nitrous oxide (N2O) mitigation are two important operational objectives. To carry out this multivariable analysis of response, a comprehensive model for the N cycle was developed and evaluated against experimental data from a laboratory-scale deammonification granular sludge sequencing batch reactor. Different aeration strategies were tested, and the manipulated variables comprised the dissolved oxygen (DO) set point in the aerated phase, aeration on/off frequency (F), and the ratio (R) between the non-aerated and aerated phase durations. Experimental results showed that a high ammonium utilization rate (AUR) in relation to the low nitrate production rate (NPR) (NPR/AUR = 0.07−0.08) and limited N2O emissions (EN2O < 2%) could be achieved at the DO set point = 0.7 mg O2/L, R ratio = 2, and F frequency = 6−7 h−1 . Under specific operational conditions (biomass concentration, NH4 + -N loading rate, and temperature), simulation results confirmed the feasible aeration strategies for the trade-offs between the NOB suppression and N2O emission. The intermittent aeration regimes led to frequent shifts in the predominating N2O production pathways, that is, hydroxylamine (NH2OH) oxidation (aerated phase) versus autotrophic denitrification (non-aerated phase). The inclusion of the extracellular polymeric substance mechanism in the model explained the observed activity of heterotrophs, especially Anaerolineae, and granule formation.
OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD
- Paweł Ziółkowski
- Łukasz Witanowski
- Piotr Klonowicz
- Stanisław Głuch
2021
This paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead method called HNMPSO. Subsequently, this article aim is to redesign and analyze the flow characteristics of the last stage of the gas-steam turbine. Values of the maximized objective function, which is the isentropic efficiency of the turbine stage, are found from 3D RANS computation of the flowpath geometry changing during the improving scheme. Among the optimized variables are parameters characterising the shape of the endwall contours within the rotor domain.
Optimization of the Relative Humidity of Reactant Gases in Hydrogen Fuel Cells Using Dynamic Impedance Measurements
- Ewa Janicka
- Michał Mielniczek
- Łukasz Gaweł
- Kazimierz Darowicki
2021 Pełny tekst ENERGIES
Water management is a key factor affecting the efficiency of proton exchange membrane fuel cells (PEMFCs). The currently used monitoring methods of PEMFCs provide limited information about which processes or components that humidity has a significant impact upon. Herein, we propose the use of a novel approach of impedance measurements using a multi-sinusoidal perturbation signal, which enables impedance measurements under dynamic operating conditions. The manuscript presents the effect of the relative humidity (RH) of the reactants on the instantaneous impedance of the middle cell in the PEMFC stack as a function of the current load. Analysis of changes in the values of equivalent circuit elements was carried out to determine which process determines the stack’s performance depending on the load range of the fuel cell during operation. Comprehensive impedance analysis showed that to ensure optimal cell operation, the humidity of the reactants should be adjusted depending on the load level. The results showed that at low-current loads, the humidity of gases should be at least 50%, while at high-current loads, the cell should operate optimally at a gas humidity of 30% or lower. The presented methodology provides an important tool for optimizing and monitoring the operation of fuel cells.
Optimization of thermal backfill configurations for desired high-voltage power cables ampacity
- Stanisław Czapp
- Filip Ratkowski
2021 Pełny tekst ENERGIES
The ampacity of high-voltage power cables depends, among others, on their core cross-sectional area as well as thermal resistivity of the thermal backfill surrounding the cables. The cross-sectional area of the power cables’ core is selected according to the expected power to be transferred via the cable system. Usually, the higher the power transfer required, the higher the cross-sectional area of the core. However, the cost of high-voltage power cables is relatively high and strictly depends on the dimensions of the core. Therefore, from the economic point of view, it is interesting to focus on the improvement of the thermal condition around the cables, by changing the dimension of the thermal backfill, instead of increasing the power cables’ core cross-sectional area. In practice, it is important to find the optimal dimensions of both cable core and thermal backfill to achieve the economically attractive solution of the power cable transfer system. This paper presents a mathematical approach to the power-cable system design, which enables selecting the cost-optimal cross-section of a power cable core depending on the dimensions of the thermal backfill. The proposal herein allows us to indicate the condition in which it is advantageous to increase the core cross-sectional area or to expand the dimension of the backfill. In this approach, the optimal backfill geometry can also be evaluated. The investment costs of the 110 kV power cable system with the core cross-sectional areas consecutively equal to 630, 800 and 1000 mm2 have been compared.
Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve
- Michał Urbaniak
- Ewa Kardas-Cinal
2021 Pełny tekst ENERGIES
The main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number of possibilities for improving energy efficiency and reducing energy consumption, one of which is the recovery and reuse of energy lost in the electrodynamic braking process. The main ways in which such energy can be used are listed, but the focus is mainly on the aspect of the so-called “energy cooperation” of trains. Then, the current state of the research and knowledge on the narrowed scope of rail traffic management and recuperative braking in rail transportation is presented; an innovative approach to the indirect optimization of the amount of recuperated electrical energy immediately usable by another vehicle by maximizing the duration of energy co-optimization is proposed; and the authors’ function is proposed to enable optimization, taking into account various parameters. The optimization was performed with the use of a proprietary, multi-criteria objective function and the Solver optimization module. Finally, the results obtained using the proposed approach are presented and illustrated with the example of train timetables used by some of the largest railway stations in Poland.
Optimization-based antenna miniaturization using adaptively-adjusted penalty factors
- Marzieh Mahrokh
- Sławomir Kozieł
2021 Pełny tekst Electronics
The continuing trend for miniaturization of electronic devices necessitates size reduction of the comprising components and circuitry. Specifically, integrated circuit-antenna modules therein require compact radiators in applications such as 5G communications, implantable and on-body devices, or internet of things (IoT). The conflict between the demands for compact size and elec-trical and field performance can be mitigated by means of constrained numerical optimization. Evaluation of performance-related constraints requires expensive electromagnetic (EM) analysis of the system at hand, therefore their explicit handling is inconvenient. A workaround is the penalty function approach where the primary objective (typically, antenna size) is complement-ed by additional terms quantifying possible constraint violations. The penalty coefficients that determine contributions of these terms, are normally adjusted manually, which hinders precise control over antenna performance figures and often leads to inferior results in terms of achieved miniaturization rates. This paper proposes a novel algorithm featuring an automated adjust-ment of the penalty factors throughout the optimization process. Our methodology is validated using three broadband antenna structures. The obtained results demonstrate that the presented adaptive adjustment permits a precise control over the constraint violations while leading to better miniaturization rates as compared to manual penalty term setup.
Optimizing FSO networks resilient to adverse weather conditions by means of enhanced uncertainty sets
- Ilya Kalesnikau
- Marinela Shehaj
- Dritan Nace
- Michał Pióro
2021 Optical Switching and Networking
This work deals with dimensioning of wireless mesh networks (WMN) composed of FSO (free space optics) links. Although FSO links realize broadband transmission at low cost, their drawback is sensitivity to adverse weather conditions causing transmission degradation on multiple links. Hence, designing such FSO networks requires an optimization model to find the cheapest configuration of link capacities that will be able to carry an acceptable level of the demanded traffic in all weather states that can be foreseen in network operation. Such a model can be achieved using robust optimization techniques, and for that it is important to find a tractable way of characterizing possible link (capacity) degradation states corresponding to weather conditions not known in advance. In the paper we show how the set of link degradation states may be represented mathematically in a compact and tractable way to be exploited in optimization. To solve this task we will make use of a generalization of a combinatorial problem of finding a minimum hitting set to deduce a compact set approximating a given set of link degradation states, (called uncertainty set). Finally, we provide a mathematical model with respect to a general form of uncertainty sets and illustrate the effectiveness of our model by means of a numerical study.
Organic syntheses greenness assessment with multicriteria decision analysis
- Marek Tobiszewski
- Witold Przychodzeń
- Marta Bystrzanowska
- Maria Milewska
2021 Pełny tekst GREEN CHEMISTRY
Green chemistry requires a metrics system that is comprehensive by the criteria included and simple in the application at the same time. We propose the application of multicriteria decision analysis for com- parative greenness assessment of organic synthesis procedures. The assessment is based on 9 criteria (the reagent, reaction efficiency, atom economy, temperature, pressure, synthesis time, solvent, catalyst and reactant) for which data points are easily extractable from synthesis protocols. The criteria are given weights by two experts to differentiate their relative importance. Two datasets are created, one of the pro- cedures for benzoic acid synthesis, the second one of procedures for γ-valerolactone synthesis. In both cases, the greenest procedure is identified and the remaining ones are ranked according to their green- ness. The proposed assessment procedure incorporates more assessment criteria than product/waster ratio mass-based metric and is much less tedious than the application of life-cycle assessment.