Repozytorium publikacji - Politechnika Gdańska

MICROSEISMIC EVENT DETECTION USING DIFFERENT ALGORITHMS ON REAL DATA FROM PATCH ARRAY GEOPHONE GRID FROM EASTERN POMERANIA FRACTURING JOB

• Mateusz Kmieć
• Michał Antoszkiewicz
• Robert Jankowski
• Marek Szkodo

2017

The microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. Hydraulic fracturing is a method of reservoir stimulation used especially for unconventional gas recovery. A matrix of several thousand geophones is placed on the surface of earth to record every little tremor of ground induced by fracturing process. Afterwards, the signal is analysed and the place of tremor occurrence is calculated. The detection of microseismic event is not trivial especially in noisy surface environment. With the lack of precise data on parameters of medium it is hard to sum signals from individual geophones so that the useful signal add up and allow to distinguish it from noise. The authors propose processing chain that allows detection of microseismic events for patch array receiver configuration. For each stage of summation different algorithm is used. Modified Kalman filter is used for ach line, then wavelet decomposition for each patch, and last STA/LTA for the final sum of signals. Microseismic strong event and perforation shot real data is analysed.

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Microseismic Monitoring of Hydraulic Fracturing - Data Interpretation Methodology With an Example from Pomerania

• Michał Antoszkiewicz
• Mateusz Kmieć
• Paweł Szewczuk
• Robert Jankowski
• Marek Szkodo

2017 Pełny tekst

Microseismic monitoring is a method for localizing fractures induced by hydraulic fracturing in search for shell gas. The data is collected from an array of geophones deployed on the surface or underground. Ground vibrations are recorded and analysed for fracture location, magnitude and breakage mechanism. For successful microseismic monitoring one need a velocity model of underlying formations. The model is further tuned with signal from perforation shots of known location. Imaging of calibration events is done using software MicSeis developed by Seismik s.r.o. MicSeis utilizes diffraction stacking of waveforms from multiple stations and is intended to image microseismic events with low signal-to-noise ratio (SNR). Imaging means detection of events in time on the seismogram records (determination of arrivals and amplitudes at each receiver), location of the event hypocenters in subsurface, determination of their origin time, and characterization (or evaluation) of detected events. The reliability of detection is further enhanced by analysis of semblance of amplitudes of the detected events. The imaging of microseismic events in MicSeis is using a grid search over all possible origin times and expected set of potential source location points in the selected rock volume. Wave propagation times from grid nodes to the geophones are computed using input velocity model. The seismic moment tensors are automatically determined from the amplitudes gathered during the grid search procedure and are used to model polarities of events which then enhance constructive interference of the event amplitudes and reduce noise influence. Function characterizing a maximum stack per time sample is calculated over whole volume and it is analyzed using the STA/LTA algorithm with a predefined threshold. Additionally a semblance value is used to verify the event detection. Once the event is detected in time, location is determined through analysis of the 3D spatial image function.

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Microstructure and Electrical Properties of Fe,Cu Substituted (Co,Mn)3O4 Thin Films

• Dagmara Grudzień
• Sebastian Molin
• Peter Vang Hendriksen
• Piotr Jasiński

2017 Pełny tekst Crystals

In this work, thin films (~1000 nm) of a pure MnCo2O4 spinel together with its partially substituted derivatives (MnCo1.6Cu0.2Fe0.2O4, MnCo1.6Cu0.4O4, MnCo1.6Fe0.4O4) were prepared by spray pyrolysis and were evaluated for electrical conductivity. Doping by Cu increases the electrical conductivity, whereas doping by Fe decreases the conductivity. For Cu containing samples, rapid grain growth occurs and these samples develop cracks due to a potentially too high thermal expansion coefficient mismatch to the support. Samples doped with both Cu and Fe show high electrical conductivity, normal grain growth and no cracks. By co-doping the Mn, Co spinel with both Cu and Fe, its properties can be tailored to reach a desired thermal expansion coefficient/electrical conductivity value.

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Microwave radiation in the synthesis of urethane prepolymers

• Justyna Kucińska-Lipka
• Maciej Sienkiewicz
• Iga Gubańska
• Sebastian Zalewski

2017 EUROPEAN POLYMER JOURNAL

This paper describes the use of microwave radiation in the synthesis of urethane prepolymers in bulk (without solvent). The prepolymers were synthesized using 1,6-hexamethylene diisocyanate (HDI) and poly (ε-caprolactone) diol (PCL) at a molar ratio of 4:1. The reaction was carried out without a catalyst in the reactor with a conventional heating system (oil bath) or in the microwave reactor (MW Reactor NOVA 09) at temperatures of 60, 80 and 100 °C. The progress of the reaction was monitored based on the degree of HDI and PCL conversion, as assessed by acidimetric titration of non-bonded isocyanate groups (0–120 min). The chemical structure of the resulting products was determined via Fourier Transform Infrared Spectroscopy. Size exclusion chromatography (GPC) was applied to determine the molecular weight distribution of products at different time points of prepolymer synthesis. The obtained results indicate that the use of microwave radiation as a heat source during prepolymer synthesis accelerates the reaction in the temperature range from 60 to 80 °C. This finding allows a significant reduction in energy required for heating the reaction mixture. The acceleration of prepolymer synthesis by the application of microwave radiation as a heat source also allows for the elimination of catalysts from the system. The aforementioned catalysts are necessary to perform the prepolymer synthesis with the use of aliphatic diisocyanates and polyols, particularly at temperatures below 100 °C. In the case of prepolymers that are further used in the synthesis of biomedical polyurethanes, the catalyst elimination is especially advantageous as the presence of residual catalyst may significantly influence the final material’s biocompatibility and disturb host cell viability.

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Mikroorganizmy w degradacji celulozy

• Agata Terebieniec
• Natalia Filipowicz

2017 Pełny tekst

Celuloza jest podstawowym składnikiem komórek roślinnych. Włókna celulozowe są bardzo ciasno upakowane w ścianach komórek, przez co utrudniają dostęp enzymom celulolitycznym oraz cząsteczkom wody. Najważniejszą rolę w procesie rozkładu celulozy pełnią celulazy, które należą do rodziny hydrolaz glikozydowych. Zdolność do hydrolizy celulozy i hemicelulozy wykazują mikroorganizmy celulolityczne. Prezentują one dwa różne mechanizmy degradacji: hydroliza przy zastosowaniu enzymów skompleksowanych w celulosomie oraz enzymów nietworzących celulosomów.

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MIKROSTRUGOWA TECHNIKA INTENSYFIKACJI WYMIANY CIEPŁA W PŁASZCZOWO-RUROWYM WYMIENNIKU CIEPŁA

• Jan Wajs
• Michał Bajor
• Dariusz Mikielewicz

2017

W pracy przedstawiono opatentowaną konstrukcję mikrostrugowego wymiennika ciepła o budowie cylindrycznej, wraz z wynikami jego systematycznych badań eksperymentalnych w warunkach konwekcji jednofazowej oraz modelowania współczynników przejmowania ciepła. W oparciu o pozyskane wyniki przeprowadzono również walidację wybranych korelacji opisujących liczbę Nusselta, dostępnych w literaturze przedmiotu. Oceny stopnia intensyfikacji wymiany ciepła dokonano za pomocą analizy porównawczej charakterystyk cieplno-przepływowych prototypu i wymiennika płaszczowo-rurowego o konstrukcji klasycznej. Charakterystyki te skonstruowano dla identycznych warunków termicznych, tj. wydatków objętościowych czynników roboczych i ich temperatur w króćcach wlotowych wymienników. Badania doświadczalne obu wymienników przeprowadzono na tym samym stanowisku.

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Mini Smart Grid system w trakcyjnym układzie zasilania

• Mikołaj Bartłomiejczyk

2017 Pełny tekst Technika Transportu Szynowego

Wraz ze wzrostem liczby tramwajów i trolejbusów wyposażonych w hamowanie odzyskowe, wzrasta popularność urządzeń zwiększających efektywność odzysku energii. Są nimi głównie superkondensatorowe zasobniki energii oraz układy falownikowe umożliwiające zwrot energii do sieci prądu przemiennego. Jednak wysoka cena tych urządzeń oraz problemy prawno-organizacyjne stanowią znaczną barierę dla ich szerszego rozpowszechnienia. W artykule przedstawiono koncepcję rozwiązania prostszego, tańszego i łatwiejszego do praktycznej implementacji: wykorzystania energii odzysku dla zasilania potrzeb nietrakcyjnych, takich jak obiekty użyteczności publicznej lub aparatura dodatkowa związana z infrastrukturą komunikacyjną. W takim układzie, wykorzystanie energii rekuperacji może się odbywać wewnątrz przedsiębiorstwa na poziomie niskiego napięcia, co w znaczny sposób upraszcza aspekty prawno-techniczne.

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Miniaturized solid phase microextratcion

• Justyna Płotka-Wasylka
• Natalia Jatkowska
• Katarzyna Owczarek
• Jacek Namieśnik

2017

Without any doubt analytical laboratories have an essential role in environmental protection due to the fact that they takes an active part in the monitoring pollutants present in air, water or soil. From the other side, the analytical activity is involved in the generation of toxic waste what is associated with the use of not eco-friendly reagents and solvents. For these reasons, green analytical chemistry (GAC) was introduced in 2000 in order to remove/reduce the side-effects of analytical practices on operators and the environment. The ideology of GAC is focused on reduction of the negative impact of chemical analyses on the environment, developments in instrumentation and methodologies, and also enabling analytical laboratories to be sustainable in terms of costs and energy. To help analysts to conduct laboratory in accordance with ideology of GAC, the guidelines and the principles of green chemistry have been introduced. Also, components of green analysis are well known and are presented in many critical reviews. In connection with emergence of the ideology and the principles of GAC, several trends in analytical chemistry occurred. Trends toward simplification, automation, portability and miniaturization are well recognized. Without any doubt a high degree of simplification, portability and automation is intrinsically involved in miniaturized systems. Different steps of the analytical process have been subjected to automation, miniaturiza­tion and portability. The integration of sample preparation, analytical separation and detection has allowed the development of fully miniaturized systems. The miniaturization of analytical systems is linked to other challenges in analytical chemistry including automation, portability and greening of analytical procedures. Moreover, rapidity, economy, improved analytical perfor­mance and the size decrease of analytical systems are among the drivers for miniatur­ization.

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Minimizing Distribution and Data Loading Overheads in Parallel Training of DNN Acoustic Models with Frequent Parameter Averaging

• Paweł Rościszewski
• Jakub Kaliski

2017

In the paper we investigate the performance of parallel deep neural network training with parameter averaging for acoustic modeling in Kaldi, a popular automatic speech recognition toolkit. We describe experiments based on training a recurrent neural network with 4 layers of 800 LSTM hidden states on a 100-hour corpora of annotated Polish speech data. We propose a MPI-based modification of the training program which minimizes the overheads of both distributing training jobs and loadingandpreprocessingtrainingdatabyusingmessagepassing and CPU/GPU computation overlapping. The impact of the proposed optimizations is greater for the more frequent neural network model averaging. To justify our efforts, we examine the influence of averaging frequency on the trained model efficiency. We plot learning curves based on the average log-probability per frame of correct paths for utterances in the validation set, as well as word error rates of test set decodings. Based on experiments with training on 2 workstations with 4 GPUs each we point that for the given network architecture, dataset and computing environment there is a certain range of averaging frequencies that are optimal for the model efficiency. For the selected averaging frequency of 600k frames per iteration the proposed optimizations reduce the training time by 54.9%.

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Minimum drag shape bodies moving in inviscid fluid - revisited

• Krzysztof Tesch
• Katarzyna Kaczorowska-Ditrich

2017 Transactions of the Institute of Fluid-Flow Machinery

This paper presents the classic approach to minimum drag shape body problem, moving at hypersonic speeds, leading to famous power law shapes with value of the exponent of 3/4. Two- and three-dimensional cases are considered. Furthermore, an exact pseudo solution is given and its uselessness is discussed. Two new solutions are introduced, namely an approximate solution due to form of the functional and solution by means of optimisation of a Bézier curve. The former transforms the variational problem to the classic problem of function optimisation by assuming certain class of functions, whereas the latter by means of discretised functional.

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MISAeksperyment038

• Dąbrówka Tyślewicz

2017

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MISAeksperyment040, artystyczna ceramika unikatowa

• Dąbrówka Tyślewicz

2017

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MISAeksperyment041 ,

• Dąbrówka Tyślewicz

2017

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MISAeksperyment042

• Dąbrówka Tyślewicz

2017

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MISAeksperyment044

• Dąbrówka Tyślewicz

2017

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MISAeksperyment048

• Dąbrówka Tyślewicz

2017

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MISAeksperyment049

• Dąbrówka Tyślewicz

2017

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MISAeksperyment050

• Dąbrówka Tyślewicz

2017

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MISAeksperyment051

• Dąbrówka Tyślewicz

2017

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MISAeksperyment052

• Dąbrówka Tyślewicz

2017

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